Behavior of Internal Stakeholders in Project †MyAssignmenthelp.com

Question: Talk about the Behavior of Internal Stakeholders in Project. Answer: Presentation The investigation of business morals guarantees the approaches and practices identified with the conceivably questionable issues. The motivation behind considering the morals is to direct the business for increasing open acknowledgment by staying away from the issues like trustee obligations, corporate social duties, segregation, pay off, insider exchanging, and corporate administration. As such, the moral thought assumes job in guaranteeing the necessary trust among shoppers and different types of market members with business. The idea of morals raised during the second 50% of twentieth century with organizations getting progressively mindful of a rising client based society. It by and large works out positively past being only a code of good and bad, and endeavors to accommodate the legitimate obligations of the business association as opposed to holding a favorable situation in serious market. Weiss (2014) in his book recognized a few instances of moral issues looked by the curren t universal business association and closed the raise of moral issues in 21st century. The report centers around the moral issue looked by the German car organization Volkswagen in 2015. Volkswagen has again stood out as truly newsworthy for reviewing about 500,000 diesel vehicles from United States in 2015. It is expected to the companys unseemly moral thought in corporate dynamic. This corporate embarrassment of Volkswagen is a numerous level moral infringement and can be seen from various edges. The connection of the case can be attracted to the natural calamity, worldwide business morals, out of line strategic approaches, just as unlawful corporate movement. This is stunning news detailed against the once appreciated German automaker for corporate bad conduct. The organization not just ignored the government furthest reaches of emanation control, yet additionally chose to conceal them. Each and every diesel vehicle sent to the United States was fitted with programming to distort the contamination level during the test yet debilitated them while they were quite the street. The report is contained three sections. The initial segment of the report gives an inside and out depiction of the case under investigation to frame a reasonable thought regarding the moral issue led by the organization. An exhaustive contextual investigation has been directed that recognizes different partners engaged with the case. The second piece of the report at that point altogether investigations the case utilizing pertinent scholastic perusing. Definite investigation of the moral issues present for the situation is finished. It tends to the inquiries with respect to the association of the partners identified with the issue. Further examination uncovers the effect of the case on different measurements. The idea of the moral issue for this situation is likewise distinguished in this area. The last piece of the report offers the perusers with certain suggestions dependent on the investigation made in the past area. This part offer the learning result of the case broke down and s uggests the essential advances that could have been taken by the association to maintain a strategic distance from the circumstance. Case Description The vehicles furnished with diesel motors are known to be better helpful over the gas vehicles in regards to toughness, cost effectiveness, and eco-friendliness. Be that as it may, these vehicles require some additional push to adhere to the rule and measures set by the Environmental assurance Agency so as to deal with hurtful and mortal impacts of nitrogen oxide. This made it harder for the car organizations to satisfy the emanation guideline while keeping the eco-friendliness unblemished. While everybody battling with keeping the eco-friendliness high in their diesel vehicles, Volkswagen presented their new line of diesel vehicles with low emanation and high eco-friendliness. It was a lot of achievement for the organization that earned them a colossal measure of benefit selling their diesel vehicles in the US advertise just as around the world. In any case, the issue stimulate when a non-benefit bunch named as the International Council on Clean Transportation proposed for an on-street emanation test for all the vehicles in the States on 2013. Their proposition was absolutely founded on the wellbeing worry of general society. This was the first run through when something like this was led and this test was not the same as the ones in the lab. The California Air Resource Board required an examination on the Volkswagen diesel models on street in the year 2014 and the duty was provide for the West Virginia University (Gates et al. 2017). The aftereffect of the test uncovered the VW diesel vehicles for a discharge level that is multiple times higher than the US guideline principles (Mansouri 2016). Further research clarifies that the organization had a product fitted in their diesel vehicles to control the emanation in the lab test and produce counterfeit outcome. Though as the security naturally handicapped itself during on str eet drive. The EPA reported that the gadget fitted in the VW vehicles could detect the testing situations by observing a few elements like motor activity, speed, gaseous tension and even the situation of the controlling wheel. The essential report distinguished the contribution of nine of the Volkswagen chief in the outflow embarrassment who have been suspended. The administrator of the VW expressed in his explanation note that it occurred because of the untrustworthy outlook of he suspended gathering which prompted this undesired episode. Consequence of the further research on October 2015 and the announcement from the CEO detailed the association of a little gathering of designers in implanting the gadget in the vehicle of which the CEO was left ignorant (Goodman 2017). The outside agent of the issue introduced an admission explanation of fifty staffs for the most part in Wolfsburg with respect to their familiarity with the discharge embarrassment exercises. Later report communicated that various designers and experts knew about the outflow fixing exercises in the manufacturing plant and they effectively educated the bosses. Be that as it may, the administrators intentionally disregarded the caution. The more profound examination working on this issue recognized a person with the capacity to code the destruction gadget program. Be that as it may, it required something other than a person to realize the idea of tricking the emanation. The last report caused the suspension of nine administrators from administrative board, quality control and affirmation, motor creators, plant directors, chiefs of sub organizations and plant supervisor (Boston, Sloat and Varnholt 2017). Explanations behind Rigging Emission Test The continuous research of the Volkswagen discharge outrage case distinguished a few reasons constrained the workers to think about this untrustworthy lead. Right off the bat, the executive of Volkswagen Mr. Hans-Dieter Potsch uncovered the main apparatus diesel outflow was led on 2005 by certain designers at the hour of inconvenience of hardest discharge principles to vehicle industry (Geuss 2017). The burden constrained them to consider the choice because of the brief timeframe and deficient financial plan apportioned for the undertaking. Be that as it may, they managed to discover an answer for this the issues, yet they intentionally liked to keep fixing than actualizing the technique (Boston, Sloat and Varnholt 2017). The second huge explanation that energized this untrustworthy lead is the exceptional corporate culture present in the organization. The way of life of commitment prompted the formation of an air of a basically brought together structure. This pressurized the representatives to convey the requests and desires for the organization regardless of whether they needed to disrupt the moral guidelines. The procedure of accomplishment no longer made a difference as the outcome was of prime intrigue (Goodman 2017). The discharge embarrassment of Volkswagen had a few outcomes that can be summarized into three significant fields that are political, monetary and socio-ecological results. Political Consequences The division of US Justice, the EPA and the Federal Trade Commission forced different criminal accusations on Volkswagen car. The organization was blamed for cheating with on the emanation test and was requested to review each and every affected model in the United States in 2015. The EPA changed the emanation test methodology and remembered for street outflow test in the rule. Besides, the examination was stretched out to different brands also. The repercussion of this fell on to different nations too and they started comparative test on the Volkswagen diesel models and thought of comparable outcomes to the one of United States (Jung and Park 2017). Affordable Consequence Charles Breyer, the region court judge of United States endorsed a last $14.7 billion settlement on October 2016. A buyback program will follow this from the organization offering the clients a sum of $10 billion. The spending plan for every vehicle was set from $12500 to $44000 contingent upon the model for the proprietors who purchased their vehicle before September 2015. The clients will possibly get the sum in the event that they offer their vehicles to the organization. The renters then again will get a money esteem in the middle of $2600 to $4900. The organization will undoubtedly pay the money to the clients as a thought of their criminal offense (Atiyeh 2017). Socio-ecological Consequences A numerous degree of social and natural outcome happened because of the infringement of the moral standards. The utilization of this perilous poison diesel motor caused a huge natural corruption in the course of recent years. Besides, the wellbeing harms caused because of this could cost more than $100 million as indicated by the report introduced by Selin (2017). Wolfsburg then again confronted quick outcome with a monetary aftermath including a brief employing suspension and diminished corporate expense income (Eddy 2017). Basic examination of the supportability issues There are different assessments and articulations being given by various creators comparable to the moral issues being looked by the contemporary business associations. Nonetheless, dominant part of the opin

Critical Summary of Cultural Effects on Eating Att Essay Example For Students

Basic Summary of Cultural Effects on Eating Att Essay itudes in IsraeliSubpopulations and Hospitalized AnorecticsIn the article Cultural Effects on Eating Attitudes in IsraeliSubpopulations and Hospitalized Anorectics (Apter Et Al, 1994), the authorsintroduce to us their postulation: because of the conflicting qualities between the westernideology of the adolescent female body and the customary Israeli subpopulationviews, there is an expanding measure of anorexia nervosa proportionate to theseverity of the western impact. To test their speculation, Apter surveyedadolescent Israeli young ladies in 10 subpopulations of Israeli culture. Throughoutthe rest of the article, Apter proceeds to demonstrate their theory by delineating tous the strategy they started up just as the outcomes they accomplished fromconducting the study. Apter discloses to us that anorexia nervosa is a serious eating disorderthat influences generally upper white collar class high school young ladies in the western world. This illness is both truly and mentally harming to these young ladies. For these young ladies, slenderness and self-appearance is the thing that they spin their livesaround. Studies infer that individuals in callings where physical appearanceis of outrageous significance are bound to build up a dietary problem. In theWestern world, in the course of recent decades dietary problems have increasedsubstantially. Individuals accept that this expansion in dietary issues is expected tothe design industry. The elegant female figure of today has become thinnerand progressively rounded (Szmulker, McCance, McCrone, Hunter, 1986). On the planet today, Apter accepts that slenderness is increasingly more asymbol of the female perfect. He finds that the Western job of a lady is nowbeginning to remember accomplishment for the work power, explicitly appealing also asthe conventional jobs as nurturant spouses and moms. Apter estimates thatthis included worry of Western belief system joined with the non-Western ethnicorigin of these teenagers could make inconveniences to such an extent that the attitudestowards food will start to look like that of anorectics. Interestingly, Apter alsohypothesizes that young people of non-Western ethnic source less uncovered toWestern philosophy would have to a lesser extent an opportunity of accomplishing a dietary issue. Utilizing a chose gathering of hospitalized anorectics as a control, they testedtheir speculation by reviewing 783 juvenile young ladies in 10 Israeli subpopulationsas well as a gathering of hospitalized anorectics. The primary test directed in the review was the abbreviated type of theEating Attitude Test known as the EAT-26. This test was managed by schoolnurses and is demonstrated to identify occasions and levels of dietary issues. Thedetermining factor in this test, as expressed by Apter, was the oral controlfactor a pointer of impulsivity and likely of sexuality. The secondtest directed, was a 17-question review that managed the way they subjectsviewed their body. As demonstrated by the benchmark group, the higher the scores onthe tests, the more probable the subjects have a dietary issue. In the consequences of the review, Apter et Al found that the Kibbutzresembled the scores nearest to that of the anorectics; be that as it may, the oralcontrol factor score was lower than anticipated. Apter guards this by attributingit to their collective lounge areas. Due to the low Western impact inthe Muslim culture, the expectation that they would have a lower score on thesurvey was bogus. They scored low in the self-perception pathology and high on thedieting factor. Apter remains with his speculation by demonstrating that the Muslimgroup has the most elevated normal weight (53.8 kg), so their anxiety withdieting may uncover a longing to get more fit as opposed to guileful slendernessculture. They likewise express that their discoveries do require further investigation;however, they feel that the Muslims are not in danger of dietary problems. .u68c418f98729187450609dd41cf96515 , .u68c418f98729187450609dd41cf96515 .postImageUrl , .u68c418f98729187450609dd41cf96515 .focused content region { min-tallness: 80px; position: relative; } .u68c418f98729187450609dd41cf96515 , .u68c418f98729187450609dd41cf96515:hover , .u68c418f98729187450609dd41cf96515:visited , .u68c418f98729187450609dd41cf96515:active { border:0!important; } .u68c418f98729187450609dd41cf96515 .clearfix:after { content: ; show: table; clear: both; } .u68c418f98729187450609dd41cf96515 { show: square; progress: foundation shading 250ms; webkit-change: foundation shading 250ms; width: 100%; murkiness: 1; progress: obscurity 250ms; webkit-progress: mistiness 250ms; foundation shading: #95A5A6; } .u68c418f98729187450609dd41cf96515:active , .u68c418f98729187450609dd41cf96515:hover { haziness: 1; progress: darkness 250ms; webkit-change: mistiness 250ms; foundation shading: #2C3E50; } .u68c418f98729187450609dd41cf96515 .focused content region { width: 100%; position: rela tive; } .u68c418f98729187450609dd41cf96515 .ctaText { outskirt base: 0 strong #fff; shading: #2980B9; text dimension: 16px; textual style weight: intense; edge: 0; cushioning: 0; content improvement: underline; } .u68c418f98729187450609dd41cf96515 .postTitle { shading: #FFFFFF; text dimension: 16px; textual style weight: 600; edge: 0; cushioning: 0; width: 100%; } .u68c418f98729187450609dd41cf96515 .ctaButton { foundation shading: #7F8C8D!important; shading: #2980B9; fringe: none; fringe span: 3px; box-shadow: none; text dimension: 14px; textual style weight: striking; line-stature: 26px; moz-outskirt sweep: 3px; content adjust: focus; content adornment: none; content shadow: none; width: 80px; min-tallness: 80px; foundation: url(https://artscolumbia.org/wp-content/modules/intelly-related-posts/resources/pictures/basic arrow.png)no-rehash; position: total; right: 0; top: 0; } .u68c418f98729187450609dd41cf96515:hover .ctaButton { foundation shading: #34495E!important; } .u68c418f9872 9187450609dd41cf96515 .focused content { show: table; stature: 80px; cushioning left: 18px; top: 0; } .u68c418f98729187450609dd41cf96515-content { show: table-cell; edge: 0; cushioning: 0; cushioning right: 108px; position: relative; vertical-adjust: center; width: 100%; } .u68c418f98729187450609dd41cf96515:after { content: ; show: square; clear: both; } READ: William blake EssayFrom these outcomes, Apter et Al closes his theory that: due to theclashing values between the western belief system of the high school female body andthe conventional Israeli subpopulation sees, there is an expanding sum ofanorexia nervosa proportionate to the seriousness of the western impact. I feel that Apter et Al didn't effectively consolidate all aspectswhen attempting to demonstrate their theory. I state this since they just took intoaccount the parts of anorexia nervosa in every subculture. They didn't takeinto account the measure of Western impact in every subculture. To make theproof of their theory progressively complete, Apter et Al ought to have led somesort of test or review that would tell the amount Western impact was available ineach subculture. In the event that Apter et Al would have taken

Cognitive Restructuring for Stress Relief Introduction

Cognitive Restructuring for Stress Relief Introduction Stress Management Management Techniques Print Cognitive Restructuring for Stress Relief By Elizabeth Scott, MS twitter Elizabeth Scott, MS, is a wellness coach specializing in stress management and quality of life, and the author of 8 Keys to Stress Management. Learn about our editorial policy Elizabeth Scott, MS Updated on August 08, 2019 How Stress Impacts Your Health Overview Signs of Burnout Stress and Weight Gain Benefits of Exercise Stress Reduction Tips Self-Care Practices Mindful Living Paul Bradbury/Getty Images There’s plenty of solid evidence that how we think about what’s going on in our lives can greatly contribute to whether or not we find events in our lives stressful. Cognitive distortions, or patterns of faulty thinking, can impact our thoughts, behaviors, and experience of stress. Our self-talk, the internal dialogue that runs in our heads, interpreting, explaining and judging the situations we encounter, can actually make things seem better or worse, threatening or non-threatening, stressful or…well, you get the picture. Some people tend to see things in a more positive light, and others tend to view things more negatively, putting themselves at a disadvantage in life. But, as our self-talk develops starting in childhood, how does one go about changing these habitual thought patterns? Cognitive restructuring, a process of recognizing, challenging, and changing cognitive distortions and negative thought patterns can be accomplished with the help of a therapist trained in cognitive therapy or cognitive behavioral therapy. However, in many cases results can also be achieved at home with the right information and commitment to change. Here are some general tips on changing negative self-talk. For more specific tips, keep reading. Awareness Is the First Step Its difficult to change something we dont know is there. With many cognitive distortions, including all-or-nothing thinking, jumping to conclusions, and emotional (versus logical) reasoning, its difficult to recognize that any distortions are taking place, and the effects of this distorted thinking follow seamlessly. To be better able to recognize distortions when they come into play, familiarize yourself with a list  and be on the lookout. Once you know what to look for, you may recognize them in yourself and others, and then youre ready for the process of cognitive restructuring that is necessary to get things back on the right track. With time and practice, this type of cognitive restructuring will become second nature to challenge your negative thinking patterns, and replacing them with more positive thoughts and views will become easy. Recognize Your Power When we feel no choice in a situation, it can create significant stress and even lead to burnout. The statement, “I can’t work out because I have to volunteer at the kids’ school again,” ignores the reality that both activities are choices. Just because one choice isn’t chosen doesn’t mean it wasn’t a choice, to begin with. Changing your ‘have to’s and ‘can’t’s’ into ‘choose to’ and ‘choose not to’ (or some smoother-sounding approximations) can actually remind you that you do have a choice in a situation, and help you feel less stressed. “I’d like to work out, but I choose to volunteer at the kids’ school instead,” feels less confined, and sounds more fun, doesn’t it? Soon, youll become more automatic in amending your cognitive distortions, and know-how to develop a more positive way of thinking, reducing stress in the process. Cut Down on the ‘Shoulds’ Its easier to tackle a challenge when you feel that youre doing it because you want to and not because you have to. In this vein, the word should is a harbinger of stress, making most of us feel that there are a right way and a wrong way to do things, and making us feel that we must do things a certain way when there may be a better way for us. When we feel the pressure of the word should, we may want to remind ourselves that when we feel we should do something, were not always right. Start questioning your shoulds and be sure that whatever you do, youre doing it because you want to and feel its the best path for yourself. This is true for others, too. Actively Focus on the Positive Along these lines, many people find that keeping a gratitude journal â€" a daily log of things for which they are grateful â€" is immensely helpful in that it not only supplies a list of blessings to look over, but it trains the mind to notice these blessings throughout the day, and it affects their whole experience of stress. Stay in the Here and Now Try to stay in the present, the specific problem, and finding a solution that works. This can effectively help you deal with a variety of stressors without becoming overwhelmed. Again, if you’re dealing with a more severe form of stress or a clinical disorder, you’ll see the best results with a trained therapist. However, these techniques for cognitive restructuring can be helpful in changing negative thought patterns to relieve daily stress; with practice, you may see a significant positive change in outlook and a decrease in your experience of stress.

Wireless sensor network - Free Essay Example

Sample details Pages: 22 Words: 6677 Downloads: 1 Date added: 2017/06/26 Category Statistics Essay Did you like this example? 1 Wireless Sensor Network In this chapter, wireless sensor network (WSN) principles are being shortly introduced and discussed. In order to increase the level of understanding for analyzing Wireless Sensor Network (WSN) systems it is useful to study the technology behind them the technologies which are presented in this section. Wireless Sensor Networks (WSNs) are distributed and independent sensors that are connected and worked together to measure quantities such as temperature, humidity, pressure, noise levels or vibrations [5]. WSNs can measure vehicular movement (velocity, location, etc.) and monitor conditions such as lightning condition, soil makeup and motion [5]. Nowadays, WSNs are utilized in many common applications such as vehicle applications. Some of vehicle applications are: vehicle tracking and detection, tire pressure monitoring, vehicle speed detection, vehicle direction indicator, traffic control, reversing aid sensors etc. Such applications can be divided in major categories such as safety, security, environment and logistics. Don’t waste time! Our writers will create an original "Wireless sensor network" essay for you Create order To implement WSN in an application and have an efficient system, first we need to consider about WSN technology, components and communication topology and protocols. Therefore, first, in this chapter, basic information about WSN components, the communication devices and process unit of WSN will be described. Then, the chapter will be followed by a description of the WSN topologies and protocols emphasizing on mesh WSN technology with ZigBee Protocol. 1.1 Wireless Sensor Network component To provide comprehensive view of WSN hardware, understanding of WSN components structure is required. Wireless sensors are small microcontrollers equipped with wireless communication device and an energy supplier. The architecture of WSNs is illustrated in Figure 31 . As Figure 31 shows the components of WSNs are sensing unit, processing unit, power supplier and communication device. The sensing unit consists of sensors and Analog to Digital Converters (ADCs). ADCs are responsible for gathering the signals and converting them into digital signals data and transfer them through each other using network topology to the processor unit. In the sensing unit, each sensor is called an end node and varies in size and cost. The mission of these multifunction sensor nodes are to sense, process data and collaborate with other nodes [8]. Wireless sensor network can be positioned in two ways, either using a complex technique with the large sensors far from the object or using several sensors with an engineered design on position and topology [5]. In addition, each node provided with a wireless communication transceiver as a communication component. In the process unit, the controller and small memory storage are responsible for managing the collaboration within the sensors to achieve the assigning task. In addition, the communication device with a transceiver makes the network connection. Above all, the essential component of WSN is the power unit, which supports the power for all units [5]. One of the unique characteristics of sensor networks is that they are equipped with an on-board processor. This feature enables them to locally process some simple computations and broadcast only necessary processed data [5]. Network communication is really complicated and needs years of study [8], but to be able to implement WSN, we need to know some basic primary concepts of communication technology such as; network topologies, network protocol and their standards and specifications. 1.2 Communication technology To cover technical aspects of WSN, network topology and network protocol studying is needed. This study will help to provide information about reliability, robustness, security and stability and of WSNs software aspect to answer the research questions RQ. 1 ,RQ. 2 and RQ. 3 . 1.2.1 Topologies in WSN Communication In network communication, the big issue is how data transfers through nodes and nodes interconnect with each other. Several basic network topologies may be used for transmitting to and receiving from a node. The Alliance for Telecommunications Industry Solutions (ATIS) the standards organization of telecommunication industry explained the network topology as The physical, real, logical or virtual arrangement of the nods/elements of a network [9]. The topology shows the diameter and the number of nodes between any two nodes. Moreover how a data process and the data routing complexities are relied on the chosen topology. Consequently, some characteristics of a sensor networks such as latency, robustness and capacity are changed by their topology [10]. Figure 32 is a graphic mapping of networks topology which shows the links of one or more nodes and explains the physical topology of the network. Despite having the same topology, two networks can differ in transmission rates because of their physical interaction, signal types and distance between nodes [9]. Table 31 describes the different types of network topology. Name Types Description Basic topology types Point-to-point Permanent A permanent connection between two endpoints and nodes Switched A dynamic point-to-point circuit that can be dropped if needed. Bus topology Linear topology All nodes are linked to a common transmission medium (bus) which has exactly two endpoints and all data is able to transfer through all nodes. Distributed bus All nodes of the network are linked like a branch to a main bus which causes more than two endpoints. Data goes in all directions to all nodes connected on the bus cable until it finds unique addresse.g. the MAC address or IP address on the network and transmit the data. Ring topology Each node is linked in a ring or loop to the closest node. The data travels in the ring only in one direction and each node can transmit only one piece of data at a time. Ring topology used control access in the network and if one node fails entire network will fail. Star topology Each node has exactly two branches linked to it. External nodes are connected to a central node. The external nodes are only permitted to communicate with the center node and a failure of an external node will cause it to be isolated from the others. Tree topology Each node is linked in different tree paths. In each branch, each node transfers the data to upper node. So, a node failure causes the whole connected branch to fail. Mesh topology Partially connected At least two nodes linked with two or more node in a network. Fully connected Direct link between any two nodes. There will be n(n-1)/2 links Mix topology types Hybrid topology An arrangement of any two or more different basic network topologies. Table 31 Topology TYPES [9]. Since Mesh topology is a main topic in the thesis, it is studied more in-depth in this section 1.2.1.1 Mesh Wireless Network Wireless mesh network is a term used when all wireless nodes are connected to each other within an ad-hoc multi-hob and mesh topology. In this network, any pair of nodes is able to communicate between each other within more than one path. In this network each node is used as a router to forward packets to the neighbor nodes which they have linked to. That means all nodes communicate directly or through other midway nodes without any manual configuration. Therefore, this network also called a self-configuration and self-organized network [11; 12]. As described in Table 31, there are two types of mesh topology Partially connected and Fully connected (See Figure 33). In a fully connected topology each node has the ability to communicate with all other nodes in the network and creates an interconnection links. By increasing the number of nodes in a mesh network, the number of links increases as well. On the other hand, in a partially connected topology, instead of direct interconnection between nodes, each node has two or more links to others to provide alternate routing and traffic balancing. Due to more links and indirect connections between nodes, traffic can flow through one or more router nodes to the destination [7] and create more reliable interconnections between nodes. Moreover, in partial network, the nodes are connected to either the node with higher rate of data transaction or the nearest neighbor node while in fully connected network all nodes have a direct links with each other. This multiple link path conducts a reliable communication. Therefore, whenever a connection fails or a node breaks down, the packages can automatically change their path by jumping from a disconnected node. This is often called the self-healing of the network. This means that the networks connection stability and reliability are not essentially affected by node failures [11]. Due to the characteristics of wireless sensor network mesh, this network is self-configuring and self-organizing network in which each end-node is also used as a router (dual role- data originator /data router) to forward the signal packages all the way back of the main gateway. Therefore, due to the characteristics of mesh networks, this network is becoming one of the most implemented networks which able to have the flexible architecture for the network, easy self-configuration and robust fault tolerance connectivity [11; 12]. Additionally, the self-configuring characteristic of mesh WSN, bring the ability for the network to connect or disconnect nodes from the network. This brings the ability to grow/decrease the network by adding/removing nodes of a system. Mesh WSN has reliable self-healing and robust fault tolerance. This means if a node fails or breaks down the signal packages jump from the disconnected node and automatically conducts a new path through the nearest node. However, the new path imposes re-routing and re-organizing to the network [5], which consumes too much power from the system. Therefore, having a power-aware protocol and algorithm is necessary for mesh network. ZigBee protocol is one of the protocols which provides this ability for WSN. 1.2.2 Protocols in WSN Communication WSN systems include variety of protocols for communication. Protocols need to program in different architectural layers. One of these architectural standard is OSI (Open System Interconnection) framework. In this session a brief introduction of each protocol and OSI are delineated. Figure 34 shows the graphic overview of all wireless network technologies. This figure illustrated IEEE PAN/LAN/MAN technologies and clearly shows how these standards and protocols can be used in different conditions. For instance, 3G protocol is used to cover a long range of audio information in a wide area network (WAN) while for the same information in a short range and personal area network (PAN), Bluetooth is better. The standard conceptual rules set for data representation, data communication and error detection across two ends in telecommunication, are called communication protocols. These abstract rules represent in different layers of communication. There are different protocol stacks introducing different architectures for these layers such as AppleTalk, Distributed Systems Architecture (DSA), Internet protocol suite (TCP/IP) and Open Systems Interconnect (ISO/OSI). Figure 35 (a) illustrates the different layers of an OSI Model and their functionalities. The OSI model has seven layers and each layer provides services for the upper layer and requests services from the lower layer. Figure 35 (b) shows the typical communication protocols layers. Each of these layers has to deal with different issues regarding the communication procedure. As the typical protocol stack model shows in Figure 35 the communication protocols should implement all layers from bottom to top. In addition, a management protocol needs to be applied in each layer to manage power efficiency, robust connectivity and connection reliability (see: Figure 35 b). Below, rules and functionality for each layer are described: * Physical layer: is responsible for signal processing and physical interface connectivity between a device and physical medium and used bit stream in its data unit. It acted as communication channel for sensing and actuation in cost-efficient and reliable manner. Some examples of this layer are: IEEE 802.11b/g Wi-Fi, IEEE 802.15.1 Bluetooth, IEEE 802.15.4 ZigBee, etc. [7] * Data link layer: provides functionality toward channel sharing, Medium Access Control (MAC-Layer), timing (e.g. data time arrival), local link and capacity. It is responsible for detecting and correcting the data errors in physical layer and control the locality data comparison. It follows the protocols such as point-to-point protocol (PPP) and IEEE 802 Local Link Control (LLC). [7] * Network layer: is responsible for network routing functionality, network security, energy and power efficiency and reliability of the communication. It includes the network topology management and manages the information and detects errors in data transfer from router to router. A number of protocols is address in this layer such as: Internet protocol (IP), Threshold Sensitive Energy Efficient Sensor Network Protocol and etc. [7]. * Transport layer: provides end-to-end transportation (distributing and gathering) of data between end users. It includes storage and responds for caching and controlling the data to recover them back to the initial message that has been sent. Best-known protocols for this layer are Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) [7]. * Upper layers: The Upper Layers are responsible for application processing, external query processing and etc. Upper layers include presentation layer session layer and application layer [7]. The summary of these standards and protocols are shown in Figure 36 Among all the standard and protocols, IEEE PAN/LAN/MAN technologies are the ones applied in the majority of commercialWSNs to support physical layer and link-data layer signal transmission. As SOHRABY and ZNATI (2007) mentioned, the most common best-known protocols are: (1) the IEEE 802.15.1 (also known as Bluetooth); (2) the IEEE 802.11a/b/g/n series of wireless LANs; (3) the IEEE 802.15.4 (ZigBee); (4) the MAN-scope IEEE 802.16 (also known as WiMax); and (5) radio-frequency identification (RFID) tagging [7]. Each of these protocols has their own benefits and constraints. The comparisons between IEEE technologies are mentioned in Table 32. As Table 32 shows the IEEE 802.15.4 standard provides data rate of 20 to 250 kbps and operates in the 2.4-GHz ISM band. This standard covers signals in range of 10 m and requires the lowest power among other IEEE class. While IEEE 802.11a/b/g/n transmits the data in the rate of 54 Mbps ideal for wireless internet connections and operates in the 2. 4-GHz ISM (Industrial, Scientific and Medical) radio band as well as the 5-GHz ISM / 5-GHz U-NII (Unlicensed National Information Infrastructure) radio band. However, it requires much higher power consumption than IEEE 802.15 [7]. Recently, researchers put much effort to develop a cost-effective standards-based wireless networking solution that supports low-to medium data rates, has low power consumption, and guarantees security and reliability [7]. ZigBee Alliance is an association of companies which aims to provide such a standard for WSN consumers. Their mission is to have a simple, reliable, low-cost, low-power and standards-based wireless platform 1.2.2.1 ZigBee standard The ZigBee standard builds on IEEE 802.15.4 and is suitable for remote monitoring and controlling applications. Although it has lower-data-rates than the other standards, its reliability, security, long life battery with less complexity mechanism make it ideal for building automation in industrial network applications. The architecture of the ZigBee stack is established on the Open System Interconnection (OSI) model. The IEEE 802.15.4 defines the physical layer (PHY) and medium access control (MAC) sub-layer and In addition, ZigBee Alliance defines other functionalities for upper layers [7]. Figure 37 is a graphic overview of ZigBee protocol stack and shows the responsibility areas of IEEE 802.15.4, ZigBee Alliance platform and users applications [7]. This picture also shows the basic functionality of each layer. The data transmission service is provided by PHY layer and the protocol in this layer enables the connection between data units and the physical radio channel. ZigBee provides three different frequency band options for PHY layer. First, the transmission data-rate of 250kbps in 16 channels at 2.45GHz (Global) frequency. Second, with 40Kbps in 10 channels at 915MHz (Americas). And the last one, with 20kbps in 1 channel at 868MHz (Europe). The higher data-rate causes a higher order in modulation design and the lower frequency cause a larger cover area and better sensitivity. Depending on the power output, the transmission distance rate can change from 1 to 100 meters. (For more detail information see: Table 71 in Appendix A) ZigBee WSN has the ability to have static or dynamic network/component with either star or mesh topology and it has three types of nodes: a ZigBee Coordinator (ZC), ZigBee Routers (ZR), and ZigBee End-Devices (ZED). In order to have a communication protocol and physical connection both PHY layer and MAC sub-layers of the architecture should be defined upon agreement between server and clients. These layers require manual administrative procedures setting for server/client gateway. The next three levels namely: the network layer, security protocol and transport layer are defined by ZigBee alliance platform automatically. The last layer, application layer, has to interact with the user-interface and other applications; it ought to be programmed with high-level language so that integration with any existing devices applications becomes more conveniently practical. The ZigBee stack in gateway is responsible for all the network functionality such as network process management, authentication of the joined nodes, binding nodes and routing the messages throughout the network. ZigBee stack as a standard protocol, has clusters and libraries for improving the implementation process, therefore, using ZigBee compare to other protocols makes the system (including both hardware and software) development process much faster and easier. On the other hand, such standardisation provides easiness of adopt with third party sensors regardless of manufacturer, which might be attached to the network later. 2 Software Aspects To address the research question regarding the reliability, robustness, and security of any WSN application, it is essential to investigate the software architecture of that network. For convenience in description of the architecture of a WSN application, it is divided into three segments: Physical devices (such as lamps, sensors, nodes), Communication Protocol (terminals and servers, bridge, switch, network topology and standard) and Carried Information (application, functions, etc.). Any attempts to retain a precise design on software architecture for each part will cause an effective data transmission, which ensures reliability and security of the system [7]. Hence achieving any desired data transmission precision level in a WSN, network management (NM) techniques are applicable. Such techniques assist in network status monitoring, reliability and security amendment, and cooperation supervision between components [7]. NM techniques could also detect and resolve network faults in addition to restoring the system respectively [7]. In practice, designing WSN application necessitates tailoring NM techniques for each architectural segment. Various NM techniques regarding each segment are summarized as follows [7; 12; 5]: a) Physical architecture: Sensing and processing management, operation and administration, fault tolerance, maintenance, energy efficiency management, configuration management, performance management, security management, network element management. b) Communication architecture: Network management, networking protocols, network topology, function management, monitoring functions, fault management, performance management, security management, service management and communication, maintenance management, network configuration and organization, network behavior, data delivery model, sensor mobility, naming and localization, sensing coverage area, communication coverage area energy efficiency management c) Information architecture: Real-time information management, mapping management, service management, analyze information, control application, business application management report management, sending and receiving commands or response, naming, localization, maintenance, fault tolerance Aforementioned NM techniques enhance quality of the system. According to ISO 9126-1 software quality model Table 41 [13; 14; 15], the quality characteristics of a system could be divided into six fundamental properties: functionality, reliability, usability, efficiency, maintainability, and portability. According to the same documentation, these characteristics are broken to sub-characteristics such as suitability, security, maturity, fault tolerance, adaptability, analyzability, stability, testability and so on [13]. However, focusing on all subcategories collectively exceeds the time horizon of this research, from this stance three dimensions namely reliability, robustness and security are brought into attention. This section will be divided to two subsections describing the architecture issues and NM techniques for (1) Reliability and Robustness, (2) Security, of WSN and other characteristics is relegated to future studies. 2.1 Reliability and Robustness In WSNs context, the probability that a network functions properly and aggregates trustworthy data without any interruption continuously, is usually referred to as reliability characteristic of the network [23; 20]. According to ISO 9126-1 software quality documentation, reliability characteristic shows the capability of a network to maintain or re-built (re-start) the service in certain period of time [13]. So, it is important that during long sensing, the network has to service up continuously. Reliable service of a network includes precise and proper sensing, delivering and sending acceptable data to the base station. In other words as Taherkordi et al. (2006) put: The less loss of interested data, leads us to higher reliability of a system. Systematic approach perceives reliability as probability of data delivery to the base station rather than point-to-point reliability [16]. Robustness defined by Sohraby et al. (2007) as: a combination of reliability, availability, and dependability requirements, reflects the degree of the protocol insensitivity to errors and misinformation. Achieving system robustness in WSN, necessitates system capability to detect, tolerate and confine errors as well as reconfigure and restart the network respectively [7]. According to the given definition by Sohraby et al. (2007), it is apprehensible that reliability and robustness share commonalities with each other; this is the main rational behind discussing these two attributes together in this section [7]. Considering the nature of communication in WSN, a network is unpredictable and prone to fail caused by any physical damages in hardware devices, energy depletion, communication link error, information collapses in packages and etc. [17; 16]. Therefore, one of the critical issues in design phase of WSN is applying fault tolerance techniques to optimize the network so that reliability and robustness attained [17]. These techniques enable the network to withstand and recover any upcoming failure and restart operation [13]. Liu et al. (2009) categorized fault tolerance techniques into: node placement, topology control, target and event detection, data gathering and aggregation, and sensor surveillance. Reminding from the beginning of this chapter architecture design divided into three segments. Table 42 depicted a summary of the plausible related faults and their solutions in each segment. In the following, each aforementioned fault tolerance techniques are being discussed in each design segment. a) Reliability and Robustness in Physical Architecture Fault: any interruption in sensor surveillance, sensors failure Solution: Node placement management, signal-effect management, hardware replacement b) Reliability and Robustness in Communication Architecture Fault: communication link errors, energy depletion Solution: topology control and event detection , replicated services in communication model, Power consumption management c) Reliability and Robustness in Information Architecture Fault: Losing the data package Solution: data gathering and aggregation management Table 42 The most probable fault and their fault tolerance solutions in WSN [17; 7; 18] 2.1.1 Reliability and Robustness of Physical Architecture: a) Reliability and Robustness in Physical Architecture Fault: any interruption in sensor surveillance Solution: Node placement management, signal-effect management Fault sensors failure Solution: hardware replacement Fault: any physical interruption in sensor surveillance Solution: Node placement management and signal-effect management First item that should be considered in designing physical components architecture for reliability and Robustness is: physical placement and signal-effect management. As it is mentioned in section 3, although the mesh network communication is self-organize topology and does not need any manual configuration to bind the network for mobile sensors, the physical architecture and the location schema of the hardware components, sensors and gateways need to be designed carefully [7]. As a characteristic of mesh WSN, the sensors in network are free of any installation restrictions, even though, the placement should be far from any physical destruction or hostile locations. Inappropriate physical placement of sensor transmitters and gateway antenna can cause noise or significant lost in signals [7]. In addition, the signal coverage is decayed by surrounding objects and materials such as metal wall and the like. (E.g. exterior wooden, concrete, brick or gypsum frame, block or wall). Especially in the case of vehicles, the main body can impose such problem and henceforth installation of the sensors in this manner would be delicate. Moreover, the signal waves might be faded and affected during the transmission, due to various physical phenomena such as reflection, diffraction or scattering [7]. These effects would cause significant interruption in sensor surveillance. Therefore, it is important to manage these signal-effects in early stage of WSN physical architecture design. Reflection occurs when electromagnetic wave of signals is duplicated due to impinge of the wave on large object or surface such as walls, buildings and the Earth [7]. Therefore, all the reflection of the walls and also the Earth should be acknowledged in physical architecture design. Diffraction refers to any defection and obstruction in waves caused by irregular sharp edges during the data transmission between the transmitter and receiver [7]. In this case, designers have to be prudent in sensors placements in the proximity of sharp edges and corner angels. Scattering refers to any deviation from straight line. Environmental obstacles in the propagation path affect passing waves from their original structure. Even small irregular object such as street signs, and lampposts might encounter and scatter the wave. Hence WSN should be design to face with any irregular scattering during the wave transmission. Above all, the mobility of sensors and surrounding objects might fade the signals and add noises that should be considered in architecture design [7]. These issues are the basic physical factors, which cause major fault in data aggregation of WSN and cut down reliability and robustness. These destructive signals need to be subtracted from the received signal paths [7] before sending the data to gateway. Therefore, reflection, diffraction and scattering should be considered not only by designers in the physical components placements, but also by programmers in network development. Fault: Sensors failure Solution: Hardware replacement The next issue that needs to be considered in designing the physical architecture of a WSN is hardware failure. Sensors energy suppliers or any damages to the sensors and/or their transmitters are the sources of hardware failure. Regardless of source of failure, the WSN must be capable of functioning as well as replacing and switching sensors when necessary. Additionally, any changes in the physical components, on one hand, needs an explicit and well-defied consideration on security issue to prevent any potential threats, and on the other hand, needs an adaptable and configurable communication connection network [18]. 2.1.2 Reliability and Robustness of Communication Architecture b) Reliability and Robustness in Communication Architecture Fault: communication link errors Solution: topology control and event detection , replicated services in communication model, Fault: energy depletion Solution: Power consumption management Fault: communication link errors Solution:Topology control and event detection , Replicated services in communication model, Communication link error is an important concern in dealing with reliability and robustness of a network in communication architecture. The sensors in WSN are prone to fail and make link errors in point-to-point reliability of communication protocol. Therefore, it is the network topology responsibility to detect the errors and guarantee the overall reliability of the system. As it is explained in section 3.2.2.1, applying mesh topology fosters the network to conduct an acceptable performance and flexible network architecture. This topology allows the sensors to organize in an easy deployment and easy configuration network [19; 12]. The mesh topology brings reliable self-healing and robust fault tolerance characteristics for the network. This means that, without any manual configuration, all sensors communicate with each other directly or through other midway sensors and generate a self-configuration and self-organized network [19; 12]. Therefore, any pair of sensors will be able to communicate between each other within more than one path. The multiple paths link between sensors would conduct a reliable communication for WSN. In this way, if a sensor fails or breaks down during the operation, the system detects the sensor failure and disconnects it from the network in response. Then, the signal packages jump from the disconnected sensor and automatically conduct a new path through the nearest sensor. Although the fault does not essentially affect the whole system functionality and the network reliability via few sensors failures, the system should be programmed in a manner that detect, locate and report the emerging failure to the base station [19]. This fault tolerance topology and re-configuration of new path imposes re-routing of the packages and re-organizing of the network [5], which consumes too much power from the system. Therefore, having a power-aware protocol and algorithm such as ZigBee is necessary for the network for energy efficient function. Fault: Energy depletion Solution:Power consumption management Energy depletion is another fault in communication. High power consumption of a sensor or power supply failure is usually the main sources of depletion. For instance, dealing with reflection, diffraction, and scattering of signals, consumes lots of power; this implies a definite need to manage the power consumption in programming WSN communication. To solve the issue regarding power consumption, three solutions are suggested: 1. Utilization of the resource-efficient algorithm for the network: The algorithm should be energy efficient, provide the most efficient power solution for the network, and enable WSN to operate in a low power level [7]. ZigBee standard protocol perceives to be a suitable solution for network communication between the sensors. As stated in previous chapter, ZigBee stack provides lightweight protocol for network, which can be used as a communication interface between bounded sensors and gateway. One of the characteristic of ZigBee is: low-data-rate transmission, which makes ZigBee as a power-efficient protocol. ZigBee standard also provides reliable binding and data transfer within WSN components. Basic ZigBee devices operate at 1mW radio frequency (RF) power and can switch to sleep mode when it is not involved in data transmission. Since wireless communication wide bandwidth demands high energy, using as narrow bandwidth as possible will assist in retaining efficient power consumption. For this purpose, the network can use channel 2.4 MHz transmission rates. Also ZigBee protocol in a network provides the ability to use 2.4 GHz Global standard, 868-868.8 MHz European standard or 902-938 MHz American s tandard as the transmission rate for different situation and manage the energy. 2. The other approach to manage the power could be programming the sensor to switch between active and sleep mode sequentially. Keeping the sensor sleep, consumes no energy. This would help the system to be more energy efficient and reduce failures regarding the energy of the system [20]. 3. Kumar Kishore (2009) suggested the third solution as applying aggregation point to reduce total of number of transmitted messages during communication network segment programming. Aggregation point is a regular sensor with the processing capability to filter out any unwanted information from the main data package before transmitting it across the network. This technique reduces both the number of the transmission messages and energy consumption and increases system power-efficiency [20]. 2.1.3 Reliability and Robustness of Information Architecture: c) Reliability and Robustness in Information Architecture Fault: Losing the data package Solution: data gathering and aggregation management Fault: Losing the data package Solution:Data collection and aggregation management As it is mentioned before, the communication links in WSNs are prone to fail and these failures always affect the transmission of the information. Also it is possible to lose the data package along the data transmission path because of either hardware or network connection failure. Obtaining reliable data transmission requires both managing the data aggregation and programming a reliable protocol for the system from the early stage of software development. In mesh WSN, every sensor is responsible to dispatch data package to the gateway. Each package of data has a selected cluster head for sending through MAC-layer. As it is mentioned in 3.2.2.1, for the communication protocol, ZigBee provides predefined data transmission clusters and libraries for MAC and PHY layers that make transfer possible. Cluster heads sequences data package dispatches during information transfer. Each node (or sensor) in the path gets the data package and checks the cluster head to make sure of the accuracy of the receiving data. To be sure that the messages have reached the destination the receiver node sends an acknowledgement to the sender node about delivering the messages. If the sender does not get the acknowledgement within its time interval, the node finds an alternative path to send the package. The message is retransmitted in certain time intervals until it is received correctly. These techniques help the real-time network to provide reliable informational communication [21; 22]. According to what is discussed, programmers have to prudently develop the cluster heads, acknowledgment message and response interval messages to increase reliability of information transmission. 2.2 Security According to ISO 9126-1 software quality documentation Table 41, Security is sub-characteristic of functionality of a system and is related to unauthorized access to system functions [23]. In WSNs, security of the network is one of the great challenges [24]. Like reliability, the security of WSN should be considered from the first stage of designing. For instance, table below shows different issues and their solution that should be monitored during each of physical architecture, communication architecture and information architecture design [25; 7; 26]. a) Security in Physical architecture Issues: Attack and damage a light or sensor, Adding an extra light or sensor, Solution: Secure protocol ,Shared Keys, naming , Localization, Secure Groups, authorization monitoring , Encryption, b) Security in Communication architecture Issues: Attack and hack the protocol, sending fake data package to the network Solution: Secure protocol, Encryption, naming , Localization, authorization monitoring c) Security in Information architecture Issues: pick off the data stream, Solution: Secure protocol, Encryption , authorization monitoring , Table 43 The Probable Issues or Threat in WSN and Their Security Solutions [25; 7; 26] As Table 43 shows, the solutions to security architecture for WSN are: Naming, Localization, Secure protocol, Secure Groups, Authorization Monitoring, Shared Keys and Encryption [25]. For more convenience all solutions are divided into two sub-categories: (a) Secure Protocol mechanism, and the (b) Naming and Localization mechanism each of which are described in the following: 2.2.1 Secure protocol WSN, by using ZigBee protocol, provides different effective security techniques to solve any security flaws [26]. Some of these techniques are: Cryptographic, Key-Transport, Frame Protection, Security Key, Access Control List, and Authorization Monitoring. To coordinate the security services on WSN, ZigBee assigns a trusted sensor as the Trust Center on the network. The responsibility of this dedicated sensor would be first to authenticate other sensors requesting to be connected into the network and second to distribute security keys to other sensors and finally enable end-to-end security between sensors and gateway [26]. Trusted Center enlists all trusted sensors. The content of the list includes the MAC addresses of sensors that are authorized to communicate. ZigBee has access control to the list and detects any unauthorized devices from the legitimate ones. In order to accept or reject the joining request, ZigBee sends authenticity message to the higher layer application where a message is observable by the end user whether in base-station or other clients. So the trust center rejects the message sent from unauthorized devices and isolates them from the network [7]. ZigBee applies security services, identified in 802.15.4 for low-level PHY and MAC layer. Additionally, ZigBee has standard security architecture for higher-level Network (NWK) and Application (APS) Layers as a comprehensive security system suit for inter-network communications [26]. In MAC layer, ZigBee secures confidentiality, integrity, and authenticity by two mechanisms with respect to hop transmission. In a single-hop transmission, it secures MAC command messages by using cryptographic algorithm, Advanced Encryption Standard (AES). In multi-hop messaging, ZigBee cannot secure the network without interaction with upper layers like the NWK layer [27]. In MAC security command for single-hop, an increased count tag is added in every message frame sent inside the network. The receiver node keeps the tags. If the node detects an old or wrong count tag, it is recognized as a security error [27]. This mechanism makes generating invalid messages difficult and reduces the threat of attacks from spamming. However The MAC layer cannot secure the process by itself, therefore security relies on the upper layers to control this process by setting up the keys and the applicable security level [27]. ZigBee uses Security Key plus Advanced Encryption Standard (AES) in upper layers for the multi-hop messaging and controlling secure processing [27].The NWK and APS are in charge of secure frames transport and APS also establishes a secure relationship between different devices in the network [26]. The detail of the Mac and upper layer security process are described in [27]. A very high-security, key-basedcryptographyalgorithm applied in upper layer by ZigBee standard is based on 128-bit keys and the AES encryption standard [7]. These keys can be categorized in three groups, described as follows: Network security Key: A shared Common key for all sensors in the network. This key is given to each sensor during the first installation or via key-transport. The network can be secured by the use of this key by all components of WSN system and prevent any illegitimate joining request [26; 7] (physically or spamming). Link security Key: A secret session key, unique between any two devices which communicate with each other. The link key is a representative of the relative Master keys [26; 7]. This key prevents any illegitimate messaging in communication and messaging level. Master security Key: Each light (senor) or component in WSN uses this key to create the link keys [26; 7]. It is noteworthy to mention that as security is not enabled in ZigBee stack by default, programmers must deploy the application at the desired security level in the planning and designing of a ZigBee network. More information regarding how to organize security and manage encryption keys are described in Section G: Security Best Practice Recommendation in the article [7]. Beside all these advantages of using ZigBee security services, ZigBee also has its own disadvantages. One of the disadvantages of ZigBee is related to the run-time for traffic based devices where they cannot be locally separated. The reason could be due to the limited power supplies and small memory size of the lights and sensors in WSN. Therefore some applications might use the same keys as cryptography key. In current ZigBee standard, the application is running on the same node at a time, referred to as an open trust model. This is especially becomes a drawback in scalability of ITS where the intention is growing the network among different vehicles. 2.2.2 Naming and Localization: Naming is used for identifying the sensor nodes. Several security applications can be built based on naming sensors. The naming can be done in two ways: low-level naming depends on location and sensor topology and high-level naming embeds on application layer. The latter is independent of location and sensor topology [7]. Both naming approaches can be used in a system simultaneously. While the high-level naming is useful for communication between different applications (like domain name in the Internet), the low-level naming is utilized for package forwarding in physical layer applications (Like IP address in the Internet) [7]. Localization schemes allocate a position to each sensor for many applications such as monitoring and tracking interrupted object, enhancement in security application and many more. The naming and localization approaches introduce the following advantages for WSN programming: In physical layer, whenever a light or sensor is enhanced to the network, the security name of the light or sensor should be authenticated by base-station or vehicle to increase the security. This minimizes the threats of adding any unauthorized extra light or sensor to the network. Also the localization helps the system to determine the exact physical location of any unauthorized movement around the vehicle. By a robust fault tolerance topology and protocol, it is possible to recognize exact broken sensor. Neighboring sensors are responsible to send a message containing location and type of the broken sensor to the base-station. A proper naming proposes lower computation and data transmission traffic on protocol, which leads into less energy consumption and efficient communication. They are additional by-products to sensor naming and localization such as vehicle defect diagnostics, and accident prevention alerting sensor. 2.3 Software Quality Framework As promised earlier in the research questions, in this section, the main quality framework is generated through merging all presented faults and NM techniques associated to reliability, robustness and security. To keep cohesiveness and coherence with the previous sections of this chapter, the framework is presented into three network architecture segments. The complete table quality software framework can be found in AppendixB. Table 44, Table 45 and Table 46 exhibit the framework for physical, communication and information architecture. Each table consists of discussed NM techniques and each of which exercising implications both in mesh network and ZigBee protocol. Also the tables indicate whether the practicality of the techniques is tested in real world or it is merely lab-proved for ZigBee protocol. Because ZigBee protocol is quiet fledgling network system compare to Bluetooth, Internet protocols and WiMAX, many of the NM techniques have been tested and provided with practical implications in real world for older existing network systems, while they have not been applied in ZigBee applications yet. For instance, techniques such as Communication Availability, Signal Effect Management and Encryption have been fully exercised in other WSNs and their associated real world practical faults and errors have been resolved. Additionally, for some NM techniques such as Energy Supply and Node Placement Management, no promising concrete practical solution have not been presented in ZigBee yet.

The Adventures Of Tom Sawyer . __________________. A Book

THE ADVENTURES OF TOM SAWYER __________________ A Book Review Presented to Mr. Parsons and Mrs. Amy Lack Woodville High School __________________ U.S. History I and English 10 __________________ by Arian Campbell April 19, 2017 The Adventures Of Tom Sawyer The Adventures Of Tom Sawyer by Mark Twain is a 271-page novel. Tom is a boy, and merely and exactly an ordinary boy on the moral side. What makes him delightful to the reader is that on the imaginative side he is very much more, and though every boy has wild and fantastic dreams, this boy cannot rest till he has somehow realized them. The story is a wonderful study of the boy-mind, which inhabits a world quite distinct from that in which he is bodily present with his elders,†¦show more content†¦Tom Sawyer lives with his Aunt Polly and his half brother Sid. He skips school to swim and is made to whitewash the fence the next day as punishment. He cleverly persuades his friends to trade him small treasures for the privilege of doing his work. He then trades the treasures for Sunday School tickets which one normally receives for memorizing verses consistently, redeeming them for a Bible, much to the surprise and bewilderment of the superintendent who thought it was simply prep osterous that this boy had warehoused two thousand sheaves of Scriptural wisdom on his premises a dozen would strain his capacity, without a doubt. Tom falls in love with Becky Thatcher, a new girl in town, and persuades her to get engaged by kissing him. But their romance collapses when she learns Tom has been engaged previously to Amy Lawrence. Shortly after Becky shuns him, he accompanies Huckleberry Finn to the graveyard at night, where they witness a trio of body snatchers, Dr. Robinson, Muff Potter, and Injun Joe, getting into a fight. While Potter is knocked unconscious during the scuffle, Injun Joe stabs the doctor to death and later pins the blame on Potter, who is arrested for the murder. Potter is then shunned by the whole town, except Huck and Tom, who knew the real story. They decided to keep mum about this incident because they are afraid of Injun Joe murdering them. Tom and Huck run away to an island. While enjoying theirShow MoreRelatedMark Twain : Seeing America s Flaws1593 Words   |  7 PagesMark Twain: Seeing America’s Flaws â€Å"You don’t know about me, without you have read a book by the name of The Adventures of Tom Sawyer , but that ain’t no matter. That book was made by Mr. Mark Twain and he told the truth, mainly. There was things he stretched, but mainly he told the truth† (qtd. in Jones 237). That was the very first line in Mark Twain’s controversial book, The Adventures of Huckleberry Finn. Samuel L. Clemens, as a young boy, grew up on the Mississippi and learned the ways of southernRead More Comparison of Tom Sawyer and Huck Finn in The Adventures of Tom Sawyer and Huckleberry Finn by Mark Twain665 Words   |  3 PagesComparison of Tom Sawyer and Huck Finn in The Adventures of Tom Sawyer and Huckleberry Finn by Mark Twain Tom Sawyer and Huck Finn were both characters created by Mark Twain. Tom Sawyer is the main character in the book The Adventures of Tom Sawyer and Huck Finn is the main character in the book The Adventures of Huckleberry Finn. Huck Finn and Tom Sawyer were alike in many ways but they were also very different. One way in which Huck Finn and Tom Sawyer are alike is that they are bothRead MoreFreedom in Mark Twains The Adventures of Tom Sawyer590 Words   |  3 Pagesin the book The Adventures of Tom Sawyer than freedom. Freedom plays an enormous role in the book Tom Sawyer. Whether it is people earning freedom or people not being granted it, every young boy in St. Petersburg wanted some form of freedom. The word freedom means the power to say and do what you want. Tom Sawyer, Huckleberry Finn and Joe Harper are all boys seeking freedom. Freedom is the key reason the boys run away to Jackson Island. Freedom is one of the main themes in the book. Tom is alwaysRead MoreThe Adventures Of Tom Sawyer By Mark Twain1558 Words   |  7 PagesThe Adventures of Tom Sawyer In 1876, a novel about a young boy growing up along the Mississippi River was written. Set in the fictional town of St. Petersburg, Mark Twain, the author of this fictional piece, based ‘The Adventures of Tom Sawyer’, largely on his personal memories of growing up in Hannibal, Missouri in the 1840s. 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Why do i say this, I say this because the book of Tom Sawyer is set in St. Petersburg, St. Petersburg may be small but it s got everything a boy could ever want. This really adds to the excitement and appeal of the book. Another thing that adds to the appeal of the book is the narrator point of view. Twain does a good job of using versatility an d verbal skill in the narrator point of view. For exampleRead MoreThe Adventures Of Huckleberry Finn By Mark Twain1103 Words   |  5 PagesDmitri Van Duine Jr English Mr. Nelson November 27th The Adventures of Huckleberry Finn: Huck Finn and Tom Sawyer The Adventures of Huckleberry Finn, Written by Mark Twain filled his stories with many examples of satire as to convey a message while also writing an interesting story. The Adventures of Huckleberry Finn revolves around the adventures of a young boy called Huckleberry Finn, who is about thirteen years old. Tom Sawyer is Huck’s best friend and around the same age as Huck. He is onlyRead MoreLiterary Analysis Term Paper for Tom Sawyer : a Classic Novel771 Words   |  4 PagesTerm Paper for Tom Sawyer: A Classic Novel Mark Twain’s book is a novel that follows the juvenile life of a small boy. You will see how much fun the main character, Tom, and his friends have by skipping school, fishing, swimming, and using with their imaginations to have a good time. The Adventures of Tom Sawyer is a classic novel for many reasons. The plot gives us an idea about how people lived in the era the book takes place in. Readers enjoy the book because they can relate to Tom and enjoy hisRead MoreTom Sawyer Character Analysis828 Words   |  4 Pages Tom Sawyer is an adventurous boy who gets into mischief and trouble, but learns from his mistakes. Although in the beginning of the book, he was a troublemaker and was always yelled at by his Aunt Polly, in the end, he became a young man and was more mature than ever. In The Adventures Of Tom Sawyer, by Mark Twain, Tom lives with his Aunt Polly and constantly gets into trouble. He witnesses a murder, goes to an island and pretends he’s a pirate, gets lost in a cave, finds buried treasure, and goesRead MoreAnalysis Of Mark Twain s The Adventures Of Tom Sawyer As Well1350 Words   |  6 Pagessense of humor to criticize the 19th society in America’s and propagate his ideal world through The Adventures of Tom Sawyer. People commented Twain as â€Å"Twain does not confine himself to telling a simple children s story. He is, as always, the satirist and commentator on the foibles of human nature†(Roberts), Twain does use his sense of satire in the classical America book: The Adventures of Tom Sawyer as well. The novel is about a group of young children who feels abhorrent about the rigid social

Bicycle Braking Systems Free Essays

Bicycle Braking Systems Year 11 Engineering Studies Merewether High School Nathan Dunshea 29/06/2012 Abstract: In this report a comparison of three Braking systems; Calliper, Drum and Disc will be made on a variety of areas including – * * Effectiveness * Performance * Features * Materials * Frictional Components * Difference from comparable car systems An Orthogonal and Pictorial drawing will also be provided on a selected section of one of the braking systems being compared. Introduction: Bicycle Braking systems are a means of which we are able to halt the movement of a bicycle through the expulsion of kinetic energy. The Kinetic potential energy that is present in a moving bicycle is converted in to 3 different forms of energy; heat, sound and light. We will write a custom essay sample on Bicycle Braking Systems or any similar topic only for you Order Now This is done through the resistance of a wheel to move when a brake applies a frictional force against the spinning movement of a wheel. Three different types of brakes are generally used on bicycles today; the Calliper, Drum and Disk systems. These three popular braking systems have their own unique set of advantages and disadvantages that persuade the population to purchase them. 2: Calliper Brake Diagram : Calliper Brake Diagram 3: Disc Brake Diagram 3: Disc Brake Diagram 4: Drum Brake Diagram 4: Drum Brake Diagram Procedure: I used the Internet to research pictures, articles and suppliers of Braking systems in order to access the appropriate information needed for this report. Results: Effectiveness, Performance, Features Comparison Effectiveness: 10: Cross-Section of a bicycle drum brake 10: Cross-Section of a bicycle drum brake The effectiveness of these Braking systems will be a measure of their ability to perform over a period of time. It is necessary for these brakes not to only perform well once, but over many instances, including moments of hard excessive braking. In today’s modern bicycle, many things will affect the braking systems ability to be effective. The weather, wear and tear over many uses, as well as the type of braking taking place can all have adverse effects on brakes. Drum brakes are not the most popular style of brake for a bicycle. This could be accredited to their effectiveness over time compared to both calliper brakes and disc brakes. Drum Brakes are typically very heavy, complicated to perform maintenance on and are often subject to brake fading. Break fading can be defined as the loss of braking force able to be exerted by the braking system at any point, and this often happens due to overheating as a result of consistent hard braking. Drum brakes are unable to dissipate heat anywhere near as efficiently as disc brakes as the frictional forces that turn kinetic energy into heat are all enclosed within the drum itself, which is often housed at the hub of the wheel. In fact, many companies have been forced to put warning labels on their hubs to make sure children aren’t unaware of the heat generated, and subsequently burn themselves. This makes them particularly susceptible to brake fading, something that both disk and calliper brakes don’t have a great problem with. In adverse weather conditions, the drum brake can show of its unique asset both the disc and calliper brake does not have. The Drum brake is fully enclosed, and therefore is not affected by rain, mud and other substances that may impede the frictional force exerted on the wheel. 12: Disc brake to be fitted to a Mountain Bike 12: Disc brake to be fitted to a Mountain Bike Disc Brakes are very popular on Mountain Bikes, which require thick wheels and are often subject to muddy terrain. Because the disc brake is mounted to the hub, a certain clearance from the ground is maintained at all times, generally keeping mud from obstructing the pads and disc. If water is to get stuck under a disc brake’s pad, there are generally holes through which it can quickly escape so to not compromise the friction produced in the system. Touring bikes have been known to prefer disc brakes to types of calliper brakes, as the long journeys and significant use of brakes would not wear out the rim as they do using a calliper brakes system. The typical Disc Brake system is a very adaptable structure as it can perform better than Calliper Brakes in the mud, rain and snow as the coefficient of friction isn’t as at risk of contaminants disturbing the system. Disc brakes are also less prone to brake fading when subject to long periods of braking pressure, as they are very good at cooling down compared to drum and calliper brakes. A disk brake is also less likely to cause a popped tyre, with the heat not being dissipated directly into the tyre as in calliper brakes. 14: Shimano Bicycle Caliper Brake 14: Shimano Bicycle Caliper Brake Calliper Brakes are generally the most common of the braking system for the everyday bicycle. Excluding the original design quality of the equipment and materials, calliper brakes are often affected mostly by the moisture that is on the rim, as that will significantly hinder the ability to stop. Tyre thickness can also pose a problem to the calliper braking system, as the arms will be under greater flexion, thus lessening brake effectiveness. However, the Calliper brake system is effective on the average road bike and is the simplest and easiest to perform maintenance on of all three designs. This system also has a very big ‘mechanical advantage’, meaning very little effort has to be put in by the rider in order to properly apply the brakes. Calliper brakes are also by far the lightest and least expensive, making them popular among non-competitive riders, with most road bikes still come fitted with this system. Performance: The performance of a braking system is based on the raw stopping power and ability for one single use. This comparison will be based purely on stopping power and performance, disregarding things such as; * Weight of system * Weather/Terrain Brake Fading * Heat Dissipation The Disc Brake is said to have the greatest stopping power, and therefore provides least stopping distance, of all three systems. This means they are often fitted to competitive riders bikes, because they are often going a higher speed and therefore need the greater stopping power that the disc brake provides compared to that of the drum and calliper braking system. In a report By Guy Kesteven for UK organisation ‘What Mountain Bike’, a variety of disc brakes were tested from many different manufacturers to test the power of each system. The test was performed as follows: â€Å"All the brakes were tested with a 180mm rotor and a 50Nm force on the lever (1N is the amount of force required to accelerate 1kg at 1m/s2), with the stock pads. To fully bed in the rotors and pads, the brakes were given 60 one-second pulls at 15km/h, followed by 30 two-second pulls at 20km/h. After a 30-second cooling-down period, the testing began. With the wheel spinning at 30km/h, each brake was applied for three seconds and then left to recover for 10 seconds. This cycle was repeated 15 times. The results were then averaged out to provide a single power rating. – Guy Kesteven; What Mountain Bike. After the test had been completed, the Formula R0 disc braking system had the greatest power of all 33 parts tested. It was found to have a power of 124 Nm when stopping, which is equal to 12. 645 kilogram-force meters. Calliper Brakes have one of the best designs in terms of their Mechanical Advantage. Very little effort has to be put in by the user to have the brakes perform as well as possible. Disc Brakes have an overall stopping power advantage over the general calliper brake, however some versions of the calliper brake have a greater stopping power than the drum brake design. With the huge variety of designs in the field of Calliper Brakes, stopping power can range from quite poor to very high. An example of this stopping power is the test carried out by Matt Pacocha in the June 2009 edition of Velonews. A group of Bicycle Calliper brakes were to be tested to measure their stopping power: â€Å"This test was performed on a flat, windless road. For each brake, the rider accelerated to 40km/hr then grabbed the brakes — hard — on a pre-determined mark and recorded stopping distance. This test was performed 10 times for each brake, and the stopping distances were averaged. † – Matt Pacocha; Velonews. At the end of the test, the Shimano 7900 dual pivot calliper brake was found to have the greatest braking force, with the shortest stopping distance of 7. 18 metres. It was also found that the average deceleration of the bicycle was 8. 59 m/s2, whilst the greatest deceleration was recorded at 10. 35 m/s2 (Over 1 G-force). Drum Brakes are less powerful than the disc brake, and therefore have a greater stopping distance in normal, controlled conditions. Compared to Calliper brakes it is not clear-cut which has a better stopping distance, as there are many different versions of each type of brake to choose from. However, it is said that the modern drum brake is able to provide a much smoother, more reliable deceleration than the majority of calliper brake systems. Features: Each of these braking systems have their own features which help to enhance the ability to stop the movement of a bicycle. Whilst some of these advantages are purely performance based, others may have features that are cost-effective or maintenance friendly. One of the most important features in the success of the disc brake is its ability to dissipate the heat generated from the frictional forces. Disc brakes are out in the open air with a large surface area, meaning the cooling process happens more quickly and efficiently. Another important, yet perhaps underestimated feature of the disc brake is it’s positioning. Disc brakes are well away from the tyres and ground, thus creating distance between the braking system and mud, dirt and other potential environmental interferences. Drum brakes however, are certainly the best in resisting those environmental factors. As the braking mechanism itself is housed within a shell of sorts, no amount of weather can have an adverse effect on the ability of the drum brake to perform its task. Once installed, drum brake system is also very low maintenance, and often doesn’t have to be managed again until a new wheel is needed. Despite this, Drum Brakes can be a hassle if maintenance must occur, as they can be difficult to access because of the shell it is housed in. Calliper Brakes are generally the cheapest of the three designs available. As they are often mounted to the bicycle at one single point, accessing the brake pads and cables is made much easier than the other systems. Another feature that is useful on the majority of road bikes with calliper brake systems is the quick release mechanism. This feature is designed as to loosen the brake system enough so the wheel can be removed without having to mess around with loosening brake cables as well. Materials used for construction and frictional components Brake Pads are perhaps the most important part of both the Disc and Calliper braking systems. The brake pad is generally made from a product that possesses a moderately high coefficient of friction, but also depends on the materials ability to absorb and dissipate the heat produced in the process of braking. If these criteria can be met without having a negative impact on overall braking performance, an appropriate material has been found. In years gone by, an asbestos based compound was the most common material from which brake pads would be made, however because of the toxic nature of asbestos that practise no longer allowed. The modern bicycle Brake Pad is enerally made from rubber compound. The rims on bicycles directly affect the performance of the Calliper braking Systems. Some bike rims today are made from an aluminium alloy, which provide a coefficient of friction when in contact with the rubber composite of the brake pads of approximately 0. 4. Other materials, such as various Carbon steels, have recently become more popular as they are light and aerodynamic. However , they do not provide a very good frictional force between the everyday brake pad, and so other materials are often preferred by the everyday cyclist. Calliper brake systems also have brake cables that transfer the motion actuated by the rider from the brake lever to the braking system itself. These brake cables are made from thin wire steel that has been braided together to improve its tensile strength and ability to perform. The Disc in the Disk brake system is an integral part of the bicycles stopping power. The Brake pad (rubber composite) must have a high enough coefficient of friction when applied to the disc to halt movement with damaging the surface. To provide this, the disc is made from metal, with stainless steel being popular among mountain bikes. A brake drum has an outer shell in which the braking system itself is contained. This outer shell is subject to weathering from the outside and heat from within. With this in mid, cast-iron is generally the material chosen as it can cope with these two burdens other materials could falter under. The shoes of the Drum brake are the parts that push outwards to produce the frictional forces needed in the brake design. These brake shoes are generally made when two pieces of sheet steel are welded together. After they are welded together, the frictional material known as brake lining is connected on to the sheet steel with either adhesive resin or other means such as a rivet. It is also important to remember that the rubber composite of bicycle tyres also has frictional forces acting from the material it is rolling on. For instance, if a cyclist was riding along a concrete surface, the coefficient of friction would be 0. 8, much higher than that of rubber or brake lining to metal (0. ). Thankfully, the relatively light weight of the human body – compared to the force exerted by our mechanical braking systems – allows us to still move along these surfaces. (FF = ? RN) How they differ from comparable car systems On most bicycles, the braking systems installed will often be very simplistic and just there to do the job. Most will have the same type of brake on both front and back wheel, wi th the braking of the bike mostly relying on human action with levers and cables, as well as the mechanical advantage some of these designs provide. However, when upgrading these systems to work on a much heavier vehicle such as a car, many things can change. It is not uncommon to have different types of brakes on the front and back set of wheels, and hydraulics become a very important part of stopping your car. In today’s modern designs, at least one set Disk Brakes are fitted to almost every car on the road. Disk Brakes are the most effective type of braking system that we could fit to our cars, however, it is still common for the front brakes to be disk, but the rear to be drum brakes. Drum brakes can be used as the parking brake, and by fitting them to the rear of the car, companies can save money by not having to install another braking system. The Disc Brake in a car is obviously in a much larger scale than that of a bicycle. Despite this, the two systems are very similar in the basic design concept. Strength of this part however, must be much greater when installed in an Automobile. Winnard Sons Ltd, a company based in the UK that deals with commercial vehicle braking components, has a guideline to the tensile strength on the brake contact surfaces of their products. Guideline tensile strength on test pieces machined from brake drum/disc contact faces: – 241 N/mm2 European Requirement minimum – 35,000 psi Amercian Requirement minimum† – Winnard Sons Ltd: Brake Disc and Brake Drum Material Specification The materials used in the brake pads of both the disk and calliper brakes are different when they are made for cars. When halting th e momentum of a car, the brake pad is put under a much greater force than when stopping a bicycle. This is due to a number of things, including the speed at which the car is travelling and the mass of the vehicle, both of which are generally higher in cars. The metals used are usually steel, copper or brass fibres, as well as a mixture of many different composites including – graphite, iron oxide, glass fibres, phosphate and rubber – that are bonded together with a resin of phenol formaldehyde. The metals that are added help to increase life span by improving the ability of the compound to dissipate heat at high speeds. The complexity of all three designs is greatly heightened when moving from bicycle to motor vehicle. One aspect of Motor Vehicle braking that creates extra pressure is the hydraulic action of the brakes. Hydraulics rely on brake fluid, typically containing ethylene glycol, to transfer pressure from the controlling unit to the brake mechanism. In a motor vehicle, drum brakes often serve a specific purpose that they would be useless for when installed on a bicycle – the park brake. As I stated earlier, these Drum brakes are fitted to the rear wheels and can save companies significant amounts of money by not having to install a completely separate parking brake. As this asset of an emergency brake is vital to a larger system, not only are they more common in cars, but they must also be bigger and exert a greater force. These three types of braking systems hold the same principles when applied to a greater size vehicle in a motor car, however many things must change to accommodate these increased forces. Conclusion: Each of these three braking systems are often used by a specific type of bicycle with a specific need. An example of this is Disc brakes being preferred by those who ride either Mountain or Touring bikes. As shown by the two field tests referenced in this report, completed by Velonews and What Mountain Bike, both Calliper brakes and disc brakes both have a very big potential to have immense stopping power. But to have that stopping power, the proper materials with appropriate frictional forces would have had to been in place. At the absolute top of the line models, every little detail is considered, i. e. : * * Weight * Frictional Forces * Materials * Angle * Type of System It was also discovered that as we transition from bicycle to car braking systems, many things must be altered. Although the basic engineering principles are often the same, there are many variables that are altered to improve to braking systems to cope with the extra forces exerted by a motor vehicle. For example, the change in materials of brake pads to accommodate the much more intense levels of heat being produced when heavy braking is taking place. I believe this report reveals that the braking system you own can make a big difference on effectiveness and performance. The features, materials used and frictional forces in play can all be positive or negative depending on the type of riding taking place. Recommendations: I recommend selecting one of these three types of braking systems based on what their use in the long run will be. If you plan to use the bike for competitive purposes when increased stopping power is necessary, I would suggest purchasing a Disc brake system. However, if the bike is simply for leisure, perhaps the more cost effective Calliper Brake system would better suit. If you are planning to ride in muddy areas where the possibility of substances interfering with the frictional forces throughout the braking system, the fully enclosed drum brake system could be the appropriate option. However, if you wish to simply have the greatest overall stopping power, I would recommend a Disk Brake system be installed. The most mportant thing to remember is that every situation is unique, and to do research in order to attain the correct brake for your needs. Bibliography: * http://www. edmunds. com/car-technology/brakes-drum-vs-disc. html * http://www. bikewebsite. com/bicycle-bra. htm * http://www. jaxquickfit. com. au/brakes * http://www. exploratorium. edu/cycling/brakes2. html * http://bikeadvice. i n/drum-brakes/ * http://www. sheldonbrown. com/gloss_dr-z. html#drum * http://www. livestrong. com/article/340500-adjust-bicycles-drum-brakes/ * http://www. skyshop. com. au/LANDING. pdf * http://www. razyguyonabike. com/doc/page/? page_id=8174 * http://sheldonbrown. com/calipers. html * http://www. bicyclestore. com. au/parts/brakes/calliper-brakes. html * http://www. 123helpme. com/view. asp? id=57299 * http://www. bike-riding-guide. com/bicycle-brakes. html * http://eecycleworks. com/VNJune%20BrakeTest. pdf * http://auto. howstuffworks. com/auto-parts/brakes/brake-parts/brake-calipers2. htm * http://urbanvelo. org/torker-graduate-commuter-bike-review/ * http://www. cycle-systems-academy. co. uk/index. php/topics/brakes/brakes-theory/mechanics-of-brakes/mechanics-of-the-system? tart=5 * http://www. physicsforums. com/showthread. php? t=158582 * http://www. longjohn. org/bremsen/bremsen_en. html * http://www. abcarticledirectory. com/Article/Bicycle-Brakes-Guide/786406 * http://www . cdxetextbook. com/brakes/brake/disc/brakefrictionmat. html * http://www. bikeforums. net/archive/index. php/t-302000. html * http://www. alibaba. com/showroom/aluminum-bike-rim. html * http://cars. about. com/od/thingsyouneedtoknow/a/discvsdrum. htm * http://www. fezzari. com/support/rb_brakes; * http://bicycletutor. com/sidepull-caliper-brakes/ * http://www. icycling. com/bikes-gear/bikes-and-gear-features/big-squeeze-road-disc-brakes * http://www. unitconversion. org/moment-of-force/newton-meters-to-kilogram-force-meters-conversion. html * http://www. bikeradar. com/mtb/gear/category/components/disc-brake-systems/product/review-formula-ro-12-46051 * http://www. winnard. co. uk/downloads/twcbd1_material_specification_2011. pdf * http://www. autoshop101. com/forms/brake03. pdf * http://www. pbr. com. au/technical/documents/hydraulicbrakesystemsguide. pdf * http://www. tcbbrakesystems. com/hdopenroad-text. html * http://www. sae. rg/events/bce/presentations/2009/okamura. pdf Append ix: Braking Power test – Matt Pacocha, Velonews: June 2009 Braking Power test – Matt Pacocha, Velonews: June 2009 What Mountain Bike UK: Calliper Brake Power Testing ——————————————– [ 1 ]. http://www. edmunds. com/car-technology/brakes-drum-vs-disc. html [ 2 ]. http://www. bikewebsite. com/bicycle-bra. htm [ 3 ]. http://www. jaxquickfit. com. au/brakes [ 4 ]. http://www. jaxquickfit. com. au/brakes [ 5 ]. http://www. exploratorium. edu/cycling/brakes2. html [ 6 ]. http://bikeadvice. in/drum-brakes/ [ 7 ]. http://www. heldonbrown. com/gloss_dr-z. html#drum [ 8 ]. http://www. livestrong. com/article/340500-adjust-bicycles-drum-brakes/ [ 9 ]. http://www. exploratorium. edu/cycling/brakes2. html [ 10 ]. http://sheldonbrown. com/sturmey-archer_3-spd. html [ 11 ]. http://www. skyshop. com. au/LANDING. pdf [ 12 ]. http://www. mountainbikestoday. com/mountain-bike-resources /should-my-mountain-bike-have-disc-brakes; [ 13 ]. http://www. crazyguyonabike. com/doc/page/? page_id=8174 [ 14 ]. http://sheldonbrown. com/calipers. html [ 15 ]. http://www. bicyclestore. com. au/parts/brakes/calliper-brakes. html [ 16 ]. ttp://www. fezzari. com/support/rb_brakes; [ 17 ]. http://www. 123helpme. com/view. asp? id=57299 [ 18 ]. http://www. bike-riding-guide. com/bicycle-brakes. html [ 19 ]. http://www. bikeradar. com/mtb/fitness/article/how-we-test-hydraulic-disc-brakes-24345/ [ 20 ]. http://www. unitconversion. org/moment-of-force/newton-meters-to-kilogram-force-meters-conversion. html [ 21 ]. http://www. cycle-systems-academy. co. uk/index. php/topics/brakes/brakes-theory/mechanics-of-brakes/mechanics-of-the-system? start=5 [ 22 ]. http://eecycleworks. com/VNJune%20BrakeTest. pdf [ 23 ]. http://eecycleworks. om/VNJune%20BrakeTest. pdf [ 24 ]. http://auto. howstuffworks. com/auto-parts/brakes/brake-parts/brake-calipers2. htm [ 25 ]. http://urbanvelo. org/torker-gra duate-commuter-bike-review/ [ 26 ]. http://www. physicsforums. com/showthread. php? t=158582 [ 27 ]. http://www. longjohn. org/bremsen/bremsen_en. html [ 28 ]. http://www. tcbbrakesystems. com/hdopenroad-text. html [ 29 ]. http://www. abcarticledirectory. com/Article/Bicycle-Brakes-Guide/786406 [ 30 ]. http://bicycletutor. com/sidepull-caliper-brakes/ [ 31 ]. http://www. cdxetextbook. com/brakes/brake/disc/brakefrictionmat. html [ 32 ]. ttp://www. alibaba. com/showroom/aluminum-bike-rim. html [ 33 ]. Paul L. Copeland, Engineering Studies – The Definitive guide [ 34 ]. http://www. bicycling. com/bikes-gear/bikes-and-gear-features/big-squeeze-road-disc-brakes [ 35 ]. http://www. bicycling. com/bikes-gear/bikes-and-gear-features/big-squeeze-road-disc-brakes [ 36 ]. http://www. autoshop101. com/forms/brake03. pdf [ 37 ]. Paul L. Copeland, Engineering Studies – The Definitive guide [ 38 ]. Paul L. Copeland, Engineering Studies – The Definitive guide [ 39 ]. http://ca rs. about. com/od/thingsyouneedtoknow/a/discvsdrum. htm [ 40 ]. How to cite Bicycle Braking Systems, Essay examples