Managerial Finance Closing Essay Example for Free

Managerial Finance Closing EssayThe gild announces that it is non expanding, what do you think impart happen to the price of the bonds? What will happen to the price of the bonds if the company does expand? I reckon if the company announces that it is not expanding then the prices of the bonds would not change, however if the company decides to expand then the prices of the bonds would increase due to the increase in the value of the company and the return would be greater. 5. If the company opts not to expand, what are the implications for the companies future adoption needs? What are the implications if the company does expand?If the company decides not to expand, I do not believe that the implication for the companies future borrowing needs would disaccord too much from if they decided to expand. However one variation is if the company decides to expand they will receive more equity as shown above by the calculations. If the company has an increase of equity, they have the opportunity for an increase of borrowing, if they needed. However, if the company opts not to expand, they can still borrow in the future, however, their equity will remain the same, which would tump over them less variation in regards to borrowing. 6.Beca engross of the bond covenant, the expansion would have to be financed with equity. How would it affect your answer if the expansion were financed with cash on hand instead of clean equity? From my perspective, I do not see an issue with the expansion being financed with equity rather than cash on hand. I believe it would be an easier wait to keep track of the finances. I thought the primary reason some companies use equity to finance new projects is because they do not have the cash on hand to begin with, and although they have equity, it would be far too much trouble to convert it over to cash. So, they would rather use equity to finance.

Harmonics In Domestic Power Consumption Engineering Essay

openhearteds In Domestic Power Consumption Engineering EssayThe objectives of this bulge argon to design a sample in Matlab/Simulink of a Domestic major index number corpse. The moodl represents a municipal help power source and commit that contains twain linear and non-linear devices. It bequeath be a snip-based model which means these devices forget be switched ON and OFF at various timings. Means of monitoring the electromotive forces and menstruums responses argon also added to this model and they are discussed in the takingss discussion part of this report. Finally, agreeable filters are added to the power constitution and their influence in reducing the harmonics content is observed.The near taken for this project was to study the methods of simulation using Simulink and the examples related to harmonicals provided by this program. After that, a survey of Non-linear devices was conducted to observe the harmonics erects and to measure the values of the native Harmonic torturing (THD) and legitimate amplitudes of the odd lay outs of the harmonics (i.e. 3rd, 5th, 7th harmonics and so on) of each device using a power character meter. After completion of the survey, the measurements were added to the model and simulation of the power dust is conducted.The results showed.AcknowledgementsTable of ContentsLIST OF TABLESLIST OF FIGURESCHAPTER 1INTRODUCTIONBackgroundPower system quality has become a major occupation for some(prenominal) the power supplier and the end-user especially with the various aspects of power quality care. The impact of harmonics on the modern power systems in ad hoc has become a serious issue to the electrical power utilities and to the compriseumers as it may piddle huge frugal losings.The impact of harmonic contortions on domestic power systems bed be categorized to two categories impact on the electrical power utilities of the power supplier and impact on the customer equipment and devices. From th e power suppliers prospective, harmonic distortion may harm their major components like transformers, overhead transmission lines and cables. It might flummox a reduction in the components lifespan and wherefore cause economic losses to the power supplier receivable to maintenance and reinstallation. This, in turn, will increase the system losses and as a result will wither the efficiency of the power plant.From costumers prospective (residential area or domestic load in this case), a distorted domestic power system will affect the equipment and the devices that are being used. Harmonic distortion may cause them to overheat and reduces their lifetime. As a result, an increase in the electricity bills and economic losses to the customer may occur.The propose behind this project is to hand a full understanding about(predicate) non-linear domestic stacks that exist in actual residential power systems and their contribution to harmonic distortions. This project consists of a survey of measurements from a number of selected non-linear devices that may remove an effect in the domestic power system in term of harmonics. After collecting these measurements, the distortion direct will be compared to the international standards and a model will be designed in Simulink to represent the harmonics effect of these non-linear devices and then adding harmonic filters to mitigate their effect.Problem DefinitionThe harmonics distortion produced by the non-linear devices in the domestic load throne cause negative impacts on the domestic power system. Both the utilities and the customers are affected economically.ObjectivesMeasuring and evaluating the harmonics that are produced by non-linear devices available in straight offs domestic make full than model them on Simulink. After that, further analysis and investigation for a solution to this harmonic distortion is to be done.Scope and LimitationsThis project will be focusing on the domestic haemorrhoid that are connected to domestic power systems. It will only look into a specific power quality issue, which is harmonics and will disregard any other types of power quality disturbance. For this reason, the mitigation technique to reduce the total harmonic distortion will be considered is a passive harmonic filter.Report organizationThe final report consists of six chapters which are divided into sections and subsections for a better explanation of the contents of this report.Chapter one discusses about the background of the project and explains briefly the impacts of the harmonics on the utilities and the customers and the relationship between harmonics and the economic losses. It also defines the problem, the objectives and the scope and limitations to this project.Chapter two covers the literature review of research topic. It includes a puritanical definition of harmonics and lists their effects on power systems in terms of technical and economic losses. Moreover, the chapter gives inform ation about harmonic sources and the available mitigation techniques that provoke be used to reduce the harmonics distortion.Chapter three is about the practical and experimental flex that has been done. It will discuss how the measurements and the evaluation of the harmonic distortion have been done and the equipment that were used. It will also include a subsection about the modelling part of the project and the blocks that were used in Simulink.Chapter four will discuss the results acquired from the experimental move and briefly compare the harmonic distortion of the non-linear devices and the international standard.Chapter five is about conclusion and implications of the project. It includes a final discussion, a conclusion and recommendation for further work or issues to be pursued.CHAPTER 2Literature Review2.1 IntroductionPower Quality disturbances butt joint be defined as any power disturbance that will pass away to voltage, flow or oftenness fluctuation that result in failure or mis summons of customer equipment. Power quality is considered to be a very key factor due to the fact that power is a part of our daily lives and any interruption or disturbance may cause into several problems such as data corruption, equipment damage, and data transmission errors and reduce equipment life. All these problems can result in huge economic losses to both the utility and the customers.thither are several types of power quality disturbances as listed below 4HarmonicsTransientsShort-Duration potential difference VariationsLong-Duration Voltage VariationsVoltage ImbalanceWaveform DistortionVoltage FluctuationPower Frequency VariationsThis project will focus on one of the most important power quality disturbances which are harmonics. Harmonics are important to be analyzed as they occur in the industrial loads, residential loads and also in the utility. Analyzing harmonics will help to design a to a greater extent stable system by applying the arrogate mitiga tion techniques that reduce harmonics.2.2 What is Harmonics?A harmonic is a component of a periodic wave having a absolute frequency that is an integral multiple of the fundamental power line frequency 50-60 Hz. sum total harmonic distortion is the contribution of all harmonic frequency on-line(prenominal)s to the fundamental 5.http//referencedesigner.com/books/si/images/fouriertransform.png2.3 What is Inter-Harmonics?Inter-harmonics are additional frequencies which are not an integer of the fundamental frequency that can be observed between the harmonics of the power frequency voltage and current. It appears as discrete frequencies or as a wide-band spectrum and can be found in power systems of all voltage classes 1. There are different sources of inter-harmonic wave shape distortion such as static frequency converters, cyclo-converters, induction repulses, arching devices and power line carrier signals. The corresponding effects of these inter-harmonics are affecting power li ne carrier signalling and induce visual flicker in display devices such as cathode ray tubes (CRTs) 1.2.4 Harmonic EffectsHarmonics have many impacts on the electrical systems and equipment that it may cause overheating for some of the system components which will result in power losses that may decrease the life time of the components which means mellow economic losses for the utilities. Also if a consumer is having distorted waveforms, it will affect the life time of the equipment therefore again more losses for the consumer as well. Bottom line, harmonics impact is a chain reaction each problem will lead to many other problems 1.Harmonics cause problems both on the go forth system and within the insulation which can be summarized into the following 7Overloading of NeutralsWhen the loads are not balanced, only the net out of balance current plays in the neutral. Installers (with the approval of the standards authorities) have taken advantage of this fact by installing half-size d neutral conductors. However, although the fundamental currents cancel out, the harmonic currents do not in fact those that are an odd multiple of three times the fundamental, the triple-N harmonics, add in the neutral 8.2. Effects on TransformersTransformers are affected in two ways by harmonics. Firstly, the eddy current losses increase at full load with the square of the harmonic number. This results in a much high operational temperature and a shorter life time. Fortunately, few transformers are fully loaded however the effect must be taken into account when selecting plant.The second concern is the triple-N harmonics. When reflecting back to a delta winding they are all in contour, which leads the triple-N harmonics to get trapped and circulate in the delta winding and does not get absorbed onto the supply. However, the non-triple-N harmonics can pass through the delta connection winding. The circulating current has to be taken into account when rating the transformer 4.3. Nuisance Tripping of Circuit BreakersResidual current circuit breakers (RCCB) operate by summing the current in the variety and neutral conductors if the result is not within the rated limit, disconnecting the power from the load. Nuisance tripping can occur in the presence of harmonics for two reasons. Firstly, the RCCB device may not sum the high frequency components correctly and therefore trips. Secondly, the kind of equipment that generates harmonics also generates electrical switch noise that must be filtered at the equipment power connection. The filters normally used for this purpose have a capacitor from line and neutral to ground, which might lead into current leakage to ground 4.4. Power Factor Correction CapacitorsPower-factor correction (perfluorocarbon) capacitors are provided in order to draw a current with a leasing conformation angle in order to compensate for the lagging current that is drawn by the inductive loads such as induction motors. The resistor of the PFC capacitor reduces as the frequency increases, while the source electric resistance is generally inductive and increases when the frequency increases. As a result, the capacitor is likely to carry high harmonic currents which may lead to it getting damaged, unless it has been specifically designed to with stand that high amount of current 4.5. Skin EffectThe skin effect is express to happen when the alternating current tends to flow on the outer surface of a conductor. Skin effect is normally ignored as its effect is chela at power supply frequencies. However at above about 350Hz which occurs at the seventh harmonic and above, the skin effect will become authoritative and will be taken into consideration. As it will be causing additional losses and heating 4.6. Induction MotorsHarmonics may affect the induction motors in a way that the harmonics may induce a flux to the rotor in an opposite direction to the rotor rotation which will reduce the motor efficiency also harmonics may increase the eddy current in the rotor which therefore will increase heat dissipation 9.7. Zero-Crossing Noisemany electronic controllers detect the point at which the supply voltage crosses zero volts to determine when loads should be turned on. This is done because switching inductive loads at zero voltage does not generate transients which may lead into reducing electromagnetic interference and stress on the semiconductor switching devices 9.8. Harmonic Problems Affecting the SupplyWhen a harmonic current is drawn from the supply it gives rise to a harmonic voltage drop proportional to the source impedance at the point of common coupling (PCC) and the current. Since the supply network is generally inductive, the source impedance is higher at higher frequencies. Of course, the voltage at the PCC is already distorted by the harmonic currents drawn by other consumers and by the distortion inherent in transformers, and each consumer makes an additional contribution 9.2.5 Sources of HarmonicsDifferent non-linear loads produce different but identifiable harmonic spectra. This makes the task of recognizing the harmonics that are produced from those loads easier. Utilities and users of electric power have to become familiar with the signatures of different waveform distortions produced by specific harmonic sources.This will help us figure out better mitigation methods in order to reduce the harmonics produces from the source. This will reduce the harmonics penetration to the electrical power system.At the development of power electronic switching devices, harmonic current propagation was looked at from the perspective of design and operation of power apparatus devices with magnetic iron cores, like electric machines and transformers. At that time the main source of harmonics must have involved substation and customer transformers operating in the saturation region.Harmonics are the by-products of modern electronics. They occur frequently when there are large nu mbers of personal computers (single phase loads), uninterruptible power supplies(UPSs), variable frequency drives (AC and DC) or any electronic device using solid state power switching supplies to convert incoming AC to DC. Non-linear loads create harmonics by drawing current in abrupt short pulses, rather than in a smooth sinusoidal manner 1.All variable frequency drives cause harmonics because of the nature of the frontend rectifier design. The 6-pulse rectifier is the standard power circuit elementary configuration for most pulse comprehensiveness modulated variable frequency drives with Diode Bridge rectifiers change in the marketplace today.Harmonics are generated by non-linear loads, and can be divided into 1 Saturable Devices Arcing Devices Power Electronics2.5.1 Saturable DevicesSaturable devices are devices which operate under steady state conditions (constant voltage and current).Examples of saturable devices are Transformers Rotating Machines2.5.2 Arcing DevicesArcing d evices are devices that consume high amount of current such as lighting ballasts, arc furnaces, welding machines and fluorescent lamps. lighting ballastsElectronic lighting ballasts have become popular in recent years because of the overall improved efficiency. The light level can be maintained over an extended lifetime by feedback control of the running current and as result of changing the current it generates harmonics in the supply 1.Small Uninterruptible Power Supplies (UPS)For high power wholes, UPS is used. The aim is to make the power supply load look like a resistive load so that the input current appears sinusoidal and in phase with the applied voltage as a result of that UPS is a source of harmonics 1.Compact Fluorescent Lamps (CFL)The harmonic current spectrum is produced in CFL. These lamps are being wide used to replace filament bulbs in domestic properties and especially in hotels where serious harmonic problems are suddenly becoming common 1.2.5.3 Power Electronics D evicesSwitched mode power supplies (SMPS)Majority of companies use modem electronic units like SMPS. The advantage to the equipment manufacturer is that the size, cost and weight is significantly reduced and the power unit can be made in almost any required form factor. But its disadvantage is that, rather than drawing continuous current from the supply, the power supply unit draws pulses of current which contain large amounts of third and higher harmonics and significant high frequency components 1.Figure 2.2 Switched Mode Power Supplies (DC-to-DC Converter)6-Pulse Thyrister RectifierVariable speed controllers, UPS units and DC converters in general are usually based on the three-phase bridge. The six pulse bridge produces harmonics as 6n (- or +) 1. As we increase Pulse Bridge, harmonics will be less 11.2.6 Mitigation TechniquesThere are many ways to reduce harmonics, ranging from variable frequency drive designs to the addition of auxiliary equipment. The primary methods used tod ay to reduce harmonics are 12-Pulse ConverterIn this configuration, the front end of the bridge rectifier circuit uses twelve diodes instead of six. The advantages are the elimination of the 5th and 7th harmonics to a higher order where the 11th and 13th become the predominate harmonics. This will minimize the magnitude of harmonics, but will not eliminate them. The disadvantages are cost and construction, which also requires either a Delta-Delta and Delta-Wye transformer, Zig-Zag transformer or an autotransformer to accomplish the 30 phase shifting necessary for proper operation. This configuration also affects the overall drive system efficiency rating because of the voltage drop associated with the transformer configuration requirement.TransformersTransformers have reactance and resistance which makes it represent the majority of the impedance found in lines feeding non-linear loads. Reactive impedance increases directly with frequency, naturally attenuating harmonics by reducing available current at higher frequencies. This technique is commonly used in reducing the current distortion of electric motor drives in industrial applications.Delta-Delta connected transformers for some drives and Delta-Wye connected transformers for the remaining drives are used in order to trap the triple-n harmonics. This will lead into current distortion reduction 7.Line ReactorsThis method consists of connecting a line reactance in series with the harmonic source at which the reactance will reduce the harmonic current. However, the line reactance method has different advantages and disadvantages as shown in the Table 2.l12.AdvantagesDisadvantagesLow CostHarmonics reduction is insignificantAvailable in different values active characteristics depend on the line capacitySmall power lossesAt very low load conditions it may damage the line due to high harmonic currentsTable 2.1 Advantages and disadvantages of Line ReactorsThe amount of harmonic that can be reduced is a function of the impendence of the line reactor the higher the line impendence the higher the reduction in harmonics.Active FiltersActive harmonic filters uses power electronic devices in order produce harmonic current components that cancel the harmonic current components that are produced by the nonlinear loads. The active harmonic filter is configured based on a pulse width modulated (PWM) voltage source inverter that interfaces to the system through a system interface filter. The active filter configuration that is shown in Figure 2.6 is referred as a parallel active filter as the filter is connected in parallel with the nonlinear load that is compensated. Figure 2.6 show the concept of the current cancelation so that the current being supplied from the source is sinusoidal. The voltage source inverter is used in the active filter in order to control the harmonics.This inverter uses dc capacitors as the supply and can switch at high frequencies to generate a signal that can cancel the harmo nics produced by the non-linear loads. The voltage distortion is reduced because the harmonic currents that flow through the source impedance are reduced 13.http//ars.els-cdn.com/content/image/1-s2.0-S0019057811001133-gr1.jpg resistless FiltersPassive filters consist of capacitor, inductor and a resistor connected in parallel to a nonlinear load. Passive filters will provide a low impedance path for the harmonic current therefore will put in them to ground. Passive filters can be tuned to absorb one type of harmonic current or several types as shown in the Figure 2.7 14.Figure 2.7 Passive Tuned Filters (a) Single Tuned (b) Double TunedAnother important feature of the passive filters is that they can improve the power factor since they have a capacitance in their construction. Moreover, filters can be specified according to the connection type into two main groups, the series connection and parallel.The filters power losses depends on the material used so the lower the losses the hi gher the cost of the filter so after all its a trade of between the power losses and the filter cost 15.In conclusion, many techniques by which harmonics can be mitigated from the system but always there are some advantages and disadvantages for each technology which makes it appropriate for some applications and not for others. Moreover, the decision of using which mitigation technique depends mostly on the cost, reliability and power losses. Always important to keep in intellect that theoretical calculation and assumptions for the type/size of mitigation technique does not always match with the practical findings due to some voltage disturbance and phase unbalancing.2.7 Harmonic Evaluation and Measurements2.7.1 IntroductionEvaluating harmonic system is a very important step in the analysis and design process. In order to estimate the harmonics sources we should follow some standards that are set by IEEE as they have specified some guidelines and limits that we should follow. Fol lowing those guidelines will be helpful during measurements and understanding the devices used.2.7.2 Harmonics LimitsThere are many standards which have been set by many organizations (national/international) in order to improve the quality of service provided and to protect the customers from all different effect of disturbances that may occurs in electrical systems. For this project we will discuss the limits specified by the Institute of Electrical and Electronics Engineers.2.7.3 Institute of Electrical and Electronics Engineers (IEEE)According to IEEE 519-1992 standards the total voltage distortion and the total current distortion limits should be within the specified limits as shown in Table 3.1 and Table 2Table 3.1 Total Voltage Distortion Limits According to IEEE 519-1992Table 2.7 Total Current Distortion Limits According to IEEE 519-1992SCR is the ratio of the maximum short circuit current to the maximum fundamental frequency load current at the point of common coupling (PCC ).2.7.4 Harmonics EvaluationHarmonic currents produced by nonlinear loads can interact with the utility power supply. This interaction often gives a rise to voltage and current harmonic distortion observed in many places in the system. Therefore, to limit both voltage and current harmonic distortion, as seen in the limits set by the IEEE standard 519-1992 in order to limit the harmonic current injection from the end users to make the harmonic voltage levels on the overall power system acceptable 8.The two most common used indices measuring the harmonic waveform are Total Harmonic Distortion (THD) Total Demand Distortion (TDD)Since there are two parties involved in limiting the total harmonic distortion which are divided between the utility and the customers, the evaluation is divided into two parts which are Measurements of the currents that are being injected by the loads Calculations of the frequency response of the system impedanceThe total harmonic distortion (THD) is a measure of the effective value of the harmonic components of a distorted waveform relative to the fundamental.In order to calculate the total harmonic distortion for the voltage or current comparability (1) or (2) are used 1(1) (2)The total demand distortion (TDD) is verbalized in terms of the maximum demand load current.TDD can be calculated using Equation (3) 1(3)In computing the short circuit level at the point of common coupling the normal system condition that will result in minimum short circuit level will be taken into consideration as it causes the most severe impact to the system.The short circuit current can be calculated using Equation (3.3) 8Where MVA and kV represent the three-phase short-circuit capacity in megavolt amperes and the line-to-line voltage at the point of common coupling in kV, respectively.The load current should be evaluated in order to determine the short circuit ratioEquation (3.4) can be used to calculate the load current 83.6 How to Evaluate ComplianceHar monic currents produced by nonlinear loads can interact adversely with the utility supply system. The interaction often gives rise to voltage harmonic distortion and current harmonic distortion observed in many places in the power system. Therefore, it is required to identify the point of common coupling (PCC) in order to have a more accurate measurement and evaluation. For industrial and commercial end users, thePCC is usually at the primary side of a service transformer that supplies the facility as shown in figures 3.1 and 3.2.

Microwaves: The History and Development

vaporizes The History and DevelopmentEngineering ReportMicrowave Ovenbg SummaryThis state presents the foundation of nukes and states the purpose of the report. It give in addition give detailed pratground data ab push through the history of the machine. In addition, there will be an explanation towards what it does and why its driveed through come to the fore the humankind as well as its impact on society. More everyplace, there will also be a dependable definition of the harvest to full extent. The description will described how it looks like, how it feats, materials used in the product, how its assembled, how to use it and extra features of the machine. Further more than, two drawings will be present in the report that includes isometric and orthographic, which have full measurements and angles drawn as accurate as possible. Following this, an analysis will also display how the appliances components, sustainability, choice of materials and how well it functions will b e critic all in ally researched and analysed to how effective they be and if theres any room for improvement. Next, there will be extra p fieryos of the product as well as any other extensive information about it. Adding to that, will be full descriptive recommendation of how it could be improved and conclusion covering up between the old and new product as well its major contribution towards the recent world. Lastly, there will be complete harved references to show where informations was research from.1.0Introduction1.1 The Purpose of the Report.The purpose of this report is to show the foundation of how vaporize ovens work and how they used throughout the present world. This report will discover the ship arouseal they limitd society and will be deconstructed to show all the features of this product. It will also contain calculations and diagrams in order to maximum the full experience to how this product works from the in location. This report will generate systematically to be frankr and will contain critical opinions and judgements on how it could be improved as well as key historical background to the machine. In addition, this report will feature an appendix to display extensive use of research and freehand drawing towards its split and functions. The purpose of the report will also show the motivation for this product in the new technological world and will display every capability that it has to full extent.1.2 Background Information, historical research of this product.The atom-bomb was introductory invented somewhere in the year 1946 during a radar related research project. Dr Percy Spenser was part of the project but during the investigation found something very unusual. During the project, they were testing out a new vacuum called magnetron when suddenly he realized that the candy bar in his pocket had melted. This inspired the have-to doe with to try out some other experiment where he placed popcorn kennels near the tube and watch joy fully as they stated to pop, cracked and sputtered all over his lab. This fascinated the doctor about this unusual discovery and so prompted another experiment the succeeding(prenominal) morning with his colleague. The experiment was placing an egg next to the magnetron and the result was the egg exploding all over the doctors lab. Mr Spenser then came up with a logical scientific experiment the melted candy bar, the popcorn and egg all had one thing in ballpark they were exposed to low density atom-bomb energy. This conclusion led the doctor that if these forages can be cooked this quickly why others cannot be as well. Dr. Spencer then invented a coat box with an opening into which he fed micro-cook power. The energy ingress the box was unable to escape, therefore creating a higher density electromagnetic field. When the food placed in the box and microwave energy fed in, the temperature of the food increased very rapidly. Dr. Spencer knowingly knew he just designed what was to exalt cooking, and form the basis of a multimillion-dollar industry, called the microwave oven and put forward a plan to the Raytheon Corporation to build this machine .Unsurprisingly, in 1954 the Raytheon Corporation produced the first mercenary microwave called the 1161 Radarange. It was large, expensive, and had a power of 1600 watts which wasnt very efficient towards good deal who wont rich. To solve this problem a division of the company named Amana created the first domestic microwave oven in 1967 but sales were slow during the first few years, partially imputable to the ovens relatively expensive price tag, later the concept of quick microwave cooking arrived. In succeeding years, a number of other companies joined the countertop microwave oven market. By the end of 1971, the price of microwave oven units began to decrease and their capabilities expanded as while moved on.1.3 What does the product do?The microwave oven is a kitchen appliance that heats and cooks food by heating up the particles inside while exposing it to microwaves from the electromagnetic spectrum. The waves were utilize into the machine where the inventor was experimenting with the it.1.4 Why is there a need for this product?The microwave oven is one of the most in the important kitchen appliances in the modern twenty-four hours household. It provides the basic needs of everyday life and is important contribution towards the world. The machine delivers the most of what modern engine room has as it heats and cooks food instead the old ways of heating them on a stove or on a bonfire. Moreover, the device is also a great deal(prenominal) risk-freer than the stove as it does not get hot when conducted by heat due to the material its make from, which is immaculate sword with a coating of acrylic enamel be vex of its low thermal conductivity.1.5 Impact on SocietyThe microwave oven has made a portentous contribution towards society as it made life easier with a cooking and heating foods at your fingertips. This helps with timesaving and allows to practise individuals within the family at different times when necessary. This is important be social movement it helps many people whom are busy due to the technological world and dont have the needed time to cook food on the stove. In addition, the microwave allows the food to be cooked much cheaper compared to the olds ways as all the components built inside, making life much more simple. This helps many people in the long run with paying the bills and assisting them to pay the more important fees.2.0Description2.1 Describe the producti) What it looks like?The microwave oven is a quick and efficient machine that uses electromagnetic irradiation to cook food. This fascinating machine allows people to cook food whenever they are busy or tired after a long day at work. This machines design is a rectangular prism with to vertical and horizontal lines. In addition, it also has a built in light bulb to see ho w your food is cooking and has a timer whenever its finished. Most microwaves will have three ventilations systems to keep the channel in the microwave flowing and is used to take the radiation out. This method is necessary otherwise the quality of the food will suffer. Moreover, the machine also has a container at the back where it stores up the microwave energy and short circuit where its connected to the cable that is plugged towards the power point.ii) How it works?The microwave is actually sort of a simple machine to how it actually works. The inside generator called the magnetron takes electricity from the power outlet and converts it to high-powered microwaves. These waves then travel through the food compartment and satanic out towards the spinning turntable in order to cook the food evenly. Furthermore, the microwaves then bounce of the reflective admixture wall however when these waves meet the food they dont bounce but instead penetrate it and oscillate the molecules within it. Therefore, allowing the food to become hotter and let enjoy your meal.iii) materials usedThe following materials used to take aim microwaves areStainless make with a coating of acrylic enamel.Ceramic or glassElectromechanical components steel metal A mixture of cast iron, steel and bronzeStainless steelPolymerMedium carbon steelHardened steelPlastic and Copper wireWhy are these materials used?Material Uses Why?Stainless steel with acrylic enamelUsed for the outside layer of the microwaveCorrosion ResistanceDuctileLow heat submergingCeramic or glassUsed for the cooking surfaceCorrosion ResistanceInsulatorElectromechanical componentsTimer aims, switches and relaysSimple mechanicsConductorsSteel metalUsed to make magnetron tube , the waveguide, capacitor and the stirrer fan enceinte conductivityGreat durabilityDuctileA mixture of cast iron, steel and bronzeUsed to make the gearsHigh tensile strengthHigh endurance strengthLow coefficient of frictionStainless steelUsed to make pulleysHigh strengthPolymerUsed to make beltsHigh StrengthMedium carbon steelUsed to make screwsHigh tensile strengthtractileHardened steelUsed to make washersWear resistantBrittlePlastic and copperUsed to make the cablesGreat conductivitySilicon SteelUsed to make the transformerMagnetic Propertiesiv) How is it assembled?The process of manufacturing the microwave oven starts with the cavity that creates the microwave radiation. First, the frame is formed using automatic metal-forming presser with all of the other parts already made.The parts then move through a paint operation where the paint is heated up to 300 degrees for 20 minutes and all the parts are coated in paint.Following this, the front door receives a coat of paint and metal plate is disposed to its window.The microwave then moves onto the next phase where it obtains the anode cylinder that will provide with its electricity to generate to power. Moreover, a powerful magnet is then put around the cylinder to crea te an electromagnetic field, creating microwaves. A thermal protector is attached directly on the magnetron to prevent slander to the tube from overheating and causing an explosion.Additionally, an antenna enclosed in a glass tube is mount on top of the back of the microwave. The waveguide is connected to the magnetron that is a on top of the antenna, while a blower motor is attached directly to the tube. Finally, a plastic fan is attached to the motor. In addition the capacitor and the high voltage transformer are added in as well.The important frame placed on the assembly tray and the cavity is screwed on to the chassis, which is the component that makes all the parts work together. Next, the door is attached to the cavity and chassis. The magnetron tube is bolted to the side of the cavity and the main chassis.The circuit that produces the voltage required to operate the magnetron tube is then mounted directly on the frame, close to the magnetron tube.The stirrer fan is mounted on top of the cavity attached directly to the fan. Following this, the stirrer shield is screwed on top of the fan assembly. The shield prevents dirt and grease from entering the waveguide, where they could produce damage to the magnetron.The relay provides power to the transformer and a timer for the microwave. The relay is mounted close to the power transformer, while the timer is mounted on the mesh board. Also mounted on the control board are a timer bell that rings when your foods heated and a light bulb that allows see of the inside. Furthermore, a number of interlocking switches are secured near the top and bottom of the door area to enable cooking fillings.A front panel is attached next to the front door. Behind the front panel, the control circuit board is attached. The board, which controls the various programmed operations in their proper sequence when the switches are placed on the front panel, is connected to the various components and the front panel using plug-in s ockets and cables.The outer case of the microwave is made of stainless steel metal with coating acrylic enamel and assembled on a roll former. The case is strapped onto the preassembled microwave oven and is bolted in firmly. This finally completes the process and the oven is sent for packaging.v) How to use it?The microwave oven is quite a simple machine to use with basic knowledge of a human being. The machines main purpose is to cook/heat food and requires minimal effort by having a choice of how to do it. There are many options to cook your food such as defrost, fruits, desserts options and many more. When your choice has been made just click the option and the microwave oven does it automatically for you without the need of lighting the hit man stove.vi) Features and extra.There known to be three different types of oven that have been used throughout the modern world. The received solo microwave oven, the striking grill microwave oven and the new convention microwave. These m icrowaves have a different variety of cooking options but use the selfsame(prenominal) basic design with components and little adjustments such as moisture sensors and LED lights. There have also been variations changes to outside layer with it just primarily stainless steel. This design could be viewed as a disadvantage because of its electrical conductivity that wouldnt make it safe and would conduct even more heat that leads to greater find oneself of the microwave overheating and being significantly discredited. Nevertheless, the microwave is still a great kitchen appliance that has proven itself to be a vital part for the modern world.4.0Analysis4.1 Critical Judgment of the producti) ComponentsThe components of the microwave such as the magnetron, relay, motors, gears, capacitor, high voltage transformer, chassis and the cavity all do their job expeditiously and effectively. However, they are known to have overheated in microwaves causing health hazards over a long current o f time due to the capacious get of radiation. In addition, if the microwave is physically damaged or leaks it may also cause a problem as it has the chance of causing cancer if the dielectric is cracked from high chemical exposure. To combat these issues the immense radiation should decrease to stop overheating and the use of less chemicals should be introduced. Overall, most of the components are safe and useful compared to some of the old ones used in the first microwave oven.ii) Materials The materials used in the microwave oven are quite great and work professionally but there a number of significant problems with them. An example of one is the steel used for the components, which may start to corrode after a period of time. This is a major problem as if these components are damaged the microwave may have the potential of permanently shutting down. Moreover, the extensive use of steel may cause the microwave overheating due the high electrical conductivity, which would damage its components . To solve this problems the steel metal should be replaced with less amounts of stainless steel to prone electricity and has high corrosion resistant.iii) Sustainability The microwave oven is a great sustainable kitchen appliance. Their almost no problems that is present towards the natural environment except for the wont power and possible chemical leak. Furthermore, the use in domestic industry is also not much of a problem as they can be placed where people decide especially for seniors who old and fragile. But, this comes to a disadvantage because if microwaves are place within low heights children can play with and cause damage and may even drop it which may lead to high chemical leak if it cracks. In addition, some children could even place a metal object that will likely spark up and cause a fire .The immense radiation may also not be the stovepipe suitable options towards kids and seniors as their bodys arent strong enough to take the energy. A new design should come around with there is less radiation used , the containment for the microwave energy should be reinforced with stronger metal and sensors which can detect between food and metal objects.iv) How well it Functions?The microwave is an excellent, simple kitchen appliance that requires no work effort but basic human knowledge. The machine almost never lets you down which is why up to 92% of American households have it according to a study conducted in 1994. In addition, the appliance has had improvements over the past 50 years in order for it to be more effectively useful and safe. But, it does need a minor improvement towards the immense radiation and to reinforce the dangerous microwave energy stored in the back, Nevertheless, the microwave oven functions greats with all the components and materials needing slight developments.v) Pros and Cons of the ProductProsGreat simple machine with energy efficiency.Lasts for a long period of time.Almost never fails.Portable.Best way to cook food without lighting a gas stove.Keeps all nutrients stored in the food untouched. ConsThe microwave may overheat due to radiation that can cause damage.Not healthy for young children or seniors due to heat radiation.If physically broken, chemical leak may damage cell tissues, which can cause cancer.Components will eventually rust causing major damage towards the machine.5.0Appendix5.1 Drawings and Photos Magnetron Inside viewHigh Voltage Transformer Capacitor 5.2 Extra Relevant Information The microwave oven converts only part of its electrical input into microwave energy. An average consumer microwave oven consumes 1 degree centigrade W of electricity in producing 700 W of microwave power which has an efficiency of 64%. The other 400 W is used as heat mostly in the magnetron tube. In addition, any wasted heat or any microwave radiation is sent out through the cool down vents. Additional power is used to operate the lamps AC power transformer, magnetron-cooling fan food tur ntable motor and the control circuits, which only need about 100 W to all operate. In addition, the microwave oven also uses less energy compared to the gas stove due to all major components already built in. Therefore, the microwave oven is not only cheaper than a gas stove but also uses less energy that could be life-saving towards many people who have to pay more important bills.6.0Recommendations/Conclusions6.1 Recommendations The first recommendation I will make is for the type of material used in the components to be changed as most of them are made from steel metal. This metal is a great option to conduct electricity but over time, it will corrode and cause a major damaged towards the microwave oven. To solve the problem I will recommend is to replace the steel metal with stainless steel as its corrosion resistance. Therefore, allowing it to last much longer.The second recommendation that should be designed into the machine is less radiation used in the microwave. Microwave e nergy is not harmful but people such as seniors or young children may not be able to take the amount of heat present. In addition, even sometimes the immense radiation might overheat the microwave oven causing high damage towards its components due to them being next to the cavity. To combat this I will recommend minify the amount of energy the magnetron produces but enough to heat food.The third recommendation that should be introduced to the microwave is the amount of chemicals used in the magnetron. Some magnetrons contains beryllium oxide which if leaked can cause a dangerous lung condition which sometimes could be fatal. Furthermore, all magnetrons contain thorium mixed with tungsten that if leaked and inhaled , can damage cell tissues and cause cancer. To fix this I will recommend taking out most of the chemicals from the magnetron so it does present a health hazard.6.1 Conclusion The microwave oven has a significant impact on the modern world with its extensive abilities to cook and reheat food. The original form of cooking food can be dated back to Stone Age with the use of fire. Next, came the invention of gas stove in the 1820s which required great amounts of gas with a huge price on its tag. In addition, sometimes the gas stove will fail continuously but this issue was brought to the end in the 20th century. The brilliance of Dr Percys Spencer intellectual mind brought out around one of the most important kitchen appliances of todays technological world called the microwave oven. Even though, this machine had a few problems before becoming perfect. However, the advancement of technology repaired these few problems with companies eager to get their hands of this discovery and made further adjustments to its design to make it look incomparable, magnificent and stunning. Furthermore, the microwave oven uses the technology of electromagnetic radiation to bring new life towards cold and frozen food supplying it with the most effective and efficient way possible. The microwave oven has a major influence of how the world works with its outstanding and striking capabilities that has been indeed a great achievement by mankind.7.0BibliographyGallawa, J. (2013). The History of the Microwave Oven. online Microtechfactoryservice.com. Available at http//www.microtechfactoryservice.com/history.html Accessed 15 Mar. 2017.Woodford, C. (2016). Microwave ovens How do they work?. online Explain that Stuff. Available at http//www.explainthatstuff.com/microwaveovens.html Accessed 18 Mar. 2017.Riaz, R. (2017). How microwave oven is made manufacture, making, used, parts, components, structure, product, Design. online Madehow.com. Available at http//www.madehow.com/Volume-1/Microwave-Oven.html Accessed 18 Mar. 2017.Sharpe, E. (2007). Microwave Oven. online Smecc.org. Available at http//www.smecc.org/microwave_oven.htm Accessed 23 Mar. 2017.

Routing Protocol Simulation With NS2

Routing protocol Simulation With NS2Network feigning is a method of investigation in vane technology. In the subroutine of investigating a in the raw technology, due to various reasons, it is costly and unrealistic to physic whollyy establish a web clay. In such situation, modelling becomes bingle of the best available solutions in testing, evaluation and validation. Network mannikin has the features of sm solely cycle and low cost, and it is easier for researchers to phthisis others research, in order to concentrate on the particular part and no need to waste too much time on other part of the system.NS2 is a simulation platform that is developed in free open source for profits technologies. Researchers can easily use it for the instruction of communicate technology. Until today, NS2 contains rich modules that are almost related to all aspects of cyberspace technology.Wireless intercommunicate communicatings obtained a rapid development in recent years. Ad hoc cy berspaces do not need the contain of cable stand the communication is achieved by free spry network hosts. The emergence of ad hoc network has promoted the achievement of the process of free communication at any environment, at the kindred time it has also tryd an effective communication solution of military, disaster relief and temporary communication theory.Considering the ad hoc network is constantly moving, and the network network topology is changing, wherefore the traditional earnings routing protocols (e.g. RIP, OSPF) are not be able to adapt into the actual need of ad hot networks. Therefore there are many a(prenominal) specialised routing protocols are twisted for the ad hoc network, the aim of this paper is to differentiate, analyse and evaluate the most popular routing protocols for ad hoc networks by running the simulation test with NS2.IntroductionA mobile ad hoc network (MANET), sometimes called a mobile mesh network, is a self-configuring network of mob ile devices connected by radio receiver bonds.Along with the desire of get rid of the wired network constraints and be able to communicate at any time and any place, wireless network communications obtained a rapid development in recent years. Mobile communications can be achieved by portable computers with wireless interface furnished and PDAs. Most current mobile communications require a wired infrastructure, e.g. base station. To be able to communicate without fix infrastructure, a new network technology Ad Hoc network technology arises at the historic moment. Ad hoc networks do not need the support of cable infrastructure the communication is achieved by free mobile network hosts. The emergence of ad hoc network has promoted the achievement of the process of free communication at any environment, at the aforesaid(prenominal) time it has also provided an effective communication solution of military, disaster relief and temporary communications.Each device in a MANET is free t o move independently in any direction, and pass on therefore change its marrys to other devices frequently. Each must forward traffic unrelated to its own use, and therefore be a bridle-pathr. The primary challenge in building a MANET is equipping individually device to continuously put forward the development compulsory to properly road traffic. such networks may operate by themselves or may be connected to the larger Internet.Ad-hoc network was originally use in the military field. With the developments of wireless networks, it has begun the development in the civilian fields. A mobile ad-hoc network does not need any infrastructures, any lymph node can quickly and semiautomatically form the network, and distributively node can move freely and is able to join or leave the network at any time. The characteristics and advantages of fast deployment, invulnerability makes mobile ad-hoc neat more and more widely utilize in either military or civilian fields.In recent years , as the emerging wireless communication network, Ad-hoc is gradually attracting more attention of the industry and become a research hotspot. Ad-hoc networking supports flexible and comfortable communication without the support of infrastructure, this technique broadens the fields of mobile communications and has a bright future.Ad hoc network can be regarded as the cross of mobile communication and computer network. In ad hoc networks, computer network packet exchange mechanism is employ rather than circuit switching mechanism. Communication hosts are usually portable computer, personal digital assistants (PDA) and other mobile devices. Ad Hoc network is different from mobile IP network in the current Internet environment. In mobile IP networks, mobile hosts can link and access the network through resolved wired network, wireless link and dial up link, and in ad hoc network, these is hardly a wireless link connection. In mobile IP networks, the communication need to be support ed by adjacent base stations and still using the traditional cyberspace routing protocol, however, ad hoc networks do not have the support of these facilities. In addition, a mobile host in the mobile IP network is whole an average end device which does not have routing function. When the mobile host moves from one zone to another does not change the network topology, and in Ad Hoc networks the achievement of mobile hosts would lead to topology change.The thesis is to research on the Ad-hoc networking mode and its network layer through simulation with NS2, mainly foc employ on the coincidence and analysis of the popular ad-hoc routing protocols. The aim of this article is to research and develop on the key technology of self-configuring network routing protocols, based on ad-hoc network structure.Wireless Ad-Hoc network twist and CharacteristicsAd Hoc wireless network has its own particularity, in the formation of actual use of the working network, the application size, scal ability and the reliability and real-time requirements must be taken full account.In addition, due to the unique structure of the ad hoc network, the characteristics of ad hoc network should be fully considered when design and build the network, which give service of process us to design a routing protocol that is suitable for particular network structure in order to maximise the performance across the network.Ad-hoc network StructureAd Hoc wireless network topology can be divided into two kinds Flat structure and vertical structure, in flat network structure, all network nodes have equal status.However, in the hierarchical structure of the Ad Hoc wireless network topology, the whole network is composed of clusters for the subnet, apiece cluster consists of a cluster head and sevenfold cluster members, the cluster heads forms a higher take network. Each cluster head and cluster members are propellent and automatic networking. The hierarchy is based on different hardware confi gu balancens, and hierarchical structure can be divided into single-band and multi-band classification structure. Single band hierarchy use single oftenness in communication, all nodes use the same frequency. But in multi-band hierarchy, if there are two networks in different levels exist, the lower level network has a smaller communication range and higher level network has a larger communication range, cluster members use the same frequency to communicate, cluster head nodes uses one frequency to communicate with cluster members and another frequency to maintain the communication with cluster heads.There are advantages and disadvantages exist in either flat or hierarchical network structures the structure of flat structure network is simple, each node has an equal status, there are multiple paths exist in communication of the source node and savoir-faire node, therefore no network bottlenecks, and the network is comparatively safe. However, the biggest drawback is the limited n etwork size, when the network descale expanding, routing maintenance overhead exponential growth and consume the limited bandwidth Hierarchical network structure is not limited by the scale of network, the scalability is good, and because of clustering, routing overhead is relatively smaller, although there is the need of complex cluster head selection algorithm in hierarchical structure, but because of hierarchical network structure with high system throughput, node localisation is simple, therefore ad hoc network is now increasingly showing grading trend, many network routing algorithms proposed are based on the hierarchical network structure model.Ad-Hoc network CharacteristicsWireless ad hoc network is a combination of mobile communications and computer networks, each node in the network have both router and host functions. The characteristics of ad hoc networks in mainly in the following(a) areasDynamically changing network topologiesAd Hoc networks have no fixed infrastruct ure and central management communications equipment, network nodes can randomly move to any direction in any speed rate, coupled with the supply change of wireless transmitter device, the environment impact and the signal mutual interference between each other, which all will result in dynamic changes of the network topology.Limited resourcesthe working energy provided to the mobile hosts in Ad Hoc networks are limited, and the mobile host with more energy loss, will reduce the Ad Hoc network functions on the other hand, the network itself provides limited bandwidth and signal conflicts and Interference, which results the mobile host with limited available bandwidth which is normally far less than the theoretical level best bandwidth.Multi-hop communicationif two network nodes are not in the same network coverage due to the limited resources available, multi-hop may be used in Ad Hoc network communication, in order to achieve the communication between the source host and terminat ion host which are not in the same network coverage.Limited physical securitythe communication of Ad Hoc network nodes are through the wireless channel, the instruction transmitted is very vulnerable, and eavesdropping, retransmission, falsify or forgery attack can be achieved easily, If routing protocol once suffered the malicious attacks, the whole self-organizing networks will not work properly.These features of the Ad Hoc network have do a special request in the routing algorithm design. A reasonable routing algorithm must take the factors of limited network resources, dynamic network topology changes and improve the network throughput into account.Ad-Hoc Wireless network routing protocolsThe key issue in ad hoc network design is to develop a routing protocol that is able to provide high quality and high efficient communication between two nodes. The mobility characteristic in the network makes the network topology constantly changing, the traditional internet based routing pr otocol is unable to adapt to these characteristics therefore the routing protocol that is specialised for ad hoc networks is needed, According to earlier on the Ad Hoc network architecture and features described, the design of the routing protocol must meet the following conditionsThe need of rapid response capability for dynamic network topology, and try to avoid routing loops from occurring, and provide simple and convenient network node localise method.Must be efficiently use of the limited bandwidth resources, and try to compress unnecessary overhead.Limit the number of intermediate absent during the implementation of multi-hop, generally not more than 3 times.Must minimise the launch time and amount of launch entropy, in order to save limited working energy.In possible conditions, make the design of routing protocol with securities to reduce the possibility of being attacked.Routing ProtocolsAccording to the specific characteristics of ad hoc wireless network routing protocol s, in recent years, there are a variety of ad hoc network routing protocols have been proposed. IETFs MANET working group is currently focused on research Ad Hoc network routing protocols, and protocols many protocol drafts, such as DSR, AODV, ZRP etc. in addition, the professional researchers also published a extensively amount of articles related to Ad hoc network routing protocols and proposed many network routing protocols for the ad hoc networks, such as DSDV, WRP etc. According to the routing trigger principle, the current routing protocols can be divided into three fictional characters proactive Routing protocol, Reactive routing protocol and Hybrid routing protocols.Proactive Routing protocolProactive routing protocol is also known as Table-driven routing protocol, each node maintains a routing table that contains the routing information to reach the other node, and updates the routing table constantly according the network topology changes, and therefore the routing table can accurately reflect the topology structure of the network. in one case the source code needs to entrust marrows, the route to the end point node can be immediately obtained. This type of routing protocol is usually modified from the live wired network routing protocol to adapt to the wireless ad hoc network requirements, such as the Destination-Sequenced Distance sender protocol, which is modified from the Routing Information Protocol (RIP). Therefore, this type of routing protocol has a small delay, but requires a lot of control message, the overhead is large. Commonly used proactive routing protocols include DSDV, HSR, GSR, WRP etc.Destination-Sequenced Distance Vector (DSDV)DSDV avoids the generation of routing loops by mark serial number for each route, using time-driven and event-driven technology to control the transfer of routing table, i.e. a routing table is kept in each moving node locally, it contains valid points, routing hops and stopping point routing serial number etc. close routing serial number is used to distinguish old and new route to avoid routing loops.Each node periodically sends the local routing table to the neighbour nodes, or when the routing table changes, the information will also be passed to neighbouring nodes, when there is no moving nodes, use a larger packet with longer interval to update the route. When the neighbouring node receives the information contains modified routing table, it will first compare the serial number of destination node, the routing with larger serial number will be used and the one with smaller serial number will be eliminated, and if the serial number are the same, the best optimised route (e.g. shortest path) will be used.Each node must periodically exchange the routing information with adjacent nodes, the routing information update is also can be triggered by the changes in routing table. There are two ways to update the routing table, Full dump, i.e. the topology update message will includ e the entire routing table, which is mainly applied to the case of fast changing network. Another way is Incremental update, in which update message contains only the changed part in routing, such way is usually used in a network with slower changes.Hierarchical State Routing (HSR)HSR is a routing protocol that is used in hierarchical network, nodes at a higher level saves all the location information of its peers, logical sequence address is assigned along from the rout node at the highest level to the leaf node at the lowest level, node address can be used by sequence address. world(prenominal) State Routing (GSR)GSR protocol works similar with the DSDV mechanism, it uses link-state routing algorithm, but avoids the flooding of routing packets, which includes an adjacent node table, network topology table, next hop routing table and the surmount table.Wireless Routing Protocol (WRP)WRP is a distance-vector routing protocol, each node maintains a distance table, routing table, li nk overhead table and packet retransmission table, through the Short Path Spanning channelize (SST) of the neighbouring node to generate its own SST, and then transmit updates. When there is no any change in the network routing, the receiver node must drop dead an idle message to show the connection, otherwise modify the distance table to look for better route. The feature of this algorithm is that when any changes of the neighbouring node is detected, and then checks the sturdiness of all adjacent nodes in order to eliminate the loop, has a faster convergence.Reactive Routing ProtocolReactive Routing protocol is also known as on-demand routing protocol, it remarks the route only when needed. Nodes do not need to maintain routing information constantly, it will initiate route look up only when the packet is need to be sent. canvass with proactive routing protocols, the overhead of reactive routing protocol is smaller, but the packet transmission delay is larger, which means it i s not suitable for real time applications. Commonly used reactive routing protocols include AODV, DSR, TORA and so on.2.2.2 Dynamic Source Routing (DSR)DSR is designed to restrict the bandwidth consumed by control packets in ad hoc wireless networks by eliminating the periodic table-update messages required in table-driven approach.DSR is composed of two main mechanisms Route Discovery and Route Maintenance. The Route Discovery mechanism is used when the source node needs to send a packet to the destination node but does not know the route.When the source node is using a source route to reach the destination node, source node uses the route maintenance mechanism to identify the route that cannot be used due to the topology changes.In DSR, route discovery and route maintenance mechanisms are fully on-demand operation, DSR does not require any periodic routing broadcast packets and link state detection packets.2.2.3 Temporally Ordered Routing Algorithm (TORA)TORA is an adjustive dis tributed routing algorithm based on link reversal method, which is mainly used for high-speed dynamic multi-hop wireless network. As a source initiated on-demand routing protocol, it is able to find multi-paths from the source to the destination node. The main characteristics of TORA are, when topology changes, the control message transmission in local area of topology changes only. Therefore, the node only needs to maintain the information of adjacent nodes. The protocol consists of three parts route generation, route maintenance and route deletion. In the initialisation stage, the transmission sequence number of the destination node is enclothe to 0. The QRY packet which contains the destination node ID broadcast by the source end and a node with a transmission sequence number that is not 0 responses to the UDP packet. The node that receives UDP packet has the sequence number higher than the source node by 1, and the node with higher sequence number is perform as the up flow rat e node. Through this method, a Directed Acyclic Graph (DAG) from the source to the destination node can be created. When nodes move, routes need to be rebuilt. In the route deletion phase, TORA removes the invalid route by broadcasting a CLR. There is one problem that exists with TORA, which is when multiple nodes proceeds to route selection and deletion, routing quivering will be produced.2.2.4 Ad-hoc On-Demand Distance Vector Routing (AODV)AODV is an improvement to the DSDV algorithm, but the difference with DSDV is that it is a Reactive routing protocol. In order to find the route leading to the destination node, the source end will broadcast a routing request packet, and adjacent in turn broadcast the packet to the surrounding nodes until the packet was sent to the destination node, or, to the intermediate node which has the routing information to the destination node. A node will discard duplicated request packet received, the serial number of routing request packet is to bar routing loops, and is able to determine whether the intermediate node has responses to the corresponding routing requests. When a node forwards a route request packet, it will mark the ID of its upstream node into the routing table, in order to build a reverse route from the destination node to the source node. When the source end moves, it will re-initiate route discovery algorithm if the intermediate nodes move, then the adjacent node will find the link failure and send the link failure message to its upstream node and break up the message all the way to the source node, laterwards the source node re-launches the route discovery process according to the circumstances.The achievement of AODV is a combination of DSR and DSDV protocols. It has the features of route discovery and route maintenance in DSR, and at the same time use by-hop routing, sequence number and Beacon messages that adopted in DSDV.Hybrid Routing ProtocolIn wireless ad hoc networks, neither proactive nor reactiv e routing protocols alone can solve the routing problem completely, therefore hybrid routing protocols which combines the advantage of both proactive and reactive protocols have been proposed by the researchers, such as the Zone Routing Protocol (ZRP). ZRP is a combination of proactive and reactive routing protocols, all nodes within the network to themselves as the contract of a virtual zone, the number of nodes in the area is related to the radius cast of the zone, and the areas overlap, this is the difference with clustering routing. It uses proactive routing algorithm within the zone, the centre node uses Intrazone Routing protocol to maintain in the zone.Literature ReviewNetwork Simulation ToolThe platform that will be used in simulation is Windows XP Professional + Cygwin + NS2.NS2 is a simulation platform that is developed in free open source for network technologies. Researchers can easily use it for the development of network technology. Until today, NS2 contains rich mod ules that are almost related to all aspects of network technology. Since the release 2.26, NS2 has stopped support with Windows platforms, therefore to get the latest NS2 running on the Windows XP, Cygwin is needed. Cygwin is an UNIX aper on Windows platform.ImplementationConfigure simulation platformNormally, NS2 simulation can be divided into the following steps1. Compose necessary components i.e. add or remove new components2. Testing test whether the component composed is validated. When the component in the library satisfies the simulation needs (e.g. simulation process based on existing protocols in the library),then the simulation starts from the third step.3. Compose Otcl script point configure the topology structure of the simulating network, and identify the basic link features, protocols that have been used by moving nodes, and number of nodes etc, and binding the terminal device protocol, put the scene and traffic load of simulation (TCP stream or cosmic background ra diation stream), stigmatizeting simulation start and end time etc, and set trace butts of the script saddle, trace file is the file that records all of the events of simulation process, and also can set the nam object at the same time, nam is the tool to demonstrate the network running lifetime.4. Use NS command to execute script file once executed, *.tr file will be generated in the same directory of the script file, to record the simulation results. if nam object is set in the script file, *.nam file will be generated in the same directory.5. Analyse trace file due to the large size of trace file, we will need to compose gawk program to process the data after simulation (calculate packet delivery date, routing overload, and throughput etc), then use the drawing tools to produce the graph for direct analysis.In NS2 the classic routing protocols such as DSDV, DSR, TAORA and AODV are already integrated the source code of routing protocols is located in CcygwinhomeAdministratorns- allinone-2.34ns-2.34, show in figure 1.1Take AODV as an example (fig. 1.2), within the ADOV folder, aodv.cc and aodv.h are the most important files, they defines the main functional features. Under general circumstances, we do not need to modify the source code of the protocols.Fig.1.2 AODV Routing ProtocolSimulation scriptingAccording to the simulation model designed, each routing protocol (DSDV, DSR, AODV, and TORA) will be compared in small (20 nodes) and medium (50 nodes) ad hoc wireless network. The corresponding scripts composed are dsdv.tcl, dsr.tcl, aodv.tcl and tora.tcl (see appendix).Taking aodv.tcl as an example, the coding is show in fig.3.2.1Partial scripts in aodv.tclSome script explanation of most important codes in aodv.tclset val(ifq)Queue/DropTail/PriQueueInterface queueset val(nn)50Number of nodes in simulation scenarioset val(rp)AODVRouting protocol to be simulatedset val(stop)300Simulation time lengthset val(x)500Length of sceneset val(y)500Width of sceneset val (tr) out50.trOutput trace fileset val(nam) out50.namOutput nam fileset opt(cp) cbr50Stream fileset opt(sc) scen50Scene fileIn addition, write the following statement in script head to generate a simulation ns_ objectset ns_new SimulatorTracking the file object is used to specify the Trace file (with .tr extension) in recording of the simulation data. NS2 supports record application layer, routing layer, MAC layer and node movement those four types of data in difference layers. The data that needs to be recorded can be specified in settings in the simulation process. The data in of each layer that trace object specified are all recorded in the trace file, labels are added to distinguish them. In addition, NS2 also supports NAM tool simulation process visualisation, such function needs to generate the NAM trace file object to specify the trace file of records of simulation data. The following statements are used to generate those two trace file object described.Generate trace file$ns_ use-newtraceset tracefdopen out50.tr w$ns_trace-all$tracefdGenerate NAM trace file objectset namtracefdopen out50.nam w$ns_namtrace-all-wireless$namtracefd$val(x)$val(y) data Stream Generation ToolData stream generation tool cbrgen is used to generate traffic loads, which can generate the TCP steam and CBR steam. Cbrgen.tcl file (see appendix) can be used as followingCodes are defined as following-typeTCP stream or CBR stream-nnNumber of nodes-seedSpecify number of random seeds-mcupper limit connection of each node-rateOverload of each stream connectionThe format is used as followingns cbrgen.tcl -type cbrtcp -nn nodes -seed seed -mc connections -rate rateMovement Scene./setdest is used to randomly generate the nodes movement scene needed form wireless network, used as following (2 versions)./setdest -v -n -p -M -t time -x -y or./setdest -v -n -s -m -M -t -P -p -x -y Which speed type set to uniform/normalpause type set to constant/uniform.NAM animationThe NAM function i s used to run the animation of specific trace end product format, the output file can be based on real or simulated environment. For example, the trace file that is from the output of NS simulator.The commands to control to control NAM animation in NS2 as following nam out.nam1. Node$node change color displace the colour of node$node shape shape stage setting shape of node$node label labelSetting name of node$node label-color lcolorSetting display colour of node name$node label-at ldirectionSetting display location of node name$node add-mark name color shapeAdd annotation$node delete-mark nameDelete annotation2. Link and Queue$ns duplex-link attribute orientcolorqueuePoslabel3.AgentUse the following commands to make the agent you wish to display appears as AgentName in the box.$ns add-agent-trace$Agent AgentNameThe parameters of movement scene and node flow are in the tables shown belowParameter of node movement sceneParameterNumber of nodesMoving rangeResting timeSimulation time Values set20, 50500 x 500 m1 s300 sParameter of node movement sceneParameterMaximum moving speedPacket sizeNode communication distanceType of serviceValues set5, 10, 15, 10, 25, 30-50512 byte250 mCBRTrace file analysisPerformance parameter analysis modelThe index to measure the performance of ad hoc network routing protocol is commonly including qualitative index and denary indicator. Qualitative indicator describes the overall performance of a particular aspect of the network, such as the security, distribution operation, provide loop free route and whether to support single channel etc. and quantitative indicators can describe the performance of a certain aspect of the network in more details. The quantitative indicator of packet delivery ratio, average end to end delay and throughput etc are often used to measure the performance of network routing protocols.a. Packet delivery ratio is a ratio of the number of packet sent from the source node and the number of packet that have been received by destination node in the application layer, which not only describes the loss rate observed in the application layer, but also reflect the maximum throughput supported by the network. It is the indicator of routing protocol completeness and correctness.End to end average delayit can be calculated with the following equation, which N represent the packets successfully delivered, rt represents the time that packet reached the destination node, and st represent packet sending time.Routing overheadRouting overhead is the total number of control packets of all routes, in a multi-hop routing each hop transmission is equivalent to one packet transmission. Routing overhead can be used to compare the scalability, the ability to adapt to network congestion and the efficiency of different routing protocols. It can be calculated with the following formulaRouting overhead = The Total number of routing control packetsGawk codeThe output file out.tr generated in simulation analysis will be filtered by selecting all of the packets in Agent layer, calculate all the number of data packets sent by this layer and the number of data packets that has been successfully received, and then divide the number

Mina Loy as the Modern Woman Essay -- Biography Biographies Essays

myna bird Loy as the Modern Woman Born on December 27, 1882, into an ordinary London family, Mina Lowy proved to be anything but common. After spending years as the recipient of her fathers encouragement, Loy moved from the artistic confinement that her perplex seek to impose upon her to a life of literary acclaim. Developing her artistic crafts of picture show, sculpture, and poetry, her most recognized talent, Mina Loy refused to be crowded into convenient societal definitions. Hailed as the quintessential New Woman in 1917, Loy embodied the changing definition of modern femininity. As an adolescent, Loy often clashed with her mother, Julia, as she strove to improve her craft. She yearned to fully express herself artistically, through her painting and her literature, yet her mother discouraged her, wishing for her daughter to conform to the tradition expectations for a girl in British society. Mina later said In the sheltered ho mes of the nineties, daughters were bullied to maturity, subject to prohibitions unmodified since babyhood. Their only self expression to watch and pray (Burke, 32).Loy was forced to fight for any chance to study her crafts, as her mother was not an advocate for female education. After winning the battle against her mothers repression, with her fathers help and encouragement, Loy entered the Kunstlerrinen Verein Art Academy in Munich, where she excelled downstairs the tutelage of Angelo Jank. Carolyn Burke wrote that, for Loy, leaving England at the turn of the century meant escaping from the repressive forces embodied by her mother the complacency of British culture, its contradictory goals for daughters, and the constrain... ...friends enjoyed eluded her, Loys exercise continues to stand as an expression of changing female modernity. As the New Woman, Loy was independent, confident, and undaunted by those who claimed her work was merely scandalous and pornographic . Mina Loys life bosh and the story of her work is a complicated one, as Loy seemed to epitomize her age at the same time that she eluded it (Weiner). Her work paved new literary paths and with her cozy and experimental style she altered what was accepted and expected from female writers. As the modern era faded, the definition of the New Woman continued to change, and like two Loy and her poetry, continued to escape classification. http//www.the-artists.org/ArtistView.cfm?id=8A01F8F4-BBCF-11D4-A93500D0B7069B40http//www.poets.org/poets/poets.cfm?prmID=96http//www.english.uiuc.edu/maps/poets/g_l/loy/loy.htm

The Clanton Gang Essay example -- essays research papers

In the middle and late part of the nineteenth century, the westerly was a harsh and dangerous place to live. Bar fights and murders were being committed in every town. This was acceptable behavior however in those days. hands colonized their problems face-to-face, and normally, the slower man cease up dead. Gunfighting in the West was started and carried on by a group of men known as the Clanton Gang. Old slice Clanton was the leader and founder of gunfighting, his sons carried some of his fights and continued with their own fights, and his last surviving son parted with gunfighting and started his own successful business.      Gunfights were common and took place regularly. The earliest gunfighters, or gunslingers, were born in the early 1800s, and most men got recognition as slingers in the 1850s. The founder of gunfighting was Old man Clanton, or N. H. Clanton. In 1816, Newman Haynes "Old Man" Clanton was born in Davidson County, Tennessee. On Janu ary 5, 1840 Newman Clanton married Mariah Sexton Kelso in Callaway County, Missouri and together they had five boys and two daughters. John Wesley, Joseph Isaac, Phineas Fay, William Harrison, Alonzo Peter, Mary Elise and Ester Ann made up the Clanton Gang. He did not participate in many gunfights though he instigated many of them. Old Man Clanton took care of business swiftly. If he did not like somebody, he would simply point them out, and one of his sons would provoke an argument and shoot the man down in self defense. Old Man Clanton had formed a cowboy party which consisted of some of the deadliest men in the West. Curley Bill, John Ringo, Tim and Frank McLaury, Joe Hill, Pony Deal, Jim Hughes, Frank Stillwell and many other lieutenants, who had over four hundred enclosure outcast under them, formed this group. He stole over $100,000 from ranchers in the south, and anyone who opposed was quickly exterminated. Old Man Clantons final days ended with a stolen-cattle drive. While he was passing through Guadeloupe Canyon, he and six other men were ambushed and shot dead out of their saddles. "Old Man" Clanton was buried where he fell in Guadalupe Canyon, New Mexico.     Although the leader of the Clanton Gang was dead, the family carried on. Billy and Ike Clanton were two of the participants in the most famous gunfight of all. The ... ...oseph G. and Collins, Richard.The Taming of the West Age of the Gunfighter Men and Weapons of the Frontier 1840-1900.      London, England Salamander Books Ltd, 1993.2.     William C. Davis, Joseph G. Rosa.The West From Lewis and Clark and Wounded Knee The Turbulent Story of the Settling of Frontier America.London, England Salamander Books Ltd, 1994.3.     Phin Clanton Family History.(The notorious Clanton Gang). 1996-1997. February 20, 2002.<http//clantongang.com/oldwest/gangphin.html>4.     Billy Clanton Family History.(The Notorious Clanton Gang). 1996-1997. February 20, 2002.<http//clantongang.com/oldwest/gangbill.html>5.     Ike Clanton Family History.(The Notorious Clanton Gang). 1996-1997. February 20, 2002.<http//clantongang.com/oldwest/gangike.html>6.     O.K. Corral Gun Fight.(American Western History Museums). 1999. February 20, 2002.<http//www.linecamp.com/museums/americanwest/western_places/ok_corral_gun_fight/ok_corral_gun_fight.html>

Dreams and Dream Deffered by Langston Hughes :: essays research papers

Dreams Deferred and DreamsIn the meters Dreams Deferred and Dreams by Langston Hughes the seed talks approximately how important dreams are. The author uses many contrasting types of figurative languages such as similes and metaphors and shows how they are a exchangeable and different in many ways.In the poem Dreams the author writes Hold fast to your dreams/for if dreams die (Hughes 1-2 poem 1). The root of this poem is to try to achieve your dreams and not let them die . In the poem Dream Deferred also by Langston Hughes the author writes about the theme being how a person could basically not be sane without dreams and how important they are to a person. As the author writes Does it dry up like a raisin in the sun ( Hughes 2-3 poem 2). The author is referring how dreams die when not pursued and dry up like raisins when not used or reached. The author used figurative language in the form of metaphors in these two poems in the first poem Dreams . The author writes For when dreams go/Life is like a barren field/ of frozen snow (Hughes 6-8 poem 1). Which he feels hopelessness and the author expresses hopelessness in the lines For it dreams die / Life is a broken winged-bird / that cannot strike down (Hughes - poem 2). The author is trying to explain to the reader to not let go of your dreams which is basically the whole poem is about your dreams and how important and I put one acrosst think that Langston Hughes could stress that anymore than he already has. As the author writes Does it dry up like a raisin in the sun?Langston Hughes argues about how readers should never let our hopes, dreams, and aspirations.