The consuming behaviours of university students purchasing smartphones Dissertation

The consuming behaviours of university students purchasing smartphones - Dissertation Example This paper investigates into the consuming behaviour of the university students in the United Kingdom with regard to their purchase of smart phones. Three most significant factors have been identified through this research work that affect smart phone purchasing behaviour of this customer base. It has been product features (of smart phones) affect their purchasing decision the most. These consumers also attach huge importance to the brand name of the product that they are going to purchase. Branded smart phones are preferred by these customers since high brand value serve as an identification of superiority of the product as well as a symbol of status in the society and peer group. Price of the product is considered by the customers while they purchase a new smart phone, but, research shows that they are often willing to spend a large sum of money in order to obtain a smart phone of very high brand name. Table of Contents 4 Introduction 4 Literature review 6 Methodology 17 Research p roblem 17 Method of analysis 28 Quantitative Method 28 Qualitative method 29 Method of data collection 31 Sampling 34 Questionnaire survey 35 Ethical considerations 38 Limitations of the Research Methodology 39 Data analysis and interpretation of findings 40 Conclusion and recommendations 52 Reference List 54 Appendices 60 Introduction Smart phones are becoming an increasingly important device that is used by the average customer in the United Kingdom. According to research, the number of smart phone users in the UK is growing continuously and rapidly. Purchase and use of smart phones depends on a number of factors, such as, the tastes and preference of the individual customer, the income level of the customer, the previous usage history of mobile phones, age and gender of the customer as well as the education level of the individual. While the demographic features of the customer base affects the smart phone purchasing behaviour of the customer, attributes of the product also take an important position in the purchasing decision made by the customers. These attributes are the product features, looks and appearance of the phone, price of the item, relative price of the phone compared to the other smart phones offered by the competing firms, awareness among the peer group about the product or its brand, customer’s knowledge about the brand and customer loyalty toward the brand. It has been through recent research works that smart phone usage among adults decreases with age. Also, over the last decade, use of smart phone has increased among the female population by a considerably high extent. Since 2010, number of female customers of smart phone has increased significantly from the number in the beginning of the twentieth century. Among the student generation, there is almost equal number of female smart phone owners as the male smart phone owners (Solomon, et al., 2006). At present the mobile phone market has expanded geographically as well as economical ly. Smart phone usage has become a modern trend of the middle class population across all countries and demand for such device is rising constantly. Smart phones can perform a vast range of functions due to which this device has moved out of its identity of a mere mobile phone and has become the ‘personal assistance device’ (pda) for the users. Several smart phone manufacturing companies are rapidly gaining popularity through the products offered by them. Several companies operate internationally,

Heart Rate and Blood Pressure Responses to Warm Whirlpool Treatment Article

Heart Rate and Blood Pressure Responses to Warm Whirlpool Treatment - Article Example The human body in normal conditions has a temperature set point of 37 degrees Centigrade, which may get altered during the circadian rhythm, after sleep loss, during hypobaria, and subsequent to dehydration. The stability in temperature that the body maintains is achieved by maintaining a balance between the rate of heat production that occurs mainly through metabolism and rate of heat lost or gained from the environment. Normal rules of thermodynamics are involved in this transfer of heat from the body and to the body. Differences between the temperature the skin and the environment is the governing factor in the thermodynamics involved (Lloyd, 1994). The thermodynamics involved in the attempt of the body to maintain the setpoint temperature of 37 degrees Centigrade is responsible for the thermal stimulus on hemodynamics, and it is for this reason that causes Ishijima and Togawa, 1999, to maintain that bathing in hot water puts stress on the heart.  The human body in normal condit ions has a temperature set point of 37 degrees Centigrade, which may get altered during the circadian rhythm, after sleep loss, during hypobaria, and subsequent to dehydration. The stability in temperature that the body maintains is achieved by maintaining a balance between the rate of heat production that occurs mainly through metabolism and rate of heat lost or gained from the environment. Normal rules of thermodynamics are involved in this transfer of heat from the body and to the body. Differences between the temperature the skin and the environment is the governing factor in the thermodynamics involved (Lloyd, 1994). The thermodynamics involved in the attempt of the body to maintain the setpoint temperature of 37 degrees Centigrade is responsible for the thermal stimulus on hemodynamics, and it is for this reason that causes Ishijima and Togawa, 1999, to maintain that bathing in hot water puts stress on the heart.   According to Press, 1991, this stress on the heart originate s from the increased pressure from the water causing vasodilation, profuse perspiration leading to a decrease in the extracellular volume of blood, increase in hematocrit levels with shortened clotting times, and an increase in the consumption of oxygen, due to the conditions of the environment saunas, spas, and hot tub baths. This raises the possibility of cardiac arrests resulting in patients during their use of saunas, spas and hot water tubs, with particular emphasis on individuals with a history of cardiovascular problems (Press, 1991). Such an understanding of the hemodynamics associated with an individual in the environmental conditions of hot tub baths, has caused physicians to warn individuals with elevated blood pressure levels and cardiac problems on the possible risks they face in hot water baths (Shin, Wilson & Wilson, 2003). Nagasawa, et al, 2001, points out that there is the risk of sudden death from hot water baths as such deaths have been associated with bathing in hot water.   This study aims to answer the question of how heart rate and blood pressure changes during a full body warm whirlpool treatment. The purpose of the study is to observe changes in the heart rate and blood pressure that occur with a warm whirlpool treatment as against the heart rate and blood pressure at rest and hypothesize the reason why certain special populations are advised precautions in the use of warm whirlpool treatments or hot tub baths. The study revolves around the hypothesis that heart rate will increase with warm whirlpool treatment and there will be a decrease in blood pressure.

International Trade Essay Example for Free

International Trade Essay Abstract One of the most confusing intolerance times is that free trade discussions are unlimited while free trade itself is growing and growing. For more than a while the government attempted to a global agreement to â€Å"lower trade barriers that have gone nowhere.† (Naim, 2007) The very last time trade was discussed they had reason to celebrate was in the late 1900’s this was when â€Å"125 nations agreed to a significant drop in trade barriers and the creation of new institution charged with supervising and liberalizing international trade, the World Trade Organization. † (Naim, 2007) â€Å"Keep in mind that, despite all the misgivings about international trade, the fact remains that countries share of economic activity related to exports is growing very fast, 1.5 faster than those with more stagnant exports.† (Naim, 2007) People know that economic growth alone may not be the right thing to help poverty; people must learn that without some kind of growth, all the efforts made will fall short. As trade grows the need for better rules is needed. International Trade The purpose of this paper is to address and discuss international trade. potential gains, the different types, the aspects and the impact of international trade. An international trade begins with what countries can do to survive the economics toughest times that must have some kind of trade. â€Å"Trading will give consumers and other countries the chance to be exposed to goods and services and not available in their countries. Almost every kind of product can be found on the international market: food, clothes, spare parts, oil, jewelry, wine, stocks, currencies, and water. Services are also traded: tourism, banking, consulting, and transportation.† (Investopedia, 2012) There are rewarding opportunities in the field of international trade intermediation, but new entrants need to be apprised of industry challenges. (Perry, 1992) International trade is â€Å"the exchange of goods and services along international borders. This trade allows for greater competition and more competitive pricing in the market. The competition results in more affordable products for the consumer.† (business dictionary, 2013) International trade also known as foreign trade has maintained since the dawn of time. Trading goods which are transported on the backs of tradesmen across tribal boundaries, and bartered and sold among neighboring, and, hopefully, accommodating tribesman. (wisegeek, 2013) Even though international trade rose national gross domestic product by providing vastly expanded economic opportunity. International trade is most commonly recognized in the exchange of goods or products. However, trading services, such as expertise in a particular field, or the ability to facilitate the trade of goods, is another common form of foreign trade. â€Å"There are many potential gains from international trade that benefit the businesses and countries that engage in trade around the world. International trade creates new markets for domestically produced products, and it often results in the introduction of new products into domestic markets. Different countries have access to different resources and are, therefore, able to produce some products more cheaply and efficiently than others. One of the major gains from international trade is that some products that would be expensive to product domestically can be imported at a much lower cost. Though there are many gains from international trade, disadvantages also exist such as the high initial costs of entering a new foreign market and the necessity of dealing with strict international trade laws.† (wisegeek, 2013) International trade is simply the exchange of services and goods across various geographical borders. The types of international trade include inter-firm trade and intra-industry trade. Both types of international trade involve the importation of goods and service. There is a difference in the methods and range in which the various trades are applied. â€Å"One type of trade included in types of international trade is intra-industry trade in which importers import goods that are similar to those produced in the country. An example of this type of sale can be seen in the importation of automobiles.† (wisegeek, 2013) In intra-firm trade, the international trade is confined to various arms or supplementary of a multi-national corporation. â€Å"Inter-firm trade occurs between different types of companies that produce different types of goods. This type of trade may be seen in case of a supplier of raw materials and a company that is importing the raw materials, which is bases in another country.† (wisegeek, 2013) â€Å"Inter-industry trade refers to the method of trade whereby parties from two countries exchange goods that are not manufactured in either country. Sometimes the reasons why the countries are not able to manufacture the items may include a lack of technical ability to produce the item or lack of raw materials. Even though it is mainly material items in inter-industry trade that are included in types of international trade, intangible items like skills and services are also involved.†(wisegeek, 2013) â€Å"International trade is conducted by businesses that are efficient enough to be competitive on the international market. Businesses in different countries tend to specialize in different sections; for example, industrialized countries may have companies that specialize in high-tech manufacturing or financial services, while developing countries may export mainly agricultural products. Governments impose tariffs or quotas to protect some domestic industries from foreign imports, and these are a barrier to international trade. Trading internationally has been facilitated by international agreements and organizations such as the World Trade Organization (WTO). Negotiations have led to reductions in tariffs and quotas that had been a brake on international trade. Although international agreements are often hard to reach, negotiations in the WTO ensure that international trade issues are thoroughly considered.† (wisegeek, 2013) â€Å"International trade disputes may be resolved more easily as a result of the introduction of mechanisms for dispute resolution through agencies such as the United Nations Commission on International Trade Law (UNCITRAL). Countries have facilitated international trade for businesses by signing bilateral investment protection agreements that make certain guarantees for investors and provide for dispute resolution.† (wisegeek, 2013) International trade is a trade that rises above international borders. This is in direct contrast to domestic trade which is the trade that occurs within a territory or local market. International trade has been made possible by advances in technology that make it easier to communicate and coordinate the transfer of goods and services across territories. The impact of international trade can be seen in various areas including the economy, jobs, outsourcing and unfair labor practices. â€Å"One impact of international trade is its effect on the economy of the nation’s engaging in the trade. This effect is felt by both less developed and more developed nations. Most developed countries benefit by purchasing raw materials and finished products from less developed countries. Less developed countries gain by getting much needed financial resources from the trade. For instance, some developing countries in Africa and the Middle East have some natural resources like crude oil, metals and precious stones that they can sell to other countries are dependent on the financial resources. Another of International trade is its effect on jobs in the more developed countries. Most companies engage in outsourcing, which is a direct outcome of international trade.† The particular impact of international trade leads to the fears that some dishonest business associates might employ cheap labor in a manner that is detrimental to the workers from poor countries. Some concerns also arise about the potential of using underage labor in the manufacturing sector, especially the apparel and toy-making sectors. This is an undesirable impact of international trade. In conclusion, international trade affects the entire American economy. The early industrial years of American economy was based entirely on the exporting goods to other countries and these exports created the revenue to sustain the country. I addressed and discussed international trade, potential gains, the different types, the aspects, and the impact of international trade. What can international trade which begins with what countries can do to survive the economics toughest times that must have some kind of trade. Trading will give consumers and other countries the chance to be exposed to goods and service and sometimes not available for other countries. References Business Dictionary, 2013. International Trade. Retrieved February 11, 2013 from http://www.businessdictionary.com/definition/international-trade.html. Wise Geek, (2013). International trade. Retrieved February 11, 2013 from www.wisegeek.com/what-are-different-aspects-of-international-trade.htm. Wise Geek, (2013). What are the different types of International trade. Retrieved February 11, 2013 from www.wisegeek.com/what-are-the-different-types-of-interentional-trade.htm Wise Geek, (2013). What are the different types of international trade. Retrieved February 12, 2013 from www.wisegeek.com/what-is-international-trade.htm. Wise Geek, (2013). What is the impact of international trade. Retrieved February 13, 2013 from www.wisegeek.com/what-is-the-impact-of-international-trade.htm. Wise Geek, (2013). What are the potential gains from international trade. Retrieved February 13, 2013 from www.wisegeek.com/what-are-the-potential-gains-from-international-trade.htm. Investopedia, 2012. What is International Trade? Retrieved February 11, 2013 from http://www.investopedia.com/articles/03/112503.asp#axzz2JgEj1WG4 Investopedia, 2012. What is International Trade? Retrieved February 11, 2013 from http://www.investopedia.com/articles/03/11503.asp#axzz2Kzwjb5ne Perry, A.C. (1992). US international trade intermediaries: A field study investigation. International Marketing Review, 9(2), 7-7. Retrieved February 16, 2013 from http://search.proquest.com/docview/224308899?accountid=41759. Naim, M. (2007). The free-trade paradox. Foreign Policy, (162), 96-96, 95. Retrieved February 12, 2013 from http://search.proquest.com/pqrl/printviewfile?accountid=41759

Dc Power Source Utilization Engineering Essay

Dc Power Source Utilization Engineering Essay Many industrial applications have begun to require higher power apparatus in recent years. Some medium voltage motor drives and utility applications require medium voltage and megawatt power level. For a medium voltage grid, it is troublesome to connect only one power semiconductor switch directly. As a result, a multilevel power inverter structure has been introduced as an alternative in high power and medium voltage situations. A multilevel inverter is a power electronic device built to synthesize a desired AC voltage from several levels of DC voltages. The concept of multilevel converters has been introduced since 1975. The term multilevel began with the three-level converter. Subsequently, several multilevel converter topologies have been developed. Plentiful multilevel converter topologies have been proposed during the last two decades. Contemporary research has engaged novel converter topologies and unique modulation schemes. Moreover, there are three different major multilevel converter structures which are cascaded H-bridges converter with separate dc sources, diode clamped (neutral-clamped), and flying capacitors (capacitor clamped) [1] Although the diode clamped multilevel inverter is commonly discussed in the literature, there has been considerable interest in the series connected or cascaded H-bridge inverter topologies [2]. However, the elementary concept of a multilevel converter to achieve higher power is to use a series of power semiconductor switches with several lower voltage dc sources to perform the power conversio n by synthesizing a staircase voltage waveform. Capacitors, batteries, and renewable energy voltage sources can be used as the multiple dc voltage sources [1]. Multilevel power conversion has become increasingly popular in recent years due to advantages of high power quality waveforms, low electromagnetic compatibility (EMC) concerns, low switching losses, and high-voltage capability. The primary disadvantage of multilevel power conversion technology is the large number of semiconductor devices required. This does not yield a significant cost increase since lower-voltage devices may be used. However, an increase in gate drive circuitry and more elaborate mechanical layout are required [3]. Project Overview This project will involve in the design and construction of a single phase 3-level H-bridge inverter using the IGBTs. An H-bridge is an electronic circuit which enables a voltage to be applied across a load in either direction. These circuits allow DC motors to run forwards and backwards. H-bridges are available as integrated circuits, or can be built from discrete components. In this single phase H-bridge inverter circuit, the IGBTs are used as power devices that will be operated as a switch by applying control signal to gate terminal of IGBTs. The insulated gate bipolar transistor or IGBT is a three-terminal power semiconductor device, noted for high efficiency and fast switching. The software that will be used is MATLAB Simulink. Simulink is a commercial tool for modeling, simulating and analyzing multidomain dynamic systems. Its primary interface is a graphical block diagramming tool and a customizable set of block libraries. The Aims and Objectives The aim of this project is to simulate a single phase 3-level H-bridge inverter (DC to AC converter) using the MATLAB Simulink and constructed it. The objectives of this project are as follows: To investigate the application of H-bridge inverter. To assemble using the software, circuits implementation, and troubleshoot for the hardware. To analyze the operation of the single-phase 3-level inverter for software and hardware. CHAPTER 2 LITERATURE REVIEW Inverter Power electronics converters may be classified into four categories based on the source and types of the desired output characteristics as shown in Figure 1.1 below: OUTPUT AC DC AC INPUTRECTIFIER REGULATORS DC CHOPPERS INVERTERS Figure 2.1: Converter Classification DC-to-AC converter is known as inverter. The function of an inverter is to change a DC input voltage to a symmetrical AC output voltage of desired magnitude and frequency. The variable output voltage could be fixed or variable at a fixed or variable frequency. Inverter can be built in many output phases which is normally use in practice like single phase inverter and three phase inverter. The implementation of the inverter circuit must to be involved in application of the power devices like SCR, MOSFET, IGBT, GTO, and Forced-Commutated Thyristor which is controlled to turning ON and turning-OFF in its operation as a converter. This inverter generally use PWM control signal for producing an AC output voltage [3]. Single Phase H-Bridge Inverter Operation The H-Bridge Inverter or sometimes called Full Bridge consists of four switches (see Figure 2.2). A boost converter is required as this system has no means of stepping up the input. Switches S1-S4, and S2-S3 make up two switch pairs. When S1and S4 are on, the output voltage is a positive pulse, and when S2 and S3 are on, the output is a negative pulse. The phase sequence, frequency, output magnitude and harmonics can be controlled through appropriate switching devices, in conjunction with other equipment. Figure 2.2: Single phase H-bridge inverter Single Phase Multilevel H-Bridges Inverter There are two types of multilevel H-bridge inverter that can be selected in this project which are separated dc source and single DC source. These two types have its pros and cons. The advantages of separated DC source are: The number of possible output voltage levels is more than twice the number of dc sources (m = 2s + 1). The series of H-bridges makes for modularized layout and packaging. This will enable the manufacturing process to be done more quickly and cheaply. while the disadvantage is: Separate dc sources are required for each of the H-bridges. This will limit its application to products that already have multiple SDCSs readily available. Each H-bridge cell requires an isolated dc source. The isolated sources are typically provided from a transformer/rectifier arrangement, but may be supplied from batteries, capacitors or photovoltaic arrays to add up the output voltages. This topology was patented by Robicon Group in 1996 and is one of the companies standard drive products.[2] On the other hand, for the single DC source multilevel H-bridge inverter, the advantage of this type of connection is only one DC supply is used. This will not limit its application to products. And the disadvantage of single DC source is transformer is needed to add up the output voltages Separated DC Source Multilevel H-Bridges Inverter A single-phase structure of an m-level cascaded inverter is illustrated in Figure 2.3. Each separate dc source (SDCS) is connected to a single-phase full-bridge, or H-bridge, inverter. Each inverter level can generate three different voltage outputs, +Vdc, 0, and -Vdc by connecting the dc source to the ac output by different combinations of the four switches, S1, S2, S3, and S4. To obtain +Vdc, switches S1 and S4 are turned on, whereas -Vdc can be obtained by turning on switches S2 and S3. By turning on S1 and S2 or S3 and S4, the output voltage is 0. The ac outputs of each of the different full-bridge inverter levels are connected in series such that the synthesized voltage waveform is the sum of the inverter outputs. The number of output phase voltage levels m in a cascade inverter is defined by m = 2s+1, where s is the number of separate dc sources [1]. Figure 2.3: Single-phase structure of a multilevel cascaded H-bridges inverter An example phase voltage waveform for a nine-level cascaded inverter and all H-bridge cell output waveforms are shown in Figure 2.4. In this thesis, all dc voltages are assumed to be equal. According to sinusoidal-liked waveform, each H-bridge output waveform must be quarter-symmetric as illustrated by V1 waveform in Figure 2.2. Obviously, no even harmonic components are available in such a waveform. To minimize THD, all switching angles must be numerically calculated. Figure 2.4: Waveform showing a nine-level output phase voltage and each H-bridge output voltage. One of the advantages of this structure is the number of possible output voltage levels is more than twice the number of dc sources (m = 2s + 1). The other advantage is the series of H-bridges makes for modularized layout and packaging. This will enable the manufacturing process to be done more quickly and cheaply. On the other hand, the main disadvantage of this topology is that separate dc sources are required for each of the H-bridges. This will limit its application to products that already have multiple SDCSs readily available. The sources are typically provided from a transformer/rectifier arrangement, but may be supplied from batteries, capacitors or photovoltaic arrays. Single DC source Multilevel H-Bridges Inverter Referred to Zhong Du1, Leon M. Tolbert, John N. Chiasson, and Burak ÃÆ'-zpineci thesis entitled A Cascade Multilevel Inverter Using a Single DC Source, a method is presented showing that a cascade multilevel inverter can be implemented using only a single DC power source and capacitors. Without requiring transformers, the scheme proposed allows the use of a single DC power source for examples a battery or a fuel cell stack while the remaining nà ¢Ã‹â€ Ã¢â‚¬â„¢1 DC sources being capacitors. Figure 2.5 shows the Single DC source Multilevel H-Bridges Inverter. The DC source for the first H-bridge (H1) is a DC power source with an output voltage of Vdc, while the DC source for the second H-bridge (H2) is a capacitor voltage to be held at Vdc/2. The output voltage of the first H-bridge is denoted by v1 and the output of the second H-bridge is denoted by v2 so that the output of this two DC source cascade multilevel inverter is v(t) = v1(t)+v2(t). By opening and closing the switches of H1 appropriately, the output voltage v1 can be made equal to à ¢Ã‹â€ Ã¢â‚¬â„¢Vdc, 0, or Vdc while the output voltage of H2 can be made equal to à ¢Ã‹â€ Ã¢â‚¬â„¢Vdc/2, 0, or Vdc/2 by opening and closing its switches appropriately. Figure 2.5: Single DC source Multilevel H-Bridges Inverter IGBTs Versus MOSFETs The power MOSFET is a device that is voltage- and not current-controlled. MOSFETs have a positive temperature coefficient, stopping thermal runaway. The on-state-resistance has no theoretical limit, hence on-state losses can be far lower. The MOSFET also has a body-drain diode, which is particularly useful in dealing with limited free wheeling currents. All these advantages and the comparative elimination of the current tail soon meant that the MOSFET became the device of choice for power switch designs. Then in the 1980s the IGBT came along. The IGBT combines the cross between the power MOSFET and a bipolar power transistor (see Figure 2.2). The IGBT has the output switching and conduction characteristics of a bipolar transistor but is voltage-controlled like a MOSFET. In general, this means it has the advantages of high-current handling capability of a bipolar with the ease of control of a MOSFET. However, the IGBT still has the disadvantages of a comparatively large current tail and no body drain diode. Early versions of the IGBT are also prone to latch up, but nowadays, this is pretty well eliminated. Another potential problem with some IGBT types is the negative temperature co-efficient, which could lead to thermal runaway and makes the paralleling of devices hard to effectively achieve. This problem is now being addressed in the latest generations of IGBTs that are based on non-punch through (NPT) technology. This technology has the same basic IGBT structure (see Figure 2.6) bu t is based on bulk-diffused silicon, rather than the epitaxial material that both IGBTs and MOSFETs have historically used [4]. Figure 2.6: NPT IGBT cross section The comparisons between MOSFETs and IGBTs are as below: Table 2.1: Comparisons between IGBTs and MOSFETs IGBTs MOSFETs Characteristics Low duty cycle Low frequency ( Narrow or small line or load variations High-voltage applications (>1000V) >5kW output power Operation at high junction temperature is allowed (>100 °C) Long duty cycles High frequency applications (>200kHz) Wide line or load variations Low-voltage applications ( Applications Motor control: Frequency Uninterruptible power supply (UPS): Constant load, typically low frequency Welding: High average current, low frequency ( Low-power lighting: Low frequency ( Switch mode power supplies (SMPS): Hard switching above 200kHz Switch mode power supplies (SMPS): ZVS below 1000 watts Battery charging [4] Applications of Inverters There are many application of inverter available today. Some of the applications are as follows: DC power source utilization An inverter converts the DC electricity from sources such as batteries, solar panels, or fuel cells to AC electricity. The electricity can be at any required voltage; in particular it can operate AC equipment designed for mains operation, or rectified to produce DC at any desired voltage. Grid tie inverters can feed energy back into the distribution network because they produce alternating current with the same wave shape and frequency as supplied by the distribution system. They can also switch off automatically in the event of a blackout. Micro-inverters convert direct current from individual solar panels into alternating current for the electric grid. Electric vehicle drives Adjustable speed motor control inverters are currently used to power the traction motor in some electric locomotives and diesel-electric locomotives as well as some battery electric vehicles and hybrid electric highway vehicles such as the Toyota Prius. Various improvements in inverter technology are being developed specifically for electric vehicle applications. In vehicles with regenerative braking, the inverter also takes power from the motor (now acting as a generator) and stores it in the batteries. Uninterruptible power supplies An uninterruptible power supply (UPS) uses batteries and an inverter to supply AC power when main power is not available. When main power is restored, a rectifier is used to supply DC power to recharge the batteries. Variable-frequency drives A variable-frequency drive controls the operating speed of an AC motor by controlling the frequency and voltage of the power supplied to the motor. An inverter provides the controlled power. In most cases, the variable-frequency drive includes a rectifier so that DC power for the inverter can be provided from main AC power. Since an inverter is the key component, variable-frequency drives are sometimes called inverter drives or just inverters. Induction heating Inverters convert low frequency main AC power to a higher frequency for use in induction heating. To do this, AC power is first rectified to provide DC power. The inverter then changes the DC power to high frequency AC power. CHAPTER 3 METHODOLOGY Introduction This chapter exposes the proposed method of this project to built single phase multilevel H-bridge inverter. This project can be divided into two main parts of study which are software and hardware implementation. For the software part, the software used is PIC24 Compiler that used to do the programming for the microcontroller part and MATLAB to do the simulation of the inverter circuit before implemented it in hardware. In addition, Proteus 7 Professional is also used to simulate the driver circuit before do the hardware. The summary of the project is shown in Figure 3.1. Software Part Prepared (Microcontroller) Hardware Part Prepared Troubleshooting Interfacing Result Figure 3.1: The project summary Design of the H-Bridge Inverter System The H-Bridge inverter system can be divided into three main stages that were constructed. It is consists of: Microcontroller Power electronics driver Power electronics inverter Each part was treated as a separate functional block system. Figure 3.2 below shows the block diagram of how each stage of the inverter system are organized. Power electronic driver circuit and microcontroller stage is the low voltage side and power electronics inverter circuit is the high voltage side. DC Voltage Input AC Output Power Electronics Inverter Circuit Microcontroller Power Electronic Driver Circuit Figure 3.2: The block diagram of the inverter system Microcontroller Microcontroller is a computer-on-a-chip optimised to control electronic devices. The microcontroller chip used for this project is PIC16F877A. In this project, microcontroller is used to develop the triggering signal for the IGBTs and interfacing to the single phase inverter circuit as a control signal for the gate driver. To implement the microcontroller part, the program for triggering the IGBTs was written in assembly language using the PIC C Compiler. It is written in the text editor or notepad called as source code. It also can be written directly in the PIC C Compiler. Then the file saved is *file.c file. After the program is successfully compiled, the *file.hex file was generated. The hex file was tested by doing the simulation in the Proteus 7 Professional to see the output generated from the program. After got the correct output, the *file.hex file then was uploaded in the PIC16F877A using the PIC programmer. The process of implementing the microcontroller is shown in Figure 3.3. This microcontroller part is the first part that was implemented in hardware. Figure 3.3: The process of implementing the microcontroller Power Electronics Driver A driver is an electronic component used to control another circuit or other component, such as a high-power transistor. Unlike the bipolar transistor, which is current driven, IGBTs, with their insulated gates, are voltage driven. It is allows user to speed up or slow down the switching speeds according to the requirements of the application. The control circuitry supplied low current driving signals that are referenced to controller-ground. A logic one signal was applied to its gate with respect to its source to turn on an IGBT switch, and this signal needs to restrain sufficient power. These requirements can not be met by the control circuit. Figure 3.5 shows a diagram of how signals need to be applied to IGBT switches for effective operation. Figure 3.4: Control signals need to be applied to the gate with respect to the source The driver chose is IR2110 which is a dual driver. The IR2110 High Voltage Bridge Driver is a power integrated circuit that is designed to drive two insulated gate devices. The typical connection of the driver is shown in Figure 3.5. The two channels of the IR2110 are completely independent of one another. The HO output is controlled by the HIN input, and the LO output is controlled by the LIN input. The two inputs of the IR2110 are logically coupled to the shutdown (SD) pin through an AND gate. If HIN and LIN both go high, then the IR2110 will be shut down until one or both inputs go low. This measure helps prevent the catastrophic situation where both Q1 and Q2 turn on at the same time and short circuit the input source. [5] Figure 3.5: Typical connection of IR2110 High Voltage Bridge Driver Isolation using the optocoupler An optocoupler or sometimes refer to as optoisolator allows two circuits to exchange signals yet remain electrically isolated. This is usually accomplished by using light to relay the signal. The standard optocoupler circuits design uses a LED shining on a phototransistor. The signal is applied to the LED, which then shines on the transistor in the ic.   The optocoupler circuit is shown in Figure 3.6 below. In this project, the optocoupler is used as the source and destination are at very different voltage levels, where the source is the microprocessor which is operating from 5V DC but it being used to control the IGBTs which is switching at higher voltage. In such situations the link between the two must be an isolated one, to protect the microprocessor from overvoltage damage. The optocouplers can be used with following advantages for driving high side IGBT in any topology: They can be used to give a very high isolation voltage Signals from DC to several MHz can be handled by opto-couplers. They can be easily interfaced to Microcomputers or other controller ICs or any PWM IC. Figure 3.6: Optocoupler circuit The circuit of low side voltage which consists of PIC, driver and optocoupler was first constructed in the Proteus 7 Professional to see the output generated to be compared with the hardware results. The circuit is as in Figure 3.7 below. Figure 3.7: Low side voltage simulation Power Electronic Inverter The power electronics inverter part is the main part of the system. This is because this circuit will perform the conversion from DC to AC. The circuit consists of four IGBT that act as a switch, DC source and also the load. Figure 3.8 shows a diagram of the H-Bridge power electronics inverter stage. Figure 3.8: H-Bridge power electronics inverter stage. But for this project, the inverter circuit used is the 3-level H-bridge inverter circuit. The circuit was first constructed in the MATLAB as in Figure 3.9 and the simulation of the circuit was done to see the result of simulation. Figure 3.9: 3-level H-bridge inverter circuit constructed in MATLAB The block parameter for the IGBTs was set as in Figure 3.10. The switching frequency used for this circuit is 50Hz. So, the period of waveform can be calculated as below: Switching frequency, f = N / Pf Fundamental period, Pf = 1 / f fundamental = 1/ 50 = 0.02s Figue 3.10: The block parameter setting for the IGBTs In addition, the phase delay or switching times of the IGBTs were also set. Table 3.1 below shows the switching time of the IGBTs. After the simulation was success, the circuit of single 3-level H-bridge inverter was constructed. Table 3.1: The switching time of the IGBTs IGBTs Switching Time IGBT 1 and IGBT 3 10 ms (à Ã¢â€š ¬) IGBT 2 and IGBT 4 0 ms (0 à Ã¢â€š ¬) IGBT 5 and IGBT 7 7 ms (à Ã¢â€š ¬/7) IGBT 6 and IGBT 8 3 ms (à Ã¢â€š ¬/3) For the switch, IRGB10B60KDPBF IGBT was selected for this design. It is very important to choose the correct switches for the inverter circuit because the performance of the design is directly depends on this. This IGBT was chosen because it has ultra fast recovery diode along, it offered benchmark efficiency for motor control and excellent current sharing in parallel operation. In addition the IGBT was selected as they are able withstand the power rating of the inverter. Table 3.2 shows some of the features of the selected IGBT. Table 3.2: The features of IRGB10B60KDPBF IGBT Characteristics Value Drain to Source Voltage (Vds) 600V Drain Current (Id) 12A Rise Time 20ns Fall Time 23ns Short Circuit Capability 10ÃŽÂ ¼s Figure 3.4: 3-level H-bridge inverter circuit

sponsorship management Essay -- essays research papers

SPONSORSHIP MANAGEMENT PRESENTED BY: JULIUS TABLE OF CONTENT 1.  Ã‚  Ã‚  Ã‚  Ã‚  What is Sponsorship? 2.   Ã‚  Ã‚  Ã‚  Ã‚  What is Management? 3.  Ã‚  Ã‚  Ã‚  Ã‚  What are the Management’s Functions? 4.  Ã‚  Ã‚  Ã‚  Ã‚  What is Sponsorship Management? 5.  Ã‚  Ã‚  Ã‚  Ã‚  Know the Game: understand what sponsorships can do and cannot do 6.  Ã‚  Ã‚  Ã‚  Ã‚  The Passion Connection 7.  Ã‚  Ã‚  Ã‚  Ã‚  How does sponsorship really enhance brand building? 8.  Ã‚  Ã‚  Ã‚  Ã‚  Understand leverage 9.  Ã‚  Ã‚  Ã‚  Ã‚  Measurement 10.  Ã‚  Ã‚  Ã‚  Ã‚  Case Study What is sponsorship? ‘As a marketer, why wouldn’t you use sponsorship? What better medium is there? With sponsorship, you already have a loyal, passionate consumer following of whatever that sponsorship is, whether it’s music or football or sailing-you already have a connection with the consumer. So if the fan that has the passion for something is the same person that is your customer, why would you not borrow some of that equity and use that as the essence of an idea around which to build your communication ‘Chris Weil, Momentum Worldwide Sponsorship is a multi-faceted strategic brand building and marketing tool, which allows a company or brand to associate with a relevant marketing asset (e.g. sport event, social cause, issues or passion), and leverage that association for the mutual benefit of all stakeholders. Sponsorship is a heaven sent opportunity that allows consumer to experience the brand. Sponsorship â€Å"embraces† the consumers while advertising â€Å"wave at them†. If there is any brand building effort that provides a sustainable competitive advantage, it is sponsorship. The value of sponsorship is being enhanced rapidly and key events and organisations are able to choose from a wide range of potential sponsors and attract high rights fees. Prime factors in the rise of sponsorship fees are the globalisation of communications, new technology of cable and satellite broadcasting, the internet and digital communications and the growing aspirations of societies for leisure and information. Sponsorship is changing too, and it now figures as part of mainstream marketing. For example, sports sponsorship is increasingly referred too now as sp... ...;  Match day tickets to staff †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Global newsletter distribution with promo activities Guinness Rugby World Cup Ambassadors †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ex-players to serve as World Cup ambassadors †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Used at trade events, staff events, etc Website †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Guinness created website †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Elements of broadcast could be downloaded as screen savers †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Average visit to website lasted 9 minutes Results †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Increased consumption in priority markets (GB=17%, Fr=37%, Australia=20%, SA=24%) †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  94% prompted awareness in GB, post activity †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Guinness was the most dominant sponsor of the Games †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Positive results in reinforcing brand essence, injecting energy, promoting newsworthiness and co temporizing the brand Conclusion †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Principles must be applied consistently over time †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Message must be consistent with brand essence †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Measure, measure, measure

To Build A Fire Character Stud Essay -- essays research papers

In "To Build a Fire," Jack London expresses his perspective of the multitude of greenhorns who flocked to the yukon in a rush for gold. It is evident that he believed that these newcomers were too inexperienced and blinded by gold fever to survive the trip. Like many of them, "the Man" is driven by his own foolish ego to act irrationally and to not follow wise advice. Though his consience continually nags at him, his ego-driven way of thought keeps pushing him blindly forward. The Man is not only representative of other fortune hunters like himself, but he also repersents every person on this planet. All of us, at some point in time, pushed our own consience aside and followed our own selfish ego. The Man was a newcomer to the land, yet when he was offered advice on how to survive the harsh conditions of the Yukon, he just laughed at it: It certainly was cold, was his thought. That man from Sulphur Creek had spoken the truth when telling how cold it sometimes got in the country. And he had laughed at him at the time! That showed that one must not be too sure of things. This shows that he is driven by his ego, and like many other young men, he thinks that he is so much better than everybody else that he does not even listen to the advice of an old man who has proably been living in the Yukon longer than the Man has been alive. Fifty degrees bleow zero stood for a bite of frost that hurt and that must be guarded against by the...

A Second Depression Predicted from History

The factors contributing to the struggle of working class Americans during the Depression are still relevant today. Clues as to the imminent occurrence of a second Depression can be found by comparing the Great Depression to today’s economic climate.The following essay compares contributing factors to the struggles of working class society during the time of the Depression and today. Key factors to be analyzed are; low wages and unemployment rates, unfair tax laws and foreign and American economic influences, as well as American spending.Low wages are as much a problem today as they were during the Depression. One out of four working families in America today are low income; earning wages which are so low that it is nearly impossible for them to survive financially (Waldron, et.al., 2004). Key characteristics in today’s poor include; low-paying jobs, inadequate benefits and little-to-no job advancement opportunities and lack of skills and/or education (2004).Presently t he economy demands high skilled workers, due to the rise in technology. Low paying service jobs are still available and needed by the economy, yet the United States has not taken the proper action to support employees of such jobs and thus their needs and those of their families, go unmet (2004). Lack of proper support by government reduces the chances for families of low paying service jobs to make or plan a solid future.Policies and regulations today are inadequate for the needs of the poor; much like during the Depression. Suggestions for the improvement of poverty-stricken American’s involve the creation of better paying jobs, better access to education, training and health care and better benefits; all these items are available to better paid employees. It is suggested that in order to accomplish these things, Americans must effectively invest public resources (2004).Research has shown that the level of education strongly influence living standards in America; for exampl e, thirty-five percent of low-income families have a parent who did not graduate high school (2004).America’s poor struggle with balancing their wages; the majority of their income is going to housing and utilities, not leaving enough for health care. This is a concern because without health care, America’s poor miss work or lose their job because of illness. The struggles of low-paid workers in America are similar to that of workers during the Depression. Education and skills were as important, and difficult, to obtain today as in the 1930s.As in the 1930s, tax structures and investments affect working Americans significantly. Public assistance varies and is mandated by state; however the maximum amount of earnings allowed by any state in America is so low, that if a family wanted to maintain health insurance after reaching the maximum income level, it is close to impossible. Some states only allow a maximum yearly income level of ten thousand dollars. Once reaching t he maximum amount, public assistance is no longer available. There were similar concerns of how to help America’s poor during the Depression.The Dust Bowl migration of the 1930s demonstrates the struggles and political policies which affected the poor during the Depression. During the Dust Bowl migration, families from Oklahoma and surrounding states headed for California during the Depression, in search for a better life in the growing agricultural state (Gregory, 2004). The Depression affected everyone, but especially farmers in Oklahoma and surrounding states; the severe drought made it all the worse.Unemployment rates were high across the country; farmers and those in the city experienced joblessness. The poor were often discriminated against by states; many states were unwilling to allow the poor to relocate to their states (Gregory, 2004). California, for example, set up a boarder patrol to keep poor migrants out of the state. It wasn’t until 1941, that the Supre me Court decided that states had no right to restrict fellow Americans from migrating to their state (2004). Â  There were attempts by some counties to help educated farmers; as well as give minor health care services.