Tuesday, August 6, 2019
Theory of Evolution by Natural Selection Essay Example for Free
Theory of Evolution by Natural Selection Essay The theory of evolution by natural selection is about the changes that occur in all living things on earth over time. This process of change, which started on the first day of life on earth and continues up to the present, is what fortifies living things and enables them to survive and perpetuate their species. Detailed in a 500-page book entitled â€Å"On the Origin of Species by Natural Selection†published by Charles Darwin in 1858, the theory of evolution by natural selection essentially holds that on this earth, only the brawny and the brainy remain standing as a result of a perpetual struggle for survival. It follows, therefore, that only the stronger and the smarter of the species get the opportunity to reproduce and keep their kinds endure. As a further result of this process of natural selection, the descendants of the surviving species only exhibit the traits (whether physical strength, size, agility, quick-wittedness, or the ability to change appearance) possessed by their ancestors that permitted them to stay alive in their particular habitats. It further follows, that as a result of this perpetual process of change, the creatures of the present are vastly different from the original or earlier creatures that lived on this earth. (Regents of the University of Michigan. , 2005) Let us take as an example the case of the â€Å"peppered moth (Biston betularia)†in England. This particular species of moth that were found living among lichens in the trunks of trees before 1800 had a generally light coloring. Its coloring, therefore, enabled it to camouflage its presence among the lichens, thereby avoiding the predating birds. With the advent of the industrial revolution, the black smoke (soot) emitted by the industrial plants obliterated the lichens and darkened the trunks of trees. This development exposed the moth to their predators, resulting to a decrease in their population. In order to survive, the moth metamorphosed and by 1819, a darker variant of the moth appeared – one that was able, once again, to escape the eyes of the predating birds. (Regents of the Univ. of Michigan, 2005) Reference Regents of the University of Michigan. (2005). Evolution and Natural Selection. Retrieved June 22, 2007, from http://www. globalchange. umich. edu/globalchange/current/lectures/selection/selection. html
Monday, August 5, 2019
Applying Cue Utilization Theory
Applying Cue Utilization Theory Evaluating Website Quality: Applying Cue Utilization Theory to WebQual Abstract      Cue Utilization Theory is applied to examine the relative importance of each of the WebQual dimensions (Informational Fit-to-Task, Tailored Information, Trust, Response Time, Ease of Understanding, Intuitive Operations, Visual Appeal, Innovativeness, Emotional Appeal, Consistent Image, On-line Completeness, and Relative Advantage) in determining consumers evaluation of website quality. Two studies have been designed for this task. Study 1 qualifies how subjects rate the predictive value (PV) and confidence value (CV) of each dimension. An analysis of these results provides an ability to fit the WebQual dimensions to a 22 model showing the relative magnitude that each dimension has on consumers evaluation of website quality. Study 2 is designed to test the viability of the model via a set of proposed hypotheses. The results from this research will contribute to the field by providing a model that developers can utilize to focus on those characteristics most determi nistic of overall website quality. 1. Introduction      In the last ten years, online shopping has become a prevalent part of the average consumers shopping experience. The consumer now has the ability to purchase virtually anything online; ranging from small-ticket items such as a rubber-band ball to bigticket items like vacation homes. With this increase in the online consumers purchasing power and propensity to purchase online, retailers have become increasingly willing to develop their e-commerce presence. Moreover, this explosion of Internet activity has prompted businesses to demand that website developers understand the qualities of a website that serve to facilitate the shopping experience for e-commerce consumers. At the same time, this growth of e-commerce has provided a virtual plethora of new options for crimes of opportunity such as identity theft. The online shopper has to worry not only about finding the perfect product, but they also have to evaluate the website to determine if they are willing to make a purchase from this site.      Valacich, Parboteeah and Wells [1] developed the Online Consumers Hierarchy of Needs to delineate the needs of the online consumer. Their model showed that certain fundamental needs exist that the online consumer must have met before they are willing to utilize a website. These fundamental needs are then further broken down into the specific website characteristic categories of Functional Convenience, Representational Delight and Structural Firmness. Functional Convenience is the category allowing the consumer to accomplish the task-athand easily and includes attributes, such as ease of ordering and tracking. Representational Delight is characterized by those dimensions that make the site visually appealing, such as graphics and sizing. Structural Firmness consists of fundamental qualities such as response time and security. Using this Hierarchy of Needs, a consumer interested in online banking would need to have their basic need for each of these characteristics met before they would be willing to use the website.      This Hierarchy of Needs model shows those characteristics that are necessary for a consumer to utilize a website, and further elaborates by showing which characteristics are most important depending on if the consumer is visiting the website for business, pleasure or a combination of the two [1]. Knowing these characteristics is important for development of the website, but also implies that the consumers level of confidence in evaluating these characteristics of a website is of particular importance to their overall assessment of a given websites quality. Traditional marketing literature suggests that when people make assessments of quality, they tend to use informational cues that are not only predictive, but also easy to assess. This is known as the Cue Utilization Theory [2], and has been paramount in evaluating consumers perceptions of product quality.      This research project elaborates on consumers inability to evaluate all relevant cues during the online shopping experience. A model is developed using Cue Utilization Theory [2] and WebQual [3] to show the attributes of a website that are the most determinant of how a consumer will react to the website. This model will provide a deeper understanding of the evaluation of existing and proposed websites with respect to consumers confidence in evaluating the cues communicated by the website. 2. Cue Utilization Theory      Richardson, Dick and Jain [2] employed Cue Utilization Theory in their research to determine how consumers viewed store brand quality vs. nationally branded merchandise. According to this theory, â€Å" products consist of an array of cues that serve as surrogate indicators of quality to shoppers†[2]. This theory purports that cues are evoked by the two separate dimensions of predictive and confidence values. The predictive value (PV) is â€Å" the degree to which consumers associate a given cue with product quality†[2]. Confidence value (CV) is â€Å" the degree to which consumers have confidence in their ability to use and judge that cue accurately†[2].      Further, based on relative differences in PV and CV, cues can be broken down into the distinct areas of extrinsic and intrinsic. The American Heritage dictionary describes intrinsic as, â€Å"Of or relating to the essential nature of a thing; inherent†[4] and extrinsic as, â€Å"not forming an essential or inherent part of a thing; extraneous.†[5] From this definition, an intrinsic attribute would be one that would fundamentally alter the focal object (e.g., product) if it was changed or absent and, per Cue Utilization Theory, would possess an inherently high degree of PV. Alternatively, an extrinsic attribute would be one that would not alter the fundamental nature of the focal object in its absence but might alter a consumers reaction or perceptions of the object. Per Cue Utilization theory, an extrinsic cue would typically have higher degrees of CV compared to PV.      For example, when looking at a video card on an e-commerce website it could be said that the product price is an example of an extrinsic attribute of the video card. While the video cards dimensions and material composition of the video card serve as intrinsic indicators. Further, you could postulate that the average consumer has a higher CV in their ability to judge the quality of the card based on the price rather than the material composition. Though the consumer knows that the dimensions and material composition of the card are important, they will tend to rely on price as an informational cue, as that is the cue that they feel the most comfortable evaluating.      When considering the quality of a website there are a myriad of dimensions that the consumer mustevaluate to determine if they intend to perform a transaction on this website. From the Valacich et al [1] article the consumers basic needs in terms of Structural Firmness, Functional Convenience and Representational Delight must all be met before the consumer will consider doing business. To determine if these needs are being met the consumer will evaluate the cues they perceive as being exhibited from the website. These cues can be further broken down into components by utilizing the WebQual model [3]. 3. WebQual      WebQual consists of 12 dimensions: Informational Fit-to-Task, Tailored Information, Trust, Response Time, Ease of Understanding, Intuitive Operations, Visual Appeal, Innovativeness, Emotional Appeal, Consistent Image, On-line Completeness, and Relative Advantage. Each of these dimensions is shown to have strong measurement validity in regards to the consumers evaluation of overall website quality [3].      Information fit-to-task is an amalgamation of information quality and functional fit-to-task [3]. In component form, information quality refers to the datas appropriateness for use or ability to meet the users needs [6]. Functional Fit-to-Task can be represented as the degree the technology assists the user at a given task [7]. Drawing these two components back together as a whole and relating them to cyberspace lends credence to the definition that information fit-to-task is assisting the user in their desired task by presenting relevant/appropriate information. Loiacono, Chen, and Goodhue [8] define this as â€Å"The information provided meets task needs and improves performance†.      The ability for consumers to tailor the information displayed on a website to meet their needs is the basic form of Tailored Information. Tailored Information is further characterized by Ghose and Dou [9] as the interactivity of the website, and represents the consumers ability to modify information presented on the website. Recent research suggests that website interactivity will lead consumers to be more positive in their evaluation of websites [9]. This concept has also been operationalized as the ability to personalize information between the consumer and the website [8,10]      Trust, in relation to websites, is defined in an extremely simple form as consumers confidence that any information entered into the website will remain confidential and that said information will be transmitted and stored in a secure fashion [8]. Furthermore, trust is having faith that the information presented on the website is true and accurate [11,12]. Lack of Trust has been cited as one of the main hindrances to completion of e-commerce transactions [14,11,15]      Response Time (aka. download time or download delay) is defined by Rose and Straub [16] as â€Å" the time it takes for a web client to fully receive, process, and display files†(p. 56), and is ranked as one of the largest impediments to electronic commerce in their research. Additional research has reinforced that Response Time can be an impediment to e-Commerce, and that is it also strongly associated with web site success [17,18]      The consumers ease in comprehending the website is the Ease of Understanding. Loiacono et al. [8] describe this in terms of a websites ease of reading and the understandability of said website. This would include things like presenting the information in a manner which is easy for the consumer to assimilate, and in a fashion such that the consumer can quickly navigate to the desired information.      Intuitive Operations deals with the usability of a website, and includes items such as navigability, link placement, operation, and changing the color of visited links [19]. Intuitive Operations could be thought of as making the webpage easy to navigate, and providing intuitive options for available tasks [8]      Visual Appeal is how aesthetically pleasing the website is to the consumer. Determining what is aesthetically pleasing is complicated though; it ranges from the overall complexity of the website [20] and the layout of the interface [21] to how many ads and graphics are appropriate on a given page[22]      Innovativeness is â€Å"The creativity and uniqueness of a site design†[8]. This could include concepts such as a website having a new way of presenting its merchandise (e.g. Woot.com) or a website attempting to tailor the information to consumer preferences (e.g. Amazon.com)      Emotional Appeal can be elicited in many forms and can be thought of as the consumers intensity of involvement given the emotions that the website elicits [8]. This is often seen in the form of testimonials presented on the website, but can also be observed by simple things such as a consumers reaction to a Valentines Day card.      Loiacono et al. [8] articulate Consistent Image as the websites ability to project a company image that is compatible with the company image shown in other forms of media channels. For instance, a traditional brick-and-mortal store would want to ensure that their website was displaying a compatible image so that they could capitalize on synergies created by marketing in multiple channels such as cost savings, market extension and improved Trus [23].      Presenting all the information required for the tasks that the website is designed for would be considered On-line Completeness. This would include tasks such as the ability to complete an online transaction on e-commerce sites. A bank for instance would want ubiquitous account access using all available channels, and the information presented in each of these channels has to be on the same update cycle as to present the customer the same information regardless of channel [6].      Relative Advantage is gaining a competitive advantage by being able to do something better than the competition. This could come in the form of providing better interaction with the customer through the website [8], being able to provide more accurate and timely data through your website than the competition [6] or being able to price products lower than the competition because of reduced prices in your supply chain. Each of these dimensions is then tied back into the consumers intention to use/reuse the site. Trust and Response Time, being key indicators, are directly linked to the consumers intention to use the site. Common sense would tell us that consumers are not going to shop on a site that does not respond rapidly to requests. Likewise, if users dont trust the site to keep their information secure, they are not likely to supply the information in the first place. The remaining dimensions are all fully mediated by Usefulness, Ease of Use and Entertainment. Usefulness mediates Informational Fit-to-Task, Tailored Information, Online Completeness and Relative Advantage. Additionally, Ease of Use is partially mediated by Usefulness. Ease of Use mediates Ease of Understanding and Intuitive Operations. Finally, Entertainment mediates Visual Appeal, Innovativeness, Emotional Appeal and Consistent Image (See WebQual model in Figure 1).      Consumers do not just browse a site and evaluate each of these individual traits though. Consumers instead tend to examine a website using those cues that they feel confident in their ability to evaluate successfully. To understand this issue further, WebQual needs to be combined with Cue Utilization Theory to explain the extrinsic/intrinsic nature of each of these dimensions. 4. Cue Utilization/WebQual Conceptual Model      As Valacich et al [1] point out; consumers must have their basic level of needs met before any of the other elements of the website can become relevant to the consumers experience. To validate that these basic needs have been met, the consumer will evaluate those features that they believe to be highly predictive of the quality of the website. This evaluation will then be indicative of their willingness to continue to use the website.      Both extrinsic and intrinsic cues serve a function in the consumers overall evaluation of the quality of a website, which means that such cues possess varying degrees of PV and CV. Literature has shown that consumers tend to use a combination of both extrinsic and intrinsic cues when evaluating the quality of a product [2]. An argument can be made about the extrinsic versus intrinsic nature of each of the dimensions in the WebQual model.      Intrinsic cues are those cues that are inherent to a website. Conceptually they are the cues that when changed fundamentally alter a characteristic of the website (e.g. Visual Appeal). Consumers tend to see these cues as being highly predictive of quality [2]. At the same time, consumers may or may not have a high degree of confidence in their ability to evaluate these intrinsic cues because these cues are often difficult to differentiate. Thus, assuming a Cue Utilization Theory perspective, a website characteristic that is perceived to be an intrinsic cue would have an inherently high degree of PV. Yet, the power of an intrinsic cue for assessments of quality will depend on the CV of the cue, with higher levels of CV being optimal.      Extrinsic cues are those cues that are used to evaluate a website but are not an inherent part of the website (e.g. Response Time). Consumers tend to have a lot of confidence in their ability to evaluate these cues in regards to assessment of quality [2]. On [the other hand, consumers typically do not rate these cues as being highly predictive (as compared to intrinsic cues) of the overall quality of the website. Considering extrinsic cues from a Cue Utilization Theory perspective, a website characteristic that is perceived to be an extrinsic cue would have an inherently high degree of CV.      Shown in Table 1 is a 22 matrix representing how each of the combinations of CV and PV will influence consumers willingness to perform tasks on a given website. As shown, characteristics with high CV and high PV are believed to have the largest effect on consumers perceptions of website quality. Those with low CV and PV would have a small to none existent effect, and those high on one dimension but low on the other would have a moderate effect. Next, we will posit about how varying degrees of cue PVs and CVs, respectively, will affect consumer perceptions of overall website quality.      Relative Advantage is often considered an important aspect of websites as discussed previously. However, from a Cue Utilization Theory perspective the consumer may experience, at most, only a vague feeling about the Relative Advantage of the website. As such they would not place much value in their confidence in assessing this characteristic, which would result in a low CV. Along the same lines the average consumer would also not really take Relative Advantage into consideration when they were performing tasks, implying a relatively low level of PV. Thus, website characteristics that fall into the quadrant in the model with low levels of both PV and CV would have a small impact on consumers willingness to perform tasks on a website. H1: A website characteristic with low CV low PV will produce a small to none existent effect on the consumers perception of website quality.      A characteristic such as Trust is highly predictive of consumers willingness to use a website, but the average consumer may not have much confidence in their ability to evaluate this characteristic. Trust in an online medium has been shown to be an attribute that is hard for the consumer to evaluate and in some cases to even define. Cue Utilization Theory suggests that though this characteristic is highly predictive of website quality, consumers lack of confidence in evaluating the characteristic may inhibit their ability to use the characteristic to assess the quality of the website. Moreover, dimensions in this quadrant, high PV/Low CV, have been shown to be relatively intrinsic to the website [2], and will have a moderate effect on the consumers evaluation of the websites quality. H2a: A website characteristic with low CV high PV will produce a moderate effect on consumers perception of website quality.      One could reason that Response Time is a good example of an extrinsic attribute because it is not part of the inherent composition of the website. Rather, Response Time could be considered extrinsic because it can vary without changing anything about the content of the website. Rose and Straub [16] have shown in their research that consumers tend to attribute lack of responsiveness to extrinsic factors such as the overall speed of the internet, their own internet connection being slow, or other factors. In general, consumers seem to be willing to give the website the benefit of the doubt when slow response times are encountered, and as such, Response Time could be considered extrinsic to the website because it doesnt fundamental change the consumers perception of the website when it is altered. Based on Cue Utilization theory attributes with a low PV and high CV (such as Response Time) will only have a moderate influence on the consumers evaluations of website qua lity, and those dimensions belonging to this quadrant would be extrinsic to the website [2]. H2b: A website characteristic with high CV low PV will produce a moderate effect on consumers perception of website quality.      Cue Utilization Theory suggests that those characteristics with High CV and PV are the most highly predictive of consumers perception of website quality. Visual Appeal could be considered an intrinsic attribute because it is a characteristic inherent to the website that consumers are confident in using to evaluate website quality. One could further speculate that Visual Appeal is intrinsic to the website because if the Visual Appeal of the website was changed it would alter the inherent nature of the website. Lindgaard, Fernandes, Dudek, and Browà ± [24] have shown in their research that consumers form opinions about websites within the first 50 milliseconds (ms) of exposure. Furthermore, this initial perception of websites is almost entirely based on Visual Appeal; this was shown by correlating the ratings between 50 ms and 500 ms. However, though this attribute is intrinsic it shows an optimally high level of CV and PV thus placing it firmly into the high impac t quadrant. Dimensions in this quadrant would exhibit the optimal balance between PV and CV (i.e., an optimal intrinsic cue), and as such this quadrant of the table is hypothesized to have the largest impact on the consumers evaluation of the websites quality. H3: A website characteristic with high CV high PV will produce the largest effect on consumers perception of website quality. 5. Research Method      To test these hypotheses two empirical studies will be administered. Study 1 is designed to determine where each of the WebQual dimensions fit into the 22 model shown in Table 1. Furthermore, this study is designed to determine if a significant difference can be perceived to exist between each of the dimensions when rank ordered by PV and CV. Study 2 will test the hypotheses by collecting data on each of these dimensions using a sample website, and comparing actual results to those found in the first study. 5.1 Study 1      This study will focus on determining the CV and PV for each of the 12 dimensions of website quality, and determining if there is a significant difference between adjacent dimensions when rank ordered. 5.1.1 Subjects. Approximately 500 subjects will be recruited from an introductory Information Systems class held on campus at a large Northwestern University. Additionally, approximately 125 subjects will also be recruited from a distance education class offered by the same university. Subjects physically present on campus will complete the survey during their regular lecture times, and the distance education participants will have one week to complete the survey on their own personal computer. All data for Study 1 will be collected during the fall of 2009. Subjects will be given course credit for completing the survey, and no other incentives will be provided. 5.1.2 Survey Procedure. The survey is broken into two sections, one for CV and one for PV. In the CV section subjects are presented with a scenario about shopping on the Internet and asked about their confidence in assessing each of the 12 WebQual dimensions when shopping on the Internet for a product (e.g. Amazon.com) or Service (e.g. Bank of America). For this series of questions, the subjects will be required to rate each of the 12 WebQual dimensions on a 10-point likert-type scale with Confident/Not Confident being the top and bottom end of the scale. Finally, the subjects are asked to rank order the dimensions from the ones they have the highest confidence in assessing to the ones they have the least confidence in assessing.      The second section is designed to measure the PV of each of the 12 dimensions. Subjects are put in a hypothetical situation where they are in charge of designing a website for their employer. The first step towards designing the website is to decide the relative importance of each of the twelve dimensions in regards to consumers evaluation of the overall website quality. For this series of questions, the subjects will be required to rate each of the 12 dimensions on a 10-point likert-type scale with Important/Not Important being the top and bottom end of the scale. The subjects are then asked to rank order each of the 12 dimensions with respect to how predictive of website quality the subject believes each dimension to be. 5.1.3 Data Analysis. Aggregating the results of this data collection will allow each of the dimensions to be mapped to a CV and PV scale. Based on the relative PV and CV scores, each of the dimensions will be integrated into the 22 matrix shown in Table 1. Furthermore, the relative magnitude of each dimension will indicate the relative effect each dimension will have on the overall rating of website quality. 5.2 Study 2      This study will utilize subjects from an introductory Information Systems class taught in the fall of 2009. Approximately 500 students will participate. This study will focus on first determining the overall quality attributed to a website by the subjects, and secondly how the subjects rate each of the twelve WebQual dimensions for each website. Using regression analysis, we should then be able to show that the model accurately predicts the website quality based on the rating of each of the 12 dimensions.      Furthermore, the pattern of results from this study will examine how well the WebQual dimensions fit to the quadrant they were assigned in Study 1, and that the model developed in Study 1 is predictive of the responses received in Study 2. Those dimensions that serve as the highest-level indicators of website quality should be rated the highest by the subjects, and those that are the lowest should be rated likewise. Ideally, this study should provide significant support for each of the proposed hypotheses, and indicate which of the dimensions should be of highest consideration when constructing a high quality website. Initial data for both of these studies should be ready to share at the conference, should the paper be accepted. 6. Discussion and Potential Contribution      As shown in the model, the most important considerations when developing a website are those attributes that reside in the high CV and high PV quadrant. Online businesses should pay particular attention to the characteristics in this quadrant, as the consumer will tend to utilize these dimensions the most when determining the overall quality of the website. All businesses seeking to perform transactions within the e-commerce channel should pay heed to these recommendations, but online retailers need to pay particular attention, as this is the primary channel through which they produce revenue.      Of secondary importance to consumers are the Low CV/High PV and High CV/Low PV quadrants. If an online business seeks to capitalize on one of the dimensions within these quadrants, they need to pay particular attention to how they will nudge the consumer into using these dimensions for evaluation of website quality. This could potentially be accomplished through educational campaigns or marketing literature. Finally, the low CV/Low PV quadrant is of limited value to the online retailer, and should be removed from consideration when developing a website. This article seeks to contribute to the field by providing a model that can be used to enable web developers to effectively predict the overall quality of a website based on its design. In following this model, the developer will need to pay particular attention to those attributes that are highly predictive, from the consumers viewpoint, of overall website quality, and as such, the website should be designed in a fashion that encourages the consumer to conduct transactions. Additionally, the consumer will be motivated to perform future transactions from this website because they are familiar with the layout and possess a high confidence in the overall quality of the website. 7. Limitations and Future Research      The primary limitation of this model is that it is an untested conceptual model. The assumptions contained herein are as of yet ungrounded in solid empirical evidence; furthermore, this model was designed around e-commerce websites designed to sell products to end consumers.      Future research could delve into decomposing those elements that are the most highly predictive of website quality. This research could take each dimension and decompose them to their base elements to discover what it is about the dimension that makes it highly predictive of website quality. Additionally, the extrinsic/intrinsic nature of each of the dimensions could be explored to determine how a company can best capitalize on these dimensions when trying to sell the consumer on the quality of their website. Either of these approaches could prove invaluable to the field, as they will begin to give the developer a specific set of principles to follow when developing a high quality website. 8. Conclusion      Cue Utilization Theory is a concept that has been used in marketing for years to determine why consumers react differently to a given product. The author of this article has overlaid Cue Utilization theory upon WebQual to design a model that is predictive of the dimensions serving to form the consumers overall feel for the quality of a website. Using this model, website designers will be able to build a website that consumers will be more confident in assessing the quality of, and as such, the consumer will gain confidence in performing transactions on this website. 9. References J.S. Valacich, D.V. Parboteeah, and J.D. Wells, â€Å"The online consumers hierarchy of needs,†Commun. ACM, Vol. 50, No. 9, pp. 84-90, 2007. P.S. Richardson, A.S. Dick, and A.K. Jain, â€Å"Extrinsic and intrinsic cue effects on perceptions of store brand quality.,†Journal of Marketing, Vol. 58, No. 4, p. 28, Oct. 1994. E.T. Loiacono, R.T. Watson, and D.L. Goodhue, â€Å"WebQual: An Instrument for Consumer Evaluation of Web Sites.,†International Journal of Electronic Commerce, Vol. 11, No. 3, pp. 51-87, Spring. 2007. â€Å"intrinsic,†The American Heritage ® Dictionary of the English Language, Fourth Edition. â€Å"extrinsic,†The American Heritage ® Dictionary of the English Language, Fourth Edition. C. Cappiello, C. Francalanci, and B. Pernici, â€Å"Time-Related Factors of Data Quality in Multichannel Information Systems.,†Journal of Management Information Systems, Vol. 20, No. 3, pp. 71-91, Winter. 2003. D.L. Goodhue and R.L. Thompson, â€Å"Task-Technology Fit and Individual Performance.,†MIS Quarterly, Vol. 19, No. 2, pp. 213-236, Jun. 1995. E.T. Loiacono, D. Chen, and D.L. Goodhue, â€Å"WebQual TM Revisited: Predicting the Intent to Reuse a Web Site,†AMCIS 2002 Proceedings, p. Paper 46, 2002. S. Ghose and W. Dou, â€Å"Interactive Functions and Their Impacts on the Appeal of Internet Presence Sites.,†Journal of Advertising Research, Vol. 38, No. 2, pp. 29-43, Mar. 1998. R.T. Rust and K.N. Lemon, â€Å"E-Service and the Consumer.,†International Journal of Electronic Commerce, Vol. 5, No. 3, pp. 85-101, Spring. 2001. D.H. McKnight, V. Choudhury, and C. Kacmar, â€Å"Developing and Validating Trust Measures for e-Commerce: An Integrative Typology.,†Information Systems Research, Vol. 13, No. 3, pp. 334-359, 2002. R. Pennington, H.D. Wilcox, and V. Grover, â€Å"The Role of System Trust in Business-to-Consumer Transactions.,†Journal of Management Information Systems, Vol. 20, No. 3, pp. 197-226, Winter. 2003. J. Kim, J
Types of power supply and their applications
Types of power supply and their applications Types of Power Supply and their applications Power supply is a device used to provide the electric energy to operate the devices running on electric power. It has many special ways to provide electric energy to a specific system â€Å"it is mother of the system†( Brown, 2001, p.1 ). The basic functionality of power supply is to convert Alternative Current voltage to regulated Direct Current voltage required by electronic devices. A typical power supply has four different modules each of them has a specific function. (Source: http://www.kpsec.freeuk.com/powersup.htm) Transformer is the first module and its function is to convert high voltage Alternative Current to low voltage Direct Current. The second module is Rectifier and its main function is to convert low voltage Alternative Current to Direct Current. The third module is Smoothing, the Direct Current produced by the Rectifier is varying, so Smoothing reduces this variation to small rippling. Last module is Regulator, it sets the Direct Current voltage to fixed value by removing the ripples. This is a basic design of power supply. The design can be huge and complicated based on the requirements. This essay will present the four major types of power supply which are Linear Regulators and Switching Mode Power Supply, Programmable Power Supply, Uninterruptible Power Supply. The first type of power supply is Linear Regulated Power Supplies. They are the basic type of power supply. they produce the regulated output voltage by dropping the input voltage. To achieve this, it relies on variable conductivity of an electronic device. Hence, the lot of power wasted in the form of heat. â€Å"it is though, a very electrically quiet power supply†(Brown, 2001, p.11). they are often used in ground based equipment and distributed power systems. Linear regulated power supply function by converting varying Alternative Current input to regulated Direct Current output. The typical circuit used in this type has two range. One allows more voltage at lower current and the other allows more current at lower voltage. Linear regulated power supplies come in two basic forms called series regulators and shunt regulators. Series regulated power supplies are most common form of linear regulated power supply. The power dissipated in series regulated device is the product of power supply output current and the voltage drop. Shunt regulated power supplies are the simpler form of Linear Regulated power supply, but they are less efficient. Simplicity is the main advantage of linear regulated power supplies. They have been widely used in industry for a long time. They are used in systems that require extremely low noise. They are more suitable and cost effective for low power applications. They are used in ground based applications and distributed power systems. Since the linear regulated power supply has very low power output voltage ripple, it is used in low noise / low ripple applications such as communication and radio device where noise is very critical. It is more efficient in the application which output voltage is almost equal to input voltage. The second type of power supply is Switching Mode (SMPS). It operates in ON-OFF mode. It uses switching circuits and energy storage elements such as capacitors and inductors to get the regulated output voltage. â€Å"These circuits are ideally lossless with 100% energy transfer†(Johnny, 2006, p.1). The main advantage of Switching Mode Power Supply is the higher efficiency because of low power dissipation. It is simpler and light weight because of the elimination of heavy low frequency transformers and generates low heat. It is used in domestic products which often have universal inputs. Mobile phones have changed their power supply technology from linear regulated to Switching Mode Technology. It is widely used in aircraft electric power such as airplane ground support. The third type of power supply is Programmable Power Supply. It provides the power through a computer interface. It generally depends on both Linear regulated and Switched Mode technologies to produce accurate output power. A Programmable power supply typically consists of microcontroller, current, voltage programming circuits such as analog to digital convertors, serial peripheral interface, keypad and a LCD display. The desired voltage parameter is given as the input to microcontroller through key pad. Intern, microcontroller convert analog voltage from a voltage source to digital through analog to digital convertor. This digital voltage is regulated through serial peripheral interface to get the desired voltage which is inputted to microcontroller through keypad. The main advantage of programmable power supply is that accurate required voltage can be produced which is not possible from either linear regulated or switching mode power supply. It is mainly used in automated equipment testing. They are also used in ultrasonic vibration measurement tools. The last type of power supply is Uninterruptible power supply. It is widely known as UPS or power back up. It is widely used as backup power to protect the devices from crashing due to sudden power loss. There are three major categories of Uninterruptible power supply, offline -standby, online and line-interactive. The first category is Offline /standby Uninterruptible power supply. It provides surge protection and battery back-up up to 20 minutes. When the input power supply falls below the threshold level, then Uninterruptible power supply turns on its power circuit providing power backup to the device up in certain time (In this type 20 minutes). Line-Interactive Uninterruptible power supply is the second category. It generally uses only one main power convertor to generate the power. â€Å"With its low cost and durability, the line-interactive UPS has been used successfully in millions of IT installations worldwide†(Hoff and Samstad , 2004) . The typical protection time varies from 5 minutes to 30 minutes. The last category is Online, the operation of Online Uninterruptible power supply is very similar to Standby or Line-Interactive type. The typical protection time varies between 5 minutes to 30 minutes. But, it provides electrical firewall between incoming utility power and sensitive electronic equipment. The main purpose of Uninterruptible power supply is to provide the protection to devices from crashing due to sudden power loss. Some of the Uninterruptible power supplies are also capable of correcting the common utility power problems such as, total loss of input voltage, momentary increase or decrease input voltage, spikes , noise. They are mainly used for surge protection and back power for computers, data centers and telecommunication equipment. They are used to provide the electric isolation for the equipment which are sensitive to power fluctuations. In conclusion, there are various sources of power being used to provide the power to the systems effectively and efficiently. For example, solar energy and wind power are being converted to electric energy to provide the power to large industrial applications. Power supplies are the heart of any system which requires electrical energy. They not only provide power but also provide the protection to the system against outside disturbances. Therefore, design and development considerations of a power supply are more important. As technology is growing, more advanced power supplies are being invented to provide best protection and efficient power to the devices.
Sunday, August 4, 2019
The Architecture Studio :: Personal Narrative Writing
The Architecture Studio All my life I had dreamed of this day. I had spent countless hours playing â€Å"architecture firm†and designing various buildings on my â€Å"Home Design 2000†program. Today was the commencement of the fall 2003 semester at State University’s College of Architecture, Planning, and Design (or CAPD for short). I stood in studio #323, affectionately known to architecture majors as the â€Å"Loft Studio.†I felt lucky to get the studio with the coolest layout and the most space, for it was well known that other classes were sure to envy this room. With the best view because of the huge picture window that spanned almost two stories, (the lower level along with the height from the loft) we were able to see the towering evergreen trees just outside the building, and had a great view of the sky (much to our dismay, we often saw the sunrise and sunset and the sunrise again all in the same day). As I lounged in my chair, feeling completely awkward but trying to look like I fit in, my eyes scanned the room full of eager faces that I would soon consider my classmates, and hopefully, friends. Right now though, each of them intimidated me. I couldn’t help but think they had all spend their entire lives preparing for the year, when all I had were dreams and ambition. Katrina Lewis was our professor, and each of us had heard rumors of how picky she was (â€Å"anal retentive†were the exact words, I believe). There were horror stories of her always giving the class busywork, and expecting total perfection, despite our lack of knowledge or experience. I pictured in my head a short spinster who wore horn-rimmed glasses and nothing but black pantsuits, but my eyes widened with surprise as she walked in the room. A tall, thin frame accompanied by short, stylish blonde hair took the place of my gray-haired visions. She couldn’t have been more than 30 years old, and she wore cute plastic-rimmed sunglasses (which, by the way, she wore every day of class†¦and never took them off). She called us over to the area where she taught, and we all grabbed chairs, being careful not to pop anybody’s bubble. She proceeded to lecture the entire three hours of class, while each of use struggled to keep our eyes open. I knew by the end of class that the rumors were true, and this would not be an easy first semester.
Saturday, August 3, 2019
Free Essays - Courage and Honesty in Sir Gawain and Green Knight :: Sir Gawain Green Knight Essays
Courage and Honesty in Sir Gawain and the Green Knight "Sir Gawain and the Green Knight" is a poem written by a poet (name unknown) approximately 6000 years ago in the late 1300's in the medieval times. This story was originally written in medieval literature with a real unique rhyme scheme, but was translated later in time to regular English for high school students and researchers to study and read. The story begins during the New Year's feast in King Arthur's court. Then a green knight enters asking all of the knights in the court if they would like to play a game. The game is he will allow which ever knight that chooses to challenge him one swing with a battle ax to try and chop off his head, but in order to play the game, the accepting knight must meet the green knight one year later at the green chapel. The brave knight Sir Gawain accepts to the challenge of the green knight. Sir Gawain takes one swing and chops off the head of the green knight. Right after the green knight's head is chopped off he gets up immediately, picks up his head and leaves. Once a year passes, Gawain sets off on a journey to find the Green Chapel. He arrives at a castle in which a lord welcomes him to stay for several days (Gawain only needs to stay there for three). The next morning the lord makes an agreement to share everything he gets during these three days with Gawain, but Gawain must agree to do the same. During days one and two the lord's wife tries hitting on Gawain, but he only allows her to give him a few kisses. At these days Gawain shares what he got to the lord for what he has hunted those days. On the third day, Gawain finally accepts to take a magic girdle from the lord's wife, but he didn't share it with the lord. This magic girdle helped Gawain survive the three fatal swing's of the green giant's ax, only leaving him with a little nick. After Gawain survives these 3 swings at his neck, the green knight then reveals his identity and explains that he is Bercilak, the lord of the castle. He also said that the three blows were taken at him in regards to the three days of their agreement.
Friday, August 2, 2019
Crucible- Abigail Williams Essay
Due to our nature, the human race will do astonishing things in the name of love and fear. Abigail Williams in â€Å"The Crucible†is a fantastic example of this. Not only are her actions absurd to try and gain John Proctor’s whole hearted affection, who was her lover, but also to gain submission of an ample portion of Salem due to fear. A large part of the submissiveness was gained by her ability to manipulate others, especially those she knows well. She starts the fire of hatred, for witches and the townspeople, within Salem. The fuel was already there; all that was needed was the last spark to get the flame going. Abigail was this spark, created by her insatiable lust for John Proctor. She instigated the witch trials, and used the produced hysteria in an attempt at personal gain, using a step by step plan. This plan developed through the play, feeding Abigail’s ambition and power. Step 1. Manipulate the town’s girls into doing witchcraft in the woods. Abigail convinced some of the teenage girls in Salem to join her in the woods. Being unmarried teenage women in this time period, they had little to do, minimal social status, and undoubtedly yearned for adventure. There were only two people lower than them in status, and that would be Abigail and Tituba because Abigail was an orphan, and Tituba a black slave. She convinced Tituba, to sing songs from Barbados about witchcraft. Abby then persuaded Ruth Putnam to believe that Tituba would be able to conjure up the spirits of her dead siblings. If it worked then she could bring to light the mystery behind all of her dead siblings. In getting others to do it with her, she will not be the only one to be punished, therefore spreading the blame across many, and if caught the blame could be transferred to the one with the least status, the slave- relieving Abby of punishment. Step 2. Drink a potion to acquire John. While in the woods Abigail drank a charm in an attempt to kill Mrs. Proctor, which in her eyes is the only person between her and John. â€Å"You drank blood, Abby! You didn’t tell him that!†(Betty, A.1, p.1244). This quote begins to give the reader an idea of what Abigail will do to gain Proctor. It would take quite a drive for someone to willingly drink blood, and in drinking it, wish death upon another person. This was a very Puritan society, and all of her actions would be looked down upon by the townspeople. First she entered the forest (the place of the Devil), then she danced (unacceptable for women of that age), then she drank a charm of blood (not accepted by society), and lastly in drinking that charm she is wishing ill upon her ‘neighbor’ which is going against one of the Commandments. The Bible was the law at the time, and going against its foundation was disgraceful. Step 3. When discovered, blame Tituba. When Abigail is being questioned by Parris, the day after being caught, about the girls’ doings in the woods, she gives away little. She reveals â€Å"We did dance, uncle, and when you leaped out of the bush so suddenly, Betty was frightened and then she fainted. And there’s the whole of it.†(Abigail, A.1, p.1238). This sentence shows an insight to Abby’s manipulative power over Parris. Fainting from fright from being caught by her father doing an illegal activity could be an explanation for Betty’s inactivity. Abigail admits to what he saw, but makes it hard for him to push the question further when she says the finalized statement ‘there’s the whole of it’. The affirmation also denies any other doings, saying the girls are innocent. Parris then grasps at another chance to question Abby, this time about possible rumors of her in the town. She skillfully maneuvers around the interrogation, and then is saved by the entrance of Mrs . Putnam. Goody Putnam reveals her and her daughter (Ruth)’s desires to figure out what caused her children to die in infancy. Step 4. Exploit Tituba’s weaknesses, while hiding behind lies. When questioned Abigail turns the accusation to Tituba saying she was alone in conjuring the spirits of Ruth’s siblings. This brings the pressure off of Abigail and onto two other people. She can then sink into the background, becoming invisible while Parris and Hale interrogate Tituba. Tituba is the unhappy slave, with witchery songs, low status, and desiring to be free and return home. Due to this, Parris and Hale break Tituba down till she admits to contracting with the devil. In a frenzy to bring pressure off herself and avoid hanging, Tituba then goes on to state names of women in the community. Sarah Good and Goody Osburn are first. Then Abigail stands up from the shadows seizing the chance of being able to accuse people and bring the attention to her in a positive way by saying â€Å"I want the light of God, I want the sweet love of Jesus! I dance for the Devil; I saw him; I wrote in his book; I go back to Jesus; I kiss His hand. I saw Sarah Good with the Devil! I saw Goody Osburn with the Devil! I saw Bridget Bishop with the Devil!†(Abigail, A.1, p.1263). These exclamations go against what she has previously sworn, yet no one seems to notice anything besides her confession and the names she says. Abby repeated the names Tituba already said, along with another, therefore strengthening the accusations while playing on the slave’s incompetence of missing one of the people, which strengthens her own position. Step 5. Use newfound status to demolish those who oppose her. Since there are so many people being accused, the town gets an aura of being unsafe and corrupt by the Devil. This causes the accused to accuse others, from old rivalries and suddenly having a chance to comeback, or from being interrogated till they give up names, multiplying the numbers, while they also believe the accusations out of fear. Fear of being accused, of being witched, or of getting hung for disbelieving the court and the Bible. In Act II sixteen people had warrants sent out for their capture. Abigail continuously accuses people who confess, adding to her credibility. She also has fainting incidents, trances, and other public displays which she credits to others using demonic powers on her, sending the message that she is an innocent orphan being harmed by the Devil because she is standing against him. This helps her gain pity, and brings more citizens to her side. An example is when Mary Warren tries to testify against Abigail, Mercy, and Susanna. The girls exclaim that Mary has sent her spirit out in a wind to make them cold. This is proven by their exclamations. Mercy: â€Å"Mary, do you send this shadow on me?†Susanna: â€Å"I freeze, I freeze!†Abigail: â€Å"It is a wind, a wind!†Danforth: â€Å"Mary Warren, do you witch her? I say to you, do you send your spirit out?†(A.3, p.1307) Danforth’s question seems to state what the other girls were implying. This goes to show what some acting can bring upon a girl and a town. By faking a wind, the girls make Mary’s testament against them invalid, therefore increasing Abigail’s power within the court, and getting rid of another challenger. Step 6. Secure Goody Proctor as a witch using credibility established within the court. After accusing Elizabeth in Act 2 because of alleged use of poppets, Abigail has to make sure there is no way out for her. When this is done and she is hung she can finally have her love, John Proctor. The townspeople generally ignore evidence and support her claims of witchery, most likely out of fear of her power. John Proctor is one of the few willing to stand against her. After many attempts, all of which failed, John resorts to drastic measures. He admits to committing adultery. â€Å"I have made a bell of my honor! I have rung the doom of my good name- you will believe me, Mr. Danforth! My wife is innocent, except she knew a whore when she saw one!†(Proctor, A.3, p.1309) In this statement, Proctor not only admits to adultery, and tries to protect his wife; he also calls Abigail a harlot. Abigail is astounded by his reveal, and undoubtedly worked up by his language towards her. This is the point where Abby seems to realize that Proctor does not love her and that she won’t ever be with him, even if Elizabeth dies. Her plan has failed, and everything she has done was for nothing. Her astonishment turns to resentment, for she then makes no attempt to same John when he is sentenced to hang. Her only thoughts now seem to be of self preservation. She was the ring leader of the witch trials, and with them coming to the end, and no chance of being with John, her power will soon be gone. She steals her uncle’s savings then flees the city. She lost a love she never truly had, and in the process left behind a broken, manipulated town. Love and fear are two of the most influential emotions, and in â€Å"The Crucible†both are experienced firsthand through Abigail. The author, Arthur Miller, uses this to his advantage making the play and characters relatable to the audience. These universal themes are relevant at all times in history which is why the play is still shown to this day. Abigail is not only a great example of those traits, but also reflects a maniacal manipulator existing in many societies. This along with other traits makes her the most important character to the play, along with the witch trials which she helped instigate for personal gain. It’s amazing what a teenage girl in a small town can do with a few words and manipulation.
Thursday, August 1, 2019
A Piece of String
Tim Gadwell Ms. Bryant April 12, 2010 Period 1-B Pg. 953 Essay In the story â€Å"A Piece of String†the story focuses on an old man named Maitre Houchecome. The story goes through a certain timeline of cause and effect which in the end results in his demise. Then on top of that he was said to have a bad experience with lying in the past. The events in the story had coincidentally occurred in sequential order rather than occurring at random times. The causes in the story produced more effects than one. IT all starts when Market Day occurs and as a result farmers and gardeners were all taking their possessions they were ready to sell to get money. Maitre Houchecome was walking towards the public square when he stopped and saw a piece of string lying on the ground. The story says Houchecome was economically like a true Norman. So as he bends over to pick up the string his back is hurting due to his reumatism and then he notices his arch nemesis Maitre Maladain, the Harness-Maker. Because Houchecome and Maladain were not on good terms with each other Houchecome felt that he needed to watch what he was doing at all times so he didn’t look stupid in front of Maladain. This choice Houchecome made showed that he was a very pride filled person and worried what people thought about him especially Maladain. Houchecome then picks up the string but then tries to conceal it so that Maladain does not se what he grabbed. He thought that Maladain would surely judge him for picking up a useless thing like that. As the day went by people were finishing up there sales and all of them went into a restaurant to eat due to the all the sales they went through. Then when they finish an announcer walks up and says that Someone lost their pocketbook (wallet) that morning along the road of Benzeville, containing 500 francs. Then the police had come and specifically asked for Maitre Houchecome and they escorted him the Mayor’s office where he learns that he was suspected of stealing the wallet. This is where cause and effect ties in, because Houchecome was acting weird and didn’t want Maladain to see what he was picking up Maladain suspected that he took the wallet and went and told the Mayor. Also because Houchecome had lied in the past it made it very hard to believe that he was innocent. Also because he was suspected he turned out his pockets and grew very angry with them. Again because of his past it made the townspeople believe that he took the wallet. This made him plead his innocence but his words were empty in the ears of the townspeople. Then the wallet gets found and still no one believes him because they think that he had a partner that had the wallet and then turned it back in to prove his innocence. The townspeople found this situation very humorous from the jump and kept teasing him and poking fun at him. This troubled Houchecome very much and he thought night and day of how to make people believe that he was innocent. He was said to have gone home ashamed indignant and was choking with anger and confusion. The situation consumed his heart and made him wear himself out for no particular reason and then he wasted away. Even in the end he was very troubled and pleaded his innocence while he was dying.
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