Stress and Strain Essay Example

Stress and Strain Essay Several mechanical properties of materials that are important in design are ascertained by applying tension, compression or shear load on the material.     Of the three, the most common mechanical stress-strain tests are performed in tension (Callister, 1997).   When performing tensile tests, the load and elongation are measured in relation to the cross-sectional area or original length of the material (before the elongation).   These geometric factors are normalized to the respective parameters of engineering stress and engineering strain. When a specimen has an original cross-sectional area Ao and original length lo is subjected to a uniaxial force F, engineering stress ÏÆ' and engineering strain ÃŽ µ (which are subsequently referred to as just stress and strain) are defined as:   and where l is the instantaneous length of the specimen (Schaffer, et. al, 1999).   For some materials, especially for most metals, subjected to low levels of tensile load, stress and strain are linearly related.   The linear relationship is referred to as Hooke’s law. As the stress is increased however, Hooke’s law ceases to be applicable as the linear relationship between stress and strain results to a curve.   At this instant plastic deformation occurs, which means that the deformation becomes permanent and nonrecoverable (Callister, 1997).   When stress is increased further, it will reach a maximum before resulting to fracture (the separation of the material into two or more pieces).   The maximum stress on the stress-strain curve is referred to as tensile strength and is the maximum stress that can be sustained by a material in tension.   When this stress is maintained, fracture will result. We will write a custom essay sample on Stress and Strain specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Stress and Strain specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Stress and Strain specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Compression tests are also done in almost the same manner as the tensile test except of course the force applied is compressive instead of tensile (Callister, 1997).   Compressive stress and strain are computed using the same formula presented above.   By convention, compressive force is taken to be negative which results to a negative stress.   In compression, since lo will be greater than l, the strain will likewise be negative.   And just like tensile strength, compressive strength is the maximum compressive stress applied to a material which when sustained results to the material being crushed.

Problem Solving Strategies

Problem Solving Strategies The type of problem solving strategy you use depends, in part, on the type of situation you are facing. For instance, finding the answer to a mathematical equation requires different skills than writing an essay on the differences between two philosophers views on religion. Problem solving is considered to be the process of finding solutions to difficult issues.  The type of  problem solving  strategy you use depends, in part, on the type of situation you are facing. For instance, finding the answer to a mathematical equation requires different skills than writing an essay on the differences between two philosophers views on religion. One has a fixed, set answer; the other is subject to interpretation. THE ART OF PROBLEM SOLVING Problem Solving Strategies Below are a few problem-solving strategies, how each works and when they are appropriate: ALGORITHMS. These types of problem-solving techniques rely on a set formula that allows you to arrive at one fixed answer. Good examples of algorithms are mathematical formula and computer programs. HEURISTIC. Heuristic problem-solving tactics are commonly referred to as rule of thumb strategies. These tactics are based on past experience and dont usually arrive at a single, fixed answer. Such problem-solving techniques are used when an exact answer isnt necessary when a range or an approximation is good enough. An example of using a heuristic problem-solving technique is estimating how long it will take you to drive home from campus. If, on previous trips, it has taken between 30 and 35 minutes, its likely that the next trip will take the same amount of time. However, unusually heavy traffic or construction could change this answer. CONSTRUCTIVE CONTROVERSY. This problem-solving technique, developed in the late 1970s, involves presenting your proposed solution to a group of other people, defending your idea, listening to their input and modifying your idea based on their feedback. This approach works well for team projects. INSIGHT. This technique is less structured, but often very effective. This is the let me sleep on it way of solving problems, such as when you awake with an answer to a problem or the answer comes to you in the shower or on the way to class. This technique relies on the subconscious using our past experiences to formulate an answer to a similar problem to those weve dealt with in the past. Since you have no way of knowing if youll arrive at an answer this way, this is obviously a poor technique to use for projects with a deadline. BRAINSTORMING. Brainstorming unleashes the talents of multiple team members on a single project. This technique involves throwing out tentative ideas, discussing each ideas merits and challenges and using the best of these possible solutions to solve the problem. DIVIDE AND CONQUER. Some projects, such as reading an entire text or writing a 5,000-word paper, can seem overwhelming. Dividing those huge projects into smaller, more manageable segments, such as reading a chapter a night or writing 500 words a week, often makes them easy to handle. RESEARCH. This problem-solving tactic makes use of other peoples past experience with similar problems to solve a current problem. As the name implies, this technique involves studying past performances and applying this acquired knowledge to the task at hand. Problem-solving strategies are a necessary part of college, the work environment, and everyday life. The better you become at the different types of strategies and at determining which type to use in which situation, the easier you will find not only your college studies but navigating the world at large. PROBLEM SOLVING SKILLS In case you are working on a problem solving assignment, and are having difficulties with it, would be happy to assist. Feel free to contact our writers and they will help you to work through the assignment. Our staff will assign writers with suitable backgrounds and adequate experience. This will result in a paper that is properly written and formatted, with thorough background research and a solid literature base. Feel free to contact us anytime  or place an order and we will gladly help you.

Capital Structure Pre and Post Global Financial Crisis Dissertation

Capital Structure Pre and Post Global Financial Crisis - Dissertation Example When debt financing is concerned, it includes borrowing from the banks, financial leasing, and bond issuing in the bond market. Equity financing mainly constitutes the retained earnings and issuing of additional shares in the stock market. Capital structure has its own importance in a company. There are primary two reasons supporting this fact. Firstly, debt and equity having differences in the costs, in the interest rates, and the required rates of return, there arises a need have an appropriate combination of debt and equity that can maximize the value of the firm by reducing the total cost of the company. This is achievable through the capital structure of the company (Broyles, 2003, pp.303-304). Secondly the knowledge and understanding of capital structure proves important since the borrowing of capital has an influence on the financial risk of the firm. The volatility of the net income or earnings per share of a company increases with the interest payments that represent additio nal fixed expenses for the company. This in turn increases the payment of interests on the issuing of bonds. The cost of equity capital also increases in the stock market as a result of borrowing. All these factors might eventually lead a company to financial distress or risk that leads to the increasing need for an appropriate capital structure (Broyles, 2003, p.304). ... primary aim of the study is to evaluate the capital structure of firms in the UK before the global economic crisis in the years around 2007 and after the financial crisis in the years 2011 or 2012. In order to achieve the above mentioned aim of the study, the following objectives have been considered: Review theories on capital structure in order to determine how it might change during a period of prolonged recession and liquidity crisis. Compare and contrast the capital structure of public UK companies in 2007 and in 2011/2012. Evaluate the extent to which any changes in capital structure are due to the ongoing global crisis. Capital Structure: An Understanding towards the Effect of Economic Crisis: There are four basic theories related to capital structure of a firm. These are: Net Income Theory of Capital Structure: This theory stresses on a firm’s ability to choose a capital structure where the level of share capital or equity is less than the debt of the firm. This helps a firm to increase its market value and thus decrease the weighted average cost of capital of the company. If the content of the debt in the capital structure mix is high, it is referred as financial leverage increasing which increases the value of the firm (Theories of Capital Structure, 2010). Thus it can be understood that when there is an economic crisis prevailing in a country, the availability of the debt reduces that affects the ration of the debt to equity and hence the capital structure of a firm would alter as a result. Net Operating income  Theory of Capital Structure: According to this theory, the concept of increasing financial leverage does not exist. It believes that changing the capital structure of a firm does not bring any change in the overall financial cost and value of the

Direct Manipulation Research Paper Example | Topics and Well Written Essays - 750 words

Direct Manipulation - Research Paper Example This gives an all the more intriguing feel to the human-computer interaction. The usage of this interface is more common in the video game development field. Most Direct Manipulation interfaces are of graphical concepts and could be now and again is alluded to as Graphical User Interface (GUI). This is on account of its use of on-screen graphical representation of actions (Heeter, 1991). Direct Manipulation interface is commenced upon a significant arrangement of standards. Quintessentially, these are the ideological demonstrations of existence of a Direct Manipulation interface. These rules or principles are as follows. The concept of realism: Firstly, the instruments in the computer are visually inseparable and indistinguishable from the real life objects they are being used to depict. For example, this is applied by having a knife in video games represente a real knife in all aspects. a helicopter in video is similar to a real world helicopter in all aspects. Moreover, actions performed on the objects in game are similar to those that would be or could be performed on similar objects in actual life. To further explain, illustrations form video games shall be drawn to exemplify this; a mobile phone in the game serves the same purpose that which it serves in real world which is to enable communication, an armored carrying vehicle serves the same purpose as its purpose in real world which is it sole purpose being of military use. Furthermore, the association between the in-game objects and actions performed on them and the objects in real world and actions performed on them is maintained even on con ceptual level. This, for example is illustrated by the fact that in video games, a motorbike will be driven as it is driven normally in the real world. There are examples of programmers going to painstaking measures in order to depict the real world phenomena such as aurora, water reflection and fire

Boeing Capital Company Analysis

Boeing Capital Company Analysis Introduction The importance that is associated with air travel cannot be undermined in any manner since provides a fast means of traveling and ensuring that business is conducted in an efficient manner by availing people where they are needed to be within a very short time. Additionally, it creates diversity by taking people to different places where they can interact with individuals from various cultures which eventually helps to enhance the spread of diverse cultural practices to the entire world. Through air travel, many economies of the world have been transformed in a manner that cannot even be comprehended, and this has helped a lot in building some of the largest economies in the world. People are provided with a chance to experience new things in life. For instance, this has helped to diversify the manner in which education is being carried out since students can now travel all over the world in search of knowledge. The Aerospace space industry continues to grow each and every other day, and this is made possible by more than 8 million individuals undertake air travel daily. On top of that, defense and security have been further enhanced by air travel since it is possible to avail safety where it is required in a matter of minutes. Description of the Company or Agency (Basically what business are you in) Boeing is one of the largest aerospace companies in the world. It does not only specialize in the manufacture of commercial jetliners, but it is also involved in the production of various other products such as space security systems and defense systems such as the fighter jets. Boeing is the largest exporter company that is located in the United States. Apart from supporting most of the airlines in the country by providing commercial airplanes, it also provides its products to other customers who are mostly government organizations in over on hundred and fifty countries. Some of the products that are designed by Boeing are customized while others are only mass produced and sold to customers why dont need to specifications to be associated with the products that they intend to buy. Most of the tailored products include satellites machines, weapons, defense systems that are electronic in nature, military aircraft, commercial aircraft, launch systems, advanced communication systems, pe rformance-based handling and training systems and even simulator machines. The company has been involved in the production of aerospace equipment for many years, and it is considered to be a leading company in this field due to the experience and the reputation that is associated with the organization. With time, it continually strives to tap into sections of the market that other aerospace companies have failed to explore. It is through the provision of a variety of services and products that can help to meet the needs of the clients in the most accurate manner. Some of the capabilities associated with Boeing Company include the ability to develop more advanced and better types of commercial airplanes because it is continually undertaking research into the market so as to understand the level of customers satisfaction based on the products that it has already availed to the market. Additionally, it can integrate the available defense systems and the military platforms, develop technology solutions that are more advanced than the ones that were already avai led in the market thanks to the team of researchers in the company that is continually looking for ways of improving the available systems. Finally, it is capable of coming up with financing options for the potential customers so as to enable more clients to gain access to its products since they normally are very expensive. Operation Description The company has an extensive knowledge about its clients, and this is enabled by an in-depth research of the market. Therefore, the company is able to understand the type of equipments that are needed by its customers. Boeings Capital Corporation (BCC) also has a collection of financial professionals why have been practicing the skill for an extended period hence they understand precisely how the market operates. BCC is one of the best financial corporations that provides support to clients who have subscribed to its services. The business is closely associated with the production of commercial planes, and Security Space Defense. The Corporation helps its customers to raise the required finance that will enable them to purchase and transfer Boeings products to their promises successfully. By the end of 2015, the company had earned a value of about four billion dollars. BCC has managed to achieve its success basically by incorporating its power of finance and its extensive network, therefore, enabling it to reach customers who are not only located in the United States but all over the World. Equipment or Aircraft For very many years, Boeing has been one of the major companies involved in the manufacture of commercial airplanes that are used in most countries. Its line of products is usually preferred by many clients simply because they are of high quality. Currently, the company can manufacture many commercial airplane versions which include Boeing 747, 743, 777,767 and finally the 787. These are in the range of the biggest commercial airplanes produced by Boeing. Other products that are still in the production line include the Boeing 777X, 737 Max, and the 787-10 Dreamliner. With each version of him Boeing, various characteristics are continually changed, and one of the most important aspects is the size which is steadily increasing for each version. Since the company started production of the Boeing line of products, it has managed to avail into the market about ten thousand commercial jets in the whole world which make about half of the fleet of the total airplanes that have ever been prod uced by any company. Additionally, the company provides cargo-carrying airplanes, which make up ninety percent of the total cargo planes in the world. The company offers its client with Commercial Aviation Services. By doing this, the company can provide unmatched all year support services to its customers which enable most of the airline companies and also the leasing companies that have subscribed to the company services to achieve operational efficiency. The Commercial Aviation Services department helps to provide aftermarket parts, modification, informations logistics services, engineering, and customer care support services. Other services provided include overhauled services, repair, and maintenance labor (Wen, 2003). Maintenance Requirements The Shared Services Corporation provides Boeing business units associated with a common pool of services so as to help in supporting the worldwide operations of the company. The shared services are of a wide variety, and they range from the maintenance and protection of Boeings international sites, Sales management, and acquisition of any property that may have been leased. The corporation is also involved in the purchasing of products that are not necessarily used in the production process and other office equipment supplies. Various human resource services which also include the recruitment of new employees are some of the services that are offered by this corporation to Boeing. Finally, Shared Services Corporation Actively participates in the management of Boeings financial matters, any expenses that may be incurred by the company as a result of travels to and from various destinations, and in availing communication services that have been customized (Holsapple, 2000). The Site Se rvices Corporation also offers Boeing with the maintenance and repairs services, reals estate management, planning of the manner in which property will be acquired, and finally the process of implementing projects that involve the construction of structures (Saraph et al 1989). Managers Roles and Responsibilities All the activities that are typically undertaken in Boeings offices are finalized by the company employees, corporation officers, and managers with the help and guidance of the Board of Directors together with Chief Executive Officers. The organizations corporate governance policies and practices are typically reviewed continuously by the organization committee. The Board of directors and the corporations officers have a long-term interest in the company. Therefore, it is important to ensure that the corporation clients, public officials, employees, suppliers, surrounding communities, and shareholders gain positively out of the operations of the organization. On top of that, the Board has managed to develop its own Code of Ethics that helps in the conducting the daily activities of the corporation so that they are in line with the various legal stipulations (Zahra, 1989). Having these regulations helps the company to continually stay on the right track as they deal with the different ethical issues that arise within the business premises as a result of the operations being carried out by various employees. Through the use of the code of ethics, the company is also able to enhance the mechanisms that already exist within the organizations and can help in reporting cases of unethical behavior occurring as this plays a crucial role in ensuring that a culture of accountability and honesty is enforced within the company premises (Pronovost et al, 2009). Staff Qualifications, Certifications, and Responsibilities Within the Shared Services Corporation, Boeing constitutes has a percentage of shares since it has employed approximately forty thousand employees who are responsible for availing about forty types of unique services all day long throughout the year. The Sites services have a bee assigned a budget of about three billion dollars which is specifically meant for the operations services. By doing this, the company can leverage scale economies so as to enable the delivery of value-added services to clients and its business partners who are involved in the manufacture and provision of defense and security and additionally the commercial airplanes that need to be availed to the company (Waldron, 2006). The company has it corporate offices located in Chicago, and it has managed to employ over one hundred and fifty employees within the United States and sixty-five more countries. The companys continued existence is a reflection of its diversity and ease in adapting to the changing market conditions such that it can last for a very long time. Additionally, one important factor that supports the continuous positive progress of the company is the fact that it has a very innovative and hardworking workforce. Our business continues to outsource more of the talented youth in the world so that they can join its workforce and continue to make it rise higher. The company does not necessarily look for academic qualification so that it can employ an individual, but rather, it explores the various ways that it can use the talent of individuals to encourage innovation in the society. Regulations and Laws The various operations of the company are guided by different by-laws that regulate the manner in which meetings will be carried out by the board of directors and various stakeholders to ensure inclusive of all parties that are interested in the operations and management of the company (Berkes, 2000). According to the laws of the company, the Annual General Meeting is supposed to be held on a particular date and time that is precisely determined by the board of directors. During such meetings, the leaders will be elected, and any other significant business transactions that need to be addressed also have to be discussed during such meetings. The board of directors has the power to call a meeting with all the stakeholders at any time that it wishes to do so. Also, in case the Secretary makes a special request for a meeting, then the board of directors is supposed to summon all the stakeholders for the meeting. The secretary can only write a special request for a meeting when there is a need to undertake an election so as to dispose of about 25% of shares held by the company. For such a request, each of the stakeholders provides a signature stating the number of shares that they own. Any business that is transacted in the course of a particular meeting is only supposed to be limited to the purpose for which the meeting was called upon, and it should not deviate to any other general matters. Any meetings that are held together with the stakeholders shall be conducted within specified premises as directed by the board of directors or as it is indicated in notices. However, there is a default location in which the meetings should be held. Notice of any meeting that should be held will be availed to stakeholders through any suitable methods but most specifically mail or an electronic transmission option. All Stakeholders have the right to vote at any meeting called forth. They also have the right to express any form of dissatisfaction towards any actions that may have been taken by the board of directors without the need of having to wait until a meeting is held (Delmas Toffel, 2004). Safety Security The shared services organization provides Boeing with various specialized services. For instance, it is responsible for offering the company with international insurance services that cover the company in case of the occurrence of a risk factor. The Shared Services is responsible for ensuring that the Security maintenance at all Boeing premises is at the highest level possible. Any premise associated with Boeing should be fully protected and most importantly the information that helps to support the continuous operation of the business. Any other risk mitigation measures should be fully installed to prevent an occurrence of damage to the company property (Tipton, 2012). The Defense, Security and Space Corporation is very diverse since it avails most advanced solutions to the market which can be used in the designing, production process, customization and offering support to clients who purchase rotorcrafts, satellite systems, weapons and fixed wings military aircraft. The organization is involved in providing clients with solutions to some of the major customer requirements by availing a full range portfolio which incorporates the 702 model of satellites. Some other defense products include the AH-64 helicopter, EA-18G aircraft that is electronics and is mostly used to attack enemies, KC-46 refueling planes, P-8 anti-aircraft/ submarine atropine (derived from the 737 commercial airliners). This organization is motivated by its capability to offer clients custom-made solutions that can address customers needs adequately and promptly and at the most suitable cost. Apart from producing products that are designed to be used by clients, this unit is responsible for the general management of security within all branches associated with Boeing. This is an operation cost reduction method since the company managers decided that it would be wise to use the services its own business units in the provision of security rather than make use of a different business organization that would only end up increasing the operation costs (Kaplan Norton, 1996). Environmental Responsibilities Working with stakeholders is important since it helps to ensure that activities that enhance environmental conservation are promoted. Due to its growth, Boeing targets to be a leader in promoting a sustainable environment as it also strives to provide its employees with the best services that can be availed in the industry. The three top tenets that Boeing aims to address are; encouraging worldwide collaboration in environmental conservation, design the future in a sustainable manner and finally coming up with sustainable innovations (Selin, 1995). The company intends to avail the best and most fuel-efficient planes in the industry. Also, it plans to provide highest quality services to its customers. All this will be achieved through; ensuring that it complies with various environmental regulations as it conducts its daily operations. Boeing has also come up with its policies and procedures that can help to ensure that environmental conservation is enhanced. Preventing environmental pollution through conservation of energy resources as this will contribute to the reduction of the levels of waste that gets disposed of by researching on the various mitigation measures. The company has managed to develop a management system that will help in improving the state of the environment both for the current and future generation through the reduction of waste that is normally released into the environment (Born, 1995). Other Management Factors Considered The Company is organized into three major business units. They are; Defense, outer space security department, and the Commercial production and supply unit. The whole company is majorly supported by a corporation known as Boeing Capital which is the primary provider of financial solutions to all the company branches worldwide (Probst, 2004). This financial firm also helps to finance other businesses that may have subscribed to its services. Other Corporations involved in supporting the major units at the company include Shared Services Organization (it avails some services to all the company branches), Boeing Engineering, Operations and Technology (this organization helps to create, purchase, implement and provide protection to the various innovations that are developed at Boeings premises) (Council, 2007). The business and finance organization is responsible for offering shared services in accounting, cost management, and financial management. The agency is responsible for providin g account payroll/payable functions to all business units associated with Boeing (Jensen, 1997). References Berkes, F., Folke, C., Colding, J. (2000). Linking social and ecological systems: management practices and social mechanisms for building resilience. Cambridge University Press. Born, S. M., Sonzogni, W. C. (1995). Integrated environmental management: strengthening the conceptualization. Environmental management, 19(2), 167-181. Council, A. C. G. (2007). Corporate governance principles and recommendations. Boeing: Shared Services. Boeing.Com, 2017, http://www.boeing.com/company/key-orgs/ssg.page. Delmas, M., Toffel, M. W. (2004). Stakeholders and environmental management practices: an institutional framework. Business strategy and the Environment, 13(4), 209-222. Holsapple, C. W., Joshi, K. D. (2000). An investigation of factors that influence the management of knowledge in organizations. The Journal of Strategic Information Systems, 9(2), 235-261. Jensen, R. S. (1997). The boundaries of aviation psychology, human factors, aeronautical decision making, situation awareness, and crew resource management. The international journal of aviation psychology, 7(4), 259-267. Kaplan, R. S., Norton, D. P. (1996). Using the balanced scorecard as a strategic management system. Probst, T. M. (2004). Safety and insecurity: exploring the moderating effect of organizational safety climate. Journal of occupational health psychology, 9(1), 3. Pronovost, P. J., Goeschel, C. A., Olsen, K. L., Pham, J. C., Miller, M. R., Berenholtz, S. M., Loeb, J. M. (2009). Reducing health care hazards: lessons from the commercial aviation safety team. Health Affairs, 28(3), w479-w489. Saraph, J. V., Benson, P. G., Schroeder, R. G. (1989). An instrument for measuring the critical factors of quality management. Decision sciences, 20(4), 810-829. Selin, S., Chevez, D. (1995). Developing a collaborative model for environmental planning and management. Environmental management, 19(2), 189-195. Tipton, H. F., Nozaki, M. K. (2012). Information Security Management Handbook, Volume 6. Auerbach Publications. Waldron, J. (2006). Safety and security. Neb. L. Rev., 85, 454. Wen, T. A. N. G., Zhong, C. H. E. N. (2003). Research of subjective trust management model based on the fuzzy set theory. Journal of software, 14(8), 1401-1408. Zahra, S. A., Pearce, J. A. (1989). Boards of directors and corporate financial performance: A review and integrative model. Journal of management, 15(2), 291-334.

Letter to My Old School Friend Essay

It been has been a long time since we last saw each other, so I took this time to write to you. Remember the time in elementary school when we had the field trip before summer vacation. It was a time when we visited the shopping plaza for the very first time in Manhattan. This was one of the memorable days of my life. It all started in science class when we decide to plan a nice surprise for our teacher for her upcoming birthday, so our enthusiastic principle appeared and said† good morning class, I have a great treat for you† and nasha exclaimed with so much curiosity â€Å"were are o the we going† and he said â€Å"to the new shopping plaza† so he gave out letter with a consent form attached with it, so after I went home and get ready for the trip tomorrow , when getting ready my consent form disappeared so I search saying in my mind I am not missing that so, I was so worried and called my friend nasha and she said â€Å" don’t worry this matter is imperceptible† and replied to her in a melancholy voice† why you saying that? If I don’t have the form I cannot go on the trip, is there a next alternative† she said† yes† so I said to her what† she said â€Å"have your parents to write a letter for me† so I told her that is a good idea. So next day I pack my things kissed my mom and rushed on the school bus ,when I got to my the classmate were all lined up to enter the bus. When we got on the bus I sit near the window. When we got there I saw the most building beautiful and creative place.

SPSS analysis on modern portfolio theory-optimal portfolio strategies in today’s capital market

Abstract This paper provides information on specific ideas embedded in single index model/construction of optimal portfolios compared to the classic Markowitz model. Important arguments are presented regarding the validity of these two models. The researcher utilises SPSS analysis to demonstrate important research findings. This type of analysis is conducted to explore the presence of any significant statistical difference between the variance of the single index model and the Markowitz model. The paper also includes implications for investors. Introduction In the contemporary environment involving business investments, selecting appropriate investments is a relevant task of most organisations. Rational investors try to minimise risks as well as maximise returns on their investments (Better, 2006). The ultimate goal is to reach a level identified as optimal portfolios. The focus in this process is on initiating the portfolio selection models, which are essential for optimising the work of investors. Research shows that the Markowitz model is the most suitable model for conducting stock selection, as this is facilitated through the use of a full covariance matrix (Bergh and Rensburg, 2008). The importance of this study reflects in the application of different models so as to develop adequate portfolios in organisations. It is essential to compare certain models because investors may be provided with sufficient knowledge about how they can best construct their portfolios. In this context, the precise variance of the portfolio selection model is important, as it reflects portfolio risk (Bergh and Rensburg, 2008). Information on the parameters of different models is significant to make the most appropriate decisions regarding portfolio creation. Markowitz is a pioneer in the research on portfolio analysis, as his works have contributed to enhancing investors’ perspectives on the available options regarding specific models of constructing optimal portfolios (Fernandez and Gomez, 2007). Research Methodology The research question presented in this study referred to the exploration of ideas embedded in single index model/construction of optimal portfolios and comparing them with the classic Markowitz model. The focus was on the construction of optimal portfolios, as the researcher was concerned with the evaluation of constructed portfolios with specific market parameters (Better, 2006). Moreover, the researcher paid attention to the stock market price index, including stocks of organisations distributed in three major sectors: services, financial, and industrial (Fernandez and Gomez, 2007). The behaviour of this index was explored through the implementation of SPSS analysis. The data covered a period of seven years, starting on January 1, 2000 and ending on December 31, 2006. It was essential to evaluate the effectiveness parameters of the single index model/construction of optimal portfolios and the Markowitz model. The criteria for the selection of companies included that all organisati ons shared the same fiscal year (ending each year on December 31) as well as they have not demonstrated any change in position. Results and Data Analysis The research methodology utilised in the study is based on the model of single index/optimal portfolios and the Markowitz model. The exploration of the relationship between these two models required the selection of 35 equally weighted optimal portfolios, as two sizes of portfolio were outlined. An approximate number of 10 optimal portfolios represented the first size, which further generated 12 portfolios. In addition, the researcher considered the option of simulating of optimal portfolios represented at second sizes (Bergh and Rensburg, 2008). The criterion of queuing randomise portfolio selection has been used to generate approximate 23 portfolios from the second size category. The researcher selected five and 10 stocks to analyse the data. The portfolio size split allowed the researcher to explore how the portfolio size could be used to affect the relationship between the single index model/optimal portfolios and the Markowitz model (Fernandez and Gomez, 2007). Results of testin g the data are provided in the table below: Optimal portfolio numberVariance of Single Index ModelVariance of the Markowitz ModelOptimal portfolio numberVariance of the Single Index ModelVariance of the Markowitz Model 100.00370.003950.00210.0023 100.00140.001750.00280.0038 100.00210.002850.00420.0051 100.00200.002150.00250.0030 100.00310.003550.00260.0024 100.00190.001950.00330.0038 100.00880.008650.00670.0071 100.00280.003750.00370.0053 100.00250.002450.00380.0043 100.00220.002350.00210.0020 100.00190.002050.00630.0061 100.00230.002650.02120.0202 Table 1: Variance of Five and 10 Optimal Portfolios Based on the results provided in the table, it can be concluded that the variance between the single index model/construction of optimal portfolios and the Markowitz model is similar. For instance, values of 0.0020 and 0.0019 for the variance of the two models are similar. This means that the results do not show substantial statistical differences between the two models. The tables below contain a descriptive summary of the results presented in the previous table: MeasureSingle Index ModelMarkowitz Model Mean0.00440.0047 Minimal0.00210.0020 Maximum0.02120.0202 Standard Deviation0.00370.0035 Table 2: Descriptive Summary of 10 Optimal Portfolios The results in Table 2 were derived from testing the performance of 10 optimal portfolios. It has been indicated that the mean for the single index model of 10 portfolios is 0.0044, while the mean for the Markowitz model is 0.0047, implying an insignificant statistical difference. The minimal value of the single index model is reported at 0.0021, while the minimal value of the Markowitz model is 0.0020. The difference is insignificant. The maximum value of the single index model is 0.0212, while the same value of the Markowitz model is 0.0202. Based on these values, it can be argued that there is a slight difference existing between the two models. The standard deviation of the single index model is 0.0037, while the standard deviation of the Markowitz model is 0.0035, which also reflects an insignificant statistical difference. MeasureSingle Index ModelMarkowitz Model Mean0.00280.0031 Minimal0.00140.0017 Maximum0.00880.0086 Standard Deviation0.00200.0019 Table 3: Descriptive Summary of 5 Optimal Portfolios Table 3 provides the results for five optimal portfolios. These results are similar to the ones reported previously (10 optimal portfolios). The mean for the single index model of 5 optimal portfolios is 0.0028, while the mean for the Markowitz model is 0.0031, implying an insignificant statistical difference. There are insignificant differences between the two models regarding other values, such as minimal and maximum value as well as standard deviation. Furthermore, the researcher performed an ANOVA analysis of 10 optimal portfolios, which are presented in the table below. It has been indicated that the effective score for the single index model and the Markowitz model is almost the same. Yet, an insignificant difference was reported between the two means and standard deviations for both models. ANOVA AnalysisSum of squaresDfConditionMeanStandard DeviationStandard Error MeanFSig. Between Groups.00011.000.003125.0018704.0005399.089.768 Within Groups.000222.000.002892.0019589.0005655 Total.00023 Table 4: ANOVA Analysis for the Variance between the Single Index Model and the Markowitz Model of 10 Portfolios From the conducted analysis, it can be also concluded that the F-test presents an insignificant statistical value, implying that the researcher rejected the hypothesis of a significant difference existing between portfolio selections with regards to risk in both models used in the study (Fernandez and Gomez, 2007). Hence, the hypothesis of a significant difference between the variance of the single index model and the Markowitz model was rejected (Lediot and Wolf, 2003). In the table below, the researcher provided the results of an ANOVA analysis conducted on five optimal portfolios: ANOVA AnalysisSum of SquaresDfConditionMeanStandard DeviationStandard Error MeanFSig. Between Groups.00011.000.004852.0036535.0007618.096.758 Within Groups.001442.000.004509.0038595.0008048 Total.00145 Table 5: ANOVA Analysis for the Variance between the Single Index Model and the Markowitz Model of 5 Portfolios The results from Table 5 show that the variance between the single index model and the Markowitz model of five optimal portfolios is almost the same. Regardless of the stock number in the selected optimal portfolios, there is no significant statistical difference between the single index model and the Markowitz model. The main finding based on the reported data is that the single index model/construction of optimal portfolios is similar to the Markowitz model with regards to the formation of specific portfolios (Bergh and Rensburg, 2008). As indicated in this study, the precise number of stocks in the constructed optimal portfolios does not impact the final result of comparing the two analysed models. The fact that these models are not significantly different from each other can prompt investors to use the most practical approach in constructing optimal portfolios (Haugen, 2001). Placing an emphasis on efficient frontiers is an important part of investors’ work, as they are focused on generating the most efficient portfolios at the lowest risk. As a result, optimally selected portfolios would be able to generate positive returns for organisations. This applies to both the single index model and the Markowitz model (Fernandez and Gomez, 2007). Conclusion and Implications of Research Findings The results obtained in the present study are important for various parties. Such results may be of concern to policy makers, investors as well as financial market participants. In addition, the findings generated in the study are similar to findings reported by other researchers in the field (Bergh and Rensburg, 2008). It cannot be claimed that either of the approaches has certain advantages over the other one. Even if the number of stocks is altered, this does not reflect in any changes of the results provided by the researcher in this study. Yet, the major limitation of the study is associated with the use of monthly data. It can be argued that the use of daily data would be a more viable option to ensure accuracy, objectivity as well as adherence to strict professional standards in terms of investment (Better, 2006). In conclusion, the similarity of the single index model and the Markowitz model encourage researchers to use both models equally because of their potential to generate optimal portfolios. Moreover, the lack of significant statistical differences between the variance of the single index model and the Markowitz model can serve as an adequate basis for investors to demonstrate greater flexibility in the process of making portfolio selection decisions (Haugen, 2001). The results obtained in the study were used to reject the hypotheses that were initially presented. As previously mentioned, the conducted F-test additionally indicates that the single index model and the Markowitz model are almost similar in scope and impact (Fernandez and Gomez, 2007). Investors should consider that portfolio selection models play an important role in determining the exact amount of risk taking while constructing optimal portfolios. Hence, investors are expected to thoroughly explore those models while they select their portfolios (Garlappi et al., 2007). Both individual and institutional investors can find the results generated in this study useful to facilitate their professional practice. A possible application of the research findings should be considered in the process of embracing new investment policies in the flexible organisational context (Bergh and Rensburg, 2008). Future research may extensively focus on the development of new portfolio selection models that may further expand the capacity of organisations to improve their performance on investment risk taking indicators. References Bergh, G. and Rensburg, V. (2008). ‘Hedge Funds and Higher Moment Portfolio Performance Appraisals: A General Approach’. Omega, vol. 37, pp. 50-62. Better, M. (2006). ‘Selecting Project Portfolios by Optimizing Simulations’. The Engineering Economist, vol. 51, pp. 81-97. Fernandez, A. and Gomez, S. (2007). ‘Portfolio Selection Using Neutral Networks’. Computers & Operations Research, vol. 34, pp. 1177-1191. Garlappi, L., Uppal, R., and Wang, T. (2007). ‘Portfolio Selection with Parameter and Model Uncertainty: A Multi-Prior Approach’. The Review of Financial Studies, vol. 20, pp. 41-81. Haugen, R. (2001). Modern Investment Theory. New Jersey: Prentice Hall. Lediot, O. and Wolf, M. (2003). ‘Improved Estimation of the Covariance Matrix of Stock Returns with an Application to Portfolio Selection’. Journal of Finance, vol. 10, pp. 603-621.