Concentrator solar cells operate under the conditions of non-uniform illumination and varying spectral content of incident sunlight. To predict the performance of such cells, an analytical model must account for varying carrier photogeneration rates within the cell. Further, the back surface junction fabricated to reduce recombination at the back contact must be included in the analysis.Most models of n+-p-p+ cells assume uniform generation rates within individual layers. In this study, a one-dimensional n+-p-p+ concentrator solar cell is modeled for all levels of illumination of incident sunlight. The photocarrier generation rate is considered as non-uniform in each layer of the cell. An absorption model is incorporated to permit the application for various spectral mixes of incident sunlight. The model also includes the effects of finite surface recombination velocities at the surfaces. Carrier transport equations for the three layers of the cell are developed and solved for the excess carrier concentrations under the assumptions of the model. Junction current density-voltage relationships for the two junctions of the cell are derived. The use of the current density equations in the evaluation of cell performance is discussed. / Department of Physics and Astronomy

Genom att läsa tidigare forskning om Generation Y, innehållsmarknadsföring och om sociala medier under uppsatsprocessen förändrades problemställningen succesivt, i enlighet med en abduktiv forskningsansats. Studiens fokus utvecklades från att undersöka alternativa marknadsföringsmetoder vid marknadsföring mot Generation Y till att omfatta på vilken social medieplattform Generation Y är mest mottaglig för innehållsbaserad marknadsföring. Syftet med denna studie är att hjälpa företag vars målgrupp är Generation Y att rikta sin innehållsmarknadsföring i rätt kanaler och på detta sätt spara tid och pengar. För att uppfylla syftet och besvara studiens problem samlades empirisk data in genom en webbaserad, kvantitativ enkätundersökning som genomfördes av totalt 301 respondenter, alla tillhörande Generation Y. Insamlade kvantitativ data ställdes sedan emot befintlig teori och analyserades. Studiens slutsats blev att Facebook är den sociala mediekanal där Generation Y känner sig mest mottagliga för innehållsmarknadsföring, följt av YouTube. / By reading earlier research on Generation Y, content marketing and on social media during the working process the problem has gradually changed, in accordance with an abductive research approach. The study focus has developed from examine marketing methods on marketing towards Generation Y to include on what social media platform Generation Y is most susceptible for content marketing. The purpose of this study is to help companies whose target market is Generation Y to aim their content marketing through the right distribution channels, to save time and money. To meet this objective and to answer the main question of this study, empirical data was collected through a web based, quantitative survey which was completed by a total of 301 respondents, all of them belonging to Generation Y. The collected quantitative data was contrasted with existing theory and was analysed. The study concluded that Facebook is the social media channel where Generation Y feel most susceptible for content marketing, followed by YouTube.

One of the consequences of competitive electricity markets and international commitments to green energy is the fast development and increase in the amount of distributed generation (DG) in distribution grids. These DGs are resulting in a change in the nature of distribution systems from being "passive", containing only loads, to "active", including loads and DGs. This will affect the dynamic behavior of both transmission and distribution systems. There are many technical aspects and challenges of DGs that have to be properly understood and addressed. One of them is the need for adequate static and dynamic models for DG units, particularly under unbalanced conditions, to perform proper studies of distribution systems with DGs (e.g., microgrids). The primary objective of this thesis is the development and implementation of dynamic and static models of various DG technologies for stability analysis. These models allow studying systems with DGs both in the long- and short-term; thus, differential and algebraic equations of various DGs are formulated and discussed in order to integrate these models into existing power system analysis software tools. The presented and discussed models are generally based on dynamic models of different DGs for stability studies considering the dynamics of the primary governor, generators, and their interfaces and controls. A new comprehensive investigation is also presented of the effects of system unbalance on the stability of distribution grids with DG units based on synchronous generator (SG) and doubly-fed induction generator (DFIG) at different loading levels. Detailed steady-state and dynamic analyses of the system are performed. Based on voltage and angle stability studies, it is demonstrated that load unbalance can significantly affect the distribution system dynamic performance. Novel, simple, and effective control strategies based on an Unbalanced Voltage Stabilizer (UVS) are also proposed to improve the system control and the stability of unbalanced distribution systems with SG- and DFIG-based DGs.

Andledningen till att vi valt att undersöka Generation Z är för att vi som blivande studie- och yrkesvägledare kommer arbeta med dessa ungdomar. Generation Z är fortfarande unga men det hindrar dem inte från att vara uppkopplade på olika sociala medier. Aldrig tidigare har en generation haft så enkelt att hitta vad de söker efter. Den här generationen ligger i vårt intresse eftersom vi som framtida studie- och yrkesvägledare ska mer försöka knyta ihop säcken med all information som ges. / The reason that we have chosen to examine Generation Z is that we as a future career counselors will work with these young people. Generation Z is still young but it does not prevent them from being online on various social media. Never before has a generation have so easy to find what they are looking for. This generation is in our interest because as future career counselor will we try to tie together all the information provided.

Business management is characterised by fast and ever–expanding development. Culture and generation play an increasingly important role in the management of businesses worldwide. Although studies have been conducted on the subjects of culture and generation, little attention has been paid to culture and generation as a combination of diversity characteristics. As more managers are realising the challenges that arise when managing diverse work environments, the modern manager must question old assumptions about how diverse people work together. In this modern age, it is important to understand diversity issues on all levels of management. Networks are based on people's backgrounds, and understanding the link between networking and diversity is becoming increasingly important. In a culturally complex country such as South Africa, experiencing the impact of diversity on a daily basis can be anticipated. Culture and generation are two terms that encompass all dimensions of diversity. This study investigates the different networking practices found among diverse cultural and generational groups at a Gauteng mine. The generational classification used in this study is based on the fact that generations differ from country to country; therefore, the classification used in this study is relevant to South African generations. Seven hypotheses were formulated pertaining to differences among cultural and generational groups with regard to networking practices. Furthermore, four cultural–generational groups were identified, namely Black Generation X'ers, Black Baby Boomers, White Generation X'ers and White Baby Boomers. Data was collected from Kusasalethu mine employees. The original sample frame comprised 3630 employees from which a sample was chosen that complied with the criteria for culture, age / generation and education. A total of 1046 employees remained from which the sample elements were chosen by making use of probability, systematic proportionate stratified sampling. Self–completion questionnaires were used for collecting the data. A total of 289 questionnaires were completed which constituted a 100% response rate. The questionnaire used was intended to obtain feedback from respondents regarding their cultural and generational diversity, as well as preferences pertaining to their networking practices. The results from the survey were used to determine the differences between diverse cultures and generations with regards to networking practices. The findings, supported by the rejection of the first null–hypothesis, indicated that there are indeed a number of salient differences between Black Generation X'ers, Black Baby Boomers, White Generation X'ers and White Baby Boomers. Specifically, the results indicated that White Baby Boomers incline to rarely use the medium of SMS when networking while this group also makes use of telephones when networking more often than Black Generation X'ers. Furthermore, Black Baby Boomers more frequently use e–mails when networking while Black Generation X'ers indicated that they rarely use e–mail as network medium. It was found that White Baby Boomers make use of one–on–one face–to–face methods more often when networking than Black Generation X'ers and White Generation X'ers. The largest number of differences was between Black Generation X'ers and White Baby Boomers. The respondents all indicated that they incline to value good relationships at work highly, that they agree that informal work environments are conducive to more effective networking practices, that they frequently have good influences on their families and that they network more during spare time than at work. The results also indicated that the mediums that are used most often when networking include the cell phone and one–on–one face–to–face methods. Respondents tended to rate sharing experiences and exchanging work ideas as very important aims for networking. By dividing diverse workforces into smaller, more manageable units or homogeneous groups, diversity management can be simplified. This is an ability for which managers can be trained and which should be applied correctly within a business environment. In view of the results, it is recommended that managers of diverse workforces should identify different generations and cultures as a way to manage them more effectively. Furthermore, managers should ensure that work environments that are conducive to good relationship building and informality need to be created. Additionally, conflict between Black Generation X'ers and White Baby Boomers should be handled cautiously with a view to ensure that effective solutions are achieved to such conflicts. Preferences with regard to network mediums should be noted, as such awareness may lead to more effective networking / communication within businesses. Management's approach to meetings needs to be reviewed for each group, because differences exist in terms of preferences in this regard. A working environment conducive to exchanging ideas and experiences should be created. Lastly, as all groups value good relationships at work, a climate that encourages openness and conflict resolution should be created. / Thesis (M.Com. (Business Management))--North-West University, Potchefstroom Campus, 2012.

Business management is characterised by fast and ever–expanding development. Culture and generation play an increasingly important role in the management of businesses worldwide. Although studies have been conducted on the subjects of culture and generation, little attention has been paid to culture and generation as a combination of diversity characteristics. As more managers are realising the challenges that arise when managing diverse work environments, the modern manager must question old assumptions about how diverse people work together. In this modern age, it is important to understand diversity issues on all levels of management. Networks are based on people's backgrounds, and understanding the link between networking and diversity is becoming increasingly important. In a culturally complex country such as South Africa, experiencing the impact of diversity on a daily basis can be anticipated. Culture and generation are two terms that encompass all dimensions of diversity. This study investigates the different networking practices found among diverse cultural and generational groups at a Gauteng mine. The generational classification used in this study is based on the fact that generations differ from country to country; therefore, the classification used in this study is relevant to South African generations. Seven hypotheses were formulated pertaining to differences among cultural and generational groups with regard to networking practices. Furthermore, four cultural–generational groups were identified, namely Black Generation X'ers, Black Baby Boomers, White Generation X'ers and White Baby Boomers. Data was collected from Kusasalethu mine employees. The original sample frame comprised 3630 employees from which a sample was chosen that complied with the criteria for culture, age / generation and education. A total of 1046 employees remained from which the sample elements were chosen by making use of probability, systematic proportionate stratified sampling. Self–completion questionnaires were used for collecting the data. A total of 289 questionnaires were completed which constituted a 100% response rate. The questionnaire used was intended to obtain feedback from respondents regarding their cultural and generational diversity, as well as preferences pertaining to their networking practices. The results from the survey were used to determine the differences between diverse cultures and generations with regards to networking practices. The findings, supported by the rejection of the first null–hypothesis, indicated that there are indeed a number of salient differences between Black Generation X'ers, Black Baby Boomers, White Generation X'ers and White Baby Boomers. Specifically, the results indicated that White Baby Boomers incline to rarely use the medium of SMS when networking while this group also makes use of telephones when networking more often than Black Generation X'ers. Furthermore, Black Baby Boomers more frequently use e–mails when networking while Black Generation X'ers indicated that they rarely use e–mail as network medium. It was found that White Baby Boomers make use of one–on–one face–to–face methods more often when networking than Black Generation X'ers and White Generation X'ers. The largest number of differences was between Black Generation X'ers and White Baby Boomers. The respondents all indicated that they incline to value good relationships at work highly, that they agree that informal work environments are conducive to more effective networking practices, that they frequently have good influences on their families and that they network more during spare time than at work. The results also indicated that the mediums that are used most often when networking include the cell phone and one–on–one face–to–face methods. Respondents tended to rate sharing experiences and exchanging work ideas as very important aims for networking. By dividing diverse workforces into smaller, more manageable units or homogeneous groups, diversity management can be simplified. This is an ability for which managers can be trained and which should be applied correctly within a business environment. In view of the results, it is recommended that managers of diverse workforces should identify different generations and cultures as a way to manage them more effectively. Furthermore, managers should ensure that work environments that are conducive to good relationship building and informality need to be created. Additionally, conflict between Black Generation X'ers and White Baby Boomers should be handled cautiously with a view to ensure that effective solutions are achieved to such conflicts. Preferences with regard to network mediums should be noted, as such awareness may lead to more effective networking / communication within businesses. Management's approach to meetings needs to be reviewed for each group, because differences exist in terms of preferences in this regard. A working environment conducive to exchanging ideas and experiences should be created. Lastly, as all groups value good relationships at work, a climate that encourages openness and conflict resolution should be created. / Thesis (M.Com. (Business Management))--North-West University, Potchefstroom Campus, 2012.

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Den svenska arbetsmarknaden står inför ett generationsskifte i och med att fyrtiotalisterna går i pension och den yngre generationen, generation Y, kommer ut på arbetsmarknaden. Den här generationen motiveras av andra faktorer än de äldre generationerna vilket innebär att organisationer behöver anpassa hur de arbetar med att motivera sina anställda. Vinstandelssystem har historiskt sett visat sig vara ett framgångsrikt koncept men det finns en oklarhet gällande om dessa system kommer att fungera på en generation som inte värdesätter trygghet och som inte drar sig för att byta arbetsgivare. Syftet med den här uppsatsen var att undersöka hur generation Y motiveras av vinstandelssystem både i det dagliga arbetet och hur det påverkar generation Y:s motivation att stanna på arbetsplatsen. Det teoretiska ramverket grundande sig i Vrooms förväntansteori och innehöll även teorier kring belöningssystem och vinstandelssystem. Handelsbankens vinstandelsstiftelse Oktogonen har använts som exempel på ett väl fungerande vinstandelssystem och undersökningen har genomförts genom kvalitativa intervjuer med anställda i Handelsbanken som tillhör generation Y. Studiens resultat visar att generation Y uppfattar vinstandelssystemet som någonting positivt men det är i sig ingenting som motiverar dem i deras dagliga arbete eller som motiverar dem att stanna kvar. Detta beror främst på tidsaspekten, att det är så pass lång tid kvar tills de får utdelning, och osäkerheten kring hur stor utdelningen de förväntas få i slutändan. Dessa två faktorer gör det svårt för de anställda att se kopplingen mellan deras prestation och belöningen. Andra faktorer som utvecklande arbetsuppgifter, lön och bra kollegor motiverar mer än vinstandelssystemet både i det dagliga arbetet och i frågan om att stanna kvar på arbetet.

This thesis experimentally validates the performance of an active islanding detection method under various scenarios. It is also analytically shown that the islanding detection method has a non-detection zone (NDZ), and a method to eliminate the NDZ is proposed. Moreover, the performance of an autonomous mode controller for islanded DG units is experimentally evaluated. Based on a robustness analysis, it is shown that the controller, which is basically designed for the nominal plant, can maintain the stability of the system despite of significant load uncertainties. The feasibility of the islanding detection method for islanding detection in two-DG systems is also experimentally investigated. Moreover, a control strategy for autonomous operation of two-DG systems is proposed, and its performance is experimentally evaluated. Then, adopting the islanding detection method and the proposed control strategy, the viability of smooth transitions from grid-connected modes to autonomous (islanded) modes in two-parallel DG systems is experimentally validated.