As more industrial processes, transportation and appliances have been automated or equipped with some level of artificial intelligence, the number and scale of interconnected systems has grown in the recent past. This is a development which can be expected to continue and therefore the research in performance of interconnected systems and networks is growing. Due to increased automation and sheer scale of networks, dynamically scaling networks is an increasing field and research into scalable performance measures is advancing. Recently, the notion gamma-robustness, a scalable network performance measure, was introduced as a measurement of interconnected systems robustness with respect to external disturbances. This thesis aims to investigate how the distribution of control effort and cost, within interconnected system, affects network performance, measured with gamma-robustness. Further, we introduce a notion of fairness and a measurement of unfairness in order to quantify the distribution of network properties and performance. With these in place, we also present distributed algorithms with which the distribution of control effort can be controlled in order to achieve a desired network performance. We close with some examples to show the strengths and weaknesses of the presented algorithms. / I och med att fler och fler system och enheter blir utrustade med olika grader av intelligens så växer både förekomsten och omfattningen av sammankopplade system, även kallat Multi-Agent Systems. Sådana system kan vi se exempel på i traffikledningssystem, styrning av elektriska nätverk och fordonståg, vi kan också hitta fler och fler exempel på så kallade sensornätverk i och med att Internet of Things och Industry 4.0 används och utvecklas mer och mer. Det som särskiljer sammankopplade system från mer traditionella system med flera olika styrsignaler och utsignaler är att dem sammankopplade systemen inte styrs från en central styrenhet. Istället styrs dem sammankopplade systemen på ett distribuerat sätt i och med att varje agent styr sig själv och kan även ha individuella mål som den försöker uppfylla. Det här gör att analysen av sammankopplade system försvåras, men tidigare forskning har hittat olika regler och förhållninssätt för agenterna och deras sammankoppling för att uppfylla olika krav, såsom stabilitet och robusthet. Men även om dem sammankopplade systemen är både robusta och stabila så kan dem ha egenskaper som vi vill kunna kontrollera ytterligare. Specifikt kan ett sådant prestandamått vara systemens motståndskraft mot påverkan av yttre störningar och i vanliga olänkade system finns det en inneboende avvägning mellan kostnad på styrsignaler och resiliens mot yttre störningar. Samma avvägning hittar vi i sammankopplade system, men i dessa system hittar vi också ytterligare en dimension på detta problem. I och med att ett visst mått av en nätverksprestanda inte nödvändigtvis betyder att varje agent i nätverket delar samma mått kan agenterna i ett nätverk ha olika utväxling mellan styrsignalskostnad och resiliens mot yttre störningar. Detta gör att vissa agenter kan ha onödigt höga styrsignalskonstander, i den mening att systemen skulle uppnå samma nätverksprestanda men med lägre styrsignalskostnad om flera av agenterna skulle vikta om sina kontrollinsatser. I det här examensarbetet har vi studerat hur olika val av kontrollinsats påverkar ett sammankopplat systems prestanda. Vi har gjort detta för att undersöka hur autonoma, men sammankopplade, agenter kan ändra sin kontrollinsats, men med bibehållen nätverksprestanda, och på det sättet minska sina kontrollkostnader. Detta har bland annat resulterat i en distruberad algoritm för att manipulera agenternas kontrollinsats så att skillnaderna mellan agenternas resiliens mot yttre störningar minskar och nätverksprestandan ökar. Vi avslutar rapporten med att visa ett par exempel på hur system anpassade med hjälp av den framtagna algoritmen får ökad prestanda. Avslutningsvis följer en diskussion kring hur vissa antaganden kring systemstruktur kan släppas upp, samt kring vilka områden framtida forskning skulle kunna fortsätta med.

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Multilingualism in the classroom is one of the many challenges found in the cumbersome bag that the South African education system is carrying over its shoulders at present. Globalisation and migration have added to the burden as factors adding further diversity to the already diverse classroom. In South Africa the spotlight is focused on equality. Equality is expected in the education system, and in the classroom and especially in tests. With 11 official languages excluding the additional languages from foreign learners it has become a daunting task to create tests that are fair across multilingual learners in one classroom. Items in tests that function differently from one group to another can provide biased marks. An investigation was done in order to detect any biased items present in a Picture Vocabulary Test. The study was lead by the main research question being: How do objects used in a Picture Vocabulary Test influence the level of validity? The first sub research question was: How do objects used in a Picture Vocabulary Test influence the level of validity? The next sub question was: To what extent is an undimensional trait measured by a Picture Vocabulary Test? The final subquestion was To what extent do the items in a Picture Vocabulary Test perform the same for the different language groups? This Picture Vocabulary Test was administered to Grade 1 learners in Afrikaans, English or Sepedi speaking schools within Pretoria, Gauteng. The sample totalling 1361 learners. The process involved a statistical procedure known as Rasch analyses. With the help of Rasch a Differential Item Functioning (DIF) analysis was done to investigate whether biased items were present in the test. The aim of this study it is to create greater awareness as to how biased items in tests can be detected and resolved. The results showed that the items in the Picture Vocabulary Test all tested vocabulary. Although items were detected that did indeed perform differently across the three language groups participating in the study. / Dissertation (MEd)--University of Pretoria, 2010. / Science, Mathematics and Technology Education / unrestricted

Nous proposons dans cette thèse d'exploiter la Modulation Hiérarchique (MH) dans un système OFDMA avec et sans utilisation des relais en vue d'améliorer d'avantage la capacité du système en tirant profit de la diversité d'utilisateurs. MH permet de transmettre un flux supplémentaire à un utilisateur de bonnes conditions radio sur une sous-porteuse initialement allouée à un utilisateur de mauvaises conditions radio. Ceci est différent des techniques classiques d’allocation de ressources proposées dans la littérature qui respectent une orthogonalité parfaite lors de l'allocation : une sous-porteuse est allouée à un seul utilisateur et aucun autre utilisateur ne pourra l'utiliser en même temps. Dans la littérature, la plupart des travaux qui se sont intéressés à l'utilisation de la MH se sont concentrés seulement sur les performances en termes de couche basse avec un nombre fixe d'utilisateurs dans le système correspondant à une configuration statique. Toutefois, cette configuration ne reflète pas la dynamicité du nombre d'utilisateurs dans un tel système, où les utilisateurs arrivent selon une loi aléatoire et partent après avoir fini leurs services. Dans cette thèse, nous exposons l'étude des performances de l'utilisation de la MH avec des configurations dynamiques d'utilisateurs correspondant à une étude au niveau flux. Cela nous permet d'évaluer les performances en termes de nouvelles métriques à savoir le temps moyen de transfert et la probabilité de blocage qui sont importantes pour l'utilisateur et pour l'opérateur. / We investigate, in this thesis, the use of Hierarchical Modulation (HM), a physical layer technique that enables to exploit multiuser diversity, for resource allocation in OFDMA-based systems with and without use of relaying, so as to improve the system capacity. HM allows the sharing of the resources, namely subcarriers and power, between users of different radio conditions by sending an additional stream to a user with good radio conditions on a subcarrier that was initially allocated to carry an original stream to a user with lower radio conditions. And this, without affecting the original user's rate nor the total amount of power assigned to the shared subcarrier. In the literature, most of the works that consider the use of HM focus solely on the physical layer performance, notably in terms of the bit error rate. And this for a static user scenario,i.e., with a fixed number of users in the system, each with an infinite service duration. This configuration however does not reflect the real system behavior where the number of users is dynamic, i.e., the users come to the system at random time epochs and leave it after a finite duration, corresponding to the completion of their services. The study of the system at the flow-level, as opposed to the packet level, for a dynamic user configuration, enables us to investigate the realistic relationship between capacity and demand and to quantify several system-level performance metrics, such as mean transfer times and blocking rates, which are meaningful both to the user and the network operator/provider.

Over the last decade, researchers and practitioners have contributed to the body of knowledge on improving business operations among public housing authorities. However, effective knowledge-sharing processes within a public housing organization remain deficient. The purpose of this quantitative study was to examine the correlations between employees' perceptions of trust, organizational fairness, supervisors' competency, and employees' willingness to share knowledge. Understanding the factors that predict employees' willingness to share knowledge is imperative to developing leaders' best practices. Social capital theory served as the theoretical framework for this study. Seventy full-time employees and leaders of the housing authorities in the State of Texas participated. A multiple, standard-regression analysis indicated significant correlations between the independent variables and employees' willingness to share knowledge. Organizational fairness was the strongest predictor. These findings may help leaders in public housing authorities improve best practices to create effective knowledge-sharing processes and open opportunities for further discussion with organizational leaders in public sector agencies. The results of this study may have implications for social change: Public housing leaders could optimize operational procedures by managing sustainability and developing effective best practices that might reduce taxpayers' burden and increase social services to low-income residents.

Business and management researchers have shown that performance appraisals have continued to remain a standard component of the human resource management (HRM) function and play an integral role in contributing to employee performance and job satisfaction levels. Recent researchers indicated that employees have continued to hold negative views about the degree of fairness and accuracy of appraisals, thus rendering the process a mere routine and periodic ritual detrimental to organizational efficiency and growth. The purpose of this study was to add to what is a paucity of data on perceptions of fairness of employees and examine the employee perceptions of fairness in performance appraisals related to job satisfaction. The conceptual framework for this study was rooted in organizational justice and motivational theory. Research questions examined the perceptions of employees of performance appraisals on job satisfaction. Qualitative data were collected in this multiple case study using face-to-face interviews of 20 participants. Data were organized, coded, and analyzed for emergent themes and patterns that aligned with the research questions. Research findings showed that employee perceptions of performance appraisals are critical and remain an invaluable component of the human resource function to benefit management executives and should include basic knowledge and employee input in the appraisal design and process. Implications for possible positive social change may include enhanced insights, knowledge, and understanding of the perceptions of performance appraisals that may enhance management decisions through fair, just, and accurate employee appraisals that will positively translate to job satisfaction.

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In revenue management practice, the issue of perceived fairness is a serious concern, because revenue management applies different prices for basically the same service. The purpose of this study is to examine the effect of hotel revenue management pricing on customers’ perceptions of fairness. Specifically, this study explores whether framing revenue management pricing as discounts rather than surcharges would significantly enhance customers’ perceived fairness. In addition to framing, this study investigates whether customers’ perceived fairness is affected by the fencing condition customers are in. Furthermore, most importantly, this study proposes that such framing and fencing condition effects are moderated by a hotel’s reputation with a revenue management pricing practice. This study found that framing and fencing condition had a significant effect on customers’ fairness perception, respectively. In addition, this study found that reputation moderated the effect of framing on perceived fairness. When the hotel had a poor reputation, framing as a discount rather than framing as a surcharge considerably increased customers’ perceived fairness. When the hotel had a good reputation, however, there was no significant difference between priced framed as a discount and a surcharge. This study supports hotel managers to understand how customers perceive fairness in revenue management practices and also provides hotel managers with broad acceptance levels of the tested revenue management pricing mechanisms.

This research study explores the influence of perceived fairness on players' playstyle in multiplayer card games. The study focuses on a card game called "Insomnia" and its modified versions to investigate players' perceptions of fairness and their subsequent behavior. Two series of playtests were conducted with different groups of participants, and data were collected through gameplay observations and semi-structured group interviews. Thematic analysis was performed on the collected data, comparing findings with existing literature to provide insights into fairness in card games and the consequent playstyles. The results reveal that players adapt their strategies and playstyles when the game becomes difficult and unfair, shifting towards cooperative actions and helping others. Furthermore, the study shows that their goals, motivations, and perceived fairness influence players' preferences and behaviors. The findings underscore the interplay between fairness, playstyle archetypes, and player behavior in multiplayer card games. The study emphasizes the significance of understanding individual motivations, social dynamics, and game design elements in shaping player experiences. It suggests that game designers should consider the complexity of player decision-making and the intricate relationship between motivations and perceptions of fairness to foster engaging gameplay.

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