To motivate effort, organizations commonly use budget-based tangible rewards (e.g., gift cards, merchandise) in lieu of or in addition to cash rewards and they can distribute tangible rewards to employees either directly (employees are given merchandise directly) or indirectly (via a redeemable points program). In conjunction with various budget-based financial rewards, employees can receive feedback about how they performed relative to other employees. However, employees can intentionally misstate their expected performance (i.e., create budget slack) when participating in the budgeting process, impairing the usefulness of budgets for planning and motivation. This dissertation investigates the effects of different types of budget-based rewards (cash, tangible, or redeemable points) on budget slack creation and performance, and whether relative performance information [RPI] moderates these effects. As predicted, results from an experiment completed by 166 undergraduate students show that participants eligible to earn redeemable points create less slack (i.e., set more difficult performance budgets) than those eligible for cash or direct tangible rewards. Further, RPI provides participants with a descriptive norm that slack creation is socially acceptable, resulting in more slack. Although I do not find support for the predicted indirect relationship between reward type or RPI on performance via their effects on budget slack, I do find that the provision of RPI has a direct positive effect on performance. Finally, supplemental analysis shows that those provided with RPI and cash rewards outperform all others. These results suggest that firms choosing to provide budget-based tangible rewards and allowing employees to participate in the budgeting process should consider using a redeemable points system rather than providing rewards directly to eligible employees. Further, before deciding whether to provide RPI to employees, firms should weigh the positive direct effects of RPI on performance against its negative effects on budget slack creation. Last, if a firm does choose to provide employees with RPI because of its positive effects on employee effort, firms may be well-advised to offer employees budget-based cash rewards instead of budget- based tangible rewards or budget-based points rewards.

Κύριος στόχος αυτής της εργασίας είναι η παρουσίαση ενός μοντέλου ανάλυσης ροής φορτίου (ΑΡΦ) το οποίο να ανταποκρίνεται στα σύγχρονα συστήματα διανομής με κατανεμημένη παραγωγή. Η ανάλυση ροής φορτίου είναι μία από τις βασικότερες τεχνικές που χρησιμοποιούνται στην μόνιμη ημιτονοειδή κατάσταση ενός συστήματος ηλεκτρικής ενέργειας και ορίζει την βέλτιστη λειτουργία του. Με την ευρεία εισαγωγή στα ΣΗΕ των ανανεώσιμων πηγών, η δομή των παραδοσιακών ΣΗΕ έχει αλλάξει. Σημαντικό μέρος της κατανάλωσης τροφοδοτείται τοπικά και κοντά στα φορτία. Η παραγωγή επομένως αποκτά ολοένα και περισσότερα χαρακτηριστικά κατανεμημένης παραγωγής. Η κατανεμημένη παραγωγή αναπτύσσεται ραγδαία τα τελευταία χρόνια στα συστήματα διανομής. Εξαιτίας αυτής της ανάπτυξης και αλλαγής της δομής του συστήματος επηρεάζεται και η ανάλυση ροής φορτίου. Στην παραδοσιακή ανάλυση ροής φορτίου δεν υπάρχουν πληροφορίες για την κατανομή φορτίου και των απωλειών μεταξύ των κατανεμημένων παραγωγών και της παραγωγής από το σύστημα ηλεκτρικής ενέργειας.. Για τον λόγο αυτό νέα μοντέλα ανάλυσης ροής φορτίου θα πρέπει να σχεδιαστούν. Με την παρούσα εργασία γίνεται μία προσπάθεια επανατοποθέτησης και νέας επίλυσης του προβλήματος της ανάλυσης ροής φορτίου ώστε αυτή να λαμβάνει υπόψη τις κατανεμημένες παραγωγές και την παραγωγή του ΣΗΕ, υπό την έννοια ότι και η κατανεμημένη παραγωγή ορίζεται σε κάθε βήμα και δεν θεωρείται εξαρχής σταθερή. Για το σκοπό αυτό επιλέγει μία νέα κατάστρωση του προβλήματος η οποία η οποία αντικαθιστά τον ζυγό αναφοράς με ένα μοντέλο κατανεμημένου ζυγού αναφοράς στις γεννήτριες παραγωγής του κατανεμημένου συστήματος. Το μοντέλο κατανεμημένου ζυγού αναφοράς εισαγάγει παράγοντες συμμετοχής για την κάθε επιμέρους παραγωγή, οι οποίοι είναι ανάλογοι της επίδρασης που έχει η κάθε μία στις απώλειες του συστήματος. Στην συνέχεια οι παράγοντες συμμετοχής υπολογίζονται με την έννοια των περιοχών γεννήτριας. Η περιοχή μίας γεννήτριας ορίζεται με βάση τη φορά ενεργού ισχύος. Αφού αυτή οριστεί, βρίσκεται η συνεισφορά κάθε παραγωγής στις απώλειες του συστήματος. Είναι προφανές ότι η περιοχή τοποθέτησης των παραγωγών καθώς και οι παράμετροι δικτύου επηρεάζουν την κατανομή των απωλειών σε αυτές. Έτσι δοκιμάζεται μία νέα μέθοδος ΑΡΦ με την τεχνική Newton-Raphson βασισμένη στη νέα δομή του συστήματος. Τα αποτελέσματα δείχνουν να είναι ενθαρρυντικά και βελτιστοποιούν τη συμμετοχή της κατανεμημένης παραγωγής στο σύστημα. / Distribution system operating environments are changing rapidly. With large number of distributed generators (DGs) installed within distribution systems, distribution systems are facing great challenges: the traditional methods for distribution system analysis and planning needs to be revised, and new tools have been developed. This thesis addresses these challenges by using a method of slack bus new modeling. The concept of the distributed slack bus model is used for distribution system analysis and planning. Its impacts on distribution applications are also investigated. The method introduces scalar participation factors to distribute uncertain real power system loss for three-phase power flow calculations. It provides a method to calculate network-based participation factors by using the generator domain based method. Three-phase power flow is a vital analysis tool for distribution systems. In this work, the main objective is to study slack bus modeling and to use the new distributed slack bus model for three-phase power flow. The new method of power flow analysis is tested in a simple power system and the results are satisfactory.

O setor de assistência à saúde atualmente, carece de técnicas de gerenciamento que visem a melhoria dos processos, permitindo a redução de custos ao otimizar os recursos existentes. O sistema de saúde, classificado como um sistema complexo devido a diversidade de interações não-lineares que apresenta, vem sendo estudado sob a ótica da engenharia de resiliência que enfatiza a necessidade de regular o seu funcionamento diante de uma situação adversa. Por sua vez, a resiliência é facilitada por meio do uso de folgas, que fornecem recursos reservas para lidar com as variabilidades. Ao passo que as folgas são importantes para manter a resiliência, também podem ser recursos ociosos que tendem a mascarar as variabilidades, quando em excesso. Portanto, um equilíbrio deve ser considerado entre o mínimo necessário para manter a resiliência do sistema e o máximo que não venha a se enquadrar como desperdício de recursos. Para isso, esse trabalho desenvolve e aplica uma framework que visa analisar qualitativa e quantitativamente as folgas a fim de reprojetar o sistema sócio-técnico complexo. O estudo foi realizado numa maternidade, referência no atendimento privado. Os processos de atravessamento do fluxo de valor da paciente foram mapeados, permitindo a identificação de 17 fontes de variabilidade e 20 recursos de folga. O reprojeto do sistema de trabalho envolveu a classificação das folgas entre os requisitos levantados, de maneira a priorizar as variabilidades menos cobertas pelas folgas. A framework se mostrou eficaz ao elencar as prioridades no redesenho das folgas e variabilidades, a fim de tornar o sistema estudado mais resiliente. / The healthcare sector currently lacks management techniques that aim to improve processes, allowing cost reduction by optimizing existing resources. The health system, classified as a complex system due to the diversity of nonlinear interactions that it presents, has been studied from the point of view of resilience engineering that emphasizes the need to regulate its functioning in the face of an adverse situation. In turn, resilience is facilitated through the use of slack, which provide reserve resources to deal with variability. While slack are important to maintaining resilience, it can also be idle resources that tend to mask variability when in excess. Therefore, a balance must be considered between the minimum necessary to maintain the resilience of the system and the maximum that doesn’t fit as a waste of resources. For this, this work develops and applies a framework that aims to analyze qualitatively and quantitatively the slack in order to redesign the complex socio-technical system. The study was performed in a maternity hospital, that is a reference in private care. The processes of flow of the patient's value were mapped, allowing the identification of 17 sources of variability and 20 resources of slack. The redesign of the work system involved the classification of slack between the requisites raised, in order to prioritize the variabilities less covered by the slack. The framework proved to be effective in highlighting the priorities in the redesign of the slack and variabilities, in order to make the studied system more resilient.

O setor de assistência à saúde atualmente, carece de técnicas de gerenciamento que visem a melhoria dos processos, permitindo a redução de custos ao otimizar os recursos existentes. O sistema de saúde, classificado como um sistema complexo devido a diversidade de interações não-lineares que apresenta, vem sendo estudado sob a ótica da engenharia de resiliência que enfatiza a necessidade de regular o seu funcionamento diante de uma situação adversa. Por sua vez, a resiliência é facilitada por meio do uso de folgas, que fornecem recursos reservas para lidar com as variabilidades. Ao passo que as folgas são importantes para manter a resiliência, também podem ser recursos ociosos que tendem a mascarar as variabilidades, quando em excesso. Portanto, um equilíbrio deve ser considerado entre o mínimo necessário para manter a resiliência do sistema e o máximo que não venha a se enquadrar como desperdício de recursos. Para isso, esse trabalho desenvolve e aplica uma framework que visa analisar qualitativa e quantitativamente as folgas a fim de reprojetar o sistema sócio-técnico complexo. O estudo foi realizado numa maternidade, referência no atendimento privado. Os processos de atravessamento do fluxo de valor da paciente foram mapeados, permitindo a identificação de 17 fontes de variabilidade e 20 recursos de folga. O reprojeto do sistema de trabalho envolveu a classificação das folgas entre os requisitos levantados, de maneira a priorizar as variabilidades menos cobertas pelas folgas. A framework se mostrou eficaz ao elencar as prioridades no redesenho das folgas e variabilidades, a fim de tornar o sistema estudado mais resiliente. / The healthcare sector currently lacks management techniques that aim to improve processes, allowing cost reduction by optimizing existing resources. The health system, classified as a complex system due to the diversity of nonlinear interactions that it presents, has been studied from the point of view of resilience engineering that emphasizes the need to regulate its functioning in the face of an adverse situation. In turn, resilience is facilitated through the use of slack, which provide reserve resources to deal with variability. While slack are important to maintaining resilience, it can also be idle resources that tend to mask variability when in excess. Therefore, a balance must be considered between the minimum necessary to maintain the resilience of the system and the maximum that doesn’t fit as a waste of resources. For this, this work develops and applies a framework that aims to analyze qualitatively and quantitatively the slack in order to redesign the complex socio-technical system. The study was performed in a maternity hospital, that is a reference in private care. The processes of flow of the patient's value were mapped, allowing the identification of 17 sources of variability and 20 resources of slack. The redesign of the work system involved the classification of slack between the requisites raised, in order to prioritize the variabilities less covered by the slack. The framework proved to be effective in highlighting the priorities in the redesign of the slack and variabilities, in order to make the studied system more resilient.

Construction literature forwards innovation as a desirable objective for firms. Innovation is argued to; improve the firm s performance, increase market share, establish a competitive advantage, and ultimately ensure firm survival. Literature has overlooked the role of organisational slack within construction firms as a determinant of innovation despite the concept being well developed within the general management literature. This research uncovers and examines the impact of organisational slack on firm-level innovation as a determinant of innovation within the construction sector. This work forwards organisational slack as an unexplored firm level determinant of innovation within the construction context. Using the resource-based view of the firm, as a framework for firms, the thesis develops links between previously established firm level determinates of innovation to and slack to support its proposal as a determinant of innovation. Following this traditional measures of innovation argued fail to accurately capture innovation in the construction context, with patents represent inventions, while R&D expenditure is not applicable within the construction. Due to these failures of traditional approaches to measuring innovation, firm level performance is forwarded as a proxy measure for innovation outcomes. Developing existing slack literature, this thesis develops hypotheses proposing inverse U-shaped (n) and U-shaped (u) relationships between the level of slack and innovation outcomes. The thesis presents mixed method research. Study 1 adopts a deductive research strategy, incorporating statistical analysis to test the hypothesised relationships. The Research Design develops and Archival analysis research method; mirroring the approaches of econometric research found in slack literature. The data analysis explores two contexts: construction and manufacturing, allowing a comparative baseline to be established. The analysis of data from this study reveals that discrepancies in the R2 between the contexts is largely the result of the inability of control variables (Age, Size and Number of employees), to explain variation in firm performance (as a proxy for innovation outcomes) in a construction context, rather than the unsuitability of slack in the construction context. In construction firms, Unabsorbed Slack and Financial Slack demonstrated statistically significant results supporting an inverse U-shaped relationship with firm performance (n) supporting Hypothesis 1a and 1b. Contrary to this Absorbed Slack and Human Resource Slack demonstrated statistically significant results demonstrating a U-relationship (u) between slack and performance supporting hypothesis 2b (H2b). Study 2 adopts a deductive research strategy, incorporating semi-structured interviews as a source of primary data in order to explore the slack-innovation relationship in greater depth. Primarily, this study provided evidence to suggest that construction firms do not directly measure innovation. Instead, firms choose to measure outcomes of changes within the firm, typically in terms of measure relating to firm financial performance. Evidence from this study supports the proposal of firm financial performance as a viable proxy for innovation outcomes in Study 1. In addition to this when faced with changes to their environment, participants responses typically supported a positive linear relationship between the level of organisational slack and the firm. This research is the first to examine the impact of organisational slack on construction firm financial performance (as a proxy for innovation). This relationship is curvilinear in nature, however, the results are inconclusive if it is inverse U shaped (n) or U shaped (u) based upon conflicting evidence from different slack variables. What can be ascertained however, is that the level of slack impacts firm level performance and theoretically impacts firm level innovation.

Internal communication is a subject increasing in importance. This subject has, as many other things, been influenced by the Internet-based and connected world that we live in today. As a result, Enterprise Social Networks has appeared as a tool for organisations to use. While the usage of this tool is growing, the existing research on the subject is yet very limited. So is the research on employees‘ needs when it comes to internal communication. In this study, we aim to fill these gaps, by exploring the use of these enterprise social networks from an organisational actor‘s perspective. In order to fulfil this purpose, a qualitative case study within multiple embedded units of analysis was used. The empirical material was gathered through in-depth semi- structured interviews as well as observations. Furthermore, we took on real-life experience by using the ESN tool ourselves. Several themes were then identified using a thematic analysis. By using this method, we conclude that organisational actors use ESNs for private, public and remote communication. We also provide the reader with five characteristics of ESNs that are perceived as important by organisational actors, namely; easy to learn, easy to use, accessible, informal and avoids disturbance. Several perceived outcomes resulting from ESN usage is then identified. We conclude the study by explaining that if organisations identify a need for an ESN, use it in the right way, and have the appropriate culture, the implementation of an ESN can be very beneficial. This, as organisational actors experience it as a good tool for internal communication.

No description available.

Un Sistema de Tiempo Real (STR) debe garantizar que sus resultados, además de correctos, cumplan también con un conjunto de restricciones temporales. En general, esto implica asegurar que sus tareas finalicen su ejecución antes de un vencimiento. Para cumplir esto, la predictibilidad y el determinismo adquieren suma importancia. El campo de aplicación clásico de los STR ha sido la industria, como por ejemplo la aviónica, la exploración espacial, equipamiento médico, sistemas de control, etc. Todos estos sistemas tienen en común el de ser de misión crítica, donde un fallo tiene consecuencias graves, como pérdidas materiales y económicas, daños al medio ambiente o poner en riesgo la vida humana. Por lo general estos sistemas son estáticos, y utilizan arquitecturas de hardware y algoritmos de efectividad comprobada. En muchas ocasiones su diseño e implementación es ad-hoc. Sin embargo, en las últimas décadas el campo de aplicación de los STR se ha extendiendo. En la actualidad son utilizados en ámbitos y productos de lo más variados: electrodomésticos, productos electrónicos de consumo, telefonía celular, automóviles, comunicaciones, sistemas de reservas de pasajes, etc. Muchos de estos sistemas están constituidos tanto por tareas críticas como por tareas no-críticas. Un fallo en la ejecución de las primeras tiene consecuencias graves, en tanto que el incumplimiento de las restricciones temporales de las últimas afecta la calidad de servicio esperada. Es vital entonces que las tareas no-críticas no afecten la correcta ejecución de las tareas críticas. Un STR con estas características se denomina heterogéneo. En los últimos años, gracias al incremento de la potencia de cálculo de los microprocesadores, y la reducción de sus costos, el número de STR que permiten que coexistan estos dos conjuntos de tareas ha aumentado. Para lograr una correcta ejecución de un STR heterogéneo, se requiere de técnicas que calculen y administren en línea, el tiempo ocioso disponible. De esta manera, el planificador puede mantener la garantía decumplimiento de las constricciones temporales de las tareas críticas, y al mismo tiempo brindar una atención aceptable a las tareas sin requerimientos estrictos. En la actualidad, microprocesadores más potentes abren la posibilidad de implementar estos métodos incluso en sistemas que antaño contaban con muy baja potencia de cálculo. Sin embargo, la sobrecarga que agregan no es despreciable, por lo que reducir el costo computacional de estos métodos sigue siendo de suma utilidad, aún cuando se dispone de hardware con mayor capacidad de computo. Existe una amplia literatura que aborda la problemática de la planificación de STR heterogéneos. Sin embargo, existe una brecha significativa entre los desarrollos teóricos en la disciplina, y las técnicas efectivamente utilizadas en la industria. Es necesario poder comprobar el costo real y las ventajas y desventajas objetivas de implementar los modelos teóricos de punta. Muchos modelos teóricos no tienen en cuenta costos adicionales presentes en implementaciones concretas. Estos son comúnmente considerados despreciables en la modelización, a fin de simplificar el análisis, la evaluación y el desarrollo del sistema. Como consecuencia, en la implementación real se estos parámetros se sobrestiman, lo que resulta en una menor eficiencia del sistema. Un ejemplo común es el uso de microprocesadores con una capacidad de cálculo por encima de la realmente requerida, lo que impacta negativamente en el consumo de energía y en los costos. Un modelo más detallado en la etapa de diseño, implementación y verificación, permitiría mejorar el desempeño del sistema final, sin abandonar la garantía de predictibilidad temporal. Igualmente importantes, se deben contar con técnicas y herramientas que permitan implementar estos modelos métodos teóricos de manera eficiente. La presente tesis se basa en la hipótesis de que los STR heterogéneos pueden ser eficaces en la planificación de sus conjuntos de tareas y en el uso de sus recursos computacionales. Bajo esta premisa, se presentan nuevos modelos y mejoras a modelos ya existentes, junto con simulaciones, pruebas y desarrollos necesarios para su verificación. El trabajo se basa fuertemente en la implementación práctica de los resultados teóricos, identificando las dificultades reales que su puesta en práctica trae aparejado. De esta manera, se busca reducir la brecha existente entre los resultados obtenidos por la investigación científica en la disciplina de los STR, y aquello concretamente utilizado e implementado realmente en la industria, la investigación y el desarrollo tecnológico. / A Real-Time System (RTS) must warrant that its results are correct and fulfill a set of temporal restrictions. This implies that each task completes its execution before a specific deadline. In order to accomplish this, the predictibility and determinism of the system as a whole is very important. These kind of systems are used in several industries, like aircraft avionics, space exploration, medical equipment, etc., which are mission critical. A failure in this systems could have catastrophic consequences, like loss of human lives. Most of the time the design and implementation of these systems is ad-hoc. In the last decades, thanks to the growth and sophistication of embedded systems, the application domain of the RTS increased. Nowdays they can be found on consumer electronics, cellphones, communications systems, cars, etc. A lot of these new kind of real-time systems are composed of both critical and noncritical tasks. A failure in the execution of the former have severe consequences, but a missed deadline of the later only affects the quality of service. Such a RTS is known as a heterogeneus one. In order to accomplish a correct execution of a heterogeneus RTS, methods and techniques that calculates and manages the system idle-time are needed. With these tools, the system scheduler can guarantee that all the time-critical tasks fulfill their deadlines. Nonetheless, these techniques add an execution overhead to the system. Although severalworks in the literature proposes solutions for many of the scheduling problems in a heterogeneus RTS, a gap exists between these results and what is actually used and implemented in the industry. Many theoretical models do not take into account the additional costs present in a concrete implementation. These are commonly considered negligible in order to simplify the analysis, evaluation and development of the system. As a consequence, some parameters are overestimated, resulting in reduced system efficiency. A common scenario is the use of microprocessors more powerful than required, with negative impact on energy consumption and production costs. A more detailed model in the design and implementation stage could improve the performance of the final system, without abandoning the guarantee of temporal predictability. Equally important, there must be techniques and tools that allow the implementation of these theoretical results. The working hipothesis of this thesis is that a heterogeneus RTS could be efficient in the scheduling of their tasks and resources. Following this premise, new models and improvements to existing ones are presented, in conjunction with several simulations and implementations of the theoretical results, in order to identify the real difficulties that the implementation brings about. This seeks to reduce the gap between the scientific research in the discipline of RTS and what actually implemented in the industry.

Yes / The performance of buried rigid pipes underneath geogrid-reinforced soil while applying incrementally increased cyclic loading was assessed using a fully instrumented laboratory rig. The influence of varying two parameters of practical importance was investigated; the pipe burial depth and the number of geogrid-layers. Measurements were taken for pipe deformation, footing settlement, strain in pipe and reinforcing layers, and pressure/soil stress on the pipe crown during various stages of cyclic loading. The research outcomes demonstrated a rapid increase in the rate of deformation of the pipe and the footing, and the rate of generated strain in the pipe and the geogrid-layers during the first 300 cycles. While applying further cycles, those rates were significantly decreased. Increasing the pipe burial depth and number of geogrid-layers resulted in reductions in the footing and the pipe deformations, the pressure on pipe crown, and the pipe strains. Redistribution of stresses, due to the inclusion of reinforcing layers, formed a confined zone surrounding the pipe providing it with additional lateral support. The pipe invert experienced a rebound, which was found to be dependent on pressure around the pipe and the degree of densification of the bedding layer. Data for strains measured in the geogrid-layers showed that despite the applied loading value and the pipe burial depth, the tensile strain in the lower geogrid-layer was usually higher than that measured in the upper layer.

A novel, general, numerical model is described that is capable of predicting the load-displacement relationship up to and at failure of multiple-bolt joints in timber of various configurations. The model is not tied to a single input function and bolt holes are permitted to be drilled oversize resulting in a slack system. The model consists of five parts. A new mathematical hysteresis model describes the stiffness of the individual bolt at each time step increment and accounts for non-linear and slack behavior; a mechanically-based structural stiffness model explains the interaction of one bolt with another bolt within a joint; an analytically-based failure model computes the stresses at each time step and initiates failure if crack length equals fastener spacing; a stochastic routine accounts for material property variation; and a heuristic optimization routine estimates the parameters needed. The core model is a modified array of differential equations whose solution describes accurate hysteresis shapes for slack systems. Hysteresis parameter identification is carried out by a genetic algorithm routine that searches for the best-fit parameters following evolutionary principles (survival of the fittest). The structural model is a linear spring model. Failure is predicted based on a newly developed 'Displaced-Volume-Method' in conjunction with beam on elastic foundation theory, elastic theory, and a modified Tsai-Wu Failure criterion. The devised computer model enhances the understanding of the mechanics of multiple-bolt joints in timber, and yields valid predictions of joint response of two-member multiple-bolt joints. This research represents a significant step towards the simulation of structural wood components. / Ph. D.