Escalation of commitment to failing investments is considered to be representative of biased forms of decision-making which may result in unproductive consequences. Decision makers adopt investment courses of action in initial conditions of uncertainty, which subsequently appear to lead to failure. When confronted with the prospect of their decisions producing losses, they commit decision errors thus escalating their commitment to their original courses of action. Several theories with rational and irrational antecedents have been developed in the literature to explain the escalation phenomenon. Fundamental theoretical differences are associated with the origin of the concept. Escalation of commitment was conceived in the decision theory context of the problem of resource allocation under uncertainty conditions. This thesis describes the resource allocation problem in order to identify and explain associated characteristics. Explanations of these characteristics reveal several problems: there are no decision rules available to handle uncertainty; decision makers consistently violate the requirements for rationality and rational economic decision making; individual utility maximization is divorced from the business objective of profit maximisation and also involves taking increased risks when there is an expectation that investment losses will be recovered; there are several criteria for and methods of investment evaluation which are computationally and analytically difficult to apply; and whether a decision error has been made is indeterminate with some investment projects whose success or failure cannot be determined until after project completion. These problems lead to the conclusion that the determination of the success or failure of an investment decision may depend on the valuation methodology selected. In this respect it is argued that investment decisions undertaken in public organisations should be evaluated using methodologies developed to measure social benefits and costs because calculations of private rates of return provide misleading assessments. Research on the escalation phenomenon is dominated by a psychological perspective, which obtains its findings from extensive investigation of individuals in controlled experimental laboratory conditions. The experimental research has identified personal pre-dispositional, social and situational influences, which contribute to escalation and de-escalation of commitment. The major research focus has resulted in two theoretical explanations for escalation of commitment. These derive from descriptive cognitive motivational theories concerned with expectancy, that encourage rational decision making and dissonance, which in turn produce irrational self justification based decisions. An alternative research focus favours explanations from prospect theory. Research, critical of the psychological explanations favours rational explanations derived from the normative theory of expected utility, which encourages individual self-interested behaviour. This thesis is concerned with explaining escalation of commitment in organisations. This necessarily involves adopting an interdisciplinary perspective. This thesis examines two world expositions, Expo 86 and Expo 88. World expositions are unusual government events whose principal purpose is to celebrate human achievements. Expo 86 was held to celebrate Vancouver’s centenary. Expo 88 was held to celebrate Australia’s bicentennial. They were not designed for their potential profitability. To justify the expenditures involved other objectives are attached to the celebratory purpose. These usually are associated with urban renewal and economic development. They are unorthodox investment projects. They involve long lead times of capital expenditure followed by short operating periods of six months or less, after which time most of the capital improvements are either disposed of or demolished. Expo 86 incurred significant financial losses and was considered an escalation prototype. It became a case study used to develop a generalized theoretical model of escalation. The model specifies how initially formulated rational decisions are replaced progressively by decisions based on self-justification, which escalate commitment. Escalation is reinforced by psychological pre-dispositional, social and structural influences. The model is an extension of research findings from individual laboratory experiments. The thesis identifies several plausible alternative theoretical explanations for escalation in organisations. These involve emotional commitment, social influences to conform to group norms, the possibilities for deviating from rational decision making principles in the presence of uncertainly and the agency theory problem which involves individuals pursuing their own rational self interests which are contrary to the objectives of an organisation. Expo 86 was directly linked to urban renewal objectives. The economic project and urban planning studies of Expo 86 concluded that the event successfully achieved the urban development objectives using social cost benefit analysis as the criterion of evaluation. These objectives were rationally conceived and executed. As a result of the examination, the thesis explores the problems associated with investment projects having multiple objectives, looks at how rational explanations can be accommodated in the theoretical model and questions whether calculations of accounting negative rates of return should be the criteria for evaluation and the determinant of whether Expo 86 qualified as a prototypical example of escalation in organisations. The analysis of Expo 88 reinforced these concerns. A longitudinal dimension was adopted in the case study. This enabled the origins of the event to be explored, the objectives to be identified and the project to be evaluated using various private and public investment criteria. Expo 88 qualified as a failed private investment project on all but one of the financial investment criteria employed. The evaluation of Expo 88 as a public investment project produced social benefits and economic impacts in excess of social costs. Expo 88 was conceived by influential individuals who promoted the initiative for an exposition on the basis that its staging would be publicly and personally beneficial. The project was associated with multiple objectives other than its celebratory purpose that included tourism development and urban renewal from which the public was expected to benefit and which promoters believed justified the event. The principal decision makers were not directly influenced by profitability considerations because information had been provided during the planning phase, which indicated that the project would produce financial losses. Because of public pronouncements it became politically necessary to include the profitability of the project as an objective. Various costly and deceptive measures were adopted in order to generate an impression of profitability. At the same time success was promoted publicly and successfully, not in terms of its profitability, but in terms of attendance figures. As a result of the analyses, the theoretical model was modified by incorporating rational motives into the original structure. Decision makers were driven by rational motives over the life of the projects. In the case of Expo 88 these rational motives derived from agency theory relationships and the pursuit of objectives concerned with economic development, celebration and political recognition. The thesis concludes with a discussion of the contributions and limitations of the research. The contributions involve modifications to the theoretical model to reflect the importance of rational motives in the decision making process, generalisation of the causes of escalation in organisations in various contingent circumstances and the impact that multiple project objectives and methodological problems concerned with evaluation criteria have on theory development. The major limitation relates to the selection of public organisations engaged in unorthodox investment projects as inappropriate representatives to examine the escalation phenomenon.

This licentiate thesis considers the modelling, simulation and experimental investigation of a rammer compactor machine. The purpose is to develop an efficient and verified method for simulation of rammer compactor machines to be used in the product development process. The experience gained through this work is also intended to be useful for studying other types of dynamic compactor machines. Rammer compactor machines perform impact soil compaction. This is more efficient than static compaction. The machines are often used in places where a high degree of compaction is needed, and where the space for operation is limited. The complexity of this type of machine makes design optimisation through traditional prototype testing impractical. This has pointed to the need for a theoretical model and simulation procedure for predicting the dynamic behaviour of the machine. To be useful for optimisation the theoretical model and simulation procedure must be verified. By concurrently working with theoretical modelling, simulations, experimental verifications, and optimisation an efficient analysis support for product development is achieved. This co-ordination works both ways in an iterative manner: experimental investigations are used to verify theoretical models and simulations; and theoretical models and simulations are used to design good experiments. This Complete Approach concept enables better decisions to be made earlier on in the development process, resulting in a decrease in time-to-market and improved quality. In this thesis, the Complete Approach concept is applied to a rammer soil compactor machine. An introductory iteration is described. The good agreement between theoretical and experimental results indicates that the theoretical model and simulation procedure should prove useful in introductory optimisation studies. The thesis discusses reasons for the remaining discrepancy and suggests improvements in both the theoretical model and the experimental set-up for future iterations. / I arbetet studeras det dynamiska beteendet av en jordpackningsmaskin. Syftet är att bygga upp en verifierad modell som kan ligga till grund för vidare produktutveckling. Ett samordnat arbetsätt, Complete Aproach / <p>http://epubl.luth.se/1402-/02/index.html</p>

Realizamos uma caracterização estrutural e eletrônica dos inibidores enzimáticos E-64 e CA030 utilizando técnicas de química quântica. Otimizações de geometria são realizadas em nível ab initio com os métodos Hartree-Fock e Teoria do Funcional da Densidade e estas estruturas são então comparadas com os resultados cristalográficos obtidos do Protein Data Bank. O cálculo do espectro de vibração infravermelho foi realizado para assegurar que as estruturas eram pontos de mínimo. Nós também fizemos a atribuição das freqüências vibracionais aos grupos funcionais das moléculas. A caracterização eletrônica é obtida com o cálculo do espectro de absorção ultravioleta-visível. Efeitos de solvente são contabilizados através da teoria de Campo de Reação Auto-Consistente. Uma análise detalhada das excitações do espectro calculado do E-64 e do CA030 é realizada e nós estudamos particularmente as transições características em torno de 200 nm. Tanto para o E-64 como para o CA030 nós identificamos o cromóforo responsável pela transição característica dos inibidores. Adicionalmente, nós levamos em consideração a influência da interação do CA030 com a catepsina B através do cálculo do espectro ultravioleta-visível do inibidor com o aminoácido cisteína. / We have made a structural and electronic characterization of the enzyme inhibitors E-64 and CA030 using quantum chemistry techniques. Geometry optimizations are performed in the ab initio level with the Hartree-Fock and Density Functional Theory methods and these structures are then compared with crystallographic results obtained from the Protein Data Bank. The infrared vibration spectrum calculation has been carried out to assure that the theoretical structures are true minima. We also have made an assignment of the vibrational frequencies to the functional groups of the molecules. The electronic characterization is performed with the calculation of the ultraviolet-visible absorption spectrum. Solvent effects are taken into account the Self Consistent Reaction Field theory. A detailed analysis of the calculated spectra of E-64 and CA030 excitations is given and we have particularly studied the characteristic transitions around 200 nm. For both the E-64 and the CA030 we have identified the chromophore responsible for the characteristic transition of the inhibitors. In addition, we have considered the influence of the interaction of the CA030 with the enzyme cathepsin B by calculating the ultraviolet-visible spectrum of the inhibitor with the cysteine amino acid.

<p>In vapour phase deposition, the knowledge and control of homogeneous and heterogeneous reactions in connection to precursor design may lead to the deposition of the desired material; structure or phase. This thesis is a document attempting to increase the knowledge of film growth in the B-N system.</p><p>In the present work, surface processes like adsorption, abstraction, migration and nucleation have been modelled on an atomic scale using density functional theory (DFT). The systems studied are mainly cubic and hexagonal boron nitride surfaces ((c-BN) vs. (h-BN)), but also the α-boron (001) surface.</p><p>It has been shown that DFT and a cluster approach is a reliable tool in modelling boron nitride surfaces and surface processes, provided that certain functionals, basis sets and geometrical constraints are used.</p><p>By using surface stabilisers such as H species in an electron- or radical-rich environment, it has been shown that <i>i)</i> the structure of cubic boron nitride surfaces can be sustained, and <i>ii)</i> c-BN may nucleate on the h-BN (001) basal plane. Furthermore, the nucleation of c-BN from arbitrary and experimental growth species is energetically preferable over a continuous growth of h-BN on the h-BN (001) edges.</p><p>An atomic layer deposition (ALD) process for boron nitride was developed. It resulted in turbostratic (t-BN), transparent, well-adherent and almost atomically smooth BN films. However, with the cubic phase of boron nitride absent in the ALD films, more effort needs to be put into both the theoretical and the experimental branches of this field of science.</p>

In vapour phase deposition, the knowledge and control of homogeneous and heterogeneous reactions in connection to precursor design may lead to the deposition of the desired material; structure or phase. This thesis is a document attempting to increase the knowledge of film growth in the B-N system. In the present work, surface processes like adsorption, abstraction, migration and nucleation have been modelled on an atomic scale using density functional theory (DFT). The systems studied are mainly cubic and hexagonal boron nitride surfaces ((c-BN) vs. (h-BN)), but also the α-boron (001) surface. It has been shown that DFT and a cluster approach is a reliable tool in modelling boron nitride surfaces and surface processes, provided that certain functionals, basis sets and geometrical constraints are used. By using surface stabilisers such as H species in an electron- or radical-rich environment, it has been shown that i) the structure of cubic boron nitride surfaces can be sustained, and ii) c-BN may nucleate on the h-BN (001) basal plane. Furthermore, the nucleation of c-BN from arbitrary and experimental growth species is energetically preferable over a continuous growth of h-BN on the h-BN (001) edges. An atomic layer deposition (ALD) process for boron nitride was developed. It resulted in turbostratic (t-BN), transparent, well-adherent and almost atomically smooth BN films. However, with the cubic phase of boron nitride absent in the ALD films, more effort needs to be put into both the theoretical and the experimental branches of this field of science.

Realizamos uma caracterização estrutural e eletrônica dos inibidores enzimáticos E-64 e CA030 utilizando técnicas de química quântica. Otimizações de geometria são realizadas em nível ab initio com os métodos Hartree-Fock e Teoria do Funcional da Densidade e estas estruturas são então comparadas com os resultados cristalográficos obtidos do Protein Data Bank. O cálculo do espectro de vibração infravermelho foi realizado para assegurar que as estruturas eram pontos de mínimo. Nós também fizemos a atribuição das freqüências vibracionais aos grupos funcionais das moléculas. A caracterização eletrônica é obtida com o cálculo do espectro de absorção ultravioleta-visível. Efeitos de solvente são contabilizados através da teoria de Campo de Reação Auto-Consistente. Uma análise detalhada das excitações do espectro calculado do E-64 e do CA030 é realizada e nós estudamos particularmente as transições características em torno de 200 nm. Tanto para o E-64 como para o CA030 nós identificamos o cromóforo responsável pela transição característica dos inibidores. Adicionalmente, nós levamos em consideração a influência da interação do CA030 com a catepsina B através do cálculo do espectro ultravioleta-visível do inibidor com o aminoácido cisteína. / We have made a structural and electronic characterization of the enzyme inhibitors E-64 and CA030 using quantum chemistry techniques. Geometry optimizations are performed in the ab initio level with the Hartree-Fock and Density Functional Theory methods and these structures are then compared with crystallographic results obtained from the Protein Data Bank. The infrared vibration spectrum calculation has been carried out to assure that the theoretical structures are true minima. We also have made an assignment of the vibrational frequencies to the functional groups of the molecules. The electronic characterization is performed with the calculation of the ultraviolet-visible absorption spectrum. Solvent effects are taken into account the Self Consistent Reaction Field theory. A detailed analysis of the calculated spectra of E-64 and CA030 excitations is given and we have particularly studied the characteristic transitions around 200 nm. For both the E-64 and the CA030 we have identified the chromophore responsible for the characteristic transition of the inhibitors. In addition, we have considered the influence of the interaction of the CA030 with the enzyme cathepsin B by calculating the ultraviolet-visible spectrum of the inhibitor with the cysteine amino acid.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: An investigation is made to find a suitable routing protocol for a millimeter wave ad hoc wireless network. It is discovered that a hierarchical routing protocol is ideal for a high node density. Due to the high bandwidth that is possibly available, with millimeter wave transmission, packets are used to keep links between nodes active and to control data packet congestion. Cluster leaders are elected and use token packets to provide nodes with more queued messages with more transmission chances, assisting the network in congestion control. Hello messages are sent frequently to keep routing information at nodes fresh and to detect broken links quickly. If a broken link is found a new route is readily available, within a second. A simulation is created to test the protocol. Changes are made to the original proactive cluster routing protocol to reduce the route length and lessen routing overhead. A theoretical model is developed to estimate the mean waiting time for a packet. Although insight is gained by modelling the latency with queueing theory it is suggested, due to the protocol’s complexity, to use other mathematical modelling techniques such as a Markov state model or a Petri net. / AFRIKAANSE OPSOMMING: Ondersoek word ingestel na ’n geskikte roete protokol vir ’n millimeter golflengte ad hoc radio pakkie netwerk. Daar word gevind dat ’n hi¨erargiese kluster roete protokol ideaal is vir ’n ho¨e digtheid van nodusse. As gevolg van die ho¨e bandwydte, wat moontlik beskikbaar is met millimeter golflengte transmissie, word pakkies gebruik om kommunikasie skakels tussen nodes in stand te hou en data pakkie verkeersopeenhoping te beheer. Kluster leiers word verkies en gebruik teken-pakkies om nodes met ’n groter data pakkie las meer transmissie kanse te gee. Sodoende word die verkeersopeenhoping van data pakkies verminder. Hallo pakkies word gereeld gestuur om die roete inligting vars te hou en gebroke kommunikasie skakels vinnig op te spoor. As ’n gebroke skakel gevind word, word ’n alternatiewe roete vinnig opgestel, binne ’n sekonde. ’n Simulasie word opgestel om die protokol te toets. Veranderinge aan die oorspronklike proaktiewe kluster protokol word aangebring om roete lengte te verklein en oorhoofse roete inligting kommunikasie te verminder. ’n Teoretiese model gebasseer op tou-staan teorie word ontwikkel om die wagtyd van ’n pakkie te bepaal. Alhoewel, insig verkry is deur die protokol te analiseer deur middel van tou-staan teorie, word daar voorgestel, as gevolg van die protokol se kompleksiteit, om eerder ander wiskundige modelleeringstegnieke te gebruik soos ’n Markov toestands model of ’n Petri net.

Les travaux portent sur l’étude de la formation de motifs sédimentaires à l’aval d’un cylindre vertical soumis à un courant. Le cylindre simule une fondation monopieu d’éolienne en mer, ou une pile de pont. Une modélisation théorique est développée. Les résultats obtenus sont en bon accord avec les résultats expérimentaux acquis au cours de la thèse. Une étude préliminaire expérimentale et théorique sur le tri sédimentaire au voisinage du cylindre est également effectuée. / This work concerns the study of sediment patterns formation downstream a vertical cylinder under a steady current. The cylinder simulates an offshore monopile foundation, or a bridge pile. A theoretical modeling is developed. The results are in good agreement with the experimental results obtained in the framework of this PhD. An experimental and theoretical preliminary study on sediment segregation in the vicinity of the cylinder is also performed.