Dissertations / Theses on the topic 'Negative moments'

Hollow-core flooring units are designed as simply supported members. However, frequently in construction, continuity is established between the units and supporting structure by the addition of insitu topping concrete and steel reinforcement. This change in structural form can result in negative bending moments and axial forces being induced in the floor by seismic and other structural actions. Significant negative moments are induced by load combinations that include the effects of seismic forces due to vertical ground motion. The focus of this research was two failure mechanisms possible under these loading conditions, a flexural failure and a shear failure. Both failure mechanisms were investigated analytically and experimentally. A brittle flexural failure was observed experimentally in a sub assembly test that contained starter bars and mesh reinforcement in the insitu topping concrete. The failure occurred at loads lower than those predicted using standard flexural theory. It appears that, due to the prestressing and low reinforcement ratio of the topping concrete, the assumption that plane sections remain plane is not appropriate for this situation. It is proposed that a strain concentration factor be introduced to account for the effects of tension stiffening. This factor improves the correlation between observed and predicted flexural strength. The second failure mode investigated was a flexure shear failure in a negative moment zone. Flexural cracks reduce the shear strength of a reinforced concrete member. Analytical predictions suggest that some hollow-core floor details could be prone to this type of brittle failure. A flexure shear failure was not observed experimentally; however, this does not eliminate the possibility of this failure mode. A summary of other failure mechanisms possible in hollow-core flooring is also presented. All failure modes should to be considered as part of establishing a hierarchy of failure in the design or retrofit of hollow-core floors.

Cette thèse explore les perspectives algorithmiques de la marche aléatoire branchante et du modèle continu d'énergie aléatoire (CREM). Nous nous intéressons notamment à la construction d'algorithmes en temps polynomial capables d'échan¬tillonner la mesure de Gibbs du modèle avec une grande probabilité, et à identifier le régime de dureté, qui consiste en toute température inverse bêta telle que de tels algorithmes en temps polynomial n'existent pas. Dans le Chapitre 1, nous fournissons un aperçu historique des modèles et moti¬vons les problèmes algorithmiques étudiés. Nous donnons également un aperçu des verres de spin à champ moyen qui motive la ligne de notre recherche. Dans le Chapitre 2, nous abordons le problème de l'échantillonnage de la mesure de Gibbs dans le contexte de la marche aléatoire branchante. Nous identifions une température inverse critique bêta_c, identique au point critique statique, où une tran¬sition de dureté se produit. Dans le régime sous-critique bêta < bêta_c, nous établissons qu'un algorithme d'échantillonnage récursif est capable d'échantillonner efficace¬ment la mesure de Gibbs. Dans le régime supercritique bêta > bêta_c, nous montrons que nous ne pouvons pas trouver d'algorithme en temps polynomial qui appartienne à une certaine classe d'algorithmes. Dans le Chapitre 3, nous portons notre attention sur le même problème d'échan¬tillonnage pour le modèle continu d'énergie aléatoire (CREM). Dans le cas où la fonction de covariance de ce modèle est concave, nous montrons que pour toute température inverse bêta < à l'infini, l'algorithme d'échantillonnage récursif considéré au Chapitre 2 est capable d'échantillonner efficacement la mesure de Gibbs. Pour le cas non concave, nous identifions un point critique bêta_G où une transition de dureté similaire à celle du Chapitre 2 se produit. Nous fournissons également une borne inférieure de l'énergie libre du CREM qui pourrait être d'un intérêt indépendant. Dans le Chapitre 4, nous étudions le moment négatif de la fonction de partition du CREM. Bien que cela ne soit pas directement lié au thème principal de la thèse, cela découle du cours de la recherche. Dans le Chapitre 5, nous donnons un aperçu de certaines orientations futures qui pourraient être intéressantes à étudier
This thesis explores the algorithmic perspectives of the branching random walk and the continuous random energy model (CREM). Namely, we are interested in constructing polynomial-time algorithms that can sample the model's Gibbs measure with high probability, and to indentify the hardness regime, which consists of any inverse temperature bêta such that such polynomial-time algorithms do not exist. In Chapter 1, we provide a historical overview of the models and motivate the algorithmic problems under investigation. We also provide an overview on the mean-field spin glasses that motivates the line of our research. In Chapter 2, we address the sampling problem of the Gibbs measure in the context of branching random walk. We identify a critical inverse temperature bêta_c, identical to the static critical point, that the a hardness transition occurs. In the subcritical regime bêta < bêta_c, we establish a recursive sampling algorithm is able to sample the Gibbs measure efficiently. In the supercritical regime bêta > bêta_c,we show that we cannot find polynomial-time algorithm that belongs to a certain class of algorithms. In Chapter 3, we turn our attention to the same sampling problem for the con¬tinuous random energy model (CREM). For the case where the covariance function of this model is concave, we show that for any inverse temperature bêta < to infinity, the recursive sampling algorithm considered in Chapter 2 is able to sample the Gibbs measure efficiently. For the non-concave case, we identify a critical point bêta_G that similar hardness transition as the one in Chapter 2 occurs. We also provide a lower bound of the CREM free energy that might be of independent interest. In Chapter 4, we study the negative moment of the CREM partition function. While this is not connected directly to the main theme of the thesis, it spins off during the course of research. In Chapter 5, we provide an outlook of some further directions that might be interesting to investigate

Antimicrobial resistance is inhibiting our ability to fight against pathogens. By selectively changing the composition and expression of influx water-filled proteins filling their outer membrane, gram- negative bacteria are able to reduce the rates at which specific polar compounds are able to permeate. A clear comprehension of the mechanism determining substrates diffusion through these pores is still missing. In this thesis, we show how biased computer simulations may offer a unique perspective in the study of molecular permeation through porins, overcoming the intrinsic limitations of both experimental techniques and standard molecular dynamics. The first test-case is Acinetobacter baumannii’s CarO. The use of substrates with varying charge and molecular weight, as well as the creation of a loop-less mutant missing the extracellular domain of the protein, allowed to determine the charge selectivity and the transition rates of polar molecules. We obtained good agreement with the results of liposome swelling assays experiments. Further, we compared the passage of two carbapenem antibiotics in a series of mutated proteins extracted from a patient undergoing long term hospital infection. We connected the mutation of few key residues to a drastic change in the internal electric field of the proteins, showing that the antibiotics follow the choreography of water molecules inside the channels. In the last section, we present a kinetic model that allows to determine for a molecule the relative probability of different conformations and the time required for the translocation through a pore. This approach allowed to connect the results of enhanced sampling MD methods with current blockages in single channel experiments.All these results together show that multiscale MD techniques can offer an exhaustive view on the mechanism of molecular diffusion through pores, helping to understand the most important charac- teristics that determine the rates of translocation of different com- pounds in gram-negative bacteria. We can use these data to com- plement experimental results and to design the next generation of antibiotics.

The Swedish Code of Judicial Procedure (Rättegångsbalken, RB) states that a judgment has binding effects and that the same matter can not be tried twice (17 ch. 11 §). The rule expresses the concept res judicata. It exists to benefit the administration of justice and to an effective economy of justice administration. It also brings security to parties in knowing a conflict has come to a final end. Moreover, the regulation is supposed to direct parties to prepare with all means required, before engaging the court with their dispute. The inconvenience with 11 § is that it is not foreseeable. It can cause a matter, that has not been examined by the court, to be covered by the binding effects – given the legal consequence of the new motion is either the same or alternative and economically equivalent to the previous one. Res judicata then prevents a new examination of the matter, even though the practical causes differ. Thus, it can be questioned if 11 § indeed provides security and predictability to disputing parties. This legal state is a consequence of a vaguely formulated law, the way it is interpreted by the Swedish Supreme Court and in legal scholar. In this essay I examine whether the rule in 11 § is better suited to be formulated by disputing parties themselves, than exclusively through hard law. Should the possibilities for disputing parties to make procedural agreements be expanded, and accordingly allowing parties to gain further insight and control over the binding effects of 17 ch. 11 § RB? The method used to answer this question is legal dogmatics. On the basis of established sources within the Swedish legal system – such as the Law, its motives, rulings from the Swedish Highest Court and legal doctrine – legal dogmatics is sufficient to establish the current legal situation, de lege lata. At the same time the method provides room for a critical perspective on the legal system and opens up for a discussion on what form the legal system should take, de lege ferenda. The conclusion presented in the essay is this. In civil disputes the conflicting parties in question have a major impact over the trial’s framework, on the basis of the principle of dispositions. In accordance with this it is logical for the legal system to allow the parties also to have an influence over the binding effects of 17 ch. 11 § RB. Conflicting parties are in some aspects well suited to make procedural agreements, especially in the form of vindicated settlements. This model, if interpreted in the procedural legal system, could result in predictability for conflicting parties and benefit the economy of justice administration.

Este trabalho enfoca a análise estrutural de um dos tipos de laje que vem ganhando espaço no mercado brasileiro, que é a laje formada por vigotas de concreto protendido. O objetivo principal do trabalho é contribuir na avaliação do comportamento desse tipo de laje com relação aos momentos fletores negativos no apoio, mediante análise teórica. Esta análise foi realizada a partir da relação momento x curvatura proposta pelo CEB-90 em conjunto com a técnica do carregamento incremental para a consideração da não-linearidade física do concreto. Esse método foi avaliado através da comparação com resultados experimentais de painéis alveolares encontrados na literatura, verificando que o modelo teórico representa satisfatoriamente o comportamento estrutural de lajes formadas por elementos pré-moldados protendidos. A partir disto, fez-se análises em situações representativas de projeto de lajes formadas por vigotas protendidas, chegando-se as seguintes conclusões: a) a utilização da continuidade favorece fortemente a redução dos deslocamentos; b) os deslocamentos praticamente independem da taxa de armadura de continuidade; c) a evolução do momento fletor negativo no apoio e momento fletor positivo máximo no vão apresentou um comportamento padrão para os casos analisados; d) esse comportamento foi independente da taxa de armadura de continuidade e e) a taxa de armadura de continuidade afetou praticamente o valor da carga última.
This work aims the structural analysis in a type of slabs that is increasing its utilization in Brazil. These slabs are made by precast prestressed joists. The main objective of this work is the evaluation of the behavior of this type of slabs by theoretical analysis of the bending moments on the supports of continuous slabs. In the theoretical analysis was carried out the consideration of the non-linear of the concrete behavior through the moment x curvature relationship of Model Code CEB-90 add incremental load technique. This methodology was appraised with experimental results of panels of hollow core slabs and this methodology was able to represent satisfactorily the behavior of slabs made by precast prestressed elements. Analysis of representative cases of slabs with precast prestressed joists was carried out and the main conclusions were: a) the use of continuity aids highly to decrease the displacements; b) displacements were practically independent of reinforcement ratio on the support; c) the development profiles of the bending moments had a standard behavior to the analysed cases; d) this behavior was independent of reinforcement ratio on the support and e) the reinforcement ratio on the support affected practically the ultimate load value.

L'objet de la présente thèse était d'examiner les caractéristiques de complexité et de dynamique du momentum psychologique (MP) en sport. Une première série d'études a tenté d'explorer qualitativement (étude 1) et quantitativement (études 2, 3 et 4) ces caractéristiques en situations naturelles de compétitions sportives. L'étude 1 a mis en évidence la richesse des contenus du MP, la diversité de ses mécanismes de déclenchement (dissonance, consonance, perturbation du flux de pensées), ainsi que ses formes de développement au cours du temps (processus d'amplification). Ces résultats témoignent de l'enracinement du MP dans une histoire d'événements signifiante. Les études 2, 3 et 4 ont montré que certains contenus affectifs du MP, tels que l'anxiété compétitive et la confiance en soi, peuvent subir des changements abrupts au cours des phases de MP, ce qui suggère le caractère non linéaire du phénomène. Par conséquent, une seconde série d'études (études 5, 6, 7 et 8) a ensuite été réalisée afin de tester expérimentalement les propriétés potentielles de non linéarité et de dépendance à l'histoire du MP en adoptant l'approche des systèmes dynamiques. Ces études étaient basées sur des scénarios de performance de prise d'ascendant (momentum positif) ou de décrochage (momentum négatif) impliquant des situations d'acteur en position virtuelle (études 5 et 6) ou réelle (étude 7), ou encore des situations de spectateur (étude 8). Le MP est apparu évoluer sous la forme d'un patron d'hystérésis négative (études 5, 6 et 8) ou d'un patron de limite critique décalée (étude 7) dans le sens où le MP négatif se déclenchait plus rapidement que le MP positif. L'hystérésis négative observée chez les spectateurs (étude 8) présentait, quant à elle, une asymétrie évoquant un déclenchement plus rapide du MP positif. Ces résultats attestent des propriétés de non linéarité et de dépendance à l'histoire du MP, montrent l'influence du degré d'implication dans la situation sur sa dynamique et confirment l'hypothèse générale selon laquelle le MP est un phénomène complexe et dynamique
The present thesis aimed to examine the characteristics of complexity and dynamics of psychological momentum (PM) in sport. A first series of studies attempted to explore qualitatively (Study 1) and quantitatively (Studies 2, 3, and 4) these characteristics in natural situations of sport competition. Study 1 evidenced the richness of PM contents, its mechanisms of emergence (dissonance, consonance, and thought flow disturbance), as well as its forms of development over time (amplification processes). These findings suggest that PM is rooted in a meaningful history of events. Studies 2, 3, and 4 showed that certain affective contents, such as competitive anxiety and self-confidence, can change abruptly during PM phases, which suggests the nonlinear character of PM. Consequently, a second series of studies (Studies 5, 6, 7, and 8) was then conducted in order to experimentally test the potential properties of non linearity and history-dependence of PM through the lens of the dynamical systems approach. These studies were based on ascending (positive momentum) versus descending (negative momentum) scenarios of performance that were virtually (Studies 5 and 6) or actually (Study 7) experienced by actors, or that were seen from the point of view of a spectator (Study 8). Variations of PM displayed patterns of negative hysteresis (Studies 5, 6, and 8) and critical boundary that was lagged so that negative PM was triggered faster than positive PM. The negative hysteresis that was found among spectators (Study 8) displayed an asymmetry that reflected a faster triggering for positive PM. These findings evidence the properties of non linearity and history-dependence of PM, show the influence of the degree of involvement in the situation on PM dynamics, and support the general hypothesis that PM is a complex and dynamical phenomenon

Il lavoro è relativo allo studio dei metodi di stima dei parametri di un nuovo modello distributivo proposto recentemente da Zenga. Il modello ha come supporto l'insieme dei numeri reali non negativi, ed è finalizzato a rappresentare distribuzioni per ordine di grandezza, quali ad esempio le distribuzioni dei tempi di attesa e distribuzioni dei redditi. Il modello, dopo aver stabilito la locazione, pone l'attenzione sull'ineguaglianza della distribuzione. Di conseguenza, per la determinazione della stima dei parametri, sembra opportuno impiegare metodi di stima che considerano i valori di statistiche campionarie relative alla locazione, quali media e mediana, e relative all'ineguaglianza. Per tali ragioni, in questo lavoro, si è dato ampio spazio a metodi di stima come il metodo dei momenti e ai metodi basati sulla minimizzazione di indici di accostamento, con l'introduzione di vincoli. Sono state e effettuate delle applicazioni su dati forniti da Eurostat, nelle quali si è confrontato l'adattamento del nuovo modello con quello della distribuzione di Dagum sulla base di indici di ineguaglianza e di scostamenti relativi fra valori campionari e valori teorici di media e mediana.

This thesis reveals the considerable influence of contemplation (sometimes referred to as mysticism) on Anglo-Saxon literature, manifested through the arrangement of narratives according to the theological concepts of apophasis and kenosis. This is demonstrated through a lengthy contextual discussion of the place of contemplation in Anglo-Saxon spirituality, and close analysis of four poems and a prose text. Although English mysticism is commonly thought to start in the High Middle Ages, this thesis will suggest that this terminus post quem should instead be resituated to the Anglo-Saxon period. The first chapter seeks to reveal the centrality of contemplation to Anglo-Saxon spirituality through analysing a range of diverse material, to evidence the monastic reader borne from this culture capable of reading and composing the texts that make up the rest of the thesis in the manner suggested. The thesis places chronologically diverse Anglo-Saxon texts in a contemplative context, with close reference to theology, phenomenology, and narrative structure, to suggest that our interpretation of them should be revised to apprehend the contemplative scheme that they advocate: to cleanse the reader of sin through inspiring penitence and kenosis (humility and emptying of one's will) and direct the mind intellectually beyond the words, images and knowledge of the terrestrial sphere (apophasis), so as to prepare them for the potential coming of God's grace in the form of a vision. This reading is supported by the close taxonomical resemblance of each text's narrative structure. The thesis thus suggests that contemplation was central to Anglo-Saxon spirituality, producing an elite contemplative audience for whom certain texts were designed as preparative apparatus.

Este trabalho aborda um dos tipos construtivos mais empregados em lajes de edificações no Brasil, que são as lajes com nervuras pré-moldadas com armação treliçada. O objetivo principal do trabalho é contribuir na avaliação da continuidade estrutural relativa aos momentos fletores negativos nos apoios destas lajes. Para a realização deste trabalho, as lajes em concreto pré-moldado formadas por vigota com armação treliçada foram analisadas segundo modelos teóricos e experimentais. Na análise teórica, a consideração da não-linearidade física do concreto é realizada a partir do uso da relação momento x curvatura proposta pelo código modelo CEB-90 em conjunto com a técnica do carregamento incremental. Os resultados do modelo teórico são confrontados com os resultados obtidos em ensaios experimentais de faixas de lajes contínuas dimensionadas com diferentes graus de redistribuição dos momentos fletores negativos. Nas análises realizadas observa-se que: a) o modelo teórico apresenta bons resultados comparados aos resultados experimentais, b) as lajes apresentam boa capacidade de rotação plástica, c) com alta taxa de armadura negativa não ocorre redistribuição de esforços, d) as flechas praticamente independem da taxa de armadura negativa e e) a força última é praticamente independente do grau de redistribuição adotado no dimensionamento.
This work deal with an usual type of slab in Brazil: slabs made by precast joist with lattice reinforcement. The goal of this work is the structural analysis of bending moments in the supports of slabs made by this kind of precast element. Theoretical and experimental models analyze this type of slab. In the theoretical analysis, the non-linear concrete behavior is done by moment x curvature relationship of Model Code CEB-90 add incremental load technique. The theoretical model is compared with experimental results of continuous strip slabs designed with different degrees of bending moment redistribution. In these analysis had been noted: a) the theoretical model presents good results compared with the experimental results, b) the slabs present good plastic rotation capacity, c) with high negative reinforcement ratio in the support does not happen moment redistribution, d) the displacement is practically independent of negative reinforcement ratio and e) the ultimate load is practically independent of redistribution degree idealized in the design.

No Brasil, o emprego de estruturas de aço constituídas por perfis formados a frio tem crescido consideravelmente, em virtude da ampla disponibilidade de laminados planos no mercado (chapas finas), bem como pela busca de soluções estruturais mais competitivas. Nesse cenário, pode-se destacar as estruturas mistas de aço e concreto destinadas aos edifícios habitacionais de pequeno porte, em que os tradicionais perfis laminados são substituídos por perfis formados a frio tanto nas vigas como nos pilares. Embora o sistema de vigas mistas possa ser considerado consolidado no campo dos perfis laminados e soldados, o comportamento estrutural no caso de perfis formados a frio necessita de investigação mais aprofundada, de modo a verificar os modos de ruína e a viabilidade do emprego dos modelos teóricos clássicos. Nesse trabalho foi desenvolvido um estudo teórico e experimental sobre as vigas mistas em perfis formados a frio duplo U enrijecido, focalizando a ligação mista (ligação viga-pilar) e consequentemente a resposta estrutural da região de momento fletor negativo. O programa experimental consistiu da análise de dois protótipos cruciformes para determinar a curva momento-rotação, o momento resistente, a rigidez, a capacidade de rotação e identificar modos de falha. Foi possível constatar maior capacidade de rotação da ligação com cantoneiras de assento e de alma quando comparada a uma ligação totalmente soldada. Comparando com o modelo experimental o método dos componentes avaliou de forma razoável a rigidez em serviço, já o método proposto por Leon et. al. superestimou muito esse parâmetro, a capacidade de rotação foi avaliada de forma satisfatória pelos dois métodos. O momento resistente negativo da viga mista obtido experimentalmente apresentou um valor intermediário entre os valores teóricos obtidos por processo plástico e elástico.
In Brazil, the cold-formed steel structures have been widely used justified by the large availability of steel sheets in the market (thin sheets) and the search for more competitive structural solutions. Thus as steel and concrete composite structures are applied in small constructions the traditional hot-rolled one is replaced by cold-formed members in the beams and columns. Even though the composite beams system is known in the hot-rolled and welded shapes field, the structural behavior of the cold-formed steel still needs more accurate investigation to verify the failure modes and the viability of the classic theoretical models. In this work a theoretical and experimental study about cold-formed steel and concrete composite beams was developed, focusing on the beam-to-column connection and the structural behavior on the region of hogging bending. For the experimental program two cruciform models of beam-column connections were analyzed to obtain the moment-rotation curves, the stiffness, and the rotation capacity. It was possible to verify the largest rotation capacity of the connection with the steel seat and web angle when compared with the totally welded connection. In the case of connection the method of the components estimates well the secant stiffness and the rotation capacity presenting a value closer to the ones obtained experimentally, Leon et al. procedures estimated well the initial stiffness and the rotation capacity, but the value of the secant stiffness is much larger than the experimental one. In the case of composite beam the ultimate strength (Mmax) experimentally obtained presented an intermediate value to the ones obtained by the plastic and elastic method.

প্লাজমা ঝিল্লি একটি প্রাথমিক কার্যকরী ইউনিট হিসাবে একটি কোষ দক্ষ কার্যকরী জন্য অপরিহার্য হিসাবে গণ্য করা হয়। এই ঝিল্লিগুলি বহিরাগত কোষের কোষের ভিতরের অংশটিকে পৃথক করে এবং পাশাপাশি এটি জুড়ে চলমান নিয়ন্ত্রনের বাধা হিসাবে কাজ করে। প্লাজমা ঝিল্লিগুলি বিভিন্ন বিভিন্ন উপাদানের সাথে গঠিত, তবে সবার মধ্যে, ঝিল্লি প্রোটিনগুলিকে বৈজ্ঞানিক সম্প্রদায়ের দ্বারা প্লাজমা ঝিল্লির প্রধান কাঠামোগত এবং কার্যকরী স্তম্ভগুলির মধ্যে সর্বসম্মতিক্রমে গ্রহণ করা হয়। বৈজ্ঞানিক গবেষণায়, ঝিল্লী প্রোটিনগুলির কার্যকারিতা গুরুতর রোগের জন্য দায়ী বলে মনে করা হয়েছে। সুতরাং, এটি কৃত্রিম ট্রান্সমেম্রেন প্রোটিন ডোমেনগুলি ডিজাইন এবং বিকাশের জন্য একটি দুর্দান্ত বৈজ্ঞানিক আগ্রহ রয়েছে যা স্বাভাবিকের ত্রুটিগুলির সমাধান করতে সক্ষম। এই প্রোটিন ডোমেনগুলির ভাঁজ গঠন এবং ট্রান্সমেমব্রেন গতিবিদ্যা পিছনে আণবিক শক্তি এবং অন্যান্য পদার্থ-রাসায়নিক প্রক্রিয়াগুলি বোঝা হালনাগাদকৃত কৃত্রিম ট্রান্সমিম্ব্রেন প্রোটিন ডোমেনগুলি বিকাশের প্রক্রিয়ার অবিচ্ছেদ্য অংশ। গত দুই দশক ধরে, বিটা-পেপটাইডগুলি আরও প্রতিশ্রুতিশীল পেপটিডোমিম্যাটিক মোটিফগুলির মধ্যে একটি হিসাবে বিবর্তন হয়েছে। প্রোটিলাইটিক হ্রাসের বিরুদ্ধে অসাধারণ স্থিতিশীলতা এবং স্থিতিশীল হেলিকাল সেকেন্ডারি স্ট্রাকচার যেমন 14 -12- এবং বিকল্প 10 / 1২-হেলিসেসগুলি 4-6 এমিনো এসিডগুলি তৈরি করার ক্ষমতা, এর পিছনে দুটি প্রধান কারণ peptidomimetics মধ্যে β-peptides এর বিমোচন এন্ট্রি। অন্যান্য গুরুত্বপূর্ণ প্যারামিটারগুলির পাশাপাশি পেপটাইডের হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্তটি ট্রান্সমেম্রেন সন্নিবেশ এবং বিস্তারের ক্ষেত্রে গুরুত্বপূর্ণ ভূমিকা বলে মনে করা হয়। পেপটাইডগুলির হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্তের সরাসরি পরীক্ষামূলক সিদ্ধান্ত অত্যন্ত চ্যালেঞ্জিং হচ্ছে, হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্তের সম্ভাব্য প্রভাবগুলি কেবলমাত্র তাত্ত্বিকভাবে প্রস্তাবিত। অতএব, এই থিসিসের প্রধান উদ্দেশ্যগুলি ট্রান্সমেম্রেন সন্নিবেশ এবং বিস্তারের পাশাপাশি পরোক্ষ পরীক্ষার মাধ্যমে সেলুলার উপসর্গের মধ্যে হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্তের সম্ভাব্য ভূমিকা পালন করা। সাধারণভাবে, β-peptides নির্দিষ্ট হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্ত থাকে তবে প্রাকৃতিকভাবে ঘটমান α-peptide analogues এর তুলনায় বিপরীত দিকে থাকে। ধারণাটি হল বিটা-পেপটাইডের একটি ধরণের সনাক্তকরণ এবং সংশ্লেষ করা যার প্রায় মোট কোনও হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্ত নেই এবং β-peptides সহ এবং হেলিক্যাল ম্যাক্রো-ডিপোল ছাড়া ট্রান্সমেমব্রেন সন্নিবেশ স্টাডিজগুলি অন্যান্য সমস্ত পরামিতিগুলিকে ধ্রুবক রাখে। ক্ষেত্রে, তারা ঝিল্লি সন্নিবেশের জন্য কোন ডিফারেনশিয়াল ক্ষমতা প্রদর্শন করে, এটি পরীক্ষামূলকভাবে নিজ নিজ পদার্থ-রাসায়নিক ঘটনায় হেলিক্যাল ম্যাক্রো-ডিপোলের ভূমিকা নির্দেশ করবে। ব্যাপক গবেষণার পরে, বিকল্প β3 / β2-amino অ্যাসিডের সংযোজিত বিকল্প 10/12-হেলিকাল β-peptides তাদের অনন্য রূপান্তরিত অভিযোজন কারণে সামগ্রিক অলঙ্কৃত হেলিক্যাল ম্যাক্রো-ডিপোল পাওয়া যায় নি। অতএব, বিভিন্ন ধরণের β-peptides সহ 14-, 12- এবং বিকল্প 10/12-হেলিক্যাল পেপটাইড তুলনীয় ট্রান্সমেম্রেন দৈর্ঘ্য এবং ক্রম সহ বিভিন্ন সিন্থেটিক কৌশল মিশ্রিত করে সংশ্লেষিত করার পরিকল্পনা করা হয়েছে, যেমন মাইক্রোওয়েভ সহায়তায় ম্যানুয়াল SPPS, অ- মাইক্রোওয়েভ সহায়তায় ম্যানুয়াল SPPS, এবং ফ্লুরোস-ট্যাগ সংযুক্ত তরল ফেজ পেপটাইড সংশ্লেষণ। পরের ধাপে, পেপাইডাইডগুলির ট্রান্সমেমব্রেন সন্নিবেশ হাইড্রোফোবিক মাইক্রো-এনভায়রনমেন্ট সংবেদনশীল ট্রপ-ফ্লোরেসেন্স স্পেকট্রোস্কপি দ্বারা পরীক্ষা করা হবে। তিনটি ভিন্ন লিপিড, ডিএলপিসি / ডিএমপিসি / পিওপিসি এর একই গোষ্ঠীটি বিভিন্ন 14-, 12-এবং বিকল্প 10/12-হেলিক্যাল পেপাইডাইডের জন্য তুলনামূলক দৈর্ঘ্যের সাথে এইভাবে নির্বাচিত হয় যে নেতিবাচক হাইড্রোফোবিক মেলেম্যাচ ধীরে ধীরে একটি প্রায় পুরোপুরি hydrophobic ম্যাচিং পরিস্থিতি। এটি ভালভাবে জানা গেছে যে নেতিবাচক হাইড্রোফোবিক মেলেম্যাচের থ্রেশহোল্ড মানের উপরে ট্রান্সমেমব্রেন সন্নিবেশ সম্ভব নয়। অন্য দিকে, ইথানল মত শর্ট চেইন অ্যালকোহল, অ্যাসিড চেইন interdigitating দ্বারা লিপিড ঝিল্লি বেধ কমানোর একটি উচ্চারণ প্রভাব ভোগ করতে পরিচিত। অতএব, ETOH এর ক্রমবর্ধমান বৃদ্ধি ঘনত্বটি বিভিন্ন পেপটাইডের জন্য ব্যবহার করা হবে এবং একই লিপিডের জন্য একই পেপাইডাইডগুলির জন্য প্রতিটি পেপাইডাইডের জন্য প্রয়োজনীয় ন্যূনতম থ্রেশহোল্ড ঘনত্বের অনুরূপ নেতিবাচক হাইড্রোফোবিক মেলেম্যাচটি সাবধানে ন্যূনতম ক্ষতিপূরণ নেতিবাচক ক্ষতিপূরণ হিসাবে পর্যবেক্ষণ করা হবে। Trp-fluorescence বর্ণালী ক্রিয়ার সাহায্যে সফল ট্রান্সমেমব্রেন সন্নিবেশের জন্য অপরিসীম প্রয়োজন। এই পরীক্ষামূলক ফলাফল থেকে, এই সিদ্ধান্তে পৌঁছানো সম্ভব হবে যে পেপাইডাইডটি ETOH- এর আরো কম ঘনত্বের প্রয়োজন, যা নেতিবাচক মেলামেশের উচ্চতর ক্ষতিপূরণ, লিপিড ঝিল্লিতে পুনর্গঠন করতে সফলভাবে, ট্রান্সমেম্রেন সন্নিবেশ এবং বিস্তারের দিকে কম প্রবণ। ক্ষেত্রে, হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্তের সাথে এবং পেপাইডাইডগুলি এই আচরণের প্রতি কোনও ডিফারেনশিয়াল প্রবণতা প্রদর্শন করে, এটি পরোক্ষভাবে নির্দেশ করে এবং পরীক্ষামূলকভাবে ট্রান্সমেম্রেন সন্নিবেশ এবং স্প্যানিংয়ের মধ্যে হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্তের উল্লেখযোগ্য ভূমিকা যাচাই করবে (যেহেতু পেপাইডাইডগুলির মধ্যে প্রধান পার্থক্য হল হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্তের উপস্থিতি এবং অনুপস্থিতি)। তাছাড়া, লিপিড পরিবেশের অভ্যন্তরে যখন চারিত্রিক হেলিক্যাল প্যাটার্নটি রক্ষণাবেক্ষণ করা হয় কিনা তা ব্যাখ্যা করার জন্য, বিভিন্ন পেপাইডাইডগুলির দ্বিতীয় হেলিক্যাল কাঠামো সমাধান এবং পাশাপাশি অভ্যন্তরীণ লিপিড ভিসিক্যালগুলিতে নির্ধারণ করা হবে। তাপমাত্রা নির্ভর সিডি-স্পেকট্রসকপি দ্বারা সমাধান হিসাবে তুলনায় লিপিড vesicles ভিতরে যখন 14- এবং 10/12-হেলিক্যাল পেপটাইড স্থিতিশীলতা পরিবর্তন করা হয় কিনা তা পরীক্ষা করা হবে। হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্তটি সমাধান বা অভ্যন্তরীণ লিপিড vesicles মধ্যে সেকেন্ডারি হেলিকাল কাঠামো স্থিতিশীল করতে কোনো প্রভাব আছে কিনা তাও ইঙ্গিত করে। অবশেষে, 6-অ্যামিনো অ্যাসিড দীর্ঘ শৃঙ্খল চেইন 14-হেলিকাল এবং 10 / 1২-হেলিকাল 5 (6) -ফ্যাম সংযুক্ত পেপটাইডগুলি মানব ব্রোঞ্চিয়াল এডেনোকার্কিনোমা সেল লাইন A549 ব্যবহার করে সেলুলার আপটেক স্টাডিজের জন্য সংশ্লেষিত হয়। প্রথমটি ক্লোজোজেনিক অ্যাস এবং এমটিটি-অ্যাস দ্বারা একই কোষ লাইনে সাইটোটক্সিসটিটি পরীক্ষা করা হয়। যদি 1 μM ঘনত্ব না হওয়া পর্যন্ত অ-সাইটোটক্সিক পাওয়া যায়, তাহলে ফ্লোরোসেন্স অ্যাক্টিভেটেড সেল সোর্সিং (FACS) দ্বারা পরিমাণগত সেলুলার উত্তোলনের দক্ষতার দিকে আরও গবেষণা 14- এবং বিকল্প 10/12-হেলিক্যাল পেপাইডাইডগুলি হয়। একটি সুপরিচিত কোষ তীক্ষ্ণ পেপটাইড, এইচআইভি -1 ট্যাট, একটি রেফারেন্স মান হিসাবে ব্যবহৃত হয়। দুটি লক্ষ্য পেপটাইডগুলির মধ্যে সেলুলার আপটেক কার্যকারিতাগুলির মধ্যে কোন পার্থক্য পরীক্ষামূলকভাবে নির্দেশ করবে যে হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্তটি ট্রান্সমেমব্রেন সন্নিবেশ এবং বিস্তারকে প্রভাবিত করে না তবে সেলুলার অ্যাকটেককেও নিয়ন্ত্রণ করে। FACS ফলাফলগুলি নিশ্চিত এবং সমর্থন করার জন্য, পেপাইডাইডগুলি কন confocal লেজার স্ক্যানিং ফ্লুরোসেন্স মাইক্রোস্কপি অধীনে দৃশ্যমান হবে। মাইক্রোস্কোপি ইমেজিং প্রদর্শন করবে যে টার্গেট পেপাইডগুলি প্রকৃতপক্ষে সেল অনুপ্রবেশের মাধ্যমে অভ্যন্তরীণ হয় কিনা বা শুধুমাত্র ঝিল্লিতে আটকা পড়ে। উপরন্তু, যদি কোন লক্ষ্য β-peptides উল্লেখযোগ্য কোষ অনুপ্রবেশ ক্ষমতা পাওয়া যায়, এটি নতুনত্ব, হাইড্রোফোবিক, uncharged সেল ভেতরে পেপটাইড (সিপিপি) প্রার্থী যারা proteases উপস্থিতি স্থিতিশীল স্থিতিশীল দিকে একটি নতুন বর্ণমালা খুলতে হবে। অবশেষে, এই সমস্ত গবেষণাগুলি পরীক্ষামূলকভাবে ট্রান্সমেম্রেন সন্নিবেশ, বিস্তার এবং সেলুলার উপসাগরীয় অঞ্চলে ঝিল্লি প্রোটিন ডোমেনের হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্তের নিয়ন্ত্রক প্রভাবের উপর আলোকপাত করবে। এই তথ্যটি এই গুরুত্বপূর্ণ পদার্থ-রাসায়নিক ঘটনাগুলিতে পেপটাইড হেলিক্যাল ম্যাক্রো-ডিপোল মুহূর্তের প্রভাবকে মোকাবেলা করবে এবং β-পেপটাইড ভিত্তিক মডেল ট্রান্সমেম্রেন ডোমেন সিস্টেমগুলি পাশাপাশি β-পেপটাইড-ভিত্তিক নতুন প্রজন্মের কোষ তীব্র পেপটাইডগুলি ডিজাইনে সহায়তা করবে।

GONÇALVES, Fabricio Mota. Evapotranspiração e coeficientes de cultivo (KC) da cana-de-açúcar irrigada por gotejamento subsuperficial. 2010. 64 f. Dissertação (Mestrado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 2010.
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Sugar cane is one of the crops with the highest level of water consumption, with a high evapotranspiration demand throughout most of its cycle. Knowledge of the sugar cane water demand, the time that irrigation should be applied, and how to irrigate the crop are becoming increasingly important for the sustainable development of irrigated sugar cane cultivation, especially in areas of low water availability, as it is the case in northea stern Brazil. The experiment was carried out at the Curu Experimental Field (property of the Embrapa Tropical Agroindustry), located in the Curu-Paraipaba Irrig ation Project, city of Paraipaba-CE (3 ° 29 '20''S, 39 ° 9' 45''W and elevation 30m), in order to determine the evapotrans piration and crop coefficients (Kc) of sugarcane (Saccharum L. officinarium), subsurface drip-irrigated. It was used the SP 6949 sugar cane variety, planted in a spacing of 1.8 m between double rows and 0.4 m between rows within the double row. As to t he irrigation, we used one lateral water line for each double row, buried at a depth of 0.15 m, w ith self-compensating drip emitters, with a flow rate of 1 L h-1, spaced 0.5 m on the water line. The crop was irrigated daily and there were three fertigations per week. The irrigation de pth was periodically adjusted, keeping the soil water potential between -8 kPa to -20 kPa. The crop evapotranspiration (ETc) was determined using a wei ghing lysimeter with a surface area of 2.25 m 2. The reference evapotranspiration (ETo) was estimated by the FAO Penman-Monteith method. The durations of the phenological stages of cane sugar were estimated through analysis of soil cover, with the use of digital images. Durations of 31, 49, 237 and 118 days were observed, respectively for initial, crop development, mid-season and late season stages. The yields achieved within and outside the lysimeter were respectively 144.4 and 108.8 t ha -1 . The total ETc observed during the cycle of the sugar cane was 1074.1 m m, with maximum values of 6.6 mm d-1 during the mid-season stage. Observed Kc values for initial, mid-season and late season stages were respectively 0.23, 1 .03 and 0.50. In the crop development stage, the relationship between Kc and the (crop) soil cover was represented with good accuracy by a negative quadratic model.
A cana-de-açúcar é uma das culturas com maior consumo de água, apresentando uma alta demanda evapotranspirativa ao longo da maior parte do seu ciclo. O conhecimento das necessidades hídricas da cana-de-açúcar, do momento de aplicação da água requerida pela mesma e a forma de aplicação torna-se cada vez mais importante para o desenvolvimento sustentável da sua produção irrigada, principalmente em regiões de pouca disponibilidade hídrica, como é o caso da região Nordeste do Brasil. O experimento foi conduzido no Campo Experimental do Curu, pertencente à Embrapa Agroindústria Tropical localizado no Perímetro Irrigado Curu-Paraipaba, município de Paraipaba-CE (3° 29’ 20’’ S, 39° 9’ 45’’ W e altitude de 30 m), com o objetivo de determinar a evapotranspiração e os coeficientes de cultivo (Kc) da cana-de-açúcar (Saccharum officinarium L.), irrigada por gotejamento subsuperficial. Utilizou-se a variedade de cana SP 6949, plantada no espaçamento de 1,8 m entre fileiras duplas e 0,4 m entre linhas dentro da fileira dupla. Na irrigação utilizou-se uma linha lateral para cada fileira dupla, enterrada na profundidade de 0,15 m, com gotejadores autocompensantes, com vazão de 1 L h-1, espaçados de 0,5 m na linha. A cultura foi irrigada com freqüência diária e foram realizadas três fertirrigações por semana. A lâmina de irrigação foi ajustada periodicamente, mantendo-se o potencial de água no solo entre -8 kPa e -20 kPa. A evapotranspiração da cultura (ETc) foi determinada utilizando-se um lisímetro de pesagem com área superficial de 2,25 m2. A evapotranspiração de referência (ETo) foi estimada pelo método FAO Penman-Monteith. As durações das fases fenológicas da cana-de-açúcar foram estimadas por meio da análise da cobertura do solo pela cultura, determinada com o uso de imagens digitais. Foram observadas durações de 31, 49, 237 e 118 dias, para as fases inicial, de desenvolvimento, intermediária e final, respectivamente. A produtividade alcançada dentro e fora do lisímetro foi de 144,4 e 108,8 t ha-1, respectivamente. A ETc total observada durante o ciclo da cana-de-açúcar foi de 1.074,1 mm, com valores máximos da ordem de 6,6 mm d-1 durante a fase intermediária. Foram observados valores de Kc iguais a 0,23, 1,03 e 0,50, para as fases inicial, intermediária e final, respectivamente. Na fase de desenvolvimento vegetativo a relação entre o Kc e a cobertura do solo pela cultura foi representada com bastante exatidão por um modelo quadrático negativo.

This thesis studies polynomial optimization, that is, the problem of minimizing the value of a polynomial over a semi-algebraic set. Such polynomial optimization problems arise in a wide variety of contexts, both in mathematics, and more generally in science and engineering. In the first part of this thesis, we study a polynomial optimization problem which arises when solving the separability problem in Quantum Information Theory. Our approach is via sums of squares decompositions for polynomials, which provide a natural relaxation for polynomial optimization. Our focus is on the development of practical computational methods to address these problems. We review classical sum of squares relaxations, and give a comparison of the computational complexities between some of the modern state-of-the-art relaxations. Using the insights gained from this analysis we develop a MATLAB package which is able to solve the separability problem in cases which were beyond the reach of previously existing software implementations. In the second part of this thesis, we study the tracial moment problem, which can be thought of as a dual problem to non-commutative polynomial optimization. For the bivariate quartic tracial moment problem, the problem is well understood when the associated Hankel matrix (which has size 7x7) is positive definite, or positive semi-definite and of rank at most 4. Here we examine the Hankel matrix when it is of rank 5 or 6 and show that there are four canonical cases to study. In two out of the four rank 6 cases, we reformulate the existence of a representing measure, to a feasibility problem of three small linear matrix inequalities and a rank constraint. Our results significantly improve previous approaches to the bivariate quartic tracial moment problem. Finally, we also study the tracial moment problem on elliptic curves, giving a reduction to the classical moment problem in two out of the three cases. Furthermore, for the classical moment problem on elliptic curves, we give sufficient conditions for a representing measure to exist.

Dissertação de Mestrado apresentada no ISPA – Instituto Universitário para obtenção de grau de Mestre na especialidade de Psicologia Educacional
O presente trabalho teve o objetivo de investigar a relação entre a frequência de práticas de Comunicação/ diálogo acerca da escola e Suporte/ apoio às tarefas, sobre Emoções Positivas e Negativas, nomeadamente o prazer, zanga e ansiedade. Procurou-se ainda perceber a importância da Solicitação percecionada pelos pais no envolvimento. Neste estudo, contou-se com a participação de 42 pais e 43 alunos de 3º e 4º ano, de uma Escola privada da zona de Lisboa. Foram utilizados dois questionários compostos por uma escala referente ao Envolvimento Parental, outra a emoções e uma terceira alusiva à Solicitação. Ademais, procedeu-se à organização de sessões de focus group com as crianças e foram distribuídas folhas de registo aos pais. Primeiramente, verificou-se que quanto mais os pais referenciavam práticas de diálogo ou apoio, mais os alunos percecionavam envolvimento. Por outro lado, foram observadas diferenças significativas em termos de Emoções Positivas, entre os grupos de alunos e pais com maior frequência de perceção de Comunicação e Suporte, e os que menos experienciaram estas práticas. No que concerne a Solicitação, quanto mais os pais se sentiram chamados a participar, mais envolvidos se percecionaram. Além disto, quanto mais foi percebido um pedido por parte dos filhos, mais as crianças experienciaram diálogo ou apoio dos pais. Os instrumentos qualitativos revelaram-se essenciais para perceber as emoções concretas e constatar uma opinião congruente entre pais e filhos relativa a momentos reais de envolvimento.
The aim of this study relied on understanding the relation between Support and Communication frequency practices and Positive and Negative Emotions: pleasure, anger, and anxiety. The importance of Invitation perceived by parents was also investigated. 42 parents and 43 students from 3rd and 4th grade from a private school in Lisbon accepted to participate in this study. They were asked to respond to a survey regarding practices of involvement, emotions, and Invitation. Furthermore, the students were invited to take part of focus group sessions, and register sheets were send to the parents. First, the results showed that, the more parents perceived to be involved, the more children perceived it too. Besides, differences were found between groups of parents and children, since the ones who perceived more practices, felt more pleasure than the others, especially the ones who alleged less involvement. Concerning Invitation, the more parents considered being asked to participate, the more they assumed to be involved. Additionally, the more parents perceived invitations from their children, the more these assumed higher frequency of practices. Moreover, the qualitative analysis had a main role in this investigation because it allowed us to identify similar opinions between fathers and sons concerning practices and emotions.

Doctor of Philosophy
Department of Physics
Itzhak Ben-Itzhak
The use of ultrafast lasers allows one to study and even control quantum mechanical systems on their natural timescales. Our aim is to study the fragmentation of small molecules in strong laser fields as a means to gain understanding of molecular dynamics and light-matter interactions. Our research group has utilized fast, positively charged molecular ion beams as targets to study and control fragmentation by strong laser fields. This approach allows for detection of all molecular fragments including neutrals, and a coincidence three-dimensional momentum imaging technique is used to characterize the fragmentation. A natural extension of these types of studies is to expand the types of molecular systems that can be studied, from positively charged molecules to neutral and negatively charged molecules. To that end, the primary technical development of this dissertation involved the generation and use of fast, negatively charged molecular beams. Using fast molecular anion beams as targets allows for the study of fragmentation in which all fragments are neutral. As a demonstration, we employ this capability to study F2- dissociation and photodetachment. The dissociation pathways are identified and used to evaluate the initial vibrational population of the F2- beam. The role of dissociation in photodetachment is also explored, and we find that it competes with other dissociative (F+F) and non-dissociative (F2) photodetachment mechanisms. Also highlighted are studies of fragmentation of LiO-, in which the dissociation into Li+O- fragments provides information about the structure of Li O-, including the bond dissociation energy, which was found to be larger than values based on theory. Studies of the autodetachment lifetimes of Li O- were also performed using a pump-probe technique. Additional experimental advancements have made successful pump-probe studies of the ionization of HD+ and Ar2+ possible. Enhancement in the ionization of dissociating HD+ and Ar2+ was observed at surprisingly large internuclear separation where the fragments are expected to behave like separate atoms. The analysis methods used to quantify this enhancement are also described. Finally, the production of excited Rydberg D* fragments from D2 molecules was studied utilizing a state-selective detection method. The carrier-envelope phase dependence of D* formation was found to depend on the range of excited final states of the atomic fragments. We also measured the excited state population of the D* fragments. Together, the studies presented in this work provide new information about fragmentation of positive, negative, and neutral molecules in strong laser fields, and the experimental developments serve as building blocks for future studies that will lead to a better understanding of molecular dynamics.

Η παρούσα μεταπτυχιακή διατριβή εντάσσεται ερευνητικά στην περιοχή της Στατιστικής θεωρίας Αποφάσεων και ειδικότερα στη μελέτη της αρνητικής διωνυμικής κατανομής καθώς επίσης και στην εκτίμηση των παραμέτρων της. Στο Κεφάλαιο 1 παρουσιάζονται κάποιοι χρήσιμοι, για την πορεία της μελέτης μας, ορισμοί και θεωρήματα. Στο Κεφάλαιο 2 μελετάται το μοντέλο της αρνητικής διωνυμικής κατανομής, δίνονται τα χαρακτηριστικά μεγέθη αυτής και παρουσιάζονται οι διαφορετικές παραμετρικοποιήσεις της. Στο Κεφάλαιο 3, εξετάζεται το πρόβλημα εκτίμησης των παραμέτρων της αρνητικής διωνυμικής κατανομής και πιο ειδικά η εκτίμηση για τις διάφορες παραμετρικοποιήσης της. Για περισσότερη ανάλυση χρησιμοποιούνται η εκτίμηση μέγιστης πιθανοφάνειας, η εκτίμηση με τη μέθοδο των ροπών και πιο εξειδικευμένες υπολογιστικές μέθοδοι εκτίμησης. Στο Κεφάλαιο 4, και για το ίδιο πρόβλημα εκτίμησης που πραγματεύεται το προηγούμενο κεφάλαιο, επιλέγεται ο βέλτιστος εκτιμητής των παραμέτρων της αρνητικής διωνυμικής κατανομής και παρουσιάζεται ένα παράδειγμα για την κατανόηση των μεθόδων εκτίμησης.
The master thesis we are going to introduce takes place in the region of Statistical Decision Theory and particularly in studying the Negative Binomial Distribution and the estimation of its parameters. In Chapter 1 some useful definitions and theorems are presented. In Chapter 2 the model of negative binomial distribution is studied and its different parameterizations are discussed. In Chapter 3 we examine the problem of estimating the parameters of our model and for its parameterizations. In particular we give the method of Maximum Likelihood Estimation, the Method of Moments and more specified Estimation Methods. In Chapter 4 and for the same estimation problem, as in previous chapter, it’s been chosen the best estimator of the parameters in our model and it’s been derived an example for the better understanding of the above methods.

While decision-making under uncertainty is a major universal problem, its implications in the field of transportation systems are especially enormous; where the benefits of right decisions are tremendous, the consequences of wrong ones are potentially disastrous. In the realm of highway systems, decisions related to the highway configuration (number of lanes, right of way, etc.) need to incorporate both the traffic demand and land price uncertainties. In the literature, these uncertainties have generally been modeled using the Geometric Brownian Motion (GBM) process, which has been used extensively in modeling many other real life phenomena. But few scholars, including those who used the GBM in highway configuration decisions, have offered any rigorous justification for the use of this model. This thesis attempts to offer a detailed analysis of various aspects of transportation systems in relation to decision-making. It reveals some general insights as well as a new concept that extends the notion of opportunity cost to situations where wrong decisions could be made. Claiming deficiency of the GBM model, it also introduces a new formulation that utilizes a large and flexible parametric family of jump models (i.e., Lévy processes). To validate this claim, data related to traffic demand and land prices were collected and analyzed to reveal that their distributions, heavy-tailed and asymmetric, do not match well with the GBM model. As a remedy, this research used the Merton, Kou, and negative inverse Gaussian Lévy processes as possible alternatives. Though the results show indifference in relation to final decisions among the models, mathematically, they improve the precision of uncertainty models and the decision-making process. This furthers the quest for optimality in highway projects and beyond.