Made available in DSpace on 2016-04-27T16:59:00Z (GMT). No. of bitstreams: 1 Patrick Oliveira de Lima.pdf: 8733714 bytes, checksum: ab9aed451f55100434d75510f10d5dba (MD5) Previous issue date: 2009-11-10 / Secretaria da Educação do Estado de São Paulo / This work has as objective, contribute to the reflection about an important moment in the process of curriculum implementation, in other words, the one which is developed inside of the classroom, analyzing how its plan can be done and where is the teacher related to this process. It has as a theoretician recital the Simon s works about hypothetical trajectories of learning (HTL), expression that he uses to refer to the prognostic from teacher to teach and he uses this expression to show the way that will make the learning process possible. It is a research of qualitative features, because the concern with the process is a constant during the research: the main interest of investigation is the one to evidence how is the planning process and the education accomplishment done, in a growing perspective of learning. The research counts on the contribution of two Math teachers of a public school from São Paulo and their performance among 80 students from high school. In this research, we developed a HTL project about logarithmic functions, searching to involve contextualized situations, interdisciplinary situations and made of activities of problems resolution, involving applications on daily situations, in another knowledge areas and main for the mathematics area. With our work, we intend to contribute to the professional development of the teachers in a consistent way that is intended to be practiced in class, by an articulation strategy between theory, teaching practice and research / O presente trabalho tem como objetivo contribuir para a reflexão sobre um momento importante do processo de implementação curricular, ou seja, aquele que se desenvolve em sala de aula, analisando como pode se dar seu planejamento e qual a participação do professor nesse processo. Tem como fundamentação teórica os trabalhos de Simon sobre trajetórias hipotéticas de aprendizagem (THA), expressão que ele utiliza tanto para fazer referência ao prognóstico do professor para ensinar como para o caminho que possibilitará o processamento da aprendizagem. Trata-se de uma pesquisa de natureza qualitativa, pois a preocupação com o processo é uma constante durante a pesquisa: o interesse principal da investigação é o de evidenciar como se dá o processo de planejamento e realização do ensino, numa perspectiva construtivista de aprendizagem. A pesquisa conta com a colaboração de dois professores de Matemática de uma escola pública estadual de São Paulo e sua atuação junto a 80 alunos de ensino médio. Em nossa pesquisa desenvolvemos uma THA sobre funções logarítmicas, buscando envolver situações contextualizadas, interdisciplinares e constituídas por atividades de resolução de problemas, envolvendo aplicações em situações do cotidiano, em outras áreas de conhecimento e internas à própria Matemática. Com nosso trabalho, pretendemos contribuir para o desenvolvimento profissional dos professores de forma coerente com que se pretende que seja sua prática em sala de aula, mediante uma estratégia de articulação entre teoria, prática docente e pesquisa

Made available in DSpace on 2016-04-27T16:59:00Z (GMT). No. of bitstreams: 1 Rubens de Souza Cabral Junior.pdf: 674945 bytes, checksum: a7b08caccbe5458769ea2ebaed6c2e34 (MD5) Previous issue date: 2009-12-02 / Secretaria da Educação do Estado de São Paulo / The research had as objective to check what are the contributions and difficulties of teachers in planning and developing a hypothetical learning trajectory (HLT) about basic knowledge of probability for high school students. The justification of our research agrees with Simon s statement (1995) that there are a lot of researches in the area of learning with constructivists approach, but very little of their results are incorporated in the classes of teachers. Initially, we did a bibliographic review of the works whose theme is the process of teaching and learning of probability. From these results we made a sequence of teaching probability which we show for three teachers develop with their students, being on tenterhooks to consider the HLT and, at the same time, create new hypotheses about the process of teaching and learning of probabilities. The research shows that teachers who took part in the study have knowledge about the Laplace s approach in introduction of the concept of probability, however they need theoretical support about the possibility of learning basic knowledge of probability using the differences of frequentist and Laplace focus. This fact limited their contributions in the elaboration and development of HLT, leading teachers to a more contemplative than criticism attitude in relation to activities presented / A investigação realizada teve como objetivo verificar quais são as contribuições e dificuldades dos professores em planejar e desenvolver uma trajetória hipotética de aprendizagem (THA) sobre noções iniciais de probabilidade para alunos do Ensino Médio. A justificativa da nossa pesquisa do tipo qualitativa vai ao encontro do que afirma Simon (1995), de que existem muitos trabalhos na área de aprendizagem com abordagem construtivista, porém muito pouco dos seus resultados está incorporado nas elaborações de aulas dos professores. Sendo assim, efetuamos, inicialmente, uma revisão bibliográfica dos trabalhos que têm como tema o processo de ensino e aprendizagem de probabilidade. A partir desses resultados, elaboramos uma sequência de ensino de probabilidade, que foi apresentada para três professores desenvolverem com os alunos, na expectativa de avaliar a THA e ao mesmo tempo elaborar novas hipóteses sobre o processo de ensino e aprendizagem de probabilidades. A pesquisa nos mostra que os professores que participaram do estudo têm conhecimento da abordagem laplaciana na introdução do conceito de probabilidade, no entanto carecem de embasamento teórico sobre a possibilidade de apreensão da noção de probabilidade utilizando-se da confrontação dos enfoques frequentista e laplaciano. Este fato limitou as suas contribuições na elaboração e desenvolvimento da THA, conduzindo os professores a uma atitude mais contemplativa do que crítica em relação às atividades apresentadas

Made available in DSpace on 2016-04-27T16:59:01Z (GMT). No. of bitstreams: 1 Americo Augusto Barbosa.pdf: 1871211 bytes, checksum: b1d025c51844683af5341ce09c48231b (MD5) Previous issue date: 2009-12-08 / Secretaria da Educação do Estado de São Paulo / This dissertation is part of the research project developed by researchers at the Pontifícia Universidade Católica of Sao Paulo, which seeks to develop support materials and curricular innovations to school, taking reference to the notion of Hypothetical Learning Trajectories (THA), a concept used by Dr Simon (1995) as part of the 'model' Cycle of Teaching and Learning of Mathematics. The objective of this research is to analyze the possibility of reconciling perspectives of learning by teaching plans related to the reasons and trigonometric functions and verify the performance of a mathematics teacher in front of a proposal aimed at teaching a constructivist perspective. To answer our questions we developed a qualitative study, collecting data through contents the observation of lessons with teachers and students from three different groups of 2nd year high school public school Education of the State of Sao Paulo. The results indicate that: it is possible to reconcile learning perspective with the planning of education and how important the work of mathematics teacher for learning to occur. We conclude that not just one good result of education, interaction and participation among students and teachers are the main instruments to be made effective a significant learning in a constructivist perspective / Esta Dissertação faz parte do projeto de pesquisa desenvolvido por pesquisadores da Pontifícia Universidade Católica de São Paulo, que procura desenvolver materiais de apoio e inovações curriculares para o Ensino Médio, tomando com referência a noção de Trajetórias Hipotéticas de Aprendizagem (THA), conceito utilizado pelo pesquisador Simon (1995) como parte do modelo de Ciclo de Ensino e de Aprendizagem de Matemática. O objetivo da pesquisa é analisar a possibilidade de compatibilizar perspectivas de aprendizagem com a planificação de ensino relacionada às razões e às funções trigonométricas e verificar a atuação do professor de matemática diante de uma proposta de ensino visando uma perspectiva construtivista. Para responder às nossas questões desenvolvemos uma pesquisa de caráter qualitativo, coletando os dados por meio de relatórios de observação das aulas com professores e alunos de três diferentes turmas de 2º ano do Ensino Médio da rede pública do Ensino Oficial do Estado de São Paulo. Os resultados obtidos indicam que: é possível compatibilizar perspectiva de aprendizagem com a planificação de ensino, e o quanto é importante a atuação do professor de matemática para que ocorra aprendizagem. Concluímos que não basta uma boa sequência de ensino, a interação e a participação entre alunos e professores são os principais instrumentos para que se efetive uma aprendizagem significativa numa perspectiva construtivista

Social dilemmas constitute a broad class of quandaries, including, for example, common pool resource (CPR) dilemmas and public good (PG) dilemmas. CPR's are characterized by non-excludability and rivalry and are often associated with overexploitation. Through similar arguments, the features non-excludability and non-rivalry give rise to under-provision of PG's. The prevalence and inefficiencies often associated with CPR's have given rise to an extensive literature and the role of resource uncertainty has not been ignored. Uncertainty combined with rivalry is often said to augment users' incentive to overexploit. However, underlying most of the theoretical research is an explicit or implicit assumption of symmetric information, or a symmetric lack of information. In reality, people generally have access to different sources of information and they may differ in their abilities to process information. In the first two papers of this thesis, the assumption of symmetry is relaxed and both papers demonstrate that from a welfare perspective, the distribution of uncertainty is also of importance. Many CPR's and PG's are natural, which can complicate the situation. In the traditional resource management literature, the exploited resource is often assumed to be properly characterized by some concave growth function. Today, there is extensive empirical evidence suggesting that many ecosystems have more complex, often non-linear dynamics. Management of such resources can be quite challenging as the non-linear dynamics can make the ecosystem flip between alternate stable states, and even marginal changes can cause radical transformations of such ecosystems. Most of the CPR models assume the shared resource to be of fixed size or to be able to generate a constant flow of services. In the third paper we aim at providing a more complete picture of the overexploitation of a common resource, by combining the institutional structure with complex ecological dynamics. We manage to raise questions and doubts about the standard assumptions. Another feature of convex-concave resources is that a state can become highly robust and sometimes an ecosystem change may even be irreversible. This is problematic if, for example, we wish to restore a degraded ecosystem. The aim of the fourth paper is to empirically analyze this question, by eliciting peoples' preferences through a hypothetical referendum on the issue. / Diss. Stockholm : Handelshögskolan, 2005

<p>Severe accidents in a Light Water Reactor (LWR) have been a subject of the research for the last three decades. The research in this area aims to further understanding of the inherent physical phenomena and reduce the uncertainties surrounding their quantification, with the ultimate goal of developing models that can be applied to safety analysis of nuclear reactors. The research is also focusing on evaluation of the proposed accident management schemes for mitigating the consequences of such accidents.</p><p>During a hypothetical severe accident, whatever the scenario, there is likelihood that the core material will be relocated and accumulated in the lower plenum in the form of a debris bed or a melt pool. Physical phenomena involved in a severe accident progression are complex. The interactions of core debris or melt with the reactor structures depend very much on the debris bed or melt pool thermal hydraulics. That is why predictions of heat transfer during melt pool formation in the reactor lower head are important for the safety assessment.</p><p>The main purpose of the present study is to advance a method for describing turbulent natural convection heat transfer of a melt pool, and to develop a computational platform for cost-effective, sufficiently-accurate numerical simulations and analyses of Core Melt-Structure-Water Interactions in the LWR lower head during a postulated severe core-melting accident.</p><p>Given the insights gained from Computational Fluid Dynamics (CFD) simulations, a physics-based model and computationally-efficient tools are developed for multi-dimensional simulations of transient thermal-hydraulic phenomena in the lower plenum of a Boiling Water Reactor (BWR) during the late phase of an in-vessel core melt progression. A model is developed for the core debris bed heat up and formation of a melt pool in the lower head of the reactor vessel, and implemented in a commercial CFD code. To describe the natural convection heat transfer inside the volumetrically decay-heated melt pool, we advanced the Effective Convectivity Conductivity Model (ECCM), which was previously developed and implemented in the MVITA code. In the present study, natural convection heat transfer is accounted for by only the Effective Convectivity Model (ECM). The heat transport and interactions are represented through an energy-conservation formulation. The ECM then enables simulations of heat transfer of a high Rayleigh melt pool in 3D large dimension geometry.</p><p>In order to describe the phase-change heat transfer associated with core debris, a temperature-based enthalpy formulation is employed in the ECM (the phase-change ECM or so called the PECM). The PECM is capable to represent possible convection heat transfer in a mushy zone. The simple approach of the PECM method allows implementing different models of the fluid velocity in a mushy zone for a non-eutectic mixture. The developed models are validated by a dual approach, i.e., against the existing experimental data and the CFD simulation results.</p><p>The ECM and PECM methods are applied to predict thermal loads to the vessel wall and Control Rod Guide Tubes (CRGTs) during core debris heat up and melting in the BWR lower plenum. Applying the ECM and PECM to simulations of reactor-scale melt pool heat transfer, the results of the ECM and PECM calculations show an apparent effectiveness of the developed methods that enables simulations of long term accident transients. It is also found that during severe accident progression, the cooling by water flowing inside the CRGTs plays a very important role in reducing the thermal load on the reactor vessel wall. The results of the CFD, ECM and PECM simulations suggest a potential of the CRGT cooling as an effective mitigative measure during a severe accident progression.</p>

Severe accidents in a Light Water Reactor (LWR) have been a subject of intense research for the last three decades. The research in this area aims to reach understanding of the inherent physical phenomena and reduce the uncertainties in their quantification, with the ultimate goal of developing models that can be applied to safety analysis of nuclear reactors, and to evaluation of the proposed accident management schemes for mitigating the consequences of severe accidents.  In a hypothetical severe accident there is likelihood that the core materials will be relocated to the lower plenum and form a decay-heated debris bed (debris cake) or a melt pool. Interactions of core debris or melt with the reactor structures depend to a large extent on the debris bed or melt pool thermal hydraulics. In case of inadequate cooling, the excessive heat would drive the structures' overheating and ablation, and hence govern the vessel failure mode and timing. In turn, threats to containment integrity associated with potential ex-vessel steam explosions and ex-vessel debris uncoolability depend on the composition, superheat, and amount of molten corium available for discharge upon the vessel failure. That is why predictions of transient melt pool heat transfer in the reactor lower head, subsequent vessel failure modes and melt characteristics upon the discharge are of paramount importance for plant safety assessment.  The main purpose of the present study is to develop a method for reliable prediction of melt pool thermal hydraulics, namely to establish a computational platform for cost-effective, sufficiently-accurate numerical simulations and analyses of core Melt-Structure-Water Interactions in the LWR lower head during a postulated severe core-melting accident. To achieve the goal, an approach to efficient use of Computational Fluid Dynamics (CFD) has been proposed to guide and support the development of models suitable for accident analysis.   The CFD method, on the one hand, is indispensable for scrutinizing flow physics, on the other hand, the validated CFD method can be used to generate necessary data for validation of the accident analysis models. Given the insights gained from the CFD study, physics-based models and computationally-efficient tools are developed for multi-dimensional simulations of transient thermal-hydraulic phenomena in the lower plenum of a LWR during the late phase of an in-vessel core melt progression. To describe natural convection heat transfer in an internally heated volume, and molten metal layer heated from below and cooled from the top (and side) walls, the Effective Convectivity Models (ECM) are developed and implemented in a commercial CFD code. The ECM uses directional heat transfer characteristic velocities to transport the heat to cooled boundaries. The heat transport and interactions are represented through an energy-conservation formulation. The ECM then enables 3D heat transfer simulations of a homogeneous (and stratified) melt pool formed in the LWR lower head. In order to describe phase-change heat transfer associated with core debris or binary mixture (e.g. in a molten metal layer), a temperature-based enthalpy formulation is employed in the Phase-change ECM (so called the PECM). The PECM is capable to represent natural convection heat transfer in a mushy zone. Simple formulation of the PECM method allows implementing different models of mushy zone heat transfer for non-eutectic mixtures. For a non-eutectic binary mixture, compositional convection associated with concentration gradients can be taken into account. The developed models are validated against both existing experimental data and the CFD-generated data. ECM and PECM simulations show a superior computational efficiency compared to the CFD simulation method. The ECM and PECM methods are applied to predict thermal loads imposed on the vessel wall and Control Rod Guide Tubes (CRGTs) during core debris heatup and melting in a Boiling Water Reactor (BWR) lower plenum. It is found that during the accident progression, the CRGT cooling plays a very important role in reducing the thermal loads on the reactor vessel wall. Results of the ECM and PECM simulations suggest a high potential of the CRGT cooling to be an effective measure for severe accident management in BWRs. / <p>QC 20100812</p>

Ξεκινώντας από το θέμα του Μένωνα, χωρίζεται σε δύο μέρη. Το πρώτο μέρος είναι εμφανές ήδη από την αρχή του διαλόγου, όταν ο νεαρός Θεσσαλός θα απευθύνει το ερώτημα στον Σωκράτη αναφορικά με ποιον τρόπο αποκτάται η αρετή. Σύμφωνα με την σωκρατική τοποθέτηση, το εν λόγω ερώτημα δεν είναι δυνατόν να απαντηθεί, αν πρωτίστως δεν διατυπωθεί ο ορισμός της αρετής, οπότε τίθεται εμμέσως ως το δεύτερο μέρος της θεματολογίας. Το ότι ο Μένων έχει μαθητεύσει πλησίον του Γοργία αποτελεί έναυσμα για τον Σωκράτη, ώστε να προκαλέσει τον συνομιλητή του να ορίσει την αρετή, προφασιζόμενος τον αμνήμονα. Ο Μένων επιχειρεί να ορίσει την έννοια της αρετής τρεις φορές, χωρίς μία ορισμένη επιτυχία, εφόσον ο Σωκράτης κατορθώνει να εντοπίζει σφάλματα. Ωστόσο, ο Μένων, οδηγούμενος σε αδιέξοδο, θα διερωτηθεί: πώς είναι δυνατόν κάποιος να ερευνήσει ένα θέμα το οποίο δεν γνωρίζει, και αν το γνωρίσει πώς γνωρίζει ότι αυτό είναι αυτό που αναζητούσε (το παράδοξο του Μένωνα). Ο Σωκράτης θα απαντήσει στην απορία του επικαλούμενος την θεωρία της ανάμνησης, σύμφωνα με την οποία η γνώση είναι ανάκληση του ήδη υπάρχοντος, έχοντας αναντιλέκτως προϋποθέσει την αθανασία της ψυχής. Μάλιστα θα προχωρήσει και σε απόδειξη της εν λόγω εκδοχής, προβαίνοντας σε ένα μαθηματικό πείραμα με έναν από τους δούλους του Μένωνα. Η θεωρητική παράμετρος που θα αποκομίσουν από την διαδικασία του πειράματος είναι η αξία της έρευνας, όταν σκοπός είναι η προσέγγιση της αλήθειας, όπου απαιτείται μάλιστα και η αποδοχή της άγνοιάς μας. Σε μια αντίστοιχη έρευνα έγκειται και ο φιλοσοφικός προσδιορισμός που επιδιώκει ο Σωκράτης και θα παρακινήσει τον Μένωνα να ερευνήσουν από κοινού για την αρετή. Αυτή τη φορά θα ακολουθήσουν την υποθετική μέθοδο μέσω της οποίας θα εξετάσουν με ποιον τρόπο αποκτάται η αρετή, εφόσον δεν κατόρθωσαν προηγουμένως στην συζήτησή τους να διατυπώσουν έναν επαρκή ορισμό.Η αρετή δεν είναι έμφυτη. Διαφορετικά, θα έπρεπε να διαφυλάττονται οι νέοι που γεννώνται ενάρετοι προκειμένου να μην διαφθαρούν. Η αρετή δεν είναι ούτε διδακτή, εφόσον, έπειτα από διάλογο που παρεμβάλλεται με τον Άνυτο, διαπιστώνουν ότι ούτε οι σοφιστές είναι οι αρμόδιοι δάσκαλοι ούτε και οι πολιτικοί κατόρθωσαν να μεταδώσουν στα τέκνα τους την αρετή. Άρα, ένα πρώτο συμπέρασμα στο οποίο οδηγούνται είναι ότι η αρετή δεν διδάσκεται. Όμως, πώς εξηγείται η διαπίστωση ότι υπάρχουν άνθρωποι που προβαίνουν σε ενάρετες πράξεις; Σε αυτό το σημείο ο Σωκράτης οδηγείται στην εκτίμηση ότι μία παράμετρος τους έχει διαφύγει της ερευνητικής προσοχής. Επαναπροσδιορίζουν τα όσα έχουν συζητηθεί και τελικώς εναποθέτουν τον ενάρετο χαρακτήρα των ανθρώπων στην εκ θεού αποκτηθείσα ορθή γνώμη, εισάγοντας με αυτόν τον τρόπο την διάκριση από την επιστήμη. Ωστόσο, ο διάλογος καταλήγει σε απορία, καθώς δεν διατυπώνεται ένας επαρκής ορισμός για την αρετή. / The main question of platonic dialogue Meno is distinct in two topics. The first one is manifested by the beginning of the dialogue, when younger Thessalian asks Socrates for the way that virtue is acquired. According to Socratic account, this question is impossible to be answered because it is required the formulation of determination of what the virtue is. That is the second topic of this dialogue that is mentioned indirectly. The fact that Meno was student of Gorgias is a Socrates' motivation to challenge his interlocutor to determine the notion of virtue, pretended his ignorance. Meno tries to determine the notion of virtue three times, without successful, since Socrates identifies many errors. However, Meno having reached deadlock wonders himself how someone can investigate something that he does not know it, and by extension if he know it how he can know that this is what he searched about (Meno's paradox). Socrates answers to that paradox with the theory of recollection, having presupposed the immortality of soul. Indeed, he proceed in the evidence of that theory by doing a geometrical experiment with one of Meno's slaves. What they reap from this experiment is the value of researching, for which is required the acceptance of our ignorance. The aim is to approach the Truth. In a similar way lies the philosophical determination that Socrates seeks and he prompts Meno to search about virtue together. In this point they follow the hypothetical method through which they search the way of acquiring the vitrue, since they did not succeed to give a sufficient definition.Areti is not inherent. Otherwise, young guys born virtuous should have been preserved in order not to be corrupted. Areti is not teachable. After the intervening dialogue with Anitos, they result to the fact that neither Sophists nor politicians are appropriate teachers and they are not able to teach the virtue to their children. Therefore, a first conclusion they lied to is that virtue is not teachable. But, how can someone explain the fact that there are people doing virtuous actions? Thus, at this point Socrates realizes that something is missed. They redefine their words and at the end they attribute the virtuous element of people in the orthi gnomi given by god. By this account they introduce the distinction between opinion and science. However, this dialogue result in query because an adequate definition about virtue is not formulated.

OPSOMMING Gebeurlikhede kan omskryf word as onsekere omstandighede van positiewe of negatiewe aard wat, onafhanklik van die verweerder se optrede en indien dit sou realiseer, waarskynlik 'n persoon se gesondheid, inkomste, verdienvermoë, lewenskwaliteit, lewensverwagting of onderhoudsafhanklikheid in die toekoms kan beïnvloed of in die verlede kon beïnvloed het en wat gevolglik op billike en realistiese wyse in ag geneem moet word ter bepaling van die skadevergoedingsbedrag. Die skadevergoedingsbedrag kan vanweë gebeurlikhede verminder of vermeerder word waar die eiser wel met `n oorwig van waarskynlikheid die volle omvang van die skade bewys het, maar die hof nie kon oortuig dat geen ander oorsaak die skade waarskynlik ook sou kon veroorsaak nie (sg "gebeurlikheids-aanpassings"). In gevalle waar die eiser nie die volle omvang van die skade op `n oorwig van waarskynlikheid kon bewys nie, kan die hof nogtans `n verminderde bedrag toeken op grond van die gebeurlikheid dat die skade wel waarskynlik in die toekoms kan realiseer (sg "gebeurlikheidstoekennings"). Die eiser moet getuienis voorlê van gebeurlikhede wat die skadevergoedingsbedrag sal verhoog, en die verweerder van gebeurlikhede wat die skadevergoedingsbedrag sal verlaag. Die waarskynlikheid dat die gebeurlikheid sal realiseer, moet deur die hof aan die hand van objektiewe maatstawwe en op grond van feitelike bewerings en logiese afleidings uit deskundige en ander getuienis in die vorm van `n waarskynlikheidsgraad van tussen vyf persent en tagtig persent uitgedruk word. Hipotetiese kousaliteit word deur die hof aangewend om gebeurlikhede op `n billike wyse in ag te neem en verwys na die kousale ketting van hipotetiese feite wat waarskynlik sou gerealiseer het indien die skadestigtende gebeurtenis nie plaasgevind het nie. Gebeurlikhede kan in twee kategorieë geklassifiseer word: Algemene gebeurlikhede wat gewoonlik in enige stadium by alle persone kan voorkom (bv vroeë dood, siekte ens) en spesifieke gebeurlikhede wat gewoonlik op spesifieke tydstippe by spesifieke individue kan voorkom (bv hertroue, egskeiding ens). Terwyl die hof geregtelik kennis behoort te kan neem van die invloed van algemene gebeurlikhede, behoort die hof hoofsaaklik op grond van ondersteunende getuienis van die invloed van spesifieke gebeurlikhede oortuig te word. Algemene gebeurlikheidsaanpassings is gewoonlik relatief laag (gemiddeld tien persent), terwyl gebeurlikheidsaanpassings vir spesifieke gebeurlikhede fluktueer (gewoonlik tussen vyf persent en vyftig persent), afhangende van die getuienis en omstandighede van die eiser. Gebeurlikheidstoekennings is gewoonlik laer as vyftig persent. SUMMARY Contingencies can be described as uncertain circumstances of a positive or negative nature which, independent of the defendant's conduct and if it should realise, would probably influence a person's health, income, earning capacity, quality of life, life expectancy or dependency on support in future or could have done so in the past, and which must consequently be taken into account in a fair and realistic manner in the quantification of damages. Contingencies can be used to increase or reduce damages in circumstances where the plaintiff succeeded in proving the full loss on a preponderance of probability, but could not convince the court that there was no probability that any other cause could also have given rise to the loss (so-called "contingency adjustments"). In circumstances where the plaintiff could not prove the full loss on a preponderance of probability, the court can nevertheless award a reduced amount on the basis of the contingency that loss could probably realise in future (so-called "contingency allowances"). The plaintiff must adduce evidence of contingencies that can increase damages, and the defendant of contingencies that can reduce damages. The degree of probability that the contingency will realise, must be expressed by the court as a percentage of between five percent and eighty percent, in view of objective measures and on the basis of factual allegations and logical deductions derived from expert and other evidence. Hypothetical causation assists the court in taking account of contingencies in a fair manner and refers to the causal link of hypothetical events which would probably have realised if the damage-causing event did not occur. Contingencies can be classified into two categories: General contingencies that usually can be present in the lives of all people at any point in time (eg early death, sickness, etc) and specific contingencies that usually are present in the lives of specific individuals at specific times (eg remarriage, divorce, etc). While the court should be able to take legal notice of the influence of general contingencies, the court should be convinced of the influence of specific contingencies primarily on the basis of supporting evidence. General contingency adjustments are usually relatively low (on average ten per cent), while contingency adjustments for specific contingencies fluctuate (usually between five per cent and fifty per cent), depending on the evidence and circumstances of the plaintiff. Contingency allowances are usually lower than fifty per cent. / Jurisprudence / LL.D

In the modern industrialized society, a long commuting time is becoming more and more common. However, commuting results in a number of different costs, for example, external costs such as congestion and pollution as well as internal costs such as individual time consumption. On the other hand, increased commuting opportunities offer welfare gains, for example via larger local labor markets. The length of the commute that is acceptable to the workers is determined by the workers' preferences and the compensation opportunities in the labor market. In this thesis the value of travel time or commuting time changes, has been empirically analyzed in four self-contained essays. First, a large set of register data on the Swedish labor market is used to analyze the commuting time changes that follow residential relocations and job relocations. The average commuting time is longer after relocation than before, regardless of the type of relocation. The commuting time change after relocation is found to differ substantially with socio-economic characteristics and these effects also depend on where the distribution of commuting time changes is evaluated. The same data set is used in the second essay to estimate the value of commuting time (VOCT). Here, VOCT is estimated as the trade-off between wage and commuting time, based on the effects wage and commuting time have on the probability of changing jobs. The estimated VOCT is found to be relatively large, in fact about 1.8 times the net wage rate. In the third essay, the VOCT is estimated on a different type of data, namely data from a stated preference survey. Spouses of two-earner households are asked to individually make trade-offs between commuting time and wage. The subjects are making choices both with regard to their own commuting time and wage only, as well as when both their own commuting time and wage and their spouse's commuting time and wage are simultaneously changed. The results show relatively high VOCT compared to other studies. Also, there is a tendency for both spouses to value the commuting time of the wife highest. Finally, the presence of hypothetical bias in a value of time experiment without scheduling constraints is tested. The results show a positive but not significant hypothetical bias. By taking preference certainty into account, positive hypothetical bias is found for the non-certain subjects.

<p><a>Proactive evaluation of road safety is one of the most important objectives of transportation engineers. While current practice typically relies on crash-based analysis after the fact to diagnose safety problems and provide corrective countermeasures on roads, surrogate measures of safety are emerging as a complementary evaluation that can allow engineers to proactively respond to safety issues. These surrogate measures attempt to address the primary limitations of crash data, which include underreporting, lack of reliable insight into the events leading to the crash, and long data collection times. </a></p> <p>Traffic conflicts are one of the most widely adopted surrogate measures of safety because they meet the following two conditions for crash surrogacy: (1) they are non-crash events that can be physically related in a predictable and reliable way to crashes, and (2) there is a potential for bridging crash frequency and severity with traffic conflicts. However, three primary issues were identified in the literature that need to be resolved for the practical application of conflicts: (1) the lack of consistency in the definition of traffic conflict, (2) the predictive validity from such events, and (3) the adequacy of traffic conflict observations.</p> <p>Tarko (2018) developed a theoretical framework in response to the first two issues and defined traffic conflicts using counterfactual theory as events where the lack of timely responses from drivers or road users can produce crashes if there is no evasive action. The author further introduced a failure-based definition to emphasize conflicts as an undesirable condition that needs to be corrected to avoid a crash. In this case, the probability of a crash, given failure, depends on the response delay. The distribution of this delay is adjusted, and the probability is estimated using the fitted distribution. As this formal theory addresses the first two issues, a complete framework for the proper identification of conflicts needs to be investigated in line with the failure mechanism proposed in this theory.</p> <p>The objective of this dissertation, in response to the third issue, is to provide a generalized framework for proper identification of traffic conflicts by considering the failure-based definition of traffic conflicts. The framework introduced in this dissertation is built upon an empirical evaluation of the methods applied to identify traffic conflicts from naturalistic driving studies and video-based tracking systems. This dissertation aimed to prove the practicality of the framework for proactive safety evaluation using emerging technologies from in-vehicle and roadside instrumentation.</p> <p>Two conditions must be met to properly claim observed traffic events as traffic conflicts: (1) analysis of longitudinal and lateral acceleration profiles for identification of response due to failure and (2) estimation of the time-to-collision as the period between the end of the evasion and the hypothetical collision. Extrapolating user behavior in the counterfactual scenario of no evasion is applied for identifying the hypothetical collision point.</p> <p>The results from the SHRP2 study were particularly encouraging, where the appropriate identification of traffic conflicts resulted in the estimation of an expected number of crashes similar to the number reported in the study. The results also met the theoretical postulates including stabilization of the estimated crashes at lower proximity values and Lomax-distributed response delays. In terms of area-wide tracking systems, the framework was successful in identifying and removing failure-free encounters from the In-Depth understanding of accident causation for Vulnerable road users (InDeV) program.</p> <p>This dissertation also extended the application of traffic conflicts technique by considering estimation of the severity of a hypothetical crash given that a conflict occurs. This component is important in order for conflicts to resemble the practical applications of crashes, including the diagnostics of hazardous locations and evaluating the effectiveness of the countermeasures. Countermeasures should not only reduce the number of conflicts but also the risk of crash given the conflict. Severity analysis identifies the environmental, road, driver, and pre-crash conditions that increase the likelihood of severe impacts. Using dynamic characterization of crash events, this dissertation structured a probability model to evaluate crash reporting and its associated severity. Multinomial logistic models were applied in the estimation; and quasi-complete separation in logistic regression was addressed by providing a Bayesian estimation of these models.</p>