<p>This paper is concerned with the newly reformed national English test for Chinese college students, called the College English Test (CET) Band 4 (or Level 4). By comparing the test before and after it was reformed, there will be a close examination with regard to the aspects of test reliability, construct validity, authenticity, interactiveness, impact and practicality. With an extra focus on how vocabulary and grammar are tested, the paper aims to investigate the extent to which the new system is considered useful and how effective it is in testing vocabulary and grammar.</p>

This paper is concerned with the newly reformed national English test for Chinese college students, called the College English Test (CET) Band 4 (or Level 4). By comparing the test before and after it was reformed, there will be a close examination with regard to the aspects of test reliability, construct validity, authenticity, interactiveness, impact and practicality. With an extra focus on how vocabulary and grammar are tested, the paper aims to investigate the extent to which the new system is considered useful and how effective it is in testing vocabulary and grammar.

Dans le vaste champ du droit international des affaires, les projets «Build, Operate and Transfer» (BOT) signifiant «Construire, Exploiter et Transférer» et leurs variantes semblent moins connus du fait qu'ils représentent un type particulier d'investissement. La réalisation de ces projets fait intervenir de nombreux acteurs (notamment l'État hôte, la société concessionnaire et les cocontractants) aux intérêts souvent divergents mais qui tendent tous à la satisfaction d'un objectif commun: la réussite du projet. L'une des particularités de ces projets est que l'État ayant un fort taux d'endettement et d'impérieuses contraintes budgétaires limitant la capacité du secteur public aux besoins croissants en matière d'infrastructures, bénéficie sous certaines conditions, la participation du secteur privé qui supporte d'énormes risques financiers. Notre étude se veut d'abord une pénétration des mécanismes contractuels des projets BOT afin de déceler les enjeux qui font leur complexité. C'est à la suite de cette analyse que succèdera l'étude des problèmes juridiques affectant l'enveloppe financière, les garanties étatiques ainsi que l'allocation des risques. Dans la troisième partie, notre réflexion sera relancée pour comprendre des questions multiples liées à la sécurisation des investissements BOT réalisés dans les pays à instabilité politique particulièrement en Afrique. Le bilan s'ouvrira sur une analyse critique des sentences arbitrales ciblées en insistant sur des principes très généraux dont l'application a fait l'objet des débats animés en droit des investissements.

Les mathématiques tropicales sont une branche des mathématiques correspondant à l'étude d'une algèbre modifiée grâce à la redéfinition de l'addition et de la multiplication. Les mathématiques tropicales sont généralement définies grâce au minimum et à l'addition (algèbre min-plus) mais le terme est parfois utilisé pour désigner l'algèbre max-plus, définie grâce au maximum et à l'addition. Briec et Horvath ont introduit une notion de convexité très proche qui apparait comme un cas limite d’opérateurs utilisés en théorie de l’optimisation par Avriel (1972) et de Ben-Tal (1977). En suivant cette ligne d’investigation, nous allons proposer, dans le domaine de l’économie de la production et de l’optimisation de portefeuille, une certaine classe de modèles économiques à élaborés à partir de ces notions. Pour ce faire, nous introduisons une nouvelle classe de technologie de production permettant de prendre en compte les structures d’homothe´tie-translation dans la mesure de productivité au travers du concept de la Convexité Max-Plus. Ensuite, nous allons établir une relation topologique entre plusieurs classes de modèles convexes généralisés connus. Nous analysons pour cela la limite de Painlevé-Kuratowski des modèles CES-CET et des technologies non paramétriques satisfaisant une hypothèse de rendements d’échelle alpha. On montre que leurs limites topologiques convergent vers les modèles de production B-convexe et Cobb-Douglas. Enfin, nous allons montrer que l'amélioration de l'efficacité technique d’une coalition d’entreprises s'avère compatible avec les technologies de semi-treillis dans un jeu coopératif. Nous introduisons ensuite, le concept d’écart absolu moyen dans la sélection du portefeuille en utilisant le « Shortage Function » qui prend en compte simultanément la réduction des inputs et l’augmentation des outputs comme dans la théorie de la production. Enfin, nous allons étendre le concept de B-convexité et de l’inverse B-convexité en se concentrant sur le calcul des mesures d’efficacité technique dans le graphe. / Tropical algebra is the tropical analogue of linear algebra by redefining the usual operation addition by the maximization operation and the usual addition operation as multiplication. Briec and Horvath introduced a concept of convexity very close to this concept quoted above which appears as one of the limits of use of the theory of optimization by Avriel (1972) and Ben-Tal (1977). Following this line of investigation, we give an overview of contributions involving a semilattice structure of production technologies and an optimization portfolio. To do that, firstly, we propose a framework allowing to consider both semilattice structure and translation homothetic properties in productivity measurement. We introduce the concept of Max-Plus convexity which combine both an upper semilattice structure and an additivity assumption. We establish a topological relation between several classes of known generalized convex models using some basic algebraic convex structures. We analyze the Painlevé-Kuratowski limit of the CES-CET and Alpha-returns to scale models. It is shown that their topological limits yield the B-convex and Cobb-Douglas production models. Moreover, we show that the improvement of technical efficiency is compatible with semilattice technologies in a cooperative game. Then, we introduce a criterion to measure portfolio efficiency based upon the minimization of the maximum absolute deviation and minimum absolute deviation from the expected return using the Shortage function. Finally, we derive simple closed-form expressions to calculate the hyperbolic measure in the case of inverse and B-Convexity that evaluates technical efficiency in the full input-output space.

Made available in DSpace on 2014-12-17T14:02:03Z (GMT). No. of bitstreams: 1 PriscilaIAPM.pdf: 1776950 bytes, checksum: 9b264328a0abdee8b5b1062e77c5928c (MD5) Previous issue date: 2006-07-03 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Strandings of live or dead aquatic mammals constitute an important instrument to provide information regarding the occurrence, biology and ecology of these species. The aim of this study was to register the stranded species of cetaceans, the frequency and the spatial-temporal distribution of theses strandings during the period of 1984 to 2005, in the coast of Rio Grande do Norte. Data was acquired through the monitoring of strandings in the north, north-west and south coast of RN, and through information obtained from institutions and newspaper archives of the State. A total of 122 strandings of cetaceans were registered along the coast of Rio Grande do Norte. Of the 14 species of cetaceans registered, four species had higher frequencies: Sotalia guianensis (n= 65), Steno bredanensis (n = 6), Globicephala macrorhynchus (n = 6) and Physeter macrocephalus (n = 7). Out of 118 strandings, 93 occurred in the south coast (78.8 %), 23 in the north coast (19.5%) and 2 (1.7%) in the north-west coast of the State. The highest frequency of strandings occurred during the months of August to March and the maximum number of strandings occurred from 2000 onwards, as a consequence of the intense monitoring of the Pequenos Cet?ceos Project in Rio Grande do Norte / Os encalhes de mam?feros aqu?ticos vivos ou mortos consistem em um instrumento importante na obten??o de informa??es sobre a ocorr?ncia, a biologia e a ecologia das esp?cies. O objetivo do presente trabalho foi registrar as esp?cies de cet?ceos encalhadas, a freq??ncia e a distribui??o espa?o-temporal destes encalhes, durante o per?odo de 1984 a 2005 no litoral do Rio Grande do Norte. Os dados foram coletados atrav?s do monitoramento de encalhes de cet?ceos no litoral norte, noroeste e sul do RN, e atrav?s do levantamento de informa??es sobre encalhes em institui??es e arquivos dos jornais do Estado. Um total de 122 cet?ceos encalhados foi registrado ao longo do litoral do Rio Grande do Norte. Foram registradas 14 esp?cies de cet?ceos, das quais quatro esp?cies apresentaram maior freq??ncia: Sotalia guianensis (n = 65), Steno bredanensis (n = 6), Globicephala macrorhynchus (n = 6) e Physeter macrocephalus (n = 7). Dentre 118 eventos de encalhes, 93 ocorreram no faixa sul (78,8 %), 23 na faixa norte (19,5%) e dois (1,7%) na faixa noroeste do Estado. A maior freq??ncia de encalhes ocorreu entre os meses de agosto a mar?o e o m?ximo n?mero de encalhes foi registrado a partir de 2000, como uma conseq??ncia do intenso monitoramento realizado pelo Projeto Pequenos Cet?ceos do Rio Grande do Norte

Dans le vaste champ du droit international des affaires, les projets «Build, Operate and Transfer» (BOT) signifiant «Construire, Exploiter et Transférer» et leurs variantes semblent moins connus du fait qu'ils représentent un type particulier d'investissement. La réalisation de ces projets fait intervenir de nombreux acteurs (notamment l'État hôte, la société concessionnaire et les cocontractants) aux intérêts souvent divergents mais qui tendent tous à la satisfaction d'un objectif commun: la réussite du projet. L'une des particularités de ces projets est que l'État ayant un fort taux d'endettement et d'impérieuses contraintes budgétaires limitant la capacité du secteur public aux besoins croissants en matière d'infrastructures, bénéficie sous certaines conditions, la participation du secteur privé qui supporte d'énormes risques financiers. Notre étude se veut d'abord une pénétration des mécanismes contractuels des projets BOT afin de déceler les enjeux qui font leur complexité. C'est à la suite de cette analyse que succèdera l'étude des problèmes juridiques affectant l'enveloppe financière, les garanties étatiques ainsi que l'allocation des risques. Dans la troisième partie, notre réflexion sera relancée pour comprendre des questions multiples liées à la sécurisation des investissements BOT réalisés dans les pays à instabilité politique particulièrement en Afrique. Le bilan s'ouvrira sur une analyse critique des sentences arbitrales ciblées en insistant sur des principes très généraux dont l'application a fait l'objet des débats animés en droit des investissements.

Problematic organic pollutants in industrial and drinking water sources are a leading cause of water scarcity. Among the advanced oxidation processes, sonolytic degradation has received considerable attention because it combines oxidation processes initiated by reactive oxidant species and a pyrolysis processes associated with the high temperatures produced during cavitation. The degradation of the semi-volatile compound, MCHM, was rapid and followed pseudo-first order kinetics. The Freundlich kinetic model for heterogeneous systems was successfully applied to describe the non-uniform distribution of MCHM at the gas-liquid interface during ultrasonic treatment. Two primary products were confirmed by GC-MS. Computational studies were also applied to assist in a better understanding of the conformational effects and the pyrolytic pathways. The first-generation antihistamine, diphenhydramine (DPH), was also readily degraded by ultrasound. The heterogeneous process was best fit to a Langmuir-Hinshelwood kinetic model, which indicated a uniform partitioning at the gas-liquid interface. The degradation of DPH was achieved primarily via the addition reaction with hydroxyl radicals to the aromatic rings. Computational studies supported the observed products and the proposed reaction pathways for the pyrolytic and oxidation degradation pathways. Ultrasound was shown to be a rapid and effective method to remediate cetirizine (CET), a second-generation antihistamine. Addition of different hydroxyl radical scavengers into the solution prior to treatment as the competition studies indicated that CET reacted with hydroxyl radicals at the gas-liquid interface and the bulk solution. When the solution was saturated by O2, CET degraded the most rapidly. Degradation products were confirmed by LC-MS analyses. Treatment of the emerging problematic perfluorinated alkyl substance, “GenX” with steady state gamma-radiation under various conditions did not lead to significant degradation. However, “GenX” does react with eaq- at near diffusion-controlled rate, k = 5×1010 M-1·s-1. Titanium dioxide photocatalysis did not lead to appreciable degradation of “GenX” under a variety of conditions even in the presence of oxalic acid or ethanol as the valence band hole quencher. Sonolysis was a promising method and led to the effective mineralization of “GenX” under argon saturated conditions. A detailed computational study of the pyrolytic degradation pathways was carried out using density function in Gaussian 09.

This thesis performs portfolio optimization using three allocation methods, Certainty Equivalence Tangency (CET), Global Minimum Variance (GMV) and Minimum Conditional Value-at-Risk (MinCVaR). We estimate expected returns and covariance matrices based on 7 stock market indices with a DCC-GARCH model including an ARMA (1.1) process and an external regressor of an implied volatility index (VIX). We then simulate returns using a rolling window of 500 daily observations and construct portfolios based on the allocation methods. The results suggest that the model can sufficiently estimate expected returns and covariance matrices and we can outperform benchmarks in form of equally weighted and historical portfolios in terms of higher returns and lower risk. Over the whole out-of-sample period the CET portfolio yields the highest mean returns and GMV and MinCVaR can significantly lower the variance. The inclusion of VIX has marginal effects on the forecasting accuracy and it seems to impair the estimation of risk.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-04-19T14:22:53Z No. of bitstreams: 1 PDF - Wilson Luiz dos Santos Filho.pdf: 775879 bytes, checksum: 770072135e50de9b9e1f8f021d84d6e2 (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-07-22T20:25:20Z (GMT) No. of bitstreams: 1 PDF - Wilson Luiz dos Santos Filho.pdf: 775879 bytes, checksum: 770072135e50de9b9e1f8f021d84d6e2 (MD5) / Made available in DSpace on 2016-07-22T20:25:32Z (GMT). No. of bitstreams: 1 PDF - Wilson Luiz dos Santos Filho.pdf: 775879 bytes, checksum: 770072135e50de9b9e1f8f021d84d6e2 (MD5) Previous issue date: 2014-11-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / From the analysis of Financial Mathematics teaching in Brazil and the confirmation that the majority of the Brazilian population deals, in an inefficient way, with financial tran- sactions, we proposed in this work a strategy to approach a kind of Financial Mathematics capable of turning this theme much more meaningful to High School Students. We recal- led the basic concepts of Financial Mathematics, went through the Financial Education in Brazil, discussed the main Amortization Systems practiced in our country with day-by-day examples and, finally, we presented an interesting application in the calculation of car loans, describing the characteristics of Leasing and Personal Credit (CDC). Besides that, we eli- cited the calculations of Total Effective Cost (CET) of a transaction, applying the use of a Financial Calculator. / A partir da análise acerca do ensino da Matemática Financeira no Brasil e da consta- tação de que grande parte do povo brasileiro lida de forma ineficiente com transações finan- ceiras, propusemos neste trabalho, uma estratégia de abordagem da Matemática Financeira capaz de tornar mais significativo aos alunos do Ensino Médio este tema. Recordamos os conceitos básicos daMatemática Financeira, passeamos pela Educação Financeira no Brasil, discutimos os principais Sistemas de Amortização praticados em nosso país com exemplos corriqueiros e, finalmente, apresentamos uma aplicação interessante no cálculo de um finan- ciamento de veículo, descrevendo as características Leasing e CDC, além de evidenciarmos o cálculo do Custo Efetivo Total (CET) de uma transação, recorrendo ao uso de uma Calcu- ladora Financeira.

Melt convection and solid phase movement play an important role in solidification processes, which significantly influence the formation of grain structures and solute segregations. In general, the melt convection and grain movement are a result of buoyancy forces. The densities within melt are different due to the variation of temperature and concentration, leading to thermally and solutally driven melt convection. Similarly, the density differences between the grains and the bulk melt cause the grain movement, leading to solid sedimentation or grain floating, as the case may be. Free, unattached solid grains are produced by partial remelting and fragmentation of dendrites, by mechanical disturbances such as stirring or vibration and by heterogeneous nucleation of grains in solidification of grain-refined alloys. In this way, movement of solid crystals during solidification can be ascertained in the following two cases. In the first case, during columnar solidification of non-grain-refined alloys, solid movement is possible in the form of dendrite fragments detached from the columnar stalks by the process of remelting and fragmentation. Movement of grains during columnar solidification gives rise to altogether different microstructure from columnar to equiaxed. In the second case, during equiaxed solidification of grain-refined alloys, the movement of solid crystals is possible in the form of equiaxed dendrite crystals nucleated due to presence of grain refiners. The rate and manner by which the free solids settle (or float) will influence macrosegregation in metal castings. Control of the solidification process is possible through an understanding of the solid movement and its effect on macrosegregation and microstructure. With this viewpoint, the overall objective of the present thesis is to study, experimentally and numerically, the phenomenon of solid phase movement during solidification. Through this study, deeper insights of the role of solid phase movement in solidification are developed which can be used for possible control of quality in castings. Both columnar and equiaxed solidification are considered. Models for transport phenomena associated with columnar solidification with solid phase movement are rarely found in the literature, because of inherent difficulty associated with consideration of microscopic features such as remelting and fragmentation. To tackle this problem, solidification modules for remelting and fragmentation are developed first, followed by integration of these molecules in a macroscopic solidification model. A Rayleigh number based fragmentation criterion is developed for detachment of dendrite fragments from the developing mushy zone, which determines the conditions favorable for fragmentation of dendrites. The criterion developed is a function of net concentration difference, liquid fraction, permeability, growth rate of mushy layer, and thermophysical properties of the material. The effect of various solidification parameters on fragmentation is highlighted. The integrated continuum model developed is applied to stimulate the solidification of aqua-ammonia system in a side-cooled rectangular cavity. The numerical results are in good qualitative agreement with those of experiments reported in literature. A gentle ramp of the mushy zone due to settling of solid crystals, as also noticed in experimental literature, is observed towards the bottom of the cavity. The influence of various modeling parameters on solid phase movement and resulting macrosegregation is investigated through a parametric study. Movement of grains during columnar solidification gives rise to altogether different microstructure and sometimes may initiate a morphological transition of the microstructure from columnar to equiaxed if the number and size of equiaxed grains ahead of the columnar front become sufficient to arrest the columnar growth. The generalised model developed, considering solid phase movement during columnar solidification is used to predict columnar-to-equiaxed transition (CET) based on a prescribed cooling rate criterion. It is found that presence of convection significantly affects the solidification behaviour. Moreover, the movement of dendrite fragments and their accumulation at the columnar front further trigger the occurrence of CET. Cooling configuration, too significantly affects the nature of CET. In unidirectional solidification cases, the locations of CET are found to be in a plane parallel to the chill face. However, for the case of the non-unidirectional solidification (as in side-cooled cavity), the locations of CET need not be in a plane parallel to the chill face. In contrast to fixed columnar solidification, equiaxed solidification is poorly understood; in particular, the phenomena associated with solid crystal movement. Movement of unattached solid crystals, formed due to heterogeneous nucleation on grain-refiners, is induced by the convective currents as well as by buoyancy effects, causing the solid to sediment or to float, depending on density of solid compared to that of the bulk melt. While moving in the bulk melt these crystals can also remelt or grow. A series of casting experiments with AI-based alloys are performed to investigate the role and influence of movement of solid crystals on macrosegregation and microstructure evolution during equiaxed solidification. Controlled experiments are designed for studying, separately, settling and floatation of equiaxed crystals for different cooling conditions and configurations. Further, these experiments are carried out in convective and non-convective cases to understand the effect of convection on solid phase movement. Temperature measurements are performed at various locations in the mould during the experiments. After the cavity is solidified, microstructural and chemical analyses of the experimental samples are carried out, several notable features are observed in temperature histories, macrosegregation pattern, and microstructures due to settling/flotation phenomenon of solid crystals. It is found that the flow behavior of solid grains has a profound influence on the progress of solidification (in terms of grain size distribution and fraction eutectic) and macrosegregation distribution. In some cases, the induced flow due to solid phase movement can cause a flow reversal. The observations and quantitative data obtained from experiments, with the help of detailed solidification conditions provided, can be used for future validations of models for equiaxed solidification. Subsequently, numerical studies are carried out, using a modified version of the macroscopic model developed for columnar solidification with motion of solid crystals, to predict the transport phenomena during equiaxed solidification. The model is applied to simulate the solidification processes corresponding to each of the experimental cases performed in this study. For a better understanding of the phenomenon of movement of solid crystals, the following two special cases of solidification are also presented: 1) without movement of solid crystals and 2) movement of solid crystals without any relative velocity between solid and liquid phases. The numerical predictions showing nature of flow field and progress of solidification are substantiated by the experimental data for the thermal analysis, qualitative microstructural Images and quantitative microstructural analysis. It is concluded, with the help of various experiments and simulations, that movement of solid crystals influences the casting quality appreciably, in terms of macrosegregation and microstructures. It is expected that the improved understanding of the role and influence of solid phase movement during solidification processes (both columnar and equiaxed) obtained through this thesis will be useful for possible control of quality of as-cast products.