Consideration of problem formulation and option assessment (PFOA) for environmental risk assessment: Bt cotton in Vietnam.

2008

A heuristic algorithm for the Capacitated Vehicle Routing Problem with Synchronized Pick-ups and Drop-offs : a case study for medications delivery and supervision in DR Congo

Dans des contextes de post-urgence tels que le vit la partie occidentale de la République Démocratique du Congo (RDC), l’un des défis cruciaux auxquels font face les hôpitaux ruraux est de maintenir un niveau de médicaments essentiels dans la pharmacie. Sans ces médicaments pour traiter les maladies graves, l’impact sur la santé de la population est significatif. Les hôpitaux encourent également des pertes financières dues à la péremption lorsque trop de médicaments sont commandés. De plus, les coûts du transport des médicaments ainsi que du superviseur sont très élevés pour les hôpitaux isolés ; les coûts du transport peuvent à eux seuls dépasser ceux des médicaments. En utilisant la province du Bandundu, RDC pour une étude de cas, notre recherche tente de déterminer la faisabilité (en termes et de la complexité du problème et des économies potentielles) d’un problème de routage synchronisé pour la livraison de médicaments et pour les visites de supervision. Nous proposons une formulation du problème de tournées de véhicules avec capacité limitée qui gère plusieurs exigences nouvelles, soit la synchronisation des activités, la préséance et deux fréquences d’activités. Nous mettons en œuvre une heuristique « cluster first, route second » avec une base de données géospatiales qui permet de résoudre le problème. Nous présentons également un outil Internet qui permet de visualiser les solutions sur des cartes. Les résultats préliminaires de notre étude suggèrent qu’une solution synchronisée pourrait offrir la possibilité aux hôpitaux ruraux d’augmenter l’accessibilité des services médicaux aux populations rurales avec une augmentation modique du coût de transport actuel.

Application of complex extreme learning machine to multiclass classification problems with high dimensionality: a THz spectra classification problem

We extend extreme learning machine (ELM) classifiers to complex Reproducing Kernel Hilbert Spaces (RKHS) where the input/output variables as well as the optimization variables are complex-valued. A new family of classifiers, called complex-valued ELM (CELM) suitable for complex-valued multiple-input–multiple-output processing is introduced. In the proposed method, the associated Lagrangian is computed using induced RKHS kernels, adopting a Wirtinger calculus approach formulated as a constrained optimization problem similarly to the conventional ELM classifier formulation. When training the CELM, the Karush–Khun–Tuker (KKT) theorem is used to solve the dual optimization problem that consists of satisfying simultaneously smallest training error as well as smallest norm of output weights criteria. The proposed formulation also addresses aspects of quaternary classification within a Clifford algebra context. For 2D complex-valued inputs, user-defined complex-coupled hyper-planes divide the classifier input space into four partitions. For 3D complex-valued inputs, the formulation generates three pairs of complex-coupled hyper-planes through orthogonal projections. The six hyper-planes then divide the 3D space into eight partitions. It is shown that the CELM problem formulation is equivalent to solving six real-valued ELM tasks, which are induced by projecting the chosen complex kernel across the different user-defined coordinate planes. A classification example of powdered samples on the basis of their terahertz spectral signatures is used to demonstrate the advantages of the CELM classifiers compared to their SVM counterparts. The proposed classifiers retain the advantages of their ELM counterparts, in that they can perform multiclass classification with lower computational complexity than SVM classifiers. Furthermore, because of their ability to perform classification tasks fast, the proposed formulations are of interest to real-time applications.

A boundary value problem approach to too-short arc optical track association

Given a short-arc optical observation with estimated angle-rates, the admissible region is a compact region in the range / range-rate space defined such that all likely and relevant orbits are contained within it. An alternative boundary value problem formulation has recently been proposed where range / range hypotheses are generated with two angle measurements from two tracks as input. In this paper, angle-rate information is reintroduced as a means to eliminate hypotheses by bounding their constants of motion before a more computationally costly Lambert solver or differential correction algorithm is run.

Node-Depth Encoding and Multiobjective Evolutionary Algorithm Applied to Large-Scale Distribution System Reconfiguration

The power loss reduction in distribution systems (DSs) is a nonlinear and multiobjective problem. Service restoration in DSs is even computationally hard since it additionally requires a solution in real-time. Both DS problems are computationally complex. For large-scale networks, the usual problem formulation has thousands of constraint equations. The node-depth encoding (NDE) enables a modeling of DSs problems that eliminates several constraint equations from the usual formulation, making the problem solution simpler. On the other hand, a multiobjective evolutionary algorithm (EA) based on subpopulation tables adequately models several objectives and constraints, enabling a better exploration of the search space. The combination of the multiobjective EA with NDE (MEAN) results in the proposed approach for solving DSs problems for large-scale networks. Simulation results have shown the MEAN is able to find adequate restoration plans for a real DS with 3860 buses and 632 switches in a running time of 0.68 s. Moreover, the MEAN has shown a sublinear running time in function of the system size. Tests with networks ranging from 632 to 5166 switches indicate that the MEAN can find network configurations corresponding to a power loss reduction of 27.64% for very large networks requiring relatively low running time.

Reconfiguration of distribution networks to minimize loss and disruption costs using genetic algorithms

In this paper a computational implementation of an evolutionary algorithm (EA) is shown in order to tackle the problem of reconfiguring radial distribution systems. The developed module considers power quality indices such as long duration interruptions and customer process disruptions due to voltage sags, by using the Monte Carlo simulation method. Power quality costs are modeled into the mathematical problem formulation, which are added to the cost of network losses. As for the EA codification proposed, a decimal representation is used. The EA operators, namely selection, recombination and mutation, which are considered for the reconfiguration algorithm, are herein analyzed. A number of selection procedures are analyzed, namely tournament, elitism and a mixed technique using both elitism and tournament. The recombination operator was developed by considering a chromosome structure representation that maps the network branches and system radiality, and another structure that takes into account the network topology and feasibility of network operation to exchange genetic material. The topologies regarding the initial population are randomly produced so as radial configurations are produced through the Prim and Kruskal algorithms that rapidly build minimum spanning trees. (C) 2009 Elsevier B.V. All rights reserved.

Den talande bokens poetik : en studie med fokus på olika unga vuxnas reception av tre fiktiva texter inlästa på band

The purpose of the research project The poetics of the talking book is to contribute to the knowledge about patterns of understanding in young adults’ reception of fiction, which they listened to through audio books. The problem explored was: How do different groups of listeners receive fictive text presented as a talking book with variations regarding use of voice, engagement and sound effects? The problem formulation rendered four specific research questions: 1. What patterns can be identified in the listeners’ answers regarding story structure and cognitive content in a comparative perspective comprising different reading styles in the taped versions of the text? 2. What patterns of understanding in interpretative reading can be identified in different listeners? 3. Which thoughts do the listeners have about what the talking book should sound like? 4. What affordances for young adults with the functional disability of mild mental retardation can be made visible through guided literature conversations? The theoretical frame of reference was formed by text–reader-oriented literary theory, psychological schema theory, and research regarding voice quality and communication. The project was carried out in two steps. The first phase was to produce the audio books with two variations of reading practice of three short stories with an existential theme in each text. The second step comprised interviewing of 32 young adults (a special group with a reading handicap in form of mild mental retardation, and a reference group with no handicap). The interviews formed as literary conversation were carried out three times during one year. The phenomenological-hermeneutic approach focused on the life worlds of the participants as meaning seeking beings. The analysis was carried out using method triangulation, mainly using phenomenological meaning concentration. The double hermeneutics in use when interpreting the interpretations of the participants revealed a capacity for aesthetic reading of fiction in the special group as well as in the reference group. The aesthetic qualities were found sufficient in all variations of reading by the professional readers of the audio book they listened to. The young adults also could describe how they wanted the audio book to sound: just as if you were reading yourself. A model describing the analytical steps and concepts in use was a result that can serve as an outline of a poetics for the talking book. Unexpected research results were how important the guided literary conversation turned out to be in order to realise the affordances given by the texts regarding exploration of existential themes in the young adults’ life worlds. Thus the result of the research project can be positioned as a piece of emancipatory research stressing the importance of including this group of young adults in the society’s conversation about culture and meaning.

Alueellistettavien virastojen toimitilojen hankinta

Tutkimus käsittelee julkisia toimitilahankintoja, alueellistamistoimia sekä päätöksentekoprosessia. Tutkimuksen tavoitteena on tutkia julkisiin toimitilahankintoihin liittyvää lainsäädäntöä, toimintamalleja ja määritellä analyyttistä hierarkiaprosessia apuna käyttäen yhdelle valtion virastolle kokonaistaloudellisesti paras mahdollinen toimitila Lappeenrannasta. Tutkimuskohteena on Liikennevirasto, joka osittain alueellistetaan Lappeenrantaan. Kirjallisuuden pohjalta muodostetaan työn laaja teoriapohja, empiirinen aineisto puolestaan koostuu asiantuntija- ja yrityshaastatteluista. Työssä on esitelty lopuksi myös muutama mielenkiintoinen jatkotutkimuksen arvoinen aihe.

Karneval i klassrum – kunskap på hjul : en studie av elevers möten med clown analyserade med narrativ metod och poetisk etnografi

The aim of this study is to contribute to the knowledge about learning in and through art related to pupils’ study processes developing clown characters in secondary school. The pre understanding of this qualitative piece of micro ethnographic research is that the elaboration of clown has openness to play, creative activity and imagination. The art form clown inspires and motivates. The clown character creates a kind and friendly atmosphere, calls upon smile, which promotes learning. It is an art form promoting deep and personal reflection and evoking questions regarding identity formation. The pre understanding finally is that existential themes are brought to articulation in the art form clown. The problem formulation for the hermeneutic phenomenological study is an exploration of the meaning potential of an arts educational work with clown from the pupils’ as well as the teacher’s perspective. The study elaborates the following research questions: 1.) How are the pupils staging themselves in the work with clown? a) How are they constructing the clown character? b) How do they reflect upon their construction? c) What are the characteristics of the working process in the elaboration of clown? 2.) What is characteristic of the teacher’s contribution to the arts educational work? 3.) What is characteristic of the meaning making in the elaboration of clown? One group of 21 pupils and their drama teacher in a Swedish secondary school in six workshops (each one 90 minutes) elaborating the clown theme is the group under study through video observation, interviews, students’ logs and drawings, teacher log and researcher’s field notes. The theoretical framework comprises three perspectives on clown: a perspective on the culture of carnival, a drama education perspective and a performance perspective. Through a content analysis of texts about clown a set of characteristics for the clown is used as analytical concepts in the subsequent analysis of the pupils’ working process when they create three clown characters: August, the white clown and the bag lady. The results are presented as fictive narratives built on the video observations and the interviews. The presentation is brought to even more condensation through poetic ethnographic writing of haiku poems by the researcher. This ethnographic writing is idiomatic to the art form under study, and can be seen as a metaphorical meta commentary to the narratives. As a main result the researcher has developed a model describing the different aspects of the clown characters and the meaning potential of the clown as learning regarding exploration of identity and elaboration of existential questions regarding life, loneliness, love, religion and death.

Certified Rapid Solution of Parametrized Linear Elliptic Equations: Application to Parameter Estimation

We present a technique for the rapid and reliable evaluation of linear-functional output of elliptic partial differential equations with affine parameter dependence. The essential components are (i) rapidly uniformly convergent reduced-basis approximations — Galerkin projection onto a space WN spanned by solutions of the governing partial differential equation at N (optimally) selected points in parameter space; (ii) a posteriori error estimation — relaxations of the residual equation that provide inexpensive yet sharp and rigorous bounds for the error in the outputs; and (iii) offline/online computational procedures — stratagems that exploit affine parameter dependence to de-couple the generation and projection stages of the approximation process. The operation count for the online stage — in which, given a new parameter value, we calculate the output and associated error bound — depends only on N (typically small) and the parametric complexity of the problem. The method is thus ideally suited to the many-query and real-time contexts. In this paper, based on the technique we develop a robust inverse computational method for very fast solution of inverse problems characterized by parametrized partial differential equations. The essential ideas are in three-fold: first, we apply the technique to the forward problem for the rapid certified evaluation of PDE input-output relations and associated rigorous error bounds; second, we incorporate the reduced-basis approximation and error bounds into the inverse problem formulation; and third, rather than regularize the goodness-of-fit objective, we may instead identify all (or almost all, in the probabilistic sense) system configurations consistent with the available experimental data — well-posedness is reflected in a bounded "possibility region" that furthermore shrinks as the experimental error is decreased.

El conflicto organizacional desde una perspectiva psicológica y sociológica

Se destaca como problema central de esta investigación determinar que estilos de dirección hay y como son las relaciones de competencia, cooperación y depredación que se presentan dentro de las distintas clases de conflictos. Para esto se realiza en una descripción de la propuesta de investigación, la formulación del problema y su justificación, se establecen los objetivos tanto generales como específicos y se describirán cuáles han sido los investigadores relevantes y como aportan a esta investigación.

Emociones y toma de decisiones éticas: desarrollo e implicaciones para la empresa

Los líderes organizacionales se deben enfrentar a retos ambientales del mundo de los negocios y diversas presiones que los ponen día a día en un alto riesgo ético. Sortear dichos riesgos ha demandado cambios sustanciales en las dinámicas de las organizaciones contemporáneas, por lo que las exigencias a los directivos de tomar decisiones acertadas en situaciones de alta complejidad moral son cada vez mayores. Estas decisiones involucran un comportamiento ético de quien las toma, lo cual a su vez está mediado por sus emociones.

Genetic Algorithm for the Determination of Linear Viscoelastic Relaxation Spectrum from Experimental Data

Conventional procedures employed in the modeling of viscoelastic properties of polymer rely on the determination of the polymer`s discrete relaxation spectrum from experimentally obtained data. In the past decades, several analytical regression techniques have been proposed to determine an explicit equation which describes the measured spectra. With a diverse approach, the procedure herein introduced constitutes a simulation-based computational optimization technique based on non-deterministic search method arisen from the field of evolutionary computation. Instead of comparing numerical results, this purpose of this paper is to highlight some Subtle differences between both strategies and focus on what properties of the exploited technique emerge as new possibilities for the field, In oder to illustrate this, essayed cases show how the employed technique can outperform conventional approaches in terms of fitting quality. Moreover, in some instances, it produces equivalent results With much fewer fitting parameters, which is convenient for computational simulation applications. I-lie problem formulation and the rationale of the highlighted method are herein discussed and constitute the main intended contribution. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 122-135, 2009

Política de compras e contratações: trajetória e mudanças na administração pública federal brasileira

A tese analisa as mudanças da política de compras e contratações da administração pública federal brasileira descrevendo de forma sistemática os seis casos nos quais as regras e procedimentos sofrem alteração substancial, na forma de leis gerais ou estatutos: a centralização das compras no período Vargas, em dois momentos decisivos (1931 e 1940); a revisão das regras de licitação pelo Decreto-lei n. 200, no contexto da reforma administrativa do governo Castello Branco; a edição de um estatuto das licitações (o Decreto-lei n 2.300) no governo Sarney; a aprovação no Legislativo de uma lei de licitações voltada para o combate à corrupção e ao direcionamento dos contratos públicos (Lei 8.666); a tentativa frustrada de uma nova lei alinhada com a reforma gerencial do primeiro governo Fernando Henrique Cardoso e a criação do pregão como nova modalidade de licitação, em 2000. A pesquisa focaliza o processo político de formulação dos problemas, especificação de soluções e tomada de decisão, com base no modelo de John Kingdon, desdobrando a análise em fluxos do processo político, dos problemas emergentes e das soluções, em cada contexto histórico específico. Os seis casos são descritos por meio de narrativas estruturadas e comparados a partir das categorias do modelo teórico para elucidar como se desenvolveu o processo de mudança, quais os atores relevantes, idéias, modelos e eventos políticos que explicam suas circunstâncias e resultado.

Análise numérica do efeito de fatores influentes da reação álcali-agregado no desempenho de estruturas de concreto

The aim of this work is the numerical simulation of the mechanical performance of concrete affected by Alkali-Aggregate Reaction or RAA, reported by Stanton in 1940. The RAA has aroused attention in the context of Civil Engineering from the early 80, when they were reported consequences of his swelling effect in concrete structures, including cracking, failure and loss of serviceability. Despite the availability of experimental results the problem formulation still lacks refinement so that your solution remains doubtful. The numerical simulation is important resource for the assessment of damages in structures caused by the reaction, and their recoveries The tasks of support of this work were performed by means of the finite element approach, about orthotropic non-linear formulation, and, thermodynamic model of deformation by RAA. The results obtained revealed that the swelling effect of RAA induced decline of the mechanical performance of concrete by decreasing the margin of safety prior to the material failure. They showed that the temperature influences, exclusively, the kinetics of the reaction, so that the failure was the more precocious the higher the temperature of the solid mass of concrete