Robustness on resource allocation problems

En problemes d'assignació de recursos, normalment s'han de tenir en compte les incerteses que poden provocar canvis en les dades inicials. Aquests canvis dificulten l'aplicabilitat de les planificacions que s'hagin fet inicialment. Aquesta tesi se centra en l'elaboració de tècniques que consideren la incertesa alhora de cercar solucions robustes, és a dir solucions que puguin continuar essent vàlides encara que hi hagi canvis en l'entorn. Particularment, introduïm el concepte de robustesa basat en reparabilitat, on una solució robusta és una que pot ser reparada fàcilment en cas que hi hagi incidències. La nostra aproximació es basa en lògica proposicional, codificant el problema en una fórmula de satisfactibilitat Booleana, i aplicant tècniques de reformulació per a la generació de solucions robustes. També presentem un mecanisme per a incorporar flexibilitat a les solucions robustes, de manera que es pugui establir fàcilment el grau desitjat entre robustesa i optimalitat de les solucions.

An approach to coded structured light to obtain three dimensional information

The human visual ability to perceive depth looks like a puzzle. We perceive three-dimensional spatial information quickly and efficiently by using the binocular stereopsis of our eyes and, what is mote important the learning of the most common objects which we achieved through living. Nowadays, modelling the behaviour of our brain is a fiction, that is why the huge problem of 3D perception and further, interpretation is split into a sequence of easier problems. A lot of research is involved in robot vision in order to obtain 3D information of the surrounded scene. Most of this research is based on modelling the stereopsis of humans by using two cameras as if they were two eyes. This method is known as stereo vision and has been widely studied in the past and is being studied at present, and a lot of work will be surely done in the future. This fact allows us to affirm that this topic is one of the most interesting ones in computer vision. The stereo vision principle is based on obtaining the three dimensional position of an object point from the position of its projective points in both camera image planes. However, before inferring 3D information, the mathematical models of both cameras have to be known. This step is known as camera calibration and is broadly describes in the thesis. Perhaps the most important problem in stereo vision is the determination of the pair of homologue points in the two images, known as the correspondence problem, and it is also one of the most difficult problems to be solved which is currently investigated by a lot of researchers. The epipolar geometry allows us to reduce the correspondence problem. An approach to the epipolar geometry is describes in the thesis. Nevertheless, it does not solve it at all as a lot of considerations have to be taken into account. As an example we have to consider points without correspondence due to a surface occlusion or simply due to a projection out of the camera scope. The interest of the thesis is focused on structured light which has been considered as one of the most frequently used techniques in order to reduce the problems related lo stereo vision. Structured light is based on the relationship between a projected light pattern its projection and an image sensor. The deformations between the pattern projected into the scene and the one captured by the camera, permits to obtain three dimensional information of the illuminated scene. This technique has been widely used in such applications as: 3D object reconstruction, robot navigation, quality control, and so on. Although the projection of regular patterns solve the problem of points without match, it does not solve the problem of multiple matching, which leads us to use hard computing algorithms in order to search the correct matches. In recent years, another structured light technique has increased in importance. This technique is based on the codification of the light projected on the scene in order to be used as a tool to obtain an unique match. Each token of light is imaged by the camera, we have to read the label (decode the pattern) in order to solve the correspondence problem. The advantages and disadvantages of stereo vision against structured light and a survey on coded structured light are related and discussed. The work carried out in the frame of this thesis has permitted to present a new coded structured light pattern which solves the correspondence problem uniquely and robust. Unique, as each token of light is coded by a different word which removes the problem of multiple matching. Robust, since the pattern has been coded using the position of each token of light with respect to both co-ordinate axis. Algorithms and experimental results are included in the thesis. The reader can see examples 3D measurement of static objects, and the more complicated measurement of moving objects. The technique can be used in both cases as the pattern is coded by a single projection shot. Then it can be used in several applications of robot vision. Our interest is focused on the mathematical study of the camera and pattern projector models. We are also interested in how these models can be obtained by calibration, and how they can be used to obtained three dimensional information from two correspondence points. Furthermore, we have studied structured light and coded structured light, and we have presented a new coded structured light pattern. However, in this thesis we started from the assumption that the correspondence points could be well-segmented from the captured image. Computer vision constitutes a huge problem and a lot of work is being done at all levels of human vision modelling, starting from a)image acquisition; b) further image enhancement, filtering and processing, c) image segmentation which involves thresholding, thinning, contour detection, texture and colour analysis, and so on. The interest of this thesis starts in the next step, usually known as depth perception or 3D measurement.

A technique for delivering individualised formative problems and examples

Active learning plays a strong role in mathematics and statistics, and formative problems are vital for developing key problem-solving skills. To keep students engaged and help them master the fundamentals before challenging themselves further, we have developed a system for delivering problems tailored to a student‟s current level of understanding. Specifically, by adapting simple methodology from clinical trials, a framework for delivering existing problems and other illustrative material has been developed, making use of macros in Excel. The problems are assigned a level of difficulty (a „dose‟), and problems are presented to the student in an order depending on their ability, i.e. based on their performance so far on other problems. We demonstrate and discuss the application of the approach with formative examples developed for a first year course on plane coordinate geometry, and also for problems centred on the topic of chi-square tests.

Measuring the value of “all play and no work”: can rigorous assessment of simulation games drive innovative teaching in construction?

The construction field is dynamic and dominated by complex, ill-defined problems for which myriad possible solutions exist. Teaching students to solve construction-related problems requires an understanding of the nature of these complex problems as well as the implementation of effective instructional strategies to address them. Traditional approaches to teaching construction planning and management have long been criticized for presenting students primarily with well-defined problems - an approach inconsistent with the challenges encountered in the industry. However, growing evidence suggests that employing innovative teaching approaches, such as interactive simulation games, offers more active, hands-on and problem-based learning opportunities for students to synthesize and test acquired knowledge more closely aligned with real-life construction scenarios. Simulation games have demonstrated educational value in increasing student problem solving skills and motivation through critical attributes such as interaction and feedback-supported active learning. Nevertheless, broad acceptance of simulation games in construction engineering education remains limited. While recognizing benefits, research focused on the role of simulation games in educational settings lacks a unified approach to developing, implementing and evaluating these games. To address this gap, this paper provides an overview of the challenges associated with evaluating the effectiveness of simulation games in construction education that still impede their wide adoption. An overview of the current status, as well as the results from recently implemented Virtual Construction Simulator (VCS) game at Penn State provide lessons learned, and are intended to guide future efforts in developing interactive simulation games to reach their full potential.

The CURE scale: a multidimensional measure of service recovery strategy

Purpose – This paper aims to address the gaps in service recovery strategy assessment. An effective service recovery strategy that prevents customer defection after a service failure is a powerful managerial instrument. The literature to date does not present a comprehensive assessment of service recovery strategy. It also lacks a clear picture of the service recovery actions at managers’ disposal in case of failure and the effectiveness of individual strategies on customer outcomes. Design/methodology/approach – Based on service recovery theory, this paper proposes a formative index of service recovery strategy and empirically validates this measure using partial least-squares path modelling with survey data from 437 complainants in the telecommunications industry in Egypt. Findings – The CURE scale (CUstomer REcovery scale) presents evidence of reliability as well as convergent, discriminant and nomological validity. Findings also reveal that problem-solving, speed of response, effort, facilitation and apology are the actions that have an impact on the customer’s satisfaction with service recovery. Practical implications – This new formative index is of potential value in investigating links between strategy and customer evaluations of service by helping managers identify which actions contribute most to changes in the overall service recovery strategy as well as satisfaction with service recovery. Ultimately, the CURE scale facilitates the long-term planning of effective complaint management. Originality/value – This is the first study in the service marketing literature to propose a comprehensive assessment of service recovery strategy and clearly identify the service recovery actions that contribute most to changes in the overall service recovery strategy.

Perspectives on the specification of Building Integrated Photovoltaic (BIPV) technology in construction projects

Innovative, low carbon technologies are already available for use in the construction of buildings, but the impact of their specification on construction projects is unclear. This exploratory research identifies issues which arise following the specification of BIPV in non-residential construction projects. Rather than treating the inclusion of a new technology as a technical problem, the research explores the issue from a socio-technical perspective to understand the accommodations which the project team makes and their effect on the building and the technology. The paper is part of a larger research project which uses a Social Construction of Technology Approach (SCOT) to explore the accommodations made to working practices and design when Building Integrated PhotoVoltaic (BIPV) technology is introduced. The approach explores how the requirements of the technology from different groups of actors (Relevant Social Groups or RSG's) give rise to problems and create solutions. As such it rejects the notion of a rational linear view of innovation diffusion; instead it suggests that the variety and composition of the Relevant Social Groups set the agenda for problem solving and solutions as the project progresses. The research explores the experiences of three people who have extensive histories of involvement with BIPV in construction, looks at how SCOT can inform our understanding of the issues involved and identifies themes and issues in the specification of BIPV on construction projects. A key finding concerns the alignment of inflection points at which interviewees have found themselves changing from one RSG to another as new problems and solutions are identified. The points at which they change RSG often occurred at points which mirror conventional construction categories (in terms of project specification, tender, design and construction).

A multicentre randomized controlled trial of an empowerment-inspired intervention for adolescents starting continuous subcutaneous insulin infusion : a study protocol

Background. Continuous subcutaneous insulin infusion (CSII) treatment among children with type 1 diabetes is increasing in Sweden. However, studies evaluating glycaemic control in children using CSII show inconsistent results. Omitting bolus insulin doses using CSII may cause reduced glycaemic control among adolescents. The distribution of responsibility for diabetes self-management between children and parents is often unclear and needs clarification. There is much published support for continued parental involvement and shared diabetes management during adolescence. Guided Self-Determination (GSD) is an empowerment-based, person-centred, reflection and problem solving method intended to guide the patient to become self-sufficient and develop life skills for managing difficulties in diabetes self-management. This method has been adapted for adolescents and parents as Guided Self-Determination-Young (GSD-Y). This study aims to evaluate the effect of an intervention with GSD-Y in groups of adolescents starting on insulin pumps and their parents on diabetes-related family conflicts, perceived health and quality of life (QoL), and metabolic control. Here, we describe the protocol and plans for study enrolment. Methods. This study is designed as a randomized, controlled, prospective, multicentre study. Eighty patients between 12-18 years of age who are planning to start CSII will be included. All adolescents and their parents will receive standard insulin pump training. The education intervention will be conducted when CSII is to be started and at four appointments in the first 4 months after starting CSII. The primary outcome is haemoglobin A1c levels. Secondary outcomes are perceived health and QoL, frequency of blood glucose self-monitoring and bolus doses, and usage of carbohydrate counting. The following instruments will be used to evaluate perceived health and QoL: Disabkids, 'Check your health', the Diabetes Family Conflict Scale and the Swedish Diabetes Empowerment Scale. Outcomes will be evaluated within and between groups by comparing data at baseline, and at 6 and 12 months after starting treatment. Results and discussion. In this study, we will assess the effect of starting an insulin pump together with the model of Guided Self-Determination to determine whether this approach leads to retention of improved glycaemic control, QoL, responsibility distribution and reduced diabetes-related conflicts in the family. Trial registration: Current controlled trials: ISRCTN22444034

Attraktivt arbete ur enhetschefers perspektiv : En kvalitativ studie genomförd i Falu kommun

Sedan 1990- talet har de offentliga organisationerna genomgått flera stora förändringar som medfört att enhetschefer inom den kommunala verksamheten fått ökat ansvar och befogenheter, vilket gör enhetschefsrollen mer komplext. Rapporter visar på svårigheter att rekrytera och behålla chefer, därför är viktigt att undersöka hur enhetschefens arbete ska kunna utvecklas till ett mer attraktivt arbete. Ett attraktivt arbete skapas genom att ge medarbetarna bra förutsättningar inom arbetsinnehåll, arbetstillfredsställelse, samt arbetsförhållanden. I chefsyrket ingår tre roller varav en är medarbetarrollen som enligt teorin inte är speciellt prioriterad eller synliggjord. Studiens syfte är att identifiera vad som gör enhetschefyrket till ett attraktivt arbete samt hur det kan utvecklas. I studien har en kvalitativ forskningsmetod används för att uppnå en djupare förståelse kring enhetschefernas arbetssituation. Detta har bidragit till att ett hermeneutiska synsätt valts, då vi strävar efter att få en ökad förståelse. Studien genomfördes på Falu kommun, där sex enhetschefer inom omvårdnadsförvaltningen intervjuades. Resultatet visar att enhetscheferna är tillfredsställda med sin arbetssituation och upplever arbetet som attraktivt. Faktorer som varierande, handlingsfrihet, problemlösning, sociala kontakter och delar av erkänsla hör till attraktivitetsfaktorer i yrket. Enhetscheferna beskriver tre utvecklingsområden för att öka attraktiviteten. Det första innefattar ledarskapet i organisationen där brister förekommer inom kommunikation och planering. Andra utvecklingsområdet handlar om arbetstakten genom att individanpassa arbetsgruppernas storlek samt tid för reflektion och återhämtning. Tredje utvecklingsområdet enhetscheferna belyser är bristen på erkänsla från organisationen. Utöver enhetschefernas brister har vi identifierat ytterligare ett utvecklingsområde för att öka attraktiviteten. Under intervjuerna har det framkommit att det råder stor avsaknad av kollegor att "bolla idéer" med vilket i sin tur medför att arbetet upplevs som ensamt. För att motverka ensamheten är chefsgruppshandledning ett alternativ, där reflektion och feedback ingår. Forskningen visar att detta även leder till ökad självkänsla, engagemang.

Agir, aprender, formar, intervir, agir uma experiência dos consultores internos na gestão do conhecimento da Petrobrás UN-RNCE

This research aims at studying the formation of internal consultants in organizational setting in the joint resolution of problems, around the conversion of knowledge. The objective of research is to understand and explain the meanings attributed by Petrobras internal consultants to their practice and training for the conversion process of tacit knowledge into explicit, around the joint resolution of their problems with their collaborators. It has directed the next question: what the meanings assigned by the consultants of Unidade de Negócios Rio Grande do Norte e Ceara (UN-RNCE) in Knowledge Management (KM), for their interventionist and formative practices in problem solving, as well as conversion of tacit knowledge in explicit? This paper has assumed that there is a dual logic integrated into its daily practices: solving troubles and converting knowledge. The thesis has considered the daily practices of these consultants are characterized as epistemic spaces and permanent education through the conversion of knowledge. It has adopted the principles of multi-referential approach as foundations, regarding the translation of a variety of angles, perspectives and prospects which allow the interpretation and understanding of complex issues that are part of conversion of knowledge. The understanding and explanation of the senses are based on the methodology of the comprehensive interview; taking ownership is the sensitive listening for comprehensive interpretation of oral discourses of ten consultants, in addition to the autoscopy that putting into practice, thus, the stance of the researcher as an intellectual craftsman. Furthermore, it has assessed that the limits and possibilities for training and learning in the conversion of knowledge arise, on one hand from a predominantly driven training culture by the paradigm of technical rationality and one the other hand, from a set of relationship to knowledge and relation to know , revealed in the search for training in other dimensions. There are tensions between the local and global demands located in a situation marked by a systemic organization of knowledge. However, the context is perceived by researchers as impregnated by the discontinuity, unpredictability and uncertainty; mobilizing a number of elements necessary for the mediation in training practices of these consultants. Finally, it has set an instrumental and technological support, restricting the formation and undermining the position of the consultancy as nuclear function in Knowledge Management

Reinternações psiquiátricas no Rio Grande do Norte: implicações e impacto das novas estratégias de atenção à saúde mental

The Brazilian Psychiatric Reform based on the desinstitucionalization of the assistance, translated to the emphasis on community/territorial treatment and in the social inclusion of the mental suffering, promoted advances in the psychiatric restructuring. In the Rio Grande do Norte (RN), we can enumerate as advances of the Brazilian Psychiatric Reform the expansion of the mental health care chain and the implementation of some strategies that, together, aims to further the psychosocial attention of the individual with psych suffering and to reduce the indices of psychiatrics readmissions in the state. In the current Brazilian‟s mental health situation we were interesting in answered the following question: what the impact of the substitutes services‟ extension in the revolving door phenomenon? This search aims to analyze the revolving door phenomenon occurrences based on the news strategies of mental health care in the Rio Grande do Norte. This is a descriptive-exploratory study with a qualitative approach, oriented by the theoretical framework of critical-dialectical approach about the Brazilian Psychiatric Reform and using the thematic oral history as method of information collects. The search was realized on the Hospital João Machado (HJM), estate reference in psychiatric treatment, and the participants was 20 professionals that work on it. The collection of information had started after the approval of the UFRN Research Ethics Committee with the opinion number 216/2011 and CAAE number 0021.0.051.000-11 and was realized using the direct observation and semi-structured interview. The study‟s results were categorized in two categories and five subcategories of analysis. CATEGORY 1) Current situation of the mental health care chain in the RN, with the subcategories: 1.1 Impact of the new services of mental health care in the revolving door phenomenon in the RN; 1.2 Implications of the new services of mental health care in assisting user to the HJM; 1.3 Issues the permeate the mental health care chain in the RN. CATEORY 2) Main causes of the revolving door phenomenon in HJM, with the categories: 2.1 Family problems; 2.2 Lack of assistance after discharge from psychiatric hospital. In summary, we conclude that the extension of the mental health care chain contributed for the reduction of the psychiatrics re-hospitalization‟s indices in RN. However, we realized that territorial services of mental health care are not the only responsible for the revolving door phenomenon. Factors as family problems and the disarticulation of the assistance after the discharge from hospital influence on the perpetuation of hospitalizations and re-hospitalizations in the local scenario. To study the revolving door phenomenon that occur in the psychiatrics‟ assistance considering the news strategies of mental health care allowed us to approach the advances and challenges brought by the RPb and by the desinstitucionatization in the state, indicating the need for further discussions and problem-solving strategies of psychosocial care.

A estratégia didática de resolução de problemas na formação de professores de química

In this work it is presented a research developed in the initial training of teachers of the chemistry graduation course at the Universidade Federal do Rio Grande do Norte (UFRN). The intervention was realized in two classes in the context of a discipline in the curricular structure with nineteen undergraduate students of chemistry. The study utilizes characteristics of the qualitative approach and uses observation, questionnaires, interviews and examination papers. The experiment involved a sequence of activities fundamented on the Problem Solving (PS) teaching strategy to approach chemical concepts. The proposal was planned and organized according to the theoretical presupposition of the work developed by the authors of the Science Education in PS, of teaching experience and from the initial hypotheses of the research. The goal was that the future teachers could experience the strategy and advance to the new meanings. The themes addressed in the activities were the difference between exercises and problems, exercises turning into problems, the steps of problem solving and some implications of the teaching strategy for the work of the teacher. The results showed evidence that through a process of collective reflection, and from the difficulties experienced in the strategy practice, the undergraduates are introduced to new perspectives of reflection and action of teaching practice, and understanding some benefits of innovative proposals for the teaching of chemistry. It also showed that, although this theme is approached, in some moments of the graduation, the future teachers don‟t know when or how to realize activities in this perspective. From the aspects that rose in research we highlighted the difficulties in the problem solving steps, the use of the strategy in school and the knowledge and skills of the teacher for planning activities in Problem Solving

Percepção do egresso de enfermagem sobre a contribuição do curso para o exercício do cuidado

O estudo avaliou a formação em enfermagem ancorada na problematização e na aprendizagem baseada em problemas a partir da percepção dos egressos. Trata-se de estudo transversal de natureza ex-post-facto. Os resultados foram analisados na triangulação das abordagens quantitativa e qualitativa e na perspectiva hermenêutica dialética. Na abordagem quantitativa 180 egressos responderam um questionário. Na qualitativa, 14 participaram das entrevistas, que buscaram sentidos relacionados ao cuidado ideal, para construção dos indicadores que revelassem a lógica da avaliação. Esses indicadores nortearam a escolha das questões para triangulação. Os resultados apontaram que 85,1% dos egressos estão inseridos no mercado de trabalho, 92,1% cursaram pós-graduação e 99,1% acreditam apresentar formação necessária ao cuidado ético, humanizado e fundamentado. A análise dos dados aponta para formação comprometida com a construção da autonomia e do conhecimento, bem como articulada aos princípios do Sistema Único de Saúde e do mundo do trabalho em enfermagem.

Logarithmic barrier-augmented Lagrangian function to the optimal power flow problem

This paper presents a new approach to solve the Optimal Power Flow problem. This approach considers the application of logarithmic barrier method to voltage magnitude and tap-changing transformer variables and the other constraints are treated by augmented Lagrangian method. Numerical test results are presented, showing the effective performance of this algorithm. (C) 2005 Elsevier Ltd. All rights reserved.

Fourth-order method for solving the Navier-Stokes equations in a constricting channel

A fourth-order numerical method for solving the Navier-Stokes equations in streamfunction/vorticity formulation on a two-dimensional non-uniform orthogonal grid has been tested on the fluid flow in a constricted symmetric channel. The family of grids is generated algebraically using a conformal transformation followed by a non-uniform stretching of the mesh cells in which the shape of the channel boundary can vary from a smooth constriction to one which one possesses a very sharp but smooth corner. The generality of the grids allows the use of long channels upstream and downstream as well as having a refined grid near the sharp corner. Derivatives in the governing equations are replaced by fourth-order central differences and the vorticity is eliminated, either before or after the discretization, to form a wide difference molecule for the streamfunction. Extra boundary conditions, necessary for wide-molecule methods, are supplied by a procedure proposed by Henshaw et al. The ensuing set of non-linear equations is solved using Newton iteration. Results have been obtained for Reynolds numbers up to 250 for three constrictions, the first being smooth, the second having a moderately sharp corner and the third with a very sharp corner. Estimates of the error incurred show that the results are very accurate and substantially better than those of the corresponding second-order method. The observed order of the method has been shown to be close to four, demonstrating that the method is genuinely fourth-order. © 1977 John Wiley & Sons, Ltd.