801 resultados para Scenario-based problem solving
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An efficient algorithm is presented for the solution of the steady Euler equations of gas dynamics. The scheme is based on solving linearised Riemann problems approximately and in more than one dimension incorporates operator splitting. The scheme is applied to a standard test problem of flow down a channel containing a circular arc bump for three different mesh sizes.
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An algorithm for solving nonlinear discrete time optimal control problems with model-reality differences is presented. The technique uses Dynamic Integrated System Optimization and Parameter Estimation (DISOPE), which achieves the correct optimal solution in spite of deficiencies in the mathematical model employed in the optimization procedure. A version of the algorithm with a linear-quadratic model-based problem, implemented in the C+ + programming language, is developed and applied to illustrative simulation examples. An analysis of the optimality and convergence properties of the algorithm is also presented.
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An iterative procedure is described for solving nonlinear optimal control problems subject to differential algebraic equations. The procedure iterates on an integrated modified simplified model based problem with parameter updating in such a manner that the correct solution of the original nonlinear problem is achieved.
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In this paper, a discrete time dynamic integrated system optimisation and parameter estimation algorithm is applied to the solution of the nonlinear tracking optimal control problem. A version of the algorithm with a linear-quadratic model-based problem is developed and implemented in software. The algorithm implemented is tested with simulation examples.
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A novel iterative procedure is described for solving nonlinear optimal control problems subject to differential algebraic equations. The procedure iterates on an integrated modified linear quadratic model based problem with parameter updating in such a manner that the correct solution of the original non-linear problem is achieved. The resulting algorithm has a particular advantage in that the solution is achieved without the need to solve the differential algebraic equations . Convergence aspects are discussed and a simulation example is described which illustrates the performance of the technique. 1. Introduction When modelling industrial processes often the resulting equations consist of coupled differential and algebraic equations (DAEs). In many situations these equations are nonlinear and cannot readily be directly reduced to ordinary differential equations.
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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.
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Many applications, such as intermittent data assimilation, lead to a recursive application of Bayesian inference within a Monte Carlo context. Popular data assimilation algorithms include sequential Monte Carlo methods and ensemble Kalman filters (EnKFs). These methods differ in the way Bayesian inference is implemented. Sequential Monte Carlo methods rely on importance sampling combined with a resampling step, while EnKFs utilize a linear transformation of Monte Carlo samples based on the classic Kalman filter. While EnKFs have proven to be quite robust even for small ensemble sizes, they are not consistent since their derivation relies on a linear regression ansatz. In this paper, we propose another transform method, which does not rely on any a priori assumptions on the underlying prior and posterior distributions. The new method is based on solving an optimal transportation problem for discrete random variables. © 2013, Society for Industrial and Applied Mathematics
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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.
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Final year research projects are an important part of undergraduate chemistry courses, allowing students to enhance transferable skills in teamworking, problem solving and presentations, at the same time as learning valuable practical skills. Several recent reports have highlighted the importance of research based studies as part of undergraduate courses. ‘We need to encourage universities to explore new models of curriculum. They should all incorporate research based study for undergraduates to cultivate awareness of research careers, to train students in research skills for employment, and to sustain the advantages of a research teaching connection,’ wrote Paul Ramsden from James Cook University, Australia, in a 2008 report for the UK’s Higher Education Academy.1 A 2010 report published by the Biopharma Skills Consortium – that promotes collaboration across the higher education sector in the area of biopharma – also stated that: ‘Companies seek recruits well placed to acclimatise quickly to the work environment. They are looking for recruits who can deploy a range of generic skills in the application of their knowledge.’2
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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.
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This thesis explores two aspects of mathematical reasoning: affect and gender. I started by looking at the reasoning of upper secondary students when solving tasks. This work revealed that when not guided by an interviewer, algorithmic reasoning, based on memorising algorithms which may or may not be appropriate for the task, was predominant in the students reasoning. Given this lack of mathematical grounding in students reasoning I looked in a second study at what grounds they had for different strategy choices and conclusions. This qualitative study suggested that beliefs about safety, expectation and motivation were important in the central decisions made during task solving. But are reasoning and beliefs gendered? The third study explored upper secondary school teachers conceptions about gender and students mathematical reasoning. In this study I found that upper secondary school teachers attributed gender symbols including insecurity, use of standard methods and imitative reasoning to girls and symbols such as multiple strategies especially on the calculator, guessing and chance-taking were assigned to boys. In the fourth and final study I found that students, both male and female, shared their teachers view of rather traditional feminities and masculinities. Remarkably however, this result did not repeat itself when students were asked to reflect on their own behaviour: there were some discrepancies between the traits the students ascribed as gender different and the traits they ascribed to themselves. Taken together the thesis suggests that, contrary to conceptions, girls and boys share many of the same core beliefs about mathematics, but much work is still needed if we should create learning environments that provide better opportunities for students to develop beliefs that guide them towards well-grounded mathematical reasoning.
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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
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Objective: It has been shown that specific competence is necessary for preventing and managing conflicts in healthcare settings. The aim of this descriptive and correlation study was to investigate and compare the self-reported conflict management competence (CMC) of nursing students who were on the point of graduating (NSPGs), and the CMC of registered nurses (RNs) with professional experience. Methods: The data collection, which consisted of soliciting answers to items measuring CMC in the Nurse Professional Competence (NPC) Scale, was performed as a purposive selection of 11 higher education institutions (HEIs) in Sweden. Three CMC items from the NPC Scale were answered by a total of 569 nursing students who were on the point of graduating and 227 RN registered nurses with professional experience. Results: No significant differences between NSPGs and RNs were found, and both groups showed a similar score pattern, with the lowest score for the item: “How do you perceive your ability to develop the group and strengthen competence in conflict management and problem-solving, based on knowledge of group dynamics?”. RNs with long professional experience (>24 months) rated their overall CMC as significantly better than RNs with short (<24 months) professional experience did (p = .05). NSPGs who had experience of international studies during their nursing education reported higher CMC, compared with those who did not have this experience (p = .03). RNs who reported a high degree of utilisation of CMC during the previous month scored higher regarding self-reported overall CMC (p < .0001). Conclusions: Experience of international studies during nursing education, or long professional experience, resulted in higher self-reported CMC. Hence, the CMC items in the NPC Scale can be suitable for identifying self-reported conflict management competence among NSPGs and RNs
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A Engenharia de Conhecimento (Knowledge Engineering - KE) atual considera o desenvolvimento de Sistemas Baseados em Conhecimento (Knowledge- Based Systems - KBSs) como um processo de modelagem baseado em modelos de conhecimento reusáveis. A noção de Métodos de Solução de Problemas (Problem- Solving Methods - PSMs) desempenha um importante papel neste cenário de pesquisa, pois representa o conhecimento inferencial de KBSs em um formalismo explícito. Não menos importante, PSMs também facilitam a compreensão do processo de raciocínio desenvolvido por humanos. PSMs são descritos em um formalismo abstrato e independente de implementação, facilitando a análise do conhecimento inferencial que muitas vezes é obscurecido em grandes bases de conhecimento. Desta forma, este trabalho discute a noção de PSMs, avaliando os problemas de pesquisa envolvidos no processo de desenvolvimento e especificação de um método, como também analisando as possibilidades de aplicação de PSMs. O trabalho apresenta a descrição e análise de um estudo de caso sobre o processo de desenvolvimento, especificação e aplicação de um PSM Interpretação de Rochas. As tarefas de interpretação de rochas são desenvolvidas por petrógrafos especialistas e correspondem a um importante passo na caracterização de rochasreservatório de petróleo e definição de técnicas de exploração, permitindo que companhias de petróleo reduzam custos de exploração normalmente muito elevados. Para suportar o desenvolvimento de KBSs neste domínio de aplicação, foram desenvolvidos dois PSMs novos: o PSM Interpretação de Rochas e o PSM Interpretação de Ambientes Diagenéticos. Tais métodos foram especificados a partir de uma análise da perícia em Petrografia Sedimentar, como também a partir de modelos de conhecimento e dados desenvolvidos durante o projeto PetroGrapher. O PSM Interpretação de Rochas e o PSM Interpretação de Ambientes Diagenéticos são especificados conceitualmente em termos de competência, especificação operacional e requisitos/suposições. Tais definições detalham os componentes centrais de um esquema de raciocínio para interpretação de rochas. Este esquema é empregado como um modelo de compreensão e análise do processo de raciocínio requerido para orientar o desenvolvimento de uma arquitetura de raciocínio para interpretação de rochas. Esta arquitetura é descrita em termos de requisitos de armazenamento e manipulação de dados e conhecimento, permitindo projetar e construir um algoritmo de inferência simbólico para uma aplicação de bancos de dados inteligentes denominada PetroGrapher.