6 research outputs found

    Constructing Breaker Sequence based System Restoration Strategy with Graph Theory

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    This paper has proposed a mapping approach to serve as an interface between the branch-bus model and the breaker-based model. In order to find the specific optimal operation for breakers in substations according to the restoration strategies, firstly, the paper has established the breaker-based model for the substation by using graphic theory, and then the optimal operation sequence for breakers has been figured out by adopting Dijkstra algorithm. Finally, a case study for a realistic power system has been analyzed to demonstrate the feasibility and efficiency of the approach.published_or_final_versio

    A Heuristic-Based Simulation for an Education Process to Learn about Optimization Applications in Logistics and Transportation

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    In the context of the DigiLab4U international project, this paper describes a simulationbased serious game that can be used as a virtual teaching lab in higher education courses, especially in Industrial and Systems Engineering, Data Science, Management Science and Operations Research, as well as Computer Science. The learning activity focuses on understanding distribution logistics problems related to transportation optimization using different techniques. These optimization challenges include the vehicle routing problem, the arc routing problem, and the team orienteering problem. As a result of the learning process in the virtual lab, it is expected that students acquire competencies and skills related to logistics and transportation challenges as well as problem-solving. These competencies and skills can be precious for students’ future careers, since they increase students’ analytical skills, capacity to understand heuristic-based algorithms, teamwork and interdisciplinary communication skills, programming skills, and statistical abilities. A preliminary version of this training activity has already been used in MSc and PhD courses held at universities in Spain, Italy, Ireland, and Portugal

    Penerapan algoritma Floyd-Warshall pada penentuan jalur terpendek evakuasi korban kecelakaan di Boyolali Jawa Tengah

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    INDONESIA: Algoritma Floyd-Warshall adalah salah satu algoritma yang dapat digunakan untuk menyelesaikan persoalan rute terpendek dan paling mudah untuk diterapkan karena dapat menemukan semua rute terpendek antara setiap pasangan posisi yang dimungkinkan dan merupakan bagian dari program dinamis yang sangat efisien dalam memecahkan persoalan rute yang optimal. Algoritma Floyd-Warshall bekerja dengan cara membandingkan setiap kemungkinan jalur pada graf untuk setiap pasangan simpul dan melakukan pengecekan pada kombinasi simpul yang dihasilkan. Masalah rute terpendek dalam kehidupan sehari-hari adalah evakuasi korban kecelakaan lalu lintas di Boyolali, Jawa Tengah. Agar evakuasi lebih efektif, diperlukan rute terdekat ke rumah sakit terdekat. Berdasarkan hasil penelitian yang telah diiterasi sebanyak n=k=23, disimpulkan bahwa penelitian menghasilkan matriks referensi berupa lintasan terpendek yang digunakan untuk menentukan rute terpendek menuju rumah sakit terdekat di Boyolali, Jawa Tengah. Rute ini dapat digunakan oleh masyarakat Boyolali dan sekitarnya serta instansi terkait mengenai rute terdekat dari jalan rawan kecelakaan rumah sakit. ENGLISH: The Floyd-Warshall algorithm is one of the algorithms that can be used to solve the shortest route problem and is the easiest to apply because it can find all the shortest routes between each possible pair of positions and is part of a dynamic program that is very efficient in solving optimal route problems. The Floyd-Warshall algorithm works by comparing each possible path on the graph for each node pair and checking the resulting node combination. The problem of the shortest route in daily life is the evacuation of victims of traffic accidents in Boyolali, Central Java. For evacuation to be more effective, a nearby route to the nearest hospital is needed. Based on the results of research that has been iterated as much as n = k = 23, it was concluded that the study produced a reference matrix in the form of the shortest trajectory used to determine the shortest route to the nearest hospital in Boyolali, Central Java. This route can be used by the people of Boyolali and surrounding areas as well as related agencies regarding the nearest route from the hospital accident-prone road towards. ARABIC: خوارزمية (Floyd-Warshall) هي إحدى الخوارزميات التي يمكن استخدامها لحل مشكلة أقصر طريق وهي الأسهل في التطبيق لأنها يمكن أن تجد جميع أقصر الطرق بين كل زوج ممكن من المواضع وهي جزء من برنامج ديناميكي فعال للغاية في حل مشاكل المسار الأمثل. تعمل خوارزمية (Floyd-Warshall) من خلال مقارنة كل مسار ممكن على الرسم البياني لكل زوج من العقد والتحقق من . مشكلة أقصر طريق في الحياة اليومية هي إجلاء ضحايا حوادث المرور في بويولالي ، جاوة الوسطى. لكي يكون الإخلاء أكثر فعالية ، هناك حاجة إلى طريق قريب إلى أقرب مستشفى. استنادا إلى نتائج البحث التي تم تكرارها بقدر (n=k=٢٣)، تم استنتاج أن الدراسة أنتجت مصفوفة مرجعية في شكل أقصر مسار يستخدم لتحديد أقصر طريق إلى أقرب مستشفى في (Boyolali) ، جاوة الوسطى. يمكن استخدام هذا الطريق من قبل سكان بويولالي والمناطق المحيطة بها وكذلك الوكالات ذات الصلة فيما يتعلق بأقرب طريق من الطريق المعرض للحوادث في المستشفى نحو.مجموعة العقد الناتجة

    Developing a Computational Framework for a Construction Scheduling Decision Support Web Based Expert System

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    Decision-making is one of the basic cognitive processes of human behaviors by which a preferred option or a course of action is chosen from among a set of alternatives based on certain criteria. Decision-making is the thought process of selecting a logical choice from the available options. When trying to make a good decision, all the positives and negatives of each option should be evaluated. This decision-making process is particularly challenging during the preparation of a construction schedule, where it is difficult for a human to analyze all possible outcomes of each and every situation because, construction of a project is performed in a real time environment with real time events which are subject to change at any time. The development of a construction schedule requires knowledge of the construction process that takes place to complete a project. Most of this knowledge is acquired through years of work/practical experiences. Currently, working professionals and/or students develop construction schedules without the assistance of a decision support system (that provides work/practical experiences captured in previous jobs or by other people). Therefore, a scheduling decision support expert system will help in decision-making by expediting and automating the situation analysis to discover the best possible solution. However, the algorithm/framework needed to develop such a decision support expert system does not exist so far. Thus, the focus of my research is to develop a computational framework for a web-based expert system that helps the decision-making process during the preparation of a construction schedule. My research to develop a new computational framework for construction scheduling follows an action research methodology. The main foundation components for my research are scheduling techniques (such as: Job Shop Problem), path-finding techniques (such as: travelling salesman problem), and rule-based languages (such as JESS). My computational framework is developed by combining these theories. The main contribution of my dissertation to computational science is the new scheduling framework, which consists of a combination of scheduling algorithms that is tested with construction scenarios. This framework could be useful in more areas where automatic job and/or task scheduling is necessary

    Modelo matemático para seleção de rotas de patrulhamento escolar: o caso da patrulha escolar de Ponta Grossa

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    Studies have shown that school violence produces harmful effects on victims and society alike. Police patrols have proved to me the most effective among the main forms of preventing school violence. School police patrols take place using squad cars that serve a network of schools and consist of placing vehicles at network schools for a given period of time (routine patrol). Nevertheless, during routine patrol police vehicles must immediately answer emergency calls at network schools that are not being patrolled at that moment (emergency patrolling). This work proposes a method based on mathematical models to assist the school patrol program in defining the routes for routine patrol and emergency routes. The approach used to solve the problem consisted of graph algorithms. Routine patrol was treated as a model of the Traveling Salesman Problem, and was solved using the Nearest Neighbor Heuristic and Tabu Search metaheuristic. The emergency situation was modeled using the Shortest Path Problem, and emergency routes were determined through the Floyd-Warshall algorithm. A case study was used to demonstrate the application of the method. Results show that the proposed method is effective to treat the problem of route selection for school patrols in cities with shortcomings in technological resources.CAPESEstudos mostram que a violência nas escolas resulta em consequências prejudiciais para as vítimas e para a sociedade. Entre os principais meios de prevenção da violência escolar tem-se o patrulhamento policial como o mais efetivo. O patrulhamento policial escolar é realizado por viaturas policiais que atendem a uma rede de escolas e consiste na manutenção das viaturas em cada escola da rede por um determinado período de tempo (patrulhamento de rotina). Contudo, durante o patrulhamento de rotina, as viaturas devem prestar atendimento imediato a chamadas de emergência em escolas da rede que não estejam sendo patrulhadas naquele momento (patrulhamento emergencial). O presente trabalho propõe um método baseado em modelos matemáticos para auxiliar o programa de patrulha escolar na definição das rotas de patrulhamento de rotina e rotas emergenciais. A abordagem aplicada para resolver o problema foi a de algoritmos de grafos. O patrulhamento de rotina foi por meio do Problema do caixeiro viajante e solucionado por meio da heurística do vizinho mais próximo e da meta-heurística de Busca tabu. A situação de emergência foi modelada utilizando o Caminho mais curto e as rotas emergenciais foram determinadas por meio do algoritmo de Floyd-Warshall. Um estudo de caso em uma rede de escolas foi utilizado para demonstrar a utilização do método. Os resultados mostram que o método proposto é efetivo para tratar o problema de seleção de rotas de patrulhamento escolar em cidades com restrições de recursos tecnológicos

    A multi-organisational approach for disaster preparedness and response:the use of optimisation and GIS for facility location, stock pre-positioning, resource allocation and relief distribution

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    From 1992 to 2012 4.4 billion people were affected by disasters with almost 2 trillion USD in damages and 1.3 million people killed worldwide. The increasing threat of disasters stresses the need to provide solutions for the challenges faced by disaster managers, such as the logistical deployment of resources required to provide relief to victims. The location of emergency facilities, stock prepositioning, evacuation, inventory management, resource allocation, and relief distribution have been identified to directly impact the relief provided to victims during the disaster. Managing appropriately these factors is critical to reduce suffering. Disaster management commonly attracts several organisations working alongside each other and sharing resources to cope with the emergency. Coordinating these agencies is a complex task but there is little research considering multiple organisations, and none actually optimising the number of actors required to avoid shortages and convergence. The aim of the this research is to develop a system for disaster management based on a combination of optimisation techniques and geographical information systems (GIS) to aid multi-organisational decision-making. An integrated decision system was created comprising a cartographic model implemented in GIS to discard floodable facilities, combined with two models focused on optimising the decisions regarding location of emergency facilities, stock prepositioning, the allocation of resources and relief distribution, along with the number of actors required to perform these activities. Three in-depth case studies in Mexico were studied gathering information from different organisations. The cartographic model proved to reduce the risk to select unsuitable facilities. The preparedness and response models showed the capacity to optimise the decisions and the number of organisations required for logistical activities, pointing towards an excess of actors involved in all cases. The system as a whole demonstrated its capacity to provide integrated support for disaster preparedness and response, along with the existence of room for improvement for Mexican organisations in flood management
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