• International Journal of Reliability and Applications
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• v.12 no.2
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• pp.79-94
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• 2011

Redundancy-reliability allocation problems in multi-stage series-parallel systems are addressed in this study. Fuzzy programming techniques are proposed for finding satisfactory solutions. First, a multi-objective programming model is formulated for simultaneously maximizing system reliability and minimizing system total cost. Due to the nature of uncertainty in the problem, the fuzzy set theory and technique are used to convert the deterministic multi-objective programming model into a fuzzy nonlinear programming problem. A heuristic method is developed to get satisfactory solutions for the fuzzy nonlinear programming problem. A Pareto optimal solution is found with maximal degree of satisfaction from the interception area of fuzzy sets. A case study that is related to the electronic control unit installed on aircraft engine over-speed protection system is used to implement the developed approach. Results suggest that the developed fuzzy multi-objective programming model can effectively resolve the fuzzy and uncertain problem when design goals and constraints are not clearly confirmed at the initial conceptual design phase.

• Management Science and Financial Engineering
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• v.12 no.1
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• pp.113-125
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• 2006

Bilevel programming problem is a two-stage optimization problem where the constraint region of the first level problem is implicitly determined by another optimization problem. In this paper we consider the bilevel quadratic/linear fractional programming problem in which the objective function of the first level is quasiconcave, the objective function of the second level is linear fractional and the feasible region is a convex polyhedron. Considering the relationship between feasible solutions to the problem and bases of the coefficient submatrix associated to variables of the second level, an enumerative algorithm is proposed which finds a global optimum to the problem.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.415-422
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• 2014

This paper presents a new approach to solve the multi area unit commitment problem (MAUCP) using an evolutionary programming based particle swarm optimization (EPPSO) method. The objective of this paper is to determine the optimal or near optimal commitment schedule for generating units located in multiple areas that are interconnected via tie lines. The evolutionary programming based particle swarm optimization method is used to solve multi area unit commitment problem, allocated generation for each area and find the operating cost of generation for each hour. Joint operation of generation resources can result in significant operational cost savings. Power transfer between the areas through the tie lines depends upon the operating cost of generation at each hour and tie line transfer limits. Case study of four areas with different load pattern each containing 7 units (NTPS) and 26 units connected via tie lines have been taken for analysis. Numerical results showed comparing the operating cost using evolutionary programming-based particle swarm optimization method with conventional dynamic programming (DP), evolutionary programming (EP), and particle swarm optimization (PSO) method. Experimental results show that the application of this evolutionary programming based particle swarm optimization method has the potential to solve multi area unit commitment problem with lesser computation time.

• The Journal of the Korea Contents Association
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• v.14 no.6
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• pp.491-498
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• 2014

Programming learning tend to improve the high thinking ability by experiencing problem solving process through programming recently, There are the previous studies that small group cooperative learning has the effect of the learning that is based logical thinking and creativity, while programming learning has relied on individual learner's thinking and principles traditionally. In this paper, it was verified the effect on improving the problem solving ability to perform by the small cooperative learning group in a problem solving process of programming learning. For this, it was developed and applied a model that include small cooperative learning group based on the problem solving 5 steps. The results of this study showed that the small cooperative learning group has positive effect of the problem solving ability in programming learning and has no relationship with cognitive style.

• Journal of Digital Convergence
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• v.10 no.9
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• pp.449-456
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• 2012

The college students who have relatively weak academic background feel more difficult in learning programming language grammars and programming skills in introductory course. At the end of semester, most of students had the negative attitude to programming and only a few students could write the programs for the given problems because they spent most of time to learn grammars instead of learning problem solving skills and logics. In this study, we propose to use Scratch in introductory programming course to help students to understand grammars and problem solving skills. It's necessary to educate first-time programmers how to solve the problems before they learn grammars of the programming language in their first programming language course. This paper shows that Scratch allows students not only to learn problem solving skills in programming but also to motivate students themselves in the class.

• Journal of the Korea Society of Computer and Information
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• v.22 no.8
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• pp.101-106
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• 2017

In this paper, we propose a new teaching-learning model with two-step feedback on programming language learning, which is a basic preliminary learning for programming. Programming learning is aimed at improving problem solving skills and thinking by experiencing problem solving through programming. For programming, the learner must know how to work with the computer and what to do with it. To do this, concrete thinking should be established and described in an accurate programming language. In recent, most studies have focused on the effects of programming learning and have not studied the effects of education on language itself. Therefore, in this study, the teaching-learning model for programming language education is presented and applied to the field, and the results are compared with the existing instructional-teaching model.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.5
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• pp.1069-1084
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• 2011

This paper considers an optimal base station clustering problem for designing a mobile (wireless) communication network. For a given network with a set of nodes (base stations), the problem is to optimally partition the set of nodes into subsets (each called a cluster) such that the associated inter-cluster traffic is minimized under certain topological constraints and cluster capacity constraints. In the problem analysis, the problem is formulated as an integer programming problem. The integer programming problem is then transformed into a binary integer programming problem, for which the associated linear programming relaxation is solved in a column generation approach assisted by a branch-and-bound procedure. For the column generation, both a heuristic algorithm and a valid inequality approach are exploited. Various numerical examples are solved to evaluate the effectiveness of the LP (Linear Programming) based branch-and-bound algorithm.

• Journal of the Korea Society of Computer and Information
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• v.23 no.9
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• pp.163-169
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• 2018

Problem solving by programming has a lot of influence on computational thinking improvement. Programming learning has been self-directed based on the individual's thoughts and principles. However, the revised informatics curriculum in 2015 puts importance on collaborative learning. Collaborative learning emphasizes results differently from cooperative learning, which emphasizes problem-solving processes. And cooperative learning leads to structured learning, such as role sharing and activity stages, within a small group, while collaborative learning leads to unstructured learning. Therefore, it is becoming more in collaborative learning that peer interaction can be affected by learners' cognitive style. In this paper, we propose the effect of cognitive style on problem solving ability in collaborative learning for problem solving by programming. As a result, collaborative learning was effective in improving problem solving ability and there was no significant difference in cognitive style.

• Journal of the Korea Society of Computer and Information
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• v.3 no.2
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• pp.37-44
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• 1998

Computers can be used in providing new ways to promote intellectual skills. A computer programming environment can create conditions under which an intellectual mode takes root. Especially problem solving skills can be promoted through programming. To investigate whether and, if so, how computer programming enhances problem solving skills, the nature of programming and problem solving skills are examined. Then, issues on the programming learning context in relation to problem solving are presented.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.310-310
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• 2000

The main problem in stereo vision is to find corresponding points in left and right image known as correspondence problem. Once correspondences determined, the depth information of those points are easily computed form the pairs of points in both image. In this paper, dynamic programming considering half-occluded region is used fer solving correspondence problem.