• Industrial Engineering and Management Systems
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• v.8 no.3
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• pp.194-200
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• 2009

This study provides a heuristic algorithm to solve the locating problem of repair service centers (RSCs). To enhance the customer service level with more satisfaction and quicker responsiveness, the locating problem of RSCs has become one of the important issues in reverse supply chain management. This problem is formulated as a zero-one mixed integer programming in which an exiting distributor will be considered to be an un-capacitated repair service center for the objective of cost-minimizing. Since logistical costs are highly interrelated with the multinational location of distributors and RSCs, the fixed cost for setting a repair service center, variable cost, transportation cost, and exchange rates are considered in this study. Recognizing the selection of un-capacitated RSCs' locations is a combinatorial optimization problem and is a zero-one mixed integer programming with NP-hard complexity, we provide a heuristic algorithm named as incremental cost matrix procedure (ICMP) to simplify the solving procedure. By using the concise and structural cost matrix, ICMP can efficiently screen the potential location with cost advantage and effectively decide which distributor should be a RSC. Results obtained from the numerical experiments conducted in small scale problem have shown the fact that ICMP is an effective and efficient heuristic algorithm for solving the RSCs locating problem. In the future, using the extended ICMP to solve problems with larger industrial scale or problems with congestion effects caused by the variation of customer demand and the restriction of the RSC capacity is worth a further investigation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.11A
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• pp.1096-1105
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• 2007

In this paper, we propose a solution on interference problem of MB-OFDM UWB system using cognitive radio. We use interference temperature model of cognitive radio that has proposed by FCC for estimating interference signal. Calculating channel capacity of MB-OFDM UWB system with interference temperature, we suggest how to solve interference problem. We have used genetic algorithm in cognitive engine's calculation process. The proposed MB-OFDM UWB System with cognitive radio shows very efficient in solving interference problem.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.2
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• pp.105-117
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• 1993

Methods for calculating k shortest paths in a network system, are based on a analogy which exists between the solution of a network problem and traditional techniques for solving linear equations. This paper modifies an algebraic structure of the K shortest path method and develops k maximum flow methods. On the basis of both theoretical and algebraic structure, three iteration methods are developed and the effective procedure of each method are provided. Finally, computational complexity is discussed for those methods.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.2
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• pp.103-108
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• 2003

The common accumulator was designed for solving the maldistribution problem of oil at the air conditioning system with two compressors. The oil level inside two compressors was visualized by using a common accumulator on the various operating conditions. As a result of the visualization, oil distribution inside two compressors was achieved appropriately according to the capacity of each compressor. Uniform distribution of oil was also accomplished at on and off operation condition.

• Journal of the Korean School Mathematics Society
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• v.3 no.1
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• pp.189-200
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• 2000

The purpose of this thesis is that the students understand the sentence stated math problems closely related to the real life and adapted the right solving strategies try to find the solution to a problem. The following research problem were proposed. 1. How repeated thinking lessons develop the understanding of problems and influence the usage of correct problem solving strategies and extensions of problem solving. 2. There are how much differences of achievement for each type of sentence stated problems by using comparative analysis of upper class, intermediate class, and lower class for each level between the experimental and comparative classes. In order to conduct this research the classes were divided into three different level - upper class, intermediate class and lower class. Each level include an experimental class and a comparative class. The two classes (experimental class and comparative class) of the same level were tested on the basis of class division record with the experimental class repeated learning papers for two weeks were used to guide the fixed thinking algorism for each sentence stated math problems. Eight common problems were chosen from a variety of textbooks : number calculation problems, velocity-distance-time problems, the density of a mixture, benefit problems, distribution problems, problems about working, ratio problems, the length of a figure problems. After conducting this research experiment The differences in achievement level between the experimental class and comparative class, were compared and analyzed through achievement tests made from the achievement test papers with seven problems, which were worth seventy points (total score). The conclusions of this thesis are as follows: Firstly, leaning activities through the usage of repeated learning papers for each level class produce an even development of achievement level especially in the case of the upper class learners, they have particular differences (between experimental class and comparative class) compared to the intermediate level and lower classes. Secondly, according to the analysis about achievement development each problems, learners easily accept the strategies of solution through the formula setting up to the problem of velocity -distance-time, and to the density of the mixture they adapted the picture drawing strategies interestingly, However each situation requires a variety of appropriate solution strategies. Teachers will have to employ other interesting solution strategies which relate to real life.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.4
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• pp.137-148
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• 2019

This paper is designed to examine the effectiveness of Computational Thinking and programming awareness by designing and applying programming classes using Havruta. In the present society, where the Fourth Industrial Revolution was in full swing, the capacity to be equipped has changed, and the education has been changed accordingly. Programming education is logically capable of thinking and improves comprehensive problem solving skills. This direction of programming education allows us to get ideas for solving problems based on computing thoughts and to create our own creative results. However, because they require the grammar of the programming language and many additional abilities, they are not easy for learners, and individual differences in competencies make learning less immersive and interesting. In this paper, to solve the problems of the uniform programming class, this study is designed and applied to the class applying the Jewish traditional teaching method, Havruta's teaching method, to find out the effect of computing thinking and programming perception.

• Journal of Information Technology Applications and Management
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• v.13 no.2
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• pp.29-39
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• 2006

There has been a tremendous need for dual homing cell switch assignment problems where calling volume and patterns are different at different times of the day. This problem of assigning cells to switches in the planning phase of mobile networks consists in finding an assignment plan which minimizes the communication costs taking into account some constraints such as capacity of switches. This optimization problem is known to be difficult to solve, such that heuristic methods are usually utilized to find good solutions in a reasonable amount of time. In this paper, we propose an evolutionary approach, based on the genetic algorithm paradigm, for solving this problem. Simulation results confirm the appropriateness and effectiveness of this approach which yields solutions of good quality.

• Journal of The Korean Association For Science Education
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• v.36 no.4
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• pp.527-538
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• 2016

The purpose of this study is to select the factors of 'Group scientific creativity' and to find out how 'Group scientific creativity' turns out in the creative problem-solving process of students. To select the factors that affect 'Group scientific creativity', this research extracted 27 influencing factors on the group creativity from the prior study and organized them according to opinions of education experts. To select factors that affect 'Group scientific creativity' in the creative problem-solving process of students, this research analyzed the group problem-solving process that has been done on 72 gifted students for two days. Main results of the study is as follows: First, nine elements such as scientific thinking, scientific knowledge, scientific information-processing capacity, motivation, challenge, age and gender, existence of diversity, creativity educational experience, and the group cohesiveness were selected as human factors. Four elements such as scientific communication skills, scientific inquiry process, autonomy, and leadership were selected as the combining factors. Also, three elements such as the learning environment, teacher types, and compensation were selected as the Environmental factors. Second, it was possible to find that the group scientific creativity influence factors affecting the creative process by analyzing the gifted students in creative-problem solving process. Based on these results, this study described additional points on the factors improving 'Group scientific-creativity.'

• Journal of Korean society of Dental Hygiene
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• v.16 no.3
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• pp.337-346
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• 2016

Objectives: This study aims to investigate and analyzed the priority of vocational core competency factors in dental hygienists in Gwangju. Methods: Expert survey was conducted and Analytic Hierarchy Process(AHP) was applied to evaluate the weighting factors. First, we established the vocational core competency defined in NCS as AHP analysis model. The vocational core competency has 10 categories and 34 sub-categories. Secondly, AHP survey was conducted by 195 dental hygienists in Gwangju. Finally, the weights representing relative importance of each factor were calculated by using AHP method. Results: The AHP analysis on 10 categories showed that the weighting of interpersonal skills(0.165) was higher than any other categories while that of numeracy(0.035) was at the bottom, and the analysis on sub-categories revealed that the most important factors in each categories included the teamwork skills(interpersonal skills), problem-solving capability(problem-solving skills), listening skills(communication skills), ethical community(professional ethics), ability to understand business(ability to understand organizational structure), applicable technical skills(technical skills), self-management skills(self-development capability), information processing capabilities(information capacity), ability to manage time(resource management capabilities) and basic math skills(numeracy). Conclusions: The results in this study can be used as basic data for the development of liberal arts curriculum for dental hygiene education.

• 한국항공운항학회:학술대회논문집
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• 2016.05a
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• pp.269-275
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• 2016

This paper considers the arrival, airport and departure capacity as a whole, through which, the network effect between airports is fully emphasized, the flight action is coordinated, and the flight demand pattern is reasonably assigned. The optimization problem of flight queues in multi-airport is studied in detail; the mathematical model of multi-airport opening non-real time flow management in terminal area is established, and related problems such as the parameters, the simplification and the solving of the model are discussed in detail to some extent. Appropriate decision making variables are taken to make the multi-airport network system linear 0-1 integer programming model, thus, the solving of the model is available and the central flow management is realized. The heuristic implicit enumeration presented in this paper can effectively solve this kind of problems. Through the simulation of some airports network system, we not only validate the algorithm presented in this paper, but also give a deep analysis of the results, which would produce reference for later practicable use. The simulation proves that this algorithm offers a good way to settle the problem of multi-airport flight queue optimization in air traffic management automation system in terminal area.