• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.184-188
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• 2001

Severe vibration was detected during test operation in motor frame of the Turbo Chiller (300RT). To identify the vibration problem, vibration measurement and modal test were carried out. From the test results, it is concluded that the severe vibration occurred due to the resonance between the motor frame horizontal mode and the motor excitation frequency. Therefore the horizontal mode of the frame could be controlled by the sensitivity analysis results for the length of the supporting plate.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.4
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• pp.657-666
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• 2004

A Design of GA-based SPS controller for power system stabilization was investigated in this paper. The design problem of SPS controller is formulated as an optimization problem using GA. The dynamic characteristic responses are considered to verify the performance of the proposed SPS under various disturbances and operation conditions. The simulation results show that the proposed SPS controller provides most of the damping and improves greatly the voltage profile of the system under two different disturbances.

• International Commerce and Information Review
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• v.7 no.4
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• pp.59-76
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• 2005

In this research, electronic commercial web-sites of artwork are analysed with ten marketing success factors such as, low price, variety of products convenience of shopping, ensure credibility DB marketing, providing information, virtual community, preoccupying the marketing, quick response, and strategic cooperation. The analysis showed that the main problem of the Korean fine art market is the lack of demand. Though the problem of the offline fine art market is not to be solved by websites, it seems that the solution should be brought through the operation of websites with long-term plans and patience.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.73-75
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• 2002

This paper presents the properly method of system security and facility countermeasures. We performed simulation for yearly peak of Korean power system in 2002 under the reactive power problem in a nuclear power plants. Analysis of the problems in power system operation by power flow, fault and stability study. Establishment of power system optimal operating plan by stabilizer and maintaining the reasonable voltage level.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1995.10b
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• pp.52-58
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• 1995

A shared-weight neural network that performed classification based on the features extracted with the fuzzy morphological operation is introduced. Learning rules for the structuring elements, degree of membership, and weighting factors are also precisely described. In application to handwritten digit recognition problem, the fuzzy morphological shared-weight neural network produced the results which are comparable to the state-of-art for this problem.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.33 no.6
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• pp.241-246
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• 1984

The power system scheduling process is formulated as an optimization problem with linear inequality constraints. AC Loadflow method is used for the problem solution and line losses are considered. The constraints under consiceration are generator power limits, load schedding limits and line capacity limits. In solving the objective function the Dual Relaxation method is adopted. Tests indicate that the method is practical for real time applications.

• Journal of Distribution Science
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• v.14 no.2
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• pp.41-45
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• 2016

Purpose - Finding an optimal path is an essential component for the design and operation of smart transportation or logistics network. Many applications in navigation system assume that travel time of each link is fixed and same. However, in practice, the travel time of each link changes over time. In this paper, we introduce a new transportation problem to find a latest departing time and delivery path between the two nodes, while not violating the appointed time at the destination node. Research design, data, and methodology - To solve the problem, we suggest a mathematical model based on network optimization theory and a backward search method to find an optimal solution. Results - First, we introduce a dynamic transportation problem which is different with traditional shortest path or minimum cost path. Second, we propose an algorithm solution based on backward search to solve the problem in a large-sized network. Conclusions - We proposed a new transportation problem which is different with traditional shortest path or minimum cost path. We analyzed the problem under the conditions that travel time is changing, and proposed an algorithm to solve them. Extending our models for visiting two or more destinations is one of the further research topics.

• Journal of Practical Engineering Education
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• v.10 no.1
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• pp.35-39
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• 2018

More and more universities are enforcing SW education for non-major undergraduates. However, they are experiencing difficulties in educating non-major students to understand computational thinking processes. In this paper, we did not use the mathematical operation problem to solve this problem. And we proposed a basic problem-solving process teaching method based on computational thinking using simple physical devices. In the proposed educational method, we teach a LED circuit using an Arduino board as an example. And it explains the problem-solving process with computational thinking. Through this, students learn core computational thinking processes such as abstraction, problem decomposition, pattern recognition and algorithms. By applying the proposed methodology, students can gain the concept and necessity of computational thinking processes without difficulty in understanding and analyzing the given problem.

• Educational Technology International
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• v.11 no.1
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• pp.145-169
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• 2010

Many universities are searching for educational methods to cultivate problem-solving ability and cooperative learning ability or already trying to implement them. Problem Based Learning(PBL) and Action Learning(AL) are effective teaching and learning methods to cultivate men of talent qualified for problem-solving and cooperative learning abilities that universities are seeking after. PBL and AL have something in common in that learning is accomplished while learners are solving the authentic problem. But, in spite of this similarity, PBL and AL have differences. However, most literatures and cases on these two models introduce only the outline of commons and differences and do not provide teachers with actual helping aids to select a model appropriate for the actual design or operation of classes. Accordingly, many teachers usually select and utilize a familiar model rather than select a proper model to the nature of a subject and the educational goal. Teaching and learning methods or learning environment should be selected appropriately to the educational goal. This study indicates the characteristics of PBL and AL that are being introduced and utilized as a principal teaching and learning method of college education and then shows how this method can be realized in the university by comparing the cases of classes applied in two methods.

• Industrial Engineering and Management Systems
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• v.11 no.2
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• pp.170-175
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• 2012

In this paper, a procedure using a genetic algorithm (GA) and a heuristic local search (HLS) is proposed for solving facility rearrangement problem (FRP). FRP is a decision problem for stopping/running of facilities and integration of stopped facilities to running facilities to maximize the production capacity of running facilities under the cost constraint. FRP is formulated as an integer programming model for maximizing the total production capacity under the constraint of the total facility operating cost. In the cases of 90 percent of cost constraint and more than 20 facilities, the previous solving method was not effective. To find effective alternatives, this solving procedure using a GA and a HLS is developed. Stopping/running of facilities are searched by GA. The shifting the production operation of stopped facilities into running facilities is searched by HLS, and this local search is executed for one individual in this GA procedure. The effectiveness of the proposed procedure using a GA and HLS is demonstrated by numerical experiment.