• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.125-126
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• 2010

In this paper, a novel multiple output converter using quasi load is proposed. Conventional multiple output converters using multi-winding transformer has poor output voltage regulations. To solve this problem, there are many proposals like post regulation method, weighted control method, and etc. However, the post regulation method regulates output voltage tightly but its conduction loss and cost are increased. And the weighted control can achieve high efficiency and low cost but its regulation is not enough. To solve these problems, this paper proposes a novel multiple output converter using quasi load. The proposed method uses a quasi load which acts like an active dummy load for tight regulation but there is rarely increase of loss and cost. The proposed method is verified by hardware test by two output(24V and 15V) flyback type converter.

• Proceedings of the Korea Association of Information Systems Conference
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• 2000.11a
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• pp.36-44
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• 2000

The purpose of this study is to introduce a more efficient forecasting technique, which could help result the reduction of cost in removing the waste of airline in-flight meals. We will use a neural network approach known to many researchers as the “Outstanding Forecasting Technique”. We employed a multi-layer perceptron neural network using a backpropagation algorithm. We also suggested using other related information to improve the forecasting performances of neural networks. We divided the data into three sets, which are training data set, cross validation data set, and test data set. Time lag variables are still employed in our model according to the general view of time series forecasting. We measured the accuracy of our model by “Mean Square Error”(MSE). The suggested model proved most excellent in serving economy class in-flight meals. Forecasting the exact amount of meals needed for each airline could reduce the waste of meals and therefore, lead to the reduction of cost. Better yet, it could enhance the cost competition of each airline, keep the schedules on time, and lead to better service.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.1
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• pp.82-88
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• 2007

This paper considers a topological optimization of a computer network design with a cost constraint. The objective is to find the topological layout of links, at maximal reliability, under the constraint that the network cost is less or equal than a given level of budget. This problem is known to be NP-hard. To efficiently solve the problem, a genetic approach is proposed. Two illustrative examples are used to explain and test the proposed approach. Experimental results show evidence that the proposed approach performs more efficiently for finding a good solution or near optimal solution in comparison with a simulated annealing method.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.2
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• pp.140-149
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• 2000

A comparative analysis was peformed on the operation cost at partial loads between ice storage systems with the two conventional control strategies, i.e., storage priority and chiller priority. The storage priority control is shown to be more economic for small cooling loads, while the chiller priority control is superior when the cooling load is as large as the design value. Based on this finding, a new control strategy is devised for an ice-storage system to minimize the operation cost at any cooling load. The new control strategy is found to be comparable to the chiller priority for large cooling loads, while it is more economic for small loads compared to the conventional control strategies. The practicality of the new control strategy is also confirmed through a performance test applying the new control strategy to an existing ice-storage system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.11
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• pp.1936-1941
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• 2010

This purpose of this paper is to propose a methodology for optimal generating operation in power system to minimize the cost of generation subject to not only system constraints but also regional $CO_2$ emission constraints. To solve this ELD problem calculated range limit on minimum and maximum power outputs by regional Equal Generator how each regional capacity is connected into one and expressed Equal Fuel Cost Function considering regional $CO_2$ emission constraints. Accordingly, being modified regional load, new power outputs considering regional $CO_2$ emission constraints were calculated by ELD. The proposed model for evaluating availability is tested on IEEE RTS(Reliability Test System)-24 in detail.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.12
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• pp.2626-2634
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• 1997

The purpose of multicasting is to reduce the network costs for transmitting the same traffic to multiple destinations. In this paper, an efficient delay-bounded multicasting routing algorithm is proposed, which satistifies the network conditions of cost minimization and can adjust the dynamic events, such as 'leave and/or join ones' from the multicast group. Also, our algorithm is designed for various network requirements such as the efficiet dynamic group support, high-quality data distribution, and adaptability to variable situation. After the delay tolerance and the maximum group size are determined according to network state and requirements for delay and cost, the dynamic delay-bounded multicast tree is constructed using partial multicast routing. We evaluate the performance of the proposed algorithm by running simulations on randomly generated test networks using a Sun Sparc 20 workstation. We were able to obtain good simulation resutls, which means solutions that lies between the minimum cost solution and the minimum delay one.

• Journal of Power Electronics
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• v.6 no.3
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• pp.253-263
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• 2006

A high performance and low cost single switch current fed energy recovery circuit (ERC) for an alternating current (AC) plasma display panel (PDP) is proposed. Since it is composed of only one power switch compared with the conventional circuit consisting of four power switches and two large energy recovery capacitors, the ERC features a simpler structure and lower cost. Furthermore, since all power switches can be switched under soft switching operating conditions, the proposed circuit has desirable merits such as increased reliability and low switching loss. Specifically, there are no serious voltage notches across the PDP with the aid of gas discharge current compensation, which can greatly reduce the current stress of all inverter switches, and provide those switches with the turn on timing margin. To confirm the validity of proposed circuit, its operation and performance were verified on a prototype for 7-inch test PDP.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06b
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• pp.74-79
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• 2007

고객이 요구한 제품은 테스트에 따라 그의 품질을 보장할 수 있기 때문에 테스트에 대한 관심과 중요성이 커지고 있는 만큼 테스트에 소요되는 비용 또한 실제 개발에 소요되는 비용에서 큰 비중을 차지하고 있고 그 중요성 또한 강조되고 있다. 하지만 실제 국내의 소프트웨어 개발 현실을 살펴 보면 제품의 개발 기한을 보장하기 위해서 테스트를 간과 함으로써 예상치 못하게 고객이 요구하는 제품의 품질을 만족시키지 못하고 있다. 또한 이러한 테스트 활동을 통한 품질 보장 활동의 필요성을 인정하지만 현재 개발 프로세스의 문제점 파악 혹은 개선 방향에 대해서 모호한 비전을 가지고 활동하기 때문에 성과가 미비하기도 하다. 본 논문에서는 국방 소프트웨어의 소프트웨어 개발 활동 내에서의 테스트 활동 및 제품의 품질에 대한 문제점을 지적하고 Cost of Quality (CoQ) 모델을 통해서 문제점을 분석함으로써 고 품질의 제품을 개발하기 위한 테스트 프로세스 개선에 대한 동기 부여 및 개선 방안을 제시하고자 한다.

• Journal of information and communication convergence engineering
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• v.21 no.2
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• pp.130-138
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• 2023

The selection of the correct examination variables for diagnosing heart disease provides many benefits, including faster diagnosis and lower cost of examination. The selection of inspection variables can be performed by referring to the data of previous examination results so that future investigations can be carried out by referring to these selected variables. This paper proposes a model for selecting examination variables using an Artificial Bee Swarm Optimization method by considering the variables of accuracy and cost of inspection. The proposed feature selection model was evaluated using the performance parameters of accuracy, area under curve (AUC), number of variables, and inspection cost. The test results show that the proposed model can produce 24 examination variables and provide 95.16% accuracy and 97.61% AUC. These results indicate a significant decrease in the number of inspection variables and inspection costs while maintaining performance in the excellent category.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.6
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• pp.767-775
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• 2018

To develop and check a Radar Processor Unit, checking the function and performance of the requirement is very important factor in developing Radar. General methods for verifying the Radar is simulation test, environment linkage test and field operation test, firstly, in case of requirement analysis phase, verify Radar algorithm and design by using mathematical method based simulation test method, and secondly, in case of unit test and integrated test phase, Test Equipment is set to simulate radar environment in the lab to verify radar function and performance. Lastly, field operation test phase is carried out to confirm the function and performance after it is mounted on the actual equipment. To successfully develop Radar Processor Unit, using the method of field operation test method after sufficient test cases are tested in radar environmental interlocking method in order to save cost and testing period and because of this reason, development of the Radar Processor Unit Test Equipment is becoming very important factor. In this paper, we introduce the concept of test equipment development and important factors in test equipment, which are target simulation, data processing and device interlocking.