• Journal of KIISE:Computer Systems and Theory
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• v.28 no.10
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• pp.520-529
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• 2001

Carry-save-adder(CSA) is one of the most effective operation cells in implementing an arithmetic hardware with high performace and small circuit area. An fundamental drawback of the existing CAS applications is that the applications are limited to the local parts of arithmetic circuit that are directly converted to additions. To resolve the limitation, we propose a set of new CSA transformation techniques: optimizing arithmetics with multiplexors, optimizing arithmetics in multiple designs, and optimizing arithmetics with multiplications. We then design a new CSA transformation algorithm which integrates the proposed techniques, so that we are able to utilize CSAs more globally. An extensive experimentation for practical designs are provided to show the effectiveness of our proposed algorithm over the conventional CSA techniques.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.97-99
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• 2007

This paper presents a fuzzy logical control method to implement an on-line optimum efficiency control for Permanent Magnet Synchronous Motor. This method real-timely adjusts the output voltage of the inverter system to achieve the optimum running efficiency of the whole system. At first, the input power is calculated during the steady state in the process of efficiency optimizing. To exactly estimate the steady state of the system, this section needs check up the speed setting on timely. The second section is to calculate input power of dc-bus. The exact measurement of the voltage and current is the vital point to acquire the input power. The third section is the fuzzy logic control unit, which is the key of the whole drive system. Based on the change of input power of dc-bus and output voltage, the variable of output voltage is gained by the fuzzy logical unit. With the on-line optimizing. the whole system call fulfill the minimum input power of dc-bus on the running state. The experimental result proves that the system applied the adjustable V/f control method and the efficiency-optimizing unit possesses optimum efficiency, and it is a better choice for simple variable speed applications such as fans and pump.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.444-449
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• 1998

A modal transducer in two-dimensional structure can be implemented by varying the distributed transducer's gain spatially. In this paper, a method based on finite element method is developed for optimizing spatial gain distribution of PVDF transducer to create the modal transducer for specific modes. Using this concept, one can design the modal transducer in two-dimensional structure having arbitrary geometry and boundary conditions. As a practical means for implementing this continuous gain distribution without repoling die PVDF film, the gain distribution is approximated by optimizing gain-weights of interface circuit. The whole spatial area of the PVDF film is divided into several electrode segments and the signals from each segment are properly weighted and summed by interface circuit. This corresponds to the approximation of a continuous function using discrete values. The electrode partition is optimized using the genetic algorithm. Gain-weights are optimized using the simplex search method. A modal sensor for first to fourth modes of aluminum plate is designed using PVDF film with gain-weighted interface circuit. Various lamination angles of PVDF film are taken into consideration to utilize the anisotropy of the PVDF film. Performance of the optimized' PVDF sensor is demonstrated by numerical simulations..

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.275-280
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• 2013

This paper presents an optimizing method for wireless charging system, specifically focused on the capsule endoscope applications. In order to increase the wireless power transfer efficiency of electro-magnetic resonance coupled coils, this paper investigates the impact factors of the power transfer efficiency in small battery capacity system and proposes a efficiency optimizing method based on frequency control. Simulation results show that the proposed efficiency optimal control method can effectively stabilize the wireless power transfer efficiency so as to successfully solve the main issue of transfer efficiency variation with distance and as well as parasitic element.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.151-159
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• 2011

Due to the Korean government's renewable energy support policy such as the renewable energy utilization building certificate and enlarging the compulsory ratio of investment on the public building, the rooftop photovoltaic projects are expanding rapidly. It is very important for the rooftop photovoltaic projects to analyze the shading effect of the adjacent structures or own facilities. But, the photovoltaic arrangements are planned by the experience of the designers or simple graphic tools. The purpose of this study is to build the process model for optimizing of rooftop photovoltaic arrangement based on three-dimensional geo-spatial information.

• Journal of Electrical Engineering and Technology
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• v.7 no.1
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• pp.109-114
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• 2012

In this paper, we utilize training strategy of hidden Markov model (HMM) to use in versatile issues such as classification of time-series sequential data such as electric transient disturbance problem in power system. For this, an automatic means of optimizing HMMs would be highly desirable, but it raises important issues: model interpretation and complexity control. With this in mind, we explore the possibility of using genetic algorithm (GA) and harmony search (HS) algorithm for optimizing the HMM. GA is flexible to allow incorporating other methods, such as Baum-Welch, within their cycle. Furthermore, operators that alter the structure of HMMs can be designed to simple structures. HS algorithm with parameter-setting free technique is proper for optimizing the parameters of HMM. HS algorithm is flexible so as to allow the elimination of requiring tedious parameter assigning efforts. In this paper, a sequential data analysis simulation is illustrated, and the optimized-HMMs are evaluated. The optimized HMM was capable of classifying a sequential data set for testing compared with the normal HMM.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.1
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• pp.1-10
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• 2019

Naval ship design and related other activities can be characterized by the complexity of the interactions among products, activities, and disciplines. Such complexities often result in inferior designs, cost overrun, and late-delivery. Hence there exist tremendous interests in both improving the design process itself and optimizing the interactions among design activities. This paper looks at the complexity of designing naval ships thereby leading to the innovation of current ship design practices using design structure matrix. It can be used to induce the optimal ordering of design activities as well as identify sources of complexities. The method presented here identifies coupled design activities useful for reducing the complexity of naval ship design as well as optimally reordering design activities. This paper recommends the use of design structure matrix method suitable for numerically optimizing the concept design process of naval ship, and reducing cost and time required in designing naval ships by modeling and analyzing the design activities and engineering tasks, defined in systems engineering planning documents.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.413-416
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• 2008

In the presence of multiple continuous queries, multi-query optimizing is a new challenge to process multiple stream data in real-time. So, in this paper, we proposed an approach to optimize multi-query of sliding window on network traffic data streams and do some comparisons to traditional queries without optimizing. We also detail some method of scheduling on different data streams, while different scheduling made different results. We test the results on variety of multi-query processing schedule, and proofed the proposed method is effectively optimized the data stream similar multi-queries.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.105-105
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• 2003

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.10a
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• pp.176-176
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• 2000