• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.575-584
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• 2016

Considering the randomness and uncertainty of wind power, a reliability model of WTGs is established based on the combination of the Weibull distribution and the Markov chain. To analyze the failure mode quickly, we use the switch-section partitioning method. After defining the first-level load zone node, we can obtain the supply power sets of the first-level load zone nodes with each WTG. Based on the supply sets, we propose the dynamic division strategy of island operation. By adopting the fault analysis method with the attributes defined in the switch-section, we evaluate the reliability of the distribution network with WTGs using a sequential Monte Carlo simulation method. Finally, using the IEEE RBTS Bus6 test system, we demonstrate the efficacy of the proposed model and method by comparing different schemes to access the WTGs.

• ETRI Journal
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• v.44 no.5
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• pp.837-848
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• 2022

Analog circuit design is comparatively more complex than its digital counterpart due to its nonlinearity and low level of abstraction. This study proposes a novel low-level hybrid of the sine-cosine algorithm (SCA) and modified grey-wolf optimization (mGWO) algorithm for machine learning-based design automation of CMOS analog circuits using an all-CMOS voltage reference circuit in 40-nm standard process. The optimization algorithm's efficiency is further tested using classical functions, showing that it outperforms other competing algorithms. The objective of the optimization is to minimize the variation and power usage, while satisfying all the design limitations. Through the interchange of scripts for information exchange between two environments, the SCA-mGWO algorithm is implemented and simultaneously simulated. The results show the robustness of analog circuit design generated using the SCA-mGWO algorithm, over various corners, resulting in a percentage variation of 0.85%. Monte Carlo analysis is also performed on the presented analog circuit for output voltage and percentage variation resulting in significantly low mean and standard deviation.

• Journal of the Korean housing association
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• v.16 no.6
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• pp.139-147
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• 2005

The purpose of this study was to determine the factors which affect older people's innovativeness toward technologies and factors which affect their demand of home automation system. The study collected data from 289 persons who are 50 years and older with experience living in an apartment currently or past. Innovativeness toward technologies of respondents were low level and the significant factors which affected their innovativeness were age, education, employment, marital status, current housing types, health status of self and spouse, consideration of home automation system for a newly-moved house. Education, employment types, consideration of home automation system for a newly-moved house, and plan for moving were the major factors which affect demand of home automation system. Also, older people's innovativeness toward technologies was the most important factor which affected demand of home automation system. Th results of this study explained that high technologies which are adopted in residential environment should be considered target consumers' abilities and attitudes for acceptance toward new ideas. Especially, for older consumers, various ideas to expand their understanding of new technologies should be developed and the positive effect of technologies to increase the quality of their later life should be educated.

• Journal of the Korean Home Economics Association
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• v.43 no.12 s.214
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• pp.29-41
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• 2005

The purpose of this study was to define the residents' current uses and satisfaction of a home automation system. The data were collected from 85 residents living in a selected intelligent apartment, from whom 72 were used for the final analysis. The results were as follows: 1) The educational background was the most significant variable affecting differences among the groups in terms of use of the home automation system. 2) Even though the over 50 years age group showed a tendency toward lower technology acceptance, their utilization rates of the home automation system were higher than those of the under 40 years age group. 3) The respondents with dual income showed higher rates of utilization of the home automation system than the single income group. 4) In spite of positive satisfaction level for the home automation system, many improvements were still requested.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.317-320
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• 2005

본 논문은 멀티-레벨 H-bridge 인버터에서 입력전압 변동에 따른 AVR(Auto Voltage Regulation)기능을 적용 그 타당성을 제안하였다. 기존의 범용 인버터에서 (V/F)로 구동되는 전동기 시스템에 있어서 인버터에 공급되는 입력 전압은 출력 주파수에 따라 출력 전압 비율을 일정하게 하고 기동에 필요한 전압을 더하여 출력하는 방식이다. 집중 제어 방식의 멀티-레벨 H-bridge 인버터에서는 Cell의 DC-Link 전압을 Master에서 받아들여서 각각의 Cell에 기준 전압값을 지령하게 된다. 그러므로 입력 전압 변동에 따른 DC-Link 전압의 변동이 발생하게 되면 상전압 Unbalance 가 발생하게 되어 부하가 원하는 출력 전압을 낼 수가 없게 된다. 또한 각각의 Cell을 제어하는 Master 제어기가 가지고 있는 문제점을 보완하여 각각의 Cell 제어기 스스로가 AVR을 수행하는 좀더 나은 방법을 제안하였다.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2005.11a
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• pp.67-72
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• 2005

The purpose of this study was to determine the factors which affect older people's innovativeness toward technologies and factors which affect their demand of home automation system. The study collected data from 289 persons who are 50 years and older with experience living in an apartment currently or past. Innovativeness toward technologies of respondents were low level and the significant factors which affect their innovativeness were age, education, employment, marital status, current housing types, health status of self and spouse, consideration of home automation system for a newly-moved house. Education, employment types, consideration of home automation system for a newly-moved house, and plan for moving were the major factors which affect demand of home automation system. Also, older people's innovativeness toward technologies was the most important factors which affect demand of home automation system. Th results of this study explained that high technologies which are adopted in residential environment should be considered target consumers' abilities and attitudes for acceptance toward new ideas. Especially, for older consumers, various ideas to expand their understanding of new technologies should be developed and the positive effect of technologies to increase the qualify of their later life should be educated.

• Cement Symposium
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• no.30
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• pp.194-198
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• 2003

• Journal of the Society of Naval Architects of Korea
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• v.56 no.6
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• pp.523-531
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• 2019

The low birthrate and the need for national defense reform in Korea drive the Navy to develop efficient human resource planning such as a manpower forecasting model. However, to our knowledge, there is no study exploring the manpower forecasting model for naval ships in Korea. The purpose of this paper is to develop a model for forecasting manpower demand in naval ships. Data for analyses were drawn from 19 ships in the Korean Navy. Results indicate that mission type is significantly related to the number of manpower. Specifically, battleships need the more manpower than the battle support ships. The results also showed that the weight of hull structure-engine and the weight of the weapons system significantly increased the number of manpower. However, the weight of the combat system was not significant. In addition, whereas the automation level of hull structure-engine and the automation level of weapon system was found to be negatively related to the number of manpower, the automation level of combat system was positively related to it. The model developed here contributes to an advanced human resource planning of the Korean Navy. Implications, limitations, and directions for future research are discussed.

• Convergence Security Journal
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• v.7 no.4
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• pp.1-8
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• 2007

Currently, the needs of open standard and integrated network, and also applications of Ethernet network based system are increasing. By applying and expanding TCP/IP based network technology from high to low control level, factory automation application has been implemented, and thus integrated factory automation system has been accomplished, which is directly interoperable between high level management program and DB system. This paper proposes a communication control device which is based on Ethernet/IP standard system for factory automation. The proposed system is workable in the environment of a network system, which is based on CIP standard interface technology. The proposed system can also contribute to improve data communication characteristics.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.10-22
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• 2022

According to the Space Development Promotion Basic Plan, more than 110 satellites are expected to be deployed by 2031. Accordingly, the operation concept and technology for satellites constellation are required, compared to the existing few multi-satellite operations. It is essential to automate and optimize the mission operation system, for efficient operation of the satellite constellation, and preparations are urgently needed for the operation of satellite constellation in domestic as well. In this study, the development direction and strategy of the mission operation system applying automation and optimization for efficient operation of the satellite constellation are proposed. The framework for evaluating the automation level and priority of the mission operation system was developed, to identify the tasks to which automation should be applied preferentially.