• Journal of Electrical Engineering and Technology
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• 제3권4호
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• pp.528-537
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• 2008

Primary frequency control(PFC) has the ability to regulate short period random variations of frequency during normal operation conditions and also to respond rapidly to emergencies. However, during the past decade, numerous significant sized blackouts occurred worldwide that resulted in serious economic losses. Therefore, the conclusion has been reached that the ability of the current PFC to meet an emergency is poor, and security of power systems should be improved. An alternative to enhance the PFC and thus security is to store excessive amounts of energy during off-peak load periods in efficient energy storage systems for substituting the primary control reserve. In this sense, superconducting magnetic energy storage(SMES) in combination with a static synchronous compensator(STATCOM) is capable of supplying power systems with both active and reactive powers simultaneously and very rapidly, and thus is able to enhance the security dramatically. In this paper, a new concept of PFC based on incorporating a STATCOM-SMES is presented. A complete detailed model is proposed and a new control scheme is designed, comprising an enhanced frequency control scheme, and a fully decoupled current control strategy in d-q coordinates with a novel controller to prevent dc bus capacitors voltage drift/imbalance. The performance of the proposed control schemes is validated through digital simulation carried out using MATLAB/Simulink.

• KIEAE Journal
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• 제6권4호
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• pp.3-10
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• 2006

To preserve scenic-view of Gwanak Mountain from the urban development, the viewshed component ratio and the scenic-view preference are investigated and analyzed by selecting view points at Nangokro. After 16 candidate view points are selected from the site, sight component ratio is measured through visual structure analysis and preference are measured by using the Likert scale. In addition, factor analysis, and regression analysis were conducted to examine the relationship between influencing factors and preference. As a result of the regression analysis of the 9 factors to influence the scenic-view preference, two factors such as degree of natural landscape and degree of arrangement around the site are chosen to influence the scenic-view preference. Through the preference factor analysis, two preference factors are selected as follows; 1) The factor of the landscape formation - Existence and nonexistence of the scenic-view conservation, degree of the landscape opening, and degree of natural landscape, degree of the landscape originality, and degree of the landscape sequence, degree of the landscape intimacy 2) The factor surrounding the landscape - Degree of arrangement around the site, degree of the landscape complexity, and atmosphere around the site.

• 보건행정학회지
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• 제8권1호
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• pp.135-154
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• 1998

In Korea, the institutional reform for the national medical insurance system is in process. Eventually, three kinds of the national medical insurance system, i.e., medical insurance program for the industrial workers, the govemment employees and the private school teachers, and the self-employeds, would be merged into an unifed system. In this study, I analyzed the annual trends of the finance in the medical insurance system in Korea, in which I found the financial instability especially in the medical insurance program for the self-employeds. The regression analysis was carried out to forecast the accumulated reserve at the end of this year for the medical insurance program for the self-employeds. I also analyzed the economic effect of the merge of the medical insurance program for the self-employeds by using the case of Japan and Korea. I found that the medical insurance for the self-employeds is expected to have financial deficit at the end of the year 1998 after the merge. In onclusion, it seems to be quite difficult to solve the financial instability in the medical insurance program for the self-employeds after it would be merged. That means that there would be a lot of problems on the way to the merge.

• The Journal of Asian Finance, Economics and Business
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• 제7권10호
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• pp.1-8
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• 2020

The objective of the study is to investigate the effect of growth opportunities on capital structure and dividend policy in Indonesia. The study employs panel data of companies listed on Indonesia Stock Exchange that distribute dividends from 2007 to 2017. Fixed and random effect regression models are used. Findings based on growth opportunities on capital structure and dividend policy in Indonesia are in line with the existing theory (i.e., contracting theory). Growth opportunities have a significant negative correlation with debt ratio and dividend yield, which suggests that firms with high growth opportunities are discouraged to generate debt to resolve underinvestment and asset-substitution problem. Firms with more investment opportunities tend to adopt a low dividend payout policy because the cash flows will be used up for investment. The positive impact of firm size on leverage is due to the low bankruptcy risk and cost of a large company. Profitability has a positive impact on the dividend policy because profitable companies can reserve larger free cash flows and, thus, pay higher dividends. The positive influence of ownership on leverage is interpreted by the unwillingness of majority stockholders to commit to equity financing in order to avoid reducing the ownership and preserve control of the company.

• 패션비즈니스
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• 제11권3호
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• pp.35-45
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• 2007

This study examined how to create 2D basic pattern of individuals by means of 3-D body figure, which is to develop a flat of individual basic pattern directly from the 3-D body scan data of each subject using that of the upper body of a male adult. In terms of methodology, this study adopted 3D body scan data on system and body to make examinations in the following steps: 1. Standard point and line were set on human body, along with 3-D definition points(feature points). 2. PB was created by modifying horizontal and longitudinal section of scan data. 3. Ways to set reserve were established in the findings of PB planar development. Respective developed flat patterns were compared with pattern findings in previous studies by means of sensory evaluation. As a result, it was found that both system and body model are basic pattern and belong to appropriate pattern as semi-tight-fit basic pattern with overall appropriate tolerances. Thus, this study came to a conclusion that it is feasible and valid to develop theories for flat development as considered herein.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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• pp.134-137
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• 2004

본 논문에서는 향후 남한의 예비력 중대방안으로 동북아 지역 (러시아, 중국, 몽고, 북한, 한국, 일본)의 지역의 전력계통연계선로의 구성 및 동북아 지역의 계절별 패턴을 고려한 조류계산을 수행하여 전력수급의 분포도를 파악하고자 한다. 특히 한반도 전체의 전력수급을 고려하여 볼 때 남-북한의 수도권 및 영남 지역의 두 지역은 향후 계속적인 전력 수요의 증가로 인한 발전력의 부족상태가 계속되리라 여겨지며, 이러한 문제의 해결방안으로 북한의 신포지역에 2,000MW KEDO 경수로를 건설하여 공급하는 방안이 있겠으나 현재 여러 가지 정치적 상황으로는 건설을 중단하게 되었다. 이러한 정치적 상황의 변화로 다른 대안이 필요하게 되었다. 이들 중의 하나가 극동러시아나 시베리아 및 중국 그리고 일본과의 연계에 의한 예비력을 확보하는 방안이 될 것이다. 본 논문에서는 동북아 지역과 연계를 할 수 있는 가능한 지역을 고려하여 연계선로를 구성하고 계절별 효과를 고려한 조류계산을 실시하여 연계 시 융통전력의 분포도를 연구하고자 한다.

• 경영과정보연구
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• 제34권4호
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• pp.31-66
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• 2015

본 연구의 목적은 독립변수로 사용된 조직 내 구성원들이 주는 미덕적 행위, 조직 내 구성원들이 받는 미덕적 행위, 조직 외 사회구성원들에게 주는 미덕적 행위, 조직 외 사회구성원들로부터 받는 미덕적 행위의 핵심범주를 질적 연구방법론을 통해 도출한 후 이들이 업무성과에 미치는 영향관계에 대한 연구모형을 설계하는 것이다. 즉, 개방코딩, 축 코딩, 선택코딩을 통해서 도출 된 핵심범주로서 조직 내 구성원들이 서로 주고받는 미덕적 행위와 조직 외 사회 구성원들과 주고받는 미덕적 행위들이 조직 동일시, 긍정적 업무관련 정체성, 정서적 몰입, 감정고갈, 집단적 자긍심의 변수들을 통해 업무성과와 어떠한 인과관계가 있는지를 질적 연구를 통해 밝혀내는 것이다. 본 연구 방법은 국내 5개 소방서를 대상으로 50명의 소방대원들을 인터뷰한 후 이들에 대한 개방코딩과 축 코딩, 선택코딩을 실시하였다. 인터뷰 자료를 근거로 개방코딩, 축 코딩, 선택코딩 후 10개의 핵심범주를 도출해 낼 수가 있었다. 질적 연구 결과 최종적으로 10개의 핵심범주, 즉 조직 내 구성원들이 주는 미덕적 행위, 조직 내 구성원들이 받는 미덕적 행위, 조직 동일시, 긍정적 업무관련 정체성, 정서적 몰입, 감정 고갈, 집단적 자긍심이 인과적 영향관계를 맺으며 업무성과에 영향을 미친다는 것을 밝혀냈다. 이러한 질적 연구 방법론에 기반 하여 최종적으로 조직 내 구성원들이 서로 주고받는 미덕적 행위와 조직 외 사회 구성원들과 주고받는 미덕적 행위들의 핵심범주를 도출해 내게 되었고, 이를 바탕으로 연구모형을 설계하였다. 따라서 본 연구의 의의는 소방대원들이 조직 내 구성원들과 주고받는 미덕적 행위와 조직 외 사회구성원들과 주고받는 미덕적 행위에 대한 핵심범주들이 질적 연구방법론을 통해 도출되어 최종적으로 이들이 업무성과에 영향을 미치게 되는 연구모형을 설계하였다는데 의의가 있을 것이다.

• 한국군사과학기술학회지
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• 제16권2호
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• pp.160-168
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• 2013

In tactical environment, tactical wireless networks are generally comprised of Tactical MANETs(T-MANETs) or Tactical WMNs(T-WMNs). The most important services in tactical network are voice and low rate data such as command control and situation awareness. These data should be forwarded via multi-hop in tactical wireless networks. Urgent and mission-critical data should be protected in this environment, so QoS(Quality of Service) must be guaranteed for specific type of traffic for satisfying the requirement of a user. In IEEE 802.11s, TDMA-based MAC protocol, MCCA(MCF Controlled Channel Access), has a function of resource reservation. But 802.11s protocol can not guarantee the end-to-end QoS, because it only supports reservation with neighbors. In this paper, we propose the routing protocol, R-HWMP(Reservation-based HWMP) which has the resource reservation to support the end-to-end QoS. The proposed protocol can reserve the channel slots and find optimal path in T-WMNs. We analyzed the performance of the proposed protocol and showed that end-to-end QoS is guaranteed using NS-2 simulation.

• 한국전자거래학회지
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• 제25권1호
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• pp.177-202
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• 2020

본 연구는 세계 무기 수출 시장의 구조적인 변화 요인을 식별하기 위한 통계적 모형을 설계하고 실증 분석 결과와 경제적 함의를 제시하고자 한다. 무기 수출의 변화 양상을 설명할 수 있는 변인은 무엇인가, 그러한 변화는 통계적으로 유의한가, 변화의 특성은 어떻게 해석될 수 있는지를 중심으로 연구 질문을 삼고 분석의 틀을 설계하였다. 실증 분석을 위해 SIPRI 데이터베이스에 수록된 무기 수출 상위 40개 국가의 거래량을 분석 대상으로 삼았다. 그리고 연구 모형을 설정하기 위한 가설을 제시하고 가설로부터 도출된 변수들의 조합에 따라 여러 회귀 모형을 구성하여 통계적 유의성을 검증하였다. 분석 결과에서 국가 보유고 변수는 무기 수출 시장의 변화와 지속적인 관계를 맺고 있는 변수로서 특징적인 의미를 보여주고 있으며, UN 안보리 상임이사국 그룹은 세계 무기 수출에 집단적인 지배력을 발휘하고 있는 것으로 나타났다. 이와 함께 2000년대를 전후로 하여 나타난 변화의 주요 동인은 국내 총생산과 국가 순 수출액과 관련이 있는 것으로 파악되었다. 전반적으로 이런 요인들이 세계 무기 수출의 흐름과 방향을 좌우해왔던 것으로 평가되며 향후에도 무기 수출 시장의 구조에 영향을 주는 변수가 될 것으로 전망된다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권12호
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• pp.1712-1720
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• 2012

We investigated the effect of the amount of body condition loss in the dry period and early lactation in 42 high-yielding Holstein-Friesian cows on milk yield and the share of fatty acids in milk fat. Energy reserves were estimated based on the body condition scoring (BCS) and backfat thickness (BFT). Milk yield and milk composition were determined over 305-d lactation. From d 6 to 60 of lactation, the concentrations of 43 fatty acids in milk fat were determined by gas chromatography. Cows were categorized based on body condition loss from the beginning of the dry period to the lowest point of the BCS curve in early lactation into three groups: low condition loss group (L) ${\leq}0.5$ points (n = 14); moderate condition loss group (M) 0.75 to 1.0 points (n = 16) and high condition loss group (H) >1.0 points (n = 12). Cows whose body energy reserves were mobilized at 0.8 BCS and 11 mm BFT, produced 12,987 kg ECM over 305-d lactation, i.e. 1,429 kg ECM more than cows whose BCS and BFT decreased by 0.3 and 5 mm, respectively. In group H, milk yield reached 12,818 kg ECM at body fat reserve mobilization of 1.3 BCS and 17 mm BFT. High mobilization of body fat reserves led to a significant (approx. 5%) increase in the concentrations of monounsaturated fatty acids-MUFA (mostly $C_{18:1}$ cis-9, followed by $C_{18:1}$ trans-11), a significant decrease in the levels of fatty acids adversely affecting human health, and a drop in the content of linoleic acid, arachidonic acid and docosahexaenoic acid in milk fat. In successive weeks of lactation, an improved energy balance contributed to a decrease in the concentrations of unsaturated fatty acids (UFA) and an increase in the conjugated linoleic acid (CLA) content of milk fat.