• Journal of Electrical Engineering and Technology
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• 제4권3호
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• pp.310-314
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• 2009

This paper presents the improvement of the voltage profiles of power system networks by the inclusion of Unified Power Flow Controller (UPFC). The mathematical model of the UPFC is incorporated in the load flow algorithm and the L-index is calculated for the different values of the control parameter r $and{\gamma}$. The positioning of the UPFC device is changed to minimize the sum of the squares of the L-indices at all load buses. The test cases considered for the improvement of voltage profile with the WSCC 9-bus and IEEE 30 bus system. With the best position of UPFC along with the control parameters the improvement in voltage profile of the power system networks are obtained. The results obtained are quite encouraging compared with other techniques used to identify the best location of UPFC.

• 자원ㆍ환경경제연구
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• 제9권5호
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• pp.811-827
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• 2000

Since improved thermal efficiency reduces capacity requirements and energy costs, electricity producers often treat thermal efficiency as a measure of management or economic performance. The conventional measure of the thermal efficiency of a fossil-fuel generation system is the ratio of total electricity generation to the simple sum of energy inputs. As a refined approach, we present a novel thermal efficiency measure using the concept of the Divisia index number. Application of this approach to the Korean power sector shows improvement of thermal efficiency of 1.1% per year during 1970-1998. This is higher than the 0.9% improvement per year given by the conventional method. The difference is attributable to the effect of fuel substitution. In the Divisia decomposition context, we also show the limitations of the popular $T{\ddot{o}}rnqvist$ index formula and the superiority of the Sato-Vartia formula.

• 대한전기학회논문지
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• 제31권7호
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• pp.11-17
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• 1982

In this paper, a reliable and convenient evaluation method for the adequacy of any radial distribution line's voltage drop is proposed for improvement of the voltage regulation of the distribution line under operation. Using the voltage measurement of the first load branch point and the last point on the given distribution line its average line voltage drop and the line voltage drop variance by pure load variation are computed. And by these values and allowable or required line drop from proper voltage regulation view point, present adequency index and operation improvement index of the line drop are newly introduced for the evaluation of the given distribution line's voltage regulation. As a result of application to the 4 cases of study, the proposed method is proved to be reliable and convenient.

• 대한수학회보
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• 제60권6호
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• pp.1621-1639
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• 2023

In this paper, we give an improvement for the second main theorems of algebraically non-degenerate meromorphic maps from generalized p-parabolic manifolds into projective varieties intersecting hypersurfaces in subgeneral position with some index, which extends the results of Han [6] and Chen-Thin [3].

• Journal of Multimedia Information System
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• 제3권3호
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• pp.53-61
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• 2016

This research proposes the index optimization as a classification task and application of the graph based KNN. We need the index optimization as an important task for maximizing the information retrieval performance. And we try to solve the problems in encoding words into numerical vectors, such as huge dimensionality and sparse distribution, by encoding them into graphs as the alternative representations to numerical vectors. In this research, the index optimization is viewed as a classification task, the similarity measure between graphs is defined, and the KNN is modified into the graph based version based on the similarity measure, and it is applied to the index optimization task. As the benefits from this research, by modifying the KNN so, we expect the improvement of classification performance, more graphical representations of words which is inherent in graphs, the ability to trace more easily results from classifying words. In this research, we will validate empirically the proposed version in optimizing index on the two text collections: NewsPage.com and 20NewsGroups.

• 한국건설관리학회논문집
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• 제17권5호
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• pp.108-119
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• 2016

국내 건설재해율은 1992년 도입된 이후 현재까지 PQ에 '환산재해율' 반영 등을 통하여 건설재해 감소 및 건설업 안전관리 체제 구축에 기여하고 있다. 또한, 최근 정부가 도입 추진 중인 종합심사낙찰제에도 '재해율' 및 '사망만인율'이 평가항목으로 구성되어 입 낙찰제도의 그 영향력이 확대되고 있다. 그러나 현행 건설재해율은 입 낙찰제도에 따라 이원화된 기준으로 산정 및 운영되고 있는 실정이므로 현 시점에서 건설재해율 평가지표에 대한 현황 검토와 효율적 운영을 위한 방안이 모색될 필요성이 대두되고 있다. 이에 본 연구에서는 건설업체의 재해관리 실무자를 대상으로 설문조사를 실시하여, 현행 건설재해율의 평가 운영에 대한 현황 검토를 통하여 문제점을 분석하고 그에 따른 개선방안을 제시하였다. 연구 결과, 건설재해율 평가지표의 일원화를 위한 산정기준, 평가대상업체 범위 설정, 건설업 공상처리 개선 측면에서의 개선방안을 제시하였다. 제시된 개선방안을 통해서 보다 효율적이고 합리적인 건설재해율 평가지표의 산정 및 운영이 가능할 것이며, 나아가 건설업체의 자율적인 안전보건 활성화 등을 통한 건설 재해 감소 효과를 기대할 수 있을 것이다.

• Journal of the Korean Data and Information Science Society
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• 제26권6호
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• pp.1335-1351
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• 2015

경기상황에 대한 기업과 소비자들의 인식을 효과적으로 파악하기 위해 기업경기실사지수 (BSI)와 소비자동향지수 (CSI)를 편제하고 있는 한국은행은 2012년부터 이 두 지수를 합성한 경제심리지수 (ESI)를 추가로 개발하여 발표하고 있다. ESI는 그 유용성을 인정받고 있으나 지수의 예측력 측면에서 개선의 여지가 있는 것으로 나타났다. 본 연구에서는 ESI에 대해 유용성 평가 작업을 실시하고 그 결과를 토대로 현행 ESI의 편제방식의 개선 또는 보완 방법을 모색하였다. 실증분석 결과 ESI 구성요소의 최적 가중치 탐색과정에서 슬라이딩 윈도우 방법을 이용한 동적 최적 가중치 탐색은 기존 ESI의 구성방식을 보완하거나 또는 경제상황을 고려하여 ESI 구성항목들의 가중치를 부여하고자 할 때 매우 유용한 방법이라고 판단할 수 있었다.

• 한국컴퓨터정보학회논문지
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• 제27권12호
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• pp.1-8
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• 2022

F2FS는 SSD(Solid State Drive)를 위한 파일시스템 중의 하나로서 리눅스 운영체제의 커널에 채용되어 널리 사용되고 있다. F2FS는 플래시 메모리의 특성을 반영하여 성능을 높이기 위한 여러 가지 방안들을 적용하였는데, 그 중의 하나가 파일별 데이터 블록들의 주소 정보를 관리하는 인덱스 구조의 개선이다. 본 논문에서는 F2FS의 인덱스 구조를 더욱 개선하여 성능을 높이는 방안을 제시하였다. F2FS는 모든 인덱스 블록들에 대하여 논리적 번호로 기록하고 이것을 물리적 번호로 매핑하는 테이블을 사용한다. 본 논문에서는 인덱스 블록들 중에서 끝단의 블록만 논리적 번호를 적용하고 앞단의 블록들은 물리적 번호를 직접 적용함으로써, 데이터 블록 접근시에 매핑 테이블을 검색하는 회수를 기존의 1~4회에서 1~2회로 줄일 수 있음을 보여주었다.

• 치위생과학회지
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• 제17권1호
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• pp.30-37
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• 2017

The purpose of this study was to reveal analyze the relationship between status of participation in an oral health care program and oral health outcomes among patients in Korea, and to evaluate the results to provide evidence regarding the feasibility of widespread implementation of the program. Patients were designated as either cooperative or non-cooperative with the oral health care program and were assigned to each group accordingly. Modified dental hygiene process (M-DHP) of the oral healthcare program was modified to form the dental hygiene process. The study included 48 patients at a dental clinic in Busan, Korea. Questionnaires were used to collect information on oral health behavior (OHB), clinical examination was used to record bleeding on probing (BOP) and O'Leary index, and phase microscopy was used to identify microorganisms. Differences between groups were evaluated using repeated measures ANOVA. Our results showed that the group cooperative with the oral health care program showed greater improvement in OHB, BOP, and O'Leary index than the non-cooperative group. Second, patient satisfaction with the M-DHP was very high, particularly for content and the friendly nature of the staff. The cooperative group showed greater improvement in oral health than the non-cooperative group for all metrics. Our results suggest that this low-coste program, if implemented, would be actively accepted and utilized in dental clinics.

• ETRI Journal
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• 제30권5호
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• pp.634-643
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• 2008

One of the ubiquitous technology fields that have received the most attention recently from technology communities worldwide is mobile radio frequency identification (RFID). Mobile handsets loaded with RFID readers enable the identification and retrieval of information on RFID tagged objects. In Korea, a variety of mobile RFID services are currently being piloted, and their commercial roll-out looks imminent. The goal of this study is to propose, ahead of the commercial launch of mobile RFID services, a customer satisfaction index (CSI) model for this service category and to then measure the CSI to derive practical implications for their providers and pointers related to the improvement of service. A web survey was conducted on Korean mobile phone subscribers who had participated in a mobile RFID pilot program. Using the results of this survey, we tested the CSI model and its hypotheses by employing a partial least-squares-based structural equation model analysis and calculated the index. We further conducted an importance-performance analysis in order to provide insights that may be useful for improving the quality of mobile RFID services.