• Journal of Power Electronics
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• 제15권4호
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• pp.1026-1034
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• 2015

In this paper, a unified control strategy using the current space vector modulation (CSVM) technique is proposed and applied to a bidirectional three-phase DC/AC converter. The operation of the converter changes with the direction of the power flow. In the charging mode, it works as a buck type rectifier; and during the discharging mode, it operates as a boost type inverter, which makes it suitable as an interface between high voltage AC grids and low voltage energy storage devices. This topology has the following advantages: high conversion efficiency, high power factor at the grid side, tight control of the charging current and fast transition between the charging and discharging modes. The operating principle of the mode analysis, the gate signal generation, the general control strategy and the transition from a constant current (CC) to a constant voltage (CV) in the charging mode are discussed. The proposed control strategy has been validated by simulations and experimental results obtained with a 1kW laboratory prototype using supercapacitors as an energy storage device.

• 전기전자학회논문지
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• 제23권2호
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• pp.557-570
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• 2019

In this study, a novel hierarchical approach is investigated to extract coronary vessel from X-ray angiogram. First, we propose to combine Decimation-free Directional Filter Bank (DDFB) and Homographic Filtering (HF) in order to enhance X-ray coronary angiographic image for segmentation purposes. Because the blood vessel ensures that blood flows in only one direction on vessel branch, the DDFB filter is suitable to be used to enhance the vessels at different orientations and radius. In the combination with HF filter, our method can simultaneously normalize the brightness across the image and increases contrast. Next, a coarse-to-fine strategy for iterative segmentation based on Otsu algorithm is applied to extract the main coronary vessels in different sizes. Furthermore, we also propose a new approach to segment very small vessels. Specifically, based on information of the main extracted vessels, we introduce a new method to extract junctions on the vascular tree and level of nodes on the tree. Then, the window based segmentation is applied to locate and extract the small vessels. Experimental results on our coronary X-ray angiography dataset demonstrate that the proposed approach can outperform standard method and attain the accuracy of 71.34%.

• 품질경영학회지
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• 제49권1호
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• pp.31-45
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• 2021

Purpose: A noncentral composite design method is to be developed to explore farther region for the first factorial design. A general guideline for sequential experimentation is provided. Methods: (1) A non-overlapping noncentral composite design (NNCD) is developed, in which the second factorial design shares one design point that indicates the best response value in the first factorial design. (2) Four composite designs are compared in terms of the four design evaluation criteria, which are D-, A, G, and I-optimality. (3) A follow-up design strategy is suggested based on the interaction effect, direction of improvement, number of factors. Results: (1) NNCD and model building method are presented, which is useful for exploring farther region from first factorial design block. (2) The performances of the four composite designs are compared. (3) A follow-up design strategy is suggested. Conclusion: (1) NNCD will be useful to explore farther region for the first factorial design. (2) A follow-up design strategy can be beneficial to the experimental practitioners for product and process design and improvement.

• Journal of information and communication convergence engineering
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• 제20권2호
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• pp.103-112
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• 2022

The goal of pattern mining is to identify novel patterns in a database. High utility itemset mining (HUIM) is a research direction for pattern mining. This is different from frequent itemset mining (FIM), which additionally considers the quantity and profit of the commodity. Several algorithms have been used to mine high utility itemsets (HUIs). The original BPSO algorithm lacks local search capabilities in the subsequent stage, resulting in insufficient HUIs to be mined. Compared to the transfer function used in the original PSO algorithm, the V-shaped transfer function more sufficiently reflects the probability between the velocity and position change of the particles. Considering the influence of the acceleration factor on the particle motion mode and trajectory, a nonlinear acceleration strategy was used to enhance the search ability of the particles. Experiments show that the number of mined HUIs is 73% higher than that of the original BPSO algorithm, which indicates better performance of the proposed algorithm.

• International Journal of Advanced Culture Technology
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• 제11권3호
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• pp.321-326
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• 2023

The purpose of this study is to create and present a formalized module of ISP (Information Strategy Plan), a smart factory consulting method that is helpful to companies or consultants who will build smart factories. Order of study is First, the theoretical research direction is established through the investigation of related papers. Second, ISP policy research practices are compared to derive practical implementation methods. Third, in order to derive a standardized module method related to the final smart factory ISP, related cases of the government and individuals are compared. As a result of previous research, ISP (Information Strategy Planning), a consulting methodology, is similar to Deming's PDCA, and is regarded as Plan (environment and current status analysis), Do (establishment of future model goals), Check (establishment of implementation plan), and Act (follow-up management). As a result of the study, we obtained the following results. The first step is to analyze the current status and identify the purpose of introduction and problems in plant operation. In the second step, establish a consulting plan and derive a proposal description, strategic task, and master plan. Step 3 establishes detailed action plans, evaluates consulting outputs and consulting, and reports performance. Step 4 is established as follow-up management consulting. The limitation of the study is that although related data were compared to develop the consulting methodology into a standardized module, FGI analysis through experts or Delphi survey were not conducted, so there is a limit to the reliability of the mapping results.

• 한국산업정보학회논문지
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• 제14권2호
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• pp.59-71
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• 2009

급변하는 경영환경 속에서 기엽이 지속적인 경쟁우위를 획득하기 위해서는 성공적인 정보기술전략과 효율적인 정보기술 투자를 위한 투자성과의 체계적인 관리가 필요하다. 따라서 본 연구에서는 정보기술전략인 운영지향성과 시장지향성이 정보기술 투자방향 및 프로세스 혁신역량과 기엽의 비재무적 성과와 재무적 성과에 미치는 영향을 분석하고자 한다. 본 연구의 실증연구에서는 SCM을 실행하고 있는 기업을 대상으로 설문조사를 실시하여 온라인과 오프라인을 통해 자료를 수집하였으며, 최종적으로 82개 의 표본을 분석에 사용하였다.

• 연구윤리
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• 제4권2호
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• pp.13-17
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• 2023

Purpose: EAJBE is actively responding to changes in academic paradigms at domestic and abroad and is carrying out measures to maximize synergy effects between academic fields with the goal of being at the world level. This study aims to present a developmental strategy for EAJBE to grow into an academic journal with international public trust and prepare for future changes. Research design, data and methodology: This paper identifies the current status from the first issue of EAJBE to the present, and analyzes the overall development strategy and direction. Results: EAJBE continues to strengthen long-term investment for internationalization and activities to attract members of excellent scholars. Specifically, first of all, EAJBE aims to operate responsible academic journals, such as guaranteeing the long term of the president of the academic society, the chairman of the editorial board, and the editor-in-chief. EAJBE also focuses on expanding investment for internationalization from a long-term perspective. Finally, EAJBE actively strives for academic exchanges between scholars abroad and at home. Conclusions: EAJBE was indexed in the KCI of the Korea Research Foundation and currently operates a rigorous academic journal to be indexed in the SCOPUS. Already, EAJBE is doing its best to become a successful model for Korean academic journals. EAJBE's path forward will be the first one that no academic society has ever reached as the world's top academic journal.

• 컴퓨터교육학회논문지
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• 제9권4호
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• pp.25-34
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• 2006

초중등 학교교육에 e-러닝 체제가 도입되고 있지만, 정규교육과정에의 도입이 어려운 형편이다. 또한, 프로젝트 학습을 정규교육과정에서 현실적으로 적용하기에는 시수 부족이나 교과 접근에 대한 어려움을 초래하고 있다. 본 연구에서는 이와 같은 문제점을 해결하기 위해 블랜디드 기반의 프로젝트 학습 진략을 수립하고 적용, 분석하였다, 이를 위해 블랜디드 학습 및 정보통신기술 기반 프로젝트학습의 개념에 대한 이론적 탐구를 하였다. 또한, 통합 교과기반 학습 주제를 선정하고 5단계 블랜디드 프로젝트 교수학습 전략을 구체화하였다. 구체화 전략은 토론, 역할 분담, 대안 평가 진략이었으며 온클래스-온라인, 온클래스-오프라인, 오프클래스 온라인의 유형으로 수업을 진행하였다. 적용 결과 학생들은 짧은 기간으로 인하여 아쉬움을 나타냈지만, 전체적으로 프로젝트 수업 효과에 긍정적인 반응을 나타냈다. 이에, 본 연구는 e-러닝을 정규학교교육에서 실천할 수 있는 가능성을 제시하였으며, 디지털 기반의 학습자 중심 수업의 방향을 제시할 수 있었다.

• 디지털산업정보학회논문지
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• 제13권1호
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• pp.173-183
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• 2017

The purpose of this study is to find out the difference of sense of self-efficacy and stress encountering strategy of university students under the stress situation depending on the smart-phone user group (addiction group, general user group). For this purpose, the study issues are established as follows. First, it has analyzed what is the correlation of smart-phone addiction, sense of self-efficacy, and stress encountering strategy. Second, it has studied if there is any difference of sense of self-efficacy and stress encountering strategy for the smart-phone user group. In order to verify such study issues, For 1,670 university students in the Chungcheong area, smart-phone addiction scale, sense of self-efficacy scale, and stress encountering method scale were administered. Looking into the study result, first, as a result of the relativity analysis, it displayed the correlation of preference of test difficulty, self-control efficacy and important negative from the smart-phone addiction and sense of self-efficacy. In addition, all sub-variables of smart-phone addiction and avoidance orientation from the stress encountering strategy displayed the important positive correlation, and from the smart-phone addiction, the virtual world orientation and pursuit of social-support displayed the important negative correlations, and all sub-variables (interference with ordinary living, virtual world striving direction, withdrawal, resistance) of smart-phone addiction and problem solving-orientation displayed the negative correlation. Second, as a result of verification for the difference of the smart-phone addiction group and general use group following the sense of self-efficacy, the general use group is shown to have higher self-control efficacy sense than the addiction group. And third, as a result of verifying the difference of stress encountering following the smart-phone addiction group and general use group, the addiction group is shown to be lower than the general use group in terms of social support pursuit and problem solution orientation with the avoidance orientation shown to be higher. This type of result is expected to provide the base data when developing the smart-phone addiction preventive education program by finding out in details for the characteristics of smart-phone addiction group for university students.

• 기술혁신학회지
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• 제11권4호
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• pp.639-670
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• 2008

Kaplan과 Norton(1992)에 의해 소개된 BSC(balanced scorecard)는 다양한 기업과 산업에서 일반적인 성과평가 도구로 활용되고 있다. BSC는 전략적 목표를 구체적인 운영지표에 연계시켜 기업의 목표달성을 효과적으로 평가할 수 있도록 해 주는 장점이 있다. 본 연구는 설립 목적상 공공성을 갖으면서 지식전문가로 구성된 국가R&D조직에 BSC시스템을 구축하고 적용한 사례를 보여준다. 이러한 공공 전문조직이 BSC를 통해 전략적 방향을 재정렬하고 전략집중형 조직(Strategy Focused Organization)으로 변화하기 위해서는, 기관의 고유 미션으로부터 시작하여 비전 재설정, 전략방향과 목표 수립, 핵심성과지표 도출, 전략지도(Strategy Map) 설정, 모니터링 시스템 구축에 이르는 BSC 전체 구축과정에서의 방법론에 대한 이해와 현실적 적용이 성공의 핵심적인 요소라 할 수 있다. 이에 본 K연구원의 사례에서는 그러한 적용과정을 보여줌으로 해서 공공연구기관의 BSC구축에 대한 유익한 시사점을 제공하고자 한다.