• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.345-349
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• 2007

본 연구에서는 계측 데이터의 성능 추이를 분석하여 엔진의 기계적 결함 여부를 탐지하기 위한 퍼지 경향감시 방법을 제안하였다. 경향감시 방법은 연료유량, 배기가스 온도, 로터회전수, 진동수와 같은 중요 엔진 파라미터를 모니터링하여 시간에 따른 변화를 분석하여 엔진 상태를 진단하는 것이다. 선형회귀분석을 통해 엔진 상태 변화를 수식화하고 퍼지 로직을 통해 진단 결과를 분석하여 예측되는 손상 원인을 제시한다.

• International Journal of Advanced Culture Technology
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• 제6권4호
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• pp.116-123
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• 2018

The purpose of this study is to analyze the trend of the prize money and the performance factors, based on the data of 1,000 pro golf players provided by KLPGA(Korea Ladies Professional Golf Association) for the past 10 years from 2008 to 2017. First, in terms of the prize money, it increased a lot if we compare the data from 2008 and from 2017. However, it is still disproportionally favorable to the top players and is extremely disadvantageous to the middle-low players. Therefore, it is necessary to considerately care middle-low players. Second, in terms of performance factors, the players' skill has been improved steadily based on all of the factors considered: the scoring average, average putting, the birdie average, par save, par break, and recovery for the past 10 years from 2008 to 2017. Despite the fact that both players' performance and income have increased, it is prominent that the inequality between the players in terms of prize money becomes severe, which should be mitigated by external systematic support to maintain the current level of world-class players of Korea.

• 해양환경안전학회지
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• 제27권7호
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• pp.918-923
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• 2021

정부는 공유수면 매립사업의 계획적인 관리를 위해, 10년 주기의 공유수면 매립기본계획을 수립하고 있다. 그러나 수시변경을 통한 매립사업을 추진하는 경우가 상당한 비중을 차지하고 있는 것으로 나타났다. 이에 기본계획의 실효성에 대한 의문이 제기되고 있으며, 이를 보완하기 위한 장기 매립 수요 추세 분석에 대한 필요성이 증가하고 있다. 이에 본 연구에서는 그간의 연간 매립 실적 자료를 활용하여 매립 수요 추세 분석을 수행하였다. 분석 결과, 국내 공유수면 매립 수요는 지속적으로 하락하는 추세인 것으로 나타났으며, 특히 매립기본계획 체제로 전환된 1990년대 이후에는 그 추세가 뚜렷하게 나타나고 있는 것으로 나타났다. 또한 2021-2030년까지 총 매립 수요는 최대 13.8 km²에서 최소 1.7 km² 수준으로 산정되었다.

• Nuclear Engineering and Technology
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• 제46권6호
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• pp.737-752
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• 2014

As condition-based maintenance (CBM) has risen as a new trend, there has been an active movement to apply information technology for effective implementation of CBM in power plants. This motivation is widespread in operations and maintenance, including monitoring, diagnosis, prognosis, and decision-making on asset management. Thermal efficiency analysis in nuclear power plants (NPPs) is a longstanding concern being updated with new methodologies in an advanced IT environment. It is also a prominent way to differentiate competitiveness in terms of operations and maintenance costs. Although thermal performance tests implemented using industrial codes and standards can provide officially trustworthy results, they are essentially resource-consuming and maybe even a hind-sighted technique rather than a foresighted one, considering their periodicity. Therefore, if more accurate performance monitoring can be achieved using advanced data analysis techniques, we can expect more optimized operations and maintenance. This paper proposes a framework and describes associated methodologies for in-situ thermal performance analysis, which differs from conventional performance monitoring. The methodologies are effective for monitoring, diagnosis, and prognosis in pursuit of CBM. Our enabling techniques cover the intelligent removal of random and systematic errors, deviation detection between a best condition and a currently measured condition, degradation diagnosis using a structured knowledge base, and prognosis for decision-making about maintenance tasks. We also discuss how our new methods can be incorporated with existing performance tests. We provide guidance and directions for developers and end-users interested in in-situ thermal performance management, particularly in NPPs with large steam turbines.

• Advances in Energy Research
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• 제6권1호
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• pp.17-33
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• 2019

This study aimed to observe trends in the literature on research, development, and innovation management in the energy sector, using performance assessment systems. The paper presented a bibliometric analysis of 40 studies on the subject. These materials come from ScienceDirect, Scopus and the Institute of Electrical and Electronics Engineers (IEEE) databases from 2006 to 2016. The results showed an increasing trend in the number of publications on the theme, showing the scientific community's interest in the subject. In addition, it was verified that the predominant language used to write the publications was English, the country that most published articles in the area was Brazil and most of the articles were produced through collaboration between researchers. It was found that the journal with the greatest number of publications on the subject was the Procedia - Social and Behavioral Sciences, while the Expert Systems with Applications journal presented the article with the greatest number of citations. This analysis allowed us to identify important points of the research and its future directions, in addition to enabling a better understanding of the world trend of the subject approached.

• Design & Manufacturing
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• 제2권3호
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• pp.10-15
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• 2008

Recently, mobile-phone with camera module has an absolute majority in the released mobile-phones. For this trend, High precision of the plastic subminiature barrel which is the core part is needed significantly because the camera module of mobile-phone must have high performance. Therefore, Structural stability of the injection mold for plastic subminiature barrel has to be guaranteed. In this paper, structural analysis of injection mold for plastic subminiature barrel is performed. Finally, the deformation trend and stability of injection mold core are analyzed.

• International Journal of Aeronautical and Space Sciences
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• 제9권2호
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• pp.64-70
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• 2008

The UAV propulsion system that will be operated for long time at more than 40,000ft altitude should have not only fuel flow minimization but also high reliability and durability. If this UAV propulsion system may have faults, it is not easy to recover the system from the abnormal, and hence an accurate diagnostic technology must be needed to keep the operational reliability. For this purpose, the development of the health monitoring system which can monitor remotely the engine condition should be required. In this study, a fuzzy trend monitoring method for detecting the engine faults including mechanical faults was proposed through analyzing performance trends of measurement data. The trend monitoring is an engine conditioning method which can find engine faults by monitoring important measuring parameters such as fuel flow, exhaust gas temperatures, rotational speeds, vibration and etc. Using engine condition database as an input to be generated by linear regression analysis of real engine instrument data, an application of the fuzzy logic in diagnostics estimated the cause of fault in each component. According to study results. it was confirmed that the proposed trend monitoring method can improve reliability and durability of the propulsion system for a long endurance UAV to be operated at medium altitude.

• Journal of Biosystems Engineering
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• 제34권4호
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• pp.228-233
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• 2009

In order to cut the round bale easily, a roughage cut-feeder for the round bale was developed in this study. This study consists of two parts. One is development of a cutting mechanism and a performance test reported in the previous paper. This is the second part of the study. For the study, recent trend of traditional cutting system was analyzed. Also, cost of the prototype cut-feeder was analyzed and determine the break-even point of farm size was determined by comparing with traditional method using a traditional cutter. A prototype cut-feeder was investigated with the fact that working performance, fiber length and shape of roughage and feeding quality was good. Operating cost of the prototype cut-feeder decreased rapidly with an increase of farm size. Break-even point in terms of farm size was 36 heads for beef and 28 heads for dairy. Also, costs estimated were 118,000 won/head year and 148,000 won/head year, respectively.

• 한국건설관리학회논문집
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• 제5권6호
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• pp.118-128
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• 2004

공동주택의 비중이 점차 확대되고, 고층화되는 추세에 따라 공동주택 유지관리의 중요성이 강조되고 있다. 이러한 필요성에 의해 최근 기존 건축물의 종합성능 평가모델이 개발되었으나, 업무의 분석이 미흡한 한계가 있다. 따라서 본 연구는 공동주택 유지관리 성능평가의 기반이 되는 유지관리 업무를 분석하여 성능평가 대상항목 도출을 목적으로 한다 유지관리 성능평가 후보항목은 기존문헌과 업무체계를 분석하여 도출하였고, 학계 전문가 및 주택관리사를 대상으로 설문을 실시하여 성능평가의 용이성, 체계성을 보완하였다. 최종적으로 결정된 성능평가 대상항목은 운영적 유지관리 성능평가 항목 14개와 기술적 유지관리 성능평가 항목 15개 항목이다.

• 유통과학연구
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• 제20권3호
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• pp.59-69
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• 2022

Purpose: The purpose of this study is to provide information for other journals as well as the continuous development of distribution science research by confirming the globalization performance of the Journal of Distribution Science (JDS), the main journal of KODISA. Research Design, Data, and Methodology: A total of 863 papers published in JDS from 2011 to 2021 searched by scienceON were divided into 4 periods and analyzed under the headings of submission system, standardity, collaboration, and degree of achievement of publication goals. SPSS 24.0 and R 4.1.1 package were used to perform the publication frequency analysis, crosstab-analysis, keyword frequency analysis, and LDA topic modeling were performed. In addition, trend analysis with weight applied to each word was performed. Results: It was found that the ratio of English-written papers, which is the indicator of a journal's starndardity, is continuously increasing, and the ratio of overseas authors, which is the indicator of collaboration, is also continuously increasing. It was confirmed through keyword trend analysis by period and LDA topic modeling results - which were weighted to confirm the degree of achievement of the journal's publication goal - that the articles published by the journal has been in agreement with monthly research topic proposed by JDS. Conclusion: By examining the five criteria for globalization, it can be concluded that JDS's efforts for globalization are achieving significant results and providing effective directions for other academic journals. However, in order for JDS to become a top academic journal, it was suggested that efforts should be made to establish a system for collaborative research by domestic and foreign authors, as well as to provide a clear definition for the monthly research topics and classification of sub-topics.