• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.673-678
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• 2008

In crushed service areas of Metro railway lines, there are problems such as the buildup discontent, the irregular operation time and rotation of rolling stocks, caused by frequently occurred train delay. Train delay is affected by operation conditions or infrastructure capacities such as train schedule, line capacity, car rotation plan, shunting movements at origin and destination, and also by transport demand characteristics. Furthermore, a delay produce another delays and spread over the following trains. So it is not easy to build up a protection and recovery plan. In this research, we conduct experimental analysis study based on the real metro data, and as a result, present the relation between the traffic demand and the dwell time. And finally, propose future research themes for improving the operation efficiency of metro railways.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 심포지엄
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• pp.37-37
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• 2003

Enzymes involved in catecholamine synthesis are present in the highest concentration in the adrenal medulla, however they were found also in other, mainly nervous tissues. Increased transcription of genes for catecholamine biosynthetic enzymes is an important mechanism to increase the capacity for epineprine/norepinephrine biosynthesis with stress. Gastrodia elata(Chinese name: Tienma), are very important Chinese herbal medicines used for the medical treatment of headaches, migraine, dizziness, epilepsy, rheumatism, neuralgia, paralysis and other neuralgic and nervous disorders. Immobilize stressed rat markedly increased tyrosine hydroxylase (TH) mRNA and dopamine-$\beta$-hydroxylase (DBH) mRNA transcription level more than control group. But treated Gastrodia elata extracts in immobilized stressed rat slightly increased TH mRNA and DBH mRNA transcription level more than normal group. In addition, we are obtained identical results in PC12 cell line. Decrease of transcription level of TH mRNA and DBH mRNA is indicating that Gastrodia elata have a anti-stress effects which decrease the transcription level of TH and DBH mRNA on catecholamine biosynthesis pathway.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.540-542
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• 2019

This paper proposes an open-phase fault control system using 3-phase neutral voltage. The proposed control system is designed as a new topology which uses the potential difference between neutral point and ground of three phase. The open-phase detection system is also configured to Y-wiring of three capacitance devices of the same capacity to each line of three phase power source R-S-T. This paper also designs a mobile phone application for remote alarm of open-phase fault.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 추계학술대회
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• pp.4-6
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• 2018

This paper proposes an open-phase fault control system using 3-phase neutral voltage. The proposed control system is designed as a new topology which uses the potential difference between neutral point and ground(G) of three phase. And the open-phase detection system is configured to Y-wiring of three capacitance devices of the same capacity to each line of three phase power source R-S-T. This paper also designs a mobile phone application for remote alarm of open-phase fault.

• International Journal of Internet, Broadcasting and Communication
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• 제14권1호
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• pp.188-193
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• 2022

The energy efficiency of memory systems is an important task in designing future computer systems as memory capacity continues to increase to accommodate the growing big data. In this article, we present an energy-efficient last-level cache management policy for future mobile systems. The proposed policy makes use of low-power PCM (phase-change memory) as the main memory medium, and reduces the amount of data written to PCM, thereby saving memory energy consumptions. To do so, the policy keeps track of the modified cache lines within each cache block, and replaces the last-level cache block that incurs the smallest PCM writing upon cache replacement requests. Also, the policy considers the access bit of cache blocks along with the cache line modifications in order not to degrade the cache hit ratio. Simulation experiments using SPEC benchmarks show that the proposed policy reduces the power consumption of PCM memory by 22.7% on average without degrading performances.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2020년도 전력전자학술대회
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• pp.328-329
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• 2020

The AC/DC converter, which connects the AC grid to the DC grid in the microgrid, is a critical component in power sharing and stable operation. Sometimes the AC/DC converters are connected in parallel to increase the transmission and reception capacity. When connected in parallel, circulating current is generated due to line impedance difference or sensor error. As a result of circulating current, there is deterioration and loss in particular PCS(Power Conversion System). In this paper, we propose droop control with novel adaptive virtual impedance for reducing circulating current. Feasibility of proposed algorithm is verified by PowerSIM simulation.

• Advances in aircraft and spacecraft science
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• 제10권5호
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• pp.393-418
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• 2023

Drones are increasingly used in logistics delivery due to their low cost, high-speed and straight-line flight. Considering the small cargo capacity, limited endurance and other factors, this paper optimized the pickup and delivery vehicle routing problem with time windows in the mode of "truck+drone". A mixed integer programming model with the objective of minimizing transportation cost was proposed and an improved adaptive large neighborhood search algorithm is designed to solve the problem. In this algorithm, the performance of the algorithm is improved by designing various efficient destroy operators and repair operators based on the characteristics of the model and introducing a simulated annealing strategy to avoid falling into local optimum solutions. The effectiveness of the model and the algorithm is verified through the numerical experiments, and the impact of the "truck+drone" on the route cost is analyzed, the result of this study provides a decision basis for the route planning of "truck+drone" mode delivery.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1254-1268
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• 2009

정부고속철도 건설계획이 1998년 IMF로 인하여 서울 시흥구간 및 대구$\sim$부산간은 기존 경부선을 이용하여 우선 개통하고, 2단계로 대구$\sim$부산구간을 신설 개통하는 것으로 변경됨에 따라 서울도심 입출구부인 서울$\sim$시흥구간은 고속열차, 일반열차 및 화물열차의 운용운행으로 일반열차 운행횟수 축소로 인한 서비스 저하, 고속철도 서비스 추가 어려움 등으로 동 구간의 신설확장에 대한 지속적인 필요성이 제기 되어 왔으며, 호남고속철도 또한 수서 출발을 위한 강남권 고속철도 건설계획이 경제성 등의 이유로 오송에서 분기하는 것으로 변경됨에 따라 강남권 및 경기남부지역 주민들의 고속철도 서비스혜택의 기회가 박탈되는 결과률 초래하였다. 경부고속철도 개통이후 국가교통체계가 고속철도 중심으로 변화하고 있고, 경부고속철도 2단계 개통, 경전선 및 전라선 복선전칠 완공, 2014년 호남고속철도 개통시 고속열차 추가수요가 발생하나, 서울$\sim$시흥구간의 선로용량 부족으로 고속열차 광명역 출발, 일반열차 운행횟수 축소 등의 파행적인 열차운영이 불가피하므로 이와 같은 문제점을 근본적으로 해소하기 위한 강북구간 (광명$\sim$화전) 의 선로확장과 더불어 강남구간 (수서$\sim$평택)의 고속철도 신설을 추진하여야 한다. 이에 따라 본 고찰에서는 수도권 고속철도 선로확충을 위한 효율적인 열차운영방안, 시설계획 등 고려 하여야 할 사항에 대하여 검토하고자 한다.

• 농촌계획
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• 제22권4호
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• pp.131-138
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• 2016

Recently, the cultivated area is reduced, the ratio of upland-field in the total cultivated area is increasing relative appeared in 36.2% in 1990 from 43.7% in 2013. If upland-field can be applied well designed-infrastructure, good income crop production is possible, however, maintenance of infrastructure and a significant portion of the upland-field is maintained under insufficient infrastructure. While imports of agricultural products expanded since the 2000s in progress, looking at the self-sufficiency of upland-field crops, it is reduced to from 90% to 42% for the pepper, it is from 90% to 74% for the garlic, cereals is reduced from 42% by 26%. As a result of these conditions, the competitiveness of farmers has weakened, the risk to meet the challenges of this area of production and supply reduction increased. This study was the first to conduct a basic evaluation index, data analysis and evaluation of indicators to diagnose the agricultural production capacity of the upland field. 12 kinds classified index of producing conditions from the natural environment and eight factors for the cultivation and production capabilities have developed for the assessment of productivity of upland-field (especially Kimchi cabbage). Through this regional imbalance was found, based on the production capabilities conditions are good in Haenam, Gangneung, Pyeongchang. 3 Regions have been low and the lowest Youngwol to 0.8992. Climate(Cultivation conditions) indicators of Mungyeong region is the highest, relatively low areas were in Taebaek. In particular, it is determined to be preferred that the area required for the enhancing the production environment based on providing the convenience for the producing and maintenance of the first production area. It is necessary Increasing part of mechanization, agro-industrial competitiveness through aggressive management plans for facilities as required in the process of post-harvest storage, processing, distribution line can be improved.

• 한국산학기술학회논문지
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• 제18권7호
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• pp.63-72
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• 2017

본 논문에서는 공정분석, 작업분석 및 동작분석을 핵심으로 하는 고전적 IE기법들을 응용하여 자동차 부품 제조현장의 운영효율성 향상을 추구하는 절차를 제안하고 구체적 적용 사례를 보인다. 제안한 운영효율성 향상 절차는 사례기업인 L사의 차량전장부품 제조 사업부에서 공정개선팀을 구성하여 개발한 고유의 절차이며, 운영효율성의 척도로는 라인밸런스효율(Balance Efficiency)과 생산능력(Production Capacity)을 사용하였다. 개발한 절차는 제조 현장의 현상을 분석하고, 문제점을 해결하는 개선안을 도출하며, 도출된 각 대안을 평가하고 최종안을 선정하여 현장에 구현함으로써 생산성 향상을 달성하는 일반적 절차를 따르고 있다. 각 단계에 사용한 방법 중 낭비요소를 찾아내는 단계에 사용되는 기능분석과 대안 평가에 적용되는 R&R(Risk & Return)평가 기법은 사례기업인 L사에서 개발한 고유의 방법인데, 특히 R&R평가 기법은 응용성과 확장가능성이 큰 기법이므로 상세히 기술한다. 개발한 절차는 여러 공정에 적용하여 개선효과를 보았는데, 본 논문에서는 구체적 사례로서 개발한 절차를 전자식 조향시스템(EPS)의 핵심 부품인 EPS모터 제조 공정에 적용한 과정과 결과를 보인다. 개선절차를 적용하여 EPS모터 제조 공정을 개선한 결과 라인밸런스효율을 7.06% 높이고 생산능력을 15.5% 증대시킴으로써 운영효율성 향상을 달성하였다.