• Title/Summary/Keyword: 상태 전환 모델

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A case study on optimal location modeling of battery swapping & charging facility for the electric bus system (전기버스를 위한 배터리 자동 교환-충전인프라 배치 최적화 모형개발 및 적용 사례 분석)

  • Kim, Seung-Ji;Kim, Wonkyu;Kim, Byung Jong;Im, Hyun Seop
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.1
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    • pp.121-135
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    • 2013
  • This paper propose an efficient algorithm for selecting electric bus charging facility location. In nature, the optimal charging facility location problem is similar to Set Covering Problem. Set Covering Problem is the problem of covering all the rows of an $m{\times}n$ matrix of ones and zeros by a subset of columns with a minimal cost. It has many practical applications of modeling of real world problems. The Set Covering Problem has been proven to be NP-Complete. In order to overcome the computational complexity involved in seeking optimal solutions, this paper present an enhanced greedy algorithm and simulated annealing algorithm. In this paper, we apply the developed algorithm to Seoul's public bus system.

A Study on Succeeding Together-Busan North & New Port (부산 북항-신항 연계발전 방안)

  • Song, Gye-Eui
    • Journal of Korea Port Economic Association
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    • v.27 no.2
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    • pp.313-331
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    • 2011
  • Due to have been more keen in East-North Asia Hub Port competition, to be accelerated Busan New Port development, and to result to supply excess position, Busan port has been confronted by many problems. Also, as facilities of North Port is old, it is impossible to secure 16m depth of water at North Port, and North Port redevelopment is being, container traffic of North Port is accelerated to shift at New Port. Therefore, it. is time to seek for connection growth plan of succeeding together-Busan North & New Port as soon as possible. Connection growth plan of succeeding together-Busan North & New Port is focused, as follows. First, it is required to set up model for connection growth plan of succeeding together-Busan North & New Port. It is valid to specialize for ULCC, to promote to global port at New Port, and it is effective to focus on feeder service and general cargo handling, and to include most space to North Port redevelopment. Second, through port function reorganization, it is required to create a synergy by port function clustering. Third, through effective connection traffic network expansion for moving T/S cargo effectively, it is required to develop Busan Port for T/S cargo-focused port. Fourth, it is required to develop port hinterland logistics zone for creating container traffic through connection development of New Port-BJFEZ. Finally, it is required to build SCM system for creating container traffic among shipper, carrier, freight forwarder and related institution.

Myth of 61.8% rule and the practical application notices (접지저항 측정의 61.8%법칙 적용의 맹점과 현실적 접근 방법)

  • Lee, Sang-Mu;Cho, Pyung-Dong
    • 한국정보통신설비학회:학술대회논문집
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    • 2005.08a
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    • pp.259-262
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    • 2005
  • Ground resistance measurement is an elementary technique for the evaluation of grounding system. There are main environmental factors to consider for correct measurement but the problem is that it is practically most cases to measure ground resistance unable to know the factors. This paper presents a methodology toward true value of resistance in the unknown circumstances, utilizing the defined term 'variation rate' of potential difference curve appearing in the distance to a current probe as in the three point fall-of-potential method which comprises the characteristics of environmental factors. This methodology is a induced result from the previous demostrated studies.

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Sustainability of Olive Flounder Production by the Systems Ecology -II. Simulating the Future of Olive Flounder Aquaculture on the Land- (시스템 생태학적 접근법에 의한 넙치생산의 지속성 평가 -2. 넙치 육상양식산업에 대한 예측-)

  • Kim Nam Kook;Son Ji Ho;Kim Jin Lee;Cho Eun Il;Lee Suk Mo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.6
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    • pp.660-665
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    • 2002
  • In Korea, an olive flounder is very popular fish food item. However, due to the increasing human population, the present catches of the olive flounder may not be sufficient to satisfy the present demand. To increase the supply of the olive flounder, aquaculture has been begun. An interest in the aquaculture of the olive flounder has been increased recently because of its characteristics of good growth and high price in the market, However, the productivity of the olive flounder aquaculture depends on economic inputs such as fuels, facilities, and labor. The rapid growths of the olive flounder aquaculture and the concerns about economic and ecological sustainability have focused peoples attention on the aquaculture industry. In this study, an energy systems model was built to simulate the variation of sustainability on the aquaculture of olive flounder, The results of simulation based on calibration data in 1995 show that olive flounder production yield and asset slowly increase to steady state because of the law of supply and demand. The results of simulation based on the variation of oil price show that the more increase the oil price, the more decrease the olive flounder economic yield and asset. Energy sources required for systems determine the sustainability of systems. Conclusionally, the present systems of the olive flounder aquaculture should be transformed to ecological-recycling systems or ecological engineering systems which depend on renewable resources rather than aquaculture systems which depend on fossil fuels, and be harmonized with the fishing fisheries by the sustainable use of renewable resources in the carrying capacity.

Technology Trends of Smart Abnormal Detection and Diagnosis System for Gas and Hydrogen Facilities (가스·수소 시설의 스마트 이상감지 및 진단 시스템 기술동향)

  • Park, Myeongnam;Kim, Byungkwon;Hong, Gi Hoon;Shin, Dongil
    • Journal of the Korean Institute of Gas
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    • v.26 no.4
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    • pp.41-57
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    • 2022
  • The global demand for carbon neutrality in response to climate change is in a situation where it is necessary to prepare countermeasures for carbon trade barriers for some countries, including Korea, which is classified as an export-led economic structure and greenhouse gas exporter. Therefore, digital transformation, which is one of the predictable ways for the carbon-neutral transition model to be applied, should be introduced early. By applying digital technology to industrial gas manufacturing facilities used in one of the major industries, high-tech manufacturing industry, and hydrogen gas facilities, which are emerging as eco-friendly energy, abnormal detection, and diagnosis services are provided with cloud-based predictive diagnosis monitoring technology including operating knowledge. Here are the trends. Small and medium-sized companies that are in the blind spot of carbon-neutral implementation by confirming the direction of abnormal diagnosis predictive monitoring through optimization, augmented reality technology, IoT and AI knowledge inference, etc., rather than simply monitoring real-time facility status It can be seen that it is possible to disseminate technologies such as consensus knowledge in the engineering domain and predictive diagnostic monitoring that match the economic feasibility and efficiency of the technology. It is hoped that it will be used as a way to seek countermeasures against carbon emission trade barriers based on the highest level of ICT technology.

Analysis of Surgical Risk Factors in Pulmonary (폐국균종의 수술위험인자 분석)

  • 김용희;이은상;박승일;김동관;김현조;정종필;손광현
    • Journal of Chest Surgery
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    • v.32 no.3
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    • pp.281-286
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    • 1999
  • Background: The purpose of this study is to analyze the types of complications, the incidences of complications, and preoperative and postoperative risk factors affecting the incidence of the complication. Material and Method: Between August 1990 and August 1997 in Asan Medical Center, 42 patients(24 men and 18 women) underwent surgical resection for pulmonary aspergilloma. The mean age was 46.6${\pm}$11.5 years(range 29 to 69 years). Hemoptysis(90%) was the most common presentation. Pulmonary tuberculosis was the most common predisposing cause(81%). The associated diseases were bronchiectasis(n=11), active puolmonary tuberculosis(n=9), diabetes mellitus(n=8), lung carcinoid(n=1), and acute myeloblastic leukemia(n=1). Lobectomy was done in 32 cases(76%), segmentectomy or wedge resection in 4, pneumonectomy in 2, and lobectomy combined with segmentectomy in 4. Result: Operative mortality was 2%. The most common postoperative complication was persistent air leakage(n=6). The variables such as age, sex, pulmonary function test, amount and duration of hemoptysis, associated diseases(diabetes mellitus, active pulmonary tuberculosis), mode of preoperative management(steroid, antifungal agent, bronchial arterial embolization), and modes of operative procedures were statistically insignificant. The radiologic extent of infiltration to normal lung parenchyme was statistically significant(p=0.04). Conclusion: We conclude that the extent of the infiltration to normal lung parenchyme in preoperative radiologic studies should be carefully evaluated to reduce the postoperative complications in surgery for pulmonary aspergilloma.

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Changes in Dormant Phase and Bud Development of 'Fuji' Apple Trees in the Chungju Area of Korea (충주지역에서 '후지' 사과나무의 휴면단계 변화 및 눈 발달)

  • Lee, ByulHaNa;Park, YoSup;Park, Hee-Seung
    • Horticultural Science & Technology
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    • v.33 no.4
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    • pp.501-510
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    • 2015
  • In this study, we investigated the onset and release of endo-dormancy under natural conditions by observing bud break characteristics in 'Fuji' apple trees using water cuttings. Through examinations of bud break rate and days to bud break, we found that the endo-dormancy of 'Fuji' apple tree continues for 70 d from 165 to 255 d after full bloom (DAFB), from late October to early January of the following year. In addition, within 20 d of first bud break, based on a final bud break rate of 60% or more, we able to identify the timing of the changeover from para-dormancy to endo-dormancy, and endo-dormancy to eco-dormancy. Analysis of the chilling requirement during the endo-dormancy period revealed that chilling accumulation up to 255 DAFB to release endo-dormancy amounted to 666 and 517 h based on the CH and Utah models, respectively. Observation of internal changes in the bud during endo-dormancy showed that flower bud differentiation begins from mid-July, and t ime of inflorescence o f the disk f lower is a vailable to f ind. The f lower buds subsequently developed slowly but steadily during endo-dormancy and in the following year in February, the developmental stage of each organ had progressed. Moreover, the flower buds of 'Fuji' apples were mostly healthy during the dormancy period, but some exhibited necrosis of flower primordium, due partial cell damage from the formation of ice crystals rather than a direct effect of the low temperature. Flower buds were formed in both the axillary buds of bourse shoots and terminal buds of spurs, but lower bud differentiation was observed for the terminal buds of spurs at rate of about 65% of total buds, which was directly related to the bud size and shoot diameter.