• Title/Summary/Keyword: Capacity changes

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Line Capacity Analysis and Capacity Parameter Evaluation (선로용량 분석체계와 용량모수평가)

  • Kim Dong-Hee;Hong Soon-Heum;Kim Young-Hoon
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1559-1565
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    • 2004
  • Railway system is consisted of various resources such as rail-line, signal, and railcar. It is necessary to efficiently utilize these limited and expensive resources as much as possible up to given line capacity. So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. In this paper, we present an improved systematic line capacity model. The proposed model has three main components ; TPS(tain performance simulator), PES (parameter evaluation simulator), LCS(line capacity simulator). The concept of each sub-component is described, including the evaluation method of capacity parameters. And capacity parameter evaluation and estimation results using sample line section data are presented.

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A Study of Relationship between Memory Variable and Cognitive Development in Children (아동의 인지발달과 기억변인과의 관계 연구)

  • 명정옥
    • Journal of the Korean Home Economics Association
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    • v.25 no.1
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    • pp.121-127
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    • 1987
  • The purpose of this study was to investigate the importance of mental capacity and to see whether it can be a barometer to predict childrne's cognitive development. The instruments used were Pictoral Test of Intelligence to select homogeneous samples, Cucui Scale for their M-power and Conservation Test. The results showed that M-power develops as age increases, and it can be a strong variable to predict their cognitive development. It has been demonstrated that capacity increases developmentally but whether this reflects changes in capacity perse, or in the efficient use of that capacity is a debatable issue. More study needs to be repeated for this matter.

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PORT EXPANSION SIMULATION MODEL

  • 노용덕
    • Proceedings of the Korea Society for Simulation Conference
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    • 1992.10a
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    • pp.1-1
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    • 1992
  • This paper presents a user-oriented port expansion simulation model that determines the future economic port capacity to meet the projected demand. The model consists of two parts; a physical impact simulation, and an economic impact simulation. The first part of the model simulates the effects caused by the port capacity expansion. The second part evaluates the port economics due to changes in the port capacity. The model was validated by applying it to the actual port expansion followed at the Port of Mobile, Alabama. A case study is then presented to demonstrate the capacity of the model with a coal handling port, the McDuffie Terminals at the Port of Mobile.

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Analysis of Line Capacity for the Special Structure in Railway (특이구조를 갖는 선로구간의 용량분석에 관한 연구)

  • Kim Dong-Hee;Hong Soon-Heum
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2003.05a
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    • pp.668-673
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    • 2003
  • Line Capacity is a criteria for transport capacity and is used to evaluate railroad investment alternatives or to decide train frequency when establish transportation plan. There are two methodologies to increase transport capacity of railway. One is to invest railroad equipment or vehicles, and the other is to improve operation efficiency through optimization. Such all efforts are intended to increase transport capacity by improving line capacity. So far, this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. In this paper, we present a new estimation method of line capacity based on the probability simulation, and apply to normal railline section and special structured railine section.

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Capacity Analysis for the Railway Investment and Operation (철도투자 및 운영을 위한 용량분석에 관한 연구)

  • Kim Dong-Hee;Hong Soon-Heum;Kim Jae-Hee
    • Proceedings of the Safety Management and Science Conference
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    • 2004.11a
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    • pp.197-203
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    • 2004
  • Railway system is consisted of various resources such as rail-line, signal, and railcar. It is necessary to efficiently utilize these limited and expensive resources as much as possible up to given line capacity. So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. In this paper, we present an improved systematic line capacity model. The proposed model has three main components ; TPS(lain performance simulator), PES(parameter evaluation simulator), LCS(line capacity simulator). The concept of each sub-component is described, including the evaluation method of capacity parameters. And capacity parameter evaluation and estimation results using sample line section data are presented.

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A Study on the Capacity Analysis for improving Railway Systems (철도시스템 개선을 위한 용량분석에 관한 연구)

  • Kim Dong-Hee;Kim Seong-Ho
    • Proceedings of the KSR Conference
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    • 2003.05a
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    • pp.272-279
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    • 2003
  • There are two methodologies to increase transport capacity of railway. One is to invest railroad equipment or vehicles, and the other is to improve operation efficiency through optimization. All of these is intended to increase transport capacity by improving the line capacity, So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. Korea Railroad Research Institute(KRRI) proposed a new line capacity estimation system based on the probability simulation method. In this research. we perform analysis of line capacity for the railway improvement alternatives, and to represent the results.

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Changes of Rheological Properties of Yoghurt by Different Kinds Stabilizers (Yoghurt의 안정제 종류에 따른 물성 변화)

  • 최순호;장운기;정종국;오동규;이부웅
    • Food Science of Animal Resources
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    • v.18 no.1
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    • pp.35-41
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    • 1998
  • The objective of this study was to examine the changes of physical properties by additions of different kinds of stabilizers milk proteins concentration, when stored at 4$^{\circ}C$ or 20$^{\circ}C$ for yoghurt. the results were summarized as follows: 1. Addition of 2% carboxyl methyl cellulose and carrageenan, gelation 0.4%, pectin and starch 0.6%, and carrageenan & pectin 0.8% in the manufacture of yoghurt increased the viscosity, water-holding capacity and protein hydration of yoghurt. 2. Addition of 3% skim milk powder, Ca-caseinate or Na-caseinate 0.6% increased the viscosity, water-holding capacity and protein hydration of yoghurt. 3. Twenty five percent of evaporation of milk promoted to build up the optimal structure of the micelles of yoghurt and improved viscosity, water-holding capacity and protein hydration of yoghurt. 4. Addition of stabilizers to yoghurt showed an increase of viscosity, water-holding capacity and protein hydration when compared with non-addition of stabilizers to yoghurt at 4$^{\circ}C$, 20$^{\circ}C$ storage for 12hrs, 96hrs followed by the decrease of it.

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The Electrochemical Characteristics of Surface-modified Carbonaceous Materials by tin Oxides and Copper for Lithium Secondary Batteries

  • Lee, Joong-Kee;Ryu, D.H.;Shul, Y.G.;Cho, B.W.;Park, D.
    • Carbon letters
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    • v.1 no.3_4
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    • pp.170-177
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    • 2001
  • Lithium intercalated carbon (LIC) are basically employed as an anode for currently commercialized lithium secondary batteries. However, there are still strong interests in modifying carbon surface of active materials of the anode because the amount of irreversible capacity, charge-discharge capacity and high rate capability are largely determined by the surface conditions of the carbon. In this study, the carbonaceous materials were coated with tin oxide and copper by fluidized-bed chemical vapor deposition (CVD) method and their coating effects on electrochemical characteristics were investigated. The electrode which coated with tin oxides gave the higher capacity than that of raw material. Their capacity decreased with the progress of cycling possibly due to severe volume changes. However, the cyclability was improved by coating with copper on the surface of the tin oxides coated carbonaceous materials, which plays an important role as an inactive matrix buffering volume changes. An impedance on passivation film was decreased as tin oxides contents and it resulted in the higher capacity.

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Resilience Assessment for Aquifers close to Groundwater Wells in the Nakdong River Estuary (낙동강 하구 지하수 관정 주변 대수층의 리질리언스 평가)

  • Soonyoung Yu;Ho-Rim Kim;Eun-Kyeong Choi;Sung-Wook Kim;Dong-Woo Ryu;Yongcheol Kim
    • Journal of Soil and Groundwater Environment
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    • v.28 no.3
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    • pp.12-28
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    • 2023
  • Each national groundwater monitoring well showed distinct change patterns in groundwater levels and electrical conductivity (EC) in the Nakdong River Estuary, implying different external forces (EFs) on each well. According to the annual average data in 1997-2020, seawater was invaded into Well C. The desalination rate of -1,062 µS/cm/year represents the adaptive capacity of the well to seawater intrusion. The water levels and EC in Well E responded to precipitation, indicating the low absorptive capacity to climate changes. Meanwhile, Well B showed constant increases in water levels, suggesting that problems by rising groundwater should be considered in the study area where confined aquifers are overlaid by clay aquitards. The other wells showed consistent water levels and EC, indicating resilience to EFs. Here, resilience is the capacity of a well to resist changes by EFs, including the absorptive and adaptive capacity. The resilience of Wells E and F to climate changes was quantitatively compared using a resilience cost (RC). The RC showed Well F was more resilient than Well E, and the bedrock aquifer was more resilient than the alluvium aquifer, supporting the usefulness of RC. The resilience assessment against EFs (e.g., changes in land use and climate) helps sustainable groundwater management.

Analysis of the Load Transfer Capacity and Study of Conductor Sizes for Contingency Levels in Distribution Systems (상정사고별 배전측 부하분담 능력 분석과 도체 규격 검토)

  • 조남훈;전영재;한용희;한병성
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.7
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    • pp.363-370
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    • 2003
  • This paper presents the analysis of the load transfer capacity and study of conductor size for variable contingencies in distribution systems. The operation capacity of feeders was changed to improve operation efficiency in KEPCO, considerations for contingencies are still based on the previous capacity. In order to cope with the changes such as operation capacity, it is necessary to study whether the present "contingency support criteria" is reasonable or not, also to confirm the whether the present criteria should be improved or not. We analyze the load transfer capacity and conductor size on a distribution system for contingency levels such as the substation-level, bank-level, feeder-level, and zone-level.one-level.