• 제목/요약/키워드: bus demand

검색결과 191건 처리시간 0.026초

Performance inspection of smart superconducting fault current controller in radial distribution substation through PSCAD/EMTDC simulation

  • MassoudiFarid, Mehrdad;Shim, Jae Woong;Lee, Jiho;Ko, Tae Kuk
    • 한국초전도ㆍ저온공학회논문지
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    • 제15권4호
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    • pp.21-25
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    • 2013
  • In power grid, in order to level out the generation with demand, up-gradation of the system is occasionally required. This will lead to more fault current levels. However, upgrading all the protection instruments of the system is both costly and extravagant. This issue could be dominated by using Smart Fault Current Controller (SFCC). While the impact of Fault current Limiters (FCL) in various locations has been studied in different situations for years, the performance of SFCC has not been investigated extensively. In this research, SFCC which has adopted the characteristics of a full bridge thyristor rectifier with a superconducting coil is applied to three main locations such as load feeder, Bus-tie position and main feeder location and its behavior is investigated through simulation in presence and absence of small Distributed Generation unit (DG). The results show a huge difference in limiting the fault current when using SFCC.

Effect of Reconfiguration and Capacitor Placement on Power Loss Reduction and Voltage Profile Improvement

  • Hosseinnia, Hamed;Farsadi, Murteza
    • Transactions on Electrical and Electronic Materials
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    • 제18권6호
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    • pp.345-349
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    • 2017
  • Reconfiguration is an important method to minimize power loss and load interruption by creating an optimal configuration of a system. Furthermore, by increasing demand and value of consumption, construction of new power plants can be postponed in networks by reconfiguration and proper arrangement of linkage switches. This method is feasible for radial networks, which create meshes of linkage switches. One convenient way to achieve a system with minimal power loss and interruption is to utilize capacitors. Optimal placement and sizing of capacitors in such applications is an important issue in the literature. In this paper, cat swarm optimization is introduced as a new metaheuristic algorithm to achieve this purpose. Simulation has been carried out in two feasible networks, 69-bus and 33-bus systems.

대중교통체계에서 바이모달 트램의 기능과 역할 (The Functions and Roles of Bimodal Tram in the Public Transportation System)

  • 윤희택;박영곤;장세기;목재균
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.2463-2466
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    • 2008
  • The public transportation in operation or to be planned domestically includes subway, LRT, bimodal tram and bus, which are independently characterized in their passenger capacity and cost. High quality service is generally accompanied by high cost of construction and operation. Thus, ITS, BIS/BMS and BRT system are recently introduced to provide high quality service to the passengers with the cost as low as possible. The bimodal tram is under development to achieve such goals in public transportation. The passenger capacity is approximately expected to be 10,000$\sim$17,000 persons/hour and the construction cost to be 10$\sim$30 million dollars/km. It is possible to construct the infrastructure gradually depending on the demand of transportation in the planned route, which can effectively reduce the initial cost to launch the service. The bimodal tram is developed to provide the advantages of subway and bus to the passengers with respect to the scheduled operation and flexibility of the lines.

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전압변동 측면에서 본 아크로 부하가 전력계통에 미치는 영향 검토 (Analysis of effects of the arc-funace on the power system from the viewpoint of voltage regulation)

  • 박현택;김재철;박경호;임상국
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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    • pp.366-369
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    • 2004
  • Arc-furnace is one of the large loads in the electric power system. When the arc-furnace operates, it may cause a bus voltage fluctuation in the power system, because it consumes a lot of reactive power. In this paper, we simulated this phenomenon by using a PSAF program with on-site measured arc-furnace load. The simulated results show that the fluctuation of bus voltage adjacent the arc-furnace was varied from $4.3%{\sim}7.8%$ the normal voltage because of reactive power consumption by arc-furnace. Therefore, we expect this study will come into use as the basic information on the probability of the demand control

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아크로 부하패턴을 고려한 전력계통 전압변동 분석 (Analysis of effects of the arc-funace on the power system Considering the toad pattern of arc-funace)

  • 박현택;김재철;손학식;임상국;오동환
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 A
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    • pp.295-297
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    • 2004
  • Arc-furnace is one of the large loads in the electric power system. When the arc-furnace operates, it may cause a bus voltage fluctuation in the power system, because it consumes a lot of reactive power. In this paper, we simulated this phenomenon by using a PSAF program with on-site measured arc-furnace load. The simulated results show that the fluctuation of bus voltage adjacent the arc-furnace was varied from $4.3\%\sim7.8\%$ the normal voltage because of reactive power consumption by arc-furnace. Therefore, we expect this study will come into use as the basic information on the probability of the demand control

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토지이용유형별 서울시 역세권 대중교통 이용수요 영향인자 실증분석 (An Empirical Analysis of Influencing Factors toward Public Transportation Demand Considering Land Use Type Seoul Subway Station Area in Seoul)

  • 오영택;김태호;박제진;노정현
    • 대한토목학회논문집
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    • 제29권4D호
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    • pp.467-472
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    • 2009
  • 현재 서울시의 대중교통 이용수요는 최근의 버스개편 등 대중교통 서비스 개선에도 불구하고 그 분담률은 크게 증가하지 못하고 있으며 특히, 지하철의 경우 오히려 감소하고 있는 추세이다. 지하철 분담률 증진을 위해서는 그 해법을 대중교통 지향형 역세권 개발(TOD : Transit Oriented Development)에서 찾을 수 있어 이에 대한 정책전환이 필요하다 할 수 있다. 따라서 본 연구는 대중교통지향형 역세권 개발을 위해 고려되어야 할 토지 및 교통 측면의 공급과 수요관련 변수들을 이용하여 유형별(주거, 비주거지역) 영향 모형을 개발하고, 분석결과를 토대로 역세권의 이용자 및 대중교통 공급수준의 영향인자를 제시하는 것이 목적이다. 첫째, 토지이용특성(주거, 비주거)에 따라 대중교통 이용자의 통행패턴이 상이하게 나타날 것이라는 대전제는 군집분석 결과를 바탕으로 증명되었다. 둘째, 주거지역에서 고려되어야 할 사항으로는 환승거리, 정류장수, 단거리노선수, 자전거면수와 같은 버스측면의 대중교통 서비스범위와 관련된 시설 공급수준이 강한 것을 알 수 있다. 셋째, 비주거 지역에서 우선적으로 고려되어야 할 사항으로는 노선수, 배차간격, 운영시간, 역간거리와 같이 도시철도와 관련된 운영특성의 공급수준이 강한 것을 알 수 있다. 이는 향후 역세권 중심의 대중교통 정책 수립시 교통측면의 영향요인들의 우선순위를 제시해 줄 수 있을 것이라 판단된다.

유비쿼터스 컴퓨팅 환경을 위한 에이전트 시스템과 인포메이션 버스 어댑터간 상호 운용성을 위한 기법 (The Methodology for Interoperability between Agent Framework and Information Bus Adapter for Ubiquitous Computing Environments)

  • 박상용;한승욱;윤희용
    • 정보처리학회논문지A
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    • 제13A권6호
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    • pp.495-500
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    • 2006
  • 유비쿼터스 컴퓨팅 환경의 관심과 요구가 고조됨에 따라 다양한 상황에 능동적이고 지능적인 에이전트의 역할이 점차 중요시 되고 있다. 이러한 에이전트는 ACL(Agent Communication Language)을 통신 언어로 사용하여 에이전트간 자율적인 상호 운용성 문제를 해결하기 위해 정보를 교환 한다. 본 논문에서는 소프트웨어 에이전트의 국제표준화 단체인 FIPA(Foundation for Intelligent Physical Agents)의 에이전트 프레임워크와 CORBA 이벤트 서비스 기반으로 자체 개발한 인포메이션 버스 어댑터간의 효율적인 통신을 보장하는 상호 운용성 기법을 제안한다. 비에이전트 플랫폼인 인포메이션 버스 어댑터와 JADE 플랫폼간 통신(메시지 교환)을 보장하기 위한 인터페이스인 EMTI(Efficient Message Transport Interface) 설계 및 구현 방법에 대해 살펴보고, 이기종 플랫폼간 다량의 메시지를 송수신하여 그 안정성과 성능에 대해 평가한다.

Working Conditions, Job Strain, and Traffic Safety among Three Groups of Public Transport Drivers

  • Useche, Sergio A.;Gomez, Viviola;Cendales, Boris;Alonso, Francisco
    • Safety and Health at Work
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    • 제9권4호
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    • pp.454-461
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    • 2018
  • Background: Working conditions and psychosocial work factors have acquired an important role explaining the well-being and performance of professional drivers, including those working in the field of public transport. This study aimed to examine the association between job strain and the operational performance of public transport drivers and to compare the expositions with psychosocial risk at work of three different types of transport workers: taxi drivers, city bus drivers, and interurban bus drivers. Method: A sample of 780 professional drivers was drawn from three transport companies in Bogota (Colombia). The participants answered the Job Content Questionnaire and a set of sociodemographic and driving performance questions, including age, professional driving experience, work schedules, and accidents and penalties suffered in the last 2 years. Results: Analyses showed significant associations between measures of socio-labor variables and key performance indicators such road traffic accidents and penalties. Furthermore, multiple linear regression analysis contributed to explain significantly suffered accidents from key variables of the Job Demand-Control model, essentially from job strain. In addition, throughout post-hoc analyses, significant differences were found in terms of perceived social support, job strain, and job insecurity. Conclusion: Work stress is an issue that compromises the safety of professional drivers. This research provides evidence supporting a significant effect of job strain on the professional driver's performance. Moreover, the statistically significant differences between taxi drivers, city bus drivers, and interurban bus drivers in their expositions to work-related stress suggest the need for tailored occupational safety interventions on each occupational group.

기상조건이 대중교통수요에 미치는 영향에 관한 연구 (The Effect of Weather Conditions on Transit Ridership)

  • 최상기;이종호;오승훈
    • 대한토목학회논문집
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    • 제33권6호
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    • pp.2447-2453
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    • 2013
  • 본 연구에서는 강우, 불쾌지수, 강설, 체감온도 등 4가지 기상조건이 대중교통수요에 어떤 영향을 미치는지 관련 통계자료를 이용해 분석을 실시하고, 설문조사를 통해 그 이유를 도출하였다. 모든 자료는 일단위로 수집하였고, 평일-주말과 여름-겨울로 구분하여 분석을 실시하였다. 분석결과, 샘플수가 부족한 강설을 제외하고는 강우, 불쾌지수, 체감온도의 기상조건이 대중교통 수요를 약 2~7% 감소시키는 것으로 나타났다. 수요의 감소폭이 통계적으로 유의한지 알아보기 위해 t-검정을 실시하였는데, 이중 강우와 체감온도가 통계적으로 유의하다는 결과를 얻었다. 상관분석 결과도 강우와 체감온도 2가지 지표가 상대적으로 높은 상관관계를 나타냈으며, 야외에 노출되어있는 버스가 지하철에 비해 높은 상관관계를 보였다. 그리고 통계적으로 유의한 결과가 나온 강우와 체감온도, 2가지 지표에 관한 설문을 실시하였다. 수도권에 거주하는 일반시민을 대상으로 설문을 실시한 결과, 평상시에 응답자 중 약 50%가 버스를 이용하였는데, 이중 강우가 발생하거나 체감온도가 낮아지면 버스 이용이 약 30%대로 감소되는 반면, 승용차와 지하철통행은 약 10% 증가되는 것으로 분석되었다. 본 연구 결과는 기후변화에 따른 대중교통정책 및 운영방법 결정에 기초자료로 사용되어질 수 있을 것으로 기대된다.

대규모행사시 주차장 이용특성 분석 (A Study for Parking Characteristic of A Large Scale Event)

  • 이영우
    • 한국산업융합학회 논문집
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    • 제9권3호
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    • pp.191-197
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    • 2006
  • Prepare need in each branch for a large scale event. especially prepare for transportation problem is very important. most research for until at now parking prepare according city management however, parking prepare for large event is a necessity which it will parking characteristic. accordingly this research is conducted study for parking prepare subject of large event. this study result, vehicle demand for parking by stadium have many but vehicle demand for parking off stadium have few. accordingly large parking supply is ineffective. shuttle bus service in principal position of city is effective. study result showed that it included 85% parking at 6~7hour before large event start time. accordingly disposition time of parking manager is desirable 6~7hour before large event start time.

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