• Title/Summary/Keyword: bus demand

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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
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.4
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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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    • v.18 no.6
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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.

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

  • Yoon, Hee-Taek;Park, Young-Kon;Chang, Seky-Mok;Mok, Jae-Kyun
    • Proceedings of the KSR Conference
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    • 2008.06a
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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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Analysis of effects of the arc-funace on the power system from the viewpoint of voltage regulation (전압변동 측면에서 본 아크로 부하가 전력계통에 미치는 영향 검토)

  • Park, Hyun-Taek;Kim, Jae-Chul;Park, Kyoung-Ho;Im, Sang-Gug
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.05a
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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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Analysis of effects of the arc-funace on the power system Considering the toad pattern of arc-funace (아크로 부하패턴을 고려한 전력계통 전압변동 분석)

  • Park Hyun Taek;Kim Jae Chul;Son Hak Sig;Kug Im Sang;Oh Dong hwan
    • Proceedings of the KIEE Conference
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    • summer
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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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An Empirical Analysis of Influencing Factors toward Public Transportation Demand Considering Land Use Type Seoul Subway Station Area in Seoul (토지이용유형별 서울시 역세권 대중교통 이용수요 영향인자 실증분석)

  • Oh, Young Taek;Kim, Tae Ho;Park, Je Jin;Rho, Jeong Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.4D
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    • pp.467-472
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    • 2009
  • Even if Seoul City administration improved its public transportation service, transportation model share in seoul has not been increased. Subway user is also decreasing. Therefore, policy transition into TOD(Transit Oriented Development) should be applied in oder to enhance subway modal share. This paper develops a influencing model by using variables of transportation demand and supply. In addition, it provides major influencing factors for users in subway station area and level of transportation supply based on the analysis results. The results show that: first, cluster analysis presents that traffic pattern is proved to be different according to land use characteristics(residence, non-residence); second, main transportation variables such as transferring distance, the number of bus stop, the number of short distant bus lines, and the number of bicycle are more supplied in residential area compared to non-residential areas; third, the number of lines, bus dispatching interval, operating time, and distance between subway stations are more supplied in non-residential areas than residential areas. All in all, the results will be useful for providing priority of considerations in case of decision-making on public transportation policy in subway station area.

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

  • Park, Sang-Yong;Han, Seung-Wok;Youn, Hee-Yong
    • The KIPS Transactions:PartA
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    • v.13A no.6 s.103
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    • pp.495-500
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    • 2006
  • The role of autonomic and intelligent agents in various environments is getting more important as demand on ubiquitous computing grows. The agents exchange information using the ACL (Agent Communication Language) to autonomously solve the problems. In this paper we propose a way of efficient interoperability technique between the agent framework built based on the international standard FIPA(Foundation for Intelligent Physical Agents) and the CORBA event service-based information bus adapter developed by us. The design and implementation of EMTI (Efficient Message Transport Interface) allowing communication between the information bus adapter which is non-agent platform and JADE platform are presented and its performance is evaluated by letting them exchange a large amount of messages.

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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    • v.9 no.4
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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.

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

  • Choi, Sang Gi;Rhee, Jong Ho;Oh, Seung Hwoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.6
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    • pp.2447-2453
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    • 2013
  • In this study, the effects of weather conditions such as rainfall, discomfort index, snowfall, and sensible temperature on public transport demand in Seoul were analyzed using statistical data. The reasons were also derived from the survey. The data for the analysis were collected over the weekdays and weekends, and seasonal data of summer and winter were also gathered separately. Rainfall amount, discomfort index, and sensible temperature except snowfall amount, whose samples were insufficient, decreased the public transport demand by 2-7%. Rainfall amount and sensible temperature were statistically significant. Correlation analysis also showed that rainfall amount and sensible temperature are highly correlated with the demand. To find the reasons, the survey was conducted on citizens living in the Seoul Metropolitan Area. About 30% of the respondents wished to give up using bus when rainfall was heavy or temperature was low. On the contrary, auto and subway users increased by 10%. The results of this study could be used as the basic data when the public transportation planning or operation related policies according to the weather condition are concerned.

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

  • Lee, Young-Woo
    • Journal of the Korean Society of Industry Convergence
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    • v.9 no.3
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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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