• Title/Summary/Keyword: Commercial Bus

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A Study on Factors Influencing Turnover of Public Parking Lots in Incheon Metropolitan City (인천광역시 공영주차장 이용실태 분석 기반 주차 회전율 영향요인 연구)

  • CHOI, Younghoon;KIM, Eungcheol
    • Journal of Urban Science
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    • v.6 no.2
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    • pp.29-34
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    • 2017
  • Although the supply of public parking lots in major cities is steadily increasing, there is still a shortage of parking spaces that take into account the characteristics of actual available parking spaces. These parking problems are caused by conflicts between users, illegal occupation and privatization of roads, interference with traffic roads, and business stagnation in commercial areas and illegal parking problems. In addition, despite various parking demand management policies and continuous supply of public parking facilities, the solution to the parking problem is uneasy due to increased construction costs and changes in social conditions. In order to solve this problem, it was judged that it would be necessary to utilize the existing public parking lots efficiently. Therefore, we collect the variables expected to affect the turnover, and use multiple regression models. The results are summarized as follows. Firstly, public parking lots can be classified into four types using utilization rate and turnover rate. Secondly, influencing factors are found including index of public transportation usage convenience, index of illegal parking, and land use characteristics in central commercial district. Thirdly, it was shown that there was little impact by the size of public parking lots, separation distance to subway distance, separation distance to bus stops, transfer zone, residential zone, and second-rated lots by parking costs. Finally, it is found that public parking lots can be improved by proving accessibility of public transit, enforcement of illegal parking, active approaches supporting public parking lots. It is also recommended that public parking cost rating system based mainly on land use characteristics should be remedied and rearranged.

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The theory of lesson plannig and the instructional structuration : A case study for urban units in Japanese high school (수업설계론과 수업구조화 - 일본 고등학교 도시단원을 사례로 -)

  • ;Sim, Kwang Taek
    • Journal of the Korean Geographical Society
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    • v.29 no.2
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    • pp.166-182
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    • 1994
  • Kyonggi Province in the late Chosun dynasty was a center of superior government offices including 'Han' River water-road transportation and was located in the middle of an 'X'-shaped arterial road network. Because of these reasons, Kyonggi Province had a faster inflow of commodities, informations and technics compared with the other province. At this period of time, every local 'Eup' (name of administrative district) had not been affected by their above administrative districts and had their own autonomy. For this reason, every 'Eup' could be developed as a town, even if its size was small when it had sufficient internal growing conditions. Moreover, the markets ('Si-Jon') in big towns and periodical markets which were spread over the Kyonggi Province played role of commercial functions of town. And because military bases for the defence of the royal capital in Kyonggi Province also took parts of a non-agricultural city role, Xyonggi Provinc had much more possibilities of growing as a town rather than the other provinces. The towns of the late Chosun Dynasty were, except the capital and superior administrative districts which were governed by the 'You-Su', small towns which had only about 3, 000-5, 000 people. Most of the town dewellers were local officials, nobles, merchants, craftmen and slaves. And the farmers who lived near town became a pseudo-towner through suburb agriculture. Among these people, the merchants were leaders of townization. The downtowns were affected by the landform and traffic roads. The most fundamental function of towns were administrative. The opcial's grade, which was dispatched to the local administrative district ('Kun' or 'Hyun'), was decided by the size of population and agricultural land of each county. Large county which was governed by a high ranking opcial had more possibilities to develop as a large town. Because they supervised other opcials of lower rank and obtained more land and population for the town. The phonomena of farm abandonment after the Japanese Invasion of Korea in 1592-1598 stimulated the development of towns for commercial function. The commercial functions of towns were evident in the Si-Jon or Nan-Jon (names of markets) in the big cities such as Hansung and Kaesung, meanffwhile in the local areas it was emerged in the shape of periodical market networks as allied with near markets (which were called as Jang-Si) or permanent markets which were grown up from periodical markets. These facts of commercial development induced the birth of commercial town. Kyonggi Province showed the weak points of its defense system during both wars (Japanese Invasion in 1592 and Manchu's Invasion in 1636). The government reinforced its defense system by adding 4 'You-Su-Bus' and several military bases. Each local districts ('Eup'), where Geo-Jins were established, were stimulated to be a town while Jin-Kwan system were, adjusted and enforced. Among Dok-Jins(name of solitary military bases), Youngjongjin was grown up as a large garrison town which only played a role of defense. The number of towns that took roles of non-agricultural functions in Kyonggi Province was 52. Among these towns, 29 were developed as big towns which had above 3, 000 people and most of these towns were located on the northwest-southeast axes of 'X'-shaped arterial trafic network in the Chosn Dynasty, This fact points out that the traffic road is one of the important causes of the development of towns. When we make hierarchy of the towns of Kyonggi Province according to its population and how many functions it had, we can make it as 6 grades. The virst grade town 'Hansung' was the biggest central town of administration, commerce and defdnse. The 2nd grade town includes 'Kaesung' which had historical inertia that it had been the capital of the Koryo Dynesty. The 3rd grade towns include some 'You- Su-Bus' such as Soowon, Kanghwa, Kwangju and also include Mapo, Yongsan and from this we can imagine that the commercial development in the late Chosun Dynasty extremely affected the townization. The 4th-6th grade towns had smiliar population but it can be discriminated by how many town functions it had. So the 4th grade towns were the core of administration, commerce and defense function. 5th grade towns had administrative functions and one of commercial and defense functions. 6th grade towns had only one of these functions. When we research and town conditions of each grades as the ratio of non-agricultural population, we can find out that the towns from the 1st grade to 4th grade show difference by degree of townization but from the 4th grade to 6th grade towns do not show big difference in general.

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Unsteady State Heat Transfer Analysis of Drum Brake System (드럼 브레이크 시스템의 비정상 열전달 해석)

  • 이계섭;국종영;천인범
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.9
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    • pp.172-181
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    • 1999
  • The brakes employed on commercial vehicles must be able to withstand three types of demanding services which are use-emergency stops from high speed, many repeated stops as in a delivery or bus route, and speed control in mountain descents. Two type of friction brakes are in use ; drum breaks and disc brakes. Drum brakes are of the internally expanding type in which two shoes fitted externally with friction material are forced outward against the inside of a rotating drum on the wheel unit. In this case, the Braking power is produced by the friction force between a drum and a lining, and is converted into heat. In this research an unsteady state heat transfer analysis for drum brake system of heavy truck has been performed by ABAQUS/standard code in the case of single-braking and the repeated braking condition. The temperature histories obtained by the finite Element analysis have been compared with the result calculated by the simplified formulation and the result obtained by the experiment of real vehicle conditions.

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Coordination of UPFC and Reactive Power Sources for Steady-state Voltage Control (정상상태 전압제어를 위한 UPFC와 조상설비의 협조)

  • Park, Ji-Ho;Lee, Sang-Duk;Jyung, Tae-Young;Jeong, Ki-Seok;Baek, Young-Sik;Seo, Gyu-Seok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.5
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    • pp.921-928
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    • 2011
  • This paper presents a new method of local voltage control to achieve coordinative control among UPFC(Unified Power Flow Controller) and conventional reactive compensation equipments, such as switched-shunt and ULTC(Under-Load Tap Changing) transformer. Reactive power control has various difficult aspects to control because of difficulty of system analysis. Recently, the progress of power electronics technologies has lead to commercial availability of several FACTS(Flexible AC Transmission System) devices. The UPFC(Unified Power Flow Controller) simultaneously allows the independent control of active and reactive power flows as well as control of the voltage profile. When conventional reactive power sources and UPFC are used to control system voltage, the UPFC reacts to the voltage deviation faster than the conventional reactive power sources. Keeping reactive power reserve in an UPFC during steady-state operation is always needed to provide reactive power requirements during emergencies. Therefore, coordination control among UPFC and conventional reactive power sources is needed. This paper describe the method to keep or control the voltage of power system of local area and to manege reactive power reserve using PSS/E with Python. The result of simulation shows that the proposed method can control the local bus voltage within the given voltage limit and manege reactive power reserve.

A Robot Controller Development of a Large-scale System for Shipbuilding

  • Kim, Soo-Ho;Kang, Gye-Hyung;Park, Ju-Yi;Chu, Gil-Whoan;Kim, Jin-Wook;Kim, Ji-Yun;Kim, Sung-Kwun
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.472-475
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    • 2005
  • This paper present a robot controller developed for shipbuilding yard. Since shipbuilding process handles large work pieces and has dusty and noisy environment, the developed controller has separated architecture into main control part and servo control part. Main control part is located in control room while servo control part is located near robot with work pieces. Commutation between two parts is done through SynqNet and RS485. Air purging system is adapted to servo control part for better reliability. We aimed open architecture in both hardware and software architecture. For open hardware architecture, we employed Compact PCI (cPCI) because it is widely used bus system and very reliable. Since lots of commercial boards are available with cPCI interface, upgrade and reconfiguration is easy. For open software architecture, Windows XP�� Embedded is selected as operating system (OS), because it is very popular OS and most hardware vender supports device driver for the windows XP.

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The Classification and Characteristics of Landscape on Urban Land Use Patterns - The Case of Metropolitan Daejeon - (도시의 토지이용 형태별 경관특성과 유형 - 대전광역시를 사례로 -)

  • Kim Dae-Hyun;Kim Dae-Soo;Joo Shin-Ha;Oh Se-Rae
    • Journal of the Korean Institute of Landscape Architecture
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    • v.33 no.4 s.111
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    • pp.1-10
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    • 2005
  • Recently, as urban landscape is growing in importance, urban landscape planning is being actively performed. for this purpose, classification of the urban landscape is definitely required. Therefore, this research focuses on classifying urban landscape in Daejeon metropolis by dividing the urban land use pattern. This results are as follows. 1. Urban land use pattern is divided into 20 classes. The residential, commercial and industrial areas, the old market and the bus terminal are evaluated negatively, whereas the areas of school, water reservoir, neighborhood park and train station are appreciated as being positive in landscape characters. 2. As a result of a cluster analysis, urban landscape has five different landscape types. These are: landscapes of medium diversity lacking green area, landscapes of high diversity lacking green area, landscapes rich in green area and with medium diversity, landscapes rich in green area and with high diversity, and landscapes rich in green area and with low diversity. 3. In landscape characters of beauty and harmony, landscapes rich in green area and with medium diversity are more positively evaluated than those rich in green area and with low diversity. This point should be taken into account for planning the urban landscape.

Suppression of Parallel Plate Modes Using Edge-Located EBG Structure in High-Speed Power Bus

  • Cho, Jonghyun;Kim, Myunghoi
    • Journal of information and communication convergence engineering
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    • v.14 no.4
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    • pp.252-257
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    • 2016
  • An edge-located electromagnetic bandgap (EL-EBG) structure using a defected ground structure (DGS) is proposed to suppress resonant modes induced by edge excitation in a two-dimensional planar parallel plate waveguide (PPW). The proposed EL-DGS-EBG PPW significantly mitigates multiple transverse-magnetic (TM) modes in a wideband frequency range corresponding to an EBG stopband. To verify the wideband suppression, test vehicles of a conventional PPW, a PPW with a mushroom-type EBG structure, and an EL-DGS-EBG PPW are fabricated using a commercial process involving printed circuit boards (PCBs). Measurements of the input impedances show that multiple resonant modes of the previous PPWs are significantly excited through an input port located at a PPW edge. In contrast, resonant modes in the EL-DGS-EBG PPW are substantially suppressed over the frequency range of 0.5 GHz to 2 GHz. In addition, we have experimentally demonstrated that the EL-DGS-EBG PPW reduces the radiated emission from -24 dB to -44 dB as compared to the conventional PPW.

A Study of TRM and ATC Determination for Electricity Market Restructuring (전력산업 구조개편에 대비한 적정 TRM 및 ATC 결정에 관한 연구)

  • 이효상;최진규;신동준;김진오
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.3
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    • pp.129-134
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    • 2004
  • The Available Transfer Capability (ATC) is defined as the measure of the transfer capability remaining in the physical transmission network for further commercial activity above already committed uses. The ATC determination s related with Total Transfer Capability (TTC) and two reliability margins-Transmission Reliability Capability (TRM) and Capacity Benefit Margin(CBM) The TRM is the component of ATC that accounts for uncertainties and safety margins. Also the TRM is the amount of transmission capability necessary to ensure that the interconnected network is secure under a reasonable range of uncertainties in system conditions. The CBM is the translation of generator capacity reserve margin determined by the Load Serving Entities. This paper describes a method for determining the TTC and TRM to calculate the ATC in the Bulk power system (HL II). TTC and TRM are calculated using Power Transfer Distribution Factor (PTDF). PTDF is implemented to find generation quantifies without violating system security and to identify the most limiting facilities in determining the network’s TTC. Reactive power is also considered to more accurate TTC calculation. TRM is calculated by alternative cases. CBM is calculated by LOLE. This paper compares ATC and TRM using suggested PTDF with using CPF. The method is illustrated using the IEEE 24 bus RTS (MRTS) in case study.

Analytical Study in Brake Judder Reduction of Medium Bus (중형 버스의 브레이크 저더 현상 개선에 대한 해석적 고찰)

  • 이계섭;서권희;국종영;천인범
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.4
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    • pp.148-156
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    • 2001
  • Brake judder, one of low Sequency vibrations in brake system is determined by the excitation of Brake Torque Variation (BTV). The largest contributor to BTV is disc thickness variation. In this study, the static loads of brake torque at Suspension Mounting Points (SW) are obtained by the quasi-static analysis using DADS. The dynamic loads with frequency of BTV at SW are derived from correlation between forced vibration analysis with static loads and brake test results. And the accelerations at steering wheel were analyzed by forced vibration analysis with dynamic loads using commercial finite element program MSC/NASTRAN so that vibration characteristics of vehicle due to brake judder were investigated. Reliability of analysis results was verified through comparing the brake test results. Also, a parametric study with natural frequencies of frame, such as the 1st torsional mode and 1st bending mode, was conducted to reduce vibration amplitudes. As a result we could detect frame natural frequency conditions to improve vibration characteristics and obtained the frame model to reduce vibration amplitude.

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Design criteria of wind barriers for traffic -Part 1: wind barrier performance

  • Kwon, Soon-Duck;Kim, Dong Hyawn;Lee, Seung Ho;Song, Ho Sung
    • Wind and Structures
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    • v.14 no.1
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    • pp.55-70
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    • 2011
  • This study investigates the design criteria required for wind barriers to protect vehicles running on an expressway under a high side wind. At the first stage of this study, the lateral deviations of vehicles in crosswinds were computed from the commercial software, CarSim and TruckSim, and the critical wind speeds for a car accident were then evaluated from a predefined car accident index. The critical wind speeds for driving stability were found to be 35 m/s for a small passenger car, yet 30 m/s for a truck and a bus. From the wind tunnel tests, the minimum height of a wind barrier required to reduce the wind speed by 50% was found to be 12.5% of the road width. In the case of parallel bridges, the placement of two edge wind barriers plus one wind barrier at center was recommended for a separation distance larger than 20 m (four lanes) and 10 m (six lanes) respectively, otherwise two wind barriers were recommended.