• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2782-2786
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• 2011

In this paper a protocol design for bus network communication between onboard signalling system and MMI(Man Machine Interface) will be presented and illustrated. Recently, many onboard signailling systems adopt hot standby for safety reasons. Hot standby is a method of redundancy in which the primary and secondary systems run simultaneously. It is convenient to use bus network(bus topology) in a hot standby system for communication between onboard signalling system and MMI. Because bus network is the simplest way to connect multiple clients such as onboard signalling system, MMI and etc. However, there are many problems when two clients want to transmit at the same time on the same bus. A effective protocol is necessary to solve that problems. We will describes protocol design which is useful when onboard signalling systems and MMIs are connected via RS485(Bus Network).

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.66-67
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• 2014

Stabilization of the DC bus voltage is an important task in DC-AC microgrid system with renewable energy source such as solar system. A battery energy storage system (BESS) has become a general solution to stabilize the DC-bus voltage in DC-AC microgrid. This paper develops the analog BESS controller which requires neither computation nor dc-bus voltage measurement, so that the system can be implemented simply and easily. Even though others methods can stabilize and control the DC-bus voltage, it has complicated structure in control and low adaptive capability. The proposed topology is simple but is able to compensate the solar source variation and stabilize the DC-bus voltage under any loads and distributed generation (DG) conditions. In addition, the design of analog controller is presented to obtain a robust system. In order to verify the effectiveness of the proposed control strategy, simulation is carried out by using PSIM software.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.211-215
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• 2016

In this paper, we utilize a service provided by the existing bus information system. To improve the limitations of the bus information system the information provided to the passenger using the bus. By applying the IoT sensor network system. congestion information of the bus provided to customer. Provides information in addition to the existing bus congestion information to passengers wishing to use public transport from the smartphone app with an existing information system. The bus congestion information in addition to the existing information to passengers who want to use public transport provided in the existing information system and smartphone apps. Prevent accidents that might occur due to congestion in the bus, efficient and convenient way to propose an improved bus information system for public transport. Developed a prototype system using the IOT sensor network verified the proposed method.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2036-2041
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• 2014

In this paper, a thermal model is developed for the bus bar system to predict the temperature variation during the transient time period and to calculate both the steady-state and transient electrical current carrying capacity (ampacity) of bus bar. The bus bar system installed in the power house of Kumaraguru College of Technology, Coimbatore has been considered. Temperature variation predicted in the modelling is validated by observing the current and steady state temperatures in different feeders of the bus bar. Magnetic field of the extreme phases R and B induces more current in the middle phase Y. Hence, the steady state temperature in the phase Y is greater than other two phases. The transient capabilities of the bus bar are illustrated by calculating the variations in the bus bar temperature when it is subjected to a step change in current during the peak hours due to increase in hostel utilities and facilities (5.30 pm to 10.30 pm). The physical and geometrical properties of the bus bar and temperature variation in the bus bar are used to estimate the thermal time constants for common bus bar cross-sections. An analytical expression for the time constant of the bus bar is derived.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1777-1782
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• 2007

Since July in 2004, starting with urban bus reorganization of Seoul metropolitan government, the change of the public transportation which integrates the urban bus and the subway of the metropolis are being continued. But the integration of such bus and the subway is staying to only a fare system mainly, and the guidance system of the subway and the bus has not changed. So we propose the concept of the new guidance system following public transportation change tendency. At first we introduce the new information system which can guide city railroad and bus altogether, and we propose new system which can guide divided by the trunk line and the branch line instead of bus and subway. Last high-functional guidance system which can give passengers tip and hint for various and effective usage of public transportation in more complicated city transit network is introduced. This new guidance system can increase competitiveness of public transportation system and stretch transportation share of it. And that guidance system is high-class contents that all public transportation business can utilize, so it can originate new industry. In conclusion, this new innovative guidance system is important field that government, local administration and public transportation business must be concerned and develop.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1601-1606
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• 2004

Nowadays, the bus system of a metropolitan area is improving very fast. According to the bus, commuter railways increase their competitive power. For this, trains get the mobility increasing, effective transferring system and unified information service. For the mobility increasing, commuting railway must be faster by flexible train diagram and facilities improvement. And finally, optimal commuter train, 'Liner' is needful. And for effective transferring system, it is necessary that railway station and transferring center of a city be merged. And it is needful that direct management bus by railway company and unification fare system on metropolitan region. Next, for information service system improving, the commuting railway station must be regional transportation hub at first. And it is needful that unified line map of trunk line transportation systems and regionally collective transportation system information book. Therefore, metropolitan commuting railways compete with trunk line bus and cooperate with feeder line bus, and can make optimal metropolitan public transportation systems.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.587-595
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• 2008

Many studies on bus scheduling optimization have been done from the 1960s to recent years for establishing rational bus schedule plan that can improve convenience of bus passengers and minimize unnecessary runs. After 2000, as part of the Intelligent Transport Systems (ITS), the importance of the schedule management and providing schedule information through bus schedule optimization has become a big issue, and much research is being done to develop optimization models that will increase bus passenger convenience and, on the side of bus management, minimize unnecessary bus operation. The purpose of this study is to calculate the optimal bus frequency and create a timetable for each bus stop by applying DTR or DTRC model that use data for each bus stop and route segment. Model verification process was implemented using data collected from bus management system (BMS) and integrated transit-fare card system for bus route of Seoul's No. 472 line. In order to evaluate the reliability and uncertainty of optimal solution, sensitivity analysis was implemented for the various parameters and assumptions used in the bus scheduling model.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.3
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• pp.318-322
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• 2014

A kind of field bus called Actuator and Sensor interface bus(AS-i) was designed in this paper. The configuration of AS-i network system used Application Specific Integrated Circuit(ASIC) SAP5S chip and PLC S7-200 station, which included CPU 224 and AS-i master module CP 243-2. We also created an example program for PLC S7-200 to control AS-i network. The fire and smoke detection system was made with AS-i network system that was designed. This system had got more advantages than other system such as number of stations, easy installation, wide working area, etc. And designed system can be used as a partner network for higher level field bus networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.2
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• pp.288-299
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• 1993

This paper proposes the new bus protocol in the tightly coupled multiprocessor system. The bus protocol uses the pipelined data transfer and block transfer scheme to increase the bus bandwidth, The bus also has the independent transfer lines for the address and data respectively, and it can transfer the data up to maximum 264 Mbytes /sec. This paper also models the multiprocessor system where each processor boards have the private cache. Simulation evaluates the bus and system performance according to hit ratio of the reference data in cache memory, In the case of using this bus, the bus is evaluated not to be saturated when up to 10 processor boards are connected to the bus. As for up to 4 memory interleavng, the performance increases linearly.

• Journal of Korean Society of Transportation
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• v.36 no.3
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• pp.184-194
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• 2018

Recently, the need to introduce bus lines on a welfare basis is increasing as public intervention in bus routes is accelerated through semi-public bus system. The main objective of this study is to establish the concept of PSO (public service obligation) bus line on a welfare basis and propose a classification method of PSO bus line under semi-public bus system. We introduced 3 indexes such as "equity" in terms of bus line distribution, "publicity" in terms of age distribution, and "profitability" in terms of bus operating revenues. On the basis of 3 indexes, we introduced the PSO bus line, which is fair and public, even if it is not profitable. Based on the concept established in this study, we divided 130 ordinary city bus lines in Busan Metropolitan City into 8 PSO bus lines. Also, considering the positive impact of public buses, which are less profitable, but improve the mobility of residents and secure public community, we suggested the need to introduce public buses in bus service shortage areas.