• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.5
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• pp.217-224
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• 2002

This paper presents an algorithm to obtain an approximate optimal solution for the service restoration and load balancing of large scale radial distribution system in a real-time operation environment. Since the problem is formulated as a combinatorial optimization problem, it is difficult to solve a large-scale combinatorial optimization problem accurately within the reasonable computation time. Therefore, in order to find an approximate optimal solution quickly, the authors proposed an algorithm which combines optimization technique called cyclic best-first search with heuristic based feeder loadings balance index for computational efficiency and robust performance. To demonstrate the validity of the proposed algorithm, numerical calculations are carried out the KEPCO's 108 bus distribution system.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.10a
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• pp.182-185
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• 2005

To survive in rapidly changing business environment, the enterprise should adapt its business process to the changing environment. The system integration is an important issue to tackle this challenge. It is unavoidable direction that SOA (Service Oriented Architecture) is accepted as an upcoming IT standard to support flexible business processes and integration. In this paper, SOA is introduced, and the Web services and ESB (Enterprise Service Bus) ate also introduced as a foundation technology to implement SOA-enabled solutions. The pilot project, which is introduced in this paper, will be a good reference for future SOA implementation.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.315-321
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• 2009

Since the KTX start its service on April 1st of 2004, KTX increased its share up to 17.4% (2008). It's the 2nd after the passenger car share of 59.2% in the national transportation, but the gap is still wide. In addition, because of the rise of goods' and oil price, the share of intercity express bus is growing up. Nevertheless Korail is trying to improve the train schedule and develop internodal transit system, the number of passengers of KTX is remain flat. KORAIL should start and proceed the tasks below. - Analysis of the 5 year's operation of KTX since the year of 2004 to make plans for the steady growth - development of the KTX operation plan for expansion of railway - preparing the operation of additional passenger rail services on the mail line for newly introduced trains. - expansion of KTX's service area after the introduction of KTX-II - introduction of other new trains - examination for the action plans to promote marketing in main-line including refinement of the rate structure

• Proceedings of the Korea Association of Information Systems Conference
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• 2005.12a
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• pp.455-462
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• 2005

In order to succeed in today's changing business environment, the enterprise should adapt their process flexible. To increase their business process flexibility they need to establish and end-to-end integration internally as well as among partners. Now that SOA (Service Oriented Architecture) is accepted as an upcoming IT standard to support flexible business processes and integration. In this paper, SOA is introduced And the Web services and ESB (Enterprise Service Bus) are also introduced as a foundation technology to implement SOA-enabled solutions. The pilot project, which introduced in this paper, will be a good reference for future SOA study.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.5669-5684
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• 2018

The new mobile edge network architecture has been required for an increasing amount of traffic, quality requirements, advanced driver assistance system for autonomous driving and new cloud computing demands on highway. This article proposes a hierarchical cloud computing architecture to enhance performance by using adaptive data load distribution for buses that play the role of edge computing server. A vehicular dynamic cloud is based on wireless architecture including Wireless Local Area Network and Long Term Evolution Advanced communication is used for data transmission between moving buses and cars. The main advantages of the proposed architecture include both a reduction of data loading for top layer cloud server and effective data distribution on traffic jam highway where moving vehicles require video on demand (VOD) services from server. Through the description of real environment based on NS-2 network simulation, we conducted experiments to validate the proposed new architecture. Moreover, we show the feasibility and effectiveness for the connected car media service on highway.

• Journal of Multimedia Information System
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• v.9 no.3
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• pp.227-232
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• 2022

Disasters are now becoming commonplace and especially the vulnerable group such as the disabled, the elderly, children and foreigners are in a state of overlapping disasters. In this situation, ATSC 3.0-based UHDTV disaster information service for the visually and hearing impaired has been developing. This study focuses on the demand data collected through in-depth interview with the impaired. The demand analysis data is very important to development process of technology. The results of the interview show that it is essential to link the UHDTV disaster signals with home-network, IoT, wearable devices, and various assistive devices for the impaired (hearing aid, smart light bulbs, warning light, etc.). In outdoor space, UHDTV disaster information must be connected to public display media, digital signage, kiosk, screens in bus or taxi. If communication aids for the visually and hearing impaired are equipped with a function that can transmit and receive disaster information, it will help to minimize disaster damage.

• Journal of Korean Society of Transportation
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• v.36 no.2
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• pp.86-97
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• 2018

City tour service has a function not only informs tourists of historical and cultural resources in the city but also contributes to improving city image making. In this study, a questionnaire was surveyed to tourists who used Suwon city tour to find out which factors make affect their intention to re-visit or recommendation to others. Structural equation model was constructed and set a hypothesis that overall city tour satisfaction would have a positive effect. The fitness of the final model was found out to be meet the statistical criteria. As a result of the final model, both satisfaction of guide and satisfaction of city tour operation were significant at 5% significance level (P<0.01). On the other hand, both satisfaction of bus facility and of promotion, customer service were statistically insignificant. Consequently, City tour service satisfaction was found to effect to the intention of re-visit and recommendation. Especially, The higher the satisfaction of guide and city tour operation, the more tendency to recommend. It is expected that local government which operates city tour bus could take advantage of this result in the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6D
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• pp.541-552
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• 2010

The light rail transit (LRT) having bus lines as subsystem is being constructed or planned in the suburban area of metropolitans and medium size cities. However, there is difficulty in establishing the service coverage (SC) of the LRT because the LRT is a completely new transit mode in Korea. The purpose of this study is to provide the basic data and techniques to be used for establishing the SC of the future LRT by understanding the SC characteristics of buses and subways and building models to estimate the walking distances of their users. Busan City is selected as the study city and the SC's of buses and subways are surveyed simultaneously. A total of 9 variables for 82 stations are collected and the cluster analysis is conducted about the variables. The station areas are divided to three types of CBD (Central Business District), sub-CBD and regional center based on the analysis. A station in each area is selected as the study station. At the walking distance (WD) analysis for each mode, the 80 percentile WD of the subway is 672 m and that of the bus is 472 m. In comparing the SC's of both modes by the type of station areas, there are not significant differences between the SC's of sub-CBD and regional center except CBD. At analysis of the relationship between the personal attributes and the WD, for subway users the WD of female is longer than that of male and apartment residents use subway more positively than single house residents do. For the models to estimate the walking distances, the simple regression models were built employing the income as independent variable by dividing the stations into CBD abd non-CBD stations.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.205-216
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• 2009

The aim of this study is to propose an integrated operation plan of information call services by multi-connecting call services which are now being serviced by each different call number services and by providing one stop service which organically links alternative transportations such as railroad, air, and bus and also related organizations as well as road traffic information. For the objective, we analyzed the current status of Korean and foreign country systems and reviewed operation technology and technical specifications of the integrated system according to 3 steps, i.e. infrastructure procurement, test bed and extended completion, stabilization and high valuable services completion. Throughout the result of this study, traffic information one stop service, convenient service, diverse related information provision service, real-time information provision, and efficient system are expected to be implemented in the traffic information call service.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.750-756
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• 2005

The network service have been achieved recently in the vehicle train, bus etc. Network portability have been processed so that it is active around NEMO WG (Network Mobility Working Group)of IETF. We organize NEMO in the railroad environment of the route among the masses traffic mean which has the forecasting. We try to present necessary for a portability network protocol to produce CoA rather efficiently.