• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.1019-1020
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• 2006

The proposed algorithm consists of two parts. One is to set up a decision tree to represent the various switching operations available. Another is to identify the most effective the set of switches using proposed search technique and a feeder load balance index. Test results on the KEPCO's 108 bus distribution system show that the performance is efficient and robust

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.1290-1293
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• 2012

오픈 소스 기반 ESB 모니터링 시스템 설계에 EIP(Enterprise Integration Pattern)을 적용하여 비즈니스 요구사항을 처리하는 통합 로직과 메시지 추적 관리를 위한 관리 로직을 분리하여, 메시지 관리 로직 처리에 따른 성능 저하 및 오류에 의한 영향도를 최소화하며 메시지 데이터를 중앙 저장 장치에 저장하여 메시지 추적 관리를 용이한 모니터링 시스템 구축 사례.

• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.35-47
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• 2005

This paper is to review a literature concerning Bus Transit Route Network Design(BTRNDP), to describe a future study direction for a systematic application for the BTRNDP. Since a bus transit uses a fixed route, schedule, stop, therefore an approach methodology is different from that of auto network design problem. An approach methodology for BTRNDP is classified by 8 categories: manual & guideline, market analysis, system analytic model. heuristic model. hybrid model. experienced-based model. simulation-based model. mathematical optimization model. In most previous BTRNDP, objective function is to minimize user and operator costs, and constraints on the total operator cost, fleet size and service frequency are common to several previous approach. Transit trip assignment mostly use multi-path trip assignment. Since the search for optimal solution from a large search space of BTRNDP made up by all possible solutions, the mixed combinatorial problem are usually NP-hard. Therefore, previous researches for the BTRNDP use a sequential design process, which is composed of several design steps as follows: the generation of a candidate route set, the route analysis and evaluation process, the selection process of a optimal route set Future study will focus on a development of detailed OD trip table based on bus stop, systematic transit route network evaluation model. updated transit trip assignment technique and advanced solution search algorithm for BTRNDP.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.233-251
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• 2023

Metropolitan buses are managed as either a direct seat type or a metropolitan express type according to the 「Passenger Transport Service Act」. However, a management system that reflects the characteristics of metropolitan buses is not currently established. Therefore, in this study, the driving characteristics of metropolitan buses, dangerous driving behavior characteristics of metropolitan bus drivers, metropolitan bus accident characteristics, and the safety management system of domestic and foreign buses and other means were investigated. Through this, a plan for strengthening the safety management of metropolitan buses suitable for Korea was presented by dividing it into short-term and mid to long term. The short-term plan is a plan that can be carried out through consultation between metropolitan bus agencies and transportation companies, and the mid to long term plan is a plan that can be implemented only when related laws are revised. Through this study, it is expected to serve as an opportunity for in-depth discussions by the government, business operators, and related experts to strengthen the safety management of metropolitan buses.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.11
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• pp.527-539
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• 2008

This paper presents a performance estimation technique based on queuing analysis for on-chip bus matrix architectures of Multi-Processor System-on-Chips(MPSoCs). Previous works relying on time-consuming simulation are not able to explore the vast design space to cope with increasing time-to-market pressure. The proposed technique gives accurate estimation results while achieving faster estimation time than cycle -accurate simulation by order of magnitude. We consider the followings for the modeling of practical memory subsystem: (1) the service time with the general distribution instead of the exponential distribution and (2) multiple-outstanding transactions to achieve high performance. The experimental results show that the proposed analysis technique has the accuracy of 94% on average and much shorter runtime ($10^5$ times faster at least) compared to simulation for the various examples: the synthetic traces and real-time application, 4-channel DVR.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.12
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• pp.637-644
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• 2004

This paper proposes an expert system with the knowledge learning capability which can enhance the safety and effectiveness of substation operation in the automated substation as well as existing substation by inferring multiple events such as main transformer fault, busbar fault and main transformer work schedule under multiple inference mode and multiple objective mode and by considering totally the switch status and the main transformer operating constraints. Especially inference mode includes the local minimum tree search method and pattern recognition method to enhance the performance of real-time bus reconfiguration strategy. The inference engine of the expert system consists of intuitive inferencing part and logical inferencing part. The intuitive inferencing part offers the control strategy corresponding to the event which is most similar to the real event by searching based on a minimum distance classification method of pattern recognition methods. On the other hand, logical inferencing part makes real-time control strategy using real-time mode(best-first search method) when the intuitive inferencing is failed. Also, it builds up a knowledge base or appends a new knowledge to the knowledge base using pattern learning function. The expert system has main transformer fault, main transformer maintenance work and bus fault processing function. It is implemented as computer language, Visual C++ which has a dynamic programming function for implementing of inference engine and a MFC function for implementing of MMI. Finally, it's accuracy and effectiveness is proved by several event simulation works for a typical substation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.2
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• pp.131-139
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• 1987

The purpose of this study is to define the primary factors obstructing the bus services that play an important part in mass transportation in almost the cities, and then to develop the models for travelling speed. To define the primary factors, two video cameras were used in this study, one for speed meter, the other for traffic condition, from which time-speed graphs were made. In the graphs, the gaps between road regulation speed and travelling speed were analyzed by monitor analysis. After this, primary delay factors were classified by quantification theory type I. and then to develop the models for travelling speed, stepwise analysis was used.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.9
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• pp.261-268
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• 2016

One of the most comfortable transportation in our day to day life is the bus, which provides real time information. In order to obtain reliable information on the arrival time of this information, BIS (Bus Information System) needs to analyse the main factor for the traffic environment. To manage the system, regional information analysis by local municipalities should be prioritized. In this paper, we analyse the features that are expected to affect traffic environment by commuting the travel to school, market, tourism and other influences around Suncheon-si, which has the facilities for education, tourism and urban locality. Data cleaning is performed on the DB information that is being collected from characterization BIS, which is organized by day of the week, day and month, to analyse the key factors of the traffic flow. If this is utilized by applying a key factor to the real time information, it is expected to provide more reliable and accurate information.

• Journal of Korean Society for Quality Management
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• v.46 no.4
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• pp.899-910
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• 2018

Purpose: Generally, since the population density is lower in suburban areas, the distance to school is inevitably long. Therefore, schools in suburban areas often operate school buses to improve student welfare. However, since school buses are usually used only during going to and from school, the utilization rates are relatively low. Therefore, this study aims to establish integrated operation plan of public school bus covering all schools. Methods: It is necessary to decide which school buses will serve the specific demand node which want to go to certain school in order to design an integrated operation plan for school buses. Therefore, a mathematical model is developed for minimizing the total number of vehicles and the distance of transportation by reflecting the characteristics of school buses and students as constraints. To solve the proposed mathematical model, CPLEX, a commercial solver, is applied. Results: To validate and to confirm the proposed process, numerical example is designed with the comparison between before and after integrated operations of school buses in terms of total operation cost. The result shows that the integrated operation can lead the reduction of the number of school buses as well as the decreasing of the fuel cost. Conclusion: This study provides the quantitative method to perform the integrated operation of school buses in suburban areas. The optimal operation strategy is required because there are more complex decision-making elements considering the integrated operation. It is expected to apply this research result at real situation to expand this services based on an optimal operation.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.2
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• pp.76-82
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• 2001

This paper presents a approach for a service restoration and optimal reconfiguration of distribution network using Genetic algorithm(GA) and Tabu search(TS) method. Restoration and reconfiguration problems in distribution network are difficult to solve in short times, because distribution network supplies power for customers combined with many tie-line switches and sectionalizing switches. Furthermore, the solutions of these problems have to satisfy radial operation conditions and reliability indices. To overcome these time consuming and sub-optimal problem characteristics, this paper applied Genetic-Tabu algorithm. The Genetic-Tabu algorithm is a Tabu search combined with Genetic algorithm to complement the weak points of each algorithm. The case studies with 7 bus distribution network showed that not the loss reduction but also the reliability cost should be considered to achieve the economic service restoration and reconfiguration in the distribution network. The results of suggested Genetic-Tabu algorithm and simple Genetic algorithm are compared in the case study also.