• 한국지리정보학회지
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• 제10권1호
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• pp.113-123
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• 2007

본 연구는 응급의료서비스를 제공하는 주요 시설인 소방파출소와 응급의료기관의 공간적 입지의 적절성 분석과 함께 응급처치를 위한 출동체계 및 후송체계와 관련된 119응급의료 활동권역의 진단을 연구 목적으로 한다. 이를 위해 부산시 119 구급관련 자료를 GIS상에서 분석 가능하도록 우선 환자 발생위치를 지번데이터와 주소를 기반으로 매칭시킴으로써 개별 개체로 입력하였으며 환자로의 출동 및 병원으로의 후송에 따른 시간을 초단위로 구축하였다. 또한 119 파출소의 위치 및 관할 구역, 응급의료기관 등을 입력하여 시간적 권역은 물론 공간적 권역의 분석을 실시하였다. 구축된 부산지역 16개 구군과 226개 읍면동별 GIS데이터를 활용한 분석결과 부산시 응급의료서비스의 5분이내 비율이 약 41%에 그쳤으며 각 구별로는 5분 초과 10분 이내의 비율이 가장 높음을 알 수 있었다. 또한 병원이용패턴에 있어서도 매우 비효율적인 활동이 이루어지고 있음을 알 수 있었다. 이와 같이 소방파출소와 응급의료기관의 출동시간대별, 후송시간대별 시공간적 분포에 대한 진단결과와 함께 이상적인 출동 및 후송 패턴을 제시하여 이를 비교함으로써 응급의료서비스 체계를 구성하는 공공시설들의 효율적 자원 활용방안을 제시하고자 하였다.

• 한국재난정보학회 논문집
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• 제17권4호
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• pp.667-673
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• 2021

연구목적: 본 연구는 2015년부터 5년 동안 부산광역시의 기온과 시기에 따른 119구조대의 벌집 제거 출동 경향을 분석하고자 하였다. 연구방법: 2015년 1월부터 2019년 12월까지 부산의 11개 소방서 출동 건수를 확인하고 구조 및 구급 활동의 원자료를 수집하였다. 5년간 부산광역시소방재난본부 산하 소방서의 벌집 제거 출동 건수를 파악하고, 그 결과를 바탕으로 온도와 월별, 행정구역별 벌집 제거 출동을 빈도와 백분율로 분석하였다. 연구결과: 월 평균기온이 20℃ 이상부터 출동 빈도가 증가하기 시작하여, 23℃ 이상 29℃ 미만에서 출동 빈도가 가장 높은 것으로 나타났고 월별 출동 건수 중 2017년 7,900건이 가장 높은 것으로 관찰되었다. 특히 벌집 제거 출동 시기가 해가 지날수록 빨라지는 것을 알 수 있었다. 부산광역시 행정구역별로 출동 건수를 비교한 결과, 기장군이 가장 많았으며, 해운대구, 금정구, 남구순으로 출동 빈도가 높은 것으로 나타났다. 결론: 기온 변화에 따른 벌집 제거 출동이 점차 빨라지고 있는 것을 확인할 수 있었고, 본 연구의 결과가 차후 도시 내 말벌 연구에 활용될 수 있을 것으로 여겨진다.

• Journal of Electrical Engineering and Technology
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• 제11권2호
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• pp.329-337
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• 2016

With the increasing deployment of distributed generators in the distribution system, a very large search space is required when dynamic programming (DP) is applied for the optimized dispatch schedules of voltage and reactive power controllers such as on-load tap changers, distributed generators, and shunt capacitors. This study proposes a new optimal voltage and reactive power scheduling method based on dynamic programming with a heuristic searching space reduction approach to reduce the computational burden. This algorithm is designed to determine optimum dispatch schedules based on power system day-ahead scheduling, with new control objectives that consider the reduction of active power losses and maintain the receiving power factor. In this work, to reduce the computational burden, an advanced voltage sensitivity index (AVSI) is adopted to reduce the number of load-flow calculations by estimating bus voltages. Moreover, the accumulated switching operation number up to the current stage is applied prior to the load-flow calculation module. The computational burden can be greatly reduced by using dynamic programming. Case studies were conducted using the IEEE 30-bus test systems and the simulation results indicate that the proposed method is more effective in terms of saving electric charges and improving the voltage profile than loss minimization.

• Journal of Electrical Engineering and Technology
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• 제7권1호
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• pp.9-16
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• 2012

The present study presents the Phasor Discrete Particle Swarm Optimization (PDPSO) algorithm, an effective optimization technique, the multi-dimensional vectors of which consist of magnitudes and phase angles. PDPSO is employed in the configuration of micro-grids. Micro-grids are concepts of distribution system that directly unifies customers and distributed generations (DGs). Micro-grids could supply electric power to customers and conduct power transaction via a power market by operating economic dispatch of diverse cost functions through several DGs. If a large number of micro-grids exist in one distribution system, the algorithm needs to adjust the configuration of numerous micro-grids in order to supply electric power with minimum generation cost for all customers under the distribution system.

• Journal of Electrical Engineering and Technology
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• 제2권2호
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• pp.152-156
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• 2007

This paper proposes a method for real-time control of both capacitors and ULTC in a distribution system to reduce the total power loss and to improve the voltage profile over the course of a day. The multi-stage consists of the off-line stage to determine dispatch schedule based on a load forecast and the on-line stage generates the time and control sequences at each sampling time. It is then determined whether one of the control actions in the control sequence is performed at the present sampling time. The proposed method is presented for a typical radial distribution system with a single ULTC and capacitors.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.298-299
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• 2011

The impacts of EV charging demands on power system such as increased peak demands may be developed by means of modeling a stochastic distribution of charging and a demand dispatch calculation. Optimization processes are proposed to determine optimal demand distribution portions so that charging costs and demands can be managed optimally. There are two optimization methods which have different effects on the outcome. These focus either on the Electric vehicle customer side (cost optimization) or the System Operator side (Load-weighted optimization).

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2006년도 추계학술대회
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• pp.379-386
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• 2006

The purpose of this paper is to analyze the implementation of the GIS infrastructure systems for the u-City, GIS base u-City represents spatial information derived fields, such as geographical distribution of the urban boundaries, physical configuration of the urban locations and cultural characteristics of the urban history. These three aspects relate to urban infrastructure systems implementation, urban monitoring center implementation, and spatial database implementation. In terms of the GIS based u-Ci쇼 urban infrastructure implementation systems, the u-City depends on IT contents and spatial features. IT contents are strongly related to IT839 strategy due to the national agenda is "u-Korea". GIS should contribute to u-City construction through the spatial analyses methods. For these methods various GIS functions will guide to u-City's distribution, location, and characteristics of urbanization. The infrastructure consists of road and road facilities, underground facilities, related agencies facilities, dispatch systems, environmental systems, and urban planning. These six units of the urban infrastructures have spatial databases that consist of spatial configuration, such as dots, lines, and polygons in order to draw the spatial distribution of the u-City GIS based u-City urban infrastructure implementation systems should deal with It convergence to generate fusion affects.

• 전기학회논문지
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• 제61권6호
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• pp.783-790
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• 2012

Electric Vehicles(EVs) and Plug-in Hybrid Electric Vehicles(PHEVs) which have the grid connection capability, represent an important power system issue of charging demands. Analyzing impacts EVs charging demands of the power system such as increased peak demands, developed by means of modeling a stochastic distribution of charging and a demand dispatch calculation. Optimization processes proposed to determine optimal demand distribution portions so that charging costs and demand can possibly be managed. In order to solve the problems due to increasing charging demand at the peak time, alternative electricity rate such as Time-of-Use(TOU) rate has been in effect since last year. The TOU rate would in practice change the tendencies of charging time at the peak time. Nevertheless, since it focus only minimizing costs of charging from owners of the EVs, loads would be concentrated at times which have a lowest charging rate and would form a new peak load. The purpose of this paper is that to suggest a scenario of load leveling for a power system operator side. In case study results, the vehicles as regular load with time constraints, battery charging patterns and changed daily demand in the charging areas are investigated and optimization results are analyzed regarding cost and operation aspects by determining optimal demand distribution portions.

• Journal of Electrical Engineering and Technology
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• 제4권1호
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• pp.1-12
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• 2009

In recent years, integration of new distributed generation (DG) technology in distribution networks has become one of the major management concerns for professional engineers. This paper presents a dynamic methodology of optimal allocation and sizing of DG units for a given practical distribution network, so that the cost of active power can be minimized. The approach proposed is based on a combined Genetic/Fuzzy Rules. The genetic algorithm generates and optimizes combinations of distributed power generation for integration into the network in order to minimize power losses, and in second step simple fuzzy rules designs based upon practical expertise rules to control the reactive power of a multi dynamic shunt FACTS Compensator (SVC, STATCOM) in order to improve the system loadability. This proposed approach is implemented with the Matlab program and is applied to small case studies, IEEE 25-Bus and IEEE 30-Bus. The results obtained confirm the effectiveness in sizing and integration of an assigned number of DG units.

• 한국정보시스템학회지:정보시스템연구
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• 제29권2호
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• pp.131-147
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• 2020

Purpose The purpose of this study is to develop intelligent vehicle parking distribution system based on LoRa network at the circumstance of traffic congestion during cultural festival in a local city. This paper proposes a parking dispatch and distribution system using a Q-learning algorithm to rapidly disperse traffics that increases suddenly because of in-bound traffics from the outside of a city in the real-time base as well as to increase parking probability in a parking lot which is widely located in a city. Design/methodology/approach The system get information on realtime-base from the sensor network of IoT (LoRa network). It will contribute to solve the sudden increase in traffic and parking bottlenecks during local cultural festival. We applied the simulation system with Queuing model to the Yudeung Festival in Jinju, Korea. We proposed a Q-learning algorithm that could change the learning policy by setting the acceptability value of each parking lot as a threshold from the Jinju highway IC (Interchange) to the 7 parking lots. LoRa Network platform supports to browse parking resource information to each vehicle in realtime. The system updates Q-table periodically using Q-learning algorithm as soon as get information from parking lots. The Queuing Theory with Poisson arrival distribution is used to get probability distribution function. The Dijkstra algorithm is used to find the shortest distance. Findings This paper suggest a simulation test to verify the efficiency of Q-learning algorithm at the circumstance of high traffic jam in a city during local festival. As a result of the simulation, the proposed algorithm performed well even when each parking lot was somewhat saturated. When an intelligent learning system such as an O-learning algorithm is applied, it is possible to more effectively distribute the vehicle to a lot with a high parking probability when the vehicle inflow from the outside rapidly increases at a specific time, such as a local city cultural festival.