• 전기의세계
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• 제18권4호
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• pp.7-15
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• 1969

In this method the condenser excite winding has the phase angle of 90 electrical degree, with the load winding in stator. The condenser excite wing is connected with the condenser while the load winding is with the full rectifer. Direct and quardrature axis components of rotating field winding are composed, of balanced two phase winding, and each one of them is connected with half wave rectifiers. Initically, small amount of lead current can be induced at the condenser excite winding by residual magnetism of rotor. The induced lead current forces the rotating field winding to be excited by synchronous alternating magnetic field. The speed electromotive force, there for, induced in rotating field winding shall electro magnetize the rotating field pole by rotating half wave rectifiers. In the case of the charging generator directly coupled with engines at the operation of wide range speed, the generated region, such as vehicles, aircraft, ships etc, is occured. In conclusion, we can take the advantage of, omitting of voltage regurator and current limiter for charging load and reducing the consumption of fuel using the generated region which can be devided in to Impossible generated region, Generated region, and suspension generated region.

• 한국항해항만학회지
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• 제40권2호
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• pp.51-56
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• 2016

Expressways mean the primary arterial highways with a high level of efficiency and safety. However, Gyeongbu and Namhae expressways connected with Busan ports are showing travel time delay by increased traffic including the medium/large-sized vehicles of about 20% compared to those of about 13% regardless of the peak periods. This study, thus, intends to analyze lane traffic characteristics in the basic 8-lane segments of the above-mentioned expressways, compute the planning and buffer times based on travel time reliability, find the lane speed showing a higher correlation with planning time between the lane speeds in the basic 8-lane segments, and finally suggest a correlation model for predicting the planning time in expressways.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.75-80
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• 1998

Statistical Energy Analysis(SEA) has been considered as a possible method for predicting responses of complex structures, especially at higher frequencies. In this paper, an SEA model of vehicle was built using 138 energy storing subsystems connected together using 1019 junctions. SEAM software program was used to build and calculate the model. To demonstrate the accuracy of the SEA model, predicted response levels were compared with measured levels. The source input levels were measured at the engine mounting parts. For the vibration levels, the agreement between the calculation results and the experimental ones was found to be good. The energy flow between connected subsystems can be presented, because the analysis method is based on the estimation of the power flow between subsystems. This paper also identifies some dominant energy flow paths from sources. It is finally presented that the SEA model can optimize the design parameters of vehicles using model parameters and energy flow paths.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.521-522
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• 2015

Many countries concern about environmental problems. Therefore, they have made regulation for mandatory reduction of greenhouse gases. Electric Vehicles(EVs) are one of the most effective counterproposals for it. EVs are usually charging for it by using actual distribution system of the Korea Electric Power Corporation(KEPCO). However, it could cause adverse effects such as increase of the power demand and voltage variation on the distribution system. To reduce adverse effects for demand power side, in this paper, charging for EVs by using PV(Photovolatic Power Generation) connected with ESS(Energy Storage System) are modeled by using Electro Magnetic Transient Program(EMTP). And then, the simulation results are compared with EVs that are connected to the distribution system of KEPCO for using charge.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권12호
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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 Electrical Engineering and Technology
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• 제10권3호
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• pp.859-864
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• 2015

This paper analyzes the impact of Plug-in Electric vehicles(PEVs) on power demand and voltage change when PEVs are connected to the domestic distribution system. Specifically, it assesses PEVs charging load by charging method in accordance with PEVs penetration scenarios, its percentage of total load, and voltage range under load conditions. Concretely, we develop EMTDC modelling to perform a voltage distribution analysis when the PEVs charging system by their charging scenario was connected to the distribution system under the load condition. Furthermore we present evaluation algorithm to determine whether it is possible to adjust it such that it is in the allowed range by applying ULTC when the voltage change rate by PEVs charging scenario exceed its allowed range. Also, detailed analysis of the impact of PEVs on power distribution system was carried out by calculating existing electric power load and additional PEVs charge load by each scenario on new-town in Korea to estimate total load increases, and also by interpreting the subsequent voltage range for system circuits and demonstrating conditions for countermeasures. It was concluded that total loads including PEVs charging load on new-town distribution system in Korea by PEVs penetration scenario increase significantly, and the voltage range when considering ULTC, is allowable in terms of voltage tolerance range up to a PEVs penetration of 20% by scenario. Finally, we propose the charging capacity of PEVs that can delay the reinforcement of power distribution system while satisfying the permitted voltage change rate conditions when PEVs charging load is connected to the power distribution system by their charging penetration scenario.

• 전기전자학회논문지
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• 제25권3호
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• pp.425-429
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• 2021

커넥티드 기반 자율주행 시스템에서 차량의 군집주행은 중앙 시스템의 계산량과 네트워크 트래픽 로드를 크게 감소시켜 줄 뿐만 아니라 교통흐름을 개선하는 효과도 얻을 수 있는 효율적인 교통운영모델이다. 효율적인 군집주행집단 관리를 위해서는 군집의 규모를 적절하게 유지하는 것이 중요하며 이를 위한 신규차량 및 타 군집 소속 차량의 효율적인 병합 제어가 필수적이다. 본 연구에서는 군집의 현재 규모와 차량의 우선순위에 따라 병합 요청을 수락 또는 거절하는 병합 제어 방안을 제시한다. 제안하는 방안은 마코프 체인 기반의 수학적 분석모델을 이용해 분석하고 검증하었다. 성능평가 결과 제안한 방안이 중앙 시스템의 부하를 적절하게 잘 관리하는 것을 확인할 수 있었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1826-1834
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• 2011

The traffic realizes that people come and go. The mobility is on the basis of location and time. The physical means for the traffic is composed of roads, vehicles and fuel. The current traffic services place emphasis on the physical elements. In the near future, with the current elements, the railroad service is considerably improved of through intangible factors including the customized customer services that the mobile-social network service is newly applied. The intangible things are connected to the increase of the time value for customers.

• 정보과학회 논문지
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• 제43권12호
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• pp.1420-1427
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• 2016

본 논문은 통신 환경이 불안정하고 토폴로지가 수시로 변하는 CV(Connected Vehicle) 환경에서 Fog computing과 SDN의 장점을 활용하는 방법에 대해 제시한다. 이를 위해서 먼저 중앙의 컨트롤러는 최신의 네트워크 토폴로지를 유지함으로써 현재 네트워크 상황을 파악할 수 있어야한다. 특히 모바일 환경에서는 컨트롤러가 수집하는 정보 중에서 노드의 움직임 정보가 중요하기 때문에 본 논문에서는 움직임 정보를 세 가지 종류로 세분화하여 관리하고 해당 정보를 효율적으로 활용하고자한다. 본 논문에서 제안하는 모바일 노드의 움직임 정보의 활용 방안은 크게 두 가지로 컨트롤 메시지 횟수를 조절함으로써 컨트롤 오버헤드를 줄이는 것과 통신 단절 시 효율적으로 복구할 수 있는 복구 프로세스를 제안하는 것이다. 복구 프로세스는 두 가지로 모바일 노드의 움직임 정보를 활용하여 연결 상태를 효율적으로 복구하는 방법과 cloud level과 fog level을 구별하여 경로 복구를 수행하는 방법이다. 시뮬레이션 결과, 주어진 환경에서 본 논문이 제안한 방법이 기존 방법에 비해 55% 가량의 컨트롤 오버헤드를 줄이고 통신 단절 시 끊김 시간을 5% 가량 단축시킬 수 있음을 확인하였다.

• 자원리싸이클링
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• 제18권2호
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• pp.62-68
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• 2009

국내 자동차 보유대수는 정차 증가하고 있으며 2007년도에 1,600만대를 초과하였다. 자동차 보유대수의 증가는 결국 폐 자동차 발생의 증가로 이어지고 있으며 폐 자동차의 재활용 필요성은 더욱 강조되고 있다. 폐 자동차의 재활용은 폐 자동차 처리를 용이하게 함과 동시에 환경파괴는 물론 부족한 자원을 대체할 수 있는 효과를 가진다. 본 연구는 폐 자동차를 재활용 했을 때의 편익과 폐 자동차를 처리했을 때의 비용을 비교하는 경제성 평가를 하였다. 비용편익 분석결과에 의하면, 폐 자동차의 부품, 철, 비철 금속 스크랩을 재활용 하였을 경우 편익이 발생하는 것으로 나타났다. 즉, 본 연구의 결과는 폐 자동차를 재활용함으로써 얻을 수 있는 경제적인 이득을 시사하고 있다. 따라서 정부는 폐 자동차 및 소재의 재활용을 의무화하여야 하고 기업은 효율적인 폐 자동차의 해체 및 재활용 방법 개발 등을 고려해야 한다고 사료된다.