• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.2
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• pp.203-210
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• 2015

This paper investigates the failure of a car with a 2.5-liter CRDi engine of the Hyundai Company. The failure is caused by intermittent poor acceleration while driving. To analyze the cause, we investigated the air intake volume, the fuel injection, and the air-fuel ratio, which were determined to be normal. The brake switch signal error was discovered while analyzing the function that limits the output of the engine. While investigating the cause, we discovered the corrosion of the pins on the connector of the brake switch. We determined that it was generated by soapy water flowing in the solar film. Therefore, the cause of the failure was the brake switch signal errors. Additionally, we determined that ECM was the normal fail-safe mode that implemented the override device for safety during normal acceleration. Based on these results, further solar film experiments must be conducted to fully elucidate the causes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3377-3395
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• 2015

Recently, several approaches to share road conditions and/or digital contents through VANETs have been proposed, and such approaches have generally considered the radial distance from the information source as well as the TTL to provision an ephemeral, geographically-limited information sharing service. However, they implement general MANETs and have not been tailored to the constrained movement of vehicles on roads that are mostly linear. In this paper, we propose a novel application-level mechanism that can be used to share road conditions, including accidents, detours and congestion, through a VANET. We assign probabilities to roads around each of the intersections in the neighborhood road network. We then use the graph representation of the road network to build a spanning tree of roads with the information source as the root node. Nodes below the root represent junctions, and the edges represent inter-connecting road segments. Messages propagate along the branches of the tree, and as the information propagates down the branches, the probability of replication decreases. The information is replicated until a threshold probability has been reached, and our method also ensures that messages are not delivered to irrelevant vehicles, independently of their proximity to the source. We evaluated the success rate and performance of this approach using NS-3 simulations, and we used IDM car following and MOBIL lane change models to provide realistic modeling of the vehicle mobility.

• Journal of Environmental Impact Assessment
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• v.20 no.2
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• pp.217-226
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• 2011

This paper was inspired by the fact that Real-time Traffic Information Service could play a key role in reducing incomplete combustion time remarkably since it can provide traffic jam information in real-time basis. Emission characteristics of experimental engines were studied with variable travel distances and speed of car in terms of traffic information provided. 12 Km distance road of Susung district in Daegu is taken as an experimental area to examine this new approach. The emission was tested while the driving was done at 8 AM, 3 PM, 6 PM which represents various traffic conditions. The reduced emission has been measured for a travel distance running at different loads (conventional shortest route and Real-time Traffic Information) and various loads (CO, VOC and NOx) are all inventoried and calculated in terms of existing emission factors. The emission has been shown to reduce linearly with travel distance : carbon monoxide (20.56%), VOC (29.21%), NOx(8.86%).

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.118-121
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• 2008

Bimodal tram is a transit with no-step floor for wheel-chaired persons, with docking to the station precisely and moving on schedule like train. Because of the automatic traveling of bimodal tram to search and follow the magnet embedded in roadway, bimodal tram should be careful about rainfall, snow and wind like a car driving on roadway in respect to natural disasters. Though response procedures in emergency are different according to the passengers' boarding, emergency mobilization is needed if any emergency situation happens. Emergency mobilization is the act of preparing for major catastrophic events, which may affect public transportation systems or their service areas, by assembling and organizing resources, including people, equipment, facilities, communications systems, expert technical support, and public information systems and protocols. Mobilization is the process that ensures that the right people will deploy appropriate resources at the correct time. Effective mobilization requires a partnership of local and state agencies. Public transportation operators and systems play vital roles in response to and recovery from emergencies and other unexpected catastrophic events. These systems, and their capabilities to mobilize resources, are profoundly affected by the decisions and directives of others during these activities. In this study, we focused on the emergency management for bimodal tram and reviewed the considerations about infrastructures under natural disasters, especially heavy rainfall.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.1068-1071
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• 2017

카 하이어링 서비스는 개개인간의 차를 공유할 수 있는 환경을 제공해주는 서비스 플랫폼이다. 카 하이어링 서비스에서는 일반적으로 웹 서버를 구축하여 자차의 대여를 원하는 개인이 해당 차량의 지역 정보, 등록 정보 등을 기입 저장한다. 이후 웹 서버를 통해 일련의 인증과정을 거친 사용자가 해당 지역에 등록되어 있는 차량의 이용을 원할 때, 서버로 본인의 유저 정보를 송신하여 차량을 대여할 수 있도록 서비스를 운영한다. 우리는 본 연구에서 비콘 기술과 영상처리를 통한 PSNR 검출을 사용하여 개인 간의 차량 대여에서 발생하는 보안성과 신뢰성 문제를 보완 향상시켜 카 하이어링 서비스를 활성화 할 수 있는 기반을 구축하고자 한다. 이를 위해 웹 서비스 구현, 인증된 사용자만이 차량을 이용할 수 있는 인증키 생성 및 암호화 알고리즘, 라즈베리파이를 비콘 스캐너로 활용한 인증키 검증 절차, 카메라 영상처리를 이용한 차량 동작 감지 방법의 구현으로 보안성을 강화한 시스템을 구축하였다.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.185-192
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• 2012

Line planning is to determine the frequency of trains on each line to satisfy origin-destination demand while minimizing total operation cost. However, different from the line planning in passenger transportation, it is more important at which intermediate stations each train should be stopped and shunted because the freight car handling works like drop-off or(and) pick-up can incur much time and high cost so that the delay deteriorates the quality of rail freight transportation service. We present an optimization model for constructing line plan in rail freight transportation to simultaneously minimize the train operation cost and total transportation time of freights. And we suggest a column generation approach for our problem, which can solve the real network instances in reasonable computation times.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.2
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• pp.309-314
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• 2017

Recently, the fields such as the service robot, the autonomous driving electric car, and the torpedo ladle cars operated autonomously to enhance the efficiency of management of the steel mill are receiving great attention. But development of automatic power supply that doesn't need human intervention be a problem. In this paper, a position tracking technology of power connector receptacle based on the computer vision is studied which can recognize and identify the position of the power connector receptacle, and finally its possibility is verified using OpenCV program.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.1004-1007
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• 2016

점차 발전하는 자동차 산업에 맞추어 운전자들에게 보다 편리한 서비스를 제공하는 스마트 카에 대한 사회적 관심 또한 증가하고 있다. 이는 최근 스마트 카를 주제로 한 각종 어플리케이션이 등장하는 속도만 봐도 몸소 알 수 있다. 실제로 많은 운전자들이 차를 운전할 때 내비게이션의 목적지를 일일이 설정하는 것에 큰 번거로움을 느끼고 있으며, 이로 인한 사고의 위험성 역시 적지 않다. 이러한 기존의 문제점과 사회적 관심을 고려하여 사용자의 일상이 결합된 스마트 카 어플리케이션 '카스텔라'를 기획하였다. 매번 도로 위에서 목적지를 조작하는 과거의 자동차 내비게이션과 달리, '카스텔라'는 사용자가 등록한 일정을 내비게이션과 연동함으로써 사용자의 일상이 결합된 맞춤 서비스를 제공한다. 또한, 자신의 차량을 상대로 사용자를 등록하여 해당 사용자가 차량의 시동을 제어하는 시스템과 당일의 날씨에 따른 안전 멘트도 제공한다. 기존의 다른 어플리케이션과 달리 사용자 일정 차량이 하나로 녹아들어 사용자의 모바일과 자동차의 연동이 보다 편리하고, 사용자가 자신의 어플리케이션에 등록한 일정을 자동차의 내비게이션에서 바로 목적지로 설정할 수 있다는 것이 특징이다.

• ETRI Journal
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• v.37 no.5
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• pp.856-866
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• 2015

A heterogeneous network (HetNet) is a network topology composed by deploying multiple HetNets under the coverage of macro cells (MCs). It can improve network throughput, extend cell coverage, and offload network traffic; for example, the network traffic of a 5G mobile communications network. A HetNet involves a mix of radio technologies and various cell types working together seamlessly. In a HetNet, coordination between MCs and small cells (SCs) has a positive impact on the performance of the networks contained within, and consequently on the overall user experience. Therefore, to improve user-perceived service quality, HetNets require high-efficiency network protocols and enhanced radio technologies. In this paper, we introduce a 5G HetNet comprised of MCs and both fixed and mobile SCs (mSCs). The featured mSCs can be mounted on a car, bus, or train and have different characteristics to fixed SCs (fSCs). In this paper, we address the technical challenges related to mSCs. In addition, we analyze the network performance under two HetNet scenarios-MCs and fSCs, and MCs and mSCs.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.9
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• pp.883-890
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• 2006

Nowadays, CPS is used widely, especially in cases which need more precise position information, such as car navigation systems and even in the mobile robot for position measuring in the outdoor environment. RTK (Real-Time Kinematics) and DGPS (Differential Global Positioning System) have more precise accuracy than the general-purposed GPS. However can't easily use them because of high prices and large size of equipments. In order fur the mobile robot to obtain precise position information it is important that CPS receiver has portability and low price. In this study, we introduce a new GPS data acquisition system that offers the precise position data using the DGPS mechanism and satisfying low cost and portability. In addition to this, we propose an improved data compensation algorithm that offers more accurate position information to the outdoor mobile robot by compensating the error rate of CPS data measured from the three points with geometrical rotation and distance formula. Proposed method is verified by comparing with the precise real position data obtained by RTK. Proposed method has more than 70% performance enhancement.