• Journal of Advanced Navigation Technology
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• v.10 no.4
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• pp.394-399
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• 2006

In this paper, we investigated performance for 5.8GHz dedicated short range communication system using OFDM which will be applied to Intelligent transportation system services. The maximum speed of a vehicle in DSRC channel is very fast as 180km/h, so a service time is very short to serve a various traffic information if hand-off is not occurred. Therefore higher bit rate is required to proved advanced and intelligent service to the drivers of various vehicle and the data transmission rate of the next generation DSRC system if being promoted over 10Mbps. The signals received in Clarke & Gans channel have been simulated using the computer simulator.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.23-28
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• 2005

The signal in wireless multi-path channel is affected by fading and ISI because of high data rate transmission, so the signal has the high error rate. The present modulation and demodulation method of DSRC system can not expect sufficient for providing data service over 1 Mbps, so the channel equalization and advanced modulation and demodulation methods are required. OFDM is generally known as an effective technique for high data rate transmission system, since it can prevent ISI by inserting a guard interval. However, a guard interval longer than channel delay spread has to be used in each OFDM symbol period, thus resulting a considerable loss in the efficiency of channel utilization Therefore the equalizer is necessary to cancel ISI to accommodate advanced ITS service with higher bit rate and longer channel delay spread condition In this paper, the channel equalizer for the OFDM -DSRC system was designed and its performance in a multi-path fading environment was evaluated with computer simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.431-435
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• 2008

2006년 11월 이후 신 차량 번호판 등장 후, 신 차량 번호판과 구 차량 번호판이 혼합되어 있다. 이에 따라 속도위반, 신호위반 단속, 무인 주차관리 시스템, 범죄 및 도주 차량 검거, 고속도로 톨게이트에서 통행료 지불로 인한 교통 체증현상을 해소하기 위한 자동 요금 징수와 같은 다양한 경우에서 자동차 번호판의 특징에 맞는 인식 시스템이 요구되고 있다. 따라서 본 논문에서는 이러한 문제를 해결하기 위해 형태학적 특징 및 차 연산과 ART2 알고리즘을 이용한 차량 번호판 인식 방법을 제안한다. 무인 카메라에서 획득된 차량 번호판 영상에서 차 연산을 이용하여 에지를 추출한 후에 블록 이진화를 한다. 이진화 된 차량 영상에서 신 구 차량 번호판의 형태학적 특성을 8방향 윤곽선 추적 알고리즘에 적용하여 잡음 영역을 제거하고, 차량의 번호판 영역을 추출한다 추출된 번호판 영역에 대하여 평균 이진화와 최대 최소 이진화를 적용하여 번호판의 개별 영역에 대한 형태학적 특성을 고려하여 잡음을 제거하고, Labeling 알고리즘을 적용하여 개별 문자를 추출한 후에 결합한다. 이렇게 분류된 개별 문자 및 숫자 코드를 ART2 알고리즘에 적용하여 학습 및 인식을 한다. 제안된 차량 번호판 추출 및 인식 방법의 성능을 평가하기 위해 녹색 번호판과 흰색 번호판 이미지 각각 100장을 대상으로 실험한 결과, 제시 된 차량 번호판 추출 및 인식 방법이 실험을 통해서 효율적인 것을 확인하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.413-417
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• 2007

2006년 11월 이후 신 차량 번호판 등장 후, 신 차량 번호판 차량이 꾸준히 증가하고 있다. 이에 따라 속도위반, 신호위반 단속, 무인 주차 관리 시스템, 범죄 및 도주 차량 검거, 고속도로 톨게이트에서 통행료 지불로 인한 교통 체증현상을 해소하기 위한 자동 요금 징수와 같은 다양한 경우에서 신 자동차 번호판의 특징에 맞는 인식 시스템이 요구되고 있다. 따라서 본 논문에서는 이러한 문제를 해결하기 위해 지능형 신 자동차 번호판 인식 방법을 제안한다. 무인 카메라에서 획득된 신 차량 영상을 그레이 레벨로 변환한 후에 블록 이진화한다. 블록 이진화된 차량 영상을 대상으로 차량의 형태학적 특징을 적용하여 잡음을 제거한 후, 번호판 영역을 추출한다. 추출된 번호판 영역에 대해 Grassfire 알고리즘을 적용하여 개별 코드를 추출한다. 차량 번호판을 인식하기 위하여 추출된 개별 코드를 퍼지 ART 알고리즘을 적용하여 학습 및 인식한다. 제안된 차량 번호판 추출 및 인식 방법의 성능을 평가하기 위해 100장의 차량 영상을 대상으로 실험한 결과, 제안된 차량 번호판 추출 및 인식 방법이 실험을 통해서 효율적인 것을 확인하였다.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1839-1850
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• 2009

The Korean railway system is a mass transit system in which a various types of trains such as common trains, high-speed train (KTX), Metropolitan Express Railway (EMU) are operated. It is operated based on a timetable and provides us with safety, regularity, quickness and comfortable service. The objective of this study is to propose a method for estimating line capacity considering high-speeding and diversification of trains. In particular, the focus of this study is on the closing gap between the result of the existing line capacity estimation method and the real-world line capacity of the operating agency of the Korean railway. For this, this study introduces a new railway capacity definition by considering TPS of line alignment according to the operation type, train control and signaling system, etc. The verification of the proposed method using a practical schedule diagram exemplification is discussed as well.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.3
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• pp.151-160
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• 2014

In this study, the effect of the automotive haptic-seat technology which can transmit the driving information by the vibro-stimulus from the seat was investigated to overcome previous system's limitation relied on the visual and audial method and to help handicap driving. A prototype haptic seat cover with 30 coin-type motors and driver module were developed for this sake. In an experiment of seat vibration stimulation being performed under virtual driving situation by targeting the elderly aged over 65 years old, average score of test subjects for total vibration recognition was 3.5/4 points and recognition rate of 87.5% was represented. In addition, a result that all the test subjects totally recognized overspeed warning signal of 4 times was represented. As a result of statistical analysis for vibration recognition score by each group depending on TMT score, a significant difference was not found and a result that tactile function of which vibration is recognized even by the aged whose visual, perceptional function is declined showed an equal ability was obtained.. In this study it was shown that the seat vibration stimulus could be used to transfer the old drivers' information while driving.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.4
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• pp.83-105
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• 2015

Taxi, one of the passenger services, is an essential transportation system in our society. In spite of the importance of taxi service, deterioration of the service quality is continuously reported. In particular, taxi service failures due to traffic accidents have emerged as the most serious social problem which may incur a considerable amount of social costs. In this study, we focus on analyzing the causes of service quality deterioration-traffic accidents of both corporately owned and privately owned taxies in Seoul. The research objective is to find out the determinants of service quality deterioration of Taxi industry and to suggest policies for improving the taxi service in Seoul. We collected the archival data from KTSA (Korea Transportation Safety Authority) and ODP (Open Data Portal), which span from 2005 to 2014. Hierarchical regression analyses and a set of mediation tests are conducted. The root factors inducing traffic accidents of taxies are divided into competitive, and profitability factors. The statistical results indicate that the accident ratio per taxi is not only affected by competitive/profitability factors such as number of active taxi drivers, number of bus passengers, and taxi fare, but also mediated by the traffic violation ratio. To alleviate the current problems with taxi service in Seoul, we conclude that the number of taxies be reduced and the taxi fare be increased. Finally, we suggest several policies to improve the endemic taxi industry problems, over-supply and the low profitability by enhancing the linkage between service quality and profitability.

• The Journal of the Korea Contents Association
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• v.16 no.12
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• pp.10-18
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• 2016

The cognitive ability of humans depends much on the vision. 'Vision' refers to the sense that receives stimulus of light through eyes. 'Gaze' refers to a function of a straight line that connects the central point of the pupil and a viewpoint in the external world, and, in general, it means a straight line that connects an object that is viewed and the eyes. There are active studies on the gaze in various academic circles including 'psychology' and 'cognitive linguistics.' As a method to objectively analyze the gaze, studies on 'eye tracking' are revitalized. A device for studies on eye tracking is an 'eye tracker.' As the fields of the study expand from development and analysis of Web pages to analysis of stores, methods of traffic signal processing, transport equipment, analysis of user experiences on image contents, and marketing analysis, there occurs a greater demand for a glasses eye-tracking than that for a fixed eye tracker. This study identifies the overview and characteristics of eye tracking and presents a way for spreading studies on eye tracking.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.1 s.35
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• pp.57-63
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• 2006

The purpose of this study is to correct data on 3 intersection ranging from Kwangchun INT. to Nongsung INT. by the means of VTR recording and site survey and to measure the responsiveness of performance index by diversifying the platoon dispersion factor in signal progression simulation. The results are as follows : 1. The value of platoon dispersion factor was 0.28-0.33. The value in up stream is lower than that of in down stream even on the same intersection. 2. The platoon index showed big changes, though performance index didn't according to platoon dispersion factor. Therefore the value of platoon dispersion factor which is inner variable in T7F can be fixed for 0.34. 3. There was only little divergence in performance index changes according to platoon dispersion factor in designing the progression or T7F model.

• Journal of the Korea Society for Simulation
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• v.20 no.1
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• pp.9-18
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• 2011

Recently, in the era of low carbon and green growth, the importance of railway transportation is being emphasized However, there is a lack of research on simulation for railway depot. This paper presents the development of the dynamic simulator for LRT(Light Rail Transit) depot. This study presents explanations of requirement analysis, architecture, database design, simulation algorithm, and design and development of the simulation tool. The dynamic LRT depot simulation tool consists of four modules; a Network Editor to create and modify information regarding railroad, train, signal, turnout, job and station, a Simulator to calculate train movement algorithm, a Reporter to show simulation results in table and graphs, and an Animator to animate simulation results dynamically. It is hoped that this study on general details of structure, design and development of LRT depot dynamic simulator will perform as a good reference to future development of new simulation tools.