• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 춘계학술대회 논문집
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• pp.218-225
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• 2000

Recently, right rail transit (L.R.T.) systems become influential as a new traffic system in urban area to solve heavy traffic problems. However, there are little research results about the dynamic interaction problems between the vehicle and structural system, even though some studies far those static problems have been carried out. Therefore, first of ail, the dynamic equations of an interaction between vehicle system and surface roughness of the vehicle path are derived before developing the dynamic equations of vehicle-structure-surface roughness system, in this study. As a vehicle model, an automated guide-way transit (A.G.T.) system is adopted. Parametric study shows that the dynamic wheel loads of the vehicle system has a tendency to increase with vehicle speeds and stiffness of suspension system. However, those dynamic wheel loads have tendencies to decrease in according to loads of the vehicle system.

• 한국콘텐츠학회논문지
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• 제4권4호
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• pp.33-43
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• 2004

본 논문에서는 기존 SNMP를 이용한 트래픽 분석 방법의 문제점을 개선시킨 SNMP 기반의 트래픽 추이 분석 알고리즘을 제안하였다. 기존 방법에서는 임계치를 적용함으로써 분석 시간이 많이 걸리며, 초기 공격 트래픽에 대해 탐지하지 못하는 취약점을 가지고 있었다. 본 논문에서는 임계치를 사용하지 않고 일주 트래픽 추이 분석, 프로토콜별 추이 분석 그리고 특정 MIB에서의 트래픽 발생 유무를 분석함으로써 기존 방법에서의 문제점을 해결할 수 있었다. 트래픽이 발생하게 되면 이 세 가지 분석 방법을 통해 이상 여부를 분석하고, 이상 트래픽이 중첩적으로 발생될 경우 현재 입력된 트래픽을 유해 트래픽으로 분석해 낼 수 있다. 제안한 알고리즘을 통해서 유해 트래픽을 빠르고 정확하게 분석해 낼 수 있으며, 이를 통해 트래픽 폭주 공격에 의한 피해를 줄일 수 있을 것이다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.2166-2178
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• 2010

현재 철도계획에 이용되고 있는 교통수요예측 지역간기종점(OD)자료는 국가교통데이타베이스(KTDB)를 이용하고 있다. KTDB의 자료는 우리나라 지역간 총통행량을 조사한 후 도로, 철도, 항공등으로 배분하는 방법을 이용하고 하고 있다. 그러나 철도의 경우는 철도역이 기존의 존과 일치하지 않거나 1개존에 다수의 철도역이 존재하여 Connector가 연결되지 않아 적용 방법상에 문제점이 있는 것으로 나타났다. 이로 인해 KTDB를 이용한 철도부분의 교통예측은 다른 교통수단에 비해 신뢰성이 크게 떨어지고 있다. 본 연구는 이러한 문제점을 검토 분석하고, 신뢰성을 높이기 위해 집계모형(Aggregate Model) 기법을 활용한 철도의 교통수요예측 방법(직접수요추정 : Direct Demand Estimation)을 제안하였다. 본 연구에서는 집계모형에 지역간의 인구, 거리, 산업체종사자수, 자동차대수, 도로연장등 사회경제지표의 연관성을 분석하여 철도분야 수요예측의 오차를 최소화할 수 있는 방법을 연구하였다.

• 한국정보과학회논문지:정보통신
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• 제32권2호
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• pp.134-146
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• 2005

Ad-Hoc Network의 실용화에 대한 기대가 커짐에 따라 다양한 응용의 안정적인 서비스를 위해 005의 지원을 위한 연구가 필요하게 되었다. Ad-Hoc Network에서 005를 지원하기 위한 기존의 연구들은 정량적인 서비스를 보장하기 어렵거나, 네트워크 오버헤드를 발생시키는 문제점을 가지고 있었다. 본 논문에서는 이러한 문제를 해결하기 위해 새로운 QFAN(QoS Framework for Ad-hoc Networks)을 제안한다. 본 논문에서 제안하는 QFAN은 네트워크 오버헤드를 최소화하면서 실시간 트래픽의 최소 대역폭을 보장할 수 있다 그리고 실시간 트래픽과 최선형 트래픽간의 잉여 대역폭에 대한 공정분배를 통해 대역폭 불균형 문제를 해결할 수 있다. 제안된 프레임웍을 실제 적용하기 위해서 TiRe(Tiny Reservation)과 ADR(Adaptive Drop Rate) 컨트롤 알고리즘을 설계하였다. 시뮬레이션을 통해 실시간 트래픽의 최소 요구 대역폭을 만족시키면서, 실시간 트래픽과 최선형 트래픽이 잉여 대역폭을 공정 분배하는 것을 확인 할 수 있었다.

• 한국경영과학회지
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• 제40권4호
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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.

• 대한교통학회:학술대회논문집
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• 대한교통학회 1999년도 제36회 학술발표회논문집
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• pp.47-52
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• 1999

The methods currently in use to evaluate traffic impacts on the transportation network involve some fundamental shortcomings. First, the methodss do not properly take into account regional and local traffic impacts on the transportation network simultaneously. Second, temporal distribution of traffic, a major contributor to transportation problems, is not accurately accounted for. Third, traffic impact studies require costly and labor-intensive efforts to collect necessary data and to establish to collect necessary data and to establish traffic impact models. In this research, a new method called AMIS is developed for congestion management, access control, and impact simulation to overcome the shortcomings involved in the current methods. The new method is designed for a variety of scenarios such as access management strategies, land use policies, traffic impacts, and other congestion management strategies. This method can effectively be used, with little modification, anywhere in the United States. It is an improvement over the current traffic impact simulation methods that produces more reliable and accurate traffic impact estimates. The case studies conducted in this research have offered evidence that the new method, AMIS, is a credible congestion management tool. Most importantly, a case study presented in this paper illustrates how the new method can be used not only to estimate regional and local impacts of alternate supply management policies in the course of a day, but virtually on an hour-by-hour basis.

• 한국항행학회논문지
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• 제18권2호
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• pp.114-120
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• 2014

본 논문에서는 비행장 관제 시뮬레이터 구현을 위해 필요한 사항을 살펴본다. 비행단계 중 비행장에서의 이착륙 단계는 항공 안전관리 측면에서 매우 중요시 다루어져야 한다. 그 이유는 전 세계 항공기 사고 및 준사고의 60%이상이이 단계에서 발생하는 것으로 조사되기 때문이다. 본 논문에서 항공교통관제 시뮬레이터의 평가 기준인 실습 유형, 장비 형태, 그리고 현실성의 충실도를 통하여 국내 항공교통관제 시뮬레이터의 구현 단계를 평가하고, 현업에 종사하는 항공교통관제사의 설문을 통해 현재 운용 중인 시뮬레이터의 문제점을 검토하여 그 해결방안을 살펴보았다. 또한 이를 바탕으로 개선된 HI-FI 항공교통관제 시뮬레이터의 구현 방향을 제시하고자 하였다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 가을 학술발표논문집 Vol.30 No.2 (3)
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• pp.49-51
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• 2003

Developers of network games have used several prediction techniques for hiding transmission delay to support the real­time requirement of network games. Nowadays many researches that are related with network game are in progress to solve delay problems more radically, such as to propose new routers architecture and transport protocols suitable to characteristics of network game traffic. So for these advanced researches the tasks to grasp the traffic characteristics of a network game are needed. In this paper we aimed to capture the traffic of MMORPG and present the statistical analysis of measured data. The measurement and the analysis were accomplished with the server of 'Lineage' that regarded as the most successful MMORPG. Next, we have implemented a traffic generator that reflects the characteristics of MMORPG and shown that the trace generated by MMORPG traffic generator had identical characteristics with actual traffic using statistical testing method. We expect that this traffic generator can be used in many researches related with a network game.

• Journal of Information Technology Applications and Management
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• 제24권4호
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• pp.187-196
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• 2017

It is urgent to prepare countermeasures for traffic congestion problems of Korea's metropolitan area where central functions such as economic, social, cultural, and education are excessively concentrated. Most users of public transportation in metropolitan areas including Seoul use the traffic cards. If various information is extracted from traffic big data produced by the traffic cards, they can provide basic data for transport policies, land usages, or facility plans. Therefore, in this study, we extract valuable information such as the subway passengers' frequent travel patterns from the big traffic data provided by the Seoul Metropolitan Government Big Data Campus. For this, we use a Hadoop (High-Availability Distributed Object-Oriented Platform) to preprocess the big data and store it into a Mongo database in order to analyze it by a sequential pattern data mining technique. Since we analysis the actual big data, that is, the traffic cards' data provided by the Seoul Metropolitan Government Big Data Campus, the analyzed results can be used as an important referenced data when the Seoul government makes a plan about the metropolitan traffic policies.

• 공학교육연구
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• 제13권5호
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• pp.20-24
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• 2010

The total number of deaths by traffic accidents is decreasing every year in our country. However, in 2009, children died in traffic accidents at a rate of 2.3 deaths per 100,000 children, which was higher than the average of OECD countries (1.9 deaths per 100,000 children). In particular, traffic accidents are showing rapid increase in school zone during the past 2 years because of problems in the designation and management of school zone. Traffic safety facilities such as road sign, reflector mirror, speed bump have the ultimate limit of vehicle accidents prevention. Thus, in school zone, children safety is still not guaranteed due to illegal parking and the absence of driver's awareness of safety. Therefore, In order to protect children from traffic accidents within school zones, we have realized a safe school zone system, which enables the drivers to better know the intended school zones and creates pedestrian environment through unmanned monitoring camera, using LabVIEW.