• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.144-145
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• 2023

육상, 철도, 항공 등 타 교통분야에서 지속적으로 사고와 인명피해가 줄어든 반면, 해양분야는 해양사고가 증가하며 실효적 해양교통안전관리에 대한 필요성이 대두되고 있다. 최근 3년간 국내 해상에서 발생한 충돌사고 중 어선을 포함한 충돌사고가 전체의 약 84%를 차지하며, 해상교통의 주요 변수인 어선을 포함한 국가의 해상교통량 파악은 반드시 필요한 실정이다. 본 연구에서는 현 정부 국정과제인 '디지털 해상 교통망 구축'과 더불어 해양교통안전관리체계 마련의 일환으로 국내 전체 선박위치발신장치(AIS, V-PASS) 데이터를 활용하여 해상교통량을 분석하고 예측 모델을 개발한다. 이를 위해 선박 밀집도를 통한 그리드별 공간가산분석과 항적 데이터 전처리 및 선형화, 선박 길이에 따른 점용면적 산정을 통한 단위 그리드별 해상교통량을 분석한다. 또한, 과거 교통량 데이터는 딥러닝 기반의 시계열 특성을 지닌 RNN과 LSTM 모델을 활용하여 교통량 예측 모형을 개발한다. 본 연구의 결과는 해상교통량과 해양사고의 연관성 분석 및 속력제한구역 등 해상정책 수립의 정량적 근거를 제공하며, 국민에게 해상교통정보 제공을 통해 교통복지 증진에 기여할 수 있다.

• Journal of Korean Society of Transportation
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• v.25 no.3
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• pp.87-97
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• 2007

This paper proposes drivers' rational belief formation under a bounded traffic environment. This is to escape the criticism that excessive rationality (e.g., a driver's calculating ability and memory capacity) is required of drivers. Under bounded traffic environments. drivers do not have structural knowledge of traffic conditions and others' decisions. Simulations are carried out using a program coded in C. Consequently, the author found the learning process of drivers and the value of information can be differentiated by route conditions and the characteristics of driver groups. Also, it was found that rational drivers form different beliefs about traffic conditions even though they have the same traffic environment in a bounded traffic environment.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.217-228
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• 2009

Sections under the influence of merging in an uninterrupted facility create irregular interaction between vehicles, such as lane change, speed acceleration and deceleration because of the merging of ramp traffic flows which have traffic characteristics different from those of the main line. This causes a confused traffic flow phenomenon(turbulence), which is considered an unstable traffic characteristic between various continuous points in consideration of v conditions. In this study, in merge influence sections, detectors by lane-point were installed to create time and space-series -traffic data. The least significant difference(LSD), as the criteria for discriminating a significant speed change between points, was calculated to examine the turbulence. As a result, turbulence in merge influence section was found to change the zones of such occurrence and the seriousness levels according to traffic condition. Thus, the maximum merge influence section due to the turbulence was created in the traffic condition before congestion when traffic increases. According to characteristics of changes in speed, merge influence section was divided into upstream 100m$\sim$downstream 100m(a section of speed reduction), and downstream 100m$\sim$downstream 400m(a section of reduced speed maintenance and acceleration).

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.19-30
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• 2010

It has become important to have some proper guidelines of how to provide public transport information services in response to the rapid IT developments and the wide spread of public information services. The current study takes a contextual approach to the analysis of public transportation information use under a dynamic decision situation, complementing the conventional cross-sectional approaches. Using the CHAID of decision tree induction based on decision table formalism applied to the survey data of activity travel and information use, the study found that the information type and medium choices are strongly affected by the decision contexts in addition to the individuals' socio-demographic characteristics. The results suggest an important implication to the market segmentation of information services for public transportation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.501-506
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• 2015

This study seeks to analyze ships traffic characteristics according to water time in order to provide the necessary data for efficient traffic management development. To analyze maritime traffic volume according to water time, 1 year amount of solar calendar data were converted into lunar calendar, and then applied the traditional water time system of West Sea by using AIS(Automatic Identification System) observation data gathered in Mokpo port for a year of 2013. As a result, it was found herein that the number of outbound ships was larger on the $2^{nd}-3^{nd}$ water times than the $7^{th}$ water times by 23-24 %. And the number of inbound ships was higher on the $12^{th}-13^{th}$ water times than the $9^{th}$ water time by 29-33 %. The hourly variation index of inbound and outbound ships according to time, in particular, was found to change in the form of sine function model. This study is expected to serve as a necessary basic material for development of maritime traffic management according to water time.

• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.31-40
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• 1998

본 연구의 목적은 기존의 Cell Transmission(1994, Daganzo) 교통류 이론을 기반으로 동적통행배정 모형을 개발하는 것이다. 이 모형은 동적 O-D 발생모듈, HOV 차선모듈, 분류부 분할모델, 링크비용함수 모듈, 최단경로 탐색 모듈등으로 구성된다. 이 모델에서 적용하는 교통류 모델은 각 링크를 동일한 특성을 가지는 셀로 구분하여 셀내의 진입시간과 진출시간을 계산하여 링크비용을 계산하는데 이것은 비용의 과대·과소 추정을 피할 수 있으며 교통지체 현상을 현실적으로 표현해 줄 수 있는 장점이 있다. 또한 HOV 차선 모듈에 의해 수단별 교통류 진행 및 비용고려가 가능하며 HOV 차선의 평가 및 분석이 가능하다. 기존의 동적통행배정모형은 매 시간대별 출발지에서 균형상태를 추구하는 통행배정기법을 사용하고 있지만 이 모델은 분류되는 노드를 가상의 출발점이라고 가정하여 각 시간대별로 최단경로를 탐색하여 균형상태를 추구해나가는 기법을 적용하고 있다. 각 셀별 차량을 목적지별, 차종별, 대기시간별로 추적하여 진행시키며 분류부에서는 최단경로를 탐색하여 배분된다. 또한 진행하고자 하는 셀의 용량과 현재 셀의 밀도를 고려함으로서 용량제약 하에서의 동적통행배정모형을 적용하고 있다. 이 모형은 고속로의 합류부 및 분류부의 교통특성을 세밀히 분석할 수 있으며, TCS 및 램프미터링과 접목하여 고속도로 운영에 이용될 수 있으며, 고속도로 중·장기적인 계획에 이용될 수 있다.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.77-86
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• 2004

In this study, we applied the Bayesian Network for the case of the mode choice models using the Seoul metropolitan area's house trip survey Data. Sex and age were used lot the independent variables for the explanation or the mode choice, and the relationships between the mode choice and the travellers' social characteristics were identified by the Bayesian Network. Furthermore, trip and mode's characteristics such as time and fare were also used for independent variables and the mode choice models were developed. It was found that the Bayesian Network were useful tool to overcome the problems which were in the traditional mode choice models. In particular, the various transport policies could be evaluated in the very short time by the established relation-ships. It is expected that the Bayesian Network will be utilized as the important tools for the transport analysis.

• Journal of Korean Society of Transportation
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• v.28 no.2
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• pp.33-43
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• 2010

The objective of this paper is to analyze expenditure structures and impact factors of household's transportation cost in order to provide policy-maker with quantitative and economic information for reducing household's transportation costs, using 1995-2007 household survey data. For this purpose, this study performed various economic analysis, including econometric regression analysis and income re-distributional effects. The four models were separately estimated with dependent variable (personal and public costs, public transit and private car costs) and independent variables (family, employ, age, education, cars, household income, region dummy variable). In addition, We analyzes impacts of transport policy instruments on the transportation expenditure. These instruments include changes of oil price and public transit fare, reform of public transport system, and extension of subway facilities. Finally, income re-distributional effects before and after transportation expenditure, using Pechman-Okner (PO) index and Wolfson index.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.6
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• pp.761-767
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• 2012

Maritime traffic assessment is important to understand the characteristics of maritime traffic and to prevent maritime accidents. The maritime traffic assessment can be calculated from the ship trajectory data observed by using AIS(Automatic Identification System). This paper developes a maritime traffic assessment tool using ship's position and speed, course, time data from ships navigating waterways. The results are represented in terms of the number of traffic quantity and traffic distribution, speed distribution, geometric collision candidates. The developed tool will contributes to advance maritime traffic safety by VTS(Vessel Traffic Services).

• Journal of Korean Society of Transportation
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• v.2 no.1
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• pp.103-119
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• 1984

복잡다기해지는 도시교통문제를 효율적으로 대처하려면 제도시교통정책에 의한 교 통분담율효과를 사전에 추정할 수 있어야 한다. 단기간의 교통분담율효과를 추정하는데 미 국 및 구라파 등지에서 널리 이용되고 있는 모형이 개별교통모형(Disaggregate Travel Demand Model)이다. 본 연구의 목적은 로짓모형(Multinomial Logit Model)을 서울시의 종 로축을 이용하는 출근통행자를 대상으로 실시한 조사결과에 적용하여 매개함수(Parameters) 를 추정함에 있다. 조사는 1980년7월5일부터 7월15일까지 10일간 종로축을 이용하는 통행자 536명에게 실시되었다. 조사실시전 서울시의 교통체계의 특성과 통행자의 행태를 면밀히 분 석하여 적합한 변수를 선정하였다. 여러 가지로 변수와 표본의 변형을 시도한 결과 교통비 용을 소득으로 나눈 변수와 시기시간(OVTT)을 거리로 나눈 변수를 포함한 모형이 가장 논 리적인 것으로 나타났다. 한편 표본은 고소득층과 저소득층으로 구분하여 추정한 모형이 비 교적 만족스러운 결과를 나타내었다. 이는 우리나라 대도시의 경우 소득계층에 따라 교통수 단선택범위가 한정되기 때문이다. 마지막으로 고소득층과 저소득층의 시간가치를 각각 산정 하였는바, 이는 교통시간의 매개변수와 교통비용의 매개변수를 나눔으로서 구해질 수 있다. 시간가치는 고소득층은 910원 저소득층은 582원으로 각각 산출되었다.