• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.3
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• pp.292-299
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• 2022

In this paper, we proposed an automatic TOD synchronization and verification method for improving the performance of air-to-ground radio(hereafter SATURN) of legacy aircraft. In order to automatically synchronize TOD with SATURN radio, it is proposed to modify the GPS antenna installed in the existing aircraft according to the minimum operating performance standard. In addition, test methods and results are presented to verify the TOD information generation capability before and after the GPS antenna modifying. It is expected that the automatic TOD synchronization method proposed in this paper can be applied to the SATURN performance improvement design.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.2
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• pp.1-15
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• 2013

It is important to empirically investigate the typological characteristics of subway station areas considering the comprehensive elements of transit-oriented development (TOD) planning so that its implementation can be effective in attaining both increase in transit ridership and decrease in inordinate automobile dependence. This article aims to identify diverse features of subway station areas in Seoul known for good public transit system. After collecting and manipulating the measures on planning elements such as density, diversity and accessibility for TOD planning by distance-based buffer from a subway station, the article tried to interpret analysis results on their typological characteristics. They can be summarized with two conclusions. First, characteristics of landuse and public transit system can be distinctly differentiated in the Seoul subway station areas. It implies that both planning elements should have not been integrated for now. Second, the characteristics of public transit system can be divided by modes. They provide us that public transit system in Seoul needs to be more strongly integrated than current system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.81-92
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• 2023

Traffic state classification is crucial for time-of-day (TOD) traffic signal control. This paper proposed a traffic state classification technique applying Deep-Embedded Clustering (DEC) method that uses a high dimensional traffic data observed at all signalized intersections in a traffic signal control sub area (SA). So far, signal timing plan has been determined based on the traffic data observed at the critical intersection in SA. The current method has a limitation that it cannot consider a comprehensive traffic situation in SA. The proposed method alleviates the curse of dimensionality and turns out to overcome the shortcomings of the current signal timing plan.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.179-187
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• 2009

This study develops a real-time signal control algorithm based on sectional travel times and includes a field test and evaluation. The objective function of the signal control algorithm is the equalization of delay of traffic movements, and the main process is calculating dissolved time of the queue and delay using the sectional travel time and detection time of individual vehicles. Then this algorithm calculates the delay variation and a targeted red time and calculates the length of the cycle and phase. A progression factor from the US HCM was applied as a method to consider the effect of coordinating the delay calculation, and this algorithm uses the average delay and detection time of probe vehicles, which were collected during the accumulated cycle for a stabile signal control. As a result of the field test and evaluation through the application of the traffic signal control algorithm on four consecutive intersections at 400m intervals, reduction of delay and an equalization effect of delay against TOD control were confirmed using the standard deviation of delay by traffic movements. This study was conducted to develop a real-time traffic signal control algorithm based on sectional travel time, using general-purpose traffic information detectors. With the current practice of disseminating ubiquitous technology, the aim of this study was a fundamental change of the traffic signal control method.

• Journal of Korean Society of Transportation
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• v.22 no.5
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• pp.19-33
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• 2004

신호교차로 운영 최적화를 위한 4가지 변수인 주기, 현시순서, 현시녹색시간, 옵셋 중에서 지금 지 정형화된 지침이 없이 전문가의 경험이나 휴리스틱한 규칙(Heuristic rule)에 의해 결정되었던 현시순서에 대해 다양한 교통조건을 고려하여 최적현시와 지체변화를 분석하였다. 교통조건은 독립/연동교차로, 교차로 기하구조, 비혼잡/혼잡상태, 통과교통량에 대한 좌회전 교통량비(LT/Thru)에 따라 Dual ring에서 구현가능한 모든 현시순서를 대상으로 최적현시를 도출하였다. 분석과정에서 비혼잡상태의 경우 LT/Thru가 작을수록 직진 중첩 동시신호가 가장 우수하게 나왔으며, LT/Thru가 크게 증가할수록 선행양방향좌회전이 양호하게 나타났다. 혼잡상태의 경우는 LT/Thru 15%에서 공통적으로 최적현시가 변하였는데 이는 포화도와 이동류별 녹색시간비율이 크게 변하면서 급작스런 주기 증가에 기인한 것으로 판단되었다. 또한 독립교차로 및 연동교차로 현시순서 분석 결과를 보면 전반적으로 선행양방좌회전 현시와 직진 중첩 동시신호 현시가 가장 양호한 것으로 나타났으며, 양방 동시신호 현시는 대체로 지체가 높게 나타나 신호운영에 비효율적인 것을 다시 한번 입증하게 되었다. 특히 연동교차로에서는 연동에 중요한 요소인 옵셋과 진행대폭(bandwidth)의 상호관계를 탄력적으로 대응할 수 있는 직진 중첩 동시신호가 최적현시로 나타났다. 본 연구는 검지기가 설치되지 않은 고정식 신호기로 운영되는 지방부 및 도시 가로망의 교통류 효율성을 높이는 중요한 자료로 사용될 것으로 판단된다. 최근에는 실시간 교통신호 제어시스템이 활발히 연구. 운영되고 있는데 이 시스템 내에 포함되어 있는 TOD방식의 고정시간 제어(pretimed control)나 패턴선택제어(pattern selection control)에도 충분히 활용할 수 있을 것으로 사료된다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.3
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• pp.52-63
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• 2009

Recently in Korea, in the case of metropolis, the urban signalized intersections are controlled by traffic information center or ITS center. Cheon-an City also established traffic information center through the 1st.-$\sim$3rd. ITS public construction and has managed this center that includes bus information service, traffic information collection and providing service, parking information service, and traffic responsive control system. In the Cheon-an metropolitan traffic signal operation, traffic signal controllers were grouped by the each main traffic flow axes and performed with coordinated signal timing for the signalized arterials, and also cycle and split changed by realtime traffic demands. Cheon-an urban traffic responsive control system was evaluated by intersection delay and speed, then it was verified that the delay decreased and vehicle speed improved. However, the rural signal control system to connect adjacency town was evaluated to have lower status than urban area due to the unimproved TOD (Time of day) plan. Therefore actuated signal control was examined for substitutive control system in isolated signal intersection. The aim of this article is to compare actuated signal control with TOD mode in the rural intersection of Cheon-an and to fine superiority of these two control mode, with evaluation of vehicle delay by using HCM(2000) method and by micro-simulation CORSlM. The result of field test show that actuated signal control gave better performance in delay comparison than the existing TOD signal control. And simulation outcome verified that non-optimized TOD has higher delay than optimized TOD mode, non-optimal actuated mode, and optimal actuated signal control mode. Particularly, these three modes delays had not different values according to the paired sample t-test. This is because small traffic demands were loaded in each links. This suggested actuated signal control is expected to be more effective than TOD mode in some rural isolated intersections which frequently need to survey for traffic volume.