• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.87-93
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• 2004

A five-day work week has a great impact on the life styles of employed persons and their families. At the same time, the changes also impact on the transportation system because travel patterns, demand, and pattern of congestion change during weekends. The negative impacts on the transportation system should be examined in order to conceive measures to maintain dependable levels of service during weekends. The first step to pursue the issue is to identify the road segments heavily affected by augmented leisure trips. In this study, characteristics of highway segments are engineered by principal analysis using data from TCS database. Scores from principal analysis are employed to distinguish highway segments for leisure trips from total 197 segments considered in this study. In addition, indexes from principal analysis are proposed to identify highway segments for leisure trips.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.188-196
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• 2023

Among marine accidents caused by bad weather, visibility restrictions caused by sea fog occurrence cause accidents such as ship strand and ship bottom damage, and at the same time involve casualties caused by accidents, which continue to occur every year. In addition, low visibility at sea is emerging as a social problem such as causing considerable inconvenience to islanders in using transportation as passenger ships are collectively delayed and controlled even if there are local differences between regions. Moreover, such measures are becoming more problematic as they cannot objectively quantify them due to regional deviations or different criteria for judging observations from person to person. Currently, the VTS of each port controls the operation of the ship if the visibility distance is less than 1km, and in this case, there is a limit to the evaluation of objective data collection to the extent that the visibility of sea fog depends on the visibility meter or visual observation. The government is building a marine weather signal sign and sea fog observation networks for sea fog detection and prediction as part of solving these obstacles to marine traffic safety, but the system for observing locally occurring sea fog is in a very insufficient practical situation. Accordingly, this paper examines domestic and foreign policy trends to solve social problems caused by low visibility at sea and provides basic data on the need for government support to ensure maritime traffic safety due to sea fog by factually investigating and analyzing social problems. Also, this aims to establish a more stable maritime traffic operation system by blocking marine safety risks that may ultimately arise from sea fog in advance.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.4
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• pp.81-99
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• 2020

Origin-destination data have been collected and utilized for demand analysis and service design in various fields such as public transportation and traffic operation. As the utilization of big data becomes important, there are increasing needs to store raw origin-destination data for big data analysis. However, it is not practical to store and analyze the raw data for a long period of time since the size of the data increases by the power of the number of the collection points. To overcome this storage limitation and long-period pattern analysis, this study proposes a methodology for compression and origin-destination data analysis with the compressed data. The proposed methodology is applied to public transit data of Sejong and Seoul. We first measure the reconstruction error and the data size for each truncated matrix. Then, to determine a range of principal components for removing random data, we measure the level of the regularity based on covariance coefficients of the demand data reconstructed with each range of principal components. Based on the distribution of the covariance coefficients, we found the range of principal components that covers the regular demand. The ranges are determined as 1~60 and 1~80 for Sejong and Seoul respectively.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.1
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• pp.33-41
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• 2012

BIS is an arrival guidance system which is able to supply passengers with bus service condition via Kiosks at a bus stop, internet and mobile service through pinpointing bus location in real time. It is very significant to improve the quality of traffic information by quality control of GIS-based bus network so as to maintain navigational information and to implement reliable BIS. Therefore this study aims to build criteria to quantitatively evaluate data quality of the product in accordance with the process in bus network data and to suggest guideline of quality control. To achieve this, we have categorized geometric and logical errors occurring during constructing bus network database by giving a specific case study on TAGO and set up sectional guideline and procedures to examine database for systematic and coherent quality control management. Proceeding from what has been said above, the outcome of our research leads to quality guarantee for objective and reliable bus network database and is fully expected to bring benefit of providing a more accurate public transportation information and improving reliability of BIS through preventing a variety of errors in system operation in advance.

• Proceedings of the KOR-KST Conference
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• 1998.10b
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• pp.508-508
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• 1998

위험물 차량사고는 일반차량의 교통사고시 발생하는 인명피해, 재산피해, 교통지체 외에 부가적으로 환경적 영향에 의한 엄청난 인명 및 재산손실을 유발시킬 수 있다. 따라서 이러한 위험물차량사고를 예방하고 피해를 최소로 줄이기 위해서는 위험물수송경로의 신중하고 체계적인 결정이 필수적이라 할 수 있다. 외국의 경우, 위험물의 방출이 미치는 환경적 영향에 대한 인식이 확대되면서 위험물 수송시 응급처리에 관한 연구, 위험물 수송에 따른 위험도 평가에 관한 연구, 위험물 수송시 고려해야할 여러 조건에 관한 연구, 위험물 수송경로 설정에 관한 연구 등이 진행되고 있다. 반면에 우리 나라는 위험물차량관리와 사고처리에 대해 실시간적인 관리를 목표로 하는 국가차원의 계획을 수립하고는 있지만, 현재 이와 관련된 연구는 거의 없는 실정이다. 앞으로 산업발달에 따른 위험물수송량의 증가와 환경의식의 변화에 따라 위험물수송 및 사고처리 등에 관한 연구가 필요할 것이다. 따라서, 본 연구는 위험물차량의 운송경로를 결정할 때 고려해야 할 여러 가지의 기준 및 목표에 따라 위험물수송경로를 설정하는 모형을 제시함으로써 위험물수송에 수반되는 위험을 최소화하면서 위험물차량의 통행시간, 거리, 비용 등을 최적화하여 위험물수송의 안전 및 운영효율성을 향상시키고자 한다. 먼저, 위험물 수송경로의 기준지표로 사용될 위험도를 산정하기 위해 링크 주변노출인구, 밀도 등을 변수로 하는 모형식을 제안하고, 두 번째로 산정된 위험도를 기반으로 최적경로를 결정하는 알고리즘을 제안하였다. 마지막으로 가상 네트웍에 본 연구에서 제안된 모형을 적용하고 현재 일반적으로 사용되는 최단경로와 비교·분석하였다.것은 운송거리와 운송비용이 각각 주요한 변수라는 것이다. 모형의 타당성을 검증하기 위해서는 logilikelihood 값을 구하여 $\rho$^2분석을 시행하였다. 여기서는 각 품목별로 $\rho$^2값이 약 0.15~0.3의 비교적 높은 수치를 보여주고 있으므로 모형의 설명력이 어느 정도 있다는 것이 아울러 증명이 되었다. 상관관계에 대한 분석에서는 영업용 차량간의 상관관계가 높게 나타났으며, 이는 곧 영업용 화물차량을 적재중량별로 구분하는 것이 별 의미가 없음을 의미한다. 다시 말하면 자가용 차량을 보유하고 있지 않은 회사는 다른 운송전문업체에 화물운송을 의뢰하게 되므로 출하중량에 따라 화물차량을 구분하는 것에 대해서 그다지 큰 고려를 하지 않는 것으로 해석할 수가 있다.적합함을 재확인함. 6. 혼잡초기를 제외한 혼잡기간 중 대기행렬길이는 밀도데이터 없이도 혼잡 상류부의 도착교통량과 병목지점 본선통과교통량만을 이용하여 추정이 가능함. 7. 이상에 연구한 결과를 토대로, 고속도로 대기행렬길이를 산정할 수 있는 기초적인 도형을 제시함.벌레를 대상으로 처리한 Phenthoate EC가 96.38%의 방제가로 약효가 가장 우수하였고 3월중순 및 4월중순 월동후 암컷을 대상으로 처리한 Machine oil, Phenthoate EC 및 Trichlorfon WP는 비교적 약효가 낮았다.>$^{\circ}$E/$\leq$30$^{\circ}$NW 단열군이 연구지역 내에서 지하수 유동성이 가장 높은 단열군으로 추정된다. 이러한 사실은 3개 시추공을 대상으로 실시한 시추공 내 물리검층과 정압

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.6
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• pp.15-22
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• 2012

A performance index of singalized intersections is a standard to optimize signal control variables and to manage traffic flow. Traffic delays is generally used to minimize the average delay time on intersections or networks, progression efficiency is used to improve travel speed of main cooridors or to provide transit signal priority. We manage traffic flows with only selecting one index between delays and progression according to the objective of traffic management and field characteristics. In real field, the driver's satisfaction is high in any performance criteria when the waiting time is shorter and the unnecessary stop in front of traffic is smaller. This paper aims to develop simulation model to represent real progression with concurrently considering delays and progression. In order to reflect an effect of level of traffic volumes and residual queues which don't be considered in prior progression model, we apply shockwave model with flow-density diagram. We derive Cell Transmission Model of Daganzo in order to develop the delay index and the progression index for the macroscopic simulation model. In order to validate the effect, we analysis traffic delays and progression efficiency with comparing this model to Transyt-7F and PASSER V.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.713-716
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• 2003

현재 국내 LBS 가 중요한 서비스로 널리 확산되기 위해서는 서비스간의 상호운용성이 제공되어야 한다. 본 논문에서는 LBS 서비스간 상호운용성을 제공하는 개방형 LBS 를 위한 경로탐색 서비스에 대한 설계 및 구현기법을 제시한다. 최단경로문제(Shortest Path Problem)는 통신망 및 교통망의 분석, 생산라인의 품질 관리 등의 다양한 분야 등의 네트워크 흐름 최적화 문제 중에서 가장 많이 연구되고 있는 문제다. 도로 교통망에서는 교차로상에서의 회전 제약 문제 등의 제한조건이 존재한다. 본 논문에서 경로탐색은 듀얼 그래프(dual graph)를 이용하여 회전제약조건을 만족하는 경로를 구할 수 있었고, 사용자 경로탐색 기준에 따른 탐색기법도 제시한다. 또한, 구현된 서비스는OpenLS의 표준화된 인터페이스를 구현하여 상호운용성(interoperability)을 지원하며, 자바를 이용한 웹서비스로 구현되어 이식성, 운영체제 및 프로그래밍 언어 독립성을 제공할 수 있는 장점이 있다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.486-489
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• 2006

현대 생활에 있어서 정확한 시간은 마치 공기와 같이 필요성이 직접적으로 확연하게 나타나지는 않지만, 첨단 통신, 항법, 금융 등의 산업 발전 및 국민의 일상 생활을 차질 없이 영위하기 위해서 없어서는 안 될 중요한 요소 중 하나이다. 광범위한 시각동기 응용 분야 중에서 본 논문에서는 특히 국민의 일상 생활과 밀접한 관계가 있는 수 ms 정도의 정확도를 갖는 타이밍 신호를 전국에 제공하기 위한 방안에 대해서 기술한다. 이러한 타이밍 신호의 응용 분야로는 열차, 지하철, 버스시간과 같이 수 초 정도의 정확도가 요구되는 경우, 인터넷통신 및 금융 거래와 같이 1초 이하의 정확도를 요구하는 경우, 교통 신호등과 같은 수백 ms 이내의 정확도가 요구되는 경우 등을 들 수 있다. 본 논문에서는 전파시계, 교통신호제어기, 전자상거래 등에서 요구되는 기준 시각을 제공하기 위한 방안 중 하나로 현재 해양수산부에서 운영하고 있는 NDGPS 비콘신호를 활용하여 전국적인 표준시의 방송 방안에 대해서 기술한다. 이를 위해서 유선전화망을 이용하여 표준시를 전송하는 방안, 수신된 표준시를 이용하여 방송할 타임태그를 작성하는 방법에 대해서 기술하였다. 또한 원격지 클럭에 대한 동기 성능을 분석하는 방법 및 이에 대한 결과를 제시하였다.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.536-543
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• 2018

In 2003, the local police system was adopted, and the personnel and installation of local police agencies were subsequently changed. According to the "Police Law", local police station shall be established under the control of chief of police department, and the criteria for the installation of local police stations were to take into consideration of population, administrative districts, area, geographical characteristics, traffic and other conditions. The chief of local police has the authority to install district police station according to the "National Police Agency and its Organization". However, it is hard to say they were applied. Futhermore, it is inappropriate to apply the laws and regulations equally across the nation. Also, it has been criticized for its difficulties of patrolling, the weakened relationship with local residents, and poor quality of security services in rural areas. Therefore, this study suggests that the criteria for the installation of the police station should be made through a comprehensive analysis of the characteristics of the areas and security needs.

• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.123-133
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• 2007

This study analyzed whether a transit network with hierarchy is efficient or not, and if transit network hierarchy has cost efficiency, then which condition guarantees the efficiency of the transit network hierarchy. The authors modeled the total cost of the transit network and suggested the conditions in which the transit network hierarchy has cost efficiency through comparing the cost of the transit network with and without hierarchy. The efficiency of transit network hierarchy is guaranteed when the travel cost savings induced by using a higher hierarchy transit network is larger than the increasing non-travel cost, which is the sum of access cost, waiting cost, and operating cost, induced by the introduction of a higher hierarchy transit network. This result is consistent with common sense and with the concept of cost and benefit analysis. If a passenger traveling within the area divided by a higher hierarchy transit network uses only a lower hierarchy transit network and the passenger traveling out of the area divided by the higher hierarchy transit network uses both lower and higher hierarchy transit networks, the travel demand using the higher hierarchy transit network is inversely proportional to the square of the line spacing. This means that the transit network becomes more efficient and small increases of travel demand guarantee the efficiency of the transit network hierarchy as the connectivity of the network becomes higher. This result shows that transit networks have economies of aggregation. This study is the first analytical research on transit network hierarchy and is expected to be a basis for numerical research. However, numerical research should complement this study, since analytical research has some limitations for considering a real network.