• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.10b
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• pp.11-25
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• 1998

Many Countries have made efforts to assist ships navigate accurately , safely and expeditiously for the safety control against increasing marine traffic , in their coastal waters. However, they are exposed in spite of these efforts,to risks of casulaties and marine polluation caused by traffic congestion when ships are navigating through waterways approaches to ports or harbors and in narrow fairways. Therefore, efficient control of VTS in Port is necessary nowadays to provide ships with necessary service , which interacts with shipping and organize the flow of traffic so as to maximize the efficiency of the port or harbor while minimizing the risk of accident and environmental pollution. Even though the navigation condition of ships is very inferior compared to other ports in Korea, such as the big difference between the ebb and flood tide, the frequent fog, the narrow fairway , the density of navigation traffic in Inchon Port is high and transportation quantity of dangerous cargoe increases gradually. In cosideration of the characteristics of natural circumstance and traffic circumstance the VTS established newly in Inchon port have to operate efficiently. The purpose of this study is to help efficient operation of VTS in Inchon port by accomplishing both the literature research and questionnaire survey. Questionnaire survey was read to the VTS personnel in Inchon Port and customer familiar to Inchon Port such as ship navigators, pilots, shipping companies and so on. Most of ship navigators who occupy half of the respondents are Korean Officer who had responded while they were calling at Inchon port. The conclusions and recommendations includes ; First, the service area should be extended over Designated area to provide the vessel with navigational assistance service regarding the information of traffic congestion area, fishing boat and small ship's activities. Second, the types of information service to be offered are ship's movement and weather condition inthe vicinity of the port and state of fairway in the approaching channel to thte fairway. Third, VTS personnel should be upgraded by the on-the-job training and continuous simulation training as well as supplement of the qualified personnel for VTS operation. Fourth , the Harbor Master System to be introduced for safe navigation and efficient port operation.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.167-175
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• 2010

The ubiquitous transportation system environments make it possible to collect each vehicle's position and velocity data and to perform more sophisticated traffic flow management at the individual vehicle or platoon level through vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) communication. It is necessary to develop a traffic flow management scheme to take advantage of the ubiquitous transportation system environments. This paper proposes an algorithm to advise the optimal speed for each vehicle according to the traffic flow condition. The algorithm aims to stabilize the traffic flow by advising the equilibrium speed to the vehicles speeding or crawling under freely flowing condition. And it aims to prevent or at least alleviate the shockwave propagation by advising the optimal speed that should dampen the speed drop under critical flow conditions. This paper builds a simulation testbed and performs some simulation experiments for the proposed algorithm. The proposed algorithm shows the expected results in terms of travel time reduction and congestion alleviation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.295-303
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• 2004

In this Paper, we discuss an active TCP link of unsynchronized transmission mode network in two-way traffic and the Improvement of its traffic patron thorough the network pathway of protocol is shown. This is because the traffic pattern is performed on the basis of existing windows which are distributing information in several periods of time in the way of interfacing LTS control module, which is controlling by an information of exceeding the time limit of feedback loop determined by RTP, with TCP. The simulation to utilize this efficiently is performed with the circumstance of bench mark based on physical modeling of the self-similarity traffic in the performance of TCP. In this paper, we use a methodology to understand and evaluate the effect of change of transmitting protocol in sticks under the condition of the self-similar traffic in two-way network and it is shown that an improvement of congestion control by self-similarity under a heavy condition.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.86-99
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• 2021

One of the methods to alleviate traffic congestion is to increase the efficiency of the roads by providing traffic condition information on road user and distributing the traffic. For this, reliability must be guaranteed, and quantitative real-time traffic speed prediction is essential. In this study, and based on analysis of traffic speed related to traffic conditions, historical data correlated with traffic flow were used as input. We developed an LSTM model that predicts speed in response to normal traffic conditions, along with a CNN-LSTM model that predicts speed in response to incidents. Through these models, we try to predict traffic speeds during the hour in five-minute intervals. As a result, predictions had an average error rate of 7.43km/h for normal traffic flows, and an error rate of 7.66km/h for traffic incident flows when there was an incident.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5D
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• pp.611-617
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• 2009

With advanced technologies applied to transportation, realtime traffic information has been necessary for not only drivers but also agencies. In normal, traffic conditions have been represented to three levels according to congestion: "free", "slow", and "jammed". Those categories and criteria are set up for traffic management even though traffic information is provided for drivers. This study examines how drivers feel current congestion levels and delves into traffic categories and criteria which they recognize. To collect data for drivers' recognition, a survey of freeway travellers is conducted answering the question about traffic flow speed from video image on a freeway section. In the result of the survey, the surveyee preferred a 4-level traffic condition including "delayed" to 3-level traffic condition. As its criteria, 20 km/h, 50 km/h, and 75 km/h were obtained. These results are expected to contribute to building more appropriate traffic information for drivers and providing an operational guideline for Traffic Monitering Centers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4D
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• pp.469-476
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• 2008

Recently, TOD gains popularity as a traffic solution measure of high density urban regeneration projects. The purpose of this study is to investigate traffic impacts of high density TOD projects, and to identify the issues to be resolved. For a case study, it chooses Gangnamgucheong station in Gangnam area served by two subway lines, and designates 400m radius from the station as a site for high-density development. The MOEs chosen for this study is traffic volume, time, distance, speed, and mode share. The SECOM model is adopted for traffic simulation. The analysis results show that high-density TOD is an effective tool for traffic improvement even with only one station area being implemented. It is found that the traffic volume increases near the station in nature where high-density development occurs, but it declines overall in the rest of Gangam area. The total travel time and distance of passenger vehicles decline, meaning that the traffic condition becomes better than before. With regulation on parking supply, the improvement becomes more vivid. In terms of the changes of traffic speed, both alternatives show 4.1% increase in speed, but the difference between alternatives is not quite noticeable because of the induced vehicle demand driven to the streets with improved traffic condition. The mode share changes occur for the benefit of subway ridership, because the study station is equipped with two subway line services. When mixed with parking supply restriction, the impact becomes clearer.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.3
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• pp.1-12
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• 2012

This paper aims at developing an active expressway entrance control effectiveness analysis tool which operators can utilize and manage traffic based on current traffic condition. For this, after identifying the current problems of tollgate-based entrance policy being used, a new set of decision element such as congestion index, decision criteria for congestion, and congestion management unit has been proposed together with the procedure of newly developed tollgate control policy. Three key parts developed are traffic condition identification module, tollgate metering module, and travel speed calculation module. Some measures of effectiveness were also identified and the newly developed effectiveness analysis tool produced better result. According to classification of traffic condition by reference speed as 80km/h, the improved tollgate entrance procedure increased 21.5% in average travel speed compared with Do-Nothing case and also increased 8.8% compared with current entrance control method.

• Journal of the Korean Society of Safety
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• v.5 no.3
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• pp.56-62
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• 1990

This study is conducted to analyze exact causes of occupational fatalities and results are as follows ： 1) The number of fatalities in establislment which employed less than 50 workers is 605(40.1％ ). Age of sixties and seventies is occupied by 10 percent with there being old-aged trend. Fatal workers who were employed less than 3 months are 39.5 percent and fatal workers who were employed more than 10 years are 11.9 percent. Safety training is necessary for newly recruited and long employed workers. 2) Accident type is, in sequence, fall from elevation, traffic accident, disease, contact with electric current, and hazardous condition is, in order, inadequate guard, hazardous method or procedure, public hazard, and agency of accident is, in sequence, temporary structure/building/structure, powered transport vehicle, passenger vehicle, hoisting or lifting apparatus, and unsafe act is, in order, driving error, failure to secure or warn. 3) The results of cross-tabulation for hazardous condition and accident type is, in sequence, traffic accident by public hazard, fall from elevation by hazardous method or procedure, fall from elevation as well as contact with elctric current by inadequate guard. The result of cross-tabulation for agency of accident and accident type is, in order, fall from elevation by temporary structure/building/structure, traffic accident of passenger vehicle and powered transport vehicle, contact with electric apparatus. The result of cross-tabulation for agency of accident and hazardous condition is, in sequence, public hazard of passenger vehicle, hazardous method or procedure of temporary structure/building/structure, publit hazard of powered transport vehicle, inadequate guard of temporary structure/building/structure. The result of cross-tabulation for unsafe act and accident type is, in sequence, traffic accident by driving error, fall from elevation by inattention to footing or surrounding, contact with electric current by secure or warn.

• Journal of Acupuncture Research
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• v.33 no.4
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• pp.15-31
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• 2016

Objectives : The aim of this study is to review the instruments used to assess patient condition and the effects of Korean medical treatment for patients injured in traffic accidents in clinical studies in the Korean medical field published in South Korea. Methods : A literature study was performed, and clinical studies on patients injured in traffic accidents visiting Korean medical clinics or hospitals were examined. Data about chief complaints, tools used to assess either patients' condition or the effectiveness of Korean medical treatment, and time point of assessment were extracted. The studies were classified according to symptom. The use-frequency and the parent category of the assessment tools were also analyzed. Results : 78 studies were selected and classified into 5 categories based on the chief complaints, neck pain, lower back pain, headache, psychological symptoms and unspecified symptoms. Various scales were used to report the patient's pain severity, and functional or psychological status resulting from traffic accidents. Pain index, in particular VAS, was most frequently used and a few mechanical instruments and Korean medicinal assessment tools were mentioned. Conclusion : Most instruments used in Korean medicine clinical studies on patients injured in traffic accidents are self-reported tools. To assess both the patient's condition precisely and the effectiveness of Korean medical treatment on patients injured in traffic accidents, more appropriate and unified tools should be designed that consider pain, functional disability, psychological status and objective assessments measured by devices together.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.3
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• pp.257-263
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• 2013

The classification of risk factors and the identification of risk acceptance criteria are core works to assess risk levels with high enough confidential level in the field of marine traffic environment. In the previous study work, the twenty kinds of risk factors and its assessment criteria for the domestic marine traffic environment were proposed. In this paper, with these previous studying results, the relative importance of the risk factors were analyzed by questionnaire survey of marine traffic experts using the analytic hierarchy process. The analysis results showed that the relative importance of the visibility restriction is the highest among the twenty kinds of risk factors, and the relative importance of the traffic condition is the highest among the five kinds of risk categories. As results from analysis, it is expected that the approaching method on the relative importance is to be one of basic techniques for the development of risk assessment models in the domestic marine traffic environment.