• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.3B
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• pp.226-236
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• 2002

In this paper, we present the channel assignment and management methods for an efficient use of traffic channel resource for supporting 12.2 Kbps, 64 Kbps, and 384 Kbps traffic with the different quality of service (QoS) in the radio network controller (RNC) in asynchronous IMT-2000 system. We first describe two types of traffic channel block assignments for utilizing the traffic channel efficiently; the partially dedicated and partially shared channel (PDPSC) assignment and the completely shared channel (CSC) assignment. The former is that some traffic channel block is completely assigned to each traffic type and the other blocks are shared with some traffic type. The latter is that all traffic channel blocks are completely shared with all traffic types. Further, for efficiently assigning, releasing, and managing the channel resource, we present the traffic channel management method which consists of the block and task management step. Through numerical examples, we evaluate the blocking probability and the mean number of required search for fading the available channel when applying our proposed channel block assignment and resource management methods.

• International Journal of Highway Engineering
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• v.17 no.2
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• pp.79-87
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• 2015

PURPOSES: According to accident statistics for road built in 2004, the ratio of accidents on frozen roads to normal roads is 0.9%, whereas the fatality ratio is 2.7%. The risk of accidents on frozen roads is very high. Measures taken every year to prevent traffic accidents of frozen roads in the winter season are still insufficient. Additionally, measures have been established mainly on rural roads. Therefore, for urban roads, analyses and measures to prevent accidents are lacking. In this study, data on accidents on frozen roads was used to search for the causes behind these accidents and measures to reduce accidents have been recommended. METHODS: In this study, collected data from the TAMS (Traffic Accident Management System), which were collected by the Seoul National Police Agency was used. The data were divided into vehicle, people, and condition of road. The analytical model used here was the Logistic Regression Model, which is frequently used for traffic safety and accident analysis. This study uses the odds ratio analysis to search for variables related to frozen road traffic accidents in each category. A total of 18 out of 47 variables were found to be the causes of accidents. RESULTS: From the results of the comparative analysis of 18 variables, the category of the condition of the road was found to be the most critical. Contrary to expectations, more accidents occurred in clear weather than in other conditions. Accidents on bridges occurred frequently, and its odds ratio was the highest compared with other road types. When BPT is operated, the probability of accidents on frozen roads is lower than in general conditions, and accidents occurred frequently on roads with less than four lanes. CONCLUSIONS : Based on the results of this study, suggestions for reducing the risk of future domestic road accidents in freezing conditions are indicated as follows. First, it is necessary to perform a technical review of the urban road traffic accidents caused by frozen roads. Second, it is necessary to establish criteria for the study of the road environment based on the major causes of road accidents on frozen roads. Third, improvements in urban road environmental factors should be made.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.137-141
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• 2005

Optimal path search algorithm should consider traffic flows of the roads as well as the distance between a departure and destination, The existing path search algorithms, however, usually don't apply the continuously changed traffic flows. In this paper, we propose a new optimal path search algorithm. the algorithm takes the current flows into consideration in order to reduce the cost to get destination. It decomposes the road networks into Fixed Grid to get variable heuristics. We also carry out the experiments with Dijkstra and $A^*$ algorithm in terms of the execution time, the number of node accesses and the accuracy of path. The results obtained from the experimental tests show the proposed algorithm outperforms the others. The algorithm is highly expected to be useful in a advanced telematics systems.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.3
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• pp.50-57
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• 2009

We propose a network node search scheme to address the network fragmentation due to high node mobility in the VANET. VANET is very similar to MANET in that a multi-hop ad-hoc network is configured by wireless communication between vehicles without any network infrastructure. However, high speed mobility, high node density, and frequent topology change induce frequent network fragmentation so that overall network traffic can be increased. In this paper, new broadcasting protocol called an adaptive relay node search protocol is proposed to decrease the network fragmentation. It reduces the network fragmentation and network traffic by researching nodes outside the dangerous area only in case of network fragmentation. Simulation results show that the proposed protocol decreases network fragmentation by up to 39.9% and increase informed rate by up to 41.9% compared to the existing broadcasting protocol.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.13-14
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• 2016

Many ships' collision accidents occur due to unlawful action at sea. And also at shore traffic, many car collision accidents occur due to unlawful action. Therefore In this study we analyzes actual collision accidents at sea with the regards of liability. and search and analyze similar car collision accidents at shore traffic to compare it with the ship collision. In result, this study suggests the liabilities of the two different types accidents are needed to change more reasonable liability apportionment.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.1
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• pp.76-84
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• 2003

Now days, It is based on GIS and GPS, it can search for the shortest path and estimation of arrival time by using the internet and cell phone to driver. But, even though good car navigation system does not create which is the shortest path when there average vehicle speed is 10 -20 Km. Therefore In order to reduce vehicle waiting time and average vehicle speed, we suggest optimal green time algorithm using fuzzy adaptive control, where there are different traffic intersection length and lane. In this paper, it will be able to forecast the optimal traffic information, estimation of destination arrival time, under construction road, and dangerous road using internet.

• Journal of the Korean Society for Railway
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• v.14 no.3
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• pp.276-284
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• 2011

In our study, we present a new LOGIT-based traffic assignment model applicable to intercity railway network. Most traffic assignment models have been developed for public transit assignment in urban area, so that they are known to produce unrealistic results in intercity railway demand analysis. Especially, since the introduction of KTX, more passengers are using a route including KTX service and the schedule becomes more compatible with transfer. Our study presents a new LOGIT-based traffic assignment model considering passenger transfer. To do so, we suggest a new route search algorithm to find K paths with non increasing order in the utility value.

• The Journal of the Korea Contents Association
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• v.19 no.2
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• pp.460-468
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• 2019

Recently, analysis techniques to extract new meanings using big data analysis and various services using these analysis techniques have been developed. Among them, the transport is one of the most important areas that can be utilized about big data. However, the existing traffic route guidance system can not recommend the optimal traffic route because they use only the traffic information when the user search the route. In this paper, we propose a realtime optimal traffic route guidance system using big data analysis. The proposed system considers the realtime traffic information and results of big data analysis using historical traffic data. And, the proposed system show the warning message to the user when the user need to change the traffic route.

• Journal of the Korea Safety Management & Science
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• v.11 no.4
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• pp.153-159
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• 2009

This study was conducted in search of the acceptance level of air traffic services from domestic airlines pilot's perspective in comparison with male controllers and female controllers. Pilots responded to the questionnaire that female ATC controllers are of significance to male controllers in terms of pronunciation, accuracy of English grammar, attitude and kindness. Besides, The ICAO aviation English proficiency level four test revealed that female controllers were found superior to male controllers in terms of rating scales of holistic descriptors.

• Journal of Oriental Neuropsychiatry
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• v.14 no.1
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• pp.175-181
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• 2003

A lot of research have been done so far in terms of traffic accident sequela, but most of them have stressed simply on physical treatments, resulting in less attention to the psychological ones. This is a case report of a patient with post-traumatic stress disorder. Although that is simply following in the wake of past therapy, we were experienced an improved case of post-traumatic stress disorder patient treated by herbal medicine, acupuncture, mental therapeutics. This case effectively describes the characteristics of the post-traumatic stress disorder, and it also suggested one approach for the treatment of the disease. This report is for the better understanding of the disease, and also the search for the advanced treatments to it hereafter.