• Journal of Fisheries and Marine Sciences Education
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• v.28 no.6
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• pp.1812-1821
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• 2016

The purpose of this study is to survey input data error of ship automatic identification system (AIS) and suggest its improvement. The effects of AIS were observed. Input data error of AIS was investigated by dividing it into dynamic data, static data by targeting actual ships and its improvement method was suggested. The findings are as follows. Looking into accidents before and after AIS is enforced to install on the ship, total collision were decreased after AIS installed. Static data error of AIS took place mainly in the case that ship name, call sign, MMSI, IMO number, ship type, location of antenna (ship length and width) were wrongly input or those data were not input initially. Dynamic data error of AIS was represented by input error of ship's heading. As errors of voyage related data take place as well, confusion is made in sailing or ship condition. Counter measures against the above are as follows. First, reliability of AIS data information should be improved. Second, incessant concern and management should be made on the navigation officers.

• Journal of the Korea Safety Management & Science
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• v.25 no.4
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• pp.105-115
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• 2023

The purpose of this study is to identify psychological anxiety factors related to firefighters' field activities and suggest improvement measures. To investigate the actual status of psychological anxiety factors, a survey was conducted on approximately 3,500 current firefighters, and the responses of 505 people who participated in the survey were analyzed. As a research method, frequency analysis and cross-analysis were conducted according to the general characteristics of the participants to determine the actual level of psychological anxiety in each work field and the results were analyzed. As a result of the analysis, it was statistically confirmed that firefighters feel a lot of psychological burden due to legal and institutional inadequacies during dispatch, return, or field activities, and frequent friction with civil servants is also a major cause of psychological anxiety. Therefore, based on the results of this study, it is proposed to establish a permanent legal support team in each city and province, designate and operate a hospital dedicated to psychological treatment, and establish a special provision for traffic accidents during the return of fire trucks so that firefighters can concentrate on their duties without psychological anxiety. do.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.213-223
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• 2021

It is very important to build a safe walking environment for children because children are more likely to be exposed to traffic accidents than adults due to their behavioral and physical characteristics. Therefore, this study analyzed the characteristics of road and transportation safety facilities that affect pedestrian traffic accidents around school zones using spatial poisson regression. The pedestrian-vehicle crash data in Seoul 2016-2018 was provided by the Traffic Accident Analysis System(TAAS). The main analysis results are as follow; First, the more intersections and the higher percentage of neighborhood roads in the school zone, the higher the risk of pedestrian traffic accidents. Second, the pedestrian push button was found to reduce the occurrence of pedestrian traffic accidents. Third, except for the pedestrian push button, none of the transportation safety facilities considered in this study were effective in reducing the risk of pedestrian traffic accidents. On the other hand, if not only the improvement of physical facilities but also non-physical factors such traffic safety education are supported, the effect for reducing traffic pedestrian traffic accidents in the school zone is expected to be further maximized.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.2
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• pp.92-104
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• 2017

Previous management for speed in road traffic system was aimed only to the improvement of mobility and safety. However, consideration for the aspect of environment and energy consumption efficiency was valued less than the former ones. Nevertheless, economical damage scope caused by climate change has been increasing and it is estimated that environmental value will be increased because of the change of external circumstances. In addition, policy for reducing carbon emission in transportation system was assessed as insufficient in improving the condition of traffic road since it only focused on the transition of private vehicle into public transportation and development of eco-friendly car. Now it is the time to prepare for the adaptation strategy and precaution for the increased number of private vehicle in Korea. For this, paradigm shift in traffic operation which includes the policy not only about the mobility but also about caring environment would be needed. It is needed to be able to monitor the actual amount of greenhouse gas in real time to reduce the amount of emitted greenhouse gas in the aspect of traffic management. In this research, a methodology which can build on-line greenhouse gas emission monitoring system by using real time traffic data and predicting the circumstance in next 5 minutes was suggested.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.946-952
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• 2011

In term of inaccuracy of information and increasing channel occupancy time, the use of voice communication in Air Traffic Control has many problems. In order to improve it, ICAO proposed digital communication and ADS-B system that is more effective for voice communication in ATC. For improvement of effectiveness to add additional parameter to designated ADS-B In-Out data group, many studies being performed. In this paper, we analysis voice communication for reduce the communication traffic in ATC and simulate to add aiming altitude parameter for comparative effect analysis of communication traffic between pilot and controller. The result of the analysis were successfully validated that reduction of communication traffic in ADS-B environments.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.1
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• pp.49-54
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• 2010

3GPP(Third Generation Partnership Project) LTE system that is the next step forward in cellular 3G services address the issues related to power saving at LTE base station. This is because that most of the energy in a typical telecommunication network is consumed by the wireless network's base station site. Power saving at LTE base station fall in with low-carbon green technology. This thesis proposes a power saving MAC protocol for LTE base station which utilizes different graded DRX/DTX(Discontinuous. Reception/Transmission). Considering traffic type in UE, proposed MAC protocol controls adaptive DRX/DTX cycle. The proposed method is more improve power saving performance than another method which is unchanged DRX/DTX by conditions. In this thesis, I propose an power saving MAC protocol in an environment where LTE base station are communicated with UE and prove improvement in performance through simulations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.11
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• pp.2002-2007
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• 2006

The path search method in the telematics system should consider traffic flow of the roads as well as the shortest time because the optimal path with minimized travel time could be continuously changed by the traffic flow. The existing path search methods are not able to cope efficiently with the change of the traffic flow. The search method to use traffic information also needs more computation time than the existing shortest path search. In this paper, a method for efficiency improvement of path search is implemented and its performance is evaluated. The method employs the fixed grid for adjustable heuristic to traffic flow. Moreover, in order to simplify the computation of estimation values, it only adds graded decimal values instead of multiplication operation of floating point numbers with due regard to the gradient between a departure and a destination. The results obtained from the experiments show that it achieves the high accuracy and short execution time as well.

• Journal of Communications and Networks
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• v.8 no.1
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• pp.13-20
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• 2006

In cellular mobile communications, how to achieve optimum system capacity with limited frequency spectrum is one of the main research issues. Many dynamic channel assignment (DCA) schemes have been proposed and studied to allocate the channels more efficiently, thus, the capacity of cellular systems is improved. Reuse partitioning (RP) is another technique to achieve higher capacity by reducing the overall reuse distance. In this paper, we present a network-based DCA scheme with the implementation of RP technique, namely dynamic reuse partitioning with interference information (DRP-WI). The scheme aims to minimize the effect of assigned channels on the availability of channels for use in the interfering cells and to reduce their overall reuse distances. The performance of DRP-WI is measured in terms of blocking probability and system capacity. Simulation results have confirmed the effectiveness of DRP-WI scheme. Under both uniform and non-uniform traffic distributions, DRP-WI exhibits outstanding performance in improving the system capacity. It can provide about 100% capacity improvement as compared to conventional fixed channel assignment scheme with 70 system channels.

• The Korean Journal of Emergency Medical Services
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• v.26 no.3
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• pp.185-199
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• 2022

Purpose: Prompt arrival of emergency vehicles at the scene is important. Therefore, special cases for emergency vehicles are being applied. However, there remain obstacles that obstruct the prompt arrival during dispatch. Methods: First, a literature review revealed five categories of problems with the emergency vehicle priority signal system. Then, the first Delphi survey was conducted to confirm the validity of the five categories. Further, a second Delphi survey was conducted to identify additional problems, and we used a 5-point Likert scale for a third Delphi survey. Results: A total of 92 items were extracted from preceding studies. The validity of the five categories was confirmed in the first Delphi survey. Then, 123 additional items were derived from the second Delphi survey, and the final 50 items were selected from 93 items obtained from the third Delphi survey. Conclusion: This study revealed problems and improvement measures for improving the operation of the emergency vehicle priority signal system that were not proposed in previous studies.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.38-48
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• 2017

Link attributes, such as speed, occupancy, and flow, are essential factors for transportation planning and operation. It is, therefore, one of the most important decision-making problems in intelligent transport system (ITS) to determine the optimal location of a sensor for collecting the information on link attributes. This paper aims to develop a model to determine the optimal location of a sensor to minimize the variability of traffic information on whole networks. To achieve this, a network sensor location model (NSLM) is developed to reflect discrete characteristics of data collection. The variability indices of traffic information are calculated based on the summation of diagonal elements of the variance-covariance matrix. To assess the applicability of the developed model, speed data collected from the dedicated short range communication (DSRC) systems were used in Daegu metropolitan area. The developed model in this study contributes to the enhancement of investment efficiency and the improvement of information accuracy in intelligent transport system (ITS).