• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.24-25
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• 2010

As the increase in maritime traffic and leisure, the marine accident risk has increased in the domestic coast. In this study, the environment and the cause of domestic marine accidents from 1990 to 2009 have been investigated and analyzed by using the statistics issues of Korean Maritime Safety Tribunal. Based on the analysis of most domestic marine accidents sum as Engine damage, Collision, Capsizing of small vessels, we propose how to use mobile telecommunication terminals for preventing marine accidents and the best countermeasures.

• Journal of Navigation and Port Research
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• v.35 no.3
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• pp.205-211
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• 2011

As the increase in maritime traffic and leisure, the marine accident risk has increased in the domestic coast. In this study, the cause and the environment of domestic marine accidents from 1990 to 2009 have been investigated and analyzed by using the statistics issues of Korean Maritime Safety Tribunal. Based on the analysis of most domestic marine accidents such as engine damage, collision, capsizing of small vessels, we propose how to use mobile telecommunication terminals for preventing marine accidents and the best countermeasures.

• Journal of Korea Multimedia Society
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• v.15 no.10
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• pp.1221-1227
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• 2012

It is expected that the vehicle safety systems using vehicle-to-vehicle communication can reduce the possibility of vehicle collision and prevent the chain crash by promptly delivering the status of neighboring vehicles. Many IEEE 802.11 DCF based Flooding schemes have been proposed, but they may generally expose the problems that the transmission efficiency is sharply declined as the vehicle density has increased and then is related to the low possibility of the channel access. Therefore, this paper proposes a collision prevention scheme using adaptively controlling the frequency of the message exchanges based on the current status of neighboring vehicles. Moreover, it is shown from simulation that the proposed scheme provides the performance gains over the existing Flooding based scheme.

• Journal of Computing Science and Engineering
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• v.5 no.4
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• pp.324-330
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• 2011

To avoid collisions, IEEE 802.11 medium access control (MAC) uses predetermined inter-frame spaces and the random back-off process. However, the retransmission strategy of IEEE 802.11 MAC results in considerable time wastage. The hidden node problem is well known in wireless networks; it aggravates the consequences of time wastage for retransmission. Many collision prevention and recovery approaches have been proposed to solve the hidden node problem, but all of them have complex control overhead. In this paper, we propose a fast retransmission scheme as a recovery approach. The proposed scheme identifies collisions caused by hidden nodes and then allows retransmission without collision. Analysis and simulations show that the proposed scheme has greater throughput than request-to-send and clear-to-send (RTS/CTS) and a shorter average waiting time.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.2
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• pp.144-152
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• 2018

This study aims to establish a mathematical formula to provide rapid and safety estimation of the damaged double hull tankers under ship-ship collision. Difference in heights between the striking and struck ships 'h' and penetration depth 'x' were considered as the main parameters. In ship-ship interaction, Large oil tankers are selected as target struck vessels, and they are struck by Very Large Crude-Oil Carrier (VLCC) class oil tanker. The residual strength of damaged ship at several locations and collision scenarios were carried out using Intelligent Supersize Finite Element Method (ISFEM) which considers the progressive collapse behavior of ship hulls strength. Based on these results, satisfactory was achieved and empirical formula was successfully established using the regression analysis method by deploying the height difference 'h' and penetration depth 'x' as the observed parameters.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.16 no.4
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• pp.63-68
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• 2008

Compared with past, helicopters have remarkably high level of safety and accidents due to mechanical defects are decreased about 15%. Most of their duties, however, are to commit at duty area which is hard to access. Because of them, collision probability is high and also has relatively higher accident rates than other aircraft with special mission. A result of analysis is that accident rate is relative high with prevention of disasters, putting out a fire and crop-dusting missions under 500ft. In addition, most of accidents are related with human factors. According to this, it is required to pilots who carry these mission that safety education and detailed analysis about their mission.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.2 no.1
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• pp.93-100
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• 2004

Shoulder impingement syndrome is cause by the collision of acromion, acrominoclaviclar joint, coracoacromino ligament, coracoid process and synovial sac, biceps brachiialis tendon, rotator cuff muscle. Treatment for Shoulder impingement syndrome is genetally classified into two different methods; preservative method and operational method. Operational method includes rotator cuff sutura, anterior acromioplasty, arthroscope decompression. Preservative method includes rest, medicinal therapy, physical therapy. Physical therapy concentrates on pain control, functional recovery and prevention of disease progress. It is also important for physical therapy to maintain the strength of rotator cuff. Strengthening rotator cuff decreases the collision and helps the stability of shoulder joint. In conclusion, it must be aware that shoulder impingement syndrome and some other shoulder problem demand different treatment, which results in a better outcome.

• Journal of the Korean Society of Marine Environment & Safety
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• v.7 no.3
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• pp.61-74
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• 2001

The prevention of marine accidents has been a major topic in marine society and various policies and countermeasures has been developed, applied to the industries. Formal Safety Assessment is a structured and systematic methodology, aimed at enhancing maritime safety, including protection of life, health, the marine environment and property, by using risk and cost-benefit assessments. In addition, it provides a means of being proactive, enabling potential hazards to be considered before a serious accident occurs. In this paper, we has been screening and ranking of hazards using fuzzy structural modeling method and quantitative risk assessment for the ship's collision in the last 10 years marine accidents.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7A
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• pp.756-765
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• 2004

Using single carrier frequency RFID system in one-to-multiple wireless communications, might be generated data loss because of data collisions. Conventional Anti-collision method prevent data loss from data collisions which are binary tree method and ALOHA. However, those two preventive measures also have week points which are strongly dependent on the time and space when passing through the recognition area. This paper suggests the full-length instruction code method which fits in to half-duplex method, prevents data collision effectively by calculating the non-transmitting time of multiple tags considering approaching time to the recognition area. After full-length instruction code method test using 13.56MHz bandwidth RFID system shows that full-length instruction code method could make better result than any other methods. Moreover, the record shows O(n) result after analyzing O-notation of conventional time-domain procedure.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.3
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• pp.68-83
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• 2019

The number of pedestrian traffic accident fatalities is three times the number of car accidents in South Korea. Serious accidents are caused especially at intersections when the vehicle turns to their right. Various pedestrian collision warning services have been developed, but they are insufficient to prevent dangerous pedestrians. In this study, P2CWS is developed to warn approaching vehicles based on the pedestrians' characteristics. In order to evaluate the performance of the service, actual pedestrian data were collected at the intersection of Daejeon, and comparative analysis was carried out according to pedestrian characteristics. As a result, the performance analysis showed a higher accordance when the characteristics of the pedestrian is considered. Accordingly, we can conclude that identifying pedestrian characteristics in predicting the pedestrian crossing is important.