• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.55-58
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• 2008

RFID(Radio frequency IDentification) leader is collision of data, when recognizing the multiple tag the inside area. This collision became the cause which delays the tag recognition time of the leader. The protocol which prevents the delay of tag recognition time of the leader the place where representative it uses QT(Query Tree) algorithms, it uses a collision bit position from this paper and are improved QT-MTC(Query Tree with Multi-Tag Cognition) algorithms which it proposes. This algorithm stored the bit position which bit possibility and the collision where the collision happens occurs in the stack and goes round a tree the number of time which, it reduced could be identified two tags simultaneously in order, it was planned. A result of performance analysis, It compared in QT protocols and the this algorithm against the tag bit which is continued a tush efficiency improvement effect was visible.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.6
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• pp.999-1005
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• 2008

RFID(Radio Frequency IDintification) leader is collision of data, when recognizing the multiple tag the inside area. This collision became the cause which delays the tag recognition time of the leader. The protocol which prevents the delay of tag recognition time of the leader the place where representative it uses QT(Query Tree) algorithms, it uses a collision bit position from this paper and are improved QT-MTC(Query Tree with Multi-Tag Cognition) algorithms which it proposes. This algorithm stored the bit position which bit possibility and the collision where the collision happens occurs in the stack and goes round a tree the number of time which, it reduced could be identified two tags simultaneously in order, it was planned. A result of performance analysis, It compared in QT protocols and the this algorithm against the tag bit which is continued a high efficiency improvement effect was visible.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10B
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• pp.885-893
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• 2008

In RFID system, reader collision happened when multiple readers try to read the tags at the same time. Because reader collision reduces tag recognition performance, it is required for RFID system to have reader anti-collision algorithm. In this paper, we propose reader anti-collision algorithm based on hierarchical structure, where a master reader controls the slave readers to avoid the reader collisions. It is verified through simulations that the proposed algorithm enhances the performance in terms of leader collision probability and tag reading time.

• Journal of IKEEE
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• v.14 no.2
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• pp.24-32
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• 2010

Slotted-ALOHA and Binary-tree method are researched for the anti-collision for RFID system. However, it is required of the rapid recognition time for all tags and the reduction of the system complexity. In this paper. the hybrid anti-collision method is proposed to solve the problems. The RFID reader with the hybrid anti-collision method groups the tags with the number which makes the maximum system throughput, then it reads each group by slotted-ALOHA method. By the computer simulation results, it is found that the hybrid method improves the tag identification time and the system throughput together with the comparison to other anti-collision methods. Therefore, the proposed hybrid anti-collision method will enhance the RFID system performance.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.6
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• pp.675-682
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• 2015

Current design codes such as AASHTO LRFD or Korean Highway Bridge Design Code recommend of using static force for designing bridge column against vehicle collisions. However, there was an accident that the bridge was collapsed shortly after vehicle impact on bridge pier in Nebraska(near Big Spring, 2003). It was found that the second largest cause of bridge collapse is collision after hydraulic causes. It can be thought that the possibility of truck-bridge collision are getting increasing as the size of truck increases and traffic condition are becoming improved. However, dynamic behavior under the impact loading seldom considered in bridge design procedure due to computational cost and time. In this study, in order to reduce the computational cost for dynamic impact analysis, model reduction method was developed. Obtained results of residual displacement were compared with the results of direct impact simulations.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.355-358
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• 2008

미국, 일본 등 해외 선진국에서는 교통사고를 과학적으로 분석하기 위해서 많은 연구가 활발히 이루어지고 있다. 특히 교통사고가 발생하면 어느 차량이 가해차량 이고 피해 차량인지 판단하기가 매우 어려운 실정이다. 본 논문에서는 이러한 문제점을 해결하기 위해서. 교통사고 발생 전후 일정 시간 동안 진행차량의 주변 상황을 자동 녹화하고, 특히 충돌방향으로 카메라의 방향을 이동시켜서 충돌 시에 차체의 방향이 변경되더라도 그에 따라 카메라의 촬영 각도를 변경시켜 충돌전후의 상황을 정확하게 녹화할 수 있는 시스템을 제안하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.172-173
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• 2021

자율운항선박의 원격제어에서 제어지연이 발생하면 선박은 충돌위험에 처하게 됨으로 이에 대한 해결방안 필요하다. 연구 목적은 자율운항선박의 원격제어에서 제어지연이 선박충돌에 미치는 영향을 조사하기 위함이다. 연구 방법은, 선박의 터닝서클을 시뮬레이션을 통해서 관측하고, 이 데이터를 이용하여 제어지연에 의한 영향을 분석하였다. 이를 위하여 제어지연(시간)에 따른 선박조종 시뮬레이션의 선회권 측정 데이터를 이용하였다. 연구 결과, 제어지연에 의해서 본선 도메인 침공당하는 방위와 최소거리 분석 가능함을 알았다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.89-94
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• 2004

Up to now a lot of the study on ship collision avoidance systems has proceeded actively. However the frequency of ship collision accidents didn't decreased. If there is collision risk in close quarters situation none the less manouvering ship for collision avoidance according to the system, only use of TCPA and DCPA as input factor for collision risk decision is not useful to avoiding collision action. For the recent 5 years by the analysis of first observation distance about approaching ship in domestic collision accidents, nearly $45\%$ of accidents is close first observation less than 2 miles. Therefor it is essential part for safety navigations to study for collision avoidance action in close encounter. In this paper, as foundation study of supporting collision avoidance manoeuvring for navigators, we proposed ship collision avoidance support model in close quarters situation through analysis of collision accidents for effective getting rid of the causes.

• Composites Research
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• v.24 no.5
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• pp.9-16
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• 2011

This paper describes the crashworthiness evaluation and performance improvement of tilting train made of sandwich composites. The applied sandwich composite of carbody structure was composed of aluminum honeycomb core and glass/epoxy & carbon/epoxy laminate composite facesheet. Crashworthiness analysis of tilting train was carried out using explicit finite element analysis code LS-DYNA 3D. The 3D finite element model and 1D equivalent model were applied to save the finite element modeling and calculation time for crash analysis. The crash conditions of tilting train were conducted according to four crash scenarios of the Korean railway safety law. It found that the crashworthiness analysis results were satisfied with the performance requirements except the crash scenario-2. In order to meet the crashworthiness requirements for crash scenario-2, the stiffness reinforcement for the laminate composite cover and metal frames of cabmask structure was proposed. Consequentially, it has satisfied the requirement for crash scenario-2.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.510-513
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• 2007

무선 센서 네트워크의 표준인 IEEE 802.15.4는 전력소모를 줄이기 위해 비컨을 사용하는 슈퍼프레임 구조를 지원하는데 이를 멀티 홈 네트워크 환경에 적용시킬 경우 비컨의 충돌이 발생한다. 네트워크의 정보를 담은 비컨이 충돌되면 노드간의 통신에 장애가 발생하고 새로 네트워크에 참여하고자하는 노드도 수용할 수 없게 된다. 이와 같은 문제를 개선하고자 본 논문에서는 현재 제안되어있는 비컨 충돌 회피 방법들을 분석하고 이를 바탕으로 이웃 노드의 정보를 이용하여 다수의 센서 노드가 중복된 시간에 비컨을 전송할 수 있도록 하여 전체 네트워크에 비컨이 전송되는 시간을 줄이는 방법을 제시한다.