• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.953-955
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• 2014

최근 차량 충돌 방지를 위한 다양한 기술이 상용화되고 있다. FMCW 기반의 레이더 시스템은 구현의 용이성으로 많은 상용차에서 전면 충돌 방지 시스템에 적용되고 있다. 측면 충돌 방지를 위한 BSD(Blind Spot Detection)와 차선변경 보조 시스템(LCA, Lane Change Assistant system)에서는 전방 레이더보다 인식거리가 줄어들고 갱신율이 낮아지므로 고속 FFT 등을 수행하는 신호처리부를 저가격으로 설계가 가능할 것이다. 본 연구에서는 TI사의 MCU인 F28335를 사용하여 근거리를 인식하는 신호처리부를 설계하였다. 이 MCU는 16채널 12bit ADC와 68KB RAM 및 512KB 플래시 메모리를 내장하고, 150MHz 부동소수점 연산을 지원하여 단일 칩으로 신호처리부의 구현이 가능하다. 구현된 시스템은 20m내외의 거리에 있는 장애물에 대하여 10Hz로 갱신이 가능하여 BSD를 위한 기본 기능이 확인되었다. 이러한 구현은 이전의 고가의 DSP나 FPGA를 사용하지 않고 15$이내의 단일 MCU와 간단한 아날로그 회로로 설계되어 저가격의 시스템으로 상용화가 가능할 것이다.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.2
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• pp.235-242
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• 2012

In RFID System, one of the problem that we must slove is to devise a good anti-collision algorithms to improve the efficiency of tag identification which is usually low because of tag collision. Among of the existing RFID anti-collision algorithm, BS (Binary Search) algorithm, though simple, has a disadvantage that the stage of times used to identify the tags increase exponentially as the number of tags does. In this paper, I propose a new anti-collision algorithm called Multi-collision reflected frame which restricts the number of stages and decided bit. Since the proposal algorithm keep the length size of UID and density of total tag when have 100%. The simulation results showed that the proposed algorithm improves the efficiency by 30~50% compared to the existing algorithm.

• The KIPS Transactions:PartA
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• v.15A no.3
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• pp.155-160
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• 2008

RFID technology has been gradually expanding its application. One of the important performance issues in RFID systems is to resolve the collision among multi-tags identification on restricted area. We consider a new anti-collision scheme based on Class Identification algorithm using Depth-First scheme. We evaluate how much performance can be improved by Class identification algorithm in the cases of Query-tree more then 17% identification rate and 150% performance.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.30-33
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• 2006

RFID(Radio Frequency Identification)은 RF주파수를 이용해서 사물이나 사람의 정보를 인식하는 자동인식 기술이다. 이 기술은 무선 주파수를 사용해서 대량의 사물을 동시에 인식 할 수 있다는 장점이 있지만, 무선 주파수를 사용하기 때문에, 프라이버시 문제와 주파수 충돌문제와 같은 부수적인 단점을 가지고 있다. 리더 충돌문제를 해결하기 위한 여러 가지 많은 연구들이 진행 되고 있지만, 현재까지 연구된 대부분은 고정적인 환경에서의 해결 방법들이다. 본 논문에서는 앞으로 다가올 모바일 사회에 대비해서, 밀집된 모바일 환경에서의 리더 충돌 방지 기법을 제안한다. 이 기법은 모바일 리더의 위치를 계산하고, 적절한 주파수를 할당하고 동적으로 RF의 세기를 조절함으로써 리더의 충돌을 방지 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.11-14
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• 2006

의견이나 이해가 서로 맞지 않는 경우 충돌은 발생한다. 유비쿼터스 컴퓨팅 환경에서 서비스를 수행하는 과정에서 발생하는 충돌의 경우 역시, 그 서비스의 요청 및 수행과정에서 발생하는 의견이해의 차이에서 비롯된다. 서비스의 수행을 결심하기 이전에 그 서비스에 연관된 의견이나 이해관계를 파악하고 그들 사이의 이견을 방지한다면, 서비스 사이에서 발생 가능한 대부분의 충돌을 방지할 수 있다. 본 논문에서는 이를 위해 유비쿼터스 컴퓨팅 환경에서 자동으로 서비스를 제공하는 시스템의 입장에서 각 서비스들이 환경과 그 환경 안의 자원들 사이의 관계에 대한 의미를 정의하고 결정함으로써, 다수의 서비스를 충돌 없이 수행할 수 있는 방법을 제안한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.2
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• pp.251-257
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• 2022

Self-driving vehicles are a type of smart vehicle with the help of ICT technology, which means a vehicle that operates without the intervention of a driver.Vehicles with vehicle safety communication technology (V2X) applied use information detected from various sensors or other vehicles/infrastructures to enable the smart vehicle to accurately and quickly predict the driver's potential danger situation, contributing to more stable autonomous driving. In this paper, among V2X communication technologies, a vehicle-to-vehicle communication (V2V) simulation communication technology is used to present a scenario for preventing collisions in autonomous vehicles. A vehicle collision prevention system based on V2V simulated communication was implemented and the suggested collision prevention application scenario was demonstrated. The suggested collision prevention utilization scenario can be considered as one application case of V2V communication technologies that are currently being developed/applied.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.330-336
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• 2020

An anti-collision system between equipment is essential on a drill floor where multiple moving machines are operated simultaneously. This is to prevent accidents by halting the machines when required, by inspecting possibility of a collision based on the relative position data sent by the equipment. In this paper, we propose a framework for an Anti-Collision System (ACS) by considering expandability of the number of machines and computational speed, to promote development of drilling machines and corresponding ACS software. Each drilling equipment is represented as an object in the software with its own message format, and the message is constructed with serialization/deserialization to manage any additional equipment or data. The data handling process receives the current status of machines from the drilling control network, and relays a collision related message (including bypass signal) back to the machines. A commercial visualization software shows the bounding boxes moving with the equipment and indicates probable collision. It has been determined that the proposed system maintains total execution time below 5ms to process data from the network and relay the information hence, the system has no effect on the machine control systems having 100ms control cycle.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.5
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• pp.85-94
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• 2008

When an RFID reader uses the same frequency or adjacent frequency with neighbor readers, the interference might occur. These interferences cause the RFID reader collision and errors during tag recognition. Therefore, the international standard for RFID and some papers proposed the methods to reduce the reader collision. The reader interference is closely related to the distance between the readers haying interference and used frequency band. In the previous RFID reader anti-collision algorithms, the location of readers inducing interference which is closely related to interference of readers is not considered. Only the reader collision is tried to reduce through frequency transfer after collisions occur or modification of frame size in relation to collision probability based a TDM(Time Division Multiplex). In this paper, the genetic algorithm using two-dimensional chromosome which reflect readers' location is proposed to prevent reader collision effectively. By executing evolutionary operation with two-dimensional chromosome, the location information having influence on reader interference can be used. The repair operation in the proposed algorithm makes all reader stably recognize their tags.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.137-143
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• 2009

It is necessary to develop driving assistant information in order to prevent a rear-end collision with a crashed car which is at the blind curve on highway. Laboratory experiments were performed using a driving simulator to keep the traffic environment constant. This research was evaluated the effect of driver behavior according to providing collision avoidance information which was consisted of advisory, caution, and warning information by the dangerous degree of traffic situation. Driver behavior was evaluated to analyze the collision avoidance with a crashed car, and glance behavior was examined to measure the eye movements to the display on which provided the collision avoidance information. After experiment, the significance was evaluated on provided collision avoidance information. As the result of this research, the number of collision accident is reduced when the phased information was provided. In addition, it is clear that auditory information is more important than visual information in the case of providing the second information.

• Journal of KIISE:Information Networking
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• v.36 no.5
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• pp.389-396
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• 2009

In RFID systems, identifying the tag attached to the subject begins with the request from a reader. When the reader sends a request, multiple tags in the reader's interrogation zone simultaneously respond to it, resulting in collision. The reader needs the anti collision algorithm which can quickly identify all the tags in the interrogation zone. We propose the Anti Collision Algorithm using Parity Mechanism(ACPM). In ACPM, a collision can be prevented because the tags which match with the prefix of the reader's request respond as followings; the group of tags with an even number of 1's in the bits to the prefix + 2nd bits responds in slot '0', while the group of tags with an odd number of 1's responds in slot '1'. The ACPM generates the request prefix so that the only existing tags according to the response in the corresponding slot. If there are two collided bits in tags, then reader identify tags by the parity mechanism. That is, it decreases the tag identification time by reducing the overall number of requests.