• Title/Summary/Keyword: Anti-collision system

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Development of a Systemized Flying Net for Safety Improvement in Architectural Building Construction (건설 공사의 안전성 향상을 위한 충돌방지형 시스템 플라잉넷의 개발)

  • Lee, Jeong-Ho;Park, Seon-Joo;Kim, Young-Suk
    • Korean Journal of Construction Engineering and Management
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    • v.12 no.5
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    • pp.71-80
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    • 2011
  • Flying net should be installed on every 3 or 4 construction floor from 8m above ground according to the rule. In the apartment housing construction, flying net installation work has been recognized the most dangerous work among the whole works because a small mistake of labors might make their death accident. Sub-contractors specialized in flying net have been developing various flying net types. However, most works of installing flying net as working with the developed system are performed outside the apartment housing, so that the risk of fall in works of installing supports and unfolding net is still high. Furthermore, as using the previously developed flying net labors might bump into the frame or the wire rope for supporting so that it makes secondary accidents. The objective of this research is to produce the proto-type of anti-collision flying net system based on the result of problem analysis on the installation and detachment process and suggest the improved anti-collision flying net system, which is able to improve safety and field applicability by conducting field experiment and analyzing performance.

Tag Identification Scheme based on Multi-Reader for Reducing Tag Authentication Time (태그 인증 시간 단축을 위한 다중 리더 기반의 태그 인식 기법)

  • Jang, Bong-Im;Jeong, Yoon-Su;Kim, Yong-Tae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.1
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    • pp.13-19
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    • 2012
  • The use of RFID is recently increasing for the realization of Ubiquitous computing. Reducing the process time of tag recognition is crucial as RFID system has to recognize multiple objects in a short amount of time. In this manuscript, therefore, an effective scheme using multi-reader is suggested to improve processing speed for tag authentication in RFID system. According to the result of performance analysis, the processing time required for tag authentication was drastically reduced in multi-reader environment than it was in a single reader. Consequently, the use of the suggested scheme cuts down on the processing time while identifying tags by using multi-reader and bring about overall performnce improvement of RFID system.

A Study On the Position Control System of the Small ROV Using Sonar Sensors (소나 센서를 이용한 소형 ROV의 위치제어시스템에 관한 연구)

  • Choi, Dong-Hyun;Um, Geun-Nam;Kim, Sang-Hyun
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.6
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    • pp.579-589
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    • 2008
  • In the past few years, there are many studies and researches of the underwater vehicles which are carried out its mission using sonar sensors. MSCL(Marine System Control Lab.) at Inha University developed test-bed small ROV, ISRO. ISRO is an open-frame type and has 4 thrusters. ISRO can control 4 motions i.e surge, sway, yaw and heave with sonar sensors. ISRO is developed for inspection of ship hull, marine structure, plant of lake or river and so on. When ROV ISRO inspects something, it is necessary to control the position of ROV ISRO's for the movement and anti-collision with structures in the underwater. In this paper, we deal with the development of a small ROV and verification of the position control system via simulation and experiment using sonar sensors.

Performance Analysis of FSA Algorithm for Tag Identification in RFID Systems (RFID 시스템에서 태그 식별을 위한 SFSA 알고리즘의 성능 분석)

  • Lim, In-Taek;Choi, Jin-Oh;Choi, Jin-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.05a
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    • pp.563-566
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    • 2008
  • In RFID system. when a variety of tags are present in the interrogation zone of a single reader at the same time, the system requires a multiple tag identification scheme that allows the reader to read data from the individual tags. Anti-collision algorithms required for the multiple tag identification are essential for the implementation of RFID system. This paper analyzed the performance of SFSA algorithm, which is easy to implement. According to the analytical results, the algorithm's performances are closely related with the number of tags and the frame size.

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Dynamic Frame Size Allocation Scheme based on Estimated Number of Tags (태그수추정에 기반한 동적 프레임 크기 할당 기법)

  • Lim, In-Taek
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.3
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    • pp.469-474
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    • 2009
  • An RFID system consists of radio frequency tags attached to objects that need to be identified and one or more electromagnetic readers. Unlike the traditional bar code system, the great benefit of RFID technology is that it allows information to be read without requiring contact between the tag and the reader. For this contact-less feature, RFID technology in the near future will become an attractive alternative to bar code in many application fields. In almost all the 13.56MHz RFID systems, FSA algorithm is used for identifying multiple tags in the reader's identification range. In FSA algorithm, the tag identification time and system efficiency depend mainly on the number of tags and frame size. In this paper, we propose a tag number estimation scheme and a dynamic frame size allocation scheme based on the estimated number of tags.

The Law and Case Study on the Domain Name Protection (도메인네임의 보호(保護)에 관한 법리(法理) 및 사례연구(事例硏究))

  • Kim, Yeon-Ho
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.15
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    • pp.169-209
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    • 2001
  • As a domain name can be registered simply by filing an application for registration, disputes over the domain name between the holder of domain name and the holder of trademark increased. Since the holder of trademark who was late for registering domain name is willing to pay for the return of domain name, cybersquatters increased. Cybersqatters are not genuine users of the Internet. This article is to compare the construction of law by American Courts and by Korean Courts and to assert the creation of the law similar to the law of US as to anti-cybersqatting. American Courts applied the Trademark Act and the Anti-Dilution Act to resolve the disputes over domain name. To apply the Trademark Act, the Court required the plaintiffs to prove that the goods or the services expressed by the domain name should be identical or similar to the goods or the services represented by the trademark. However, there were many cases where the holder of domain name used it for the goods or the services irrelevant to those of the holder of trademark. Also, the Anti-Dilution Act could not successfully protect the holder of trademark from cybersquatters because it required that the trademark should be famous or distinctive. As a result, the US promulgated a new law which is designed to prohibit cybersquatters from being free of sanction by the existing laws. Korea Courts applied the Trademark Act and the Unfair Competition Prohibition Act to the cases disputing domain name. Likewise in the US, Korean Courts must cope with the issue of identity of the goods or the services, and the famousness or distinctiveness of trademark. The Courts hesitate to give a winning judgement to the holder of trademark simply because the domain name of alleged violator confused the trademark. Some scholars advocate the broadening of construction of the Unfair Competition Prohibition Act to illegalize cybersquatting but it is beyond the meaning of the law. Accordingly, it is a time to make a law similar to the Anti-Cybersquatting Act of the US. The law must be a fair and reasonable compromise to resolve the collision between system of registration of domain name and the system of registration of trademark. Some commentators advocate that the registration of domain name should be examined just as the one of trademark and to facilitate it, the Patent and Trademark Office should have jurisdiction of registration of domain name. But it abandons the distinction of domain name and trademark and results in obstructing e-commerce. By adopting the Anti-Cybersqatting Act, we can prohibit it. In other cases, we get a reasonable adjustment between the holder of domain name and the holder of trademark through the Trademark Act and the Unfair Competition Prohibition Act.

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Synthesis of Forsterite with High Q and Near Zero TCf for Microwave/Millimeterwave Dielectrics

  • Ohsato, Hitoshi;Ando, Minato;Tsunooka, Tsutomu
    • Journal of the Korean Ceramic Society
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    • v.44 no.11
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    • pp.597-606
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    • 2007
  • With the advent of ubiquitous age, the high quality dielectric materials have been required for the wireless communications available to the millimeterwave as well as microwave frequencies. The utilizable region for the frequency has been expanding to the millimeter-wave region because of the shortage of radio frequency (RF) resources. These high frequencies would be expected for ultra high speed LAN, ETS and car anti-collision system on the intelligent transport system (ITS) and so on. Silicates are good candidates for microwave/millimeterwave dielectrics, because of their low dielectric constant ${\epsilon}_r$ and high quality factor (High Q). Forsterite ($Mg_2SiO_4$) is one of the silicates with low ${\epsilon}_r$ of 6.8 and Q f of 240000 GHz. In this paper, we reviewed following three categories for synthesis of forsterite: (1) Synthesis of high Q forsterite (2) Adjust the temperature coefficient of resonant frequency $TC_f$ (3) Diffusion of $SiO_{4^-}$ and Mg-ions on the formation of forsterite.

STAC/EPS Algorithm for Fast Tag Identification in RFID System (RFID 시스템에서 고속 태그 식별을 위한 STAC/EPS 알고리즘)

  • Lim, Intaek
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.5
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    • pp.931-936
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    • 2016
  • The PS algorithm divides the number of tags within the identification range of reader into smaller groups by increasing the transmission power incrementally and identifies them. It limits the number of responding tags by grouping the tags within the identification range of the reader, and thus can reduce the probability of tag collision. Also, in the PS algorithm, the reader takes advantages of the difference of identification ranges. This algorithm uses the fixed frame size at every scan. Therefore, it has problems that the performance can be shown variously according to the number of tags and frame size. In this paper, we propose an EPS algorithm that allocates the optimal frame size by estimating the number of tags at each scan, and apply it into the STAC protocol. The simulation results showed that STAC/EPS algorithm can improve the identification delay about 45% compared with STAC protocol. Also, it provides a stable identification delay regardless of power level increase.

Performance Analysis of RFID Interference Suppression System Based on the Gold Code (골드 코드 기반의 RFID 간섭제거 시스템 성능분석)

  • khadka, Grishma;Hwang, Suk-Seung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.10
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    • pp.1491-1497
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    • 2013
  • Radio frequency identification (RFID) is an important and essential components of ubiquitous computing, with the development of wireless communication technologies and mobile computing environment. Recently, RFID becomes the mainstream application that helps fast handling and uniquely identifying the physical objects. It utilizes the electromagnetic energy for data transmission from a tag to a reader in the presence of arbitrary interference and noise. In order to employ the portable mobile RFID reader, a tag-collision problem between two or more adjacent tags should be considered. In this paper, we present the operation of RFID system in which numerous tags are present in the interrogation zone of a single reader at the same time. Since there may exist a number of tagged objects in the narrow area, multiple RFID tags may interfere each other, caused to degrade the data reliability and efficiency of the RFID system. In order to suppress interference signals from multiple neighboring tags, we present an application of Gold code for RFID communication system, which uses spread spectrum technique. In this RFID system, data bits are spreaded in each tags with the unique Gold code and the spreaded data bits are despreaded in the reader with the same Gold code. The performance analysis of the considered RFID anti-collision system is illustrated via computer simulation examples.

Ship Detection Using Background Estimation of Video and AIS Informations (영상의 배경추정기법과 AIS정보를 이용한 선박검출)

  • Kim, Hyun-Tae;Park, Jang-Sik;Yu, Yun-Sik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.12
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    • pp.2636-2641
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    • 2010
  • To support anti-collision between ship to ship and sea-search and sea-rescue work, ship automatic identification system(AIS) that can both send and receive messages between ship and VTS Traffic control have been adopted. And port control system can control traffic vessel service which is co-operated with AIS. For more efficient traffic vessel service, ship recognition and display system is required to cooperated with AIS. In this paper, we propose ship detection system which is co-operated with AIS by using background estimation based on image processing for on the sea or harbor image extracted from camera. We experiment with on the sea or harbor image extracted from real-time input image from camera. By computer simulation and real world test, the proposed system show more effective to ship monitoring.