• Journal of information and communication convergence engineering
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• 제6권1호
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• pp.110-116
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• 2008

A RFID is an automatic data collection system based on the radio frequency and is the key technology of ubiquitous computing environments. Since the locations of objects attached by RFID tags can be acquired by readers, it is possible to query the locations of tags. To query tags efficiently, the data of RFID tags should be modeled and indexed. However, since the location information of tags, the predicates of queries, are differ from coordinates of moving objects, it is difficult to model tags under the concept of moving objects, In this paper, we propose the location model of tags to represents the trajectories of tags. The location model is composed of the set and graph based approaches.

• 한국정보컨버전스학회:학술대회논문집
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• 한국정보컨버전스학회 2008년도 International conference on information convergence
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• pp.47-52
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• 2008

A radio-frequency identification(RFID) tag is a small, inexpensive microchip that emits an identifier in response to a query from a nearby reader. The price of these tags promises to drop to the range of $0.05 per unit in the next several years, offering a viable and powerful replacement for barcodes. The challenge in providing security for low-cost RFID tags is that they are computationally weak devices, unable to perform even basic symmetric-key cryptographic operations. Security researchers often therefore assume that good privacy protection in RFID tags is unattainable. In this paper, we explore a notion of minimalist cryptography suitable for RFID tags. We consider the type of security obtainable in RFID devices with a small amount of rewritable memory, but very limited computing capability. Our aim is to show that standard cryptography is not necessary as a starting point for improving security of very weak RFID devices. Our contribution is threefold: 1. We propose a new formal security model for authentication and privacy in RFID tags. This model takes into account the natural computational limitations and the likely attack scenarios for RFID tags in real-world settings. It represents a useful divergence from standard cryptographic security modeling, and thus a new view of practical formalization of minimal security requirements for low-cost RFID-tag security. 2. We describe protocol that provably achieves the properties of authentication and privacy in RFID tags in our proposed model, and in a good practical sense. Our proposed protocol involves no computationally intensive cryptographic operations, and relatively little storage. 3. Of particular practical interest, we describe some reduced-functionality variants of our protocol. We show, for instance, how static pseudonyms may considerably enhance security against eavesdropping in low-cost RFID tags. Our most basic static-pseudonym proposals require virtually no increase in existing RFID tag resources.

• 한국통신학회논문지
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• 제35권2B호
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• pp.263-268
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• 2010

본 논문에서는 작은 폐쇄된 철재 캐비닛 안에 설치된 작은 UHF RFID 태그를 사용하여 열쇠관리 시스템을 개발하였다. 보안상 열쇠를 안전한 곳에 보관하기 위해서 잠글 수 있는 철재 캐비닛을 사용하였고, 열쇠의 유무를 실시간으로 파악하기 위해서 RFID 리더기와 안테나 그리고 설계된 태그가 사용되었다. 철재 캐비닛에는 6개의 랙에 360개의 태그 안테나가 있다. 각 1개의 랙에는 60개의 태그안테나와 열쇠, 열쇠고리가 보관되어 관리된다. 태그 안테나용 RFID 칩은 Gen2를 사용하였고, 시스템 안에 응용 프로그램은 태그의 정보 ID와 수신 안테나 정보를 TCP/IP 프로토콜을 통하여 호스트 컴퓨터에게 전달하여 호스트 컴퓨터에 데이터베이스와 연동하는 프로그램이다. 또한 360개의 태그를 읽기를 위한 여러 실험과 비교 결과와 최적의 안테나의 위치에 의한 인식률과 리더기 Bios에 따른 인식률도 비교 하였다.

• 대한전자공학회논문지TC
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• 제43권2호
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• pp.44-48
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• 2006

본 연구는 국내외RFID 태그 개발업체 현황을 살펴보고, 요즘 해외에서 많은 관심을 끌고있는 RFID Chipless태그 생산 방식별 해외 업체 현황 및 해외 주요 개발업체의 기술 현황을 살펴보아 국내 chipless 태그의 개발 방향을 수립하는데 도움을 주고자 했다. 구체적으로 해외의 대표적인 chipless .태그 개발업체인 Inkode사와 RFSAW사의 제품 정보 기록 방법, 정보 해독 방법, 제품 특성 등을 조사 하였다.

• 제어로봇시스템학회논문지
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• 제12궈1호
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• pp.15-22
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• 2006

This paper presents an efficient localization scheme for an indoor mobile robot using RFID tags on the floor. The mobile robot carries an RFID reader at the bottom, which reads the RFID tags on the floor to localize the mobile robot. Each RFID tar on the floor stores its own absolute position which is used to calculate the position and velocity of the mobile robot. Locating the RFID tags on the floor, which constructs an intelligent sensor space, may require several factors to be considered: economics feasibility and accuracy. In this paper, the optimal allocation scheme of the RFID tags on the floor to satisfy the accuracy constraint has been proposed and verified by the experiments. Based on the RFID reading, the mobile robot navigation has been successfully demonstrated to avoid obstacles and to reach the goal within a pre-specified time.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.203-206
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• 2005

Recently, the RFID(Radio Frequency Identification) technology has gained significant attention. One of the performance issues in RFID systems is to resolve the tag collision among responses from RFID tags. In this paper, we proposed a new scheme for estimation of the number of tags in the reader filed. The scheme is used by anti-collision algorithm to identify multiple tags efficiently. And we also present the simulation result that shows the proposed scheme to estimate tags efficiently and also to improve the systems efficiency.

• Journal of information and communication convergence engineering
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• 제7권2호
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• pp.164-169
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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 (Framed Slot ALOHA) 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.

• 경영과학
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• 제29권3호
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• pp.1-11
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• 2012

This paper considers a localization problem in time difference of arrival (TDOA)-based radio frequency identification (RFID) systems. To estimate the position of a target tag, this paper suggests three localization algorithms that use benchmark tags. The benchmark tags are the same type as the target tag, but either the locations or distance of the benchmark tags are known. Two algorithms use the benchmarks for auxiliary information to improve the estimation accuracy of the other localization algorithms such as least squared estimator (LSE). The other one utilizes the benchmarks as essential tags to estimate the location. Numerical tests show that the localization accuracy can be improved by using benchmark tags especially when an algorithm using the LSE is applied to the localization problem. Furthermore, this paper shows that our benchmark algorithm is valuable when the measurement noise is large.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1797-1801
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• 2005

SLAM(Simultaneous localization and mapping) and AI(Artificial intelligence) have been active research areas in robotics for two decades. In particular, localization is one of the most important issues in mobile robot research. Until now expensive sensors like a laser sensor have been used for the mobile robot's localization. Currently, as the RFID reader devices like antennas and RFID tags become increasingly smaller and cheaper, the proliferation of RFID technology is advancing rapidly. So, in this paper, the smart floor using passive RFID tags is proposed and, passive RFID tags are mainly used to identify the mobile robot's location on the smart floor. We discuss a number of challenges related to this approach, such as RFID tag distribution (density and structure), typing and clustering. In the smart floor using RFID tags, because the reader just can senses whether a RFID tag is in its sensing area, the localization error occurs as much as the sensing area of the RFID reader. And, until now, there is no study to estimate the pose of mobile robot using RFID tags. So, in this paper, two algorithms are suggested to. We use the Markov localization algorithm to reduce the location(X,Y) error and the Kalman Filter algorithm to estimate the pose(q) of a mobile robot. We applied these algorithms in our experiment with our personal robot CMR-P3. And we show the possibility of our probability approach using the cheap sensors like odometers and RFID tags for the mobile robot's localization on the smart floor.

• 한국정보통신학회논문지
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• 제13권3호
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• pp.469-474
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• 2009

RFID 시스템은 식별되고자하는 사물에 부착된 태그들과 이를 인식하는 리더로 구성된다. 기존의 바코드 시스템과는 달리, 태그와 리더간에 접촉이 없이도 저장된 정보를 읽을 수 있는 특징이 있다. 이러한 비접촉 특성으로 인하여 RFID 기술은 다양한 응용 분야에서 바코드를 대신할 기술이 될 것이다. 13.56MHz 대역을 사용하는 대부분의 RFID 시스템은 리더 의 식별 영역에 있는 다중 태그를 식별하기 위하여 FSA 알고리즘을 사용한다. FSA 알고리즘인 경우, 식별 영역내에 있는 태그의 수와 프레임의 크기에 따라 태그식별 지연 시간과 시스템 효율이 크게 변화한다. 본 논문에서는 이러한 RFID 시스템에서 태그의 수를 추정하고, 추정한 태그의 수를 기반으로 프레임 크기를 동적으로 할당하는 기법을 제안한다.