• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.9-17
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• 2015

One of RFID features is that each RFID tag has a unique identifying code. Logistic System utilizes RFID tag as location tracing, understanding stock or etc. On the other hand, there is a problem of overall lower recognition rate by getting the information of non-mobility tags with no need for reading. To solve this problem, we trace and analyze variation of moving and moveless RFID tag sensitivity by the hour. In analyzed data, we verify that tag sensitivity of mobile RFID is gradually increase while non-mobility tag has same intensity value. In order to detect mobile tag, we generate a function using Matlab with analyzed data and separate moving tags from non-mobility tags by software. As a result, we can confirm that non-mobility tags are detected by software and recognition rate of RFID tag is improved by separating moveless tag.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.1B
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• pp.85-94
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• 2010

Many RFID systems use dynamic slotted ALOHA to identify the label information of the RFID tags. One of the key problems in the RFID system is how to estimate the number of RFID tags up to the desired level of accuracy. In this paper, we present the framework of tag estimation algorithm for the collision-oblivious (CO) reader which can only decide whether the tag response is successful or not. Thus, the CO reader must rely on the success estimator to predict the RFID tag population. We propose two estimation algorithms to predict the number of RFID tags, named the memoryless success estimator (MSE) and the intersection-based success estimator (ISE). The MSE considers only the estimate obtained at the current inventory round, while the ISE finds an appropriate intersection interval of the existing estimates collected at every inventory round. Through the simulation results, we demonstrate that the ISE is a fast, accurate, and controllable estimator whose performance is close to that of the collision/idle estimators.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1493-1498
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• 2012

RFID technology plays an important role in building a ubiquitous environment. As RFID tags are widely used, it is necessary to enhance the performance of massive tag writes. A tag write tends to fail since it is performed through the weak radio wave communication. In this paper, we propose a write scheme that to enhance the performance of massive RFID tag writes. In proposed scheme, tag writes performed in parallel by multiple readers connected to a middleware. Write operations are distributed among readers and tags are written in groups. We show that proposed scheme can increase the success ratio of massive tag writes through experimental tests.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.8
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• pp.1943-1949
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• 2010

In this paper, we developed a RFID tag antenna using one-sheet inlay pattern which consist of two different frequencies in one layer. The antenna in one-sheet inlay RFID tag does not use different kind RFID antennas in a card but implement 13.56MHz and 900MHz RFID tag antennas in one sheet. In order to evaluate the usability of proposed method, we configured test equipments and designed 6 different patterns and test the recognition distance of each pattern. Among the one-sheet inlay RFID tag antenna designs, the pattern no.5 has good performance with recognition distance of 5.34m at 900MHz and 3.5m at 13.56MHz.

• 전자공학회논문지 IE
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• v.48 no.4
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• pp.7-12
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• 2011

This paper described a metal mount RFID tag that works reliably on metallic surface. The proposed method is to use commercial RFID tags, Styrofoam103.7 material is attached on back side of RFID tag. Styrofoam103.7 material which has 2.5 mm thickness and 1.03 relative permittivity, was attached on back side of RFID tag. In order to verify the performance of proposed method, we evaluated the experiment on the supply chain system of electric transformers using RFID. The experimental results on supply chain of electric transformers show that the proposed tags can communicate with readers from a distance of 2 m. The results of recognition rates are comparable to commercial metallic mountable tags.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.61-64
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• 2004

RFID 시스템에서 태그와 리더 사이의 통신은 Radio Frequency를 이용해서 이루어짐으로 공격자에 의해 도청될 수 있으며, 태그의 정보가 노출되면 사용자의 프라이버시 침해 문제를 가져올 수 있다. RFID 태그의 프라이버시를 보호하기 위해 제안된 대부분의 기존 방식들은 태그의 ID를 식별하기 위해 모든 태그에 대한 정보를 가지고 식별 과정을 수행해야 하는 비효율성을 가지고 있다. 본 논문에서는 태그의 출력을 매번 다르게 변화시켜, 태그에 대한 위치 추적을 불가능하게 하고, 3번의 지수연산만으로 해당 태그를 식별할 수 있는 RFID 가변 정보화 방식을 제안한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.195-202
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• 2011

RFID(Radio Frequency IDentification) is a system to identify objects and its usage is being extended to distribution, healthcare, and air&port etc. RFID is a contactless system environment, and reducing tag authentication time is important because multiple tags are identified at the same time. Studies about RFID system so far is, however, mostly to improve security vulnerability in the tag authentication process. Therefore, this paper suggests an efficient scheme to decrease the time of tag authentication which is also safe for the security of tag authentication process. The proposed scheme cuts down on the tag ID search time because it searches only the classified relevant ID in the database, which is one of many components of RFID system, by using identification bits for tag ID search. Consequently, the suggested scheme decreases process time for tag ID authentication by reducing the processing time and the load of the database. It also brings performance improvement of RFID system as it improves the energy applicability of passive tag.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.10
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• pp.909-914
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• 2012

The paper introduces the RFID location based Tree Management System (TMS) using UHF RFID tag and GPS. The bolt shape tag has been developed since the wood material has high dielectric constant. Since the characteristics and impedance of tag antenna can be changed by the material next to the tag, the plastic bolt shape tag antenna has to be carefully designed with consideration of the high dielectric constant of the wood material. The RFID TMS system has been utilized with the bolt shape tag antenna and GPS. The TMS system uses and links Google map to locate the location of the trees. Therefore, this system allow us to manage the trees economically and efficiently.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.12
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• pp.1013-1022
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• 2012

Tag collection is one of the major concerns in radio frequency identification(RFID) system. All tags in RFID reader's transmission range send response message back to the reader in response to collection request message on the given rf channel. When multiple tags respond simultaneously, tag-collision may occur. Tag-collision problem is one of the most important issues in active RFID performance. To mitigate this problem, frame slotted ALOHA(FSA) anti-collision protocol is widely used in active RFID system. Several studies show that the maximum system efficiency of FSA anti-collision protocol is 36.8%. In this paper, we propose an efficient slotted CSMA/CA protocol to improve tag collection performance. We compare our protocol to the FSA anti-collision protocol. For the experiment, an 433MHz active RFID system is implemented, which is composed of an RFID reader and multiple tags. We evaluated the tag collection performance using one RFID reader and 40 tags in the real test bed. The experimental result shows that proposed protocol improves the tag collection time, round and collision probability by 18%, 37.4% and 77.8%, respectively.

• Journal of the Korea Society of Computer and Information
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• v.14 no.7
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• pp.89-95
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• 2009

This paper proposes a tag indexing scheme for RFID tag using spatial index. The tag being used for the inventory management and the tag's location is determined by the position of readers. Therefore, the reader recognizes the tag, which is attached products and thereby their positions can be traced down. In this paper, we propose hTag-tree( Hybrid Tag index) which manages RFID tag attached products. hTag-tree is a new index, which is based on tag's attributes with fast searching, and this tag index manages RFID tags using reader's location. This tag index accesses rapidly to tags for insertion, deletion and updating in dynamic environment. This can minimize the number of node accesses in tag searching comparing to previous techniques. Also, by the extension of MER in present tag index, it is helpful to stop the lowering of capacity which can be caused by parent node approach. The proposed index experiment deals with the comparison of tag index. Fixed Interval R-tree, and present spatial index, R-tree comparison. As a result, the amount of searching time is significantly shortened through hTag-tree node access in data search. This shows that the use of proposed index improves the capacity of effective management of a large amount of RFID tag.