• 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.

• The KIPS Transactions:PartD
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• v.17D no.2
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• pp.157-166
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• 2010

More recently, RFID (Radio Frequency Identification) systems have begun to find greater use in various industrial fields. The use of RFID system in these application domains has been promoted by efforts to develop the RFID tags which are low in cost, small in size, and high in performance. The RFID applications enable the real-time capture and update of RFID tag information, while simultaneously allowing business process change through real-time alerting and alarms. These be developed to monitor person or objects with RFID tags in a place and to provide visibility and traceability of the seamless flows of RFID tags. In this time, the RFID readers should be placed in diverse locations, the RFID flows between these readers can be tested based on various scenarios. However, due to the high cost of RFID readers, it may be difficult to prepare the similar environment equipped with RFID read/write devices. In this paper, we propose a simulator to allow RFID application testing without installing physical devices. It can model the RFID deployment environment, place various RFID readers and sensors on this model, and move the RFID tags through the business processes. This simulator can improve the software development productivity by accurately testing RFID middleware and applications. In addition, when data security cannot be ensured by any fault, it can decide where the problem is occurred between RFID hardware and middleware.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.01a
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• pp.227-228
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• 2012

실외에서의 위치추적은 GPS(Global Positioning System) 등의 다양한 방법이 활용가능하다. 하지만 실내에서는 사용이 어려워 비전, RFID 및 Zigbee 등을 활용한 다양한 연구가 진행되고 있다. 본 연구에서는 비교적 비용 효과적으로 구축이 가능한 수동형 RFID 태그를 기반 이동형 로봇의 위치 추적 알고리즘을 제안하도록 한다. 총 7 종의 태그에 대하여 각 태그가 가지고 있는 특성을 실험을 통하여 분석하고 분석한 결과에 따라 태그를 배치하여 효과적으로 로봇의 이동에 따른 위치 추적 및 이동방향 예측방법을 기술한다. 제안하는 방법을 실험실 환경에서 레고 마인드스톰을 활용하여 그 효용성을 나타내도록 한다.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.40-50
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• 2009

Incorrect deployment of RFID readers occurs reader-to-reader interferences in many applications using RFID technologies. Reader-to-reader interference occurs when a reader transmits a signal that interferes with the operation of another reader, thus preventing the second reader from communicating with tags in its interrogation zone. Interference detected by one reader and caused by another reader is referred to as a reader collision. In RFID systems, the reader collision problem is considered to be the bottleneck for the system throughput and reading efficiency. In this paper, we propose a novel RFID reader anti-collision algorithm based on evolutionary algorithm(EA). First, we analyze characteristics of RFID antennas and build database. Also, we propose EA encoding algorithm, fitness algorithm and genetic operators to deploy antennas efficiently. To show superiority of our proposed algorithm, we simulated our proposed algorithm. In the result, our proposed algorithm obtains 95.45% coverage rate and 10.29% interference rate after about 100 generations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.33-34
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• 2010

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.67-74
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• 2009

Incorrect deployment of RFID readers occurs reader-to-reader interferences in many applications using RFID technologies. Reader-to-reader interference occurs when a reader transmits a signal that interferes with the operation of another reader, thus preventing the second reader from communicating with tags in its interrogation zone. Interference detected by one reader and caused by another reader is referred to as a reader collision. In RFID systems, the reader collision problem is considered to be the bottleneck for the system throughput and reading efficiency. In this paper, we propose a novel RFID reader anti-collision algorithm based on evolutionary algorithm(EA). First, we analyze characteristics of RFID antennas and build database. Also, we propose EA encoding algorithm, fitness algorithm and genetic operators to deploy antennas efficiently. To show superiority of our proposed algorithm, we simulated our proposed algorithm. In the result, our proposed algorithm obtains 95.45% coverage rate and 10.29% interference rate after about 100 generations.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.2
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• pp.164-172
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• 2008

This paper presents the efficient localization of a mobile robot traveling on the floor with tags installed, using the spatial and temporal information acquired from passive RFID environment. Compared to previous research, the proposed localization method can reduce the position estimation error and also cut down the initial cost tag installation cost. Basically, it is assumed that a mobile robot is traveling over a series of straight line segments, each at a certain constant velocity, and that the number of tags sensed by a mobile robot at each sampling instant is at most one. First, the velocity and position estimation of a mobile robot starting from a known position, which is valid for all segments except the first one. Second, for the first segment in which the starting position is unknown, the velocity and position estimation is made possible by enforcing a mobile robot to traverse at least two tags at a constant velocity with the steering angle unchanged. Third, through experiments using our passive RFID localization system, the validity and performance of the mobile robot localization proposed in this paper is demonstrated.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.400-402
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• 2001

컴포넌트는 소프트웨어 재사용의 핵심 기술로 인식되고 있으며, 현재 많은 수의 컴포넌트가 개발되고 사용되고 있다[9]. 많은 수의 컴포넌트들 중에서 특정 도메인에 이미 적절하다고 판단된 컴포넌트를 검색해서 사용하는 과정이 필수적이며[6], 이를 위해서 컴포넌트에 대한 정확한 명세서가 뒷받침 되어야 한다. 본 논문에서 다루고 있는 컴포넌트 모델의 하나인 썬(Sun)社의 EJB ver1.1 은 배치설명파일(Deployment Descriptor)을 XML로 기술하고 있으며, DTD로 Validation 체크를 하고 있다. 그러나 DTD 는 표현할 수 있는 데이터 타입에서 한계를 가지며 하나의 XML은 여러 개의 DTD 파일을 가질수 없기 때문에 확장성에서도 취약함을 나타낸다. 이를 해결하기 위해서 XSchema 로 변환하였다. 또한 현재 EJB 의 배치설명파일에서는 컴포넌트의 결합 및 의존성에 대한 표현이 부족하기 때문에 이를 보완하기 위해서 컴포넌트 Contract 에 대한 속성들을 기반으로 하여 새로운 태그를 지정해보도록한다.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.530-535
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• 2021

In this paper, the design method for a chipless RFID tag using ELC resonators is proposed. A four-bit chipless RFID tag is designed in a two by two array configuration using three ELC resonators with different resonant peak frequencies and one compact IDC resonator. The resonant peak frequency of the bistatic RCS for the IDC resonator is 3.125 GHz, whereas those of the three ELC resonators are adjusted to be at 4.225 GHz, 4.825 GHz, and 5.240 GHz, respectively, by using the gap between the capacitor-shaped strips in the ELC resonator. The spacing between the resonators is 1 mm. Proposed four-bit tag is fabricated on an RF-301 substrate with dimensions of 50 mm×20 mm and a thickness of 0.8 mm. It is observed from experiment results that the resonant peak frequencies of the fabricated four-bit chipless RFID tag are 3.290 GHz, 4.295 GHz, 4.835 GHz, and 5.230 GHz, respectively, which is similar to the simulation results with errors in the range between -2.3% and 0.2%.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.10
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• pp.1-5
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• 2011

A magnetic resonant coil system for enhancement of wireless power transfer efficiency of NFC devices was proposed. The NFC system consists of resonant coils arrange between source coil and device coil. The effects of resonant coil was measured using a 13.56MHz RFID reader and tag system and simulated by 3D RF simulator. The measurement results from RFID reader and tag show that the maximum distance of signal transmission is increased by 96.72% and received voltage of RFID tag is grew by 17.95% thanks to the magnetic resonant coils.