• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.2
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• pp.481-487
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• 2013

To successfully accomplish a bit synchronization, a synchronizer should exploit a preamble pattern. A MFM (modified frequency modulation) flag is uses as a preamble in a PJM (phase jitter modulation) mode RFID standard. In the recent work, a synchronizer for a PJM mode tag was proposed, which is composed of several correlators. In this paper, we present a new bit synchronizer in which a coarse synchronization is done as in the previous work while a fine synchronization is performed via exploiting a violation bit included in the MFM flag. We show that the proposed synchronizer can significantly reduce the overall hardware complexity at the expense of slight burden to a demodulator structure. Through simulation, we also show that its performance is comparable to that of the previous system despite its hardware simplicity.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.6 s.312
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• pp.61-67
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• 2006

In this paper it was introduced that embedded RFID Reader /Writer system including PXA255 ARM chip which enables the Tag signal to be used by data and video processing via IEEE 802.11 communication protocol. Embedded RFID R/W middle ware was developed which transmit the searched result in the data base using the received Tag signal via IEEE 802.11 communication protocol. Developed embedded RFID R/W system was composed of three parts - PXA255 ARM chid (Core Part) 13.56 MHz RFID Reader /Writer, wireless LAN for data communication with server and TFT-LCD terminal. Once this system receives the Tag signal through the serial port, it transmits the data through the wireless LAN to the server and it displays the received image data which was processed by the server onto the TFT-LCD screen. Embedded RFID R/W Middle ware transmits the received Tag signal from RFID R/W to the embedded system, which activates the socket program to connect to the window server via IEEE 802.11 communication protocol and transmits the Tag signal. Window server program searches the Database using this Tag information and displays the result on to the TFT-LCD window in the embedded system via IEEE 802.11 protocol.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.703-704
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• 2006

RFID/USN means a way of attaching RFID to all required objects to identify them and exchanging the required information through the network. High frequency (13.56MHz) has been commonly used in the field of processing management in Korea, and extremely short wave (433.92MHz) has been used for harbor logistics management by being attached to containers in the US. As for SCM field where we need to have a broader understanding, the research on $860{\sim}960MHz$, a sort of extremely short wave has been most actively conducted. Therefore, in-this study, in order to understand the features of all frequencies ranging and to design and implementation of RFID Middle System suitable for realizing u-Logistics by using those diverse frequencies.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.2
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• pp.98-102
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• 2006

Recent development of Information Technology, the ubiquitous computing environment is on the rise. At the same time, RFID technology and its related applications are actively investigated. In this paper, a portable merchandise information providing system using cheap wireless transmission module is developed in order to overcome the mobility limitation of the wired RFID system. The TRF6901 chipset of 900MHz band from TI is used for the wireless transmission module and the MPS430F149 is used for the MPU. It is expected that the developed system can be applied to numerous innovative wireless applications such as library circulation desk for lending service and automated door system for entrance control.

• 전자공학회논문지 IE
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• v.48 no.4
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• pp.40-46
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• 2011

In this paper, we introduce a hybrid RFID reader to recognize the pets. There is no the RFID reader to recognize a different types of frequency simultaneously. The RFID reader with 134.2 KHz has disadvantages with limited recognition radius and direction. The developed reader is dual-frequency RFID reader (134.2 KHz, 13.56 MHz) that is capable of identifying the pets with a different types of tags. The prototype model in the field test shows that the recognition coverage increases compared to the imported reader.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.807-812
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• 2015

In RFID system, when multiple tags respond simultaneously, a collision can occur. A method that solves this collision is referred as anti-collision algorithm. In 13.56MHz RFID system of Auto-ID center, STAC protocol is defined as an anti-collision algorithm for multiple tag reading. The PS algorithm divides the tags within the identification range of reader into smaller groups by increasing the transmission power incrementally and identifies them. In this paper, we propose a STAC/PS algorithm that the PS algorithm is applied in the STAC protocol. Through simulations, it is demonstrated that the collision rate for the proposed algorithm is about 50% lower than STAC protocol. Therefore, the STAC/PS algorithm can achieve faster tag identification speed compared with STAC protocol due to the low collision rate.

• Proceedings of the IEEK Conference
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• summer
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• pp.334-338
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• 2004

In this paper, we suggest a new antenna structure for RFID(Radio Frequency IDentification) reader. Conventional RFID reader uses a loop antenna. The central area of a loop antenna shows a low magnetic field strength especially for the case of a large loop antenna diameter. We propose a parallel-fed multiple loop antenna. Simulation results and measured results show that we can adjust field distribution with the number of turns and diameter of an inner loop antenna to obtain a longer reading distance. Simulation results for the specific case of a proposed antenna structure show that at the center point of a proposed parallel-fed multiple loop antenna, the typical card area averaged magnetic field strength is 2.53A/m, which is higher than the case of a conventional type single loop antenna of 0.44A/m and the case of a series-fed multiple loop antenna of 0.96A/m when we drive with same source signal. We realized the antenna for the case of 13.56MHz RFID reader and the performance of reading distance was much more improved than the case of a conventional antenna.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.9
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• pp.1569-1574
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• 2008

Almost all the RFID systems in the 13.56MHz ISM band adopt the FSA algorithm as the anti-collision algorithm. The FSA algorithm is based on the slotted ALOHA with a fixed frame size. The FSA, though simple, has a disadvantage that when the number of tags is variable, the system performance degrades because of the fixed frame size. Therefore, this paper proposes a new OFSA. The proposed OFSA algorithm dynamically allocates the optimal frame size at every frame based on the number of tags in the reader's identification range. According to the simulation results, the system efficiency of the proposed algorithm should be maintained optimally. Also, the proposed algorithm always obtained the minimum tag identification delay.

• Journal of Advanced Navigation Technology
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• v.13 no.3
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• pp.393-398
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• 2009

In this paper, we study the design and implementation of an auto recognition system by using wireless sensor node. RFID system has a limited communication range and communication network is damaged, it is impossible to communicate. Therefore, easy installation and low cost wireless system are required in an area where the installation of communication between RFID system and monitoring system is difficult, or a portable RFID system is installed. The auto recognition system in this study is implemented by the combination of 13.56MHz RFID system using MLX12115 RFID chip of Melexis company and wireless sensor node system using CC2420 Zigbee chip of Chipcon company. As a result, we develop an auto recognition system which makes it possible to get tag's information wirelessly. Also, it has a simple circuit structure and is small in size.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.444-446
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• 2011

RFID(13.56MHz)를 이용한 자동 트래킹 시스템은 기본적으로 RFID 안테나와 리더부, Card(Tag)로 구성된다. 본 논문에서는 RFID 안테나의 크기와 출력 거리에 영향을 미치는 최적 Capacitance 값을 도출하는 방법을 제시한다. 제시한 방법의 타당성을 검토하기 위하여 RFID 안테나의 크기가 $0.0856{\times}0.05398m$이고 출력거리가 10~12cm에 가장 적합한 Capacitance 값을 도출하여 시제품를 설계 제작하여 정상적인 동작 상태를 확인하였다.