• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.7 s.361
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• pp.9-15
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• 2007

In this paper, we present the design of Schottky diodes and voltage multiplier for UHF-band passive RFID applications. The Schottky diodes were fabricated using Titanium (Ti/Al/Ta/Al)-Silicon (n-type) junction in $0.35\;{\mu}m$ CMOS process. The Schottky diode having $4{\times}10{\times}10\;{\mu}m^{2}$ contact area showed a turn-on voltage of about 150 mV for the forward diode current of $20\;{\mu}A$. The breakdown voltage is about -9 V, which provides sufficient peak inverse voltage necessary for the voltage multiplier in the RFID tag chip. The effect of the size of Schottky diode on the turn-on voltage and the input impedance at 900 MHz was investigated using small-signal equivalent model. Also, the effect or qualify factor of the diode on the input voltage to the tag chip is examined, which indicates that high qualify factor Schottky diode is desirable to minimize loss. The fabricated voltage multiplier resulted in a output voltage of more than 1.3 V for the input RF signal of 200mV, which is suitable for long-range RFID applications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.1-8
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• 2016

Automation of inventory management in a steel plate factory was a difficult problem unresolved for a long time. And now, it is also necessary to work diligently in the steel industry on efficient inventory management of thick plates. So far, the environmental characteristics of stacked thick plates means it is not easy to apply advanced technology for their automatic identification. In this paper, we propose a thick-plate robotic scanning system based on radio-frequency identification (RFID) that can provide quick and accurate inventory management by acquiring plate information after the scanning automatically recognizes the RFID tags under difficult load conditions. This system is equipped with a crane to move the plates in a pulled-up operation. It is equipped with a plate-only linear dipole antenna only for scanning the position of the plate tag. Only the linear dipole antenna, while moving the x-axis and y-axis information, automatically identifies the tag information attached to the plate. The tag information acquired by the system is used for stockpiling and is managed by steel plate inventory control software. The effectiveness of the proposed system is verified through field performance evaluation. As a result, the recognition rate of the plate tags is 99.9% at a maximum distance of 320 cm. The developed thick-plate antenna showed excellent performance compared to an existing commercial antenna.

• Journal of the Korean Society for information Management
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• v.28 no.1
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• pp.171-193
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• 2011

This study aims to analyse the necessity of the subject heading construction for the word based classification and to suggest a methodology that uses various knowledge organization systems(KOS). For this purpose, six kinds of KOS were collected for the 20 selected works in each subject. The collected subjects were analysed in terms of constructing a subject heading for the word based classification. The result of the analysis shows that there is a noticeable difference between the library oriented KOS and commercial oriented KOS. In addition, user oriented tags are more similar to the commercial sector's concerning subject categorization than the library oriented ones. However, there is no noticeable difference among the library oriented KOS, commercial sector oriented KOS, and user oriented tags regarding the subject vocabulary. Some practical implications were suggested for the application to the Korean libraries based on the findings of this study.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.373-377
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• 2012

The management system using the current RFID technology has the effects of reducing working hours and improvement in data processing, but it is not proper for human resource allocation since it is dominantly worked for physical resources. In this paper, we analyzed personnel control system using RFID of diverse environment and kinds of design in ship which analyzes presents of a monitoring system for safety operation and increase of efficiency in order to overcome the limitations and problems of current personnel operation management techniques using RFID.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.78-79
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• 2009

본 연구에서는 ZnO계 투명전극 소재를 이용하여 RFID 태그 안테나에 적용 가능성 여부를 확인하였다. Si 기판위에 RF 스퍼터링 공정에 의해 Ga-doped ZnO 투명 마이크로스트립 스파이혈 안테나를 $2{\mu}m$를 증착하여 구현하고 그 전기적 특성을 측정하였다. HFSS 전자계 시뮬레이터를 사용하여 13.56MHz HF 주파수 대역에서 태그 안테나로서의 가능성을 검증한 후 Ga-doped ZnO 타겟을 사용한 RF 스퍼터링 공정에 의하여 스파이럴 안테나 패턴을 구현하였다. 마이크로스트립 선폭 및 선 간격을 $50\sim200{\mu}m$때 영역에서 조절하면서 안테나 패턴을 설계하였다. S 파라메터, 자기공진주파수 및 Q값을 시뮬레이션으로부터 도출하였다. Al $2{\mu}m$ 증착한 시편에 비하여 약 -10dB 정도의 이득저하가 발생하였으나 리더-태그를 밀착시킨 조건에서 1.7V (13.56MHz) 전압검출이 가능하였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.4
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• pp.64-71
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• 2008

SAW (Surface Acoustic Waves) ID (identification) tags have been designed and implemented for RFID (Radio frequency IDentification) systems. With SAW ID tag of pulse position encoding method, the data capacity increased 3 times compared with SAW ID tag of amplitude on/off method. Two different kinds of SAW ID tag receiver systems, heterodyne and homodyne receiver systems, were made. The direct conversion receiver showed better isolation property, 10 dB improvement than the heterodyne receiver to increase wireless interrogation distance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.15-21
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• 2014

Due to the development of manufacturing technology scaling, more transistors can be placed on a cache memories of a processor. However, processors become more vulnerable to the soft errors because of highly integrated transistors, the reliability of cache memory must consider seriously at the design level. Various researches are proposed to overcome the vulnerability of soft error, but researches of tag bit are proposed very rarely. In this paper, we revaluate the reliability improvement technique for tag bit, and analyse the protection rate of write-back operation, which is a typical case of not satisfying temporal locality. We also propose the methodology to improve the protection rate of write-back operation. The experiments of the proposed scheme shows up to 76.8% protection rate without performance degradations.

• 전자공학회논문지 IE
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• v.48 no.2
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• pp.52-60
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• 2011

RFID is method used on wireless system. However, this mechanism is not used for authentication and security. Therefore, it is very vulnerable to attacks such as dropping attacks and traffic attacks. the RFID Tags are of the limited nature due to environment factors and there is greater constraints in designing authentication protocol. If we do not RFID to secure corporate information and product all the information will be exposed. The attacker will break into the RFID system and stop the distribution system. So, this paper proposes a new authentication protocol which provides not only unlimited access to Tag&Reader and connection between Tag and Reader bet also provides authentication mechanism by defining the key distribution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11A
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• pp.1159-1166
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• 2006

In this paper, we have designed a RFID reader receiver system for improving the performance of the passive Tag based 9$'908.5{\sim}914MHz'$ RFID reader, and analyzed the system performance according to the frequency, the reader, and tag properties. The commercial receive system causes a loss in sensitivity because of 24 capacitors and 6 inductors. So we have designed an improved system using a circulator, LNA and a SAW filter. The experimental results show that the use of a circulator to separate the Tx/Rx paths eliminates interference, the LNA improves the sensitivity of the Rx module and SAW filter eliminates the noise and spurious components in the received signal.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.12 s.115
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• pp.1240-1248
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• 2006

This paper presents an UHF band(911 MHz) RFID tag antenna which has near-isotropic radiation pattern and easy conjugate impedance matching characteristics to any commercial chips of usual practice through the application of an inductively-coupled feeding. The proposed antenna of compact size $40{\times}46mm\;(0.12{\times}0.14{\lambda})$ has, at normal incidence, the maximum RCS of $-18.5dBm^2$ and the 3 dB RCS bandwidth of 9 MHz(1 %) in case of short chip load. It has the maximum and minimum RCS' of $-16.9dBm^2\;and\;-21.4dBm^2$ depending on the incident angles. The difference of about 4.5 dB is relatively small compared with that (about 70 dB) of a pure dipole antenna. The designed antenna has been fabricated and its RCS' have been measured varying the angles of incidence. The measured RCS' have been found to have good agreement with the simulated ones.