• 한국통신학회논문지
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• 제35권3B호
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• pp.462-473
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• 2010

RFID(Radio-Frequency IDentification) 시스템은 개인 정보의 노출 및 위치 추적과 같은 보안상 문제점을 가지고 있다. 이러한 문제점을 해결하기 위해 해쉬함수와 같은 암호학적 접근방법들은 안전성을 증명하고 있지만 태그의 연산능력과 저장 공간의 한계로 인해 현실적으로 적용하기 어렵다. 최근의 경량 인증기법들은 단순 연산자만을 사용하여 높은 효율성을 보장하지만 안전성에 관한 주장이 충분하지 못하다. 본 논문에서는 안전한 RFID 인증을 위해서 대칭키 방식의 AES(Advanced Encryption Standard)를 이용하며 대칭키 방식에서의 고정된 키를 사용하던 문제를 단계적인 키 변환을 통해 해결한다. 프로토콜에서 태그와 서버의 동일한 대칭키는 태그, 리더, 백-엔드-서버에서 각각 생성된 난수를 이용하여 차례로 변환되며 태그와 리더의 출력 값을 항상 변경한다. 이와 같이 단계적으로 변환된 키를 이용할 경우 태그 정보의 노출 문제를 해결하며 도청, 재전송, 위치추적 및 스푸핑과 같은 공격에도 안전한 상호 인증이 이루어진다.

• 중소기업융합학회논문지
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• 제4권2호
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• pp.1-5
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• 2014

RFID/USN은 u-Korea를 구현하는 핵심 인프라로서 무한한 성장 잠재력을 내포하고 있으며 향후 인터넷에 이어 산업 전반에 커다란 변혁을 가져올 수 있는 분야로 대두되고 있다. 우리나라의 경우 u-Korea 비전과 세계적인 RFID/USN 기술을 확보하여 세계 시장을 선점하고자 하는 IT839 정책에 따라 RFID/USN에 대한 관심도가 사회 전반적으로 증대되어 USN에 대한 연구가 활발히 이루어지고 있으며 앞으로 USN 인프라 구축이 완료됨에 따라 USN을 활용하기 위한 USN 어플리케이션들이 빠르게 증가할 것이다. USN 인프라 기반의 어플리케이션 개발을 보다 손쉽게 하기 위해 USN 미들웨어의 필요성이 대두되며 디렉토리 서비스는 USN 미들웨어를 구성하는 핵심 서비스 중의 하나이다. 그러나 USN 구성요소인 WSN의 특성 등을 고려할 때 USN 인프라에 적합한 디렉토리 서비스는 검색에 중점을 둔 기존의 디렉토리 서비스와 달리 갱신문제가 나타날 수 있으며 본 논문은 이를 극복할 수 있는 디렉토리 서비스의 설계 및 구현에 대해 논한다.

• 산업경영시스템학회지
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• 제32권2호
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• pp.120-131
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• 2009

Most world-leading companies are aware that Environment and Health and Safety Issues are critical to the product quality and sustainable growth of their company. Environment-friendly efforts are seen in almost all aspects of business operations in an advanced nation. The Extended Producer Responsibility(EPR) and EU Directive on Waste Electric and Electronic Equipment(WEEE) attempt to tackle the growing quantity of WEEE by making producers responsible for the costs of the collection and recycling of their products at the End-of-Life(EOL). To implement the RFID-based integration system for EOL household electric appliances, such as washing machines and refrigerators, we analyzed the process of collecting, recovering, and recycling the EOL products returned from the distribution points. Furthermore, we proposed a soon-to-be process using the RFID-based integration system in the metropolitan recycling center(MRC). This soon-to-be process model is composed of RFID tags, readers, ALEs, applications and several devices. Through the introduction of the RFID-based integration system, we are expecting to see increasing traceability and real-time management for EOL products from customers, and also improvements in valuable reusable materials(VRM) produced from recycling processes.

• 산업경영시스템학회지
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• 제38권1호
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• pp.170-181
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• 2015

Generally, because individual agricultural product possesses its own distinctive characteristics and shows different characteristics at each stage of the agricultural supply chain, it is necessary to develop a proper enterprise architecture for managing information system. In this paper, we propose an enterprise architecture based on RFID/USN technology that can be used as a reference enterprise architecture for u-IT application in the agriculture sectors, which is called the u-Farm enterprise architecture with taking heterogeneous characteristics of agricultural products into account for. In addition, we also developed the RFID/USN middleware platform as a core infrastructure technology. Fo evaluation of the performance of the proposed u-Farm architecture and the RFID/USN middleware platform, the field-trial evaluation at the apple Agricultural Processing Center (APC) has been executed and the results shows that the proposed architecture and platform perform well in terms of information integration over the whole SCM process from the farming stage to delivering statge to the customers. It is expected that the proposed u-Farm enterprise architecture can be utilized as a standard information architecture, and the RFID/USN middleware platform can be a infrastructure platform for future u-IT based information technology applications and services in the agricultural environment.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.879-881
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• 2010

사회의 급속한 발전으로 다변화되어 핵가족화, 1인가구화 등 전통적인 가족기능의 변화로 인해 노인들은 고향집에 홀로 남겨지는 경우가 많다. 그러면서 노인들이 홀로 있으면서 건강관리와 안전상의 문제가 제기되어 왔다. RFID 기술의 급속한 발전과 함께, 그 애플리케이션은 우리 삶의 모든 영역을 확장하고 다양한 산업의 주요 주제가 되어있다. 현대사회의 급속한 경제성장, 그리고 과학과 의학의 발전은 노인들의 평균수명 연장이 연장되었고 그로인해 노인들의 안전한 보호시스템이 필요한 실정이다. 본 논문에서의 self-care 시스템은 RFID(Radio Frequency Identification)를 이용하며, 사용자를 인증하고 TTS(Text To Speech)로 문자신호를 음성신호로 변환하고, 적외선 방사 기술을 이용하여 집을 효과적으로 보호하고 또 전자 혈압 측정기를 통하여 고령자의 신체를 검사하는 기술로 설계된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권1호
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• pp.165-182
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• 2014

An RFID systems employ efficient Anti-Collision Algorithms (ACAs) to enhance the performance in various applications. The EPC-Global G2 RFID system utilizes Frame Slotted Aloha (FSA) as its ACA. One of the common approaches used to maximize the system performance (tag identification efficiency) of FSA-based RFID systems involves finding the optimal value of the frame length relative to the contending population size of the RFID tags. Several analytical models for finding the optimal frame length have been developed; however, they are not perfectly optimized because they lack precise characterization for the timing details of the underlying ACA. In this paper, we investigate this promising direction by precisely characterizing the timing details of the EPC-Global G2 protocol and use it to derive a precise-optimal frame length model. The main objective of the model is to determine the optimal frame length value for the estimated number of tags that maximizes the performance of an RFID system. However, because precise estimation of the contending tags is difficult, we utilize a parametric-heuristic approach to maximize the system performance and propose two simple schemes based on the obtained optimal frame length-namely, Improved Dynamic-Frame Slotted Aloha (ID-FSA) and Exponential Random Partitioning-Frame Slotted Aloha (ERP-FSA). The ID-FSA scheme is based on the tag set estimation and frame size update mechanisms, whereas the ERP-FSA scheme adjusts the contending tag population in such a way that the applied frame size becomes optimal. The results of simulations conducted indicate that the ID-FSA scheme performs better than several well-known schemes in various conditions, while the ERP-FSA scheme performs well when the frame size is small.

• 산업기술연구
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• 제26권A호
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• pp.147-152
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• 2006

Wireless Sensor Networks provide a new paradigm for sensing and disseminating information from various environments, with the potential to serve many and diverse applications. Recent advancement in wireless communications and electronics has enabled the development of low-cost sensor networks. The sensor networks can be used for various application areas. For different application areas, there are different technical issues that researchers are currently resolving. The current state of the art of sensor networks is captured in this article, where solutions are discussed under their related protocol stack layer sections. This article also points out the open research issues and intends to spark new interests and developments in this field. In order to evaluate the application of field monitoring system, lab tests, field test and FEM analysis are conducted. Therefore the accuracy of RFID wireless sensor data is verified.

• 한국전기전자재료학회논문지
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• 제16권10호
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• pp.881-886
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• 2003

This paper describes the design and implementation of a passive transponder chip for RFID applications. Passive transponders do not have their own power supply, and therefore all power required for the operation of a passive transponder must be drawn from the field of the reader. The designed transponder consists of a full wave rectifier to generate a dc supply voltage, a 128-bit mask ROM to store the information, and Manchester coding and load modulation circuits to be used for transmitting the information from the transponder to the reader. The transponder with a size 410 x 900 ${\mu}$m$^2$ has been fabricated using 0.65 ${\mu}$m 2-poly, 2-metal CMOS process. The measurement results show the data transmission rate of 3.9 kbps at RF frequency 125 kHz.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.3997-4015
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• 2014

Radio frequency identification (RFID) is an emerging wireless communication technology which allows objects to be identified automatically. The tag anti-collision is a significant issue for fast identifying tags due to the shared wireless channel between tags and the reader during communication. The EPCglobal Class-1 Generation-2 which uses Q algorithm for the anti-collision is widely used in many applications such as consumer electronic device and supply chain. However, the increasing application of EPCglobal Class-1 Generation-2 which requires the dynamic environment makes the efficiency decrease critically. Furthermore, its frame length (size) determination and frame termination lead to the suboptimal efficiency. A new anti-collision algorithm is proposed to deal with the two problems for large-scale RFID systems. The algorithm has higher performance than the Q algorithm in the dynamic environment. Some simulations are given to illustrate the performance.

• 전기학회논문지
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• 제56권11호
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• pp.1982-1987
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• 2007

This paper presents the design and analysis of LNA-Mixer for 2.45GHz RFID reader. The LNA is implemented by PCSNIM method for low power consumption. The Mixer is implemented by using the Gilbert-type configuration, current bleeding technique and the resonating technique for the tail capacitance. The connection between the two designed circuits is made by active balun. This LNA-Mixer has about 22dB gain and 8.5dB Noise Figure for -50dBm input RF power, LO power is 0dBm, RF frequency is 2.45 GHz and IF frequency is 100kHz. The layout of LNA-Mixer for one-chip design in a 0.18-um TSMC process has $2.5mm{\times}1.0mm$ size.