• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.1247-1252
• /
• 2005

Recently, Ubiquitous Computing is being actively researched and one of the main technology in ubiquitous computing environment is recognized as RFID system. The RFID system is automatic recognition technique using radio frequency that attached a tag to product read information and able to record without physical contact. In this paper, classification of tag, an operation, structure and etc of the RFID system and described on the 900MHz region radio antenna radiation characteristics.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1478-1482
• /
• 2005

Since it is a very issue that figures out a current position of mobile robots, various methods have been proposed until nowadays. This paper proposes the sensor model of RFID(Radio Frequency Identification) and position estimation algorithm for mobile robots. We designed the sensor model of RFID in experimenting repeatedly. The sensor model of RFID in this case is that of stochastics according to sensing rate. Based on this stochastic sensor model, we designed the algorithm which estimates distance and direction of RFID tag. Therefore we made sure that RFID tag is used as landmark.

• The KIPS Transactions:PartA
• /
• v.12A no.5 s.95
• /
• pp.405-412
• /
• 2005

In the process of distributing blood many troubles are arising. In order to establish a drastic solution, the current distribution must be reviewed as well as its problems must be clearly grasped. This paper introduces RFID(Radio Frequency Identification) system to solve the problems, which arise in the process of distribution, and to systemically manage blood. Among various RFID systems, the reader and tag suitable to the blood distribution are designed. Likewise, through constructing a DB that can cognize electronic tags, objects and blood-distributing RFID system are designed.

• Proceedings of the Korea Society of Information Technology Applications Conference
• /
• 2005.11a
• /
• pp.267-270
• /
• 2005

An RFID patch antenna for metallic object has been designed. The effects of variation of distance between the tag antenna and ground of the antenna have been studied. Various dielectric constants, thickness, permittivity, width of transmission line and length of transmission line have been used to design the better tag antenna for metallic object.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.817-819
• /
• 2011

Most of the sources of security and privacy issues in RFID technology arise from the violation of the air interface between a tag and its read. Most of the sources of security and privacy issues in RFID technology arise from the violation of the air interface between a tag and its reader. This paper will approach consideration of security analysis with cryptographic primitive based on hardware basis.

• Proceedings of the KAIS Fall Conference
• /
• 2008.05a
• /
• pp.104-107
• /
• 2008

본 논문에서 제안하는 시스템은 기존의 RFID 시스템의 보안성을 높이기 위하여 2차원 배열 기법을 이용하여 안전성을 확보할 수 있게 되었다. 제안하는 시스템은 RFID Tag의 고유 ID 값인 UID값과 2차원 배열을 이용하여 태그와 리더간 인증을 하게 된다. 제안하는 시스템에서 암 복호화를 하기 위해서는 태그의 고유 ID값인 UID값과 관리자가 정의한 키셋을 이용한 암 복호화 과정에서의 안전성을 기존의 다른 시스템과의 비교를 통해 우수함을 입증한다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.12
• /
• pp.8760-8766
• /
• 2015

In this paper a technology which gives directions to people and also localization of the robotic vacuum cleaners inside some spacious buildings is developed. For this purpose, it is confirmed that which pattern has a small error in dealing with the indoor localization with various RFID tag arrangements attached on the ground. This experiment was conducted by using MT92(900MHz range Antenna) and ALR 9900+(Reader). As a result, the square arrangement has the least error, 21.19cm, among other patterns which are diamond, rectangle and regular hexagon. However, it is necessary to consider the number of tags in the unit area, from this point of view the regular hexagon arrangement is the most efficient arrangement among other patterns because it needs only 6 tags in the unit area.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.10a
• /
• pp.578-581
• /
• 2007

For tracing tag locations, a trajectories should be modeled and indexed in radio frequency identification (RFID) systems. The trajectory of a tag can be represented as a line that connects two spatiotemporal locations captured when the tag enters and leaves the vicinity of a reader. If a tag enters but does not leave a reader, its trajectory is represented only as a point captured at entry. Because the information that the tag stays in the reader is missing from the trajectory represented only as a point, we should extend the region of a query to find the tag that remains in a reader. In this paper, we propose an interval data model of tag's trajectory in order to solve the problem. Trajectories of tags are represented as two kinds of intervals; dynamic intervals which are time-dependent lines and static intervals which are fixed lines. We also show that the interval data model has better performance than others with a cost model

• Journal of Internet Computing and Services
• /
• v.8 no.4
• /
• pp.51-59
• /
• 2007

This paper presents the development of RFID educational system based on using 900MHz air interface between the reader and the active tag. The software of reader and the active tag is developed on embedded environment, and the software of PC controlling the reader is based on window OS operated as the server. The AT89C51ED2 VLSI chip is used for the processor of the reader and the active tag. As the development environment, Keil compiler is used for the reader and the active tag of which the programing language is C. The visual C language of the visual studio on the PC activated as the server is used for development language. To verify the function of the system, PC gets the tag's identification number through the reader and send the data to with the active tag memory a certain contents as "wite" operation. Finally the data written from the active tag's memory is sent to the PC via the reader as "read" operation and compare the received data with one already sent to the tag.

• 한국정보통신설비학회:학술대회논문집
• /
• 2008.08a
• /
• pp.469-472
• /
• 2008

In this paper, we discuss the recent trends on the passive UHF RFID tag chip design techniques and several important system parameters. We also summarize link budget studies on both conventional and modem UHF RFID communications. The paper highlights the reverse link limited case, which has known to be the minor concern if reader continuous wave (CW) can reach the tag in sufficient level. This makes sense when the tag sensitivity is rather high (over 10-12${\mu}W$); however, since the tag chip fabrication technologies have been developed by time, the tag chip threshold levels are now less-dominant in determining link margin. If the tag limitation can be alleviated, the forward link limited case can be resolved; thus, we rather focus on the path-loss problem. Since the path-losses are still exist in both forward and reverse links, and it can be doubled while CW travels the reader-tag-reader path because forward link and reverse link are on the same distance. Consider if reader receiver sensitivity is very high in the worst case. In this case, weaken tag response (i.e., backscatters) cannot reach the level that reader receiver can process tag data; bit-error rate can be higher. Overall, backscatter levels should be high enough so that reader receiver can correctly function. After discussing link budget, we carried out practical measurements on fading effects between two circularly polarized UHF RFID antennas in a small scale area.