• Journal of Korea Society of Industrial Information Systems
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• v.13 no.2
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• pp.80-87
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• 2008

RFID systems are being studied and developed in the area of the industry and marketplace. Recently RFID systems are core element of the ubiquitous technologies in individual life and industry. However, RFID systems often cause some serious problems such as violation of privacy and information security because their contactless devices communicate each other by radio frequency In this paper, we propose multiple objects RFID tag scheme including tag structure and authentication protocol. The proposed RFID tag structure maintains several object IDs of different applications in a tag memory. The tag structure allows those applications to access object IDs simultaneously. The authentication protocol for multiple objects tag is designed ta overcome the problems of security and privacy. The protocol has robustness against various attacks in low cost RFID systems. We evaluate the efficiency of proposed scheme and compare security of our scheme with several traditional schemes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1497-1501
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• 2005

Branch instructions which make the sequential instruction flow changed cause pipeline stalls in microprocessor. The pipeline hazard due to branch instructions are the most serious problem that degrades the performance of microprocessors. Branch target buffer predicts whether a branch will be taken or not and supplies the address of the next instruction on the basis of that prediction. If the hanch target buffer predicts correctly, the instruction flow will not be stalled. This leads to the better performance of microprocessor. In this paper, the architecture of a ta8 memory that branch target buffer and TLB can share is presented. Because the two tag memories used for branch target buffer and TLB each is replaced by single combined tag memory, we can expect the smaller chip size and the faster prediction. This shared tag architecture is more advantageous for the microprocessors that uses more bits of address and exploits much more instruction level parallelism.

• Journal of KIISE:Information Networking
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• v.34 no.5
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• pp.316-327
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• 2007

RFID (Radio Frequency Identification) is one of the most promising air interface technologies in the future for object identification using radio wave. If there are multiple tags within the range of the RFID tag reader, all tags send their tag identifications to the reader at the same time in response to the reader's query. This causes collisions on the reader and no tag is identified. A multi-tag identification problem is a core issue in the RFID. It can be solved by anti-collision algorithm such as slot based ALHOA algorithms and tree based algorithms. This paper, proposes a collision tree based anti-collision algorithm using collision tree in RFID system. It is a memory-less algorithm and is an efficient RFID anti-collision mechanism. The collision tree is a mechanism that can solve multi-tag identification problem. It is created in the process of querying and responding between the reader and tags. If the reader broadcasts K bits of prefix to multiple tags, all tags with the identifications matching the prefix transmit the reader the identifications consisted of k+1 bit to last. According to the simulation result, a proposed collision tree based anti-collision algorithm shows a better performance compared to tree working algorithm and query tree algorithm.

• Applied Chemistry for Engineering
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• v.23 no.6
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• pp.515-520
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• 2012

In this review, the fabrication of silicon based memory capacitor and organic memory thin film transistors (TFTs) was discussed for their potential identification tag applications and biosensor applications. Metal or non-metal nanoparticles (NPs) could be capped with chemicals or biomolecules such as protein and oligo-DNA, and also be self-assembly monolayered on corresponding target biomolecules conjugated dielectric layers. The monolayered NPs were formed to be charging elements of a nano floating gate layer as forming organic memody deivces. In particular, the strong and selective binding events of the NPs through biomolecular interactions exhibited effective electrostatic phenomena in memory capacitors and TFTs formats. In addition, memory devices fabricated as organic thin film transistors (OTFTs) have been intensively introduced to facilitate organic electronics era on flexible substrates. The memory OTFTs could be applicable eventually to the development of new conceptual devices.

• The KIPS Transactions:PartC
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• v.15C no.6
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• pp.469-480
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• 2008

The recently proposed RFID(Radio Frequency Identification) authentication protocol based on a hash function can be divided into two types according to the type of information used for authentication between a reader and a tag: either a value fixed or one updated dynamically in a tag memory. In this paper, we classify the protocols into a static ID-based and a dynamic-ID based protocol and then analyze their respective strengths and weaknesses. Also, we define a new security model including forward/backward traceability, synchronization, forgery attacks. Based on the model, we analyze the previous protocols and propose a new dynamic-ID based RFID mutual authentication protocol. Our protocol provide enhanced RFID user privacy compared to previous protocols and identify a tag efficiently in terms of the operation quantity of a tag and database.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.28-36
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• 2008

This paper describes a low-power CMOS analog front-end block for UHF band RFID tag chips. It satisfies ISO/IEC 18000-6C and includes a memory block for test. For reducing power consumption, it operates with an internally generated power supply of 1V. An ASK demodulator using a current-mode schmitt trigger is proposed and designed. The proposed demodulator can more exactly demodulate than conventional demodulator with low current consumption. It is designed using a $0.18{\mu}m$ CMOS technology. Measurement results show that it can operate properly with an input as low as $0.25V_{peak}$ and consumes $2.63{\mu}A$. The chip size is $0.12mm^2$.

• Journal of Internet of Things and Convergence
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• v.9 no.2
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• pp.1-9
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• 2023

This study was conducted for the purpose of improving the usability of the product through the usability evaluation of the voice tag reader to improve the life convenience of the visually impaired. Perceived usability evaluation was conducted for 19 evaluation items based on the evaluation model considering the usability principle and the characteristics of the visually impaired. A total of 50 participants were included for the analysis. As a result of the perceived usability evaluation of the visually impaired, the safety of the voice tag reader, voice and sound quality, and accuracy of voice information were relatively satisfactory. It was found that the reader received a low evaluation in terms of efficiency in use, including the size and weight of the reader, and the convenience of carrying and storing. For the usability improvement, the procedure for using a product needs to be more simplified, and it would be helpful to input and supply tags for commonly used objects in advance.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.24-27
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• 2007

주기억 색인 기법인 Tmr-트리가 R-트리에 비해서 삽입시간이 오래 걸린다는 단점이 있다. 본 논문은 L2 캐시를 최대한 활용하여 기존 Tmr-트리의 장점을 가지는 새로운 CSTmr-트리(Cache Sensitive Tmr-트리)구조를 제안하고, 이 구조에 삽입, 삭제 등의 알고리즘을 제안하였다. 제안한 구조와 알고리즘을 다른 인덱스 구조와 비교하여 CSTmr-트리의 우수성을 보인다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.1001-1010
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• 1999

Thermo-mechanical behavior of discontinuous shape memory alloy(SMA) reinforced polymeric composite has been studied using modified shear lag theory and finite element(FE) analysis with 2-D multi-fiber model. The aligned and staggered models of short-fiber arrangement are employed. The effects of fiber overlap and aspect ratio on the thermomechanical responses such as the thermal expansion coefficient are investigated. It is found that the increase of both tensile stress(resistance stress) in SMA fiber and compressive stress in polymer matrix with increasing aspect ratio is the main cause of low thermal deformation of the composite.

• IE interfaces
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• v.20 no.2
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• pp.227-234
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• 2007

The national product identifier(NPI) currently used in the national product asset management system does not accommodate ISO or EPC standards due to the limitation of tag memory. For this reason, we propose a new NPI which accommodates not only ISO item identification standards but also the memory capacity of ISO tags. First of all, memory structures of ISO/IEC 18000-6C and EPC tags are analyzed from the view point of product identifier structure. Second, ISO/IEC 15459 and EPC identification standards as item identifier structures for the product asset management are analyzed. Third, based on these analyses, the NPI used for the current RFID-based product asset management system is analyzed and its problems are presented. Finally, a new NPI structure is proposed suitable for ISO/IEC 18000-6C and ISO/IEC 15459.