• Journal of the Korean Graphic Arts Communication Society
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• v.13 no.1
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• pp.93-104
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• 1995

Liquid crystal-polymer composite(LCPC) films promising new materials for both projection displays and vision product. LCPC films consist of a continous liquid crystal phase embedded in a three- dimensional network of polymer matrix. The liquid crystal in these LC phases can be elecrtrically switched giving rise to an opaque scattering off-stats and a transparent, non-scatting on- stats. In this work. a premixture is composed of LC, UV-curable monomer and photonitiator. LCPC films are formed by photopolymerization induced phase separation from this premixture. In conclusion, structure and electro-optical properties of LCPC films strongly depends on the selection of monomer, LC content and curing rate.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.109-117
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• 2016

The most important mission of RFID reader is identify EPC (Electronic Product Code) of RFID tag of products that located within distinguishable range of RFID reader. RFID reader transmits query message to RFID tags through wireless channel and RFID tags send unique EPC to response its query message simultaneously. therefore tag collision occurred frequently. RFID tags collision resolution algorithm required to apply RFID technology to various industries. In this paper, we propose enhanced M-ary algorithm that collision bits location is used by not only RFID reader but also tags. the main feature of the proposed algorithm is that integrate multiple query message of M-ary QT algorithm to the single query message by analyze multiple response messages from tags. the simulation results show that the proposed algorithm give better performance than M-ary QT algorithm in terms of the number of query-response, identification efficiency and communication overhead.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.334-344
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• 2009

The EPCglobal Network is a system which provides the information of items to suppliers, consumers, and customers by granting identification numbers on the goods based on the technologies of EPC(Electronic Product Code) and RFID(Radio Frequency Identification), and connecting the space to store those information by network. The EPCglobal architecture framework is also a service consolidating supply and process chain by using EPC for the common goal of business corporations. In the national level, it is necessary to define standard vocabularies for each location and logistics business process for RFID environment using the pre-constructed logistics information infrastructure. Therefore, we define the standard vocabularies and partially user vocabularies for international logistics on EPCglobal network architecture. Finally, we believe that our vocabularies contribute to describing the events fur the EPCglobal network architecture and actually providing usable platform via the XML implementation.

• The Journal of the Korea Contents Association
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• v.7 no.6
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• pp.185-194
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• 2007

Today, there is in the world-wide cognition about RFID technology due to established standard, EPC(Electronic Product Code). RFID technology will have wide influence over various fields. Especially, RFID technology's advantages will have positive influence on logistics field. We can solve limited various problems presented in SCM by applying RFIB technology. We can have higher cantrol system, better benefits and actual decision information. Many organizations, however, still have hesitated now because RFID technology has not been validated and RFID technology is in early stage. Other problems are employee resistance against new technology and lack of academic empirical research on assimilation RFID technology for organization. Above reasons I mentioned make me study on analysis on assimilation RFID technology decision in SCM field. This study attempts to analyze the assimilation RFID technology factor from previous researches by using AHP. This outcomes of study will be helpful when we assimilate RFID technology in SCM fields.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.771-774
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• 2010

In this paper, BER performance of LDPC(Low-Density Parity-Check) decoder for WiMAX is analyzed, and optimal design conditions of LDPC decoder are derived. The min-sum LDPC decoding algorithm which is based on an approximation of LLR sum-product algorithm is modeled and simulated by Matlab, and it is analyzed that the effects of LLR approximation bit-width and maximum iteration cycles on the bit error rate(BER) performance of LDCP decoder. The parity check matrix for IEEE 802.16e standard which has block length of 2304 and code rate of 1/2 is used, and AWGN channel with QPSK modulation is assumed. The simulation results show that optimal BER performance is achieved for 7 iteration cycles and LLR bit-width of (8,6).

• Journal of Intelligence and Information Systems
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• v.11 no.2
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• pp.105-121
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• 2005

To realize a ubiquitous logistics management system using the smart object of Electronic Product Code(EPC) enabled RFID tag, the design and management of RFID Information Service is very important. RFID Information Service searches, transfers and responds to the other's PML request, but Physical Markup Language (PML) data management between trading system elements has issues of standardization of PML data description and processing, and problems of data traffic and communication time overload because of the innate distributed characteristics. As a complementary study, this research analyzes the usage patterns and data types of PML. On that analysis we provide a design of the distributed RFID Information Service architecture of PML data management that is using DB middleware. Standalone and Integrated type of RFID IS were proposed.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.590-595
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• 2005

RFID is rising as a means which recognizes products efficiently and correctly. The use of RFID technology can reduce the expense of excess stocktaking, forgery, labor and improve supply network. RFID technology uses RF to recognize the products. EPC, a small tag, is attached to each product, which includes specific product information. Each EPC is only one and can recognize each product. If EPC tag moves to a specific location, the reader reads the tag, the data of which get to be stored in EPC information service, a data storage system. All services can approach EPC information service through web and whenever users demand services, they are provided with the data they want. This study shows an inventory control system is implemented by EPC information service.

• Journal of the Korean Society of Fashion and Beauty
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• v.6 no.1
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• pp.16-20
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• 2008

Ubiquitous computing which is called, the innovation of the 21st Century is a core technology of next generation. RFID technology is noticed, and physical distribution, home network, telematics, like industry automatization are developed by using various technique. Particulary, They use RFID technology for fashion and beauty industry, So, supplying network management, physical distribution management and warehouse management are investigated for the automatization. What we have investigated so far, a traceability system is made of ubiquitous sensor network for monitoring fashion and beauty industry environment. The proposed system using EPC network can provide information of industrial products traceability quickly and efficiently. Moreover, this system with RFID Technology gives intelligence of distribution and record. In this paper, We recommend the vision of Ubiquitous convergence of fashion and beauty industry.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.4
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• pp.240-245
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• 2006

Viterbi decoder is composed of BMU(Branch metric Unit), ACSU(Add Compare Select Unit), and SMU(Survivor path Memory Unit). For high speed viterbi decoders, ACSU is the main bottleneck due to the compare-select and feedback operation. Thus, many studies have been advanced to solve the problem. For example, M-step look ahead technique and Minimized method are typical high speed algorithms. In this paper, we designed a bit-level ACSU(K=3, R=1/2, 4bit soft decision) based on those algorithms and switched the matrix product order in the backward direction of Minimized method so as to apply Code-Optimized-Array in order to reduce the area complexity. For experimentation, we synthesized our design by using SYNOPSYS Design compiler, with TSMC 0.18 um library, and verified the timing by using CADENCE verilog-XL.

• Journal of Communications and Networks
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• v.17 no.4
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• pp.351-361
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• 2015

In this paper, a new decoding scheme is proposed to improve the error correcting performance of low-density parity-check (LDPC) codes in high signal-to-noise ratio (SNR) region by using post-processing. It behaves as follows: First, a conventional LDPC decoding is applied to received LDPC codewords one by one. Then, we count the number of word errors in a predetermined number of decoded codewords. If there is no word error, nothing needs to be done and we can move to the next group of codewords with no delay. Otherwise, we perform a proper post-processing which produces a new soft-valued codeword (this will be fully explained in the main body of this paper) and then apply the conventional LDPC decoding to it again to recover the unsuccessfully decoded codewords. For the proposed decoding scheme, we adopt a simple product code structure which contains LDPC codes and simple algebraic codes as its horizontal and vertical codes, respectively. The decoding capability of the proposed decoding scheme is defined and analyzed using the parity-check matrices of vertical codes and, especially, the combined-decodability is derived for the case of single parity-check (SPC) codes and Hamming codes used as vertical codes. It is also shown that the proposed decoding scheme achieves much better error correcting capability in high SNR region with little additional decoding complexity, compared with the conventional LDPC decoding scheme.