• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.1-11
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• 2004

This paper presents an implementation of smart antenna system channel card that executes modulation/demodulation. Operations and performances of modules of implemented channel card is confirmed and field test of channel card shows the performance of smart antenna systems. Based on the analysis obtained from the field test in cdma2000 1x environments which contains multipath lading, it is confirmed that smart antenna system channel card provide exact beampattern to the DOA and performance of proposed channel card has better FER by 5∼8 times, compared to 2 antenna diversity system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.81-86
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• 2016

In this paper, we present multi-channel authentication based security card design. Since this security card is written on the transparent paper, security information is extracted by overlaying the card with smartphone screen. This method removes the limitations of physical layout in previous security card and improves the security level. Furthermore, our security card is secure when our card is exposed to malicious users.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12A
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• pp.1172-1176
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• 2008

In this paper, we describe the implementation and performance of a dual-mode Software Define Radio (SDR) smart antenna base station system. SDR technology enables a communication system to be reconfigured through software downloads to the flexible hardware platform that is implemented using programmable devices such as Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGAs), and microprocessors. The presented base station channel card comprises the physical layer (pHY) including the baseband modem as well as the beamforming module. This channel card is designed to support TDD High-Speed Downlink Packet Access (HSDPA) as well as Wireless Broadband Portable Internet (WiBro) utilizing the SDR technology. We first describe the operations and functions required in WiBro and TDD HSDPA. Then, we explain the channel card design procedure and hardware implementation. Finally, we evaluate WiBro and TDD HSDPA performance by simulation and actual channel-card-based processing. Our smart antenna base-station dual-mode channel card shows flexibility and tremendous performance gains in terms of communication capacity and cell coverage.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.5
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• pp.641-649
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• 2016

In this paper, a novel time-domain measurement technique on a high parallelism probe card with protection resistors installed is proposed. The measured signal amplitude decreases when the measurement is performed by Needle Auto Calibration (NAC) probing on a high parallelism probe card with installed resistors. Therefore, the original signals must be carefully reconstructed, and the compensation coefficient, which is related to the number of channel branches and the value of protection resistors, must be introduced. The accuracy of the reconstructed signals is analyzed based on the varying number of channel branches and various protection resistances. The results demonstrate that the proposed technique is appropriate for evaluating the overall signal performance of probe cards with Automatic Test Equipment (ATE), which enhances the efficiency of probe card performance test dramatically.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.3
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• pp.501-507
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• 2015

The online banking service handles a banking business over the internet, it is necessary to ensure that all financial transactions are processed securely. So, there are various authentication technique for e-banking service : a certificate, a personal identification number(PIN), a security card and a one-time password(OTP). Especially, the security card is most important means including secret information. If the secret information of card is leaked, it means not only loss of security but also easy to attack because security card is a difficult method to get. In this paper, we propose that a multi-channel security card saves an secret information in distributed channel. Proposed multi-channel security card reduces vulnerability of the exposed and has a function to prevent phishing attacks through decreasing the amount of information displayed and generating secret number randomly.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.6
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• pp.1045-1053
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• 2014

In this paper, we assume that the information leakage through side-channel signal may occur from the card payment terminal and newly introduce a real application attack model. The attack model is a side channel attack based on vibration signals, which are detected by a small sensor attached on card terminal by attacker. This study is similar to some other studies regarding side channel attack. However, this paper is different in that it is based on the non-language model. Because the financial transaction information such as a card number, password, mobile phone number and etc cannot have a constant pattern. In addition, there was no study about card terminal. Therefore, this new study is meaningful. We collected vibration signals on card terminal with a small wireless sensor and analyzed signal data with statistical signal processing techniques using spectrum of frequency domain and principal component analysis and pattern recognition algorithms. Finally, we evaluated the performances by using real data from the sensor.

• ETRI Journal
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• v.10 no.4
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• pp.118-126
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• 1988

A numerical analysis was performed for the flow field in the vertical channels consist of dummy cards and active cards to define the hydrodynamic role of dummy card which is often installed in electronic equipment between active cards to control the cooling air distribution. For a given velocity profile at the inlet and a pressure-based boundary condition at the outlet of the computation domain, the percentage of the flow rate distribution through active channel and dummy channel formed by an active card and dummy card, respectively, were investigated. As a result of present analysis, the pecentage of flow rate through active channel increases quadraticaly with the increase of the ratio of the height of barrier to the width of the dummy channel.

• The Magazine of the IEIE
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• v.22 no.12
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• pp.27-44
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• 1995

초고속 통신망에 근간이 되는 ATM 통신망에 SUN W/S, PC 컴퓨터들을 접속시키는 ATM Adapter Card은 하드웨어, 시스템 소프트웨어 및 응용 소프트웨어로 구성된다. 하드웨어의 구조 및 시스템 소프트웨어의 구조, 성능에 따라서 ATM Adapter Card 위에서 수행되는 응용 소프트웨어의 성능을 결정할 것이다. ATM Adapter Card는 효율적으로 Native ATM 응용 소프트웨어를 지원할 뿐 아니라, 기존의 TCP/IP 응용 소프트웨어를 수용하는 IPoverATM, LAN Emulation 기능도 지원하여야 한다. 또한 PVC(Permanent Virtual Channel), SVC(Siganlling Virtual Channel)을 위하여 ATM Forum UNI 3.1에 준한 Signalling도 필요하다. 이러한 조건들을 만족시키기위하여, 현재 개발 완료된 SUN W/S SBus용 디바이스 드라이버는 DLPI(Data Link Provider Interface), STREAM 방식으로 구현하였으며, 현재 개발 중인 PC PCI용 ATM Adapter Card의 디바이스 드라이버는 NDIS 3.0 방식으로 구현 다양한 Transport Layer를 ATM망에 수용하도록 하였다. Signalling은 Daemon Process를 이용하여 구현하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1571-1578
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• 1999

In this paper, we present the Modulator Channel Card and VLSI chip for the Radio Transceiver Unit (RTU) of direct sequence code division multiple access (DS-CDMA) Wireless Local Loop (WLL) System. The Modulator Channel Card is designed and implemented using ASIC's, FPGA's and DSP's. The ASIC, compliance with Common Air Interface specification proposed by ETRI, has 40K gates which is designed to operate at 32MHz, and is fabricated using $0.6\mu\textrm{m}$ CMOS process. The ASIC carries out for I- or Q- phase data channel signal processing at a time, where each data channel processing consists of channel coding, block interleaving, scrambling, Walsh modulation, Pseudo-Noise (PN) spreading, and baseband filtering. The Modulator Channel Card has been integrated as a part of RTU of WLL system and is confirmed that it meets all functional and performance requirements.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.4 no.5
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• pp.51-63
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• 1981

The credit card system has been introduced as a new sales method in the marketing field in Daegu city since 1978. In order to increase its efficiency of distribution channel. we should like to find the better ways in the credit card system. For this study, we choice randomly 420 persons credit card holders of a department store in Daegu city. Since the credit card holders purchase products and obtain the utility and satisfactions. salesmen should establish the improvement strategis to meet needs and desires of credit card holders. we conclude that the establishment of the management systems should be based on the management concepts of modern marketing for consumer profit. Than the advantages of credit card sale should not only be recognized but also to translated into material gains by its successful utilization. When credit card sale would come to this, I believe that credit card sale will be helpful for business men activity and consumer's life.