• Title/Summary/Keyword: variable blocks

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Efficient Design of Structured LDPC Codes (구조적 LDPC 부호의 효율적인 설계)

  • Chung Bi-Woong;Kim Joon-Sung;Song Hong-Yeop
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.1C
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    • pp.14-19
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    • 2006
  • The high encoding complexity of LDPC codes can be solved by designing structured parity-check matrix. If the parity-check matrix of LDPC codes is composed of same type of blocks, decoder implementation can be simple, this structure allow structured decoding and required memory for storing the parity-check matrix can be reduced largely. In this parer, we propose a construction algorithm for short block length structured LDPC codes based on girth condition, PEG algorithm and variable node connectivity. The code designed by this algorithm shows similar performance to other codes without structured constraint in low SNR and better performance in high SNR than those by simulation

An Analytical Solution for the Unsteady Close-Contact Melting by Convective Heating (대류가열 비정상 접촉융해에 대한 해석해)

  • Yoo, Ho-Seon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.3
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    • pp.450-458
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    • 2000
  • This study deals with the unsteady close-contact melting of solid blocks on a flat surface subject to convective heating. Normalizing the model equations in reference to the steady solution successfully leads them to cover constant heat flux and isothermal limits at small and large extremes of the Biot number, respectively. The resulting equations admit a compactly expressed analytical solution, which includes the previous solutions as a subset. Based on the steady solution, the characteristics of close-contact melting can be categorized into constant heat flux, transition, and isothermal regimes, the boundaries of which appear to be nearly independent of the contact force. The unsteady solutions corresponding to Biot numbers in the transition regime show intermediate behaviors between those of the two limits. With a proper approximation, the present solution procedure can cope with the case of variable fluid temperature and heat transfer coefficient. Regardless of imposed conditions, the mean normalized Nusselt number during the unsteady process asymptotically approaches to a constant value as the Biot number comes close to each limit.

CMOS Integrated Fingerprint Sensor Based on a Ridge Resistivity (CMOS공정으로 집적화된 저항형 지문센서)

  • Jung, Seung-Min
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.10a
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    • pp.571-574
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    • 2008
  • In this paper, we propose $256{\times}256$ pixel array fingerprint sensor with an advanced circuits for detecting. The pixel level simple detection circuit converts from a small and variable sensing current to binary voltage out effectively. We minimizes an electrostatic discharge(ESD) influence by applying an effective isolation structure. The sensor circuit blocks were designed and simulated in standard CMOS $0.35{\mu}m$ process. Full custom layout is performed in the unit sensor pixel and auto placement and routing is performed in the full chip.

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Coding Efficiency Improvement By Applying Rate-Distortion Optimization To 3D-DCT Based Integral Image Compression Method (3D-DCT 기반 집적영상 압축 방법의 율-왜곡 최적화를 통한 부호화 효율 향상 방법)

  • Jeon, Ju-Il;Kang, Hyun-Soo
    • The Journal of the Korea Contents Association
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    • v.12 no.9
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    • pp.1-8
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    • 2012
  • In this paper, we propose a rate-distortion optimization method to improve the coding efficiency of the conventional 3D-DCT based compression method using adaptive block mode selection for integral images. In the conventional 3D-DCT based compression method, 3D-DCT blocks of variable block sizes are adaptively selected depending on the characteristics of integral images, and then 3D-DCT is performed. The proposed method applies a rate-distortion optimization to determine the optimal block mode. In addition, we suggest the optimal Lagrangian parameter for integral images. Experimental results show that the proposed method gives bit-rate reduction of about 5%.

Design and Implementation of the 155Mbps Adaptive CODEC for Ka-band Satellite Communications

  • Park, Eun-A;Chang, Dae-Ig;Kim, Nae-Soo
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1940-1943
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    • 2002
  • In this paper, we presented the design and implementation of 155Mbps satellite Modem adaptively compensated against the rain attenuation. In order to compensate the rain attenuation over high-speed satellite ink, the adaptive coding schemes with variable coding rates and the pragmatic TCM that can be decoded both the QPSK and TC-8PSK using same Viterbi decoder was studied and analyzed. The pragmatic TCM with rate 213, selected to the optimal parameters for implementation, was modeled by VHDL in this paper. The key design issues are how to achieve a high data rate and how to integrated into a single ASIC chip various functions such as the different data rates, Scrambler/descrambler, Interleaver, Encoder/decoder, and BPSK/QPSK/8PSK modulator/demodulator. The implemented 155M0ps adaptive MODEM has the simplified interface circuits among the many functional blocks, and parallel processing architecture to achieve the high data rate. This 155Mbps adaptive MODEM was designed and implemented by single ASIC chip with the 0.25 $\mu\textrm{m}$ CMOS standard cell technology.

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A Software Architecture for High-speed PCE (Path Computation Element) Protocol (고성능 PCE (Path Computation Element) 프로토콜 소프트웨어 구조)

  • Lee, Wonhyuk;Kim, Seunhae;Kim, Hyuncheol
    • Convergence Security Journal
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    • v.13 no.6
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    • pp.3-9
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    • 2013
  • With the rapidly changing information communication environment and development of technologies, the informati on networks are evolved from traditional fixed form to an active variable network that flexible large variety of data can be transferred. To reflect the needs of users, the next generation using DWDM (Dense Wavelength Division M ultiplexing) transmission system and OXC (Optical Cross Connect) form a dynamic network. After that GMPLS (Ge neralized Multi-Protocol Label Switching) can be introduced to dynamically manage and control the Reconfigurable Optical Add-drop Multiplexer (ROADM)/Photonic Cross Connect (PXC) based network. This paper propose a softw are architecture of Path Computation Element (PCE) protocol that has proposed by Internet Engineering Task Force (IETF) to path computation. The functional blocks and Application Programming Interface (API) of the PCE protoco l implementation are also presented.

Fingerprint Sensor Based on a Skin Resistivity with $256{\times}256$ pixel array ($256{\times}256$ 픽셀 어레이 저항형 지문센서)

  • Jung, Seung-Min
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.3
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    • pp.531-536
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    • 2009
  • In this paper, we propose $256{\times}256$ pixel array fingerprint sensor with an advanced circuits for detecting. The pixel level simple detection circuit converts from a small and variable sensing current to binary voltage out effectively. We minimizes an electrostatic discharge(ESD) influence by applying an effective isolation structure around the unit pixel. The sensor circuit blocks were designed and simulated in standard CMOS $0.35{\mu}m$ process. Full custom layout is performed in the unit sensor pixel and auto placement and routing is performed in the full chip.

The Nature of the Fracture Patterns Observed at Mawrth Vallis, Mars (화성 Mawrth Vallis 지역에서 관찰되는 파쇄 패턴의 성질)

  • LEE, Cha-Bok
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.2
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    • pp.145-159
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    • 2012
  • Fracture patterns observed in the phyllosilicate-bearing layers of the Mawrth Vallis region are analyzed using High Resolution Imaging Science Experiment image data in order to understand the causes of polygonal fracturing. HiRISE data show that the different mineralogies have distinct surface textures and morphologies. The majority of the nontronite-bearing rocks typically appear to have been heavily eroded and are fractured into irregular shaped blocks with variable size, whereas most of the montmorillonite-bearing rocks have polygons which are relatively consistent in size and shape. The majority of the fracture patterns observed in the nontronite-bearing outcrops are interpreted to be a result of unloading stresses. While the polygonal fractures developed in the montmorillonite-bearing layers appear to be a product of desiccation.

The Role of Ethnocentrism and Firms Reputation of a Country of Origin on Consumer Purchase Intention

  • Nadia Jimenez;Sonia San Martin
    • Asia Marketing Journal
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    • v.11 no.2
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    • pp.97-119
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    • 2009
  • The growth of international trade and the formation of supranational economic and political trading blocks have noticeably widened the presence on the market of products of different national origins. This has stimulated interest in explaining the Country-of-Origin (COO) role in domestic and international markets and its consequences on consumer behaviour. Since the consumer purchasing decisions can be decisive to the success of a company's strategy in domestic and foreign markets, the objective of this study is to present empirical evidence on the extent to which reputation of firms associated to a certain COO are related to consumer purchase intention. Additionally our study considers ethnocentrism as a variable that partially explains the rejection of imports products based on its foreign origin. The empirical application of the proposed model is related to the purchase of Korean automobiles which represents 5.7% of the national market share in Spain. Structural equation modelling was used to analyse the data collected from 202 personal interviews carried out in a large Spanish region. The results show that reputation of firms associated to a certain COO in an important factor to establish business relationships involving consumers and firms from different countries and increase intentions to purchase Korean products. Additionally, ethnocentric consumers prefer to purchase domestic products rather than foreign imports as an attempt to protect national economy however the negative effect of ethnocentrism is weaker than positive effect of firms reputation of a COO.

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Design of a Low Power Digital Filter Using Variable Canonic Signed Digit Coefficients (가변 CSD 계수를 이용한 저전력 디지털 필터의 설계)

  • Kim, Yeong-U;Yu, Jae-Taek;Kim, Su-Won
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.38 no.7
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    • pp.455-463
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    • 2001
  • In this Paper, an approximate processing method is proposed and tested. The proposed method uses variable CSD (VCSD) coefficients which approximate filter stopband attenuation by controlling the precision of the CSD coefficient sets. A decimation filter for Audio Codec '97 specifications has been designed having processor architecture that consists of program/data memory, arithmetic unit, energy/level decision, and sinc filter blocks, and fabricated with 0.6${\mu}{\textrm}{m}$ CMOS sea-of-gate technology. For the combined two halfband FIR filters in decimation filter, the number of addition operations were reduced to 63.5%, 35.7%, and 13.9%, compared to worst-case which is not an adaptive one. Experimental results show that the total power reduction rate of the filter is varying from 3.8 % to 9.0 % with respect to worst-case. The proposed approximate processing method using variable CSD coefficients is readily applicable to various kinds of filters and suitable, especially, for the speech and audio applications, like oversampling ADCs and DACs, filter banks, voice/audio codecs, etc.

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