• Title/Summary/Keyword: information expression

Search Result 3,009, Processing Time 0.04 seconds

Iterative Decoding Performance for Gray Coded QAM Signals with I/Q Phase Unbalance (I/Q 위상 불균형을 동반한 Gray 부호화된 QAM 신호의 반복 복호 성능)

  • Kim Ki-Seol;Park Sang-Kyu
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.31 no.6A
    • /
    • pp.611-616
    • /
    • 2006
  • In this paper, we propose a practical implementation method of a soft bit decision expression for an R-QAM (Gray coded Rectangular Quadrature Amplitude Modulation) signal based on the Max-Log-MAP algorithm. The parameters of the soft decision expression for the practical implementation can be obtained with simple arithmetic functions associated with some deterministic parameters such as a received value, distances between symbols, and the order of modulation on a signal space. Also, we analyze the performance of an iterative decoding scheme for the QAM signal with I/Q phase unbalance. The unbalance results from the non-ideal characteristic of components such as a phase shifter between in-phase and quadrature paths for quadrature modulator/demondulator.

Performance Analysis of MCR-DS/CDMA Systems Using a Simplified Expression for the Improved Gaussian Approximation (향상된 정규 근사법의 간략화된 표현을 이용한 MCR-DS/CDMA 시스템의 성능 분석)

  • 주민철;김귀훈;김형명
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.25 no.8B
    • /
    • pp.1357-1370
    • /
    • 2000
  • In this paper, we investigate the performance of asynchronous multiple-chip-rate (MCR)-DS/CDMA systems, where singles are transmitted at different chip rates, processing gains, and transmitted powers according to the required services and their own bit rates. A simplified expression for the improved Gaussian approximation (SEIGA), which is hewn for as a very accurate and simple tool for the performance evaluation, is applied to MCR systems, The correlations between chip waveforms and integrations are utilized instead of correlations between chip sequences which are used in conventional method [6] [7][8], and since this approach makes use of the system model parameter directly, we obtain more direct relationship among system parameters. Simulation results show that the performance of MCR-DS/CDMA systems can be evaluated more accurately by using the proposed procedure than by using the GA.

  • PDF

Effects of Adipokine Retnla on the Regulation of High-Density Lipoprotein Metabolism

  • Lee, Mi-Ran
    • Journal of the Korea Society of Computer and Information
    • /
    • v.21 no.12
    • /
    • pp.139-145
    • /
    • 2016
  • In this paper, we propose to evaluate the effect of Resistin-like molecule alpha (Retnla) on the expression of transporters involved in modulating concentrations of peripheral cholesterol and plasma high-density lipoprotein (HDL) cholesterol. High levels of blood cholesterol are a well-recognized risk factor for atherosclerosis and are eliminated via the process of reverse cholesterol transport (RCT). We recently showed that Retnla ameliorates hypercholesterolemia and atherosclerosis by increasing biliary cholesterol secretion, the final step of the process, in low-density lipoprotein receptor-deficient mice. However, the role of Retnla in HDL-mediated cholesterol efflux, initial step of RCT pathway, is not yet clear. To identify cholesterol transport genes regulated by Retnla, we performed an extensive microarray-based gene expression screen using livers from Retnla-overexpressing (Tg) mice and control animals. The most significant change in Retnla-Tg mice was an upregulation of ATP-binding cassette sub-family G member 4 (Abcg4) transport and was validated using quantitative RT-PCR. The validated gene was also induced by treatment of purified Retnla protein in RAW 264.7 cells incubated with acetylated low-density lipoprotein and Hepa1c1c7 cells. Taken together, these results indicates that Retnla might also accelerate initial step of RCT pathway, suggesting therapeutic value of Retnla in the treatment of hypercholesterolemia and atherosclerosis.

A low-power systolic structure for MP3 IMDCT Using addition and shift operation (덧셈과 쉬프트 연산을 사용한 MP3 IMDCT의 저전력 Systolic 구조)

  • Jang Young Beom;Lee Won Sang
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.29 no.10C
    • /
    • pp.1451-1459
    • /
    • 2004
  • In this paper, a low-power 32-point IMDCT structure is proposed for MP3. Through re-odering of IMDCT matrices, we propose the systolic structure operating with 16, 8, 4, 2, and 1 cycle, respectively. To reduce power consumption, multiplication of each sub blocks are implemented by add and shift operation with CSD(Canrmic sigled digit) form coefficients. To reduce, furthermore, the number of adders, we utilize the common sub-expression sharing techniques. With these techniques, the relative power consumption of the proposed structure is reduced by 58.4% comparison to the conventional structure using only 2's complement form coefficient. Validity of the proposed structure is proved through Verilog-HDL coding.

Bit Error Rate of Underlay Decode-and-Forward Cognitive Networks with Best Relay Selection

  • Ho-Van, Khuong;Sofotasios, Paschalis C.;Alexandropoulos, George C.;Freear, Steven
    • Journal of Communications and Networks
    • /
    • v.17 no.2
    • /
    • pp.162-171
    • /
    • 2015
  • This paper provides an analytic performance evaluation of the bit error rate (BER) of underlay decode-and-forward cognitive networks with best relay selection over Rayleigh multipath fading channels. A generalized BER expression valid for arbitrary operational parameters is firstly presented in the form of a single integral, which is then employed for determining the diversity order and coding gain for different best relay selection scenarios. Furthermore, a novel and highly accurate closed-form approximate BER expression is derived for the specific case where relays are located relatively close to each other. The presented results are rather convenient to handle both analytically and numerically, while they are shown to be in good agreement with results from respective computer simulations. In addition, it is shown that as in the case of conventional relaying networks, the behaviour of underlay relaying cognitive networks with best relay selection depends significantly on the number of involved relays.

Bit Error Rate of Generalized Triangular QAM (일반화된 TQAM의 비트 오류 확률)

  • Cho, Kyongkuk
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.39A no.5
    • /
    • pp.229-236
    • /
    • 2014
  • Quadrature Amplitude Modulation (QAM) is widely used in contemporary wired and wireless communications systems. In this paper, I propose a generalized triangular quadrature amplitude modulation (gTQAM) that includes the square quadrature amplitude modulation (SQAM), TQAM, and ${\Theta}$-QAM as special cases. Therefore, the proposed gTQAM forming a lattice of arbitrary triangles provides a versatile structure in signal constellations compared to other QAM schemes. For M-ary gTQAM, I derive an exact closed-form expression for the bit error rate (BER), and present the optimal signal constellations for given SNR values from the derived BER expression. Finally, I validate the derived BER results through computer simulations.

Linking DNA Sequence Motifs with Gene Expression Patterns Based on a Low-Dimensional Mapping (저차원공간으로의 매핑에 기반한 DNA서열 요소 및 유전자 발현 패턴간 관련성 분석)

  • Lee Jongwoo;Zhang Byoung-Tak
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2005.07b
    • /
    • pp.235-237
    • /
    • 2005
  • 마이크로 어레이(micro array)로 표현되는 유전자 발현 패턴(gene expression pattern)들과 해당 유전자의 upstream에 위치한 DNA 서열 요소(motif)들은 유전자 발현에 밀접한 관련을 맺고 있는데 이들간의 매핑관계를 알아내는 것은 생물전산학 분야에서 중요한 문제 중 하나이다. 본 고에서는 유전자 발현 패턴 데이터와 해당 DNA에 포함된 것으로 알려진 모티프 프로파일에 대해 대응분석(correspondence analysis)을 수행하고 2차원 평면에 매핑하여 특정 유전자 발현과 밀접하게 관련된다고 여겨지는 후보 모티프를 시각적으로 직관적으로 동정하는 방법을 제시한다. 또한 유전자 발현 패턴은 일정한 길이로 나누어 가능한 모든 패턴에 대해 클러스터링을 행하여 이에 대한 인덱스로 데이터를 표현하여 패턴의 인식성과 발현 순차성을 높이는 반면 복잡도를 줄이도록 하였다. 실험에서 두가지 형태의 모티프 프로파일과 효모 Saccharomyces cerevisiae 포자형성 데이터 집합에 대하여 대응 분석을 통한 시각화된 결과를 이용해 유전자 발현과 깊게 관련되는 것으로 알려진 모티프들이 대응 유전자 발현과의 상관성이 잘 동정되고 있음을 알 수가 있다.

  • PDF

A Study on the Domestic Program Using Virtual Studio Production (가상스튜디오를 이용한 국내프로그램 활용사례에 관한 연구)

  • Lee, Jun-Sang;Lee, Joo-Shin;Kim, Chee-Yong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2010.05a
    • /
    • pp.339-342
    • /
    • 2010
  • This thesis is the analysis of programing cases by which each broadcasting station generates visual studio. When the broadcasting stations make programs, they overcome the visual limitation of expression by using visual studio other than the real set. This trend is the progress toward more realistic and delicate image by almost perfect image expression, not just broadcasting production by mere synthesis operation. It suggests the development direction toward visual studio production by analyzing production cases using domestic visual studio.

  • PDF

Tester Structure Expression Language and Its Application to the Environment for VLSI Tester Program Development

  • Sato, Masayuki;Wakamatsu, Hiroki;Arai, Masayuki;Ichino, Kenichi;Iwasaki, Kazuhiko;Asakawa, Takeshi
    • Journal of Information Processing Systems
    • /
    • v.4 no.4
    • /
    • pp.121-132
    • /
    • 2008
  • VLSI chips have been tested using various automatic test equipment (ATE). Although each ATE has a similar structure, the language for ATE is proprietary and it is not easy to convert a test program for use among different ATE vendors. To address this difficulty we propose a tester structure expression language, a tester language with a novel format. The developed language is called the general tester language (GTL). Developing an interpreter for each tester, the GTL program can be directly applied to the ATE without conversion. It is also possible to select a cost-effective ATE from the test program, because the program expresses the required ATE resources, such as pin counts, measurement accuracy, and memory capacity. We describe the prototype environment for the GTL and the tester selection tool. The software size of the prototype is approximately 27,800 steps and 15 manmonths were required. Using the tester selection tool, the number of man-hours required in order to select an ATE could be reduced to 1/10. A GTL program was successfully executed on actual ATE.

A Study of Performance Improvement through using extending Display of Iphone(smart phone) LCD(TFT or AMOLED) to overcome expression limit of Normal LCD(Seg) for Car audio (CAR audio용 일반 Seg LCD의 표현의 한계를 극복하기 위한 IPHONE(SMART PHONE) LCD(AMOLED,TFT)의 확장 DISPLAY 사용에 대한 성능 개선에 관한 연구)

  • Hwang, Man-Tae;Kim, Yound-Cil
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2010.10a
    • /
    • pp.325-328
    • /
    • 2010
  • In this paper, To overcome expression limit of Normal LCD(Seg) for Car audio, We research using Smart phone(Iphone) LCD to overcome weakness of seg LCD, We can express detail LCD DISPLAY using Smartphone(iphone), We can call Car to phone, Smartphone(Iphone) Display can Normal Car audio function Display, using phone Application for car to phon.

  • PDF