• 제목/요약/키워드: orthogonal group

검색결과 146건 처리시간 0.027초

INFINITE FAMILIES OF RECURSIVE FORMULAS GENERATING POWER MOMENTS OF TERNARY KLOOSTERMAN SUMS WITH SQUARE ARGUMENTS ASSOCIATED WITH O-(2n, q)

  • Kim, Dae-San
    • 대한수학회지
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    • 제48권2호
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    • pp.267-288
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    • 2011
  • In this paper, we construct eight infinite families of ternary linear codes associated with double cosets with respect to certain maximal parabolic subgroup of the special orthogonal group $SO^-$(2n, q). Here q is a power of three. Then we obtain four infinite families of recursive formulas for power moments of Kloosterman sums with square arguments and four infinite families of recursive formulas for even power moments of those in terms of the frequencies of weights in the codes. This is done via Pless power moment identity and by utilizing the explicit expressions of exponential sums over those double cosets related to the evaluations of "Gauss sums" for the orthogonal groups $O^-$(2n, q).

가변성 고속 비트율을 위한 새로운 AOCG-OFDM 변조 기술 (A Novel AOCG-OFDM Modulation Technique for Variable-high-bit-rate)

  • 공형윤
    • 한국인터넷방송통신학회논문지
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    • 제10권2호
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    • pp.159-165
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    • 2010
  • 다중 부호 변조는 무선 환경에서 고속의 데이터 전송을 위해 개발되었지만 직교 부호(OC)의 제한된 자원과 높은 평균 전력 대 최대 전력 비(PAPR)와 같은 치명적인 두 가지 문제점을 가지고 있다. 본 논문에서는 위와 같은 문제점을 해결하고 사용자의 요구된 서비스 질(QoS)에 따라 네 가지 변수들로 조절 할 수 있는 가변성 고속 비트율을 얻기 위하여 AOCG(Advanced Orthogonal Code Group)-OFDM(Orthogonal Frequency Division Multiplexing) 이라 부르는 새로운 변조 기술을 제안한다.

무선 페이딩 환경에 적합한 인터리브된 초직교 길쌈 부호화 UWB-IR 시스템의 성능 분석 (Performance Analysis of Interleaved Super Orthogonal Convolutional Coded UWB-IR System for Wireless Fading Environment)

  • 김창중;이호경
    • 한국전자파학회논문지
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    • 제16권6호
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    • pp.556-562
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    • 2005
  • 본 논문에서는 무선 페이딩 환경에 적합한 인터리브된 초직교 길쌈 부호화 초광대역 임펄스 라디오 (Interleaved Super-Orthogonal Convolutional Coded Ultra Wide-Band Impulse Radio: ISOC-UWB-IR) 시스템을 제안하고, 그 시스템의 성능을 변환함수 상한(transfer function bounding)을 이용하여 분석하였다. ISOC-UWB-IR 시스템에 사용되는 인터리빙 기법은 복잡도와 성능에 따라 펄스 단위, 펄스 부그룹 단위, 펄스 그룹 단위 중에서 선택될 수 있다. 성능 분석 결과 레이리 페이딩 환경에서 ISOC-UWB-IR 시스템의 성능은 초직교 길쌈 부호(Super-Orthogonal Convolutional Code: SOC)부호기의 부호율보다 인터리빙 방식의 종류에 더 많은 영향을 받는 것으로 나타났다.

Quasi-Orthogonal STBC with Iterative Decoding in Bit Interleaved Coded Modulation

  • 성창경;김지훈;이인규
    • 한국통신학회논문지
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    • 제33권4A호
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    • pp.426-433
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    • 2008
  • In this paper, we present a method to improve the performance of the four transmit antenna quasi-orthogonal space-time block code (STBC) in the coded system. For the four transmit antenna case, the quasi-orthogonal STBC consists of two symbol groups which are orthogonal to each other, but intra group symbols are not. In uncoded system with the matched filter detection, constellation rotation can improve the performance. However, in coded systems, its gain is absorbed by the coding gain especially for lower rate code. We propose an iterative decoding method to improve the performance of quasi-orthogonal codes in coded systems. With conventional quasi-orthogonal STBC detection, the joint ML detection can be improved by iterative processing between the demapper and the decoder. Simulation results shows that the performance improvement is about 2dB at 1% frame error rate.

THE CLASSIFICATION OF SELF-ORTHOGONAL CODES OVER ℤp2 OF LENGTHS ≤ 3

  • Choi, Whan-Hyuk;Kim, Kwang Ho;Park, Sook Young
    • Korean Journal of Mathematics
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    • 제22권4호
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    • pp.725-742
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    • 2014
  • In this paper, we find all inequivalent classes of self-orthogonal codes over $Z_{p^2}$ of lengths $l{\leq}3$ for all primes p, using similar method as in [3]. We find that the classification of self-orthogonal codes over $Z_{p^2}$ includes the classification of all codes over $Z_p$. Consequently, we classify all the codes over $Z_p$ and self-orthogonal codes over $Z_{p^2}$ of lengths $l{\leq}3$ according to the automorphism group of each code.

추력을 최대화하기 위한 횡자속 선형전동기의 최적설계 (Optimum Design of Transverse Flux Linear Motor for Maximizing Thrust Force)

  • 홍도관;우병철;강도현;장정환;김종무;박건우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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    • pp.1159-1161
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    • 2005
  • This study uses a design of experiments to explain correlations between the objective function and design variables. Analysis of means, analysis of variance and table of orthogonal array were carried out. The change of shape design variable for TFLM based on the table of orthogonal array is made. Therefore this study carried to decide design variables for maximizing thrust force of TFLM. we showed improved design variables.

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Orthogonal Stimulus-Response as a Tool to Formulate Traditional Chinese Medicinal Herbal Combination - New Scientific-Based TCM Herbal Formulating Method -

  • Loh, Yean Chun;Tan, Chu Shan;Yam, Mun Fei;Oo, Chuan Wei;Omar, Wan Maznah Wan
    • 대한약침학회지
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    • 제21권3호
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    • pp.203-206
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    • 2018
  • Objectives: There is an increasing number of complex diseases that are progressively more difficult to be controlled using the conventional "single compound, single target" approach as demonstrated in our current modern drug development. TCM might be the new cornerstone of treatment alternative when the current treatment option is no longer as effective or that we have exhausted it as an option. Orthogonal stimulus-response compatibility group study is one of the most frequently employed formulas to produce optimal herbal combination for treatment of multi-syndromic diseases. This approach could solve the relatively low efficacy single drug therapy usage and chronic adverse effects caused by long terms administration of drugs that has been reported in the field of pharmacology and medicine Methods: The present review was based on the Science Direct database search for those related to the TCM and the development of antihypertensive TCM herbal combination using orthogonal stimulus-response compatibility group studies approach. Results: Recent studies have demonstrated that the orthogonal stimulus-response compatibility group study approach was most frequently used to formulate TCM herbal combination based on the TCM principles upon the selection of herbs, and the resulting formulated TCM formula exhibited desired outcomes in treating one of global concerned complex multi-syndromic diseases, the hypertension. These promising therapeutic effects were claimed to have been attributed by the holistic signaling mechanism pathways employed by the crude combination of herbs. Conclusion: The present review could serve as a guide and prove the feasibility of TCM principles to be used for future pharmacological drug research development.

PIC 그룹 복호화를 이용한 최적화된 Double-ABBA 유사 직교 시공간 부호 (An Optimized Double-ABBA Quasi-Orthogonal Space Time Code with PIC Group Decoding)

  • 모하마드 아부 하니프;이문호;박주용
    • 전자공학회논문지
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    • 제50권1호
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    • pp.21-26
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    • 2013
  • 본 논문에서는 그룹(group)을 2개의 심볼(symbol)로 나누는 시스템을 제안하는데, 이 두 개의 더해진 심볼들은 다중화에 의해 분리된 후 역다중화 기술을 이용해 다시 합해진다. 제안된 시스템에서 간단한 PIC(Partial Interference Cancelation) 그룹 복호화 기술은 Double-ABBA(D-ABBA) 유사 직교(Quasi-Orthogonal) 시공간 부호(Space Time Code)를 위해 사용된다. 이 부호는 고차 MIMO(Multiple Input Multiple Output) 시공간 블록 부호화에서 복호화시에 복잡도를 줄여준다. 그리고 기존의 방법과 제안된 방법과의 성능을 비교한다.

CONSTRUCTION OF RECURSIVE FORMULAS GENERATING POWER MOMENTS OF KLOOSTERMAN SUMS: O+(2n, 2r) CASE

  • Kim, Dae San
    • 대한수학회지
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    • 제57권3호
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    • pp.585-602
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    • 2020
  • In this paper, we construct four infinite families of binary linear codes associated with double cosets with respect to a certain maximal parabolic subgroup of the orthogonal group O+(2n, 2r). And we obtain two infinite families of recursive formulas for the power moments of Kloosterman sums and those of 2-dimensional Kloosterman sums in terms of the frequencies of weights in the codes. This is done via Pless' power moment identity and by utilizing the explicit expressions of exponential sums over those double cosets related to the evaluations of "Gauss sums" for the orthogonal groups O+(2n, 2r).