• 제목/요약/키워드: K-best

검색결과 15,186건 처리시간 0.039초

Performance Analysis of Dual-Hop Cooperative Transmission with Best Relay Selection in a Rayleigh Fading Channel

  • Nessa, Ahasanun;Lee, Woo-Yong;Kim, Yong-Sun;Kwak, Kyung-Sup
    • 한국통신학회논문지
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    • 제34권7A호
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    • pp.530-539
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    • 2009
  • Wireless Relaying is a promising solutions to overcome the channel impairments and provides high data rate coverage that appear for beyond 3G mobile communications. In this paper we present end to end BER performance of dual hop wireless communication systems equipped with multiple Decode and Forward relays over Rayleigh fading channel with the best relay selection. We compare the BER performance of the best relay with the BER performance of single relay. We select the best relay based on the end to end channel conditions. We further calculate the outage probability of the best relay. It is shown that the outage probability of the best relay is equivalent to the outage probability when all relays take part in the transmission. We apply Orthogonal Space Time Block coding(OSTBC) at the source terminal. Numerical and simulation results are presented to verify our analysis.

BEST RANDOM PROXIMITY PAIR THEOREMS FOR RELATIVELY U-CONTINUOUS RANDOM OPERATORS WITH APPLICATIONS

  • Okeke, Godwin Amechi
    • East Asian mathematical journal
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    • 제33권3호
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    • pp.271-289
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    • 2017
  • It is our purpose in this paper to introduce the concept of best random proximity pair for subsets A and B of a separable Banach space E. We prove some best random approximation and best random proximity pair theorems of certain classes of random operators, which is the stochastic verse of the deterministic results of Eldred et al. [22], Eldred et al. [18] and Eldred and Veeramani [19]. Furthermore, our results generalize and extend recent results of Okeke and Abbas [42] and Okeke and Kim [43]. Moreover, we shall apply our results to study nonlinear stochastic integral equations of the Hammerstein type.

온라인 뉴스 베스트 댓글의 특성 분석 (Analyzing the Characteristics of Online News Best Comments)

  • 김진우;조혜인;이봉규
    • 디지털콘텐츠학회 논문지
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    • 제19권8호
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    • pp.1489-1497
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    • 2018
  • 온라인 뉴스에 개인의 참여가 활성화되면서 댓글의 중요성은 더욱 커지고 있다. 특히 이용자들에게 많은 공감을 받는 '베스트 댓글'은 주된 여론으로 인식되고 큰 영향력을 가진다. 따라서 본 연구는 온라인 뉴스 댓글 데이터를 이용하여 베스트 댓글의 특성을 알아보고자 하였다. 이를 위해 일반 댓글과 차이점을 보일 가능성이 있는 요소를 설정 후, 데이터를 수치화하여 일반 댓글과 베스트 댓글의 차이를 분석하였다. 본 연구는 최근 댓글 조작 등의 문제 해결에 실마리를 제공하고 개인 및 학술단체, 정부기관 등을 주체로 하여금 기초 자료로 활용될 것으로 기대된다.

다중 송수신 안테나 시스템 기반에서 오차 전달을 고려한 효율적인 K-BEST 복호화 알고리듬 (An Efficient K-BEST Lattice Decoding Algorithm Robust to Error Propagation for MIMO Systems)

  • 이성호;신명철;서정태;이충용
    • 대한전자공학회논문지TC
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    • 제42권7호
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    • pp.71-78
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    • 2005
  • K-Best 알고리듬은 일정한 최대 복잡도를 가지기 때문에 ML (Maximum Likelihood) 수신기나 sphere decoding 수신기에 비해 실시간 구현에 적합한 알고리듬으로 알려져 있다. 그러나 ML 수신기에 가까운 성능을 내기 위해 충분히 큰 K값을 적용할 경우 여전히 높은 복잡도를 가지게 되며, 구현에 좀 더 적합하도록 작은 K값을 적용할 경우, 최대 복잡도는 낮아지는 반면오차 전달(error propagation)에 의해 높은 SNR 영역에서 에러 플로링(error flooring)이 발생하는 문제점이 있다. 본 논문에서는 이러한 오차 전달 문제를 해결하기 위해 각 레벨 별로 K값을 감소시키는 K-reduction 기법을 제안하였으며, 모의 실험을 통해 연산량 및 비트 오차 확률 측면에서 이득이 있음을 확인하였다.

Logical Combinations of Neural Networks

  • Pradittasnee, Lapas;Thammano, Arit;Noppanakeepong, Suthichai
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -2
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    • pp.1053-1056
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    • 2000
  • In general, neural networks based modeling involves trying multiple networks with different architectures and/or training parameters in order to achieve the best accuracy. Only the single best-trained neural network is chosen, while the rest are discarded. However, using only the single best network may never give the best solution in every situation. Many researchers, therefore, propose methods to improve the accuracy of neural networks based modeling. In this paper, the idea of the logical combinations of neural networks is proposed and discussed in detail. The logical combination is constructed by combining the corresponding outputs of the neural networks with the logical “And” node. The experimental results based on simulated data show that the modeling accuracy is significantly improved when compared to using only the single best-trained neural network.

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Node.js 취약점 분석 방법론에 대한 연구 (A Study on the Vulnerability Analysis Methodology of Node.js)

  • 이범진;문시우;유재욱;신정훈;김경곤
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2019년도 추계학술발표대회
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    • pp.479-482
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    • 2019
  • Node.js 는 자바스크립트 런타임으로 확장성 있는 웹 애플리케이션 개발에 주로 사용되는 플랫폼이다. 자바스크립트는 수 년에 걸쳐 많은 발전을 이뤘으며 현재는 Node.js 로 서버 사이드까지 자리 잡아 웹이라는 생태계에서 빼놓을 수 없는 요소가 되었다. 본 논문은 Node.js 에 관한 전반적인 이론을 포함하여 자바스크립트 특성으로 인하여 Node.js 에서 자주 발견되는 취약점의 탐색 방법을 모듈 관점에서 다뤄보고자 한다. 또한 취약점이 발생하는 다양한 패턴과 해당 패턴을 막기 위하여 적용된 Mitigation 을 실제 모듈을 예시로 살펴보며 분석해보고자 한다.

On Certain Extension of Hilbert's Integral Inequality with Best Constants

  • Li, Yongjin;Lin, Yu;He, Bing
    • Kyungpook Mathematical Journal
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    • 제48권3호
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    • pp.457-463
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    • 2008
  • In this paper, by introducing a new function with two parameters, we give another generalizations of the Hilbert's integral inequality with a mixed kernel $k(x, y) = \frac {1}{A(x+y)+B{\mid}x-y{\mid}}$ and a best constant factors. As applications, some particular results with the best constant factors are considered.

Wireless MAN에서 Best Effort 서비스를 위한 MAC 방식의 지연 공평성 (Delay Fairness of MAC Schemes for Best Effort Service in Wireless MAN)

  • 박진경;신우철;하준;최천원
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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    • pp.168-171
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    • 2003
  • IEEE 802.16 Wireless MAN standard specifies the air interface of fixed point-to-multipoint broadband wireless access systems providing multiple services. Among the service classes supported by the wireless MAN, the best effort service class is ranked on the lowest position in priority and is assisted by a MAC scheme based on reservation ALOHL Such MAC scheme must include a number of components, while many of them are not specified in the standard. In this paper, we thus reveal main components of a MAC scheme supporting the best effort service and present candidate schemes implementing such components. Combining schemes for implementing components, we then construct distinctive MAC schemes supporting best effort service. In designing a MAC scheme, the delay performance induced by the scheme should be considered since scarce resource may be available for the best effort service after the preemptive resource occupation by other service classes. In this paper, we focus on the delay fairness among the subscriber stations using the best effort service. For evaluating a MAC scheme in delay fairness, we present two definitions of delay fairness and provide a criterion for optimal MAC scheme according to each definition of delay fairness. Using a simulation method we investigate the mean delay performance exhibited by each MAC scheme arid find an optimal scheme in delay fairness. From numerical examples, we observe that SR/ED/PG+P scheme has strong delay fairness compared with MR/ED/PG+P and SR/ED/PG+D schemes according to a definition of delay fairness. However, other schemes are rather shown to have better delay fairness when the other definition is adopted.

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SOME ALGORITHMS OF THE BEST SIMULTANEOUS APPROXIMATION

  • Rhee, Hyang J.
    • 충청수학회지
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    • 제22권2호
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    • pp.141-148
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    • 2009
  • We consider various algorithms calculating best onesided simultaneous approximations. We assume that X is a compact subset of $\mathbb{R}^{m}$ satisfying $X=\overline{intX}$, S is an n-dimensional subspace of C(X), and $\mu$ is any 'admissible' measure on X. For any l-tuple $f_1,\;{\cdots},\;f_{\ell}$ in C(X), we present various ideas for best approximation to F from S(F). The problem of best (both one and two-sided) approximation is a linear programming problem.

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