• 제목/요약/키워드: distance functions

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다중경로와 임펄스 잡음이 있는 수중 통신 채널의 블라인드 등화를 위한 확률분포-거리 최소화 알고리듬 (A PDF-distance minimization algorithm for blind equalization for underwater communication channels with multipath and impulsive noise)

  • 김남용
    • 한국정보통신학회논문지
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    • 제15권2호
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    • pp.299-306
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    • 2011
  • 다음은 이 논문에서는 임펄스 잡음과 함께 다중경로 특성을 가진 수중 통신 채널에 대해, 확률거리 최소화와 델타함수열을 이용한 블라인드 적응등화 알고리듬을 소개하고 임펄스 잡음에 대한 강인성을 입증하였다. 기존의 자승평균오차 기반의 CMA는 임펄스 잡음 환경에서 다중경로 채널을 보상하지 못하는 현상을 보였고 엔트로피에 기반을 둔 코렌트로피 등화알고리듬도 일반적 변조방식에서 성능이 만족스럽지 못한 것으로 나타났으나, 델타함수열을 이용한 확률분포 거리최소화 방법은 이러한 임펄스 잡음 문제와 다중경로 채널 블라인드 등화문제를 동시에 해결함을 보였고, 임펄스 잡음에 대해 탁월한 강인성을 가짐을 이론적 분석과 함께 시뮬레이션 실험을 통해 입증하였다.

FOOTPRINT AND MINIMUM DISTANCE FUNCTIONS

  • Nunez-Betancourt, Luis;Pitones, Yuriko;Villarreal, Rafael H.
    • 대한수학회논문집
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    • 제33권1호
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    • pp.85-101
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    • 2018
  • Let S be a polynomial ring over a field K, with a monomial order ${\prec}$, and let I be an unmixed graded ideal of S. In this paper we study two functions associated to I: The minimum distance function ${\delta}_I$ and the footprint function $fp_I$. It is shown that ${\delta}_I$ is positive and that $fp_I$ is positive if the initial ideal of I is unmixed. Then we show that if I is radical and its associated primes are generated by linear forms, then ${\delta}_I$ is strictly decreasing until it reaches the asymptotic value 1. If I is the edge ideal of a Cohen-Macaulay bipartite graph, we show that ${\delta}_I(d)=1$ for d greater than or equal to the regularity of S/I. For a graded ideal of dimension ${\geq}1$, whose initial ideal is a complete intersection, we give an exact sharp lower bound for the corresponding minimum distance function.

Monte Carlo Investigation of Spatially Adaptable Magnetic Behavior in Stretchable Uniaxial Ferromagnetic Monolayer Film

  • Laosiritaworn, Yongyut;Laosiritaworn, Wimalin
    • Journal of Magnetics
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    • 제20권1호
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    • pp.11-20
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    • 2015
  • In this work, Monte Carlo simulation was employed to model the stretchable Ising monolayer film to investigate the effect of the spatial distance variation among magnetic atoms on magnetic behavior of the film. The exchange interaction was considered as functions of initial interatomic distance and the stretched distance (or the strain). Following Bethe-Slater picture, the magnetic exchange interaction took the Lennard-Jones potential-like function. Monte Carlo simulations via the Wolff and Metropolis algorithms were used to update the spin systems, where equilibrium and dynamic magnetic profiles were collected. From the results, the strain was found to have strong influences on magnetic behavior, especially the critical behavior. Specifically, the phase transition point was found to either increase or decrease depending on how the exchange interaction shifts (i.e. towards or away from the maximum value). In addition, empirical functions which predict how the critical temperatures scale with initial interatomic distance and the strain were proposed, which provides qualitatively view how to fine tune the magnetic critical point in monolayer film using the substrate modification induced strain.

The Estimating Equations Induced from the Minimum Dstance Estimation

  • Pak, Ro-Jin
    • Journal of the Korean Data and Information Science Society
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    • 제14권3호
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    • pp.687-696
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    • 2003
  • This article presents a new family of the estimating functions related with minimum distance estimations, and discusses its relationship to the family of the minimum density power divergence estimating equations. Two representative minimum distance estimations; the minimum $L_2$ distance estimation and the minimum Hellinger distance estimation are studied in the light of the theory of estimating equations. Despite of the desirable properties of minimum distance estimations, they are not widely used by general researchers, because theories related with them are complex and are hard to be computationally implemented in real problems. Hopefully, this article would be a help for understanding the minimum distance estimations better.

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Comparison of time series clustering methods and application to power consumption pattern clustering

  • Kim, Jaehwi;Kim, Jaehee
    • Communications for Statistical Applications and Methods
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    • 제27권6호
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    • pp.589-602
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    • 2020
  • The development of smart grids has enabled the easy collection of a large amount of power data. There are some common patterns that make it useful to cluster power consumption patterns when analyzing s power big data. In this paper, clustering analysis is based on distance functions for time series and clustering algorithms to discover patterns for power consumption data. In clustering, we use 10 distance measures to find the clusters that consider the characteristics of time series data. A simulation study is done to compare the distance measures for clustering. Cluster validity measures are also calculated and compared such as error rate, similarity index, Dunn index and silhouette values. Real power consumption data are used for clustering, with five distance measures whose performances are better than others in the simulation.

Comparative Characteristics Of Information Technologies And Technologies Of Distance Learning Of Higher Education Institutions

  • Dibrova, Valentyna;Sovhira, Svitlana;Liakhovska, Yuliia;Burdun, Victor;Boichuk, Nelia;Saikivska, Liliia
    • International Journal of Computer Science & Network Security
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    • 제21권5호
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    • pp.69-72
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    • 2021
  • The article discusses the features of the use of distance technologies to intensify the learning process of students. The advantages and disadvantages of distance learning are shown. The role and functions of the teacher in distance learning have been adjusted. Information and methodological support for distance learning of students is proposed. Analyzed pedagogical, psychological, methodological and philosophical literature, educational standards, charters of higher educational institutions and other documents. Studied foreign experience in conducting classes using information technology.

병렬처리를 위한 효율적인 사상 기법 (Efficient Mapping Scheme for Parallel Processing)

  • 김석수;전문석
    • 한국정보처리학회논문지
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    • 제3권4호
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    • pp.766-780
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    • 1996
  • 본 논문은 통신 오버헤드의 정확한 특성을 사용하여 병렬처리를 위한 사상 기법을 표현했다. 목적 함수의 집합은 시스템 그래프에 문제 그래프를 사상하는 것의 최적화 를 평가하기 위해서 정형화했다. 이것 중에 하나는 병렬처리의 실시간 응용에 특히 적절하다. 목적함수는 문제 그래프에서 연결선이 가중치를 갖고 있고, 시스템 그래프 에서 연결선을 위해 명목거리보다 실제거리를 고용했다는 점에서 기존의 것과 차이가 있다. 이것은 통신오버헤드를 더 정확하게 측량할 수 있다. 효율적인 사상 기법이 목적함수를 위해서 개발되었고, 초기할당과 쌍교환의 두 단계에서 최적화 과정이 이루 어진다. 이 사상 기법은 시스템 그래프로서 하이퍼큐브를 사용하여 테스트했다.

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Analysis of Fuzzy Entropy and Similarity Measure for Non Convex Membership Functions

  • Lee, Sang-H.;Kim, Sang-Jin
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제9권1호
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    • pp.4-9
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    • 2009
  • Fuzzy entropy is designed for non convex fuzzy membership function using well known Hamming distance measure. Design procedure of convex fuzzy membership function is represented through distance measure, furthermore characteristic analysis for non convex function are also illustrated. Proof of proposed fuzzy entropy is discussed, and entropy computation is illustrated.

CLASSIFICATIONS OF METRIC FUNCTIONS ON THE PLANE

  • KIM, SEHUN;KIM, BYUNGJIN;KIM, JUNGON;KIM, HARAM;KIM, BYUNG HAK
    • Journal of applied mathematics & informatics
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    • 제36권1_2호
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    • pp.93-105
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    • 2018
  • There are many metric functions in the plane. In this paper we are to classify the metric functions on the plane using two ways such as using sum of distances between some points when start point and end point is fixed, and using area of transferred triangle consisted of distances between 3 points.