• 제목/요약/키워드: Compact

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OCM방법을 이용한 Compact Code의 구성에 관한 연구 (A Study on the Composition of Compact Code using Octal-Compact Mapping Technique)

  • 김경태;민용식
    • 한국통신학회논문지
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    • 제9권3호
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    • pp.103-107
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    • 1984
  • 데이터 통신의 급격한 발전으로 인하여 각종 정보를 손쉽게 이용할 수 있게 되었다. 이같이 얻은 정보들을 송수신함에 있어서 가능한 한 비트수를 최소화하여 정보를 전송하는 것이 필요로 하게 되었다. 즉 8개의 symbol을 다룬 경우의 entropy가 평균적으로 3.5bytes로서 다른 방식에서 사용된 것보다 적어도 1byte이상 축약되는 OCM(Octal-Compact Mapping)방식을 제시함과 이같이 최소화로 인해 redundancy가 상당히 감소되며 동시에 기존에 사용한 data compression 방식보다 효율성이 좋은 방식을 본 논문에서 제시하였다.

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소형 이중 원형편파 안테나를 이용한 도플러 레이다 개발 (Development of Doppler Radar Using Compact Dual-Circularly Polarized Antenna)

  • 김태홍;이현진
    • 전기학회논문지P
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    • 제64권3호
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    • pp.121-124
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    • 2015
  • In this paper, we developed the compact Doppler radar using the compact dual-circularly polarized antenna for medical application. The operating frequency is 2.47 GHz for considering ISM band. In order to decrease the size of the entire system, we designed the compact antenna and located the circuit board at the back of the antenna. The simulation of the proposed antenna was performed by the finite difference time domain (FDTD) method. The total volume of the proposed system is $65{\times}45{\times}6mm^3$ including the antenna. From the experiment, the developed bio-radar could be used to support the device for medical applications.

차량 탑재용 컴팩트 디스크 플레이어의 전달률에 관한 실험적 연구 (An Experimental Study of the Transmissibility of Vehicle Compact Disk Player)

  • 이태근;김병삼
    • 한국소음진동공학회논문집
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    • 제15권6호
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    • pp.764-771
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    • 2005
  • This study investigates the 3-axis transmissibility of the vehicle compact disk player's mainbase which is supported by dampers and springs. These dampers and springs as the important element ' determining the vibration performance of vehicle compact disk Player are used to minimize the vibration which is induced by driving the vehicle. In order to determine the analysis frequency band, we investigated the excitation frequency of road from the vehicle test. As the characteristics of damper and spring were changed, we carried out the vibration test and investigated the change of transmissibility, Also, we carried out the sensitivity analysis for transmissibility and we found out that the properties of damper were the dominant element in the vibration performance of vehicle compact disk player.

SHIFT GENERATED DUAL FRAMES FOR LOCALLY COMPACT ABELIAN GROUPS

  • Ahmadi, Ahmad;Askari-Hemmat, Ataollah
    • 대한수학회지
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    • 제49권3호
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    • pp.571-583
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    • 2012
  • Let $G$ be a metrizable, ${\sigma}$-compact locally compact abelian group with a compact open subgroup. In this paper we define the Gramian and the dual Gramian operators for shift invariant subspaces of $L^2(G)$ and we use them to characterize shift generated dual frames for shift in- variant spaces, which forms a frame for a subspace of $L^2(G)$. We present necessary and sufficient conditions for which standard dual is a unique SG-dual frame of type I and type II.

Relativistic Jets as Compact Radio Sources

  • Lee, Sang-Sung
    • 천문학회보
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    • 제39권2호
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    • pp.39-39
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    • 2014
  • Studies of compact radio sources since the discovery of quasars have revealed a variety of physical properties: both in morphology and kinematics from sub-parsec to Mega-parsec scales, radiation mechanisms at frequencies from the radio to ${\gamma}$-rays, theoretical models for relativistic jets, etc. The frontier discovery of Very Long Baseline Interferometry (VLBI) observations for the compact extragalactic radio sources have triggered the extensive studies to investigate the underlying physics of the relativistic jets. In this context, the highest resolution VLBI surveys of ultra-compact radio sources provide the potentially important statistical basis for future study. As a tool of this study, a new millimeter VLBI network in Korea, the Korean VLBI Network (KVN) will paly an important role. We present results from large VLBI surveys of compact radio sources at millimeter wavelengths and discuss the prospects with the KVN on this study.

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Test result of striated HTS compact cables for low AC loss

  • Kim, Y.;Kim, W.S.;Lee, J.K.
    • 한국초전도ㆍ저온공학회논문지
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    • 제15권2호
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    • pp.44-47
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    • 2013
  • Large AC loss from the second generation (2G) high temperature superconducting (HTS) wires has been one of the major bottlenecks in power applications with HTS materials. Moreover, the large power applications also require the large current capacity from the HTS wires, which makes them produce larger AC losses. In order to reduce the AC loss from the HTS conductors with large current capacity, an HTS compact cable with some striations on the superconducting layers has been proposed. In this paper, we prepared some sample HTS compact conductors with striations, and measured their magnetization loss from the external magnetic field. We also made some slits on the superconducting layer of the HTS wire by laser cutting to reduce the aspect ratio of the superconducting layers. It would make the low eddy current loss and magnetic decoupling. Finally, the magnetization losses of the sample HTS compact conductors were measured and analyzed.

COMPACT INTERPOLATION ON AX = Y IN ALG𝓛

  • Kang, Joo Ho
    • Journal of applied mathematics & informatics
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    • 제32권3_4호
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    • pp.441-446
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    • 2014
  • In this paper the following is proved: Let $\mathcal{L}$ be a subspace lattice on a Hilbert space $\mathcal{H}$ and X and Y be operators acting on $\mathcal{H}$. Then there exists a compact operator A in $Alg\mathcal{L}$ such that AX = Y if and only if ${\sup}\{\frac{{\parallel}E^{\perp}Yf{\parallel}}{{\parallel}E^{\perp}Xf{\parallel}}\;:\;f{\in}\mathcal{H},\;E{\in}\mathcal{L}\}$ = K < ${\infty}$ and Y is compact. Moreover, if the necessary condition holds, then we may choose an operator A such that AX = Y and ${\parallel}A{\parallel}=K$.