• Title/Summary/Keyword: dual space

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Development of a Dual-Circular Polarizer for the KVN Receivers

  • Chung, Moon-Hee;Je, Do-Heung;Han, Seog-Tae;Lee, Jung-Won
    • Journal of Astronomy and Space Sciences
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    • v.26 no.3
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    • pp.345-354
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    • 2009
  • A stepped septum polarizer has been designed and fabricated for the 43 GHz band KVN receiver system. The dual-circular polarizer converts left and right hand circularly polarized signals into linear polarizations in two separated rectangular waveguides. Measurements show that the performance of the designed septum polarizer covering 42-48 GHz frequency band is adequate to meet the requirement of KVN receivers. Especially, a polarizer for the KVN receiver of 85-95 GHz frequency band can be fabricated by scaling the dimensions of the septum polarizer developed in this paper.

Maximum Ratio Transmission for Space-Polarization Division Multiple Access in Dual-Polarized MIMO System

  • Hong, Jun-Ki;Jo, Han-Shin;Mun, Cheol;Yook, Jong-Gwan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.8
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    • pp.3054-3067
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    • 2015
  • The phenomena of higher channel cross polarization discrimination (XPD) is mainly observed for future wireless technologies such as small cell network and massive multiple-input multiple-output (MIMO) system. Therefore, utilization of high XPD is very important and space-polarization division multiple access (SPDMA) with dual-polarized MIMO system could be a suitable solution to high-speed transmission in high XPD environment as well as reduction of array size at base station (BS). By SPDMA with dual-polarized MIMO system, two parallel data signals can be transmitted by both vertically and horizontally polarized antennas to serve different mobile stations (MSs) simultaneously compare to conventional space division multiple access (SDMA) with single-polarized MIMO system. This paper analyzes the performance of SPDMA for maximum ratio transmission (MRT) in time division duplexing (TDD) system by proposed dual-polarized MIMO spatial channel model (SCM) compare to conventional SDMA. Simulation results indicate that how SPDMA utilizes the high XPD as the number of MS increases and SPDMA performs very close to conventional SDMA for same number of antenna elements but half size of the array at BS.

Some Properties of the Closure Operator of a Pi-space

  • Mao, Hua;Liu, Sanyang
    • Kyungpook Mathematical Journal
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    • v.51 no.3
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    • pp.311-322
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    • 2011
  • In this paper, we generalize the definition of a closure operator for a finite matroid to a pi-space and obtain the corresponding closure axioms. Then we discuss some properties of pi-spaces using the closure axioms and prove the non-existence for the dual of a pi-space. We also present some results on the automorphism group of a pi-space.

Internal force-based coordinated motion control of dual redundant manipulator

  • Kim, Hyunsoo;Chung, Wan-Kyun;Youm, Youngil
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.237-240
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    • 1996
  • Internal Force based control of dual redundant manipulator is proposed. One is resolved acceleration type control in the decoupled joint space which includes null motion space and the other is in the impedance control fashion in which the desired impedances are decoupled in three subspace, internal motion controlled space, orthogonal to that space, and the null motion controlled space. The internal force is formulated with its basis set meaningful. The object dynamics is also briefly evolved beforehand.

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Dual-Mode Framework for Space Object Collision Risk Assessment (우주 물체 충돌 위험 분석을 위한 이중 모드 프레임워크)

  • Kim, Siwoo;Lee, Jinsung;Choi, Eun-Jung;Cho, Sungki;Ahn, Jaemyung
    • Journal of Space Technology and Applications
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    • v.2 no.1
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    • pp.13-29
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    • 2022
  • Recently, the number of space objects around the Earth has increased rapidly, necessitating systematic space risk management. This paper proposes a dual-mode framework for assessing the risk of collision between space objects. The proposed framework consists of microscopic and macroscopic modes. The former focuses on one-to-one collision events, and the latter assesses the overall collision risk inside a cell located in space. Two risk assessment case studies using the proposed two modes demonstrate the effectiveness of the proposed framework.

Mixed Dual-rail Data Encoding Method Proposal and Verification for Low Power Asynchronous System Design (저전력 비동기식 시스템 설계를 위한 혼합형 dual-rail data encoding 방식 제안 및 검증)

  • Chi, Huajun;Kim, Sangman;Park, Jusung
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.7
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    • pp.96-102
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    • 2014
  • In this paper, we proposed new dual-rail data encoding that mixed 4-phase handshaking protocol and 2-phase handshaking protocol for asynchronous system design to reduce signal activities and power consumption. The dual-rail data encoding 4-phase handshaking protocol should leat to much signal activities and power consumption by return to space state. Ideally, the dual-rail data encoding 2-phase handshaking protocol should lead to faster circuits and lower power consumption than the dual-rail 4-phase handshaking protocol, but can not designed using standard library. We use a benchmark circuit that contains a multiplier block, an adder block, and latches to evaluate the proposed dual-rail data encoding. The benchmark circuit using the proposed dual-rail data encoding shows an over 35% reduction in power consumption with 4-phase dual-rail data encoding.