• 제목/요약/키워드: beam-forming

검색결과 352건 처리시간 0.029초

동적 핸드오프와 전력제어를 고려한 적응배열 시스템의 네트워크 시뮬레이션 (System Level Network Simulation of Adaptive Array with Dynamic Handoff and Power Control)

  • Yeong-Jee Chung;Jeffrey H. Reed
    • 한국시뮬레이션학회논문지
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    • 제8권4호
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    • pp.33-51
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    • 1999
  • In this study, the system level network simulation is considered with adaptive array antenna in CDMA mobile communication system. A network simulation framework is implemented based on IS-95A/B system to consider dynamic handoff, system level network behavior, and deploying strategy into the overall CDMA mobile communication network under adaptive array algorithm. Its simulation model, such as vector channel model, adaptive beam forming antenna model, handoff model, and power control model, are described in detail with simulation block. In order to maximize SINR of received signal at antenna, Maximin algorithm is particularly considered, and it is computed at each simulation snap shot with SINR based power control and handoff algorithm. Graphic user interface in this system level network simulator is also implemented to define the simulation environments and to represent simulation results on real mapping system. This paper also shows some features of simulation framework and simulation results.

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상류형 풍력 터빈의 주요 소음원과 방사소음에 대한 실험적/이론적 고찰 (Experimental and Theoretical Study on Main Noise Sources and Its Radiations of Upwind Wind Turbines)

  • 이광세;정철웅;신수현;정성수
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2010년도 춘계학술대회 논문집
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    • pp.72-73
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    • 2010
  • In this paper, the main noise sources and its radiated noise levels of upwind horizontal-axis wind turbines are experimentally and theoretically investigated. Theoretical predictions for indentifying the dominant source locations are made by using the empirical noise prediction model of Brooks et al. (1989) for the airfoil self noise. Through the comparison of theoretical results with the experimental results, turbulence-boundary-layer-trailing-edge (TBL-TE) noise is revealed to be the dominant source over all frequency range and separation and stall (S-S) noise is possibly important in the relative lower frequency range compared with TBL-TE noise.

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단일타원 펄스형 Nd:YAG 레이저의 최적동작에 관한 연구 (Optimal operating characteristics of single-elliptical Nd:YAG laser)

  • 곽병구;김동현;정종한;조정수;김희제
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 C
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    • pp.1756-1758
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    • 1996
  • In order to optimize the operational characteristics of single elliptical pulsed Nd:YAG laser designed and fabricator compactly, it is very important to design the resonator shape and the PFN(Pulse Forming Network) suitably. We have been shown that the EMTP(Electro-Magnetic Transient Program) simulation. was used effectively in designing PFN. And Next, we have been compared current pulse width, laser beam profile and damping parameter with laser output energy. In this paper, we have suggested the optimalization of PFN design and the best operational condition.

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다단메쉬 및 펄스중첩법을 적용한 펄스형 Nd:YAG의 Surfacing Process (Surfacing Process of Pulsed Nd:YAG laser by using Multiple mesh and Pulse Superposition Technique)

  • 정종한;홍정환;김동현;김희제;조정수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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    • pp.373-375
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    • 1997
  • In this study, we designed multiple mesh circuit consisting of 3-6 meshes and pulse superposition one consisting of a 3 mesh, and fabricated the electrical power supply and the single elliptical resonator. We developed the two pulse superposition technique forming the step pulse shapes of pulsed Nd:YAG laser with single shot multivibrator and 2 SCRs. Laser beam generated by multiple mesh circuit and superposition one respectively irradiated target surface to analyze process state of surface with spark and vapor. And it was obtained experimental results that all superposition meshes had common points which the best efficiency was obtained at delay time 0[${\mu}s$], followed by, no superposition and obtained at delay time 250[${\mu}s$].

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Development of Multimedia CRTs Using Low-Voltage-Drive Electron Guns

  • Soichiro, Okuda;Tetsuya, Shiroishi;Shuhei, Nakata;Katsumi, Oono;Fumiaki, Murakami;Hideya, Itoh
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.379-381
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    • 2002
  • Mitsubishi Electric Corporation has marketed a series of multimedia CRTs enabling bright picture windows in a high-resolution date display screen. The key components of the multimedia CRTs named Diamondtran $M^2$ are a high-gm (low drive-voltage) electron gun and an aperture grille mask. A high-gm electron gun has been developed by designing a beam forming region with high-gm configuration combining with a high current-density cathode. The development of next generation high-gm guns are also introduced

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RF 바이어스 조건하에서 증착된 a-C:H 박막을 이용한 네마틱 액정의 배향 효과 (Alignment Effects for Nematic Liquid Crystal using a-C:H Thin Films Deposited at Rf Bias Condition)

  • 황정연;박창준;서대식;안한진;백홍구
    • 한국전기전자재료학회논문지
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    • 제17권5호
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    • pp.526-529
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    • 2004
  • The nematic liquid crysta](NLC) aligning capabilities using a-C:H thin film deposited at the three kinds of rf bias condition were investigated. A high pretilt angle of NLC on low substrate rf bias applied a-C:H thin films was observed and the low pretilt angle of the NLC on high substrate rf bias applied a-C:H thin films was observed. Consequently, the high NLC pretilt angle and the good aligning capabilities of LC alignment by the IB alignment method on the a-C:H thin film deposited at 1 W rf bias condition can be achieved. It is considered that pretilt angle of the NLC may be attributed to substrate rf bias condition and IB energy time. Therefore, LC alignment is affected by topographical structure forming strong IB energy.

플라즈마 쉬스 (Sheath)를 이용한 이온 주입법 (Ion Implantation Using Plasma Sheath)

  • 조무현
    • 한국표면공학회지
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    • 제23권1호
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    • pp.1-7
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    • 1990
  • Ion implantation is a well established superior superior surface modification technique for the improvement of wear resistance, hardenece, hardness, corrosion resistance, biocompaibity, surface friction, as well as for the modification of surface electric conductance. Conventional ion implantaion is a line-of-sight process witch ues the ion beam accelerator techniques. Plasma sheath ion implantation (PSII), as a new technique, is described in this paper. In PSII high voltage pulse is applied to a target material placed directly in a plasma, forming a think ion-matrix sheath around the target. Ions accelerate through the sheath drop and bombard the traget from all sides simultaneosuslyregardless of the target shape. This paper describes the principle of PSII, which has non-line-of sight characteristics, as well as the experimental appratus.

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고속철도 차량의 소음 측정을 위한 마이크로폰 어레이 설계에 관한 연구 (Designing a Microphone Array System for Noise Measurements on High-Speed Trains)

  • 노희민;최성훈;홍석윤
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2011년도 추계학술대회 논문집
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    • pp.717-722
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    • 2011
  • In this paper, noise source localization of the Korean high speed train was conducted by using delay and sum beam-forming method of a microphone array. At first, the microphone array having irregular configuration was designed and the resolution of which was analyzed from parameters such as 3-dB bandwidth and maximum side-lobe level. After the demonstration, the microphone array was applied on the high speed train and noise localization of the high speed train driving at 300 km/h was performed successfully.

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ESD 기법을 이용한 투명전도막 형성 기술 (Transparent Electrode Forming Technology using ESD Coating Methode)

  • 김정수;김동수
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 추계학술대회 논문집
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    • pp.348-348
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    • 2009
  • The conductive coating method is used for various industrial fields. For example, Sputtering process is used to coat ITO layer in LCD or OLED panel manufacture process and fabricate a base layer of substrate of an electric printing device. However, conventional coating processes (beam sputtering, spin coating etc.) has a problems in the industrial manufacturing process. These processes have a very high cost and critical manufacturing environment as a vacuum process. Recently, many researchers have proposed various printing process instead of conventional coating processes. In this paper, we propose an ESD printing process in ITO coating layer and apply to fabricate a conductive coating film. Furthermore, the effect of the nozzle and also the applied voltage on different configuration of the nozzle head was also studied for better understanding of the Electro Static deposition process.

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음선 추적법 기반 TRM을 이용한 반사 및 굴절 환경 속의 소음원 탐색에 대한 연구 (Source finding in reflection and refraction environment using based on ray tracing method TRM)

  • 문상일;이재형;최종수
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2014년도 추계학술대회 논문집
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    • pp.727-732
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    • 2014
  • The goal is to find the position of the sound source with the TRM at reflections and refractions environment. The Fermat's principle applied to the ray tracing method are expected to follow the acoustic path in order to obtain acoustic distance and transmittance to. Utilizing them in the TRM was confirmed rear reflectance affect on estimated position, resolution and side lobe. And the TRM performance were superior to one of the beam forming techniques.

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