• 제목/요약/키워드: performance estimation system

검색결과 2,460건 처리시간 0.027초

Joint Blind Parameter Estimation of Non-cooperative High-Order Modulated PCMA Signals

  • Guo, Yiming;Peng, Hua;Fu, Jun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권10호
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    • pp.4873-4888
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    • 2018
  • A joint blind parameter estimation algorithm based on minimum channel stability function aimed at the non-cooperative high-order modulated paired carrier multiple access (PCMA) signals is proposed. The method, which uses hierarchical search to estimate time delay, amplitude and frequency offset and the estimation of phase offset, including finite ambiguity, is presented simultaneously based on the derivation of the channel stability function. In this work, the structure of hierarchical iterative processing is used to enhance the performance of the algorithm, and the improved algorithm is used to reduce complexity. Compared with existing data-aided algorithms, this algorithm does not require a priori information. Therefore, it has significant advantage in solving the problem of blind parameter estimation of non-cooperative high-order modulated PCMA signals. Simulation results show the performance of the proposed algorithm is similar to the modified Cramer-Rao bound (MCRB) when the signal-to-noise ratio is larger than 16 dB. The simulation results also verify the practicality of the proposed algorithm.

광통신용 페룰 가공을 위한 초미세 고기능 동축가공 연삭시스템용 이송계의 특성 평가 (Performance Estimation of Feeding System for developing coaxial grinding system of light communicative ferrule)

  • 안건준;최병옥;이호준;황창기
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.10-14
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    • 2005
  • This report deals with a feeding system of the Coaxal grinding machine, processing optical ferrule. This report also examines the applicability of using the feeding system for the Coaxial grinding machine, by mean of conducting performance estimation. The results are as follow; Repeatability of regulating wheel is $17{\mu}m$, R/W rotation accuracy is between $30\;\~\;40{\mu}m$. This means 'Rotation accuracy' is lower than the concentricity level. Backlash generation level at the feeding system of the grinding wheel is under $1{\mu}m$, thereby positioning accuracy is controlled within $2{\mu}m$ In terms of repeatability, you can find occasional error at the returning process from the starting point. This error is resulted from the measurement tolerance of the starting point sensor. We will get the repeatability level under control by $1{\mu}m$, through improving the soft-ware used and up-grading the sensor at the starting point.

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구간 추정 기법을 이용한 이동통신 시스템의 통화 성공률 시험 방법 (A Testing Method for Evaluating the Call Success Rate of a Mobile Communication System using Interval Estimation)

  • 황익순;박재성
    • 한국정보과학회논문지:정보통신
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    • 제37권6호
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    • pp.494-498
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    • 2010
  • 시스템의 성능 요구 사항은 일반적으로 해당 시스템이 제공하는 서비스의 품질과 높은 연관성을 가진다. 예를 들어 이동통신 시스템에서 통화 성공률은 서비스 품질과 직결되는 사항으로 매우 높은 중요도를 가지며 체계적인 성능 시험 방법이 요구되고 있다. 본 논문에서는 구간 추정 기법을 이용하여 이동통신 시스템의 통화 성공률을 시험하는 방안을 제안한다. 또한 제안된 시험 방안을 기반으로 방송통신위원회에서 최근 시행한 3G 이동전화 서비스 품질 평가에서 사용된 판정 기준에 대해 고찰해 보고 문제점에 대해 살펴본다.

Performance Investigation of Space-Time Block Coded Multicarrier DS-CDMA in Time-Varying Channels

  • Narzullaev, Anvar;Ryu, Kwan-Woong;Park, Yong-Wan
    • ETRI Journal
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    • 제28권5호
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    • pp.684-687
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    • 2006
  • In this letter, we evaluate the system performance of a space-time block coded (STBC) multicarrier (MC) DS-CDMA system over a time selective fading channel, with imperfect channel knowledge. The average bit error rate impairment due to imperfect channel information is investigated by taking into account the effect of the STBC position. We consider two schemes: STBC after spreading and STBC before spreading in the MC DS-CDMA system. In the scheme with STBC after spreading, STBC is performed at the chip level; in the scheme with STBC before spreading, STBC is performed at the symbol level. We found that these two schemes have various channel estimation errors, and that the system with STBC before spreading is more sensitive to channel estimation than the system with STBC after spreading. Furthermore, derived results prove that a high spreading factor (SF) in the MC DS-CDMA system with STBC before spreading leads to high channel estimation error, whereas for a system with STBC after spreading this statement is not true.

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대역 확산 신호를 위한 지연 시간 추정 알고리즘 (A Super-Resolution Time Delay Estimation Algorithm for Spread Spectrum Signals)

  • 신준호;명승일;장은영;박형래
    • 한국통신학회논문지
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    • 제37권2A호
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    • pp.119-127
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    • 2012
  • 본 논문에서는 대역 확산 (spread spectrum) 방식의 실시간 위치 추적 시스템 (RTLS: real-time locating system)을 위한 초 분해능 지연 시간 추정 (super-resolution time delay estimation) 알고리즘을 개발하고 다중 경로 환경에서 성능을 분석한다. 기존의 코릴레이션 방식은 주변에 장애물이 없는 line-of-sight (LOS) 환경에서는 비교적 정확한 지연 시간 추정이 가능하나 지연 시간의 차이가 한 칩 이내인 근접 다중 경로 환경에서는 성능이 급격히 저하되는 문제점이 있다. 따라서 본 논문에서는 도래각 추정에 이용되는 MUSIC 알고리즘을 이용하여 근접 다중 경로 환경에서도 신호의 지연 시간을 추정할 수 있는 초 분해능 지연 시간 추정 알고리즘을 개발하고 이를 ISO/IEC 24730-2.1 RTLS 시스템에 적용하여 성능을 분석한다.

Improved Estimation Method for the Capacitor Voltage in Modular Multilevel Converters Using Distributed Neural Network Observer

  • Mehdi Syed Musadiq;Dong-Myung Lee
    • 전기전자학회논문지
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    • 제27권4호
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    • pp.430-438
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    • 2023
  • The Modular Multilevel Converter (MMC) has emerged as a key component in HVDC systems due to its ability to efficiently transmit large amounts of power over long distances. In such systems, accurate estimation of the MMC capacitor voltage is of utmost importance for ensuring optimal system performance, stability, and reliability. Traditional methods for voltage estimation may face limitations in accuracy and robustness, prompting the need for innovative approaches. In this paper, we propose a novel distributed neural network observer specifically designed for MMC capacitor voltage estimation. Our observer harnesses the power of a multi-layer neural network architecture, which enables the observer to learn and adapt to the complex dynamics of the MMC system. By utilizing a distributed approach, we deploy multiple observers, each with its own set of neural network layers, to collectively estimate the capacitor voltage. This distributed configuration enhances the accuracy and robustness of the voltage estimation process. A crucial aspect of our observer's performance lies in the meticulous initialization of random weights within the neural network. This initialization process ensures that the observer starts with a solid foundation for efficient learning and accurate voltage estimation. The observer iteratively updates its weights based on the observed voltage and current values, continuously improving its estimation accuracy over time. The validity of proposed algorithm is verified by the result of estimated voltage at each observer in capacitor of MMC.

A STUDY ON FUEL ESTIMATION ALGORITHMS FOR A GEOSTATIONARY COMMUNICATION & BROADCASTING SATELLITE

  • Eun, Jeong-Won
    • Journal of Astronomy and Space Sciences
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    • 제17권2호
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    • pp.249-256
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    • 2000
  • It has been developed to calculate fuel budget for a geostationary communication and broadcasting satellite. It is quite essential that the pre-launch fuel budget estimation must account for the deterministic transfer and drift orbit maneuver requirements. After on-station, the calculation of satellite lifetime should be based on the estimation of remaining fuel and assessment of actual performance. These estimations step from the proper algorithms to produce the prediction of satellite lifetime. This paper concentrates on the fuel estimation method that was studied for calculation of the propellant budget by using the given algorithms. Applications of this method are discussed for a communication and broadcasting satellite.

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성능요인에 따른 무기체계 적정가격 추정방안 연구: 헬기발사형 대전차 유도무기를 중심으로 (A Study on the Estimation of the Proper Price of Weapon System by Performance Factors: Focused on Heli-Launched Anti-Tank Guided Missiles)

  • 박상현;강언비;전정환
    • 한국군사과학기술학회지
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    • 제24권1호
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    • pp.133-143
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    • 2021
  • In government procurement programs, cost estimation and analysis support funding decisions and are the basis for other major decisions, too. Such estimating and analyzing the cost of the weapon systems are crucial in execution of the defense budget. However, existing cost estimations and analyses have focused on domestic R&D projects, thus those are not valid in application to foreign weapon acquisitions. This study aims at foreign weapon systems that are acquired from Direct Commercial Sales. Because the data for price estimation of a foreign weapon is usually not available, we suggest a price estimation model based on performance factors of the weapon. In this study, the proper price of the weapon system is estimated using the parametric cost estimating model. Using the data of helicopter-launched anti-tank guided missiles worldwide, we analyze the effect of each performance factor on the weapon system price by regression analysis, and use step-wise and ridge regression analysis to remove multi-collinearity. This study hopefully contributes to more reasonable decision making on proper price of weapons.

칼만 필터를 이용한 개선된 PID 제어기 설계 (The Design of an Improved PID Controller by Using the Kalman Filter)

  • 차인혁;권태종;한창수
    • 대한기계학회논문집A
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    • 제24권1호
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    • pp.7-15
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    • 2000
  • This paper suggests an auto-tuning I'll) control algorithm that uses the advantage of PID controller and improves the system performance. The PID gains being designed by th- conventional method are tuned through the plant parameter estimation. The Extended Kalman Filter is used for the estimation. It works as an observer and noise filter. Moreover, as the plant state and the uncertain parameter could be estimated simultaneously, the proposed algorithm is very useful in the tracking control of a system with uncertain parameter. The auto-tuning I'll) controller could maintain the system performance in the case that the plant parameters are uncertain or varying. The proposed control algorithm requires a correct estimation of the plant parameter. The controller stability and the performance is considered through the stability criteria and a servo motor model. The Kalman filter estimates the most sensitive plant parameter, which is determined by the sensitivity analysis.

AT-DMB 시스템에서 채널추정을 이용한 기본계층 수신 성능 향상기법 (Improving the Base-Layer BER performance at AT-DMB using a Channel Estimation)

  • 방극준
    • 전자공학회논문지 IE
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    • 제49권2호
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    • pp.46-51
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    • 2012
  • AT-DMB 시스템의 신호 전송은 향상계층은 채널등화를 거친 Coherent Detection을 사용하지만 기본계층은 T-DMB와 마찬가지로 차동변복조를 사용한다. 본 논문에서는 이와같은 구조에서 어차피 향상계층 수신을 위하여 사용되는 채널추정 결과를 기본계층에 적용하여 기본계층의 수신성능을 향상시킬 수 있음을 보여준다. 제안하는 방법은 AT-DMB 수신단의 차동복조앞단에서 수신신호에 채널등화를 적용한 후 수신신호 성상도를 가장 가까운 ${\pi}$/4-shift DQPSK 성상도점으로 집중화시킨 후 차동복조를 적용함으로서 코딩을 적용하지 않은 상태에서 AWGN $10^{-4}BER$ 기준으로 약 2dB 성능향상을 얻을 수 있음을 보였다.