• 제목/요약/키워드: Particle Systems

검색결과 1,099건 처리시간 0.026초

Bimodal 방법을 이용한 하전입자 응집 모델링 (Development of Simple Bimodal Model for Charged Particle Coagulation)

  • 김상복;송동근;홍원석;신완호
    • 한국입자에어로졸학회지
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    • 제10권1호
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    • pp.27-31
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    • 2014
  • A simple bimodal model has been developed to analyze charged particle coagulation by modifying previously suggested bimdal model for evolution of particle generation and growth. In the present model, two monodisperse modes are used and 40 charge nodes are assigned to each mode to account both change of the particle size and charge distribution. In addition, we also implemented the effect of electrostatic dispersion loss in the present model. Based on the developed model, we analyzed coagulation of asymmetric bipolar charged particles by computing evolutions of particle number concentration, geometric mean diameter of particles, charge asymmetric ratio and geometric standard deviation of particle size distribution for various initial charge asymmetric ratios. The number concentration of asymmetric bipolar charged particles decreases faster than that of neutral particles but that does not give faster growth of particles since the electrostatic dispersion loss overwhelms particle growth by coagulation.

실시간 탄도 궤적 목표물 추적을 위한 GPU 기반 병렬적 입자군집최적화 기법 (Parallelized Particle Swarm Optimization with GPU for Real-Time Ballistic Target Tracking)

  • 한윤호;이헌철;권혁훈;최원석;정보라
    • 대한임베디드공학회논문지
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    • 제17권6호
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    • pp.355-365
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    • 2022
  • This paper addresses the problem of real-time tracking a high-speed ballistic target. Particle filters can be considered to overcome the nonlinearity in motion and measurement models in the ballistic target. However, it is difficult to apply particle filters to real-time systems because particle filters generally require much computation time. This paper proposes an accelerated particle filter using graphics processing unit (GPU) for real-time ballistic target tracking. The real-time performance of the proposed method was tested and analyzed on a widely-used embedded system. The comparison results with the conventional particle filter on CPU (central processing unit) showed that the proposed method improved the real-time performance by reducing computation time significantly.

Feeder Reconfiguration Using Binary Coding Particle Swarm Optimization

  • Wu, Wu-Chang;Tsai, Men-Shen
    • International Journal of Control, Automation, and Systems
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    • 제6권4호
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    • pp.488-494
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    • 2008
  • This paper proposes an effective approach based on binary coding Particle Swarm Optimization (PSO) to identify the switching operation plan for feeder reconfiguration. The proposed method considers the advantages and disadvantages of existing particle swarm optimization method and redefined the operators of PSO algorithm to fit the application field of distribution systems. Shift operator is proposed to construct the binary coding particle swarm optimization for feeder reconfiguration. A typical distribution system of Taiwan Power Company is used in this paper to demonstrate the effectiveness of the proposed method. The test results show that the proposed method can apply to feeder reconfiguration problems more effectively and stably than existing method.

산란이론과 신경회로에 의한 입자크기계측 (Particle Sizing Using Light Scattering and Neural Networks)

  • 남부희;이상재;박민현;이영진;이석원;류태우;방병렬
    • 제어로봇시스템학회논문지
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    • 제6권6호
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    • pp.447-453
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    • 2000
  • Using the scattering theory of laser light, we analyze the particle sizing method. The scattered profile measured by the photodetector is sampled, scale conditioned by a 32 channel analog-to-digital converter, and is analyzed with the transform matrix from the light energy signals to the weights of the particle sizes. The particle size distribution is classified using the Hopfield neural network method as well as the conventional nonnegative least square method.

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Object Tracking in 3-D Space with Passive Acoustic Sensors using Particle Filter

  • Lee, Jin-Seok;Cho, Shung-Han;Hong, Sang-Jin;Lim, Jae-Chan;Oh, Seong-Jun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제5권9호
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    • pp.1632-1652
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    • 2011
  • This paper considers the object tracking problem in three dimensional (3-D) space when the azimuth and elevation of the object are available from the passive acoustic sensor. The particle filtering technique can be directly applied to estimate the 3-D object location, but we propose to decompose the 3-D particle filter into the three planes' particle filters, which are individually designed for the 2-D bearings-only tracking problems. 2-D bearing information is derived from the azimuth and elevation of the object to be used for the 2-D particle filter. Two estimates of three planes' particle filters are selected based on the characterization of the acoustic sensor operation in a noisy environment. The Cramer-Rao Lower Bound of the proposed 2-D particle filter-based algorithm is derived and compared against the algorithm that is based on the direct 3-D particle filter.

파티클 필터에 기반한 새로운 상태 예측 방법 (A New Approach of State Estimation based on Particle Filter)

  • 박성근;류경진;황재필;김은태
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2006년도 춘계학술대회 학술발표 논문집 제16권 제1호
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    • pp.245-248
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    • 2006
  • A particle filter is one of the most famous filters. The reason why the particle filter is widely used is that particle deals with the state estimation problem for not only linear models with Gaussian noise but also the non-linear models with non-Gaussian noise and it receives great attention from many engineering fields. In the point of view state estimator, particle filter is feedforward observer. According to the characteristic of dynamic system, the feedforward observer can estimate real state. However, the speed of convergence of feedforward observer between the actual state and the estimated state cannot be satisfied. Since the particle filter is a sort of feedforward observer, the convergence speed of particle filter is slow, and the particle filter cannot estimate actual state like particle collapse problem. In order to overcome the limitation of particle filter as a kind of feedfoward estimator, we propose a new particle filter which has feedback term, called particle filter with feedback. Our proposed method is analyzed theoretically and studied by computer simulation. Comparisons are made with other filtering mehod.

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광산란 계측기의 미세먼지 측정 정확도 향상을 위한 수분제거 전처리 기술 개발 (Development of Drying Systems for Accurate Measurement of Particulate Matter by means of Optical Particle Measuring Instruments)

  • 강두수;오정은;이상열;신희준;봉하경;최주현;김대성
    • 한국입자에어로졸학회지
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    • 제14권4호
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    • pp.191-203
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    • 2018
  • IIn this study, we have developed drying systems for reducing the error by humidity on measuring particulate matter (PM) in the ambient air with optical particle measuring instruments. Two types of drying systems were designed: drying systems using heating and dilution methods. In addition, 3 types of drying systems using a heating method were designed: Type A (1 hole), B (3 holes) and C (7 holes). After making them, the laboratory and field tests were carried out to evaluate the developed drying systems. As a result, it was shown that the PM concentrations obtained by PM monitoring devices with drying systems agree well with that of the reference devices. Therefore, it could be concluded that the drying systems can be applied to PM monitoring devices for real-time monitoring of the ambient aerosols.

Magnetic Properties of the Ultrafine Co Particle Systems

  • Perov, N.;Sudarikova, N.;Bagrets, A.
    • Journal of Magnetics
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    • 제8권1호
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    • pp.7-12
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    • 2003
  • The method for evaluation of the particle size distribution of fine particles from hysteresis loop measurements is Presented. The method is illustrated on the SiO$_2$-based Co nanoparticle systems. The influence of technological conditions of sample preparation onto particle size distribution is investigated.

퍼지 시스템과 Particle Swarm Optimization(PSO)을 이용한 Prewarping 기술 (Prewarping Techniques Using Fuzzy system and Particle Swarm Optimization)

  • 장우석;강환일
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2006년도 추계학술대회 학술발표 논문집 제16권 제2호
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    • pp.272-274
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    • 2006
  • In this paper, we concentrate on the mask design problem for optical micro-lithography. The pre-distorted mask is obtained by minimizing the error between the designed output image and the projected output image. We use the particle swarm optimization(PSO) and fuzzy system to insure that the resulting images are identical to the desired image. Our method has good performance for the iteration number by an experiment.

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A Hybridization of Adaptive Genetic Algorithm and Particle Swarm Optimization for Numerical Optimization Functions

  • Yun, Young-Su;Gen, Mitsuo
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2008년도 추계 공동 국제학술대회
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    • pp.463-467
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    • 2008
  • Heuristic optimization using hybrid algorithms have provided a robust and efficient approach for solving many optimization problems. In this paper, a new hybrid algorithm using adaptive genetic algorithm (aGA) and particle swarm optimization (PSO) is proposed. The proposed hybrid algorithm is applied to solve numerical optimization functions. The results are compared with those of GA and other conventional PSOs. Finally, the proposed hybrid algorithm outperforms others.

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