• 제목/요약/키워드: Particle-based system

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멀티 리간드의 특이적 상호작용이 입자-세포간 상호작용에 미치는 영향 (Effect of Specific Interaction of Multi-Ligands on the Specific Interaction between Particle and Cell)

  • 윤정현;이세영
    • 대한의용생체공학회:의공학회지
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    • 제43권2호
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    • pp.94-101
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    • 2022
  • Recent advancement of micro/nano technology enables the development of diverse micro/nano particle-based delivery systems. Due to the multi-functionality and engineerability, particle-based delivery system are expected to be a promising method for delivery to the target cell. Since the particle-based delivery system should be delivered to the various kinds of target cell, including the cardiovascular system, cancer cell etc., it is frequently decorated with multiple kinds of targeting molecule(s) to induce specific interaction to the target cell. The surface decorated molecules interact with the cell surface expressed molecule(s) to specifically form a firm adhesion. Thus, in this study, the probability of adhesion is estimated to predict the possibility to form a firm adhesion for the multi-ligand decorated particle-based delivery system.

미세 입자 계수기를 위한 입자 검출 챔버 개발 (Development of Particle Detection Chamber for Particle Counter)

  • 엄우용
    • 전자공학회논문지
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    • 제51권1호
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    • pp.219-224
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    • 2014
  • 본 논문에서는 미세 입자의 크기와 굴절률, 그리고 레이저 파장과 산란광을 얻는 수신단의 각도 등 여러 변수에 대하여 Mie 산란 이론을 적용하여 미세 입자의 산란 특성에 대하여 연구하였고, 이를 바탕으로 미세 입자 검출을 위한 광학계를 구성하고 산란 신호를 획득하여 그 특성을 분석하였다. 그리고 이러한 특성들을 바탕으로 미세 입자 검출기를 위한 입자 검출 챔버를 개발하고 성능을 분석한다.

Directional Particle Filter Using Online Threshold Adaptation for Vehicle Tracking

  • Yildirim, Mustafa Eren;Salman, Yucel Batu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권2호
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    • pp.710-726
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    • 2018
  • This paper presents an extended particle filter to increase the accuracy and decrease the computation load of vehicle tracking. Particle filter has been the subject of extensive interest in video-based tracking which is capable of solving nonlinear and non-Gaussian problems. However, there still exist problems such as preventing unnecessary particle consumption, reducing the computational burden, and increasing the accuracy. We aim to increase the accuracy without an increase in computation load. In proposed method, we calculate the direction angle of the target vehicle. The angular difference between the direction of the target vehicle and each particle of the particle filter is observed. Particles are filtered and weighted, based on their angular difference. Particles with angular difference greater than a threshold is eliminated and the remaining are stored with greater weights in order to increase their probability for state estimation. Threshold value is very critical for performance. Thus, instead of having a constant threshold value, proposed algorithm updates it online. The first advantage of our algorithm is that it prevents the system from failures caused by insufficient amount of particles. Second advantage is to reduce the risk of using unnecessary number of particles in tracking which causes computation load. Proposed algorithm is compared against camshift, direction-based particle filter and condensation algorithms. Results show that the proposed algorithm outperforms the other methods in terms of accuracy, tracking duration and particle consumption.

Design and Fabrication of CLYC-Based Rotational Modulation Collimator (RMC) System for Gamma-Ray/Neutron Dual-Particle Imager

  • Kim, Hyun Suk;Lee, Jooyub;Choi, Sanghun;Bang, Young-bong;Ye, Sung-Joon;Kim, Geehyun
    • Journal of Radiation Protection and Research
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    • 제46권3호
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    • pp.112-119
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    • 2021
  • Background: This work aims to develop a new imaging system based on a pulse shape discrimination-capable Cs2LiYCl6:Ce (CLYC) scintillation detector combined with the rotational modulation collimator (RMC) technique for dual-particle imaging. Materials and Methods: In this study, a CLYC-based RMC system was designed based on Monte Carlo simulations, and a prototype was fabricated. Therein, a rotation control system was developed to rotate the RMC unit precisely, and a graphical user interface-based software was also developed to operate the data acquisition with RMC rotation. The RMC system was developed to allow combining various types of collimator masks and detectors interchangeably, making the imaging system more versatile for various applications and conditions. Results and Discussion: Operational performance of the fabricated system was studied by checking the accuracy and precision of the collimator rotation and obtaining modulation patterns from a gamma-ray source repeatedly. Conclusion: The prototype RMC system showed reliability in its mechanical properties and reproducibility in the acquisition of modulation patterns, and it will be further investigated for its dual-particle imaging capability with various complex radioactive source conditions.

Automation of an Interactive Interview System by Hand Gesture Recognition Using Particle Filter

  • Lee, Yang-Weon
    • Journal of information and communication convergence engineering
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    • 제9권6호
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    • pp.633-636
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    • 2011
  • This paper describes a implementation of virtual interactive interview system. A hand motion recognition algorithm based on the particle filters is applied for this system. The particle filter is well operated for human hand motion recognition than any other recognition algorithm. Through the experiments, we show that the proposed scheme is stable and works well in virtual interview system's environments.

입자군집 최적화에 기초한 최적 퍼지추론 시스템의 구조설계 (Structural Design of Optimized Fuzzy Inference System Based on Particle Swarm Optimization)

  • 김욱동;이동진;오성권
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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    • pp.384-386
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    • 2009
  • This paper introduces an effectively optimized Fuzzy model identification by means of complex and nonlinear system applying PSO algorithm. In other words, we use PSO(Particle Swarm Optimization) for identification of Fuzzy model structure and parameter. PSO is an algorithm that follows a collaborative population-based search model. Each particle of swarm flies around in a multidimensional search space looking for the optimal solution. Then, Particles adjust their position according to their own and their neighboring-particles experience. This paper identifies the premise part parameters and the consequence structures that have many effects on Fuzzy system based on PSO. In the premise parts of the rules, we use triangular. Finally we evaluate the Fuzzy model that is widely used in the standard model of gas data and sew data.

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Occluded Object Motion Estimation System based on Particle Filter with 3D Reconstruction

  • Ko, Kwang-Eun;Park, Jun-Heong;Park, Seung-Min;Kim, Jun-Yeup;Sim, Kwee-Bo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제12권1호
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    • pp.60-65
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    • 2012
  • This paper presents a method for occluded object based motion estimation and tracking system in dynamic image sequences using particle filter with 3D reconstruction. A unique characteristic of this study is its ability to cope with partial occlusion based continuous motion estimation using particle filter inspired from the mirror neuron system in human brain. To update a prior knowledge about the shape or motion of objects, firstly, fundamental 3D reconstruction based occlusion tracing method is applied and object landmarks are determined. And optical flow based motion vector is estimated from the movement of the landmarks. When arbitrary partial occlusions are occurred, the continuous motion of the hidden parts of object can be estimated by particle filter with optical flow. The resistance of the resulting estimation to partial occlusions enables the more accurate detection and handling of more severe occlusions.

홀로그래피 입자속도 측정시스템의 개발과 분무 액적에의 적용 (Development of Holographic Particle Velocimetry System and Its Application to Spray Droplets)

  • 추연준;강보선
    • 한국분무공학회지
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    • 제10권3호
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    • pp.17-28
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    • 2005
  • The Holographic Particle Velocimetry system can be a promising optical tool for the measurements of three dimensional particle velocities. In this study, diffused illumination holographic system to measure the sizes and 3D velocities of moving particles based on automatic image processing was developed. First of all basic optical systems for pulse laser recording, continuous laser reconstruction, and image acquisition, were constructed. To determine the position of particles in the optical axis, new three auto-focusing parameters(AEP), namely, Correlation Coefficient, Sharpness Index, and Depth Intensity were introduced and verified. The developed system was applied to spray droplets to validate the capability of the system. Three dimensional positions of particles viewed from two sides were decided using AFP and then 3D velocities of Particles were extracted by particle tracking algorithm. Comparison of measurement results of sizes and 3D velocities of particles with those obtained by laser instrument, PDPA, showed good consistency of the developed holographic system.

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Visual Attention Model Based on Particle Filter

  • Liu, Long;Wei, Wei;Li, Xianli;Pan, Yafeng;Song, Houbing
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권8호
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    • pp.3791-3805
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    • 2016
  • The visual attention mechanism includes 2 attention models, the bottom-up (B-U) and the top-down (T-D), the physiology of which have not yet been accurately described. In this paper, the visual attention mechanism is regarded as a Bayesian fusion process, and a visual attention model based on particle filter is proposed. Under certain particular assumed conditions, a calculation formula of Bayesian posterior probability is deduced. The visual attention fusion process based on the particle filter is realized through importance sampling, particle weight updating, and resampling, and visual attention is finally determined by the particle distribution state. The test results of multigroup images show that the calculation result of this model has better subjective and objective effects than that of other models.

산포된 플라즈마 기반의 가속입자 자료 가시화 (Visualization of Scattered Plasma-based Particle Acceleration Data)

  • 신한솔;유태준;이건
    • 한국멀티미디어학회논문지
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    • 제18권1호
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    • pp.65-70
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    • 2015
  • Particle accelerator has mainly used in nuclear field only because of the large scale of the facility. However, since laser-plasma particle accelerator which has smaller size and spends less cost developed, the availability of this accelerator is expended to various research fields such as industrial and medical. This paper suggests a visualization system to control the laser-plasma particle accelerator efficiently. This system offers real-time 3D images via convert HDF file comes from plasma data obtained from PIC simulation into OpenGL texture type to analyse and modify plasma data. After that, it stores high-resolution rendering images of the data with external renderer hereafter.