• 제목/요약/키워드: nParticle

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Particle Filtering과 계층적인 Boosting 알고리즘을 기반으로 한 다중 객체 추적 연구 (Multi-target tracking using Particle Filtering and Hierarchical Boosting Algorithm)

  • 양이화;전문구
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2012년도 한국컴퓨터종합학술대회논문집 Vol.39 No.1(B)
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    • pp.516-518
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    • 2012
  • 본 논문은 Particle Filtering과 계층적인 Boosting 알고리즘을 이용한 다중 객체 추적 기법을 제안한다. Particle Filtering을 이용하여 각 객체를 단일 객체로 추적하고 Boosting 기반의 데이터 연관 알고리즘을 사용하여 영상에서 움직이는 물체들을 추적한다. 본 제안한 알고리즘에서는 객체들의 이동경로 정확한 감지를 위해 Particle Filtering을 통해 각 객체가 움직이는 예측 정보를 이용하고, Boosting 알고리즘을 계측적인 형태로 설계함에 따라 데이터 물체의 추적 정확도를 높일 수 있도록 하였다.

전기집진에서의 난류 입자 이산 (Turbulent Particle Dispersion Effects on Electrostatic Precipitation)

  • 최범석
    • 연구논문집
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    • 통권28호
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    • pp.39-47
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    • 1998
  • Industrial electrostatic precipitation is a very complex process, which involves multiple-way interaction between the electric field, the fluid flow, and the particulate motion. This paper describes a strongly coupled calculation procedure for the rigorous computation of particle dynamics during electrostatic precipitation. The turbulent gas flow and the particle motion under electrostatic forces are calculated by using the commercial computational fluid dynamics (CFD) package FLUENT linked to a finite-volume solver for the electric field and ion charge. Particle charge is determined from both local electrical conditions and the cell residence time which the particle has experienced through its path. Particle charge density and the particle velocity are averaged in a control volume to use Lagrangian information of the particle motion in calculating the gas and electric fields. The turbulent particulate transport and the effects of particulate space charge on the electrical current flow are investigated. The calculated results for poly-dispersed particles are compared with those for mono-dispersed particles, and significant differences are demonstrated.

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N2 plasma treatment of pigments with minute particle sizes to improve their dispersion properties in deionized water

  • Zhang, Jingjing;Park, Yeong Min;Tan, Xing Yan;Bae, Mun Ki;Kim, Dong Jun;Jang, Tae Hwan;Kim, Min Su;Lee, Seung Whan;Kim, Tae Gyu
    • Journal of Ceramic Processing Research
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    • 제20권6호
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    • pp.589-596
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    • 2019
  • Pigments with minute particle sizes, such as carbon black (CB) and pigment red 48:2 (P.R.48:2), are the most important types of pigment and have been widely used in many industrial applications. However, minute particles have large surface areas, high oil absorption and low surface energy. They therefore tend to be repellent to the vehicle and lose stability, resulting in significant increases in viscosity or reaggregation in the vehicle. Therefore, finding the best way to improve the dispersion properties of minute particle size pigments presents a major technical challenge. In this study, minute particle types of CB and P.R.48:2 were treated with nitrogen gas plasma generated via radio frequency-plasma enhanced chemical vapor deposition (RF-PECVD) to increase the dispersion properties of minute particles in deionized (DI) water. The morphologies and particle sizes of untreated and plasma treated particles were evaluated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The average distributions of particle size were measured using a laser particle sizer. Fourier transform infrared spectroscopy was carried out on the samples to identify changes in molecular interactions during plasma processing. The results of our analysis indicate that N2 plasma treatment is an effective method for improving the dispersibility of minute particles of pigment in DI water.

Ar, He 및 $N_2$ 가스의 $\alpha$-입자 저지능과 저지 단면적 측정 (The Stopping Power and Cross-section Measurement of $\alpha$-particle in Ar, He and $N_2$ gases)

  • 이정훈;황재광;황한열;정원모;주관식
    • Journal of Radiation Protection and Research
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    • 제13권2호
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    • pp.1-8
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    • 1988
  • 3MeV에 서 5.4MeV 사이의 $\alpha$-입자에 대한 저지능과 저지 단면적을 He, Ar, 및 $N_2$ 가스에 대해서 측정했다. Srivastava의 저지능 공식을 본 실험결과에 적용시켜 그 타당성을 알아보았다. 그결과 Ar의 경우는 매우 잘 일치됨을 보여주며, He의 경우는 27-28%, $N_2$의 경우는 13-26%의 불일치를 보여주고 있다.

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GIS내 파티클의 상태에 따른 전기적 방전 신호 분석 (Analysis of Electrical discharge signal according to particle state in GIS)

  • 이동준;이곤;곽희로;김경화;권동진
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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    • pp.1084-1086
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    • 1999
  • The breakdown was caused by particle in GIS and various methode was suggested to find particle in GIS. In this paper, four states of particle was imitated which are particle on electrode, particle on enclosure, particle on spacer and crossing particle. The discharge voltage of each states was classified by four voltages which are initial, development, later and close discharge voltage. $\Phi$-Q-N pattern was analyzed according to the states and to the discharge voltages. In the result, the electrical discharge pattern according to the particle states may be distinguished.

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DPF 재생이 경유승용차의 미세입자 배출에 미치는 영향 연구 (Effect of DPF Regeneration on the Nano Particle Emission of Diesel Passenger Vehicle)

  • 권상일;박용희;김종춘;이창식
    • 한국자동차공학회논문집
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    • 제15권3호
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    • pp.153-159
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    • 2007
  • Nano-Particles are influenced on the environmental protection and human health. The relationships between transient vehicle operation and nano-particle emissions are not well-known, especially for diesel passenger vehicles with DPF. In this study, a diesel passenger vehicle was measured on condition of DPF regeneration and no regeneration on a chassis dynamometer test bench. The particulate matter (PM) emission from this vehicle was measured by its number, size and mass measurement. The mass of the total PM was evaluated with the standard gravimetric measurement method while the total number and size concentrations were measured on a NEDC driving cycle using Condensation Particle Counter (CPC) and EEPS. Total number concentration by CPC was $1.5{\times}10^{1l}N/km$, which was 20% of result by EEPS. This means about 80% of total particle emission is consist of volatile and small-sized particles(<22nm). During regeneration, particle emission was $6.2{\times}10^{12}N/km$, was emitted 400 times compared with the emission before regeneration. As for the particle size of $22{\sim}100nm$ was emitted mainly, showing peak value of near 40nm in size. This means regeneration decreased the mean size of particles. Regarding regeneration, PM showed no change while the particle number showed about 6 times difference between before and after regeneration. It seems that the regeneration influences on particle number emissions are related to DPF-fill state and filtration efficiency.

$Fe_2O_3$몰비 및 B\ulcorner첨가가 Sr-Ferrite 특성에 미치는 영향 (Effect of Molar Ratio of $Fe_2O_3$ and BaO Addition on the Characteristics of Sr-Ferrite)

  • 문기훈;심영재;조성걸
    • 한국세라믹학회지
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    • 제34권5호
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    • pp.453-460
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    • 1997
  • Sr-ferrite having magnetoplumbite structure is similar to Ba-ferrite in magnetic characteristics, but better magnetic characteristics for using motor application. To improve remanence magnetic flux density(Br) and coercive force(iHc), it is necessary that sintered ferrites must have high density and grain size less than 1 $\mu$m. By varying n values in SrO.nFe2O3 basic composition, calcination temperature, and BaO addition, Sr-ferrite powder and sintered specimen was prepared. The n values, calcination temperature, and BaO addition affected secondary phase formation, particle size, and particle shape. BaO addition enhanced Fe2O3 secondary phase and hexagonal shape particle. Fe2O3 phase reduced sintered density which greatly decreased Br.

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1단 전기집진기에서 난류확산과 2차유동이 입자의 농도분포에 미치는 영향 (Effects of Turbulence Diffusion and Secondary Flows on the Particle Concentration Distribution in Single Stage ESP)

  • 정상현;김상수;김용진
    • 대한기계학회논문집
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    • 제19권9호
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    • pp.2271-2282
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    • 1995
  • Numerical simulations for the effects of secondary flow and turbulence diffusion on the particle concentration distributions have been carried out for the single stage electrostatic precipitator. The electrohydrodynamic secondary flow, particle concentration distribution and collection efficiency have been evaluated as a function of dimensionless parameters such as Re, $N_{end}$, $P_{e}$ x. The results of simulations show that for increasing secondary flow intensity the concentration distribution is drastically deformed and collection efficiency is decreased which is more than due to turbulent diffusion.n.n.

Case study of Creating CG Handheld Steadicam using maya nParticle

  • Choi, Chul Young
    • International journal of advanced smart convergence
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    • 제10권3호
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    • pp.157-162
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    • 2021
  • With the recent increase in YouTube content, many YouTubers are shooting with a handheld camera. Audiences are increasingly accustomed to the movement of handheld cameras. As the camera moves faster than the camera movement of the old movies, and the camera moves splendidly to the music of the music video, the camera movement in CG animation is also needed to change. The handheld Steadicam creates a natural camera movement by compensating so that the screen does not vibrate significantly even when the vibration is large and by minimizing rotation. In order to implement such camera movement, we tried to make a handheld Steadicam using nParticle simulation of Maya software and apply it to the scene to verify whether it is possible to implement the necessary natural and various movement.

방사선빔 조사를 이용한 질화갈륨 기반 트랜지스터의 내방사선 특성 연구 (Radiation Hardness Evaluation of GaN-based Transistors by Particle-beam Irradiation)

  • 금동민;김형탁
    • 전기학회논문지
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    • 제66권9호
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    • pp.1351-1358
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    • 2017
  • In this work, we investigated radiation hardness of GaN-based transistors which are strong candidates for next-generation power electronics. Field effect transistors with three types of gate structures including metal Schottky gate, recessed gate, and p-AlGaN layer gate were fabricated on AlGaN/GaN heterostructure on Si substrate. The devices were irradiated with energetic protons and alpha-particles. The irradiated transistors exhibited the reduction of on-current and the shift of threshold voltage which were attributed to displacement damage by incident energetic particles at high fluence. However, FET operation was still maintained and leakage characteristics were not degraded, suggesting that GaN-based FETs possess high potential for radiation-hardened electronics.