• Title/Summary/Keyword: Distribution density

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Plasma Density Measurement of Hg-Ar by LIF Method (LIF를 이용한 Hg-Ar의 플라즈마 밀도 측정)

  • Choi, Yong-Sung;Hwang, Jong-Sun;Park, Kye-Choon;Song, Min-Jong;Kim, Hyeong-Gohn;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.12a
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    • pp.27-32
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    • 2006
  • In this paper, we introduced a LIF measurement method and summarized the theoretical side. When an altered wavelength of laser and electric power, lamp applied electric power, we measured the relative density of the metastable state in mercury after observing a laser induced fluorescence signal of 404.8nm and 546.2nm, and confirmed the horizontal distribution of plasma density in the discharge lamp. Due to this generation, the extinction of atoms in a metastable state occurred through collision, ionization, and excitation between plasma particles. The density and distribution of the metastable state depended on the energy and density of plasma particles, intensely. This highlights the importance of measuring density distribution in plasma electric discharge mechanism study. The results confirmed the resonance phenomenon regarding the energy level of atoms along a wavelength change, and also confirmed that the largest fluorcscent signal in 436nm, and that the density of atoms in 546.2nm ($6^3S_1{\rightarrow}6^3P_2$) were larger than 404.8nm ($6^3S_1{\rightarrow}6^3P_2$). According to the increase of lamp applied electric power, plasma density increased, too. When increased with laser electric power, the LIF signal reached a saturation state in more than 2.6mJ. When partial plasma density distribution along a horizontal axis was measured using the laser induced fluorescence method, the density decreased by recombination away from the center.

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Robustness of Predictive Density and Optimal Treatment Allocation to Non-Normal Prior for The Mean

  • Bansal, Ashok K.;Sinha, Pankaj
    • Journal of the Korean Statistical Society
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    • v.22 no.2
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    • pp.235-247
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    • 1993
  • The predictive density function of a potential future observation and its first four moments are obtained in this paper to study the effects of a non-normal prior of the unknown mean of a normal population. The derived predictive density function is modified to study changes in utility curves, used to choose the optimum treatment from a given set of treatments, at a given level of stimulus due to slight deviations from normality of the prior distribution. Numerical illustrations are provided to exhibit some effectsl.

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Critical Current Density Distribution Analysis of HTS Tape (고온초전도 테이프의 임계전류밀도 분포 해석)

  • 강준선;나완수;권영길;손명환;김석환
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2002.02a
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    • pp.277-280
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    • 2002
  • It is well known that the critical current of a HTS tape has anisotropic characteristic in magnetic field. We are interested in critical current density distribution of a HTS tape. We assumed the experimentally obtained Ic-B curves do represent the local properties of HTS tapes and calculated the critical current density distribution of HTS tapes using numerical method. Also we predicted the critical current of the tapes.

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Groove Shape Optimization of a Composition Brake Shoe by Finite Element Method (유한요소법에 의한 합성제륜자 홈의 형상 최적화)

  • 구병춘;최경진;옥희동;윤용석
    • Proceedings of the KSR Conference
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    • 1999.05a
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    • pp.226-231
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    • 1999
  • A composition brake shoe composed of iron, graphite, kevlar, barium sulphate, etc. was developed for Diesel locomotives. The density distribution of the shoe depends on groove shapes of the shoe (or punch shape). In this study, we investigated the influence of the punch shape on the density distribution, stresses, etc. The inclination of the groove exerts more influence on the density distribution than the groove filet radius.

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Wave Energy Distribution at Jeju Sea and Investigation of Optimal Sites for Wave Power Generation (파력발전 적지 선정을 위한 제주 해역 파랑에너지 분포특성 연구)

  • HONG KEY-YONG;RYU HWANG-JIN;SHIN SEUNG-HO;HONG SEOK-WON
    • Journal of Ocean Engineering and Technology
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    • v.18 no.6 s.61
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    • pp.8-15
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    • 2004
  • Wave power distribution is investigated to determine the optimal sites for wave power generation at Jeju sea which has the highest wave energy density in the Korean coastal waters. The spatial and seasonal variation of wave power per unit length is calculated in the Jeju sea area based on the monthly mean wave data from 1979 to 2002 which is produced by the SWAN wave model simulation in prior research. The selected favorable locations for wave power generation are compared in terms of magnitude of wave energy density and distribution characteristics of wave parameters. The results suggest that Chagui-Do is the most optimal site for wave power generation in the Jeju sea. The seasonal distribution of wave energy density reveals that the highest wave energy density occurs in the northwest sea in the winter and it is dominated by wind waves, while the second highest one happens at south sea in the summer and it is dominated by a swell sea. The annual average of wave energy density shows that it gradually increases from east to west of the Jeju sea. At Chagui-Do, the energy density of the sea swell sea is relatively uniform while the energy density of the wind waves is variable and strong in the winter.

Comparison of Wind Energy Density Distribution Using Meteorological Data and the Weibull Parameters (기상데이터와 웨이블 파라메타를 이용한 풍력에너지밀도분포 비교)

  • Hwang, Jee-Wook;You, Ki-Pyo;Kim, Han-Young
    • Journal of the Korean Solar Energy Society
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    • v.30 no.2
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    • pp.54-64
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    • 2010
  • Interest in new and renewable energies like solar energy and wind energy is increasing throughout the world due to the rapidly expanding energy consumption and environmental reasons. An essential requirement for wind force power generation is estimating the size of wind energy accurately. Wind energy is estimated usually using meteorological data or field measurement. This study attempted to estimate wind energy density using meteorological data on daily mean wind speed and the Weibull parameters in Seoul, a representative inland city where over 60% of 15 story or higher apartments in Korea are situated, and Busan, Incheon, Ulsan and Jeju that are major coastal cities in Korea. According to the results of analysis, the monthly mean probability density distribution based on the daily mean wind speed agreed well with the monthly mean probability density distribution based on the Weibull parameters. This finding suggests that the Weibull parameters, which is highly applicable and convenient, can be utilized to estimate the wind energy density distribution of each area. Another finding was that wind energy density was higher in coastal cities Busan and Incheon than in inland city Seoul.

Analysis of bone-remodeling by the influence of external fixator with FEM (FEM을 이용한 외부고정구 영향에 의한 골-재형성에 대한 해석)

  • 김영은;이원식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.2
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    • pp.436-444
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    • 1991
  • A computational method has been developed to analyze the bone-remodeling induced by external fixator. The method was based on the Finite Element Method (FEM) in combination with numerical formulation of adaptive bone-remodeling theories. As a feed-back control variable, compressive strain and effective stress were used to determine the surface remodeling and internal (density) remodeling respectively. Surface remodeling and internal remodeling were combined at each time step to predict the rel situation. A noticeable shape and density change were detected at the region between two pins and density change was decreased with time increment. At final time step, the shape and density distribution were converged closely to its original intact bone model. Similar change was detected in stress distribution. The altered stress distribution due to the pin and external fixator converged to the intact stress distribution with time.

Estimation of Non-Gaussian Probability Density by Dynamic Bayesian Networks

  • Cho, Hyun-C.;Fadali, Sami M.;Lee, Kwon-S.
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.408-413
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    • 2005
  • A new methodology for discrete non-Gaussian probability density estimation is investigated in this paper based on a dynamic Bayesian network (DBN) and kernel functions. The estimator consists of a DBN in which the transition distribution is represented with kernel functions. The estimator parameters are determined through a recursive learning algorithm according to the maximum likelihood (ML) scheme. A discrete-type Poisson distribution is generated in a simulation experiment to evaluate the proposed method. In addition, an unknown probability density generated by nonlinear transformation of a Poisson random variable is simulated. Computer simulations numerically demonstrate that the method successfully estimates the unknown probability distribution function (PDF).

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Effects of Particle Size Distribution of Alumina on Behaviors of Tape Casting (테이프 케스팅 거동에 미치는 알루미나의 입도분포의 영향)

  • 윤원균;김정주;조상희
    • Journal of the Korean Ceramic Society
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    • v.34 no.11
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    • pp.1173-1181
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    • 1997
  • Effects of particle size distribution of alumina ceramics on behaviors of tape casting were investigated with emphases on the rheological characteristic of slurry, green density, green sheet strength, and sintering density. For the control of particle size distribution of alumina, the commercial grade low soda alumina, which had different mean particle size of 3.58 ${\mu}{\textrm}{m}$ and 0.42 ${\mu}{\textrm}{m}$, were chosen and blended together. As results, the mixing of 80 wt% fine powder and 20 wt% coarse powder(designated to FC20) led to the increase of packing density and strength of green sheet, and made it easy to handle during processing without lowering of sintering density. Besides, the pseudoplastic behavior of slurry decreased with increase of the fraction of coarse alumina powder.

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Topology Optimization of Connection Component System Using Density Distribution Method (밀도분포법을 이용한 부재의 연결구조 최적화)

  • 한석영;유재원
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.12 no.4
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    • pp.50-56
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    • 2003
  • Most engineering products contain more than one component. Failure occurs either at the connection itself or in the component at the point of attachment of the connection in many engineering structures. The allocation and design of connections such as bolts, spot-welds, adhesive etc. usually play an important role in the structure of multi-components. Topology optimization of connection component provides more practical solution in design of multi-component connection system. In this study, a topology optimization based on density distribution approach has been applied to optimal location of fasteners such as T-shape, L-shape and multi-component connection system. From the results, it was verified that the number of iteration was reduced, and the optimal topology was obtained very similarly comparing with ESO method. Therefore, it can be concluded that the density distribution method is very suitable for topology optimization of multi-component structures.