• 제목/요약/키워드: Triangle Distribution Function

검색결과 17건 처리시간 0.029초

Langmuir 프로브 전압의 파형에 따른 아르곤 플라즈마의 전자에너지 분포함수 측정에 관한 연구 (A Study on the measurement of Electron Energy Distribution Function in Ar plasma measured by the waveforms of Langmuir probe voltages)

  • 김두환;박정후
    • 대한전기학회논문지:전기물성ㆍ응용부문C
    • /
    • 제48권5호
    • /
    • pp.391-395
    • /
    • 1999
  • In this paper, we have obtained the Electron Energy Distribution Function(EEDF) in plasma by using two differentiators and investigated the EEDFs by sawtooth and triangle waveform voltages with the working pressures and the positions of single probe. It is found that as the working pressure is decreased, the EEDFs approach to theMaxwellian distribution independent of the waveforms of probe voltage. On the otherhand, as the position of probe is moved from the center of the plasma to its edge, the EEDF of sawtooth waveform probe voltage approaches to the Maxwellian distribution, but the EEDF of triangle waveform probe voltage deviates from the Maxwellian distribution.

  • PDF

Estimation for the Half-Triangle Distribution Based on Progressively Type-II Censored Samples

  • Han, Jun-Tae;Kang, Suk-Bok
    • Journal of the Korean Data and Information Science Society
    • /
    • 제19권3호
    • /
    • pp.951-957
    • /
    • 2008
  • We derive some approximate maximum likelihood estimators(AMLEs) and maximum likelihood estimator(MLE) of the scale parameter in the half-triangle distribution based on progressively Type-II censored samples. We compare the proposed estimators in the sense of the mean squared error for various censored samples. We also obtain the approximate maximum likelihood estimators of the reliability function using the proposed estimators. We compare the proposed estimators in the sense of the mean squared error.

  • PDF

크리프 균열성장 모델에 대한 확률론적 수명예측 프로그램 (Probabilistic Remaining Life Assessment Program for Creep Crack Growth)

  • 김건영;;강명수
    • 한국정밀공학회지
    • /
    • 제16권6호
    • /
    • pp.100-107
    • /
    • 1999
  • This paper describes a probabilistic remaining life assessment program for the creep crack growth. The probabilistic life assessment program is developed to increase the reliability of life assessment. The probabilistic life assessment involves some uncertainties, such as, initial crack size, material properties, and loading condition, and a triangle distribution function is used for random variable generation. The resulting information provides the engineer with an assessment of the probability of structural failure as a function of operating time given the uncertainties in the input data. This study forms basis of the probabilistic life assessment technique and will be extended to other damage mechanisms.

  • PDF

Bayesian estimations on the exponentiated half triangle distribution under Type-I hybrid censoring

  • Kim, Yong-Ku;Kang, Suk-Bok;Seo, Jung-In
    • Journal of the Korean Data and Information Science Society
    • /
    • 제22권3호
    • /
    • pp.565-574
    • /
    • 2011
  • The exponenetiated distribution has been used in reliability and survival analysis especially when the data is censored. In this paper, we derive Bayesian estimation of shape parameter and reliability function in the exponenetiated half triangle distribution based on Type-I hybrid censored data. Here we consider conjugate prior and noninformative prior and obtained corresponding posterior distributions. As an illustration, the mean square errors of the estimates are computed. Comparisons are made between these estimators using Monte Carlo simulation study.

톱니파 및 삼각파 프로브 bias 전압에 의해 측정된 전자에너지 분포함수의 비교에 관한 연구 (A Study on the Comparision of Electron Energy Distribution Function measured by sawtooth and triangle waveform probe bias voltages)

  • 김두환;신중흥;김규섭;박영찬;조정수;박정후
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1996년도 하계학술대회 논문집 C
    • /
    • pp.1844-1847
    • /
    • 1996
  • In the paper, we have obtained electron energy distribution function (EEDF) in plasma by using two differentiators. In addition, we have investigated the comparision of the EEDFs by sawtooth and triangle waveform voltages. It is found that as pressure is decreased, electron density is decreased, and plasma potential is increased. And as the position of probe moves the outer of plasma, plasma potential is decreased, and electron temperature is decreased.

  • PDF

접지임피던스 분석을 위한 접지전극의 전류분포 수치계산 (Numerical Calculation of Longitudinal Current Distribution in Grounding Electrode for Analyzing the Grounding Impedance)

  • 조성철;이복희
    • 조명전기설비학회논문지
    • /
    • 제27권1호
    • /
    • pp.46-52
    • /
    • 2013
  • The current distribution passing through grounding electrode is required for calculating an impedance of grounding electrode using the electromagnetic field model. In this paper the numerical calculation for currents passing through a grounding electrode as a function of frequency was given. The proposed approach is based on the wire antenna model(AM) in the frequency domain. The Pocklington's equation driven from the wire antenna theory was numerically calculated by the Galerkin's method. The triangle function was applied to both the basis function and the weighting function. The current distribution of a horizontal ground electrode was simulated in MATLAB. Also these results were compared with the data obtained from the CDEGS HIFREQ calculation.

Consideration of Image Quality of Dithered Picture by Constrained Average Method Using Various Probability Distribution Models

  • Sato, Mitsuhiro;Hasegawa, Madoka;Kato, Shigeo
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2002년도 ITC-CSCC -3
    • /
    • pp.1495-1498
    • /
    • 2002
  • The constrained average method is one of dither methods which combines edge emphasis and grayscale rendition to provide legibility of textual region and proper quality of continuous tone region. How-ever, image quality of continuous tone region is insufficient compared to other dither methods, such as ordered dither methods or the error diffusion method. The constrained average method uses a uniform distribution function to decide number of lit pixels related to the average intensity in a picture area. However, actual distribution of continuous tone region is closer to the Laplacian distribution or triangle distribution. In this paper, we introduce various probability distributions and the actual luminance distribution to decide the threshold value of the constrained average method in order to improve image quality of dithered image.

  • PDF

Parametric modeling and shape optimization design of five extended cylindrical reticulated shells

  • Wu, J.;Lu, X.Y.;Li, S.C.;Xu, Z.H.;Wang, Z.D.;Li, L.P.;Xue, Y.G.
    • Steel and Composite Structures
    • /
    • 제21권1호
    • /
    • pp.217-247
    • /
    • 2016
  • Five extended cylindrical reticulated shells are proposed by changing distribution rule of diagonal rods based on three fundamental types. Modeling programs for fundamental types and extended types of cylindrical reticulated shell are compiled by using the ANSYS Parametric Design Language (APDL). On this basis, conditional formulas are derived when the grid shape of cylindrical reticulated shells is equilateral triangle. Internal force analysis of cylindrical reticulated shells is carried out. The variation and distribution regularities of maximum displacement and stress are studied. A shape optimization program is proposed by adopting the sequence two-stage algorithm (RDQA) in FORTRAN environment based on the characteristics of cylindrical reticulated shells and the ideas of discrete variable optimization design. Shape optimization is achieved by considering the objective function of the minimum total steel consumption, global and locality constraints. The shape optimization for three fundamental types and five extended types is calculated with the span of 30 m~80 m and rise-span ratio of 1/7~1/3. The variations of the total steel consumption along with the span and rise-span ratio are analyzed with contrast to the results of shape optimization. The optimal combination of main design parameters for five extended cylindrical reticulated shells is investigated. The total steel consumption affected by distribution rule of diagonal rods is discussed. The results show that: (1) Parametric modeling method is simple, efficient and practical, which can quickly generate different types of cylindrical reticulated shells. (2) The mechanical properties of five extended cylindrical reticulated shells are better than their fundamental types. (3) The total steel consumption of cylindrical reticulated shells is optimized to be the least when rise-span ratio is 1/6. (4) The extended type of three-way grid cylindrical reticulated shell should be preferentially adopted in practical engineering. (5) The grid shape of reticulated shells should be designed to equilateral triangle as much as possible because of its reasonable stress and the lowest total steel consumption.

Response of dynamic interlaminar stresses in laminated plates under free vibration and thermal load

  • Zhu, S.Q.;Chen, X.;Wang, X.
    • Structural Engineering and Mechanics
    • /
    • 제25권6호
    • /
    • pp.753-765
    • /
    • 2007
  • The response histories and distribution of dynamic interlaminar stresses in composite laminated plates under free vibration and thermal load is studied based on a thermoelastodynamic differential equations. The stacking sequence of the laminated plates may be arbitrary. The temperature change is considered as a linear function of coordinates in planes of each layer. The dynamic mode of displacements is considered as triangle series. The in-plane stresses are calculated by using geometric equations and generalized Hooke's law. The interlaminar stresses are evaluated by integrating the 3-D equations of equilibrium, and utilizing given boundary conditions and continuity conditions of stresses between layers. The response histories and distribution of interlaminar stress under thermal load are presented for various vibration modes and stacking sequence. The theoretical analyses and results are of certain significance in practical engineering application.

Adaptive group of ink drop spread: a computer code to unfold neutron noise sources in reactor cores

  • Hosseini, Seyed Abolfazl;Afrakoti, Iman Esmaili Paeen
    • Nuclear Engineering and Technology
    • /
    • 제49권7호
    • /
    • pp.1369-1378
    • /
    • 2017
  • The present paper reports the development of a computational code based on the Adaptive Group of Ink Drop Spread (AGIDS) for reconstruction of the neutron noise sources in reactor cores. AGIDS algorithm was developed as a fuzzy inference system based on the active learning method. The main idea of the active learning method is to break a multiple input-single output system into a single input-single output system. This leads to the ability to simulate a large system with high accuracy. In the present study, vibrating absorber-type neutron noise source in an International Atomic Energy Agency-two dimensional reactor core is considered in neutron noise calculation. The neutron noise distribution in the detectors was calculated using the Galerkin finite element method. Linear approximation of the shape function in each triangle element was used in the Galerkin finite element method. Both the real and imaginary parts of the calculated neutron distribution of the detectors were considered input data in the developed computational code based on AGIDS. The output of the computational code is the strength, frequency, and position (X and Y coordinates) of the neutron noise sources. The calculated fraction of variance unexplained error for output parameters including strength, frequency, and X and Y coordinates of the considered neutron noise sources were $0.002682{\sharp}/cm^3s$, 0.002682 Hz, and 0.004254 cm and 0.006140 cm, respectively.