• Title/Summary/Keyword: Joint Probability Density Function

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Joint probability density function of droplet sizes and velocities in a transient diesel spray (간헐디젤분무의 액적크기 및 속도의 공동확률밀도함수)

  • Kim, Jong-Hyeon;Gu, Ja-Ye;O, Du-Suk
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.5
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    • pp.607-617
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    • 1998
  • Comparisons of joint probability density distribution obtained from the raw data of measured droplet sizes and velocities in a transient diesel fuel spray with computed joint probability density function were made. Simultaneous droplet sizes and velocities were obtained using PDPA. Mathematical probability density functions which can fit the experimental distributions were extracted using the principle of maximum likelihood. Through the statistical process of functions, mean droplet diameters, non-dimensional mass, momentum and kinetic energy were estimated and compared with the experimental ones. A joint log-hyperbolic density function presents quite well the experimental joint density distribution which were extracted from experimental data.

Seismic Behaviors of a Bridge System in the Stochastic Perspectives (추계론적 이론을 이용한 교량내진거동분석)

  • Mha, Ho-Seong
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.6 s.46
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    • pp.53-58
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    • 2005
  • Semi-analytical methodology to examine the dynamic responses of a bridge is developed via the joint probability density function. The evolution of joint probability density function is evaluated by the semi-analytical procedure developed. The joint probability function of the bridge responses can be obtained by solving the path-integral solution of the Fokker-Planet equation corresponding to the stochastic differential equations of the system. The response characteristics are observed from the joint probability density function and the boundary of the envelope of the probability density function can provide the maxima ol the bridge responses.

Numerical Study on Turbulent Nonpremixed Pilot Stabilized Flame using the Transported Probability Density Function Model (수송확률밀도함수 모델을 이용한 난류비예혼합 파일럿 안정화 화염장 해석)

  • Lee, Jeong-Won;Kim, Yong-Mo
    • Journal of the Korean Society of Combustion
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    • v.15 no.4
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    • pp.15-21
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    • 2010
  • The transported probability density function(PDF) model has been applied to simulate the turbulent nonpremixed piloted jet flame. To realistically account for the mixture fraction PDF informations on the turbulent non-premixed jet flame, the present Lagrangian PDF transport approach is based on the joint velocity-composition-turbulence frequency PDF formulation. The fluctuating velocity of stochastic fields is modeled by simplified Langevin model(SLM), turbulence frequency of stochastic fields is modeled by Jayesh-Pope model and effects of molecular diffusion are represented by the interaction by exchange with the mean (IEM) mixing model. To validate the present approach, the numerical results obtained by the joint velocity-composition-turbulence frequency PDF model are compared with experimental data in terms of the unconditional and conditional means of mixture fraction, temperature and species and PDFs.

A study on the stability of Keyblock in underground excavation with consideration of joint persistence (절리 영속성을 고려한 지하굴착에서의 Keyblock 안정성 고찰)

  • 조태진;김석윤
    • Tunnel and Underground Space
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    • v.8 no.4
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    • pp.351-358
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    • 1998
  • A statistical method for assessing the joint persistence based on the in-situ measurement of joint trace length has been derived. This method utilizes the probability density distribution of either the joint trace length or the diameter of hypothetically circular joint diameter depending on the relative size of joint surface to that of the potential keyblock. The stability of potential keyblock with different sizes and joint persistences has been also calculated to illustrate the applicability of the developed method to the design and the safe excavation of large scale underground openings.

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Joint-characteristic Function of the First- and Second-order Polarization-mode-dispersion Vectors in Linearly Birefringent Optical Fibers

  • Lee, Jae-Seung
    • Journal of the Optical Society of Korea
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    • v.14 no.3
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    • pp.228-234
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    • 2010
  • This paper presents the joint characteristic function of the first- and second-order polarization-modedispersion (PMD) vectors in installed optical fibers that are almost linearly birefringent. The joint characteristic function is a Fourier transform of the joint probability density function of these PMD vectors. We regard the random fiber birefringence components as white Gaussian processes and use a Fokker-Planck method. In the limit of a large transmission distance, our joint characteristic function agrees with the previous joint characteristic function obtained for highly birefringent fibers. However, their differences can be noticeable for practical transmission distances.

Analysis of a basic single-electron logic-cell considering three-dimensional joint probability distribution (3차원 확률분포함수를 고려한 단일전자 기본 논리 셀의 해석)

  • 유윤섭;황성우
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.7
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    • pp.143-148
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    • 1996
  • Detailed analyses have been presentd for a basic single-electron-logic-cell consisting of two single-electron-transistors (SETs) in series. The interconnection between two SETs has been treated as a coulomb island and the joint probability density function of all three coulomb islands (two from the SETs and one form the interconnection) has been exactly calculated. The average number of electrons in each coulomb island and the steady-state ouptut voltage have been calculated and analyzed.

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Joint Optimization Algorithm Based on DCA for Three-tier Caching in Heterogeneous Cellular Networks

  • Zhang, Jun;Zhu, Qi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.7
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    • pp.2650-2667
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    • 2021
  • In this paper, we derive the expression of the cache hitting probability with random caching policy and propose the joint optimization algorithm based on difference of convex algorithm (DCA) in the three-tier caching heterogeneous cellular network assisted by macro base stations, helpers and users. Under the constraint of the caching capacity of caching devices, we establish the optimization problem to maximize the cache hitting probability of the network. In order to solve this problem, a convex function is introduced to convert the nonconvex problem to a difference of convex (DC) problem and then we utilize DCA to obtain the optimal caching probability of macro base stations, helpers and users for each content respectively. Simulation results show that when the density of caching devices is relatively low, popular contents should be cached to achieve a good performance. However, when the density of caching devices is relatively high, each content ought to be cached evenly. The algorithm proposed in this paper can achieve the higher cache hitting probability with the same density.

ON CHARACTERIZING THE GAMMA AND THE BETA q-DISTRIBUTIONS

  • Boutouria, Imen;Bouzida, Imed;Masmoudi, Afif
    • Bulletin of the Korean Mathematical Society
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    • v.55 no.5
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    • pp.1563-1575
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    • 2018
  • In this paper, our central focus is upon gamma and beta q-distributions from a probabilistic viewpoint. The gamma and the beta q-distributions are characterized by investing the nature of the joint q-probability density function through the q-independence property and the q-Laplace transform.

A Note on Possibilistic Correlation

  • Hong, Dug-Hun
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.9 no.1
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    • pp.1-3
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    • 2009
  • Recently, Carlsson, Full\acute{e}$r and Majlender [1] presented the concept of possibilitic correlation representing an average degree of interaction between marginal distribution of a joint possibility distribution as compared to their respective dispersions. They also formulated the weak and strong forms of the possibilistic Cauchy-Schwarz inequality. In this paper, we define a new probability measure. Then the weak and strong forms of the Cauchy-Schwarz inequality are immediate consequence of probabilistic Cauchy-Schwarz inequality with respect to the new probability measure.

Structural reliability estimation based on quasi ideal importance sampling simulation

  • Yonezawa, Masaaki;Okuda, Shoya;Kobayashi, Hiroaki
    • Structural Engineering and Mechanics
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    • v.32 no.1
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    • pp.55-69
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    • 2009
  • A quasi ideal importance sampling simulation method combined in the conditional expectation is proposed for the structural reliability estimation. The quasi ideal importance sampling joint probability density function (p.d.f.) is so composed on the basis of the ideal importance sampling concept as to be proportional to the conditional failure probability multiplied by the p.d.f. of the sampling variables. The respective marginal p.d.f.s of the ideal importance sampling joint p.d.f. are determined numerically by the simulations and partly by the piecewise integrations. The quasi ideal importance sampling simulations combined in the conditional expectation are executed to estimate the failure probabilities of structures with multiple failure surfaces and it is shown that the proposed method gives accurate estimations efficiently.