• 제목/요약/키워드: density function

검색결과 3,246건 처리시간 0.031초

Influence of impulsive line source and non-homogeneity on the propagation of SH-wave in an isotropic medium

  • Kakar, Rajneesh
    • Interaction and multiscale mechanics
    • /
    • 제6권3호
    • /
    • pp.287-300
    • /
    • 2013
  • In this paper, the effect of impulsive line on the propagation of shear waves in non-homogeneous elastic layer is investigated. The rigidity and density in the intermediate layer is assumed to vary quadratic as functions of depth. The dispersion equation is obtained by using the Fourier transform and Green's function technique. The study ends with the mathematical calculations for transmitted wave in the layer. These equations are in complete agreement with the classical results when the non-homogeneity parameters are neglected. Various curves are plotted to show the effects of non-homogeneities on shear waves in the intermediate layer.

손실함수에 의한 베이지안 퍼지 가설검정 (A Bayesian Fuzzy Hypotheses Testing with Loss Function)

  • 강만기;한성일;최규탁
    • 한국지능시스템학회:학술대회논문집
    • /
    • 한국퍼지및지능시스템학회 2003년도 추계 학술대회 학술발표 논문집
    • /
    • pp.45-48
    • /
    • 2003
  • We propose some properties of Bayesian fuzzy hypotheses testing by revision for prior possibility distribution and posterior possibility distribution using weighted fuzzy hypotheses H$\sub$0/($\theta$) versus H$_1$($\theta$) on $\theta$ with loss function.

  • PDF

Marginal distribution of crossing time and renewal numbers related with two-state Erlang process

  • Talpur, Mir Ghulam Hyder;Zamir, Iffat;Ali, M. Masoom
    • Journal of the Korean Data and Information Science Society
    • /
    • 제20권1호
    • /
    • pp.191-202
    • /
    • 2009
  • In this study, we drive the one dimensional marginal transform function, probability density function and probability distribution function for the random variables $T_{{\xi}N}$ (Time taken by the servers during the vacations), ${\xi}_N$(Number of vacations taken by the servers) and ${\eta}_N$(Number of customers or units arrive in the system) by controlling the variability of two random variables simultaneously.

  • PDF

빔 단면형상에 대한 구조물 신뢰성 최적설계 (Reliability Based Design Optimization for Section Shape of Simple Structures)

  • 임준수;임홍재;이상범;허승진
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2002년도 춘계학술대회논문집
    • /
    • pp.672-676
    • /
    • 2002
  • In this paper, a reliability-based design optimization method, which enables the determination of optimum design that incorporate confidence range for structures, is studied. Response surface method and Monte Carlo simulation are utilized to determine limit state function. The proposed method is applied to the I-type steel structure for reliability based optimal design.

  • PDF

저압 수은 방전에서의 근사화한 충돌 단면적을 사용한 전자 에너지 분포함수 해석 (The analysis of electron energy distribution function using the approximated collision cross section in the low-pressure mercury discharge)

  • 류명선;이진우;지철근
    • 한국조명전기설비학회:학술대회논문집
    • /
    • 한국조명전기설비학회 1989년도 추계학술발표회논문집
    • /
    • pp.19-24
    • /
    • 1989
  • The electron energy distribution function in mercury discharge positive columns are calculated numerically from the Boltzmann eqation under a set of parameters, such as the electron temperature to. the atomic temperature Tw. the electron number density no. and the electric field E. Especially, using the approximation that collision cross sections only depend on the energy, the calculated electron energy distribution function was shown that it falls off rapidly in the high energy tail.

  • PDF

A Combination Capture-Recapture and Line Transect Model in Clustered Population

  • Choi, Jin-Sik;Pyong, Nam-Kung
    • Communications for Statistical Applications and Methods
    • /
    • 제6권3호
    • /
    • pp.729-748
    • /
    • 1999
  • In this paper we present combined estimator of capture-recapture and line transect model using bivariate detection function and detection probability according to objects being in cluster population. Here bivariate detection function use distance and cluster size. The simulation shows that combined estimator approaches the more true value the larger size parameter. Therefore this estimator using the bivariate detection function is more efficient in estimate the population size and density by size parameter.

  • PDF

Empirical modelling approaches to modelling failures

  • Baik, Jaiwook;Jo, Jinnam
    • International Journal of Reliability and Applications
    • /
    • 제14권2호
    • /
    • pp.107-114
    • /
    • 2013
  • Modelling of failures is an important element of reliability modelling. Empirical modelling approach suitable for complex item is explored in this paper. First step of the empirical modelling approach is to plot hazard function, density function, Weibull probability plot as well as cumulative intensity function to see which model fits best for the given data. Next step of the empirical modelling approach is select appropriate model for the data and fit the parametric model accordingly and estimate the parameters.

  • PDF

粒子狀 物質中 金屬成分의 密度分布 (Density Distributions of Metallic Compounds in Particulate Matters)

  • 허문영;김형춘;손동헌
    • 한국대기환경학회지
    • /
    • 제2권2호
    • /
    • pp.9-18
    • /
    • 1986
  • For identification and apportionment of sources emitting particulate matters in environment, the multi-elemental characterization of size-density fractionated particulate matters was carried out. Eight types of samples were tested; soil, flyash released from burning of bunker-Coil, diesel oil, coal, and soft coal, urban road-way dust, urban dust fall, and airborne particulate matter. The fractions of particulate matters obtained by heavy liquid separation methos with a series of dichloromethane-bromoform were then analyzed using atomic absorption spectrophotometry for Ni, Cr, Cu, An, Fe, Al, and Mg. Each sample showed a different concentration profile as a function of density, and a number of useful conclusions concerning characterization of elemental distribution were obtained. From the density distributions of elements in soil, the maximum value was found for all elements in the density range of 2.2 $\sim 2.9g.cm^{-3}$, including the density of $SiO_2$. However, the distribution of metallic compounds with the density lower than $2.2g.cm^{-3}$ was prevalent in urban roadway dust, urban dust fall, and airborne particulate matter. And the density distribution curves of these urban dusts also have the higher distribution at the density of 2.2 - 2.9g.cm^{-3}$, including the density of wind-blown silica. This tendency generally was prevalent in the natural source elements, such as Al, Fe, Mn, and Mg. The maximum values were found in the density ranges of 1.3 $\sim 2.2g.cm^{-3}$ from the density distribution of elements in oil fired flyash. These distributions of anthropogenic source elements, such as Zn, Ni, Cu, and Cr were higher predominately than those of natural source elements. And the higher distribution was found in the density range of $2.2 \sim 2.9g.cm^{-3}$ from the density distribution of elements in coal and soft-coal fired flyash. These distributions showed similar patterns to soil. But anthropogenic source elements somewhat predominated at the density ranges of $1.3 \sim 2.2g.cm{-3} and 2.9g.cm^{-3}$ to soil. Therefore the higher distribution of anthropogenic source elements in the density ranges of $1.3 \sim 2.2g.cm^{-3} and 2.9g.cm^{-3}$ was considered as anthropogenic origin.

  • PDF

도심 인구구심력의 유효범위 변동성 측정 (Variability in the Effective Spatial Range of the Population Centripetal Force of CBD)

  • 남광우;강인주;임두현
    • 한국지리정보학회지
    • /
    • 제12권2호
    • /
    • pp.120-131
    • /
    • 2009
  • 본 연구는 다핵구조를 형성하고 있는 대도시의 도시공간구조 진단을 위해 도심 및 부도심의 인구분포상의 구심력 및 유효범위의 변동성을 측정하였다. 이를 위해 부산광역시를 대상으로 1995년부터 2005년까지 5년 간격으로 도심 및 부도심의 인구구심력의 유효범위 변화를 측정하고자 5km 단위로 범위를 확장하여 인구밀도함수 중 음지수함수를 활용한 결정계수 값의 변동성을 분석하였다. 이를 통해 인구분포에 대한 공간적 영향권역의 변동성을 파악하여 도심 및 부도심의 생성, 성장, 쇠퇴 등의 진행과정에 따른 각 과정별 도심 및 부도심의 인구구심력의 유효범위와 도심 및 부도심간의 충돌과정에서의 유효범위 변화과정을 분석하였다. 분석결과를 요약하면 중앙동은 지속적인 결정계수의 감소를 보이고 있으며 서면(부전동)은 설명력이 큰 변화없이 유지되고 있는 것으로 나타났다. 도심으로부터 5km씩 거리를 늘려 인구밀도함수를 적용한 경우에도 부전동의 경우는 10km이후부터 중앙동은 15km구간 이후부터 대체로 증가하였다. 전체적으로는 부산의 인구가 감소추세임에도 불구하고 지속적인 분산화 단계인 것으로 나타나 보다 효율적인 도시공간구조를 형성하기 위해 도심 및 부도심지역의 도심기능강화와 인접지역의 양호한 주거지역 공급이 필요한 것으로 판단된다. 본 연구의 결과는 도시공간구조의 변동성이 갖는 구체적인 공간적 차원의 정보를 제시하여 효율적 공간구조의 재편을 위한 정책적 접근의 기초자료로의 활용이 기대된다.

  • PDF

난소절제와 Genistein 투여가 간 미토콘드리아 기능에 미치는 영향 (Effect of Ovariectomy and Genistein on Hepatic Mitochondrial Function)

  • 이영민;정명호;이연숙;송지현
    • Journal of Nutrition and Health
    • /
    • 제37권9호
    • /
    • pp.786-793
    • /
    • 2004
  • Women with menopause or rats with ovariectomy is associated with increased body weight, body fat and insulin resistance, which are components of metabolic syndrome. Increased prevalence of metabolic syndrome after menopause might be associated with mitochondrial dysfunction, since mitochondrial oxidative and phosphorylation activity is strongly correlated with insulin sensitivity. Although estradiol replacement prevents the metabolic syndrome, harmful effect of estradiol hampers the casual usage to prevent the metabolic syndrome. It has been reported that genistein has a mild estrogenic activity, decreases fat mass in mice and has an antidiabetic role in diabetic rats. Although insulin resistance is closely related to mitochondrial functions, there has not been yet any study in regard to the effect of dietary genistein on mitochondrial function in the insulin resistant female subjects induced by ovariectomy or similar situation. The present study investigated whether the supplementation of genistein in the high fat diet affected the mitochondrial function of high fat fed ovariectomized rats. Female Sprague Dawley rats (8 weeks old) were assigned to the following groups: sham-operated+ high fat diet (S, n=6); sham-operated + high fat diet with 0.1% genistein (S + G, n=7); ovariectomized + high fat diet (OVX, n=8); ovariectomized + high fat diet with 0.1% genistein (OVX+ G, n=8). Ovariectomy significantly increased body weight compared with S group. Genistein consumption in ovariectomized (OVX + G) rats decreased body weight gain compared with OVX rats. Liver weights were increased by ovariectomy. The hepatic mitochondrial protein density expressed as mg per g liver was lower in the OVX group than in the S group. However, OVX + G group showed the increased mitochondrial protein density similar to the level of S group. When mRNA levels of genes related to mitochondria such as peroxisome proliferator-activated receptor ${\gamma}$ coactivator 1 (PGC-1) and cytochrome c oxidase subunit III (COX III) were measured, there were decreases in the mRNA levels of PGC-1 and COX III in S + G, OVX and OVX + G group. The activity of cytochrome c oxidase was not different between groups. We could observe the decrease in succinate dehydrogenase (SDH) activity per g liver in OVX rats. Genistein supplement increased SDH activity. In conclusion, genistein supplementation to the OVX rats enhanced mitochondrial function by increasing mitochondrial protein density and SDH activity. The improvement in mitochondrial function by genistein can contribute to the improvement in metabolic syndrome.