• 제목/요약/키워드: longitudinal distribution

검색결과 569건 처리시간 0.034초

Bayesian Conway-Maxwell-Poisson (CMP) regression for longitudinal count data

  • Morshed Alam ;Yeongjin Gwon ;Jane Meza
    • Communications for Statistical Applications and Methods
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    • 제30권3호
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    • pp.291-309
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    • 2023
  • Longitudinal count data has been widely collected in biomedical research, public health, and clinical trials. These repeated measurements over time on the same subjects need to account for an appropriate dependency. The Poisson regression model is the first choice to model the expected count of interest, however, this may not be an appropriate when data exhibit over-dispersion or under-dispersion. Recently, Conway-Maxwell-Poisson (CMP) distribution is popularly used as the distribution offers a flexibility to capture a wide range of dispersion in the data. In this article, we propose a Bayesian CMP regression model to accommodate over and under-dispersion in modeling longitudinal count data. Specifically, we develop a regression model with random intercept and slope to capture subject heterogeneity and estimate covariate effects to be different across subjects. We implement a Bayesian computation via Hamiltonian MCMC (HMCMC) algorithm for posterior sampling. We then compute Bayesian model assessment measures for model comparison. Simulation studies are conducted to assess the accuracy and effectiveness of our methodology. The usefulness of the proposed methodology is demonstrated by a well-known example of epilepsy data.

유한요소법을 이용한 용접부의 열전달 및 잔류응력 해석에 관한 연구 (A Study on Analysis of Heat Transfer and Residual Stress on the Weld Zone using FEM)

  • 김일수
    • 한국생산제조학회지
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    • 제9권5호
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    • pp.96-104
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    • 2000
  • This paper represents to develop a computer software system which is capable to analyze the phase transformation of high strength steel(BV-AH32) and to predict heat transfer and welding residual stress due to phase transformation during Gas Metal Arc(GMA) welding. The developed model was considered temperature dependent properties such as young's modules, coefficient of thermal expansion and yield stress as well as the double ellipsoidal heat distribution by the moving arc. From the results, it was found that the longitudinal and transverse residual stresses calculated by the coupled analysis of heat transfer, residual stress and phase transformation showed good agreement with the experimental data. In addition, the temperature distribution as well as longitudinal and transverse residual stresses of weldment by the 1-pass and 2-pass of welding were also determined.

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FEM을 이용한 용접부의 열전달 및 잔류응력 해석 (Analysis of Meat transfer and Residual Stress on the Weld Zone Using FEM)

  • 김일수;박창언;김학형;정영재
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 1999년도 특별강연 및 추계학술발표대회 개요집
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    • pp.310-313
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    • 1999
  • This paper represents to develop a computer software system which is capable to analyze the phase transformation of high strength steel(BV-AH32) and to predict heat transfer, residual stress due to phase transformation during Gas Metal Arc(GMA) welding. The developed model was taken into account temperature dependent of young's modules, coefficient of thermal expansion and yield stress as well as the double ellipsoidal heat distribution by the moving arc. The results showed that the longitudinal and transverse residual stresses calculated by the coupled analysis of heat transfer, residual stress and phase transformation are in good agreement with the experimental data. In addition, the temperature distribution as well as longitudinal and transverse residual stresses of weldment were determined at the 1-pass and 2-pass of welding.

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축대칭 중공실린더의 길이방향 온도분포하의 열탄성응력 해석에 관한 연구 (A Study on the Thermal Stress Analysis of Axi-Symmetric Hollow Cylinder)

  • 이상진;조진
    • 대한기계학회논문집A
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    • 제20권10호
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    • pp.3152-3159
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    • 1996
  • Previous works about the cylindrical shape elastic body which is under longitudinal temperature distribution mostly show the results of free expansion, therefore exact thermo-elastic analysis is needed. The object of this work is to analyze the thermo-elastic problem of the hollow cylinder when the cylinder is under longitudinal temperature distribution. In this paper, the analytical solution is found by using Galerkin vector, and it is compared by the results of FEM. For displacements of cylinder, analytical values are almost same as the results of FEM, but free expansion is not fit for analytical solution and the results of FEM. stresses from analytical solution and the results of FEM show good agreement also. but the results are different near the end boundary, since St. Venant principle is applied.

White-LED 및 Lightguide를 채용한 고효율 scanner 조명 시스템 (Illumination system utilizing light-guide and white LED for document scanner application)

  • 김경록;조정혁;김수현;이동훈;김현석;김형채
    • 한국광학회:학술대회논문집
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    • 한국광학회 2008년도 동계학술발표회 논문집
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    • pp.235-236
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    • 2008
  • A configuration of illumination for high-speed color document scanner has been proposed utilizing white light emitting diode and transparent plastic lightguide. The design of illumination system including lightguide for high optical efficiency and uniform image quality is performed based on a simulation using ray-tracing method. The device characteristics are also experimentally evaluated in terms of illumination distribution against longitudinal and transverse direction on document plane. Uniform illumination distribution about 85% of in longitudinal and transverse direction is realized by control of mechanical dimension and position of lightguide.

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A Study on Classification of Chinese Men's Body Types - Focused in Beijing and Shanghai -

  • Lim, Soon;Sohn, Hee-Soon;Kim, Jee-Yeon
    • 패션비즈니스
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    • 제6권6호
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    • pp.78-88
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    • 2002
  • The purpose of this study is to provide for some basic data useful to production of the apparels fit and measured well for the Chinese men. For this purpose, 389 men aged between 20 and 49 and living in Beijing and Shanghai, China were sampled to be measured for their constitutions. Then, their constitutions were classified and thereupon, according to the Men's Wear Specifications (GB/T 1335.1-1997), National Standards of People's Republic of China. The collected data were statistically processed using SAS 6.12 for technical statistical analysis, correlation analysis, factor analysis, group-wise analysis. The results of this study can be summarized as follows; 1. As a result of the factor analysis aiming to determine Chinese men's constitutional components, five components could be identified: constitutional obesity, lateral body size, longitudinal body size, shoulder and back width, and shoulder drooping. 2. As a result of classifying Chinese men's constitutions according to drop measurements, four types could be identified. Y type had the lowest obesity and the highest longitudinal body size. A type had a lower obesity and had an average longitudinal body size. B Type had the second highest obesity, the smallest longitudinal body size and shoulders/back width. C Type had the highest obesity, upper body length and shoulders/back width. 3. In terms of distribution, 'B' type (39.10%) of the sample, followed by 'A' type (29.26%), 'C' type (19.95%) and 'Y' type (11.70%). In all, the results of this study suggests that 'B' type represents the Chinese men in contrast with GB specifying that 'A' type represents the Chinese men. On the other hand, Beijing region was dominated most by 'B' type (37.06%), followed by 'A' type (28.82%), 'C' type (22.35%) and 'Y' type (11.76%), while Shanghai region was dominated most by 'B' type (41.13%), followed by 'A' type (31.21%), 'C' type (19.15%) and 'Y' type (8.51%).

부착특성을 고려한 휨모멘트-곡률 관계에 관한 연구 (Study on the Relationships of Bending Moment-Corvature Based on Bond Property)

  • 장일영
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1991년도 봄 학술발표회 논문집
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    • pp.81-85
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    • 1991
  • The object of this study is to propose the bending moment-curvature relationships based on the bond properties between concrete and steel for noncraking zone, and evaluate the flexural displacement of reinforced concrete members. The bond-slip relationship and the strain hardening effect of steel were taken into account in order to evaluate the spacing of the cracks and the curvature distribution. Calculated curvature distribution along the longitudinal axis was transformed into equivalent curvature distribution. The flexural displacement was calculated by means of double intergral of the equivalent curvature. Calculated values are in good agreement with the experimental data.

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초전도 선재에서의 전류 분포 해석 (Current Distribution Analysis of Multifilamentary Superconducting Wire)

  • 이지광;김동훈;한송엽;차귀수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 A
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    • pp.44-46
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    • 1996
  • Superconducting cable is using by bundling and twisting with many strands for large current capacity. As a result of the twisting, the magnetic field whose direction is parallel to a sound axis by the transport current of themselves is produced in the cable. Not only the externally exposed longitudinal field but also longitudinal component of self field make a influence on a.c loss and a.c quench current degradation. In this paper, we calculate the saturated region flowing with the critical current density in a strand in case of various twist pitch, transport current and external longitudinal field.

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Poisson's Ratio Scanning Using Immersion Ultrasonic Testing

  • Oh, Seo-Young;Kim, Young-H.;Shin, Yo-Sub;Cho, Hyun-Joon
    • 비파괴검사학회지
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    • 제28권6호
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    • pp.519-523
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    • 2008
  • Poisson's ratio is one of elastic constants of elastic solids. However, it has not attracted attention due to its narrow range and difficult measurement. Transverse wave velocity as well as longitudinal wave velocity should be measured for nondestructive measurement of Poisson's ratio. Hard couplant for transverse wave prevents transducer from scanning over specimen. In the present work, a novel measurement of Poisson's ratio distribution was proposed. Immersion method was employed for the scanning over the specimen. Echo signals of normal beam longitudinal wave were collected. Transverse wave modes generated by mode conversion were identified. From transit time of longitudinal and transverse waves, Poisson's ratio can be determined without information of specimen thickness. This technique was demonstrated for aluminum and steel specimens.