• Title/Summary/Keyword: Half-normal model

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Abundance Estimation of the Finless Porpoise, Neophocaena phocaenoides, Using Models of the Detection Function in a Line Transect (Line Transect에서 발견율함수 추정에 사용되는 모델에 따른 상괭이, Neophocaena phocaenoides의 자원개체수 추정)

  • Park, Kyum-Joon;Kim, Zang-Geun;Zhang, Chang-Ik
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.40 no.4
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    • pp.201-209
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    • 2007
  • Line transect sampling in a sighting survey is one of most widely used methods for assessing animal abundance. This study applied distance data, collected from three sighting surveys using line transects for finless porpoise that were conducted in 2004 and 2005 off the west coast of Korea, to four models (hazard-rate, uniform, half-normal and exponential) that can use a variety of detection functions, g (x). The hazard-rate model, a derived model for the detection function, should have a shoulder condition chosen using the AIC (Akaike Information Criterion), as the most suitable model. However, it did not describe a shoulder shape for the value of g(x) near the track tine and underestimated g (x), just as the exponential model did. The hazard-rate model showed a bias toward overestimating the densities of finless porpoises with a higher coefficient of variation (CV) than the other models did. The uniform model underestimated the densities of finless porpoise but had the lowest CV. The half-normal model described a detection function with a shape similar to that of the uniform model. The half-normal model was robust for finless porpoise data and should be able to avoid density underestimation. The estimated abundance of finless porpoise was 3,602 individuals (95% CI=1,251-10,371) inshore in 2005 and 33,045 individuals (95% CI=24,274-44,985) offshore in 2004.

Black Hispanic and Black Non-Hispanic Breast Cancer Survival Data Analysis with Half-normal Model Application

  • Khan, Hafiz Mohammad Rafiqullah;Saxena, Anshul;Vera, Veronica;Abdool-Ghany, Faheema;Gabbidon, Kemesha;Perea, Nancy;Stewart, Tiffanie Shauna-Jeanne;Ramamoorthy, Venkataraghavan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9453-9458
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    • 2014
  • Background: Breast cancer is the second leading cause of cancer death for women in the United States. Differences in survival of breast cancer have been noted among racial and ethnic groups, but the reasons for these disparities remain unclear. This study presents the characteristics and the survival curve of two racial and ethnic groups and evaluates the effects of race on survival times by measuring the lifetime data-based half-normal model. Materials and Methods: The distributions among racial and ethnic groups are compared using female breast cancer patients from nine states in the country all taken from the National Cancer Institute's Surveillance, Epidemiology, and End Results cancer registry. The main end points observed are: age at diagnosis, survival time in months, and marital status. The right skewed half-normal statistical probability model is used to show the differences in the survival times between black Hispanic (BH) and black non-Hispanic (BNH) female breast cancer patients. The Kaplan-Meier and Cox proportional hazard ratio are used to estimate and compare the relative risk of death in two minority groups, BH and BNH. Results: A probability random sample method was used to select representative samples from BNH and BH female breast cancer patients, who were diagnosed during the years of 1973-2009 in the United States. The sample contained 1,000 BNH and 298 BH female breast cancer patients. The median age at diagnosis was 57.75 years among BNH and 54.11 years among BH. The results of the half-normal model showed that the survival times formed positive skewed models with higher variability in BNH compared with BH. The Kaplan-Meir estimate was used to plot the survival curves for cancer patients; this test was positively skewed. The Kaplan-Meier and Cox proportional hazard ratio for survival analysis showed that BNH had a significantly longer survival time as compared to BH which is consistent with the results of the half-normal model. Conclusions: The findings with the proposed model strategy will assist in the healthcare field to measure future outcomes for BH and BNH, given their past history and conditions. These findings may provide an enhanced and improved outlook for the diagnosis and treatment of breast cancer patients in the United States.

Bayesian Analysis of GLEM with Half-Normal Prior

  • Bhattacharya, Samir K.;Lal, Ram
    • Journal of the Korean Statistical Society
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    • v.14 no.2
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    • pp.95-99
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    • 1985
  • In this paper, Bayesian analysiss of the general linear econometric model is carried out by using a multinomal prior for the vector of unknown regression coefficents and a half-normal prior for the standard deviation of the disturbances.

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Study of Membrane Potential Analysis According to Applying Doksam-tang to a Human Heart Failure Model (인체심장의 심부전모델에서의 獨蔘湯 투여에 따른 심장막전위 분석에 관한 연구)

  • Jeong, Dae-Yeong;Lee, Boo-Kyun;Hong, Jin-Woo;An, Won-Gun
    • Herbal Formula Science
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    • v.23 no.1
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    • pp.121-131
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    • 2015
  • Objectives : This study was conducted to investigate the membrane potential to apply Doksam-tang to a human heart failure model. Methods : The human heart model was built by Luo et al. CellML model, Priebe et al. CellML model, and a human heart mesh file. Doksam-tang gives channel the half maximal inhibitory concentration(IC 50 ), half maximal effective concentration(EC 50 ) values and compounds concentrations. These data load into the laptop with Ubuntu OS, and build the library with the data. Results : While results of the study with the heart failure model shows abnormal membrane potential from the normal heart model, the study with applying Doksam-tang to heart failure model shows restoring membrane potential that is similar to normal heart model. Conclusions : These results of the testings suggest that a conception of novel technique to investigate the effects of Korean herbal medicine.

Vibration Analysis of Body Mount System on Chassis Frame (섀시 프레임 상의 바디 마운트계의 진동해석)

  • Lee, Chang-Ro;Ryu, Bong-Jo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.2
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    • pp.141-146
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    • 2010
  • This paper describes the static and dynamic characteristics of body mount system which are to be considered in the early design stage. At every location of body mount the static load and dynamic response to road input were calculated using the half car model. Normal mode analysis for the half car model was also performed. In the analysis the design parameters such as the stiffness of mount rubbers and their distribution on mount location were examined for improving ride comfort especially in the lower frequency range.

Chronopharmacokinetics of Vancomycin in Normal Volunteers (반코마이신의 시간 약물동태학)

  • Choi, Jun Shik;You, Jae Sin;Choi, Byung Cheol;Kim, Jin;Bum, Jin Pil;Choi, Kyung Eob
    • Korean Journal of Clinical Pharmacy
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    • v.6 no.2
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    • pp.1-6
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    • 1996
  • Carcadian rhythm dependence of vancomycin pharmacokinetics was evaluated in 5 normal volunteers receiving a single intravenous 1.0 g dose of vancomycin at 8 o'clock in the morning and another occasion at 8 o'clock in the evening in a crossover manner. The serum data were subjected to simultaneous computer nonlinear least squares regression analysis using a two-compartment pbarmacokinetic model. The mean half-life of vancomycin was $4.78\pm0.81$ hr in the morning and $4.25\pm0.51$ hr in the evening. The mean total body clearance of vancomycin was $1.29\pm0.58$ hr in the morning and $5.58\pm0.48$ hr in the evening. No circadian rhythm was found to be apparent in normal volunteers. The mean in intrasubject difference in the half-life between 8 A.M. and 8 P.M. was $15.4\%$ with fluctuations ranging from $10.4\sim33.8\%$, It is reasonable to consider individual circadian rhythm for effective dosage regimen of vancomycin in clinical chronotherapeutics.

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Numerical analysis of the receding contact problem of two bonded layers resting on an elastic half plane

  • Yaylaci, Murat;Terzi, Cemalettin;Avcar, Mehmet
    • Structural Engineering and Mechanics
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    • v.72 no.6
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    • pp.775-783
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    • 2019
  • The present study deals with the numerical analysis of the symmetric contact problem of two bonded layers resting on an elastic half plane compressed with a rigid punch. In this context, Finite Element Method (FEM) based software called ANSYS and ABAQUS are used. It is assumed that the elastic layers have different elastic constants and heights and the external load is applied to the upper elastic layer by means of a rigid stamp. The problem is solved under the assumptions that the contact between two elastic layers, and between the rigid stamp are frictionless, the effect of gravity force is neglected. To validate the constructed model and obtained results a comparison is performed with the analytical results in literature. The numerical results for normal stresses and shear stresses are obtained for various parameters of load, material and geometry and are tabulated and illustrated.

Rayleigh waves in nonlocal porous thermoelastic layer with Green-Lindsay model

  • Ismail Haque;Siddhartha Biswas
    • Steel and Composite Structures
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    • v.50 no.2
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    • pp.123-133
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    • 2024
  • The paper deals with the propagation of Rayleigh waves in a nonlocal thermoelastic isotropic layer which is lying over a nonlocal thermoelastic isotropic half-space under the purview of Green-Lindsay model and Eringen's nonlocal elasticity in the presence of voids. The normal mode analysis is employed to the considered equations to obtain vector matrix differential equation which is then solved by eigenvalue approach. The frequency equation of Rayleigh waves is derived and different particular cases are also deduced. The effects of voids and nonlocality on different characteristics of Rayleigh waves are presented graphically.

The effect of magnetic field and inclined load on a poro-thermoelastic medium using the three-phase-lag model

  • Samia M. Said
    • Geomechanics and Engineering
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    • v.37 no.3
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    • pp.243-251
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    • 2024
  • In the current work, a poro-thermoelastic half-space issue with temperature-dependent characteristics and an inclined load is examined in the framework of the three-phase-lag model (3PHL) while taking into account the effects of magnetic and gravity fields. The resulting coupled governing equations are non-dimensional and are solved by normal mode analysis. To investigate the impacts of the gravitational field, magnetic field, inclined load, and an empirical material constant, numerical findings are graphically displayed. MATLAB software is used for numerical calculations. Graphs are used to visualize and analyze the computational findings. It is found that the physical quantities are affected by the magnetic field, gravity field, the nonlocal parameter, the inclined load, and the empirical material constant.

Influence of an inclined load on a nonlocal fiber-reinforced visco-thermoelastic solid via 3PHL

  • Samia M. Said
    • Structural Engineering and Mechanics
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    • v.90 no.6
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    • pp.569-575
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    • 2024
  • The objective of this study is to investigate the influence of an inclined load, location, and time on the behavior of a fiber-reinforced visco-thermoelastic half-space. The displacement, stress, and temperature distributions are derived from the normal mode analysis. The problem is analyzed using a three-phase-lag model. MATLAB programming is employed to ascertain the physical fields with appropriate boundary conditions and to perform numerical computations. The outcomes are then examined with different inclination loads, time, and location settings.