• Title/Summary/Keyword: Gamma regression

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BLOOD METABOLITES LEVELS IN RELATION TO AGE AND LIVE WEIGHT IN YOUNG BUFFALO CALVES

  • Sikka, P.;Sethi, R.K.;Tomer, A.K.S.;Chopra, S.C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.7 no.2
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    • pp.201-205
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    • 1994
  • Thirty buffalo calves were randomly categorized into three groups on the basis of age, i.e. birth to 6 months; 6 to 12 months and 12-24 months. Blood samples were collected to monitor certain vital metabolites in relation to age and prediction of performance in growing buffalo calves. Amongst the various blood parameters estimated the serum glucose, cholesterol and gamma globulins have shown highly significant correlations with age and live weight-gain of the animal as well. However, the multiple regression analysis clearly indicated the influence of age and live body weight on blood metabolites in buffalo calves.

Interactions between Hydrodesulfurization of Thiophene and Hydrodenitrogenation of Pyridine and the Kinetic Analysis (수첨탈황과 탈질반응에서 Thiophene과 Pyridine의 상호영향과 그 속도론적 해석)

  • 박종희;한창훈;김경림
    • Journal of Korean Society for Atmospheric Environment
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    • v.4 no.1
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    • pp.13-22
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    • 1988
  • Interactions between hydrodesulfurization of thiophene and hydrodenitrogenation of pyridine and the kinetic analysis were studied over $Ni-W/\gamma-Al_2O_3$ catalysts and this study was made at temperatures ranging from 473-673 K and at total pressures ranging from 10-25 $\times 10^5$ Pa. Hydrodesulfurization of thiophene was inhibited by presence of pyridine at all temperatures studied, and the rate of pyridine hydrodenitrogenation was slower than that of thiophene hydrodesulfurization in the operating conditions. Pyridine hydrodenitrogenation was also inhibited by the presence of thiophene at low temperatures but was enhanced by the thiophene at temperatures higher than 613K. Thiophene reaction rate was determined by multiple linear regression analysis using Langmuir-Hinshelwood-Hougen-Watson model and the result was given to be $r = kP_T^p_H/(1+K_Tp_T+K_Pp_P)^2$. At each temperature, reaction rate constants and absorption equilibrium equilibrium constants were determined and the activation energy was 12.98 kcal/gmol from Arrhenius plot.

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A Study on the Analysis of Hydrologic Similarity of the Catchment Response(I) (유역응답의 수문학적 상사성해석에 관한 연구(I))

  • 조홍제;이상배
    • Water for future
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    • v.23 no.4
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    • pp.421-434
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    • 1990
  • The problems of hydrologic similarity among river basins was analyzed by a geomorphologic response model using Hortons*s ordering scheme. The Nash model was used for deriving the geomorphologic response function, and for the optimization of the responsefunction, imcomplete gamma function andRosso*s regression equation were used. The application of this method was tested on some observed flood data of Pyungchang river basin and Wi Stream basin and Bocheong stream, and predictions of hydrologic response were compared with that of the Moment method. The results show that the proposed model and dimensionless instantaneous unit hydrograph can be used for the runoff analysis of an ungauged basin and the analysis of hydrologic similarity.

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Utilization of Brabender Visco-Amylograph to Detect Irradiated Starches

  • Yi, Sang-Duk;Oh, Man-Jin;Yang, Jae-Seung
    • Preventive Nutrition and Food Science
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    • v.5 no.1
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    • pp.20-24
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    • 2000
  • A study was carried out to establish the detection method of irradiated corn, potato, and sweet potato starches. The samples were packed in polyethylene bags and irradiated with 1, 3, 5, 7, 10, and 15 kGy using a Co-60 irradiator. The maximum viscosity of irradiated and unirradiated corn, potato, and sweet potato starches reduced by increase of irradiation dose levels and showed significant differences which clearly showed the effect of irradia-tion dose levels (p<0.05). Regression expressions and coefficients (p<0.000) or corn, potato, and sweet potato starches were y=-38.538x+718.23(r2=0.9761), y=669.97e-0.1372x (r2=0.9820) and y=-42.544x+730.26(r2=0.9939), respectively. Nor-malized parameter A,B and C values showed a dose dependent relationship and were a better parameter for detecting the irradiated starches than that of the maximum viscosity itself.

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Effects on Regression Estimates under Misspecified Generalized Linear Mixed Models for Counts Data

  • Jeong, Kwang Mo
    • The Korean Journal of Applied Statistics
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    • v.25 no.6
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    • pp.1037-1047
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    • 2012
  • The generalized linear mixed model(GLMM) is widely used in fitting categorical responses of clustered data. In the numerical approximation of likelihood function the normality is assumed for the random effects distribution; subsequently, the commercial statistical packages also routinely fit GLMM under this normality assumption. We may also encounter departures from the distributional assumption on the response variable. It would be interesting to investigate the impact on the estimates of parameters under misspecification of distributions; however, there has been limited researche on these topics. We study the sensitivity or robustness of the maximum likelihood estimators(MLEs) of GLMM for counts data when the true underlying distribution is normal, gamma, exponential, and a mixture of two normal distributions. We also consider the effects on the MLEs when we fit Poisson-normal GLMM whereas the outcomes are generated from the negative binomial distribution with overdispersion. Through a small scale Monte Carlo study we check the empirical coverage probabilities of parameters and biases of MLEs of GLMM.

An Exploratory Study on the Main Factors Affecting Health Perception of the Patients Following Cardiac Valve Replacement Surgery (판막치환수술후 환자들의 건강인지도에 영향을 미치는 제요인에 관한 연구)

  • 김금순;전동희
    • Journal of Korean Academy of Nursing
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    • v.15 no.1
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    • pp.52-58
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    • 1985
  • This study was attempted to investigate the main factors affecting health perception of the patients following cardiac valve replacement surgery. Data were collected from Sept. 1 to Oct. 31, 1984 through administration of questionnaire developed for this study by the researcher. The subject was 95 patients who received follow up care following cardiac valve replacemert surgery at S.N.U.H. The data were analyzed by T-test, oneway ANOVA, pearson correlation and multiple regression according to dependent variables. The results were as follows. \circled1 Average self-health perception of those patients. were 4.62, (maximum; 7 minimum; 1) and they showed on affirmative response for their health condition, \circled2 There was significant difference in health perception according to sex difference. Men had higher health perception than women. (t=2,83, p=0.006) \circled3 There was significant difference in health perception according to occupation. Those who had occupation showed higher health perception those who had no occupation. (t=3.25, p=0.002) \circled4 The longer post-operative period elapsed, the higher health perception was, and there was significant difference in health perception (f=0.2958, p=0.002). \circled5 The higher age was, the lower health perception was, and there was a significant difference in health perception. (${\gamma}$= -0.2485, p=0.008) \circled6 The fewer subjective psychosomatic symptoms were, the higher health perception was, and there was a significant difference in health perception. (f = -0.4988, p=0.0000) \circled7 The more active daily activities were, the higher health perception was, and there was a significant difference in health perception. (${\gamma}$=0.6359 p=0.0000) \circled8 The main factors predicting health perception .are like these. \circled1 Daily activities (42.7%), highest variable. \circled2 Psychosomatic symptoms (7.29%) \circled3 Elapsed period after cardiac valve replacement surgery (1.89%) \circled4 Existence of occupation (1.87%) \circled5 Sex (1.78%) \circled6 Age (0.8%).

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Kinetics of Catalytic Oxidation of Vinyl Chloride over CrOx/γ-alumina (CrOx/γ-alumina 촉매상에서 Vinyl Chloride의 산화반응 속도해석)

  • Lee, Hae-Wan;Kim, Young Chai;Moon, Sei-Ki
    • Applied Chemistry for Engineering
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    • v.10 no.1
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    • pp.85-92
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    • 1999
  • The complete catalytic oxidation of vinyl chloride was investigated over chromium oxide supported ${\gamma}$-alumina using a fixed bed micro-reactor at temperature between 240 and $300^{\circ}C$ and concentration between 600 and 3500 ppm. The oxidation of vinyl chloride was nonlinear in the concentration of vinyl chloride and zeroth order in the concentration of oxygen. The addition of HCl and $H_2O$ as products to the feed stream didn't influence the conversion of vinyl chloride. Several kinetic rate model were tested to describe the data over the range of condition investigated, and developed a model which provide the best correlation of experimental data. The resulting model of kinetic rate was derived by assuming that the reacting occurred via adsorption and subsequent decomposition of the vinyl chloride onto the oxygen covered chromium oxide surface, with the reaction being inhibited by the adsorption of vinyl chloride. The percent standard deviation between the predicted and experimental was about 5.2%, and the activation energy was 18.9 kcal/mol.

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Peritumoral Brain Edema after Stereotactic Radiosurgery for Asymptomatic Intracranial Meningiomas : Risks and Pattern of Evolution

  • Hoe, Yeon;Choi, Young Jae;Kim, Jeong Hoon;Kwon, Do Hoon;Kim, Chang Jin;Cho, Young Hyun
    • Journal of Korean Neurosurgical Society
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    • v.58 no.4
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    • pp.379-384
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    • 2015
  • Objective : To investigate the risks and pattern of evolution of peritumoral brain edema (PTE) after stereotactic radiosurgery (SRS) for asymptomatic intracranial meningiomas. Methods : A retrospective study was conducted on 320 patients (median age 56 years, range 24-87 years) who underwent primary Gamma Knife radiosurgery for asymptomatic meningiomas between 1998 and 2012. The median tumor volume was 2.7 cc (range 0.2-10.5 cc) and the median follow-up was 48 months (range 24-168 months). Volumetric data sets for tumors and PTE on serial MRIs were analyzed. The edema index (EI) was defined as the ratio of the volume of PTE including tumor to the tumor volume, and the relative edema indices (rEIs) were calculated from serial EIs normalized against the baseline EI. Risk factors for PTE were analyzed using logistic regression. Results : Newly developed or increased PTE was noted in 49 patients (15.3%), among whom it was symptomatic in 28 patients (8.8%). Tumor volume larger than 4.2 cc (p<0.001), hemispheric tumor location (p=0.005), and pre-treatment PTE (p<0.001) were associated with an increased risk of PTE. rEI reached its maximum value at 11 months after SRS and decreased thereafter, and symptoms resolved within 24 months in most patients (85.7%). Conclusion : Caution should be exercised in decision-making on SRS for asymptomatic meningiomas of large volume (>4.2 cc), of hemispheric location, or with pre-treatment PTE. PTE usually develops within months, reaches its maximum degree until a year, and resolves within 2 years after SRS.

Associations of Polymorphisms in Four Immune-related Genes with Antibody Kinetics and Body Weight in Chickens

  • Ahmed, A.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.8
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    • pp.1089-1095
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    • 2010
  • Four biological candidate genes, natural resistance associated macrophage protein 1 (SLC11A1 or NRAMP), prosaposin (PSAP), interferon Gamma (IFNG), and toll-like receptor 4 (TLR4), were examined to identify single nucleotide polymorphisms (SNP) and associations of the SNP with antibody response kinetics in hens. An $F_2$ population was produced by mating $G_0$ highly inbred (<99%) males of two MHC-congenic Fayoumi lines with highly inbred Leghorn hens. The $F_2$ hens (n = 158) were injected twice with SRBC and whole, fixed Brucella abortus (BA). Blood samples were obtained before each immunization, at 7 d after primary immunization, and at several time points after secondary immunization. Minimum titers (Ymin) and the time needed to reach them (Tmin), and maximum (Ymax) titers and the time needed to reach them (Tmax), were estimated from the seven post-secondary immunization titers using a nonlinear regression model. The $F_2$ hens were genotyped for the four candidate genes by using PCR-RFLP for one SNP per gene, which identified the parental allele. General linear models were used to test associations of SNP genotypes with antibody response parameters and BW measured at 4 ages. The IFNG SNP was highly significantly (p<0.0125) associated with primary response to SRBC, Tmin to BA, Ymin to BA, and 12-week BW. The current study demonstrated that the novel IFNG promoter SNP was associated with antibody kinetics for BA and SRBC in laying hens, and also with BW, suggesting that this cytokine may play a pivotal role in the relationship between immune function and growth.

A Study on the Geomorphologic Synthesis of Hydrologic Response (수문응답의 지형학적 합성방법에 관한 연구)

  • Cho, Hong Je;Lee, Sang Bae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.10 no.1
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    • pp.99-108
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    • 1990
  • A Synthetic Unit Hydrograph Method was investigated for representation of the effective rainfall-direct runoff hydrograph by using a Geomorphologic Instantaneous Unit Hydrograpb(GIUH) proposed by Gupta et al(1980). The response function of the basin was assumed to be the two-parameter gamma probability density function. The physical parameters of the response function(Nash Model) was determined by using the regression eqs. were parameterized in terms of Horton order ratios and the relations between the basin lag time and time-scale parameter. The capability of the Synthetic Unit Hydrograph to the real basin was tested for the Pyungchang river basin and Wi Stream basin, and its capability to reproduce the hydrologic response was investigate and compared with the Moment Method and the Least Square Method used incomplete gamma function. The representation of the peak flow, the time to peak and the hydrographs the derived Synthetic Unit Hydrograph were tested on some obseved flood data and showed promising, and it was approved to be used for prediction of the ungaged basins.

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