• Title/Summary/Keyword: Beta function model

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Effects of the Sensory Impairment on Functioning Levels of the Elderly (노인의 감각장애와 기능상태에 관한 연구)

  • 송미순
    • Journal of Korean Academy of Nursing
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    • v.23 no.4
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    • pp.678-693
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    • 1993
  • The purposes of this study were to describe the level of vision and hearing impairments, depression and functional capacity, among Korean institutionalized elderly and to examine the relation-ship between sensory impairments, depression, and functional capacity in these people. The final pupose was to test the cognitive function path model using sensory competencies as predictors. A convenience sample of thirty nine male and 90 female subjects with a mean age of 80.5 were the subjects of this study. The subjects were tested for cognitive function, and vision and hearing impairments. Physical function and social function were measured by observation of designated task performance by the subjects. Their level of de-pression was measured using a Geriatric Depression Scale administered through an interview. Individual subjective ratings of hearing and vision were marked by the subjects, on a ladder scale. The results of the study showed that 48.8% of the subjects had a hearing impairment, 63.5% had a vision impairement, and 36.4% had both a vision and hearing impairement. The four sensory groups (no sensory impairement, hearing impairement, vision impairement, hearing and vision impairement) were tested for differences in depression, physical function, social behavior and cognitive function. The only significant difference that was found was in cognitive function, between the no sensory impairement group and the hearing and vision impairement group(F=3.25, P<.05), Subjective ratings of hearing showed a significant correlation with cognitive function(r=.34, p<.001) and with social behavior(r=.31, p<.001). There was no correlation between subjective vision ratings and cognitive function or social behavior. However there was a significant correlation between vision and hearing(r=.49, p<.001). There was also a significant negative correlation between age and vision(r=-.21, p<.01) and between age and hear-ing(r=-.34, p<.001). There was a significant correlation between depression and physical function (r=-.32, p<.001) but there was no correlation between depression and cognitive function or social behavior. Based on the literature review and the result, this study, a path model of sensory competence-> cognitive function- >social behavior was developed and tested : Perceived vision and perceived hearing were the exogenous variahles and cognitive function and social behavior were the endogeneous variables in the model. The path analysis result demonstrated an accept-able fit (GFI=.997, AGFI=.972, X$^2$=.72 (p=.396), RMSR=.019) between the data and the model. There was a significant direct effect($\beta$=.38) of perceived hearing on cognitive function. There was a significant direct effect ($\beta$=.32) of cognitive function on social behavior. The total effect of hearing on social behavior was $\beta$=.32 including the indirect effect ($\beta$=.12) . However perceived vsion had little effect ($\beta$=-.08) on cognitive function. The result of path analysis confirms that hearing levels influence cognitive function, and both hearing and cognitive function levels influence social behavior. However, vision has little effect on cognitive function or on social behavior. For the next study, a combined model of the pre viously developed environment - >depression- > physical and social function model, and the present cognitive function model, should be tested to further refine the functional capacity model. There also a need for longitudinal study of functional capacity and sencory competence in order to better understand how declining sensory competence influences functional capacity and how it effects in-creasing dependency and nursing needs in the elderly.

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An Attempt to Model Distributions of Machined Component Dimensions in Production

  • Cogun, Can;Kilinc, Biinyamin
    • Journal of Mechanical Science and Technology
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    • v.16 no.1
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    • pp.60-74
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    • 2002
  • In this study, normal, log-normal, triangular, uniform. Weibull, Erlang and unit beta probability density functions are tried to represent the behaviour of frequency distributions of workpiece dimensions collected from various manufacturing firms. Among the distribution functions, the unit beta distribution function is found to be the best fit using the chi-square test of fit. An attempt is made for the adoption of the unit beta model to x-bar charts of quality control in manufacturing. In this direction, upper and lower control limits (UCL and LCL) of x-bar control charts of dimension measurements are estimated for the beta model, and the observed differences between the beta and normal model control limits are discussed for the measurement sets.

A Study on a One-step Pairwise GM-estimator in Linear Models

  • Song, Moon-Sup;Kim, Jin-Ho
    • Journal of the Korean Statistical Society
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    • v.26 no.1
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    • pp.1-22
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    • 1997
  • In the linear regression model $y_{i}$ = .alpha. $x_{i}$ $^{T}$ .beta. + .epsilon.$_{i}$ , i = 1,2,...,n, the weighted pairwise absolute deviation (WPAD) estimator was defined by minimizing the dispersion function D (.beta.) = .sum..sum.$_{{i $w_{{ij}}$$\mid$ $r_{j}$ (.beta.) $r_{i}$ (.beta.)$\mid$, where $r_{i}$ (.beta.)'s are residuals and $w_{{ij}}$'s are weights. This estimator can achive bounded total influence with positive breakdown by choice of weights $w_{{ij}}$. In this paper, we consider a more general type of dispersion function than that of D(.beta.) and propose a pairwise GM-estimator based on the dispersion function. Under some regularity conditions, the proposed estimator has a bounded influence function, a high breakdown point, and asymptotically a normal distribution. Results of a small-sample Monte Carlo study are also presented. presented.

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Prediction of Silking Date of Corn Hybrids Using Beta Function Model in South Korea (Beta 함수 모형을 이용한 국내 옥수수 품종의 출사기 예측)

  • Shim, Kyo-Moon;Kim, Yong-Seok;Lee, Jin-Seok;Jung, Myung-Pyo;Choi, In-tae;Kim, Hojung
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.19 no.3
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    • pp.102-109
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    • 2017
  • A temperature-based Beta function model was developed for corn hybrids (Zea mays L.). The beta function based on the hourly temperature was fitted to the phenology data (silking date) obtained for six years from 2008 through 2013 at four survey sites. Using the Beta function model, silking dates for two corn hybrids with the different ecotype ('Danok3', 'Ilmichal') were estimated over two years from 2014 through 2015 at four sites, and then the performance of the model was evaluated based on the data for the same period. The silking dates estimated by the model were predicted earlier than those observed at survey sites. Still, the correlation between estimates and observation was relatively high (r=0.859). The accuracy of the model differed by the survey site and the year, which was likely due to the considerably large standard deviation of the parameter calibrated in this study.

Inventory Model with Partial Backorders

  • Park Kyung S.
    • Journal of the military operations research society of Korea
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    • v.9 no.1
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    • pp.69-74
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    • 1983
  • This article presents a deterministic inventory model for situations in which, during the stockout period, a fraction ${\beta}$ of the demand is backordered and the remaining fraction $1-{\beta}$ is lost. By defining a time proportional backorder cost and a fixed penalty cost per unit lost, a convex objective function representing the average annual cost of operating the inventory system is obtained. The optimal operating policy variables are calculated directly. At the extremes ${\beta}\;=\;1$ and ${\beta}\;=\;0$ the model presented reduces to the usual backorders and lost sales case, respectively.

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The Mixing Properties of Subdiagonal Bilinear Models

  • Jeon, H.;Lee, O.
    • Communications for Statistical Applications and Methods
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    • v.17 no.5
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    • pp.639-645
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    • 2010
  • We consider a subdiagonal bilinear model and give sufficient conditions for the associated Markov chain defined by Pham (1985) to be uniformly ergodic and then obtain the $\beta$-mixing property for the given process. To derive the desired properties, we employ the results of generalized random coefficient autoregressive models generated by a matrix-valued polynomial function and vector-valued polynomial function.

Kinetics for the Growth of Alcaligenes eutrophus and the Biosynthesis of Poly-${\beta}$-hydroxybutyrate (Alcaligenes eutrophus 균주의 성장과 Ploy-${\beta}$-hydroxybutyrate 생합성에 대한 속도론)

  • Lee, Yong-Woo;Yoo, Young-Je
    • Microbiology and Biotechnology Letters
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    • v.19 no.2
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    • pp.186-192
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    • 1991
  • It is very important to have a good kinetic model which considers the effects of both ammonium and glucose for the control and optimization of the poly-${\beta}$-hydroxybutyrate (PHB) fermentation. A kinetic model for the growth of Alcaligenes eutrophus and the biosynthesis of PHB under both ammonium and glucose limitation was proposed. Growth rate of residual biomass was expressed as a function of concentrations of residual biomass, glucose and ammonium having glucose inhibition. PHB production rate was expressed as a function of concentrations of residual biomass, glucose, ammonium and PHB content having ammonium and product inhibitions. Novel approaches were made to estimate the parameters in the model equations which considered two limiting substrates. Model parameters were evaluated by graphical and simplex methods. The proposed kinetic model fitted the data very well.

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The Relative Factors to Insulin Resistance and β Cell Function Determined by Homeostasis Model Assessment in Nondiabetic Adults

  • Kwon, Se-Young;Na, Young-Ak
    • Korean Journal of Clinical Laboratory Science
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    • v.45 no.4
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    • pp.131-138
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    • 2013
  • Insulin resistance and pancreatic beta cell dysfunction have been established as being related to the diabetes. Lately, what is emphasizing is that those have been shown as something related to the metabolic syndrome and cardiovascular disease. Homeostasis model assessment (HOMA), simple index is calculated on blood levels of fasting glucose and insulin. And HOMA has been widely validated and applied for insulin resistance and pancreatic beta cell dysfunction. We also assessed the factors relative to insulin resistance and ${\beta}$ cell function determined by HOMA. The data from the 2010 Korean National Health and Nutrition Examination Survey were used. Analysis was done for 3,465 nondiabetic subjects (male 1,357, female 2,108). At baseline, anthropometric measurements were done and fasting glucose, insulin, lipid (Total cholesterol, HDL cholesterol, LDL cholesterol and Triglycerides) profiles were measured. HOMA-insulin resistance (HOMA-IR) and beta cell function (HOMA ${\beta}$-cell) were calculated from fasting glucose and insulin levels. In male, the value of HOMA-IR and HOMA ${\beta}$-cell was the highest among 30's and decreased as the age increased. In female, the value of HOMA-IR increased with age, while HOMA ${\beta}$-cell decreased. High HOMA-IR and low HOMA ${\beta}$-cell were associated with the highest value of fasting glucose and systolic blood pressure. Low HOMA-IR and high HOMA ${\beta}$-cell showed the lowest concentration of fasting glucose and the highest concentration of HDL cholesterol. High HOMA-IR and high HOMA ${\beta}$-cell were connected with BMI, Total cholesterol, LDL cholesterol, and Triglycerides. There was a negative correlation between HOMA ${\beta}$-cell and age. The correlation coefficients of HOMA-IR and HOMA ${\beta}$-cell showed the highest value among weight, BMI and WC.

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Effects of fermented ginseng on memory impairment and β-amyloid reduction in Alzheimer's disease experimental models

  • Kim, Joonki;Kim, Sung Hun;Lee, Deuk-Sik;Lee, Dong-Jin;Kim, Soo-Hyun;Chung, Sungkwon;Yang, Hyun Ok
    • Journal of Ginseng Research
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    • v.37 no.1
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    • pp.100-107
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    • 2013
  • This study examined the effect of fermented ginseng (FG) on memory impairment and ${\beta}$-amyloid ($A{\beta}$) reduction in models of Alzheimer's disease (AD) in vitro and in vivo. FG extract was prepared by steaming and fermenting ginseng. In vitro assessment measured soluble $A{\beta}42$ levels in HeLa cells, which stably express the Swedish mutant form of amyloid precursor protein. After 8 h incubation with the FG extract, the level of soluble $A{\beta}42$ was reduced. For behavioral assessments, the passive avoidance test was used for the scopolamine-injected ICR mouse model, and the Morris water maze was used for a transgenic (TG) mouse model, which exhibits impaired memory function and increased $A{\beta}42$ level in the brain. FG extract was treated for 2 wk or 4 mo on ICR and TG mice, respectively. FG extract treatment resulted in a significant recovery of memory function in both animal models. Brain soluble $A{\beta}42$ levels measured from the cerebral cortex of TG mice were significantly reduced by the FG extract treatment. These findings suggest that FG extract can protect the brain from increased levels of $A{\beta}42$ protein, which results in enhanced behavioral memory function, thus, suggesting that FG extract may be an effective preventive or treatment for AD.

Impaired Taste Associative Memory and Memory Enhancement by Feeding Omija in Parkinson's Disease Fly Model

  • Poudel, Seeta;Lee, Youngseok
    • Molecules and Cells
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    • v.41 no.7
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    • pp.646-652
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    • 2018
  • Neurodegeneration can result in memory loss in the central nervous system (CNS) and impairment of taste and smell in the peripheral nervous system (PNS). The neurodegeneration seen in Parkinson's disease (PD) is characterized by functional loss of dopaminergic neurons. Recent studies have also found a role for dopaminergic neurons in regulating taste memory rewards in insects. To investigate how taste memories and sugar sensitivity can be affected in PD, we utilized the $DJ-1{\beta}$ mutant fruit fly, $DJ-1{\beta}^{ex54}$, as a PD model. We performed binary choice feeding assays, electrophysiology and taste-mediated memory tests to explore the function of the $DJ-1{\beta}$ gene in terms of sugar sensitivity as well as associative taste memory. We found that PD flies exhibited an impaired ability to discriminate sucrose across a range of sugar concentrations, with normal responses at only very high concentrations of sugar. They also showed an impairment in associative taste memory. We highlight that the taste impairment and memory defect in $DJ-1{\beta}^{ex54}$ can be recovered by the expression of wild-type $DJ-1{\beta}$ gene in the dopaminergic neurons. We also emphasized the role of dopaminergic neurons in restoring taste memory function. This impaired memory property of $DJ-1{\beta}^{ex54}$ flies also allows them to be used as a model system for finding supplementary dietary foods that can improve memory function. Here we provide evidence that the associative taste memory of both control and $DJ-1{\beta}^{ex54}$ flies can be enhanced with dietary supplementation of the medicinal plant, omija.