• Title/Summary/Keyword: gamma model

검색결과 1,212건 처리시간 0.027초

팔당댐 유역의 데이터 기반 수질 예측 모형 구성을 위한 사전 불확실성 분석 (Preliminary Uncertainty Analysis to Build a Data-Driven Prediction Model for Water Quality in Paldang Dam)

  • 이은정;금호준
    • Ecology and Resilient Infrastructure
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    • 제9권1호
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    • pp.24-35
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    • 2022
  • 수질분야에서 물재해 안정성 강화를 위해 과거와 현재의 수질을 분석하여 예측하는 기술을 지속적으로 고도화하는 것이 필요하며 데이터 기반의 예측 모형이 하나의 대안으로 대두되고 있다. 데이터 기반 모형은 복잡하고 광범위한 자료의 양을 기반으로 구축되기 때문에 보다 신뢰도 있는 결과를 얻을 수 있는 입력자료의 조합을 위한 상관관계 분석방법의 적용이 필수적이다. 본 연구에서는 보다 신속하고 정확한 데이터 기반의 수질 예측 모형을 구성하기 위한 선행단계로 Gamma Test를 적용하였다. 먼저 팔당댐의 다양한 수문조건에 따른 해당 유역의 복잡성과 정밀성이 재현된 과거와 현재의 일단위 수질을 최대한 확보하고자 물리적 기반 모형 (HSPF, EFDC)을 구동하였다. 팔당댐 수질예측지점과 팔당댐으로 유입되는 주요 하천의 수질을 대상으로 Gamma Test를 수행한 후 해석결과 (Gamma, Gradient, Standar Error, V-Ratio)를 통해 최적의 자료조합을 선정하는 방법을 제시하였다. 본 연구의 결과는 데이터 기반 모형 구축 시 반복적인 수행과정을 생략하여 시간을 단축하면서 보다 효율적으로 최적의 입력자료를 선정할 수 있는 정량적인 기준을 보여준다.

중년후기 여성의 건강증진행위 모형구축 (A Model for Health Promoting Behaviors in Late-middle Aged Woman)

  • 박재순
    • 여성건강간호학회지
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    • 제2권2호
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    • pp.298-331
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    • 1996
  • Recent improvements in living standard and development in medical care led to an increased interest in life expectancy and personal health, and also led to a more demand for higher quality of life. Thus, the problem of women's health draw a fresh interest nowadays. Since late-middle aged women experience various physical and socio-psychological changes and tend to have chronic illnesses, these women have to take initiatives for their health control by realizing their own responsibility. The basic elements for a healthy life of these women are understanding of their physical and psychological changes and acceptance of these changes. Health promoting behaviors of an individual or a group are actions toward increasing the level of well-being and self-actualization, and are affected by various variables. In Pender's health promoting model, variables are categorized into cognitive factors(individual perceptions), modifying factors, and variables affecting the likelihood for actions, and the model assumes the health promoting behaviors are affected by cognitive factors which are again affected by demographic factors. Since Pender's model was proposed based on a tool broad conceptual frame, many studies done afterwards have included only a limited number of variables of Pender's model. Furthermore, Pender's model did not precisely explain the possibilities of direct and indirect paths effects. The objectives of this study are to evaluate Pender's model and thus propose a model that explains health promoting behaviors among late-middle aged women in order to facilitate nursing intervention for this group of population. The hypothetical model was developed based on the Pender's health promoting model and the findings from past studies on women's health. Data were collected by self-reported questionnaires from 417 women living in Seoul, between July and November 1994. Questionnaires were developed based on instruments of Walker and others' health promotion lifestyle profile, Wallston and others' multidimensional health locus of control, Maoz's menopausal symptom check list and Speake and others' health self-rating scale. IN addition, items measuring self-efficacy were made by the present author based on past studies. In a pretest, the questionnaire items were reliable with Cronbach's alpha ranging from .786 to .934. The models for health promoting behaviors were tested by using structural equation modelling technique with LISREL 7.20. The results were summarized as follows : 1. The overall fit of the hypothetical model to the data was good (chi-square=4.42, df=5, p=.490, GFI=.995, AGFI=.962, RMSR=.024). 2. Paths of the model were modified by considering both its theoretical implication and statistical significance of the parameter estimates. Compared to the hypothetical model, the revised model has become parsimonious and had a better fit to the data (chi-square =4.55, df=6, p=.602, GFI=.995, AGFI=.967, RMSR=.024). 3. The results of statistical testing were as follows : 1) Family function internal health locus of control, self-efficacy, and education level exerted significant effects on health promoting behaviors(${\gamma}_{43}$=.272, T=3.714; ${\beta}_[41}$=.211, T=2.797; ${\beta}_{42}$=.199, T=2.717; ${\gamma}_{41}$=.136, T=1.986). The effect of economic status, physical menopausal symptoms, and perceived health status on health promoting behavior were insignificant(${\gamma}_{42}$=.095, T=1.456; ${\gamma}_{44}$=.101, T=1.143; ${\gamma}_{43}$=.082, T=.967). 2) Family function had a significance direct effect on internal health locus of control (${\gamma}_{13}$=.307, T=3.784). The direct effect of education level on internal health locus of control was insignificant(${\gamma}_{11}$=-.006, T=-.081). 3) The directs effects of family functions & internal health locus of control on self-efficacy were significant(${\gamma}_{23}$=.208, T=2.607; ${\beta}_{21}$=.191, T=2.2693). But education level and economic status did not exert a significant effect on self-efficacy(${\gamma}_{21}$=.137, T=1.814; ${\beta}_{22}$=.137, T=1.814; ${\gamma}_{22}$=.112, T=1.499). 4) Education level had a direct and positive effect on perceived health status, but physical menopausal symptoms had a negative effect on perceived health status and these effects were all significant(${\gamma}_{31}$=.171, T=2.496; ${\gamma}_{34}$=.524, T=-7.120). Internal health locus and self-efficacy had an insignificant direct effect on perceived health status(${\beta}_{31}$=.028, T=.363; ${\beta}_{32}$=.041, T=.557). 5) All predictive variables of health promoting behaviors explained 51.8% of the total variance in the model. The above findings show that health promoting behaviors are explained by personal, environmental and perceptual factors : family function, internal health locus of control, self-efficacy, and education level had stronger effects on health promoting behaviors than predictors in the model. A significant effect of family function on health promoting behaviors reflects an important role of the Korean late-middle aged women in family relationships. Therefore, health professionals first need to have a proper evaluation of family function in order to reflect the family function style into nursing interventions and development of strategies. These interventions and strategies will enhance internal health locus of control and self-efficacy for promoting health behaviors. Possible strategies include management of health promoting programs, use of a health information booklets, and individual health counseling, which will enhance internal health locus of control and self-efficacy of the late-middle aged women by making them aware of health responsibilities and value for oneself. In this study, an insignificant effect of physical menopausal symptoms and perceived health status on health promoting behaviors implies that they are not motive factors for health promoting behaviors. Further analytic researches are required to clarify the influence of physical menopausal symptoms and perceived health status on health promoting behaviors with-middle aged women.

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장기유출랑의 추계학적 모의 발생에 관한 연구 (I) (Studies on the Stochastic Generation of Long Term Runoff (1))

  • 이순혁;맹승진;박종국
    • 한국농공학회지
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    • 제35권3호
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    • pp.100-116
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    • 1993
  • It is experienced fact that unreasonable design criterion and unsitable operation management for the agricultural structures including reservoirs based on short terms data of monthly flows have been brought about not only loss of lives, but also enormous property damage. For the solution of this point at issue, this study was conducted to simulate long series of synthetic monthly flows by multi-season first order Markov model with selection of best fitting frequency distribution and to make a comparison of statistical parameters between observed and synthetic flows of six watersheds in Yeong San and Seom Jin river systems. The results obtained through this study can be summarized as follows. 1.Both Gamma and two parameter lognormal distribution were found to be suitable ones for monthly flows in all watersheds by Kolmogorov-Smirnov test while those distributions were judged to be unfitness in Nam Pyeong of Yeong San and Song Jeong and Ab Rog watersheds of Seom Jin river systems in the $\chi$$^2$ goodness of fit test. 2.Most of the arithmetic mean values for synthetic monthly flows simulated by Gamma distribution are much closer to the results of the observed data than those of two parameter lognomal distribution in the applied watersheds. 3.Fluctuation for the coefficient of variation derived by Gamma distribution was shown in general as better agreement with the results of the observed data than that of two parameter lognormal distribution in the applied watersheds both in Yeong San and Seom Jin river systems. Especially, coefficients of variation calculated by Gamma distribution are seemed to be much closer to those of the observed data during July and August. 4.It can be concluded that synthetic monthly flows simulated by Gamma distribution are seemed to be much closer to the observed data than those by two parameter lognormal distribution in the applied watersheds. 5.It is to be desired that multi-season first order Markov model based on Gamma distribution which is confirmed as a good fitting one in this study would be compared with Harmonic synthetic model as a continuation follows.

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월유출량의 모의발생에 관한 비교 연구 (Comparative Studies on the Simulation for the Monthly Runoff)

  • 박명근;서승덕;이순혁;맹승진
    • 한국농공학회지
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    • 제38권4호
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    • pp.110-124
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    • 1996
  • This study was conducted to simulate long seres of synthetic monthly flows by multi-season first order Markov model with selection of best fitting frequency distribution, harmonic synthetic and harmonic regression models and to make a comparison of statistical parameters between observes and synthetic flows of five watersheds in Geum river system. The results obtained through this study can be summarized as follow. 1. Both gamma and two parameter lognormal distributions were found to be suitable ones for monthly flows in all watersheds by Kolmogorov-Smirnov test. 2. It was found that arithmetic mean values of synthetic monthly flows simulated by multi-season first order Markov model with gamma distribution are much closer to the results of the observed data in comparison with those of the other models in the applied watersheds. 3. The coefficients of variation, index of fluctuation for monthly flows simulated by multi-season first order Markov model with gamma distribution are appeared closer to those of the observed data in comparison with those of the other models in Geum river system. 4. Synthetic monthly flows were simulated over 100 years by multi-season first order Markov model with gamma distribution which is acknowledged as a suitable simulation modal in this study.

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강인한 성능을 가지는 모델추종형 $H_{\infty}$ 제어 시스템의 설계 (A Design on Model-Following $H_{\infty}$ Control System Having Robust Performance)

  • 황현준
    • 한국정보통신학회논문지
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    • 제13권5호
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    • pp.913-921
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    • 2009
  • 본 연구에서는 강인한 성능을 가지는 해집단내에서 기준모델의 출력을 최적으로 추종하도록 유전 알고리즘을 사용하여 가중치 함수와 설계 파라메타 ${\gamma}$를 동시에 최적화함으로써, 강인한 성능에 관한 필요충분조건식을 만족함은 물론 설계사양에 따른 만족스러운 응답특성을 보이는 강인한 성능을 가지는 모델추종형 $H_{\infty}$ 제어기의 설계법을 제시하고 시뮬레이션을 통하여 그 유용성을 확인한다.

Non-linear modelling to describe lactation curve in Gir crossbred cows

  • Bangar, Yogesh C.;Verma, Med Ram
    • Journal of Animal Science and Technology
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    • 제59권2호
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    • pp.3.1-3.7
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    • 2017
  • Background: The modelling of lactation curve provides guidelines in formulating farm managerial practices in dairy cows. The aim of the present study was to determine the suitable non-linear model which most accurately fitted to lactation curves of five lactations in 134 Gir crossbred cows reared in Research-CumDevelopment Project (RCDP) on Cattle farm, MPKV (Maharashtra). Four models viz. gamma-type function, quadratic model, mixed log function and Wilmink model were fitted to each lactation separately and then compared on the basis of goodness of fit measures viz. adjusted $R^2$, root mean square error (RMSE), Akaike's Informaion Criteria (AIC) and Bayesian Information Criteria (BIC). Results: In general, highest milk yield was observed in fourth lactation whereas it was lowest in first lactation. Among the models investigated, mixed log function and gamma-type function provided best fit of the lactation curve of first and remaining lactations, respectively. Quadratic model gave least fit to lactation curve in almost all lactations. Peak yield was observed as highest and lowest in fourth and first lactation, respectively. Further, first lactation showed highest persistency but relatively higher time to achieve peak yield than other lactations. Conclusion: Lactation curve modelling using gamma-type function may be helpful to setting the management strategies at farm level, however, modelling must be optimized regularly before implementing them to enhance productivity in Gir crossbred cows.

인쇄업에서 배출되는 반응성 VOCs 종류와 흡착 제거 방법의 적용 (Volatile organic compounds emitted from printing processes and their removal by adsorption)

  • 안해영;이윤경;송지현
    • 실내환경 및 냄새 학회지
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    • 제17권4호
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    • pp.396-403
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    • 2018
  • In this study, volatile organic compounds (VOCs) emitted from printing industries were analyzed, and an inorganic adsorbent, ${\gamma}-alumina$, was selected for the effective control of the VOC emissions. Printing processes commonly require inks, thinners, and cleaners, and they were mixed organic solvents containing aromatic compounds, ketones, and alcohols. Therefore, toluene, methyl ethyl ketone (MEK), and isopropyl alcohol (IPA) were selected as model compounds for this study. The adsorptive properties using ${\gamma}-alumina$ were determined for the model compounds. Both batch isotherm and continuous flow column tests demonstrated that the adsorption capacity of MEK and IPA was 3~4 times higher than that of toluene. The column test performed at an inlet toluene concentration of 100 ppm showed that an 80% breakthrough for toluene was observed after 3 hours, but both MEK and IPA were continuously adsorbed during the same time period. A numerical model simulated that the ${\gamma}-alumina$ could remove toluene at a loading rate of 0.4 mg/min only for a 4-hour period, which might be too short of a duration for real applications. Consequently, lifetime enhancement for ${\gamma}-alumina$ must be implemented, and ozone oxidation and regeneration would be feasible options.

A Model for Diffusive Shock Acceleration of Protons in Intracluster Shocks and Gamma-ray and Neutrino Emissions from Clusters of Galaxies

  • Ha, Ji-Hoon;Ryu, Dongsu;Kang, Hyesung
    • 천문학회보
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    • 제44권2호
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    • pp.54.3-54.3
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    • 2019
  • During the formation of large-scale structures in the universe, shocks with the sonic Mach number Ms <~ 5 are naturally induced by supersonic flow motions of baryonic matter in the intracluster medium (ICM). Cosmic rays (CRs) are expected to be accelerated via diffusive shock acceleration (DSA) at these ICM shocks, although the existence of CR protons in the ICM remains to be confirmed through gamma-ray observations. Based on the results obtained from kinetic plasma simulations, we build an analytic DSA model for weak, quasi-parallel shocks in the test-particle regime. With our DSA model, the CR acceleration efficiency ranges ~ 0.001 - 0.02 in supercritical quasi-parallel shocks with sonic Mach number Ms ~ 2.25 - 5, and the acceleration would be negligible in subcritical shocks wth Ms <~ 2.25. Adopting our DSA model, we estimate gamma-ray and neutrino emissions from clusters of galaxies by performing cosmological hydrodynamic simulations. The estimated gamma-ray flux is below the Fermi-LAT upper limit. In addition, the possible neutrino emission due to the decay of charged pions in galaxy clusters would be about <~ 1% of the atmospheric neutrino intensity in the energy range of <~ 100 GeV. In this talk, we will discuss the implication of our results.

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여성의 자궁절제술후 삶의 질 구조모형 (A Structural Model for Quality of Life in Women Having Hysterectomies)

  • 김숙남
    • 대한간호학회지
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    • 제29권1호
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    • pp.161-173
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    • 1999
  • The purpose of this study was to develope and test the structural model for quality of life in women having hysterectomies. A hypothetical model was constructed on the basis of previous studies and a review of literature. The conceptual framework was built around eight constructs. Exogenous variables included in this model were marital intimacy, importance of uterus, professional support, positive coping behavior and pre-operative symptoms. Endogenous variables were spouse's support, sense of loss and quality of life. Empirical data for testing the hypothetical model was collected using a self-report questionnare from 203 women having hysterectomies at the outpatient clinics of four general hospitals and a mail survey in Pusan City. The Data was collected from December, 1997 to January, 1998. Reliability of the eight instruments was tested with Cronbach's alpha which ranged from 0.639-0.915. For the data analysis, SPSS 7.5 WIN Program and LISREL 8.12 WIN Program were used for descriptive statistics and covariance structural analysis. The results of covariance structure analysis were as follows : 1. Hypothetical model showed a good fit with the empirical data. [$\chi$$^2$=6.93(df=5, P=.23), GFI=.99, AGFI=.94, RMSR=.019, NNFI=.97, NFI=.98, CN=440, standardized residuals(-2.14-2.10)] 2. For the parsimony of model, a modified model was constructed by deleting 3 paths and adding 1 path according to the criteria of statistical significance and meaning. 3. The modified model also showed a good fit with the data. [$\chi$$^2$=5.26(df=7, P=.63), GFI=.99, AGFI=.97, RMSR=.014, NNFI=1.02, NFI=.99, CN=710, standardized residuals(-1.46-1.70)] Results of the testing of the hypothesis were as follows : 1. Marital intimacy(${\gamma}$11=.78, t=14.37) and professional support(${\gamma}$13=.12, t=2.12) had a significant direct effect on the spouse's support. 2. Pre-operative symptoms(${\gamma}$25=.32, t=3.12), importance of uterus(${\gamma}$22=.20, t=2.61) and spouse's support($\beta$2l=-.19, t=-2.43) had a significant direct effect on the sense of loss. 3. Sense of loss($\beta$32=-.66, t=-9.83) had a direct effect on the quality of life. Marital intimacy had a direct(${\gamma}$31=.19, t=3.33), indirect(${\gamma}$31=.14, t=2.52) and total effect(${\gamma}$31=.25, t=4.41) on the quality of life. Professional support had a direct effect(${\gamma}$33=.11, t=2.07) and total effect(${\gamma}$33=.13, t=2.31) on the quality of life. The direct effect of pre-operative symptoms(${\gamma}$35=-.36, t=4.02) and positive coping behavior(${\gamma}$34=.15, t=2.06) had the insignificant effect on the quality of life while, due to the idirect effect these variables had overall significant effect on the quality of life. The results of this study showed that the sense of loss had the most significant direct effect on the quality of life. Marital intimacy, pre -operative symptoms and spouse's support had a significant direct effect on this sense of loss. These four variables, the sense of loss, marital intimacy, pre-operative symptoms and spouse's support, were identified as relatively important variables. The results of this study suggested that there is needed to determine if nursing intervention would alleviate this sense of loss and promote a greater quality of life in women who have had hysterectomies.

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규모문제를 고려한 수문응답의 해석: 2. 적용 및 분석 (Hydrologic Response Analysis Considering the Scale Problem: Part 2. Application and Analysis)

  • 성기원;선우중호
    • 물과 미래
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    • 제28권5호
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    • pp.117-127
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    • 1995
  • 해상도를 고려하는 GIUH 모형에 대한 적용과 분석을 평창강 유역의 소유역인 이목정유역에 대하여 수행하였다. 모형의 적용과 Fractal 분석을 위해 1:25,000, 1:50,000 그리고 1:100,000 축척의 지도를 이용하였다. 따라서 축척간의 비율이 일정한 값을 갖는다. 링크의 길이는 해상도 1mm의 구장기를 이용하였고 Fractal 차원은 Richardson 방법을 사용하였다. 지도의 축척에 따라 매개변수들의 현저한 변화를 발견하였으며 이러한 경향은 매개변수의 물리적 의미를 상실하게 한다. 그런데 Fractal 변환과 의 Melton지형법칙은 이러한 규모문제를 효과적으로 조정해주는 역할을 할 수 있다. 그리고 이 방법은 하도망과 유역간의 연관성을 모형에 반영할 수 있는 장점이 있다. 이 연구에서 제안한 GIUH의 적용성을 검증하기 위해 지수형 GIUH 모형과 비교하였다. 그 결과 제안된 2모수 gamma GIUH 모형이 좋은 재현성을 보였다. 따라서 Fractal 이론을 도입한 2모수 gamma GIUH 모형은 축척을 고려하는 IUH를 유도하는데 있어서 적절하다고 할 수 있다.

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