• Nutrition Research and Practice
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• 제13권3호
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• pp.256-262
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• 2019

BACKGROUND/OBJECTIVES: The objectives of this study were to evaluate the accuracy of the Dietary Reference Intakes (DRI) for estimating the energy requirements of older adults, and to develop and validate new equations for predicting the energy requirements of this population group. MATERIALS/METHODS: The study subjects were 25 men and 23 women with a mean age of $72.2{\pm}3.9\;years$ and $70.0{\pm}3.3\;years$, and mean BMI of $24.0{\pm}2.1$ and $23.9{\pm}2.7$, respectively. The total energy expenditure (TEE) was measured by using the doubly labeled water (DLW) method, and used to validate the DRI predictive equations for estimated energy requirements (EER) and to develop new EER predictive equations. These developed equations were cross-validated by using the leave-one-out technique. RESULTS: In men, the DRI equation had a -7.2% bias and accurately predicted the EER (meaning EER values within ${\pm}10%$ of the measured TEE) for 64% of the subjects, whereas our developed equation had a bias of -0.1% and an accuracy rate of 84%. In women, the bias was -6.6% for the DRI equation and 0.2% for our developed equation, and the accuracy rate was 74% and 83%, respectively. The predicted EER was strongly correlated with the measured TEE, for both the DRI equations and our developed equations (Pearson's r = 0.915 and 0.908, respectively). CONCLUSIONS: The DRI equations provided an acceptable prediction of EER in older adults and these study results therefore support the use of these equations in this population group. Our developed equations had a better predictive accuracy than the DRI equations, but more studies need to be performed to assess the performance of these new equations when applied to an independent sample of older adults.

• 대한간호학회지
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• 제27권4호
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• pp.796-806
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• 1997

The majority of studies on breastfeeding consists of descriptive correlational studies identifying the incidence and correlates of breastfeeding. The theory of planned behavior has been shown to yield great predictive power for behavioral goals over which individuals have only limited control such as improving school grades and weight loss. The purpose of this study was to test the "theory of planned behavior" in the prediction of breastfeeding of mothers who delivered vaginally, One hundred mothers who delivered vaginally in one general hospital in Seoul and one general hospital and three private hospitals in Taejeon participated in this study. The instruments used for data collection in this study were developed by the researchers following the guidelines suggested by Ajzen & Fishbein(1980) and Ajzen & Madden(1986). The instruments included measurement of attitude, subjective norm, perceived behavioral control and intention. The collected data were analyzed using descriptive statistics, Pearson product moment correlation, hierachical multiple regression and logistic regression. The results are as follows ; 1. Intention to breastfeed correlated significantly with attitude, subjective norm and perceived behavioral control. Both attitude and subjective norm did not make a significant contribution to the prediction of intention, but the addition of perceived behavioral control to the regression equation greatly improved the model's predictive power, increasing the R²from .05 to .52. 2. Intention to breastfeed alone had a significant predictive effect on actual breastfeeding, resulting in a regression coefficient of .16(X²=8 60, p<.01), but when perceived behavioral control was added to the equation, intention was not a significant predictive variable and only perceived behavioral control showed significant predictive power on actual breastfeeding, resulting in a regression coefficient of .12(X²=4.69, p<.05). In sum, breastfeeding behavior lent only partial support to the second version of the theory of planned behavior, and because perceived behavioral control had a strong effect on intention to breastfeed and actual breastfeeding, It would be desirable to develop nursing intervention programs which focus on strengthening the perceived behavioral control for the promotion of breastfeeding.

• Nuclear Engineering and Technology
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• 제35권5호
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• pp.399-411
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• 2003

A model predictive control method is applied to design an automatic controller for thermal power control in a reactor core. The basic concept of the model predictive control is to solve an optimization problem for a finite future at current time and to implement as the current control input only the first optimal control input among the solutions of the finite time steps. At the next time step, the second optimal control input is not implemented and the procedure to solve the optimization problem is then repeated. The objectives of the proposed model predictive controller are to minimize the difference between the output and the desired output and the variation of the control rod position. The nonlinear PWR plant model (a nonlinear point kinetics equation with six delayed neutron groups and the lumped thermal-hydraulic balance equations) is used to verify the proposed controller of reactor power. And a controller design model used for designing the model predictive controller is obtained by applying a parameter estimation algorithm at an initial stage. From results of numerical simulation to check the controllability of the proposed controller at the $5\%/min$ ramp increase or decrease of a desired load and its $10\%$ step increase or decrease which are design requirements, the performances of this controller are proved to be excellent.

• 한국수자원학회논문집
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• 제36권3호
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• pp.507-520
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• 2003

V형 여울은 하천 양안에 설치하여 여울의 가운데로 물의 흐름을 집중시켜 하도 중앙 직하류에 세굴로 인한 소(pool)를 형성하는 역할을 하는 인공 여울이다. V형 여울의 설치 목적은 평탄화된 하도에 소를 형성시켜 갈수시 어류의 서식처 노는 피난처를 제공하고, 홍수시에는 유속이 약한 구간을 발생시켜 어류의 피난처를 제공하는 것이다. 본 연구에서는 V형 여울의 수리 모형 실험을 실시하여 각 조건에 따른 세굴심을 측정하여 세굴 특성을 분석하였고, 나아가 수리량 조건 및 V형 여울 형태와 세굴 간의 정량적인 관계를 실험 결과로부터 도출하였다. 또한 V형 여울과 형태가 유사한 수제에서의 세굴심에 대한 기존의 연구 결과와 V형 여울의 경우를 비교하였다. 그 결과 Breusers와 Raudkivi(1991)가 제안한 수제에서의 세굴심 예측식은 V형 여울에서의 세굴심을 과소평가하지만 V형 여울께서의 세굴 특성을 일부 반영하는 것으로 나타났다. V형 여울의 세굴에 영향을 주는 인자들의 무차원화를 통해 V형 여울에서의 세굴심 예측식을 제안하였고 제안된 예측식은 V형 여울의 적용에 있어서 세굴심을 추정하는데 사용될 수 있고 판단된다. V형 여울의 세굴에 지배적인 영향을 주는 인자는 여울 중앙에서의 프루드 수이고, 그밖에 여울과 흐름의 각도와 여울 개구부의 폭도 부분적으로 영향을 준다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.26-32
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• 2000

It was confirmed that the life predictive equation by LMP-ISM are effective only up to 10$^2$hours and can not be used for long times of 10$^3$~10$^{5}$ hours, but that by ISM can be used for long times creep life prediction with more reliability. The predictive creep life equation of ISM has better reliability than those by LMP and LMP-ISM, and its realizably is getting better for long time creep prediction(10$^3$~10$^{5}$ H).

• 터널과지하공간
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• 제5권2호
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• pp.89-94
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• 1995

Regression analysis and a comparative study were carried out for 52 blast vibration data which were monitored by changing the monitoring distance and charge per delay. The results are as follows: 1) The square and cube root scalings and general equation which have a confidence level at the point of 90% and 99% are V90=33300(SD)-2.026 , V90=23600(SD)-1.993, V90=26300W0.755 R-2.007 and V99=48400(SD)-2.026, V99=34000(SD)-1.993 , V99=38100W0.755R-2.007, respectively. 2) There is need to decide the allowable max. charge weight per delay considering the cross points comparatively of the nomogram constructed using several predictived equations. 3) It is necessary to derive the predictive equation on the basis of blast vibration level monitored in field and to decide safe vibration level and the confidence level.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 추계학술발표대회 개요집
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• pp.29-31
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• 2005

The purpose of this study is to establish the predictive equation of the distortion at the ES and SA weldment of Cr-Mo low alloy steel. In order to do it, the effect of heat input, plate thickness and strip wire width for ESW on the distortion at the ES and SA weldment was evaluated using FEA. Based on the results, the principal factors controlling the distortion of the ES and SA weldment were identified and the predictive equation was established.

• 한국해양공학회지
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• 제15권2호
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• pp.53-60
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• 2001

It was confirmed that the life predictive equation by LMP and LMP-ISM are effective only up to 10$^2$hours and can not be used for long times of $10^3~10^5$ hours, but that by ISM can be used for long times creep life prediction with more reliability. The predictive creep life equation of ISM has better reliability than those by LMP and LMP-ISM, and its realizably is getting better for long time creep prediction($10^3~10^5$ h).

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.75-78
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• 2008

The predictive equation of void-closure was developed to evaluate void crush ratio with respect to the process variables in the cogging process of a large round bar. The comprehensive finite element analysis with the process variables such as reduction ratio and die width ratio was carried out. The predictive equation of void-closure for cogging process was established on the basis of the regression analysis with the extensive FE analysis results and verified by comparing the predicted results with FEA results with various forging passes.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.203-207
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• 1992

In this paper, a new GPC(Generalized Predictive Control) algorithm which is robust to disturbances isproposed. This controller minimizes the LQ cost function when the disturbance maximizes this cost function. The solution is obtained from the min-max problem which can be solved by differential game theory and has the non-recursive form which does not use the Riccati equation. Its another solution for state space models is investigated.