• Environmental Analysis Health and Toxicology
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• 제18권3호
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• pp.183-191
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• 2003

Although the variety and quantities of chemicals used have been increasing, no management strategies have been developed for these chemicals in our country. Therefore, it is important to identify the hazardous characteristics of chemicals and establish reasonable and effective management plans for them. However, because insufficient resources are available to evaluate all aspects of many varieties of chemicals, studies on suitable chemical ranking and scoring (CRS) system should be performed to ensure effective screening of priority chemicals.. In addition, because most CRS systems have their own goals, it is impossible for only one generic system to be consistent with all the uses that have been developed. Therefore, priority systems should be developed with specific and clearly defined purposes in our nation. In this study, we investigated and discussed exist-ing CRS systems, and proposed several elements and principles when designing CRS systems. First of all, the system should have clearly defined goals, keep neutral, and employ simple methods. In addition, researchers need to perform sensitivity analysis to find the main variables responsible for uncertainties and use the tiered approach to compose the effective management strategies for chemicals.

• Structural Engineering and Mechanics
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• 제11권4호
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• pp.373-392
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• 2001

The main idea behind the paper is to present two alternative methods of homogenization of the heat conduction problem in composite materials, where the heat conductivity coefficients are assumed to be random variables. These two methods are the Monte-Carlo simulation (MCS) technique and the second order perturbation second probabilistic moment method, with its computational implementation known as the Stochastic Finite Element Method (SFEM). From the mathematical point of view, the deterministic homogenization method, being extended to probabilistic spaces, is based on the effective modules approach. Numerical results obtained in the paper allow to compare MCS against the SFEM and, on the other hand, to verify the sensitivity of effective heat conductivity probabilistic moments to the reinforcement ratio. These computational studies are provided in the range of up to fourth order probabilistic moments of effective conductivity coefficient and compared with probabilistic characteristics of the Voigt-Reuss bounds.

• 대한간호학회지
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• 제37권4호
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• pp.529-539
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• 2007

Purpose: This quantitative meta analysis sought to determine the effectiveness of SMIs. Method: Forty-six experimental studies with a randomized or nonequivalent control group pre-post test design were included in the analysis. The selected studies were classified according to the sample characteristics, the types and methods of the interventions, and the types of outcome variables. Six intervention types were distinguished: cognitive-behavioral intervention(CBT), relaxation techniques(RT), exercise(EX), multimodal programs 1 and 2(MT1, 2), and organization-focused interventions(OTs). Effect sizes were calculated for the 4 outcome categories across intervention types: psycho-social outcome, behavioral-personal resources, physiologic, and organizational outcome. Results : Individual worker-focused interventions(ITs) were more effective than OTs. A small but significant overall effect was found A moderate effect was found for RT, and small effects were found for other ITs, The effect size for OTs was the smallest. The interventions involving CBT and RT appeared to be the preferred means of reducing worker's psycho-social and organizational outcomes. With regard to physiologic outcomes, RT appeared to be most effective. CBT appeared to be most effective in reducing psycho-social outcomes. The effects of OT were non-significant, except for the psycho-social outcomes. Conclusions: SMIs are effective. Interventions involving RT and CBT are more effective than other types.

• The Journal of Asian Finance, Economics and Business
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• 제4권1호
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• pp.19-23
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• 2017

Based on a simultaneous-equation model consisting of aggregate demand and short-run aggregate supply, this paper estimates a reduced-form equation specifying that the equilibrium real GDP is a function of the real effective exchange rate, the government deficit as a percent of GDP, the real interest rate, foreign income, labor productivity, the real oil price, the expected inflation rate, and the interactive and intercept binary variables accounting for a potential change in the slope of the real effective exchange rate and shift in the intercept. Applying the exponential GARCH technique, it finds that aggregate output in Australia has a positive relationship with the real effective exchange rate during 2003.Q3 - 2013.Q2, the government deficit as a percent of GDP, U.S. real GDP, labor productivity and the real oil price and a negative relationship with the real effective exchange rate during 2013.Q3 - 2016.Q1, the real lending rate and the expected inflation rate. These results suggest that real appreciation was expansionary before 2013.Q3 whereas real depreciation was expansionary after 2013.Q2 and that more government deficit as a percent of GDP would be helpful to stimulate the economy. Hence, the impact of real appreciation or real depreciation on real GDP may change overtime.

• Child Health Nursing Research
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• 제7권3호
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• pp.308-321
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• 2001

Behavior modification is an approach to decrease degree of obesity through changing maladaptive eating habit and life style. It produces small amount of weight loss but it has few side effects and low dropout rate. It also has great effectiveness on maintenance of decreased weight. This study was performed to investigate effects of behavior modification on physical variables, fat and thin habit, and self-esteem in obese elementary school children. Sixty two students of 4th, 5th, and 6th grade were selected from two elementary schools located in the suburbs of Seoul. Thirty four children in one school were assigned to experimental group and twenty eight children in another school were assigned to control group. All subjects were healthy and were not on any type of obesity control. Behavior modification, in this study, was consisted of introduction, self-monitoring and stimuli control, education about diet and physical activities, individual counseling and reinforcement, requesting personal assistance, cognitive restructuring, and closing and long-term planning. Experimental group was received 60～70 minutes of behavior modification once a week for 8 weeks from October 16 to December 22, 2000. Control group was not received any intervention. Data were collected before and after intervention by measuring physical variables, fat and thin habit, and self-esteem. Physical variables consisted of obesity index, skinfold thickness, body fat(percentage of body fat, fat mass, fat free mass), serum lipids(total cholesterol, HDL-C, LDL-C, triglyceride) and serum leptin. The results were as follows ; 1. physical variables 1) Obesity index of the experimental group was significantly decreased after behavior modification. But there was no significant difference between two groups. 2) The increase of skinfold thickness was significantly low in the experimental group compared to the control group. 3) Percentage of body fat and fat mass were significantly decreased in the experimental group. Fat free mass was significantly increased in the experimental group. 4) Total cholesterol, HDL-C, triglyceride and serum leptin between the experimental group and control group showed no significant difference. LDL-C was significantly decreased in the control group. 2. Thin habit score was significantly increased in the experimental group. In subcategories of habit, thin scores of life style, attitude, social relationship, nutrition were signifi- cantly increased in the experimental group. 3. Self-esteem score was significantly increased in the experimental group. These results indicate that behavior modification is effective in decreasing percentage of body fat and fat mass, in less increasing skinfold thickness and in increasing fat free mass, thin habit, and self-esteem. In conclusion, behavior modification can be used as safe and effective strategy for managing obesity in elementary school children.

• 콘크리트학회지
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• 제5권4호
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• pp.167-178
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• 1993

본 논문의 목적은 R.C.보 최적설계에 이산수학계획법을 적용하여 상세설계를 포함하는 실제설계의 가능성을 연구하기 위한 것이다. 이산최적문제에서 설계변수로는 단면의 총높이, 폭, 유효높이 및 길이방향철근의 단면적 그리고 전단철근의 단면적과 길이 방향철근의 절단점과 같은 상세변수 등이 고려되었다. 목적함수는 경비함수로 취했으며, 제약조건으로는 강도설계법에 의한 설계휨강도, 전단강도, 연성, 사용성, 콘크리트 덮개 및 철근간격, 복부보강 그리고 정착길이와 길이방향철근의 절단점 등에 관한 시방서 요구사항을 고려하여 문제를 형성하였다. 이산변수를 갖는 최적설계를 효율적으로 실행하기 위해 첫째단계에서 Feasible Direction Methed를 이용하여 연속최적해를 구했으며, 둘째단계에서 분기한계법(Branch and bound method)을 이용하여 이산최적해를 얻는 최적화 알고리즘을 제안하였다. 제안된 알고리즘의 신뢰도를 검증하기 위해 2개의 이산설계변수를 갖는 수치예에 적용하여 도해법 및 rounde-up method와 그 결과를 비교하였고, 단순지지된 R.C.보 및 2경간연속 R.C.보에 적용하여 제안된 알고리즘의 신뢰도, 효율성 및 적용성을 입증하였다.

• 산업융합연구
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• 제19권4호
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• pp.65-74
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• 2021

본 연구는 단거리 달리기선수의 고강도 훈련 시 중탄산염 섭취가 혈액변인에 미치는 영향 규명하는데 연구의 목적이 있다. S시 남·여 단거리달리기 선수로 등록된 운동경력 3년 이상의 엘리트 선수 30명을 대상으로 통제집단, 훈련집단, 중탄산염 투여와 훈련집단의 세 집단으로 설정 후, 고강도 운동프로그램은 통제집단과 중탄산염 투여와 훈련집단을 대상으로 80-90%HRmax 운동강도를 2-3주마다 증가시키며, 총 8주간, 주 5일, 1회 90분 실시하였다. 중탄산염 섭취는 중탄산염 투여와 훈련집단을 대상으로 체중 1kg당 300mg을 고강도 운동프로그램 시작 90분 전 1일 1회 8주간 섭취하였다. 연구결과, 단거리달리기 선수의 고강도 훈련 시 중탄산염의 섭취가 혈액변인에 미치는 효과는 중탄산염 투여와 훈련집단에서 수소이온농도의 상승과 젖산의 감소에 긍정적인 효과가 나타났으며, Ca²⁺, Na⁺, K⁺은 훈련집단과 중탄산염 투여와 훈련집단에서 유의한 증가가 나타났다. Mg²⁺은 세 집단 모두에서 유의한 변화를 나타내지 않았다. 고강도 훈련 시 중탄산염의 섭취가 혈액변인의 변화 중 수소이온농도의 증가와 젖산의 감소에 효과적인 변화가 나타나는 것을 확인 할 수 있다. 따라서 고강도 운동 시 중탄산염의 섭취가 운동능력의 개선에 효과적임을 알 수 있다.

• 한국전산구조공학회논문집
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• 제15권2호
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• pp.281-291
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• 2002

본 연구에서는 직사각형 단면을 갖는 프리스트레스 철근콘크리트보(PRC)의 최소경비설계를 수행하였다. 목적함수로서 건설경비는 콘크리트 경비, 긴장재 경비, 철근 경비 그리고 거푸집 경비를 포함하였으며 이를 최소화하였다. 설계제약조건으로는 시방서상의 최대처짐제약, 휨 및 전단강도제약, 연성제약 그리고 설계변수에 대한 상·하한 제약을 고려하였다. 쿤-터커 필요조건을 이용하여 최적성 규준을 설계변수의 항으로 명시적으로 유도하였으며, 이때 설계변수로는 보의 유효깊이, 긴장재의 최대편심거리 그리고 철근비로 취하였고, 긴장재의 형상은 2차 포물선함수로 가정하였다. 또한 본 연구에서는 요소별로 변화하는 단면을 갖는 경우와 전경간에 걸쳐 일정한 단면을 갖는 경우에 대하여 고려하였고, 긴장재의 경간별 최대편심을 설계변수화 하였다. 그리고 수치예를 들어 개발된 기법의 적용성과 효율성을 보였다.

• 재활간호학회지
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• 제10권2호
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• pp.116-124
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• 2007

Purpose: This study was to suggest the direction to the exercise intervention development for the stroke survivors. Method: 12 domestic and 54 foreign research papers about the exercise intervention for the stroke patients published during 1998~2007 were analyzed. Result: Among the papers, quasi-experimental design(75.8%) and multidisciplinary approach(60.6%) were the most frequent ones. The mean age of the respondents was 63.3 and the intervention was supplied for 7.14 weeks. The frequency of exercise was 3.87 per week and the exercise time was 1.88 hours. And physical research variables - such as ambulation, muscle strength, activities of daily living and balance - were more than psychosocial variables. This study suggested that the exercise intervention for the stroke survivors need to include aerobic exercise, muscle strengthening exercise, flexible exercise, body coordination, balance exercise. In addition we confirmed that the exercise intervention was revealed as an effective physiological parameters; such as maximum oxygen uptake quantity, blood pressure. Conclusion: We suggest that the further researchs are needed which include the intensity of exercise into the quantity of the exercise. Also researchers need to extend the motion intervention time for an effective sociopsychological variable and to try the meta analysis for the effective exercise intervention for the stroke survivors.

• Structural Engineering and Mechanics
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• 제86권3호
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• pp.337-348
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• 2023

The optimization of reinforced concrete (RC) cantilever retaining walls is a complex problem and requires the use of advanced techniques like metaheuristic algorithms. For this purpose, an optimization model must first be developed, which involves mathematical complications, multidisciplinary knowledge, and programming skills. This task has proven to be too arduous and has halted the mainstream acceptance of optimization. Therefore, it is necessary to unravel the complications of optimization into an easily applicable form. Currently, the most commonly used method for designing retaining walls is by following the proportioning limits provided by the ACI handbook. However, these limits, derived manually, are not verified by any optimization technique. There is a need to validate or modify these limits, using optimization algorithms to consider them as optimal limits. Therefore, this study aims to propose updated proportioning limits for the economical design of a RC cantilever retaining wall through a comprehensive parametric investigation using the genetic algorithm (GA). Multiple simulations are run to examine various design parameters, and trends are drawn to determine effective ranges. The optimal limits are derived for 5 geometric and 3 reinforcement variables and validated by comparison with their predecessor, ACI's preliminary proportioning limits. The results indicate close proximity between the optimized and code-provided ranges; however, the use of optimal limits can lead to additional cost optimization. Modifications to achieve further optimization are also discussed. Besides the geometric variables, other design parameters not covered by the ACI building code, like reinforcement ratios, bar diameters, and material strengths, and their effects on cost optimization, are also discussed. The findings of this investigation can be used by experienced engineers to refine their designs, without delving into the complexities of optimization.