• Environmental Analysis Health and Toxicology
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• v.18 no.3
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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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• v.11 no.4
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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.

• Journal of Korean Academy of Nursing
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• v.37 no.4
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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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• v.4 no.1
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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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• v.7 no.3
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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.

• Magazine of the Korea Concrete Institute
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• v.5 no.4
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• pp.167-178
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• 1993

The objective of this paper is to look into the possibility of the detailed and practical optimum design of rt:inforced concrete beam using methods oi discrete mathematical programming. In this discrete optimum formulation, the design variables are the overall depth, width and effective depth of members, and area of longitudinal reinforcement. In addition, the details such as the amount of web reinforcement and cutoff points of longitudinal reinforcement are also considered as variables. Total cost has been used as the objective function. The constraints include the code requirments such as flexural strength, shear strength, ductility, serviceability, concrete cover. spacing, web reinforcement, and development length and cutoff points of longitudinal renforcement. An optimization algorithm is presented for effective optimum design of R.C. beam with discrete de sign variables. First, the continuous variable optimization can be achieved by Feasible Direction Method. Using the results obtained from the continuous variable optimization, a branch and bound method is used to obtained the discrete design values. The proposed algorithm is applied to test problem for reliability, and the results are compared with those of graphical method and rounded-up method. And a simply supported R.C. beam and a two-span continuous R.C. beam are presented as numerical examples for effectiveness and applicability. It is considered that the presented algorithm can be effectively applied to the discrete optimum design of R.C. beams.

• Journal of Industrial Convergence
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• v.19 no.4
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• pp.65-74
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• 2021

The purpose of this study was to investigate the effect of bicarbonate intake on blood variables during high-intensity training of sprinters. 30 male/female elites with more than 3 years of experience that are registered to S city as a sprinter was categorized into three groups: control group, training group, and HCO₃^- and training group. Training group and HCO₃^- and training group went through a high-intensity exercise program (80-90% HR max) which escalated every 2-3 weeks, for 90 minutes at a time, 5 days a week, 8 weeks in total. HCO₃^- and Training group took in 300mg of bicarbonate per one kilogram of body weight, in 90 minutes before the start of the high-intensity exercise program, once a day for 8 weeks. As a result of the study, the effect of bicarbonate intake on blood variables during high-intensity training of sprinters showed a positive effect on the increase of pH and the decrease of lactic acid in HCO₃^- and training group. Also, the increase of Ca²⁺, Na⁺, K⁺ was shown in training group and HCO₃^- and training group, whereas there were no indications of significant change in Mg²⁺ in all three groups. It can be confirmed that the intake of bicarbonate during high-intensity training shows effective changes in the increase of pH and the decrease in lactic acid among changes in blood variables. Therefore, it can be seen that the intake of bicarbonate during high-intensity exercise is effective in improving exercise capacity.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.2
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• pp.281-291
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• 2002

This paper describes the minimum cost design of prestressed reinforced concrete (PRC) hem with rectangular section. The cost of construction as objective function which includes the costs of concrete, prestressing steel, non prestressing steel, and formwork is minimized. The design constraints include limits on the minimum deflection, flexural and shear strengths, in addition to ductility requirements, and upper-Lower bounds on design variables as stipulated by the specification. The optimization is carried out using the methods based on discretized continuum-type optimality criteria(DCOC). Based on Kuhn-Tucker necessary conditions, the optimality criteria are explicitly derived in terms of the design variables - effective depth, eccentricity of prestressing steel and non prestressing steel ratio. The prestressing profile is prescribed by parabolic functions. In this paper the effective depth is considered to be freely-varying and one uniform for the entire multispan beam respectively. Also the maximum eccentricity of prestressing force is considered in every span. In order to show the applicability and efficiency of the derived algorithm, several numerical examples of PRC continuous beams are solved.

• The Korean Journal of Rehabilitation Nursing
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• v.10 no.2
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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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• v.86 no.3
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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.