• 대한안전경영과학회지
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• 제20권3호
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• pp.1-9
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• 2018

This study is intended to look into the effect of construction safety supervision system on risk control and reduction. To achieve this, a survey was carried out to 114 companies in construction, ordering, contract and management. The overall findings were as follows. The effect of construction safety supervision system on risk control and reduction showed that factors of supervision system, supervision cost and supervision method had a positive effect on risk control and reduction. And their perception of the introduction of safety supervision system in construction sites according to process showed that there was a difference between them according to the field of ordering, contract and supervision. There was the biggest difference between owner and contractor in double supervision system, but no difference between them in the perception of risk reduction. These results show that all ordering, contract and supervision are positively needed for the introduction of construction safety supervision. This means that there is a difference between owner and contractor in the perception of process according to system operation. All companies agree to system improvement by the settlement of safety supervision system for the prevention of safety accidents and safe construction, but the systematic complement of safety supervision is the burden of contractor. And there is a big difference between owner and contractor in the perception of responsibility and concern for cost burden.

• Advances in aircraft and spacecraft science
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• 제1권3호
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• pp.353-378
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• 2014

This paper deals with the early development of the Anuloid, an innovative disk-shaped VTOL aircraft. The Anuloid concept is based on the following three main features: the use of a ducted fan powered by a turboshaft for the lift production to take-off and fly; the Coanda effect that is developed through the circular internal duct and the bottom portion of the aircraft to provide further lift and control capabilities; the adoption of a system of ducted fixed and swiveling radial and circumferential vanes for the anti-torque mechanism and the flight control. The early studies have been focused on the CFD analysis of the Coanda effect and of the control vanes; the flyability analysis of the aircraft in terms of static performances and static and dynamic stability; the preliminary structural design of the aircraft. The results show that the Coanda effect is stable in most of the flight phases, vertical flight has satisfactory flyability qualities, whereas horizontal flight shows dynamic instability, requiring the development of an automatic control system.

• 한방비만학회지
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• 제10권2호
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• pp.17-25
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• 2010

Objectives This study was performed to figure out the effects of I-razin in overweight children without any exercise or specific diet. Methods Twenty-eight children those who were diagnosed overweight have been recruited. They were randomly assigned treatment or control group under block randomization. Treatment group were treated with I-razin for 8 weeks, and control group were treated with placebo medication under same conditions. Anthropometry, fat computed tomography and blood test have been done before and after the treatment. Results Eleven subjects in treatment group and seventeen in control group were evaluated. BMI, waist circumference, glucose, total cholesterol, and triglyceride were decreased in the treatment group. And reduction of BMI, glucose, and triglyceride in the treatment group were greater than control group. But there was no statistically significance. No side effects have been notice during the study period and no adverse effect on liver has been observed. Conclusion This study could not demonstrate effect of I-razin compared with control group. However, treatment group has a tendency of weight loss without side effect. Additional studies with large population are thought to be necessary to clarify the effect of I-razin.

• 대한전기학회논문지:전력기술부문A
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• 제54권7호
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• pp.366-374
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• 2005

The purpose of this study is to find out main factors affecting public enterprise's environment , which improves the performance of public enterprise. In detail, under the premises of keeping publicity in Korea Electricity Industry, the main target of this study is to seek after factors enhancing entrepreneurship and deals with publicity which is related with entrepreneurship. Questionnaires are distributed to the employee of public enterprise, public servants, and civil corps. A total of 553 copies are collected. The main contents of questionnaires are related with the effect of publicity and entrepreneurship by government control, competitive environment and shareholding structure in Korea Electricity Power Corporation(KEPCO). The results of this survey are as follows : First government control is negatively related to the entrepreneurship while it is positively related to the Publicity. Second, this suey shows that competitive environment has a Positive influence on promoting both publicity and entrepreneurship. Third this survey in connection with shareholding structure indicates that present structure in KEPCO has a positive effect on publicity but negative effect on entrepreneurship. According to this empirical results, it is verified that the main issues on the performance of KEPCO ue related with the level of government control and competitive environment in its industry.

• 한국패션뷰티학회지
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• 제5권4호
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• pp.119-129
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• 2007

This study was designed to investigate what an effect Meridian massage widely practiced in the skin and fatness clinics gives to the control of women's lower body fatness. 8 woman students in the J beauty school in Seoul were selected as experimental group. After measuring their femoral or thigh circumference, 4 weeks of Meridian massage was practiced. Another 8 women who were not included in the experiment were selected as the control group. As the results of 4 week Meridian control on lower body fatness, P value of the variance analysis was over 0.05, meaning that there was not a statistical significance. But the measurement of femoral or thigh circumference decreased from 55.85 cm to 53.34 cm, indicating that more often Meridian massage was practiced, the more lower body fatness decreased. This suggests that Meridian massage gives a positive effect to lower body fatness control. In a survey after the experiment, more than 88% of the survey participants answered that Meridian massage was effective to removal of edema, decrease in thigh circumference, and deep sleep, indicating that satisfaction with Meridian massage was high. Based on the findings of this study, it is necessary to study further on quantifying the effect of Meridian massage, which is practiced just to control lower body fatness.

• Journal of Acupuncture Research
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• 제23권4호
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• pp.115-121
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• 2006

Objectives : This study was designed to investigate the scavenging effect on Nitric Oxide of BUM. Methods : The scavenging effect on NO concentrations 2, 6, 12 and 24 hours after treatment with Vit C. and BUM at 1, 10, $100{\mu}g/ml$ were estimated. And those was compared with control group. Results : 1. The concentration of NO 2 hours after treatment with BUM at 1, 10, 1$100{\mu}g/ml$ were decreased compared with control group. 2. The conecntration of NO 6 hours after treatment with BUM at 1, 10, 1$100{\mu}g/ml$ were decreased compared with control group. 3. The concentration of NO 12 hours after treatment with BUM at 1, 10, $100{\mu}g/ml$ were decreased compared with control group. 4. The concentration of NO 24 hours after treatment with BUM at 1, $100{\mu}g/ml$ were decreased compared with control group. Conclusion : The scavenging effect of BUM on NO was dose-dependent.

• 대한안전경영과학회지
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• 제26권1호
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• pp.15-24
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• 2024

The purpose of this study is to improve the stack effect of the staircase and the failure to take into account the opening of the outside door of the staircase, which are the disadvantages of the existing smoke control only vestibule. As a result of the study, the new vestibule and the staircase simultaneous smoke control are equipped with an exhaust flap damper with an effective opening area of about 0.25 m² in the upper part of the staircase, and a ventilator-type air supply fan of about 5 m³/s in the lower part, and take measures to prevent overpressure in the staircase. If you use the new simultaneous smoke control method of the vestibule and staircase, you can achieve the following effects. First, it is possible to open the external entrance door. Second, it can reduce the stack effect. Third, the staircase door closes automatically without fail. And a new method of preventing overpressure was proposed for the vestibule.

• 산업경영시스템학회지
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• 제32권1호
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• pp.117-129
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• 2009

The bullwhip effect is known as the significant factor which causes unnecessary inventory, lost sales or cost increase in supply chains. Therefore, the causes of the bullwhip effect must be examined and removed. In this paper, we develop two analytical tools for the bullwhip effect control in supply chains. First, we develop the quantitative models for computing the bullwhip effect in a three-stage supply chain consisted of a single retailer, a single distributor and a single manufacturer when the fixed-interval replenishment policy is applied at each stage. The quantitative models are developed under the different conditions for the demand forecasting and share of customer demand information. They are validated through the computational experiments. Second, we develop a simulation-based decision support system for the bullwhip effect control in a more diverse dynamic supply chain environment. The system includes a what-if analysis function to examine the effects of varying input parameters such as operating policies and costs on the bullwhip effect.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.609-614
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• 1998

A new small signal modeling of an average current mode control is proposed. In order to analyze the characteristics of the control scheme, the discrete and continuous time small signal models are derived. The derivation are mainly come from the analysis of the sampling effect presented in the current control loop. By the mathematical interpretation of practical sampler representing the sampling effect of a current control loop, the small signal models of an average current mode control can be easily derived. The instability of the current control loop, which gives rise to the subharmonic oscillation, can be identified by the proposed models. To show the usefulness of the proposed models, the simulation and experiment are carried out. The results show that the predicted results by the proposed model are much better agreed with the measured ones than that of the conventional model, even though the high gain of the compensation network of a current control loop is employed.

• Structural Engineering and Mechanics
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• 제14권1호
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• pp.21-38
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• 2002

A control algorithm combining viscous and non-linear Reid damping mechanisms has been recently proposed by the authors to command active friction dampers. In this paper, friction dampers and the proposed algorithm are applied to control the seismic responses of a nonlinear 20-story building. Piezoelectric stack actuators are used to implement the control algorithm. The capacity of each damper is determined by the practical size of piezoelectric actuators and the availability of power supply. The saturation effect of the actuators on the building responses is investigated. To minimize the peak story drift ratio or floor acceleration of the building structure, a practical sequential procedure is developed to sub-optimally place the dampers on various floors. The effectiveness of active friction dampers and the efficiency of the proposed sequential procedure are verified by subjecting the building structure to four earthquakes of various intensities. The performance of 80 dampers and 137 dampers installed on the structure is evaluated according to 5 criteria. Numerical simulations indicated that the proposed control algorithm effectively reduces the seismic responses of the uncontrolled 20-story building, such as inelastic deformation. The sub-optimal placement of dampers based on peak acceleration outperforms that based on peak drift ratio for structures subjected to near-fault ground motions. Saturation of piezoelectric actuators has adverse effect on floor acceleration.