• Journal of KSNVE
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• v.6 no.5
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• pp.595-605
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• 1996

If the control force designed on the basis of the mathematical model with parameter errors is applied to control the actual system, the closed-loop performance of the actual system will be degraded depending on the degree of the errors, In this study, the effect of parameter errors on the robustness of several natural controls has been analyzed and compared. Every asymptoic stability condition for the natural controls has been derived using Lyapunov approach, and the characteristics of the stability conditions has also been compared. The extent of deviation of the closed-loop performance from the designed one for the natural controls is derived using operator techniques, and evaluated by numerical method. It has been found that the optimal control, acceleration feedback control, and acceleration-position feedback control among the considered natural controls would be robust one with respect to the parameter errors.

• Korean Journal of Human Ecology
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• v.12 no.5
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• pp.619-634
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• 2003

The purpose of this study was to the real situation of the safety education in the kindergarten by investigating the actual condition of the safety education and kindergarten teachers' knowledge about it. Questionnaire was adopted to obtain data required for pertinent analysis. The subjects were 234 kindergarten teachers located in Choongnam and Daejeon province. SPSSWIN v10.0 was utilized to calculate percentage, mean and standard deviation and to conduct t-test, one-way ANOVA and Duncan's multiple range test. The main results of this study were as follows. There was a significant difference between the actual condition of the safety education and kindergarten teachers' knowledge about it according to demographic variables. Especially, these differences were due to teachers' academic career, age, teaching experience, and the experience of bringing up children by themselves. The importance of the safety education must be emphasized. There were urgent needs to develop the way of teaching and the program about the safety education.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.1040-1043
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• 2004

The purpose of this study is to present a fundamental data for evaluating aircraft noise of building site development. By the field experiments and an predicted equal noise level contour using the INM program, actual condition in the building site development arranged district was investigated. In order to get the results, Analysis of factors effected on noise level, sound level on the rate of increase to aircraft demand and difference on the aircraft noise levels according to floor level in apartment house was carried out.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.567-571
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• 1989

This paper describes the improvement of thermal power plant turbine control system by analyzing nonlinear characteristics. The turbine control depends on the frequency variation and boiler condition. The nonlinearity of turbine control is the result of governor/valve properties, steam condition and boiler thermal unbalance. Nonlinear analysis is divided into two; main steam valve position - turbine output anal governor response. Of course, every analysis must be done on considering plant operating condition. In this paper, after analyzing turbine control nonlinearity by numerical method and actual results, the sensitive operating load which corresponds to frequency is proposed, on guarranteed boiler stability. This idea is implemented at Pyung Tack thermal power plant, and the practical results are showed.

• Progress in Medical Physics
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• v.28 no.4
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• pp.164-170
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• 2017

One of the methods to consider the effect of respiratory motion of a tumor target in radiotherapy is to establish a treatment plan with the internal target volume (ITV) created based on an accurate analysis of the target motion displacement. When this method is applied to intensity modulated radiotherapy (IMRT), it is expected to yield a different treatment dose distribution under the motion condition according to the IMRT method. In this study, we prepared ITV-based IMRT plans with conventional IMRT using fixed gantry angle beams, RapidArc using volumetric modulated arc therapy, and tomotherapy using helical therapy. Then, the variation in dose distribution caused by the target motion was analyzed by the dose measurement in the actual motion condition. A delivery quality assurance plan was prepared for the established IMRT plan and the dose distribution in the actual motion condition was measured and analyzed using a two-dimensional diode detector placed on a moving phantom capable of simulating breathing movements. The dose measurement was performed considering only a uniform target shape and motion in the superior-inferior (SI) direction. In this condition, it was confirmed that the error of the dose distribution due to the target motion is minimum in tomotherapy. This is thought to be due to the characteristic of tomotherapy that treats the target sequentially by dividing it into several slices. When the target shape is uniform and the main target motion direction is SI, it is considered that tomotherapy for the ITV-based IMRT method has a characteristic which can reduce the dose difference compared with the plan dose under the target motion condition.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.37-45
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• 2015

PURPOSES : The purpose of this study is to validate the design criteria of the concrete modular road system, which is a new semi-bridge-type concept road, through a comparison of numerical analysis results and actual loading test results under static axial loads. METHODS : To design the semi-bridge-type modular road, both the bridge design code and the concrete structural design code were adopted. The standard truck load (KL-510) was applied as the major traffic vehicle for the design loading condition. The dimension of the modular slab was designed in consideration of self-weight, axial load, environmental load, and combined loads, with ultimate limit state coefficients. The ANSYS APDL (2010) program was used for case studies of center and edge loading, and the analysis results were compared with the actual mock-up test results. RESULTS : A full-scale mock-up test was successfully conducted. The maximum longitudinal steel strains were measured as about 35 and 83.5 micro-strain (within elastic range) at center and edge loading locations, respectively, under a 100 kN dual-wheel loading condition by accelerating pavement tester. CONCLUSIONS : Based on the results of the comparison between the numerical analysis and the full-scale test, the maximum converted stress range at the edge location is 32~51% of the required standard flexural strength under the two times over-weight loading condition. In the case of edge loading, the maximum converted stresses from the Westergaard equation, the ANSYS APDL analysis, and the mock-up test are 1.95, 1.7, and 2.3 times of that of the center loading case, respectively. The primary reason for this difference is related to the assumption of the boundary conditions of the vertical connection between the slab module and the crossbeam module. Even though more research is required to fully define the boundary conditions, the proposed design criteria for the concrete modular road finally seems to be reasonable.

• Journal of the Korean Institute of Rural Architecture
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• v.13 no.1
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• pp.55-62
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• 2011

The purpose of this study is to clarify the actual condition of real certification schools of environment-friendly architecture per ecological environment elements through extracting ecological environment elements which is possible to analyze in quantity certification standards of environment friendly architecture. As the method of this study, firstly, certification as an examination on certification system of environment-friendly architecture, summary of certification system of environment-friendly architecture and eco-school pilot model project, ecological environment elements which is possible for quantitative analysis of ecological environment certification standards were extracted. Secondly, actual condition of ecological environment elements per school grade by collecting actual data of certification schools environment-friendly architecture were analyzed. The average of ecological area ratio was 24.5 percent in case of this certification regardless of school grade and region and it was analyzed that the natural based green area ratio was 22.9 percent, bio-tope area ratio was 0.60 percent and ecological learning places area ratio was 0.39 percent.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.434-437
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• 2003

In apartment project, BCWS is a critical management factor and has a great influence on the success of the project. But due to the characteristics of large apartment complex, there are several problems in making out a time schedule of work as well as production and management of precise bcws from the allocation of resources. In this study, Actual condition survey was executed in terms of the calculation and the management of BCWS. This study propose better solutions for efficient calculation of bcsw through the analysis of the problems and the origins relating to BCWS from a field area.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1859-1863
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• 2007

A new type of a fretting wear tester has been designed and developed in order to simulate the actual vibration behavior of a nuclear fuel rod for springs/dimples in room temperature. When considering the actual contact condition between fuel rod and spring/dimple, if fretting wear progress due to the flow-induced vibration (FIV) under a specific normal load exerted on the fuel rod by the elastic deformation of the spring, the contacting force between the fuel rod and dimple that were located in the opposite side should be decreased. Consequently, the evaluation of developed spacer grids against fretting wear damage should be performed with the results of a cell unit experiments because the contacting force is one of the most important variables that influence to the fretting wear mechanism. Therefore, it is necessary to develop a new type of fretting test rig in order to simulate the actual contact condition. In this paper, the development procedure of a new fretting wear tester and its performance were discussed in detail.

• The Journal of the Korea Contents Association
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• v.8 no.3
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• pp.190-196
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• 2008

In these days we can often see examples of suicide. Nowaday suicide becomes a serious social problem in Korean society. The number of suicides increased continuously from 3,157 in 1990 to 10,688 in 2006. The suicide rate per 100,000 person increased progressively from 9.1 in 1991 to 26.1 in 2005 and hit the highest level in 2005. In 2006, The suicide rate decreased after the lapse of 6 years. However, It is still high actual condition with 23.0.