• Advances in Computational Design
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• 제1권3호
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• pp.265-274
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• 2016

The present paper describes the results of numerical modeling of a dam founded on loose liquefiable deposit using PLAXIS-3D finite element software. Effect of a different dam water level on parameters like displacements, Excess Pore water pressures, Liquefaction potential and Accelerations is studied. El- Centro earthquake motion is applied as input earthquake motion. The results of this study show that different upstream dam water level greatly affects the displacements, excess pore pressure and displacement tendency of the underlying foundation soils and the dam.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1993년도 봄 학술회 논문집
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• pp.1-8
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• 1993

This paper concerns the analytical concept of tunnel design for the case where the groundwater level remains almost to a standstill even though the steady state groundwater flow occurs through tunnel drainage systems. The effect of the seepage force is considered in analysis. Two case strudies are made : the one the round shape tunnel ; the other the horse shape. The design moments, shear forces and axial forces are calculated and these results are compared to the case of water proof tunnel design as well as the case of the tunnel design without groundwater consideration.

• 한국물환경학회지
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• 제23권5호
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• pp.697-704
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• 2007

This study proposes an integrated technique of Genetic Algorishim (GA) and Geographic Information System (GIS) for designing the water quality monitoring networks. To develop solution scheme of the integrated system, fitness functions are defined by the linear combination of five criteria which stand for the operation objectives of water quality monitoring stations. The criteria include representativeness of a river system, compliance with water quality standards, supervision of water use, surveillance of pollution sources and examination of water quality changes. The fitness level is obtained through calculations of the fitness functions and input data from GIS. To find the most appropriate parameters for the problems, the sensitivity analysis is performed for four parameters such as number of generations, population sizes, probability of crossover, and probability of mutation. Using the parameters resulted from the sensitivity analysis, the developed system proposed 110 water quality monitoring stations in the Nakdong River. This study demonstrates that the integrated technique of GA and GIS can be utilized as a decision supporting tool in optimized design for a water quality monitoring network.

• Smart Structures and Systems
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• 제16권4호
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• pp.683-699
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• 2015

Time Domain Reflectometry (TDR) has been extensively applied for various laboratory and field studies. Numerous different TDR probes are currently available for measuring soil moisture content and detecting interfaces (i.e., due to landslides or structural failure). This paper describes the development of an innovative spiral-shaped TDR probe that features much higher sensitivity and resolution in detecting interfaces than existing ones. Finite element method (FEM) simulations were conducted to assist the optimization of sensor design. The influence of factors such as wire interval spacing and wire diameter on the sensitivity of the spiral TDR probe were analyzed. A spiral TDR probe was fabricated based on the results of computer-assisted design. A laboratory experimental program was implemented to evaluate its performance. The results show that the spiral TDR sensor featured excellent performance in accurately detecting thin water level variations with high resolution, to the thickness as small as 0.06 cm. Compared with conventional straight TDR probe, the spiral TDR probe has 8 times the resolution in detecting the water level changes. It also achieved 3 times the sensitivity of straight TDR probe.

• Structural Engineering and Mechanics
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• 제62권2호
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• pp.209-224
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• 2017

Elevated water tanks are considered as important structures due to its post-earthquake requirements. Elevated water tank on reinforced concrete frame staging is widely used in India. Different response reduction factors depending on ductility of frame members are used in seismic design of frame staging. The study on appropriateness of response reduction factor for reinforced concrete tank staging is sparse in literature. In the present paper a systematic study on estimation of key components of response reduction factors is presented. By considering the various combinations of tank capacity, height of staging, seismic design level and design response reduction factors, forty-eight analytical models are developed and designed using relevant Indian codes. The minimum specified design cross section of column as per Indian code is found to be sufficient to accommodate the design steel. The strength factor and ductility factor are estimated using results of nonlinear static pushover analysis. It was observed that for seismic design category 'high' the strength factor has lesser contribution than ductility factor, whereas, opposite trend is observed for seismic design category 'low'. Further, the effects of staging height and tank capacity on strength and ductility factors for two different seismic design categories are studied. For both seismic design categories, the response reduction factors obtained from the nonlinear static analysis is higher than the code specified response reduction factors. The minimum dimension restriction of column is observed as key parameter in achieving the desired performance of the elevated water tank on frame staging.

• Nuclear Engineering and Technology
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• 제51권1호
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• pp.163-169
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• 2019

The robust controller synthesis and analysis of the water level process in the U-tube system generator (UTSG) is addressed in this paper. The parameter uncertainties of the steam generator (SG) are modeled as multiplicative perturbations which are normalized by designing suitable weighting functions. The relative errors of the nominal SG model with respect to the other operating power level models are employed to specify the weighting functions for normalizing the plant uncertainties. Then, a robust controller is designed based on ${\mu}$-synthesis and D-K iteration, and its stability robustness is verified over the whole range of power operations. A gain-scheduled controller with $H_{\infty}$-synthesis is also designed to compare its robustness with the proposed controller. The stability analysis is accomplished and compared with the previous QFT design. The ${\mu}$-analysis of the system shows that the proposed controller has a favorable stability robustness for the whole range of operating power conditions. The proposed controller response is simulated against the power level deviation in start-up and shutdown stages and compared with the other concerning controllers.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 추계학술발표회요약집
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• pp.351.1-351
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• 1999

• 한국의상디자인학회지
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• 제24권1호
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• pp.45-57
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• 2022

A rash guard, also known as rash vest or rashie, is functional sportswear that protects the wearer's skin from various dangers during outdoor sports activities. It is durable and comfortable since it is designed considering muscle movement. In modern society, more and more people enjoy leisure activities due to an increase in income level and increased leisure hours. Water leisure activities are increasingly enjoyed in the summer. As the way people think of leisure evolves, people are more inclined toward dynamic leisure sports rather than static facility tourism. Therefore, more research on rash guards is required. By identifying and analyzing the design preferences and purchase behaviors of young adults on rash guards, this study aims to provide basic data on the actual sportswear behaviors concerning those who are most active in water sports, people in their 20s and 30s. Furthermore, the study aims to contribute to a healthy exercise lifestyle for women who enjoy water sports and the growth of the water sportswear market. In the study, a survey was conducted using a questionnaire to investigate the wearing behaviors and purchase preferences as well as the wearing satisfaction on rash guards. For the study, 200 copies of the questionnaire were distributed and collected to be used as analysis data. The questionnaire consisted of 36 questions, 6 about demographic characteristics, 11 about purchase preferences, and 19 about wearing satisfaction. The collected data was analyzed using the statistical program SPSS 8.0. The study results can be used as basic data to investigate the design preferences and wearing behaviors of rash guards of women in their 20s and 30s. The results found numerous complaints on comfortableness and durability, which suggests more concern and improvements are necessary in those areas when designing patterns for rash guards.

• Advances in materials Research
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• 제4권3호
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• pp.165-178
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• 2015

Friction coefficient of epoxy metal matrix composites were investigated. The main objective was to increase the friction coefficient through rubber sole sliding against the epoxy floor coating providing appropriate level of resistance. This was to avoid the excessive movement and slip accidents. Epoxy metal matrix composites were reinforced by different copper wire diameters. The epoxy metal matrix composites were experimentally conducted at different conditions namely dry, water and detergent wetted sliding, were the friction coefficient increased as the number of wires increased. When the wires were closer to the sliding surface, the friction coefficient was found to increase. The friction coefficient was found to increase with the increase of the copper wire diameter in epoxy metal matrix composites. This behavior was attributed to the fact that as the diameter and the number of wires increased, the intensity of the electric field, generated from electric static charge increased causing an adhesion increase between the two sliding surfaces. At water wetted sliding conditions, the effect of changing number of wires on friction coefficient was less than the effect of wire diameter. The presence of water and detergent on the sliding surfaces decreased friction coefficient compared to the dry sliding. When the surfaces were detergent wetted, the friction coefficient values were found to be lower than that observed when sliding in water or dry condition.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 추계학술대회 논문집
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• pp.77-80
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• 2003

As rapid growth of energy demand in line with modern society's industrialization led to environmental pollution by fossil fuels, there are more and more interest and international research on energization of water, which is clean energy and comprising $70\%$ of earth. In offshore countries, the water is commercially used already and water has very attractive characteristics in terms of economy and efficiency compared to the existing gas welder. Brown Gas welder does not produce $CO_2$ from combustion of Hydrogen-Oxygen-Gas, which was gained by electrolysis of water, In this paper, the result from operating characteristic improvement of Gas Generator and Current-Controlled converter is to be considered into design in electrode, source/ controller, standized into level of whole system design base.