• Journal of Industrial Technology
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• v.20 no.B
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• pp.9-14
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• 2000

Sound insulation performance is investigated on the corrugated panel used for a rail way vehicle. Random incidence sound transmission loss is calculated by using the equivalent orthotropic plate model. Analysis results on several kinds of corrugated panels are in good agreement with the measured data. The analysis method is applied to predict the sound transmission loss of the corrugated panel used for Korean high speed train.

• Journal of the Korean Applied Science and Technology
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• v.40 no.6
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• pp.1298-1308
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• 2023

This study collected 245 questionnaires from college students in Gyeonggi-do and analyzed them using SPSS statistical packages, with the aim of identifying the status of hair loss perception due to the relationship between stress and hair loss received by college students and analyzing the correlation between stress and hair loss perception by type. As a result of the study, it was analyzed that the biggest problem caused by hair loss was 'loss of confidence', and in particular, people who were stressed about career/employment and studies were analyzed to consider the problem of 'loss of confidence' the most serious. As a result of cross-analysis of the general characteristics of awareness and the 'most recent stress' item, and as a result of correlation analysis between stress by type and hair loss status that constitutes hair loss awareness, it was analyzed that all types of stress affect hair loss in college students. Among them, career/employment stress and academic stress were found to be the most influential stress, and in the event of hair loss, it was analyzed that they were more willing to engage in hair loss treatment for career/employment, study, and appearance before interpersonal relationships or economic problems. Therefore, this study is of great significance in that it classified stress by type and analyzed the correlation through empirical research methods by specifying the contents of hair loss recognition into three categories: hair loss status, hair loss management, and hair loss treatment.

• Nuclear Engineering and Technology
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• v.17 no.4
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• pp.256-266
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• 1985

The loss of coolant flow accident is analyzed for the pressurized water reactor of Korea Nuclear Unit-1. The loss of coolant flow accident is classified into three types in accordance with its severity; partial loss of coolant flow, complete loss of coolant flow and pump locked rotor accident. Analysis has been carried out in three stages; system transient and average core analysis, DNBR calculation and hot spot analysis. The purpose of developing KTRAN is to simulate the transient fast. For the DNBR calculation, the thermal hydraulic codes, SCAN and COBRA IV-1, are adopted. And for the hot spot analysis, the fuel thermal transient code LTRAN is employed. This code system should be fast responding to the transient analysis. In case the transient occurs, severity comes within a couple of seconds. So response should be fast to accomodate the following sequence of the accident. Unfortunately this purpose could not be achieved by KTRAN. However, the calculated results are well comparable with FSAR results in range. Thereby, the effectiveness of KTRAN code analysis in this type of accident is proven.

• Journal of Family Relations
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• v.20 no.4
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• pp.105-130
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• 2016

Objectives: The purpose of this study was to explore the moderating effect of stress coping styles on the relationships between loss experiences and depression of the men and women elderly. Method: The subjects of the study were 116 men and 156 women aged over 60 years. For the data analysis, frequency, Cronbach's ${\alpha}$. Pearson's correlation coefficients, and multiple regression were used. Results: The main results were as follows: First, elderly men reported higher role loss experience, relation loss experience, and problem-focused coping styles than elderly women. Also elderly women reported higher bereavement experience than elderly men. Second, there were main effects of health loss experience, economy loss experience, role loss experience, relation loss experience, problem-focused coping style, and emotion-focused coping style on depression of elderly men and women. Third, problem-focused coping styles moderated the relationships between physical health loss experience, economy loss experience, role loss experience and depression in the elderly men group. Last, social support-seeks coping styles moderated the relationships between economy loss experience and depression in the elderly women group. Conclusions: These results were discussed in terms of educational programs related stress coping strategies for the elderly.

• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1229-1239
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• 2014

Optimal Distributed Generation (DG) output and reconfiguration are among the well accepted approach to reduce power loss in a distribution network. In the past, most of the researchers employed optimal DG output and reconfiguration separately. In this work, a simultaneous DG output and reconfiguration analysis is proposed to maximize power loss reduction. The impact of the separated analysis and simultaneous analysis are investigated. The test result on the 33 bus distribution network with 3 units of DG operated in PV mode showed the simultaneous analysis gave the lowest power loss (global optimal) and faster results compared to other combined methods. All the analyses for optimizing the DG as well as reconfiguration are used the Artificial Bee Colony Optimization technique.

• Journal of Construction Engineering and Project Management
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• v.3 no.3
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• pp.23-34
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• 2013

As climate change and environmental pollution become one of the biggest global issues today, new renewable energy, especially solar photovoltaic (PV) system, is getting great attention as a sustainable energy source. However, initial investment cost of PV system is considerable, and thus, it is crucial to predict electricity generation accurately before installation of the system. This study analyzes the loss ratio of solar photovoltaic electricity generation from the actual PV system monitoring data to predict electricity generation more accurately in advance. This study is carried out with the following five steps: (i) Data collection of actual electricity generation from PV system and the related information; (ii) Calculation of simulation-based electricity generation; (iii) Comparative analysis between actual electricity generation and simulation-based electricity generation based on the seasonality; (iv) Stochastic approach by defining probability distribution of loss ratio between actual electricity generation and simulation-based electricity generation ; and (v) Case study by conducting Monte-Carlo Simulation (MCS) based on the probability distribution function of loss ratio. The results of this study could be used (i) to estimate electricity generation from PV system more accurately before installation of the system, (ii) to establish the optimal maintenance strategy for the different application fields and the different season, and (iii) to conduct feasibility study on investment at the level of life cycle.

• YAKHAK HOEJI
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• v.55 no.2
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• pp.98-105
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• 2011

To search the minimum structural requirement of tricyclic isoxazole analogues (1~30) as new class potent antidepressant, thee-dimensional quanti- tative-structure relationship (3D-QSAR) models between substituents ($R_1{\sim}R_5$) of tricyclic isoxazoles and their antidepressant activity against medetomidine-induced loss of righting were performed and discussed quantitatively using comparative molecular field analysis (CoMFA) and comparative molecular similarity indies analysis (CoMSIA) methods. The correlativity and predictability ($r^2$=0.484 and $q^2$=0.947) of CoMSIA-2 model were higher than those of the rest models. The inhibitory activity against medetomidine-induced loss of righting was dependent on electrostatic field (43.4%), hydrophobic field (35.3%), and steric field (21.2%) of tricyclic isoxazoles. From the CoMSIA-2 contour maps, it is predicted that the antidepressant activity of potent antidepressants against medetomidine-induced loss of righting will be able to increase by the substituents ($R_1{\sim}R_5$) which were in accord with CoMSIA field.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.7
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• pp.831-840
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• 1999

In this work, an aerothermodynamic calculation model for cooled axial flow turbine blades with trailing edge ejection is suggested and a mean line performance analysis of a turbine stage with nozzle cooling is carried out. A unique model regarding the interaction between coolant and main gas is proposed, while existing correlations are adopted to predict viscous loss and blade outflow angle. The interactions considered are the heat transfer from main gas to coolant and the temperature and pressure losses by the mixing of two streams due to the trailing edge coolant ejection. For a stator blade without ejection, trailing edge loss calculated by the trailing edge analysis is compared with that calculated by loss correlation. The effect of heat transfer effectiveness of coolant passage on the mixing loss is analyzed. For a model turbine stage with nozzle cooling, parametric analyses are carried out to investigate the effect of main design variables(coolant mass flow ratio, temperature and ejection area) on the stage performance.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.375-385
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• 2013

As climate change and environmental pollution become one of the biggest global issues today, new renewable energy, especially solar photovoltaic (PV) system, is getting great attention as a sustainable energy source. However, initial investment cost of PV system is considerable, and thus, it is crucial to predict electricity generation accurately before installation of the system. This study analyzes the loss ratio of solar photovoltaic electricity generation from the actual PV system monitoring data to predict electricity generation more accurately in advance. This study is carried out with the following five steps: (i) Data collection of actual electricity generation from PV system and the related information; (ii) Calculation of simulation-based electricity generation; (iii) Comparative analysis between actual electricity generation and simulation-based electricity generation based on the seasonality; (iv) Stochastic approach by defining probability distribution of loss ratio between actual electricity generation and simulation-based electricity generation ; and (v) Case study by conducting Monte-Carlo Simulation (MCS) based on the probability distribution function of loss ratio. The results of this study could be used (i) to estimate electricity generation from PV system more accurately before installation of the system, (ii) to establish the optimal maintenance strategy for the different application fields and the different season, and (iii) to conduct feasibility study on investment at the level of life cycle.

• International Journal of Automotive Technology
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• v.7 no.4
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• pp.423-439
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• 2006

This paper proposes a hybrid analytic method for the prediction of vibrational and acoustic responses of reverberant system in the medium-to-high frequency ranges by using the PFA(Power Flow Analysis) algorithm and SEA(Statistical Energy Analysis) coupling concepts. The main part of this method is the application of the coupling loss factor(CLF) of SEA to the boundary condition of PFA in reverberant system. The hybrid method developed shows much more promising results than the conventional SEA and equivalent results to the classical PFA for various damping loss factors in a wide range of frequencies. Additionally, this paper presents applied results of hybrid power flow finite element method(hybrid PFFEM) by formulating the new joint element matrix with CLF to analyze the vibrational responses of built-up structures. Finally, the analytic results of coupled plate structures and an automobile-shaped structure using hybrid PFFEM were predicted successively.