• Steel and Composite Structures
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• v.11 no.4
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• pp.273-290
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• 2011

In current ductility-based earthquake-resistant design, the estimation of design forces continues to be carried out with the application of response modification factors on elastic design spectra. It is well-known that the response modification factor (R) takes into account the force reduction, strength, redundancy, and damping of structural systems. The key components of the response modification factor (R) are force reduction ($R_{\mu}$) and strength ($R_S$) factors. However, the response modification and strength factors for structural systems presented in design codes were based on professional judgment and experiences. A numerical study has been accomplished to evaluate force reduction, strength, and response modification factors for special steel moment resisting frames. A total of 72 prototype steel frames were designed based on the recommendations given in the AISC Seismic Provisions and UBC Codes. Number of stories, soil profiles, seismic zone factors, framing systems, and failure mechanisms were considered as the design parameters that influence the response. The effects of the design parameters on force reduction ($R_{\mu}$), strength ($R_S$), and response modification (R) factors were studied. Based on the analysis results, these factors for special steel moment resisting frames are evaluated.

• Structural Engineering and Mechanics
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• v.41 no.3
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• pp.365-378
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• 2012

In this study, strength reduction factors are investigated for SDOF systems with period range of 0.1-3.0 s with elastoplastic behavior considering soil structure interaction for 64 different earthquake motions recorded on different site conditions such as rock, stiff soil, soft soil and very soft soil. Soil structure interacting systems are modeled and analyzed with effective period, effective damping and effective ductility values differing from fixed-base case. For inelastic time history analyses, Newmark method for step by step time integration was adapted in an in-house computer program. Results are compared with those calculated for fixed-base case. A new equation is proposed for strength reduction factor of interacting system as a function of structural period of system (T), ductility ratio (${\mu}$) and period lengthening ratio (T/T). It is concluded that soil structure interaction reduces the strength reduction factors for soft soils, therefore, using the fixed-base strength reduction factors for interacting systems lead to non-conservative design forces.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.727-732
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• 2009

The objective of this study is to analyze and evaluate design factors relating to sound reduction performance in dry wall system. The main contents of this study are as follows. 1) Analysis and pre-evaluation of sound reduction performance of drywall system ; The sound reduction performance was pre-evaluated by INSUL simulation and these results of analyzing walls were analyzed by screening DOE(design of experiment) for selecting major factors that dominant influence the sound reduction performance. These main factors relating to sound reduction performance can be used for development of 1st grade sound reduction performance drywall system. 2) Design and evaluation of 1st grade sound reduction performance drywall system; The evaluation test of the sound reduction performance gave vaues higher than 1st grade (Rw+C=64). When campared with existing dry wall system, respectivelly, the new system shows performance higher than 8 dB.

• Computers and Concrete
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• v.19 no.6
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• pp.725-736
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• 2017

This paper presents the two-, three-, and four-lane transverse reduction factor based on FEA method, probability theory, and the recently actual traffic flow data. A total of 72 composite girder bridges with various spans, number of lanes, loading mode, and bridge type are analyzed with time-varying static load FEA method by ANSYS, and the probability models of vehicle load effects at arbitrary-time point are developed. Based on these probability models, in accordance to the principle of the same exceeding probability, the multi-lane transverse reduction factor of these composite girder bridges and the relationship between the multi-lane transverse reduction factor and the span of bridge are determined. Finally, the multi-lane transverse reduction factor obtained is compared with those from AASHTO LRFD, BS5400, JTG D60 or Eurocode. The results show that the vehicle load effect at arbitrary-time point follows lognormal distribution. The two-, three-, and four-lane transverse reduction factors calculated by using FEA method and probability respectively range between 0.781 and 1.027, 0.616 and 0.795, 0.468 and 0.645. Furthermore, a correlation between the FEA and AASHTO LRFD, BS5400, JTG D60 or Eurocode transverse reduction factors is made for composite girder bridges. For the two-, three-, and four-lane bridge cases, the Eurocode code underestimated the FEA transverse reduction factors by 27%, 25% and 13%, respectively. This underestimation is more pronounced in short-span bridges. The AASHTO LRFD, BS5400 and JTG D60 codes overestimated the FEA transverse reduction factors. The FEA results highlight the importance of considering span length in determining the multi-lane transverse reduction factors when designing two-lane or more composite girder bridges. This paper will assist bridge engineers in quantifying the adjustment factors used in analyzing and designing multi-lane composite girder bridges.

• Journal of the Korea Fashion and Costume Design Association
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• v.21 no.1
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• pp.73-85
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• 2019

The purpose of this study was to discover the effects of clothing involvement and risk perception, which can influence risk reduction behavior. The subjects of this study were young male consumers living in Seoul and Kyunggi-do who had purchased fashion products from an Internet shopping mall. Questionnaires were collected from July 1, 2018 to July 8, 2018 and 300 questionnaires were used in the data analysis. The data was analyzed utilizing a factor analysis, a regression, ANOVA and a Duncan-test. The results of this study were as follows. Clothing involvement factors influenced various risk perceptions and risk perception influenced risk reduction behaviors. Among the various risk perception factors, psychological risk was the most important factor, which was influenced by clothing involvement factors. The usage of media was the most important factor, which was influenced by various risk perception factors. Finally clothing involvement and risk perception influenced risk reduction behaviors. Among the various risk reduction factors, the usage of media was the most important factor, which was influenced by clothing involvement and risk perception factors.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.5
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• pp.634-643
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• 2007

This study was performed to develop a tailored multi-disciplinary obesity management program, as well as an obesity assessment sheet identified the general characteristics and psychological and environmental factors related to weight loss success for obese premenopausal women participating in obesity management programs performed at weight reduction health centers. The results are as follows. The primary general characteristics related to successful weight reduction in the obesity management programs were education level, occupational status, reason for obesity onset, aids used in weight control, basis of frequency, and reason for weight reduction. The initial psychological factors related to successful weight reduction were less stress and disordered eating. The initial environmental factors included an expression of ones opinion and the eating environment. Animal protein and animal fat consumption were significantly less in the unsuccessful group than in those who were unsuccessful at weight loss. The consumption of crude fiber was significantly greater in the successful group than in the unsuccessful group. Psychological factors such as stress, depression, and disordered eating, and the environmental factor of eating environment were significantly better in the successful group than in the unsuccessful group. In conclusion, we have found evidence to suggest what is required in determining the types of programs most suitable for obese women prior to starting an obesity management program.

• Journal of Korea Entertainment Industry Association
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• v.14 no.4
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• pp.381-392
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• 2020

This study identified the impact of environmental factors and job satisfaction of health organization workers on a reduction rate depending on their lifestyles. The research used 575 questionnaires as final assay data, which were obtained by health care workers who work for hospitals or higher-level hospitals, which are located in Jeolla-do through direct survey method. The results are as follows. First, with the result, which is an analysis of differences in environmental factors, job satisfaction, and reduction rates (inpatient/outpatient), there was a significant difference in the environmental factors of medical institutions based on the age, marital status, job position, and the years of employment, and there was also a significant difference in job satisfaction based on the age, academic career, marital status, occupational description, and monthly income. In an inpatient reduction rate, a significant difference was shown in the age, academic career, and occupational description. In an outpatient reduction rate, a significant difference was shown in the age, marital status, job position, and the years of employment. Second, with the results of correlation analysis, which are determinations of a relationship between environmental factors, job satisfaction, and reduction rate, it was figured out that there is a negative correlation between inpatient reduction rate and job satisfaction, a negative correlation between inpatient reduction rate and the environmental factors, and also a negative correlation between outpatient reduction rate and job satisfaction. There is a significant positive correlation between the outpatient reduction rate and environmental factors, and between job satisfaction and environmental factors. Third, with the results of the impacts that the environmental factors and job satisfaction have on the reduction rate, there was a negative influence of the environmental factors on the inpatient reduction rate, and also a negative influence of job satisfaction on the inpatient reduction rate. There was a significant positive influence of the environmental factors on the outpatient reduction rate, but there was no negative influence of job satisfaction on the outpatient reduction rate.

• Journal of the Ergonomics Society of Korea
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• v.36 no.5
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• pp.559-568
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• 2017

Objective: The aim of this study is to investigate the effective managerial factors influencing dose reduction of the nozzle dam installation and removal tasks ranking within top 3 in viewpoint of average collective dose of nuclear power plant maintenance job. Background: International Commission on Radiation Protection (ICRP) recommended to reduce unnecessary dose and to minimize the necessary dose on the participants of maintenance job in radiation fields. Method: Seven sessions of nozzle dam installation and removal task logs yielded a multiple regression model with collective dose as a dependent variable and work time, number of participants, space doses before and after shield as independent variables. From the sessions in which a significant reduction in collective dose occurred, the effective managerial factors were elicited. Results: Work time was the most important factor contributing to collective dose reduction of nozzle dam installation and removal task. Introduction of new technology in nozzle dam design or maintenance job is the most important factor for work time reduction. Conclusion: With extended task logs and big data processing technique, the more accurate prediction model illustrating the relationship between collective dose reduction and effective managerial factors would be developed. Application: The effective managerial factors will be useful to reduce collective dose of decommissioning tasks as well as regular preventive maintenance tasks for a nuclear power plant.

• Journal of environmental and Sanitary engineering
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• v.18 no.2
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• pp.27-33
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• 2003

This survey was performed to investigate the NOx emission factors at 3 Municipal Solid Waste Incinerators(MSWI) and 5 Power generation boilers in Seoul. The NOx concentrations were measured before and after control systems. The results were as follows. 1) The NOx reduction efficiencies of Selective Catalytic Reduction (SCR) using ammonia as reducing agent ranged from 53.7% to 89.9%. The NOx reduction efficiencies of SCR using methanol as reducing agent, Non- Selective Catalytic Reduction (NSCR) using ethanol as reducing agent and low-NOx burner were 20.8%, 29.1% and 24.7%, respectively. 2) The NOx emission factors at A-1, A-2 and A-3 facilities of MSWI were 0.786, 0.127 and 0.594 kg Nox/ton fuel, respectively. The factors of A-1 and A-3 facilities were higher than the average value of Korea. 3) The NOx emission factors at B-1, B-2, B-3, B-4 and B-5 facilities of Power generation boiler were 2.109, 0.726, 4.106, 8.378 and 5.168 kg Nox/ton fuel, respectively. The factors of B-4 and B-5 facilities were higher than the average value of Korea.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.609-621
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• 2020

This study identified the impacts of organizational commitment on medical service reduction rates by lifestyles of medical institution workers with a medium of environmental factors in a medical institution, and it conducted a survey targeting 300 medical institution workers in Jeolla-do, South Korea. The results are as follows. First, there was a significant difference in an organizational commitment by sociodemographic characteristics based on age, academic career, gender, marital status, occupational description, monthly earnings, the years of employment, and the type of hospital. Second, there was a significant difference in environmental factors by sociodemographic characteristics based on marital status, the years of employment, and the type of hospital. Third, there was a significant difference in the inpatient reduction rate based on the occupational description, years of employment, and the type of hospital. In the outpatient reduction rate, a significant difference was shown based on age, marital status, occupational description, the years of employment, and the type of hospital. Fourth, when analyzing the relationship between organizational commitment, environmental factors, and the reduction rate, there was a significant positive correlation between inpatient reduction rate and outpatient reduction rate. Fifth, when analyzing the impacts on the inpatient reduction rate by deploying organizational commitment and environmental factors at the same time, it was shown that the environmental factors mediated partially in organizational commitment and inpatient reduction rate. In the case of outpatient reduction rate, it was shown that the environmental factors mediated completely in organizational commitment and outpatient reduction rate. The present study is aimed to contribute to providing the baseline data for an efficient operational plan and effective workforce management of medical institutions.