• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.5
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• pp.370-376
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• 2004

The overall aim of this paper is to determine coupling loss factor of welding point between shell and cylinder using loss factor and structural loss factor. For this purpose, two kinds of loss factor were adopted. One is loss factor of each sub structure, another is structural loss factor based on the complex welded or assembled structure. Using these two parameters, it ispossible to derive the coupling loss factor which represent characteristic condition of SEA theory. Coupling loss factor of conjunction in complex structure was expressed as power balance equation. The derived equation for a coupling loss factor has been simplified on the assumption of one way (uni-directional) power flow between multi-sub structures. Using these conditions, it is possible to find the equation of coupling loss factor expressed as above two loss factors. To check the effectiveness of above equation, this paper used two-stage application. The first approach was application between simple cylinder and shell. The next was adopted rotary compressor. Rotary compressor has three main conjunctions between shell and internal vibration part. This equation was applied to find out the optimum welding point with respect to reduce the noise propagation. It shows the effective tool to evaluate the coupling loss factor in complex structure

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.969-972
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• 2003

The overall aim of this paper is to determine coupling loss factor of welding point between shell and cylinder using loss factor and structural loss factor. For this purpose, two kinds of loss factor were adopted. One is loss factor of each sub structure, another is structural loss factor based on the complex welded or assembled structure. Using these two parameters, it is possible to derive the coupling loss factor which represent characteristic condition of SEA theory. Coupling loss factor of conjunction in complex structure was expressed as power balance equation. The derived equation for a coupling loss factor has been simplified on the assumption of one way(nl- directional) power flow between multi-sub structures. Using these conditions, it is possible to find the equation of coupling loss factor expressed as above two loss factors. To check the effectiveness of above equation, this paper used two stage application. The first approach was application between simple cylinder and shell. The next was adopted rotary compressor. Rotary compressor has three main conjunctions between shell and internal vibration part. This equation was applied to find out the optimum welding Point with respect to reduce the noise propagation. It shows the effective tool to evaluate the coupling loss factor in complex structure

• Physical Therapy Korea
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• v.25 no.2
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• pp.22-29
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• 2018

Background: Deficits of both ankle dorsiflexion range of motion (DFROM) and dynamic balance are shown in persons with chronic ankle instability and the elderly, with the risk of falls. Objects: This study aims to investigate the relationship between DFROM and dynamic balance in elderly subjects and young adults. Methods: Fifty-nine subjects were divided into three groups: ankle stability young group (SY), ankle instability young group (IY) and ankle stability older group (SO). We recruited three old subjects with ankle instability, but excluded them during a pilot testing due to the safety issue. DFROM was measured by weight bearing lunge test (WBLT) and dynamic balance was measured via star excursion balance test (SEBT) in anteromedial, medial, and posteromedial directions. The group differences in WBLT and SEBT and each group's correlation between WBLT and SEBT were detected using the R statistical software package. Results: The dorsiflexion range of motion was significantly different between the SY, IY, and SO groups. The SO group showed the highest DFROM and IY group showed the lowest DFROM (SY: $45.88{\pm}.66^{\circ}$, IY: $39.53{\pm}1.63^{\circ}$, SO: $47.94{\pm}.50^{\circ}$; p<.001). However, the SO group showed the lowest dynamic balance score for all SEBT directions (SY: $87.24{\pm}2.05cm$, IY: $83.20{\pm}1.30cm$, SO: $77.23{\pm}2.07cm$; p<.05) and there was no relationship between the dorsiflexion range of motion and dynamic balance in any group. Conclusion: Our findings suggest that ankle DFROM is not a crucial factor for dynamic stability regardless of aging and ankle instability. Other factors such as muscle strength or movement coordination should be considered for training dynamic balance. Therefore, we need to establish the rehabilitation process by measuring and treating ROM, balance, and muscle strength when treating young adults with and without ankle instability as well as elderly people.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.5
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• pp.77-87
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• 2018

The Purpose of This study is amid competition, High-quality human resources in food service industry make a lot of efforts. Especially, Work and Life Balance(WLB) is a considerable factor when modern workers decide and maintain the workplace and also it could be supposed as one strategic method that corporations could attract and maintain talented people. This study built a exploratory model that there is causal relationship of WLB(work and life balance) to employee's organizational commitment. Additionally this study examine the Moderating Effect of perceived value of work between WLB(work and life balance) and organizational commitment. This study utilized total 217 responses from workers of food service industrial employees and as analysis methods, it used descriptive statistic analysis, correlation analysis, multiple regression analysis, and hierarchical analysis. Results of analysis are as follows. First this study found that the work-life balance could give significant effects to the organizational commitment. work-growth balance and work-leisure balance has positive significance effect with the organizational commitment but work-family balance was not statistically significant. Second, The significance of this study indicates that perceived value of work plays a role as moderating variable influencing the relationship between work and growth balance and employee organizational commitment. Lastly, this study suggested the implication of the result, the limitation and the direction of future study. The results of this study provide suggestion to the company.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.178-184
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• 2021

This study was conducted to empirically verify the factors that affect work-life balance according to the age of social workers. The subjects of the study were social workers working at social welfare centers, welfare centers for the disabled, and welfare centers for the elderly located in Jeollabuk-do, and 313 copies of 42 facilities that participated in the survey were used for the final analysis. The research method used a multi-level model that calculated individual factors (Level 1) and institutional factors (Level 2). The main research results are as follows. First, 20.2% of the total variance in the work-life balance of social workers was found to be different for each local welfare center. Second, as a result of examining the factors affecting work-life balance of social workers by age, it was found that job demands had a negative effect on work-life balance in all age groups. In particular, in their 30s, family demands and women's work-life balance were more negative than men's, and economic status was found to be an important influencing factor on work-life balance. Based on these results, we discussed ways to improve work-life balance for social workers.

• Journal of Environmental Science International
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• v.17 no.10
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• pp.1069-1073
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• 2008

Indoor air quality can be affected by indoor sources, ventilation, decay and outdoor levels. Although technologies exist to measure these factors, direct measurements are often difficult. The purpose of this study was to develop an alternative method to characterize indoor environmental factors by multiple indoor and outdoor measurements. Using a mass balance model and regression analysis, penetration factor (ventilation rate divided by the sum of ventilation rate and deposition constant) and source strength factor (source strength divided by the sum of ventilation rate and deposition constant) were calculated using multiple indoor and outdoor measurements. Subsequently, the ventilation rate and $NO_2$ generation rate were estimated. Mean of ventilation rate was 1.41 ACH in houses, assuming a residential N02 deposition constant of 0.94 $hr^{-1}$. Mean generation rate of $NO_2$ was 16.5 ppbv/hr. According to house characterization, inside smoking and family number were higher $NO_2$ generation rates, and apartment was higher than single-family house. In conclusion, indoor environmental factors were effectively characterized by this method using multiple indoor and outdoor measurements.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.1
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• pp.22-28
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• 2010

Approximate analysis for a building installed with a friction damper is performed to get insight of its dynamic behavior. Energy balance equation is used to have a closed analytical form solution of dynamic magnification factor(DMF). It is found out that DMF is dependent on friction force ratio and resonance frequency. Approximation of DMF and equivalent damping ratio of a friction damper is proposed with such assumption that the building with a friction damper shows harmonic steady-state response and narrow banded response behavior near resonance frequency. Linear transfer function from input external force to output building displacement is suggested from the simplified DMF equation. Root mean square of a building displacement is derived under earthquake-like random excitation. Finally, design procedure of a friction damper is proposed by finding friction force corresponding to target control ratio. Numerical analysis is carried out to verify the proposed design procedure.

• Structural Engineering and Mechanics
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• v.63 no.1
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• pp.23-35
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• 2017

A nonlinear static procedure considering work-energy principle and global failure mechanism to estimate base shears of reinforced concrete (RC) frame-type structures is presented. The relative energy equation comprising of elastic vibrational energy, plastic strain energy and seismic input energy is obtained. The input energy is modified with a factor depending on damping ratio and ductility, and the energy that contributes to damage is obtained. The plastic energy is decreased with a factor to consider the reduced hysteretic behavior of RC members. Given the pre-selected failure mechanism, the modified energy balance equality is written using various approximations for modification factors of input energy and plastic energy in scientific literature. External work done by the design lateral forces distributed to story levels in accordance with Turkish Seismic Design Code is calculated considering the target plastic drift. Equating the plastic energy obtained from energy balance to external work done by the equivalent inertia forces considering, a total of 16 energy-based base shears for each frame are derived considering different combinations of modification factors. Ductility related parameters of modification factors are determined from pushover analysis. Relative input energy of multi degree of freedom (MDOF) system is approximated by using the modal-energy-decomposition approach. Energy-based design base shears are compared with those obtained from nonlinear time history (NLTH) analysis using recorded accelerograms. It is found that some of the energy-based base shears are in reasonable agreement with the mean base shear obtained from NLTH analysis.

• Journal of the Korea Computer Industry Society
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• v.2 no.2
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• pp.203-210
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• 2001

To estimate relational models and test the theoretical hypotheses of binary tree search algorithms, we built binary search trees with random permutations of n (number of nodes) distinct numbers, which ranged from three to seven. Probabilities for building binary search trees corresponding to each possible height and balance factor were estimated. Regression models with variables of number of nodes, height, and average number of comparisons were estimated and the theorem of O(1g(n)) was accepted experimentally by a Lack of Test procedure. Analysis of Variance model was applied to compare the average number of comparisons with three groups by height and balance factor of the trees to test theoretical hypotheses of a binary search tree performance statistically.

• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.183-192
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• 2002

Indoor air quality is affected by source strength of pollutants, ventilation rate, decay rate, outdoor level and so on. Although technologies exist to measure these factors directly, direct measurements of all factors are impractical in most field studies. The purpose of this study was to develop an alternative methods to estimate these factors by multiple measurements. Daily indoor and outdoor NO$_2$concentrations for 21 days in 20 houses in summer and winter, Seoul. Using a mass balance model and linear regression analysis, penetration factor (ventilation divided by sum of air exchange rate and deposition constant) and source strength factor(emission rate divided by sum of air exchange rate and deposition constant) were calculated. Subsequently, the ventilation and source strength were estimated. During sampling period, geometric mean of natural ventilation was estimated to be 1.10$\pm$1.53 ACH, assuming a residential NO$_2$decay rate of 0.8 hr$^{-1}$ in summer. In winter, natural ventilation was 0.75$\pm$1.31 ACH. And mean source strengths in summer and winter were 14.8ppb/hr and 22.4ppb/hr, respectively. Although the method showed similar finding previous studies, the study did not measure ACH or the source strength of the house directly. As validation of natural ventilations, infiltrations were measured with $CO_2$tracer gas in 18 houses. Relationship between ventilation and infiltration was statistically correlated (Pearson r=0.63, p=0.02).