• Journal of ILASS-Korea
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• v.21 no.1
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• pp.7-12
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• 2016

In this study, to research in-cylinder flow characteristics of spark-ignited engine with intake valve closing timing change for Miller cycle. 3D simulation study were used 6 different intake valve profile with $CAD10^{\circ}$ gap for retard intake valve closing timing. Comparison of In-cylinder flow pattern characteristic were accompanied between Base and LIVC. And the efficiency of volume and the work of compression were analyzed with simulation study. When intake valve closing angle was retarded in $CAD50^{\circ}$, the pressure in cylinder was decreased about 12~13 bar and volume efficiency was reduced about 16%. The efficiency of volume and the work of compression were reduced on LIVC.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.2
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• pp.90-99
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• 1999

Fume extracting welding gun is one of the promising options for reducing the welder's fume exposure. The performance of the gun was assessed on the basis of capture efficiency. Capture efficiencies were measured in a test chamber recommended by American Welding Society. The overall capture efficiency was turned out to be above 95%. But it did not include the effect of crossdraft existing in the real work environment because all experiments were conducted in a closed chamber. It thus needs more work in the future. In addition, the future directions for improving the pres ent commercial techniques of the gun were discussed.

• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.58-66
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• 2015

This paper aims to compare the use of Centrifugal Turbine and Tesla Turbine in an application of Organic Rankine Cycle (ORC) Machine using Isopentane as working fluid expanding. The working fluid has boiling point below boiling water and works in low-temperature sources between $80-120^{\circ}C$ which can be produced from waste heat, solar-thermal energy and geothermal energy etc. The experiment on ORC machine reveals that the suitability of high pressure pump for working fluid has result on the efficiency of work. In addition, Thermodynamics theory on P-h diagram also presented the effect of heat sources' temperature and flow rate on any work. Thus, the study and design on ORC machine has to concern mainly on pressure pump, flow rate and optimized temperature. Result experiment and calculate ORC Machine using centrifugal Turbine efficiency better than Tesla turbine 30% but Tesla Turbine is cheaper and easily structure. Further study on the machine can be developed throughout the county due to its low cost and efficiency.

• The Journal of the Korea Contents Association
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• v.19 no.5
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• pp.64-73
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• 2019

This study analyzed the efficiency by using the DEA model to evaluate the competitiveness of specialty construction firms. The target of the analysis is 300 firms with continuous data from 2010 to 2017 as listed and externally listed firms. Significant analysis results are as follows. First, the efficiency of specialty construction firms is lower than that of general construction industry. Second, efficiency by type was highest in facilities construction and dismantling work. This shows that the relevant industries such as reinforced concrete works and scaffolding and demolition work are relatively efficient in specialty construction industry. Third, the efficiency of specialty construction industry is affected by economic fluctuations. When the construction industry is in the expansion phase, the efficiency value is high and the efficiency value is low in the down phase. Finally, in the scale profitability analysis, specialty construction industry was most analyzed by DRS. This means that it is effective to scale down for the efficiency of the firm.

• Korean Journal of Materials Research
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• v.21 no.9
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• pp.491-496
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• 2011

Transparent conducting oxides (TCOs) used in the antireflection layer and current spreading layer of heterojunction solar cells should have excellent optical and electrical properties. Furthermore, TCOs need a high work function over 5.2 eV to prevent the effect of emitter band-bending caused by the difference in work function between emitter and TCOs. Sn-doped $In_2O_3$ (ITO) film is a highly promising material as a TCO due to its excellent optical and electrical properties. However, ITO films have a low work function of about 4.8 eV. This low work function of ITO films leads to deterioration of the conversion efficiency of solar cells. In this work, ITO films with various Zn contents of 0, 6.9, 12.7, 28.8, and 36.6 at.% were fabricated by a co-sputtering method using ITO and AZO targets at room temperature. The optical and electrical properties of Zn-doped ITO thin films were analyzed. Then, silicon heterojunction solar cells with these films were fabricated. The 12.7 at% Zn-doped ITO films show the highest hall mobility of 35.71 $cm^2$/Vsec. With increasing Zn content over 12.7, the hall mobility decreases. Although a small addition of Zn content increased the work function, further addition of Zn content over 12.7 at.% led to decreasing electrical properties because of the decrease in the carrier concentration and hall mobility. Silicon heterojunction solar cells with 12.7 at% Zn-doped ITO thin films showed the highest conversion efficiency of 15.8%.

• Journal of Venture Innovation
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• v.5 no.4
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• pp.41-56
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• 2022

This study was conducted to empirically analyze the effect of various job characteristics on job satisfaction under the smart work environment, which has become a hot topic recently. To this end, job characteristics under the smart work environment were subdivided into job autonomy, job flexibility, and job efficiency. In addition, although these job characteristics had a direct effect on job satisfaction, the learning agility of employees was also considered to be important factors. Job autonomy, job flexibility, and job efficiency all had a significant positive (+) effect on job satisfaction. In the case of learning agility, it was found that there was a mediating effect in all paths. The results of this study had academic significance in that they empirically tested the relationship between job characteristics of smart work and job satisfaction according to the progress to contact free society..

• Journal of Information Technology Services
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• v.13 no.4
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• pp.65-78
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• 2014

In this study, I explored the causal relationship between acceptance attitudes and the expected effects of smart work. With the rapid development of smart technologies, lots of organizations try to innovate in the conventional working styles for maximizing organizational effectiveness and efficiency. Although many organizations wish to foster smart working environment, they don't have confidence in detailed action plans and effects from it. Therefore, this study that explores the causal relationship between acceptance attitudes and effects may have crucial meaning to organizations pursuing smart work. In this research empirically conducted by questionnaire survey, the acceptance attitudes as predictors and the expected effects of smart work as influenced variables were used. This research analyzed 118 collected data and multiple regression analysis. As a result of analysis, teleworking shows the positive relations to all of dependent variables. And others have a positive or negative influence on cognitive effects of smart work. Results of this study may give implications to organizations that want to implement smart work environment.

• Journal of Information Technology Applications and Management
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• v.21 no.1
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• pp.151-163
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• 2014

This paper explores the causal relationship between acceptance attitudes and expected effects of smart work. With the rapid development of smart technologies, lots of organizations try to innovate in the conventional working styles for maximizing organizational effectiveness and efficiency. Although many organizations wish to foster smart working environment, they don't have confidence in detailed action plans and effects from it. Therefore, this study that explores the causal relationship between acceptance attitudes and effects may have crucial meaning to organizations pursuing smart work. In this research empirically conducted by questionnaire survey, the acceptance attitudes as predictors and the expected effects of smart work as influenced variables were used. This research analyzed 118 collected data and multiple regression analysis. As a result of analysis, teleworking shows the positive relations to all of dependent variables. And others have a positive or negative influence on effects of smart work. Results of this study may give implications to organizations that want to implement smart work environment.

• Management & Information Systems Review
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• v.13
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• pp.141-162
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• 2003

This article discusses the issues of the estimated size and characteristics of irregular employment work force in Korea after IMF economic crisis in 1997. The issues of the estimated size of irregular employment work force originated from different concepts and its operationalizations among the labor economists, despite their utilization of the same labor force data, 'Economically Active Population Survey(EAPA)' collected from Korea National Statistical Office(KNSO). And the issues contribute toward the understandings of the irregular employment and the limits of the EAPA, despite its various usefulness. This article also describes the summary characteristics of irregular employment work force from both sides of labor supply and its demand. The major characteristics of irregular employment work force on the labor supply side appears in the concentration of social minorities, i.e. woman, the aged, lower educated and skilled populations. On the labor demand of irregular employment work force, the majority of it concentrated on the establishments under 10 employees, and probably the important incentives for irregular employment work force of the firms is labor cost efficiency. Finally, this article propose an alternative against the discrimination between the regular and irregular work force.

• Journal of Families and Better Life
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• v.10 no.2
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• pp.99-112
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• 1992

This research was designed to illuminate that work domains and family domains are not separated but interacting spheres and to suggest efficient coping strategies than alleviate work/family role conflicts. The subjects of this study were 395 employed professional wives living in Seoul. Korea. Survey methods were questionnaires. Data analysis strategies were percentile, frequency, one-way-anova and multiple classification analysis. The results were as follows; 1)Employed wives experienced time-based conflicts and strain-based role conflicts. This finding supports the scarcity approach that multiple roles inevitably create strain. 2) Individual, family and work-related variables were predictors of work/family role conflicts. This findings indicate that work domains and family domains cannot be regraded as separated spheres. 3) Employed wives tried to meet all the given roles demands not by reducing role responsibilities, but by increasing the efficiency of role performance. This finding reflects the characteristics of employed wives who try to perform successfully all the responsibilities. 4)The negative correlation of coping strategies and work/family role conflicts suggests that strategies can function effectively in alleviating the work/family role conflicts.