• Environmental and Resource Economics Review
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• v.14 no.1
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• pp.167-199
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• 2005

The following policy implications can be drawn from this study: 1) The Air Pollution Emission Amount Report published by the Ministry of Environment since 1991 classifies industries into 4 sectors, i. e., heating, manufacturing, transportation and power generation. Currently, the usability of report is very low and extra efforts should be given to refine the current statistics and to improve the industrial classification. 2) Big pollution industries are as follows - s7, s17 and s20. The current air pollution control policy for these sectors compared to other sectors are found to be inefficient. This finding should be noted in the implementation of future air pollution policy. 3) s10 and s17 are found to be a big polluting industrial sector and its pollution reduction effect is also significant. 4) The effect of emission coefficient (${\Delta}f$) has the biggest impact on the reduction of emission amount change and the effect of economic growth coefficient (${\Delta}y$) has the biggest impact on the increase of emission volume. The effect of production technology factor (${\Delta}D$) and the effect of the change of the final demand structure (${\Delta}u$) are insignificant in terms of the change of emission volume. 5) Further studies on emission estimation techniques on each industry sector and the economic analysis are required to promote effective enforcement of the total volume control system of air pollutants, the differential management of pollution causing industrial sectors and the integration of environment and economy. 6) Korea's economic growth in 1990 is not pollution-driven in terms of the Barry Commoner's hypothesis, even though the overall industrial structure and the demand structure are not environmentally friendly. It indicates that environmental policies for the improvement of air quality depend mainly on the government initiatives and systematic national level consideration of industrial structures and the development of green technologies are not fully incorporated.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.31-37
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• 2017

In this paper, we implemented for the development of a high output induction lamp system, which lamp design is optimized by gas type, mixing ratio, pressure and discharge tube size, amalgam type and mixing ratio, and characteristics of ferrite core in the lamp. It's the circuit design by improving the power factor and efficiency according to the driving method, which has analyzing the characteristics according to the waveform and frequency. Finally, luminaries design part for applying the optimal lighting system considering the surrounding environment, the characteristics of the lighting circuit for electrodeless lamp has analyzed and the improvement has been proceeded. In conclusion, the driving frequency has optimized at 135kHz with degrading $7{\sim}10^{\circ}C$ based on the results of the optical characteristics of the induction lamp on peak noise FET(Q3,Q4) damage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8700-8706
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• 2015

The first driving device of the power bogies for the Korean high-speed railway vehicle consists of the traction motor (TM) and the motor reduction gears unit (MRU). Although TM and MRU are the mechanically integrated structures, their time between overhauls (TBO) have two separate intervals due to different technical requirements(i.e. TBO of MRU: $1.8{\times}10^6km$, TBO of TM: $2.5{\times}10^6km$). Therefore, to reduce the unnecessary number of preventive maintenances, it is important to evaluate the optimal TBO with a viewpoint of reliability-center maintenance towards cost-effective solution. In this study, derived from the field data in maintenance, fault tree analysis and failure rate of the subsystem considering criticality of the components are evaluated respectively. To minimize the conventional total maintenance cost, the same optimal TBO of the components is derived from genetic algorithm considering target reliability and improvement factor. In this algorithm, a chromosome which comprised of each individual is the minimum preventive maintenance interval. The fitness function of the individual in generation is acquired through the formulation using an inverse number of the total maintenance cost. Whereas the lowest common multiple method produces only a four percent reduction compared to what the existing method did, the optimal TBO of them using genetic algorithm is $2.25{\times}10^6$km, which is reduced to about 14% comparing the conventional method.

• Clinics in Shoulder and Elbow
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• v.3 no.2
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• pp.61-67
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• 2000

Purpose: Most proximal humeral fractures are minimally displaced and can be treated satisfactorily with a conservative method. But in many comminuted fractures, hemiarthroplasty is usually done as a primary treatment. The authors evaluated how much functional improvement was achieved after hemiarthroplasty and which factors influence on the final functional results. Materials and Methods: Eleven hemiarthroplasties were performed for three- and four-part fractures(including fracture-dislocation) between April 1992 and June 1999. There were eight women and three men, and the mean age was 65 years. According to Neer classification, six was three-part fracture and five was four-part fracture. Six patients were injured on their right shoulder and five on the left shoulder. Among the five four-part fractures, three had axillary nerve injury and among the six three-part fractures, only one patient had axillary nerve injury. The average follow-up period was 2.4 years(1 year-7 years) after operation. The functional results were evaluated with the UCLA scoring system(Modification for hemiarthroplasty). In addition to the overall results, we compared the results according to the classification of the fracture, the cause of injury, and whether the axillary nerve was injured. Results: At the last follow-up, average total UCLA score was 18.2. The mean score for pain was 7.0, mean muscle power and motion score was 5.5 and 5.7 respectively. The pain relief was more satisfactory than any other functional results. The average score for three-part fractures was 22, and the average for four-part fractures was 13.6. The average score for the patients fractured by vehicle accidents was 15.3, and 19.3 for the patients fractured by slip-down injury. In patients without axillary nerve injury, the average score was 20, and with axillary nerve injury, the score was 15. Conclusion: Shoulder hemiarthroplasty, for the treatment of proximal humeral fractures, cannot restore the shoulder function to normal, but can achieve the functional result to some degree, especially for the activity of daily living. And as for pain, we think that it is relatively effective measure. And we think that the severer the comminution, the more the chance of axillary nerve injury, and the poorer the functional results. In conclusion, the severity of initial injury seems to be the major prognostic factor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.314-323
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• 2019

This study examined the factors affecting clinical practice adaptation to provide basic data for the improvement of clinical practice adaptation for the first year of clinical practice. The subjects were 153 nursing students and medical students in G-do. Data were collected from April 1 to April 30, 2019, and analyzed using a t-test, ANOVA, Pearson correlation coefficient, and multiple regression using IBM SPSS WIN/21.0. The mean of college adjustment, character, interpersonal competence, communicative competence, and clinical practice adaptation was 3.37 points, 3.82, 3.61, 3.56, and 3.54, respectively. Clinical practice adaptation was related to college adjustment, character, interpersonal competence, and communicative competence (p<.001). The most influential factor in clinical practice was interpersonal competence (β=.502, p<.001), followed by department adaptation (β=-.215, p<.001) and college adjustment (β=.174, p=.010), respectively. The explanatory power was 41.1% (F=34.11, p<.001). Therefore, a way to improve interpersonal competence is needed to advance clinical practice adaptation. In the character building program for adjustment to college life, systematic education is needed, including the opportunity to think about and understand oneself, continuous meeting to understand and accept others. In addition, repeated communication training to improve interpersonal competence is needed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.145-160
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• 2018

Long subsea tunnel is subject to many restrictions in terms of spatial limitation when vertical or inclined shafts are built for tunnel ventilation. So, the construction of some artificial island is required to provide ventilation. But, because of construction difficulty and cost increase, it is necessary to minimize the artificial island construction. As a result, ventilation distance become longer and supply airflow becomes excessive due to air leakage, So, duct mounting for temporary ventilation is impossible or fan pressure and power increase exponentially. Therefore, in order to build a long subsea tunnel, it is necessary to overcome these practical problems and to develop technical solution that can keep the comfortable condition of tunnel environment during construction. In previous study, we have found that air leakage is the key factor in solving these problems and experimental results show that the new connection method has a leakage rate of about $1.46mm^2/m^2$ (Jo et al., 2017). In this study, we present the experimental results of the measurement of the leakage rate of the prototype with the new connection method, and analyze experimentally the improvement of the leakage rate when applying the flexible cover inside the duct to improve the leakage performance of the existing connection method.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.2
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• pp.63-67
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• 2010

The organic solar cells with Glass/ITO/PEDOT:PSS/P3HT:PCBM/Al structure were fabricated using regioregular poly (3-hexylthiophene) (P3HT) polymer:(6,6)- phenyl $C_{61}$-butyric acid methyl ester (PCBM) fullerene polymer as the bulk hetero-junction layer. The P3HT and PCBM as the electron donor and acceptor materials were spin casted on the indium tin oxide (ITO) coated glass substrates. The optimum mixing concentration ratio of photovoltaic layer was found to be P3HT:PCBM = 4:4 in wt%, indicating that the short circuit current density ($J_{SC}$), open circuit voltage ($V_{OC}$), fill factor (FF) and power conversion efficiency (PCE) values were about 4.7 $mA/cm^2$, 0.48 V, 43.1% and 0.97%, respectively. To investigate the effects of the post annealing treatment, as prepared organic solar cells were post annealed at the treatment time range from 5min to 20min at $150^{\circ}C$. $J_{SC}$ and $V_{OC}$ increased with increasing the post annealing time from 5min to 15min, which may be originated from the improvement of the light absorption coefficient of P3HT and improved ohmic contact between photo voltaic layer and Al electrode. The maximum $J_{SC},\;V_{OC}$, FF and PCE values of organic solar cell, which was post annealed for 15min at $150^{\circ}C$, were found to be about 7.8 $mA/cm^2$, 0.55 V, 47% and 2.0%, respectively.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.659-664
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• 2009

LNG carriers have, up to 2006, mainly been driven by steam turbines. The Boil-Off Gas from the LNG cargo tanks has so far been used as fuel. This is a costly solution that requires special skills during construction and operation. Alternative propulsion systems offer far better fuel economical efficiency than steam turbines. Instead of previous practice using Boil-Off Gas as a fuel, the Re-liquefaction system establishes a solution to liquefy the Boil-Off Gas and return the LNG to the cargo tanks. This Re-liquefaction of Boil-Off Gases on LNG carriers results in increased cargo deliveries and allows owners and operators to choose the most optimum propulsion system. In this study, thermodynamic cycle analysis has been performed on two type of LNG Re-liquefaction system which was designed and adopted for the Q-Flex(216,000$m^3$) and Q-Max(266,000$m^3$) LNG carrier under construction at Korea ship yards and variable key factor was simulated to compare efficiency, power and nitrogen consumption of each Re-liquefaction system.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.453-463
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• 2017

Due to the increase in the size of buildings and scale, the importance of construction engineering that reflects the constructability from the design stage of the project is increasing. Especially, engineering efforts related to facilities, equipment and construction methods for temporary work at the design stage can significantly contribute to improvement of constructability and project performance. The purpose of this study is to derive construction engineering tasks on temporary work at the design phase of the high-rise building projects. 27 preliminary tasks were firstly investigated through literature review and experts' group interview, and the necessity and importance analysis of each tasks were then performed based on questionnaire survey. Most of the tasks related to plans on structural framework and lifting equipment were analyzed as relatively more important ones. Lastly, 21 engineering tasks, which are classified into 5 factors, were proposed through factor analysis. The factors were determined as 1) structural framework, measurement and circulation, 2) lifting equipment and pumping, 3) space zoning, 4) water supply, 5) temporary facility, electric power supply and lighting. The results of this study can be used as basic data for establishing efficient work process of construction engineering on temporary work at the design phase.

• The Journal of the Korea Contents Association
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• v.19 no.11
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• pp.325-336
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• 2019

The purpose of this study is to analyze the structural relationship between internal capabilities and job satisfaction using the 7S model and propose measures to improve management performance through internal factors. For this study, seven research hypotheses were set up, and the survey conducted among members of all professions working in general hospitals in small and medium-sized cities in the provinces. From September 20 to October 20, 2016, 385 people were surveyed, and 327 pieces of data (84.9%) used for the study. Multiple regression analyses were performed to verify the effects of internal capabilities on job satisfaction. The analysis results showed that the explanatory power of the research model was suitable by showing 69.1%, and among the 7S factors, the leadership style (β=.392^**), the organizational structure (β=.129^*), the membership (β=.232^**), and the management technique (β=.204^*) showed a positive influence on job satisfaction. That has been confirmed to affect job satisfaction as the standardized factor values increase. Relationships between strategies, systems, and shared values on job satisfaction could not be identified. Significantly observed in the relationship between some internal capacity factors and job satisfaction is that internal capacity can be used as an alternative to an organization's performance improvement measures. Internal capacity can be affected by various environmental variables, such as establishment classification, size, and location. Further implications will also be provided for measuring future internal satisfaction levels separately from internal and external factors.