• Korea Trade Review
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• v.46 no.2
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• pp.323-335
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• 2021

With the advent of the 4th Industrial Revolution, there is a rising interest in the impact of these changes on Korea's trade. While the previous studies related to the 4th Industrial Revolution are very limited in the field of trade research, this study attempts an empirical analysis regarding the effect of the use of the 4th Industrial Revolution technology on the performance of exporters, based on the data of the Survey of Business Activities during 2017-2019 by the Korean government statistical office. Through the empirical analysis in combination with the propensity score matching (PSM) and the difference-in-difference (DID) analysis, this research confirms that the use of the 4th Industrial Revolution technology has a positive effect on the export performance of Korean exporters.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.7
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• pp.419-428
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• 2010

This paper presents the optimization process of liquid desiccant cooling system using LiCl aqueous solution as a working fluid. Operating conditions(mass flow rate, conditioner outlet concentration, difference concentration) and design factors for heat exchangers(difference temperature of the district heating water, leaving temperature difference of the conditioner, leaving temperature difference of the regenerator, air temperature difference of the conditioner, air temperature difference of the regenerator) were optimized by response surface method. As a result, we obtained the 7.297 kW of cooling capacity and 0.788 of COP at optimized condition. Effect of difference temperature of hot water on system performances was also examined. As difference temperature of the district heating water increases, the cooling capacity increases and COP decreases.

• Journal of Korean Public Health Nursing
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• v.10 no.2
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• pp.37-50
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• 1996

To analyze the roles by abilities between manpower through the analysis of industrial health service agency personnel, 115 industrial health service agency personnel in 19 Industrial Health Service Agency personnel scattered in Seoul and Kyungki areas have been investigated according to the questionnaires formulated in line with the Likert 5-point scale from September 1 through October 30, 1995 and the following significant result has been obtained: 1. The job abilities by fields. 1) In the field of health care, the level of medical personnel's job ability was 3.30 on average and that of industrial hygienists' was 2.54 on average, which showed that the level of medical personnel's job ability was higher. 2) In the field of health management, there was a difference between the level of medical personnel's job ability and that of industrial hygienists' only in the health education but there was not so much difference between manpower' which showed that it was 3.00 on average. 3) In the field of working environment management. the level of industrial hygienists' job ability was 4.03 on average and that of medical personnel's was 2.62, which showed that the level of industrial hygienists' job ability was higher than that of medical personnel's. 2. The job abilities by manpower. As for the job ability by manpower. on the health care the medical personnel's ability was more excellent than the industrial hygienists' and on the working environment management the latter's{industrial hygienists') ability was more excellent than the former's(the medical personnel's). However. the field that a difference between both manpower as mentioned above was not recognized was the health management. 3. As for the difference of potential factors between manpower. in Factor '1' the industrial hygienists' 80.7 points by percentage was higher than the medical personnel's 52.5 points and in Factor '2' the latter's(medical personnels's) 72.6 points by percentage was higher than the former's{industrial hygienists') 50.6 points in the level of job abilities. The above result shows that the industrial health service agency personnel can be classified into the job with a difference between manpower and that without any difference manpower. Therefore, the following issues: First: The field of health care shall be defined as the medical personnel's exclusive job. Second: The field of working environment management shall be defined as the industrial hygienists' exclusive job. Third: The field of health management shall be defined as a common job to lead the limits of time and space in the collective group occupational health management to be controlled effectively.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.7 no.2
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• pp.75-81
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• 2003

Compact schemes are shown to be effective for a class of problems including convection-diffusion equations when combined with multigrid algorithms [7, 8] and V-cycle convergence is proved[5]. We apply the multigrid algorithm for an semianalytic finite difference scheme, which is desinged to preserve high order accuracy despite of singularities.

• Journal of Digital Convergence
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• v.6 no.3
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• pp.121-129
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• 2008

This paper aimed to exam the influence factor of purchasing decision making of industrial buyer and analyzed their effects on success. From the previous studies, we extracted influence factor which are buying center, character of Industrial goods provider. The result showed the difference in the purchasing decision-making process in accordance with the type of buying task(Hypothesis 1). And a test was made the difference in the mode of purchase decision-making(Hypothesis 2). A test was made the difference in supplier's evaluative criterion in accordance with the type of buying task(Hypothesis 3).

• Journal of Korean Public Health Nursing
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• v.8 no.1
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• pp.63-72
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• 1994

The purpose of this study was to estimate the industrial worker's knowledge, attitude, and practice about occupational health and to provide the basic data for the development of industrial health services. The study was undertaken from January 15 to January 30, 1993. 549 industrial workers at the Industrial Complex located in Chonbuk Province were participated in this study. The results were as follows; 1. The Knowledge, Attitude and Practice leveles of Workers about Occupational Health. The levels were measured by five point scale. The mean score of knowledge was 2. 59 point out of 4. The mean score of attitude was 2.37 point out of 4. The mean score of practice was 2. 38 point out of 4. 2. The analysis of their knowledge" attitude, and practice about general characteristics. 1) There was significant difference among different age groups. $(P{\leqq}0.0001)$ -. The group of age 25-29 was the highest value in knowledge and attitude. -. The group of age over 50 was highest value in practice. 2) There was significant difference between sexual groups in all items. -. Male workers were higher than Female workers in all items. (P=0.0000) 3) There was significant difference according to the marital status in all items. -. Married workers were higher than Single workers in all items. (P = 0.0000) 4) There was significant difference among different groups of educational level in attitude and practice. (P<0.05) The value was positivly correlated to their educational level. 5) There was significant difference among the groups of job-part in knowledge and practice. (P=0.000, P=0.031) -. Office workers were higher than Production workers in all items. 6) There was significant difference among different group of job experience in knowledge and attitude. (P=0.0000. P=0.0387) The value was positively correlated to the years length of job experience. 7) There was significant difference among the groups of different monthly income in all items. (P=0.000) The value was positively correlated to their monthly income.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.9 no.2
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• pp.55-64
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• 2005

In this paper, generalized difference methods(GDM) for one-dimensional viscoelastic problems are proposed and analyzed. The new initial values are given in the generalized difference scheme, so we obtain optimal error estimates in $L^p$ and $W^{1,p}(2\;{\leq}\;p\;{\leq}\;{\infty})$ as well as some superconvergence estimates in $W^{1,p}(2\;{\leq}\;p\;{\leq}\;{\infty})$ between the GDM solution and the generalized Ritz-Volterra projection of the exact solution.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.67
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• pp.11-18
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• 2001

The efficiency and robustness of the scale estimator based on the Gini's mean difference are well known in Nam et al.(2000). In this paper we propose use of robust control limits based on the Gini's mean difference for the control of the process deviation. To compare the performances of the proposed control chart with the existing R-chart or S-chart, some Monte Carlo simulations are performed. The simulation results show that the use of the Gini's mean difference in construction of the control limits has good performance.

• Journal of Labour Economics
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• v.31 no.3
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• pp.21-46
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• 2008

This paper estimates of the effect of Clean Workplace Program on industrial accident rates among firms with fewer than 50 workers. The program subsidizes selected firms for work environment improvement. After controling for selectivity and fixed effects in difference-in-difference model, we find that the program reduces the accident rates by 0.34%p, which amount to a decline of 15.8% in total accident rates.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.22 no.3
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• pp.201-215
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• 2018

In this paper we consider a class of singularly perturbed system of delay differential equations of convection diffusion type with integral boundary conditions. A finite difference scheme on an appropriate piecewise Shishkin type mesh is suggested to solve the problem. We prove that the method is of almost first order convergent. An error estimate is derived in the discrete maximum norm. Numerical experiments support our theoretical results.