• Journal of Environmental Health Sciences
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• v.19 no.4
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• pp.90-102
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• 1993

A study on the factors affecting subjective symptoms of labor working in textile industries was carried out from June I to 30 in 1991. A total of 870 laborers were selected from the textile industries at Taegu, Kyungbuk in Korea. The purpose of this study was to determine the factors affecting subjective symptoms and improve the health condition of the labor in the industries. The results of this study can be summarized as follows: 1. 72.5% of the respondents were females and 27.5% were males. 45% of them were in the age group of between 20 and 29 years old, 25.7% were between 10 and 19 years old and 14.4% were between 30 and 39 years old. 57.6% finished high school level education, 70.6% were single, 31.2% had religion of Buddhism and 57.3% lived in the dormitory. Financially, 45% of them partially supported their family members. 2. 34.5% of the respondants were working in the administrative areas and the rest were working in the production areas. The period of working was 1~4 years. 64.7% of them owned their houses. 72.9% worked for a shift. 15.9% were satisfied with their job and 17.1% were not satisfied with their job. 3. 44.0% of the respondants complained about eye problems and more females than males complained about problems. 4. The laborers in the age group of between 40 and 49 years old complained about serious headache and younger laborers complained about respiratory problems. 5. 50% of unmarried laborers complained about eye problems, 40% of night workers felt aches in their empty stomach. 6. 54.4% of the respondents working in manufacturing department complained about eye problems, 29.5% of working in processing department complained about headache and 43.4% of the respondents working in spinning department complained about shoulder ache. 7. Most laborers went to the drug stores for their health. 8. 60.7% of teen ages complained about their irregular menstruation. 51.7% of the in twenties complained about pain during the period. 45.8% of the respondents in thirties complained about nervous system. The women working nights show 74.1% in all three and highest complaint rate. According to the conclusion of this study, it is recommended that more money should be spent on better health education for the laborers in textile industries. Also it is recommended that the policies and supports for them should be strengthened.

• Journal of Society of Preventive Korean Medicine
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• v.8 no.1
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• pp.19-32
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• 2004

This study was conducted to evaluated musculoskeletal subjective symptoms and the degree of stress of industrial workers to present fundamental materials of preventive oriental medicine for improving their health and quality of life. During the medical examination with oriental medicine method, presence of subjective symptoms of musculoskeletal pain, Psychosocial Well-being Index(PWI) and life style were checked by using questionnaire method in 474 industrial workers. The collected data were analyzed with crosstabs, ANOVA and T-test. The results were as follows; 1. In general differences according to musculoskeletal subjective symptoms, education level of high school graduation had significantly higher distribution than that of below middle school or above university graduation in the pain present group. 2. In the musculoskeletal subjective symptoms and the degree of stress, all of Factor1, Factor2. Factor3, Factor4. and PWI had higher score in pain present group than in pain free group and the difference was statistically significant. 3. According to degree of stress and general character of subjects, single and education level of high school graduation had high score in Factor2, Factor3 and PWI. Factor1 and Factor3 was high in income group of low 1.49 million won. Factor2, Factor4, and PWI was high significantly in income group of 1.50 - 2.99 million won. In job type, manufacturing worker group had significantly high score in Factor3. 4. In degree of stress and life style difference, there was significant difference in PWI score in the field of alcohol chinking, smoking, exercise, obesity except sleeping hours. In the present study. as a result, it is found out that musculoskeletal subjective symptoms present group had higher score in psychosocial stress across the fields than symptom-free group and it is recommended that continuous studies on the relationship of job-related musculoskeletal disorders and psychosocial stress should be performed for improvement and prevention of mental and physical health of industrial worke

• Resources Recycling
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• v.14 no.6 s.68
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• pp.28-36
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• 2005

A hydrometallurgical process to leach cobalt from the waste cathodic active material, $LiCoO_{2}$, and subsequently to separate it by solvent extraction was developed. The optimum leaching conditions for high recovery of colbalt and lithium were obtained: 2.0 M sulfuric acid, 5 $vol.\%$ hydrogen peroxide, $75^{\circ}C$ leaching temperature, 30 minutes leaching time and an initial pulp density of 100 g/L. The respective leaching efficiencies for Co and Li were $93\%$ and $94.5\%$. About $85\%$ Co was extracted from the sulfuric acid leach liquor containing 44.72 g/L Co and 5.43 g/L Li, using 1.5 M Cyanex272 as an extractant at the initial pH 5.0 and in organic to aqueous phase ratio of 1.6:1 under the single stage extraction conditions. The Co in the raraffinate was completely extracted by 0.5 M Na-Cyanex272 at the inital pH 5.0, and an organic to aqueous phase ratio of 1;1. The cobalt sulfate solution of higher than $99.99\%$ purity could be recovered from waste $LiCoO_{2}$, using a series of hydrometallurgical processes: sulfuric acid leaching of waste $LiCoO_{2}$- solvent extraction of Co by Na-Cyanex 271 - scrubbing of Li by sodium carbonate solution - stripping of Co by sulfuric acid solution.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.243-246
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• 2016

Data transfer technique is one of the key elements of the IT infrastructure, in accordance with each environment and function, using some kind of protocol. Using the three protocols such as WCDMA, AIS, and TRS at sea IT industry. so It uses three protocols saw has a problem that the operation of each protocol-specific server. so server maintenance costs increase and sea Device Manager has been placed in a situation which operates to develop each of the protocol-specific analysis program. The reason of the protocol is divided into three, marine equipment (lighthouses, buoys, light buoy) manufacturing companies and the date of manufacture, such as, communication environment (distance, communication speed) because such is wrong all, trying to unify this and enormous cost and time is a situation that can not be the exchange occurred when. So in the Ministry of Maritime Affairs and Fisheries, the number of frequency of use is low, communication performance is seeking to refrain from Kure each local organizations and companies the use of low TRS protocol. his paper is intended to conduct research on the basis of the actual data to analyze whether the method is how economical to store a single DB by analyzing other types of protocols. This reduces the shortage of marine IT industry, even a little, shall helps reduce administrative costs.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.125-130
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• 2019

This research is about alternative measure of main components for sprinkler system like automatic wet pipe sprinkler system, dry pipe sprinkler system, pre-action sprinkler system, vacuum sprinkler system, deluge sprinkler system, and so on. By replacing the alarm check valve, dry valve, pre-operated valve, and deluge open valve with a solenoid valve, it be can be simplifed the various processes of the manufacturing process into one process, it creates an environment in which one standardized product can be produced simultaneously on a single machine. Therefore, it could improve the price competitiveness of products, reduce the maintenance cost, and help the adaptability of new sprinkler systems in the future. There is a benefit when it comes to apply to sprinkler system. Only replace the valve which is used to control primary and secondary valve such as wet, dry, pre operated, vacuum, deluge system valve. Other components such as retarding chambers, automatic air compressors, accelerators or adjusters, supervisory panels, vacuum pumps, and manual starters can be used as they are, so they can be easily applied to existing sprinkler system. It is needed to legal and institutional study for solenoid valve applied sprinkler system to commercialize.

• Composites Research
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• v.32 no.1
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• pp.65-70
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• 2019

The aircraft composites wing parts are usually integrated with adhesive or fastener. These laminated composites have weak interlaminar strength, which can lead to delamination. In order to compensate the disadvantages of laminated composites, it is possible to improve the strength, durability, shock and fatigue resistance by reinforcing the fiber in the thickness direction. In addition, using a single structure near-net-shape saves the manufacturing time and the number of fasteners, thus can reduce the overall cost of the composite parts. In this study, compression test, tensile test and open-hole tensile test are carried out for three structural architecture of 3D (three-dimensional) textile preforms: orthogonal(ORT), layer-to-layer(LTL) and through-the-thickness(TTT) patterns. Among these, the orthogonal textile composite shows the highest Young's modulus and strength in tensile and compression. The notch sensitivity of the orthogonal textile composite was the smallest as compared with UD (unidirectional) and 2D (two-dimensional) fabric laminates.

• Journal of Navigation and Port Research
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• v.44 no.6
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• pp.509-516
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• 2020

Korea has gradually been developing port distriparks in major domestic trade ports to diversify their function and create added-value. New tenant companies are needed to help achieve these goals, but no research has been done on selection criteria. To provide such criteria, this study conducted a comparative analysis of the productivity of tenant companies in Busan New Port Distripark based on their characteristics. SFP (single-factor productivity) was measured using the operational data of 67 companies in the distripark over the past - three years (2017-2019). The results indicate that the logistics business and the manufacturing business have strengths in cargo volume productivity and in sales productivity respectively. Also, Northern distripark, a relatively older facility, was found to be more productive than Ung-dong distripark. Finally, the effect of investment-both foreign and in FAC/EQ (facility and equipment)-on productivity showed an inverse relationship with productivity, with the companies with under-average investments being more productive than those whose investments were above average. Therefore, to enhance the productivity and competitiveness of port distriparks, tenant companies must be subject to supplemented system and law for increasing employment and cargo volume, and reestablished selection criteria.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.71-78
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• 2021

Implant treatment, which was first attempted in fully edentulous patients, is now widely used in partially edentulous, and a single tooth missing patients. Moreover, implant treatment has become an essential treatment modality in modern dentistry. The material of fabricating implant prostheses has also become more diverse than before, one of which is the use of high-performance polymers. The frequency of using high-performance polymers, which have been used in the medical field, is also increased in the dental field compared to the past. In the first case, a PEKK abutment and a PFG crown (cement-screw-retaining type) were fabricated in the lower left second premolar, and in the second case, a PEKK abutment and a monolithic zirconia crown (cement-screw-retaining type) were fabricated in the missing upper left first molar, and in the third case two PEKK abutments and a splinted PFM crowns (cement-screw-retaining type) were fabricated and connected to the upper right first and second molar implants. Through these procedures the patients obtained esthetically and functionally satisfactory results after 4 years of follow-up.

• Composites Research
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• v.35 no.3
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• pp.139-146
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• 2022

In this study, we study fabrication methods suitable for CNT fibers-based composite. We try to fabricate a composite material using a small amount of CNT fiber preparation of woven fabrics or stitched unidirectional fabrics consisting of CNT fiber is not achievable currently. The composite materials on the basis of CNT fibers have been mainly manufactured filament winding method due to productivity issues and difficulties in composite processes. We develop a new method to prepare CNT fibers-based composite using resin infiltrated CNT fibers-based films. Because CNT fibers have numerous nanopores inside, unnecessary resin can remain after curing and decrease the mechanical properties of the composites. To remove the excess resin, pressure should be applied during the process, but the pressure applied through VaRTM was not enough to remove the excess resin. To obtain the composite with high ratio of CNT fibers, higher pressure using hot press machine and foams next to the resin-infiltrated CNT fibers are necessary. We can obtain the composite having a mass ratio of 58.5 wt% based on the new suggested method and diluted epoxy. The specific strength of the composite reach 0.525 N/tex. This study presents a new process method that can be applied to the manufacturing of CNT fiber composite materials in the future.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.191-196
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• 2021

This paper proposes to strengthen the technological capabilities of small and medium enterprises on the establishment of a component standardization system and the localization of parts, which is the basis of the marine wind industry. The wind industry is a natural energy industry that countries around the world are paying attention to, and continues to invest and research and development. In particular, most companies are focusing on research and investment in component development, the smallest unit. Therefore, it is believed that we should focus on the three most fundamental and underlying wind industry, an eco-friendly energy industry that could determine the fate of the nation in the future. First, an understanding of the roadmap for standardization should be prioritized. Second, it is necessary to establish a domestic standardization of international standards according to domestic conditions. Third, localization of high value-added single products and components should be achieved by lowering dependence on overseas imports. In the future, it is hoped that the wind industry, centered on small and medium-sized enterprises, will become a solid-based national industry and be completed as a national infrastructure leading the global wind market.