• 한국기계가공학회지
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• 제13권2호
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• pp.124-130
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• 2014

In a mass manufacturing system of optical fibers, the sufficient cooling of glass fibers freshly drawn from a draw furnace is essential, asinadequately cooled glass fibers can lead to poor resin coating on the fiber surface and possibly fiber breakage during the process. In order to improve fiber cooling at a high drawing speed, it is common to use a helium injection into a glass fiber cooling unit in spite of the high cost of the helium supply. The present numerical analysis carried out three-dimensional thermo-fluid computations of the cooling gas flow and heat transfer on moving glass fiber to determine the cooling performance of glass fiber cooling depending on the method of helium injection. The results showed that afront injection of helium is most effective compared to a uniform or rear injection for reducing air entrainment into the unit and thus cooling the glass fibers at a high fiber drawing speed. However, above a certain amount of injected helium, there was no more increase of the cooling effect regardless of the helium injection method.

• 한국의상디자인학회지
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• 제7권3호
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• pp.157-165
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• 2005

The purpose of this research is to investigate the actual conditions of the manufacturer's design processes. Questionnaires were sent out, and 57 interviews were used as research methods including designers, programmers, and merchandisers working for a knit manufacturer in Seoul, followed by a frequency analysis using SPSS 12.0. The results are as follows: knitted fabric goods were the top choices in casual wear. Brand image depended on 'elegance', 'modernity', and 'romanticism', among other lifestyle pursuits. The distribution ratio of the 'basic' and the 'trendy' knit was at 3:7 or 7:3, while the ratio of 6:4 or 4:6 was more common. Knit structure was proven to be the most important factor in the changes in designs. Style and yam ranked second and third, respectively. In addition, details (embroidery and beading), color, pattern, and processing were among the other factors, in order of importance. Based on the difficulty in designing and manufacturing knitted fabric goods, 'manufacturing cost:' 'lack of a manufacturing facility for small production,' and 'limited delivery time' were among the reasons cited in the questionnaire. These results appeared to have been caused by small-scale manufacturers or small-scale manufacturing facilities that made small volume production difficult. The results of the interviews on knitted fabrics that were most frequently used and with the highest sales volumes showed that plain, lace, links & links, miss, and 1:1 rib were ranked accordingly for S/S use, while jacquard, cable, 1:1 rib, links & links, milano, plain, and half cardigan were ranked accordingly for F/W use.

• Smart Structures and Systems
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• 제26권4호
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• pp.495-506
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• 2020

Monitoring of complex processes faces several challenges mainly due to the lack of relevant sensory information or insufficient elaborated decision-making strategies. These challenges motivate researchers to adopt complex data processing and analysis in order to improve the process representation. This paper presents the development and implementation of quality monitoring framework based on a model-driven approach using embedded artificial intelligence strategies. In this work, the strategies are applied to the supervision of a microfabrication process aiming at showing the great performance of the framework in a very complex system in the manufacturing sector. The procedure involves two methods for modelling a representative quality variable, such as surface roughness. Firstly, the hybrid incremental modelling strategy is applied. Secondly, a generalized fuzzy clustering c-means method is developed. Finally, a comparative study of the behavior of the two models for predicting a quality indicator, represented by surface roughness of manufactured components, is presented for specific manufacturing process. The manufactured part used in this study is a critical structural aerospace component. In addition, the validation and testing are performed at laboratory and industrial levels, demonstrating proper real-time operation for non-linear processes with relatively fast dynamics. The results of this study are very promising in terms of computational efficiency and transfer of knowledge to manufacturing industry.

• 한국산업보건학회지
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• 제26권4호
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• pp.454-465
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• 2016

Objectives: The purpose of this study was to evaluate trends in asbestos exposure among asbestos-handling industries from 2000 to 2005. Methods: The data included the number of industries and workers exposed, concentrations of asbestos and the amount exceeded, and the type and size of industry by year. These data were collected by 46 regional employment and labor offices in Korea using work environment monitoring reports. A total of 1,481 samples from 284 industries were extracted from the reports and were analyzed with no data modification. Results: The means of asbestos concentration decreased from $0.84f/cm^3$ to $0.03f/cm^3$ during the period 2000-2005. Among the total of 1,481 samples, 11 samples(0.7%) exceeded the KOEL, and 178 samples(12.0%) were ACGIH TLV. The insulating paper product manufacturing industry was found to have the highest level of asbestos, followed by the fireproofing manufacturing industry, brake lining products manufacturing industry, commutator products manufacturing industries, and construction materials manufacturing industry. The number of asbestos handling industries decreased from 48 industries with 1,155 employees to 37 industries during the period of 2000 to 2005, but the number of asbestos workers expanded to the point that 1,182 employees could be found in 2005. Conclusion: Based on these results, the strengthening of the KOEL and new regulations turned out to help reduce asbestos exposure levels. This study recommends that retrospective exposure to asbestos based on various industry types should be assessed.

• Korean Journal of Acupuncture
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• 제22권2호
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• pp.127-149
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• 2005

This study is designed to investigate the method of manufacturing herbal acupuncture through literature of oriental medicine. The findings of this study are as follows; 1. The methods of manufacturing herbal acupuncture go through the process of abstraction, purification, mixing, filtration, putting and tight sealing in the container, sterilization, quality control, printing and packing 2. There are many ways to manufacturing herbal acupuncture, for example water-alcohol precipitation, alcohol-water precipitation, liquid-liquid abstract, acid-base abstract, metal base precipitation, distillation, molecular structure, polyamide absorption, dialysis, and ion exchange, etc. And popular method is water-alcohol precipitation. This is through alcohol precipitate extracting the principal ingredients from water abstraction. This is very simple and efficient way using melting characteristics of compounds in herb to water and ethanol. 3. Sterilization of herbal acupuncture is through heating-pressure, boiling, steam flowing, low temperature, filtering, radiation, cooling, and microwaves. Nowadays filtering is commonly used. And sterilization is estimated by an examination of asepsis . 4. Herbal acupuncture must be undergo study and experiment to clinical use. The problems of herbal acupuncture are turbidity, instability, causing hemolysis, pain, and fever. So many provisions (addition, sterilization, and filtration etc.) must be prepared. 5. The theory of manufacturing herbal acupuncture is from oriental medicine, not western. So it must be corresponded to oriental medical theory, for example Gimi(氣味), Guigyung(歸經), Ingyung(引經), Bosa(補瀉), and Match of Herb. It is recommended that further study of many other sided investigations in the future.

• 한국경제지리학회지
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• 제19권2호
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• pp.209-224
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• 2016

본 연구는 지난 10년간 제조업체들이 급격히 유입되고 있는 수도권의 비도시지역의 개별입지 제조업체들의 실태와 그 특성을 파악하고, 이로 인해 나타나는 문제점을 도출하는데 목적을 두었다. 공장등록통계 원시자료를 이용하여 지난 10년 동안 비도시지역으로 유입된 개별입지 제조업체의 분포 특성을 지도화를 통해 분석하였다. 그 결과 약 90%의 제조업체들은 서울과 인접한 일부 10개 지역으로만 군집하고 있으며, 유입된 제조업종들은 지역별로 상당한 차이를 보이고 있다. 가장 많은 제조업체가 유입된 화성시 장안면을 대상으로 설문조사와 현지조사를 수행한 결과 제조업체들이 무분별하게 비도시지역에 입지하면서 농촌 마을의 토지이용 및 환경오염 및 농촌 마을 공동체에 부정적 영향을 주는 것으로 나타났다. 본 연구 결과는 수도권 비도시지역의 바람직한 산업입지 정책을 수립하는데 필요한 시사점을 제공하였다.

• 한국기계가공학회지
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• 제12권6호
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• pp.132-141
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• 2013

Robotic Drilling Systems(RDSs) set the standard for the factory automation systems in aerospace manufacturing. With the benefits of cost effective drilling and predictive maintenance, RDSs can provide greater flexibility in the manufacturing process. The system can be easily adopted to manage very complex and time-consuming processes, such as automated fastening hole drilling processes of large aircraft sections, where it would be difficult accomplished by workers following teaching or conventional guided methods. However, in order to build an RDS based on a CAD model, the precise calibration of the Tool Center Point(TCP) must be performed in order to define the relationships between the fastening-hole target and the End Effector(EEF). Based on the kinematics principle, the robot manipulator requires a new method to correct the 3D errors between the CAD model of the reference coordinate system and the actual measurements. The system can be called as a successful system if following conditions can be met; a. seamless integration of the industrial robot controller and the IO Level communication, b. performing pre-defined drilling procedures automatically. This study focuses on implementing a new technology called iGPS into the fastening-hole-drilling process, which is a critical process in aircraft manufacturing. The proposed system exhibits better than 100-micron 3D accuracy under the predefined working space. Based on the proposed EEF fastening-hole machining process, the corresponding processes and programs are developed, and its feasibility is studied.

• 대한치과기공학회지
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• 제42권1호
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• pp.9-16
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• 2020

Purpose: The purpose of this study was to compare the marginal and internal fit of lithium disilicate ceramic inlay produced by heat pressing that inlay pattern made by subtractive manufacturing and additive manufacturing method. Methods: A mandibular lower first molar that mesial occlusal cavity (MO cavity) die was prepared. After fabricating an epoxy resin model using a silicone impression material, epoxy resin die was scanned with a dental model scanner to design an MO cavity inlay. The designed STL pile was used to fabricate wax patterns and resin patterns, and then lithium disilicate ceramic inlays were fabricated using hot-press method. For the measurement of the marginal and internal gap of the lithium disilicate, silicone replica method was applied, and gap was measured through an optical microscope (x 80). Data were tested for significant differences using the Mann-Whitney Utest. Results: The marginal fit was 103.56±9.92㎛ in the MIL-IN group and 81.57±9.33㎛ in the SLA-IN group, with a significant difference found between the two groups (p<0.05). The internal fit was 120.99±17.52㎛ in the MIL-IN group and 99.18±6.65㎛ in the SLA-IN group, with a significant difference found between the two groups (p<0.05). Conclusion: It is clinically more appropriate to apply the additive manufacturing than subtractive manufacturing method in producing lithium disilicate inlay using CAD/CAM system.

• 한국산업보건학회지
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• 제29권2호
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• pp.259-269
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• 2019

Objective: This study was conducted to prepare fundamental data and assess the relationship between level of exposure to airborne respirable dust, chest radiation findings, and the results of pulmonary function tests among workers in a cloth manufacturing factory. Methods: The number of total subjects was 144 (124 female and 20 male) workers in a cloth manufacturing factory in the city of Busan. This study measured the concentration of airborne respirable dust by gravimetric analysis and performed pulmonary function testing, and got chest radiation findings from December 1, 2016 to March 31, 2017. Collected data was analyzed using the IBM SPSS statistical package program (ver. 24.0). Results: The mean concentration of respirable dust was the highest in the cutting process. The effecting factors on $FEV_1/FVC$ were age, sex, and working process. The effecting factors on chest radiation findings were doing no exercise and concentration of respirable dust. Conclusions: Based on the above results, the authors consider there to be a need to secure sufficient working space and improve the engineering systems, for example the overall or local ventilation, in order to minimize the exposure to respirable dust. Health education and health promotion activities should also be improved in order to maintain optimal health status. The authors expect further studies to be performed on pulmonary function testing, chest radiation findings, and symptoms related to pulmonary function, including continuous observation, among workers in a cloth manufacturing factory.

• 한국재료학회지
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• 제29권1호
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• pp.23-29
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• 2019

Three-dimensional(3D) printing is a process for producing complex-shaped 3D objects by repeatedly stacking thin layers according to digital information designed in 3D structures. 3D printing can be classified based on the method and material of additive manufacturing process. Among the various 3D printing methods, digital light processing is an additive manufacturing technique which can fabricate complex 3D structures with high accuracy. Recently, there have been many efforts to use ceramic material for an additive manufacturing process. Generally, ceramic material shows low processability due to its high hardness and strength. The introduction of additive manufacturing techniques into the fabrication of ceramics will improve the low processability and enable the fabrication of complex shapes and parts. In this study, we synthesize silica composite material that can be applied to digital light processing. The rheological and photopolymeric properties of the synthesized silica composite are investigated in detail. 3D objects are also successfully produced using the silica composite and digital light processing.