• Journal of the Semiconductor & Display Technology
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• v.19 no.3
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• pp.100-105
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• 2020

Recently, as display and semiconductor devices have been miniaturized and highly integrated, there is a demand for optimization of the structural characteristics of the thin film accordingly. The sputtering device has the advantage of stably obtaining a desired thin film depending on the material selected for the target. However, due to the structural characteristics of the sputtering equipment, the structural characteristics of the film may be different depending on the incidence angle of the sputtering target material to the substrate. In this study, the characteristics of the thin film material according to the scattering angle of the target material and the incidence position of the substrate were studied to find the optimization design rule of the sputtering equipment. To this end, a Si thin film of 1 ㎛ or less was deposited on the Si(100) substrate, and then the microstructure, reflectance, surface roughness, and thin film crystallinity of the thin film formed for each substrate location were investigated. As a result of the study, it was found that as the sputter scattering angle increased and the substrate incident angle decreased, the gap energy along with the surface structure of the thin film increased from 1.47 eV to 1.63 eV, gradually changing to a non-conductive tendency.

• Korean Journal of Materials Research
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• v.29 no.11
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• pp.670-676
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• 2019

We study substrate support structures and materials to improve uptime and shorten preventive maintenance cycles for chemical vapor deposition equipment. In order to improve the rolling of the substrate support, the bushing device adopts a ball transfer method in which a large ball and a small ball are mixed. When the main transfer ball of the bushing part of the substrate support contacts the substrate support, the small ball also rotates simultaneously with the rotation of the main ball, minimizing the resistance that can be generated during the vertical movement of the substrate support. As a result of the improvement, the glass substrate breakage rate is reduced by more than 90 ~ 95 %, and the equipment preventive maintenance and board support replacement cycles are extended four times or more, from once a month to more than four months, and the equipment uptime is at least 15 % improved. This study proposes an optimization method for substrate support structure and material improvement of chemical vapor deposition equipment.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.279-285
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• 2021

The materials, parts, and equipment industries are the backbone of the manufacturing industry and a key element of competitiveness. However, in the case of Korea, as it relies on foreign countries for core materials, parts, and equipment, it is in danger of not only industrial competitiveness, but also security. This study first looked at the outline and current address of the materials, parts, and equipment industries, identified problems and improvements, and examined the efforts and achievements so far for the localization of materials, parts, and equipment in Korea. In addition, after looking at the improvement measures for the government's material, parts, and equipment industry at the institutional level or at the ecological level, the current status and actual condition of localization of local materials, parts and equipment were investigated, and problems and improvements were analyzed. Lastly, this study presented a technology development plan for localization of parts and materials in the region and various institutional improvement plans related to commercialization.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.6
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• pp.598-602
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• 2023

With the purpose of instilling an awareness of the safety of users of electrical equipment and inducing voluntary facility improvement through the safety rating system for general low voltage electrical equipment, simulation and field application of the safety rating of general low voltage electrical equipment were conducted. For the introduction and application of the safety rating system for general low-voltage electrical equipment, data related to domestic safety was investigated and analyzed, cases of introduction in other fields were reviewed, and for design, the 4M risk assessment method of the Korea Occupational Safety and Health Agency and the cases of safety index development in Korea were analyzed and standardized. Safety rating system simulations were conducted for general low-voltage electrical equipment, and problem improvement measures were prepared by analyzing the results through on-site verification and simulation applied to the initial design. Design standards for the introduction of the safety rating system for general low-voltage electrical equipment were prepared, and 394 youth training facilities were applied to the field to see if the design standards were practically applicable to the field. With the application of the safety rating system for low-voltage electrical equipment for general use, youth training facilities that had been classified as 'appropriate' were able to induce an upgrade to a higher level through voluntary facility improvement according to the application of grades (A to E). As a result of inducing voluntary repair projects based on the results of the 1st and 2nd inspection of youth training facilities, it was confirmed that 86 facilities received grade A, 225 facilities received grade B, and only 311 facilities received grade A to B out of a total of 394 facilities, and there was no grade E.

• IE interfaces
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• v.18 no.4
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• pp.431-443
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• 2005

This paper describes a web-based system called DESIGNER for the analysis and design for automated material handling equipment(MHE) applications in manufacturing. DESIGNER models the processes for system integration, economic analysis, performance analysis, and automated storage/retrieval system(AS/RS) design. Based on the information specified by users, the various analysis modules are invoked to meet the needs of the material handling applications. The results of the analyses provide system users with useful data for material handling system design and decision on investment in automated MHE. Example problems are also presented to demonstrate the use of the system.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.2
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• pp.110-115
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• 2011

Objectives: The aim of this study is to survey for finding asbestos containing equipment at the laboratories using picture based questionnaire and polarized light microscopic analysis. Methods: This study was conducted from 2009 to 2010 at a university in Seoul. In 2009, picture based questionnaire was distributed to 100 laboratories during the regular laboratory air quality monitoring. In 2010, we emailed all professors of the same university who have laboratories to participate voluntarily this survey. For the laboratories consented to participate survey, picture based questionnaire was distributed and collected. Suspected asbestos containing material and apparatus were collected at the laboratories which replied they have suspected material and equipment. Collected samples were analyzed with polarized light microscope at the laboratory accredited by ministry of employment and labor in Korea. Results: Total of 18 out of 100 laboratories reported that they had suspected asbestos containing equipment in 2009. Twenty-three samples were collected and three samples (13%), one heating mantle and two pairs of insulation gloves, contained asbestos. Thirty four laboratories reported they had suspected asbestos containing material or equipment in 2010. Sixty samples were collected and four of them (6%), two pairs of insulation gloves, one packing rope in dry oven and, one pair of tongs, contained asbestos. All founded asbestos was chrysotile and the content of chrysotile was more than 90% for all equipment except heating mantle which has less than 1%. Conclusions: We confirmed that asbestos was still used at the laboratories though strict regulations on asbestos use in Korea. The method of picture based questionnaire invented in this study could be applied for asbestos survey to other research institute or university where there are many laboratories because of its simplicity and accessibility without huge man power, cost and time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.207-210
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• 2001

Electrical equipment for railway is always experiencing wear and degradation by mechanical, electrical and environmental stress in service and the fault or the accident of high voltage main circuit directly causes operation interruption. Particularly propulsion drive of high speed switching inverter takes the form of specific degradation mechanism such as fast rising transient surge, reflective overvoltage and harmonic stress, and it is known that it threatens the long life and the reliability of electrical equipment. In this paper, statistics of fault and accident on main electrical equipment for railway are presented and also insulation degradation mechanism, which governs end life of electrical device, is analyzed. Finally the method of fault respondence and reliability improvement on the main electrical equipments will be reviewed in order to prevent operation interruption.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.2
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• pp.153-158
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• 2005

Recently, as the feasibility study shows that trans-Korea railway and trans-continental railway are advantageous, interest in high-speed railway system is increasing. Because railway vehicle is environment-friendly and safe compared with airplane and ship, its market-sharing increases gradually. KHST(Korean High Speed Train) has been developed by KRRI (Korea Railroad Research Institute) for last 6 years to satisfy the need. An electric railway system is composed of high-tech subsystems, among which main electric equipment such as transformers and converter are critical components determining the performance of rolling stock. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A now method to measure temperature was applied to the measurement system. By using the system, fault diagnosis and performance evaluation of electric equipment in Korean High Speed Train was conducted during test running.

• Transactions of Materials Processing
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• v.17 no.1
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• pp.9-12
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• 2008

Recently, industries and academic institutes have been interested in the rheology forming technology for light weight materials. However, this rheocasting process has advantages such as the high initial investment cost and the lower mechanical properties than thixocasting. In this study, the continuous fabrication of rheological material with a spiral stirring equipment(mechanical stirring system) was newly devised to overcome the disadvantages of rheocasting process. The experimental parameters were stirring time($0{\sim}1200sec$), stirring velocity ($0{\sim}100rpm$) and stirring temperature($650{\sim}680^{\circ}C$). The optimal conditions for fabricated rheological material of A6061 alloy were stirring time at 300sec, stirring velocity at 60rpm and stirring temperature at $650^{\circ}C$. At these results, the equivalent diameter was $45{\sim}65{\mu}m$, mean roundness was $1.4{\sim}1.6$ and Vickers hardness was 60Hv.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.453-456
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• 2004

This paper surveys the latest findings on vegetable-oil-based dielectric coolants in power systems. In recent years, environmental concerns have been increased on the use of poorly biodegradable mineral oils in distribution and power transformers in regions where spills from leaks and equipment failure could contaminate the surroundings. In addition, there are demands to improve equipment efficiencies in power systems. In this reason, researches were started in the mid 1990s to develop a fully biodegradable dielectric coolants. Vegetable oil was considered the most likely candidate for a fully biodegradable dielectric coolants. Vegetable-oil-based dielectric coolants provide the advantages of high level of biodegradability, renewable natural resource, non-toxic properties, enhanced fire safety, more effective cooling and good dielectric strength for many electrical equipment.