• 대한산업공학회지
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• 제42권4호
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• pp.270-279
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• 2016

A glass product manufacturing company transports a large number of flat glass products from a manufacturing firm to a building construction site. The products are transported using specially designed racks, which assure fewer glass breakages during the deliveries. This study determines the sizes of the racks which minimize the total logistics cost including costs for rack purchasing, handling, transportation, and inventory costs. The determination of the rack size should consider tradeoff relationships between the amount of glasses piled in a rack and the number of racks loaded on a truck, and affects the required number of racks and the truck operational cost. A truck loading algorithm is proposed to maximize a high truck utilization, and an enumeration method is proposed to determine the optimal combination of rack sizes considering the total logistics cost. The numerical example is solved by using a real data.

• 한국생산제조학회지
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• 제25권6호
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• pp.440-444
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• 2016

Owing to the introduction of various IT devices with emphasis on portability and design, the TFT (thin film transistor liquid crystal display) panel applied to IT devices has the same shape as the product, and the portability requirement of IT devices has resulted in a need for panels with higher rigidity. In this study, the effect of grinding conditions such as the feed rate and edge speed of edge grinding on the surface roughness and chipping of the machined surface is investigated using a metal bond wheel. During edge grinding of alkari-free glass, weak mechanical property of glass results in big chipping owing to generation of tensile stress at the end of grining operation. The results of this study show that the grinding characteristics of alkali-free glass are obtained and meet industry requirements.

• 한국정밀공학회지
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• 제21권2호
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• pp.122-129
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• 2004

There is an increasing need for large flat panel display devices. PDP (Plasma Display Panel) is one of the most promising candidates for this need. Thermal shock failure of PDP glass during manufacturing process is a critical issue in PDP industry since it is closely related to the product yield and the production speed. In this study, thermal shock resistance of PDP glass is measured by water quenching test and an analysis scheme is described for estimating transient temperature and stress distributions during thermal shock. Based on the experimental data and the analysis results, a simple procedure for predicting the thermal shock failure of PDP glass is proposed. The fast cooling process for heated glass plates can accelerate the speed of PDP production, but often leads to thermal shock failure of the glass plates. Therefore, a design guideline for preventing the failure is presented from a viewpoint of high speed PDP manufacturing process. This design guideline can be used for PDP process design and thermal -shock failure prevention.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1526-1531
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• 2007

Data transmission capacity that is required in 2010 is forecasted that increase by optical communication capacity more than present centuple, and is doing increased demand of optical communication related industry product present. Specially, Lid glass' application that is one of optical communication parts is used in optical communication parts manufacture of Fiber array, Ferrule array, Fanout Black, Silica optical waveguide chip and splitter etc. Also, it is used widely for communication network system, CATV, ATM-PON, FTTH and system. But, Lid glass need much processing times and becomes cause in rising prices of optical communication parts because production cost is expensive. The objectives, of this work is to suggest the micro concave and convex pattern manufacturing technology on borosilicate plate using high temperature and compression molding method. As a result, could developed micro pattern Mold more than 5 pattern, and reduce Lid Glass manufacture cycle time.

• 공학논문집
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• 제6권1호
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• pp.15-27
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• 2004

현재 유리병의 대량생산을 목적으로 하는 자동 제병공장에서는 저렴하면서도 질 좋은 유리를 생산하고자 하는 것이 첫째 목적이다. 이 목적에 가장 경제적으로 접근하면서 수입 원료에 비하여 훨씬 저렴한 국내산 원료의 효율적인 활용방안의 연구와 에너지절감 및 환경 친화적인 자원재활용 등을 목적으로 파유리를 사용하고 그 양을 늘리기를 원하고 있다. 그러나 소다석회유리에서 $Al_2 O_3$의 함량이 2%미만일 때는 물리화학적인 장점이 실현될 수 있으나, 국내에서는 이러한 좋은 규사를 채광 할 수 없고, 채광 가능한 제품은 $Al_2 O_3$의 함량이 4%이상이므로 국내산 규사만으로 유리조성의 $Al_2 O_3$의 함량을 2%미만으로 조절하기는 불가능한 실정이다. 따라서 낮은 품질의 유리물로서 생산이 가능한 200ml 이하의 소형 유리병(특히 갈색약품 병) 생산 공장에서는 국내산 규사만을 사용하여 유리물을 만들고 있으나, $Al_2 O_3$함량증가에 따라 발생되는 결점(Cord, Knot, 실투, 기포 등)의 증가로 생산효율이 크게 떨어지고 있다. 또한 파유리 투입 시 병유리와는 조성상의 이질성에서 오는 결점의 발생과 파유리 사용량의 증가에 따른 유리물점도 상승으로 용해로 바닥의 온도가 낮은 유리물 정체부위의 실투발생 등 생산 공정에 나쁜 영향을 미치는 여러 가지 문제점들이 발생하게 되었다. 실험을 통해 얻은 결과를 여러 가지 분석 방법을 통해 관찰, 분석하여 이러한 문제점을 해결하였다.

• 펄프종이기술
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• 제34권5호
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• pp.49-55
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• 2002

A new method is proposed for the on-line measurement of the fiber orientation of sheet materials. The measurement of fiber orientation is very important in manufacturing paper sheets, non-woven fabrics, and glass sheets, because fiber orientation strongly affects product properties represented by, for example, dimensional stability of paper. A method developed in this research utilizes anisotropy of dielectric constants of sheet materials as a key characteristic to determine the fiber orientation. The new on-line sensor, consisting of 5 microwave dielectric resonators set in different directions, was designed to detect the fiber orientation while paper is running with high speed on a paper machine. This sensor can determine the direction and the degree of fiber orientation from the measured direction of the maximal dielectric constant and its variation, respectively. The fundamental performance of this system was examined by the static measurement of printing grade paper, which gave a satisfactory result. Then, the dynamic measurements were done at a speed of 1,000 m/min by using a high-speed test-coating machine.

• 제어로봇시스템학회논문지
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• 제17권6호
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• pp.566-572
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• 2011

In recent semiconductor and FPD (Flat Panel Display) manufacturing processes, high clean-class delivery operation is required more and more for short working time and better product quality. Traditionally SLIM (Single-sided Linear Induction Motor) is widely used in the liner drive applications because of its simplicity in the rail structure. A magnetically levitated (Maglev) unmanned vehicle with SLIM traction, which is powered by a CPS (Contactless Power Supply) can be a high precision delivery solution for this industry. In this paper unmanned FPD-carrying vehicle, which can levitate without contacting the rail structure, is suggested for high clean-class FPD delivery applications. It can be more acceptable for the complex facilities composed with many processes which require longer rails, because of simple rail structure. The test setup consists of a test vehicle and a rounded rail, in which the vehicle can load and unload products at arbitrary position commanded through wireless communications of host computer. The experimental results show that the suggested vehicle and rail have reasonable traction servo and robust electromagnetic suspensions without any contact. The resolution of point servo errors in the SLIM traction system is accomplished under 1mm. The maximum gap error is ${\pm}0.25mm$ with nominal air gap length of 4.0mm in the electromagnetic suspensions. This type of automated delivery vehicle is expected to have significant role in the clean delivery like FPD glass delivery.

• 산업경영시스템학회지
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• 제39권1호
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• pp.140-152
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• 2016

It is very important for the competitiveness and sustainable management of enterprises that the rapid changes in the managerial environments quickly and accurately are responded. For example, the large-scale investment accompanied by bad alternatives in accordance with misunderstanding of the managerial environments yields the huge cost and effort to modify and improve. In firm management, the quality of products and the productivity are influenced by changes of the endogenous factors yielded in manufacturing process and the exogenous factors as market, etc. These changes include not only changes in 4M (man, machine, material, method) but also those in the market, competitors, and technologies in the process of commodification, i.e., first, such disturbances make dispersion of the process big and odd. By Shewhart chart it can be checked that the process monitored is control-in or out. Business administration executes activities for input stabilization by monitoring changes in 4Ms, comparing with the standards, and taking measures for any abnormality. Second, TRM (technology road map) is to prospect product deployment and technological trend by predicting technologies in the competitive environment as the market, and to suggest the future directions of business. So, TRM must be modified and improved according to DR (design review) stages and changes in mass-production like input material change. Therefore, a role of TRM in input stabilization for reducing cost and man-hour is important. This study purposed to suggest that the environment changes are classified into endogenous factors and exogenous factors in production process, and then, quality and productivity should be stabilized efficiently through connection between TRM and input stabilization, and to prove that it is more effective for the display industry to connect TRM with input stabilization rather than to use TRM separately.

• International Journal of Ocean System Engineering
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• 제2권3호
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• pp.185-194
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• 2012

A Macroscopic combination of two or more distinct materials is commonly referred to as a "Composite Material", having been designed mechanically and chemically superior in function and characteristic than its individual constituent materials. Composite materials are used not only for aerospace and military, but also heavily used in boat/ship building and general composite industries which we are seeing increasingly more. Regardless of the various applications for composite materials, the industry is still limited and requires better fabrication technology and methodology in order to expand and grow. An example of this is that the majority of fabrication facilities nearby still use an antiquated wet lay-up process where fabrication still requires manual hand labor in a 3D environment impeding productivity of composite product design advancement. As an expert in the advanced composites field, I have developed fabrication skills with the use of machinery based on my past composite experience. In autumn 2011, the Korea government confirmed to fund my project. It is the development of a composite sanding machine. I began development of this semi-robotic prototype beginning in 2009. It has possibilities of replacing or augmenting the exhaustive and difficult jobs performed by human hands, such as sanding, grinding, blasting, and polishing in most often, very awkward conditions, and is also will boost productivity, improve surface quality, cut abrasive costs, eliminate vibration injuries, and protect workers from exposure to dust and airborne contamination. Ease of control and operation of the equipment in or outside of the sanding room is a key benefit to end-users. It will prove to be much more economical than normal robotics and minimize errors that commonly occur in factories. The key components and their technologies are a 360 degree rotational shoulder and a wrist that is controlled under PLC controller and joystick manual mode. Development on both of the key modules is complete and are now operational. The Korean government fund boosted my development and I expect to complete full scale development no later than 3rd quarter 2012. Even with the advantages of composite materials, there is still the need to repair or to maintain composite products with a higher level of technology. I have learned many composite repair skills on composite airframe since many composite fabrication skills including repair, requires training for non aerospace applications. The wind energy market is now requiring much larger blades in order to generate more electrical energy for wind farms. One single blade is commonly 50 meters or longer now. When a wind blade becomes damaged from external forces, on-site repair is required on the columns even under strong wind and freezing temperature conditions. In order to correctly obtain polymerization, the repair must be performed on the damaged area within a very limited time. The use of pre-impregnated glass fabric and heating silicone pad and a hot bonder acting precise heating control are surely required.