• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.75-79
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• 1995

The results of an experimental study on the manufacture and the mechanical properties of fiber reinforced calcium silicates-cement composites utilizing by products (fly ash or cement sludge) for construction materials are presented in this paper. As the test results show, compressive, tensile, and flexural strength, fracture toughness of fiber reinforced calcium silicates-cement composites were improved by increasing the fly ash and fiber contents, but were decreased by increasing cement sludge contents. Somehat, especially increasing fiber contents the fracture toughness of the composites were remarkably increased. Also, the mechanical properties of the composites reinforcing alkali-resistance GF were higher than those of the composites reinforcing Samoa Pulp.

• International Journal of Advanced Culture Technology
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• 제2권1호
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• pp.30-32
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• 2014

3D printing technology polymeric material or plastic and metallic powder to suit the drafting of additive manufacturing would gradually products soars. 3D printing technologyapplication of a wide variety of industrial sectors. 3D printing technology enables raw materials consumption is less, the supply chain are shorter depending on the load and reduce the use of fossil fuels.Emergence of 3D printing technology so called the third industrial revolution in ICT market, quickly spread worldwide.In the future, 3D printing technology is simply beyond bio-technology, Nano-engineering, the manufacture of the product, incorporating a variety of technologies to improve the quality of life of human beings have played an important role will be.

• Proceedings of the Korean Society For Composite Materials Conference
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.220-223
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• 2002

This paper introduces the development procedure of paddle type small-scaled composite rotor blade for helicopter hingeless rotor system. Paddle type composite blade design was done by using CORDAS program developed by KARI and dynamic analysis for hingeless hub with blade is done by using FLIGHTLAB which is commercial software for helicopter comprehensive analysis. The procedure to manufacture complicated shape of paddle type blade tip was developed and composite blades were manufactured after establishing the effective curing method. Through this research, the development technology of composite rotor blade with complex aerodynamic shape were accumulated and these will be applied to the related research field, for example, full size composite blade development, etc.

• Journal of the Korean Society of Manufacturing Process Engineers
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• 제6권4호
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• pp.65-70
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• 2007

In this study, we analyzed about that after design form manufacture master pattern in Rapid Prototyping-RP through design program, processes to manufacture prototype using Vacuum Casting. In Rapid Prototyping-RP, there is an en-or by shrinkage of resin and, in Vacuum Casting, there is an error by shrinkage of silicon. To select condition which shrinkage become the minimum of each process, manufactured prototype after using Full Factorial Design of Design of Experiments, We could confirm shrinkage using reverse engineering and that result came into effect ANOVA 2-way. We applied errors of each process to master pattern, and then presented the method to improve flood control precision of prototype of Vacuum Casting.

• Journal of the Korean Society for Precision Engineering
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• 제26권1호
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• pp.82-88
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• 2009

Ultra-precision turning is highly needed to manufacture molds for precision lens. In this study, micro-turning combined with elliptical vibration cutting (EVC), which is known to enhance micro- machining quality, was investigated by installing a rotary stage into the micro-grooving machine. From machining experiments involving materials of copper, brass, and aluminum and single and poly crystalline diamond tools, it was found that EVC produced thinner and curlier chips and that better surface finish could be achieved, compared with conventional turning, owing to prohibition of formation of burrs and built-up edges. Therefore, we found EVC micro turning could be readily utilized to manufacture precision mold.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.428-432
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• 2003

The technical combination of RP and RT has a potential for rapid manufacturing of three-dimensional parts. In the present work a new RP system, $VLM-_{ST}$, is proposed to manufacture net shapes of 3D prototypes. ㅁ human head shape and a kob shape are manufactured by the $VLM-_{ST}$ apparatus. In addition, a new RT technology, which utilizes a RTV molding technique and a triple reverse process technique, is proposed to manufacture net shapes of 3D plastic parts using prototypes of $VLM-_{ST}$. A plastic part of the knob shape os produced by the proposed RT technology. The combination of the proposed RP and RT enables the manufacturing of a plastic knob within two days.

• International Journal of CAD/CAM
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• 제6권1호
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• pp.99-104
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• 2006

Engineering graph plays an important role in design and manufacture, such as architecture, machinery, manufacture, military. However, almost no persons consider the security and copyright of two-dimensional engineering graph. A novel method for two-dimensional engineering graph watermark based U system is proposed in this paper. Watermarks generated by this technique can be successfully extracted even after rotation, translation and scaling transform.

• Journal of the Korean Institute of Telematics and Electronics D
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• 제34D권2호
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• pp.10-20
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• 1997

This paper describes the design, the manufacture and the development of th eautomatic gain control unit which ajdusts the gain of IF processor in the high sensitive & multifunctional receiver unit (HMR) for pulse doppler radar system. Accodording to the effective distnce of target, radar cross section, and a lot of external environments (such as clutter), the receiving stage of RADAR system often deviates from dynamic range. To solve this kind o fproblem, continuous/pulse wave AGC are realized, make it possible to control the gain characteristics of receiver stably, and can increase dynamic range linearly by adjusting the gain slope of receiver which is limited by 1-dB gain compression point. In this study, AGC unit is designed to regulate the total gain of receiver by using te analog feedback theory. It also has rapid enough response to process pulse signal. This study presents the gain control method of IF, the real manufacture technique (the package-type components) and the measurement performance of AGC.

• Journal of Korean Society for Quality Management
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• 제22권4호
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• pp.160-167
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• 1994

Even though the woollen-yarn-making process as a whole has received much attention from customers in recent years, but yet there exist many problems to improve quality, productivity, and working environment in a small-medium woollen-yarn manufacture. To achieve the aim for improvement of quality and productivity, we have performed a period of education and training for workers. And thus this paper reports a study carried out them in the company located in near Pusan. Also, this paper describes a study how has a small-medium company introduced the education for the workers by authors. Among the possible outcome of this study is that the company does encounter considerable difficulties in the education and training. But to improve the quality and productivity, we assert that the company has to overcome these courses. We all recognize that the employer has been prepared for education and training to improve the employees' working conditions for a long time.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.237-242
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• 2004

In design stage of high precision manufacture/inspection FAB building, it is necessary to investigate the vibration allowable limits of high precision equipment and to study a structure dynamic characteristics of C/R and Sub-structure in order to provide a structure vibration environment to satisfy thess allowable limits. The aim of this study is to investigate the dynamic characteristics of PC-Type mock-up structures designed for next TFT LCD FAB through vibration measurement and analysis procedure, therefore, to provide a proper dynamic structure design for high precision manufacture/inspection work process, which satisfy thess allowable limits.