• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.93-96
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• 2000

In this paper, physical properties of planting concrete using Recycled aggregates made with demolished concrete and construction wastes are investigated. According to the test results. It shows that recycled aggregates made with demolished concrete and construction wastes have low physical properties compared with crushed stone. But, recycled aggregates made with construction wastes shows better performance in absorption ratio, unit weight and thermal conductivity than crushed stone. According it is thought that they are available for being applied to planting concrete considering the sides of efficient recycling of construction wastes and saving the manufacturing cost.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1236-1239
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• 2008

Through the optimization design of the pneumatic components it leads the energy efficiency increasement and resources saving. Also it effects on the high speed operation, low speed operation, low weight, and complexity of pneumatic systems. In this paper the development of the software will be described based on Object-Oriented technology, which will provide function for development of pneumatic system without any deep knowledge about pneumatic system.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 춘계학술대회 논문집
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• pp.17-20
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• 2002

Recently tube hydroforming technology has been one of the most important technology in automotive industry in the point of saving weight and high quality for collision accidents. In this paper, experimental studies for axial compression tests of hydroformed tubes are performed to investigate the collapse absorption characteristics. The collapse absorption abilities are discussed and compared for as-received, hydroformed, and press formed tubes.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
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• pp.181-184
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• 2001

This paper has been studied driving circuits in electrical valves. Also in this paper, opto-couplers of driving circuit are replaced with digital one chip of Altera company. Designs in order to realization of one chip are carried out with Altera Max Plus II. For compact size and light weight, the realization with one chip is necessary in the electrical valves. This paper has designed and presented the digital schemetic circuits, finally the driving circuits are sucessfully operated with the designed chip and showed the saving of area in the driving circuits of electric valves.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1005-1006
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• 2011

• 한국잠사곤충학회지
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• 제42권1호
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• pp.24-27
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• 2000

A new silkworm variety 'Yangwonjam'for both of spring and autumn rearing season is F$_1$hybrid between Jam 143, a Japanese race bred from H5R1/P8503 and Jam 144, a Chinese race from M8312/8190. This is the first both parent sex-limited larval marking variety in Korea, and which contributes to eggs production of F$_1$hybrid silkworm with saving labor. Jam 143, Japanese parent of the 'Yangwonjam'showed high GCA in pupation percentage and Jam 144, Chinese parent showed high GCA in pupation percentage and single cocoon weight. In the local adaptability test performed at 8 local areas in spring of 1998, Yangwonjam records 1% higher in pupation percentage and 5%, 4% lower in single cocoon weight, cocoon yield from 10,000 3rd molted larvae respectively than the check variety Kumokjam. Also in the resistance test against unfavorable rearing condition performed in spring of 1997, Yangwonjam records 9%, 14% lower in single cocoon weight, cocoon shell weight respectively than the check variety, but showed 1% higher in pupation percentage than check variety.

• 항공우주시스템공학회지
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• 제10권1호
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• pp.43-50
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• 2016

In order to suggest the optimal manufacturing technology of composite wings of solar-powered unmanned aerial vehicles, this study compared forming technologies to reduce wing weight for long-endurance flight and to improve the manufacturing process for cost-saving and mass production. It compared the manufacturing time and weight of various composite wing molding technologies, including cocuring, secondary bonding, and manufacturing by balsa. As a result, wing weight was reduced through cocuring methods such as band type composite fiber/tape lamination technology, which enabled prolonged flight duration. In addition, the reduced manufacturing time led to a lower cost, which is a good example of weight lightening for not only small solar-powered UAVs, but also composite aircraft.

• 대한조선학회논문집
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• 제33권3호
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• pp.103-111
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• 1996

이미 저자들에 의해 기존의 경사처짐법을 일반화하여 일반화 경사처짐법을 정립하였으며, 일차적으로 횡강도 해석 측면에서 그 유용성을 확인하기 위해 유조선을 대상으로 frame modeling을 통한 횡강도 해석을 수행한 바 있다. 본 연구에서는 설계 측면에서의 일반화 경사처짐법의 유용성을 확인하기 위해 일반화 경사처짐법과 이산화 변수를 고려한 최적화 기법을 결합하여 최소 중량 설계 프로그램을 개발하였다. 이 프로그램을 통해 주어진 설계 조건하에서 최소 중량을 주는 유조선의 설계 치수를 결정할 수 있었으며, 실적선에 비해 상당한 양의 선각 중량이 감소가 되는 설계가 가능함을 보여 주었다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.278-282
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• 2003

There is a strong industrial demands for the development of light-vehicle to improve fuel efficiency. It is more effective to reduce weight of the parts directly driven by an automobile engine. So the saving in weight of wheels which is operated by an automobile engine improve fuel efficiency more than other parts. There are many step of sheet metal forming in fabricating automotive wheel, so that it is difficult to design process and tools of multi-stage stamping. Traditionally, design process and tools have depended on the experience of skilled workers and it has done by trial and error methods. However, it needs too much costs and time. Taguchi methods has an advantage of the number of required experiments and reliability compared with trial and error method. In this study, Taguchi methods and response surface methods are applied to design process and tools of automotive wheel. As a result, the principal variables are selected and process conditions are optimized.

• Structural Engineering and Mechanics
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• 제43권6호
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• pp.795-821
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• 2012

The size and topology of geometrically nonlinear dome structures are optimized thereby minimizing both its entire weight & joint (node) displacements and maximizing load-carrying capacity. Design constraints are implemented from provisions of American Petroleum Institute specification (API RP2A-LRFD). In accordance with the proposed design constraints, the member responses computed by use of arc-length technique as a nonlinear structural analysis method are checked at each load increment. Thus, a penalization process utilized for inclusion of unfeasible designations to genetic search is correspondingly neglected. In order to solve this complex design optimization problem with multiple objective functions, Non-dominated Sorting Genetic Algorithm II (NSGA II) approach is employed as a multi-objective optimization tool. Furthermore, the flexibility of proposed optimization is enhanced thereby integrating an automatic dome generating tool. Thus, it is possible to generate three distinct sphere-shaped dome configurations with varying topologies. It is demonstrated that the inclusion of brace (diagonal) members into the geometrical configuration of dome structure provides a weight-saving dome designation with higher load-carrying capacity. The proposed optimization approach is recommended for the design optimization of geometrically nonlinear dome structures.