• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.3
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• pp.207-215
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• 2004

The objective of the present study is to understand the strengthening effects of reinforced concrete beam applied external prestressing with strand or CFRP(Carbon Fiber Reinforced Plastic). In the present study, the structural tests was performed to find the effects of stiffness and ductility for the strengthening RC beam. The experimental results show that proposed methods can increase the bending capacity such as strength, stiffness of the beam significantly and the ranged between 57% and 75% of the load-carrying capacity of the control beam.

• Journal of the Korea Concrete Institute
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• v.27 no.1
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• pp.11-20
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• 2015

An unbonded post-tensioned anchor using a 15.2 mm diameter 7-wire strand was developed based on finite element analysis and experimental testing. In order to evaluate its performance, static load tests and load transfer tests were conducted following KCI-PS101. The static load tests and additional strand tensile tests confirmed that the developed anchor had a capacity more than nominal tensile strength of a 7-wire strand without any damage or deterioration. According to the result of load transfer tests for many different reinforcing details, specimens with no additional reinforcing bars sustained at least 1.64 times the nominal tensile strength of the strand.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.843-854
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• 2013

This paper presents experimental research work for the evaluation of ultimate flexural behaviors of prestressed concrete beams with a corroded tendon. In order to evaluate the effects of loss of prestress or loss of tendon area on the ultimate flexural strength of prestressed concrete beams, static load tests are conducted using five prestressed concrete beams. After exposing prestressing tendons in two test beams using 25mm drill bit, the exposed tendons were corroded using an accelerating corrosion equipment to simulate loss of tendon area. During the tests, steel strains, concrete strains and displacements at the center of test beams were measured, and acoustic emission measurements were conducted to detect wire fractures. Based on the test results, evaluation method for predicting flexural strength of prestressed concrete beams with corroded tendons is investigated. In addition, evaluation methods for predicting the existence of corroded tendons in post-tensioned prestressed concrete beams at service loads are discussed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.2
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• pp.163-173
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• 2012

This study covers the nonlinear analysis of anchor head for high strength prestressing strand and presents necessary process in improving the performance of anchor head. The surface of wedge for strand is contacted to the surface of the wedge hole on anchor head when it is fitted into the wedge hole, and the contact condition changes according to the level of load applied through the wedge. In order to analyze detailed behavior, nonlinear material model and contact element were used in analysis. It was found from the analysis that the behavior of anchor head is affected by the interaction with the wedge contacted so that the wedge in FE model should have the same figure as the actual object. Circular array of wedge hole presents better stress distribution than layer array even though the small difference in maximum deformation. Increment of thickness of anchor head and distance of wedge hole also improve the performance of anchor head.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.6
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• pp.1723-1730
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• 2014

The use of strand wire in structure has been increased by the recent development of construction technologies. Until now, in spite of difficult problems in measuring strand stresses within PSC girders, indirect estimation with a load cell or accelerometer has been often used. In this paper, the electrical resistance strand meter for effective measurement of strand stresses is proposed with experiments considering material, location and thickness of sensor. The reliability and feasibility of the strand meter is enhanced through the experiment with 29.9m PSC girder.

• Journal of Digital Contents Society
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• v.11 no.4
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• pp.513-518
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• 2010

As the number of the deaf who go out into the society has been increasing, in most of the lectures, the demands for the sign language interpretation and the accuracy of the interpretation have become more important. Especially, in order to improve the accuracy of the sign language interpretation, the interpreter must be aware of the appearances of the lecturer and the contents of the lecture, and at the same time, the interpreter must look toward the audience. This research introduces a system which can be effective in a small classrooms or auditorium, by providing the maximum information about the lecturer and the contents of the lecture. Also, in order to verify the effectiveness of the proposed system, this research includes the discussions about the related systems and test methods. In conclusion, delivering the images of the lecturer and the contents of the lecture to the interpreter by employing the proposed system has been proved effective.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.395-401
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• 2022

In this study, the transfer length of strand was measured for three types of HCS member(H200, H320, and H400) manufactured by the pretension method. Strain gauges were attached in longitudinal direction at regular intervals on the sides of the HCS members, and the strain was measured during the cutting process of HCS. The stain at the cutting point was zero, and gradually increases in the central direction of the member, converging to a constant value after passing the transfer length. In the case of H200 members in which the strands were arranged one by one, the transfer lengths were formed within the range of the design equation (up to 762 mm). The transfer length of the H320 member and the H400 member, in which three strands were arranged, was higher than the design range (850 mm or more).

• Nuclear industry
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• v.38 no.7
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• pp.9-19
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• 2018

존 켈리 회장은 7월 12일 경주시 힐튼호텔에서 열린 '원자력 안전 및 해체산업 육성 국제 포럼'에 참석하여 'Perspectives on the Future of Nuclear Power in the United States'를 주제로 특별강연을 했다. 켈리 회장은 강연을 통해 미 행정부의 원자력정책, 미국 원자력산업의 단기 도전 과제, 전력 생산에서의 이산화탄소 감축과 원전 역할, 원전의 지속적인 운영, 미국에서 진행되는 신형 원자로 설계 등을 피력했다. 켈리 회장은 이날 언론과의 인터뷰에서 "한국은 원자력산업 강국인데, 원전 안전성에 대한 과학적인 근거보다 정치적 이슈로 신규 원전을 짓지 않고 수명 연장 대신 조기 폐쇄를 결정한 것은 우려할 사안"이라고 말하고 "원전산업 축소는 장기적으로 기업의 전력 확보가 어려워져 경제적 타격을 입는다. 특히 한국은 원전을 수출하면서 탈원전정책을 펴면 수출에 지장을 받지 않을까 걱정된다."고 밝혔다. 켈리 회장은 MIT 원자력공학박사로 미국 에너지부(DOE) 원자력에너지 기술책임자를 지냈다. 본고는 발표 내용을 정리한 것이다.

• The Science & Technology
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• v.10 no.9 s.100
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• pp.144-147
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• 1977

한국과학기술정보센터(KORSTIC)와 전경련의 공동주최로 강등차랑 일본과학기술정보센터(JICST) 이사장 초청 강연회가 9월 7일 3.1 빌딩 32층에서 개최되었다. 「일본산업계의 기술정보 이용」이라는 주제로 강연에서 강리사장은 「연구개발력이 약한 기업은 미래가 없으며 불황이라도 닥치는 날이면 도산하는 예도 있다」고 말하면서 「그러므로 산업발전을 위해서는 기술개발이 절대로 필요하며 그 전제로서 비용이 적게드는 과학기술정보를 잘 활용할 것」을 기업간부들에게 권하였다. 현재 세계에는 연간 400만건의 과학기술정보가 홍수처럼 쏟아지고 있으므로 이를 자국의 필요에 맞게 제품화하는 것이 정보센터의 큰 임무인 동시에 제품화된 정보가 수요자의 필요에 맞게 그리고 수요자가 쉽게 구할 수 있도록 서어비스를 다양화하는 것도 중요하다고 강조하면서 일본에서는 500억대 단말기로 전국적으로 Network를 확대할 계획이라고 말하였다. 다음은 이날 강리사장이 행한 강연전문이다.

• Journal of Sericultural and Entomological Science
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• v.28 no.2
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• pp.65-73
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• 1986

These studies are carried out to improve silk availability for anticrease by useing methacrylate monomer polymerization method with in silk fiber. For this purpose, degree of anticrease, stiffness and shrinkage of various silk fabrics, included finish or not, after repeat of washings and polyster fabric was compared as standard. The adopted samples are ; 1. Polyester, Georgette, Woven density…90cm-85g/m 2. Silk, Twill, Degumed, Light, Woven density…90cm-90g/m 3. Silk, Twill, Degumed, Heavy, Woven density…90cm-200g/m 4. Silk, Stain, Degumed, Light, Woven density…90cm-90g/m The reached results are as followings. 1. The results of improving on anticrease by the finished method were about ten per cent increase against their original samples. 2. The light density silks showed satisfactory improve for anticrease, but the heavy one remained as rather poor condition. 3. The results for degree of textile stiffness were investigated to make sure reserve their textile feeling and observed to be good condition upon the finish work. 4. Textile shrinkage after the repeat of soap wash was investigated on indivisual test sample and silk fabrics showed more shrinkage than polyester which it seemed to be tentering shrinkage druning their general finishing processes. 5. The investigation showed that anticrease, stiffness and shrinkage of the sample textile were more or less deteriorated regardless silk or polyester by the repeat of washings. These matters are considered that such results were obtained because of the fiber fatigue nature. 6. The report reached that silk textiles should be used by dry cleaning methed after finish of any resin finish to reserve their improved anticrease nature.