• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2002.10a
• /
• pp.445-452
• /
• 2002

토목 및 건축구조물에 대한 합리적이고 정확한 설계, 시공은 물론 구조물 시공후의 안전 점검, 보수ㆍ보강 등을 위한 계측은 구조물의 사용성을 항상 최적의 상태로 유지하고 구조물의 공용수명을 연장시키는데 있어 매우 중요하다. 일반적으로 사용단계의 구조물은 시간이 경과함에 따라 초기의 설계, 시공상 오류에 의한 초기결함, 반복하중 그리고 취약한 환경 등 외부 조건에 노출될 경우에는 구조물 본연의 성능을 점차 상실하게 되어 심지어는 인명과 재산권을 위협하는 대형 붕괴사고를 일으키기도 한다. (중략)

• Computational Structural Engineering
• /
• v.3 no.3
• /
• pp.133-140
• /
• 1990

Analysis of cable structures is complex because their force - displacement relationships are highly nonlinear and also because large deformations introduce geometric nonlinearity. Therefore, we must take account their geometric nonlinearity in the analysis and find the equilibrated shape of cable structures. In this paper, to slove these problems, numerical procedures involving geometrical nonlinearity are introduced. They are applicable to general cable net, flexible transmission lines and suspended cable roof. These procedures are divided into two parts; one is to obtain the equilibrated shapes and stresses of the cable structures with uniform load by flexibility iteration method, the other is to analyse the equilibrated structures subjected to nodal external forces by nonlinear finite element method.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2011.07a
• /
• pp.359-360
• /
• 2011

본 논문에서는 고속으로 디지털 홀로그램을 생성할 수 있는 하드웨어구조를 제안하였다. 수정된 컴퓨터 생성 홀로그램(computer-generated hologram, CGH) 알고리즘을 이용하고, 전체 화소에서 홀로그램의 한 화소씩 연산하는 방법을 선택하여 홀로그램 한 화소씩 계산하고 바로 출력 하여 메모리 병목현상을 제거하기 위한 파이프라인 기반의 하드웨어 구조를 제안하였다. CGH 알고리즘을 바탕으로 입력부, 연산부, 및 정규화부로 구성된 디지털 홀로그램 생성기의 구조를 제안하였고, 객체의 화소만 저장하여 반복 사용하기 때문에 메모리의 사용량을 줄일 수 있었다. 제안한 하드웨어는 세로 방향으로 확장을 하여 동작을 병렬화시킬 수 있다. 제안한 하드웨어는 1K의 광원에 대해 HD급 홀로그램을 초당 약 87장을 생성할 수 있었다.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2011.04a
• /
• pp.144-147
• /
• 2011

본 논문에서는 기존의 선형정적해석 절차를 변형하여 부재의 이력모델 응용을 통해 부재 파괴여부에 따라 힌지처리 및 재해석의 반복과정을 자동으로 수행하는 새로운 연쇄붕괴 프로그램을 제안하였다. 6m 4경간의 철근콘크리트 골조에 철골 가새를 보강 설치한 예제구조물에 대하여 최하층 기둥부재를 제거한 후 기존 해석법과 제안 해석법을 통해 선형정적해석을 수행하였고, 그 결과를 비교 분석하였다. 해석 결과, 두 절차 간 부재단위의 파괴여부 및 구조물 힌지 분포 경향의 동일함을 보여 해석의 신뢰성을 확보하였으며. 기존 해석법에 비해 수행단계의 시간이 매우 짧고 자동 반복해석으로 인한 오류의 가능성도 최소화 할 수 있음을 확인하였다.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2011.04a
• /
• pp.67-70
• /
• 2011

해안에 위치한 철근콘크리트 구조물 및 사회 간접 시설물들은 염해피해에 대한 우려가 있다. 염해피해로 인한 철근의 부식현상이 발생하면 철근과 콘크리트 부착성능의 저하로 인한 부재의 내력감소를 가져 올 수 있다. 따라서 본 연구에서는 염해부식이 진행되어 콘크리트와 철근간의 부착 및 비부착 여부에 따른 성능을 확인하기 위하여 완전 비부착된 보-기둥 접합부를 철근부착용 고무튜브를 이용하여 제작하였다. 제작된 실험체로 준정적 반복횡하중을 이용한 실험을 통해 성능평가를 수행하였다. 비부착된 보-기둥 접합부의 비선형 해석을 하기 위해 4절점 래티스 모델로 개선하여 적용하였다.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.12 no.1
• /
• pp.29-35
• /
• 1999

접촉하는 두 물체 사이의 접합부에서는 국북적인 응력집중현상이 발생하여 기계 구조물의 마멸이나 파손의 직접적인 원인이 된다. 기존의 방법들은 복잡한 수식 처리와 반복 계산 때문에 접촉특성에 따라서 해석하기에 어려움이 많았다. 본 논문에서는 마찰이 있는 접촉문제를 반복계산 없이 효과적으로 해석하기 위해서 선형상보성 접촉조건과 가상일의 원리로부터 접촉요소를 개발하여 이를 사용한 유한요소 해석발법을 제안하였다. 연구결과로 평면 및 곡면 접촉문제나 다물체 접촉문제를 기존의 해석방법에 비해 훨씬 편리하고 정확하게 접촉현상을 규명할 수 있었다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.5 no.5
• /
• pp.409-412
• /
• 2004

This paper shows that the proposed Turbo TCM(Turbo Trellis Coded Modulation) has a good performance with a little complexity of decoder. The encoder structure, which is connected with Turbo Codes, is the proposed modulation technique for an efficient bandwidth, This method is used symbol by symbol MAP decoder of iteration similar to binary Turbo Codes in the receiver. The result shows that the BER performance according to iteration is improved about 2,5dB at $BER=10^{-2}$ compared to Turbo Codes with Gray mapping.

• (The) Research of the performance art and culture
• /
• no.34
• /
• pp.383-421
• /
• 2017

Because the Jitsori and the Hotsori of the Beompae(the Korean Budhhist chant) has no meter and no Jangdan(a Rhythmic cycle of the Korean Music), so it is hard to analyze the melody of the Beompae. Also the melody of the Beompae is different from that of the other Korean traditional music, so studying of the Beompae has been out of the limelight of many scholars, studying the Korean music. But the melody of Beompae had been handed down for thousands of years in Korea, it and other Korean trditional music, had exchanged the impacts each other for a longtime. So I thinks that the Korean Beomapae have shared the similarity of the musical features with the other Korean traditional music. Because the Beompae of the Bulmosan Yeongsanjae on the Geongsangnamdo province has also no meters and no Jangdan, it is difficult to understand, too. But because the Onghoge of Bulmosan Yeongsanjae have a well-regulated melodic structure in comparison with the Beompae of the Seoul province, so called Geongjae Beompae, it seem to be easy to analyze its melody. So I will analyze the melody of Bulmosan Yeongsanjae Onghoge. This analyze should be contribute to investigate the rule of the melodic progress method on the convoluted Beompae melody. Onghoge has been sung on the procedure for Siryeon, Samsiniun(Goebuliun), Jojeonjeoman, Sinjungjakbeop. And the monk for the ritual has sung the chant first to purify the ritual place and to protect the soul. They has called the song, Onghoge a Jitsori at the Bulmosan Yeongsanjae preservation society of the Gyeongnam province. Commonly, there were Jitsori and Hotsori in the Beompae melody, and the melody of Jitsori is longer than that of the Hotsori. So, the melody of Onghoge is lengthened. In other word, the melody of the Onghoge show the lengthened and curved melodic feture of the Beompae very well. Hahn Manyeong, who had studied on the Beompae, Budhhist chant, said that the Hotsori has five letters in a phrase, and there were 4 phrases in a song. And he had insisted that the form of the song, Hotsori, is ABAB. I analyze the melody of the Onghoge by the Hahn's method. I will extract the Wonjeom(a primary tone of a skeletal melodic structure) from the melody of Onghoge, and in the progress of the Wonjeom of Onghoge melodies, I will arrange the repeat of the Wonjeom melody. It is a structural melody of Onghoge. The first phrase of Bulmosan Yeongsanjae Onghoge, 'Pal bu geum gang ho do ryang(八部金剛護道場)' have 4 structural melodies, the second phrase 'Gong sin sog bu bo cheon wang(空神速赴報天王)', the third phrase 'Sam gye je cheon ham le jip(三界諸天咸來集)', the firth phrase 'Yeo geum bul chal bo jeong sang(如今佛刹補禎祥)' have 2 structural melodies each. The structural melodies of Onghoge are 10 in total. And the structural melody of the Onghoge is formed the shape of 'Mi - La - do - La - Mi'. All of the Onghoge melodies is repeated 10 times by the melodic shape. The form of the Onghoge is not ABAB by Hahn, but is 10 times repeat of the shape.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.17 no.1
• /
• pp.85-93
• /
• 2013

In order to make a more reasonable evaluation on the stiffness of the high-strength mortar-filled sleeve bar splices under cyclic loading, we investigated and analyzed the existing experiment data of 106 full-sized reinforcing bar splices with test variables such as compressive strength of mortar, development length of reinforcement and sleeve type, etc. The following were found: 1) If mortar and the reinforcement development length with $f_{g^*}$(L/d) of more than 340 is used, the cast iron sleeve bar splices for SD350 and SD400 will have the stiffness of higher than A class of the AIJ code. 2) If mortar and the reinforcement development length with $f_{g^*}$(L/d) of more than 400 is used, the cast iron sleeve splices and pipe sleeve splices for SD500 will have the stiffness of higher than A class of the AIJ code.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.4
• /
• pp.313-319
• /
• 2017

Fiber optics sensors that have been mainly applied to aerospace areas are now finding applicability in other areas, such as transportation, including railways. Among the sensors, the fiber Bragg grating (FBG) sensors have led to a steep increase due to their properties of absolute measurement and multiplexing capability. Generally, the FBG sensors adhere to structures and sensing modules using adhesives such as an epoxy. However, the measurement errors that occurred when the FBG sensors were used in a long-term application, where they were exposed to environmental thermal load, required calibration. For this reason, the thermal curing of adhesives needs to be investigated to enhance the reliability of the FBG sensor system. This can be done at room temperature through cyclic thermal load tests using four types of specimens. From the test results, it is confirmed that residual compressive strain occurs to the FBG sensors due to an initial cyclic thermal load. In conclusion, signals of the FBG sensors need to be stabilized for applying them to a long-term SHM.