• Structural Engineering and Mechanics
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• 제67권1호
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• pp.9-20
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• 2018

In this paper, a framework is proposed for dynamic analysis of train-bridge systems with a damaged pier after barge collision. In simulating the barge-pier collision, the concrete pier is considered to be nonlinear-inelastic, and the barge-bow is modeled as elastic-plastic. The changes of dynamic properties and deformation of the damaged pier, and the additional unevenness of the track induced by the change of deck profile, are analyzed. The dynamic analysis model for train-bridge coupling system with a damaged pier is established. Based on the framework, an illustrative case study is carried out with a $5{\times}32m$ simply-supported PC box-girder bridge and the ICE3 high-speed train, to investigate the dynamic response of the bridge with a damaged pier after barge collision and its influence on the running safety of high-speed train. The results show that after collision by the barge, the vibration properties of the pier and the deck profile of bridge are changed, forming an additional unevenness of the track, by which the dynamic responses of the bridge and the car-body accelerations of the train are increased, and the running safety of high-speed train is affected.

• 한국통신학회논문지
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• 제28권6C호
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• pp.561-569
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• 2003

본 논문에서는 Alamouti［1］, Tarokh［14］, Xia［11］에 의해 도입된 직교 시공간 부호를 포함한 임의의 선형 직교 시공간 블록 부호에 대해, 느린 레일라이 페이딩 채널(slow Rayleigh fading channel)의 쌍간 오율(pairwise error probability)의 정확한 표현이 2개의 전송된 부호어 행렬(codeword matrices) 사이의 부호어 심볼 거리(codeword symbol distance)가 아니라, 2개의 메시지 벡터(messgae vector) 사이의 메시지 심볼 거리(message symbol distance)의 식으로 유도된다. 1차원 성분의 심볼 오율을 이용하여, 선형 직교 시공간 부호의 심볼 오율의 정확한 폐형의 표현이 QPSK, 16-QAM, 64-QAM과 256-QAM에 대해 유도된다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2008년도 International Meeting of the Microbiological Society of Korea
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• pp.147-149
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• 2008

• 국제초고층학회논문집
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• 제2권3호
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• pp.171-178
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• 2013

The emergence of a growing number of tall buildings, often with unusual shapes and innovative structural systems, has led to the realization of the need for and the importance of field measurements. The new China Central Television (CCTV) Tower in Beijing is one of tall buildings with a highly unusual shape and a complex structural system, requiring field measurements to identify its dynamic characteristics for the subsequent dynamic analysis of the tower under wind excitation, seismic-induced ground motion and traffic-induced ground motion. The structural system and the finite element model of the CCTV Tower are first introduced in this paper. The computed natural frequencies and mode shapes are then presented as a reference for the field measurement. After introducing the arrangement of the ambient vibration measurement, the field measured natural frequencies and damping ratios of the CCTV Tower are presented and the measured natural frequencies are finally compared with the computed ones. It was found that the structural damping ratios of the CCTV Tower are small and the computed natural frequencies are smaller than the measured ones by about 12~17%.

• BMB Reports
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• 제47권7호
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• pp.388-392
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• 2014

Berberine, a type of isoquinoline alkaloid isolated from Chinese medicinal herbs, has been reported to have various pharmacological activities. Studies have demonstrated that berberine has beneficial effects on vascular remodeling and alleviates restenosis after vascular injury. However, its mechanism of action on vascular smooth muscle cell migration is not fully understood. We therefore investigated the effect of berberine on human aortic smooth muscle cell (HASMC) migration. Boyden chamber assay was performed to show that berberine inhibited HASMC migration dose-dependently. Real-time PCR and Western blotting analyses showed that levels of matrix metalloproteinase (MMP)-2, MMP-9, and urokinase-type plasminogen activator (u-PA) were reduced by berberine at both the mRNA and protein levels. Western blotting assay further confirmed that activities of c-Fos, c-Jun, and NF-${\kappa}B$ were significantly attenuated. These results suggest that berberine effectively inhibited HASMC migration, possibly by down-regulating MMP-2, MMP-9, and u-PA; and interrupting AP-1 and NF-${\kappa}B$ mediated signaling pathways.

• Structural Engineering and Mechanics
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• 제81권1호
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• pp.69-79
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• 2022

The dynamic responses of a pier-pile-soil system subjected to a barge/flotilla collision are analyzed. A coupled high-speed train and bridge system with a damaged pier after barge/flotilla collision is established by taking the additional unevenness of the track induced by the damaged pier as the self-excitation of the system. The whole process of a CRH2 high-speed train running on the 6×32 m simply-supported PC (prestressed concrete) box-girder bridge with a damaged pier is simulated as a case study. The results show that the lateral displacements and accelerations of the bridge with a damaged pier are much greater than the ones before the collision. The running safety indices of the train increase with the train speed as well as with the number of barges in the flotilla. In flotilla collision, the lateral wheel/rail forces of the train exceed the allowable values at a certain speed, which influences the running safety of the trains.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1990년도 Proceedings of International Symposium on Korean Ginseng, 1990, Seoul, Korea
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• pp.87-94
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• 1990

• Journal of applied mathematics & informatics
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• 제17권1_2_3호
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• pp.419-432
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• 2005

In this paper we study the no-wait or no-idle permutation flowshop scheduling problem with an increasing and decreasing series of dominating machines. The objective is to minimize one of the five regular performance criteria, namely, total weighted completion time, maximum lateness, maximum tardiness, number of tardy jobs and makespan. We establish that these five cases are solvable by presenting a polynomial-time solution algorithm for each case.

• Journal of applied mathematics & informatics
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• 제17권1_2_3호
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• pp.93-107
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• 2005

Based on the recently developed ABS algorithm for solving linear Diophantine equations, we present a special ABS algorithm for solving such equations which is effective in computation and storage, not requiring the computation of the greatest common divisor. A class of equations always solvable in integers is identified. Using this result, we discuss the ILP problem with upper and lower bounds on the variables.

• Journal of applied mathematics & informatics
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• 제17권1_2_3호
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• pp.185-194
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• 2005

A Server-Proxies-Users communication system is studied by using Stackelberg strategy theory of game. A new model, in which the server, proxies and users are not equal is established, and that is a three-level programming. The solution existence of the model is proved.