Vibration suppression in high-speed trains with negative stiffness dampers

Shi, Xiang,Zhu, Songye,Ni, Yi-qing,Li, Jianchun Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.21 No.5

This work proposes and investigates re-centering negative stiffness dampers (NSDs) for vibration suppression in high-speed trains. The merit of the negative stiffness feature is demonstrated by active controllers on a high-speed train. This merit inspires the replacement of active controllers with re-centering NSDs, which are more reliable and robust than active controllers. The proposed damper design consists of a passive magnetic negative stiffness spring and a semi-active positioning shaft for re-centering function. The former produces negative stiffness control forces, and the latter prevents the amplification of quasi-static spring deflection. Numerical investigations verify that the proposed re-centering NSD can improve ride comfort significantly without amplifying spring deflection.

Performance analysis of vehicle suspension systems with negative stiffness

Xiang Shi,Wei Shi,Lanchang Xing 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.1

This work evaluates the influence of negative stiffness on the performances of various vehicle suspension systems, and proposes a re-centering negative stiffness device (NSD). The re-centering NSD consists of a passive magnetic negative stiffness spring and a positioning shaft with a re-centering function. The former produces negative stiffness control forces, and the latter prevents the amplification of static spring deflection. The numerical simulations reveal that negative stiffness can improve the ride comfort of a vehicle without affecting its road holding abilities for either passive or semi-active suspension systems. In general, the improvement degree of ride comfort increases as negative stiffness increases. For passive suspension system, negative stiffness brings in negative stiffness feature in the control forces, which is helpful for the ride comfort of a vehicle. For semi-active suspensions, negative stiffness can alleviate the impact of clipped damping in semi-active dampers, and thus the ride comfort of a vehicle can be improved.

Advanced Z80 Emulator in MASSCOMP

Xiang, Shi Zhao 대한전자공학회 1992 HICEC:Harbin International Conference on Electroni Vol.1 No.1

In older to raise the availability and meet the urgent needs of microcomputer principle teaching, we have developed on MASSCOMP or Massachusetts Computer, a large mainframe multi-user system with up to 64 terminals, Z80 Emulator (Z80SS V1.0) and Advanced Z80 Emulator(Z80SS V2.0) in C language. This paper addresses the struchure, function, effect and technical features of these two systems.

A model experiment of damage detection for offshore jacket platforms based on partial measurement

Shi Xiang,Li Hua-jun,Yang Yong-chun,Gong Chen 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.29 No.3

Noting that damage occurrence of offshore jacket platforms is concentrated in two structural regions that are in the vicinity of still water surface and close to the seabed, a damage detection method by using only partial measurement of vibration in a suspect region was presented in this paper, which can not only locate damaged members but also evaluate damage severities. Then employing an experiment platform model under white-noise ground excitation by shaking table and using modal parameters of the first three modes identified by a scalar-type ARMA method on undamaged and damaged structures, the feasibility of the damage detection method was discussed. Modal parameters from eigenvalue analysis on the structural FEM model were also used to help the discussions. It is demonstrated that the damage detection algorithm is feasible on damage location and severity evaluation for broken slanted braces and it is robust against the errors of baseline FEM model to real structure when the principal errors is formed by difference of modal frequencies. It is also found that Z-value changes of modal shapes also play a role in the precise detection of damage.

Review in isothermal amplification technology in food microbiological detection

Xiang Li,Xiaolong Zhang,Xiaoli Shi,Hongfei Shi,Zhouping Wang,Chifang Peng 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.12

Food-borne diseases caused by microbial contamination have always been a matter of great concern to human beings. Hence, the research on these problems has never stopped. With the development of microorganism amplification technology, more and more detection methods have come into our vision. However, traditional detection technologies presents more or less drawbacks, such as complicated operation, low accuracy, low sensitivity, long-time detection, and so on. Therefore, more convenient, accurate, and sensitive measurement for the microorganism are needed. Isothermal amplification technology is one of the alternative approach containing the above mentioned advantages. This work mainly summarizes the principles of loop-mediated isothermal amplification (LAMP) and rolling circle amplification (RCA) which belong to isothermal amplification. Meanwhile, the application of LAMP and RCA in food microorganism detection is introduced.

Nonlinear impact of negative stiffness dampers on stay cables

Shi, Xiang,Zhu, Songye Techno-Press 2018 Structural monitoring and maintenance Vol.5 No.1

Negative stiffness dampers (NSDs) have been proven an efficient solution to vibration control of stay cables. Although previous studies usually assumed a linear negative stiffness behavior of NSDs, many negative stiffness devices produce negative stiffness with nonlinear behavior. This paper systematically evaluates the impact of nonlinearity in negative stiffness on vibration control performance for stay cables. A linearization method based on energy equivalent principle is proposed, and subsequently, the impact of two types of nonlinear stiffness, namely, displacement hardening and softening stiffness, is evaluated. Through the Hilbert transform (HT) of free vibration responses, the effects of nonlinear stiffness of an NSD on the modal frequencies, damping ratios and frequency response functions of a stay cable is also investigated. The HT analysis results validate the accuracy of the linearization method.

Advanced Z80 Emulator in MASSCOMP

Shi Zhao Xiang 대한전자공학회 1992 대한전자공학회 Conference Vol.1992 No.2

중국 2차원문화 환경에서의 IP(지적 재산권) 확대재생산에 대한 연구

석향란(Xiang-Lan Shi) 한국애니메이션학회 2018 애니메이션연구 Vol.14 No.1

2015년 이후 중국의 모든 문화콘텐츠 산업은 전성기를 맞아 급속도로 성장하고 있다. 세계시장에서의 〈몽키 킹〉에 대한 호응은 고전 IP 서유기가 가지고 있는 본연의 내재적 가치뿐만 아니라, 『서유기』 IP가 가지는 캐릭터성과 공간성, 서사구조 측면에서 새롭게 가치 증식과 재생산 될 수 있는 IP의 확장영역을 찾아보고, IP 확대재생산 실현 과정을 첫째로는 국제화 시장을 타깃으로 한 이야기의 취사선택과 혁신, 둘째로는 수용자의 전연령화(全龄化)를 위한 캐릭터의 재가공, 셋째로는 중국 전통문화를 디지털 매체의 표현기술을 활용한 중국무술 요소의 차용으로 분석하였다. 또한 〈몽키 킹〉의 성공은 팬들의 자발적인 홍보로 인해서 부각되었는데, 이러한 원활한 수용자 소통현상을 ‘자래수(自来水)’현상으로 살펴보았다. 따라서 본 연구는 중국 2차원문화 환경에서 IP 확대재생산에 대한 적절한 발전 경로를 논의 하였다. Since 2015, all cultural contents industry in China has been growing rapidly. In response to the 〈Monkey King〉 in the world market, not only the intrinsic value of the classic IP 〈Journey to the West〉 but also the IP that can be newly added value and reproduced in terms of character, space and narrative structure. The process of realizing IP enlargement and reproduction analyzed as follows: First, the selection and innovation of stories targeting the global market. Second, the reprocessing of characters for the all ages. And third, Chinese traditional culture as borrowing of Chinese martial arts using technology of expression of digital media. In addition, the success of 〈Monkey King〉 was highlighted by the voluntary publicity of fans. I have observed this phenomenon of these users’ communication as ‘Running Water’ phenomenon. Therefore, this study discussed the appropriate development path for IP enlargement reproduction in Chinese Two-Dimensional Cultural environment.

Toll-like Receptor 5 Agonist Inhibition of Growth of A549 Lung Cancer Cells in Vivo in a Myd88 Dependent Manner

Zhou, Shi-Xiang,Li, Feng-Sheng,Qiao, Yu-Lei,Zhang, Xue-Qing,Wang, Zhi-Dong Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

The purpose of this study was to examine the effect of a Toll-like receptor 5 (TLR5) agonist, CBLB502, on the growth and radiosensitivity of A549 lung cancer cells in vivo. Expression of myeloid differentiation factor 88 (MyD88) or TLR5 was stably knocked down in human lung cancer cells (A549) using lentivirus expressing short hairpin RNA targeting human MyD88 or TLR5. Lack of MyD88 or TLR5 expression enhanced tumor growth in mouse xenografts of A549 lung cancer cells. CBLB502 inhibited the growth of A549 lung cancer cells, not A549-MyD88-KD cells in vivo in the murine xenograft model. Our results showed that the inhibition of A549 by CBLB502 in vivo was realized through regulating the expression of neutrophil recruiting cytokines and neutrophil infiltration. Finally, we found that activation of TLR5 signaling did not affect the radiosensitivity of tumors in vivo.

Research of the Interconnection of Workflow System Based on Web Service

Gang Yuan,Rui-zhi Sun,Yong Xiang,Yin-xue Shi 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.2

In order to achieve the interconnection between different workflow management systems, it was proposed that all the distributed workflow systems would be encapsulated as web services to perform the entire business process collaboratively by the way of processes’ composition in this paper. By analyzing the comparison between the composition of processes and ordinary Web service, we studied interactive control, the parameters required to be passed through the distributed workflow systems, the workflow system service’s interfaces and its packaging. Furthermore we put forward a general method of the workflow systems interactive interfaces’ extension and the way of the workflow service’s encapsulating and invoking. By this approach, it can easily combine the processes or process fragments which deployed on different workflow systems without other agents and components. It also provides support for the interconnection of the workflow systems in distributed environment, and ultimately achieves a coordinated operation between different workflow engines.