Policy optimization for vibration isolator stiffness control during agile attitude maneuvers

2022 ◽  
Vol 165 ◽  
pp. 108279
Author(s):  
Xuexuan Zhao ◽  
Zhaokui Wang ◽  
Gangtie Zheng
Keyword(s):  
Vibration Isolator ◽  
Stiffness Control ◽  
Policy Optimization

Vibration Isolator System for Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 182-183
Author(s):  
K. Ohi ◽  
M. Mizuno ◽  
T. Kasai ◽  
Y. Ohkura ◽  
K. Mizuno ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Magnetic Fields ◽  
Environmental Conditions ◽  
Vibration Isolator ◽  
Air Conditioners ◽  
Vibration Isolators ◽  
Large Size ◽  
Electron Microscopes

In recent years, with electron microscopes coming into wider use, their installation environments do not necessarily give their performance full play. Their environmental conditions include air-conditioners, magnetic fields, and vibrations. We report a jointly developed entirely new vibration isolator which is effective against the vibrations transmitted from the floor.Conventionally, large-sized vibration isolators which need the digging of a pit have been used. These vibration isolators, however, are large present problems of installation and maintenance because of their large-size.Thus, we intended to make a vibration isolator which1) eliminates the need for changing the installation room2) eliminates the need of maintenance and3) are compact in size and easily installable.

EVALUASI PROGRAM/PROYEK PENGEMBANGAN KAWASAN EKONOMI KHUSUS SEI MANGKE DALAM RANGKA PELAKSANAAN KEBIJAKAN MP3EI 2011-2025 DI KORIDOR EKONOMI SUMATERA

2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Firrean Firrean
Keyword(s):  
Local Government ◽  
Evaluation Process ◽  
Spatial Arrangement ◽  
Policy Program ◽  
Evaluative Research ◽  
Policy Optimization ◽  
Economic Zones ◽  
North Sumatra

Special Economic Zones (SEZ) is a region with certain limits within the jurisdiction of Indonesia which is set to perform economic functions and obtain certain facilities. One SEZ developed in North Sumatra Province and included in the National Strategic Area (KSN) Medan - Binjai - Deli Serdang - Karo is SEZ Sei Mangke. SEZ Sei Mangke is defined in PP 29 of 2012 on 27 February 2012 and is the first KEK in Indonesia which was inaugurated its operation by President Joko Widodo on January 27, 2015. KSN Mebidangro itself is an area of priority spatial arrangement because it has a very important influence nationally against state sovereignty, defense and state security, economic, social, cultural, and / or environment, including areas designated as world heritage. This research is an evaluative research intended to find out the end of a policy program in order to determine recommendation of last policy by using CIPO model which includes four stages: (1) context, (2) input, (3) process, and (4) output. The research method used is case study by applying qualitative research that aims to make an accurate interpretation of the characteristics of the object under study. Findings on the evaluation context indicate that the program is generally running well, but some aspects of synergy and policy optimization as well as financing support from central and local government need to be improved. In the input evaluation, and evaluation process some aspects need to be improved because the findings show the weakness of some aspects is the result of lack of synergy and optimization of policy and support from local government. Interesting from the evaluation of ouput is that with some weaknesses in the input and process components, it turns out the evaluation findings ouput show Seek Mangke SEZ development can still run well. The recommendation of this research is to improve the quality of policy synergy / program of SEZ Seek development by improving several aspects that are categorized in each stage of evaluation

Beneficial performance of a quasi-zero stiffness vibration isolator with generalized geometric nonlinear damping

2020 ◽  
pp. 095745652097238
Author(s):  
Chun Cheng ◽  
Ran Ma ◽  
Yan Hu
Keyword(s):  
Damping Ratio ◽  
Nonlinear Damping ◽  
Vibration Isolator ◽  
Equivalent Damping ◽  
Frequency Responses ◽  
Geometric Nonlinear ◽  
Resonant Region ◽  
Force Transmissibility ◽  
Isolation Performance ◽  
Force And Displacement Transmissibility

Generalized geometric nonlinear damping based on the viscous damper with a non-negative velocity exponent is proposed to improve the isolation performance of a quasi-zero stiffness (QZS) vibration isolator in this paper. Firstly, the generalized geometric nonlinear damping characteristic is derived. Then, the amplitude-frequency responses of the QZS vibration isolator under force and base excitations are obtained, respectively, using the averaging method. Parametric analysis of the force and displacement transmissibility is conducted subsequently. At last, two phenomena are explained from the viewpoint of the equivalent damping ratio. The results show that decreasing the velocity exponent of the horizontal damper is beneficial to reduce the force transmissibility in the resonant region. For the case of base excitation, it is beneficial to select a smaller velocity exponent only when the nonlinear damping ratio is relatively large.

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