The General Evaluation Method for Control Performance of Reentry Vehicle

2021 ◽  
pp. 679-689
Author(s):  
Zeyu Kang ◽  
Shufan Wu ◽  
Xiaoliang Wang ◽  
Jianhui Yu
Keyword(s):  
Evaluation Method ◽  
Control Performance ◽  
Reentry Vehicle ◽  
General Evaluation

scholarly journals Evaluation Method of Relative Humidity Changes in Below-Grade Concrete Structure Space Depending on Different Waterproofing Material and Installation Method

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 742
Author(s):  
Ki-won An ◽  
Kyu-hwan Oh ◽  
Bo Jiang ◽  
Xingyang He ◽  
Sang-keun Oh
Keyword(s):  
Relative Humidity ◽  
Linear Regression ◽  
Concrete Structure ◽  
Evaluation Method ◽  
Linear Regression Analysis ◽  
Evaluation Criteria ◽  
Cumulative Probability ◽  
Control Performance ◽  
Negative Side ◽  
Positive Side

An evaluation method for assessing the difference in the relative humidity (RH) control performance of waterproofing material is proposed. For a demonstration of this evaluation method, two waterproofing materials (urethane coating and cementitious waterproofing material) installed with different methods (positive and negative side of concrete structure respectively) are exposed to temperature conditions representing three seasonal conditions: Summer (40 °C), spring/autumn (20 °C) and winter (4 °C). Condensation level changes on the inner side of the waterproofing material installed specimen is measured, and for derive criteria for comparison, three parameters based on the average RH, intercept RH (derived from a linear regression analysis of RH measurement), and maximum relative humidity are derived for each different waterproofing material installed specimen. Based on quality specification for underground concrete structures, the demonstration evaluation establishes provisional standard criteria of below 70% RH, and all three parameters are evaluated to determine whether the tested waterproofing material/method complies to the performance requirement. Additional analysis through linear regression and cumulative probability density graphs are derived to evaluate the RH consistency and range parameters. The evaluation regime demonstrates a quantitative RH analysis method and apparatus, and a newly designed evaluation criteria is used to compare the RH control performance of positive-side installed urethane waterproofing materials and negative-side installed cementitious waterproofing material.

A general evaluation method for the diabatic journal bearing

1974 ◽  
Vol 336 (1606) ◽  
pp. 307-325 ◽  
Keyword(s):  
Evaluation Method ◽  
Journal Bearing ◽  
Design Method ◽  
Three Dimensional ◽  
Algebraic Equations ◽  
Mixing Conditions ◽  
General Evaluation ◽  
Wide Range ◽  
Energy Equations ◽  
Independent Parameters

A design method is described for the steadily loaded, full journal bearing. This is presented as a non-iterative set of algebraic equations, where a dependent bearing parameter, e. g. eccentricity or power-loss, is predicted in terms of known independent parameters which include bearing geometry, running conditions and oil characteristics. The method is developed from a regression analysis of accurately computed, fully thermohydrodynamic, solutions for the bearing. These solutions are generated by simultaneously solving the Reynolds and energy equations in the oil film, the Laplace equation in the bearing material and the oil-mixing conditions at inlet. A quasi three-dimensional finite-difference technique is used. Both the particular solutions and the predictions of the design method compare favourably with a wide range of experimental data, the latter showing an improvement in accuracy and economy on existing design methods.

A Formation Mechanism and Tribological Properties of PTFE Transfer Film

2021 ◽  
Author(s):  
Hai Wang ◽  
Xiaowen Qi ◽  
Yu Dong ◽  
Bingli Fan ◽  
Changxin Liu ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Film Thickness ◽  
Tribological Properties ◽  
Dry Friction ◽  
Evaluation Method ◽  
Transfer Film ◽  
Intermolecular Force ◽  
Test Load ◽  
General Evaluation

Abstract Polytetrafluoroethylene (PTFE), as one of the most widely used solid lubricating materials, is thought to be very efficient at forming transfer film because of terrific low intermolecular force. This work investigates the tribological properties of PTFE transfer film under dry friction, and further explores its formation process and evolution mechanism. The friction coefficient is the lowest when the transfer film thickness is in range of 8-12 μm. An evaluation method for transfer film is proposed. The results show that the quality of the transfer film is closely related to the test load and velocity. This method is expected to be a general evaluation method for polymer transfer film, which can further directly evaluate the wear state of polymers, and even directly predict the tribological properties of polymers and abrasion life.

General Evaluation Method for Safety Control of Human-Care Robots

2000 ◽  
Author(s):  
Koji Ikuta ◽  
Makoto Nokata ◽  
Hideki Ishii
Keyword(s):  
Control Strategy ◽  
Evaluation Method ◽  
Control Strategies ◽  
Safety Control ◽  
General Evaluation ◽  
Care Robots ◽  
Safety Design ◽  
New Type ◽  
Human Care ◽  
And Control

Abstract In this paper, the first danger-evaluation method for use in various kinds of control strategies for human-care robots is proposed. In the case of a careless collision between a robot and a human, impact force and impact stress are chosen as evaluation values, and a danger index is defined to quantitatively evaluate the effectiveness of each safety strategy used for control. As in the previous paper on safety design, this proposed method allows us to assess the contribution of each safety control strategy to the overall safety performance of a human-care robot. In addition, a new type of robot simulation system for danger-evaluation is constructed on a workstation. The system simplifies the evaluation of danger in both the design and control of human-care robots to quantify the effectiveness of various safety strategies. Here we describe the results obtained, the successful optimization of a safety control strategy for human-care robots.

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