机器人腕力传感器的动态负载效应

本文从时域和频域两方面研究机器人腕力传感器在加载情况下的动态响应，进行动态建模和频谱分析，探讨负载效应的影响。     

可移动机器人的运动学模型与控制原理

本文首先对可移动机器人的运动学进行了分析，建立了运动学模型与控制结构图，然后采用时域分析法对此系统进行了校正，最后通过对此系统的仿真与时测实验，对各校正环节的参数进行了整定。     

Materials modelling: A bridge from atoms to bulk properties

The use of molecular-level materials modelling techniques in the development of advanced performance polymers is discussed, with particular emphasis upon bridging the large difference in the scales of dimensions between atomic structure and fabricated parts. The advantages and disadvantages of bulk quantitative structure-property relations and atomistic modelling are assessed, and the method of group interaction modelling is suggested as a means of bridging the dimensional scales.After a brief introduction to the concept of group interaction modelling, examples of modelling the engineering properties of polymers are presented which are difficult to model quantitatively by any other means. The important phase transitions from the crystal and glassy states of matter to those of rubber- and liquidlike states are shown quantitatively to be due to the same isoenergetic condition. The viscoelastic properties of a polymer are critical for many applications and expressions are derived for the loss and storage components of the complex modulus, with reference to failure initiation conditions. The effect of crosslinking in thermosets upon the glass transition temperature and viscoelastic properties is outlined. Finally, the scaling of time from atomic vibrations to the years involved in creep and ageing effects are discussed.     

心理因素对分析数据的影响及预防措施

研究了分析人员的心理状态、情绪变化、内在动机等对分析数据的影响,提出了具体的对策和预防措施     

Adaptive user modelling in intelligent telephone and email assistants

With the burgeoning complexity and capabilities of modern information appliances and services, user modelling is becoming an increasingly important research area. Simple user profiles already personalise many software products and consumer goods such as digital TV recorders and mobile phones. A user model should be easy to initialise, and it must adapt in the light of interaction with the user. In many cases, a large amount of training data is needed to generate a user model, and adaptation is equivalent to retraining the system. This paper briefly outlines the user modelling problem and work done at BTexact on an intelligent personal assistant (IPA) which incorporates a user profile. We go on to describe FILUM, a more flexible method of user modelling, and show its application to the telephone assistant and email assistant components of the IPA, with tests to illustrate its usefulness.     

Multi-dimensional analysis of soil moisture dynamics in trickle irrigated fields. II: Model testing

The mathematical model which was developed in part I of this work for multi-dimensional analysis of soil moisture in irrigated fields is converted into computer algorithms. The algorithms are capable of emulating many field conditions of practical applications during both design and operation phases. The model is subjected to various tests, the results of which are reported here. The tests in various modes of simulations verified the numerical performance of the model and the accuracy of its predictions. The model provides a powerful tool for detailed studies of soil moisture dynamics in one or multi-dimensional problems irrigated fields     

Reaction scheme and kinetic modelling for the MTO process over a SAPO-18 catalyst

A kinetic model for simulation of the MTO process over SAPO-18 catalyst in a wide range of operating conditions has been proposed. The kinetic model predicts the experimental evolution of reaction products with time on stream, which follows three consecutive periods: initiation (where olefin production increases), a period of maximum olefin production and a period in which this production decreases. The kinetic scheme takes into account these three steps that evolve with time on stream: formation of active intermediate compounds, an step where olefins are formed by reaction of oxygenates (methanol/DME) with these intermediates and deactivation of intermediates by degradation to coke. The presence of water in the reaction medium attenuates the reaction rate of these steps. Discrimination of kinetic equations and calculation of the parameters of best fit have been carried out by solving the mass conservation equations of the individual components of the kinetic scheme together with the kinetic equation for deactivation and taking into account the effect of water on the kinetics of each step.     

Crushing behaviour of the energy absorbing 'tensor skin' panels

ABSTRACT Research results concerning the simulation of the crushing behaviour of composite systems with energy absorption characteristics are presented in the present work. The study is focused on the ‘tensor skin’ concept, an energy absorbing composite system that was originally developed to improve the crashworthiness of helicopters under water impact and which is promising for utilization in the construction of the lower part of composite fuselage aircraft. The ‘tensor skin’ concept comprises a folded or corrugated composite construction, which upon loading unfolds by forming ‘plastic hinges’, leading to an increase in the load bearing capability of the structure. The numerical modelling issues and the critical aspects of the simulation are discussed. Verification of the numerical simulation procedure is performed by experimental work. The experimental results utilized to assess and validate the numerical procedure were derived within the European Research Project ‘Design for Crash Survivability – CRASURV’ (BRITE – Aeronautics Area). The results of the simulations are generally in good agreement with experimental data.     

On a three-dimensional axisymmetric boundary-value problem of nonlinear elastic deformation: Asymptotic solution and exponentially small error

In this paper, we study a three-dimensional axisymmetric boundary-value problem of a slender cylinder composed of a nonlinearly elastic material subjected to an axial force. Starting from the field equations, after a transformation and proper scalings, we identify a small variable and two small parameters, which characterize the present problem. Then, by an approach involving compound series-asymptotic expansions, a nonlinear ODE is derived, which governs the axial strain (the first-term in the series expansion). By imposing the zero radial displacement conditions at two ends, we manage to get the analytical solution of the axial strain, from which all other physical quantities can be deduced and thus the three-dimensional displacement field can be determined. Graphical results are presented, which show that there are two boundary layers near the two ends while the middle part is in a state of almost uniform extension. The asymptotic structure of the analytical solution is derived, which offers clear explanations to the structure of the deformed configuration and shows that the thickness of both boundary layers is of the order of the radius. We also point out the relevance of the present results to the St. Venant’s problem. In particular, we obtain the explicit uniformly-valid exponentially small error term, when the obtained deformed configuration is compared to the configuration of a uniform extension.     

Semianalytical Model for Drawdown due to Pumping a Partially Penetrating Large Diameter Well

A semianalytical model is developed for computing drawdowns in and around a partially penetrating large diameter well. The new model can take into account an unsteady pumping discharge and thus drawdowns during recovery can be computed. This model can also yield the unsteady contributions from well and aquifer storages to the pumped discharge. While developing the model, the flow from the bottom of the well is also accounted.