Prediction and Output Estimation of Pattern Moving in Non-Newtonian Mechanical Systems Based on Probability Density Evolution

A prediction framework based on the evolution of pattern motion probability density is proposed for the output prediction and estimation problem of non-Newtonian mechanical systems,assuming that the system satisfies the generalized Lipschitz condition.As a complex nonlinear system primarily governed by statistical laws rather than Newtonian mechanics,the output of non-Newtonian mechanics systems is difficult to describe through deterministic variables such as state variables,which poses difficulties in predicting and estimating the system’s output.In this article,the temporal variation of the system is described by constructing pattern category variables,which are non-deterministic variables.Since pattern category variables have statistical attributes but not operational attributes,operational attributes are assigned to them by posterior probability density,and a method for analyzing their motion laws using probability density evolution is proposed.Furthermore,a data-driven form of pattern motion probabilistic density evolution prediction method is designed by combining pseudo partial derivative(PPD),achieving prediction of the probability density satisfying the system’s output uncertainty.Based on this,the final prediction estimation of the system’s output value is realized by minimum variance unbiased estimation.Finally,a corresponding PPD estimation algorithm is designed using an extended state observer(ESO)to estimate the parameters to be estimated in the proposed prediction method.The effectiveness of the parameter estimation algorithm and prediction method is demonstrated through theoretical analysis,and the accuracy of the algorithm is verified by two numerical simulation examples.

Aerodynamic characteristics of a high-speed train crossing the wake of a bridge tower from moving model experiments

In a strong crosswind,the wake of a bridge tower will lead to an abrupt change of the aerodynamic forces acting on a vehicle passing through it,which may result in problems related to the transportation safety.This study investigates the transient aerodynamic characteristics of a high-speed train moving in a truss girder bridge and passing by a bridge tower in a wind tunnel.The scaled ratio of the train,bridge,and tower are 1:30.Effects of various parameters such as the incoming wind speed,train speed,and yaw angle on the aerodynamic performance of the train were considered.Then the sudden change mechanism of aerodynamic loads on the train when it crosses over the tower was further discussed.The results show that the bridge tower has an apparent shielding effect on the train passing through it,with the influencing width being larger than the width of the tower.The train speed is the main factor affecting the influencing width of aerodynamic coefficients,and the mutation amplitude is mainly related to the yaw angle obtained by changing the incoming wind speed or train speed.The vehicle movement introduces an asymmetry of loading on the train in the process of approaching and leaving the wake of the bridge tower,which should not be neglected.

An Analysis of the Dynamic Behavior of Damaged Reinforced Concrete Bridges under Moving Vehicle Loads by Using the Moving Mesh Technique

This work proposes a numerical investigation on the effects of damage on the structural response of Reinforced Concrete(RC)bridge structures commonly adopted in highway and railway networks.An effective three-dimensional FE-based numerical model is developed to analyze the bridge’s structural response under several damage scenarios,including the effects of moving vehicle loads.In particular,the longitudinal and transversal beams are modeled through solid finite elements,while horizontal slabs are made of shell elements.Damage phenomena are also incorporated in the numerical model according to a smeared approach consistent with Continuum Damage Mechanics(CDM).In such a context,the proposed method utilizes an advanced and efficient computational strategy for reproducing Vehicle-Bridge Interaction(VBI)effects based on a moving mesh technique consistent with the Arbitrary Lagrangian-Eulerian(ALE)formulation.The proposed model adopts a moving mesh interface for tracing the positions of the contact points between the vehicle’s wheels and the bridge slabs.Such modeling strategy avoids using extremely refined discretization for structural members,thus drastically reducing computational efforts.Vibrational analyses in terms of damage scenarios are presented to verify how the presence of damage affects the natural frequencies of the structural system.In addition,a comprehensive investigation regarding the response of the bridge under moving vehicles is developed,also providing results in terms of Dynamic Amplification Factor(DAFs)for typical design bridge variables.

Announcement of the 6th FOSECO Cup Excellent Foundry Papers of Foundry Institution of Chinese Mechanical Engineering Society (2003)

In order to encourage the foundry science and technology staff of our country to actively participate in the foundry academic activities, and in order to promote the development of China foundry technology and the improvement of China foundry academic levels, the second stage work (final judgement) of the 6th FOSECO Cup Excellent Foundry Papers organized by Foundry Institution of Chinese Mechanical Engineering Society (FICMES) was carried out in Chengdu, Sichuan Province on May 17-20, 2004. Two gold award papers and 10 silver award papers were awarded, and the other 34 papers recommended into the final judgement were nominated as excellent papers.

ACTA MECHANICA SINICA The Chinese Society of Theoretical and Applied Mechanics

AIMS AND SCOPEThis journal has two independent editions—one in Chinese and the other in English.The Chinese bimonthly Acta Mechanica Sinica was first published in 1957, while the Englishquarterly, Acta Mechanica Sinica (English Series), was founded in 1985. High quality originalworks on all aspects of the science of mechanics are published in either of the editions. A

RECOVERY OF URANIURN FROM CARBONATE SOLUTIONS USING STRONGLY BASIC ANION EXCHANGER 3. THE MECHANISMS OF RECOVERY PROCESSES

A moving boundary model under considering the volume change of spherical resin beads during ion exchange processes was employed to recognize the mechanisms of recovering uranium from carbonate solutions using strongly basic anion exchanger Two important factors, swelling and ion exchange, which directly affect the volume of ion exchangers were taken into account. An ion exchange mechanism has been found for the forward reaction RCl/[UO2 CO3)3]4- at pH 8.5～10.0, where the rate is controlled by liquid-film diffusion at low concentration of the tetravalent uranyl complex anion [UO2 (CO3)3]4-, and is partical diffusion governing at high concentration of the complex anion. The mechanism of RCl/U(Ⅳ) at pH 5. 5～7. 5 is a chemical reaction taking place at the moving boundary of the unreacted nucleus. For the reverse reaction RnU/NaCl, the uranyl tricarbonate complex anion in the resin phase is replaced by Cl- ions with an ion exchange mechanism always determined by particle diffusion. The other forms of uranium in the solid phase loaded on the resin at pH 5. 5～7. 5 should belong to non-exchangeable uranium. The mechanism of the reverse reaction RnU/HCl is always chemical reaction which is not restricted to the moving boundary of the unreacted core.

Human Rights NGOs and the United Nations Human Rights Council——Participation by the China Society for Human Rights Studies in the Universal Periodic Review Mechanism

Since its founding in 1993, the China Society for Human Rights Studies （CSHRS） has extensively participated inthe human rights work of the United Nations （UN） and has actively carried out international exchange and cooperation. In May 2012, the UN Human Rights Council （UNHRC） initiated the second round of country reviews on human rights.

Analysis on the crossing obstacle of wheel-track hybrid mobile robot

A novel wheel-track hybrid mobile robot with many movement patterns is designed.According to different environments,it can switch between the pure wheel pattern and the pure track one.According to a homogeneous coordinate transformation matrix,gravity stability and its obstacle performance are analyzed.Its gravity equation and climbing obstacle conditions are established.Experimental results show that this hybrid mobile robot could fully possess the advantages of both the wheel and the track mechanisms and achieve a good obstacle climbing capability.

Innovative design and motion mechanism analysis for a multi-moving state autonomous underwater vehicles

In order to achieve the functional requirements of multi-moving state, a new autonomous underwater vehicle(AUV) provided with the functions such as the submarine vectorial thrust, landing on the sea bottom, wheel driving on the ground and crawling on the ground was designed. Then five new theories and methods were proposed about the motion mechanism of the AUV such as vectorial thruster technology, design of a new wheel propeller, kinematics and dynamics, navigation control and the ambient flow field in complex sea conditions, which can all conquer conventional technique shortages and predict the multi-moving state performance under wave disturbance. The theoretical research can realize the results such as a vectorial transmission shaft with the characteristics of spatial deflexion and continual circumgyratetion, parameterized design of the new wheel propeller with preferable open-water performance and intensity characteristics satisfying multi-moving state requirements, motion computation and kinetic analysis of AUV's arbitrary postures under wave disturbance, a second-order sliding mode controller with double-loop structure based on dynamic boundary layer that ensures AUV's trajectory high-precision tracking performance under wave disturbance, fast and exact prediction of the ambient flow field characteristics and the interaction mechanism between AUV hull and wheel propellers. The elaborate data obtained from the theoretical research can provide an important theoretical guidance and technical support for the manufacture of experimental prototype.

Quantum and Classical Approach Applied to the Motion of a Celestial Body in the Solar System

According to the classical mechanics the energy of a celestial body circulating in the solar system is a constant term. This energy is defined by the masses product of the larger and smaller body entering into a mutual attraction as well as the size of the major semiaxis characteristic for the corresponding Kepler orbit. A special situation concerns the planet interaction with the Sun because of a systematic decrease of the Sun mass due to the luminosity effect. The aim of the paper is to point out that even in the case of perfectly constant interacting masses the energy of the moving body should decrease when a quantum treatment of the body motion is considered. The rate of the energy decrease is extremely small, nevertheless it gives a shortening of the distance between the interacting bodies leading to a final effect of a touch of the larger body and a smaller one.