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Traditional animation needs complex animation technology, which is mainly operated by hand. Therefore, traditional animation production needs a lot of work, which will lead to a variety of problems, such as long cycle, high rework rate, high cost and so on. With the development of computer technology, great changes have taken place in animation production, including speed, effect, etc., which has created a variety of methods in two-dimensional and three-dimensional animation production. Through computer-aided, the traditional manual animation technology has been gradually replaced by computer, which has become a key issue in animation art production. By combining the advantages of manual animation and computer animation, we can continuously improve the ability of animation industry. Through the synthesis editor, we can improve the animation action and accelerate technology research, which can achieve a new animation world. First of all, this paper analyzes the commonly used 3D animation production software. Then, this paper analyzes the animation action and acceleration technology.

In this paper we critically examine a concept which we term the ‘ponderomotive snowplow’. It has been alluded to by a number of authors, but a complete description is given by Sazegari et al (2006 Phys. Plasmas 13 033102). In this paper we present a critical analysis of this concept. As a strictly model problem, this is a valid idea. However it does not account for the longitudinal electrostatic field that must be generated in an actual laser-plasma interaction. Both analytic and numerical investigations indicate that the effects of this are hard to neglect, and lead to an effective ponderomotive snowplow that works—as described by Sazegari—as an effective electron accelerator being hard to realize.

In the past, the horizontal sealing mechanism of the bulk material packaging machine has a cam type and a cylinder type. The cylinder type horizontal sealing mechanism has a great impact when the speed changes, while the cam type horizontal sealing mechanism will cause noise and vibration. In this paper, the three-dimensional model of horizontal sealing device for bulk material packaging machine is carried out by SOLIDWORKS software, and the motion simulation analysis is carried out by using the add-in SOLIDWORKS motion. The results show that the acceleration of the horizontal sealing head for the horizontal sealing device occurs in 1/4 and 3/4 of the entire movement cycle. The horizontal sealing device can adjust the speed to meet the horizontal sealing requirements of different packaging bags. The horizontal sealing device of the bulk material packaging machine designed in this paper provides a reference for improving the packaging efficiency of products.

The paper deals with the planar problem of vibration isolation. The active vibration damper is mounted on an oscillating mass with a vibroactive unit at a point that does not coincide with the mass center and the action of the vibroactive force does not coincide with the mass center. An active dynamic vibration damper is an electrodynamic drive in which the translational movement of the moving mass is carried out according to information about acceleration from an accelerometer mounted on an oscillating mass with a vibroactive unit. The paper gives an assessment of the vibration isolation effectiveness, depending on the mismatch with the mass center of the vibrational force application points, the settings of the active damper and accelerometer.

Aimed at intelligent vehicles operating in complex driving environment, the paper is described on the basis that the reference trajectory has been determined. According to the vehicle running state and obstacle information, the vehicle’s running track can be adjusted in real time to solve the path planning problem and according to the re-planned reference track, the following control is carried out in the paper to avoid obstacles. Firstly, a point mass model is established which ignores the car body size. Secondly, on the premise that the size of obstacles is smaller than the car body size, according to the obstacle information obtained by the sensor and the established point mass model, the obstacle avoidance penalty function is established, then the objective function of the path planner is established. Finally, two working conditions: single obstacle and two obstacles, are set up to simulate and verify the designed obstacle avoidance trajectory following system. By observing the distance between the actual track and obstacles under different simulated speeds, varied range of front wheel angle and centre of mass side deflection angle, different range of angular velocity of lateral swing and lateral acceleration to verify whether the vehicles can successfully avoid obstacles with different speed and numbers of obstacles in order to maintain good driving stability in the process. Simulation results show that, under the control of the path following system added to the planning layer, intelligent vehicles in a complex driving environment can autonomously plan their paths, avoid obstacles, follow the path, and ensure good driving stability meanwhile.

Horizontal forces between the crane and the crane runway girder occur during a motion of an overhead travelling crane on the crane runway. There are several methods for calculation of these forces. The most significant load caused by motion of crane is the skewing and the acceleration of the crane and of the crab. This paper deals with the acceleration of the crane and with the skewing of the crane. In present the skewing of crane is defined as the motion of the overhead bridge crane with the constant velocity but with the angle relative to the crane runway. The transverse forces caused by acceleration of the crane are calculated separately. But the skewing of the crane can occur also during the accelerating of the crane. Present standards don’t take this situation into account. A dynamical model presented in this paper describes motion of the overhead double bridge crane during its acceleration. The basic assumption of this model is that there the contact between the rim of the firs crane wheel and the rail of the crane runway.

This study was conducted to develop a simple and inexpensive experimental apparatus that can measure the position of an object moving along a straight line at certain time intervals. For the construction of the apparatus, a battery-powered toy car, a fine-tipped paint brush, gouache (or watercolour) paint and paper tape were used. The working principle of the device is this: a short time after the toy car is turned on, its wheels start to turn with a constant angular velocity. A paint brush attached to one wheel also turns with a constant angular velocity. The paper tape is placed at a distance where the brush can touch it. Thus, with each round of the wheel, the brush lightly touches the paper tape and leaves a paint mark. Since the wheel turns at a constant angular velocity, the brush touches the tape once in each turn and leaves behind an equal amount of paint at equal intervals (one cycle at (T) time intervals). When the paper tape is pulled by attaching it to the object for which the motion is to be analyzed, lines are formed on the paper. By measuring the distance between the lines, the motion of the object can be analyzed and the position of the object can be identified at various moments. In this way, the speed and acceleration of the object can be measured.

The paper deals with the impact of shocks on cargo securing during the road freight transport. Commonly used methods of cargo securing do not take into account the different quality of roads, therefore the cargo securing doesn´t have to comply with principles of safe fastening. The paper highligths the different values of shocks and inertia forces on different quality roads (highway and 3rd class road) based on data of conducted transport experiments. The resulting shocks (values of acceleration coefficients) are statistically significantly higher on 3rd class road than on highway even at half average speed. The optimization of calculation using acceleration coefficients and their correlation with the resulting inertia forces is included in separated part. The output of the paper is a methodical procedure to optimize the cargo securing during the road transport.

An algorithm for acceleration/deceleration control is proposed in this paper to improve the flexibility of the heavy-duty motion system. The algorithm is based on the five-segment S-type acceleration/deceleration curve. During the acceleration switching time, a circular arc is used to smooth the curve, and the running time of each stage could be reasonably allocated by cyclic iteration. A parameter is defined to quantify the degree of flexibility of the acceleration/deceleration process to match the actual project. This paper will build the model to compare the good and bad point of different algorithms. The result shows that the vibration and impact during the acceleration and deceleration process can be effectively reduced, which means that the flexibility of the system has been greatly improved.

The current temperature field model of plate rolling process is generally based on CPU programming, due to the influence of computer performance, the accuracy and speed of the model can not be improved at the same time. To solve this problem, this paper studies the temperature field model with particle swarm optimization to modify the heat transfer coefficients, and the parallel program of this model is written under CUDA architecture, on premise of ensuring the accuracy of the model, the computation speed of the model is improved. To get the best acceleration, this paper analyzes the factors affecting GPU performance, the accuracy and speed of the temperature field model before and after modification are compared under the best acceleration configuration. Final temperature field model calculation error reduced to an average of 15.57 °C, better than the model based on the empirical formula, the computing speed is also improved, which is 1.78 times that of CPU.

The engineering technology of deep foundation pit support is complex and comprehensive, and it is necessary to consider the relationship between safety and engineering cost, and the optimal design of foundation pit support is especially important. Anchor support is a common support way for deep foundation pit support, in allusion to the shortcomings of particle swarm optimization; this paper adopts genetic algorithm, step length acceleration method and improved particle swarm optimization to carry out optimal design for foundation pit anchor support. The optimization results show that the combination with genetic algorithm improves the diversity of particle populations, the particle swarm optimization combined with the step length acceleration method has faster convergence performance, and the mathematical model of anchor supporting structure design is established. Through the case study of the foundation pit support of the super-high-rise building with frame shear wall structure, it was found that the engineering cost of the improved anchor support scheme after the improved particle swarm optimization is lower. The research in this paper provides a mathematical model for foundation anchor support.

Deep networks have achieved great success in many areas in recent years. However, with the increasing sophistication of deep neural networks (DNNs), the memory consumption and computational cost expand exponentially, greatly hindering their application in mobile devices and other limited resources. Therefore, there is impending necessity to consider model compression and acceleration without affecting the inference accuracy. In this paper, we review the recent popular techniques for compressing and accelerating deep networks. Those methods could be broadly divided into four categories: parameter pruning and sharing, low rank approximation, sparse regularization constraints and network weight low-bit quantization. The advantages and disadvantages of different compression and acceleration methods are also described in detail, other types of approach are also introduced in our paper, and future prospects for the field are given finally.

The shaking table test is an irreversible process for a nonlinear model structure. Therefore, how to choose ground motion and determine the input sequence are particularly important for the success of the shaking table test. In this paper, a 1/4 scale CFRP reinforced concrete frame structure specimen model is designed and made according to the similarity theory. By using the finite element analysis software SAP2000, the finite element model of CFRP reinforced concrete frame specimen is established. Four seismic waves are selected in the simulated shaking table test process, and the dynamic time history analysis of a total of 52 working conditions is carried out, including unidirectional, bidirectional and three-directional ground motion input, and the acceleration and displacement response of the structure are obtained. Taking story drift ratio as the evaluation index, the seismic performance of the structure is evaluated. This paper provides theoretical guidance for the subsequent shaking table test.

In this paper, the driver’s seatbelt detection algorithm is transplanted to the PYNQ embedded platform of XILINX to meet the technical requirements of automatic identification and detection of whether the driver wears a seatbelt or not. In this paper, aiming at the characteristics of the hardware of the FPGA, the driver’s seatbelt detection algorithm is realized by IP core from XILINX open source. Vehicle detection is realized by using YOLO object detection algorithm with 3 bit weight and 1 bit activation, and driver’s seatbelt classification is realized by using binary model with 1 bit weight and 1 bit activation. On the PYNQ embedded hardware of XILINX, the acceleration of the algorithm is realized by calling the hardware of FPGA on the ARM side.

With the acceleration of urbanization, more and more large-scale deep foundation pit projects are being carried out in the city. Due to the requirements of site and construction technology, it is necessary to design a supporting form that can be used as a supporting system without affecting the construction. In this paper, the large open ring beam structure is proposed as the supporting system, and the direct beam supporting system and the proposed ring beam supporting system are analyzed by finite element method. The structure shows that the ring beam structure proposed in this paper has better effect. The support form proposed in this paper provides an effective reference for design and optimization of foundation pit support form.

The vibration of perforated plate contains various complex physical phenomena in the fluid field, which is a key issue in fluid-structure interaction. Perforated plates have been widely used in power plants but the flow induced noise and vibration may give arise to some serious adverse impact. Therefore, it is of great significance to clarify the random vibration characteristics and noise problem of perforated plates in parallel flow. In this paper, the perforated plates were experimentally studied in a wind tunnel. Acceleration signal sensors are used to analyze the displacement and deformation of perforated plates and the pressure signals are measured by SETRA C266 micro pressure differential sensor, and the pulsating characteristics of perforated plates are analyzed by fast fourier transform (FFT), respectively. Through the analysis, it is found that the main pressure fluctuations of the flow direction are concentrated in the middle position and the tail. And the pressure fluctuations on the left and right sides of the perforated plates is very close in the spanwise position, and less than the center. Some key factors on the random vibration of perforated plates are discussed including wind velocity, hole diameter, hole pitch, plate thickness and the clearance height between the perforated plate and the cavity (It is means back space gap height). The analysis of the results indicated the impact of each factor. In detail, lower wind velocity and smaller hole diameter are beneficial to reduce the random vibration of perforated plate, however, larger hole pitch size and larger plate thickness are favorable to reduce the random vibration. The test results of this paper can provide a basis for the design of perforated plates.

In this paper, a miniaturized electron optic tracking system (EOTS) is proposed to improve the disturbance suppression performance when attached to near space aerostat. The electron optic tracking system, widely used in moving platforms can isolate the movement of the carrier and has high stability accuracy. However, the payload weight is limited for near space aerostats. The miniaturization of EOTS can effectively improve load distribution. To satisfy the demand of lightweight, micro-electro-mechanical system (MEMS) accelerometer is used in EOTS instead of fiber-optic gyroscopes (FOG). This paper employs position and acceleration double close-loop control method with MEMS linear accelerometer to improve the system performance especially in medium frequency. Meanwhile the disturbance observer (DOB) is introduced to suppress the measurably external disturbance. Furthermore, the disturbance performance of the EOTS is verified by MATLAB/Simulink. The results show that the improved miniaturized system can increase the payload of the aerostat effectively when the total load is limited.

In terms of the optimal power shift schedule of combined harvesting machinery, in order to improve the accuracy on solving optimal power shift points, this paper deduces the solving method to obtain the optimal power shift law of harvesting machinery based on the analyzing the characteristics of harvesting machinery. Two shift control parameters that have significant impacts on the optimal power shift point of harvesting machinery are put forward in the paper, namely the mass parameter and power distribution parameter. Taking the 4YZ-4- type combined maize harvester as an example, through the numerical calculation of MATLAB, it is found out that the change of mass parameter and power distribution parameters have significant impacts on the optimal power shift point. When the quality of harvesting machinery increases, the speed of the optimal power shift point will increase and the acceleration will decrease. When the power distribution coefficient of the driving axle of the harvesting machine increases, the corresponding speed at the optimal power shift point will decrease and the corresponding acceleration will increase.

The purpose of this paper is to highlight the analysis of the way in which the automobile can enter the state of instability when curving and the influence of some construction parameters (position of the weight centre, axle track, elasticity of the tires) and functional parameters (speed, acceleration, braking) which can influence the dynamic behavior. In this paper, there are described some dynamic simplified models of the automobile when curving, the way in which the experimental determinations have been made when a real automobile is involed in many circular routes with speeds and rays that we know. This paper also describes the methodology of study and the devices used as equipment for the automobile during the study on routes in order to register some specific parameters important for limiting the possibility of the appearance of lateral slips.

In this paper, we consider the Universe at the late stage of its evolution and deep inside the cell of uniformity. At these scales, we can consider the Universe to be filled with dust-like matter in the form of discretely distributed galaxies, a $K$-essence scalar field, playing the role of dark energy, and radiation as matter sources. We investigate such a Universe in the mechanical approach. This means that the peculiar velocities of the inhomogeneities (in the form of galaxies) as well as the fluctuations of the other perfect fluids are non-relativistic. Such fluids are designated as coupled because they are concentrated around the inhomogeneities. In the present paper, we investigate the conditions under which the $K$-essence scalar field with the most general form for its action can become coupled. We investigate at the background level three particular examples of the $K$-essence models: (i) the pure kinetic $K$-essence field, (ii) a $K$-essence with a constant speed of sound and (iii) the $K$-essence model with the Lagrangian $bX+cX^2-V(\phi)$. We demonstrate that if the $K$-essence is coupled, all these $K$-essence models take the form of multicomponent perfect fluids where one of the component is the cosmological constant. Therefore, they can provide the late-time cosmic acceleration and be simultaneously compatible with the mechanical approach., Comment: 26 pages, no figures. Conclusions extended and references updated. Version accepted in JCAP

A procedure for dynamic force calibration using sinusoidal excitations of force transducers is described. The method is based on a sinusoidal excitation of force transducers equipped with an additional top mass excited with an electrodynamic shaker system. The acting dynamic force can in this way be determined according to Newton's law as mass times acceleration, whereby the acceleration is measured on the surface of the top mass with the aid of laser interferometers. The dynamic sensitivity, which is the ratio of the electrical output signal of the force transducer and the acting dynamic force, is the main point of interest of such a dynamic calibration. In addition to the sensitivity, the parameter stiffness and damping of the transducer can also be determined. The first part of the paper outlines a mathematical model to describe the dynamic behaviour of a transducer. This is followed by a presentation of the traceability of the measured quantities involved and their uncertainties. The paper finishes with an example calibration of a 25?kN strain gauge force transducer.

With the development of structure optimization, building materials and construction technology, the study of the P-Δ effect is becoming more and more important in the pursuit of layers, flexibility and light quality. Based on the research status of P-Δ effect at home and abroad, this paper selects thenegative property fictitious member method to calculate the P-Δ effect of the multi-layer frame structure under the combined effect of horizontal and vertical ground motion. This paper discusses the influence of the stiffness-to-weight ratio, structural damping, and the vertical acceleration response of the structure. The results show that the damping and structural acceleration responses have a significant effect on the structural P-Δ effect. Under the premise of considering both, the stiffness-to-weight ratio of the structure, that is, the frequency of the structure, has a greater influence on the P-Δ effect of the structure under earthquakes. With the increase of the stiffness-to-weight ratio, the effect of P-Δ effect on structural response is increased and decreased.

When transmission lines pass through microtopographic area, the acceleration effect of wind speed should be taken into consideration during designing. However, the acceleration ratio coefficient of wind speed should not be selected simply according to mountain slope as specified by standards. In order to comprehensively consider the impact of wind direction and microtopography upon acceleration ratio of wind speed. This paper selects the acceleration ratios of wind speed at the height of 10m-120m in a tower position at 24 angles of direction wind by virtue of CFD simulation analysis. Combined with the line trend, this paper compares and calculates the change rule of wind loads on tower body and lead/ground wires after considering the pre/post-impact of acceleration ratio of wind speed. Through analysis, this paper forms suggestions on wind-resistant design for lead/ground wires in transmission lines in microtopographic area as well as accident analysis for reference.

This paper describes the possibility of estimating the health of a rail track in order to improve the comfort and ride quality of rail transportation by using the measured acceleration signal. The irregularities present in the track are the primary causes of vibration and these should be identified and the faults rectified to increase the safety of train travel. In this paper, a differential evolution technique based track measurement system (DE-TMS) is proposed to measure the health of the track. The abnormality of the track has been measured using micro electro mechanical system (MEMS) accelerometers which are mounted in the axle box. A new sensing method is used to estimate the exact location of the irregularity even when the signal is absent. The DE-TMS is simulated and compared with two other optimization techniques such as the particle swarm optimization technique and the covariance matrix adaptation with evolutionary strategy to evaluate the performance. The comparison results from the investigation show that the proposed DE-TMS provides cost-effective maintenance, and increase the safety of rail transportation. Finally, an experimental study was performed in four different irregularity cases and the results are estimated.

This paper outlines the solution that the Team of Austria found to problem number 7, 'skateboarder', presented in the finals of the 22nd International Young Physicists' Tournament (IYPT) in Tianjin, China. We investigated how a skateboarder can accelerate from rest on a horizontal surface without touching an external support. The focus was laid on a tic-tac, which is a repeated turning of the whole body and the skateboard from one side to the other. We based our investigation on papers examining the acceleration in slalom skateboarding. We performed video analyses to give a qualitative explanation and gathered quantitative data on the motion of the skateboarder using an inertial measurement unit. It was shown that an important feature of a tic-tac is that the pivot in the rotation is not in the middle of the rear truck. This makes acceleration possible even if the deck is not tilted. With the mathematical analysis we put forward, we could calculate the effects of the controlling motions the skateboarder performs on the velocity of the skateboard as a system with non-holonomic constraints. Subsequently, we show that the calculations are in general agreement with our experimental data. Previous assumptions for the frictional forces were revised and we suggest a more accurate method to measure the wheel angle through the tilt of the deck.

This paper proposes an efficient precision acceleration with temperature and humidity acquisition system based on 24-bit A/D Converter, IIC temperature and humidity sensor, Ethernet controller and microcontroller. This paper expounds in detail the realization of acquisition hardware, UDP protocol in microcontroller, the acquisition software as well as many other important aspects of the system. On the basis of the foregoing, build the entire acquisition system and apply it to the road roughness measuring instrument. Through the practice of the vehicle-mounted environment inspection, experimental results show that this system can stable operation for a long time and have a good application prospect.

The paper presents the results of the studies assessing the resistance of the existing bridge structures located in areas of varying seismic intensity. The basis for the analysis was an exemplary reinforced concrete road flyover of a slab span structure. Numerical calculations by the Finite Element Method were carried out, using the response spectrum approach in the dynamic analysis, with the use of the standard response spectra according to the Eurocode 1998 and the standard acceleration response spectra for the Upper Silesian Coal Basin and the Legnica-Glogow Copper District. For each individual analyzed case, the structure response to the assigned kinematic excitation was compared with the effects of load combinations adopted at the design stage, setting the limit values of the design horizontal ground acceleration in the horizontal plane (ag,H max ) and the vertical plane (ag,V max ). This allowed to assess the effect of seismicity of a specific area on the design dynamic resistance of the studied object. The paper discusses the manner of interpretation and the scope of applicability of the obtained results.

In this paper we present the synthesis of the cam for a distribution mechanism used for Miller-Atkinson cycle and described in previous works. The input data contain the angles at which the valve opens and closes, respectively, the dimensions of the main parts, the maximum displacement of the valve. and the law of motion of the valve. The authors consider that the law of motion of the valve is described by numerical values, even if in the simulation process they use analytical formulae for this displacement. The head of the valve is considered to be circular. A particular case of flat head of the valve is also described. The relative displacement of the lever and the valve is discussed in two hypotheses: symmetric position and asymmetric position of the contact point with respect to the axis of the valve. The contact between the head of the valve is assured by a cylindrical roller. The contact between the cam and the lever is considered with a roller tappet. In all cases the cam is obtained by numerical synthesis using a convenient angular degree. A great attention is paid to the convexity of the cam. The resulted cam is transformed in a convex one using the Jarvis March. The authors also perform a comparison between the theoretical profile of the cam and the profile of the convex cam. The reduced velocity and acceleration are obtained in all cases. Some aspects of the wear are discussed using the relative linear and angular velocities. The paper closes with a paragraph of conclusions.

This paper presents new methodologies for measuring the hand tremor of surgeons. A means to measure and evaluate the surgeon hand tremor in real time during operating practice can serve to assess the ergonomics of operating conditions. Tremor information is also important for determining surgical performance, particularly in microsurgical tasks. Micro-surgeons often work continuously for several hours with the most complex part occurring toward the end of the procedure. During these procedures the surgeon often uses a binocular microscope and is working at the threshold of perception and manual tool point control. The resulting performance is sensitive to hand tremor. In this paper, maximum tremor amplitude was determined by integrating the acceleration signals measured from three-axis piezoelectric accelerometers. New methods of removing the drift in the acceleration signals through empirical mode decomposition, and of determining the maximum tremor amplitude through proper orthogonal decomposition are presented. An experimental calibration demonstrates that the average error between the maximum tremor calculated by the proposed new method and the measured amplitude is below 5%. The paper also presents the results of the new techniques applied in the operating room in practice. Some of the tasks investigated focused on tool control in microsurgery.

This paper describes the failure analysis of an uncooled infrared focal plane array (IRFPA) under a high-g inertial load system using finite element simulation and experimental validation methods. The uncooled IRFPA, responding to a source of infrared (IR) radiation with spectral range from 8 µ mt o 14µm, is a cantilever array, which consists of two materials with mismatched thermal expansion coefficients. The radiance distribution of the IR source could be obtained by measuring the thermal–mechanical rotation angle distribution of every pixel in the cantilever array using a visible optical readout method. Based on this principle, room-temperature infrared imaging was developed under a static gravity environment, as described in our previous paper (Li C et al 2006 Meas. Sci. Technol. 17 1981–6). But under a dynamic inertial load, the rotation angle of every pixel includes not only the thermal–mechanical part but also a part induced by the inertial load. In the elastic deformation range, with a linearly increasing acceleration, the deformation angle induced by the inertial load increases linearly, which is validated by finite element simulation. This linear change in deformation, which can be subtracted from the total rotation angle in the optical readout using certain arithmetic, will not influence the imaging result. It is noteworthy that failure stress will occur when the deformation angle induced by the inertial load moves into the plastic deformation range, and the optical readout cannot image the IR object. Through finite element simulation the critical load resulting in IRFPA failure is 2715g, and this can be validated through impact using a Hopkinson bar after the IRFPA is placed in vacuum. By finite element simulation, the initial IRFPA surface profile without IR radiance after the 2715g load showed a conicoid characteristic. Simulation of the failure analysis of the uncooled IRFPA under 2715g acceleration predicts the military application of IRFPAs for an uncooled infrared imaging system in the high-g tactical range.

This paper sets up the measure and control system of the dynamic characteristics of the extra long stroke cylinder. In the different types of the control conditions (e.g. different control law, operating pressure and direct control valves), using the measure and control system to measure the relation between the pressure and the velocity of the motion of the long stroke cylinder and to observe the stick slip phenomenon of the motion of the long stroke cylinder. In the innovate measurement system, two pressure sensors are set on the long stroke cylinder to measure the difference of the pressure between the inlet and the exhaust of the long stroke cylinder. In additions, a draw line encoder is set on the system to measure the position and the velocity of the motion of the long stroke cylinder. The measuring data of the measure system is transferred to the computer via A/D interface card and counter card, and Home-made program of Haptic Interface Device is used to control the system, saving the data of the motion of the long stroke cylinder. The system uses different types of direction control valve to control the motion of the long stroke cylinder and compares the difference of the motion of the long stroke cylinder. The results show that the motion of the cylinder that pauses in the middle of the cylinder stroke and causes the stick slip phenomenon is more violent than the stick slip phenomenon in other position. When the length of the pause time reaches the some range, the acceleration of the motion of the cylinder will be rised substantially. This paper not only focuses on the testing method of the dynamic characteristics of the motion of the long stroke cylinder, but also includes the analysis of the dynamic characteristics of the motion of the long stroke cylinder. It provides the data of the dynamic characteristics of the motion of the long stroke cylinder to improve and design the pneumatic system of the long stroke cylinder.

In this paper, we consider the effects of a magnetic field on the dynamics of the early universe. As predicted by Matravers and Tsagas (2000 Phys. Rev. D 62 103519) we find that the coupling between spatial curvature and primordial magnetic field permeating a perfectly conducting barotropic fluid can inhibit the accelerated expansion but may also induce acceleration in a variety of cases not considered in the above paper.

To determine the maximum possible length of freestanding micromachined cantilevers, in this paper we provide a theoretical analysis of three important forces on cantilevers, namely acceleration, Casimir and Coulomb forces. The analysis provides theoretical limits to cantilever lengths separate from the well-known effects of surface adhesion and capillary collapse. This analysis offers an insight into the problem of in-use stiction in microstructures, which is a major source of functional failure in dynamic micromechanical systems. In this paper we conclude with a table that lists the maximum free standing length of microstructures that would offer reliable operation without stick–slip motion, excluding the possible effects of surface adhesion.

A significant effect of the acceleration of electrons by the ion field (AEIF) on the widths of spectral lines in high-density plasmas was first studied in one of our previous papers. That theory was successfully applied for explaining Hα widths measured in an underwater laser-produced plasma. In the present paper an advanced theory of the effect of the AEIF on shifts of spectral lines is developed. Its results are applied to two sets of experiments where Hα shifts were measured in high-density plasmas. For the experiment in the underwater laser-produced plasma, where the temperature was relatively low (T = 0.77 eV), we eliminated a factor of two discrepancy between the standard theory (ST) of the shifts and the experimental shifts and achieved excellent agreement with the experimental shifts. We also demonstrated that, for the condition of this experiment, another new source of the shift - the dipole ionic-electronic shift (DIES) introduced previously - plays an even more important role than it had been thought in the earlier paper on the DIES. We provide a more convincing proof of the existence of the DIES. For the experiments in a gas-liner pinch, where the temperature was significantly higher (up to 10 eV) than in the above experiment, we eliminated a discrepancy - up to a factor of two - between the ST of the shifts and the experimental Hα shifts. For the conditions of this experiment, practically the entire difference between the results of the present theory and the results of the ST of the shifts is due to the AEIF. Thus, we showed that the development of the advanced AEIF theory is important for explaining the experimental shifts in high-density plasmas. We also clarified some issues concerning a comparison of our theory with an experiment in a laser-driven pressure cell and with other theoretical works.

Network reconfiguration for loss reduction in the distribution system is a significant way to save resources. It's an extremely hard optimization problem because of a plenty of switches in a distribution network. This paper presents an efficient Gravitational Search Algorithm (GSA) and its improvement based on elite strategy and adaptive position (ES-APGSA) to reduce grid loss using reconfiguration. The new algorithm can improve the speed of iterations and avoid the local convergence. In addition, the encoding method based on ring network is proposed which makes the dimensions of the particles much lower leading to an acceleration of the process. The correctness and effectiveness of the methods suggested in this paper is verified through the simulation results of IEEE33-node system.

This paper presents a thermal convection-based sensor, which is fabricated using carbon nanotube (CNT) yarn. The key element in this device is the non-symmetrically distributed, heated air medium around the heater, particularly when it experiences acceleration and/or changes in inclination. Therefore, it can withstand much higher accelerations/inclination than conventional sensors that use a proof mass. However, a major challenge for the design of this type of sensor is the high heating power (in the order of tens of milliwatts) required to facilitate thermal convection in a sealed chamber. In order to reduce the high heating power, CNTs are investigated as materials for both the heater and the temperature sensors. Moreover, this paper discusses experiments that were performed by varying several parameters, such as the heating power, distance between the heater and temperature sensors, the gas medium used, and air pressure.

A 75–100 MeV H- compact cyclotron CYCIAE-100 is being constructed at China Institute of Atomic Energy (CIAE). About 200 μA proton beam will be provided by CYCIAE-100. The imperfection of magnetic fields will remarkably affect the acceleration orbit and beam envelope in CYCIAE-100. The effects to the accelerating beam by the imperfection fields, especially the field components Br on the mid-plane will be analyzed in detail with tracking code COMA. Poles misalignment that causes magnetic imperfection will be described in the paper. According to the simulation results, the tolerance of the poles machining and assembly will be illustrated in this paper.

This paper reviews an active control algorithm adopted for an active-passive composite tuned mass damper, which is a unique vibration control device equipped into an office building in Tokyo in 1993. The main purpose of this device is to subdue the response motion of tall buildings under random disturbances such as wind pressures and small earthquakes. The main topics in this paper are: (1) the principle of the acceleration feedback algorithm, (2) the expected control performance, (3) the multi-modal control algorithm, (4) the observed performance of the applications using the algorithm.

The electric vehicles solutions based on the individually controlled electric motors propel a single wheel allow to improve the dynamic properties of the vehicle by varying the distribution of the driving torque. Most of the literature refer to the vehicles with a track typical for passenger cars. This paper examines whether the narrow vehicle (with a very small track) torque vectoring bring a noticeable change of the understeer characteristics and whether torque vectoring is possible to use in securing a narrow vehicle from roll over (roll mitigation). The paper contains road tests of the steering characteristics (steady state understeer characteristic quasi-static acceleration with a fixed steering wheel (SH = const) and on the constant radius track (R = const)) of the narrow vehicle. The vehicle understeer characteristic as a function of a power distribution is presented.

In this paper, a vibration-based MEMS electromagnetic energy harvester (EM-EH) device with two-degree-of-freedom (2DOF) configuration has been presented, modeled and characterized. The proposed 2DOF system comprises a primary subsystem for power generation, and an accessory subsystem for frequency tuning. A lumped parametric 2DOF model is built and examined in respect of energy harvesting capabilities. By controlling the mass ratio and frequency ratio, the first two resonances of primary mass can be tuned close to each other while maintaining comparable magnitudes. The 2DOF configuration is expected to be more adaptive and efficient than the conventional 1DOF structure, which could only operate near its sole resonance. The 2DOF EM-EH chip is fabricated on silicon-on-insulator (SOI) wafer through double-sided deep reactive-ion etching (DRIE). Induction coil is only patterned on the primary mass for energy conversion. With current prototype at an acceleration of 0.12 g, two resonances of 326 and 391 Hz with output voltages of 3.6 and 6.5 mV are obtained respectively, providing good validation for the modeling results. This paper offers new insights of implementing a multimodal MEMS EM-EH device.

An earthquake has three important characteristics; namely, amplitude, frequency content and duration. Amplitude and frequency content have a direct impact but not necessarily the sole cause of structural damage. Regarding the duration, some researchers show a high correlation between strong motion duration and structural damage whereas some others find no relation. This paper focuses on the ground motion durations characterized by Arias Intensity (AI). High duration may increase the damage state of structure for the damage accumulation. This paper investigates the response time histories (acceleration, velocity and displacement) of RC buildings under the different strong motion durations. Generally, eight earthquake records were selected from different soil type, and these records were grouped according to their PGA and frequency ranges. Maximum plastic rotation and drift response was chosen as damage indicator. In general, there was a positive correlation between strong motion duration and damage; however, in some PGA and frequency ranges input motions with shorter durations might cause more damage than the input motions with longer durations. In soft soils, input motions with longer durations caused more damage than the input motions with shorter durations.

The generation of betatron radiations by laser-accelerated electron beams is of great interest in the scientific community as it has many applications. In this paper, we propose a new method for the generation of short wavelength betatron radiations. In the new scheme, a high power laser pulse is sent into a capillary plasma waveguide at an off-axis position to intentionally enhance the betatron oscillation amplitude, which can lead to the production of shorter wavelength radiations. We demonstrated that the idea works by 2D particle-in-cell simulations and we also developed a theory to explain the phenomena. In this paper, details of the results are described.

Acoustic wave sensors are so called because they use a mechanical, or acoustic, wave as their detection mechanism. They are very sensitive and intrinsically reliable devices, which makes them extremely versatile. Three of the papers in this special feature present potential applications of acoustic wave sensors: measurement of liposome adhesion, for cell detection and as immunosensors. Whereas the acoustic wave device acts as an active sensor in those applications, rupture event scanning—discussed in a fourth paper—takes advantage of the extreme acceleration at the sensor surface at ultrasonic frequencies. The other two papers give a more general theoretical background: one provides a conceptual framework in which the behaviour of a wide range of acoustic wave sensors employing guiding layers can be understood; the other is about modelling acoustic microsensors focusing on the transduction mechanism in (bio)chemical quartz crystal resonator sensors. The common aspect of all the papers is a utilization of acoustic wave devices exceeding by far the known microbalance principle. The overall goal of this special feature is therefore to help the reader understand the current state of knowledge in this area and to help those who are considering the use of acoustic wave sensors. I hope this will be a valuable contribution to the literature.

Increasing the bias voltage is a method of reducing the motional resistance of the capacitive disk resonator to match the impedance of the RF circuit. But there are few reports on the study of reliable working range of bias voltage under the shock and vibration environment. Therefore, the reliability of disk resonator under the step and pulse acceleration impact respectively is systematically analyzed in this paper. By the expression of the biggest inertial acceleration the disk can bear under the reliable condition, the maximal reliable range curves of the disk resonator under the dynamic impact environment are obtained. According to the actual sizes of disk in the literature, it can be seen that when a step shock of 13000 g is supplied, the reliability range is reduced to 75% compared with the original state. For the pulse shock, the reliability range is related to the pulse amplitude and time width. Research of this paper can provide the basis for the selection of bias voltage of disk resonator under the inertial shock.

Respiratory gas analyses are used to explore the influence of increased gravity on the physiology of breathing. Due to the mass, size and intricacy of standard measurement systems, previous studies were limited to a maximum acceleration of + 5 gz (head-to-foot direction). Furthermore, no in situ mainstream measurements of oxygen and carbon dioxide concentration were possible under hypergravity conditions so far. This paper shows a first study which demonstrates a respiratory sensor system developed at the Institute for Aerospace Engineering at TU Dresden. This system is suitable for an in situ measurement of respiratory changes up to + 9 gz (maximum acceleration of jet pilots) and therefore provides a possibility for detailed physiological analyses in future. Three jet pilots were equipped with this system and accelerated under a defined profile up to 7, 8 and + 9 gz. The breathing air flow, oxygen and carbon dioxide concentration were recorded with our miniaturized solid state electrolyte gas sensors, which are also described in this paper. The analysed data show significant changes of the measured respiratory parameters depending on the G-level, the acceleration rate (G-rate of onset [g s−1]) and the examination time.

This paper investigates the applicability of an electromagnetic generator with repulsively stacked magnets for harvesting energy from traffic-induced bridge vibrations. First, the governing equation for electro-mechanical coupling is presented. The magnetic field for repulsive pole arrangements is discussed and the model is validated from a magnet falling test. The detailed design, fabrication, and test results of a prototype device are presented in the paper. An experimental vibration shaker test is conducted to assess the performance of the energy harvester. Field test and numerical simulation at the 3rd Nongro Bridge in South Korea shows that the device can generate an average power of 0.12 mW from an input rms acceleration of 0.25 m s−2 at 4.10 Hz. With further frequency tuning and design improvement, an average power of 0.98 mW could be potentially harvested from the ambient vibration of the bridge.

This paper presents a new method for tracking multiple targets in video sequences. A common dilemma that multiple target tracking methods have to face in practice is reducing computational cost and addressing occlusion to achieve efficient and robust long-duration tracking. Existing methods mainly focus on deriving the measurement-to-track assignment through probabilistic analysis, in which the motions of targets are considered to be independent of each other. These methods tend to be computationally expensive due to the complexity of implementation for the visual tracking task. In this paper, we propose a collaboration model in which the acceleration difference between two targets is used to calculate the motion correlation value based on the two-dimensional Gaussian function. By the collaboration model, the location of occluded target is estimated using the motion information from other targets. In order to sense the occurrence of an occlusion accurately before estimating the location of target, we also propose a border-based occlusion decision method which is integrated into our tracking framework. The proposed approach is computationally efficient and robust. Experimental results exhibit the performance of the tracker based on our approach.

The concept of harvesting electrical energy from ambient vibration sources has been a popular topic of research in recent years. Recently, the realisation that the majority of ambient vibration sources are often stochastic in nature has led to a large body of work which has focused on the response of energy harvesters to random excitations – most of which approximate environmental excitations as being Gaussian white noise. Of particular interest here are recent findings which demonstrate the advantages that Duffing-type nonlinearities can introduce into energy harvesters. The aim of this paper is to identify how well these results can be applied to that of a real energy harvesting scenario. More specifically, the response of an energy harvester to excitation via human motion is studied using digital simulations in conjunction with acceleration data obtained from a human participant. As well as assessing whether Duffing-type nonlinearities can have a beneficial impact on device performance this paper aims to investigate whether Gaussian white noise can indeed be used as a good approximation for this particular ambient vibration source.