Dynamic Characteristic Analysis of Planar Piezoelectric Six-Axis Force/Torque Sensor

The article presents a hierarchy of performance properties of vehicles for the transportation of heavy indivisible goods. Different methods can be used to determine the performance properties measures. The article presents the measurers of performance properties, the numerical values of which are obtained by using the method of mathematical modelling and simulation, the method of natural mathematical modelling and experimental methods of evaluation. The article identifies the problem of logistics in the Far North and in regions with no road infrastructure. The question under discussion is a burning question. The solutions to the problem have been discussed. One of the solutions to the problem is the development of new vehicles for the transportation of heavy indivisible loads in the Far North. For each vehicle it is necessary to take into account its functional purpose. Only a certain set of the most important perfomance properties should be taken into account. The most significant properties characterizing the mobility property are determined.

Axial force is one of the main factors which affect the pump safety and reliability during the operation of pumps, especially in multi-stage centrifugal pumps. 150QJ20 type deep-well centrifugal pump (DCP) is selected as an example to research the pump performance and axial force with the numerical simulation and experiment method. The numerical simulation results were compared with experimental measurements, and such result was analyzed. The results show that the change trend of the pump performance and axial force acquired by numerical and experiment is similar. At rated operating point, the error of axial force between the numerical simulation and experimental measurements is less than 3%. This confirmed the feasibility of predict the pump performance by numerical simulation method.

Aiming at researching the QoS performance of slotted CSMA/CA mechanism in beacon-enabled IEEE802.15.4, this paper analyzes the effect relationship between QoS and superframe parameters through analytic mathematical model and simulation method. Firstly, the nodes’ sleeping time of WSNs is deduced from duty cycle mathematical formulation. Therefore, the energy consumption directly related to sleeping time can be evaluated. In order to analyze and evaluate the effect relationship between QoS and superframe parameters more accurate and more comprehensively, all kinds of simulation instances with different superframe parameters, including different duty cycles as well as same duty cycle but with different values of Beacon Order (BO) and SuperFrame Order (SO) are simulated. The results show that the mathematical model analysis of QoS performance is consistent with the simulation. The studies also provide a reference to further research of adaptive transmission mechanism in beacon-enabled IEEE802.15.4.

The present paper proposes a numerical simulation method for analyzing water impact on elastic structures.In order to accurately evaluate the structural strength of marine structures under severe water impact, the characteristics associated with the dynamic structural response to an impact load, the magnitude of which changes rapidly, must be examined. Until now, a simplified two-step method has been widely used for this purpose. This method entails estimation of a time series of the hydrodynamic force on a structure, assuming that the body is rigid. This is followed by response analysis of the structure by applying the previously estimated force history. However, when the structure is relatively flexible, the two-step method may not be applicable because it neglects the coupling effect between the fluid and structure. Thus, a numerical simulation method that considers fluid-structure coupling is prepared. The new method consists of two components, i.e., a 2-D numerical simulation method that utilizes the computational fluid dynamics (CFD) for flow field analysis and a modal analysis technique for solving the dynamic structural response of the cylindrical shell in its transverse section. Information such as fluid pressure, motion and deformation of the structure, is exchanged between the two components at each time-step of the numerical simulation. A series of drop model experiments was also conducted to verify the accuracy of the newly developed numerical simulation method. The experiments consisted of dropping a cylindrical model made of an aluminium plate onto a still water surface. The motion of the model and strain on the shell plate were measured. Experimental data taken from a published report were also used for comparison.The following results were obtained : 1. In the case of a light-weight model, the rigid body motion of the dropped model changed remarkably upon impacting the water surface. This deceleration influenced the pressure field around the model remarkably as well as the elastic response of the model structure, i.e., strain-time history. The accuracy of the numerical simulation was improved substantially by considering the deceleration effect of the rigid body motion during water entry.2. Although the predicted elastic response by the two-step method agreed fairly well with measured response in the case of a cylinder with high rigidity, the method cannot predict the elastic response of a cylindrical shell with low rigidity. By carrying out the above mentioned coupling simulation, the accuracy of the computed elastic response becomes noticeably improved. Thus, the proposed simulation method appears to be effective.

In this paper, the numerical simulation method for the protection performance of liquid armor based on STF can be roughly summarized into two ways, containing the shell element simulation method based on the inter-yarns friction coefficient and the coupled Euler-Lagrangian simulation method. The shell element simulation method of inter-yarns friction coefficient has a single consideration for STF performance, but it has high calculation efficiency and low calculation cost. The coupled Euler-Lagrangian simulation method fully considers the shear thickening characteristics of STF, and comprehensively considers the characteristics of STF. The simulated performance gets closer to the actual situation, and it can also reveal the effect of STF in improving the protection performance.

Development and application of airborne and aerospace hyperspectral imager press for high precision geometry and spectral calibration of pixels of image cube. The research of geometry and spectral calibration of pushbroom hyperspectral imager, its target is giving the coordinate of angle field of view and center wavelength of each detect unit in focal plane detector of hyperspectral imager, and achieves the high precision, full field of view, full channel geometry and spectral calibration. It is importance for imaging quantitative and deep application of hyperspectal imager. The paper takes the geometry and spectral calibration of pushbroom dispersive hyperspectral imager as case study, and research on the constitution and analysis of imaging mathematical model. Aimed especially at grating-dispersive hyperspectral imaging, the specialty of the imaging mode and dispersive method has been concretely analyzed. Based on the analysis, the theory and feasible method of geometry and spectral calibration of dispersive hyperspectral imager is set up. The key technique has been solved is As follows: 1). the imaging mathematical model and feasible method of geometry and spectral calibration for full pixels of image cube has been set up, the feasibility of the calibration method has been analyzed. 2). the engineering model and method of the geometry and spectral calibration of pushbroom dispersive hyperspectral imager has been set up and the calibration equipment has been constructed, and the calibration precision has been analyzed.

The workshop on Mathematical Modelling and Mathematical Methods in Energy was held in COPEL Building, Curitiba, Brazil from 29 November to 1 December 2004 with more than 100 participants. The scientific programme consisted of 20 invited talks and 20 contributed papers. All talks were well attended with deep discussions. The participants came from Brazil, Canada, China and U.S.A. The following mathematical modelling and methods applied in energy area such as petrol and electric energy were discussed: partial differential equations, singular value decomposition (SVD), eigenvalue problems, preconditioning techniques and optimization. All participants, especially people from energy engineering, recognized the importance of participation and collaboration with mathematicians for their researches. The present volume contains seven selected papers essentially devoted to numerical linear algebra with applications in energy area. We thank the referees who helped us in doing the editorial work. Their efforts and suggestions made it possible to publish scientific papers with high quality. We appreciate the support of the Scientific Committee of the Workshop consisting of José Luiz Alqueres (ALSTOM, Brazil), Ricardo Biloti (UFPR, Brazil), Mario Jorge Dias Carneiro (UFMG, Brazil), Paulo Afonso Bracarense Costa (CGEE-MCT, Brazil), Djalma M. Falcão (UFRJ, Brazil), Clovis Gonzaga (UFSC, Brazil), Sergio Granville (PSR, Brazil), Fernando Gruppelli (COPEL, Brazil), Dan Marchesin (IMPA, Brazil), Claudia Sagastizabal (IMPA, Brazil), Robson Luiz Schiefler (COPEL), Jurandyr Schmidt (PETROBRAS), Carlos Tomei (PUC-Rio, Brazil), Lei Wang (PowerTech Labs, Canada), and Jin Yun Yuan (UFPR, Brazil). The workshop was sponsored by Araucária Foundation, Brazilian National Agency of Electric Energy, Brazilian Society of Mathematics, COPEL, Global Progress of Brazilian Mathematics-Millennium Institute (IM-AGIMB), Ministry of Education, Federal University of Paraná and Federl University of Santa Catarina. Last, but not the least, we thank all participants for their contribution and efforts in making the Workshop an interesting, pleasant and successful event.

지상의 모든 물체는 고유의 분광 반사율을 갖고 있으며, 이러한 특성을 이용하여 지상 물체의 분류와 목표물 탐지 등이 가능하다. 정확한 분석을 위해서는 취득된 원격탐사 자료를 분광 반사율로 변환해야 한다. 이를 위한 절대복사보정 기법으로는 자료 제공 기관에서 명시한 변환 수식을 이용하는 방법, 지상에서 측정한 분광 반사율만으로 단순 경험적 회귀 분석을 이용하는 방법, ATCOR/FLAASH 같은 수학적 모델을 이용하는 방법 등이 있다. 본 연구에서는 CASI 초분광 영상의 분광 반사율 자료를 이용하여 RapidEye 위성영상의 대리복사보정을 수행하고, 그 결과를 다른 복사보정 기법 결과 및 지상 자료와 비교하였다. 실험 결과 제안 기법이 ATCOR 및 New Kurucz 2005 기법보다 높은 유사성을 보였으며, 일반적으로 활용되는 ELM 기법과 유사한 결과를 도출하였다.

Optimal design of acoustic performance for automotive air-cleaner

The lithology of the roof of the mining roadway is compound and the thickness of each layer varies considerably, and it is disturbed by dynamic load all the year round. The above factors has caused a huge difference in the stability of the roadway surrounding rock. Taking the 11,020 lower tunnel of a mine in Henan Province as the engineering geological background, using on-site investigation, formula derivation, numerical simulation and other methods, the composite roof roadway model group was established to study the deflection evolution characteristics of the surrounding rock under dynamic load disturbance, and summarize the plastic zone of the surrounding rock of the roadway Deformation and evolution of roof surrounding rock to evaluate the stability of surrounding rock with different roof structures. The research results show that the change of the roof surrounding rock structure will also lead to the change of the center deflection of the roadway roof. Therefore, the center deflection of the surrounding rock of various roof composite structures is different, and the deflection is the most direct indicator of the stability of the surrounding rock. The center deflection (\(\omega_{0}\)) of the soft rock type is the largest, the center deflection (\(\omega_{0}\))of the upper soft and the lower hard type, and the soft and hard type is larger, and the soft and hard progressive type, thin, hard and thick soft type (\(\omega_{0}\)) is the smallest, and the dynamic load The relationship between the magnitude of deflection before and after the disturbance is consistent. By constructing a composite roof roadway numerical model group, using the plastic failure zone of the roadway as the evaluation standard, the surrounding rock stability is evaluated and divided, and then the cross-point field measurement method is used to verify the stability of the surrounding rock on the roof of different composite structures. And the development of composite roof roadway surrounding rock deformation and failure mechanism and numerical simulation method has important theoretical significance and practical value for the analysis and control of composite roof roadway surrounding rock stability.

The materials of the article consider the main methodological provisions of calculations and optimization of NPP power unit equipment parameters using mathematical modeling methods. For the effective implementation of tasks related to determining the optimal parameters and structures of NPP power unit equipment using mathematical modeling and well-developed multifactor optimization methods, it is necessary to fulfill a number of requirements at their productions. Practice shows that it is impractical to optimize with the help of a single mathematical (simulation) model the entire set of parameters characterizing a given power unit, because with such a formulation, the optimization tasks are often mutually incorrect due to a significant discrepancy in the accuracy of various source information, unequal influence of parameters on the target function, specific differences in the mathematical description of various units and elements of the power unit. In order to effectively optimize the parameters of NPP power units, it is necessary to create a system of interconnected mathematical models, which include: a group of detailed mathematical models of individual units and elements of power unit equipment; more generalized mathematical models for the main equipment of power units built on their basis; complete mathematical model of power units.

ABSTRACTA convergence identification method for oscillatory numerical simulation is proposed, in which the numerical solution can converge at the inflection point with respect to the time step. In addition, an algorithm to verify the appropriate time step is also proposed. The feasibility of the proposed method is further verified by its application to a case study involving combined natural and magnetohydrodynamics convection in a Joule-heated cavity using finite-volume methods. It is found that the two approaches have the same results and can judge the validity of the time step used in accurate computation of fluid flow and heat transfer.

The dynamic characteristics of the flow around the pile directly determine the distribution law of the force of the flow on the pile, which is the basis of the calculation of the flow load of the hydraulic structure. At present, the model test and numerical simulation methods are mainly used to study the flow characteristics around the pile. There are problems of model scale effect and test accuracy in the laboratory model test, and inherent problems in the numerical simulation method, such as the determination of medium parameters, mesh division, and boundary conditions. Therefore, the research results cannot reflect the actual situation of the interaction between water flow and pile. This paper developed a field test system for measuring the hydrodynamic pressures on surface of piles which are the vital foundations of wharves under superhigh Reynolds number. And the analysis methods of in-situ data, which can realize the multifunction including calibration and transformation for test data, frequency and time-domain statistical analysis process, were put forward according to the theory of stationary random process and mathematical statistics method. A representative frame wharf located in the upper reaches of the Yangtze River was performed as a case study, and the developed system was utilized to operate the in-situ test on this practice. Application showed that the field test system and the analysis methods can be applied to obtain the more accurate distribution of the pile surface hydrodynamic pressure. And the drag coefficient in wharf field ranged from 0.30 to 0.40. These findings in this paper may provide significant technical support for the in-situ test in similar structures and some reference for drag force calculation of flow around pile in the engineering design.

Calibration is vital to improving the accuracy of the strapdown inertial navigation system (SINS). Calibration is one of the crucial phases before the operation of SINS and requires high accuracy and speed. Traditional system-level calibration methods have the disadvantages of long calibration times and complicated path design. A fast calibration method for the lever arm and other error parameters is proposed in this article. To shorten the calibration time and improve the calibration accuracy, a backtracking calibration method in inertial frames based on the reduced-order Kalman filter is proposed. Simulations and experiments are given to illustrate the effectiveness of the novel calibration method. The calibration process can be completed in 10 min, which is greatly shortened compared with traditional methods. The calibration time is shortened, and the calibration accuracy is improved. Furthermore, navigation experiments show that the velocity and position accuracies of the SINS are improved significantly after compensation with the calibration results, fully illustrating the significance of the proposed calibration method in improving the navigation performance.

Numerical simulation of the factors influencing dust in drilling tunnels: Its application