In practical engineering problem solution,what are the basically three major categories of method?
Traditional design procedures often do not account for system-level dynamic behaviors.
For the FEA of a system, the total DOFs for a given mesh model is equal to the number of nodes multiplied by the number of DOFs per node.
A linear static analysis is an analysis where a linear relation holds between applied forces and displacements.
The core of PDE method is to reduces the degrees of Freedom from infinite to finite with the help of discretization or meshing
Regarding nonlinear analysis, what kind of nonlinearity is meant
A.
Geometric Nonlinearity
C.
Kinematic Nonlinearity
A nonlinear analysis is an analysis where a nonlinear relation holds between applied forces and displacements.
Interpolation functions are used to interpolate the field variables over the element. Often, polynomials are selected as interpolation functions. The degree of the polynomial depends on the number of ...
The data we obtain through simulation can also help us establish correlations between the resources and their yield, both individually and collectively.
Because there are always some unnecessary model details need to be removed to simplify the meshing step,geometry cleanup is an important step in pre-processing
FEA is suitable for complex problems where an analytical solutions cannot be found.
When the geometric model is prepared, we don't need to give out the material definition.
The first step to visualize the simulation data with MATLAB Virtual Reality ToolBox/Simulink 3D Animation is to create the virtual scene.
What are the modeling method using MATALB?
How many steps does it take to create a virtual scene for a mass-spring-damper system
the reader is advised to starting from scratch every time instead of start writing his/her own code by modifying an existing one
What is the first step in the animation simulation model
A.
create the virtual scene
According to this paper, in order to make the virtual scene more realistic, we can change the color, material and texture of objects in the scene, which need to be carried out several steps?
How many steps does it take to create a Simulink Model
Simulink is an advanced modeling tools to build simulation models, with Simulink you need to write code
What is the relationship between the camera coordinate system and the image coordinate system?
B.
perspective projection
C.
Translational transform
What is the composition of lens distortion?
What can be represented in terms of the change between the coordinate system and the camera coordinate system?
C.
a 3×3 rotation matrix R and a translation vector t
D.
a 4×4 rotation matrix R and a translation vector t
In which variable is the number of images to be calibrated stored?
What form are external parameters shown?
What is the calibration function of the camera in Matlab?
The depth of field adversely affects the visual perception and image post-processing.
Why does the pixel-based approach lead to the error recognition of focusing pixels?
A.
focus measures are susceptible to noise
D.
The effect of defocus pixels
The depth of field problem can be solved by fusing a set of image sequences into fully aggregated images.
The inspection of road diseases such as cracks and pits is unessential for road maintenance.
There are two main steps in the image detection of road diseases: road surface extraction and disease detection.
Which is not the benefit of the use of electronic controllers ()?
A.
improving dynamic performance
C.
increased energy efficiency
D.
improved operator controllability
What are the common methods of road detection?
A.
by manual visual observation
B.
to use road inspection vehicle
C.
unmannedaerial vehicle (UAV) technologies combined with digital image processing
D.
"Three dimensional integration" test
The advantages of commercial HIL tools include ():
C.
Synchronize with the real machine.
Matlab software is a famous one in the simulation technology industry
The commercial HIL software include ():
At most of the circumstances, the running speed of the construction machines is relatively high.
MBDyn is a free open-source general-purpose Multibody Dynamics analysis software.
Accuracy in mechanical engineering is inside of the 10% tolerance comparing to the result of testing.
The sensors used in the construction machinery are mostly working at a low sampling rate which less than 1000Hz.
ALGLIB is a cross-platform numerical analysis and data processing library.
In DotNumerics library, which methods are supported().
OpenModelica is an open-source modeling and simulation environment intended for industrial and academic usage.
Maplesim’s code generation can not generate ()。
MapleSim is the combination of Modelica, an open, process-oriented, system-level modeling language.
We can use those softwares to get mechanical 3D files().
A virtual environment is an environment in which simulation activities of everyday life are made
For the simulation of a machine system, we need to consider this factors().
B.
The definition of the model’s dynamics, movements, velocities and sequences.
C.
Simulation of all movements
What is the first step of achieving autonomous?
The simulation of information collection is that this process can be conducted in Visual C++ by programming method.
The development of automated vehicles requires the integration of multiple sensors.
The sensors commonly used in automated operating system groups are ____.
There are two essential issues to be resolved for developing a safety device for an unmanned vehicle:__,__.
When the vehicle drives along a straight path or curve path, the two front wheels show the same motion characteristics.
The velocity of the vehicle can be decomposed into __ velocity along the center axis and __ velocity.
The model of Kalman filter use the ____ for prediction, and the ____ for correction.
The position and attitude of an object do not include ____.
Which formula is included in the kinematic modeling equation of tracked vehicle?
The receiver of the GNSS is always fixed at a higher level over the center of gravity of vehicles to avoid the degradation of GNSS signal by obstruction, and it will not affect the receiving device.
The position obtained by the receiver of the GNSS can be used directly.
An autonomous vehicle must be capable of running along predetermined paths in an open field.
化工热力学着重研究热力学函数在工程中的应用,不包括( )。
“三要素”是化工热力学内容的基本组成部分,“三要素”不包括( )。
由可测性质推算不可测或难测性质,是化工热力学的重要任务之一。
在p-T图上,表达汽液平衡的蒸气压曲线始于三相点而终止于临界点。
对于纯物质,当p>pc、T>Tc时,物质以液态存在。
室温下加压可使天然气变成液化天然气(LNG)。(天然气的主成分甲烷:Tc= -82.55℃,pc=4.60 MPa。)
van der Waals方程中参数a是分子间的引力常数,参数b是体积修正项。
van der Waals方程虽然精度有限,在实际中较少使用,但推导这个方程的思路值得借鉴,后来的许多立方型EOS都是在vdW方程的基础上进行改进而发展起来的。
RK方程适用于非极性和弱极性的化合物,应用于极性及含有氢键的物质,也有较好的精度。
vdW、RK和PR方程都具有各自固定的临界压缩因子值。
对一定的物质来说,维里系数仅仅是温度的函数,与表征分子间势能函数的参数有关,不受压力和密度的影响。
virial系数把宏观热力学和统计力学、分子结构等联系起来。
对比态原理的内容是相同对比温度和对比压力下,不同气体的对比摩尔体积近似相等。
三参数对比态原理的第三参数应该能灵敏的反映物质分子间相互作用力。
偏心因子可用于正常流体,也可用于H2、He等量子流体或强极性流体和氢键流体。
偏心因子ω表示分子的偏心度或非球性,对简单球形流体(氩、氪、氙)的ω=0。
普遍化方法只是估算的方法,它不能用来代替pVT可靠的实验数据。
普遍化第二virial系数法只适合于低压非极性气体,适用范围较窄。
二元交互作用参数一般在0~0.2之间,其值较小,因此对气液平衡计算精度的影响可忽略。
状态方程的混合规则很多,不同的混合规则有不同的计算精度和适用范围。
立方型状态方程可以根据临界压缩因子的大小大体判断方程的精度。
对学过的状态方程的精度差异,下列那个是不正确的( )。
Maxwell关系式的主要作用是( )。
B.
用某个热力学函数代替另一不易测定的热力学函数的偏微商
C.
将不可测定的S与可以测定p-V-T联系了起来
热力学基本方程(即四大微分方程),下列哪个不是( )。
z为x、y的连续函数,有全微分dz=Mdx+Ndy,则有( )。
如dU=TdS−pdV等热力学基本方程适用于不做非体积功、组成一定的任何。
以(T,V)为变量进行热力学性质的计算时,常常首先计算哪两个热力学性质( )。
如果要求某一状态下的焓值和熵值,必须要确定参考态以作为计算的起始点。
关于剩余性质MR,理想气体性质Mig,下列公式正确的是( )。