matlab有限元网格划分程序 DistMesh is a simple MATLAB code for generation of unstructured triangular and tetrahedral meshes. It was developed by Per-Olof Persson (now at UC Berkeley) and Gilbert Strang in the Department of Mathematics at MIT. A detailed description of the program is provided in our SIAM Review paper, see documentation below. One reason that the code is short and simple is that the geometries are specified by Signed Distance Functions. These give the shortest distance from any point in space to the boundary of the domain. The sign is negative inside the region and positive outside. A simple example is the unit circle in 2-D, which has the distance function d=r-1, where r is the distance from the origin. For more complicated geometries the distance function can be computed by interpolation between values on a grid, a common representation for level set methods. For the actual mesh generation, DistMesh uses the Delaunay triangulation routine in MATLAB and tries to optimize the node locations by a force-based smoothing procedure. The topology is regularly updated by Delaunay. The boundary points are only allowed to move tangentially to the boundary by projections using the distance function. This iterative procedure typically results in very well-shaped meshes. Our aim with this code is simplicity, so that everyone can understand the code and modify it according to their needs. The code is not entirely robust (that is, it might not terminate and return a well-shaped mesh), and it is relatively slow. However, our current research shows that these issues can be resolved in an optimized C++ code, and we believe our simple MATLAB code is important for demonstration of the underlying principles. To use the code, simply download it from below and run it from MATLAB. For a quick demonstration, type "meshdemo2d" or "meshdemond". For more details see the documentation.
标签： matlab有限元网格划分程序
上传时间： 2015-08-12
上传用户：凛风拂衣袖
Matlab 画三维立体图形 The aim of geom3d library is to handle and visualize 3D geometric primitives such as points, lines, planes, polyhedra... It provides low-level functions for manipulating 3D geometric primitives, making easier the development of more complex geometric algorithms. Some features of the library are: - creation of various shapes (3D points, 3D lines, planes, polyhedra...) through an intuitive syntax. Ex: createPlane(p1, p2, p3) to create a plane through 3 points. - derivation of new shapes: intersection between 2 planes, intersection between a plane and a line, between a sphere and a line... - functions for 3D polygons and polyhedra. Polyhedra use classical vertex-faces arrays (face array contain indices of vertices), and support faces with any number of vertices. Some basic models are provided (createOctaedron, createCubeoctaedron...), as well as some computation (like faceNormal or centroid) - manipulation of planar transformation. Ex.: ROT = createRotationOx(THETA); P2 = transformPoint3d(P1, ROT); - direct drawing of shapes with specialized functions. Clipping is performed automatically for infinite shapes such as lines or rays. Ex: drawPoint3d([50 50 25; 20 70 10], 'ro'); % draw some points drawLine3d([X0 Y0 Z0 DX DY DZ]); % clip and draw straight line Some functions require the geom2d package. Additional help is provided in geom3d/Contents.m file, as well as summary files like 'points3d.m' or 'lines3d.m'.
标签： Matlab 画三维立体图形
上传时间： 2015-11-02
上传用户：A1321
We introduce a sub-cell WENO reconstruction method to evaluate spatial derivatives in the high-order ADER scheme. The basic idea in our reconstruction is to use only r stencils to reconstruct the point-wise values of solutions and spatial derivatives for the 2r-1 th order ADER scheme in one dimension, while in two dimensions, the dimension-by-dimension sub-cell reconstruction approach for spatial derivatives is employed. Compared with the original ADER scheme of Toro and Titarev (2002) [2] that uses the direct derivatives of reconstructed polynomials for solutions to evaluate spatial derivatives, our method not only reduces greatly the computational costs of the ADER scheme on a given mesh, but also avoids possible numerical oscillations near discontinuities, as demonstrated by a number of one- and two-dimensional numerical tests. All these tests show that the 5th-order ADER scheme based on our sub-cell reconstruction method achieves the desired accuracy, and is essentially non-oscillatory and computationally cheaper for problems with discontinuities.
标签： 高精度格式
上传时间： 2016-01-13
上传用户：ccsdcczd
Guided vehicles (GVs) are commonly used for the internal transportation of loads in warehouses, production plants and terminals. These guided vehicles can be routed with a variety of vehicle dispatching rules in an attempt to meet performance criteria such as minimizing the average load waiting times. In this research, we use simulation models of three companies to evaluate the performance of several real-time vehicle dispatching rules, in part described in the literature. It appears that there is a clear difference in average load waiting time between the different dispatching rules in the different environments. Simple rules, based on load and vehicle proximity (distance-based) perform best for all cases. The penalty for this is a relatively high maximum load waiting time. A distance-based rule with time truncation, giving more priority to loads that have to wait longer than a time threshold, appears to yield the best possible overall performance. A rule that particularly considers load-waiting time performs poor overall. We also show that using little pre-arrival information of loads leads to a significant improvement in the performance of the dispatching rules without changing their performance ranking.
标签： Testing and classifying vehicle dispatching rules in three real-world settings
上传时间： 2016-04-01
上传用户：五块钱的油条
The TAS3204 is a highly-integrated audio system-on-chip (SOC) consisting of a fully-programmable, 48-bit digital audio processor, a 3:1 stereo analog input MUX, four ADCs, four DACs, and other analog functionality. The TAS3204 is programmable with the graphical PurePath Studio™ suite of DSP code development software. PurePath Studio is a highly intuitive, drag-and-drop environment that minimizes software development effort while allowing the end user to utilize the power and flexibility of the TAS3204’s digital audio processing core. TAS3204 processing capability includes speaker equalization and crossover, volume/bass/treble control, signal mixing/MUXing/splitting, delay compensation, dynamic range compression, and many other basic audio functions. Audio functions such as matrix decoding, stereo widening, surround sound virtualization and psychoacoustic bass boost are also available with either third-party or TI royalty-free algorithms. The TAS3204 contains a custom-designed, fully-programmable 135-MHz, 48-bit digital audio processor. A 76-bit accumulator ensures that the high precision necessary for quality digital audio is maintained during arithmetic operations. Four differential 102 dB DNR ADCs and four differential 105 dB DNR DACs ensure that high quality audio is maintained through the whole signal chain as well as increasing robustness against noise sources such as TDMA interference. The TAS3204 is composed of eight functional blocks: Clocking System Digital Audio Interface Analog Audio Interface Power supply Clocks, digital PLL I2C control interface 8051 MCUcontroller Audio DSP – digital audio processing 特性 Digital Audio Processor Fully Programmable With the Graphical, Drag-and-Drop PurePath Studio™ Software Development Environment 135-MHz Operation 48-Bit Data Path With 76-Bit Accumulator Hardware Single-Cycle Multiplier (28 × 48)
上传时间： 2016-05-06
上传用户：fagong
Color appearance models aim to extend basic colorimetry to the level of specifying the perceived color of stimuli in a wide variety of viewing conditions
标签： appearance Color model
上传时间： 2016-05-21
上传用户：wisewater
High-speed Precision Numerically Controlled Tapping Using Dual Predictive Control
标签： 神经网络控制
上传时间： 2016-07-20
上传用户：ss183968ss
msp430The LDC1312 and LDC1314 are 2- and 4-channel, 1• Easy-to-use – minimal configuration required 12-bit inductance to digital converters (LDCs) for • Measure up to 4 sensors with one IC inductive sensing solutions. With multiple channels • Multiple channels support environmental and and support for remote sensing, the LDC1312 and aging compensation LDC1314 enable the performance and reliability benefits of inductive sensing to be realized at minimal• Multi-channel remote sensing provides lowest cost and power. The products are easy to use, onlysystem cost requiring that the sensor frequency be within 1 kHz • Pin-compatible medium and high-resolution and 10 MHz to begin sensing. The wide 1 kHz to 10 options MHz sensor frequency range also enables use of very small PCB coils, further reducing sensing– LDC1312/4: 2/4-ch 12-bit LDC solution cost and size.– LDC1612/4: 2/4-ch 28
上传时间： 2016-07-22
上传用户：tongmoonsky
12V or Adjustable, High-Efficiency,Low IQ, Step-Up DC-DC Controller
上传时间： 2016-10-20
上传用户：oyjwle
Connecting 32-bit controlled applications in the industrial, commercial and consumer markets is fast becoming a necessity rather than an option. Many new applications, such as remote data collection, home automation and networked appliances, require secure, high-performance connectivity at an economical price. Freescale Semiconductor gives design engineers the flexibility to choose the right 32-bit microcontroller from a broad portfolio of ColdFire® embedded controllers.
上传时间： 2017-02-18
上传用户：traff07
