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matlab有限元網(wǎng)格劃分程序
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.
標(biāo)簽：
matlab有限元網(wǎng)格劃分程序
上傳時(shí)間：
2015-08-12
上傳用戶：凜風(fēng)拂衣袖
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We show in the context of a new economic geography model that when
labor is heterogenous trade liberalization may lead to industrial agglomeration
and inter-regional trade. Labor heterogeneity gives local monopoly
power to firms but also introduces variations in the quality of the job match.
Matches are likely to be better when there are more firms and workers in
the local market, giving rise to an agglomeration force which can offset the
forces against, trade costs and the erosion of monopoly power. We derive
analytically a robust agglomeration equilibrium and illustrate its properties
with numerical simulations
標(biāo)簽：
經(jīng)濟(jì)、城市化和經(jīng)濟(jì)增長
上傳時(shí)間：
2016-04-02
上傳用戶：kinda233
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The Flexiforce A301 is our smallest standard piezoresistive
force sensor.
標(biāo)簽：
FLX-A
301
上傳時(shí)間：
2017-04-13
上傳用戶：guoggn
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The first practical examples of mobile communications were used in many countries like
the USA, the UK and Germany in military services, and played a significant role in the
First World War to transfer important information from the front to headquarters to take
further actions. Good and secure wireless communications were an important need for all
military services – army, navy and air force. In this respect, the Second World War was a big
experimental battlefield for the development and evolution of mobile radio. It was in the
interests of governments that after the Second World War the military investment should
be paid back by civilian use, and all western European countries started their so-called first
generation of mobile communication networks.
標(biāo)簽：
Multimedia
Business
Mobile
The
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
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Micro-Electro-Mechanical Systems (MEMS) are miniature systems composed
ofintegratedelectricalandmechanicalpartstosenseand/orcontrolthingsonaμmscale.
The concept of MEMS is attributed to Richard Feynman’s famous talk on December
29th, 1959 [2,3]. Dr. Feynman foresaw many aspects of future MEMS development
with his insight in microphysics. In particular, material properties in the μm scale are
differentfrombulkpropertiesandthescalingdownofintegratedcircuits(IC)fabrication
technology has been a major driving force of MEMS development.
標(biāo)簽：
Performance
High
MEMS
RF
上傳時(shí)間：
2020-06-06
上傳用戶：shancjb
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Nowadays sensors are part of everyday life in a wide variety of fields: scientific
applications, medical instrumentation, industrial field, ...and, last but not least,
popular mass production and low-cost goods, like smartphones and other mobile
devices. Markets and business behind the field of sensors are quite impressive.
A common trend for consumer applications is miniaturization which requires, on
one side, a lot of research, development efforts, and resources but, on the other
hand, allows costs and final application size reduction. In this scenario scientific
community and industries are very active to drive innovation.
標(biāo)簽：
Magnetometers
Lorentz
force
MEMS
上傳時(shí)間：
2020-06-06
上傳用戶：shancjb
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Modern information technologies and the advent of machines powered by artificial
intelligence (AI) have already strongly influenced the world of work in the 21st century.
Computers, algorithms and software simplify everyday tasks, and it is impossible
to imagine how most of our life could be managed without them. However, is it
also impossible to imagine how most process steps could be managed without
human force? The information economy characterised by exponential growth
replaces the mass production industry based on economy of scales
標(biāo)簽：
AI-and-Robotics-IBA-GEI-April
2017
上傳時(shí)間：
2020-06-10
上傳用戶：shancjb
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This paper presents a new type of electromagnetic damper with rotating inertial mass that has been devel
oped to control the vibrations of structures subjected to earthquakes. The electromagnetic inertial mass
damper (EIMD) consists of a ball screw that converts axial oscillation of the rod end into rotational motion
of the internal flflywheel and an electric generator that is turned by the rotation of the inner rod. The EIMD is
able to generate a large inertial force created by the rotating flflywheel and a variable damping force devel
oped by the electric generator. Device performance tests of reduced-scale and full-scale EIMDs were under
taken to verify the basic characteristics of the damper and the validity of the derived theoretical formulae.
Shaking table tests of a three-story structure with EIMDs and earthquake response analyses of a building
with EIMDs were conducted to demonstrate the seismic response control performance of the EIMD. The
EIMD is able to reduce story drifts as well as accelerations and surpasses conventional types of dampers
in reducing acceleration responses.
標(biāo)簽：
electromagnetic
response
Seismic
control
using
上傳時(shí)間：
2021-11-04
上傳用戶：a1293065
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近年來反季節(jié)種植已成火熱趨勢,溫室大棚的普及十分迅速,而溫室大棚對自動化、智能化的要求也越來越迫切,本系統(tǒng)將溫室大棚的溫濕度、二氧化碳濃度各個(gè)方面的檢測,通風(fēng)、澆灌、溫度、噴灑農(nóng)藥等各個(gè)方面的控制進(jìn)行綜合系統(tǒng)研究,實(shí)現(xiàn)溫室大棚對自動化、智能化的要求。這一系統(tǒng)是基于單片機(jī)控制的智能檢測,控制系統(tǒng)包含單片機(jī)主控模塊、感應(yīng)檢測模塊、傳感模塊,顯示、控制模塊等[1]。從而提高溫室大棚的種植效率,減少勞動力,提高利潤等。In recent years,counter-season planting has become a hot trend featuring the rapid popularization of greenhouse and urgent requirement for the automation and intellectualization of greenhouse.This paper offers a comprehensive and systematic study of the monitoring of temperature,humidity and carbon dioxide concentration in the greenhouse and the control of ventilation,irrigation,temperature and pesticide spraying in order to achieve automation and intellectualization in greenhouse.This system is based on the intelligent detection controlled by single chip computer with the control system including the main control module,induction detection module,sensing module,display and control module of single chip computer,which is effective in improving planting efficiency of greenhouse,reducing labor force and increasing profits.
標(biāo)簽：
智能溫室大棚
控制系統(tǒng)
上傳時(shí)間：
2022-03-27
上傳用戶：
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簡介本應(yīng)用筆記說明了無傳感器無刷直流（Brushless DC，BLDC）電機(jī)控制算法，該算法采用dsPIC數(shù)字信號控制器（digital signal controller，DSC）實(shí)現(xiàn)。該算法對電機(jī)每相的反電動勢（back-Electromotive force，back-EMF）進(jìn)行數(shù)字濾波，并基于濾得的反電動勢信號來決定何時(shí)對電機(jī)繞組換相。這種控制技術(shù)不需要使用離散式低通濾波硬件和片外比較器。BLDC電機(jī)的應(yīng)用非常廣泛。本應(yīng)用筆記中描述的算法適合于電氣RPM范圍在40k到100k的BLDC電機(jī)。運(yùn)行于此RPM范圍內(nèi)的一些BLDC電機(jī)應(yīng)用可以是模式化RC電機(jī)、風(fēng)扇、硬盤驅(qū)動、氣泵以及牙鉆等。本應(yīng)用筆記中描述的算法可在以下兩個(gè)Microchip開發(fā)板平臺上實(shí)現(xiàn)：·PICDEMTA MCLV開發(fā)板·dsPICDEMTM MC1開發(fā)板PICDEMTM MC LV 開發(fā)板包括一片dsPIC30F3010DSC。上述算法在該器件上得以實(shí)現(xiàn)，因?yàn)樵撈骷赑ICDEMTM MCLV開發(fā)板中。然而，您也可使用dsPIC30F2010作為替代處理器以節(jié)約成本。該板的默認(rèn)配置包含一個(gè)5MHz的晶振。在測試該算法時(shí)使用7.37MHz的晶振。PICDEM MCLV開發(fā)板上所使用的資源如下：
標(biāo)簽：
電動勢
傳感器
bldc
上傳時(shí)間：
2022-06-30
上傳用戶：
