matlab有限元網格劃分程序 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.
標簽： matlab有限元網格劃分程序
上傳時間： 2015-08-12
上傳用戶：凜風拂衣袖
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
標簽： 經濟、城市化和經濟增長
上傳時間： 2016-04-02
上傳用戶：kinda233
The FlexiForce A301 is our smallest standard piezoresistive Force sensor.
上傳時間： 2017-04-13
上傳用戶：guoggn
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.
標簽： Multimedia Business Mobile The
上傳時間： 2020-06-01
上傳用戶：shancjb
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.
標簽： Performance High MEMS RF
上傳時間： 2020-06-06
上傳用戶：shancjb
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.
標簽： Magnetometers Lorentz Force MEMS
上傳時間： 2020-06-06
上傳用戶：shancjb
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
標簽： AI-and-Robotics-IBA-GEI-April 2017
上傳時間： 2020-06-10
上傳用戶：shancjb
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.
標簽： electromagnetic response Seismic control using
上傳時間： 2021-11-04
上傳用戶：a1293065
近年來反季節種植已成火熱趨勢,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,本系統將溫室大棚的溫濕度、二氧化碳濃度各個方面的檢測,通風、澆灌、溫度、噴灑農藥等各個方面的控制進行綜合系統研究,實現溫室大棚對自動化、智能化的要求。這一系統是基于單片機控制的智能檢測,控制系統包含單片機主控模塊、感應檢測模塊、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.
上傳時間： 2022-03-27
上傳用戶：
簡介本應用筆記說明了無傳感器無刷直流（Brushless DC，BLDC）電機控制算法，該算法采用dsPIC數字信號控制器（digital signal controller，DSC）實現。該算法對電機每相的反電動勢（back-Electromotive Force，back-EMF）進行數字濾波，并基于濾得的反電動勢信號來決定何時對電機繞組換相。這種控制技術不需要使用離散式低通濾波硬件和片外比較器。BLDC電機的應用非常廣泛。本應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。運行于此RPM范圍內的一些BLDC電機應用可以是模式化RC電機、風扇、硬盤驅動、氣泵以及牙鉆等。本應用筆記中描述的算法可在以下兩個Microchip開發板平臺上實現：·PICDEMTA MCLV開發板·dsPICDEMTM MC1開發板PICDEMTM MC LV 開發板包括一片dsPIC30F3010DSC。上述算法在該器件上得以實現，因為該器件包含在PICDEMTM MCLV開發板中。然而，您也可使用dsPIC30F2010作為替代處理器以節約成本。該板的默認配置包含一個5MHz的晶振。在測試該算法時使用7.37MHz的晶振。PICDEM MCLV開發板上所使用的資源如下：
上傳時間： 2022-06-30
上傳用戶：
