Use the fast Fourier transform function fft to analyse following signal. Plot the original signal, and the magnitude of its spectrum linearly and logarithmically. Apply Hamming window to reduce the leakage. . The hamming window can be coded in Matlab as for n=1:N hamming(n)=0.54+0.46*cos((2*n-N+1)*pi/N); end; where N is the data length in the FFT.
標(biāo)簽： matlab fft
上傳時(shí)間： 2015-11-23
上傳用戶：石灰?guī)r123
Use fft to analyse signal by plotting the original signal and its spectrum.
標(biāo)簽： matlab fft
上傳時(shí)間： 2015-11-23
上傳用戶：石灰?guī)r123
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.
標(biāo)簽： 高精度格式
上傳時(shí)間： 2016-01-13
上傳用戶：ccsdcczd
Our original effort in writing this book was to create a starting point for those in the business community who did not have a high level of technical expertise but needed to have some understanding of the technical functions of their information and communication technologies (ICT) in a corporate environment. As was true with the first edition of this book, if you are already an engineer, find some other form of pleasure reading—this text is not designed for you!
標(biāo)簽： Communications Introduction Technologies to
上傳時(shí)間： 2020-05-27
上傳用戶：shancjb
Since the original publication of Manual 74 in 1991, and the preceding “Guidelines for Transmission Line Structural Loading” in 1984, the understanding of structural loadings on transmission line structures has broadened signifi cantly. However, improvements in computational capa- bility have enabled the transmission line engineer to more easily deter- mine structural loadings without properly understanding the parameters that affect these loads. Many seasoned professionals have expressed concern for the apparent lack of recent information on the topic of struc- tural loadings as new engineers enter this industry. The Committee on Electrical Transmission Structures is charged with the responsibility to report, evaluate, and provide loading requirements of transmission struc- tures. This task committee was therefore formed to update and revise the 1991 manual.
標(biāo)簽： Transmission Guidelines Electrical Line for
上傳時(shí)間： 2020-06-07
上傳用戶：shancjb
Thepredecessorvolumeofthisbookwaspublishedin1996.Intheyears since then, some things have changed and some have not. Two of the things that have not changed are the desire for better models and faster simulations. I performed the original simulations on my “hyperfast” 133-MHz computer! At the time, I thought if I could just getafastercomputer,allofourSPICEproblemswouldbehistory,right? TodayIamsimulatingonacomputerthathasa2.6-GHzprocessorwith 512 MB of RAM, and I would still say that simulations run too slow. The computer technology has evolved, but so have the models. In 1996 wewereperformingsimulationson100-kHzpowerconverters,whereas today I routinely see 1- and 2-MHz power converters.
標(biāo)簽： Switch-Mode Simulation Supply Power
上傳時(shí)間： 2020-06-07
上傳用戶：shancjb
In this new edition of the book, only minor changes were made to the original nine chapters but three new chapters treat topics of increasing interest to GPS users and equipment developers. One topic, improving the GPS receiver sensi- tivity may extend their operations into buildings, which is becoming important for emergency rescue and urban warfare.
標(biāo)簽： Fundamentals_of_Global_Positionin g_System
上傳時(shí)間： 2020-06-09
上傳用戶：shancjb
The basic topic of this book is solving problems from system and control theory using convex optimization. We show that a wide variety of problems arising in system and control theory can be reduced to a handful of standard convex and quasiconvex optimization problems that involve matrix inequalities. For a few special cases there are “analytic solutions” to these problems, but our main point is that they can be solved numerically in all cases. These standard problems can be solved in polynomial- time (by, e.g., the ellipsoid algorithm of Shor, Nemirovskii, and Yudin), and so are tractable, at least in a theoretical sense. Recently developed interior-point methods for these standard problems have been found to be extremely efficient in practice. Therefore, we consider the original problems from system and control theory as solved.
標(biāo)簽： Linear_Matrix_Inequalities_in_Sys tem
上傳時(shí)間： 2020-06-10
上傳用戶：shancjb
摘要：本文在分析1GBT的動(dòng)態(tài)開關(guān)特性和過流狀態(tài)下的電氣特性的基礎(chǔ)上，通過對(duì)常規(guī)的IGBT推挽驅(qū)動(dòng)電路進(jìn)行改進(jìn)，得到了具有良好過流保護(hù)特性的IGBT驅(qū)動(dòng)電路。該電路簡(jiǎn)單，可靠，易用，配合DSP等控制芯片能達(dá)到很好的驅(qū)動(dòng)效果Abstract：Based on the studies on the dynamic switching and over-current characteristics of IGBT，this paper makes some improvments to the original push-pull driving circuit，obtains a new IGBT driving circuit which has a good over-current protection function.The circuit is simple，reliable and easy to use.Combined with controlling chips such as DSP it will do a great job in driving applications.關(guān)鍵詞：IBGT：開關(guān)特性；驅(qū)動(dòng)；過流保護(hù)；Key Words:IGBT；switching characteristics；driving:over-current protection
標(biāo)簽： 分立元件 igbt 驅(qū)動(dòng)電路
上傳時(shí)間： 2022-06-21
上傳用戶：
This documentation is the original work and copyrighted property of X-Powers. Reproduction in whole orin part must obtain the written approval of X-Powers and give clear acknowledgement to the copyrightowner.
標(biāo)簽： AC101
上傳時(shí)間： 2022-06-28
上傳用戶：xsr1983
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