A new cable fault location method based on wavelet reconstruction is proposed. In this method the difference between the currents of faulty phase and sound phase under the high voltage pulse excitation is used as the measured signal and is decomposed in multi-scale by wavelet transform, then reconstructed in single scale. Comparing with traditional fault location method by travelling wave, the presented method will not be interfered by the reflected wave from the branch joint of cables or from other positions where the impedances are not matched and not be influenced by fault types, otherwise, the reflected waves can be recognized even the faulty position is near to the measuring terminal, at the same time, the influence of the wave speed uncertainty can be reduced. The correctness of the proposed method is proved by simulation results.
標簽: method reconstruction location proposed
上傳時間: 2016-02-04
上傳用戶:maizezhen
Multirate filters provide a practical approach to designing and implementing finite response (FIR) filters with narrow spectral constraints. By changing the input data rate at one or more intermediate points the filter lengths and computational rates can be greatly reduced when compared to a standard single-rate filter implementation.
標簽: implementing Multirate designing practical
上傳時間: 2016-07-01
上傳用戶:dengzb84
Because of the poor observability of Inertial Navigation System on stationary base, the estimation error of the azimuth will converge very slowly in initial alignment by means of Kalmari filtering, and making the time initial alignment is longer. In this paper, a fast estimation method of the azimuth error is creatively proposed for the initial alignment of INS on stationary base. On the basis of the the fast convergence of the leveling error, the azimuth error can be directly calculated. By means of this fast initial alignment method, the time of initial alignment is reduced greatly. The computer simulation results illustrate the efficiency of the method.
標簽: observability Navigation estimation stationary
上傳時間: 2014-01-03
上傳用戶:wuyuying
The MAX481E, MAX483E, MAX485E, MAX487E–MAX491E, and MAX1487E are low-power transceivers for RS-485 and RS-422 communications in harsh environments. Each driver output and receiver input is protected against ±15kV electrostatic discharge (ESD) shocks, without latchup. These parts contain one driver and one receiver. The MAX483E, MAX487E, MAX488E, and MAX489E feature reduced slewrate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, thus allowing error-free data transmission up to 250kbps. The driver slew rates of the MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E are not limited, allowing them to transmit up to 2.5Mbps.
標簽: MAX transceivers 485 low-power
上傳時間: 2013-12-22
上傳用戶:小寶愛考拉
"Readers can pick up this book and become familiar with C++ in a short time. Stan has taken a very broad and complicated topic and reduced it to the essentials that budding C++ programmers need to know to write real programs. His case study is effective and provides a familiar thread throughout the book.
標簽: familiar Readers become short
上傳時間: 2014-01-19
上傳用戶:luke5347
We analyze, both analytically and numerically, the effectiveness of cloaking an infinite cylinder from observations by electromagnetic waves in three dimensions. We show that, as truncated approximations of the ideal permittivity and permeability tensors tend towards the singular ideal cloaking fields, so that the anisotropy ratio tends to infinity, the D and B fields blow up near the cloaking surface. Since the metamaterials used to implement cloaking are based on effective medium theory, the resulting large variation in D and B will pose a challenge to the suitability of the field averaged characterization of " and 碌. We also consider cloaking with and without the SHS (softand- hard surface) lining, shown in [6] to be theoretically necessary for cloaking in the cylindrical geometry. We demonstrate numerically that cloaking is significantly improved by the SHS lining, with both the far field of the scattered wave significantly reduced and the blow up of D and B prevented.
標簽: effectiveness analytically numerically cloaking
上傳時間: 2017-03-30
上傳用戶:zxc23456789
Introduction ? ? The ARM Cortex -A8 microprocessor is the first applications microprocessor in ARM!ˉs new Cortex family. With high performance and power efficiency, it targets a wide variety of mobile and consumer applications including mobile phones, set-top boxes, gaming consoles and automotive navigation/entertainment systems. The Cortex-A8 processor spans a range of performance points depending on the implementation, delivering over to 2000 Dhrystone MIPS (DMIPS) of performance for demanding consumer applications and consuming less than 300mW for low-power mobile devices. This translates into a large increase in processing capability while staying with the power levels of previous generations of mobile devices. Consumer applications will benefit from the reduced heat dissipation and resulting lower packaging and integration costs.
標簽: microprocessor Introduction applications Cortex
上傳時間: 2013-12-09
上傳用戶:xzt
A fractal is generally "a rough or fragmented geometric shape that can be split into parts, each of which is (at least approximately) a reduced-size copy of the whole,"[1] a property called self-similarity. The term was coined by Benoî t Mandelbrot in 1975 and was derived from the Latin fractus meaning "broken" or "fractured." A mathematical fractal is based on an equation that undergoes iteration, a form of feedback based on recursion.[2]
標簽: fragmented generally geometric fractal
上傳時間: 2014-01-18
上傳用戶:as275944189
The TJA1040 is an advanced high speed CAN transceiver for use in automotive and general industrial applications. It supports the differential bus signal representation described in the international standard for in-vehicle high speed CAN applications (ISO11898). CAN (Controller Area Network) is the standard protocol for serial in-vehicle bus communication, particularly for Engine Management and Body Multiplexing. The TJA1040 provides a Standby mode, as known from its functional predecessors PCA82C250 and PCA82C251, but with significantly reduced power consumption. Besides the excellent low-power behavior the TJA1040 offers several valuable system improvements. Highlights are the absolute passive bus behavior if the device is unpowered as well as the excellent EMC performance.
標簽: CAN
上傳時間: 2015-03-23
上傳用戶:Yuan Lo
A major societal challenge for the decades to come will be the delivery of effective medical services while at the same time curbing the growing cost of healthcare. It is expected that new concepts-particularly electronically assisted healthcare will provide an answer. This will include new devices, new medical services as well as networking. On the device side, impressive innovation has been made possible by micro- and nanoelectronics or CMOS Integrated Circuits. Even higher accuracy and smaller form factor combined with reduced cost and increased convenience of use are enabled by incorporation of CMOS IC design in the realization of biomedical systems. The compact hearing aid devices and current pacemakers are good examples of how CMOS ICs bring about these new functionalities and services in the medical field. Apart from these existing applications, many researchers are trying to develop new bio-medical solutions such as Artificial Retina, Deep Brain Stimulation, and Wearable Healthcare Systems. These are possible by combining the recent advances of bio-medical technology with low power CMOS IC technology.
上傳時間: 2017-02-06
上傳用戶:linyj