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1.
This paper proposes a method to reduce the vibration of the three-phase HB-type stepping motor with cogging torque by the feedforward compensation control. The compensation signal to suppress the vibration of the motor frame is obtained by the repetitive controller installing an online Fourier transformer and utilizing an acceleration sensor attached to the motor frame or an acoustic sensor such as a microphone placed close to the frame. The sensor is used only for the acquisition of the feedforward compensation data. The feedforward compensation signal at an arbitrary operating point is derived from the amplitude and phase data of the frequency components and the operating point data. Compensation data obtained by the repetitive controller is applied to the operating point changed by reference frequency and load condition in steady state. The compensation signal for the new operating point will be generated from compensation data utilizing polynomial equation approximation and linear interpolation method. The effectiveness of this proposed method is confirmed by the experimental results.  相似文献   
2.
Su  J. Ritter  P.R. 《Software, IEEE》1991,8(2):26-33
The testing and quality assurance of the Motif 1.0 graphical user-interface software are described. The testing goals, which fell into three general categories (code coverage, defect-density, and defect-arrival rate), and a deliverable formal test suite are examined. The three phases of the testing process-evaluation, test development, and regression testing-and the tools used in testing are discussed  相似文献   
3.
Numerous power utilities have installed advanced distributed temperature sensing (DTS) systems to measure the temperature of underground cables. This paper presents a general procedure for real-time assessment of underground cable ratings based on DTS. After the identification and location of hot spots on a cable, the cable installation data, load, and DTS-recorded temperature over a period of time are used to estimate soil thermal parameters and assess cable ratings under normal and overloading conditions. In order to accurately estimate soil thermal parameters, a combined technique of the finite-element method and gradient-based optimization is used. The technique was validated in the laboratory and applied to a rating assessment of a 230-kV/500-MVA cable circuit. The assessed continuous and emergency ratings are helpful in improving the operation of this circuit.  相似文献   
4.
The current-voltage characteristics of the P-N double quantum well resonant interband tunneling (RIT) diodes in InAlAs-InGaAs system have been improved in this letter. The peak-to-valley current ratio (PVCR) is as high as 144 at room temperature. As we know, this is the highest room temperature PVCR ever reported in any tunneling devices. Moreover, the influence of the central barrier thickness varying from 10 Å to 30 Å on the device characteristics is also studied  相似文献   
5.
The major steps of sewerage rehabilitation include inspection of sewerage, assessment of structural conditions, computation of structural condition grades, and determination of rehabilitation methods and materials. Conventionally, sewerage rehabilitation planning relies on experts with professional background that is tedious and time-consuming. This paper proposes an automation model of planning optimal sewerage rehabilitation strategies for the sewer system by integrating image process, clustering technology, optimization, and visualization display. Firstly, image processing techniques, such as wavelet transformation and co-occurrence features extraction, were employed to extract various characteristics of structural failures from CCTV inspection images. Secondly, a classification neural network was established to automatically interpret the structural conditions by comparing the extracted features with the typical failures in a databank. Then, to achieve optimal rehabilitation efficiency, a genetic algorithm was used to determine appropriate rehabilitation methods and substitution materials for the pipe sections with a risk of mal-function and even collapse. Finally, the result from the automation model can be visualized in a geographic information system in which essential information of the sewer system and sewerage rehabilitation plans are graphically displayed. For demonstration, the automation model of optimal sewerage rehabilitation planning was applied to a sewer system in east Taichung, Chinese Taiwan.  相似文献   
6.
A sublambda traffic-grooming scheme on wavelength-division-multiplexed (WDM) rings, which is called optical burst transport (OBT), is proposed. The network protocol and architecture allow increased flexibility to tailor the transport network behavior for efficient delivery of bursty data traffic. Using different network parameters, its performance is analyzed via simulation, and the implementation issues including the media-access-control (MAC) protocol, tunable-filter controller, and burst-mode receiver are addressed. Finally, the feasibility of the OBT with an experimental testbed built by the authors is demonstrated and a streaming-video application is used to present its overall functionality.  相似文献   
7.
Polycrystalline A1N thin films were deposited by RF reactive magnetron sputtering on Pt(111)/Ti electrode films. The substrates were tilted by an angle ranging from 40 degrees to 70 degrees with respect to the target normal. A low deposition temperature and a high sputter gas pressure were found ideal for tilted growth. The resulting grain tilt angle amounts to about half the substrate tilt angle. For coupling evaluation, 5 GHz solidly mounted resonator structures have been realized. The tilted grain A1N films exhibited a permittivity in the 9.5-10.5 range and loss tangent of 0.3%. Two shear modes as well as the longitudinal mode could be clearly identified. The coupling coefficient k2(eff) of the fundamental thickness shear mode (TS0) was found to be about 0.5%, which is compatible with a c-axis tilt of about 6 degrees.  相似文献   
8.
SBA15–TiO2 samples prepared by introducing titanium with a grafting method and having TiO2 loadings below 15 wt.% have been characterized by XRF, XRD, IR, porosimetry, SEM, HRTEM, and UV–Visible diffuse reflectance. Differently from the samples reported in the literature characterized by a high TiO2 loading, no evidences have been found for the presence of titania particles inside or outside the mesopores of SBA-15. Three different titanium species were instead evidenced to be present. The first two derive from the reaction of titanium with silanol groups in the corona area of inner SBA-15 walls leading to the formation of either TiO4 tetrahedral sites (by reaction by hydroxyl nests of surface defect sites) and/or pseudo-octahedral surface sites anchored by two (or more) Si or Ti ions through bridging oxygens. The third species derives from the reaction of titanium in the regions with high sylanol density, e.g. in the micropores located in the corona of SBA-15 channels, leading to the formation of TiO2-like nanoareas (probably Si-doped) with dimensions of around 1–2 nm maximum. The potential interest of these materials as photocatalysts, for the presence of a TiO2-like nanoareas highly accessible by reactants, is discussed.  相似文献   
9.
Multimedia Tools and Applications - Deep learning has made essential contributions to the development of visual object detection and recognition. Identifying fast-moving objects from the viewpoint...  相似文献   
10.
Wei  Shikui  Jiang  Su  Jin  Wenxian  Zhao  Yao  Ni  Rongrong  Zhu  Zhenfeng 《Multimedia Systems》2015,21(2):207-216
Multimedia Systems - Recently, the frame fusion based video copy detection scheme provides a possibility to detect copies in a continuous query video stream. However, its computational complexity...  相似文献   
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