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Considering that the operating angle of attack (AOA) of a blade element on a variable-speed wind turbine (VSWT) cannot be maintained at a single value due to the slow dynamic behavior of the turbine, the multi-AOA based airfoil design is gradually becoming a significant approach to improve the efficiency of energy capture for the blade element. However, a key issue of this method, the selection of...
The atomic H-masers are widely used in time keeping nowadays. BIPM has changed clock frequency prediction method since September 2011 based on weighting the clocks according to their predictability. An H-maser characterized by a very significant frequency drift can be used in time keeping because its behavior can be well predicted. The clock ensemble of UTC(NIM) consists 6 H-masers (5 at the new campus)...
NIM has started to switch formally generating of UTC(NIM) to the new campus since Oct 14th 2012. After that, 6 H-masers (Symmetricom MHM-2010) and 7 industrial Cs clocks (Symmetricom 5071A) at the two campuses have been involved in TAI corporation. One calibration of the time transfer link between National Institute of Metrology (NIM), P. R. China, and Physikalisch-Technische Bundesanstalt (PTB),...
L-DACS1 is the broadband candidate transmission scheme for the future L-band Digital Aeronautical Communication System. This paper reports on FPGA implementation of a L-DACS1 PHY. And technical specification and FPGA implementation feasibility of the PHY are verified. This paper's contributions include (i) FPGA implementation of a L-DACS1 PHY, (ii) the design of the L-DACS1 PHY tested on Xillinx platform.
The gyro theodolite with suspension-belt (GAK1, JT15) is traditionally and commonly used in mine surveying for the orientation. However, with the rapidly development of underground engineering, the traditional instruments can't meet the constructive needs of the long and large tunnels. Allow for its insufficiency in practical application, this paper discussed the key technology, technical characteristics...
This paper estimated the local model to predict ionosphere TEC on a scale of day. Ionosphere TEC were obtained from the two-way satellite time and frequency transfer (TWSTFT), based on these data a sine function was fitted by iteration to get the prediction model of diurnal ionosphere TEC. This model simply and directly reflected the characteristic of the diurnal ionosphere behavior, and was consistent...
In order to detect the land surface temperature abnormal area caused by the under ground coal fire, we used the thermal infrared remote sensing method. On the basis of discussing the way to inversion land surface temperature from ASTER satellite image, we get the land surface temperature image from the ASTER thermal infrared band. Then make threshold segmentation to get the thermal abnormal information...
The femtosecond pump-probe experimental device was designed to investigate reflection and dielectric properties of TbDyFe thin films. Tb0.27Dy0.73Fe2 thin films were prepared by DC magnetron sputtering and the component, surface topography and crystalline property of TbDyFe thin films were measured by scanning electronic microscope (SEM) and atom force microscope (AFM). The extremum of reflectivity...
In this paper, we propose a new blind speech authentication method to verify the authenticity and integrity of speech. In this method, linear predictive coding (LPC) and least significant bit (LSB) steganography are combined, using LPC prediction error (LPCPE) as invariable features of speech and inserting these features into least significant bits of speech samples. When verifying the speech, we...
Power transmission voltage is higher than the rated voltage according to the standard, in order to avoid the voltage drop because of the power loss and the overload. However when the load in the power network is light, the excessively high electrical network voltage may cause the load equipment to give off heat, and reduce service life. At the same time the power consumption and electrical bill disbursement...
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