Beijing has experienced a rapid urban sprawl over the past three decades, along with accelerated socio-economic development. This study investigated the change patterns and figured out the driving forces of urban expa...
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ISBN:
(纸本)9783037857427
Beijing has experienced a rapid urban sprawl over the past three decades, along with accelerated socio-economic development. This study investigated the change patterns and figured out the driving forces of urban expansion in the study area. To obtain urban class, decision tree classification techniques were used to identify the land cover types using four scenes of Landsat images from four periods of 1978-era, 1992-era, 2000-era and 2010-era. Then, the urban areas were identified by excluding water, agriculture, forest, grassland and bare land. The analysis results showed that: 1) urban construction land had been expanded very quickly and the urban area is mainly in the south-central part of the municipality;2) the urban area increased by 96284.97 ha and the ratio was 5.88%;and 3) population growth, economic development, urban construction and industrial structure adjustment could explain the expansion. These analysis results can provide significant information on the monitoring and management of sustainable urban development.
A new incident source with different angles was constructed for dealing with wide-angle scattering problems. Considering the impendence matrix in method of moments (MOM) is independent from incident angles, the equiva...
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A 38×38×4mm3 wideband circularly polarized (CP) antenna with Hybrid Metasurface (MTS) for wearable devices is proposed. The proposed antenna achieves CP radiation by cutting corners on a square microstrip pa...
A 38×38×4mm3 wideband circularly polarized (CP) antenna with Hybrid Metasurface (MTS) for wearable devices is proposed. The proposed antenna achieves CP radiation by cutting corners on a square microstrip patch. A hybrid MTS is placed above a square patch with cut corners, achieving broadband radiation performance. The working mechanism of hybrid MTS is analyzed by characteristic mode analysis (CMA). The simulated -10dB bandwidth is 40.1% (4.61-6.82 GHz) and the 3dB axial ratio bandwidth is 25.2% (5.16-6.55 GHz) with a peak gain of 8.1 dBi. In addition, the antenna has a front-to-back ratio of approximately 20 dB, which makes it suitable for wearable applications.
A UWB MIMO antenna based on angle diversity technology is proposed in this paper. This antenna integrates Vivaldi antenna and UWB slot antenna with a compact size of 26×26mm 2 , the difference of radiation patter...
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ISBN:
(数字)9781728167039
ISBN:
(纸本)9781728167046
A UWB MIMO antenna based on angle diversity technology is proposed in this paper. This antenna integrates Vivaldi antenna and UWB slot antenna with a compact size of 26×26mm 2 , the difference of radiation pattern can realize lower coupling between different antenna units. Less than -19 dB isolation between different ports can be obtained through the whole UWB band (3.1-10.6GHz). In addition, the combination of one C-Shaped structure and two L-Shaped structures (CLL) avoids the interference of WLAN (5.125-5.825GHz) band. The proposed antenna has good performance, which is suitable for UWB communication system.
Accurate endpoint detection is a necessary capability for speech recognition. A new energy measure method based on the empirical mode decomposition (EMD) algorithm and Teager energy operator (TEO) is proposed to locat...
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Accurate endpoint detection is a necessary capability for speech recognition. A new energy measure method based on the empirical mode decomposition (EMD) algorithm and Teager energy operator (TEO) is proposed to locate endpoint intervals of a speech signal embedded in noise. With the EMD, the noise signals can be decomposed into different numbers of sub-signals called intrinsic mode functions (IMFs), which is a zero-mean AM-FM component. Then TEO can be used to extract the desired feature of the modulation energy for IMF components. In order to show the effectiveness of the proposed method, examples are presented to show that the new measure is more effective than traditional measures. The present experimental results show that the measure can be used to improve the performance of endpoint detection algorithms and the accuracy of this algorithm is quite satisfactory and acceptable.
A novel structure based on the coplanar electromagnetic band-gap (EBG) power plane is proposed to realize the ultrawideband suppression of simultaneous switching noise (SSN). The proposed EBG structure is realized wit...
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ISBN:
(数字)9781728181813
ISBN:
(纸本)9781728181820
A novel structure based on the coplanar electromagnetic band-gap (EBG) power plane is proposed to realize the ultrawideband suppression of simultaneous switching noise (SSN). The proposed EBG structure is realized with a combination of L-shaped Bridge and slit EBG structure which is inserted by a complementary split ring resonator (CSRR). From the simulated results of the proposed EBG structure, a wideband suppression of SSN ranges from 340 MHz to 20 GHz is achieved with a high mitigation level of -40 dB. Compared with the earlier published structures, the suppression effect is greatly improved.
A $\boldsymbol{40}\times\boldsymbol{40}\times \boldsymbol{1.6}\mathbf{mm}^{3}$ ultra-wideband MIMO antenna is proposed in this paper. The antenna realizes four-notched band characteristics by embedding different typ...
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A $\boldsymbol{40}\times\boldsymbol{40}\times \boldsymbol{1.6}\mathbf{mm}^{3}$ ultra-wideband MIMO antenna is proposed in this paper. The antenna realizes four-notched band characteristics by embedding different types of slits in the radiating element. The antenna has good UWB performance, with four-band rejection to avoid interference caused by four narrow frequency bands WiMAX(3.3-3.8GHz), WLAN(S.1-S.8GHz), INSAT(6.7-7.3GHz) and ITV 8GHz (8.13-8.38GHz). It achieves better than - 15dB of isolation, and impedance bandwidth from 3.06-15.5GHz.
In this paper, a novel camera parameters calibration algorithm is proposed by exploiting defocus information. The proposed algorithm is based on two defocus images of the same scene obtained by changing camera's a...
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In this paper, a novel camera parameters calibration algorithm is proposed by exploiting defocus information. The proposed algorithm is based on two defocus images of the same scene obtained by changing camera's aperture numbers. Both images can be arbitrarily blurred. The blur difference between the two defocused images was estimated. Combining with imaging geometry of the thin lens, the corresponding camera parameters can be calibrated. This proposed algorithm remove the limit of calibration algorithm given by Soon-Yong Park that one of the images used in calibration must be focused. And it is valid without process of scale normalization. The calibrated parameters yield consistent results in depth estimation. Experimental results on synthetic and real images are presented to demonstrate the effectiveness of the proposed algorithm.
SVM (Support Vector Machines) is a novel algorithm of machine learning which is based on SLT (Statistical Learning Theory). It can solve the problem characterized by nonlinear, high dimension, small sample and local m...
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SVM (Support Vector Machines) is a novel algorithm of machine learning which is based on SLT (Statistical Learning Theory). It can solve the problem characterized by nonlinear, high dimension, small sample and local minimizing perfectly. For non-linear problem, the forecasting technique of FCTR (First classification, then regression) was proposed, based on the classification approach of SVM and has carried on the simulation experiment. The experiment shows that the fitting value which obtains using the return to first would be more precise than directly. Using this method to food production forecast, its accuracy is superior to other production forecasting methods.
This paper presents an ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna with a small size of 41×41×1.6mm 3 . Double notched bands are obtained by introducing C-shaped slot and L-shaped slot...
ISBN:
(数字)9781728181813
ISBN:
(纸本)9781728181820
This paper presents an ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna with a small size of 41×41×1.6mm 3 . Double notched bands are obtained by introducing C-shaped slot and L-shaped slot. The proposed antenna exhibits good UWB performance, it achieves impedance bandwidth from 3.1GHz to 10.8GHz, and better than -15dB of isolation over the entire operating band, with adaptable double band rejection to avoid interference caused by two narrow frequency bands WLAN (5.15-5.85 GHz) and X-band satellite communication systems (7.25-7.75 GHz).
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