In recent years, high resolution sonar images have been used for mapping the seafloor for a wide variety of purposes, such as the detection, localization and eventually classification of objects lying on sea beds. How...
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The objectives of this study were to investigate the measurement methodology of the protein content in skimmed milk by laser light scattering(LLS). There was a definition that the ratio of the scattering light(at 90&#...
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ISBN:
(纸本)9787121113154
The objectives of this study were to investigate the measurement methodology of the protein content in skimmed milk by laser light scattering(LLS). There was a definition that the ratio of the scattering light(at 90° scattering angles, relative to the incident beam direction) intensity to the transmitted light intensity, which was called scattered transmitted ratio(STR). Using the STR theory, we constructed a sensing system to measure the protein content. The sensing system contains a laser beam of 658nm wavelength, sample reservoir and two photodiodes which measure the scattered light I⊥ and transmitted light I respectively. Through data analysis, the relationship model was established between the protein content and the STR. Comparing with Kjeldahl determination of nitrogen, the STR method described in this study can also accurately measure the protein content.
Wideband analog signals push contemporary analog-to-digital conversion (ADC) systems to their performance limits. The recent development of compressive sampling theory enables direct analog-to-information conversion o...
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ISBN:
(纸本)9787121113154
Wideband analog signals push contemporary analog-to-digital conversion (ADC) systems to their performance limits. The recent development of compressive sampling theory enables direct analog-to-information conversion of compressible signals at sub-Nyquist rates. In this paper, we implement sub-Nyquist sampling by use of Modulated Wide Converter (MWC) and introduce the Orthogonal Matching Pursuit (OMP) method into reconstruction algorithm. The paper analyzes sampling behavior of MWC within frequency domain, discusses the sampling principle and employs OMP method to search the support set of unknown signal vector in the reconstruction stage. The numerical experiments demonstrate that the system can implement sub-Nyqiust rate sampling and perfect reconstruction for sparse wideband analog signals.
A source and channel coding scheme for image transmission over noisy channel is presented in this paper. There is crude block structure in the wavelet coefficient of images. Coding each image blocks independently and ...
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A source and channel coding scheme for image transmission over noisy channel is presented in this paper. There is crude block structure in the wavelet coefficient of images. Coding each image blocks independently and reassigning its bitstream can achieve the resynchronization of decoding image in receiving terminal to improve the image's ability to resist noisy. But different image block has different character, and has different energy distribution, so it's hard to implement consistency in rate-distortion performance. Paper proposes a classification method based on high frequency subband energy distribution of wavelet. Give different codeword length to different type image block to achieve better rate distortion performance. Experimental results show that the proposed scheme is able to provide better image quality than scheme without using the classification method in range of some BER.
The analysis and study on MIMO channels capacity is benifit to 4G network's construction and optimization in the future. On the condition of invariable coefficient of channels, MIMO channel capacity and its approx...
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ISBN:
(纸本)9787121113154
The analysis and study on MIMO channels capacity is benifit to 4G network's construction and optimization in the future. On the condition of invariable coefficient of channels, MIMO channel capacity and its approximate expression in low SNR was deduced when equal transmit energy scheme was adopted. When waterfilling power algorithm was applied capacacity was also given in detail with CSI at the transmitter. The above two power allocation schemes were compared in the same enviroment by simulation: In the instance of power not being added, waterfilling algorithm is optimal but it is too complex on the operation;If the channel was Rayleigh i.i.d approximatively MIMO channel limit capacity expression was deduced. The tendency of change on ergodic capacity and outage capacity was simulated in various antenna configurations: ergodic capacity and outage capacity improved with rising number of transmit antennas and receive antennas.
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