Organic matter （OM）, total nitrogen （TN）, organic phosphorous （OP） and total phosphorous （TP）content of soil in northwest water-level fluctuating zone （WLFZ） of Lake Chaohu under natural and different artifi...Organic matter （OM）, total nitrogen （TN）, organic phosphorous （OP） and total phosphorous （TP）content of soil in northwest water-level fluctuating zone （WLFZ） of Lake Chaohu under natural and different artificial conditions were ana- lyzed to study the variation of OM, TN, OP and TP. It showed： Flooding and air- drying help to increase soil OM content in study area. Process of flooding and air- drying is conducive to soil adsorption of nitrogen and it can enhance spatial hetero- geneity of soil OM, TN, OP, process of flooding and air-drying also can reduce the difference of TP contents among different points. Riprap embankment is not con- ducive to maintaining soil organic matter under flooded conditions, emergent plants are conducive to maintaining soil organic matter under flooded conditions. Soil with high nitrogen content will release nitrogen to overlying water under flooded condi- tions. Under drying after flooding conditions, demand for phosphorus of vegetation growth will reduce TP content in soil, bare area will enrich phosphorus, when the next flood cover up a greater release of phosphorus will happen展开更多
A novel nonlinear multi-input multi-output MIMO detection algorithm is proposed which is referred to as an ordered successive noise projection cancellation OSNPC algorithm. It is capable of improving the computation p...A novel nonlinear multi-input multi-output MIMO detection algorithm is proposed which is referred to as an ordered successive noise projection cancellation OSNPC algorithm. It is capable of improving the computation performance of the MIMO detector with the conventional ordered successive interference cancellation OSIC algorithm. In contrast to the OSIC in which the known interferences in the input signal vector are successively cancelled the OSNPC successively cancels the known noise projections from the decision statistic vector. Analysis indicates that the OSNPC is equivalent to the OSIC in error performance but it has significantly less complexity in computation.Furthermore when the OSNPC is applied to the MIMO detection with the preprocessing of dual lattice reduction DLR the computational complexity of the proposed OSNPC-based DLR-aided detector is further reduced due to the avoidance of the inverse of the reduced basis of the dual lattice in computation compared to that of the OSIC-based one. Simulation results validate the theoretical conclusions with regard to both the performance and complexity of the proposed MIMO detection scheme.展开更多
Full duplex radio increases the frequency efficiency but its performance is limited by the self-interference （SI）. We first analyze the multiple noises in the full duplex radio system and model such noises as an α ...Full duplex radio increases the frequency efficiency but its performance is limited by the self-interference （SI）. We first analyze the multiple noises in the full duplex radio system and model such noises as an α - stable distribution. Then we formulate a novel non-Gaussian SI problem. Under the maximum correntropy criterion （MCC）, a robust digital non-linear self-interference cancellation algorithm is proposed for the SI channel estimation. A gradient descent based algorithm is derived to search the optimal solution. Simulation results show that the proposed algorithm can achieve a smaller estimation error and a higher pseudo signal to interference plus noise ratio （PSINR） than the well-known least mean square （LMS） algorithm and least square （LS） algorithm.展开更多
This paper describes a linear interference cancellation multi user detector for synchronous DS CDMA systems under the condition that all spread spectrum code waveforms have the constant cross correlating coefficien...This paper describes a linear interference cancellation multi user detector for synchronous DS CDMA systems under the condition that all spread spectrum code waveforms have the constant cross correlating coefficients. The basic idea is to get the estimation for total multiple access interference (MAI) of all users using a reference code waveform, then subtract the total MAI from the received signal. The structure of such a detector is nearly similar to the conventional detector. The BER expression obtained in the paper shows significant performance improvement compared to the other detectors.展开更多
This paper suggests a scheme of image denoising based on two-dimensional discrete wavelet transform. The denoising algorithm is described with some operators. By thresholding the wavelet transform coefficients of nois...This paper suggests a scheme of image denoising based on two-dimensional discrete wavelet transform. The denoising algorithm is described with some operators. By thresholding the wavelet transform coefficients of noisy images, the original image can be reconstructed correctly. Different threshold selections and thresholding methods are discussed. A new robust local threshold scheme is proposed. Quantifying the performance of image denoising schemes by using the mean square error, the performance of the robust local threshold scheme is demonstrated and is compared with the universal threshold scheme. The experiment shows that image denoising using the robust local threshold performs better than that using the universal threshold.展开更多
Linear dispersion codes (LDCs) were originally designed based on maximum likelihood detection. They do not have good performance when using ordered successive interference cancellation (OSIC) detection. In this paper,...Linear dispersion codes (LDCs) were originally designed based on maximum likelihood detection. They do not have good performance when using ordered successive interference cancellation (OSIC) detection. In this paper,we propose a new improved linear dispersion codes transmission scheme to combat performance loss of original LDCs when using OSIC detection. We introduce an interleaver to each data substream transmitted over different antennas after LDCs encoder. Furthermore,a new computer search criterion for a linear transformation matrix is also proposed. New search criterion is to minimize the symbol error rate based on OSIC detection. Computer simulations show that the performance of proposed LDCs transmission scheme is better than the original LDCs.展开更多
Chronic hepatitis C is a leading cause of hepatocellular carcinoma (HCC) worldwide.Interferon (IFN) ther-apy decreases the incidence of HCC in patients with chronic hepatitis C.Prevention of chronic-hepatitis-C-relate...Chronic hepatitis C is a leading cause of hepatocellular carcinoma (HCC) worldwide.Interferon (IFN) ther-apy decreases the incidence of HCC in patients with chronic hepatitis C.Prevention of chronic-hepatitis-C-related HCC is one of the most important issues in current hepatology.We have previously reported that male gender and high titer of hepatitis C virus (HCV) RNA are predictive factors for the development of HCC in HCV-related cirrhosis.Clinical efforts at eradicat-ing or reducing the viral load may reduce the risk for HCC.Furthermore,because HCC often recurs after ablation therapy,we performed a trial of IFN in pa-tients with chronic liver disease caused by HCV to see whether IFN therapy decreases recurrence after abla-tion therapy of HCV-related HCC.By using IFN therapy as a secondary prevention,patients with HCC who had received complete tumor ablation showed better sur-vival,primarily as a result of the preservation of liver function and also probably prevention of recurrence.Postoperative IFN therapy appears to decrease recur-rence after ablation therapy such as radiofrequency ablation (RFA) therapy of HCV-related HCC.We believe that there is a survival benefit in secondary prevention using IFN therapy.However,a controlled study is es-sential to obtain conclusive evidence of the efficacy of this strategy.展开更多
The model of energy cost in a wireless sensor network （WSN）environment is built, and the energy awareness and the wireless interference mainly due to different path loss models are studied. A special case of a clust...The model of energy cost in a wireless sensor network （WSN）environment is built, and the energy awareness and the wireless interference mainly due to different path loss models are studied. A special case of a clustering scheme, a twodimensional grid clustering mechanism, is adopted. Clusterheads are rotated evenly among all sensor nodes in an efficient and decentralized manner, based on the residual energy in the battery and the random backoff time. In addition to transmitting and receiving packets within the sensors＇ electrical and amplification circuits, extra energy is needed in the retransmission of packets due to packet collisions caused by severe interference. By analysis and mathematical derivation, which are based on planar geometry, it is shown that the total energy consumed in the network is directly related to the gridstructure in the proposed grid based clustering mechanism. The transmission range is determined by cluster size, and the path loss exponent is determined by nodal separation. The summation of overall interference is caused by all the sensors that are transmitting concurrently. By analysis and simulation, an optimal grid structure with the corresponding grid size is presented, which balances between maximizing energy conservation and minimizing overall interference in wireless sensor networks.展开更多
In MIMO full duplex system,power amplifier(PA) nonlinearity limits the self-interference(SI) cancellation seriously. Most existing methods need to model and estimate the PA nonlinearity in order to reconstruct the SI,...In MIMO full duplex system,power amplifier(PA) nonlinearity limits the self-interference(SI) cancellation seriously. Most existing methods need to model and estimate the PA nonlinearity in order to reconstruct the SI,however the estimation error caused by the mismatch between the estimated PA model and the actual PA property still impacts the cancellation ability,especially when the transmit power is high. In this paper we propose a polarization oblique projection based self-interference cancellation method which does not need to estimate the PA nonlinearity coefficients. It exploits the polarization state information of the signals which is immune to the PA nonlinearity,and establishes an oblique projection operator to cancel the SI. Numerical results and analysis demonstrate that it can cancel the nonlinear SI effectively. Moreover the signal to interfere plus noise ratio(SINR) and the achievable sum rate do not deteriorate when the transmit power is high. Further,the upper bound of the achievable sum rate can be more than twice that of the half duplex.展开更多
We investigate the quantum-classical transition in a system of two coupled kicked rotors. We lind that when the mass of one kicked rotor is much smaller than the other＇s, the influence of the light kicked rotor is st...We investigate the quantum-classical transition in a system of two coupled kicked rotors. We lind that when the mass of one kicked rotor is much smaller than the other＇s, the influence of the light kicked rotor is still able to make decoherence of the heavy one. This leads to the quantum-classical transition of the heavy kicked rotor. We demonstrate this by two different coupling potentials.展开更多
To improve the spectrum efficiency, this paper considers the multiuser detection with the MU-MIMO technology for multiuser MIMO-OFDM system uplink with the same subcarrier shared by multiple users. A low complexity mu...To improve the spectrum efficiency, this paper considers the multiuser detection with the MU-MIMO technology for multiuser MIMO-OFDM system uplink with the same subcarrier shared by multiple users. A low complexity multiuser detection algorithm with recursively successive zero-forcing and successive interference cancellation(RSZF-SIC) based on nullspace is proposed. The RSZF process based on the block diagonalization(BD) technique eliminates the co-channel interference(CCI) by a recursive method based on the nullspace orthogonal theorem. The SIC process detects the user signals respectively with the reasonable user detection sequence based on the results of the RSZF process. The computational complexity of the proposed algorithm is effectively reduced by reducing the total number of singular value decomposition(SVD) operations and the dimension of the SVD matrix in the recursive procedure. The performance of the proposed algorithm is improved in terms of bit error rate and sum capacity of the system, especially in the highSNR regime.展开更多
基金Supported by the Major Science and Technology Program for Water Pollution Control and Treatment(2012ZX07103-0042012ZX07103-003-03)~~
文摘Organic matter （OM）, total nitrogen （TN）, organic phosphorous （OP） and total phosphorous （TP）content of soil in northwest water-level fluctuating zone （WLFZ） of Lake Chaohu under natural and different artificial conditions were ana- lyzed to study the variation of OM, TN, OP and TP. It showed： Flooding and air- drying help to increase soil OM content in study area. Process of flooding and air- drying is conducive to soil adsorption of nitrogen and it can enhance spatial hetero- geneity of soil OM, TN, OP, process of flooding and air-drying also can reduce the difference of TP contents among different points. Riprap embankment is not con- ducive to maintaining soil organic matter under flooded conditions, emergent plants are conducive to maintaining soil organic matter under flooded conditions. Soil with high nitrogen content will release nitrogen to overlying water under flooded condi- tions. Under drying after flooding conditions, demand for phosphorus of vegetation growth will reduce TP content in soil, bare area will enrich phosphorus, when the next flood cover up a greater release of phosphorus will happen
基金The National Science and Technology Major Project(No.2012ZX03004005-003)the National Natural Science Foundation of China(No.61171081,61201175)the Innovation Technology Fund of Jiangsu Province(No.BC2012006)
文摘A novel nonlinear multi-input multi-output MIMO detection algorithm is proposed which is referred to as an ordered successive noise projection cancellation OSNPC algorithm. It is capable of improving the computation performance of the MIMO detector with the conventional ordered successive interference cancellation OSIC algorithm. In contrast to the OSIC in which the known interferences in the input signal vector are successively cancelled the OSNPC successively cancels the known noise projections from the decision statistic vector. Analysis indicates that the OSNPC is equivalent to the OSIC in error performance but it has significantly less complexity in computation.Furthermore when the OSNPC is applied to the MIMO detection with the preprocessing of dual lattice reduction DLR the computational complexity of the proposed OSNPC-based DLR-aided detector is further reduced due to the avoidance of the inverse of the reduced basis of the dual lattice in computation compared to that of the OSIC-based one. Simulation results validate the theoretical conclusions with regard to both the performance and complexity of the proposed MIMO detection scheme.
基金supported by the National Natural Science Foundation of China under Grants 61372092"863" Program under Grants 2014AA01A701
文摘Full duplex radio increases the frequency efficiency but its performance is limited by the self-interference （SI）. We first analyze the multiple noises in the full duplex radio system and model such noises as an α - stable distribution. Then we formulate a novel non-Gaussian SI problem. Under the maximum correntropy criterion （MCC）, a robust digital non-linear self-interference cancellation algorithm is proposed for the SI channel estimation. A gradient descent based algorithm is derived to search the optimal solution. Simulation results show that the proposed algorithm can achieve a smaller estimation error and a higher pseudo signal to interference plus noise ratio （PSINR） than the well-known least mean square （LMS） algorithm and least square （LS） algorithm.
文摘This paper describes a linear interference cancellation multi user detector for synchronous DS CDMA systems under the condition that all spread spectrum code waveforms have the constant cross correlating coefficients. The basic idea is to get the estimation for total multiple access interference (MAI) of all users using a reference code waveform, then subtract the total MAI from the received signal. The structure of such a detector is nearly similar to the conventional detector. The BER expression obtained in the paper shows significant performance improvement compared to the other detectors.
基金Supported by the National Natural Science Foundation of China(No.59775070)
文摘This paper suggests a scheme of image denoising based on two-dimensional discrete wavelet transform. The denoising algorithm is described with some operators. By thresholding the wavelet transform coefficients of noisy images, the original image can be reconstructed correctly. Different threshold selections and thresholding methods are discussed. A new robust local threshold scheme is proposed. Quantifying the performance of image denoising schemes by using the mean square error, the performance of the robust local threshold scheme is demonstrated and is compared with the universal threshold scheme. The experiment shows that image denoising using the robust local threshold performs better than that using the universal threshold.
文摘Linear dispersion codes (LDCs) were originally designed based on maximum likelihood detection. They do not have good performance when using ordered successive interference cancellation (OSIC) detection. In this paper,we propose a new improved linear dispersion codes transmission scheme to combat performance loss of original LDCs when using OSIC detection. We introduce an interleaver to each data substream transmitted over different antennas after LDCs encoder. Furthermore,a new computer search criterion for a linear transformation matrix is also proposed. New search criterion is to minimize the symbol error rate based on OSIC detection. Computer simulations show that the performance of proposed LDCs transmission scheme is better than the original LDCs.
文摘Chronic hepatitis C is a leading cause of hepatocellular carcinoma (HCC) worldwide.Interferon (IFN) ther-apy decreases the incidence of HCC in patients with chronic hepatitis C.Prevention of chronic-hepatitis-C-related HCC is one of the most important issues in current hepatology.We have previously reported that male gender and high titer of hepatitis C virus (HCV) RNA are predictive factors for the development of HCC in HCV-related cirrhosis.Clinical efforts at eradicat-ing or reducing the viral load may reduce the risk for HCC.Furthermore,because HCC often recurs after ablation therapy,we performed a trial of IFN in pa-tients with chronic liver disease caused by HCV to see whether IFN therapy decreases recurrence after abla-tion therapy of HCV-related HCC.By using IFN therapy as a secondary prevention,patients with HCC who had received complete tumor ablation showed better sur-vival,primarily as a result of the preservation of liver function and also probably prevention of recurrence.Postoperative IFN therapy appears to decrease recur-rence after ablation therapy such as radiofrequency ablation (RFA) therapy of HCV-related HCC.We believe that there is a survival benefit in secondary prevention using IFN therapy.However,a controlled study is es-sential to obtain conclusive evidence of the efficacy of this strategy.
文摘The model of energy cost in a wireless sensor network （WSN）environment is built, and the energy awareness and the wireless interference mainly due to different path loss models are studied. A special case of a clustering scheme, a twodimensional grid clustering mechanism, is adopted. Clusterheads are rotated evenly among all sensor nodes in an efficient and decentralized manner, based on the residual energy in the battery and the random backoff time. In addition to transmitting and receiving packets within the sensors＇ electrical and amplification circuits, extra energy is needed in the retransmission of packets due to packet collisions caused by severe interference. By analysis and mathematical derivation, which are based on planar geometry, it is shown that the total energy consumed in the network is directly related to the gridstructure in the proposed grid based clustering mechanism. The transmission range is determined by cluster size, and the path loss exponent is determined by nodal separation. The summation of overall interference is caused by all the sensors that are transmitting concurrently. By analysis and simulation, an optimal grid structure with the corresponding grid size is presented, which balances between maximizing energy conservation and minimizing overall interference in wireless sensor networks.
基金supported by the National Natural Science Foundations of China under Grant No.61501050 and No.61271177
文摘In MIMO full duplex system,power amplifier(PA) nonlinearity limits the self-interference(SI) cancellation seriously. Most existing methods need to model and estimate the PA nonlinearity in order to reconstruct the SI,however the estimation error caused by the mismatch between the estimated PA model and the actual PA property still impacts the cancellation ability,especially when the transmit power is high. In this paper we propose a polarization oblique projection based self-interference cancellation method which does not need to estimate the PA nonlinearity coefficients. It exploits the polarization state information of the signals which is immune to the PA nonlinearity,and establishes an oblique projection operator to cancel the SI. Numerical results and analysis demonstrate that it can cancel the nonlinear SI effectively. Moreover the signal to interfere plus noise ratio(SINR) and the achievable sum rate do not deteriorate when the transmit power is high. Further,the upper bound of the achievable sum rate can be more than twice that of the half duplex.
基金supported by National Natural Science Foundation of China under Grant No.10875087
文摘We investigate the quantum-classical transition in a system of two coupled kicked rotors. We lind that when the mass of one kicked rotor is much smaller than the other＇s, the influence of the light kicked rotor is still able to make decoherence of the heavy one. This leads to the quantum-classical transition of the heavy kicked rotor. We demonstrate this by two different coupling potentials.
基金supported by the Fundamental Research Funds for the Central Universities (Grant No. HIT. NSRIF. 201149)Postdoctoral Science-Research Foundation of Heilongjiang (Grant No. LBH-Q11108)the National Natural Science Foundation of China (61071104)
文摘To improve the spectrum efficiency, this paper considers the multiuser detection with the MU-MIMO technology for multiuser MIMO-OFDM system uplink with the same subcarrier shared by multiple users. A low complexity multiuser detection algorithm with recursively successive zero-forcing and successive interference cancellation(RSZF-SIC) based on nullspace is proposed. The RSZF process based on the block diagonalization(BD) technique eliminates the co-channel interference(CCI) by a recursive method based on the nullspace orthogonal theorem. The SIC process detects the user signals respectively with the reasonable user detection sequence based on the results of the RSZF process. The computational complexity of the proposed algorithm is effectively reduced by reducing the total number of singular value decomposition(SVD) operations and the dimension of the SVD matrix in the recursive procedure. The performance of the proposed algorithm is improved in terms of bit error rate and sum capacity of the system, especially in the highSNR regime.
