Principles and performances of quantum stochastic filters are studied for nonlinear time-domain filtering of communication signals. Filtering is realized by combining neural networks with the nonlinear Schroedinger eq...Principles and performances of quantum stochastic filters are studied for nonlinear time-domain filtering of communication signals. Filtering is realized by combining neural networks with the nonlinear Schroedinger equation and the time-variant probability density function of signals is estimated by solution of the equation. It is shown that obviously different performances can be achieved by the control of weight coefficients of potential fields. Based on this characteristic, a novel filtering algorithm is proposed, and utilizing this algorithm, the nonlinear waveform distortion of output signals and the denoising capability of the filters can be compromised. This will make the application of quantum stochastic filters be greatly extended, such as in applying the filters to the processing of communication signals. The predominant performance of quantum stochastic filters is shown by simulation results.展开更多
Aim To develop an information processing system with real time processing capability and artistic user interface for the optoelectronic antagonism general measuring system. Methods The A/D board and the multifun...Aim To develop an information processing system with real time processing capability and artistic user interface for the optoelectronic antagonism general measuring system. Methods The A/D board and the multifunctional board communicating with every instruments were designed, data collecting and processing were realized by selecting appropriate software platform. Results Simulating results show the information processing system can operate correctly and dependably, the measuring rules, interactive interface and data handling method were all accepted by the user. Conclusion The designing approach based on the mix platform takes advantages of the two operating systems, the desired performances are acquired both in the real time processing and with the friendly artistic user interface.展开更多
By the use of cross-correlation measures, the response of a symmetric Schmitt trigger (ST) driven by a random binary signal and white Gaussian noise is investigated. The results show that the information transmission...By the use of cross-correlation measures, the response of a symmetric Schmitt trigger (ST) driven by a random binary signal and white Gaussian noise is investigated. The results show that the information transmission can be enhanced when a certain amount of noise is presented, i.e., aperiodic stochastic resonance (ASR). Then, the influence of signal amplitude and the ST threshold on ASR is examined, the applicability of the ST in reducing the noise level of random signal transmission and improving the quality of output signal via ASR effect is illustrated. This research is of great interest in the field of digital communications.展开更多
Within the framework of universal composability,an appropriate ideal functionality that captures the basic security requirements of three party password-based key exchange was defined. An efficient real-word three par...Within the framework of universal composability,an appropriate ideal functionality that captures the basic security requirements of three party password-based key exchange was defined. An efficient real-word three party password-based key exchange protocol was also proposed.This protocol securely realizes the ideal functionality with respect to static party corruption.Thus it provides security guarantees under arbitrary composition with other protocols.展开更多
Wireless communication with unmanned aerial vehicles(UAVs) has aroused great research interest recently. This paper is concerned with the UAV's trajectory planning problem for secrecy energy efficiency maximizatio...Wireless communication with unmanned aerial vehicles(UAVs) has aroused great research interest recently. This paper is concerned with the UAV's trajectory planning problem for secrecy energy efficiency maximization(SEEM) in the UAV communication system. Specifically, we jointly consider the secrecy throughput and UAV's energy consumption in a three-node(fixed-wing UAV-aided source, destination, and eavesdropper) wiretap channel. By ignoring the energy consumption on radiation and signal processing, the system's secrecy energy efficiency is defined as the total secrecy rate normalized by the UAV's propulsion energy consumption within a given time horizon. Nonetheless, the SEEM problem is nonconvex and thus is intractable to solve. As a compromise, we propose an iterative algorithm based on sequential convex programming(SCP) and Dinkelbach's method to seek a suboptimal solution for SEEM. The algorithm only needs to solve convex problems, and thus is computationally efficient to implement. Additionally, we prove that the proposed algorithm has Karush-KuhnTucker(KKT) point convergence guarantee. Lastly, simulation results demonstrate the efficacy of our proposed algorithm in improving the secrecy energy efficiency for the UAV communication system.展开更多
Wireless mesh network is a new emerging field with its potential applications in extremely unpredictable and dynamic environments.However,it is particularly vulnerable due to its features of open medium,dynamic changi...Wireless mesh network is a new emerging field with its potential applications in extremely unpredictable and dynamic environments.However,it is particularly vulnerable due to its features of open medium,dynamic changing topology, cooperative routing algorithms.The article surveys the state of the art in security for wireless mesh networks.Firstly,we analyze various possible threats to security in wireless mesh networks.Secondly,we introduce some representative solutions to these threats,including solutions to the problems of key management,secure network routing,and intrusion detection.We also provide a comparison and discussion of their respective merits and drawbacks,and propose some improvements for these drawbacks.Finally,we also discuss the remaining challenges in the area.展开更多
We propose a procedure to forecast short time series with stable seasonal pattern.This new method is motivated by the observations that short time series arise in many situations for the fierce competition.The quantit...We propose a procedure to forecast short time series with stable seasonal pattern.This new method is motivated by the observations that short time series arise in many situations for the fierce competition.The quantity to be predicted is a yearly accumulation assuming that the partially accumulated data within the year are available.A simple model is proposed to describe the relation-ship between the yearly accumulation and partial accumulation and analytic results are obtained for both the point prediction and the predicative distribution.A comparison will be conducted between this model and traditional time series forecasting model with data from telecommunication industry. This method works better than the traditional models when only small amount of data are available. It can also be applied to forecast individual observations with a proper disaggregation algorithm.展开更多
This paper presents a method to reduce the energy consumption of multi-core systems characterized by processor cores and buses with discrete frequency levels under timing constraints.The proposed method takes the tran...This paper presents a method to reduce the energy consumption of multi-core systems characterized by processor cores and buses with discrete frequency levels under timing constraints.The proposed method takes the transformations of the original task graphs,which include dependent tasks located in different iterations,as inputs.The proposed method utilizes mapping selection as well as joint processor and communication frequency scaling to implement energy reduction.We conduct experiments on several random task graphs.Experimental results show that the proposed method can achieve substantial energy reduction compared with previous work under the same hard timing constraints.展开更多
To measure the signals with high freq u ency(>500 MHz),a sampling frequency down conversion method is introduced.This pa per analyzes the intermodulation signals and figures out the relationship betwee n the interm...To measure the signals with high freq u ency(>500 MHz),a sampling frequency down conversion method is introduced.This pa per analyzes the intermodulation signals and figures out the relationship betwee n the intermodulation signal and intermediate frequenc y signal.Based on the frequency conversion technology,an exclusion algorithm i s proposed a nd the actual implementation of the algorithm is given.The application resu lts show that the exclusion algorithm can identify the intermodulation signal exactly and eliminate the bad influence on the frequency measurement.展开更多
Applying IEEE802.11MAC protocols in baltery-powered devices make power consumption critical demand upon implementation.A statistical study on operator/bit usage,the weight of operator and operator type in the programs...Applying IEEE802.11MAC protocols in baltery-powered devices make power consumption critical demand upon implementation.A statistical study on operator/bit usage,the weight of operator and operator type in the programs has been done,including converting the MAC functions from SDL to C to ASM with tow RISC targts. The study shows that implementing MAC. functions should consider real-time protocol re3quirements by dividing MAC functions into sets. We enhance the set of time-critical functions implemented to dedicated hardwere and the set of non-time-critical functions implemented to software run with embedded processor. This heterogeneous system is proposed in consideration of our study results to reduce popwer consumption.展开更多
In Discrete Multi-Tone (DMT) modulation systems, the well-known technique to overcome the Inter-Carrier Interference (ICI)/Inter-Symbol Interference (ISI) caused by the inadequate Cyclic Prefix (CP) length is to use a...In Discrete Multi-Tone (DMT) modulation systems, the well-known technique to overcome the Inter-Carrier Interference (ICI)/Inter-Symbol Interference (ISI) caused by the inadequate Cyclic Prefix (CP) length is to use a Time-Domain Equalizer (TDE) at the receiver front-end. An algorithm used to calculate the coefficients of the optimal shortening Time Domain Equalizer (TDE) was given by Melsa. However, this algorithm requires that the length of the TDE must be smaller than or equal to the memory length of the target impulse response. This paper modifies this algorithm and makes it not only fit for calculating the coefficients of the TDE with arbitrary length, but also have a much less computational time.展开更多
This paper presents a new idea for an a lyzing the complicated shock signal.Based on this kind of analysis,an equivale nt power spectral density(PSD) chart is drawn for vibration environmental test,which is carried to...This paper presents a new idea for an a lyzing the complicated shock signal.Based on this kind of analysis,an equivale nt power spectral density(PSD) chart is drawn for vibration environmental test,which is carried to test the vehicle loading instrument's vibration behavior.T he environment test is equivalent to the condition under which the vehicle and t he instrument is experiencing a firing period.Exactly speaking,the short time vibration during the firing period is a complicated shock event.The paper point s out the deficiency of the commonly used half sine equivalence for the shock an d vibration environment test and gives the procedure of how to draw the PSD char t through the actual acceleration data.展开更多
Principal Component Analysis(PCA)is one of the most important feature extraction methods,and Kernel Principal Component Analysis(KPCA)is a nonlinear extension of PCA based on kernel methods.In real world,each input da...Principal Component Analysis(PCA)is one of the most important feature extraction methods,and Kernel Principal Component Analysis(KPCA)is a nonlinear extension of PCA based on kernel methods.In real world,each input data may not be fully assigned to one class and it may partially belong to other classes.Based on the theory of fuzzy sets,this paper presents Fuzzy Principal Component Analysis(FPCA)and its nonlinear extension model,i.e.,Kernel-based Fuzzy Principal Component Analysis(KFPCA).The experimental results indicate that the proposed algorithms have good performances.展开更多
A novel semi-fragile audio watermarking algorithm in DWT domain is proposed in this paper.This method transforms the original audio into 3-layer wavelet domain and divides approximation wavelet coefficients into many ...A novel semi-fragile audio watermarking algorithm in DWT domain is proposed in this paper.This method transforms the original audio into 3-layer wavelet domain and divides approximation wavelet coefficients into many groups.Through computing mean quantization of per group,this algorithm embeds the watermark signal into the average value of the wavelet coefficients.Experimental results show that our semi-fragile audio watermarking algorithm is not only inaudible and robust against various common images processing,but also fragile to malicious modification.Especially,it can detect the tampered regions effectively.展开更多
基金The National Natural Science Foundation of China(No60472054)the High Technology Research Program of JiangsuProvince(NoBG2004035)the Foundation of Excellent Doctoral Dis-sertation of Southeast University (No0602)
文摘Principles and performances of quantum stochastic filters are studied for nonlinear time-domain filtering of communication signals. Filtering is realized by combining neural networks with the nonlinear Schroedinger equation and the time-variant probability density function of signals is estimated by solution of the equation. It is shown that obviously different performances can be achieved by the control of weight coefficients of potential fields. Based on this characteristic, a novel filtering algorithm is proposed, and utilizing this algorithm, the nonlinear waveform distortion of output signals and the denoising capability of the filters can be compromised. This will make the application of quantum stochastic filters be greatly extended, such as in applying the filters to the processing of communication signals. The predominant performance of quantum stochastic filters is shown by simulation results.
文摘Aim To develop an information processing system with real time processing capability and artistic user interface for the optoelectronic antagonism general measuring system. Methods The A/D board and the multifunctional board communicating with every instruments were designed, data collecting and processing were realized by selecting appropriate software platform. Results Simulating results show the information processing system can operate correctly and dependably, the measuring rules, interactive interface and data handling method were all accepted by the user. Conclusion The designing approach based on the mix platform takes advantages of the two operating systems, the desired performances are acquired both in the real time processing and with the friendly artistic user interface.
文摘By the use of cross-correlation measures, the response of a symmetric Schmitt trigger (ST) driven by a random binary signal and white Gaussian noise is investigated. The results show that the information transmission can be enhanced when a certain amount of noise is presented, i.e., aperiodic stochastic resonance (ASR). Then, the influence of signal amplitude and the ST threshold on ASR is examined, the applicability of the ST in reducing the noise level of random signal transmission and improving the quality of output signal via ASR effect is illustrated. This research is of great interest in the field of digital communications.
基金Project(60573036)supported by the National Natural Science Foundation of china
文摘Within the framework of universal composability,an appropriate ideal functionality that captures the basic security requirements of three party password-based key exchange was defined. An efficient real-word three party password-based key exchange protocol was also proposed.This protocol securely realizes the ideal functionality with respect to static party corruption.Thus it provides security guarantees under arbitrary composition with other protocols.
基金supported in part by the National Natural Science Foundation of China under Grant 61631004 and 61571089
文摘Wireless communication with unmanned aerial vehicles(UAVs) has aroused great research interest recently. This paper is concerned with the UAV's trajectory planning problem for secrecy energy efficiency maximization(SEEM) in the UAV communication system. Specifically, we jointly consider the secrecy throughput and UAV's energy consumption in a three-node(fixed-wing UAV-aided source, destination, and eavesdropper) wiretap channel. By ignoring the energy consumption on radiation and signal processing, the system's secrecy energy efficiency is defined as the total secrecy rate normalized by the UAV's propulsion energy consumption within a given time horizon. Nonetheless, the SEEM problem is nonconvex and thus is intractable to solve. As a compromise, we propose an iterative algorithm based on sequential convex programming(SCP) and Dinkelbach's method to seek a suboptimal solution for SEEM. The algorithm only needs to solve convex problems, and thus is computationally efficient to implement. Additionally, we prove that the proposed algorithm has Karush-KuhnTucker(KKT) point convergence guarantee. Lastly, simulation results demonstrate the efficacy of our proposed algorithm in improving the secrecy energy efficiency for the UAV communication system.
基金Project supported by the Shanghai Minicipal Natural Science Foundation(Grant No09ZR1414900)the National High Technology Development 863 Program of China(Grant No2006AA01Z436,No2007AA01Z452,No2009AA01Z118)
文摘Wireless mesh network is a new emerging field with its potential applications in extremely unpredictable and dynamic environments.However,it is particularly vulnerable due to its features of open medium,dynamic changing topology, cooperative routing algorithms.The article surveys the state of the art in security for wireless mesh networks.Firstly,we analyze various possible threats to security in wireless mesh networks.Secondly,we introduce some representative solutions to these threats,including solutions to the problems of key management,secure network routing,and intrusion detection.We also provide a comparison and discussion of their respective merits and drawbacks,and propose some improvements for these drawbacks.Finally,we also discuss the remaining challenges in the area.
文摘We propose a procedure to forecast short time series with stable seasonal pattern.This new method is motivated by the observations that short time series arise in many situations for the fierce competition.The quantity to be predicted is a yearly accumulation assuming that the partially accumulated data within the year are available.A simple model is proposed to describe the relation-ship between the yearly accumulation and partial accumulation and analytic results are obtained for both the point prediction and the predicative distribution.A comparison will be conducted between this model and traditional time series forecasting model with data from telecommunication industry. This method works better than the traditional models when only small amount of data are available. It can also be applied to forecast individual observations with a proper disaggregation algorithm.
文摘This paper presents a method to reduce the energy consumption of multi-core systems characterized by processor cores and buses with discrete frequency levels under timing constraints.The proposed method takes the transformations of the original task graphs,which include dependent tasks located in different iterations,as inputs.The proposed method utilizes mapping selection as well as joint processor and communication frequency scaling to implement energy reduction.We conduct experiments on several random task graphs.Experimental results show that the proposed method can achieve substantial energy reduction compared with previous work under the same hard timing constraints.
文摘To measure the signals with high freq u ency(>500 MHz),a sampling frequency down conversion method is introduced.This pa per analyzes the intermodulation signals and figures out the relationship betwee n the intermodulation signal and intermediate frequenc y signal.Based on the frequency conversion technology,an exclusion algorithm i s proposed a nd the actual implementation of the algorithm is given.The application resu lts show that the exclusion algorithm can identify the intermodulation signal exactly and eliminate the bad influence on the frequency measurement.
文摘Applying IEEE802.11MAC protocols in baltery-powered devices make power consumption critical demand upon implementation.A statistical study on operator/bit usage,the weight of operator and operator type in the programs has been done,including converting the MAC functions from SDL to C to ASM with tow RISC targts. The study shows that implementing MAC. functions should consider real-time protocol re3quirements by dividing MAC functions into sets. We enhance the set of time-critical functions implemented to dedicated hardwere and the set of non-time-critical functions implemented to software run with embedded processor. This heterogeneous system is proposed in consideration of our study results to reduce popwer consumption.
文摘In Discrete Multi-Tone (DMT) modulation systems, the well-known technique to overcome the Inter-Carrier Interference (ICI)/Inter-Symbol Interference (ISI) caused by the inadequate Cyclic Prefix (CP) length is to use a Time-Domain Equalizer (TDE) at the receiver front-end. An algorithm used to calculate the coefficients of the optimal shortening Time Domain Equalizer (TDE) was given by Melsa. However, this algorithm requires that the length of the TDE must be smaller than or equal to the memory length of the target impulse response. This paper modifies this algorithm and makes it not only fit for calculating the coefficients of the TDE with arbitrary length, but also have a much less computational time.
文摘This paper presents a new idea for an a lyzing the complicated shock signal.Based on this kind of analysis,an equivale nt power spectral density(PSD) chart is drawn for vibration environmental test,which is carried to test the vehicle loading instrument's vibration behavior.T he environment test is equivalent to the condition under which the vehicle and t he instrument is experiencing a firing period.Exactly speaking,the short time vibration during the firing period is a complicated shock event.The paper point s out the deficiency of the commonly used half sine equivalence for the shock an d vibration environment test and gives the procedure of how to draw the PSD char t through the actual acceleration data.
文摘Principal Component Analysis(PCA)is one of the most important feature extraction methods,and Kernel Principal Component Analysis(KPCA)is a nonlinear extension of PCA based on kernel methods.In real world,each input data may not be fully assigned to one class and it may partially belong to other classes.Based on the theory of fuzzy sets,this paper presents Fuzzy Principal Component Analysis(FPCA)and its nonlinear extension model,i.e.,Kernel-based Fuzzy Principal Component Analysis(KFPCA).The experimental results indicate that the proposed algorithms have good performances.
基金We wish to thank the National Basic Research Program of China （973 Program） for Grant 2007CB311203, the National Natural Science Foundation of China for Grant 60821001, the Specialized Research Fund for the Doctoral Program of Higher Education for Grant 20070013007 under which the present work was possible.
文摘A novel semi-fragile audio watermarking algorithm in DWT domain is proposed in this paper.This method transforms the original audio into 3-layer wavelet domain and divides approximation wavelet coefficients into many groups.Through computing mean quantization of per group,this algorithm embeds the watermark signal into the average value of the wavelet coefficients.Experimental results show that our semi-fragile audio watermarking algorithm is not only inaudible and robust against various common images processing,but also fragile to malicious modification.Especially,it can detect the tampered regions effectively.
