Ⅱ.Anaphoric RepetitionAccording to Otto Jespersen,anaphoric repetition means that a wordis repeated and for emphasis given front position:a.There was to be no outrage,and no outrage there was.(noun repeated)Charles K...Ⅱ.Anaphoric RepetitionAccording to Otto Jespersen,anaphoric repetition means that a wordis repeated and for emphasis given front position:a.There was to be no outrage,and no outrage there was.(noun repeated)Charles Kengsley,Hypatiab.She signed delicately and delicately she panted.(adverb repeated)Anthony Hope,Dolly Dialoguesc.She found him perfect,and perfect in her sight he remained.(adjectiverepeated)展开更多
In the high speed target environment,there exists serious Doppler effect in the low pulse repetition frequency（LPRF） modulated frequency stepped frequency（MFSF） radar signal.The velocity range of the target is lar...In the high speed target environment,there exists serious Doppler effect in the low pulse repetition frequency（LPRF） modulated frequency stepped frequency（MFSF） radar signal.The velocity range of the target is large and the velocity is high ambiguous,so the single method is difficult to satisfy the velocity measurement requirement.For this problem,a novel method is presented,it is a combination of cross-correlation inner frame velocity measurement and range-Doppler coupling velocity measurement.The cross-correlation inner frame method,overcoming the low Doppler tolerance of the cross-correlation between frames,can obtain the coarse velocity of the high speed target,and then the precision velocity can be obtained with the range-Doppler coupling method.The simulation results confirm the method is effective,and also it is well real-time and easy to the project application.展开更多
Pulse repetition interval(PRI)modulation recognition and pulse sequence search are significant for effective electronic support measures.In modern electromagnetic environments,different types of inter-pulse slide rada...Pulse repetition interval(PRI)modulation recognition and pulse sequence search are significant for effective electronic support measures.In modern electromagnetic environments,different types of inter-pulse slide radars are highly confusing.There are few available training samples in practical situations,which leads to a low recognition accuracy and poor search effect of the pulse sequence.In this paper,an approach based on bi-directional long short-term memory(BiLSTM)networks and the temporal correlation algorithm for PRI modulation recognition and sequence search under the small sample prerequisite is proposed.The simulation results demonstrate that the proposed algorithm can recognize unilinear,bilinear,sawtooth,and sinusoidal PRI modulation types with 91.43% accuracy and complete the pulse sequence search with 30% missing pulses and 50% spurious pulses under the small sample prerequisite.展开更多
In order to obtain coding gain along with diversity gain,rotation code was applied to cooperative diversity employing decoded-and-forward cooperative protocol.Different from the same two symbols transmitted in convent...In order to obtain coding gain along with diversity gain,rotation code was applied to cooperative diversity employing decoded-and-forward cooperative protocol.Different from the same two symbols transmitted in conventional repetition-coded scheme,two different symbols were transmitted separately in two successive timeslots in the proposed rotation-coded cooperative diversity.In this way,constellation spread in the available two-dimensional signal space rather than on a single-dimensional line in repetition-coded scheme,which was supposed to be responsible for the additional coding gain.Under the proposed cooperative transmission model,upper bounds for the symbol-error-rate(SER)of cooperative diversity based on repetition code and rotation code were derived respectively.Both analytical and simulated results show that cooperative diversity based on rotation code can obtain an improved coding gain(by about 2 dB)than repetition-coded scheme without the expense of power or bandwidth.展开更多
Recognition of pulse repetition interval(PRI)modulation is a fundamental task in the interpretation of radar intentions.However,the existing PRI modulation recognition methods mainly focus on single-label classificati...Recognition of pulse repetition interval(PRI)modulation is a fundamental task in the interpretation of radar intentions.However,the existing PRI modulation recognition methods mainly focus on single-label classification of PRI sequences.The prerequisite for the effectiveness of these methods is that the PRI sequences are perfectly divided according to different modulation types before identification,while the actual situation is that radar pulses reach the receiver continuously,and there is no completely reliable method to achieve this division in the case of non-cooperative reception.Based on the above actual needs,this paper implements an algorithm based on the recurrence plot technique and the multi-target detection model,which does not need to divide the PRI sequence in advance.Compared with the sliding window method,it can more effectively realize the recognition of the dynamically varying PRI mo dulation.展开更多
The field tests were carried out to examine the reinforcement effect of a geogrid on various conditions of embankment height,the number of passages of vibratory roller,the number of reinforced layer of geogrid,and soi...The field tests were carried out to examine the reinforcement effect of a geogrid on various conditions of embankment height,the number of passages of vibratory roller,the number of reinforced layer of geogrid,and soil properties.The test results of the dynamic earth pressure indicate that the soil reinforced by geogrid is very effective to increase the stiffness of soil,especially in soft soil.The dynamic earth pressure ratio,which is defined as the ratio of dynamic earth pressure to self weight of soils,exponentially decreases as the embankment height increases.The dynamic earth pressure ratio increases up to 80% for soft soils reinforced by both one layer of geogrid in place of no reinforced soils and two layers in place of a single layer of geogrid.展开更多
Narrowband radar has been successfully used for high resolution imaging of fast rotating targets by exploiting their micro-motion features.In some practical situations,however,the target image may suffer from aliasing...Narrowband radar has been successfully used for high resolution imaging of fast rotating targets by exploiting their micro-motion features.In some practical situations,however,the target image may suffer from aliasing due to the fixed pulse repetition interval(PRI)of traditional radar scheme.In this work,the random PRI signal associated with compressed sensing(CS)theory was introduced for aliasing reduction to obtain high resolution images of fast rotating targets.To circumvent the large-scale dictionary and high computational complexity problem arising from direct application of CS theory,the low resolution image was firstly generated by applying a modified generalized Radon transform on the time-frequency domain,and then the dictionary was scaled down by random undersampling as well as the atoms extraction according to those strong scattering areas of the low resolution image.The scale-down-dictionary CS(SDD-CS)processing scheme was detailed and simulation results show that the SDD-CS scheme for narrowband radar can achieve preferable images with no aliasing as well as acceptable computational cost.展开更多
Some typical structural schemes of learning control have been investigated.The schemes involve the pattern recognitionbased learning control,iterative learning control,repetitive learning control,and connectionist lea...Some typical structural schemes of learning control have been investigated.The schemes involve the pattern recognitionbased learning control,iterative learning control,repetitive learning control,and connectionist learning control,etc.This study focuses on the control mechanism and provides a basis for potential applications.Most of the structural schemes have been applied to various control fields.展开更多
An adaptive repetitive control scheme is presented for a class of nonlinearly parameterized systems based on the fuzzy basis function network （FBFN）. The parameters of the fuzzy rules are tuned with adaptive schemes...An adaptive repetitive control scheme is presented for a class of nonlinearly parameterized systems based on the fuzzy basis function network （FBFN）. The parameters of the fuzzy rules are tuned with adaptive schemes. To attenuate chattering effectively, the discontinuous control term is approximated by an adaptive PI control structure. The bound of the discontinuous control term is assumed to be unknown and estimated by an adaptive mechanism. Based on the Lyapunov stability theory, an adaptive repetitive control law is proposed to guarantee the closed-loop stability and the tracking performance. By means of FBFNs, which avoid the nonlinear parameterization from entering into the adaptive repetitive control, the controller singularity problem is solved. The proposed approach does not require an exact structure of the system dynamics, and the proposed controller is utilized to control a model of permanent-magnet linear synchronous motor subject to significant disturbances and parameter uncertainties. The simulation results demonstrate the effectiveness of the proposed method.展开更多
PCR-based DNA fingerprinting, REP-PCR(repetitive element PCR), RAPD(randomly amplified polymorphic DNA) and16 S r DNA sequence analyses were used to characterize 23 Acidithiobacillus ferrooxidans strains isolated from...PCR-based DNA fingerprinting, REP-PCR(repetitive element PCR), RAPD(randomly amplified polymorphic DNA) and16 S r DNA sequence analyses were used to characterize 23 Acidithiobacillus ferrooxidans strains isolated from different environments.(GTG)5 and BOXA1 R primer were selected for REP-PCR. Twenty arbitrary primers were used for RAPD to acquire DNA profiles from A. ferrooxidans. Both RAPD and REP-PCR produce complex banding patterns and show good discriminatory ability in differentiating closely related strains of A. ferrooxidans. The strains are clustered into 4 or 5 major groups and reveal genomic diversity using(GTG)5-PCR, BOX-PCR and RAPD analysis. Phylogenetic tree based on 16 S r DNA sequences of 23 strains and related strains shows that they are clustered into two distinct groups. Twelve strains are highly related to a new Acidithiobacillus named Acidithiobacillus ferrivorans. The results indicate that PCR-based methods are effective in revealing genetic diversity among A. ferrooxidans.展开更多
A discrete observer-based repetitive control(RC) design method for a linear system with uncertainties was presented based on two-dimensional(2D) system theory. Firstly, a 2D discrete model was established to describe ...A discrete observer-based repetitive control(RC) design method for a linear system with uncertainties was presented based on two-dimensional(2D) system theory. Firstly, a 2D discrete model was established to describe both the control behavior within a repetition period and the learning process taking place between periods. Next, by converting the designing problem of repetitive controller into one of the feedback gains of reconstructed variables, the stable condition was obtained through linear matrix inequality(LMI) and also the gain coefficient of repetitive system. Numerical simulation shows an exceptional feasibility of this proposal with remarkable robustness and tracking speed.展开更多
文摘Ⅱ.Anaphoric RepetitionAccording to Otto Jespersen,anaphoric repetition means that a wordis repeated and for emphasis given front position:a.There was to be no outrage,and no outrage there was.(noun repeated)Charles Kengsley,Hypatiab.She signed delicately and delicately she panted.(adverb repeated)Anthony Hope,Dolly Dialoguesc.She found him perfect,and perfect in her sight he remained.(adjectiverepeated)
文摘In the high speed target environment,there exists serious Doppler effect in the low pulse repetition frequency（LPRF） modulated frequency stepped frequency（MFSF） radar signal.The velocity range of the target is large and the velocity is high ambiguous,so the single method is difficult to satisfy the velocity measurement requirement.For this problem,a novel method is presented,it is a combination of cross-correlation inner frame velocity measurement and range-Doppler coupling velocity measurement.The cross-correlation inner frame method,overcoming the low Doppler tolerance of the cross-correlation between frames,can obtain the coarse velocity of the high speed target,and then the precision velocity can be obtained with the range-Doppler coupling method.The simulation results confirm the method is effective,and also it is well real-time and easy to the project application.
基金supported by the National Natural Science Foundation of China(61801143,61971155)the National Natural Science Foundation of Heilongjiang Province(LH2020F019).
文摘Pulse repetition interval(PRI)modulation recognition and pulse sequence search are significant for effective electronic support measures.In modern electromagnetic environments,different types of inter-pulse slide radars are highly confusing.There are few available training samples in practical situations,which leads to a low recognition accuracy and poor search effect of the pulse sequence.In this paper,an approach based on bi-directional long short-term memory(BiLSTM)networks and the temporal correlation algorithm for PRI modulation recognition and sequence search under the small sample prerequisite is proposed.The simulation results demonstrate that the proposed algorithm can recognize unilinear,bilinear,sawtooth,and sinusoidal PRI modulation types with 91.43% accuracy and complete the pulse sequence search with 30% missing pulses and 50% spurious pulses under the small sample prerequisite.
基金Project(2006AA01Z270)supported by the National High Technology Research and Development Program of ChinaProject(U0635003)supported by the National Natural Science Foundation of Guangdong Province,ChinaProject(2007F07)supported by the National Science Foundation of Shaanxi Province,China
文摘In order to obtain coding gain along with diversity gain,rotation code was applied to cooperative diversity employing decoded-and-forward cooperative protocol.Different from the same two symbols transmitted in conventional repetition-coded scheme,two different symbols were transmitted separately in two successive timeslots in the proposed rotation-coded cooperative diversity.In this way,constellation spread in the available two-dimensional signal space rather than on a single-dimensional line in repetition-coded scheme,which was supposed to be responsible for the additional coding gain.Under the proposed cooperative transmission model,upper bounds for the symbol-error-rate(SER)of cooperative diversity based on repetition code and rotation code were derived respectively.Both analytical and simulated results show that cooperative diversity based on rotation code can obtain an improved coding gain(by about 2 dB)than repetition-coded scheme without the expense of power or bandwidth.
基金supported by the National Defense Science and Technology Outstanding Youth Science Fund Project(2018-JCJQ-ZQ-023)the Hunan Provincial Natural Science Foundation of Innovation Research Group Project(2019JJ10004)。
文摘Recognition of pulse repetition interval(PRI)modulation is a fundamental task in the interpretation of radar intentions.However,the existing PRI modulation recognition methods mainly focus on single-label classification of PRI sequences.The prerequisite for the effectiveness of these methods is that the PRI sequences are perfectly divided according to different modulation types before identification,while the actual situation is that radar pulses reach the receiver continuously,and there is no completely reliable method to achieve this division in the case of non-cooperative reception.Based on the above actual needs,this paper implements an algorithm based on the recurrence plot technique and the multi-target detection model,which does not need to divide the PRI sequence in advance.Compared with the sliding window method,it can more effectively realize the recognition of the dynamically varying PRI mo dulation.
文摘The field tests were carried out to examine the reinforcement effect of a geogrid on various conditions of embankment height,the number of passages of vibratory roller,the number of reinforced layer of geogrid,and soil properties.The test results of the dynamic earth pressure indicate that the soil reinforced by geogrid is very effective to increase the stiffness of soil,especially in soft soil.The dynamic earth pressure ratio,which is defined as the ratio of dynamic earth pressure to self weight of soils,exponentially decreases as the embankment height increases.The dynamic earth pressure ratio increases up to 80% for soft soils reinforced by both one layer of geogrid in place of no reinforced soils and two layers in place of a single layer of geogrid.
基金Projects(61171133,61271442)supported by the National Natural Science Foundation of ChinaProject(61025006)supported by the National Natural Science Foundation for Distinguished Young Scholars of ChinaProject(B110404)supported by the Innovation Program for Excellent Postgraduates of National University of Defense Technology,China
文摘Narrowband radar has been successfully used for high resolution imaging of fast rotating targets by exploiting their micro-motion features.In some practical situations,however,the target image may suffer from aliasing due to the fixed pulse repetition interval(PRI)of traditional radar scheme.In this work,the random PRI signal associated with compressed sensing(CS)theory was introduced for aliasing reduction to obtain high resolution images of fast rotating targets.To circumvent the large-scale dictionary and high computational complexity problem arising from direct application of CS theory,the low resolution image was firstly generated by applying a modified generalized Radon transform on the time-frequency domain,and then the dictionary was scaled down by random undersampling as well as the atoms extraction according to those strong scattering areas of the low resolution image.The scale-down-dictionary CS(SDD-CS)processing scheme was detailed and simulation results show that the SDD-CS scheme for narrowband radar can achieve preferable images with no aliasing as well as acceptable computational cost.
文摘Some typical structural schemes of learning control have been investigated.The schemes involve the pattern recognitionbased learning control,iterative learning control,repetitive learning control,and connectionist learning control,etc.This study focuses on the control mechanism and provides a basis for potential applications.Most of the structural schemes have been applied to various control fields.
基金supported by the National Natural Science Foundation of China (61203041)the Chinese National Post-doctor Science Foundation (2011M500217)
文摘An adaptive repetitive control scheme is presented for a class of nonlinearly parameterized systems based on the fuzzy basis function network （FBFN）. The parameters of the fuzzy rules are tuned with adaptive schemes. To attenuate chattering effectively, the discontinuous control term is approximated by an adaptive PI control structure. The bound of the discontinuous control term is assumed to be unknown and estimated by an adaptive mechanism. Based on the Lyapunov stability theory, an adaptive repetitive control law is proposed to guarantee the closed-loop stability and the tracking performance. By means of FBFNs, which avoid the nonlinear parameterization from entering into the adaptive repetitive control, the controller singularity problem is solved. The proposed approach does not require an exact structure of the system dynamics, and the proposed controller is utilized to control a model of permanent-magnet linear synchronous motor subject to significant disturbances and parameter uncertainties. The simulation results demonstrate the effectiveness of the proposed method.
基金Project(2010CB630901)supported by the National Basic Research Program of China
文摘PCR-based DNA fingerprinting, REP-PCR(repetitive element PCR), RAPD(randomly amplified polymorphic DNA) and16 S r DNA sequence analyses were used to characterize 23 Acidithiobacillus ferrooxidans strains isolated from different environments.(GTG)5 and BOXA1 R primer were selected for REP-PCR. Twenty arbitrary primers were used for RAPD to acquire DNA profiles from A. ferrooxidans. Both RAPD and REP-PCR produce complex banding patterns and show good discriminatory ability in differentiating closely related strains of A. ferrooxidans. The strains are clustered into 4 or 5 major groups and reveal genomic diversity using(GTG)5-PCR, BOX-PCR and RAPD analysis. Phylogenetic tree based on 16 S r DNA sequences of 23 strains and related strains shows that they are clustered into two distinct groups. Twelve strains are highly related to a new Acidithiobacillus named Acidithiobacillus ferrivorans. The results indicate that PCR-based methods are effective in revealing genetic diversity among A. ferrooxidans.
基金Project(61104072) supported by the National Natural Science Foundation of China
文摘A discrete observer-based repetitive control(RC) design method for a linear system with uncertainties was presented based on two-dimensional(2D) system theory. Firstly, a 2D discrete model was established to describe both the control behavior within a repetition period and the learning process taking place between periods. Next, by converting the designing problem of repetitive controller into one of the feedback gains of reconstructed variables, the stable condition was obtained through linear matrix inequality(LMI) and also the gain coefficient of repetitive system. Numerical simulation shows an exceptional feasibility of this proposal with remarkable robustness and tracking speed.
