The spherical oscillation of a gas bubble in liquids is important to growth in liquids during rectified diffusions( e. g., the onset of the sonoluminescence and the enhancement of sonochemical reactions). The present ...The spherical oscillation of a gas bubble in liquids is important to growth in liquids during rectified diffusions( e. g., the onset of the sonoluminescence and the enhancement of sonochemical reactions). The present paper numerically shows stability maps( divided into four zones),in which gas bubbles maintain the linearly spherical oscillation without nonlinear disturbance of rectified diffusions within a large range of bubble radius. The critical pressures of spherical and diffusional oscillations are two decisive indexes determining the stability status. Specifically,the stability boundaries and influential factors( including acoustic parameters and gas concentration in liquids) were discussed and analyzed. The results show that the variations of gas concentration and acoustic parameters dramatically changed the stable status of the gas bubbles. The gas bubble maintained stable status when external parameters and gas concentration were set between the two critical values properly. The cases of high-frequency and low-frequency limits were also introduced at the end of the whole paper.展开更多
Deep Neural Networks(DNNs)have become the tool of choice for machine learning practitioners today.One important aspect of designing a neural network is the choice of the activation function to be used at the neurons o...Deep Neural Networks(DNNs)have become the tool of choice for machine learning practitioners today.One important aspect of designing a neural network is the choice of the activation function to be used at the neurons of the different layers.In this work,we introduce a four-output activation function called the Reflected Rectified Linear Unit(RRe LU)activation which considers both a feature and its negation during computation.Our activation function is"sparse",in that only two of the four possible outputs are active at a given time.We test our activation function on the standard MNIST and CIFAR-10 datasets,which are classification problems,as well as on a novel Computational Fluid Dynamics(CFD)dataset which is posed as a regression problem.On the baseline network for the MNIST dataset,having two hidden layers,our activation function improves the validation accuracy from 0.09 to 0.97 compared to the well-known Re LU activation.For the CIFAR-10 dataset,we use a deep baseline network that achieves 0.78 validation accuracy with 20 epochs but overfits the data.Using the RRe LU activation,we can achieve the same accuracy without overfitting the data.For the CFD dataset,we show that the RRe LU activation can reduce the number of epochs from 100(using Re LU)to 10 while obtaining the same levels of performance.展开更多
Rectifying circuit,as a crucial component for converting alternating current into direct current,plays a pivotal role in energy harvesting microsystems.Traditional silicon-based or germanium-based rectifier diodes hin...Rectifying circuit,as a crucial component for converting alternating current into direct current,plays a pivotal role in energy harvesting microsystems.Traditional silicon-based or germanium-based rectifier diodes hinder system integration due to their specific manufacturing processes.Conversely,metal oxide diodes,with their simple fabrication techniques,offer advantages for system integration.The oxygen vacancy defect of oxide semiconductor will greatly affect the electrical performance of the device,so the performance of the diode can be effectively controlled by adjusting the oxygen vacancy concentration.This study centers on optimizing the performance of diodes by modulating the oxygen vacancy concentration within InGaZnO films through control of oxygen flows during the sputtering process.Experimental results demonstrate that the diode exhibits a forward current density of 43.82 A·cm^(−2),with a rectification ratio of 6.94×10^(4),efficiently rectifying input sine signals with 1 kHz frequency and 5 V magnitude.These results demonstrate its potential in energy conversion and management.By adjusting the oxygen vacancy,a methodology is provided for optimizing the performance of rectifying diodes.展开更多
The global adoption of Electric Vehicles(EVs)is on the rise due to their advanced features,with projections indicating they will soon dominate the private vehicle market.However,improper management of EV charging can ...The global adoption of Electric Vehicles(EVs)is on the rise due to their advanced features,with projections indicating they will soon dominate the private vehicle market.However,improper management of EV charging can lead to significant issues.This paper reviews the development of high-power,reliable charging solutions by examining the converter topologies used in rectifiers and converters that transfer electricity from the grid to EV batteries.It covers technical details,ongoing developments,and challenges related to these topologies and control strategies.The integration of rapid charging stations has introduced various Power Quality(PQ)issues,such as voltage fluctuations,harmonic distortion,and supra-harmonics,which are discussed in detail.The paper also highlights the benefits of controlled EV charging and discharging,including voltage and frequency regulation,reactive power compensation,and improved power quality.Efficient energy management and control strategies are crucial for optimizing EV battery charging within microgrids to meet increasing demand.Charging stations must adhere to specific converter topologies,control strategies,and industry standards to function correctly.The paper explores microgrid architectures and control strategies that integrate EVs,energy storage units(ESUs),and Renewable Energy Sources(RES)to enhance performance at charging points.It emphasizes the importance of various RES-connected architectures and the latest power converter topologies.Additionally,the paper provides a comparative analysis of microgrid-based charging station architectures,focusing on energy management,control strategies,and charging converter controls.The goal is to offer insights into future research directions in EV charging systems,including architectural considerations,control factors,and their respective advantages and disadvantages.展开更多
The Vienna rectifier is a widely adopted solution for high-power rectification due to its efficiency and straightforward design.However,its performance can degrade under unbalanced three phase voltage conditions,leadi...The Vienna rectifier is a widely adopted solution for high-power rectification due to its efficiency and straightforward design.However,its performance can degrade under unbalanced three phase voltage conditions,leading to current zero-crossing distortion and compromised dynamic response.This paper investigates the causes of these distortions,identifying a phase shift between the input current and the grid voltage as a primary factor,and proposes an effective distortion phase identification strategy.Furthermore,the dynamic performance is enhanced through improved current reference calculations and a refined power feedforward strategy.This approach optimizes the system's response to load changes and maintains output voltage stability under unbalanced conditions.Simulation results validate the effectiveness of the proposed methods in reducing current distortion and improving overall performance.展开更多
A control strategy of repetitive control without inductorance decoupling was proposed to address the problem of high total harmonic distortion(THD)rate of the network-side current caused by the reduced stability of th...A control strategy of repetitive control without inductorance decoupling was proposed to address the problem of high total harmonic distortion(THD)rate of the network-side current caused by the reduced stability of the rectifier module of the DC charging pile under weak grid as well as the dead zone and nonlinearity of switching devices during charging.Firstly,the parallel repetitive control was constructed in the inner current loop,and the proportional-integral(PI)+repetitive controller based on parallel structure was designed.For system compensation,a second-order low-pass filter was selected to correct the system,and the network-side current harmonics were actively suppressed without increasing the filtering device,which effectively improves the quality of grid-connected current.Secondly,based on the synthetic vector method,the controller parameters were designed to realize the elimination of main pole by establishing two synchronous rotation coordinate system vector differential equations,so as to realize the inductanceless decoupling to cope with the influence of network-side inductance fluctuation on the stability of the control system under weak grid.By theoretical analysis and simulation,the proposed control strategy was embedded into the self-developed digital signal processor for the rectifier module of DC charging pile,simulated dynamic and steady-state operation experiments were conducted,and comparative analysis was performed to prove the feasibility of the proposed control strategy.展开更多
In this study,Computational Fluid Dynamics(CFD)together with a component transport model are exploited to investigate the influence of dimensionless parameters,involving the height of the rectifier grid and the instal...In this study,Computational Fluid Dynamics(CFD)together with a component transport model are exploited to investigate the influence of dimensionless parameters,involving the height of the rectifier grid and the installation height of the first catalyst layer,on the flow field and the overall denitration efficiency of a cement kiln’s SCR(Selective catalytic reduction)denitrification reactor.It is shown that accurate numerical results can be obtained by fitting the particle size distribution function to the actual cement kiln fly ash and implementing a non-uniform particle inlet boundary condition.The relative error between denitration efficiency derived from experimental data,numerical simulation,and real-time system pressure drop ranges from 4%to 9%.Optimization of the SCR reactor is achieved when the rectifier grid thickness ratio k/H≥0.030,the rectifier grid height ratio h/H=0.04,and the spacing between the rectifier grid and the first catalyst layer l/H=0.10.Under these conditions,airflow distribution and particle dispersion upstream of the catalyst result in increased denitration efficiencies of 3.21%,3.43%,and 3.27%,respectively,compared to the least favorable operating conditions.展开更多
Parvalbumin-positive(PV^(+))interneuron dysfunction is believed to be linked to autism spectrum disorder(ASD),a neurodevelopmental disorder characterized by social deficits and stereotypical behaviors.However,the mech...Parvalbumin-positive(PV^(+))interneuron dysfunction is believed to be linked to autism spectrum disorder(ASD),a neurodevelopmental disorder characterized by social deficits and stereotypical behaviors.However,the mechanisms behind PV^(+)interneuron dysfunction remain largely unclear.Here,we found that a deficiency of Biorientation Defective 1(Bod1)in PV^(+)interneurons led to an ASD-like phenotype in Pvalb-Cre;Bod1f/f mice.Mechanistically,we observed that Bod1 deficiency induced hypoactivity of PV^(+)interneurons and hyperactivity of calcium/calmodulin-dependent protein kinaseⅡalpha(CaMKⅡα)neurons in the medial prefrontal cortex,as determined by whole-cell patch-clamp recording.Additionally,Bod1 deficiency decreased the power of highgamma oscillation,assessed by in vivo multi-channel electrophysiological recording.Furthermore,we found that Bod1 deficiency enhanced the inwardly rectifying K^(+)current,leading to an increase in the resting membrane potential of PV^(+)interneurons.Importantly,the gain-of-function of Bod1 improved social deficits and stereotypical behaviors in Pvalb-Cre;Bod1f/f mice.These findings provide mechanistic insights into the PV^(+)interneuron dysfunction and suggest new strategies for developing PV^(+)interneuron-targeted therapies for ASD.展开更多
The face velocities of the high efficiency particulate air filters and the ultra low penetration airfilters in fan filter units (FFUs) have large relative standard deviation and turbulivity. It seriously affects the ...The face velocities of the high efficiency particulate air filters and the ultra low penetration airfilters in fan filter units (FFUs) have large relative standard deviation and turbulivity. It seriously affects the unidirectivity of the flow in the unidirectional flow clean zone and cleanroom. The cross contamination in this kind of unidirectional flow area is hardly controlled. It is significant to find optional method for keeping the face velocity uniformity of FFU and reducing the face velocity turbulivity of FFU, furthermore, to keep the cleanliness level under FFUs. The normal and easy method is to add flow rectifiers under filters. FFUs with various flow rectifiers have been tested. The uniformity and turbulivity of facevelocity under the FFU are presented in this paper. The influence of the facevelocity uniformity and turbulivity on the contamination boundary of the unidirectional flow is studiedas well.展开更多
Currently,there are many limitations to classify images of small objects.In addition,there are limitations such as error detection due to external factors,and there is also a disadvantage that it is difficult to accur...Currently,there are many limitations to classify images of small objects.In addition,there are limitations such as error detection due to external factors,and there is also a disadvantage that it is difficult to accurately distinguish between various objects.This paper uses a convolutional neural network(CNN)algorithm to recognize and classify object images of very small moths and obtain precise data images.A convolution neural network algorithm is used for image data classification,and the classified image is transformed into image data to learn the topological structure of the image.To improve the accuracy of the image classification and reduce the loss rate,a parameter for finding a fast-optimal point of image classification is set by a convolutional neural network and a pixel image as a preprocessor.As a result of this study,we applied a convolution neural network algorithm to classify the images of very small moths by capturing precise images of the moths.Experimental results showed that the accuracy of classification of very small moths was more than 90%.展开更多
For neural networks(NNs)with rectified linear unit(ReLU)or binary activation functions,we show that their training can be accomplished in a reduced parameter space.Specifically,the weights in each neuron can be traine...For neural networks(NNs)with rectified linear unit(ReLU)or binary activation functions,we show that their training can be accomplished in a reduced parameter space.Specifically,the weights in each neuron can be trained on the unit sphere,as opposed to the entire space,and the threshold can be trained in a bounded interval,as opposed to the real line.We show that the NNs in the reduced parameter space are mathematically equivalent to the standard NNs with parameters in the whole space.The reduced parameter space shall facilitate the optimization procedure for the network training,as the search space becomes(much)smaller.We demonstrate the improved training performance using numerical examples.展开更多
On the basis of detailed analysis of a novel harmonic counteracting method which can be used to effectively compensate the supply line harmonic currents of a passive single phase diode bridge rectifier, this paper pr...On the basis of detailed analysis of a novel harmonic counteracting method which can be used to effectively compensate the supply line harmonic currents of a passive single phase diode bridge rectifier, this paper presents two simpler single phase diode bridge rectifier configurations and their alternatives which can achieve low supply line current THD(total harmonic distortion) too. Moreover, this paper also proposes a few passive hamonic counteracting networks for multi single phase rectifiers which are connected in parallel.展开更多
Conditions have been studied under which a polychromatic optical superlattice can form and trap the Coulomb cluster of two strongly interacting ions. In our previous work （Krasnov I V and Kamenshchikov L P 2014 Opt. ...Conditions have been studied under which a polychromatic optical superlattice can form and trap the Coulomb cluster of two strongly interacting ions. In our previous work （Krasnov I V and Kamenshchikov L P 2014 Opt. Comm. 312 192） this new all-optical method of obtaining and confining the Coulomb clusters was demonstrated by numerical simulations for special values of the optical superlattice parameters and in the case of Yb ions. In the present paper the conditions are explicitly formulated, under which the long-lived two-ion cluster in the superlattice cell is formed. The peculiarity of these conditions is the renormalization of the ion-ion Coulomb interaction. Notably, the renormalized Coulomb force is determined by the effective charge which depends on the light field parameters and can strongly differ from the ＂bare＂ ion charge. This result can be accounted for by the combined manifestation of the quantum fluctuations of optical forces, nonlinear dependence of these forces on the velocity, and non-Maxwellian （Tsallis type） velocity distribution of the ions in the optical superlattice. Explicit analytical formulas are also obtained for the parameters of the optical two-ion cluster.展开更多
Security systems are the need of the hour to protect data from unauthorized access.The dissemination of confidential information over the public network requires a high level of security.The security approach such as ...Security systems are the need of the hour to protect data from unauthorized access.The dissemination of confidential information over the public network requires a high level of security.The security approach such as steganography ensures confidentiality,authentication,integrity,and non-repudiation.Steganography helps in hiding the secret data inside the cover media so that the attacker can be confused during the transmission process of secret data between sender and receiver.Therefore,we present an efficient hybrid security model that provides multifold security assurance.To this end,a rectified Advanced Encryption Standard(AES)algorithm is proposed to overcome the problems existing in AES such as pattern appearance and high computations.The modified AES is used for the encryption of the stego image that contains the digitally signed encrypted secret data.The enciphering and deciphering of the secret data are done using the Rivest–Shamir–Adleman(RSA)algorithm.The experiments are conducted on the images of the USC-SIPI standard image database.The experimental results prove that the proposed hybrid system outperforms other SOTA(state-of-the-art)approaches.展开更多
基金Sponsored by the Fundamental Research Fund for Central Universities(Grant No.2017XS063)
文摘The spherical oscillation of a gas bubble in liquids is important to growth in liquids during rectified diffusions( e. g., the onset of the sonoluminescence and the enhancement of sonochemical reactions). The present paper numerically shows stability maps( divided into four zones),in which gas bubbles maintain the linearly spherical oscillation without nonlinear disturbance of rectified diffusions within a large range of bubble radius. The critical pressures of spherical and diffusional oscillations are two decisive indexes determining the stability status. Specifically,the stability boundaries and influential factors( including acoustic parameters and gas concentration in liquids) were discussed and analyzed. The results show that the variations of gas concentration and acoustic parameters dramatically changed the stable status of the gas bubbles. The gas bubble maintained stable status when external parameters and gas concentration were set between the two critical values properly. The cases of high-frequency and low-frequency limits were also introduced at the end of the whole paper.
文摘Deep Neural Networks(DNNs)have become the tool of choice for machine learning practitioners today.One important aspect of designing a neural network is the choice of the activation function to be used at the neurons of the different layers.In this work,we introduce a four-output activation function called the Reflected Rectified Linear Unit(RRe LU)activation which considers both a feature and its negation during computation.Our activation function is"sparse",in that only two of the four possible outputs are active at a given time.We test our activation function on the standard MNIST and CIFAR-10 datasets,which are classification problems,as well as on a novel Computational Fluid Dynamics(CFD)dataset which is posed as a regression problem.On the baseline network for the MNIST dataset,having two hidden layers,our activation function improves the validation accuracy from 0.09 to 0.97 compared to the well-known Re LU activation.For the CIFAR-10 dataset,we use a deep baseline network that achieves 0.78 validation accuracy with 20 epochs but overfits the data.Using the RRe LU activation,we can achieve the same accuracy without overfitting the data.For the CFD dataset,we show that the RRe LU activation can reduce the number of epochs from 100(using Re LU)to 10 while obtaining the same levels of performance.
文摘Rectifying circuit,as a crucial component for converting alternating current into direct current,plays a pivotal role in energy harvesting microsystems.Traditional silicon-based or germanium-based rectifier diodes hinder system integration due to their specific manufacturing processes.Conversely,metal oxide diodes,with their simple fabrication techniques,offer advantages for system integration.The oxygen vacancy defect of oxide semiconductor will greatly affect the electrical performance of the device,so the performance of the diode can be effectively controlled by adjusting the oxygen vacancy concentration.This study centers on optimizing the performance of diodes by modulating the oxygen vacancy concentration within InGaZnO films through control of oxygen flows during the sputtering process.Experimental results demonstrate that the diode exhibits a forward current density of 43.82 A·cm^(−2),with a rectification ratio of 6.94×10^(4),efficiently rectifying input sine signals with 1 kHz frequency and 5 V magnitude.These results demonstrate its potential in energy conversion and management.By adjusting the oxygen vacancy,a methodology is provided for optimizing the performance of rectifying diodes.
文摘The global adoption of Electric Vehicles(EVs)is on the rise due to their advanced features,with projections indicating they will soon dominate the private vehicle market.However,improper management of EV charging can lead to significant issues.This paper reviews the development of high-power,reliable charging solutions by examining the converter topologies used in rectifiers and converters that transfer electricity from the grid to EV batteries.It covers technical details,ongoing developments,and challenges related to these topologies and control strategies.The integration of rapid charging stations has introduced various Power Quality(PQ)issues,such as voltage fluctuations,harmonic distortion,and supra-harmonics,which are discussed in detail.The paper also highlights the benefits of controlled EV charging and discharging,including voltage and frequency regulation,reactive power compensation,and improved power quality.Efficient energy management and control strategies are crucial for optimizing EV battery charging within microgrids to meet increasing demand.Charging stations must adhere to specific converter topologies,control strategies,and industry standards to function correctly.The paper explores microgrid architectures and control strategies that integrate EVs,energy storage units(ESUs),and Renewable Energy Sources(RES)to enhance performance at charging points.It emphasizes the importance of various RES-connected architectures and the latest power converter topologies.Additionally,the paper provides a comparative analysis of microgrid-based charging station architectures,focusing on energy management,control strategies,and charging converter controls.The goal is to offer insights into future research directions in EV charging systems,including architectural considerations,control factors,and their respective advantages and disadvantages.
文摘The Vienna rectifier is a widely adopted solution for high-power rectification due to its efficiency and straightforward design.However,its performance can degrade under unbalanced three phase voltage conditions,leading to current zero-crossing distortion and compromised dynamic response.This paper investigates the causes of these distortions,identifying a phase shift between the input current and the grid voltage as a primary factor,and proposes an effective distortion phase identification strategy.Furthermore,the dynamic performance is enhanced through improved current reference calculations and a refined power feedforward strategy.This approach optimizes the system's response to load changes and maintains output voltage stability under unbalanced conditions.Simulation results validate the effectiveness of the proposed methods in reducing current distortion and improving overall performance.
基金supported by National Natural Science Foundation of China(No.61903291)Shaanxi Province Key R&D Program(No.2022GY-134)。
文摘A control strategy of repetitive control without inductorance decoupling was proposed to address the problem of high total harmonic distortion(THD)rate of the network-side current caused by the reduced stability of the rectifier module of the DC charging pile under weak grid as well as the dead zone and nonlinearity of switching devices during charging.Firstly,the parallel repetitive control was constructed in the inner current loop,and the proportional-integral(PI)+repetitive controller based on parallel structure was designed.For system compensation,a second-order low-pass filter was selected to correct the system,and the network-side current harmonics were actively suppressed without increasing the filtering device,which effectively improves the quality of grid-connected current.Secondly,based on the synthetic vector method,the controller parameters were designed to realize the elimination of main pole by establishing two synchronous rotation coordinate system vector differential equations,so as to realize the inductanceless decoupling to cope with the influence of network-side inductance fluctuation on the stability of the control system under weak grid.By theoretical analysis and simulation,the proposed control strategy was embedded into the self-developed digital signal processor for the rectifier module of DC charging pile,simulated dynamic and steady-state operation experiments were conducted,and comparative analysis was performed to prove the feasibility of the proposed control strategy.
基金Anhui Province Key Research and Development Plan of the Ecological Environment Project(No.202104i07020016).
文摘In this study,Computational Fluid Dynamics(CFD)together with a component transport model are exploited to investigate the influence of dimensionless parameters,involving the height of the rectifier grid and the installation height of the first catalyst layer,on the flow field and the overall denitration efficiency of a cement kiln’s SCR(Selective catalytic reduction)denitrification reactor.It is shown that accurate numerical results can be obtained by fitting the particle size distribution function to the actual cement kiln fly ash and implementing a non-uniform particle inlet boundary condition.The relative error between denitration efficiency derived from experimental data,numerical simulation,and real-time system pressure drop ranges from 4%to 9%.Optimization of the SCR reactor is achieved when the rectifier grid thickness ratio k/H≥0.030,the rectifier grid height ratio h/H=0.04,and the spacing between the rectifier grid and the first catalyst layer l/H=0.10.Under these conditions,airflow distribution and particle dispersion upstream of the catalyst result in increased denitration efficiencies of 3.21%,3.43%,and 3.27%,respectively,compared to the least favorable operating conditions.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFE0108600 to Y.M.L.)the National Natural Science Foundations of China(Grant Nos.82473918 and 82104162 to X.X.L.).
文摘Parvalbumin-positive(PV^(+))interneuron dysfunction is believed to be linked to autism spectrum disorder(ASD),a neurodevelopmental disorder characterized by social deficits and stereotypical behaviors.However,the mechanisms behind PV^(+)interneuron dysfunction remain largely unclear.Here,we found that a deficiency of Biorientation Defective 1(Bod1)in PV^(+)interneurons led to an ASD-like phenotype in Pvalb-Cre;Bod1f/f mice.Mechanistically,we observed that Bod1 deficiency induced hypoactivity of PV^(+)interneurons and hyperactivity of calcium/calmodulin-dependent protein kinaseⅡalpha(CaMKⅡα)neurons in the medial prefrontal cortex,as determined by whole-cell patch-clamp recording.Additionally,Bod1 deficiency decreased the power of highgamma oscillation,assessed by in vivo multi-channel electrophysiological recording.Furthermore,we found that Bod1 deficiency enhanced the inwardly rectifying K^(+)current,leading to an increase in the resting membrane potential of PV^(+)interneurons.Importantly,the gain-of-function of Bod1 improved social deficits and stereotypical behaviors in Pvalb-Cre;Bod1f/f mice.These findings provide mechanistic insights into the PV^(+)interneuron dysfunction and suggest new strategies for developing PV^(+)interneuron-targeted therapies for ASD.
文摘The face velocities of the high efficiency particulate air filters and the ultra low penetration airfilters in fan filter units (FFUs) have large relative standard deviation and turbulivity. It seriously affects the unidirectivity of the flow in the unidirectional flow clean zone and cleanroom. The cross contamination in this kind of unidirectional flow area is hardly controlled. It is significant to find optional method for keeping the face velocity uniformity of FFU and reducing the face velocity turbulivity of FFU, furthermore, to keep the cleanliness level under FFUs. The normal and easy method is to add flow rectifiers under filters. FFUs with various flow rectifiers have been tested. The uniformity and turbulivity of facevelocity under the FFU are presented in this paper. The influence of the facevelocity uniformity and turbulivity on the contamination boundary of the unidirectional flow is studiedas well.
文摘Currently,there are many limitations to classify images of small objects.In addition,there are limitations such as error detection due to external factors,and there is also a disadvantage that it is difficult to accurately distinguish between various objects.This paper uses a convolutional neural network(CNN)algorithm to recognize and classify object images of very small moths and obtain precise data images.A convolution neural network algorithm is used for image data classification,and the classified image is transformed into image data to learn the topological structure of the image.To improve the accuracy of the image classification and reduce the loss rate,a parameter for finding a fast-optimal point of image classification is set by a convolutional neural network and a pixel image as a preprocessor.As a result of this study,we applied a convolution neural network algorithm to classify the images of very small moths by capturing precise images of the moths.Experimental results showed that the accuracy of classification of very small moths was more than 90%.
文摘For neural networks(NNs)with rectified linear unit(ReLU)or binary activation functions,we show that their training can be accomplished in a reduced parameter space.Specifically,the weights in each neuron can be trained on the unit sphere,as opposed to the entire space,and the threshold can be trained in a bounded interval,as opposed to the real line.We show that the NNs in the reduced parameter space are mathematically equivalent to the standard NNs with parameters in the whole space.The reduced parameter space shall facilitate the optimization procedure for the network training,as the search space becomes(much)smaller.We demonstrate the improved training performance using numerical examples.
文摘On the basis of detailed analysis of a novel harmonic counteracting method which can be used to effectively compensate the supply line harmonic currents of a passive single phase diode bridge rectifier, this paper presents two simpler single phase diode bridge rectifier configurations and their alternatives which can achieve low supply line current THD(total harmonic distortion) too. Moreover, this paper also proposes a few passive hamonic counteracting networks for multi single phase rectifiers which are connected in parallel.
文摘Conditions have been studied under which a polychromatic optical superlattice can form and trap the Coulomb cluster of two strongly interacting ions. In our previous work （Krasnov I V and Kamenshchikov L P 2014 Opt. Comm. 312 192） this new all-optical method of obtaining and confining the Coulomb clusters was demonstrated by numerical simulations for special values of the optical superlattice parameters and in the case of Yb ions. In the present paper the conditions are explicitly formulated, under which the long-lived two-ion cluster in the superlattice cell is formed. The peculiarity of these conditions is the renormalization of the ion-ion Coulomb interaction. Notably, the renormalized Coulomb force is determined by the effective charge which depends on the light field parameters and can strongly differ from the ＂bare＂ ion charge. This result can be accounted for by the combined manifestation of the quantum fluctuations of optical forces, nonlinear dependence of these forces on the velocity, and non-Maxwellian （Tsallis type） velocity distribution of the ions in the optical superlattice. Explicit analytical formulas are also obtained for the parameters of the optical two-ion cluster.
基金Deanship of Scientific Research at King Khalid University for funding this work through Large Group Research Project under Grant Number RGP2/162/44.
文摘Security systems are the need of the hour to protect data from unauthorized access.The dissemination of confidential information over the public network requires a high level of security.The security approach such as steganography ensures confidentiality,authentication,integrity,and non-repudiation.Steganography helps in hiding the secret data inside the cover media so that the attacker can be confused during the transmission process of secret data between sender and receiver.Therefore,we present an efficient hybrid security model that provides multifold security assurance.To this end,a rectified Advanced Encryption Standard(AES)algorithm is proposed to overcome the problems existing in AES such as pattern appearance and high computations.The modified AES is used for the encryption of the stego image that contains the digitally signed encrypted secret data.The enciphering and deciphering of the secret data are done using the Rivest–Shamir–Adleman(RSA)algorithm.The experiments are conducted on the images of the USC-SIPI standard image database.The experimental results prove that the proposed hybrid system outperforms other SOTA(state-of-the-art)approaches.
