For the gray attributes of the equipment program and its difficulty to carry out the quantitative assessment of the equipment program information, the gray relation projection method is simply reviewed. Combining the ...For the gray attributes of the equipment program and its difficulty to carry out the quantitative assessment of the equipment program information, the gray relation projection method is simply reviewed. Combining the super-data envelopment analysis（DEA） model and the gray system theory, a new super-DEA for measuring the weight is proposed, and a gray relation projection model is established to rank the equipment programs. Finally, this approach is used to evaluate the equipment program. The results are verified valid and can provide a new way for evaluating the equipment program.展开更多
In terms of the diffusive process of the gases injected from rocket exhaust into the ionosphere and the relevant chemical reactions between the gases and the composition of ionosphere, the modifications in ionosphere ...In terms of the diffusive process of the gases injected from rocket exhaust into the ionosphere and the relevant chemical reactions between the gases and the composition of ionosphere, the modifications in ionosphere caused by the injected hydrogen and carbon dioxide gas from the rocket exhaust are investigated. The results show that the diffusive process of the injected gases at the ionospheric height is very fast, and the injected gases can lead to a local depletion of electron concentration in the F-region. Furthermore, the plasma ＇hole＇ caused by carbon dioxide is larger, deeper and more durable than that by the hydrogen.展开更多
In magnetized collisional plasmas, owing to the differences between attenuations of left- and right-handed polarized waves, the Faraday rotation angle differs from that in collision- aless plasmas. In this paper, the ...In magnetized collisional plasmas, owing to the differences between attenuations of left- and right-handed polarized waves, the Faraday rotation angle differs from that in collision- aless plasmas. In this paper, the attenuation rates of left- and right-handed polarized waves are analyzed, and the Faraday angle is expressed by the real and imaginary parts of refractive index of the magnetized plasma, with clear physics meaning. Furthermore, the dependence of Faraday angle on collision frequency is calculated and discussed.展开更多
Numerical simulations by the code of Object-Oriented PIC （Particle-in-Cell） and the Monte Carlo Collision （MCC） method were carried out in order to obtain an insight into the characteristics of plasmas generated b...Numerical simulations by the code of Object-Oriented PIC （Particle-in-Cell） and the Monte Carlo Collision （MCC） method were carried out in order to obtain an insight into the characteristics of plasmas generated by glow discharges in low pressure helium in a four-anode DC glow discharge device. The results show that, the pressure, the external mirror magnetic field, and the virtual breadth of the annular electrode affect the radial distribution of the plasma density and temperature. The simulations are instructive for further experiments.展开更多
Abstract In the four-anode device, the mirror magnetic field affects the characteristics of charged particles motion, so that the current-voltage relations of glow discharge are changed. Firstly, the discharge device ...Abstract In the four-anode device, the mirror magnetic field affects the characteristics of charged particles motion, so that the current-voltage relations of glow discharge are changed. Firstly, the discharge device is introduced, and the distribution of mirror magnetic field generated by the loops surrounding the discharge chamber is presented. Both the discharge current-voltage characteristics and the radial distributions of electron density are measured, respectively, with/without the magnetic field. When the discharge occurs in a 99.99% helium with a pressure ranging from 100 Pa to 800 Pa without magnetic field, the voltage, sustaining a certain abnormal glow discharge current, decreases with the increase in gas pressure. With a mirror magnetic field of certain intensity, the discharge voltage increases with the current in a rate slower than that without the magnetic field. Moreover, when the magnetic field intensity increases, the discharge voltage first decreases then increases. Simultaneously, the mirror magnetic field affects the moving characteristics of charged particles, and causes a more inhomogeneous electron density.展开更多
We develop an improved design of thin gap chamber （TGC） simulation signal source. To further simulate the feature of TGC detector, a novel thought is proposed. The TGC source has 256 channels. Every channel can rand...We develop an improved design of thin gap chamber （TGC） simulation signal source. To further simulate the feature of TGC detector, a novel thought is proposed. The TGC source has 256 channels. Every channel can randomly output the signal in 25 ns. The design is based on true random number generator （TRNG）. Considering the electrical connection between the TGC source and the developing trigger electronics, the GFZ connector is used. The experimental results show that the improved TGC simulation signal source can uniformly output the random signal in every channel. The output noise is less than 3 mVrms.展开更多
In this paper,a novel secret data-driven carrier-free(semi structural formula)visual secret sharing(VSS)scheme with(2,2)threshold based on the error correction blocks of QR codes is investigated.The proposed scheme is...In this paper,a novel secret data-driven carrier-free(semi structural formula)visual secret sharing(VSS)scheme with(2,2)threshold based on the error correction blocks of QR codes is investigated.The proposed scheme is to search two QR codes that altered to satisfy the secret sharing modules in the error correction mechanism from the large datasets of QR codes according to the secret image,which is to embed the secret image into QR codes based on carrier-free secret sharing.The size of secret image is the same or closest with the region from the coordinate of(7,7)to the lower right corner of QR codes.In this way,we can find the QR codes combination of embedding secret information maximization with secret data-driven based on Big data search.Each output share is a valid QR code which can be decoded correctly utilizing a QR code reader and it may reduce the likelihood of attracting the attention of potential attackers.The proposed scheme can reveal secret image visually with the abilities of stacking and XOR decryptions.The secret image can be recovered by human visual system(HVS)without any computation based on stacking.On the other hand,if the light-weight computation device is available,the secret image can be lossless revealed based on XOR operation.In addition,QR codes could assist alignment for VSS recovery.The experimental results show the effectiveness of our scheme.展开更多
Differently from pure data encryption,secret image sharing(SIS)mainly focuses on image protection through generating a secret image into n shadow images(shares)distributed to n associated participants.The secret image...Differently from pure data encryption,secret image sharing(SIS)mainly focuses on image protection through generating a secret image into n shadow images(shares)distributed to n associated participants.The secret image can be reconstructed by collecting sufficient shadow images.In recent years,many SIS schemes are proposed,among which Shamir’s polynomial-based SIS scheme and visual secret sharing(VSS)also called visual cryptography scheme(VCS)are the primary branches.However,as the basic research issues,the security analysis and security level classification of SIS are rarely discussed.In this paper,based on the study of image feature and typical SIS schemes,four security levels are classified as well as the security of typical SIS schemes are analyzed.Furthermore,experiments are conducted to evaluate the efficiency of our analysis by employing illustrations and evaluation metrics.展开更多
Shamir proposed a classic polynomial-based secret sharing(SS)scheme,which is also widely applied in secret image sharing(SIS).However,the following researchers paid more attention to the development of properties,such...Shamir proposed a classic polynomial-based secret sharing(SS)scheme,which is also widely applied in secret image sharing(SIS).However,the following researchers paid more attention to the development of properties,such as lossless recovery,rather than the principle of Shamir’s polynomial-based SS scheme.In this paper,we introduce matrix theory to analyze Shamir’s polynomial-based scheme as well as propose a general(k,n)threshold SIS construction based on matrix theory.Besides,it is proved that Shamir’s polynomial-based SS scheme is a special case of our construction method.Both experimental results and analyses are given to demonstrate the effectiveness of the proposed construction method.展开更多
Secret image sharing (SIS) can be utilized to protect a secret image during transmit in the public channels. However, classic SIS schemes, e.g., visual secret sharing (VSS) and polynomial-based scheme, are not suitabl...Secret image sharing (SIS) can be utilized to protect a secret image during transmit in the public channels. However, classic SIS schemes, e.g., visual secret sharing (VSS) and polynomial-based scheme, are not suitable for progressive encryption of greyscale images in noisy environment, since they will result in different problems, such as lossy recovery, pixel expansion, complex computation, "All-or-Nothing"and robustness. In this paper, a novel progressive secret sharing (PSS)method based on the linear congruence equation, namely LCPSS, is proposed to solve these problems. LCPSS is simple designed and easy to realize, but naturally has many great properties, e.g., (k, n) threshold,progressive recovery, lossless recovery, lack of robustness and simple computation.展开更多
The visual quality of the recovered secret image is usually evaluated by contrast in visual cryptography (VC). Precisely, the reconstructed secret image can be recognized as the original secret image when contrast is ...The visual quality of the recovered secret image is usually evaluated by contrast in visual cryptography (VC). Precisely, the reconstructed secret image can be recognized as the original secret image when contrast is greater than zero. It is important for the user to know the clarity of the revealed secret image corresponding to different contrast values. In this paper, the clarity corresponding to contrast is investigated through conducting subjective evaluation scores and objective evaluation indexes, which can be extended to general applications.展开更多
Personality prediction on social network has become a hot topic.At present,most studies are using single-task classification/regression machine learning.However,this method ignores the potential association between mu...Personality prediction on social network has become a hot topic.At present,most studies are using single-task classification/regression machine learning.However,this method ignores the potential association between multiple tasks.Also an ideal prediction result is difficult to achieve based on the small scale training data,since it is not easy to get a lot of social network data with personality label samples.In this paper,a robust multi-task learning method(RMTL)is proposed to predict Big-Five personality on Micro-blog.We aim to learn five tasks simultaneously by extracting and utilizing appropriate shared information among multiple tasks as well as identifying irrelevant tasks.For a set of Sina Micro-blog users’information and personality labeled data retrieved by questionnaire,we validate the RMTL method by comparing it with 4 single-task learning methods and the mere multi-task learning.Our experiment demonstrates that the proposed RMTL can improve the precision rate,recall rate of the prediction and F value.展开更多
基金supported by the National Natural Science Foundation of China(7107307971222106+2 种基金70901069)the Research Foundation of the National Excellent Doctoral Dissertation of Chinathe Research Fund for the Doctoral Program of Higher Education(20133402110028)
文摘For the gray attributes of the equipment program and its difficulty to carry out the quantitative assessment of the equipment program information, the gray relation projection method is simply reviewed. Combining the super-data envelopment analysis（DEA） model and the gray system theory, a new super-DEA for measuring the weight is proposed, and a gray relation projection model is established to rank the equipment programs. Finally, this approach is used to evaluate the equipment program. The results are verified valid and can provide a new way for evaluating the equipment program.
基金supported by Pre-research Fund of Weapon and Equipment of China(No.9140A31030310JB39)
文摘In terms of the diffusive process of the gases injected from rocket exhaust into the ionosphere and the relevant chemical reactions between the gases and the composition of ionosphere, the modifications in ionosphere caused by the injected hydrogen and carbon dioxide gas from the rocket exhaust are investigated. The results show that the diffusive process of the injected gases at the ionospheric height is very fast, and the injected gases can lead to a local depletion of electron concentration in the F-region. Furthermore, the plasma ＇hole＇ caused by carbon dioxide is larger, deeper and more durable than that by the hydrogen.
基金supported by Program for New Century Excellent Talents (NCET) of China
文摘In magnetized collisional plasmas, owing to the differences between attenuations of left- and right-handed polarized waves, the Faraday rotation angle differs from that in collision- aless plasmas. In this paper, the attenuation rates of left- and right-handed polarized waves are analyzed, and the Faraday angle is expressed by the real and imaginary parts of refractive index of the magnetized plasma, with clear physics meaning. Furthermore, the dependence of Faraday angle on collision frequency is calculated and discussed.
文摘Numerical simulations by the code of Object-Oriented PIC （Particle-in-Cell） and the Monte Carlo Collision （MCC） method were carried out in order to obtain an insight into the characteristics of plasmas generated by glow discharges in low pressure helium in a four-anode DC glow discharge device. The results show that, the pressure, the external mirror magnetic field, and the virtual breadth of the annular electrode affect the radial distribution of the plasma density and temperature. The simulations are instructive for further experiments.
基金Program for New Century Excellent Talents in University (NCET) of ChinaFundation of the Key Lab of Infrared and Low Temperature Plasma of Anhui Province of China(No.2007A003003U)
文摘Abstract In the four-anode device, the mirror magnetic field affects the characteristics of charged particles motion, so that the current-voltage relations of glow discharge are changed. Firstly, the discharge device is introduced, and the distribution of mirror magnetic field generated by the loops surrounding the discharge chamber is presented. Both the discharge current-voltage characteristics and the radial distributions of electron density are measured, respectively, with/without the magnetic field. When the discharge occurs in a 99.99% helium with a pressure ranging from 100 Pa to 800 Pa without magnetic field, the voltage, sustaining a certain abnormal glow discharge current, decreases with the increase in gas pressure. With a mirror magnetic field of certain intensity, the discharge voltage increases with the current in a rate slower than that without the magnetic field. Moreover, when the magnetic field intensity increases, the discharge voltage first decreases then increases. Simultaneously, the mirror magnetic field affects the moving characteristics of charged particles, and causes a more inhomogeneous electron density.
基金Supported by the State Key Laboratory of Particle Detection and Electronicsthe National Natural Science Foundation of China under Grant No 11375179
文摘We develop an improved design of thin gap chamber （TGC） simulation signal source. To further simulate the feature of TGC detector, a novel thought is proposed. The TGC source has 256 channels. Every channel can randomly output the signal in 25 ns. The design is based on true random number generator （TRNG）. Considering the electrical connection between the TGC source and the developing trigger electronics, the GFZ connector is used. The experimental results show that the improved TGC simulation signal source can uniformly output the random signal in every channel. The output noise is less than 3 mVrms.
文摘In this paper,a novel secret data-driven carrier-free(semi structural formula)visual secret sharing(VSS)scheme with(2,2)threshold based on the error correction blocks of QR codes is investigated.The proposed scheme is to search two QR codes that altered to satisfy the secret sharing modules in the error correction mechanism from the large datasets of QR codes according to the secret image,which is to embed the secret image into QR codes based on carrier-free secret sharing.The size of secret image is the same or closest with the region from the coordinate of(7,7)to the lower right corner of QR codes.In this way,we can find the QR codes combination of embedding secret information maximization with secret data-driven based on Big data search.Each output share is a valid QR code which can be decoded correctly utilizing a QR code reader and it may reduce the likelihood of attracting the attention of potential attackers.The proposed scheme can reveal secret image visually with the abilities of stacking and XOR decryptions.The secret image can be recovered by human visual system(HVS)without any computation based on stacking.On the other hand,if the light-weight computation device is available,the secret image can be lossless revealed based on XOR operation.In addition,QR codes could assist alignment for VSS recovery.The experimental results show the effectiveness of our scheme.
文摘Differently from pure data encryption,secret image sharing(SIS)mainly focuses on image protection through generating a secret image into n shadow images(shares)distributed to n associated participants.The secret image can be reconstructed by collecting sufficient shadow images.In recent years,many SIS schemes are proposed,among which Shamir’s polynomial-based SIS scheme and visual secret sharing(VSS)also called visual cryptography scheme(VCS)are the primary branches.However,as the basic research issues,the security analysis and security level classification of SIS are rarely discussed.In this paper,based on the study of image feature and typical SIS schemes,four security levels are classified as well as the security of typical SIS schemes are analyzed.Furthermore,experiments are conducted to evaluate the efficiency of our analysis by employing illustrations and evaluation metrics.
文摘Shamir proposed a classic polynomial-based secret sharing(SS)scheme,which is also widely applied in secret image sharing(SIS).However,the following researchers paid more attention to the development of properties,such as lossless recovery,rather than the principle of Shamir’s polynomial-based SS scheme.In this paper,we introduce matrix theory to analyze Shamir’s polynomial-based scheme as well as propose a general(k,n)threshold SIS construction based on matrix theory.Besides,it is proved that Shamir’s polynomial-based SS scheme is a special case of our construction method.Both experimental results and analyses are given to demonstrate the effectiveness of the proposed construction method.
文摘Secret image sharing (SIS) can be utilized to protect a secret image during transmit in the public channels. However, classic SIS schemes, e.g., visual secret sharing (VSS) and polynomial-based scheme, are not suitable for progressive encryption of greyscale images in noisy environment, since they will result in different problems, such as lossy recovery, pixel expansion, complex computation, "All-or-Nothing"and robustness. In this paper, a novel progressive secret sharing (PSS)method based on the linear congruence equation, namely LCPSS, is proposed to solve these problems. LCPSS is simple designed and easy to realize, but naturally has many great properties, e.g., (k, n) threshold,progressive recovery, lossless recovery, lack of robustness and simple computation.
文摘The visual quality of the recovered secret image is usually evaluated by contrast in visual cryptography (VC). Precisely, the reconstructed secret image can be recognized as the original secret image when contrast is greater than zero. It is important for the user to know the clarity of the revealed secret image corresponding to different contrast values. In this paper, the clarity corresponding to contrast is investigated through conducting subjective evaluation scores and objective evaluation indexes, which can be extended to general applications.
文摘Personality prediction on social network has become a hot topic.At present,most studies are using single-task classification/regression machine learning.However,this method ignores the potential association between multiple tasks.Also an ideal prediction result is difficult to achieve based on the small scale training data,since it is not easy to get a lot of social network data with personality label samples.In this paper,a robust multi-task learning method(RMTL)is proposed to predict Big-Five personality on Micro-blog.We aim to learn five tasks simultaneously by extracting and utilizing appropriate shared information among multiple tasks as well as identifying irrelevant tasks.For a set of Sina Micro-blog users’information and personality labeled data retrieved by questionnaire,we validate the RMTL method by comparing it with 4 single-task learning methods and the mere multi-task learning.Our experiment demonstrates that the proposed RMTL can improve the precision rate,recall rate of the prediction and F value.
