In this paper an analytical solution for the stability of the fully developed flow drive in a magneto-hydro-dynamic pump with pulsating transverse Eletro-magnetic fields is presented. To do this, a theoretical model o...In this paper an analytical solution for the stability of the fully developed flow drive in a magneto-hydro-dynamic pump with pulsating transverse Eletro-magnetic fields is presented. To do this, a theoretical model of the flow is developed and the analytical results are obtained for both the cylindrical and Cartesian configurations that are proper to use in the propulsion of marine vessels. The governing parabolic momentum PDEs are transformed into an ordinary differential equation using approximate velocity distribution. The numerical results are obtained and asymptotic analyses are built to discover the mathematical behavior of the solutions. The maximum velocity in a magneto-hydro-dynamic pump versus time for various values of the Stuart number, electro-magnetic interaction number, Reynolds number, aspect ratio, as well as the magnetic and electrical angular frequency and the shift of the phase angle is presented. Results show that for a high Stuart number there is a frequency limit for stability of the fluid flow in a certain direction of the flow. This stability frequency is dependent on the geometric parameters of a channel.展开更多
We discuss some methods for constructing recommender systems. An important feature of the methods studied here is that we assume the availability of a description, representation, of the objects being considered for r...We discuss some methods for constructing recommender systems. An important feature of the methods studied here is that we assume the availability of a description, representation, of the objects being considered for recommendation. The approaches studied here differ from collaborative filtering in that we only use preferences information from the individual for whom we are providing the recommendation and make no use the preferences of other collaborators. We provide a detailed discussion of the construction of the representation schema used. We consider two sources of information about the users preferences. The first are direct statements about the type of objects the user likes. The second source of information comes from ratings of objects which the user has experienced.展开更多
Pure inertial navigation system(INS) has divergent localization errors after a long time. In order to compensate the disadvantage, wireless sensor network(WSN) associated with the INS was applied to estimate the mobil...Pure inertial navigation system(INS) has divergent localization errors after a long time. In order to compensate the disadvantage, wireless sensor network(WSN) associated with the INS was applied to estimate the mobile target positioning. Taking traditional Kalman filter(KF) as the framework, the system equation of KF was established by the INS and the observation equation of position errors was built by the WSN. Meanwhile, the observation equation of velocity errors was established by the velocity difference between the INS and WSN, then the covariance matrix of Kalman filter measurement noise was adjusted with fuzzy inference system(FIS), and the fuzzy adaptive Kalman filter(FAKF) based on the INS/WSN was proposed. The simulation results show that the FAKF method has better accuracy and robustness than KF and EKF methods and shows good adaptive capacity with time-varying system noise. Finally, experimental results further prove that FAKF has the fast convergence error, in comparison with KF and EKF methods.展开更多
In agriculture the identification and classification of weed seeds are technically and economically important. This work bears on the study of the morphological characteristics of the widespread weeds seeds in the nor...In agriculture the identification and classification of weed seeds are technically and economically important. This work bears on the study of the morphological characteristics of the widespread weeds seeds in the north east of Algeria （the Setifian high plateau）. Fourteen characteristics were used to identify ninety one species of seeds which belong to nineteen botanical families. The morphological characteristics in which the study was based on are： form, color, size, solidity, brightness, smoothness, seed length, seed width, seed caliber, outgrowths, outgrowths form, outgrowths color, outgrowths length, outgrowths width, weight per 100 seeds. Considerable differences were noticed between the various species of weeds seeds. The study of morphological characteristics of seeds allows identifying the different seeds mixed with cultivated plant, it also allows knowing the various species of weeds in fields. So such studies help to develop different strategies to control weeds.展开更多
This paper focuses on the problem of seeking complete axiomatization for finite processes in the process calculus called symbolic probabilistic π-calculus introduced by Wu,Palamidessi and Lin.We provide inference sys...This paper focuses on the problem of seeking complete axiomatization for finite processes in the process calculus called symbolic probabilistic π-calculus introduced by Wu,Palamidessi and Lin.We provide inference systems for both strong and weak symbolic probabilistic bisimulations and also prove their soundness and completeness.This is the first work,to our knowledge,that provides complete axiomatization for symbolic probabilistic bisimulations in the presence of both nondeterministic and probabilistic choice.展开更多
文摘In this paper an analytical solution for the stability of the fully developed flow drive in a magneto-hydro-dynamic pump with pulsating transverse Eletro-magnetic fields is presented. To do this, a theoretical model of the flow is developed and the analytical results are obtained for both the cylindrical and Cartesian configurations that are proper to use in the propulsion of marine vessels. The governing parabolic momentum PDEs are transformed into an ordinary differential equation using approximate velocity distribution. The numerical results are obtained and asymptotic analyses are built to discover the mathematical behavior of the solutions. The maximum velocity in a magneto-hydro-dynamic pump versus time for various values of the Stuart number, electro-magnetic interaction number, Reynolds number, aspect ratio, as well as the magnetic and electrical angular frequency and the shift of the phase angle is presented. Results show that for a high Stuart number there is a frequency limit for stability of the fluid flow in a certain direction of the flow. This stability frequency is dependent on the geometric parameters of a channel.
文摘We discuss some methods for constructing recommender systems. An important feature of the methods studied here is that we assume the availability of a description, representation, of the objects being considered for recommendation. The approaches studied here differ from collaborative filtering in that we only use preferences information from the individual for whom we are providing the recommendation and make no use the preferences of other collaborators. We provide a detailed discussion of the construction of the representation schema used. We consider two sources of information about the users preferences. The first are direct statements about the type of objects the user likes. The second source of information comes from ratings of objects which the user has experienced.
基金Project(2013AA06A411)supported by the National High Technology Research and Development Program of ChinaProject(CXZZ14_1374)supported by the Graduate Education Innovation Program of Jiangsu Province,ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Pure inertial navigation system(INS) has divergent localization errors after a long time. In order to compensate the disadvantage, wireless sensor network(WSN) associated with the INS was applied to estimate the mobile target positioning. Taking traditional Kalman filter(KF) as the framework, the system equation of KF was established by the INS and the observation equation of position errors was built by the WSN. Meanwhile, the observation equation of velocity errors was established by the velocity difference between the INS and WSN, then the covariance matrix of Kalman filter measurement noise was adjusted with fuzzy inference system(FIS), and the fuzzy adaptive Kalman filter(FAKF) based on the INS/WSN was proposed. The simulation results show that the FAKF method has better accuracy and robustness than KF and EKF methods and shows good adaptive capacity with time-varying system noise. Finally, experimental results further prove that FAKF has the fast convergence error, in comparison with KF and EKF methods.
文摘In agriculture the identification and classification of weed seeds are technically and economically important. This work bears on the study of the morphological characteristics of the widespread weeds seeds in the north east of Algeria （the Setifian high plateau）. Fourteen characteristics were used to identify ninety one species of seeds which belong to nineteen botanical families. The morphological characteristics in which the study was based on are： form, color, size, solidity, brightness, smoothness, seed length, seed width, seed caliber, outgrowths, outgrowths form, outgrowths color, outgrowths length, outgrowths width, weight per 100 seeds. Considerable differences were noticed between the various species of weeds seeds. The study of morphological characteristics of seeds allows identifying the different seeds mixed with cultivated plant, it also allows knowing the various species of weeds in fields. So such studies help to develop different strategies to control weeds.
基金the National Basic Research Program (973) of China (No.2003CB317005)the National Nature Science Foundation of China (Nos.60573002 and 60703033)
文摘This paper focuses on the problem of seeking complete axiomatization for finite processes in the process calculus called symbolic probabilistic π-calculus introduced by Wu,Palamidessi and Lin.We provide inference systems for both strong and weak symbolic probabilistic bisimulations and also prove their soundness and completeness.This is the first work,to our knowledge,that provides complete axiomatization for symbolic probabilistic bisimulations in the presence of both nondeterministic and probabilistic choice.
