Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its ave...Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its average queue length is closely related to the load level. This paper proposes an effective fuzzy congestion control algorithm based on fuzzy logic which uses the pre- dominance of fuzzy logic to deal with uncertain events. The main advantage of this new congestion control algorithm is that it discards the packet dropping mechanism of RED, and calculates packet loss according to a preconfigured fuzzy logic by using the queue length and the buffer usage ratio. Theo- retical analysis and Network Simulator (NS) simulation results show that the proposed algorithm achieves more throughput and more stable queue length than traditional schemes. It really improves a router's ability in network congestion control in IP network.展开更多
This paper used Active Radio Frequency Identification （Active RFID） technology to identify in which rooms fathers and their chitd tend to stay together and talk, and in which rooms they stay separately in seven one-...This paper used Active Radio Frequency Identification （Active RFID） technology to identify in which rooms fathers and their chitd tend to stay together and talk, and in which rooms they stay separately in seven one-child families living in Chinese urban apartment houses. The father was found to stay together with the child 0.5%-25% of the time when both father and chitd stayed at home. The use of the living room as the place in which the child stays with the father and tatks was found to be highest （five out of seven families）, fotlowed by the dining room and the child＇s room. In over half of the cases when the child stays with,the father in the living room or dining room and either of them tatk, the chitd spoke over 1.6 times more than the father. However, in the child＇s room, the child always spoke tess than the father, and the duration of the child＇s speech was less than 70% of that of the father. Findings showed that the instances in which child and father stay in different rooms fell into two groups. First, five of the seven subject fathers tended to stay in the living room, whereas the children stayed either in their room or in their parents＇ room to use the PC. Second, two fathers stayed in the studio or dining room to work, while their chitdren stayed in the living room or their own rooms. For both groups, the duration展开更多
This paper first suggests the use of the Fourier frequency transmission method of two dimensions function （ 2D FFT） to analyze radial rotating errors that occurred in a rotor. Based on this method a magnetic rotor i...This paper first suggests the use of the Fourier frequency transmission method of two dimensions function （ 2D FFT） to analyze radial rotating errors that occurred in a rotor. Based on this method a magnetic rotor is measured. The authors point out that the main cause to affect radial rotating accuracy of the rotating shaft at a high speed is the dynamic imbalance of the shaft itself. Finally the feedforward control scheme is suggested to improve the accuracy of the shaft in an active magnetic bearing （ AMB ） system.展开更多
The classical theory of mass-spring-damper-type dynamical systems on the ordinary flat space R^3 may be generalized to higher-dimensional Riemannian manifolds by reformulating the basic underlying physical principles ...The classical theory of mass-spring-damper-type dynamical systems on the ordinary flat space R^3 may be generalized to higher-dimensional Riemannian manifolds by reformulating the basic underlying physical principles through differential geometry.Nonlinear dynamical systems have been studied in the scientific literature because they arise naturally from the modeling of complex physical structures and because such dynamical systems constitute the basis for several modern applications such as the secure transmission of information.The flows of nonlinear dynamical systems may evolve over time in complex,non-repeating(although deterministic) patterns.The focus of the present paper is on formulating the general equations that describe the dynamics of a point-wise particle sliding on a Riemannian manifold in a coordinate-free manner.The paper shows how the equations particularize in the case of some manifolds of interest in the scientific literature,such as the Stiefel manifold and the manifold of symmetric positive-definite matrices.展开更多
基金Supported by the National High Technology Research and Development of China (863 Program) (No.2003AA121560)the High Technology Research and Development Program of Jiangsu Province (No.BEG2003001).
文摘Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its average queue length is closely related to the load level. This paper proposes an effective fuzzy congestion control algorithm based on fuzzy logic which uses the pre- dominance of fuzzy logic to deal with uncertain events. The main advantage of this new congestion control algorithm is that it discards the packet dropping mechanism of RED, and calculates packet loss according to a preconfigured fuzzy logic by using the queue length and the buffer usage ratio. Theo- retical analysis and Network Simulator (NS) simulation results show that the proposed algorithm achieves more throughput and more stable queue length than traditional schemes. It really improves a router's ability in network congestion control in IP network.
文摘This paper used Active Radio Frequency Identification （Active RFID） technology to identify in which rooms fathers and their chitd tend to stay together and talk, and in which rooms they stay separately in seven one-child families living in Chinese urban apartment houses. The father was found to stay together with the child 0.5%-25% of the time when both father and chitd stayed at home. The use of the living room as the place in which the child stays with the father and tatks was found to be highest （five out of seven families）, fotlowed by the dining room and the child＇s room. In over half of the cases when the child stays with,the father in the living room or dining room and either of them tatk, the chitd spoke over 1.6 times more than the father. However, in the child＇s room, the child always spoke tess than the father, and the duration of the child＇s speech was less than 70% of that of the father. Findings showed that the instances in which child and father stay in different rooms fell into two groups. First, five of the seven subject fathers tended to stay in the living room, whereas the children stayed either in their room or in their parents＇ room to use the PC. Second, two fathers stayed in the studio or dining room to work, while their chitdren stayed in the living room or their own rooms. For both groups, the duration
文摘This paper first suggests the use of the Fourier frequency transmission method of two dimensions function （ 2D FFT） to analyze radial rotating errors that occurred in a rotor. Based on this method a magnetic rotor is measured. The authors point out that the main cause to affect radial rotating accuracy of the rotating shaft at a high speed is the dynamic imbalance of the shaft itself. Finally the feedforward control scheme is suggested to improve the accuracy of the shaft in an active magnetic bearing （ AMB ） system.
基金supported by the Grant 'Ricerca Scientifica di Ateneo(RSA-B)2014'
文摘The classical theory of mass-spring-damper-type dynamical systems on the ordinary flat space R^3 may be generalized to higher-dimensional Riemannian manifolds by reformulating the basic underlying physical principles through differential geometry.Nonlinear dynamical systems have been studied in the scientific literature because they arise naturally from the modeling of complex physical structures and because such dynamical systems constitute the basis for several modern applications such as the secure transmission of information.The flows of nonlinear dynamical systems may evolve over time in complex,non-repeating(although deterministic) patterns.The focus of the present paper is on formulating the general equations that describe the dynamics of a point-wise particle sliding on a Riemannian manifold in a coordinate-free manner.The paper shows how the equations particularize in the case of some manifolds of interest in the scientific literature,such as the Stiefel manifold and the manifold of symmetric positive-definite matrices.
