Sampled-data fuzzy controller for continuous nonlinear systems

The sampled-data fuzzy control of nonlinear systems is presented. The consequents of the fuzzy controller rules are linear sampled-data sub-controllers. As a result, the fuzzy controller is a weighted sum of some linear sampled-data sub-controllers that can be implemented by a microcontroller or a digital computer to lower the implementation cost. Consequently, a hybrid fuzzy controller consisting of continuous-time grades of memberships and discrete-time sub-controller is obtained. The system stability of the fuzzy control system is investigated on the basis of Lyapunov-based approach. The sampling activity introduces discontinuity to complicate the system dynamics and make the stability analysis difficult. The proposed fuzzy controller exhibits a favourable property to alleviate the conservativeness of the stability analysis. Furthermore, linear matrix inequality-based performance conditions are derived to guarantee the system performance of the fuzzy control system. An application example is given to illustrate the merits of the proposed approac

Approximately Median-Unbiased Estimation of Autoregressive Models with Applications to U.S. Macroeconomic and Financial Time Series

This paper introduces approximately median-unbiased estimators for univariate AR( p ) models with time trends. Confidence intervals also are considered. The methods are applied to the Nelson–Plosser macroeconomic data series, the extended Nelson–Plosser macroeconomic data series, and some annual stock dividend and price series. The results show that most of the series exhibit substantially greater persistence than least squares estimates and some Bayesian estimates suggest. For example, for the extended Nelson–Plosser data set, eight of the fourteen series are estimated to have a unit root, while six are estimated to be trend stationary. In contrast, the least squares estimates indicate trend stationarity for all of the series

The distillable entanglement of multiple copies of Bell states

It is impossible to discriminate four Bell states through local operations and classical communication (LOCC), if only one copy is provided. To complete this task, two copies will suffice and be necessary. When $n$ copies are provided, we show that the distillable entanglement is exactly $n-2$.Comment: An argument in the original paper is replaced by a procedure of strict proo

PRIVACY ISSUES IN ONLINE SOCIAL NETWORKS: USER BEHAVIORS AND THIRD-PARTY APPLICATIONS

In contemporary society, social networking websites has developed dramatically and became an indispensable component in our daily life. Since it can help create a more feature-rich online social community, third-party service has been widely adopted in online social networks (OSNs). Integrating these third-party sites and applications has not only extended business of both social network server and third party and but also promises to break down the garden walls of social-networking sites. While at the same time it dramatically raises concerns on privacy leakage. This article mainly focuses on the privacy disclosure issues caused by user’s behavior and third-party applications and websites. On the one hand, because of the diversity of usage behaviors, the revelation of personal information varies significantly. A survey is conducted to present empirical and quantitative result. On the other hand, the access mechanism between OSN and third party is not perfect enough. Besides, it could be a potential source of privacy leak that third-party services sometimes act as advertisers and information aggregators of a user\u27s traversals. The relevant reasons and internal and external threats are presented. Finally, possible solutions to reduce the increasing information disclosure are provided. Actions should be taken along three fronts: the government, the users themselves as well as the third parties

Optimally Conclusive Discrimination of Non-orthogonal Entangled States Locally

We consider one copy of a quantum system prepared with equal prior probability in one of two non-orthogonal entangled states of multipartite distributed among separated parties. We demonstrate that these two states can be optimally distinguished in the sense of conclusive discrimination by local operations and classical communications(LOCC) alone. And this proves strictly the conjecture that Virmani et.al. [8] confirmed numerically and analytically. Generally, the optimal protocol requires local POVM operations which are explicitly constructed. The result manifests that the distinguishable information is obtained only and completely at the last operation and all prior ones give no information about that state.Comment: 4 pages, no figure, revtex. few typos correcte

A Necessary And Sufficient Condition of Distillability with unite fidelity from Finite Copies of a Mixed State: The Most Efficient Purification Protocol

It is well known that any entangled mixed state in $2\otimes 2$ systems can be purified via infinite copies of the mixed state. But can one distill a pure maximally entangled state from finite copies of a mixed state in any bipartite system by local operation and classical communication? This is more meaningful in practical application. We give a necessary and sufficient condition of this distillability. This condition can be expressed as: there exists distillable-subspaces. According to this condition, one can judge whether a mixed state is distillable or not easily. We also analyze some properties of distillable-subspaces, and discuss the most efficient purification protocols. Finally, we discuss the distillable enanglement of two-quibt system for the case of finite copies.Comment: a revised versio

Local Concurrent Error Detection and Correction in Data Structures Using Virtual Backpointers

Coordinated Science Laboratory was formerly known as Control Systems LaboratorySDIO/IST managed by the Office of Naval Research / N00014-86-K-0519National Aeronautics and Space Administration / NASA NAG 1-602Joint Services Electronics Program / N00014-84-C-014

Differential Geometry of Bipartite Quantum States

We investigate the differential geometry of bipartite quantum states. In particular the manifold structures of pure bipartite states are studied in detail. The manifolds with respect to all normalized pure states of arbitrarily given Schmidt ranks or Schmidt coefficients are explicitly presented. The dimensions of the related manifolds are calculated.Comment: 10 page

Degree of entanglement for two qubits

In this paper, we present a measure to quantify the degree of entanglement for two qubits in a pure state.Comment: 5 page