3115667
Synchronization of Rikitake Chaotic Attractor via Partial System States
This paper treats the chaotic synchronization problem for Rikitake chaotic systems via unidirectional coupling with partial systems states. Two control approaches, namely the self coupling of single state variable and nonlinear feedback controller with partial systems states, are investigated. Based on the Lyapunov stability technique, control laws based on single variable of driven system are derived such that the two identical Rikitake chaotic systems are asymptotically synchronized, where the control scheme doesn't need additional energy and it just relies on the self coupling of single state variable of the chaotic systems. Meanwhile, the complete synchronization for two identical Rikitake chaotic systems by feedback control laws with partial systems states is also derived using the conditions of asymptotical stability and exponential stability. Finally, numerical experimental results of two synchronized Rikitake chaotic systems are presented.
31796281
Reliable Robust Controller Design for Nonlinear State-Delayed Systems Based on Neural Networks
An approach is investigated for the adaptive guaranteed cost control design for a class of nonlinear state-delayed systems. The nonlinear term is approximated by a linearly parameterized neural networks( LPNN). A linear state feedback H∞ control law is presented. An adaptive weight adjustment mechanism for the neural networks is developed to ensure H∞ regulation performance. It is shown that the control gain matrices and be transformed into a standard linear matrix inequality problem and solved via a developed recurrent neural network.
21487383
Coordinated Collective Motion of Groups of Autonomous Mobile Robots with Directed Interconnected Topology
Coordinated collective motion of groups of autonomous mobile robots is studied. A qualitative analysis for the collective dynamics of multiple autonomous robots with directed interconnected topology using nearest neighbor rules is given. A necessary and sufficient graphical condition is proposed to guarantee that the headings of all robots converge to the same heading. The graph having a globally reachable node plays a crucial role in convergence analysis. Furthermore, we show that the globally reachable node having no neighbors serves as a group leader as a special case
10763979
Flocking Motion of Mobile Agents with a Leader Based on Distance-Dependent Adjacency Matrix
In this study, a novel procedure is presented for control and analysis of multiple autonomous agents with point mass dynamics achieving flocking motion with a time variant leader. Two control laws are proposed for a group of autonomous agents to achieve flocking formations related to two different centers (mass center and geometric center) of the flock. The first one is designed for flocking motion based on mass center and the second for geometric center. Distance-dependent adjacency matrix is used to quantify the way agents influence each other. Theoretical analysis is established to indicate the stability (cohesiveness, collision avoidance and velocity matching) of the control systems using classical Lyapunov theory. Finally, a simulation example is demonstrated to validate the theoretical results.
25796104
Classification of Cancer Types Based on Decision Tree Analysis of Gene Function Expression Profiles
17432242
Opportunistic Optical Hyperchannel and Its Distributed QoS Assuring Access Control
Light-trail is proposed as a candidate to carry IP traffic over wavelength-division multiplexing optical networks given its capability of enabling high-speed provisioning and accommodating multigranularity traffic. In a light-trail, the optical shutters at the start node and the end node are configured to be in OFF state and the optical shutters at the intermediate nodes are configured to be in ON state. Thus, an optical bus is formed, allowing traffic multiplexing without the state change of any optical shutter. This, however, limits the system throughput and also makes it impossible to implement a fully distributed medium access control (MAC) protocol to assure quality of service (QoS) in a light-trail. With the recent development on ultrafast optical shutter, we propose an improved light-trail architecture, called opportunistic hyperchannel in this paper. In an opportunistic hyperchannel, an intermediate node can dynamically control its optical shutter which makes it possible to design a fully distributed QoS assuring MAC protocol. We then present a QoS assuring distributed dynamic scheduling protocol, namely, minimum source round robin (minSrcRR) protocol, for opportunistic hyperchannels. Theoretical analysis on the effectiveness of the proposed QoS assuring protocol and the worst-case delay bound are also derived in this paper. The simulation results quantitatively demonstrate the advantage of opportunistic hyperchannels and the effectiveness of minSrcRR protocol.
725973
Transcript-level annotation of Affymetrix probesets improves the interpretation of gene expression data
BackgroundThe wide use of Affymetrix microarray in broadened fields of biological research has made the probeset annotation an important issue. Standard Affymetrix probeset annotation is at gene level, i.e. a probeset is precisely linked to a gene, and probeset intensity is interpreted as gene expression. The increased knowledge that one gene may have multiple transcript variants clearly brings up the necessity of updating this gene-level annotation to a refined transcript-level.ResultsThrough performing rigorous alignments of the Affymetrix probe sequences against a comprehensive pool of currently available transcript sequences, and further linking the probesets to the International Protein Index, we generated transcript-level or protein-level annotation tables for two popular Affymetrix expression arrays, Mouse Genome 430A 2.0 Array and Human Genome U133A Array. Application of our new annotations in re-examining existing expression data sets shows increased expression consistency among synonymous probesets and strengthened expression correlation between interacting proteins.ConclusionBy refining the standard Affymetrix annotation of microarray probesets from the gene level to the transcript level and protein level, one can achieve a more reliable interpretation of their experimental data, which may lead to discovery of more profound regulatory mechanism.
16267058
Petroleum-contaminated groundwater remediation systems design: A data envelopment analysis based approach
Groundwater contamination is one of important environmental problems at petroleum-related sites, which is causing more and more attention. It can bring serious adverse effects on the environment and human health. Design of a groundwater remediation system is desired for supporting the management of petroleum-contaminated sites. Due to high remediation cost and extensive alternatives, efficient remediation design needs to be determined. Data envelopment analysis (DEA) is an approach to measure the relative efficiencies of decision-making units (DMUs) with multiple inputs and multiple outputs without underlying assumptions. However, few of these studies were applied to the design of groundwater remediation systems, where efficient alternatives for remediation systems design need to be determined. This paper proposes a hybrid decision support approach based on data envelopment analysis to determine the most preferable design alternatives for groundwater remediation systems. The total remediation system cost, amount of additional wells, and manpower requirements will be employed as the input variables, while the removal efficiency and technical feasibility as the output variables. The proposed approach will be applied to a case study of designing a groundwater remediation system at a petroleum-contaminated site in western Canada. The most preferable design alternative can be obtained to provide effective decision support for cleaning up the contaminated site.
3506701
Color texture moments for content-based image retrieval
We adopt a local Fourier transform as a texture representation scheme and derive eight characteristic maps for describing different aspects of cooccurrence relations of image pixels in each channel of the (SVcosH, SVsinH, V) color space. Then we calculate the first and second moments of these maps as a representation of the natural color image pixel distribution, resulting in a 48-dimensional feature vector. The novel low-level feature is named color texture moments (CTM), which can also be regarded as a certain extension to color moments in eight aspects through eight orthogonal templates. Experiments show that this new feature can achieve good retrieval performance for CBIR.