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.
18580310
1-Persistent Collision-Free CSMA Protocols for Opportunistic Optical Hyperchannels
Recently, a new WDM optical network infrastructure named SMART [1], which is capable of dynamically setting up, modifying, and tearing down optical connections, was proposed. The performance of SMART is determined by the performance of its hyperchannels, which are essentially optical buses or light-trails. Previously proposed CSMA protocols for unidirectional optical buses can be used as distributed medium access control protocols for hyperchannels. However, these protocols are either unfair, or not work-conserving. In this paper, we propose a class of work-conserving, collision-free, and fair CSMA protocols for opportunistic hyperchannels which are tailored hyperchannels for SMART. We show that the performances of our proposed protocols are much better than that of p i -persistent CSMA and that of priority-based CSMA protocol in terms of throughput and fairness.
2034529
Maximizing Throughput of an Optical Opportunistic Hyperchannel Subject to QoS Constraint
Opportunistic hyperchannel was proposed as an improvement of light-trail to carry IP traffic over wavelength division multiplexing (WDM) optical networks given its capability of enabling high speed provisioning and accommodating multi- granularity traffic. In an opportunistic hyperchannel, 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 can be self-adjusted to be in ON/OFF according to actual traffic. With this ability, an opportunistic hyperchannel can be dynamically divided into multiple segments, and each segment can independently accommodate a request. Thus, an opportunistic hyperchannel can amplify the system throughput. In this paper, we present a centralized dynamic scheduling protocol named prioritized maximum independent set (PMIS), and introduce a data structure called 2-dimensional priority search tree (2D-PST) that supports PMIS. With 2D-PST, one round of PMIS can be carried out in O(k . log n . log m) time to maximize the system throughput under the constraint of assuring quality of service (QoS) for opportunistic hyperchannels. The simulation results quantitatively demonstrate the effectiveness of PMIS protocol.
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.
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.
16456710
News Summarization Based on Semantic Similarity Measure
This paper proposed a new method of news summarization based on semantic similarity measure. It used Latent semantic indexing (LSI) to measure sentence similarity, then it used Singular Value Decomposition (SVD) to reduce the dimension of the word-sentence matrix, it used new clustering algorithm to cluster all the sentences. It ordered all the sentences according to their relevant positions in the original document. Experimental result shows that the proposed method can improve the performance of summary.
28503977
Adoption of Cognitive Radio Scheme to Class-Based Call Admission Control
By using cognitive radio technology, opportunistic spectrum access has the potential to solve the underused spectrum problem. In this paper, by first introducing a specific cognitive radio scheme, we analyze the secondary user's capacity and the collision probability. Employing this scheme, we build two call admission control models for three classes of service, namely, handoff voice calls, new voice calls and data calls. We show that they achieve improved blocking probability and throughput by exploiting the cognitive radio scheme. Further, we show a tradeoff between collision probability and blocking/throughput in the call admission control.
32202333
A Clustering-Based Approach for Tracing Object-Oriented Design to Requirement
Capturing the traceability relationship between software requirement and design allows developers to check whether the design meets the requirement and to analyze the impact of requirement changes on the design. This paper presents an approach for identifying the classes in object-oriented software design that realizes a given use case, which leverages ideas and technologies from Information Retrieval (IR) and Text Clustering area. First, we represent the use case and all classes as vectors in a vector space constructed with the keywords coming from them. Then, the classes are clustered based on their semantic relevance and the cluster most related to the use case is identified. Finally, we supplement the raw cluster by analyzing structural relationships among classes. We conduct an experiment by using this clustering-based approach to a system - Resource Management Software. We calculate and compare the precision and recall of our approach and nonclustering approaches, and get promising results.