Term rewriting and its application to recognizing handwritten Hindu numerals

In this paper the theoretical basis is presented and the implementation of a term rewriting system based on algebraic specifications is described. The input to this system is represented by an algebraic specification language, which forms not only the set of axioms but also the sorts, variables, operators and terms of a specific simulated theory or application. Rewriting and matching mechanisms provide the formal methodology for evaluating terms and proving assertions in an algebraic theory. Specifications are evaluated by interpreting terms by means of rewrite rules. The rules are described by the axioms of the specifications where the finite termination and congruence properties are assumed. A term rewriting system to recognize handwritten Hindu numerals is introduced as a case study. Besides rewriting, a robust algorithm is proposed to segment the numeral's image into strokes based on feature points and to identify cavity features. A syntactic representation (term) of the input image is matched and rewritten against a set of rules. Experimental results proved that the proposed system is tolerant to recognize a variety of numeral shapes with 96% successful recognition rate.     

FA–QABC–MRTA: a solution for solving the multi-robot task allocation problem

Intelligent Service Robotics - The problem of task allocation in a multi-robot system is the situation where we have a set of tasks and a number of robots; then each task is assigned to the...     

A Review of Security in Internet of Things

Wireless Personal Communications - The application of VANET can be divided into two types: security and non-security. Non-secure applications are primarily used to provide entertainment...     

Robustness improvement of component-based cloud computing systems

The Journal of Supercomputing - With the increasing popularity of Cloud computing systems, the demand for highly dependable Cloud applications has increased significantly. For this, reliability and...     

Robust Connectivity-Based Internet of Vehicles Clustering Algorithm

Wireless Personal Communications - Recent advances in networking and the emergence of the Internet of Things (IoT) have facilitated the development of the Internet of Vehicles (IoV), a distributed...     

DCA-DS: A Distributed Clustering Algorithm Based on Dominating Set for Internet of Vehicles

In this paper, we propose a new Distributed Clustering Algorithm Based on Dominating Set (DS) for Internet of Vehicles, called DCA-DS. To construct the DS, DCA-DS algorithm introduces a new parameter, called node span, which represents the number of the node neighbours that are not unclustered, including the node itself. DCA-DS algorithm is based on a simple heuristic method that uses a greedy strategy, where the node having the largest span is included in the DS, therefore it acts as new CH and all its neighbours become Cluster Members (CMs). This process repeats iteratively until there are no unclustered nodes left. Moreover, the node, which can hear two CHs or more, will act as Cluster Gateway (CG). Furthermore, DCA-DS algorithm takes care of the maintenance phase to keep clusters stability and structure. The proposed approach is implemented in NS-2 network simulator and VanetMobiSim mobility simulator to evaluate its performance.

     

A study of achievable speedup in distributed simulation via NULLmessages

The results of an experimental study on distributed simulation of three open queuing networks are reported. The distributed simulation scheme considered is a simple variation of the scheme given by K.M. Chandy and J. Misra (1979) using NULL messages. A new approach is used to study the relationship between the overhead and performance of a distributed simulator, and the approach is illustrated by studying these three example networks. Two measures of ideal speedup of distributed simulation over sequential simulation are defined and measured. These values of ideal speedup are much less than simply the number of processors, and hence provide a more realistic value for the ideal speedup     

A fault tolerant routing scheme for hypercubes

An efficient distributed fault‐tolerant routing algorithm for the hypercube is proposed based on the existence of a complete set of node‐disjoint paths between any two nodes. Node failure and repairs may occur dynamically provided that the total number of faulty nodes at any time is less than the node‐connectivity n of the n‐cube. Each node maintains for each possible destination which of the associated node‐disjoint paths to use. When a message is blocked by a node failure, the source node is warned and requested to switch to a different node‐disjoint path. The methods used to identify the paths, to propagate node failure information to source nodes, and to switch from one routing path to another incur little communication and computation overhead. We show that if the faults occur reasonably apart in time, then all messages will be routed on optimal or near optimal paths. In the unlikely case where many faults occur in a short period, the algorithm still delivers all messages but via possibly longer paths. An extension of the obtained algorithm to handle link failures in addition to node failures is discussed. We also show how to adapt the algorithm to n‐ary n‐cube networks. The algorithm can be similarly adapted to any interconnection network for which there exists a simple characterization of node‐disjoint paths between its nodes. This revised version was published online in June 2006 with corrections to the Cover Date.