Ajit K. Mandal

On the correctness issues in two-process mutual exclusion algorithms

Correctness issues in two process mutual exclusion algorithms are investigated. A new theorem is proposed and proved that describes the key concept involved in such algorithms. For the purpose of proving the techniques developed in [3] are used. Result of this theorem is applied to two different algorithms of which one could be proved incorrect. Technique developed in [3] is also used to prove the correct algorithm.

Application of Dijkstra's weakest precondition calculus to Dining Philosophers problem

Dijkstras weakest precondition calculus is used to model the well known Dining Philosophers problem. Process and state definitions are done in such a manner that only the deadlock property of the system is highlighted. Care has been taken to choose the proper details such that it is not too elaborate to obscure the requirements also not be too abstract to mask the actual analytical needs. State transition rules specify the system behavior. Intuitive reasoning as well as formal technique has been applied to get the deadlock condition. Two well known solutions are specified and proved. The proof technique being analytical, its complexity does not depend on the size of the problem. The second solution requires an event ordering and therefore a temporal ordering predicate has been used to prove its correctness.

Image recognition with fuzzy ADALINE neurons

The paper aims at extending the scope of application of Widrow-Hoffs ADALINE model from binary to gray level (fuzzy) pattern recognition. The condition of stability for the extended ADALINE model is derived, and the algorithm for training the multilayer feedforward neural net consisting of ADALINE neurons is presented. The time required for training the neural net is insignificantly small. The scheme for the recognition of objects from their gray level images using the fuzzy ADALINE model is translation, rotation and size invariant.

Development of a Fiber-Optic Current Sensor With Range-Changing Facility Using Shunt Configuration

Considering that a magneto-optic Faraday effect may play an important role in the design of multirange electric current measurements, a novel range-changing facility using shunts is proposed and fabricated to demonstrate the effectiveness of an intensity-modulated fiber-optic current sensor. The current sensing over three orders of magnitude is demonstrated in a single-mode fiber of 633-nm wavelength with a suitable laser source. The design of the sensor is based on a dual prototype of the Rogowsky coil carrying the laser beam encircling the current path. The experimental results are presented which agree well with the theoretical predictions of the performance analysis of the sensor.

Fuzzy rule extraction using robust particle swarm optimization

Automatic fuzzy rule extraction assumes the realization of fuzzy if-then rules using a pre-assigned structure rather than an optimal one. In this paper, Particle Swarm Optimization (PSO) is used to simultaneously evolve the structure and the parameters of the fuzzy rule base. However, the existing PSO based adaptation employs randomness, which makes the rate of convergence dependent on the initial states and the end result can not be reproduced repeatedly with a pre-assigned value of iterations. The algorithm has been modified by removing the randomness in parameter learning, making it very robust. The scheme provides the flexibility in extracting the optimal set of fuzzy rules for a prescribed residual error in function approximation and prediction. Simulation studies and the comprehensive analysis demonstrate that an efficient learning technique as well as the structure development of the fuzzy system, can be achieved by the proposed approach.

Concurrent Resolution in Logic Programming Using Petri Net Models

The paper provides a new approach for automated reasoning in a logic program using extended Petri net models. The design includes extension of classical linear resolution of first order logic clauses by multi-resolution, where a set of clauses can be resolved concurrently without sacrificing any inference, thereby speeding-up the execution of the logic program. The speed-up and utilization rate of resources are used as the performance evaluation metric to compare the performance of the proposed system with the classical one.

Some investigations on deadlock freedom issues of a cyclically connected system using Dijkstra's weakest precondition calculus

Weakest precondition calculus is used to specify a system implemented by a cyclic interconnection of sequential processes. From this specification a predicate is derived that describes the deadlock freedom property of the system. Invariance of the predicate is proved from the specification.

Building 3-D Visual Perception of a Mobile Robot Employing Extended Kalman Filter

The paper aims at designing a novel scheme for sensory data fusion by a mobile robot for reconstructing its 3-D world from their multiple gray images. Extended Kalman filter has been employed for determining the coordinates of the 3-D vertices and equation of the planes of the obstacles in the robots workspace from their multiple images. The geometric relations among these 3-D planes are then determined by using a logic program for recognizing the obstacles. The time required for recognition of a typical planer obstacle such as a box on a Pentium-III client with 64 MB RAM and a Pioneer-2 type robot server including the time involvement for the motion of the robot around the obstacle is approximately 18 seconds.

Design of a high speed logic engine for distributed decision support systems

The paper provides a new approach to designing a massively parallel logic engine for automated reasoning in a distributed decision support system. The design includes extension of classical linear resolution of first order logic clauses by multi-resolution, where a set of clauses can be resolved concurrently without sacrificing any inference, thereby speeding-up the execution of a logic program. The speed-up and utilization rate of resources are used as the performance evaluation metric to compare the performance of the proposed system with the classical one. A high level logic architecture of the proposed multi-resolution system is presented to explore possible parallelism and pipelining among the tasks, thus determining the execution time of typical logic programs. Possible application of the proposed system in query evaluation of a logic program based database systems is also introduced.

Optimal Rule Extraction of RBFN Based System Using Hierarchical Self Organised Evolution

Abstract The fuzzy if-then rule extraction invariably assumes a preassigned structure instead of an optimal one. The paper presents the development of a hierarchical self organized radial basis function network (RBFN) that simultaneously evolve the structure and parameter of the Fuzzy rule-base. Robust particle swarm optimization (RPSO) is used as a tool for the learning of the state reproducing the result repeatedly with a preassigned value of iteration. Also the multi dimensional crossover vector is introduced as a set of Accommodation Boundary of the data set to employ desired number of linguistic fuzzy rules. Experiments conducted and comprehensive analyses show that the proposed method produces smaller number of rules with respect to the other methods along with comparable error. Also the computational time for learning will decrease significantly in this method as the concept of iteration during a learning cycle has been removed. The effect of different membership function has also been studied during the recruitment of node.