Mixed-sensitivity approach to H/sub /spl infin// control of power system oscillations employing multiple FACTS devices

This paper demonstrates the enhancement of inter-area mode damping by multiple flexible AC transmission systems (FACTS) devices. Power system damping control design is formulated as an output disturbance rejection problem. A decentralized H/sub /spl infin// damping control design based on the mixed-sensitivity formulation in the linear matrix inequality (LMI) framework is carried out. A systematic procedure for selecting the weights for shaping the open loop plant for control design is suggested. A 16-machine, five-area study system reinforced with a controllable series capacitor (CSC), a static VAr compensator (SVC), and a controllable phase shifter (CPS) at different locations is considered. The controllers designed for these devices are found to effectively damp out inter-area oscillations. The damping performance of the controllers is examined in the frequency and time domains for various operating scenarios. The controllers are found to be robust in the face of varying power-flow patterns, nature of loads, tie-line strengths, and system nonlinearities, including device saturations.     

A novel technique for isolation of pure sperm heads from disintegrated mammalian spermatozoa

The phenomenon of differential charge distribution on sperm surface membrane has been utilised here in a low e.m.f. (electro motive force) capillary electrophoresis system to effect separation of sperm heads from disintegrated mixed spermatozoal subfractions. Washed caudal sperm of goat (Black Bengal variety) and ejaculated washed human sperm were fractionated by sonication into head, mid-piece and tail portions. Routine techniques of density gradient centrifugation on Percoll and/or sucrose were performed with sonicated spermatozoa for separation into their respective subfractions. The products obtained were not free of contamination in either case. Mixed sperm fractions when subjected to the afore mentioned modified capillary electrophoresis technique only the head pieces exhibited high affinity for migration towards the cathode terminal. With this method around 50% of the total sperm heads were separated and collected in absolutely pure form at the cathode side within 2 hrs. at 150 volts (V) and 1.5 milliampere (mA) current at 37.5 degrees C. A 4 cm. long capillary tube with a bore size 1.2 mm. was used for this purpose.     

Evaluation of Petroleum Impurities in Motor Spirit and Diesel Oils Using Artificial Neural Network

Studies have been conducted for the ternary mixture of motor spirit, diesel, and kerosene oil samples using artificial neural network (ANN). American standard for testing materials (ASTM) distillation data of samples were used for the evaluation of respective components. Results of such evaluation of the samples were found to comply well with experimental values.     

An economic production lot size model with increasing demand, shortages and partial backlogging

In this paper, an economic production quantity model is developed for a production–inventory system where the demand rate increases with time, the production rate is finite and adjustable in each cycle over an infinite planning horizon and shortages are permitted. The cost of adjusting the production rate depends linearly on the magnitude of the change in the production rate. During the stock‐out period, a known fraction of the unsatisfied demands is backordered while the remaining fraction is lost. The model is formulated taking the demand rate as a general increasing function of time and the optimal production policy is obtained for the special case of a linearly increasing demand rate. The proposed model is also shown to be suitable for a prescribed time horizon. A procedure to find approximately the minimum total cost of the system over a finite time horizon is suggested. A numerical example is taken to illustrate the solution procedure of the developed model.     

Acoustic-optic filters

Optical filters are an important building block in the next generation of optical communication systems. Optical networks seem to be headed towards densely packed wavelength-division multiplexing (WDM) systems. These WDM systems require optical filters for the purpose of wavelength selection and switching. Numerous optical filters have been proposed including acousto-optical filters, electro-optical filters, and Fabry-Perots. Acoustically tunable optical filters (ATOFs) are considered promising. ATOFs are not only an important WDM device; they have great potential in many other applications such as optical spectroscopy. The acousto-optic tunable filter has a unique combination of desirable properties. These properties make it a potentially important building block     

A recursive algorithm for maximum likelihood-based identificationof blur from multiple observations

A maximum likelihood-based method is proposed for blur identification from multiple observations of a scene. When the relations among the blurring functions are known, the estimate of blur obtained using the proposed method is very good. Since direct computation of the likelihood function becomes difficult as the number of images increases, we propose an algorithm to compute the likelihood function recursively.