Variations in normal color vision. III. Unique hues in Indian and United States observers

Basic color categories are thought to share a common pattern across linguistic groups, yet the focal colors defining those categories can vary substantially within any single group. We asked whether focal colors can also differ systematically across different groups of individuals living in potentially different color environments, by measuring focal and unique hues for observers in India and the United States. Differences between groups were generally small relative to the within-group variations, consistent with a strong common basis for color naming across diverse contexts. However, for most hues the average settings differed significantly across subpopulations. These differences persisted across testing conditions and thus probably reflect longer-term contextual influences on color appearance judgments. They suggest that while color categories may be qualitatively similar, precisely how the hue spectrum is parsed may differ quantitatively across different populations of observers. Both the between-group and the within-group differences are inconsistent with the differences predicted by common peripheral sources of variation in color vision (e.g., in lens or macular pigment) and may reflect an influence of environmental or cultural differences in focal color choices.     

Far-infrared fizeau interferometry

We present an interferometry using a far-infrared light as a tool for surface topography measurement of rough reflective surfaces. The method is based on the optical configuration of classical Fizeau interferometry, but we achieve roughness tolerance by using a long-wavelength infrared light (lambda = 10.6 mum). The method is called far-infrared Fizeau interferometry. We conducted a rigorous mathematical analysis to describe the true intensity distribution of fringe patterns while considering multiple reflections and surface roughness. The mathematical derivation is verified with experimental data obtained from specimens with various values of reflectivity and roughness. The effect of reflectivity and roughness on fringe contrast is discussed.     

Microcomputer based digital differential relaying for generator protection: Real time test results

The paper presents the development of a digital differential relaying scheme around a 16-bit microprocessor for generator winding protection. It uses a simple filter algorithm which is based on cross-correlation with a heptagonal wave for the extraction of fundamental frequency components of differential and sum currents. Application of this filter and use of the real parts alone, instead of both the real and imaginary parts, of the fundamental frequency components for the relaying reduces the computation requirement drastically, thus enabling implementation of a complete three-phase differential relay on a single microprocessor without requiring a coprocessor or multiplier. The relay has been tested in real time on simulated generator currents representing internal-, external- and no-fault conditions separately. The test results agree well with the results of off-line evaluation reported earlier and point to a successful implementation of the differential relaying algorithm on a microprocessor in real time.     

Low field magnetoresistance and hall effect in thin metallic films

Using the Boltzmann transport equation, expressions have been derived for the magnetoresistance and Hall coefficient in thin metallic films. The analysis has been carried out for low magnetic flux density (～10⁴ gauss) and is a special case of more general work by Sondheimer. It has been found that the Hall coefficient shows a size effect. To a first order approximation, metals are known not to exhibit magnetoresistance. Reduction of the thickness introduces a constraint on the motion of the charge carriers in the magnetic field and hence they do show a magnetoresistance to a first order approximation. The theoretical and experimental data match well with data on potassium and gold thin films.     

Estimation of rate coefficients from pulsed microcatalytic reactors: Oxidation of ethylene over silver catalyst

The experimental conditions and requirements for the continuity equation to reduce to a total differential equation are analyzed. These lead to a simple method for obtaining rate coefficients from pulsed microcatalytic reactors, provided that the conversions are limited to differential conversions. Coefficients obtained this way, for ethylene oxidation over silver, are compared with estimations from steady state data.     

Fuzzy Logic Based Group Maturity Rating for Software Performance Prediction

Driven by market requirements,software services organizations have adopted various software engineering process models (such as capability maturity model (CMM),capability maturity model integration (CMMI),ISO 9001:2000,etc.) and practice of the project management concepts defined in the project management body of knowledge.While this has definitely helped organizations to bring some methods into the software development madness,there always exists a demand for comparing various groups within the organization in terms of the practice of these defined process models.Even though there exist many metrics for comparison,considering the variety of projects in terms of technology,life cycle,etc.,finding a single metric that caters to this is a difficult task.This paper proposes a model for arriving at a rating on group maturity within the organization.Considering the linguistic or imprecise and uncertain nature of software measurements,fuzzy logic approach is used for the proposed model.Without the barriers like technology or life cycle difference,the proposed model helps the organization to compare different groups within it with reasonable precision.     

Growth and characterization of Hg1-xCdxTe epitaxial films by isothermal vapour phase epitaxy (ISOVPE)

Growth of Hg_1-xCd_xTe epitaxial films by a new technique called asymmetric vapour phase epitaxy (ASVPE) has been carried out on CdTe and CZT substrates. The critical problems faced in normal vapour phase epitaxy technique like poor surface morphology, composition gradient and dislocation multiplication have been successfully solved. The epitaxial films have been electrically characterized by using the Hall effect and capacitance-voltage (C-V) measurements.     

QoS based multicast routing algorithms for real time applications

In recent years, there has been a lot of interest in providing real-time multimedia services like digital audio and video over packet-switched networks such as Internet and ATM. These services require certain quality of service (QoS) from the network. The routing algorithm should take QoS factor for an application into account while selecting the most suitable route for the application. In this paper, we introduce a new routing metric and use it with two different heuristics to compute the multicast tree for guaranteed QoS applications that need firm end-to-end delay bound. We then compare the performance of our algorithms with the other proposed QoS-based routing algorithms. Simulations were run over a number of random networks to measure the performance of different algorithms. We studied routing algorithms along with resource reservation and admission control to measure the call throughput over a number of random networks. Simulation results show that our algorithms give a much better performance in terms of call throughput over other proposed schemes.