A Convenient Synthesis of Some Coumarin Derivatives Using SnCl2 · 2H2O as Catalyst

Some substituted coumarins have been synthesized by von-Pechmann condensation using SnCl₂ · 2H₂O (10 mol %) as catalyst in ethanolic medium. The reactions are simple, easy in handling and environmentally benign.     

Yield optimization for complex reactor systems

For complex reactions, the choice of reactor type is important for attaining optimum product yields. Strategies for specifying reactor types have beenIn this paper, product yield in a Van de Vusse reaction scheme has been studied for a wide range of the rate constants, in a reactor system consisting     

Connection Analysis: A Practical Interprocedural Heap Analysis for C

This paper presents a practical heap analysis technique, connection analysis, that can be used to disambiguate heap accesses in C programs. The technique is designed for analyzing programs that allocate many disjoint objects in the heap such as dynamically-allocated arrays in scientific programs. The method statically estimates connection matrices which encode the connection relationships between all heap-directed pointers at each program point. The results of the analysis can be used by parallelizing compilers to determine when two heap-allocated objects are guaranteed to be disjoint, and thus can be used to improve array dependence and interference analysis. The method has been implemented as a context-sensitive interprocedural analysis in the McCAT optimizing/parallelizing C compiler. Experimental results are given to compare the accuracy of connection analysis versus a conservative estimate based on points-to analysis.     

Development of simulated emotion speech database for excitation source analysis

The work presented in this paper is focused on the development of a simulated emotion database particularly for the excitation source analysis. The presence of simultaneous electroglottogram (EGG) recordings for each emotion utterance helps to accurately analyze the variations in the source parameters according to different emotions. The work presented in this paper describes the development of comparatively large simulated emotion database for three emotions (Anger, Happy and Sad) along with neutrally spoken utterances in three languages (Tamil, Malayalam and Indian English). Emotion utterances in each language are recorded from 10 speakers in multiple sessions (Tamil and Malayalam). Unlike the existing simulated emotion databases, instead of emotionally neutral utterances, emotionally biased utterances are used for recording. Based on the emotion recognition experiments, the emotions elicited from emotionally biased utterances are found to show more emotion discrimination as compared to emotionally neutral utterances. Also, based on the comparative experimental analysis, the speech and EGG utterances of the proposed simulated emotion database are found to preserve the general trend in the excitation source characteristics (instantaneous F0 and strength of excitation parameters) for different emotions as that of the classical German emotion speech-EGG database (EmoDb). Finally, the emotion recognition rates obtained for the proposed speech-EGG emotion database using the conventional mel frequency cepstral coefficients and Gaussian mixture model based emotion recognition system, are found to be comparable with that of the existing German (EmoDb) and IITKGP-SESC Telugu speech emotion databases.     

Robust object matching for persistent tracking with heterogeneous features

This paper addresses the problem of matching vehicles across multiple sightings under variations in illumination and camera poses. Since multiple observations of a vehicle are separated in large temporal and/or spatial gaps, thus prohibiting the use of standard frame-to-frame data association, we employ features extracted over a sequence during one time interval as a vehicle fingerprint that is used to compute the likelihood that two or more sequence observations are from the same or different vehicles. Furthermore, since our domain is aerial video tracking, in order to deal with poor image quality and large resolution and quality variations, our approach employs robust alignment and match measures for different stages of vehicle matching. Most notably, we employ a heterogeneous collection of features such as lines, points, and regions in an integrated matching framework. Heterogeneous features are shown to be important. Line and point features provide accurate localization and are employed for robust alignment across disparate views. The challenges of change in pose, aspect, and appearances across two disparate observations are handled by combining a novel feature-based quasi-rigid alignment with flexible matching between two or more sequences. However, since lines and points are relatively sparse, they are not adequate to delineate the object and provide a comprehensive matching set that covers the complete object. Region features provide a high degree of coverage and are employed for continuous frames to provide a delineation of the vehicle region for subsequent generation of a match measure. Our approach reliably delineates objects by representing regions as robust blob features and matching multiple regions to multiple regions using Earth Mover's Distance (EMD). Extensive experimentation under a variety of real-world scenarios and over hundreds of thousands of Confirmatory Identification (CID) trails has demonstrated about 95 percent accuracy in vehicle reacquisition with both visible and Infrared (IR) imaging cameras.     

Role of sample size in the nucleation kinetics of phase transformations in steel alloys

Certain commercial steel alloys exhibit a two-step phase transformation process during solidification when substantial undercooling of the liquid allows access to the metastable phase. This two-step transformation leads to a desirable microstructure under certain conditions. Electrostatic Levitation (ESL) and Electromagnetic Levitation (EML) are two methods of containerless processing used to study how nucleation and growth kinetics influence the transformation delay between phases. Because the two facilities show substantially different delay results, the test environment differences have been analyzed to determine the root cause of this deviation. In particular, the difference in sample size between ESL and EML is examined and modeling shows that this difference is not the controlling factor in determining transformation delay behavior.     

An investigation of mating and population maintenance strategies in hybrid genetic heuristics for product line designs

This research builds on prior work on developing near optimal solutions to the product line design problems within the conjoint analysis framework. In this research, we investigate and compare different genetic algorithm operators; in particular, we examine systematically the impact of employing alternative population maintenance strategies and mutation techniques within our problem context. Two alternative population maintenance methods, that we term “Emigration” and “Malthusian” strategies, are deployed to govern how individual product lines in one generation are carried over to the next generation. We also allow for two different types of reproduction methods termed “Equal Opportunity” in which the parents to be paired for mating are selected with equal opportunity and a second based on always choosing the best string in the current generation as one of the parents which is referred to as the “Queen bee”, while the other parent is randomly selected from the set of parent strings. We also look at the impact of integrating the artificial intelligence approach with a traditional optimization approach by seeding the GA with solutions obtained from a Dynamic Programming heuristic proposed by others. A detailed statistical analysis is also carried out to determine the impact of various problem and technique aspects on multiple measures of performance through means of a Monte Carlo simulation study. Our results indicate that such proposed procedures are able to provide multiple “good” solutions. This provides more flexibility for the decision makers as they now have the opportunity to select from a number of very good product lines. The results obtained using our approaches are encouraging, with statistically significant improvements averaging 5% or more, when compared to the traditional benchmark of the heuristic dynamic programming technique.     

Expressive speech synthesis: a review

The objective of the present work is to provide a detailed review of expressive speech synthesis (ESS). Among various approaches for ESS, the present paper focuses the development of ESS systems by explicit control. In this approach, the ESS is achieved by modifying the parameters of the neutral speech which is synthesized from the text. The present paper reviews the works addressing various issues related to the development of ESS systems by explicit control. The review provided in this paper include, review of the various approaches for text to speech synthesis, various studies on the analysis and estimation of expressive parameters and various studies on methods to incorporate expressive parameters. Finally the review is concluded by mentioning the scope of future work for ESS by explicit control.     

VLC Enabled Hybrid Wireless Network for B5G/6G Communications

Wireless Personal Communications - In the present scenario, there is a boom in the demand of the users to achieve increased capacity, high data, low latency, and high-performance rates. 5G New...     

A two-unit priority standby system subject to random shocks and Releigh failure-time distribution

This paper deals with the cost-benifit analysis of a two-unit priority standby system subject to random shocks. The priority unit gets preference both for repair and operation over the ordinary unit and has three modes- Normal, Quasi-normal and Total-failure. The ordinary unit has only two-modes- Normal and Total-failure. The distributions of shock-time, repair-time of the ordinary unit and failure time of the priority unit are negative exponential. The distribution of the repair-time of the priority unit is taken to be general while the time to failure of ordinary unit follows Releigh distribution. Various characteristics related to system effectiveness have been obtained by using the regenerative point technique.