Synthesis and characterization of indium xanthates and their use for the preparation of beta-In2S3 nanoparticles

Synthesis and characterization of various classical indium xanthate complexes of the type [InCl(3-n)(S2COR)n] (n = 1, 2, or 3; R = Me, Et, Pr(i), and Bu(s)) have been discussed. Crystalline beta-ln2S3 nanoparticles were obtained by the solvent thermolysis of indium tris-alkylxanthates in ethylene glycol at 196 degrees C, and were characterized by elemental analysis, IR, powder XRD, and XPS techniques. TEM results showed that the size of beta-In2S3 nanoparticles depended on the nature of the precursor used. The optical properties of beta-In2S3 nanocrystals have shown quantum confinement of the excitonic transition.     

Ion cyclotron resonance heating system on Aditya

An ion cyclotron resonance heating (ICRH) system has been designed, fabricated indigenously and commissioned on Tokamak Aditya. The system has been commissioned to operate between 20.0 and 47.0 MHz at a maximum power of 200 kW continuous wave (CW). Duration of 500 ms is sufficient for operation on Aditya, however, the same system feeds the final stage of the 1.5 MW ICRH system being prepared for the steady-state superconducting tokamak (SST-1) for a duration of 1000 s. Radio frequency (RF) power (225 kW) has been generated and successfully tested on a dummy load for 100 s at 30.0 MHz. Lower powers have been coupled to Aditya in a breakdown experiment. We describe the system in detail in this work.     

On the Rapid Prototyping of a Portable Multi Media Acquisition System for Intelligent Meeting Capture

Emerging multi-modal signal processing applications require a sustained effort on the part of the developer to realize and deploy an application. A rapid prototyping platform will reduce the effort, cost, and time required to develop and deploy an application. In this paper, a rapid prototyping platform is developed for realizing a multi-modal signal processing application that involve real time interfacing of multi-modal signals both at the input and the output. The platform allows the designer to simulate various applications and produce the required product only after entire testing has been done. A portable intelligent meeting capture system that can be rapidly deployed in smart meeting rooms is implemented on this platform. The setup consists of a microphone array which computes the two-dimensional direction of arrival (DOA). The azimuth and the elevation angles are computed using advanced signal processing algorithms like GCC-PHAT, MUSIC which are implemented on the Real Time Operating System (RT-OS). The DOAs are communicated to a wireless networked camera which steers in real time towards the active speaker. Performance evaluation of the rapidly prototyped system is tested in real time meetings in terms of average error deviations in the DOA. The accuracy of the results indicate further miniaturization of the system. The possibilities of using this platform for developing multi-modal signal processing in general is also described.     

Performance Comparison of DCT and VQ Based Techniques for Iris Recognition

Iris recognition enjoys universality, high degree of uniqueness and moderate user co-operation. This makes iris recognition systems unavoidable in emerging security ＆ authentication mechanisms. An iris recognition system based on vector quantization （VQ） techniques is proposed and its performance is compared with the discrete cosine transform （DCT）. The proposed system does not need any pre-processing and segmentation of the iris. We have tested Linde-Buzo- Gray （LBG）, Kekre＇s proportionate error （KPE） algorithm and Kekre＇s fast codebook generation （KFCG） algorithm for the clustering purpose. Proposed vector quantization based method using KFCG requires 99.99% less computations as that of full 2-dimensional DCT. Further, the KFCG method gives better performance with the accuracy of 89.10% outperforming DCT that gives accuracy around 66.10%.