Showing papers by "Techno India published in 2004"

Intellectual capital: Measurement effectiveness

Abstract: Intellectual capital (IC), knowledge management and intangible assets are important factors in determining the value of an organization, as reflected in the growth of the knowledge management industry. There is however, a lack of effective measurement techniques to specify and optimize the value of IC. This paper presents a detailed review of existing techniques and establish the need for a more comprehensive approach. The proposed framework addresses IC valuation issues across the IC cycle. People, process, and technology are measured and correlated in the final step with social and financial measures, thus providing a new framework.

ANN approach for condition monitoring of power transformers using DGA

Abstract: Power transformer being a major apparatus in a power system, monitoring of its in-service behavior is necessary to avoid catastrophic failures, costly outages. Dissolved gas analysis (DGA) is an important tool for transformer fault diagnosis. The ratio methods used in the DGA have an advantage that they are independent of volume of gases involved. But the main draw back of the ratio methods is that they fail to cover all ranges of data. ANN approach is adopted as a remedy for the drawback of ratio methods in this paper.

Self-rotation of red blood cells in optical tweezers: prospects for high throughput malaria diagnosis.

Abstract: A simple and sensitive approach for detection of malarial parasite in blood samples is demonstrated. The approach exploits our finding that, in hypertonic buffer, a normal red blood cell (RBC) rotates by itself when trapped by an optical tweezers. The rotational speed increases linearly at lower trap-beam powers and more rapidly at higher powers. In contrast, under the same experimental conditions, RBC having a malarial parasite does not rotate. The rotational speeds of other RBCs from malaria-infected sample are of an order of magnitude less than that for normal RBC and also increase much more slowly with an increase in trap beam power than that for normal RBC. The difference in rotational speeds could be exploited for the diagnosis of malaria.

Optical binding between dielectric particles.

Abstract: We report observation of optical binding between two dielectric particles with dimensions less than the wavelength of the interacting light. The observed dependence of the separation of optically bound particles on the polarization of the trapping beam is in agreement with earlier theoretical predictions.

Spatial Decision Support System for Watershed Management

Abstract: A prototype spatial decision support system (SDSS) is presented for watershed management. The SDSS integrates landuse/landcover derived from the remote sensing data, real-time hydrological data, geographic information system, and a model-based subsystem for computing soil loss, land capability classification and engineering measures. A graphical user interface has been developed to allow effective use by decision makers. The model-based subsystem employs a process-based soil erosion model to compute soil loss in spatial environment. Computed pixel-based soil loss information is an input to the land capability classification and watershed management modules. The developed SDSS can help the end users in avoiding the laborious procedures of soil erosion calculations and analysing various thematic layers to get suitable watershed management practices. The SDSS for watershed management is applied to the Tones watershed in India to compute soil loss, to prioritise watersheds, and to suggest various watershed management practices.

The influence of nickel and copper on the austempering of ductile iron

Abstract: In the present investigation, the effect of alloying elements on the austempering process, austempered microstructure, and structural parameters of two austempered ductile irons (ADI) containing 0.6% Cu and 0.6% Cu/1.0% Ni as the main alloying elements was investigated. The optical metallography and x-ray diffraction were used to study the changes in the austempered structure. The effect of alloying additions on the austempering kinetics was studied using the Avrami equation. Significantly more upper bainite was observed in the austempered Cu-Ni alloyed ADI than in Cu alloyed ADI. The volume fraction of retained austenite (Xγ), the carbon level in the retained austenite (Cγ), and the product XγCγ in an austempered structure of Cu-alloyed ADI are higher than in Cu-Ni-alloyed ADI. The austempering Kinetics is slowed down by the addition of Ni.

Effect of pH on uptake and photodynamic action of chlorin p6 on human colon and breast adenocarcinoma cell lines.

Abstract: The effect of reducing the extracellular pH from 7.4 to 6.0 on the uptake and photosensitivity of chlorin p6, a potential photosensitising drug, has been investigated using two mammalian cell lines, human colon (Colo-205) and breast (MCF-7) adenocarcinoma cells. In Colo-205 cells, the uptake and phototoxicity of chlorin p6 was observed to increase as the pH of the incubation medium decreased. For light doses of up to [similar]6 kJ m(-2), although there was no evidence of mitochondrial damage, a significant reduction in Neutral Red uptake was observed, signifying damage to lysosomes. At higher light doses, significant mitochondrial damage was observed, accompanied by saturation of the lysosomal damage. This suggests light-induced relocalization of the photosensitizer from lysosomes to mitochondria. Furthermore, it was found that for a given light dose, lysosomes exhibit greater photosensitivity at lower pH. Since chlorin p6 is known to aggregate at pH 6.0, this observation suggests that the dye accumulation in these cells mainly takes place through endocytosis. In contrast, no significant variation in uptake, photosensitivity, and sites of photodamage was observed for MCF-7 cells at different extracellular pH. Additionally, the lower photosensitivity of lysosomes as compared to mitochondria in these cells suggests chlorin p6 is taken up through diffusion rather than endocytosis.

Effects of a slow ion beam on ion-acoustic waves

Abstract: The influence of a slow ion beam on an ion-acoustic wave is studied theoretically and experimentally. A kinetic dispersion relation of an ion-beam–plasma system predicts a critical value of the ion-beam density above which the ion-acoustic wave is transformed into the fast mode of the ion beam. Below the critical value, the ion-acoustic wave propagates without transforming into the fast mode of space charge waves for any beam velocity. A dispersion relation based on a fluid model does not provide such a critical value for the ion-beam density. Experimentally, the ion-beam density is controlled carefully to test the presence of the critical density at which the change in topology of dispersion roots appears.

Differences in the Activation State of Ribulose-1,5-bisphosphate Carboxylase/Oxygenase in Barley, Pea, and Wheat at Two Altitudes

Abstract: Activation state of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) is an important parameter determining the rate of net photosynthesis (PN) in situ for which no information is available with reference to altitude. We analyzed activation state along with PN in three plant species and their cultivars grown at low (LA, 1 300 m) and high (HA, 4 200 m) altitudes. No significant change in PN and the initial activity of RuBPCO was obtained with reference to altitude. However, activation state of RuBPCO was reduced significantly in the HA plants as compared to the LA ones. Hence low partial pressure of CO2 prevailing at HA might be responsible for the lower activation state of RuBPCO.

Detailed cache coherence characterization for OpenMP benchmarks

Abstract: Past work on studying cache coherence in shared-memory symmetric multiprocessors (SMPs) concentrates on studying aggregate events, often from an architecture point of view. However, this approach provides insufficient information about the exact sources of inefficiencies in parallel applications. For SMPs in contemporary clusters, application performance is impacted by the pattern of shared memory usage, and it becomes essential to understand coherence behavior in terms of the application program constructs -- such as data structures and source code lines.The technical contributions of this work are as follows. We introduce ccSIM, a cache-coherent memory simulator fed by data traces obtained through on-the-fly dynamic binary rewriting of OpenMP benchmarks executing on a Power3 SMP node. We explore the degrees of freedom in interleaving data traces from the different processors and assess the simulation accuracy by comparing with hardware performance counters. The novelty of ccSIM lies in its ability to relate coherence traffic -- specifically coherence misses as well as their progenitor invalidations -- to data structures and to their reference locations in the source program, thereby facilitating the detection of inefficiencies. Our experiments demonstrate that (a) cache coherence traffic is simulated accurately for SPMD programming styles as its invalidation traffic closely matches the corresponding hardware performance counters, (b) we derive detailed coherence information indicating the location of invalidations in the application code, i.e, source line and data structures and (c) we illustrate opportunities for optimizations from these details. By exploiting these unique features of ccSIM, we were able to identify and locate opportunities for program transformations, including interactions with OpenMP constructs, resulting in both significantly decreased coherence misses and savings of up to 73% in wall-clock execution time for several real-world benchmarks.

Channel estimation techniques with long training sequence for IEEE802.11A

Abstract: We compare and evaluate the channel estimation schemes for IEEE802.11a and present their performance for different SNRs. Time-domain truncation approach for the channel estimation is considered for the fact that the taps with least energy degrade the performance as they become more noisy in low SNR conditions. In the paper, the problem formulation is based on the PLCP preamble of IEEE802.11a in which the long preamble sequence consists of only +1 or -1 or 0. Three popular techniques of equalization, Per-tone, least squares (LS), and minimum mean square error (MMSE) are compared in their performance for various SNR conditions.

Built-in self-test technique for selective detection of neighbourhood pattern sensitive faults in memories

Abstract: Traditional tests for memories are based on conventional fault models, involving the address decoder, individual memory cells and a limited coupling between them. The algorithms used in these tests have been successively augmented to consider stronger coupling conditions. Built-in self-test (BIST) solutions for testing memories today incorporate hardware for test pattern generation and application for a variety of these algorithms. This paper presents a BIST implementation for detection of neighbourhood pattern sensitive faults (NPSFs) in random access memories (RAMs). These faults are of different classes and types. More specifically, active, passive and static faults for distance 1 and 2 neighbourhoods, of types 1 and 2, are considered. It is shown how the proposed address generation and test pattern generation schemes can be made scaleable for the given fault type under consideration.

Chemical synthesis of polypyrrole nano/microstructures using track etch membranes

Abstract: Among the different strategies to synthesize nanoscopic materials reported in the literature, template synthesis is an elegant approach [1–3]. This technique consists of including metallic or organic constituents inside the void spaces of nanoporous host materials. Though there now exists a huge range of hosts, track-etched membranes present a significant advantage because they lead to the production of different kinds of nanotubules and nanowires with monodisperse diameters and lengths. Martin and Hulteen [4–6] have used these membranes as templates to prepare nanofibrils composed of metals, semiconductors, and conducting polymers, most of their work has focused on the chemical synthesis of polypyrrole, polyaniline, and polymethylthiophene. In the present work, the chemical growth of polypyrrole nanofibrils obtained from polycarbonate nanoporous particle track-etched membranes is studied. The morphologies of the obtained microstructures have been carefully analyzed using a scanning electron microscope. A two-probe method has been used to measure the electrical conductivity of template-synthesized polypyrrole microstructures. The nuclear track filter used here as a template was of Makrofol KG foil (polycarbonate from Bayer AG), 60 μm thick, having average pore diameter ∼ 6 μm with pore density 1 × 106 m−2. This was prepared by irradiating the foil with 238U, energy ca. 13.64 MeV/n at 90 ◦C at the UNILAC facility available at GSI, Darmstadt, Germany, followed by chemical amplification of the damage trails by etching in 6N NaOH, at 60 ± 2 ◦ C for 35 min. In order to produce see-through pores, optimum etch time and etch conditions were preset. As shown in Fig. 1, the polycarbonate membrane was used as a dividing wall in a two-compartment cell. In the first compartment, an aqueous pyrrole solution (0.5 M) was added and allowed to diffuse through the membrane for 10 min prior to the introduction of the oxidant reagent ferric chloride (0.4 M) in the second compartment. The monomer and the oxidant reagent diffuse toward each other through the pores of the membrane and react to yield the polymer. The polymerization process was continued for 1 hr 30 min. For the morphological characterization of the polypyrrole microstructures by means of scanning electron microscopy (SEM), specimens were observed by dissolving the polycarbonate matrix in dicholoromethane. The cleaned and dried samples were mounted on the specially designed aluminum stubs with the help of double sided adhesive tape and viewed under a “Jeol, JSM 6100 Scanning Microscope” at an accelerating voltage of 20 KV. Images were recorded on the photographic film in the form of negatives at different magnifications. Fig. 2 shows scanning electron micrographs of polypyrrole microstructures. Fig. 3 shows a scanning electron micrograph of a single polypyrrole microtube. The electrical conductivity of the polypyrrole microstructures established inside the pores was obtained by measuring the bulk resistance across the filled membrane by a two-probe method. Since the polypyrrole surface layers on the membrane can contribute to the resistance measurement but cannot be completely removed because they ensure the contact between the polypyrrole nanostructures and electrical wires [7], we tried to limit the thickness of these surface layers. Cai et al. [7] indicated that such thin layers did not contribute to the membrane resistance. One side of the membrane was held on the copper electrode and two copper wires contacted the other side of the membrane. Silver paste ensured a good contact and allowed specification of a well-defined crosssection for calculating the conductivity. The conductivity along a single fiber can be calculated from the resistance measurement that provides the bulk resistance of the composite membrane. Assistance R can be written as

Patterned Alignment of Liquid Crystals

Abstract: In this study the μ-rubbing technique is used to micro-pattern polyimide alignment layers using a metallic sphere at different loads. Optical and atomic force microscopy shows that the width of the patterns ranges from 12-40 μm and depth ranges from 2-14 nm. Our primary finding is that μ-rubbing induces planar alignment in polyimides. We performed μ-rubbing on pre-rubbed polyimide perpendicular to the rubbing direction. It is found that μ-rubbing erases the alignment properties of the pre-rubbing procedure. Liquid crystal cells were constructed using the pre-rubbed polyimide substrates with μ-rubbed patterns on one side and a homogeneously rubbed polyimide layer on the other side. Therefore the pre-rubbed polyimide layers are crossed and consequently a twisted nematic alignment is observed outside the micro-patterns. Within the micro-patterns, the directions of the pre-rubbing and μ-rubbing are parallel, a planar alignment observed. In another configuration, liquid crystal cells were made with pre-rubbed polyimide substrates having micro-patterns on both sides to give grid pattern with planar and twisted nematic configuration. Studies were extended to determine the pretilt of the micro patterned area.

A balanced multicast overlay protocol - appcast

Abstract: With IP multicast not gaining wide acceptance, researchers turned to alternative multicast mechanisms like application level multicast. Application level multicast (ALM) protocols arrange the participating hosts into an overlay topology; maintain it and distribute data over that topology. ALM topology building algorithms define a definite relationship among the participating members and thereby create topologies like tree, mesh, hierarchy etc. We propose a new ALM protocol, simulate the protocols and compare the results.

Peak current detector based control of DC-DC buck converter for portable application

Abstract: This paper presents a control scheme for DC-DC converters designed for battery operated systems. These systems require very high efficiency to prolong the battery life The inductor peak current is maintained constant either by oscillator on/off time control or monoshot on time control. But these types of control require a fixed and accurate value of inductor and they require preprogramming of monoshot/oscillator. The proposed control scheme uses a peak current detector for the inductor peak current detection. Therefore it rules out maintaining a very precise value of inductor size and any kind of preprogramming. A design and its implementation have been carried out in a 1.5 /spl mu/ BiCMOS process and both simulation and experimental results are presented.

Post-dispersion compensation for 10-Gbit/s RZ, Gaussian, and NRZ pulses for indirect modulated optical links using standard fiber and FBG

Abstract: In this paper, we have analyzed the simulation results for 10 Gbit/s indirect modulated optical links with post-dispersion compensation for the signal formats, return to zero (RZ), non-return to zero (NRZ) and gaussian pulse using 100kms standard fiber and Fiber Bragg Grating (FBG). The performance characteristics like Q-factor from minimum bit error rate and eye diagrams at the output are obtained by simulating optical links using different signal formats. It is observed that the optical link with NRZ pulse offer maximum eye opening, Q-factor from minimum BER and the electrical SNR varies from 18.06 to 28.3 dB at -800 ps/km to -1600 ps/km respectively.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Image registration in the JPEG-compressed domain

Abstract: A novel approach for image mosaicing in the JPEG compressed domain is presented in this paper. This technique employs the Hausdorff Distance Metric (HDM) to compute the regions of overlap between two JPEG images. The DCT blocks of the two overlapping images having significant activity are identified using a variance measure and the HDM metric is employed directly between these DCT blocks to estimate the translation parameter. The results obtained demonstrate reduction in the time taken for the registration step by a factor of 10-30, as compared to a traditional feature-based approach in the uncompressed domain.

Mosaicing MPEG video sequences

Abstract: Video Mosaicing is the process of obtaining single unified picture from multiple frames of a video sequence. It involves finding the geometric transformation parameters between frames and aligning them to form a single image representing content of full video. The proposed mosaicing method takes advantage of the information encoded by MPEG in the form of motion vectors, DCT blocks and the error information for generating the mosaics. Only the motion vectors corresponding to blocks of high activity region are considered for finding affine parameters. The feasibility of the method has been tested on panorama views from various MPEG sequences. The performance of proposed method was evaluated against the existing uncompressed domain methods.

Study of mode shapes and measurement of vibrations in square plates using DSPI and wavelet transform

Abstract: In this paper the study of out-of-plane or transverse vibrations in a square plate using digital speckle pattern interferometry (DSPI) is presented. To improve the accuracy of measurement, earlier we have suggested filtering scheme based on proper use of average/median filters followed by Symlet wavelet filter. In this paper we present a different filtering scheme to reduce the speckle noise and improve the accuracy of measurement of DSPI fringes by proper choice of average filter, sampling and thresholding followed by Symlet/Biorthogonal wavelet filter. The speckle index of filtered pattern is calculated and compared with speckle index of unfiltered fringe pattern. It is observed that speckle index is significantly reduced after filtering the DSPI fringe pattern. Experimentally obtained resonance frequencies for the square plate for the boundary condition fixed at all edges were compared with that of classical theory for thin plates. The resonance frequencies obtained from DSPI show good agreement with that of obtained from the classical theory.

Mosaicing of MPEG compressed video: a unified approach

Abstract: The mosaicing system proposed in this paper consists of a temporal segmentation module and a motion estimation module carried out in the MPEG (1&2) domain. The input MPEG video is temporally segmented into shots by the segmentation module and each shot is mosaiced separately. The output of the system is a set of mosaics, each of which captures the panorama of each shot uniquely. The camera motion parameters are computed for each shot using the MPEG motion vectors; frames from a shot are then aligned and integrated into a static mosaic for each shot. The proposed system is 200-300% faster in executing the registration step for our input video sequences.

Information Theory and its Two basic Applications

Abstract: Entropy, relative entropy and mutual information which are three fundamental quantities in information theory are discussed. The difference between entropy of an information source and thermodynamic entropy is given. The meaning of the term information source is discussed in detail. Two applications of information theory: data compression and data transmission are given. Entropy also gives the lower limit up to which lossless compression can be achieved. When rate of transmission is less than or equal to the capacity of the channel, reliable communication can be obtained on a noisy channel. The theoretical limits given by information theory motivate researchers to find new practical systems to reach closer to these limits.