549 research outputs found
A knowledge-based machine vision system for space station automation
A simple knowledge-based approach to the recognition of objects in man-made scenes is being developed. Specifically, the system under development is a proposed enhancement to a robot arm for use in the space station laboratory module. The system will take a request from a user to find a specific object, and locate that object by using its camera input and information from a knowledge base describing the scene layout and attributes of the object types included in the scene. In order to use realistic test images in developing the system, researchers are using photographs of actual NASA simulator panels, which provide similar types of scenes to those expected in the space station environment. Figure 1 shows one of these photographs. In traditional approaches to image analysis, the image is transformed step by step into a symbolic representation of the scene. Often the first steps of the transformation are done without any reference to knowledge of the scene or objects. Segmentation of an image into regions generally produces a counterintuitive result in which regions do not correspond to objects in the image. After segmentation, a merging procedure attempts to group regions into meaningful units that will more nearly correspond to objects. Here, researchers avoid segmenting the image as a whole, and instead use a knowledge-directed approach to locate objects in the scene. The knowledge-based approach to scene analysis is described and the categories of knowledge used in the system are discussed
Bayesian network based computer vision algorithm for traffic monitoring using video
This paper presents a novel approach to estimating the 3D velocity of vehicles from video. Here we propose using a Bayesian Network to classify objects into pedestrians and different types of vehicles, using 2D features extracted from the video taken from a stationary camera. The classification allows us to estimate an approximate 3D model for the different classes. The height information is then used with the image co-ordinates of the object and the camera's perspective projection matrix to estimate the objects 3D world co-ordinates and hence its 3D velocity. Accurate velocity and acceleration estimates are both very useful parameters in traffic monitoring systems. We show results of highly accurate classification and measurement of vehicle's motion from real life traffic video streams.Kumar, P.; Ranganath, S.; Weimin, H
Framework for real time behavior interpretation from traffic video
© 2005 IEEE.Video-based surveillance systems have a wide range of applications for traffic monitoring, as they provide more information as compared to other sensors. In this paper, we present a rule-based framework for behavior and activity detection in traffic videos obtained from stationary video cameras. Moving targets are segmented from the images and tracked in real time. These are classified into different categories using a novel Bayesian network approach, which makes use of image features and image-sequence- based tracking results for robust classification. Tracking and classification results are used in a programmed context to analyze behavior. For behavior recognition, two types of interactions have mainly been considered. One is interaction between two or more mobile targets in the field of view (FoV) of the camera. The other is interaction between targets and stationary objects in the environment. The framework is based on two types of a priori information: 1) the contextual information of the camera’s FoV, in terms of the different stationary objects in the scene and 2) sets of predefined behavior scenarios, which need to be analyzed in different contexts. The system can recognize behavior from videos and give a lexical output of the detected behavior. It also is capable of handling uncertainties that arise due to errors in visual signal processing. We demonstrate successful behavior recognition results for pedestrian– vehicle interaction and vehicle–checkpost interactions.Kumar, P.; Ranganath, S.; Huang Weimin; Sengupta, K
Cooperative multitarget tracking with efficient split and merge handling
Copyright © 2006 IEEEFor applications such as behavior recognition it is important to maintain the identity of multiple targets, while tracking them in the presence of splits and merges, or occlusion of the targets by background obstacles. Here we propose an algorithm to handle multiple splits and merges of objects based on dynamic programming and a new geometric shape matching measure. We then cooperatively combine Kalman filter-based motion and shape tracking with the efficient and novel geometric shape matching algorithm. The system is fully automatic and requires no manual input of any kind for initialization of tracking. The target track initialization problem is formulated as computation of shortest paths in a directed and attributed graph using Dijkstra's shortest path algorithm. This scheme correctly initializes multiple target tracks for tracking even in the presence of clutter and segmentation errors which may occur in detecting a target. We present results on a large number of real world image sequences, where upto 17 objects have been tracked simultaneously in real-time, despite clutter, splits, and merges in measurements of objects. The complete tracking system including segmentation of moving objects works at 25 Hz on 352times288 pixel color image sequences on a 2.8-GHz Pentium-4 workstationPankaj Kumar, Surendra Ranganath, Kuntal Sengupta, and Huang Weimi
Thermomechanical effect in cholesteric liquid crystals
We discuss some possible experimental geometries for studying Leslie's thermomechanical effect in cholesteric liquid crystals. The discussion includes the effect of a temperature gradient (i) along and (ii) perpendicular to the helical axis. The feasibility of observing the effect and of extracting the thermomechanical coefficients is examined
PERCEIVED SOCIAL SUPPORT AMONG ELDERLY INDIVIDUALS RESIDING IN URBAN BENGALURU: A CROSS-SECTIONAL STUDY
Introduction
Increase in life expectancy results in an increasing elderly population which contributes to 9.3% of global population. With epidemiological transition of diseases, the burden of chronic morbidity conditions will also increase with an effect on Quality of life, which demands social support especially among elderly individuals. Hence the present study was taken up to assess social support among elderly individuals residing in urban field practice area of Bangalore Medical College & Research Institute (BMCRI), Bengaluru.
Objective: To assess the perceived social support among elderly population residing in the urban field practice area of BMCRI
Methodology:
A cross sectional study was conducted to assess the perceived social support among 100 elderly population residing in the urban field practice area of BMCRI. Simple random sampling technique was used. Data was collected using validated Multidimensional Scale of Perceived Social Support (MSPSS) questionnaire along with socio-demographic factors.
Results: In this study, the mean age of the elderly individuals was 67.0 + 5.90 years, total social support score was 59.2 + 17.97. Perceived social support was found to be statistically significant found between characteristics gender, educational status, marital status, earning status, marital status, earning status, support obtained for medication and previous hospitalization. (p<0.05
Controlled Inhibition of the Mesenchymal Stromal Cell Pro-inflammatory Secretome via Microparticle Engineering
Mesenchymal stromal cells (MSCs) are promising therapeutic candidates given their potent immunomodulatory and anti-inflammatory secretome. However, controlling the MSC secretome post-transplantation is considered a major challenge that hinders their clinical efficacy. To address this, we used a microparticle-based engineering approach to non-genetically modulate pro-inflammatory pathways in human MSCs (hMSCs) under simulated inflammatory conditions. Here we show that microparticles loaded with TPCA-1, a small-molecule NF-κB inhibitor, when delivered to hMSCs can attenuate secretion of pro-inflammatory factors for at least 6 days in vitro. Conditioned medium (CM) derived from TPCA-1-loaded hMSCs also showed reduced ability to attract human monocytes and prevented differentiation of human cardiac fibroblasts to myofibroblasts, compared with CM from untreated or TPCA-1-preconditioned hMSCs. Thus, we provide a broadly applicable bioengineering solution to facilitate intracellular sustained release of agents that modulate signaling. We propose that this approach could be harnessed to improve control over MSC secretome post-transplantation, especially to prevent adverse remodeling post-myocardial infarction.United States. National Institutes of Health (HL097172)United States. National Institutes of Health (HL095722
Pheromone Trapping Protocols for Brinjal Shoot and Fruit Borer, Leucinodes orbonalis Guenee (Lepidoptera: Pyralidae): Evaluation of Trap Design, Quantity and Dispenser
Studies were conducted at the Indian Institute of Horticultural Research, Bangalore, and Central Horticultural Experiment Station, Bhubaneshwar, India, to evaluate trap design, quantity of pheromone loading and dispensers for attracting brinjal shoot and fruit borer, Leucinodes orbonalis Guenee (Lepidoptera: Pyralidae) using indigenously synthesized pheromone lure [synthesized by Indian Institute of Chemical Technology (IICT), Hyderabad], during 2003 and 2004. A water trap consisting of plastic container (20 cm dia. and 7.5 cm depth) with a facility to place the pheromone septum was designed. Pheromone load of 4 mg in both water trap and Pest Control India (PCI®) delta trap was observed to catch higher number of male moths compared to dispensers with lesser loading. When trap designs were compared, water trap with pheromone lure was observed to attract higher number of males than Pest Control India (PCI®) delta trap. Among the different pheromone dispensers tested, rubber septum was superior to plastic vial or plastic septum. Rubber septum supplied by Bio Pest Management® captured significantly higher number of moths compared to rubber and plastic septum supplied by difTerent firms. A comparison of IICT synthesized lures along with some commercially available lures indicated that Bio Pest Management® lure dispensed in rubber outperformed PCI® and IICT lures
Dietary restriction of tyrosine and phenylalanine lowers tyrosinaemia associated with nitisinone therapy of alkaptonuria.
BACKGROUND: Alkaptonuria (AKU) is caused by homogentisate 1,2-dioxygenase deficiency that leads to homogentisic acid (HGA) accumulation, ochronosis and severe osteoarthropathy. Recently, nitisinone treatment, which blocks HGA formation, has been effective in AKU patients. However, a consequence of nitisinone is elevated tyrosine that can cause keratopathy. The effect of tyrosine and phenylalanine dietary restriction was investigated in nitisinone-treated AKU mice, and in an observational study of dietary intervention in AKU patients. METHODS: Nitisinone-treated AKU mice were fed tyrosine/phenylalanine-free and phenylalanine-free diets with phenylalanine supplementation in drinking water. Tyrosine metabolites were measured pre-nitisinone, post-nitisinone, and after dietary restriction. Subsequently an observational study was undertaken in 10 patients attending the National Alkaptonuria Centre (NAC), with tyrosine >700μmol/L who had been advised to restrict dietary protein intake and where necessary, to use tyrosine/phenylalanine-free amino acid supplements. RESULTS: Elevated tyrosine (813μmol/L) was significantly reduced in nitisinone-treated AKU mice fed a tyrosine/phenylalanine-free diet in a dose responsive manner. At 3 days of restriction, tyrosine was 389.3μmol/L, 274.8μmol/L and 144.3μmol/L with decreasing phenylalanine doses. In contrast, tyrosine was not effectively reduced in mice by a phenylalanine-free diet; at 3 days tyrosine was 757.3μmol/L, 530.2μmol/L and 656.2μmol/L, with no dose response to phenylalanine supplementation. In NAC patients, tyrosine was significantly reduced (p=0.002) when restricting dietary protein alone, and when combined with tyrosine/phenylalanine-free amino acid supplementation; 4 out of 10 patients achieved tyrosine <700μmol/L. CONCLUSION: Tyrosine/phenylalanine dietary restriction significantly reduced nitisinone-induced tyrosinaemia in mice, with phenylalanine restriction alone proving ineffective. Similarly, protein restriction significantly reduced circulating tyrosine in AKU patients
Surface-plasmon-polariton wave propagation supported by anisotropic materials: multiple modes and mixed exponential and linear localization characteristics
The canonical boundary-value problem for surface-plasmon-polariton (SPP)
waves guided by the planar interface of a dielectric material and a plasmonic
material was solved for cases wherein either partnering material could be a
uniaxial material with optic axis lying in the interface plane.Numerical
studies revealed that two different SPP waves, with different phase speeds,
propagation lengths, and penetration depths, can propagate in a given direction
in the interface plane; in contrast, the planar interface of isotropic
partnering materials supports only one SPP wave for each propagation direction.
Also, for a unique propagation direction in each quadrant of the interface
plane, it was demonstrated that a new type of SPP wave--called a
surface-plasmon-polariton-Voigt (SPP-V) wave--can exist. The fields of these
SPP-V waves decay as the product of a linear and an exponential function of the
distance from the interface in the anisotropic partnering material; in
contrast, the fields of conventional SPP waves decay only exponentially with
distance from the interface. Explicit analytic solutions of the dispersion
relation for SPP-V waves exist and help establish constraints on the
constitutive-parameter regimes for the partnering materials that support
SPP-V-wave propagation
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