108 research outputs found
Task level disentanglement learning in robotics using βVAE
Humans observe and infer things in a disentanglement way. Instead of remembering all pixel by pixel, learn things with factors like shape, scale, colour etc. Robot task learning is an open problem in the field of robotics. The task planning in the robot workspace with many constraints makes it even more challenging. In this work, a disentanglement learning of robot tasks with Convolutional Variational Autoencoder is learned, effectively capturing the underlying variations in the data. A robot dataset for disentanglement evaluation is generated with the Selective Compliance Assembly Robot Arm. The disentanglement score of the proposed model is increased to 0.206 with a robot path position accuracy of 0.055, while the state-of-the-art model (VAE) score was 0.015, and the corresponding path position accuracy is 0.053. The proposed algorithm is developed in Python and validated on the simulated robot model in Gazebo interfaced with Robot Operating System
Realization of Programmable BPSK Demodulator-Bit Synchronizer using Multirate Processing
This paper presents the design and implementation of programmable BPSK demodulator and bit synchronizer. The demodulator is based on the Costas loop design whereas the bit synchronizer is based on Gardner timing error detector. The advantage of this design is that it offers programmability using multi-rate processing and does not rely on computation of filter coefficients, NCO angle input for each specific data rate and thus avoids computational complexities. The algorithm and its application were verified on Matlab-Simulink and was implemented on ALTERA platform. A 32 kHz BPSK demodulator–bit synchronizer pair catering for data rates from 1 kbps to 8 kbps was implemented.DOI:http://dx.doi.org/10.11591/ijece.v4i3.556
Profile of pharmacological effects of combination of buspirone with selected antidepressants: a behavioral study in mice
Background: Antidepressants are commonly prescribed drugs. Co-existing disorders like anxiety require therapy with other drugs. The profiles of pharmacological effects of these drugs on central nervous system are influenced by the administration of these drugs either as single or combination. This study is designed to observe the behavioral effects of antidepressants along with the antianxiety agent buspirone in mice.Methods: Four antidepressant drugs belonging to different groups are selected for the study. Amitriptyline, citalopram, venlafaxine and mirtazapine are given orally for 2 weeks. Subsequently, buspirone is added to each antidepressant drug for a period of 3 weeks. The behavioral effects in mice are observed at weekly intervals using photoactometer, rotarod, forced swim test and elevated plus maze.Results: The antidepressant drugs amitriptyline and citalopram showed any change in spontaneous motor activity recorded by photoactometer. In rotarod test venlafaxine showed an increase in values, which showed further increase when buspirone was added. In the forced swim test also, venlafaxine showed a different pattern of effects when compared to other antidepressants. In the elevated plus maze test, the four antidepressants did not show any increase in the time spent in open arm excepting citalopram. Venlafaxine showed an increase in time spent in closed arm.Conclusions: The test drugs do not show any significant depression of central nervous system at the dose used. Venlafaxine showed a different pattern of activity in the rotarod test and swim test. The variation in response is attributed to their effects on central neurotransmitter
Very low thermal conductivity in lanthanum phosphate-zirconia ceramic nanocomposites processed using a precipitation-peptization synthetic approach
A wet chemical synthetic approach involving precipitation-peptization mechanisms was successfully adopted for the development of LaPO4-ZrO2 nanocomposites with the ZrO2 content varying in the 5-20 wt% range. Stoichiometric lanthanum phosphate, formed as nanofibrils during the precipitation reaction with orthophosphoric acid, was subsequently transformed into nanorods of ~10 nm width and <100 nm length upon peptization at pH 2. Zirconia dispersions were homogeneously incorporated as ultrafine particulates through zirconium oxychloride hydrolysis using ammonia. The nanocomposite precursor thus obtained could be densified to >98% TD for the LaPO4-10 wt% ZrO2 composition upon sintering at 1600 °C. The addition of ZrO2 to LaPO4 impeded densification and grain growth inhibition of up to 50% was obtained for LaPO4-20 wt% ZrO2 nanocomposites. Furthermore, the nanocomposites indicated very low thermal conductivity values (1 W m-1 K-1) compared to single phase LaPO4. The non-reactivity of LaPO4 and ZrO2 at high temperatures and the low thermal conductivity values of LaPO4-ZrO2 render them effective for high temperature thermal insulation applications. © 2016 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique
Unique occurrence of large-sized diamondback squid Thysanoteuthis rhombus (Troschel, 1857) in the Gulf of Mannar
The presence of the large-sized diamondback squid Thysanoteuthis rhombus (Troschel, 1857) in the Gulf of Mannar biosphere was confirmed after a two-decade absence, based on a single specimen observed during landings at the Pamban lighthouse Fish Landing Centre. A squid measuring 633 mm in mantle length and weighing 15.1 kg was caught in the hook and line at a depth of 20 m. The discovery of this species in the Gulf of Mannar unequivocally confirms that the population is still present in the ecosyste
Hydrothermal syntheses of tungsten doped TiO 2 and TiO 2 /WO 3 composite using metal oxide precursors for charge storage applications
Synthesis of advanced functional materials through scalable processing routes using greener approaches is essential for process and product sustainability. In this article, syntheses of nanoparticles of titanium dioxide (TiO₂), tungsten trioxide (WO₃), WO₃-doped titanium dioxide (W-TiO₂) and TiO₂/WO₃ composite at hydrothermal conditions using corresponding metal oxide precursors are described. Electrochemical charge storage capabilities of the above materials are measured using cyclic voltammetry, charge-discharge cycling and electrochemical impedance spectroscopy in aqueous KOH electrolyte. The TiO₂ and the WO₃ nanoparticle showed a specific charge (Q) of ∼12 and ∼36 mA h g⁻¹ at a current density of 2 A g⁻¹ in 6 M KOH, respectively. The Q of TiO₂ increased upon W doping up to 25 mA h g−1 for 5 wt% W-TiO2 and the WO₃/TiO₂ composite showed the highest storage capability (Q ∼40 mA h g⁻¹). Changes in the charge storage capabilities of the doped and composite materials have been correlated to materials properties.Bhupender Pal acknowledges the Research & Innovation
Department of Universiti Malaysia Pahang (http://ump.edu.my) for award of Postdoctoral Fellowship. This project is funded under Flagship Strategic Leap 3 of Universiti Malaysia Pahang (Grant Number # RDU 172201)
Large Scale Synthesis of Binary Composite Nanowires in the Mn2O3-SnO2 System with Improved Charge Storage Capabilities
Large scale production of electrochemical materials in non-conventional morphologies such as nanowires has been a challenging issue. Besides, functional materials for a given application do not often offer all properties required for ideal performance; therefore, a composite is the most sought remedy. In this paper, we report large scale production of a composite nanowire, viz. Mn2O3-SnO2, and their constituent binary nanowires by a large scale electrospinning pilot plant consisting of 100 needles. Electrochemical characterization of thus produced composite nanowires showed nearly threefold increase in the discharge capacity compared to their single component counterparts: Mn2O3-SnO2 ∼53 mA h g−1 (specific capacitance, CS ∼384 F g−1); Mn2O3 ∼18 mA h g−1 (CS ∼164 F g−1); and SnO2 ∼14 mA h g−1 (CS ∼128 F g−1) at 1 A g−1 in 6 M KOH. The EIS studies showed that the characteristic resistances and time of the composite electrode are appreciably lower than their constituents. Owing to the scalability of the synthesis processes and promising capacitive properties achieved would lead the composite material as a competitive low-cost and high-performance supercapacitor electrode
Nanoparticles: tech trends in healthcare
Nanotechnology is the use of matter on an atomic, molecular, and supramolecular scale for various purposes. Nanotechnology field of application is very much diverse which includes surface science, organic chemistry, molecular biology, semiconductor physics, energy storage, engineering, microfabrication, and molecular engineering. Its medical application ranges from biological devices, nano-electronic biosensors, and to future biological machines. The main issue nowadays for nanomedicine involve understanding the issues related to toxicity and environmental impact of nanoscale materials. Lot more functionalities can be added to nanomaterials by interfacing them with biological structures. The size of nanomaterials is similar most biological molecules and so useful for both in vivo and in vitro biomedical research and applications. The integration of nanomaterials with biology had paved path to the development of diagnostic devices, contrast agents, analytical tools, physical therapy applications and drug delivery vehicles
Measurement and analysis of photonuclear reactions on thick target samples of biological importance
A novel method for quantification of trace elements in herbal samples using photon activation analysis is reported. Seven trace elements have been detected and their concentrations have been estimated from residue yields after the photo-nuclear reaction. This method can complement the conventional neutron activation analysis for trace elemental detection. The data is useful for setting referral standards for quality assurance of herbs and herbal formulations commercially available for therapeutic purposes. This is a relatively simple, novel and sensitive method for trace elemental analysis which can be scaled to suit industrial and statutory requirements of standardization and quality control
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