1,238 research outputs found

    ICT Tools for building Digital Learning Environment

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    The paper presents brief information about recent advances in information technology, components of IT that facilitated the building of digital learning environment. Various ICT-based enabling technologies that can be used for information storage, handling and dissemination have been discussed

    A two-fluid actuarial model with an alternating payoff policy

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    A two-fluid actuarial model with an alternating payoff polic

    Price of anarchy in non-cooperative load balancing games

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    We investigate the price of anarchy of a load balancing game with K dispatchers. The service rates and holding costs are assumed to depend on the server, and the service discipline is assumed to be processor-sharing at each server. The performance criterion is taken to be the weighted mean number of jobs in the system, or equivalently, the weighted mean sojourn time in the system. Independent of the state of the servers, each dispatcher seeks to determine the routing strategy that optimizes the performance for its own traffic. The interaction of the various dispatchers thus gives rise to a non-cooperative game. For this game, we first show that, for a fixed amount of total incoming traffic, the worst-case Nash equilibrium occurs when each player routes exactly the same amount of traffic, i.e., when the game is symmetric. For this symmetric game, we provide the expression for the loads on the servers at the Nash equilibrium. Using this result, we then show that, for a system with two or more servers, the price of anarchy, which is the worst-case ratio of the global cost of the Nash equilibrium to the global cost of the centralized setting, is lower bounded by K(2√K-1) and upper bounded by √K, independent of the number of servers

    A fluctuation theory for Markov chains

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    A fluctuation theory for Markov chains on an ordered countable state space is developed, using ladder processes. These are shown to be Markov renewal processes. Results are given for the joint distribution of the extremum (maximum or minimum) and the first time the extremum is achieved. Also a new classification of the states of a Markov chain is suggested. Two examples are given

    Characterizing multiparticle entanglement in symmetric N-qubit states via negativity of covariance matrices

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    We show that higher order inter-group correlations involving even number of qubits are necessarily positive semidefinite for separable symmetric N qubit states. This identification leads to a family of inseparability conditions based on the negativity of 2kth order inter-group covariance matrices of symmetric N-qubit systems. These conditions have a simple structure and detect multiparty entanglement in both pure and mixed symmetric multiqubit states. The correlation observables involved are feasible experimental quantities and do not demand full state determination through quantum state tomography

    Dielectrophoresis-Based Particle Sensor Using Nanoelectrode Arrays

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    A method has been developed for concentrating, or partly separating, particles of a selected species from a liquid or gas containing these particles, and flowing in a channel. An example of this is to promote an accumulation (and thus concentration) of the selected particle (e.g., biological species such as E. coli, salmonella, anthrax, tobacco mosaic virus or herpes simplex, and non-biological materials such as nano- and microparticles, quantum dots, nanowires, nano - tubes, and other inorganic particles) adjacent to the first surface. Additionally, this method can also determine if the particle species is present in the liquid. This is accomplished by providing an insulating material in an interstitial volume between two or more adjacent nanostructure electrodes. It can also be accomplished by providing a functionalizing substance, located on a selected region of the insulating material surface, which promotes attachment of the selected species particles to the functionalized surface, and measuring a selected electrical property such as electrical impedance, conductance, or capacitance. A time-varying electrical field E, having a root-mean-square intensity of E(sup 2) rms, with a non-zero gradient in a direction transverse to the liquid or fluid flow direction, is produced by a nanostructure electrode array with a very high-magnitude gradient near exposed electrode tips. A dielectrophoretic force causes the selected particles to accumulate near the electrode tips, if the medium and selected particles have substantially different dielectric constants. An insulating material surrounds most of the nanostructure electrodes, and a region of the insulating material surface is functionalized to promote attachment of the selected particle species to the surface. An electrical property value Z(meas) is measured at the functionalized surface, and is compared with a reference value Z(ref) to determine if the selected species particles are attached to the functionalized surface. Some advantages of this innovation are that an array of nanostructure electrodes can provide an electric field intensity gradient that is one or more orders of magnitude greater than the corresponding gradient provided by a conventional microelectrode arrangement, and that, as a result of the high-magnitude field intensity gradients, a nanostructure concentrator can trap particles from high-speed microfluidic flows. This is critical for applications where the entire analysis must be performed in a few minute

    MUCOADHESIVE POLYMERIC FILMS OF ACYCLOVIR PRONIOSOMES FOR BUCCAL ADMINISTRATION

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    Objective: The aim of the present work was to formulate and evaluate proniosomes of the poorly soluble drug, acyclovir incorporated in mucoadhesive polymeric films for improved buccal mucosal permeability of the drug while achieving prolonged release. Methods: Acyclovir was formulated as proniosomes using Span 60 and cholesterol. The prepared proniosomes were loaded into mucoadhesive polymeric films prepared with varying quantities of carbopol 934P and HPMC K15M. The proniosome incorporated films were evaluated for physicomechanical characters, mucoadhesion, swelling index, drug content, in vitro drug release and ex vivo permeation through porcine buccal mucosa. Results: Hydration of the proniosomes produced spherical vesicles or niosomes, which was confirmed by Scanning Electron Microscopy. The optimized formulation selected on the basis of vesicle size, entrapment efficiency PDI, Zetz potential and in vitro drug release was selected for incorporation into mucoadhesive polymeric films. All the films showed excellent physicomechanical characters. Formulations with higher proportions of carbopol produced slower in vitro drug release. The kinetics of release of drug from all the formulations appeared to be zero-order based on their regression coefficient values. Comparative evaluation of ex vivo permeation from niosomal and non-niosomal films indicated that the former demonstrated improved mucosal permeation and drug release was also sustained for the 8 h period. Conclusion: Mucoadhesive films impregnated with acyclovir loaded proniosomes could be a potential approach for buccal delivery of acyclovir for improving its absorption and bioavailability.&nbsp

    A 3D Face Modelling Approach for Pose-Invariant Face Recognition in a Human-Robot Environment

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    Face analysis techniques have become a crucial component of human-machine interaction in the fields of assistive and humanoid robotics. However, the variations in head-pose that arise naturally in these environments are still a great challenge. In this paper, we present a real-time capable 3D face modelling framework for 2D in-the-wild images that is applicable for robotics. The fitting of the 3D Morphable Model is based exclusively on automatically detected landmarks. After fitting, the face can be corrected in pose and transformed back to a frontal 2D representation that is more suitable for face recognition. We conduct face recognition experiments with non-frontal images from the MUCT database and uncontrolled, in the wild images from the PaSC database, the most challenging face recognition database to date, showing an improved performance. Finally, we present our SCITOS G5 robot system, which incorporates our framework as a means of image pre-processing for face analysis
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