482 research outputs found

    Double Relaxation via AdS/CFT

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    We exploit the AdS/CFT correspondence to investigate thermalization in an N=2 strongly coupled gauge theory including massless fundamental matter (quark). More precisely, we consider the response of a zero temperature state of the gauge theory under variation of an external electric field leading to a time-dependent current. The holographic dual of the above set-up is given by introducing a time-dependent electric field on the probe D7-brane embedded in an AdS_5 X S^5 background. In the dual gravity theory, due to a time-dependent electric field an apparent horizon forms on the brane which, according to AdS/CFT dictionary, is the counterpart of the thermalization process in the gauge theory. We classify different functions for time-dependent electric field and study their effect on the apparent horizon formation. In the case of pulse functions where the electric field varies from zero to zero, apart from non-equilibrium phase, we observe that two apparent horizons form on the brane. On the gauge theory side, it means that the state of the gauge theory experiences two different temperatures during the time evolution.Comment: 28 pages, 13 figures, published versio

    Al-Quran recitation speech signals time series segmentation for speaker adaptation using dynamic time warping

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    The transformation of the whole traditional process of Al-Quran Recitation into automated system application could raise the issues of robustness and integrity of recitation and correction quality and acceptance. There are several existing variations especially involve of rhythm, tone and length of recitation for different speaker. Dynamic Time warping (DTW) is used as dynamic programming to normalize the recitation speech length of speaker which warp the speech spectrum amplitude in time series for the experts and learners. DTW is used to gain the same length of recitation which warp the amplitudes, rhythm and tone into same length in time series segments based on formant frequency frame for different recitation speakers. There are 8 experts and 10 users from the Malay Muslim community had three selected surahs for Al-Quran recitation session. The aim of the paper is to normalize Al-Quran recitation speech signals as speaker adaption between experts and learner then represent each recitation speech signal at same vocal tract formant frequency that can be used in robust Automatic Recitation Recognition (ARR) to evaluate the performance of recitation evaluation.Keywords: Al-Quran speech recitation, Automatic Recitation Recognition, speaker adaptation, vocal tract length normalizatio

    Influence of thermal radiation on unsteady MHD free convection flow of jeffrey fluid over a vertical plate with ramped wall temperature

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    Influence of thermal radiation on unsteady magnetohydrodynamic (MHD) free convection flow of Jeffrey fluid over a vertical plate with ramped wall temperature is studied. The Laplace transform technique is used to obtain the analytical solutions. Expressions for skin friction and Nusselt number are also obtained. Results of velocity and temperature distributions are shown graphically for embedded parameters such as Jeffrey fluid parameter , Prandtl number P r, Grashof number G r, Hartmann number H a, radiation parameter R d, and dimensionless time τ. It is observed that the amplitude of velocity and temperature profile for isothermal are always higher than ramped wall temperature

    What are we paying for? A cost-effectiveness analysis of patented denosumab and generic alendronate for postmenopausal osteoporotic women in Australia

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    Zoledronic acid and denosumab were funded by the Australian government for the management of osteoporosis at an equivalent price to alendronate. The price of alendronate has declined by around 65 %, but the price of the other two therapies has remained stable. Using data published since the listing, this paper reports current estimates of the value of denosumab compared to alendronate from an Australian health system perspective.A cohort-based state transition model was developed that predicted changes in bone mineral density (BMD), and calibrated fracture probabilities as a function of BMD, age and previous fracture to estimate differences in costs and QALYs gained over a 10-year time horizon.The base-case incremental cost per QALY gained for denosumab versus alendronate was 246,749.Thereisanearzeroprobabilitythatdenosumabiscosteffectiveatathresholdvalueof246,749. There is a near zero probability that denosumab is cost-effective at a threshold value of 100,000 per QALY gained. If the price of denosumab was reduced by 50 %, the incremental cost per QALY gained falls to $50,068.Current Australian legislation precludes price reviews when comparator therapies come off patent. The presented analysis illustrates a review process, incorporating clinical data collected since the original submission to inform a price at which denosumab would provide value for money.Jonathan Karnon, Ainul Shakirah Shafie, Nneka Orji and Sofoora Kawsar Usma

    Numerical solution of unsteady free convection flow in a second grade fluid

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    In this paper, the problem of unsteady free convection flow moves along a vertical plate in a second grade fluid is studied. The vertical plate with constant temperature is considered. The dimensional governing equations are transformed into non dimensional equations using appropriate dimensionless variables and solved numerically using Finite Difference Method. Numerical results for velocity and temperature profiles are displayed graphically for viscoelastic parameter, Grashof number and Prandtl number and discussed in details. It is found that, increasing the values of Grashof number and time leads to increase in the velocity profiles. Increasing the values of the Prandtl number and viscoelastic parameter is found to decrease the velocity profile. It is further found that, increasing the values of Prandtl number tends to decrease the thermal boundary layer thickness

    Analysis of heat transfer for unsteady MHD free convection flow of rotating Jeffrey nanofluid saturated in a porous medium

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    In this article, the influence of thermal radiation on unsteady magnetohydrodynamics (MHD) free convection flow of rotating Jeffrey nanofluid passing through a porous medium is studied. The silver nanoparticles (AgNPs) are dispersed in the Kerosene Oil (KO) which is chosen as conventional base fluid. Appropriate dimensionless variables are used and the system of equations is transformed into dimensionless form. The resulting problem is solved using the Laplace transform technique. The impact of pertinent parameters including volume fraction φ, material parameters of Jeffrey fluid λ1, λ, rotation parameter r, Hartmann number Ha, permeability parameter K, Grashof number Gr, Prandtl number Pr, radiation parameter Rd and dimensionless time t on velocity and temperature profiles are presented graphically with comprehensive discussions. It is observed that, the rotation parameter, due to the Coriolis force, tends to decrease the primary velocity but reverse effect is observed in the secondary velocity. It is also observed that, the Lorentz force retards the fluid flow for both primary and secondary velocities. The expressions for skin friction and Nusselt number are also evaluated for different values of emerging parameters. A comparative study with the existing published work is provided in order to verify the present results. An excellent agreement is found

    Hybrid renewable energy power system model based on electrification requirements of one Fathom bank Malaysia

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    Renewable energy resources are becoming inexorably in the field of generating electrical power due to the fast development of technology, given to its advantages over non-renewable energy resources. Though the source is available in enormous amount, energy produced from single renewable energy resources such as tidal current may fluctuate with the time and the hour of the day or month, depending on the tides. Thus, by having a hybrid power system consisting two or more renewable energy resources coming into play at the same time would be more reliable to support the targeted area. However, the availability of renewable energies depends on the climate change, therefore having a storage battery or backup power is often essential. In this case, the main purpose of this research is to develop an off-grid hybrid tidal current and solar power system along with backup power to support One Fathom Bank Lighthouse in Malaysia with the intention to reduce the dependency on diesel generators. Having the ability to evaluate economic and technical feasibility of power system, HOMER software is used to run simulation and analyze the best combination of components to form a hybrid power system for the lighthouse. The results are based on the best components and sizing in compliance with the load demand and diesel fuel consumption to provide a reliable and cost-effective system

    Design and development of plasma antenna for wi-fi application

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    The term plasma is often referred to as the fourth state of matter. When sufficient ionized, plasma can be a conductor element. Plasma antenna is a type of radio antenna that represents the use of ionized gas as a conducting medium instead of metal conductors. The main objective in this research is to design plasma antenna at 2.4 GHz by using commercial fluorescent tube. In this work the commercial fluorescent lamp was chosen because it was low cost to produce plasma element. The plasma antenna in this research was made from fluorescent lamp that functioned as a radiating element with target frequency at 2.4 GHz for Wi-Fi application. The commercial fluorescent lamp consisted of argon gas and mercury vapor with a diameter of 28 mm and a length 589.8 mm. The result showed that a fluorescent tube, can be used to work as a plasma antenna for Wi-Fi application.Keywords: plasma antenna; plasma element; coupling sleeve; Wi-fi applicatio

    Adaptive background reconstruction for street surveillance

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    In recent years, adaptive background reconstruction works have found interest in many researchers. However, the existing algorithms that have been proposed by other researchers still in the early stage of development and many aspects need to be improved. In this paper, an adaptive background reconstruction is presented. Past pixel observation is used. The proposed algorithm also has eliminated the need of the pre-training of non-moving objects in the background. The proposed algorithm is capable of reconstructing the background with moving objects in video sequence. Experimental results show that the proposed algorithms are able to reconstruct the background correctly and handle illumination and adverse weather that modifies the background

    PGI15 Comparison of Knowledge, Attitude and Practice Among Hepatitis-B Patients and Healthy Population Regarding Hepatitis-B

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