Search results for: waves
274 Developing Biocompatible Iridium Oxide Electrodes for Bone-Guided Extra-Cochlear Implant
Authors: Yung-Shan Lu, Chia-Fone Lee, Shang-Hsuan Li, Chien-Hao Liu
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Recently, various bioelectronic devices have been developed for neurologic disease treatments via electro-stimulations such as cochlear implants and retinal prosthesis. Since the electric signal needs electrodes to be transmitted to an organism, electrodes play an important role of stimulations. The materials of stimulation electrodes affect the efficiency of the delivered currents. The higher the efficiency of the electrodes, the lower the threshold current can be used to stimulate the organism which minimizes the potential damages to the adjacent tissues. In this study, we proposed a biocompatible composite electrode composed of high-charge-capacity iridium oxide (IrOₓ) film for a bone-guide extra-cochlear implant. IrOₓ was exploited to decrease the threshold current due to its high capacitance and low impedance. The IrOₓ electrode was fabricated via microelectromechanical systems (MEMS) photolithography and examined with in-vivo tests with guinea pigs. Based on the measured responses of brain waves to sound, the results demonstrated that IrOₓ electrodes have a lower threshold current compared with the Platinum (Pt) electrodes. The research results are expected to be beneficial for implantable and biocompatible electrodes for electrical stimulations.Keywords: cochlear implants, electrode, electrical stimulation, iridium oxide
Procedia PDF Downloads 189273 Hall Coefficient in the Presence of Strong Electromagnetic Waves Caused by Confined Electrons and Phonons in a Rectangular Quantum Wire
Authors: Nguyen Quang Bau, Nguyen Thu Huong, Dang Thi Thanh Thuy
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The analytic expression for the Hall Coefficient (HC) caused by the confined electrons in the presence of a strong electromagnetic wave (EMW) including the effect of phonon confinement in rectangular quantum wires (RQWs) is calculated by using the quantum kinetic equation for electrons in the case of electron - optical phonon scattering. It is because the expression of the HC for the confined phonon case contains indexes m, m’ which are specific to the phonon confinement. The expression in a RQW is different from that for the case of unconfined phonons in a RQW or in 2D. The results are numerically calculated and discussed for a GaAs/GaAsAl RQW. The numerical results show that HC in a RQW can have both negative and positive values. This is different from the case of the absence of EMW and the case presence of EMW including the effect of phonon unconfinement in a RQW. These results are also compared with those in the case of unconfined phonons in a RQW and confined phonons in a quantum well. The conductivity in the case of confined phonon has more resonance peaks compared with that in case of unconfined phonons in a RQW. This new property is the same in quantum well. All results are compared with the case of unconfined phonons to see differences.Keywords: Hall coefficient, rectangular quantum wires, electron-optical phonon interaction, quantum kinetic equation, confined phonons
Procedia PDF Downloads 280272 Acoustic Blood Plasmapheresis in Polymeric Resonators
Authors: Itziar Gonzalez, Pilar Carreras, Alberto Pinto, Roque Ruben Andres
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Acoustophoretic separation of plasma from blood is based on a collection process of the blood cells, driven by an acoustic radiation force. The number of cells, their concentration, and the sample hydrodynamics are involved in these processes. However, their influence on the acoustic blood response has not yet been reported in the literature. Addressing it, this paper presents an experimental study of blood samples exposed to ultrasonic standing waves at different hematocrit levels and hydrodynamic conditions. The experiments were performed in a glass capillary (700µm-square cross section) actuated by a piezoelectric ceramic at 1MHz, hosting 2D orthogonal half-wavelength resonances transverse to the channel length, with a single-pressure-node along its central axis where cells collected driven by the acoustic radiation force. Four blood dilutions in PBS of 1:20, 1:10, 1:5, and 1:2 were tested at eight flow rate conditions Q=0:120µL/min. The 1:5 dilution (H=9%) demonstrated to be optimal for the plasmapheresis at any of the flow rates analyzed, requiring the shortest times to achieve plasma free of cells. The study opens new possibilities to optimize processes of plasmapheresis processes by ultrasounds at different hematocrit conditions in future personalized diagnoses/treatments involving blood samples.Keywords: ultrasounds, microfluidics, flow rate, acoustophoresis, polymeric resonators
Procedia PDF Downloads 135271 Time and Kinematics of Moving Bodies
Authors: Muhammad Omer Farooq Saeed
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The purpose of the proposal is to find out what time actually is! And to understand the natural phenomenon of the behavior of time and light corresponding to the motion of the bodies at relatively high speeds. The utmost concern of the paper is to deal with the possible demerits in the equations of relativity, thereby providing some valuable extensions in those equations and concepts. The idea used develops the most basic conception of the relative motion of the body with respect to space and a real understanding of time and the variation of energy of the body in different frames of reference. The results show the development of a completely new understanding of time, relative motion and energy, along with some extensions in the equations of special relativity most importantly the time dilation and the mass-energy relationship that will explain all frames of a body, all in one go. The proposal also raises serious questions on the validity of the “Principle of Equivalence” on which the General Relativity is based, most importantly a serious case of the bending light that eventually goes against its own governing concepts of space-time being proposed in the theory. The results also predict the existence of a completely new field that explains the fact just how and why bodies acquire energy in space-time. This field explains the production of gravitational waves based on time. All in all, this proposal challenges the formulas and conceptions of Special and General Relativity, respectively.Keywords: time, relative motion, energy, speed, frame of reference, photon, curvature, space-time, time –differentials
Procedia PDF Downloads 69270 Effect of Heat Stress on the Physiology of the Cork Oak
Authors: J. Zekri, N. Souilah, W. Abdelaziz, D. Alatou
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Our study shall focus on the ability of trees cork oak that showed vis-à-vis sensitivity to climate change, including late spring frosts. The combination of these factors resulted in damage alarmed, therefore forest ecosystems weakened trees that can affect their ability to support other abiotic and biotic stresses, For this we tested its tolerance to thermal variations and cold weather conditions by estimating some stress markers (quantification of proteins, RNA, soluble sugars) that are quantified to evaluate the cold tolerance of seedlings. Sowing of cork oak (Quercus suber L.) is grown in controlled conditions at 25° C ± 2° C in long days 16h. These seedlings are transferred at low temperatures between 5° C and -6° C for a period of 3 hours. Biochemical analyzes were performed in the various organs of the cork oak seedlings. Cool temperatures induced a significant accumulation of proline in different organs of seedlings and the optimum concentrations were observed in the roots with very high concentrations (4 times larger than those of the control). The accumulation of soluble sugars is significantly in stems and roots at 0° C. Protein concentrations are very high in leaves of both growth and high waves in rod at -4° C to -2° C. Tolerance cork oak seems to be at the thermal limit of -2°C. The concentration of these metabolites in the various organs showed the ability oak cork hardening during the winter.Keywords: climate change, thermal change, semi-aride, biochemical markers, heat stress
Procedia PDF Downloads 249269 High-Resolution ECG Automated Analysis and Diagnosis
Authors: Ayad Dalloo, Sulaf Dalloo
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Electrocardiogram (ECG) recording is prone to complications, on analysis by physicians, due to noise and artifacts, thus creating ambiguity leading to possible error of diagnosis. Such drawbacks may be overcome with the advent of high resolution Methods, such as Discrete Wavelet Analysis and Digital Signal Processing (DSP) techniques. This ECG signal analysis is implemented in three stages: ECG preprocessing, features extraction and classification with the aim of realizing high resolution ECG diagnosis and improved detection of abnormal conditions in the heart. The preprocessing stage involves removing spurious artifacts (noise), due to such factors as muscle contraction, motion, respiration, etc. ECG features are extracted by applying DSP and suggested sloping method techniques. These measured features represent peak amplitude values and intervals of P, Q, R, S, R’, and T waves on ECG, and other features such as ST elevation, QRS width, heart rate, electrical axis, QR and QT intervals. The classification is preformed using these extracted features and the criteria for cardiovascular diseases. The ECG diagnostic system is successfully applied to 12-lead ECG recordings for 12 cases. The system is provided with information to enable it diagnoses 15 different diseases. Physician’s and computer’s diagnoses are compared with 90% agreement, with respect to physician diagnosis, and the time taken for diagnosis is 2 seconds. All of these operations are programmed in Matlab environment.Keywords: ECG diagnostic system, QRS detection, ECG baseline removal, cardiovascular diseases
Procedia PDF Downloads 297268 Study of Electron Cyclotron Resonance Acceleration by Cylindrical TE₀₁₁ Mode
Authors: Oswaldo Otero, Eduardo A. Orozco, Ana M. Herrera
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In this work, we present results from analytical and numerical studies of the electron acceleration by a TE₀₁₁ cylindrical microwave mode in a static homogeneous magnetic field under electron cyclotron resonance (ECR) condition. The stability of the orbits is analyzed using the particle orbit theory. In order to get a better understanding of the interaction wave-particle, we decompose the azimuthally electric field component as the superposition of right and left-hand circular polarization standing waves. The trajectory, energy and phase-shift of the electron are found through a numerical solution of the relativistic Newton-Lorentz equation in a finite difference method by the Boris method. It is shown that an electron longitudinally injected with an energy of 7 keV in a radial position r=Rc/2, being Rc the cavity radius, is accelerated up to energy of 90 keV by an electric field strength of 14 kV/cm and frequency of 2.45 GHz. This energy can be used to produce X-ray for medical imaging. These results can be used as a starting point for study the acceleration of electrons in a magnetic field changing slowly in time (GYRAC), which has some important applications as the electron cyclotron resonance ion proton accelerator (ECR-IPAC) for cancer therapy and to control plasma bunches with relativistic electrons.Keywords: Boris method, electron cyclotron resonance, finite difference method, particle orbit theory, X-ray
Procedia PDF Downloads 159267 Covid Encephalopathy and New-Onset Seizures in the Context of a Prior Brain Abnormality: A Case Report
Authors: Omar Sorour, Michael Leahy, Thomas Irvine, Vladimir Koren
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Introduction: Covid encephalitis is a rare yet dangerous complication, particularly affecting the older and immunocompromised. Symptoms range from confusion to delirium, coma, and seizures. Although neurological manifestations have become more well-characterized in COVID patients, little is known about whether priorneurological abnormalities may predispose patients to COVID encephalopathy. Case Description: A 73 y.o. male with a CT and MRI-confirmed stable, prior 9 mm cavernoma in the right frontal lobe and no past history of seizures was hospitalized with generalized weakness, abdominal pain, nausea, and shortness of breath with subsequent COVID pneumonia. Three days after the initial presentation, the patient developed a spontaneous generalized tonic-clonic seizure consistent with presumed COVID encephalitis, along with somnolence and confusion. A day later, the patient had two other seizure episodes. Follow-up EEG suggested an inter-ictal epileptic focus with sharp waves corresponding to roughly the same location as the patient’s pre-existing cavernoma. The patient’s seizures stopped shortly thereafter, while his encephalopathy continued for days. Conclusion: We illustrate that a pre-existing anatomic cortical abnormality may act as a potential nidus for new-onset seizure activity in the context of suggested COVID encephalopathy. Future studies may further demonstrate that manifestations of COVIDencephalopathy in certain patients may be more predictable than initially assumed.Keywords: cavernoma, covid, encephalopathy, seizures
Procedia PDF Downloads 171266 Investigation on a Wave-Powered Electrical Generator Consisted of a Geared Motor-Generator Housed by a Double-Cone Rolling on Concentric Circular Rails
Authors: Barenten Suciu
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An electrical generator able to harness energy from the water waves and designed as a double-cone geared motor-generator (DCGMG), is proposed and theoretically investigated. Similar to a differential gear mechanism, used in the transmission system of the auto vehicle wheels, an angular speed differential is created between the cones rolling on two concentric circular rails. Water wave acting on the floating DCGMG produces and a gear-box amplifies the speed differential to gain sufficient torque for power generation. A model that allows computation of the speed differential, torque, and power of the DCGMG is suggested. Influence of various parameters, regarding the construction of the DCGMG, as well as the contact between the double-cone and rails, on the electro-mechanical output, is emphasized. Results obtained indicate that the generated electrical power can be increased by augmenting the mass of the double-cone, the span of the rails, the apex angle of the cones, the friction between cones and rails, the amplification factor of the gear-box, and the efficiency of the motor-generator. Such findings are useful to formulate a design methodology for the proposed wave-powered generator.Keywords: amplification of angular speed differential, circular concentric rails, double-cone, wave-powered electrical generator
Procedia PDF Downloads 156265 Advanced Driver Assistance System: Veibra
Authors: C. Fernanda da S. Sampaio, M. Gabriela Sadith Perez Paredes, V. Antonio de O. Martins
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Today the transport sector is undergoing a revolution, with the rise of Advanced Driver Assistance Systems (ADAS), industry and society itself will undergo a major transformation. However, the technological development of these applications is a challenge that requires new techniques and great machine learning and artificial intelligence. The study proposes to develop a vehicular perception system called Veibra, which consists of two front cameras for day/night viewing and an embedded device capable of working with Yolov2 image processing algorithms with low computational cost. The strategic version for the market is to assist the driver on the road with the detection of day/night objects, such as road signs, pedestrians, and animals that will be viewed through the screen of the phone or tablet through an application. The system has the ability to perform real-time driver detection and recognition to identify muscle movements and pupils to determine if the driver is tired or inattentive, analyzing the student's characteristic change and following the subtle movements of the whole face and issuing alerts through beta waves to ensure the concentration and attention of the driver. The system will also be able to perform tracking and monitoring through GSM (Global System for Mobile Communications) technology and the cameras installed in the vehicle.Keywords: advanced driver assistance systems, tracking, traffic signal detection, vehicle perception system
Procedia PDF Downloads 155264 New Modification Negative Stiffness Device with Constant Force-Displacement Characteristic for Seismic Protection of Structures
Authors: Huan Li, Jianchun Li, Yancheng Li, Yang Yu
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As a seismic protection method of civil and engineering structures, weakening and damping is effective during the elastic region, while it somehow leads to the early yielding of the entire structure accompanying with large excursions and permanent deformations. Adaptive negative stiffness device is attractive for realizing yielding property without changing the stiffness of the primary structure. In this paper, a new modification negative stiffness device (MNSD) with constant force-displacement characteristic is proposed by combining a magnetic negative stiffness spring, a piecewise linear positive spring and a passive damper with a certain adaptive stiffness device. The proposed passive control MNSD preserves no effect under small excitation. When the displacement amplitude increases beyond the pre-defined yielding point, the force-displacement characteristics of the system with MNSD will keep constant. The seismic protection effect of the MNSD is evaluated by employing it to a single-degree-of-freedom system under sinusoidal excitation, and real earthquake waves. By comparative analysis, the system with MNSD performs better on reducing acceleration and displacement response under different displacement amplitudes than the scenario without it and the scenario with unmodified certain adaptive stiffness device.Keywords: negative stiffness, adaptive stiffness, weakening and yielding, constant force-displacement characteristic
Procedia PDF Downloads 159263 Ground Response Analyses in Budapest Based on Site Investigations and Laboratory Measurements
Authors: Zsolt Szilvágyi, Jakub Panuska, Orsolya Kegyes-Brassai, Ákos Wolf, Péter Tildy, Richard P. Ray
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Near-surface loose sediments and local ground conditions in general have a major influence on seismic response of structures. It is a difficult task to model ground behavior in seismic soil-structure-foundation interaction problems, fully account for them in seismic design of structures, or even properly consider them in seismic hazard assessment. In this study, we focused on applying seismic soil investigation methods, used for determining soil stiffness and damping properties, to response analysis used in seismic design. A site in Budapest, Hungary was investigated using Multichannel Analysis of Surface Waves, Seismic Cone Penetration Tests, Bender Elements, Resonant Column and Torsional Shear tests. Our aim was to compare the results of the different test methods and use the resulting soil properties for 1D ground response analysis. Often in practice, there are little-to no data available on dynamic soil properties and estimated parameters are used for design. Therefore, a comparison is made between results based on estimated parameters and those based on detailed investigations. Ground response results are also compared to Eurocode 8 design spectra.Keywords: MASW, resonant column test, SCPT, site response analysis, torsional shear test
Procedia PDF Downloads 400262 Kids and COVID-19: They Are Winning With Their Immunity
Authors: Husham Bayazed
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The infant immune system has a reputation for being weak and underdeveloped when compared to the adult immune system, but the comparison isn’t quite fair. At the start, as the COVID-19 pandemic drags on and evolves, many Pediatricians and kids' parents have been left with renewed questions about the consequences and sequel of infection on children and the steps to be taken if their child, has the symptoms of COVID-19 or tests positive. Recent Findings: Literature reviews and recent studies revealed that children are better than adults at controlling SARS-CoV-2. There was conflicting evidence on age-related differences in ACE2 expression in the nose and lungs. But scientists who measured the ‘viral load’ in children's upper airways have seen no clear difference between children and adults. Moreover, the hypothesis is that kids might be more exposed to other coronaviruses common cold with a production of ready protective antibodies to lock on to the pandemic coronavirus. But the evidence suggests that adults also have this immunity too. Strikingly, these ‘cross-reactive’ antibodies don’t offer any special protection. Summary: One of the few silver linings of the Covid-19 pandemic is that children are relatively spared. The kid's Innate Immunity is hardly the whole story, the innate immune response against SARS-CoV-2 infection is early initiative calm with low immunological tone to prevent an overactive immunity and with rapidly repair damage to the lungs in contrast to stormy waves in adults. Therefore, Kids are at much lower risk of Covid-19 infection and they are still winning the battle against Covid-19 with their innate immunity.Keywords: kids, Covid-19, immunity, ACT2
Procedia PDF Downloads 94261 Noise Source Identification on Urban Construction Sites Using Signal Time Delay Analysis
Authors: Balgaisha G. Mukanova, Yelbek B. Utepov, Aida G. Nazarova, Alisher Z. Imanov
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The problem of identifying local noise sources on a construction site using a sensor system is considered. Mathematical modeling of detected signals on sensors was carried out, considering signal decay and signal delay time between the source and detector. Recordings of noises produced by construction tools were used as a dependence of noise on time. Synthetic sensor data was constructed based on these data, and a model of the propagation of acoustic waves from a point source in the three-dimensional space was applied. All sensors and sources are assumed to be located in the same plane. A source localization method is checked based on the signal time delay between two adjacent detectors and plotting the direction of the source. Based on the two direct lines' crossline, the noise source's position is determined. Cases of one dominant source and the case of two sources in the presence of several other sources of lower intensity are considered. The number of detectors varies from three to eight detectors. The intensity of the noise field in the assessed area is plotted. The signal of a two-second duration is considered. The source is located for subsequent parts of the signal with a duration above 0.04 sec; the final result is obtained by computing the average value.Keywords: acoustic model, direction of arrival, inverse source problem, sound localization, urban noises
Procedia PDF Downloads 62260 Electrodynamic Principles for Generation and Wireless Transfer of Energy
Authors: Steven D. P. Moore
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An electrical discharge in the air induces an electromagnetic (EM) wave capable of wireless transfer, reception, and conversion back into electrical discharge at a distant location. Following Norton’s ground wave principles, EM wave radiation (EMR) runs parallel to the Earth’s surface. Energy in an EMR wave can move through the air and be focused to create a spark at a distant location, focused by a receiver to generate a local electrical discharge. This local discharge can be amplified and stored but also has the propensity to initiate another EMR wave. In addition to typical EM waves, lightning is also associated with atmospheric events, trans-ionospheric pulse pairs, the most powerful natural EMR signal on the planet. With each lightning strike, regardless of global position, it generates naturally occurring pulse-pairs that are emitted towards space within a narrow cone. An EMR wave can self-propagate, travel at the speed of light, and, if polarized, contain vector properties. If this reflective pulse could be directed by design through structures that have increased probabilities for lighting strikes, it could theoretically travel near the surface of the Earth at light speed towards a selected receiver for local transformation into electrical energy. Through research, there are several influencing parameters that could be modified to model, test, and increase the potential for adopting this technology towards the goal of developing a global grid that utilizes natural sources of energy.Keywords: electricity, sparkgap, wireless, electromagnetic
Procedia PDF Downloads 188259 Fano-Resonance-Based Wideband Acoustic Metamaterials with Highly Efficient Ventilation
Authors: Xi-Wen Xiao, Tzy-Rong Lin, Chien-Hao Liu
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Ventilated acoustic metamaterials have attracted considerable research attention due to their low-frequency absorptions and efficient fluid ventilations. In this research, a wideband acoustic metamaterial with auditory filtering ability and efficient ventilation capacity were proposed. In contrast to a conventional Fano-like resonator, a Fano-like resonator composed of a resonant unit and two nonresonant units with a large opening area of 68% for fluid passages was developed. In addition, the coupling mechanism to improve the narrow bandwidths of conventional Fano-resonance-based meta-materials was included. With a suitable design, the output sound waves of the resonant and nonresonant states were out of phase to achieve sound absorptions in the far fields. Therefore, three-element and five-element coupled Fano-like metamaterials were designed and simulated with the help of the finite element software to obtain the filtering fractional bandwidths of 42.5% and 61.8%, respectively. The proposed approach can be extended to multiple coupled resonators for obtaining ultra-wide bandwidths and can be implemented with 3D printing for practical applications. The research results are expected to be beneficial for sound filtering or noise reductions in duct applications and limited-volume spaces.Keywords: fano resonance, noise reduction, resonant coupling, sound filtering, ventilated acoustic metamaterial
Procedia PDF Downloads 115258 Time-Evolving Wave Packet in Phase Space
Authors: Mitsuyoshi Tomiya, Kentaro Kawamura, Shoichi Sakamoto
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In chaotic billiard systems, scar-like localization has been found on time-evolving wave packet. We may call it the “dynamical scar” to separate it to the original scar in stationary states. It also comes out along the vicinity of classical unstable periodic orbits, when the wave packets are launched along the orbits, against the hypothesis that the waves become homogenous all around the billiard. Then time-evolving wave packets are investigated numerically in phase space. The Wigner function is adopted to detect the wave packets in phase space. The 2-dimensional Poincaré sections of the 4-dimensional phase space are introduced to clarify the dynamical behavior of the wave packets. The Poincaré sections of the coordinate (x or y) and the momentum (Px or Py) can visualize the dynamical behavior of the wave packets, including the behavior in the momentum degree also. For example, in “dynamical scar” states, a bit larger momentum component comes first, and then the a bit smaller and smaller components follow next. The sections made in the momentum space (Px or Py) elucidates specific trajectories that have larger contribution to the “dynamical scar” states. It is the fixed point observation of the momentum degrees at a specific fixed point(x0, y0) in the phase space. The accumulation are also calculated to search the “dynamical scar” in the Poincare sections. It is found the scars as bright spots in momentum degrees of the phase space.Keywords: chaotic billiard, Poincaré section, scar, wave packet
Procedia PDF Downloads 452257 Unstructured-Data Content Search Based on Optimized EEG Signal Processing and Multi-Objective Feature Extraction
Authors: Qais M. Yousef, Yasmeen A. Alshaer
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Over the last few years, the amount of data available on the globe has been increased rapidly. This came up with the emergence of recent concepts, such as the big data and the Internet of Things, which have furnished a suitable solution for the availability of data all over the world. However, managing this massive amount of data remains a challenge due to their large verity of types and distribution. Therefore, locating the required file particularly from the first trial turned to be a not easy task, due to the large similarities of names for different files distributed on the web. Consequently, the accuracy and speed of search have been negatively affected. This work presents a method using Electroencephalography signals to locate the files based on their contents. Giving the concept of natural mind waves processing, this work analyses the mind wave signals of different people, analyzing them and extracting their most appropriate features using multi-objective metaheuristic algorithm, and then classifying them using artificial neural network to distinguish among files with similar names. The aim of this work is to provide the ability to find the files based on their contents using human thoughts only. Implementing this approach and testing it on real people proved its ability to find the desired files accurately within noticeably shorter time and retrieve them as a first choice for the user.Keywords: artificial intelligence, data contents search, human active memory, mind wave, multi-objective optimization
Procedia PDF Downloads 175256 X-Ray Dynamical Diffraction Rocking Curves in Case of Third Order Nonlinear Renninger Effect
Authors: Minas Balyan
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In the third-order nonlinear Takagi’s equations for monochromatic waves and in the third-order nonlinear time-dependent dynamical diffraction equations for X-ray pulses for forbidden reflections the Fourier-coefficients of the linear and the third order nonlinear susceptibilities are zero. The dynamical diffraction in the nonlinear case is related to the presence in the nonlinear equations the terms proportional to the zero order and the second order nonzero Fourier coefficients of the third order nonlinear susceptibility. Thus in the third order nonlinear Bragg diffraction case a nonlinear analogue of the well known Renninger effect takes place. In this work, the ‘third order nonlinear Renninger effect’ is considered theoretically and numerically. If the reflection exactly is forbidden the diffracted wave’s amplitude is zero both in Laue and Bragg cases since the boundary conditions and dynamical diffraction equations are compatible with zero solution. But in real crystals due to some percent of dislocations and other localized defects, the atoms are displaced with respect to their equilibrium positions. Thus in real crystals susceptibilities of forbidden reflection are by some order small than for usual not forbidden reflections but are not exactly equal to zero. The numerical calculations for susceptibilities two order less than for not forbidden reflection show that in Bragg geometry case the nonlinear reflection curve’s behavior is the same as for not forbidden reflection, but for forbidden reflection the rocking curves’ width, center and boundaries are two order sensitive on the input intensity value. This gives an opportunity to investigate third order nonlinear X-ray dynamical diffraction for not intense beams – 0.001 in the units of critical intensity.Keywords: third order nonlinearity, Bragg diffraction, nonlinear Renninger effect, rocking curves
Procedia PDF Downloads 406255 A Hybrid Traffic Model for Smoothing Traffic Near Merges
Authors: Shiri Elisheva Decktor, Sharon Hornstein
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Highway merges and unmarked junctions are key components in any urban road network, which can act as bottlenecks and create traffic disruption. Inefficient highway merges may trigger traffic instabilities such as stop-and-go waves, pose safety conditions and lead to longer journey times. These phenomena occur spontaneously if the average vehicle density exceeds a certain critical value. This study focuses on modeling the traffic using a microscopic traffic flow model. A hybrid traffic model, which combines human-driven and controlled vehicles is assumed. The controlled vehicles obey different driving policies when approaching the merge, or in the vicinity of other vehicles. We developed a co-simulation model in SUMO (Simulation of Urban Mobility), in which the human-driven cars are modeled using the IDM model, and the controlled cars are modeled using a dedicated controller. The scenario chosen for this study is a closed track with one merge and one exit, which could be later implemented using a scaled infrastructure on our lab setup. This will enable us to benchmark the results of this study obtained in simulation, to comparable results in similar conditions in the lab. The metrics chosen for the comparison of the performance of our algorithm on the overall traffic conditions include the average speed, wait time near the merge, and throughput after the merge, measured under different travel demand conditions (low, medium, and heavy traffic).Keywords: highway merges, traffic modeling, SUMO, driving policy
Procedia PDF Downloads 106254 Uncovering Consumer Culture-Driven Media in Disguise of Feminism: A Multimodal Content Analysis of Sisters Who Make Wave
Authors: Zhen Li
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In contemporary China, the rise of consumer culture and feminism has facilitated the ‘She-Economy’, where Chinese women’s consumption power has been boosted along with the thriving Chinese economy. Domestic reality TV shows such as Sisters Who Make Waves (hereafter SWMW) target female audiences by bringing women's issues such as age, appearance, and balance between family and career to the discussion. Against this backdrop, this study adopted multimodal content analysis to investigate how SWMW failed to live up to the feminist goals the show had claimed and how serious women’s issues were consumed and capitalized by the consumer media culture from consumer culture and feminist perspectives. The findings reveal that while the female-themed work claims to uncover the charm that age brings to women over their thirties, it merely mentions female anxiety and uses feminism in disguise to achieve commercial success without in-depth thinking and discussion of what real-life issues women in China are tackling. They further show that the mass media-promoted modern femininity combined with consumerism deepens anxiety over aging among female audiences. The study sheds light on understanding the new development of Chinese femininity and the impact of consumer culture on feminist consciousness in contemporary China.Keywords: consumer culture, feminism, multimodal content analysis, she-economy
Procedia PDF Downloads 92253 Detection of Defects in CFRP by Ultrasonic IR Thermographic Method
Authors: W. Swiderski
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In the paper introduced the diagnostic technique making possible the research of internal structures in composite materials reinforced fibres using in different applications. The main reason of damages in structures of these materials is the changing distribution of load in constructions in the lifetime. Appearing defect is largely complicated because of the appearance of disturbing of continuity of reinforced fibres, binder cracks and loss of fibres adhesiveness from binders. Defect in composite materials is usually more complicated than in metals. At present, infrared thermography is the most effective method in non-destructive testing composite. One of IR thermography methods used in non-destructive evaluation is vibrothermography. The vibrothermography is not a new non-destructive method, but the new solution in this test is use ultrasonic waves to thermal stimulation of materials. In this paper, both modelling and experimental results which illustrate the advantages and limitations of ultrasonic IR thermography in inspecting composite materials will be presented. The ThermoSon computer program for computing 3D dynamic temperature distribuions in anisotropic layered solids with subsurface defects subject to ulrasonic stimulation was used to optimise heating parameters in the detection of subsurface defects in composite materials. The program allows for the analysis of transient heat conduction and ultrasonic wave propagation phenomena in solids. The experiments at MIAT were fulfilled by means of FLIR SC 7600 IR camera. Ultrasonic stimulation was performed with the frequency from 15 kHz to 30 kHz with maximum power up to 2 kW.Keywords: composite material, ultrasonic, infrared thermography, non-destructive testing
Procedia PDF Downloads 295252 Ultrasonic Techniques to Characterize and Monitor Water-in-Oil Emulsion
Authors: E. A. Alshaafi, A. Prakash
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Oil-water emulsions are commonly encountered in various industrial operations and at different stages of crude oil production and processing. Emulsions are often difficult to track and treat and can cause a number of costly problems which need to be avoided. The characteristics of the emulsion phase can vary with crude composition and types of impurities present in oil. The objectives of this study are the development of ultrasonic techniques to track and characterize emulsion phase generated during production and cleaning of crude oil. The position of emulsion layer is monitored with the help of ultrasonic probes suitably placed in the vessel. The sensitivity of the technique and its potential has been demonstrated based on extensive testing with different oil samples. The technique is also being developed to monitor emulsion phase characteristics such as stability, composition, and droplet size distribution. The ultrasonic parameters recorded are changes in acoustic velocity, signal attenuation and its frequency spectrum. Emulsion has been prepared with light mineral oil sample and the effects of various factors including mixing speed, temperature, surfactant, and solid particles concentrations have been investigated. The applied frequency for ultrasonic waves has been varied from 1 to 5 MHz to carry out a sensitivity analysis. Emulsion droplet structure is observed with optical microscopy and stability is examined by tracking the changes in ultrasonic parameters with time. A model based on ultrasonic attenuation spectroscopy is being developed and tested to track changes in droplet size distribution with time.Keywords: ultrasonic techniques, emulsion, characterization, droplet size
Procedia PDF Downloads 175251 DG Allocation to Reduce Production Cost by Reducing Losses in Radial Distribution Systems Using Fuzzy
Authors: G. V. Siva Krishna Rao, B. Srinivasa Rao
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Electrical energy is vital in every aspect of day-to-day life. Keen interest is taken on all possible sources of energy from which it can be generated and this led to the encouragement of generating electrical power using renewable energy resources such as solar, tidal waves and wind energy. Due to the increasing interest on renewable sources in recent times, the studies on integration of distributed generation to the power grid have rapidly increased. Distributed Generation (DG) is a promising solution to many power system problems such as voltage regulation, power loss and reduction in operational cost, etc. To reduce production cost, it is important to minimize the losses by determining the location and size of local generators to be placed in the radial distribution systems. In this paper, reduction of production cost by optimal size of DG unit operated at optimal power factor is dealt. The optimal size of the DG unit is calculated analytically using approximate reasoning suitable nodes and DG placement to minimize production cost with minimum loss is determined by fuzzy technique. Total Cost of Power generation is compared with and without DG unit for 1 year duration. The suggested method is programmed under MATLAB software and is tested on IEEE 33 bus system and the results are presented.Keywords: distributed generation, operational cost, exact loss formula, optimum size, optimum location
Procedia PDF Downloads 484250 Effect of Far Infrared and Endothelial Cell Growth Supplement on Human Umbilical Vascular Endothelial Cells
Authors: Ming-Tzu Tsai, Jui-Ting Hsu, Chia-Chieh Lin, Feng-Tsai Chiang, Cheng-Chin Huang
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Far infrared (FIR), an invisible and short electromagnetic waves ranges from 6-14 μm also defines as the “growth ray.” Although the mechanism of FIR is still unknown, most data have suggested that FIR could accelerate the skin microcirculation by elevating the blood flow and nitric-oxide (NO) synthesis. In this present work, the effect of FIR irradiation and endothelial cell growth supplement (ECGS) on human umbilical vascular endothelial cells (HUVECs) was evaluated. To understand whether the cell viability and NO production of HUVECs affected by NO, cells with/without ECGS were treated in the presence or absence of L-NAME, an eNOS inhibitor. For FIR exposure, FIR-emitted ceramic powders consisted of a variety of well-mixed metal oxides were developed. The results showed that L-NAME did had a strong effect on the inhibition of NO production, especially in the ECGS-treated group. However, the cell viability of each group was rarely affected in the presence of L-NAME. Cells with the incubation of ECGS showed much higher cell viability compared to the control. Moreover, NO production of HUVECs exposed to FIR irradiation was significantly inhibited in the presence of L-NAME. It suggested that NO could play a role modulating the downstream signals of HUVECs during FIR exposure.Keywords: far-infrared irradiation (FIR), nitric oxide (NO), endothelial nitric oxide synthase (eNOS), endothelial cell growth supplement (ECGS)
Procedia PDF Downloads 429249 Investigating Jacket-Type Offshore Structures Failure Probability by Applying the Reliability Analyses Methods
Authors: Majid Samiee Zonoozian
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For such important constructions as jacket type platforms, scrupulous attention in analysis, design and calculation processes is needed. The reliability assessment method has been established into an extensively used method to behavior safety calculation of jacket platforms. In the present study, a methodology for the reliability calculation of an offshore jacket platform in contradiction of the extreme wave loading state is available. Therefore, sensitivity analyses are applied to acquire the nonlinear response of jacket-type platforms against extreme waves. The jacket structure is modeled by applying a nonlinear finite-element model with regards to the tubular members' behave. The probability of a member’s failure under extreme wave loading is figured by a finite-element reliability code. The FORM and SORM approaches are applied for the calculation of safety directories and reliability indexes have been detected. A case study for a fixed jacket-type structure positioned in the Persian Gulf is studied by means of the planned method. Furthermore, to define the failure standards, equations suggested by the 21st version of the API RP 2A-WSD for The jacket-type structures’ tubular members designing by applying the mixed axial bending and axial pressure. Consequently, the effect of wave Loades in the reliability index was considered.Keywords: Jacket-Type structure, reliability, failure probability, tubular members
Procedia PDF Downloads 172248 Contested Fathering: Cameroonian Fathers Facing the Welfare State Parenthood
Authors: Mathias Ebot, Päivi Harinen
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This article focuses on challenges of parenthood for Sub-Saharan African fathers in Finland. In this analysis Finland represents a Nordic welfare society where family relationships are strongly guided by national family policies and discourses. These policies are based on both traditional ideas of a proper Finnish family, as well as on the contemporary waves of female liberation and emphasis on children’s rights. We analyze how especially Cameroonian fathers perceive their parenthood positions and how they characterize and frame their fathering experiences in relation to the mainstream sociopolitical, cultural and national representations of fatherhood in Finland. The analysis is based on interviews and narrative reports collected among Cameroonian fathers living in Finland with their African spouses. The scrutiny shows that in the context where the mainstream cultural and national family representation is created by equality between parents and also between parents and their children, and where “good fatherhood” is created by embodied presence and warm relationships with children these fathers have difficulties: They have to fulfill another fatherhood duty – bread-winning – and thus ensure their labor possibilities all the time, from very marginalized positions of the labor market. When comparing their fatherhood position with the one in Cameroon they also feel embarrassed as the Finnish educational system teaches and encourages their children to challenge their authority as up-raising adults, which in Cameroon could not be possible.Keywords: Cameroonian fathers, perception, fathering experiences, Finland
Procedia PDF Downloads 414247 Kids and COVID-19: They are Winning with Their Immunity
Authors: Husham Bayazed, Fatimah Yousif
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Purpose of Presentation: The infant immune system has a reputation for being weak and underdeveloped when compared to the adult immune system, but the comparison isn’t quite fair. At the start, as the COVID-19 pandemic drags on and evolves, many Pediatricians and kids' parents have been left with renewed questions about the consequences and sequel of infection on children and the steps to be taken if their child has the symptoms of COVID-19 or tests positive. Recent Findings Literature reviews and recent studies revealed that children are better than adults at controlling SARS-CoV-2. There was conflicting evidence on age-related differences in ACE2 expression in the nose and lungs. But scientists who measured the ‘viral load’ in children's upper airways have seen no clear difference between children and adults. Moreover, the hypothesis is that kids might be more exposed to other coronaviruses common cold, with a production of ready protective antibodies to lock on to the pandemic coronavirus. But the evidence suggests that adults also have this immunity too. Strikingly, these ‘cross-reactive’ antibodies don’t offer any special protection. Summary One of the few silver linings of the Covid-19 pandemic is that children are relatively spared. The kid's Innate Immunity is hardly the whole story, the innate immune response against SARS-CoV-2 infection is early initiative calm with low immunological tone to prevent an overactive immunity and with rapidly repair damage to the lungs in contrast to stormy waves in adults. Therefore, Kids are at much lower risk of Covid-19 infection, and they are still winning the battle against Covid-19 with their innate immunity.Keywords: Covid-19, kids, ACE2 receptors, immunity
Procedia PDF Downloads 97246 State Estimation Based on Unscented Kalman Filter for Burgers’ Equation
Authors: Takashi Shimizu, Tomoaki Hashimoto
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Controlling the flow of fluids is a challenging problem that arises in many fields. Burgers’ equation is a fundamental equation for several flow phenomena such as traffic, shock waves, and turbulence. The optimal feedback control method, so-called model predictive control, has been proposed for Burgers’ equation. However, the model predictive control method is inapplicable to systems whose all state variables are not exactly known. In practical point of view, it is unusual that all the state variables of systems are exactly known, because the state variables of systems are measured through output sensors and limited parts of them can be only available. In fact, it is usual that flow velocities of fluid systems cannot be measured for all spatial domains. Hence, any practical feedback controller for fluid systems must incorporate some type of state estimator. To apply the model predictive control to the fluid systems described by Burgers’ equation, it is needed to establish a state estimation method for Burgers’ equation with limited measurable state variables. To this purpose, we apply unscented Kalman filter for estimating the state variables of fluid systems described by Burgers’ equation. The objective of this study is to establish a state estimation method based on unscented Kalman filter for Burgers’ equation. The effectiveness of the proposed method is verified by numerical simulations.Keywords: observer systems, unscented Kalman filter, nonlinear systems, Burgers' equation
Procedia PDF Downloads 153245 Generation of Electro-Encephalography Readiness Potentials by Intention
Authors: Seokbeen Lim, Gilwon Yoon
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The readiness potential in brain waves is a brain activity related with an intention whose potential arises even before its conscious intention. This study was carried out in order to understand the generation and mechanism of the readiness potential more. The experiment with two subjects was conducted in two ways following the Oddball task protocol. Firstly, auditory stimuli were randomly presented to the subjects. The subject was allowed to press the keyboard with the right index finger only when the subject heard the target stimulus but not the standard stimulus. Secondly, unlike the first one, the auditory stimuli were randomly presented, and the subjects pressed the keyboard in the same manner, but at the same time with grasping action of the left hand. The readiness potential showed up for both of these experiments. In the first Oddball experiment, the readiness potential was detected only when the target stimulus was presented. However, in the second Oddball experiment with the left hand action of grasping something, the readiness potential was detected at the presentation of for both standard and target stimuli. However, detected readiness potentials with the target stimuli were larger than those of the standard stimuli. We found an interesting phenomenon that the readiness potential was able to be detected even the standard stimulus. This indicates that motor-related readiness potentials can be generated only by the intention to move. These results present a new perspective in psychology and brain engineering since subconscious brain action may be prior to conscious recognition of the intention.Keywords: readiness potential, auditory stimuli, event-related potential, electroencephalography, oddball task
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