Search results for: high speed machining

Authors: Varsha Shah, Patel Pritesh, Patel Sagar, PrasantaKundu, RanjanMaheshwari

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Performance of vehicle depends on driving patterns and vehicle drive train configuration. Driving patterns depends on traffic condition, road condition and driver behavior. HEV design is carried out under certain constrain like vehicle operating range, acceleration, decelerations, maximum speed and road grades which are directly related to the driving patterns. Therefore the detailed study on HEV performance over a different drive cycle is required for selection and sizing of HEV components. A simple hardware is design to measured velocity v/s time profile of the vehicle by operating vehicle on Indian roads under real traffic conditions. To size the HEV components, a detailed dynamic model of the vehicle is developed considering the effect of inertia of rotating components like wheels, drive chain, engine and electric motor. Using vehicle model and different Indian drive cycles data, total tractive power demanded by vehicle and power supplied by individual components has been calculated.Using above information selection and estimation of component sizing for HEV is carried out so that HEV performs efficiently under hostile driving condition. Complete analysis is carried out in LABVIEW.

Keywords: BLDC motor, Driving cycle, LABVIEW Ultracapacitors, Vehicle Dynamics,

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Authors: Mohamed Adel Serhani, Abdelghani Benharref, Rachida Dssouli, Rabeb Mizouni

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Nowadays, people are going more and more mobile, both in terms of devices and associated applications. Moreover, services that these devices are offering are getting wider and much more complex. Even though actual handheld devices have considerable computing power, their contexts of utilization are different. These contexts are affected by the availability of connection, high latency of wireless networks, battery life, size of the screen, on-screen or hard keyboard, etc. Consequently, development of mobile applications and their associated mobile Web services, if any, should follow a concise methodology so they will provide a high Quality of Service. The aim of this paper is to highlight and discuss main issues to consider when developing mobile applications and mobile Web services and then propose a framework that leads developers through different steps and modules toward development of efficient and secure mobile applications. First, different challenges in developing such applications are elicited and deeply discussed. Second, a development framework is presented with different modules addressing each of these challenges. Third, the paper presents an example of a mobile application, Eivom Cinema Guide, which benefits from following our development framework.

Keywords: Mobile applications, development of mobile applications, efficient mobile application, secure mobile application.

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Authors: N. P. Dhanalakshmi, R. Nagarajan

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The sonochemical decolorization and degradation of azo dye Methyl violet using Fenton-s reagent in the presence of a high-frequency acoustic field has been investigated. Dyeing and textile effluents are the major sources of azo dyes, and are most troublesome among industrial wastewaters, causing imbalance in the eco-system. The effect of various operating conditions (initial concentration of dye, liquid-phase temperature, ultrasonic power and frequency and process time) on sonochemical degradation was investigated. Conversion was found to increase with increase in initial concentration, temperature, power level and frequency. Both horntype and tank-type sonicators were used, at various power levels (250W, 400W and 500W) for frequencies ranging from 20 kHz - 1000 kHz. A 'Process Intensification' parameter PI, was defined to quantify the enhancement of the degradation reaction by ultrasound when compared to control (i.e., without ultrasound). The present work clearly demonstrates that a high-frequency ultrasonic bath can be used to achieve higher process throughput and energy efficiency at a larger scale of operation.

Keywords: Fenton oxidation, process intensification, sonochemical degradation of MV, ultrasonic frequency.

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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.

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Authors: Hong Yi Huang, Wei Ti Kuo, Yi You Huang

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Non-viral gene carriers composed of biodegradable polymers or lipids have been considered as a safer alternative for gene carriers over viral vectors. We have developed multi-functional nano-micelles for both drug and gene delivery application. Polyethyleneimine (PEI) was modified by grafting stearic acid (SA) and formulated to polymeric micelles (PEI-SA) with positive surface charge for gene and drug delivery. Our results showed that PEI-SA micelles provided high siRNA binding efficiency. In addition, siRNA delivered by PEI-SA carriers also demonstrated significantly high cellular uptake even in the presence of serum proteins. The post-transcriptional gene silencing efficiency was greatly improved by the polyplex formulated by 10k PEI-SA/siRNA. The amphiphilic structure of PEI-SA micelles provided advantages for multifunctional tasks; where the hydrophilic shell modified with cationic charges can electrostatically interact with DNA or siRNA, and the hydrophobic core can serve as payloads for hydrophobic drugs, making it a promising multifunctional vehicle for both genetic and chemotherapy application.

Keywords: polyethyleneimine, gene delivery, micelles, siRNA

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Authors: Wanyu Mao, Hongfang Ma, Haitao Zhang, WeixinQian, Weiyong Ying

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The nature of adsorbed species on catalytic surface over an industrial precipitated iron-based high temperature catalyst during FTS was investigated by in-situ DRIFTS and chemical trapping. The formulation of the mechanism of oxygenates formation and key intermediates were also discussed. Numerous oxygenated precursors and crucial intermediates were found by in-situ DRIFTS, such as surface acetate, acetyl and methoxide. The results showed that adsorbed molecules on surface such as methanol or acetaldehyde could react with basic sites such as lattice oxygen or free surface hydroxyls. Adsorbed molecules also had reactivity of oxidizing. Moreover, acetyl as a key intermediate for oxygenates was observed by investigation of CH3OH + CO and CH3I + CO + H2. Based on the nature of surface properties, the mechanism of oxygenates formation on precipitated iron-based high temperature catalyst was discussed.

Keywords: Iron-based catalysts, intermediates, oxygenates, in-situ DRIFTS, chemical trapping.

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Authors: Y. Sunecher, N. Mamode Khan, V. Jowaheer

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This paper considers the modelling of a non-stationary bivariate integer-valued autoregressive moving average of order one (BINARMA(1,1)) with correlated Poisson innovations. The BINARMA(1,1) model is specified using the binomial thinning operator and by assuming that the cross-correlation between the two series is induced by the innovation terms only. Based on these assumptions, the non-stationary marginal and joint moments of the BINARMA(1,1) are derived iteratively by using some initial stationary moments. As regards to the estimation of parameters of the proposed model, the conditional maximum likelihood (CML) estimation method is derived based on thinning and convolution properties. The forecasting equations of the BINARMA(1,1) model are also derived. A simulation study is also proposed where BINARMA(1,1) count data are generated using a multivariate Poisson R code for the innovation terms. The performance of the BINARMA(1,1) model is then assessed through a simulation experiment and the mean estimates of the model parameters obtained are all efficient, based on their standard errors. The proposed model is then used to analyse a real-life accident data on the motorway in Mauritius, based on some covariates: policemen, daily patrol, speed cameras, traffic lights and roundabouts. The BINARMA(1,1) model is applied on the accident data and the CML estimates clearly indicate a significant impact of the covariates on the number of accidents on the motorway in Mauritius. The forecasting equations also provide reliable one-step ahead forecasts.

Keywords: Non-stationary, BINARMA(1, 1) model, Poisson Innovations, CML

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Authors: Perminderjit Singh, Randeep Singh

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The performance, emission and combustion characteristics of a single cylinder four stroke variable compression ratio multi fuel engine when fueled with different blends of rice bran oil methyl ester and ethanol are investigated and compared with the results of standard diesel. Bio diesel produced from Rice bran oil by transesterification process has been used in this study. Experiment has been conducted at a fixed engine speed of 1500 rpm, 50% load and at compression ratios of 16.5:1, 17:1, 17.5:1 and 18:1. The impact of compression ratio on fuel consumption, brake thermal efficiency and exhaust gas emissions has been investigated and presented. Optimum compression ratio which gives best performance has been identified. The results indicate longer ignition delay, maximum rate of pressure rise, lower heat release rate and higher mass fraction burnt at higher compression ratio for waste cooking oil methyl ester when compared to that of diesel. The brake thermal efficiency at 50% load for Rice bran oil methyl ester blends and diesel has been calculated and the blend B40 is found to give maximum thermal efficiency. The blends when used as fuel results in reduction of carbon monoxide, hydrocarbon and increase in nitrogen oxides emissions.

Keywords: Biodiesel, Rice bran oil, Transesterification, Ethanol, Compression Ratio.

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Authors: Eiichi Sasaki, Shin-ichi Takehiro, Michio Yamada

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We study bifurcation structure of the zonal jet flow the streamfunction of which is expressed by a single spherical harmonics on a rotating sphere. In the non-rotating case, we find that a steady traveling wave solution arises from the zonal jet flow through Hopf bifurcation. As the Reynolds number increases, several traveling solutions arise only through the pitchfork bifurcations and at high Reynolds number the bifurcating solutions become Hopf unstable. In the rotating case, on the other hand, under the stabilizing effect of rotation, as the absolute value of rotation rate increases, the number of the bifurcating solutions arising from the zonal jet flow decreases monotonically. We also carry out time integration to study unsteady solutions at high Reynolds number and find that in the non-rotating case the unsteady solutions are chaotic, while not in the rotating cases calculated. This result reflects the general tendency that the rotation stabilizes nonlinear solutions of Navier-Stokes equations.

Keywords: rotating sphere, two-dimensional flow, bifurcationstructure

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Authors: Hazem M. El-Bakry

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In this paper, a new technique for fast painting with different colors is presented. The idea of painting relies on applying masks with different colors to the background. Fast painting is achieved by applying these masks in the frequency domain instead of spatial (time) domain. New colors can be generated automatically as a result from the cross correlation operation. This idea was applied successfully for faster specific data (face, object, pattern, and code) detection using neural algorithms. Here, instead of performing cross correlation between the input input data (e.g., image, or a stream of sequential data) and the weights of neural networks, the cross correlation is performed between the colored masks and the background. Furthermore, this approach is developed to reduce the computation steps required by the painting operation. The principle of divide and conquer strategy is applied through background decomposition. Each background is divided into small in size subbackgrounds and then each sub-background is processed separately by using a single faster painting algorithm. Moreover, the fastest painting is achieved by using parallel processing techniques to paint the resulting sub-backgrounds using the same number of faster painting algorithms. In contrast to using only faster painting algorithm, the speed up ratio is increased with the size of the background when using faster painting algorithm and background decomposition. Simulation results show that painting in the frequency domain is faster than that in the spatial domain.

Keywords: Fast Painting, Cross Correlation, Frequency Domain, Parallel Processing

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Authors: Gabriel Sitler, Yousef Sardahi, Asad Salem

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This paper presents an optimal and robust sliding mode controller (SMC) to regulate the position of the knee joint angle for patients suffering from knee injuries. The controller imitates the role of active orthoses that produce the joint torques required to overcome gravity and loading forces and regain natural human movements. To this end, a mathematical model of the shank, the lower part of the leg, is derived first and then used for the control system design and computer simulations. The design of the controller is carried out in optimal and multi-objective settings. Four objectives are considered: minimization of the control effort and tracking error; and maximization of the control signal smoothness and closed-loop system’s speed of response. Optimal solutions in terms of the Pareto set and its image, the Pareto front, are obtained. The results show that there are trade-offs among the design objectives and many optimal solutions from which the decision-maker can choose to implement. Also, computer simulations conducted at different points from the Pareto set and assuming knee squat movement demonstrate competing relationships among the design goals. In addition, the proposed control algorithm shows robustness in tracking a standard gait signal when accounting for uncertainty in the shank’s parameters.

Keywords: Optimal control, multi-objective optimization, sliding mode control, wearable knee exoskeletons.

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Authors: Khalid A. Al-Afandy, El-Sayyed El-Rabaie, Osama Salah, Ahmed El-Mhalaway

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This paper presents a high secure data hiding technique using image cropping and Least Significant Bit (LSB) steganography. The predefined certain secret coordinate crops will be extracted from the cover image. The secret text message will be divided into sections. These sections quantity is equal the image crops quantity. Each section from the secret text message will embed into an image crop with a secret sequence using LSB technique. The embedding is done using the cover image color channels. Stego image is given by reassembling the image and the stego crops. The results of the technique will be compared to the other state of art techniques. Evaluation is based on visualization to detect any degradation of stego image, the difficulty of extracting the embedded data by any unauthorized viewer, Peak Signal-to-Noise Ratio of stego image (PSNR), and the embedding algorithm CPU time. Experimental results ensure that the proposed technique is more secure compared with the other traditional techniques.

Keywords: Steganography, stego, LSB, crop.

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Authors: Jiménez Villanueva Mayra Alejandra, Ortíz Casallas Diana Carolina, Luengas Contreras Lely Adriana

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This document details the process of developing a wireless device that captures the basic movements of the foot (plantar flexion, dorsal flexion, abduction, adduction.), and the knee movement (flexion). It implements a motion capture system by using a hardware based on optical fiber sensors, due to the advantages in terms of scope, noise immunity and speed of data transmission and reception. The operating principle used by this system is the detection and transmission of joint movement by mechanical elements and their respective measurement by optical ones (in this case infrared). Likewise, Visual Basic software is used for reception, analysis and signal processing of data acquired by the device, generating a 3D graphical representation in real time of each movement. The result is a boot in charge of capturing the movement, a transmission module (Implementing Xbee Technology) and a receiver module for receiving information and sending it to the PC for their respective processing. The main idea with this device is to help on topics such as bioengineering and medicine, by helping to improve the quality of life and movement analysis.

Keywords: abduction, adduction, A / D converter, Autodesk 3DMax, Infrared Diode, Driver, extension, flexion, Infrared LEDs, Interface, Modeling OPENGL, Optical Fiber, USB CDC(Communications Device Class), Virtual Reality.

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Authors: Tatyana Alexandrova, Alexandr Alexandrov, Nadezhda Nikolaeva

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A problem of complex mineral resources development is urgent and priority, it is aimed at realization of the processes of their ecologically safe development, one of its components is revealing the influence of the forms of element compounds in raw materials and in the processing products. In view of depletion of the precious metal reserves at the traditional deposits in the XXI century the large-size open cast deposits, localized in black shale strata begin to play the leading role. Carbonaceous (black) shales carry a heightened metallogenic potential. Black shales with high content of carbon are widely distributed within the scope of Bureinsky massif. According to academician Hanchuk`s data black shales of Sutirskaya series contain generally PGEs native form. The presence of high absorptive towards carbonaceous matter gold and PGEs compounds in crude ore results in decrease of valuable components extraction because of their sorption into dissipated carbonaceous matter.

Keywords: Сarbonaceous rocks, bitumens, precious metals, concentration, extraction.

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Authors: Chlopicka Joanna, Barton Henryk, Kryczyk Jadwiga, Francik Renata

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Recent studies demonstrated that high-fat diet increases oxidative stress in plasma and in a variety of tissues. Many researchers have been looking for natural products, which can reverse the effect of high fat diet. Recently, buckwheat is becoming common ingredient in functional food because of it properties. In study on buckwheat, it is known that, this plant plays roles as anti-oxidative, anti-inflammatory and anti-hypertensive. Nevertheless still little is known about buckwheat groats. The aim of this study was to investigate the effects of addition of buckwheat groats to the fat diet (30% lard), on some antioxidant and oxidant stress parameters in plasma and selected tissues in Wistar rats. The experiment was carried out with three months old male Wistar rats ca. 250g of body weight fed for 5 weeks with either a high-fat (30% of lard) diet or control diet, with or without addition of buckwheat groats. In plasma biochemistry and the activities of the antioxidant enzymes were measured selected tissues: glutathione peroxidase (GPX), catalase (CAT) and the levels of total and reduced glutathione (GSH), free thiol groups (pSH), antioxidant potential of plasma (FRAP) and oxidant stress indices - proteins carbonyl groups (CO) and malonyldialdehyde concentration (MDA). Activity of catalase (CAT) in plasma of rats was significantly increased in buckwheat groats groups and activity of GPx3 in plasma of rats was decreased in buckwheat groups as compared to control group. The reduced glutathione (GSH) in plasma of rats was significantly increased and protein CO was significantly decreased in buckwheat groups as compared to controls. The lowered concentration of GSH was found in serum of rats fed buckwheat groats addition but it accompanied in 7-fold increase in reduced-to-oxidized glutatione ratio, significant increase in HDL and decrease in nonHDL concentration. Conclusions: Buckwheat groats indicate a beneficial effect in inhibiting protein and lipid peroxidation in rats and improved lipid profile. These results suggest that buckwheat groats exert a significant antioxidant potential and may be used as normal food constituent to ameliorate the oxidant-induced damage in organism. 

Keywords: Antioxidant, buckwheat, high-fat diet, rats.

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Authors: Richard Lewis

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The following assumptions of the Big Bang theory are challenged and found to be false: the cosmological principle, the assumption that all matter formed at the same time and the assumption regarding the cause of the cosmic microwave background radiation. The evolution of the universe is described based on the conclusion that the universe is finite with a space boundary. This conclusion is reached by ruling out the possibility of an infinite universe or a universe which is finite with no boundary. In a finite universe, the centre of the universe can be located with reference to our home galaxy (The Milky Way) using the speed relative to the Cosmic Microwave Background (CMB) rest frame and Hubble's law. This places our home galaxy at a distance of approximately 26 million light years from the centre of the universe. Because we are making observations from a point relatively close to the centre of the universe, the universe appears to be isotropic and homogeneous but this is not the case. The CMB is coming from a source located within the event horizon of the universe. There is sufficient mass in the universe to create an event horizon at the Schwarzschild radius. Galaxies form over time due to the energy released by the expansion of space. Conservation of energy must consider total energy which is mass (+ve) plus energy (+ve) plus spacetime curvature (-ve) so that the total energy of the universe is always zero. The predominant position of galaxy formation moves over time from the centre of the universe towards the boundary so that today the majority of new galaxy formation is taking place beyond our horizon of observation at 14 billion light years.

Keywords: Cosmic microwave background, dark energy, dark matter, evolution of the universe.

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Authors: H. Yousefnia, S. Zolghadri, A. Golabi Dezfuli

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Abstract—[Tris (1,10-phenanthroline) lanthanum(III)] trithiocyanate is a new compound that has shown high ability for stopping the synthesis of DNA and also acting as a photosensitizer. Nowadays, the radiation dose assessment resource (RADAR) method is known as the most common method for absorbed dose calculation. 177Lu was produced by (n, gamma) reaction in a research reactor. 177Lu-PL3 was prepared in the optimized condition. The radiochemical yield was checked by ITLC method. The biodistribution of the complex was investigated by intravenously injection to wild-type rats via their tail veins. In this study, the absorbed dose of 177Lu-PL3 to human organs was estimated by RADAR method. 177Lu was prepared with a specific activity of 2.6-3 GBq.mg-1 and radionuclide purity of 99.98 %. Final preparation of the radiolabelled complex showed high radiochemical purity of > 99%. The results show that liver and spleen have received the highest absorbed dose of 1.051 and 0.441 mSv/MBq, respectively. The absorbed dose values for these two dose-limiting tissues suggest more biological studies special in tumor-bearing animals.

Keywords: Internal dosimetry, Lutetium-177, radar.

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Authors: Paul O. Udofot, Emem B. Inyang

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The study investigated the variability in aptitude amidst interactive effects of several social and environmental factors that could influence individual tendencies to engage in entrepreneurship in Nigeria. Consequently, the study targeted a population having similar backgrounds in type and level of higher education that are tailored toward enterprise management and development in the Niger Delta region of Nigeria. A two-stage sampling procedure was used to select 67 respondents. Primarily, the study assessed the salient pattern of entrepreneurship aptitude of respondents, and estimated and analyzed the index against their personal characteristics. Male respondents belonged to two extremes of aptitude index ranges (poor and high). Though female respondents did not exhibit a poor entrepreneurship aptitude index, the incidence percentage of the high index range of entrepreneurship aptitude among male trainees was more than the combined incidence percentage of their female counterparts. Respondents’ backgrounds outside gender presented a serious influence on entrepreneurship uptake likelihood if all situations were normal.

Keywords: Aptitude, entrepreneurship, entrepreneurial orientation, gender divide, intention, trainee.

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Authors: Suleiman M. Elhamali, K. M. Etmimi, A. Usha

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The paper presents the results of microhardness and microstructure of low carbon steel surface melted using carbon dioxide laser with a wavelength of 10.6μm and a maximum output power of 2000W. The processing parameters such as the laser power, and the scanning rate were investigated in this study. After surface melting two distinct regions formed corresponding to the melted zone MZ, and the heat affected zone HAZ. The laser melted region displayed a cellular fine structures while the HAZ displayed martensite or bainite structure. At different processing parameters, the original microstructure of this steel (Ferrite+Pearlite) has been transformed to new phases of martensitic and bainitic structures. The fine structure and the high microhardness are evidence of the high cooling rates which follow the laser melting. The melting pool and the transformed microstructure in the laser surface melted region of carbon steel showed clear dependence on laser power and scanning rate.

Keywords: Carbon steel, laser surface melting, microstructure, microhardness.

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Authors: Evgeniia V. Mekhonoshina, Vladimir Ya. Modorskii, Vasilii Yu. Petrov

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At present, vibrations of rotors of gas transmittal unit evade sustainable forecasting. This paper describes elastic oscillation modes in resilient supports and rotor impellers modeled during computational experiments with regard to interference in the system of gas-dynamic flow and compressor rotor. Verification of aeroelastic approach was done on model problem of interaction between supersonic jet in shock tube with deformed plate. ANSYS 15.0 engineering analysis system was used as a modeling tool of numerical simulation in this paper. Finite volume method for gas dynamics and finite elements method for assessment of the strain stress state (SSS) components were used as research methods. Rotation speed and material’s elasticity modulus varied during calculations, and SSS components and gas-dynamic parameters in the dynamic system of gas-dynamic flow and compressor rotor were evaluated. The analysis of time dependence demonstrated that gas-dynamic parameters near the rotor blades oscillate at 200 Hz, and SSS parameters at the upper blade edge oscillate four times higher, i.e. with blade frequency. It has been detected that vibration amplitudes correction in the test points at magnetic bearings by aeroelasticity may correspond up to 50%, and about -π/4 for phases.

Keywords: Centrifugal compressor, aeroelasticity, interdisciplinary calculation, oscillation phase displacement, vibration, nonstationarity.

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Authors: Wen W. Zhang, Qian Chen

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Electron multiplying charge coupled devices (EMCCDs) have revolutionized the world of low light imaging by introducing on-chip multiplication gain based on the impact ionization effect in the silicon. They combine the sub-electron readout noise with high frame rates. Signal-to-noise Ratio (SNR) is an important performance parameter for low-light-level imaging systems. This work investigates the SNR performance of an EMCCD operated in Non-inverted Mode (NIMO) and Inverted Mode (IMO). The theory of noise characteristics and operation modes is presented. The results show that the SNR of is determined by dark current and clock induced charge at high gain level. The optimum SNR performance is provided by an EMCCD operated in NIMO in short exposure and strong cooling applications. In contrast, an IMO EMCCD is preferable.

Keywords: electron multiplying charge coupled devices, noise characteristics, operation modes, signal-to-noise ratioperformance

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Authors: Jin-Hyeok Kim, Won-Chul Choi, Seung-Ri Jin, Dong-Jo Park

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In this paper, an analysis of a target location estimation system using the best linear unbiased estimator (BLUE) for high performance radar systems is presented. In synthetic environments, we are here concerned with three key elements of radar system modeling, which makes radar systems operates accurately in strategic situation in virtual ground. Radar Cross Section (RCS) modeling is used to determine the actual amount of electromagnetic waves that are reflected from a tactical object. Pattern Propagation Factor (PPF) is an attenuation coefficient of the radar equation that contains the reflection from the surface of the earth, the diffraction, the refraction and scattering by the atmospheric environment. Clutter is the unwanted echoes of electronic systems. For the data fusion of output results from radar detection in synthetic environment, BLUE is used and compared with the mean values of each simulation results. Simulation results demonstrate the performance of the radar system.

Keywords: Best linear unbiased estimator (BLUE) , data fusion, radar system modeling, target location estimation

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Authors: Sanaa Chafik, ImaneDaoudi, Mounim A. El Yacoubi, Hamid El Ouardi

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Locality Sensitive Hashing (LSH) is one of the most promising techniques for solving nearest neighbour search problem in high dimensional space. Euclidean LSH is the most popular variation of LSH that has been successfully applied in many multimedia applications. However, the Euclidean LSH presents limitations that affect structure and query performances. The main limitation of the Euclidean LSH is the large memory consumption. In order to achieve a good accuracy, a large number of hash tables is required. In this paper, we propose a new hashing algorithm to overcome the storage space problem and improve query time, while keeping a good accuracy as similar to that achieved by the original Euclidean LSH. The Experimental results on a real large-scale dataset show that the proposed approach achieves good performances and consumes less memory than the Euclidean LSH.

Keywords: Approximate Nearest Neighbor Search, Content based image retrieval (CBIR), Curse of dimensionality, Locality sensitive hashing, Multidimensional indexing, Scalability.

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Authors: Chien-Jen Liu, Shu Ching Yang

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Using the technology acceptance model (TAM), this study examined the external variables of technological complexity (TC) to acquire a better understanding of the factors that influence the acceptance of computer application courses by learners at Active Aging Universities. After the learners in this study had completed a 27-hour Facebook course, 44 learners responded to a modified TAM survey. Data were collected to examine the path relationships among the variables that influence the acceptance of Facebook-mediated community learning. The partial least squares (PLS) method was used to test the measurement and the structural model. The study results demonstrated that attitudes toward Facebook use directly influence behavioral intentions (BI) with respect to Facebook use, evincing a high prediction rate of 58.3%. In addition to the perceived usefulness (PU) and perceived ease of use (PEOU) measures that are proposed in the TAM, other external variables, such as TC, also indirectly influence BI. These four variables can explain 88% of the variance in BI and demonstrate a high level of predictive ability. Finally, limitations of this investigation and implications for further research are discussed.

Keywords: Technology acceptance model (TAM), technological complexity, partial least squares (PLS), perceived usefulness.

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Authors: G. S. Ayyappan, M. Raja Raghavan, R. Poonthalir, Kota Srinivas, B. Ramesh Babu

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Electrical energy demand in the World and particularly in India, is increasing drastically more than its production over a period of time. In order to reduce the demand-supply gap, conserving energy becomes mandatory. Induction motors are the main driving force in the industries and contributes to about half of the total plant energy consumption. By effective monitoring and control of induction motors, huge electricity can be saved. This paper deals about the design and development of such a system, which employs iLON Smart Server and motor performance monitoring nodes. These nodes will monitor the performance of induction motors on-line, on-site and in-situ in the industries. The node monitors the performance of motors by simply measuring the electrical power input and motor shaft speed; coupled to genetic algorithm to estimate motor efficiency. The nodes are connected to the iLON Server through RS485 network. The web server collects the motor performance data from nodes, displays online, logs periodically, analyzes, alerts, and generates reports. The system could be effectively used to operate the motor around its Best Operating Point (BOP) as well as to perform the Life Cycle Assessment of Induction motors used in the industries in continuous operation.

Keywords: Best operating point, iLON smart server, motor asset management, LONWORKS, Modbus RTU, motor performance.

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Authors: Bruno Henrique Rocha Fernandes, Amir Rezaee, Jucelia Appio

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The relation between Human Resource Management (HRM) practices and organizational performance remains the subject of substantial literature. Though many studies demonstrated positive relationship, still major influencing variables are not yet clear. This study considers the Person-Environment Fit (PE Fit) and its components, Person-Supervisor (PS), Person-Group (PG), Person-Organization (PO) and Person-Job (PJ) Fit, as possible explanatory variables. We analyzed PE Fit as a moderator between HRM practices and financial performance in the “best companies to work” in Brazil. Data from HRM practices were classified through the High Performance Working Systems (HPWS) construct and data on PE-Fit were obtained through surveys among employees. Financial data, consisting of return on invested capital (ROIC) and price earnings ratio (PER) were collected for publicly traded best companies to work. Findings show that PO Fit and PJ Fit play a significant moderator role for PER but not for ROIC.

Keywords: Financial performance, human resource management, high performance working systems, person-environment fit.

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Authors: Tsuneyuki Namekata, Yoko Namekata

Abstract:

It is known that the mean investment evolves from a very low initial value to some high level in the Continuous Prisoner's Dilemma. We examine how the cooperation level evolves from a low initial level to a high level in our Demographic Multi-level Donor-Recipient situation. In the Multi-level Donor-Recipient game, one player is selected as a Donor and the other as a Recipient randomly. The Donor has multiple cooperative moves and one defective move. A cooperative move means the Donor pays some cost for the Recipient to receive some benefit. The more cooperative move the Donor takes, the higher cost the Donor pays and the higher benefit the Recipient receives. The defective move has no effect on them. Two consecutive Multi-level Donor-Recipient games, one as a Donor and the other as a Recipient, can be viewed as a discrete version of the Continuous Prisoner's Dilemma. In the Demographic Multi-level Donor-Recipient game, players are initially distributed spatially. In each period, players play multiple Multi-level Donor-Recipient games against other players. He leaves offspring if possible and dies because of negative accumulated payoff of him or his lifespan. Cooperative moves are necessary for the survival of the whole population. There is only a low level of cooperative move besides the defective move initially available in strategies of players. A player may modify and expand his strategy by his recent experiences or practices. We distinguish several types of a player about modification and expansion. We show, by Agent-Based Simulation, that introducing only the modification increases the emergence rate of cooperation and introducing both the modification and the expansion further increases it and a high level of cooperation does emerge in our Demographic Multi-level Donor-Recipient Game.

Keywords: Agent-based simulation, donor-recipient game, emergence of cooperation, spatial structure, TFT, TF2T.

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Authors: Dib Djalel, Haddouche Ali, Chellali Benachiba

Abstract:

When a lightning strike falls near an overhead power line, the intense electromagnetic field radiated by the current of the lightning return stroke coupled with power lines and there induced transient overvoltages, which can cause a back-flashover in electrical network. The indirect lightning represents a major danger owing to the fact that it is more frequent than that which results from the direct strikes. In this paper we present an analysis of the electromagnetic coupling between an external electromagnetic field generated by the lightning and an electrical overhead lines, so we give an important and original contribution: We are based on our experimental measurements which we carried in the high voltage laboratories of EPFL in Switzerland during the last trimester of 2005, on the recent works of other authors and with our mathematical improvement a new particular analytical expression of the electromagnetic field generated by the lightning return stroke was developed and presented in this paper. The results obtained by this new electromagnetic field formulation were compared with experimental results and give a reasonable approach.

Keywords: Lightning, overhead lines, electromagneticcoupling, return stroke, models, induced overvoltages.

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Authors: Fahme Dabaj, Havva Başak

Abstract:

The aim of this study is to find out and analyze the role of gender and age on the perceptions of students to the distant online program offered by Vocational High School in Sakarya University. The research is based on a questionnaire as a mean of data collection method to find out the role of age and gender on the student-s perceptions toward online education, and the study progressed through finding relationships between the variables used in the data collection instrument. The findings of the analysis revealed that although the students registered to the online program by will, they preferred the traditional face-to-face education due to the difficulty of the nonverbal communication, their incompetence of using the technology required, and their belief in traditional face-toface learning more than online education. Regarding gender, the results showed that the female students have a better perception of the online education as opposed to the male students. Regarding age, the results showed that the older the students are the more is their preference towards attending face-toface classes.

Keywords: Distance education, online education, interneteducation, student perceptions.

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Authors: Berna Eren Tokgoz, Mahdi Safa, Seokyon Hwang

Abstract:

Power distribution systems are essential and crucial infrastructures for the development and maintenance of a sustainable society. These systems are extremely vulnerable to various types of natural and man-made disasters. The assessment of resilience focuses on preparedness and mitigation actions under pre-disaster conditions. It also concentrates on response and recovery actions under post-disaster situations. The aim of this study is to present a methodology to assess the resilience of electric power distribution poles against wind-related events. The proposed methodology can improve the accuracy and rapidity of the evaluation of the conditions and the assessment of the resilience of poles. The methodology provides a metric for the evaluation of the resilience of poles under pre-disaster and post-disaster conditions. The metric was developed using mathematical expressions for physical forces that involve various variables, such as physical dimensions of the pole, the inclination of the pole, and wind speed. A three-dimensional imaging technology (photogrammetry) was used to determine the inclination of poles. Based on expert opinion, the proposed metric was used to define zones to visualize resilience. Visual representation of resilience is helpful for decision makers to prioritize their resources before and after experiencing a wind-related disaster. Multiple electric poles in the City of Beaumont, TX were used in a case study to evaluate the proposed methodology.  

Keywords: Photogrammetry, power distribution systems, resilience metric, system resilience, wind-related disasters.

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