Search results for: surface runoff network
1136 Influence of Cavity Length on Forward-facing Cavity and Opposing Jet Combined Thermal Protection System Cooling Efficiency
Authors: Hai-bo Lu, Wei-qiang Liu
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A numerical study on the influence of forward-facing cavity length upon forward-facing cavity and opposing jet combined thermal protection system (TPS) cooling efficiency under hypersonic flow is conducted, by means of which the flow field parameters, heat flux distribution along the outer body surface are obtained. The numerical simulation results are validated by experiments and the cooling effect of the combined TPS with different cavity length is analyzed. The numerical results show that the combined configuration dose well in cooling the nose of the hypersonic vehicle. The deeper the cavity is, the weaker the heat flux is. The recirculation region plays a key role for the reduction of the aerodynamic heating.Keywords: Thermal protection, hypersonic vehicle, aerodynamic heating, forward-facing cavity, opposing jet
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17301135 Application of Neuro-Fuzzy Dynamic Programming to Improve the Reactive Power and Voltage Profile of a Distribution Substation
Authors: M. Tarafdar Haque, S. Najafi
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Improving the reactive power and voltage profile of a distribution substation is investigated in this paper. The purpose is to properly determination of the shunt capacitors on/off status and suitable tap changer (TC) position of a substation transformer. In addition, the limitation of secondary bus voltage, the maximum allowable number of switching operation in a day for on load tap changer and on/off status of capacitors are taken into account. To achieve these goals, an artificial neural network (ANN) is designed to provide preliminary scheduling. Input of ANN is active and reactive powers of transformer and its primary and secondary bus voltages. The output of ANN is capacitors on/off status and TC position. The preliminary schedule is further refined by fuzzy dynamic programming in order to reach the final schedule. The operation of proposed method in Q/V improving is compared with the results obtained by operator operation in a distribution substation.Keywords: Neuro-fuzzy, Dynamic programming, Reactive power, Voltage profile.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16291134 Detecting Defects in Textile Fabrics with Optimal Gabor Filters
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This paper investigates the problem of automated defect detection for textile fabrics and proposes a new optimal filter design method to solve this problem. Gabor Wavelet Network (GWN) is chosen as the major technique to extract the texture features from textile fabrics. Based on the features extracted, an optimal Gabor filter can be designed. In view of this optimal filter, a new semi-supervised defect detection scheme is proposed, which consists of one real-valued Gabor filter and one smoothing filter. The performance of the scheme is evaluated by using an offline test database with 78 homogeneous textile images. The test results exhibit accurate defect detection with low false alarm, thus showing the effectiveness and robustness of the proposed scheme. To evaluate the detection scheme comprehensively, a prototyped detection system is developed to conduct a real time test. The experiment results obtained confirm the efficiency and effectiveness of the proposed detection scheme.Keywords: Defect detection, Filtering, Gabor function, Gaborwavelet networks, Textile fabrics.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23561133 Characteristics of Suspended Solids Removal by Electrocoagulation
Authors: C. Phalakornkule, W. Worachai, T. Satitayut
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The electrochemical coagulation of a kaolin suspension was investigated at the currents of 0.06, 0.12, 0.22, 0.44, 0.85 A (corresponding to 0.68, 1.36, 2.50, 5.00, 9.66 mA·cm-2, respectively) for the contact time of 5, 10, 20, 30, and 50 min. The TSS removal efficiency at currents of 0.06 A, 0.12 A and 0.22 A increased with the amount of iron generated by the sacrificial anode, while the removal efficiencies did not increase proportionally with the amount of iron generated at the currents of 0.44 and 0.85 A, where electroflotation was clearly observed. Zeta potential measurement illustrated the presence of the highly positive charged particles created by sorption of highly charged polymeric metal hydroxyl species onto the negative surface charged kaolin particles at both low and high applied currents. The disappearance of the individual peaks after certain contact times indicated the attraction between these positive and negative charged particles causing agglomeration. It was concluded that charge neutralization of the individual species was not the only mechanism operating in the electrocoagulation process at any current level, but electrostatic attraction was likely to co-operate or mainly operate.Keywords: Coagulation, Electrocoagulation, Electrostatics, Suspended solids, Zeta potential
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27181132 The Behavior of Dam Foundation Reinforced by Stone Columns: Case Study of Kissir Dam-Jijel
Authors: Toufik Karech, Abderahmen Benseghir, Tayeb Bouzid
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This work presents a 2D numerical simulation of an earth dam to assess the behavior of its foundation after a treatment by stone columns. This treatment aims to improve the bearing capacity, to increase the mechanical properties of the soil, to accelerate the consolidation, to reduce the settlements and to eliminate the liquefaction phenomenon in case of seismic excitation. For the evaluation of the pore pressures, the position of the phreatic line and the flow network was defined, and a seepage analysis was performed with the software MIDAS Soil Works. The consolidation calculation is performed through a simulation of the actual construction stages of the dam. These analyzes were performed using the Mohr-Coulomb soil model and the results are compared with the actual measurements of settlement gauges implanted in the dam. An analysis of the bearing capacity was conducted to show the role of stone columns in improving the bearing capacity of the foundation.
Keywords: Earth dam, dam foundation, numerical simulation, stone columns, seepage analysis, consolidation, bearing capacity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11271131 An Investigation into Sealing Materials for Vacuum Glazing
Authors: Paul Onyegbule, Harjit Singh
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Vacuum glazing is an innovative transparent thermal insulator that has application in high performance window, especially in renewable energy. Different materials as well as sealing methods have been adopted to seal windows with different temperatures. The impact of temperatures on sealing layers has been found to have significant effects on the microstructure of the seal. This paper seeks to investigate the effects of sealing materials specifically glass powder and flux compound (borax) for vacuum glazing. The findings of the experiment conducted show that the sealing material was rigid with some leakage around the edge, and we found that this could be stopped by enhancing the uniformity of the seal within the periphery. Also, we found that due to the intense tensile stress from the oven surface temperature of the seal at 200 0C, a crack was observed at the side of the glass. Based on the above findings, this study concludes that a glass powder with a lower melting temperature of below 250 0C with the addition of an adhesive (borax flux) should be used for future vacuum seals.
Keywords: Double glazed windows, U-value, borax powder, edge seal.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 8151130 Electroremediation of Cu-Contaminated Soil
Authors: Darius Jay R. Bongay, Roberto L. Ngo
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This study investigated the removal efficiency of electrokinetic remediation of copper-contaminated soil at different combinations of enhancement reagents used as anolyte and catholyte. Sodium hydroxide (at 0.1, 0.5, and 1.0 M concentrations) and distilled water were used as anolyte, while lactic acid (at 0.01, 0.1, and 0.5 M concentrations), ammonium citrate (also at 0.01, 0.1, and 0.5 M concentrations) and distilled water were used as catholyte. A continuous voltage application (1.0 VDC/cm) was employed for 240 hours for each experiment. The copper content of the catholyte was determined at the end of the 240-hour period. Optimization was carried out with a Response Surface Methodology - Optimal Design, including F test, and multiple comparison method, to determine which pair of anolyte-catholyte was the most significant for the removal efficiency. "1.0 M NaOH" was found to be the most significant anolyte while it was established that lactic acid was the most significant type of catholyte to be used for the most successful electrokinetic experiments. Concentrations of lactic acid should be at the range of 0.1 M to 0.5 M to achieve maximum percent removal values.
Keywords: Electrokinetic remediation, copper contamination, heavy metal contamination, soil remediation
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17271129 Contrast-Enhanced Multispectal Upconversion Fluorescence Analysis for High-Resolution in-vivo Deep Tissue Imaging
Authors: Lijiang Wang, Wei Wang, Yuhong Xu
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Lanthanide-doped upconversion nanoparticles which can convert near-infrared lights to visible lights have attracted growing interest because of their great potentials in fluorescence imaging. Upconversion fluorescence imaging technique with excitation in the near-infrared (NIR) region has been used for imaging of biological cells and tissues. However, improving the detection sensitivity and decreasing the absorption and scattering in biological tissues are as yet unresolved problems. In this present study, a novel NIR-reflected multispectral imaging system was developed for upconversion fluorescent imaging in small animals. Based on this system, we have obtained the high contrast images without the autofluorescence when biocompatible UCPs were injected near the body surface or deeply into the tissue. Furthermore, we have extracted respective spectra of the upconversion fluorescence and relatively quantify the fluorescence intensity with the multispectral analysis. To our knowledge, this is the first time to analyze and quantify the upconversion fluorescence in the small animal imaging.
Keywords: Multispectral imaging, near-infrared, upconversion fluorescence imaging, upconversion nanoparticles.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17161128 High Efficiency Electrolyte Lithium Battery and RF Characterization
Authors: Wei Quan, Liu Chao, Mohammed N. Afsar
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The dielectric properties and ionic conductivity of novel "ceramic state" polymer electrolytes for high capacity lithium battery are characterized by Radio frequency and Microwave methods in two broad frequency ranges from 50 Hz to 20 KHz and 4 GHz to 40 GHz. This innovative solid polymer electrolyte which is highly ionic conductive (10-3 S/cm at room temperature) from -40oC to +150oC can be used in any battery application. Such polymer exhibits properties more like a ceramic rather than polymer. The various applied measurement methods produced accurate dielectric results for comprehensive analysis of electrochemical properties and ion transportation mechanism of this newly invented polymer electrolyte. Two techniques and instruments employing air gap measurement by Capacitance Bridge and in-waveguide measurement by vector network analyzer are applied to measure the complex dielectric spectra. The complex dielectric spectra are used to determine the complex alternating current electrical conductivity and thus the ionic conductivity.
Keywords: Polymer electrolyte, dielectric permittivity, lithium battery, ionic relaxation, microwave measurement.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24241127 Gene Network Analysis of PPAR-γ: A Bioinformatics Approach Using STRING
Authors: S. Bag, S. Ramaiah, P. Anitha, K. M. Kumar, P. Lavanya, V. Sivasakhthi, A. Anbarasu
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Gene networks present a graphical view at the level of gene activities and genetic functions and help us to understand complex interactions in a meaningful manner. In the present study, we have analyzed the gene interaction of PPAR-γ (peroxisome proliferator-activated receptor gamma) by search tool for retrieval of interacting genes. We find PPAR-γ is highly networked by genetic interactions with 10 genes: RXRA (retinoid X receptor, alpha), PPARGC1A (peroxisome proliferator-activated receptor gamma, coactivator 1 alpha), NCOA1 (nuclear receptor coactivator 1), NR0B2 (nuclear receptor subfamily 0, group B, member 2), HDAC3 (histone deacetylase 3), MED1 (mediator complex subunit 1), INS (insulin), NCOR2 (nuclear receptor co-repressor 2), PAX8 (paired box 8), ADIPOQ (adiponectin) and it augurs well for the fact that obesity and several other metabolic disorders are inter related.
Keywords: Gene networks, NCOA1, PPARγ, PPARGC1A, RXRA.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 45441126 Effective Relay Communication for Scalable Video Transmission
Authors: Jung Ah Park, Zhijie Zhao, Doug Young Suh, Joern Ostermann
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In this paper, we propose an effective relay communication for layered video transmission as an alternative to make the most of limited resources in a wireless communication network where loss often occurs. Relaying brings stable multimedia services to end clients, compared to multiple description coding (MDC). Also, retransmission of only parity data about one or more video layer using channel coder to the end client of the relay device is paramount to the robustness of the loss situation. Using these methods in resource-constrained environments, such as real-time user created content (UCC) with layered video transmission, can provide high-quality services even in a poor communication environment. Minimal services are also possible. The mathematical analysis shows that the proposed method reduced the probability of GOP loss rate compared to MDC and raptor code without relay. The GOP loss rate is about zero, while MDC and raptor code without relay have a GOP loss rate of 36% and 70% in case of 10% frame loss rate.Keywords: Relay communication, Multiple Description Coding, Scalable Video Coding
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14371125 Coerced Delay and Multi Additive Constraints QoS Routing Schemes
Authors: P.S. Prakash, S. Selvan
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IP networks are evolving from data communication infrastructure into many real-time applications such as video conferencing, IP telephony and require stringent Quality of Service (QoS) requirements. A rudimentary issue in QoS routing is to find a path between a source-destination pair that satisfies two or more endto- end constraints and termed to be NP hard or complete. In this context, we present an algorithm Multi Constraint Path Problem Version 3 (MCPv3), where all constraints are approximated and return a feasible path in much quicker time. We present another algorithm namely Delay Coerced Multi Constrained Routing (DCMCR) where coerce one constraint and approximate the remaining constraints. Our algorithm returns a feasible path, if exists, in polynomial time between a source-destination pair whose first weight satisfied by the first constraint and every other weight is bounded by remaining constraints by a predefined approximation factor (a). We present our experimental results with different topologies and network conditions.Keywords: Routing, Quality-of-Service (QoS), additive constraints, shortest path, delay coercion.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13051124 Web 2.0 in Higher Education: The Instructors’ Acceptance in Higher Educational Institutes in Kingdom of Bahrain
Authors: Amal M. Alrayes, Hayat M. Ali
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Since the beginning of distance education with the rapid evolution of technology, the social network plays a vital role in the educational process to enforce the interaction been the learners and teachers. There are many Web 2.0 technologies, services and tools designed for educational purposes. This research aims to investigate instructors’ acceptance towards web-based learning systems in higher educational institutes in Kingdom of Bahrain. Questionnaire is used to investigate the instructors’ usage of Web 2.0 and the factors affecting their acceptance. The results confirm that instructors had high accessibility to such technologies. However, patterns of use were complex. Whilst most expressed interest in using online technologies to support learning activities, learners seemed cautious about other values associated with web-based system, such as the shared construction of knowledge in a public format. The research concludes that there are main factors that affect instructors’ adoption which are security, performance expectation, perceived benefits, subjective norm, and perceived usefulness.
Keywords: Web 2.0, Higher education, Acceptance, Students’ perception.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13091123 Ultrasound Assisted Method to Increase the Aluminum Dissolve Rate from Acidified Water
Authors: Wen Po Cheng, Chi Hua Fu, Ping Hung Chen, Ruey Fang Yu
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Aluminum salt that is generally presents as a solid phase in the water purification sludge (WPS) can be dissolved, recovering a liquid phase, by adding strong acid to the sludge solution. According to the reaction kinetics, when reactant is in the form of small particles with a large specific surface area, or when the reaction temperature is high, the quantity of dissolved aluminum salt or reaction rate, respectively are high. Therefore, in this investigation, water purification sludge (WPS) solution was treated with ultrasonic waves to break down the sludge, and different acids (1 N HCl and 1 N H2SO4) were used to acidify it. Acid dosages that yielded the solution pH of less than two were used. The results thus obtained indicate that the quantity of dissolved aluminum in H2SO4-acidified solution exceeded that in HCl-acidified solution. Additionally, ultrasonic treatment increased the rate of dissolution of aluminum and the amount dissolved. The quantity of aluminum dissolved at 60℃ was 1.5 to 2.0 times higher than that at 25℃.Keywords: Coagulant, Aluminum, Ultrasonic, Acidification, Temperature, Sludge.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22761122 Electrical Characteristics of Biomodified Electrodes using Nonfaradaic Electrochemical Impedance Spectroscopy
Authors: Yusmeeraz Yusof, Yoshiyuki Yanagimoto, Shigeyasu Uno, Kazuo Nakazato
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We demonstrate a nonfaradaic electrochemical impedance spectroscopy measurement of biochemically modified gold plated electrodes using a two-electrode system. The absence of any redox indicator in the impedance measurements provide more precise and accurate characterization of the measured bioanalyte at molecular resolution. An equivalent electrical circuit of the electrodeelectrolyte interface was deduced from the observed impedance data of saline solution at low and high concentrations. The detection of biomolecular interactions was fundamentally correlated to electrical double-layer variation at modified interface. The investigations were done using 20mer deoxyribonucleic acid (DNA) strands without any label. Surface modification was performed by creating mixed monolayer of the thiol-modified single-stranded DNA and a spacer thiol (mercaptohexanol) by a two-step self-assembly method. The results clearly distinguish between the noncomplementary and complementary hybridization of DNA, at low frequency region below several hundreds Hertz.
Keywords: Biosensor, electrical double-layer, impedance spectroscopy, label free DNA.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30871121 Knowledge Representation Based On Interval Type-2 CFCM Clustering
Authors: Myung-Won Lee, Keun-Chang Kwak
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This paper is concerned with knowledge representation and extraction of fuzzy if-then rules using Interval Type-2 Context-based Fuzzy C-Means clustering (IT2-CFCM) with the aid of fuzzy granulation. This proposed clustering algorithm is based on information granulation in the form of IT2 based Fuzzy C-Means (IT2-FCM) clustering and estimates the cluster centers by preserving the homogeneity between the clustered patterns from the IT2 contexts produced in the output space. Furthermore, we can obtain the automatic knowledge representation in the design of Radial Basis Function Networks (RBFN), Linguistic Model (LM), and Adaptive Neuro-Fuzzy Networks (ANFN) from the numerical input-output data pairs. We shall focus on a design of ANFN in this paper. The experimental results on an estimation problem of energy performance reveal that the proposed method showed a good knowledge representation and performance in comparison with the previous works.
Keywords: IT2-FCM, IT2-CFCM, context-based fuzzy clustering, adaptive neuro-fuzzy network, knowledge representation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26171120 Permanent Magnet Synchronous Generator – Unsymmetrical Point Operation
Authors: P. Pistelok
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The article presents the concept of an electromagnetic circuit generator with permanent magnets mounted on the surface rotor core designed for single phase work. Computation field-circuit model was shown. The spectrum of time course of voltages in the idle work was presented. The cross section with graphically presentation of magnetic induction in particular parts of electromagnetic circuits was presented. Distribution of magnetic induction at the rated load point for each phase was shown. The time course of voltages and currents for each phases for rated power were displayed. An analysis of laboratory results and measurement of load characteristics of the generator was discussed. The work deals with three electromagnetic circuits of generators with permanent magnet where output voltage characteristics versus rated power were expressed.
Keywords: Permanent magnet generator, permanent magnets, vibration, course of torque, single phase work, asymmetrical three phase work.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23761119 Selection of Intensity Measure in Probabilistic Seismic Risk Assessment of a Turkish Railway Bridge
Authors: M. F. Yilmaz, B. Ö. Çağlayan
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Fragility curve is an effective common used tool to determine the earthquake performance of structural and nonstructural components. Also, it is used to determine the nonlinear behavior of bridges. There are many historical bridges in the Turkish railway network; the earthquake performances of these bridges are needed to be investigated. To derive fragility curve Intensity measures (IMs) and Engineering demand parameters (EDP) are needed to be determined. And the relation between IMs and EDP are needed to be derived. In this study, a typical simply supported steel girder riveted railway bridge is studied. Fragility curves of this bridge are derived by two parameters lognormal distribution. Time history analyses are done for selected 60 real earthquake data to determine the relation between IMs and EDP. Moreover, efficiency, practicality, and sufficiency of three different IMs are discussed. PGA, Sa(0.2s) and Sa(1s), the most common used IMs parameters for fragility curve in the literature, are taken into consideration in terms of efficiency, practicality and sufficiency.
Keywords: Railway bridges, earthquake performance, fragility analyses, selection of intensity measures.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9021118 Experimental Study of Hyperparameter Tuning a Deep Learning Convolutional Recurrent Network for Text Classification
Authors: Bharatendra Rai
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Sequences of words in text data have long-term dependencies and are known to suffer from vanishing gradient problem when developing deep learning models. Although recurrent networks such as long short-term memory networks help overcome this problem, achieving high text classification performance is a challenging problem. Convolutional recurrent networks that combine advantages of long short-term memory networks and convolutional neural networks, can be useful for text classification performance improvements. However, arriving at suitable hyperparameter values for convolutional recurrent networks is still a challenging task where fitting of a model requires significant computing resources. This paper illustrates the advantages of using convolutional recurrent networks for text classification with the help of statistically planned computer experiments for hyperparameter tuning.
Keywords: Convolutional recurrent networks, hyperparameter tuning, long short-term memory networks, Tukey honest significant differences
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1151117 Deformation of Metallic Foams with Closed Cell at High Temperatures
Authors: Emrah Ersoy, Yusuf Özçatalbas
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The aim of this study is to investigate formability of Al based closed cell metallic foams at high temperature. The foam specimens with rectangular section were produced from AlMg1Si0.6TiH20.8 alloy preform material. Bending and free bending tests based on gravity effect were applied to foam specimens at high temperatures. During the tests, the time-angular deformation relationships with various temperatures were determined. Deformation types formed in cell walls were investigated by means of Scanning Electron Microscopy (SEM) and optical microscopy. Bending deformation about 90° was achieved without any defect at high temperatures. The importance of a critical temperature and deformation rate was emphasized in maintaining the deformation. Significant slip lines on surface of cell walls at tensile zones of bending specimen were observed. At high strain rates, the microcrack formation in boundaries of elongated grains was determined.Keywords: Al alloy, Closed cell, hot deformation, metallic foam.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21801116 Blind Identification Channel Using Higher Order Cumulants with Application to Equalization for MC−CDMA System
Authors: Mohammed Zidane, Said Safi, Mohamed Sabri, Ahmed Boumezzough
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In this paper we propose an algorithm based on higher order cumulants, for blind impulse response identification of frequency radio channels and downlink (MC−CDMA) system Equalization. In order to test its efficiency, we have compared with another algorithm proposed in the literature, for that we considered on theoretical channel as the Proakis’s ‘B’ channel and practical frequency selective fading channel, called Broadband Radio Access Network (BRAN C), normalized for (MC−CDMA) systems, excited by non-Gaussian sequences. In the part of (MC−CDMA), we use the Minimum Mean Square Error (MMSE) equalizer after the channel identification to correct the channel’s distortion. The simulation results, in noisy environment and for different signal to noise ratio (SNR), are presented to illustrate the accuracy of the proposed algorithm.
Keywords: Blind identification and equalization, Higher Order Cumulants, (MC−CDMA) system, MMSE equalizer.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17811115 Influences of Si and C- Doping on the Al-27 and N-14 Quardrupole Coupling Constants in AlN Nanotubes: A DFT Study
Authors: A.Seif, H.Aghaie, K.Majlesi
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A computational study at the level density functional theory (DFT) was carried out to investigate the influences of Si and C-doping on the 14N and 27Al quadrupole coupling constant in the (10, 0) zigzag single ? walled Aluminum-Nitride nanotube (AlNNT). To this aim, a 1.16nm, length of AlNNT consisting of 40 Al atoms and 40 N atoms were selected where the end atoms are capped by hydrogen atom. To follow the purpose, three Si atoms and three C atoms were doped instead of three Al atoms and three N atoms as a central ring in the surface of the Si and C-doped AlNNT. At first both of systems optimized at the level of BLYP method and 6-31G (d) basis set and after that, the NQR parameters were calculated at the level BLYP method and 6-311+G** basis set in two optimized forms. The calculate CQ values for both optimized AlNNT systems, raw and Si and C-doped, reveal different electronic environments in the mentioned systems. It was also demonstrated that the end nuclei have the largest CQ values in both considered AlNNT systems. All the calculations were carried out using Gaussian 98 package of program.Keywords: DFT, Quadrupole Coupling Constant, Si and CDoping, Single-Walled AlN nanotubes.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15501114 CFD Modeling of PROX Microreactor for Fuel Processing
Authors: M. Vahabi, M. H. Akbari
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In order to investigate a PROX microreactor performance, two-dimensional modeling of the reacting flow between two parallel plates is performed through a finite volume method using an improved SIMPLE algorithm. A three-step surface kinetics including hydrogen oxidation, carbon monoxide oxidation and water-gas shift reaction is applied for a Pt-Fe/γ-Al2O3 catalyst and operating temperatures of about 100ºC. Flow pattern, pressure field, temperature distribution, and mole fractions of species are found in the whole domain for all cases. Also, the required reactive length for removing carbon monoxide from about 2% to less than 10 ppm is found. Furthermore, effects of hydraulic diameter, wall temperature, and inlet mole fraction of air and water are investigated by considering carbon monoxide selectivity and conversion. It is found that air and water addition may improve the performance of the microreactor in carbon monoxide removal in such operating conditions; this is in agreement with the pervious published results.Keywords: CFD, Fuel Processing, PROX, Reacting Flow, SIMPLE algorithm.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14411113 Antimicrobial Properties of Copper in Gram-Negative and Gram-Positive Bacteria
Authors: Travis J. Meyer, Jasodra Ramlall, Phyo Thu, Nidhi Gadura
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For centuries humans have used the antimicrobial properties of copper to their advantage. Yet, after all these years the underlying mechanisms of copper mediated cell death in various microbes remain unclear. We had explored the hypothesis that copper mediated increased levels of lipid peroxidation in the membrane fatty acids is responsible for increased killing in Escherichia coli. In this study we show that in both gram positive (Staphylococcus aureus) and gram negative (Pseudomonas aeruginosa) bacteria there is a strong correlation between copper mediated cell death and increased levels of lipid peroxidation. Interestingly, the non-spore forming gram positive bacteria as well as gram negative bacteria show similar patterns of cell death, increased levels of lipid peroxidation, as well as genomic DNA degradation, however there is some difference in loss in membrane integrity upon exposure to copper alloy surface.
Keywords: Antimicrobial, copper, gram positive, gram negative.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 55931112 Treatment of Eutrophic-lake Water by Free Water Surface Wetland
Authors: Haodong Wu, Ping Huang, Junsan Wang
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In China, with the rapid urbanization and industrialization, and highly accelerated economic development have resulted in degradation of water resource. The water quality deterioration usual result from eutrophication in most cases, so how to dispose this type pollution water higher efficiently is an urgent task. Hower, different with traditional technology, constructed wetlands are effective treatment systems that can be very useful because they are simple technology and low operational cost. A pilot-scale treatment including constructed wetlands was constructed at XingYun Lake, Yuxi, China, and operated as primary treatment measure before eutrophic-lake water draining to riverine landscape. Water quality indices were determined during the experiment, the results indicated that treatment removal efficiencies were high for Nitrate nitrogen, Chlorophyll–a and Algae, the final removal efficiency reached to 95.20%, 93.33% and 99.87% respectively, but the removal efficiency of Total phosphorous and Total nitrogen only reach to 68.83% and 50.00% respectively.Keywords: Constructed wetland, Eutrophic-lake water, Nutrientremoval, Removal efficiency
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18301111 Evolution of Fuzzy Neural Networks Using an Evolution Strategy with Fuzzy Genotype Values
Authors: Hidehiko Okada
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Evolution strategy (ES) is a well-known instance of evolutionary algorithms, and there have been many studies on ES. In this paper, the author proposes an extended ES for solving fuzzy-valued optimization problems. In the proposed ES, genotype values are not real numbers but fuzzy numbers. Evolutionary processes in the ES are extended so that it can handle genotype instances with fuzzy numbers. In this study, the proposed method is experimentally applied to the evolution of neural networks with fuzzy weights and biases. Results reveal that fuzzy neural networks evolved using the proposed ES with fuzzy genotype values can model hidden target fuzzy functions even though no training data are explicitly provided. Next, the proposed method is evaluated in terms of variations in specifying fuzzy numbers as genotype values. One of the mostly adopted fuzzy numbers is a symmetric triangular one that can be specified by its lower and upper bounds (LU) or its center and width (CW). Experimental results revealed that the LU model contributed better to the fuzzy ES than the CW model, which indicates that the LU model should be adopted in future applications of the proposed method.
Keywords: Evolutionary algorithm, evolution strategy, fuzzy number, feedforward neural network, neuroevolution.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15451110 Material Failure Process Simulation by Improve Finite Elements with Embedded Discontinuities
Authors: Juárez-Luna Gelacio, Ayala Gustavo, Retama-Velasco Jaime
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This paper shows the advantages of the material failure process simulation by improve finite elements with embedded discontinuities, using a new definition of traction vector, dependent on the discontinuity length and the angle. Particularly, two families of this kind of elements are compared: kinematically optimal symmetric and statically and kinematically optimal non-symmetric. The constitutive model to describe the behavior of the material in the symmetric formulation is a traction-displacement jump relationship equipped with softening after reaching the failure surface.
To show the validity of this symmetric formulation, representative numerical examples illustrating the performance of the proposed formulation are presented. It is shown that the non-symmetric family may over or underestimate the energy required to create a discontinuity, as this effect is related with the total length of the discontinuity, fact that is not noticed when the discontinuity path is a straight line.
Keywords: Variational formulation, strong discontinuity, embedded discontinuities, strain localization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17701109 Finite Element Method for Calculating Temperature Field of Main Cable of Suspension Bridge
Authors: Heng Han, Zhilei Liang, Xiangong Zhou
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In this paper, the finite element method is used to study the temperature field of the main cable of the suspension bridge, and the calculation method of the average temperature of the cross-section of the main cable suitable for the construction control of the cable system is proposed. By comparing and analyzing the temperature field of the main cable with five diameters, a reasonable diameter limit for calculating the average temperature of the cross section of the main cable by finite element method is proposed. The results show that the maximum error of this method is less than 1 ℃, which meets the requirements of construction control accuracy. For the main cable with a diameter greater than 400 mm, the surface temperature measuring points combined with the finite element method shall be used to calculate the average cross-section temperature.
Keywords: Suspension bridge, main cable, temperature field, finite element.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3571108 Improving Location Management in Mobile IPv4 Networks
Authors: Haidar Safa, Hassan Artail, Ahmad Mehio, Hicham Zahr, Ziad Matragi
Abstract:
The Mobile IP Standard has been developed to support mobility over the Internet. This standard contains several drawbacks as in the cases where packets are routed via sub-optimal paths and significant amount of signaling messages is generated due to the home registration procedure which keeps the network aware of the current location of the mobile nodes. Recently, a dynamic hierarchical mobility management strategy for mobile IP networks (DHMIP) has been proposed to reduce home registrations costs. However, this strategy induces a packet delivery delay and increases the risk of packet loss. In this paper, we propose an enhanced version of the dynamic hierarchical strategy that reduces the packet delivery delay and minimizes the risk of packet loss. Preliminary results obtained from simulations are promising. They show that the enhanced version outperforms the original dynamic hierarchical mobility management strategy version.
Keywords: Location management, Mobile IP (MIP), Home Agent, Foreign Agent.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14461107 Combining Color and Layout Features for the Identification of Low-resolution Documents
Authors: Ardhendu Behera, Denis Lalanne, Rolf Ingold
Abstract:
This paper proposes a method, combining color and layout features, for identifying documents captured from lowresolution handheld devices. On one hand, the document image color density surface is estimated and represented with an equivalent ellipse and on the other hand, the document shallow layout structure is computed and hierarchically represented. The combined color and layout features are arranged in a symbolic file, which is unique for each document and is called the document-s visual signature. Our identification method first uses the color information in the signatures in order to focus the search space on documents having a similar color distribution, and finally selects the document having the most similar layout structure in the remaining search space. Finally, our experiment considers slide documents, which are often captured using handheld devices.Keywords: Document color modeling, document visual signature, kernel density estimation, document identification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1375