Search results for: effective atomic number
5716 Effective Density for the Classification of Transport Activity Centers
Authors: Dubbale Daniel A., Tsutsumi J.
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This research work takes a different approach in the discussion of urban form impacts on transport planning and auto dependency. Concentrated density represented by effective density explains auto dependency better than the conventional density and it is proved to be a realistic density representative for the urban transportation analysis. Model analysis reveals that effective density is influenced by the shopping accessibility index as well as job density factor. It is also combined with the job access variable to classify four levels of Transport Activity Centers (TACs) in Okinawa, Japan. Trip attraction capacity and levels of the newly classified TACs was found agreeable with the amount of daily trips attracted to each center. The trip attraction data set was drawn from a 2007 Okinawa personal trip survey. This research suggests a planning methodology which guides logical transport supply routes and concentrated local development schemes.Keywords: Effective density, urban form, auto-dependency, transport activity centers
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15155715 Free Convection in a MHD Porous Cavity with using Lattice Boltzmann Method
Authors: H.A. Ashorynejad, M. Farhadi, K.Sedighi, A.Hasanpour
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We report the results of an lattice Boltzmann simulation of magnetohydrodynamic damping of sidewall convection in a rectangular enclosure filled with a porous medium. In particular we investigate the suppression of convection when a steady magnetic field is applied in the vertical direction. The left and right vertical walls of the cavity are kept at constant but different temperatures while both the top and bottom horizontal walls are insulated. The effects of the controlling parameters involved in the heat transfer and hydrodynamic characteristics are studied in detail. The heat and mass transfer mechanisms and the flow characteristics inside the enclosure depended strongly on the strength of the magnetic field and Darcy number. The average Nusselt number decreases with rising values of the Hartmann number while this increases with increasing values of the Darcy number.Keywords: Lattice Boltzmann method , Natural convection , Magnetohydrodynamic , Porous medium
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20085714 Induced Acyclic Path Decomposition in Graphs
Authors: Abraham V. M., I. Sahul Hamid
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A decomposition of a graph G is a collection ψ of graphs H1,H2, . . . , Hr of G such that every edge of G belongs to exactly one Hi. If each Hi is either an induced path in G, then ψ is called an induced acyclic path decomposition of G and if each Hi is a (induced) cycle in G then ψ is called a (induced) cycle decomposition of G. The minimum cardinality of an induced acyclic path decomposition of G is called the induced acyclic path decomposition number of G and is denoted by ¤Çia(G). Similarly the cyclic decomposition number ¤Çc(G) is defined. In this paper we begin an investigation of these parameters.Keywords: Cycle decomposition, Induced acyclic path decomposition, Induced acyclic path decomposition number.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15755713 Incremental Learning of Independent Topic Analysis
Authors: Takahiro Nishigaki, Katsumi Nitta, Takashi Onoda
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In this paper, we present a method of applying Independent Topic Analysis (ITA) to increasing the number of document data. The number of document data has been increasing since the spread of the Internet. ITA was presented as one method to analyze the document data. ITA is a method for extracting the independent topics from the document data by using the Independent Component Analysis (ICA). ICA is a technique in the signal processing; however, it is difficult to apply the ITA to increasing number of document data. Because ITA must use the all document data so temporal and spatial cost is very high. Therefore, we present Incremental ITA which extracts the independent topics from increasing number of document data. Incremental ITA is a method of updating the independent topics when the document data is added after extracted the independent topics from a just previous the data. In addition, Incremental ITA updates the independent topics when the document data is added. And we show the result applied Incremental ITA to benchmark datasets.Keywords: Text mining, topic extraction, independent, incremental, independent component analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10585712 Particle Swarm Optimization with Reduction for Global Optimization Problems
Authors: Michiharu Maeda, Shinya Tsuda
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This paper presents an algorithm of particle swarm optimization with reduction for global optimization problems. Particle swarm optimization is an algorithm which refers to the collective motion such as birds or fishes, and a multi-point search algorithm which finds a best solution using multiple particles. Particle swarm optimization is so flexible that it can adapt to a number of optimization problems. When an objective function has a lot of local minimums complicatedly, the particle may fall into a local minimum. For avoiding the local minimum, a number of particles are initially prepared and their positions are updated by particle swarm optimization. Particles sequentially reduce to reach a predetermined number of them grounded in evaluation value and particle swarm optimization continues until the termination condition is met. In order to show the effectiveness of the proposed algorithm, we examine the minimum by using test functions compared to existing algorithms. Furthermore the influence of best value on the initial number of particles for our algorithm is discussed.Keywords: Particle swarm optimization, Global optimization, Metaheuristics, Reduction.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16215711 Attribute Selection Methods Comparison for Classification of Diffuse Large B-Cell Lymphoma
Authors: Helyane Bronoski Borges, Júlio Cesar Nievola
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The most important subtype of non-Hodgkin-s lymphoma is the Diffuse Large B-Cell Lymphoma. Approximately 40% of the patients suffering from it respond well to therapy, whereas the remainder needs a more aggressive treatment, in order to better their chances of survival. Data Mining techniques have helped to identify the class of the lymphoma in an efficient manner. Despite that, thousands of genes should be processed to obtain the results. This paper presents a comparison of the use of various attribute selection methods aiming to reduce the number of genes to be searched, looking for a more effective procedure as a whole.Keywords: Attribute selection, data mining.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14175710 Soft-Sensor for Estimation of Gasoline Octane Number in Platforming Processes with Adaptive Neuro-Fuzzy Inference Systems (ANFIS)
Authors: Hamed.Vezvaei, Sepideh.Ordibeheshti, Mehdi.Ardjmand
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Gasoline Octane Number is the standard measure of the anti-knock properties of a motor in platforming processes, that is one of the important unit operations for oil refineries and can be determined with online measurement or use CFR (Cooperative Fuel Research) engines. Online measurements of the Octane number can be done using direct octane number analyzers, that it is too expensive, so we have to find feasible analyzer, like ANFIS estimators. ANFIS is the systems that neural network incorporated in fuzzy systems, using data automatically by learning algorithms of NNs. ANFIS constructs an input-output mapping based both on human knowledge and on generated input-output data pairs. In this research, 31 industrial data sets are used (21 data for training and the rest of the data used for generalization). Results show that, according to this simulation, hybrid method training algorithm in ANFIS has good agreements between industrial data and simulated results.Keywords: Adaptive Neuro-Fuzzy Inference Systems, GasolineOctane Number, Soft-sensor, Catalytic Naphtha Reforming
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21945709 Exploring the Need to Study the Efficacy of VR Training Compared to Traditional Cybersecurity Training
Authors: Shaila Rana, Wasim Alhamdani
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Effective cybersecurity training is of the utmost importance, given the plethora of attacks that continue to increase in complexity and ubiquity. VR cybersecurity training remains a starkly understudied discipline. Studies that evaluated the effectiveness of VR cybersecurity training over traditional methods are required. An engaging and interactive platform can support knowledge retention of the training material. Consequently, an effective form of cybersecurity training is required to support a culture of cybersecurity awareness. Measurements of effectiveness varied throughout the studies, with surveys and observations being the two most utilized forms of evaluating effectiveness. Further research is needed to evaluate the effectiveness of VR cybersecurity training and traditional training. Additionally, research for evaluating if VR cybersecurity training is more effective than traditional methods is vital. This paper proposes a methodology to compare the two cybersecurity training methods and their effectiveness. The proposed framework includes developing both VR and traditional cybersecurity training methods and delivering them to at least 100 users. A quiz along with a survey will be administered and statistically analyzed to determine if there is a difference in knowledge retention and user satisfaction. The aim of this paper is to bring attention to the need to study VR cybersecurity training and its effectiveness compared to traditional training methods. This paper hopes to contribute to the cybersecurity training field by providing an effective way to train users for security awareness. If VR training is deemed more effective, this could create a new direction for cybersecurity training practices.
Keywords: Virtual reality cybersecurity training, VR cybersecurity training, traditional cybersecurity training, evaluating efficacy.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10835708 Research of the Factors Affecting the Administrative Capacity of Enterprises in the Logistic Sector of Bulgaria
Authors: R. Kenova, K. Anguelov, R. Nikolova
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The human factor plays a major role in boosting the competitive capacity of logistic enterprises. This is of particular importance when it comes to logistic companies. On the one hand they should be strictly compliant with legislation; on the other hand, they should be competitive in terms of pricing and of delivery timelines. Moreover, their policies should allow them to be as flexible as possible. All these circumstances are reason for very serious challenges for the qualification, motivation and experience of the human resources, working in logistic companies or in logistic departments of trade and industrial enterprises. The geographic place of Bulgaria puts it in position of a country with some specific competitive advantages in the goods transport from Europe to Asia and back. Along with it, there is a number of logistic companies, that operate in this sphere in Bulgaria. In the current paper, the authors aim to establish the condition of the administrative capacity and human resources in the logistic companies and logistic departments of trade and industrial companies in Bulgaria in order to propose some guidelines for improving of their effectiveness. Due to independent empirical research, conducted in Bulgarian logistic, trade and industrial enterprises, the authors investigate both the impact degree and the interdependence of various factors that characterize the administrative capacity. The study is conducted with a prepared questionnaire, in format of direct interview with the respondents. The volume of the poll is 50 respondents, representatives of: general managers of industrial or trade enterprises; logistic managers of industrial or trade enterprises; general managers of forwarding companies – either with own or with hired transport; experts from Bulgarian association of logistics; logistic lobbyist and scientists of the relevant area. The data are gathered for 3 months, then arranged by a specialized software program and analyzed by preset criteria. Based on the results of this methodological toolbox, it can be claimed that there is a correlation between the individual criteria. Also, a commitment between the administrative capacity and other factors that determine the competitiveness of the studied companies is established. In this paper, the authors present results of the empirical research that concerns the number and the workload in the logistic departments of the enterprises. Also, what is commented is the experience, related to logistic processes management and human resources competence. Moreover, the overload level of the logistic specialists is analyzed as one of the main threats for making mistakes and losing clients. The paper stands behind the thesis that there is indispensability of forming an effective and efficient administrative capacity, based on the number, qualification, experience and motivation of the staff in the logistic companies. The paper ends with recommendations about the qualification and experience of the specialists in logistic departments; providing effective and efficient administrative capacity in the logistic departments; interdependence of the human factor and the other factors that influence the enterprise competitiveness.
Keywords: Administrative capacity, human resources, logistic competitiveness, staff qualification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6155707 Effect of Various Concentrations of Humic Acid on Growth and Development of Eggplant Seedlings in Tissue Cultures at Low Nutrient Level
Authors: Kullanart Obsuwan, Suluck Namchote, Natdhera Sanmanee, Kamolchanok Panishkan, Sirichai Dharmvanij
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Humic acids (HAs) have been shown to activate some ion uptakes along with stimulating the lateral roots at effective concentration of micronutrients. However, the effects of HA on ion adsorption by plant roots are not easily explainable due to the varieties of HAs that differ from origins. Therefore, this study was aimed to investigate the effect of various concentrations of HA obtained from the compost derived from mix manures and some agricultural wastes on the growth of eggplant seedlings (Solanum melongena L. cv. Chao Praya) in tissue cultures at low nutrient level. Egg plant seeds were surfaced sterilized and germinated in ½ Murashige and Skoog medium (MS) without HA added or in ¼ MS supplemented with 0, 25, 50, 75 and 100 ppm of HAs. Then, they were cultured for 4 weeks under the controlled environment. The results showed that seedlings grown on ¼MS supplemented with HAs at the concentration of 25 and 50 ppm had the average plant heights (2.49 and 2.28 cm, respectively) higher than the other treatments. Both treatments also significantly showed the maximum average fresh and dry weights (p<0.05). Also the later yielded the highest average number of leaves and the longest average root length (p<0.05). However, there was no statistically different in the number of roots among treatments (p>0.05). This suggested that HAs at the concentration of 25 and 50 ppm could improve the growth of egg plant seedlings in tissue cultures at low nutrient level (¼ MS).Keywords: growth, seedling, humic acid, fresh weght, dry weight, tissue culture
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24985706 Effect of Nanoparticle Diameter of Nano-Fluid on Average Nusselt Number in the Chamber
Authors: A. Ghafouri, N. Pourmahmoud, I. Mirzaee
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In this numerical study, effects of using Al2O3-water nanofluid on the rate of heat transfer have been investigated. Physical model is a square enclosure with insulated top and bottom horizontal walls, while the vertical walls are kept at different constant temperatures. Two appropriate models are used to evaluate the viscosity and thermal conductivity of nanofluid. The governing stream-vorticity equations are solved using a second order central finite difference scheme, coupled to the conservation of mass and energy. The study has been carried out for the nanoparticle diameter 30, 60 and 90 nm and the solid volume fraction 0 to 0.04. Results are presented by average Nusselt number and normalized Nusselt number in different range of φ and D for mixed convection dominated regime. It is found that different heat transfer rate is predicted when the effect of nanoparticle diameter is taken into account.Keywords: Nano-fluid, nanoparticle diameter, heat transfer enhancement, square enclosure, Nusselt number.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16945705 Using Molecular Dynamics to Assess Mechanical Properties of PAN-Based Carbon Fibers Comprising Imperfect Crystals with Amorphous Structures
Authors: A. Ito, S. Okamoto
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We constructed an atomic structure model for a PAN-based carbon fiber containing amorphous structures using molecular dynamics methods. It was found that basic physical properties such as crystallinity, Young’s modulus, and thermal conductivity of our model were nearly identical to those of real carbon fibers. We then obtained the tensile strength of a carbon fiber, which has no macro defects. We finally determined that the limitation of the tensile strength was 19 GPa.
Keywords: Amorphous, carbon fiber, molecular dynamics, tensile strength.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30035704 Using Artificial Neural Network to Forecast Groundwater Depth in Union County Well
Authors: Zahra Ghadampour, Gholamreza Rakhshandehroo
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A concern that researchers usually face in different applications of Artificial Neural Network (ANN) is determination of the size of effective domain in time series. In this paper, trial and error method was used on groundwater depth time series to determine the size of effective domain in the series in an observation well in Union County, New Jersey, U.S. different domains of 20, 40, 60, 80, 100, and 120 preceding day were examined and the 80 days was considered as effective length of the domain. Data sets in different domains were fed to a Feed Forward Back Propagation ANN with one hidden layer and the groundwater depths were forecasted. Root Mean Square Error (RMSE) and the correlation factor (R2) of estimated and observed groundwater depths for all domains were determined. In general, groundwater depth forecast improved, as evidenced by lower RMSEs and higher R2s, when the domain length increased from 20 to 120. However, 80 days was selected as the effective domain because the improvement was less than 1% beyond that. Forecasted ground water depths utilizing measured daily data (set #1) and data averaged over the effective domain (set #2) were compared. It was postulated that more accurate nature of measured daily data was the reason for a better forecast with lower RMSE (0.1027 m compared to 0.255 m) in set #1. However, the size of input data in this set was 80 times the size of input data in set #2; a factor that may increase the computational effort unpredictably. It was concluded that 80 daily data may be successfully utilized to lower the size of input data sets considerably, while maintaining the effective information in the data set.Keywords: Neural networks, groundwater depth, forecast.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25165703 A Numerical Study of the Effect of Side-Dump Angle on Fuel Droplets Sizing in a Three- Dimensional Side-Dump Combustor
Authors: M. Mojtahedpoor, M. M. Doustdar
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A numerical study on the effect of side-dump angle on fuel droplets sizing and effective mass fraction have been investigated in present paper. The mass of fuel vapor inside the flammability limit is named as the effective mass fraction. In the first step we have considered a side-dump combustor with dump angle of 0o (acrossthe cylinder) and by increasing the entrance airflow velocity from 20 to 30, 40 and 50 (m/s) respectively, the mean diameter of fuel droplets sizing and effective mass fraction have been studied. After this step, we have changed the dump angle from 0o to 30o,45o and finally 60o in direction of cylinderand also we have increased the entrance airflow velocity from 20 up to 50 (m/s) with the amount of growth of 10(m/s) in each step, to examine its effects on fuel droplets sizing as well as effective mass fraction. With rise of entrance airflow velocity, these calculations are repeated in each step too. The results show, with growth of dump-angle the effective mass fraction has been decreased and the mean diameter of droplets sizing has been increased. To fulfill the calculations a modified version of KIVA-3V code which is a transient, three-dimensional, multiphase, multicomponent code for the analysis of chemically reacting flows with sprays, is used.Keywords: Side-Dump combustor, Droplets sizing, Side-Dump angle, KIVA-3V
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16525702 Nanoindentation of Thin Films Prepared by Physical Vapor Deposition
Authors: Dhiflaoui Hafedh, Khlifi Kaouthar, Ben Cheikh Larbi Ahmed
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These Monolayer and multilayer coatings of CrN and AlCrN deposited on 100Cr6 (AISI 52100) substrate by PVD magnetron sputtering system. The microstructures of the coatings were characterized using atomic force microscopy (AFM). The AFM analysis revealed the presence of domes and craters that are uniformly distributed over all surfaces of the various layers. Nanoindentation measurement of CrN coating showed maximum hardness (H) and modulus (E) of 14 GPa and 190 GPa, respectively. The measured H and E values of AlCrN coatings were found to be 30 GPa and 382 GPa, respectively. The improved hardness in both the coatings was attributed mainly to a reduction in crystallite size and decrease in surface roughness. The incorporation of Al into the CrN coatings has improved both hardness and Young’s modulus.Keywords: CrN/AlCrN, coatings, hardness, nano-indentation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22335701 Vortex-Shedding Suppression in Mixed Convective Flow past a Heated Square Cylinder
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The present study investigates numerically the phenomenon of vortex-shedding and its suppression in twodimensional mixed convective flow past a square cylinder under the joint influence of buoyancy and free-stream orientation with respect to gravity. The numerical experiments have been conducted at a fixed Reynolds number (Re) of 100 and Prandtl number (Pr) of 0.71, while Richardson number (Ri) is varied from 0 to 1.6 and freestream orientation, α, is kept in the range 0o≤ α ≤ 90o, with 0o corresponding to an upward flow and 90o representing a cross-flow scenario, respectively. The continuity, momentum and energy equations, subject to Boussinesq approximation, are discretized using a finite difference method and are solved by a semi-explicit pressure correction scheme. The critical Richardson number, leading to the suppression of the vortex-shedding (Ric), is estimated by using Stuart-Landau theory at various free-stream orientations and the neutral curve is obtained in the Ri-α plane. The neutral curve exhibits an interesting non-monotonic behavior with Ric first increasing with increasing values of α upto 45o and then decreasing till 70o. Beyond 70o, the neutral curve again exhibits a sharp increasing asymptotic trend with Ric approaching very large values as α approaches 90o. The suppression of vortex shedding is not observed at α = 90o (cross-flow). In the unsteady flow regime, the Strouhal number (St) increases with the increase in Richardson number.Keywords: bluff body, buoyancy, free-stream orientation, vortex-shedding.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22715700 Preparation and Characterization of Self Assembled Gold Nanoparticles on Amino Functionalized SiO2 Dielectric Core
Authors: M.E.khosroshahi , M.S.Nourbakhsh
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Wet chemistry methods are used to prepare the SiO2/Au nanoshells. The purpose of this research was to synthesize gold coated SiO2 nanoshells for biomedical applications. Tunable nanoshells were prepared by using different colloidal concentrations. The nanoshells are characterized by FTIR, XRD, UV-Vis spectroscopy and atomic force microscopy (AFM). The FTIR results confirmed the functionalization of the surfaces of silica nanoparticles with NH2 terminal groups. A tunable absorption was observed between 470-600 nm with a maximum range of 530-560 nm. Based on the XRD results three main peaks of Au (111), (200) and (220) were identified. Also AFM results showed that the silica core diameter was about 100 nm and the thickness of gold shell about 10 nm.Keywords: Gold nanoshells, Synthesis, UV-vis spectroscopy, XRD, AFM
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32795699 Computational Analysis of the Scaling Effects on the Performance of an Axial Compressor
Authors: Junting Xiang, Jörg Uwe Schlüter, Fei Duan
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The miniaturization of gas turbines promises many advantages. Miniature gas turbines can be used for local power generation or the propulsion of small aircraft, such as UAV and MAV. However, experience shows that the miniaturization of conventional gas turbines, which are optimized at their current large size, leads to a substantial loss of efficiency and performance at smaller scales. This may be due to a number of factors, such as the Reynolds-number effect, the increased heat transfer, and manufacturing tolerances. In the present work, we focus on computational investigations of the Reynolds number effect and the wall heat transfer on the performance of axial compressor during its size change. The NASA stage 35 compressor is selected as the configuration in this study and computational fluid dynamics (CFD) is used to carry out the miniaturization process and simulations. We perform parameter studies on the effect of Reynolds number and wall thermal conditions. Our results indicate a decrease of efficiency, if the compressor is miniaturized based on its original geometry due to the increase of viscous effects. The increased heat transfer through wall has only a small effect and will actually benefit compressor performance based on our study.
Keywords: Axial compressor, CFD, heat transfer, miniature gas turbines, Reynolds number.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32185698 Effect of Inductance Ratio on Operating Frequencies of a Hybrid Resonant Inverter
Authors: Mojtaba Ghodsi, Hamidreza Ziaifar, Morteza Mohammadzaheri, Payam Soltani
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In this paper, the performance of a medium power (25 kW/25 kHz) hybrid inverter with a reactive transformer is investigated. To analyze the sensitivity of the inverster, the RSM technique is employed to manifest the effective factors in the inverter to minimize current passing through the Insulated Bipolar Gate Transistors (IGBTs) (current stress). It is revealed that the ratio of the axillary inductor to the effective inductance of resonant inverter (N), is the most effective parameter to minimize the current stress in this type of inverter. In practice, proper selection of N mitigates the current stress over IGBTs by five times. This reduction is very helpful to keep the IGBTs at normal temperatures.
Keywords: Analytical analysis, hybrid resonant inverter, reactive transformer, response surface method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7345697 Effect of Impact Angle on Erosive Abrasive Wear of Ductile and Brittle Materials
Authors: Ergin Kosa, Ali Göksenli
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Erosion and abrasion are wear mechanisms reducing the lifetime of machine elements like valves, pump and pipe systems. Both wear mechanisms are acting at the same time, causing a “Synergy” effect, which leads to a rapid damage of the surface. Different parameters are effective on erosive abrasive wear rate. In this study effect of particle impact angle on wear rate and wear mechanism of ductile and brittle materials was investigated. A new slurry pot was designed for experimental investigation. As abrasive particle, silica sand was used. Particle size was ranking between 200- 500 μm. All tests were carried out in a sand-water mixture of 20% concentration for four hours. Impact velocities of the particles were 4.76 m/s. As ductile material steel St 37 with Vickers Hardness Number (VHN) of 245 and quenched St 37 with 510 VHN was used as brittle material. After wear tests, morphology of the eroded surfaces were investigated for better understanding of the wear mechanisms acting at different impact angles by using Scanning Electron Microscope. The results indicated that wear rate of ductile material was higher than brittle material. Maximum wear rate was observed by ductile material at a particle impact angle of 300 and decreased further by an increase in attack angle. Maximum wear rate by brittle materials was by impact angle of 450 and decreased further up to 900. Ploughing was the dominant wear mechanism by ductile material. Microcracks on the surface were detected by ductile materials, which are nucleation centers for crater formation. Number of craters decreased and depth of craters increased by ductile materials by attack angle higher than 300. Deformation wear mechanism was observed by brittle materials. Number and depth of pits decreased by brittle materials by impact angles higher than 450. At the end it is concluded that wear rate could not be directly related to impact angle of particles due to the different reaction of ductile and brittle materials.Keywords: Erosive wear, particle impact angle, silica sand, wear rate, ductile-brittle material.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30235696 Nurses’ Views on ‘Effective Nurse Leader’ Characteristics in Iraq
Authors: S. Abed, S. O’Neill
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This research explored ward nurses’ views about the characteristics of effective nurse leaders in the context of Iraq as a developing country, where the delivery of health care continues to face disruption and change. It is well established that the provision of modern health care requires effective nurse leaders, but in countries such as Iraq the lack of effective nurse leaders is noted as a major challenge. In a descriptive quantitative study, a survey questionnaire was administered to 210 ward nurses working in two public hospitals in a major city in the north of Iraq. The participating nurses were of the opinion that the effectiveness of their nurse leaders was evident in their ability to demonstrate: good clinical knowledge, effective communication and managerial skills. They also viewed their leaders as needing to hold high-level nursing qualifications, though this was not necessarily the case in practice. Additionally, they viewed nurse leaders’ personal qualities as important, which included politeness, ethical behaviour, and trustworthiness. When considered against the issues raised in interviews with a smaller group (20) of senior nurse leaders, representative of the various occupational levels, implications identify the need for professional development that focuses on how the underpinning competencies relate to leadership and how transformational leadership is evidenced in practice.
Keywords: Health care, nurse education, nurse leadership, nursing in Iraq, transformational leadership.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16135695 The Diophantine Equation y2 − 2yx − 3 = 0 and Corresponding Curves over Fp
Authors: Ahmet Tekcan, Arzu Özkoç, Hatice Alkan
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In this work, we consider the number of integer solutions of Diophantine equation D : y2 - 2yx - 3 = 0 over Z and also over finite fields Fp for primes p ≥ 5. Later we determine the number of rational points on curves Ep : y2 = Pp(x) = yp 1 + yp 2 over Fp, where y1 and y2 are the roots of D. Also we give a formula for the sum of x- and y-coordinates of all rational points (x, y) on Ep over Fp.Keywords: Diophantine equation, Pell equation, quadratic form.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12665694 The Study of Rapeseed Characteristics by Factor Analysis under Normal and Drought Stress Conditions
Authors: Ali Bakhtiari Gharibdosti, Mohammad Hosein Bijeh Keshavarzi, Samira Alijani
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To understand internal characteristics relationships and determine factors which explain under consideration characteristics in rapeseed varieties, 10 rapeseed genotypes were implemented in complete accidental plot with three-time repetitions under drought stress in 2009-2010 in research field of agriculture college, Islamic Azad University, Karaj branch. In this research, 11 characteristics include of characteristics related to growth, production and functions stages was considered. Variance analysis results showed that there is a significant difference among rapeseed varieties characteristics. By calculating simple correlation coefficient under both conditions, normal and drought stress indicate that seed function characteristics in plant and pod number have positive and significant correlation in 1% probable level with seed function and selection on the base of these characteristics was effective for improving this function. Under normal and drought stress, analyzing the main factors showed that numbers of factors which have more than one amount, had five factors under normal conditions which were 82.72% of total variance totally, but under drought stress four factors diagnosed which were 76.78% of total variance. By considering total results of this research and by assessing effective characteristics for factor analysis and selecting different components of these characteristics, they can be used for modifying works to select applicable and tolerant genotypes in drought stress conditions.Keywords: Correlation, drought stress, factor analysis, rapeseed.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7015693 Estimation of the Moisture Diffusivity and Activation Energy in Thin Layer Drying of Ginger Slices
Authors: Ebru Kavak Akpinar, Seda Toraman
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In the present work, the effective moisture diffusivity and activation energy were calculated using an infinite series solution of Fick-s diffusion equation. The results showed that increasing drying temperature accelerated the drying process. All drying experiments had only falling rate period. The average effective moisture diffusivity values varied from 2.807x10-10 to 6.977x10-10m2 s_1 over the temperature and velocity range. The temperature dependence of the effective moisture diffusivity for the thin layer drying of the ginger slices was satisfactorily described by an Arrhenius-type relationship with activation energy values of 19.313- 22.722 kJ.mol-1 within 40–70 °C and 0.8-3 ms-1 temperature range.Keywords: Ginger, Drying, Activation energy, Moisture diffusivity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27105692 Improved Modulo 2n +1 Adder Design
Authors: Somayeh Timarchi, Keivan Navi
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Efficient modulo 2n+1 adders are important for several applications including residue number system, digital signal processors and cryptography algorithms. In this paper we present a novel modulo 2n+1 addition algorithm for a recently represented number system. The proposed approach is introduced for the reduction of the power dissipated. In a conventional modulo 2n+1 adder, all operands have (n+1)-bit length. To avoid using (n+1)-bit circuits, the diminished-1 and carry save diminished-1 number systems can be effectively used in applications. In the paper, we also derive two new architectures for designing modulo 2n+1 adder, based on n-bit ripple-carry adder. The first architecture is a faster design whereas the second one uses less hardware. In the proposed method, the special treatment required for zero operands in Diminished-1 number system is removed. In the fastest modulo 2n+1 adders in normal binary system, there are 3-operand adders. This problem is also resolved in this paper. The proposed architectures are compared with some efficient adders based on ripple-carry adder and highspeed adder. It is shown that the hardware overhead and power consumption will be reduced. As well as power reduction, in some cases, power-delay product will be also reduced.Keywords: Modulo 2n+1 arithmetic, residue number system, low power, ripple-carry adders.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 29045691 Preparation of Nanophotonics LiNbO3 Thin Films and Studying Their Morphological and Structural Properties by Sol-Gel Method for Waveguide Applications
Authors: A. Fakhri Makram, Marwa S. Alwazni, Al-Douri Yarub, Evan T. Salim, Hashim Uda, Chin C. Woei
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Lithium niobate (LiNbO3) nanostructures are prepared on quartz substrate by the sol-gel method. They have been deposited with different molarity concentration and annealed at 500°C. These samples are characterized and analyzed by X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Atomic Force Microscopy (AFM). The measured results showed an importance increasing in molarity concentrations that indicate the structure starts to become crystal, regular, homogeneous, well crystal distributed, which made it more suitable for optical waveguide application.
Keywords: Lithium niobate, morphological properties, Pechini method, thin film.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19645690 The Effect of X-Ray on Plasma and Erythrocyte Concentration of Zn and Cu in Radiology Staff of Tehran Oil Hospital
Authors: L. Nekoozad, M. Salehi Barough, B. Salmasian
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Introduction: Some parameters should be considered to investigate the chronic effects of radiation absorption in radiation workers. Trace elements are parameters which small changes in them can cause significant effects on live systems. The role of trace element concentration in human health is significant. These elements play an important role in the developing and functioning of the immune system, cellular respiration, and oxidation processes. Considering the importance and necessity of this issue and few studies, measurements of concentration changes of these elements due to the absorbed dose are important. Purpose: This study aimed to determine the biological effects of occupational dose absorption on plasma and erythrocyte concentration of Zn and Cu in the radiology staff of Tehran Oil Hospital. Material and methods: In this analytical-comparative study, 72 people have entered. 36 people (18 males and 18 females) were selected as radiology staff in the diagnostic and therapeutic departments of Tehran Oil Hospital. And 36 people (18 males and 18 females) were selected as general section staff in the same hospital as a control group. Radiology and control groups’ age and sex were matched. 10 ml of venous blood was taken from all people. An atomic absorption spectrometer was used to obtain zinc and copper plasma concentrations. Levine test was used to compare these results validity. Results: The mean concentrations of copper and zinc were measured as 0.951 and 0.754 mg/L in the plasma phase and 3.2 and 0.401 mg/L in the RBC phase for the radiology group. Copper and zinc average concentrations, respectively 0.976 and 0.813 mg/L in the plasma phase and 2.906 and 0.476 mg/L in the RBC phase, were measured for the control group. These elements Concentrations in the plasma phase were significantly different from that of the control group, but the concentrations in the red blood cell phase did not show a significant difference compared to the control group. In comparison, a separate comparison between men and women in the experimental and control groups showed a significant difference in the values of the elements mentioned. With a significant increase in samples, a better justification than the available statistical results can be extracted. Conclusions: Within this study results, chronic occupational probabilistic absorption destructive effects (even within the permitted range) on blood trace element concentration have been confirmed.
Keywords: Chronic absorption, atomic absorption spectrometry, radiology staff, trace element concentration.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7125689 Relay Node Placement for Connectivity Restoration in Wireless Sensor Networks Using Genetic Algorithms
Authors: Hanieh Tarbiat Khosrowshahi, Mojtaba Shakeri
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Wireless Sensor Networks (WSNs) consist of a set of sensor nodes with limited capability. WSNs may suffer from multiple node failures when they are exposed to harsh environments such as military zones or disaster locations and lose connectivity by getting partitioned into disjoint segments. Relay nodes (RNs) are alternatively introduced to restore connectivity. They cost more than sensors as they benefit from mobility, more power and more transmission range, enforcing a minimum number of them to be used. This paper addresses the problem of RN placement in a multiple disjoint network by developing a genetic algorithm (GA). The problem is reintroduced as the Steiner tree problem (which is known to be an NP-hard problem) by the aim of finding the minimum number of Steiner points where RNs are to be placed for restoring connectivity. An upper bound to the number of RNs is first computed to set up the length of initial chromosomes. The GA algorithm then iteratively reduces the number of RNs and determines their location at the same time. Experimental results indicate that the proposed GA is capable of establishing network connectivity using a reasonable number of RNs compared to the best existing work.
Keywords: Connectivity restoration, genetic algorithms, multiple-node failure, relay nodes, wireless sensor networks.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11035688 The Locker Problem with Empty Lockers
Authors: David Avis, Luc Devroye, Kazuo Iwama
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We consider a cooperative game played by n players against a referee. The players names are randomly distributed among n lockers, with one name per locker. Each player can open up to half the lockers and each player must find his name. Once the game starts the players may not communicate. It has been previously shown that, quite surprisingly, an optimal strategy exists for which the success probability is never worse than 1 − ln 2 ≈ 0.306. In this paper we consider an extension where the number of lockers is greater than the number of players, so that some lockers are empty. We show that the players may still win with positive probability even if there are a constant k number of empty lockers. We show that for each fixed probability p, there is a constant c so that the players can win with probability at least p if they are allowed to open cn lockers.
Keywords: Locker problem, pointer-following algorithms.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12935687 Feature-Driven Classification of Musical Styles
Authors: A. Buzzanca, G. Castellano, A.M. Fanelli
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In this paper we address the problem of musical style classification, which has a number of applications like indexing in musical databases or automatic composition systems. Starting from MIDI files of real-world improvisations, we extract the melody track and cut it into overlapping segments of equal length. From these fragments, some numerical features are extracted as descriptors of style samples. We show that a standard Bayesian classifier can be conveniently employed to build an effective musical style classifier, once this set of features has been extracted from musical data. Preliminary experimental results show the effectiveness of the developed classifier that represents the first component of a musical audio retrieval systemKeywords: Musical style, Bayesian classifier.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1297