Search results for: Hamid Reza Pourshaghaghi
581 Getting to Know the Types of Asphalt, Its Manufacturing and Processing Methods and Its Application in Road Construction
Authors: Hamid Fallah
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Asphalt is generally a mixture of stone materials with continuous granulation and a binder, which is usually bitumen. Asphalt is made in different shapes according to its use. The most familiar type of asphalt is hot asphalt or hot asphalt concrete. Stone materials usually make up more than 90% of the asphalt mixture. Therefore, stone materials have a significant impact on the quality of the resulting asphalt. According to the method of application and mixing, asphalt is divided into three categories: hot asphalt, protective asphalt, and cold asphalt. Cold mix asphalt is a mixture of stone materials and mixed bitumen or bitumen emulsion whose raw materials are mixed at ambient temperature. In some types of cold asphalt, the bitumen may be heated as necessary, but other materials are mixed with the bitumen without heating. Protective asphalts are used to make the roadbed impermeable, increase its abrasion and sliding resistance, and also temporarily improve the existing asphalt and concrete surfaces. This type of paving is very economical compared to hot asphalt due to the speed and ease of implementation and the limited need for asphalt machines and equipment. The present article, which is prepared in descriptive library form, introduces asphalt, its types, characteristics, and its application.Keywords: asphalt, type of asphalt, asphalt concrete, sulfur concrete, bitumen in asphalt, sulfur, stone materials
Procedia PDF Downloads 57580 Effects of Strain-Induced Melt Activation Process on the Structure and Morphology Mg₂Si in Al-15%Mg₂Si Composite
Authors: Reza Eslami-Farsani, Mohammad Alipour
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The effect of deformation on the semisolid microstructure and degree of globularity of Al–15%Mg₂Si composite produced by the strain induced melt activation (SIMA) process was studied. Deformation of 25% was used. After deformation, the samples were heated to a temperature above the solidus and below the liquidus point and maintained in the isothermal conditions at three different temperatures (560, 580 and 595 °C) for varying time (5, 10, 20 and 40 min). The microstructural study was carried out on the alloy by the use of optical microscopy. It was observed that strain induced deformation and subsequently melt activation has caused the globular morphology of Mg₂Si particles. The results showed that for the desired microstructures of the alloy during SIMA process, the optimum temperature and time are 595 °C and 40 min respectively.Keywords: deformation, semisolid, SIMA, Mg₂Si phase, modification
Procedia PDF Downloads 270579 The Appropriate Patent System to Promote Economic Growth in Afghanistan
Authors: Mohammad Reza Fooladi
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The patent system which fits with industrial and economic situation in the country, by strengthening research and development, technology transfer and increasing foreign investment can provide economic and industrial growth of the countries. However, the extent and manner of support should be commensurate with the country's conditions and comply with significant rules to have a positive effect on research and development, technology transfer and the amount of foreign investment. The present article tries to while reviewing the state of effectiveness of the patent system on economic growth, to illustrate the characteristics of the patent system fits Afghanistan and according to this matter provide the necessary recommendations about the improvement of laws and regulations related to the patent in Afghanistan.Keywords: patent, economic growth, technology transfer, Afghanistan
Procedia PDF Downloads 407578 Effect of Nano-SiO2 Solution on the Strength Characteristics of Kaolinite
Authors: Reza Ziaie Moayed, Hamidreza Rahmani
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Today, with developments in science and technology, there is an excessive potential for the use of nanomaterials in various fields of geotechnical project such as soil stabilization. This study investigates the effect of Nano-SiO2 solution on the unconfined compression strength and Young's elastic modulus of Kaolinite. For this purpose, nano-SiO2 was mixed with kaolinite in five different contents: 1, 2, 3, 4 and 5% by weight of the dry soil and a series of the unconfined compression test with curing time of one-day was selected as laboratory test. Analyses of the tests results show that stabilization of kaolinite with Nano-SiO2 solution can improve effectively the unconfined compression strength of modified soil up to 1.43 times compared to the pure soil.Keywords: kaolinite, Nano-SiO2, stabilization, unconfined compression test, Young's modulus
Procedia PDF Downloads 384577 The Discourse Analysis of Friday Sermons in Pakistan: A Social Perspective
Authors: Syed Hamid Farooq Bukhari
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This study intends to clarify the Friday sermon by evaluating the formation of its discourse, the composition, and selection of its subject matters, the structure, and functions of its rules as well as the outline of its communication proceeds, and the distinctiveness of its words along with definite provisions. In this research, a qualitative and descriptive method is used to draw out conclusions. This paper considers the sermon mechanism of the speech and advances it contextually. The information was composed in Pakistan and several of its mosques supposing the imams of the city and the location of the mosques. The presentation and analysis of the facts have directed to the subsequent conclusions: (1) the Friday sermon holds verbal discussion that has habitual and classic formation, (2) the approaches of the formation of the subjects consist of storytelling, quotation as well as the use of accepted terms, (3) the composition of the codes involves Arabic, English, Urdu, and many other local languages, (4) the expressions of the speech include all types of sermon acts, (5) different requisites emerge in the sermons demonstrating that the Friday sermon functions as an index or usage of verbal communication in an exacting field.Keywords: Friday, sermons, Pakistan, social
Procedia PDF Downloads 158576 An Improved Cuckoo Search Algorithm for Voltage Stability Enhancement in Power Transmission Networks
Authors: Reza Sirjani, Nobosse Tafem Bolan
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Many optimization techniques available in the literature have been developed in order to solve the problem of voltage stability enhancement in power systems. However, there are a number of drawbacks in the use of previous techniques aimed at determining the optimal location and size of reactive compensators in a network. In this paper, an Improved Cuckoo Search algorithm is applied as an appropriate optimization algorithm to determine the optimum location and size of a Static Var Compensator (SVC) in a transmission network. The main objectives are voltage stability improvement and total cost minimization. The results of the presented technique are then compared with other available optimization techniques.Keywords: cuckoo search algorithm, optimization, power system, var compensators, voltage stability
Procedia PDF Downloads 542575 The Method for Synthesis of Chromium Oxide Nano Particles as Increasing Color Intensity on Industrial Ceramics
Authors: Bagher Aziz Kalantari, Javad Rafiei, Mohamad Reza Talei Bavil Olyai
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Disclosed is a method of preparing a pigmentary chromium oxide nano particles having 50 percent particle size less than about 100nm. According to the disclosed method, a substantially dry solid composition of potassium dichromate and carbon active is heated in CO2 atmosphere to a temperature of about 600ºc for 1hr. Thereafter, the solid Cr2O3 product was washed twice with distilled water. The other aim of this study is to assess both the colouring performance and the potential of nano-pigments in the ceramic tile decoration. The rationable consists in nano-pigment application in several ceramics, including a comparison of colour performance with conventional micro-pigments.Keywords: green chromium oxide, nano particles, colour performances, particle size
Procedia PDF Downloads 329574 Effect of IGF-I on Ovine Oocytes Maturation and Subsequent Embryo Development following in Vitro Fertilization (IVF)
Authors: Babak Qasemi-Panahi, Gholamali Moghaddam, Seyed-Abbas Rafat, Hossein Daghigh Kia, Mansoureh Movahedin, Reza Hadavi
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The objective of this study was to determine the effects of IGF-I on ovine oocytes maturation and subsequent development of embryos derived from in vitro fertilization (IVF). In vitro maturation (IVM) of oocytes and in vitro culture (IVC) of embryos was conducted with or without 100 ng/mL IGF-1. In the IGF-I treated group, mean percentage of oocyte maturation was significantly higher than the control group (57.67 ± 3.04 versus 49.81 ± 3.04%, respectively, P < 0.05). However, in comparison with control group, there was no significant effect of IGF-1 on rates of cleavage, morula, and blastocyst formation (85% versus 84%; 63% versus 65%, and 40% to 39%, respectively). These data demonstrate that IGF-I has a positive effect on ovine oocyte maturation rate, but it has not the significant outcome on embryo development.Keywords: ovine, IGF-I, IVM, ICSI
Procedia PDF Downloads 682573 Quartic Spline Method for Numerical Solution of Self-Adjoint Singularly Perturbed Boundary Value Problems
Authors: Reza Mohammadi
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Using quartic spline, we develop a method for numerical solution of singularly perturbed two-point boundary-value problems. The purposed method is fourth-order accurate and applicable to problems both in singular and non-singular cases. The convergence analysis of the method is given. The resulting linear system of equations has been solved by using a tri-diagonal solver. We applied the presented method to test problems which have been solved by other existing methods in references, for comparison of presented method with the existing methods. Numerical results are given to illustrate the efficiency of our methods.Keywords: second-order ordinary differential equation, singularly-perturbed, quartic spline, convergence analysis
Procedia PDF Downloads 355572 The Extent of Big Data Analysis by the External Auditors
Authors: Iyad Ismail, Fathilatul Abdul Hamid
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This research was mainly investigated to recognize the extent of big data analysis by external auditors. This paper adopts grounded theory as a framework for conducting a series of semi-structured interviews with eighteen external auditors. The research findings comprised the availability extent of big data and big data analysis usage by the external auditors in Palestine, Gaza Strip. Considering the study's outcomes leads to a series of auditing procedures in order to improve the external auditing techniques, which leads to high-quality audit process. Also, this research is crucial for auditing firms by giving an insight into the mechanisms of auditing firms to identify the most important strategies that help in achieving competitive audit quality. These results are aims to instruct the auditing academic and professional institutions in developing techniques for external auditors in order to the big data analysis. This paper provides appropriate information for the decision-making process and a source of future information which affects technological auditing.Keywords: big data analysis, external auditors, audit reliance, internal audit function
Procedia PDF Downloads 62571 Numerical Study of Developing Laminar Forced Convection Flow of Water/CuO Nanofluid in a Circular Tube with a 180 Degrees Curve
Authors: Hamed K. Arzani, Hamid K. Arzani, S.N. Kazi, A. Badarudin
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Numerical investigation into convective heat transfer of CuO-Water based nanofluid in a pipe with return bend under laminar flow conditions has been done. The impacts of Reynolds number and the volume concentration of nanoparticles on the flow and the convective heat transfer behaviour are investigated. The results indicate that the increase in Reynolds number leads to the enhancement of average Nusselt number, and the increase in specific heat in the presence of the nanofluid results in improvement in heat transfer. Also, the presence of the secondary flow in the curve plays a key role in increasing the average Nusselt number and it appears higher than the inlet and outlet tubes. However, the pressure drop curve increases significantly in the tubes with the increase in nanoparticles concentration.Keywords: laminar forced convection, curve pipe, return bend, nanufluid, CFD
Procedia PDF Downloads 292570 Synthesis and Characterization of Biodegradable Elastomeric Polyester Amide for Tissue Engineering Applications
Authors: Abdulrahman T. Essa, Ahmed Aied, Omar Hamid, Felicity R. A. J. Rose, Kevin M. Shakesheff
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Biodegradable poly(ester amide)s are promising polymers for biomedical applications such as drug delivery and tissue engineering because of their optimized chemical and physical properties. In this study, we developed a biodegradable polyester amide elastomer poly(serinol sebacate) (PSS) composed of crosslinked networks based on serinol and sebacic acid. The synthesized polymers were characterized to evaluate their chemical structures, mechanical properties, degradation behaviors and in vitro cytocompatibility. Analysis of proton nuclear magnetic resonance and Fourier transform infrared spectroscopy revealed the structure of the polymer. The PSS exhibit excellent solubility in a variety of solvents such as methanol, dimethyl sulfoxide and dimethylformamide. More importantly, the mechanical properties of PSS could be tuned by changing the curing conditions. In addition, the 3T3 fibroblast cells cultured on the PSS demonstrated good cell attachment and high viability.Keywords: biodegradable, biomaterial, elastomer, mechanical properties, poly(serinol sebacate)
Procedia PDF Downloads 348569 Wireless Sensor Networks Optimization by Using 2-Stage Algorithm Based on Imperialist Competitive Algorithm
Authors: Hamid R. Lashgarian Azad, Seyed N. Shetab Boushehri
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Wireless sensor networks (WSN) have become progressively popular due to their wide range of applications. Wireless Sensor Network is made of numerous tiny sensor nodes that are battery-powered. It is a very significant problem to maximize the lifetime of wireless sensor networks. In this paper, we propose a two-stage protocol based on an imperialist competitive algorithm (2S-ICA) to solve a sensor network optimization problem. The energy of the sensors can be greatly reduced and the lifetime of the network reduced by long communication distances between the sensors and the sink. We can minimize the overall communication distance considerably, thereby extending the lifetime of the network lifetime through connecting sensors into a series of independent clusters using 2SICA. Comparison results of the proposed protocol and LEACH protocol, which is common to solving WSN problems, show that our protocol has a better performance in terms of improving network life and increasing the number of transmitted data.Keywords: wireless sensor network, imperialist competitive algorithm, LEACH protocol, k-means clustering
Procedia PDF Downloads 93568 Interest Rate of Managers and Tourism Officials over E-Tourism Development: Case Study of Lenjan City
Authors: Akram Shahriyari, Reza Mokhtari Malek Abadi
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E-tourism is among the issues that have recently been entered into the field of tourism. In order to achieve this type of tourism, Information and Communications Technology (or ICT) infrastructures as well as Co-governmental organizations and tourism resources are important. In this study, the opinions of managers and tourism officials about the e-tourism in Lenjan city were measured; it also surveyed the impact of level of digital literacy of managers and tourism officials on attracting tourists in Lenjan city. This study was conducted in Lenjan, one of the environs of the Esfahan province. This study is a documentary – survey and the sources include library resources and also questionnaires. The results obtained indicate that if managers use ICT, it may help e-tourism to be developed in the region, and increasing managers’ beliefs on e-tourism and upgrading their level of digital literacy may affect e-tourism development.Keywords: ICT, e-tourism, opinion of managers and officials, Lejnan
Procedia PDF Downloads 426567 Numerical Investigation of Natural Convection of Pine, Olive and Orange Leaves
Authors: Ali Reza Tahavvor, Saeed Hosseini, Nazli Jowkar, Behnam Amiri
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Heat transfer of leaves is a crucial factor in optimal operation of metabolic functions in plants. In order to quantify this phenomenon in different leaves and investigate the influence of leaf shape on heat transfer, natural convection for pine, orange and olive leaves was simulated as representatives of different groups of leaf shapes. CFD techniques were used in this simulation with the purpose to calculate heat transfer of leaves in similar environmental conditions. The problem was simulated for steady state and three-dimensional conditions. From obtained results, it was concluded that heat fluxes of all three different leaves are almost identical, however, total rate of heat transfer have highest and lowest values for orange leaves and pine leaves, respectively.Keywords: computational fluid dynamic, heat flux, heat transfer, natural convection
Procedia PDF Downloads 351566 A Cost-Effective Evaluation of Proper Control Process of Air-Cooled Heat Exchanger
Authors: Ali Ghobadi, Eisa Bakhoda, Hamid R. Javdan
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One of the key factors in air cooled heat exchangers operation is the proper control of process stream outlet temperature. In this study, performances of two different air cooled heat exchangers have been considered, one of them condenses Propane and the other one cools LPG streams. In order to predict operation of these air coolers at different operating conditions. The results of simulations were applied for both economical evaluations and operational considerations for using convenient air cooler control system. In this paper, using On-Off fans method and installing variable speed drivers have been studied. Finally, the appropriate methods for controlling outlet temperature of process fluid streams as well as saving energy consumption were proposed. Using On-Off method for controlling studied Propane condenser by multiple fans is proper; while controlling LPG air cooler with lesser fans by means of two variable speed drivers is economically convenient.Keywords: air cooled heat exchanger, simulation, economical evaluation, energy, process control
Procedia PDF Downloads 402565 Development of a Testing Rig for a Cold Formed-Hot Rolled Steel Hybrid Wall Panel System
Authors: Mina Mortazavi, Hamid Ronagh, Pezhman Sharafi
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The new concept of a cold formed-hot rolled hybrid steel wall panel system is introduced to overcome the deficiency in lateral load resisting capacity of cold-formed steel structures. The hybrid system is composed of a cold-formed steel part laterally connected to hot rolled part. The hot rolled steel part is responsible for carrying the whole lateral load; while the cold formed steel part is only required to transfer the lateral load to the hot rolled part without any local failure. The vertical load is beared by both hot rolled, and cold formed steel part, proportionally. In order to investigate the lateral performance of the proposed system, it should be tested under simultaneous lateral and vertical load. The main concern is to deliver the loads to each part during the test to simulate the real load distribution in the structure. In this paper, a detailed description of the proposed wall panel system and the designed testing rig is provided.Keywords: cold-formed steel, hybrid system, wall panel system, testing rig design
Procedia PDF Downloads 414564 Peat Soil Stabilization Methods: A Review
Authors: Mohammad Saberian, Mohammad Ali Rahgozar, Reza Porhoseini
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Peat soil is formed naturally through the accumulation of organic matter under water and it consists of more than 75% organic substances. Peat is considered to be in the category of problematic soil, which is not suitable for construction, due to its high compressibility, high moisture content, low shear strength, and low bearing capacity. Since this kind of soil is generally found in many countries and different regions, finding desirable techniques for stabilization of peat is absolutely essential. The purpose of this paper is to review the various techniques applied for stabilizing peat soil and discuss outcomes of its improved mechanical parameters and strength properties. Recognizing characterization of stabilized peat is one of the most significant factors for architectural structures; as a consequence, various strategies for stabilization of this susceptible soil have been examined based on the depth of peat deposit.Keywords: peat soil, stabilization, depth, strength, unconfined compressive strength (USC)
Procedia PDF Downloads 564563 The Application of to Optimize Pellet Quality in Broiler Feeds
Authors: Reza Vakili
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The aim of this experiment was to optimize the effect of moisture, the production rate, grain particle size and steam conditioning temperature on pellet quality in broiler feed using Taguchi method and a 43 fractional factorial arrangement was conducted. Production rate, steam conditioning temperatures, particle sizes and moisture content were performed. During the production process, sampling was done, and then pellet durability index (PDI) and hardness evaluated in broiler feed grower and finisher. There was a significant effect of processing parameters on PDI and hardness. Based on the results of this experiment Taguchi method can be used to find the best combination of factors for optimal pellet quality.Keywords: broiler, feed physical quality, hardness, processing parameters, PDI
Procedia PDF Downloads 175562 An Agent-Service Oriented Framework for Online Contracts in Virtual Organizations
Authors: Zahra Raeisi, Reza Akbari
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Contracting is known as one of the important tasks in virtual organization creation. Contracting is a costly process in terms of time and effort. One way to cut the time and effort is conducting contract electronically. The online contracting enable us to form virtual organization (VO) dynamically. This work presents an agent-service oriented framework for online contracting in virtual organizations. The proposed framework considers the main aspects and steps of traditional contracting process and uses the efficiency of service and agent based methodologies in order to provide a flexible and efficient way to establish contracts electronically in a VO.Keywords: service oriented architecture, online contracts, agent-oriented architecture, virtual organization
Procedia PDF Downloads 496561 Potentials for Change in the MENA Region: A Socioeconomic Perspective
Authors: Shaira Karishma Sheriff, Zarinah Hamid
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The Arab Spring, which commenced during the end of 2010 and accelerated during 2011, was caused primarily due to poverty, unemployment and a general recession in the Middle East and North African (MENA) region. The core motivation of this revolution could be said to be the need for political, economic and social reforms that the region desires to experience. Though GDP growth has been significant in the region, the income distribution mechanism in MENA countries has been ineffective. This results in low levels of education, substandard health care facilities, unemployment, and poverty. This paper argues that MENA countries have great potential for experiencing socioeconomic development by being less dependent on oil exports and enhancing their services sector through better education which would eventually lead to job creation. Furthermore, the region can encourage better trade and political integration by forming transparent and accountable governments. The notion of Nation-State needs to be addressed and the countries in the region need to look for ways to develop effective supra-national institutions for better political and economic integration that goes beyond geographical borders.Keywords: political reforms, social reforms, economic development, nation-state, economic integration
Procedia PDF Downloads 429560 Modified Step Size Patch Array Antenna for UWB Wireless Applications
Authors: Hamid Aslani, Ahmed Radwan
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In this paper, a single element microstrip antenna is presented for UWB applications by using techniques as partial ground plane and modified the shape of the patch. The antenna is properly designed to have a compact size and constant gain against frequency. The simulated results have done using two EM software and show good agreement with the measured results for the fabricated antenna. Then a designing of two elements patch antenna array for UWB in the frequency band of 3.1-10 GHz is presented in this paper. The array is constructed by means of feeding two omni-directional modified circular patch elements with a modified power divider. Experimental results show that the array has a stable radiation pattern and low return loss over a broad bandwidth of 64% (3.1–10 GHz). Due to its planar profile, physically compact size, wide impedance bandwidth, directive performance over a wide bandwidth proposed antenna is a good candidate for portable UWB applications and other UWB integrated circuits.Keywords: ultra wide band, radiation performance, microstrip antenna, size miniaturized antenna
Procedia PDF Downloads 254559 Fractal-Wavelet Based Techniques for Improving the Artificial Neural Network Models
Authors: Reza Bazargan lari, Mohammad H. Fattahi
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Natural resources management including water resources requires reliable estimations of time variant environmental parameters. Small improvements in the estimation of environmental parameters would result in grate effects on managing decisions. Noise reduction using wavelet techniques is an effective approach for pre-processing of practical data sets. Predictability enhancement of the river flow time series are assessed using fractal approaches before and after applying wavelet based pre-processing. Time series correlation and persistency, the minimum sufficient length for training the predicting model and the maximum valid length of predictions were also investigated through a fractal assessment.Keywords: wavelet, de-noising, predictability, time series fractal analysis, valid length, ANN
Procedia PDF Downloads 363558 Study and Historical Rooting the Causes of the Decline of Islamic Civilization (Case Study: From the 11th Century to the Contemporary Era)
Authors: Sajjad Shalsouz, Hamid karamipour
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Islamic civilization after a period of glory in the ninth and tenth centuries AD, known as the Islamic Renaissance, stagnated and declined from the eleventh century, despite the political and military power of Islamic governments, faced a scientific and cultural decline in later, foreign invaders such as the Mongol invasion, the Crusades, and Timur invasions also caused severe political, social, and economic instability, some of which were never remedied. Lack of growth of intellectual sciences in Islamic societies, which is necessary for the growth and development of any civilization, and lack of attention of the ruling class and the masses to this important factor, the tyranny of kings, social and economic turmoil from the thirteenth century onwards, absence of Islamic societies from global developments all intensified and stabilized the decline Islamic civilizations, the consequences of which are still evident. This article tries to deal with the historical factors of this decline and decadence from the 11th century to the contemporary era by examining historical events and issues and achieves a desirable and efficient result in this field.Keywords: Islamic civilization, decline, historical factors, intellectual sciences
Procedia PDF Downloads 92557 Random Subspace Ensemble of CMAC Classifiers
Authors: Somaiyeh Dehghan, Mohammad Reza Kheirkhahan Haghighi
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The rapid growth of domains that have data with a large number of features, while the number of samples is limited has caused difficulty in constructing strong classifiers. To reduce the dimensionality of the feature space becomes an essential step in classification task. Random subspace method (or attribute bagging) is an ensemble classifier that consists of several classifiers that each base learner in ensemble has subset of features. In the present paper, we introduce Random Subspace Ensemble of CMAC neural network (RSE-CMAC), each of which has training with subset of features. Then we use this model for classification task. For evaluation performance of our model, we compare it with bagging algorithm on 36 UCI datasets. The results reveal that the new model has better performance.Keywords: classification, random subspace, ensemble, CMAC neural network
Procedia PDF Downloads 323556 Social Data-Based Users Profiles' Enrichment
Authors: Amel Hannech, Mehdi Adda, Hamid Mcheick
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In this paper, we propose a generic model of user profile integrating several elements that may positively impact the research process. We exploit the classical behavior of users and integrate a delimitation process of their research activities into several research sessions enriched with contextual and temporal information, which allows reflecting the current interests of these users in every period of time and infer data freshness. We argue that the annotation of resources gives more transparency on users' needs. It also strengthens social links among resources and users, and can so increase the scope of the user profile. Based on this idea, we integrate the social tagging practice in order to exploit the social users' behavior to enrich their profiles. These profiles are then integrated into a recommendation system in order to predict the interesting personalized items of users allowing to assist them in their researches and further enrich their profiles. In this recommendation, we provide users new research experiences.Keywords: user profiles, topical ontology, contextual information, folksonomies, tags' clusters, data freshness, association rules, data recommendation
Procedia PDF Downloads 255555 Study of Nanocrystalline Scintillator for Alpha Particles Detection
Authors: Azadeh Farzaneh, Mohammad Reza Abdi, A. Quaranta, Matteo Dalla Palma, Seyedshahram Mortazavi
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We report on the synthesis of cesium-iodide nanoparticles using sol-gel technique. The structural properties of CsI nanoparticles were characterized by X-ray diffraction and Scanning Electron Microscope (SEM) Also, optical properties were followed by optical absorption and UV–vis fluorescence. Intense photoluminescence is also observed, with some spectral tuning possible with ripening time getting a range of emission photon wavelength approximately from 366 to 350 nm. The size effect on CsI luminescence leads to an increase in scintillation light yield, a redshift of the emission bands of the on_center and off_center self_trapped excitons (STEs) and an increase in the contribution of the off_center STEs to the net intrinsic emission yield. The energy transfer from the matrix to CsI nanoparticles is a key characteristic for scintillation detectors. So the scintillation spectra to alpha particles of sample were monitored.Keywords: nanoparticles, luminescence, sol gel, scintillator
Procedia PDF Downloads 589554 Reliability Assessment of Various Empirical Formulas for Prediction of Scour Hole Depth (Plunge Pool) Using a Comprehensive Physical Model
Authors: Majid Galoie, Khodadad Safavi, Abdolreza Karami Nejad, Reza Roshan
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In this study, a comprehensive scouring model has been developed in order to evaluate the accuracy of various empirical relationships which were suggested for prediction of scour hole depth in plunge pools by Martins, Mason, Chian and Veronese. For this reason, scour hole depths caused by free falling jets from a flip bucket to a plunge pool were investigated. In this study various discharges, angles, scouring times, etc. have been considered. The final results demonstrated that the all mentioned empirical formulas, except Mason formula, were reasonably agreement with the experimental data.Keywords: scour hole depth, plunge pool, physical model, reliability assessment
Procedia PDF Downloads 529553 The Evaluation of Signal Timing Optimization and Implement of Transit Signal Priority in Intersections and Their Effect on Delay Reduction
Authors: Mohammad Reza Ramezani, Shahriyar Afandizadeh
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Since the intersections play a crucial role in traffic delay, it is significant to evaluate them precisely. In this paper, three critical intersections in Tehran (Capital of Iran) had been simulated. The main purpose of this paper was to optimize the public transit delay. The simulation had three different phase in three intersections of Tehran. The first phase was about the current condition of intersection; the second phase was about optimized signal timing and the last phase was about prioritized public transit access. The Aimsun software was used to simulate all phases, and the Synchro software was used to optimization of signals as well. The result showed that the implement of optimization and prioritizing system would reduce about 50% of delay for public transit.Keywords: transit signal priority, intersection optimization, public transit, simulation
Procedia PDF Downloads 467552 SC-LSH: An Efficient Indexing Method for Approximate Similarity Search in High Dimensional Space
Authors: Sanaa Chafik, Imane Daoudi, 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
Procedia PDF Downloads 319