Search results for: Reza Mohammadi
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 643

Search results for: Reza Mohammadi

553 Risk Based on Computer Auditing and Measures of ‎Prevention

Authors: Mohammad Hadi Khorashadi Zadeh, Amin Karkon, Seyd Mohammad Reza Mashhoori

Abstract:

The technology of computer audit played a major role in the progress and prospects of a proper application to improve the quality and efficiency of audit work. But due to the technical complexity and the specific risks of computer audit, it should be shown effective in audit and preventive action. Mainly through research in this paper, we propose the causes of audit risk in a computer environment and the risk of further proposals for measures to control, to some extent reduce the risk of computer audit and improve the audit quality.

Keywords: computer auditing, risk, measures to prevent, information management

Procedia PDF Downloads 484
552 Defining Affecting Factors on Rate of Car E-Customers' Satisfaction – a Case Study of Iran Khodro Co.

Authors: Majid Mohammadi, Mohammad Yosef Zadeh, Vahid Naderi Darshori

Abstract:

The main purpose of this research is concreting of satisfaction literature for obtain index with online content in carmaker industry. The study measures customer satisfaction of online and collect from similar studies with reference to a model of online satisfaction, they are attempting to complete. Statistical communities of research are online customers' carmaker Iran Khodro has been buying the company's products in the last six months. One of the innovative measures in this study is that, customer reviews are obtained through an Internet site. Reliability of the data collected in this study, the Cronbach's alpha coefficient was approved. The coefficient of 0.828 was calculated for the questionnaire. To test the hypothesis, the Pearson correlation coefficient was used. To ensure the correctness of initial theoretical model, we used regression analyzes and structural equation weight and finally, the results obtained with little change to the basic model of research, are improved and completed. At last obtain the perceived value has most direct effect on online car customers satisfaction.

Keywords: customer satisfaction, online satisfaction, online customer, car

Procedia PDF Downloads 382
551 Seismic Investigation on the Effect of Surface Structures and Twin Tunnel on the Site Response in Urban Areas

Authors: Seyed Abolhasan Naeini, Saeideh Mohammadi

Abstract:

Site response has a profound effect on earthquake damages. Seismic interaction of urban tunnels with surface structures could also affect seismic site response. Here, we use FLAC 2D to investigate the interaction of a single tunnel and twin tunnels-surface structures on the site response. Soil stratification and properties are selected based on Line. No 7 of the Tehran subway. The effect of surface structure is considered in two ways: Equivalent surcharge and geometrical modeling of the structure. Comparison of the results shows that consideration of the structure geometry is vital in dynamic analysis and leads to the changes in the magnitude of displacements, accelerations and response spectrum. Therefore it is necessary for the surface structures to be wholly modeled and not just considered as a surcharge in dynamic analysis. The use of twin tunnel also leads to the reduction of dynamic residual settlement.

Keywords: superstructure, tunnel, site response, surcharge, interaction

Procedia PDF Downloads 128
550 Assessing Secondary School Curricula in the light of Developing Quality of Life Standards of High School Students

Authors: Othman Ali Alghtani, Yahya Abdul-Ekhalq Ali, Abdullah Abdul-Ekhalq Ali, Ahmed Al Sadiq Abdul Majeed, Najwa Attian Al-Mohammadi, Obead Mozel Alharbi, Sabri Mohamed Ismail, Omar Ibrahim Asiri

Abstract:

This study assessed the curricula of secondary schools given requirements to enhance the quality of life of students. The components of quality of life were described to build a list of standards and indicators. A questionnaire assessing the dimensions of mental (cognitive and emotional), physical, digital, and social health, and environmental awareness was prepared. A descriptive-analytical approach was used on a sample of 258 teachers and educational supervisors in Tabuk. The results indicated shortcomings in the secondary school curricula regarding developing standards and indicators of components of quality of life. Results also indicated that secondary school curricula incorporated few practices to improve student’s quality of life. No significant differences were found regarding the core subject, job, gender, and years of experience.

Keywords: assessing curricula, teacher practices, quality of life, teaching practices

Procedia PDF Downloads 222
549 Synchronization of Chaotic T-System via Optimal Control as an Adaptive Controller

Authors: Hossein Kheiri, Bashir Naderi, Mohamad Reza Niknam

Abstract:

In this paper we study the optimal synchronization of chaotic T-system with complete uncertain parameter. Optimal control laws and parameter estimation rules are obtained by using Hamilton-Jacobi-Bellman (HJB) technique and Lyapunov stability theorem. The derived control laws are optimal adaptive control and make the states of drive and response systems asymptotically synchronized. Numerical simulation shows the effectiveness and feasibility of the proposed method.

Keywords: Lyapunov stability, synchronization, chaos, optimal control, adaptive control

Procedia PDF Downloads 448
548 In-Situ Reactive Growth of Silver Nanoparticles on Cotton Textile for Antiviral and Electromagnetic Shielding Applications

Authors: Hamed Mohammadi Mofarah, Mutalifu Abulikemu, Ghassan E. Jabbour

Abstract:

Personal protective equipment (PPE) is finding increasing interest in incorporating silver nanoparticles (NPs) for various applications including microbial disinfection and shielding against electromagnetic waves. In this venue, we present an in situ reactive coating approach where silver nanoparticles are self-assembled on the surface of cotton yarn. The impacts of a variety of experimental parameters on the average size of the synthesized silver NPs were investigated. These include vacuum conditions, the concentration of the silver salt solution and reducer, temperature, and curing time. Silver NPs with an average size ranging from 10 to 50 nanometers were self-assembled as a result of careful regulation of such reaction conditions. The disinfection efficacy against the COVID surrogate virus of the functional textile reached a rate of 99.99%. On the other hand, the silver NPs decorated textile demonstrated an electromagnetic shielding ranging from 31 dB to 45 dB were achieved for the frequency range 8.2-12.4 GHz.

Keywords: antiviral, COVID, electromagnetic shielding, in-situ reactive coating, SARS CoV 2, silver nanoparticles, smart textile

Procedia PDF Downloads 60
547 Risk-Based Computer Auditing and Measures of Prevention

Authors: Mohammad Hadi Khorashadi Zadeh, Amin Karkon, Seyd Mohammad Reza Mashhoori ‎

Abstract:

the technology of Computer audit played a major role in the progress and ‎prospects of a proper application to improve the quality and efficiency of audit ‎work. But due to the technical complexity and the specific risks of computer ‎audit, it should be shown effective in audit and preventive action. Mainly through ‎research in this paper, we proposes the causes of audit risk in a computer ‎environment and the risk of further proposals for measures to control, to some ‎extent reduce the risk of computer audit and improve the audit quality.‎

Keywords: computer auditing, risk, measures to prevent, information technology

Procedia PDF Downloads 454
546 Reliability-Based Life-Cycle Cost Model for Engineering Systems

Authors: Reza Lotfalian, Sudarshan Martins, Peter Radziszewski

Abstract:

The effect of reliability on life-cycle cost, including initial and maintenance cost of a system is studied. The failure probability of a component is used to calculate the average maintenance cost during the operation cycle of the component. The standard deviation of the life-cycle cost is also calculated as an error measure for the average life-cycle cost. As a numerical example, the model is used to study the average life cycle cost of an electric motor.

Keywords: initial cost, life-cycle cost, maintenance cost, reliability

Procedia PDF Downloads 565
545 Optimal Capacitor Placement in Distribution Using Cuckoo Optimization Algorithm

Authors: Ali Ravangard, S. Mohammadi

Abstract:

Shunt Capacitors have several uses in the electric power systems. They are utilized as sources of reactive power by connecting them in line-to-neutral. Electric utilities have also connected capacitors in series with long lines in order to reduce its impedance. This is particularly common in the transmission level, where the lines have length in several hundreds of kilometers. However, this post will generally discuss shunt capacitors. In distribution systems, shunt capacitors are used to reduce power losses, to improve voltage profile, and to increase the maximum flow through cables and transformers. This paper presents a new method to determine the optimal locations and economical sizing of fixed and/or switched shunt capacitors with a view to power losses reduction and voltage stability enhancement. For solving the problem, a new enhanced cuckoo optimization algorithm is presented.The proposed method is tested on distribution test system and the results show that the algorithm suitable for practical implementation on real systems with any size.

Keywords: capacitor placement, power losses, voltage stability, radial distribution systems

Procedia PDF Downloads 347
544 Nonlinear Vibration Analysis of a Functionally Graded Micro-Beam under a Step DC Voltage

Authors: Ali Raheli, Rahim Habibifar, Behzad Mohammadi-Alasti, Mahdi Abbasgholipour

Abstract:

This paper presents vibration behavior of a FGM micro-beam and its pull-in instability under a nonlinear electrostatic pressure. An exponential function has been applied to show the continuous gradation of the properties along thickness. Nonlinear integro-differential-electro-mechanical equation based on Euler–Bernoulli beam theory has been derived. The governing equation in the static analysis has been solved using Step-by-Step Linearization Method and Finite Difference Method. Fixed points or equilibrium positions and singular points have been shown in the state control space. In order to find the response to a step DC voltage, the nonlinear equation of motion has been solved using Galerkin-based reduced-order model and time histories and phase portrait for different applied voltages have been shown. The effects of electrostatic pressure on stability of FGM micro-beams having various amounts of the ceramic constituent have been investigated.

Keywords: FGM, MEMS, nonlinear vibration, electrical, dynamic pull-in voltage

Procedia PDF Downloads 431
543 A Seismic Study on The Settlement of Superstructures Due to the Tunnel Construction

Authors: Seyed Abolhasan Naeini, Saeideh Mohammadi

Abstract:

Rapid urban development leads to the construction of urban tunnels for transport. Passage of tunnels under the surface structures and utilities prompted the changes in the site conditions and hence alteration of the dynamic response of surface structures. Therefore, in this study, the effect of the interaction of tunnel-superstructure on the site response is investigated numerically. For this purpose, Fast Lagrangian Analysis of Continua (FLAC 2D) is used, and stratification and properties of soil layers are selected based on the line No 7 of Tehran subway. The superstructure is modeled both as an equivalent surcharge and the actual structure, and the results are compared. A comparison of the results shows that consideration of structure geometry is necessary for dynamic analysis and it leads to the changes in displacements and accelerations. Consequently, the geometry of the superstructure should be modeled completely instead of the application of an equivalent load. The effect of tunnel diameter and depth on the settlement of superstructures is also studied. Results show that when the tunnel depth and diameter grow, the settlements increase considerably.

Keywords: tunnel, FLAC2D, settlement, dynamic analysis

Procedia PDF Downloads 103
542 Realistic Testing Procedure of Power Swing Blocking Function in Distance Relay

Authors: Farzad Razavi, Behrooz Taheri, Mohammad Parpaei, Mehdi Mohammadi Ghalesefidi, Siamak Zarei

Abstract:

As one of the major problems in protecting large-dimension power systems, power swing and its effect on distance have caused a lot of damages to energy transfer systems in many parts of the world. Therefore, power swing has gained attentions of many researchers, which has led to invention of different methods for power swing detection. Power swing detection algorithm is highly important in distance relay, but protection relays should have general requirements such as correct fault detection, response rate, and minimization of disturbances in a power system. To ensure meeting the requirements, protection relays need different tests during development, setup, maintenance, configuration, and troubleshooting steps. This paper covers power swing scheme of the modern numerical relay protection, 7sa522 to address the effect of the different fault types on the function of the power swing blocking. In this study, it was shown that the different fault types during power swing cause different time for unblocking distance relay.

Keywords: power swing, distance relay, power system protection, relay test, transient in power system

Procedia PDF Downloads 343
541 Nutritional Composition of Iranian Desi and Kabuli Chickpea (Cicer arietinum L.) Cultivars in Autumn Sowing

Authors: Khosro Mohammadi

Abstract:

The grain quality of chickpea in Iran is low and instable, which may be attributed to the evolution of cultivars with a narrow genetic base making them vulnerable to biotic stresses. Four chickpea varieties from diverse geographic origins were chosen and arranged in a randomized complete block design. Mesorhizobium Sp. cicer strain SW7 was added to all the chickpea seeds. Chickpea seeds were planted on October 9, 2013. Each genotype was sown 5 m in length, with 35 cm inter-row spacing, in 3 rows. Weeds were removed manually in all plots. Results showed that analysis of variance on the studied traits showed significant differences among genotypes for N, P, K and Fe contents of chickpea, but there is not a significant difference among Ca, Zn and Mg continents of chickpea. The experimental coefficient of variation (CV) varied from 7.3 to 15.8. In general, the CV value lower than 20% is considered to be good, indicating the accuracy of conducted experiments. The highest grain N was observed in Hashem and Jam cultivars. The highest grain P was observed in Jam cultivar. Phosphorus content (mg/100g) ranged from 142.3 to 302.3 with a mean value of 221.3. The negative correlation (-0.126) was observed between the N and P of chickpea cultivars. The highest K and Fe contents were observed in Jam cultivar.

Keywords: cultivar, genotype, nitrogen, nutrient, yield

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540 Effective Photodegradation of Tetracycline by a Heteropoly Acid/Graphene Oxide Nanocomposite Based on Uio-66

Authors: Anasheh Maridiroosi, Ali Reza Mahjoub, Hanieh Fakhri

Abstract:

Heteropoly acid nanoparticles anchored on graphene oxide based on UiO-66 were synthesized via in-situ growth hydrothermal method and tested for photodegradation of a tetracycline as critical pollutant. Results showed that presence of graphene oxide and UiO-66 with high specific surface area, great electron mobility and various functional groups make an excellent support for heteropoly acid and improve photocatalytic efficiency up to 95% for tetracycline. Furthermore, total organic carbon (TOC) analysis verified 79% mineralization of this pollutant under optimum condition.

Keywords: heteropoly acid, graphene oxide, MOF, tetracycline

Procedia PDF Downloads 96
539 Optimal Sizes of Energy Storage for Economic Operation Management

Authors: Rohalla Moghimi, Sirus Mohammadi

Abstract:

Batteries for storage of electricity from solar and wind generation farms are a key element in the success of sustainability. In recent years, due to large integration of Renewable Energy Sources (RESs) like wind turbine and photovoltaic unit into the Micro-Grid (MG), the necessity of Battery Energy Storage (BES) has increased dramatically. The BES has several benefits and advantages in the MG-based applications such as short term power supply, power quality improvement, facilitating integration of RES, ancillary service and arbitrage. This paper presents the cost-based formulation to determine the optimal size of the BES in the operation management of MG. Also, some restrictions, i.e. power capacity of Distributed Generators (DGs), power and energy capacity of BES, charge/discharge efficiency of BES, operating reserve and load demand satisfaction should be considered as well. In this paper, a methodology is proposed for the optimal allocation and economic analysis of ESS in MGs on the basis of net present value (NPV). As the optimal operation of an MG strongly depends on the arrangement and allocation of its ESS, economic operation strategies and optimal allocation methods of the ESS devices are required for the MG.

Keywords: microgrid, energy storage system, optimal sizing, net present value

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538 Factors Influencing the Usage of ERP in Enterprise Systems

Authors: Mohammad Reza Babaei, Sanaz Kamrani

Abstract:

The main problems That arise In adopting most Enterprise resources planning (ERP) strategies come from organizational, complex information systems like the ERP integrate the data of all business areas within the organization. The implementation of ERP is a difficult process as it involves different types of end users. Based on literature, we proposed a conceptual framework and examined it to find the effect of some of the individual, organizational, and technological factors on the usage of ERP and its impact on the end user. The results of the analysis suggest that computer self-efficacy, organizational support, training, and compatibility have a positive influence on ERP usage which in turn has significant influence on panoptic empowerment and individual performance.

Keywords: factor, influencing, enterprise, system

Procedia PDF Downloads 337
537 Modeling and Optimization of Micro-Grid Using Genetic Algorithm

Authors: Mehrdad Rezaei, Reza Haghmaram, Nima Amjadi

Abstract:

This paper proposes an operating and cost optimization model for micro-grid (MG). This model takes into account emission costs of NOx, SO2, and CO2, together with the operation and maintenance costs. Wind turbines (WT), photovoltaic (PV) arrays, micro turbines (MT), fuel cells (FC), diesel engine generators (DEG) with different capacities are considered in this model. The aim of the optimization is minimizing operation cost according to constraints, supply demand and safety of the system. The proposed genetic algorithm (GA), with the ability to fine-tune its own settings, is used to optimize the micro-grid operation.

Keywords: micro-grid, optimization, genetic algorithm, MG

Procedia PDF Downloads 473
536 Disposable Coffee Cups Recycling

Authors: Sasan Mohammadi

Abstract:

Due to our passion for coffee, we use 16 billion throwaway coffee cups yearly. Coffee lovers throughout the globe have discovered the hard way that their paper cups are not recyclable, despite what coffee businesses have repeatedly assured them [1] A disposable, single-use coffee cup comprises a paper and polyethylene layer. Polyethylene is a typical material used to fill a coffee cup's inside to keep its structure and provide water and heat resistance. In addition, the polyethylene layer prevents recycling since it is difficult to separate the plastic liner from the paper layer [2]. In addition, owing to the plastic membrane lining many of these cups, they cannot be recycled and may take up to 30 years to biodegrade [3]. Most of researcher try to separate plastic part ,but it is not economical and easy.For this purposes,it is not yet happen. In our research we don't separate plastic, just we make a homogeneous pulp with cold water.then fix it in mold and dry it,after completely drying cycle we heated the product in 100 degree of centigrade this cause a sintering effect by plastic particle between paper fibers.This method increase 30 percent the strength of product.This product has a good sound proof and thermal isolation. This means we can use it as insulator.with low density we can control the the density by percentage of air solved in pulp.

Keywords: recycling, disposable coffee cup, insolator, low density

Procedia PDF Downloads 41
535 Women's Concerns in Disasters at Family Level in Iranian Context

Authors: Maryam Nakhaei, Hamid Reza Khankeh, Mitra Moodi, Leila Daddoust

Abstract:

Although individuals (men and women) experience disasters in different ways, because of important women’s roles in the family, we aim to shed more light on their issues in doing family. In this report, we present an overview of the main qualitative and quantitative findings of different projects have been conducted in the regions affected by disaster in Iran. This paper explores women’s needs and experiences after disaster at the family level in 'disaster response behavior', 'personal health' including reproductive health and needs of pregnant women, 'livelihood responsibilities', and 'marital relationships'. This clarification can help not only to ensure that their needs are adequately addressed but also to plan family based strategies which consider their strengths.

Keywords: disaster, family, women, Iran

Procedia PDF Downloads 285
534 Study the Behavior of Different Composite Short Columns (DST) with Prismatic Sections under Bending Load

Authors: V. Sadeghi Balkanlou, M. Reza Bagerzadeh Karimi, A. Hasanbakloo, B. Bagheri Azar

Abstract:

In this paper, the behavior of different types of DST columns has been studied under bending load. Briefly, composite columns consist of an internal carbon steel tube and an external stainless steel wall that the between the walls are filled with concrete. Composite columns are expected to combine the advantages of all three materials and have the advantage of high flexural stiffness of CFDST columns. In this research, ABAQUS software is used for finite element analysis then the results of ultimate strength of the composite sections are illustrated.

Keywords: DST, stainless steel, carbon steel, ABAQUS, straigh columns, tapered columns

Procedia PDF Downloads 355
533 Identification and Molecular Characterization of Cryptosporidium Spp. in Pre-Wean Dairy Calves in Mashhad, Northeastern of Iran

Authors: Mohammad Asadpour, Gholamreza Razmi, Gholamreza Mohammadi, Abolghasem Naghibi

Abstract:

Cryptosporidium Spp., protozoan parasites of the phylum Apicomplexa, have a wide spectrum of hosts including humans, domestic animals and wild mammals, birds, reptiles, amphibians and fish. Dairy cattle have been identified in numerous reports as a major source of environmental contamination with this pathogen. In this study, a Polymerase Chain Reaction (PCR), Restriction Fragment Length Polymorphism (RFLP) analysis of the Small-Subunit (SSU) rRNA gene was used to detect and identify Cryptosporidium Spp. in 300 fecal specimens from 1 to 30 days pre-wean calves in 10 farms in Mashhad, Iran. Eighty five (28.3%) and forty five (15%) of the specimens were positive for Cryptosporidium by microscopic and PCR examination respectively. Restriction digestion of the PCR products by VSPI and Ssp1 restriction enzymes and analysis of sequence data revealed the presence of C. parvum, bovine genotype in all isolates. Our findings suggest that cattle can be a source of Cryptosporidial infections for humans and animals in Mashhad area. This is the first published description of Cryptosporidium sub genotyping in Mashhad.

Keywords: cryptosporidium, genotype, dairy calves, 18S rRNA, Mashhad

Procedia PDF Downloads 392
532 A New Learning Automata-Based Algorithm to the Priority-Based Target Coverage Problem in Directional Sensor Networks

Authors: Shaharuddin Salleh, Sara Marouf, Hosein Mohammadi

Abstract:

Directional sensor networks (DSNs) have recently attracted a great deal of attention due to their extensive applications in a wide range of situations. One of the most important problems associated with DSNs is covering a set of targets in a given area and, at the same time, maximizing the network lifetime. This is due to limitation in sensing angle and battery power of the directional sensors. This problem gets more complicated by the possibility that targets may have different coverage requirements. In the present study, this problem is referred to as priority-based target coverage (PTC). As sensors are often densely deployed, organizing the sensors into several cover sets and then activating these cover sets successively is a promising solution to this problem. In this paper, we propose a learning automata-based algorithm to organize the directional sensors into several cover sets in such a way that each cover set could satisfy coverage requirements of all the targets. Several experiments are conducted to evaluate the performance of the proposed algorithm. The results demonstrated that the algorithms were able to contribute to solving the problem.

Keywords: directional sensor networks, target coverage problem, cover set formation, learning automata

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531 Using Digitally Reconstructed Radiographs from Magnetic Resonance Images to Localize Pelvic Lymph Nodes on 2D X-Ray Simulator-Based Brachytherapy Treatment Planning

Authors: Mohammad Ali Oghabian, Reza Reiazi, Esmaeel Parsai, Mehdi Aghili, Ramin Jaberi

Abstract:

In this project a new procedure has been introduced for utilizing digitally reconstructed radiograph from MRI images in Brachytherapy treatment planning. This procedure enables us to localize the tumor volume and delineate the extent of critical structures in vicinity of tumor volume. The aim of this project was to improve the accuracy of dose delivered to targets of interest in 2D treatment planning system.

Keywords: brachytherapy, cervix, digitally reconstructed radiographs, lymph node

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530 Facile Fabrication of Nickel/Zinc Oxide Hollow Spheres Nanostructure and Photodegradation of Congo Red

Authors: Seyed Mohsen Mousavi, Ali Reza Mahjoub, Behjat Afshari

Abstract:

In this work, Nickel/Zinc Oxide hollow spherical structures with high surface area using the template Fructose was prepared by the hydrothermal method using a ultrasonic bath at room temperature was produced and were identified by FTIR, XRD, FE-SEM. The photocatalytic activity of synthesized hollow spherical Nickel/Zinc Oxide was studied in the destruction of Congo red as Azo dye. The results showed that the photocatalytic activity of Nickel/ Zinc Oxide hollow spherical nanostructures is improved compared with zinc oxide hollow sphere and other morphologies.

Keywords: azo dye, hollow spheres, photocatalyst, nickel/zinc oxide

Procedia PDF Downloads 600
529 Techno-Economic Analysis of Solar Energy for Cathodic Protection of Oil and Gas Buried Pipelines in Southwestern of Iran

Authors: M. Goodarzi, M. Mohammadi, A. Gharib

Abstract:

Solar energy is a renewable energy which has attracted special attention in many countries. Solar cathodic protectionsystems harness the sun’senergy to protect underground pipelinesand tanks from galvanic corrosion. The object of this study is to design and the economic analysis a cathodic protection system by impressed current supplied with solar energy panels applied to underground pipelines. In the present study, the technical and economic analysis of using solar energy for cathodic protection system in southwestern of Iran (Khuzestan province) is investigated. For this purpose, the ecological conditions such as the weather data, air clearness and sunshine hours are analyzed. The economic analyses were done using computer code to investigate the feasibility analysis from the using of various energy sources in order to cathodic protection system. The overall research methodology is divided into four components: Data collection, design of elements, techno economical evaluation, and output analysis. According to the results, solar renewable energy systems can supply adequate power for cathodic protection system purposes.

Keywords: renewable energy, solar energy, solar cathodic protection station, lifecycle cost method

Procedia PDF Downloads 506
528 Numerical Study of Off-Design Performance of a Highly Loaded Low Pressure Turbine Cascade

Authors: Shidvash Vakilipour, Mehdi Habibnia, Rouzbeh Riazi, Masoud Mohammadi, Mohammad H. Sabour

Abstract:

The flow field passing through a highly loaded low pressure (LP) turbine cascade is numerically investigated at design and off-design conditions. The Field Operation And Manipulation (OpenFOAM) platform is used as the computational Fluid Dynamics (CFD) tool. Firstly, the influences of grid resolution on the results of k-ε, k-ω, and LES turbulence models are investigated and compared with those of experimental measurements. A numerical pressure under-shoot is appeared near the end of blade pressure surface which is sensitive to grid resolution and flow turbulence modeling. The LES model is able to resolve separation on a coarse and fine grid resolutions. Secondly, the off-design flow condition is modeled by negative and positive inflow incidence angles. The numerical experiments show that a separation bubble generated on blade pressure side is predicted by LES. The total pressure drop is also been calculated at incidence angle between -20◦ and +8◦. The minimum total pressure drop is obtained by k-ω and LES at the design point.

Keywords: low pressure turbine, off-design performance, openFOAM, turbulence modeling, flow separation

Procedia PDF Downloads 332
527 Numerical Investigation of Embankment Settlement Improved by Method of Preloading by Vertical Drains

Authors: Seyed Abolhasan Naeini, Saeideh Mohammadi

Abstract:

Time dependent settlement due to loading on soft saturated soils produces many problems such as high consolidation settlements and low consolidation rates. Also, long term consolidation settlement of soft soil underlying the embankment leads to unpredicted settlements and cracks on soil surface. Preloading method is an effective improvement method to solve this problem. Using vertical drains in preloading method is an effective method for improving soft soils. Applying deep soil mixing method on soft soils is another effective method for improving soft soils. There are little studies on using two methods of preloading and deep soil mixing simultaneously. In this paper, the concurrent effect of preloading with deep soil mixing by vertical drains is investigated through a finite element code, Plaxis2D. The influence of parameters such as deep soil mixing columns spacing, existence of vertical drains and distance between them, on settlement and stability factor of safety of embankment embedded on soft soil is investigated in this research.

Keywords: preloading, soft soil, vertical drains, deep soil mixing, consolidation settlement

Procedia PDF Downloads 189
526 Communication Layer Security in Smart Farming: A Survey on Wireless Technologies

Authors: Hossein Mohammadi Rouzbahani, Hadis Karimipour, Evan Fraser, Ali Dehghantanha, Emily Duncan, Arthur Green, Conchobhair Russell

Abstract:

Human population growth has driven rising demand for food that has, in turn, imposed huge impacts on the environment. In an effort to reconcile our need to produce more sustenance while also protecting the world’s ecosystems, farming is becoming more reliant on smart tools and communication technologies. Developing a smart farming framework allows farmers to make more efficient use of inputs, thus protecting water quality and biodiversity habitat. Internet of Things (IoT), which has revolutionized every sphere of the economy, is being applied to agriculture by connecting on-farm devices and providing real-time monitoring of everything from environmental conditions to market signals through to animal health data. However, utilizing IoT means farming networks are now vulnerable to malicious activities, mostly when wireless communications are highly employed. With that in mind, this research aims to review different utilized communication technologies in smart farming. Moreover, possible cyber-attacks are investigated to discover the vulnerabilities of communication technologies considering the most frequent cyber-attacks that have been happened.

Keywords: smart farming, Internet of Things, communication layer, cyber-attack

Procedia PDF Downloads 205
525 Temperament and Character Dimensions as Personality Predictors of Relationship Quality: An Actor-Partner Interdependence Model

Authors: Dora Vajda, Somayyeh Mohammadi, Sandor Rozsa

Abstract:

Predicting the relationship satisfaction based on the personality characteristics of both partners has a long history. The association between relationship quality and personality traits has been previously demonstrated. Personality traits are most commonly assessed using the Five-Factor Model. The present study has focused on Cloninger's psychobiological model of personality that accounts for dimensions of both temperament and character. The goal of this study was to examine the actor and partner effect of couple's personality on relationship outcomes. In total, 184 heterosexual couples completed the Temperament and Character Inventory (TCI) and the Dyadic Adjustment Scale. The analysis was based on Actor-Partner Interdependence Model (APIM) using multilevel modeling (MLwiN). Results showed that character dimensions Self-Directedness and Cooperativeness had a statistically meaningful actor and partner effect on both partner's relationship quality. However, male's personality temperament dimension Reward Dependence had an only actor effect on his relationship quality. The findings contribute to the literature by highlighting the role of character dimensions of personality in romantic relationships.

Keywords: APIM (actor-partner interdependence model), MLwiN, personality, relationship quality

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524 Fast Terminal Sliding Mode Controller For Quadrotor UAV

Authors: Vahid Tabrizi, Reza GHasemi, Ahmadreza Vali

Abstract:

This paper presents robust nonlinear control law for a quadrotor UAV using fast terminal sliding mode control. Fast terminal sliding mode idea is used for introducing a nonlinear sliding variable that guarantees the finite time convergence in sliding phase. Then, in reaching phase for removing chattering and producing smooth control signal, continuous approximation idea is used. Simulation results show that the proposed algorithm is robust against parameter uncertainty and has better performance than conventional sliding mode for controlling a quadrotor UAV.

Keywords: quadrotor UAV, fast terminal sliding mode, second order sliding mode t

Procedia PDF Downloads 509