Search results for: Seyed Shahram Shekarforoush
242 Assessment of Breast, Lung and Liver Effective Doses in Heart Imaging by CT-Scan 128 Dual Sources with Use of TLD-100 in RANDO Phantom
Authors: Seyedeh Sepideh Amini, Navideh Aghaei Amirkhizi, Seyedeh Paniz Amini, Seyed Soheil Sayyahi, Mohammad Reza Davar Panah
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CT-Scan is one of the lateral and sectional imaging methods that produce 3D-images with use of rotational x-ray tube around central axis. This study is about evaluation and calculation of effective doses around heart organs such as breast, lung and liver with CT-Scan 128 dual sources with TLD_100 and RANDO Phantom by spiral, flash and conventional protocols. In results, it is showed that in spiral protocol organs have maximum effective dose and minimum in flash protocol. Thus flash protocol advised for children and risk persons.Keywords: X-ray computed tomography, dosimetry, TLD-100, RANDO, phantom
Procedia PDF Downloads 474241 ANN Modeling for Cadmium Biosorption from Potable Water Using a Packed-Bed Column Process
Authors: Dariush Jafari, Seyed Ali Jafari
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The recommended limit for cadmium concentration in potable water is less than 0.005 mg/L. A continuous biosorption process using indigenous red seaweed, Gracilaria corticata, was performed to remove cadmium from the potable water. The process was conducted under fixed conditions and the breakthrough curves were achieved for three consecutive sorption-desorption cycles. A modeling based on Artificial Neural Network (ANN) was employed to fit the experimental breakthrough data. In addition, a simplified semi empirical model, Thomas, was employed for this purpose. It was found that ANN well described the experimental data (R2>0.99) while the Thomas prediction were a bit less successful with R2>0.97. The adjusted design parameters using the nonlinear form of Thomas model was in a good agreement with the experimentally obtained ones. The results approve the capability of ANN to predict the cadmium concentration in potable water.Keywords: ANN, biosorption, cadmium, packed-bed, potable water
Procedia PDF Downloads 430240 Anticipation of Bending Reinforcement Based on Iranian Concrete Code Using Meta-Heuristic Tools
Authors: Seyed Sadegh Naseralavi, Najmeh Bemani
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In this paper, different concrete codes including America, New Zealand, Mexico, Italy, India, Canada, Hong Kong, Euro Code and Britain are compared with the Iranian concrete design code. First, by using Adaptive Neuro Fuzzy Inference System (ANFIS), the codes having the most correlation with the Iranian ninth issue of the national regulation are determined. Consequently, two anticipated methods are used for comparing the codes: Artificial Neural Network (ANN) and Multi-variable regression. The results show that ANN performs better. Predicting is done by using only tensile steel ratio and with ignoring the compression steel ratio.Keywords: adaptive neuro fuzzy inference system, anticipate method, artificial neural network, concrete design code, multi-variable regression
Procedia PDF Downloads 284239 Effect of Waste Bottle Chips on Strength Parameters of Silty Soil
Authors: Seyed Abolhasan Naeini, Hamidreza Rahmani
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Laboratory consolidated undrained triaxial (CU) tests were carried out to study the strength behavior of silty soil reinforced with randomly plastic waste bottle chips. Specimens mixed with plastic waste chips in triaxial compression tests with 0.25, 0.50, 0.75, 1.0, and 1.25% by dry weight of soil and tree different length including 4, 8, and 12 mm. In all of the samples, the width and thickness of plastic chips were kept constant. According to the results, the amount and size of plastic waste bottle chips played an important role in the increasing of the strength parameters of reinforced silt compared to the pure soil. Because of good results, the suggested method of soil improvement can be used in many engineering problems such as increasing the bearing capacity and settlement reduction in foundations.Keywords: reinforcement, silt, soil improvement, triaxial test, waste bottle chips
Procedia PDF Downloads 285238 Targeted Effects of Subsidies on Prices of Selected Commodities in Iran Market
Authors: Sayedramin Hashemianesfehani, Seyed Hossein Hosseinilargani
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In this study, we attempt to realize that to what extent the increase in selected commodities in Iran Market is originated from the implementation of the targeted subsidies law. Hence, an econometric model based on existing theories of increasing and transferring prices in order to transferring inflation is developed. In other words, world price index and virtual variables defined for targeted subsidies has significant and positive impact on the producer price index. The obtained results indicated that the targeted subsidies act in Iran has influential long and short-term impacts on producer price indexes. Finally, world prices of dairy products and dairy price with respect to major parameters is carried out to obtain some managerial results.Keywords: econometric models, targeted subsidies, consumer price index (CPI), producer price index (PPI)
Procedia PDF Downloads 359237 The Impact of Online Advertising on Consumer Purchase Behaviour Based on Malaysian Organizations
Authors: Naser Zourikalatehsamad, Seyed Abdorreza Payambarpour, Ibrahim Alwashali, Zahra Abdolkarimi
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The paper aims to evaluate the effect of online advertising on consumer purchase behavior in Malaysian organizations. The paper has potential to extend and refine theory. A survey was distributed among Students of UTM university during the winter 2014 and 160 responses were collected. Regression analysis was used to test the hypothesized relationships of the model. Result shows that the predictors (cost saving factor, convenience factor and customized product or services) have positive impact on intention to continue seeking online advertising.Keywords: consumer purchase, convenience, customized product, cost saving, customization, flow theory, mass communication, online advertising ads, online advertising measurement, online advertising mechanism, online intelligence system, self-confidence, willingness to purchase
Procedia PDF Downloads 480236 Characterization of Anisotropic Deformation in Sandstones Using Micro-Computed Tomography Technique
Authors: Seyed Mehdi Seyed Alizadeh, Christoph Arns, Shane Latham
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Geomechanical characterization of rocks in detail and its possible implications on flow properties is an important aspect of reservoir characterization workflow. In order to gain more understanding of the microstructure evolution of reservoir rocks under stress a series of axisymmetric triaxial tests were performed on two different analogue rock samples. In-situ compression tests were coupled with high resolution micro-Computed Tomography to elucidate the changes in the pore/grain network of the rocks under pressurized conditions. Two outcrop sandstones were chosen in the current study representing a various cementation status of well-consolidated and weakly-consolidated granular system respectively. High resolution images were acquired while the rocks deformed in a purpose-built compression cell. A detailed analysis of the 3D images in each series of step-wise compression tests (up to the failure point) was conducted which includes the registration of the deformed specimen images with the reference pristine dry rock image. Digital Image Correlation (DIC) technique based on the intensity of the registered 3D subsets and particle tracking are utilized to map the displacement fields in each sample. The results suggest the complex architecture of the localized shear zone in well-cemented Bentheimer sandstone whereas for the weakly-consolidated Castlegate sandstone no discernible shear band could be observed even after macroscopic failure. Post-mortem imaging a sister plug from the friable rock upon undergoing continuous compression reveals signs of a shear band pattern. This suggests that for friable sandstones at small scales loading mode may affect the pattern of deformation. Prior to mechanical failure, the continuum digital image correlation approach can reasonably capture the kinematics of deformation. As failure occurs, however, discrete image correlation (i.e. particle tracking) reveals superiority in both tracking the grains as well as quantifying their kinematics (in terms of translations/rotations) with respect to any stage of compaction. An attempt was made to quantify the displacement field in compression using continuum Digital Image Correlation which is based on the reference and secondary image intensity correlation. Such approach has only been previously applied to unconsolidated granular systems under pressure. We are applying this technique to sandstones with various degrees of consolidation. Such element of novelty will set the results of this study apart from previous attempts to characterize the deformation pattern in consolidated sands.Keywords: deformation mechanism, displacement field, shear behavior, triaxial compression, X-ray micro-CT
Procedia PDF Downloads 189235 Experimental Procedure of Identifying Ground Type by Downhole Test: A Case Study
Authors: Seyed Abolhassan Naeini, Maedeh Akhavan Tavakkoli
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Evaluating the shear wave velocity (V_s) and primary wave velocity (Vₚ) is necessary to identify the ground type of the site. Identifying the soil type based on different codes can affect the dynamic analysis of geotechnical properties. This study aims to separate the underground layers at the project site based on the shear wave and primary wave velocity (Sₚ) in different depths and determine dynamic elastic modulus based on the shear wave velocity. Bandar Anzali is located in a tectonically very active area. Several active faults surround the study site. In this case, a field investigation of downhole testing is conducted as a geophysics method to identify the ground type.Keywords: downhole, geophysics, shear wave velocity, case-study
Procedia PDF Downloads 138234 Reliability Assessment and Failure Detection in a Complex Human-Machine System Using Agent-Based and Human Decision-Making Modeling
Authors: Sanjal Gavande, Thomas Mazzuchi, Shahram Sarkani
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In a complex aerospace operational environment, identifying failures in a procedure involving multiple human-machine interactions are difficult. These failures could lead to accidents causing loss of hardware or human life. The likelihood of failure further increases if operational procedures are tested for a novel system with multiple human-machine interfaces and with no prior performance data. The existing approach in the literature of reviewing complex operational tasks in a flowchart or tabular form doesn’t provide any insight into potential system failures due to human decision-making ability. To address these challenges, this research explores an agent-based simulation approach for reliability assessment and fault detection in complex human-machine systems while utilizing a human decision-making model. The simulation will predict the emergent behavior of the system due to the interaction between humans and their decision-making capability with the varying states of the machine and vice-versa. Overall system reliability will be evaluated based on a defined set of success-criteria conditions and the number of recorded failures over an assigned limit of Monte Carlo runs. The study also aims at identifying high-likelihood failure locations for the system. The research concludes that system reliability and failures can be effectively calculated when individual human and machine agent states are clearly defined. This research is limited to the operations phase of a system lifecycle process in an aerospace environment only. Further exploration of the proposed agent-based and human decision-making model will be required to allow for a greater understanding of this topic for application outside of the operations domain.Keywords: agent-based model, complex human-machine system, human decision-making model, system reliability assessment
Procedia PDF Downloads 168233 Calculation of Stress Intensity Factors in Rotating Disks Containing 3D Semi-Elliptical Cracks
Authors: Mahdi Fakoor, Seyed Mohammad Navid Ghoreishi
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Initiation and propagation of cracks may cause catastrophic failures in rotating disks, and hence determination of fracture parameter in rotating disks under the different working condition is very important issue. In this paper, a comprehensive study of stress intensity factors in rotating disks containing 3D semi-elliptical cracks under the different working condition is investigated. In this regard, after verification of modeling and analytical procedure, the effects of mechanical properties, rotational velocity, and orientation of cracks on Stress Intensity Factors (SIF) in rotating disks under centrifugal loading are investigated. Also, the effects of using composite patch in reduction of SIF in rotating disks are studied. By that way, the effects of patching design variables like mechanical properties, thickness, and ply angle are investigated individually.Keywords: stress intensity factor, semi-elliptical crack, rotating disk, finite element analysis (FEA)
Procedia PDF Downloads 364232 Effect of Hot Equal Channel Angular Pressing Process on Mechanical Properties of Commercial Pure Titanium
Authors: Seyed Ata Khalkhkali Sharifi, Gholamhossein Majzoubi, Farhad Abroush
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Developing mechanical properties of pure titanium has been reviewed in this paper by using ECAP process. At the first step of this article, the experimental samples were prepared as mentioned in the standards. Then pure grade 2 Ti was processed via equal-channel angular pressing (ECAp) for 2 passes following route-A at 400°C. After processing, the microstructural evolution, tensile, fatigue, hardness properties and wear behavior were investigated. Finally, the effect of ECAP process on these samples was analyzed. The results showed improvement in strength values with a slight decrease in ductility. The analysis on 30 points within the sample showed hardness increase in each pass. Also, it was concluded that fatigue properties were increased too.Keywords: equal-channel angular pressing, titanium, mechanical behavior, engineering materials and applications
Procedia PDF Downloads 258231 Concept Analysis of Professionalism in Teachers and Faculty Members
Authors: Taiebe Shokri, Shahram Yazdani, Leila Afshar, Soleiman Ahmadi
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Introduction: The importance of professionalism in higher education not only determines the appropriate and inappropriate behaviors and guides faculty members in the implementation of professional responsibilities, but also guarantees faculty members' adherence to professional principles and values, ensures the quality of teaching and facilitator will be the teaching-learning process in universities and will increase the commitment to meet the needs of students as well as the development of an ethical culture based on ethics. Therefore, considering the important role of medical education teachers to prepare teachers and students in the future, the need to determine the concept of professional teacher and teacher, and the characteristics of teacher professionalism, we have explained the concept of professionalism in teachers in this study. Methods: The concept analysis method used in this study was Walker and Avant method which has eight steps. Walker and Avant state the purpose of concept analysis as follows: The process of distinguishing between the defining features of a concept and its unrelated features. The process of concept analysis includes selecting a concept, determining the purpose of the analysis, identifying the uses of the concept, determining the defining features of the concept, identifying a model, identifying boundary and adversarial items, identifying the precedents and consequences of the concept, and defining empirical references. is. Results: Professionalism in its general sense, requires deep knowledge, insight, creating a healthy and safe environment, honesty and trust, impartiality, commitment to the profession and continuous improvement, punctuality, criticism, professional competence, responsibility, and Individual accountability, especially in social interactions, is an effort for continuous improvement, the acquisition of these characteristics is not easily possible and requires education, especially continuous learning. Professionalism is a set of values, behaviors, and relationships that underpin public trust in teachers.Keywords: concept analysis, medical education, professionalism, faculty members
Procedia PDF Downloads 154230 A Model Predictive Control Based Virtual Active Power Filter Using V2G Technology
Authors: Mahdi Zolfaghari, Seyed Hossein Hosseinian, Hossein Askarian Abyaneh, Mehrdad Abedi
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This paper presents a virtual active power filter (VAPF) using vehicle to grid (V2G) technology to maintain power quality requirements. The optimal discrete operation of the power converter of electric vehicle (EV) is based on recognizing desired switching states using the model predictive control (MPC) algorithm. A fast dynamic response, lower total harmonic distortion (THD) and good reference tracking performance are realized through the presented control strategy. The simulation results using MATLAB/Simulink validate the effectiveness of the scheme in improving power quality as well as good dynamic response in power transferring capability.Keywords: electric vehicle, model predictive control, power quality, V2G technology, virtual active power filter
Procedia PDF Downloads 430229 Evaluation Metrics for Machine Learning Techniques: A Comprehensive Review and Comparative Analysis of Performance Measurement Approaches
Authors: Seyed-Ali Sadegh-Zadeh, Kaveh Kavianpour, Hamed Atashbar, Elham Heidari, Saeed Shiry Ghidary, Amir M. Hajiyavand
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Evaluation metrics play a critical role in assessing the performance of machine learning models. In this review paper, we provide a comprehensive overview of performance measurement approaches for machine learning models. For each category, we discuss the most widely used metrics, including their mathematical formulations and interpretation. Additionally, we provide a comparative analysis of performance measurement approaches for metric combinations. Our review paper aims to provide researchers and practitioners with a better understanding of performance measurement approaches and to aid in the selection of appropriate evaluation metrics for their specific applications.Keywords: evaluation metrics, performance measurement, supervised learning, unsupervised learning, reinforcement learning, model robustness and stability, comparative analysis
Procedia PDF Downloads 73228 A Secure Routing Algorithm for Underwater Wireless Sensor Networks
Authors: Seyed Mahdi Jameii
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Underwater wireless sensor networks have been attracting the interest of many researchers lately, and the past three decades have beheld the rapid progress of underwater acoustic communication. One of the major problems in underwater wireless sensor networks is how to transfer data from the moving node to the base stations and choose the optimized route for data transmission. Secure routing in underwater wireless sensor network (UWCNs) is necessary for packet delivery. Some routing protocols are proposed for underwater wireless sensor networks. However, a few researches have been done on secure routing in underwater sensor networks. In this article, a secure routing protocol is provided to resist against wormhole and sybil attacks. The results indicated acceptable performance in terms of increasing the packet delivery ratio with regards to the attacks, increasing network lifetime by creating balance in the network energy consumption, high detection rates against the attacks, and low-end to end delay.Keywords: attacks, routing, security, underwater wireless sensor networks
Procedia PDF Downloads 418227 The Impact of Knowledge Management on Different Innovation Types in Small and Medium Enterprises
Authors: Shahnaz Piroozfar, Seyed Arash Halajzadeh, Abouzar Ilkhani
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Nowadays, in unpredictable business environments, enterprises face a great challenge to meet customer’s requirements. The performance of an enterprise has a significant impact on its activities and has to be evaluated continuously. One of the most important indicators to evaluate performance is named ‘innovation’. There are various indicators of innovation in the product/service sectors. These cause different innovation types to emerge, in product sectors. Additionally there are basic enablers to these innovation types, including an innovative culture, a customer oriented organizational culture, etc. Also one of these enablers is called enterprise system, which includes: SCM, CRM, ERP, KM etc. Knowledge management as a solution is a necessity in a competitive world. Implementation solutions such as KM are expensive, so enterprises need to answer how KM systems affect different performance indicators like innovation. This paper aims to develop a model to evaluate the impact of KM on innovation in SMEs.Keywords: innovation, knowledge management, SMEs, enterprise
Procedia PDF Downloads 693226 Annual Water Level Simulation Using Support Vector Machine
Authors: Maryam Khalilzadeh Poshtegal, Seyed Ahmad Mirbagheri, Mojtaba Noury
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In this paper, by application of the input yearly data of rainfall, temperature and flow to the Urmia Lake, the simulation of water level fluctuation were applied by means of three models. According to the climate change investigation the fluctuation of lakes water level are of high interest. This study investigate data-driven models, support vector machines (SVM), SVM method which is a new regression procedure in water resources are applied to the yearly level data of Lake Urmia that is the biggest and the hyper saline lake in Iran. The evaluated lake levels are found to be in good correlation with the observed values. The results of SVM simulation show better accuracy and implementation. The mean square errors, mean absolute relative errors and determination coefficient statistics are used as comparison criteria.Keywords: simulation, water level fluctuation, urmia lake, support vector machine
Procedia PDF Downloads 367225 Investigation on the Effect of Sugarcane Bagasse/HDPE Composition on the Screw Withdrawal Resistance of Injection Molded Parts
Authors: Seyed Abdol Mohammad Rezavand, Mohammad Nikbakhsh
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Withdrawal resistance of screws driven into HDPE/Sugarcane Bagasse injection molded parts was investigated. After chemical treatment and drying, SCB was pre-mixed with HDPE using twin extruder. The resulting granules are used in producing samples in injection molding machine. SCB with the quantity of %10, %20, and %30 was used. By using a suitable fixture, screw heads can take with tensile test machine grips. Parts with screws in the center and edge were fasten together. Then, withdrawal resistance was measured with tensile test machine. Injection gate is at the one edge of the part. The results show that by increasing SCB content in composite, the withdrawal resistance is decreased. Furthermore, the withdrawal resistance at the edges (near injection gate and the end of the filling path of mold cavity) is more than that of the center.Keywords: polyethylene, sugarcane bagasse, wood plastic, screw, withdrawal resistance
Procedia PDF Downloads 583224 Vectorial Capacity and Age Determination of Anopheles Maculipinnis S. L. (Diptera: Culicidae), in Esfahan and Chahar Mahal and Bakhtiari Provinces, Central Iran
Authors: Fariba Sepahvand, Seyed Hassan Moosa-kazemi
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The objective was to determine the population dynamics of Anopheles maculipinnis s.l. in relation to probable malaria transmission. The study was carried out in three villages in Isfahan and charmahal bakhteari provinces of Iran, from April to March 2014. Mosquitoes were collected by Total catch, Human and Animal bait collection. An. maculipinnis play as a dominant vector with exophagic and endophilic behavior. Ovary dissection revealed four dilatations indicate at least 9% of the population can reach to the dangerous age to potentially malaria transmission. Two peaks of blood feeding were observed, 9.00-10.00 P.M, and the 12.00-00.01 A.M. The gonotrophic cycle, survival rate, life expectancy of the species was 4, 0.82 and five days, respectively. Vectorial capacity was measured as 0.028. In conclusion, moderate climatic conditions support the persistence, density and longevity of An maculipinnis s.l. could result in more significant malaria transmission.Keywords: age determination, Anopheles maculipinnis, center of Iran, Malaria
Procedia PDF Downloads 246223 Response of Yield and Morphological Characteristic of Rice Cultivars to Heat Stress at Different Growth Stages
Authors: Mohammad Taghi Karbalaei Aghamolki, Mohd Khanif Yusop, Fateh Chand Oad, Hamed Zakikhani, Hawa Zee Jaafar, Sharifh Kharidah, Mohamed Hanafi Musa, Shahram Soltani
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The high temperatures during sensitive growth phases are changing rice morphology as well as influencing yield. In the glass house study, the treatments were: growing conditions [normal growing (32oC+2) and heat stress (38oC+2) day time and 22oC+2 night time], growth stages (booting, flowering and ripening) and four cultivars (Hovaze, Hashemi, Fajr, as exotic and MR219 as indigenous). The heat chamber was prepared covered with plastic, and automatic heater was adjusted at 38oC+2 (day) and 22oC+2 (night) for two weeks in every growth stages. Rice morphological and yield under the influence of heat stress during various growth stages showed taller plants in Hashsemi due to its tall character. The total tillers per hill were significantly higher in Fajr receiving heat stress during booting stage. In all growing conditions and growth stages, Hashemi recorded higher panicle exertion and flag leaf length. The flag leaf width in all situations was found higher in Hovaze. The total tillers per hill were more in Fajr, although heat stress was imposed during booting and flowering stages. The indigenous MR219 in all situations of growing conditions, growth stages recorded higher grain yield. However, its grain yield slightly decreased when heat stress was imposed during booting and flowering. Similar results were found in all other exotic cultivars recording to lower grain yield in the heat stress condition during booting and flowering. However, plants had no effect on heat stress during ripening stage.Keywords: rice, growth, heat, temperature, stress, morphology, yield
Procedia PDF Downloads 276222 Experimental Investigation of Soil Corrosion and Electrical Resistance in Depth by Geoelectrical Method
Authors: Seyed Abolhassan Naeini, Maedeh Akhavan Tavakkoli
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Determining soil engineering properties is essential for geotechnical problems. In addition to high cost, invasive soil survey methods can be time-consuming, so geophysical methods can be an excellent choice to determine soil characteristics. In this study, geoelectric investigation using the Wenner arrangement method has been used to determine the amount of soil corrosion in soil layers in a project site as a case study. This study aims to assess the degree of corrosion of soil layers to a depth of 5 meters and find the variation of soil electrical resistance versus depth. For this purpose, the desired points in the study area were marked and specified, and all withdrawals were made within the specified points. The collected data have been processed by standard and accepted methods, and the results have been presented in the form of calculation tables and curves of electrical resistivity with depth.Keywords: Wenner array, geoelectric, soil corrosion, electrical soil resistance
Procedia PDF Downloads 102221 Streamlining Cybersecurity Risk Assessment for Industrial Control and Automation Systems: Leveraging the National Institute of Standard and Technology’s Risk Management Framework (RMF) Using Model-Based System Engineering (MBSE)
Authors: Gampel Alexander, Mazzuchi Thomas, Sarkani Shahram
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The cybersecurity landscape is constantly evolving, and organizations must adapt to the changing threat environment to protect their assets. The implementation of the NIST Risk Management Framework (RMF) has become critical in ensuring the security and safety of industrial control and automation systems. However, cybersecurity professionals are facing challenges in implementing RMF, leading to systems operating without authorization and being non-compliant with regulations. The current approach to RMF implementation based on business practices is limited and insufficient, leaving organizations vulnerable to cyberattacks resulting in the loss of personal consumer data and critical infrastructure details. To address these challenges, this research proposes a Model-Based Systems Engineering (MBSE) approach to implementing cybersecurity controls and assessing risk through the RMF process. The study emphasizes the need to shift to a modeling approach, which can streamline the RMF process and eliminate bloated structures that make it difficult to receive an Authorization-To-Operate (ATO). The study focuses on the practical application of MBSE in industrial control and automation systems to improve the security and safety of operations. It is concluded that MBSE can be used to solve the implementation challenges of the NIST RMF process and improve the security of industrial control and automation systems. The research suggests that MBSE provides a more effective and efficient method for implementing cybersecurity controls and assessing risk through the RMF process. The future work for this research involves exploring the broader applicability of MBSE in different industries and domains. The study suggests that the MBSE approach can be applied to other domains beyond industrial control and automation systems.Keywords: authorization-to-operate (ATO), industrial control systems (ICS), model-based system’s engineering (MBSE), risk management framework (RMF)
Procedia PDF Downloads 95220 Formulating the Stochastic Finite Elements for Free Vibration Analysis of Plates with Variable Elastic Modulus
Authors: Mojtaba Aghamiri Esfahani, Mohammad Karkon, Seyed Majid Hosseini Nezhad, Reza Hosseini-Ara
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In this study, the effect of uncertainty in elastic modulus of a plate on free vibration response is investigated. For this purpose, the elastic modulus of the plate is modeled as stochastic variable with normal distribution. Moreover, the distance autocorrelation function is used for stochastic field. Then, by applying the finite element method and Monte Carlo simulation, stochastic finite element relations are extracted. Finally, with a numerical test, the effect of uncertainty in the elastic modulus on free vibration response of a plate is studied. The results show that the effect of uncertainty in elastic modulus of the plate cannot play an important role on the free vibration response.Keywords: stochastic finite elements, plate bending, free vibration, Monte Carlo, Neumann expansion method.
Procedia PDF Downloads 394219 Investigation of Static Stability of Soil Slopes Using Numerical Modeling
Authors: Seyed Abolhasan Naeini, Elham Ghanbari Alamooti
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Static stability of soil slopes using numerical simulation by a finite element code, ABAQUS, has been investigated, and safety factors of the slopes achieved in the case of static load of a 10-storey building. The embankments have the same soil condition but different loading distance from the slope heel. The numerical method for estimating safety factors is 'Strength Reduction Method' (SRM). Mohr-Coulomb criterion used in the numerical simulations. Two steps used for measuring the safety factors of the slopes: first is under gravity loading, and the second is under static loading of a building near the slope heel. These safety factors measured from SRM, are compared with the values from Limit Equilibrium Method, LEM. Results show that there is good agreement between SRM and LEM. Also, it is seen that by increasing the distance from slope heel, safety factors increases.Keywords: limit equilibrium method, static stability, soil slopes, strength reduction method
Procedia PDF Downloads 163218 Investigation of the Effect of Excavation Step in NATM on Surface Settlement by Finite Element Method
Authors: Seyed Mehrdad Gholami
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Nowadays, using rail transport system (Metro) is increased in most cities of The world, so the need for safe and economical way of building tunnels and subway stations is felt more and more. One of the most commonly used methods for constructing underground structures in urban areas is NATM (New Austrian tunneling method). In this method, there are some key parameters such as excavation steps and cross-sectional area that have a significant effect on the surface settlement. Settlement is a very important control factor related to safe excavation. In this paper, Finite Element Method is used by Abaqus. R6 station of Tehran Metro Line 6 is built by NATM and the construction of that is studied and analyzed. Considering the outcomes obtained from numerical modeling and comparison with the results of the instrumentation and monitoring of field, finally, the excavation step of 1 meter and longitudinal distance of 14 meters between side drifts is suggested to achieve safe tunneling with allowable settlement.Keywords: excavation step, NATM, numerical modeling, settlement.
Procedia PDF Downloads 139217 A Study on How to Improve PMBOK (Project Management Body of Knowledge) Guidelines Performance by Simulation
Authors: Fatemeh Jaferi, Moslem Parsa, Seyed Mehdi Sajadi
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The project-oriented organizations are more appropriate for sustainable environments. Any effective project-oriented organization should institutionalize its project management processes in such a manner to yield the greatest possible profits. The aim of this paper is to study the relationship between the project management PMBOK guideline (Project Management Body of Knowledge) and simulation technology in project-oriented organizations. The methodology involves using five steps for applying these two tools aimed at enhancing project management processes in the Lorestan Gas Corporation, as one of the project-oriented organization. Results show the implementation of such management approach leads to a 5% performance improvement and using PMBOK can be instrumental in effective delay management. The implementation of the aforementioned improvement package was effective in improving the efficiency of organizational processes; in terms of optimizing the resource utilization that has manifested itself in resource losses and cost reductions.Keywords: project-orientation, processes, PMBOK, optimization, organization, management
Procedia PDF Downloads 403216 Numerical Study of Modulus of Subgrade Reaction in Eccentrically Loaded Circular Footing Resting
Authors: Seyed Abolhasan Naeini, Mohammad Hossein Zade
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This article is an attempt to present a numerically study of the behaviour of an eccentrically loaded circular footing resting on sand to determine its ultimate bearing capacity. A surface circular footing of diameter 12 cm (D) was used as shallow foundation. For this purpose, three dimensional models consist of foundation, and medium sandy soil was modelled by ABAQUS software. Bearing capacity of footing was evaluated and the effects of the load eccentricity on bearing capacity, its settlement, and modulus of subgrade reaction were studied. Three different values of load eccentricity with equal space from inside the core on the core boundary and outside the core boundary, which were respectively e=0.75, 1.5, and 2.25 cm, were considered. The results show that by increasing the load eccentricity, the ultimate load and the modulus of subgrade reaction decreased.Keywords: circular foundation, sand, eccentric loading, modulus of subgrade reaction
Procedia PDF Downloads 346215 Proposing a Boundary Coverage Algorithm for Underwater Sensor Network
Authors: Seyed Mohsen Jameii
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Wireless underwater sensor networks are a type of sensor networks that are located in underwater environments and linked together by acoustic waves. The application of these kinds of network includes monitoring of pollutants (chemical, biological, and nuclear), oil fields detection, prediction of the likelihood of a tsunami in coastal areas, the use of wireless sensor nodes to monitor the passing submarines, and determination of appropriate locations for anchoring ships. This paper proposes a boundary coverage algorithm for intrusion detection in underwater sensor networks. In the first phase of the proposed algorithm, optimal deployment of nodes is done in the water. In the second phase, after the employment of nodes at the proper depth, clustering is executed to reduce the exchanges of messages between the sensors. In the third phase, the algorithm of "divide and conquer" is used to save energy and increase network efficiency. The simulation results demonstrate the efficiency of the proposed algorithm.Keywords: boundary coverage, clustering, divide and conquer, underwater sensor nodes
Procedia PDF Downloads 341214 Numerical Investigation of Wastewater Rheological Characteristics on Flow Field Inside a Sewage Network
Authors: Seyed-Mohammad-Kazem Emami, Behrang Saki, Majid Mohammadian
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The wastewater flow field inside a sewage network including pipe and manhole was investigated using a Computational Fluid Dynamics (CFD) model. The numerical model is developed by incorporating a rheological model to calculate the viscosity of wastewater fluid by means of open source toolbox OpenFOAM. The rheological properties of prepared wastewater fluid suspensions are first measured using a BrookField LVDVII Pro+ viscometer with an enhanced UL adapter and then correlated the suitable rheological viscosity model values from the measured rheological properties. The results show the significant effects of rheological characteristics of wastewater fluid on the flow domain of sewer system. Results were compared and discussed with the commonly used Newtonian model to evaluate the differences for velocity profile, pressure and shear stress. Keywords: Non-Newtonian flows, Wastewater, Numerical simulation, Rheology, Sewage Network
Procedia PDF Downloads 130213 Hybrid Diagrid System for High-Rise Buildings
Authors: Seyed Saeid Tabaee, Mohammad Afshari, Bahador Ziaeemehr, Omid Bahar
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Nowadays, using modern structural systems with specific capabilities, like Diagrid, is emerging around the world. In this paper, a new resisting system, a combination of both Diagrid axial behavior and proper seismic performance of regular moment frames in tall buildings, named 'Hybrid Diagrid' is presented. The scaled specimen of the suggested hybrid system was built and tested using IIEES shaking table. The natural frequency and structural response of the analytical model were updated with the real experimental results. In order to compare its performance with the traditional Diagrid and moment frame systems, time history analysis was carried out. Extensive analysis shows the efficient seismic responses and economical behavior of Hybrid Diagrid structure with respect to the other two systems.Keywords: hybrid diagrid system, moment frame, shaking table, tall buildings, time history analysis
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