bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilization of Construction Waste Tiles as a Replacement for Fine Aggregates in Concrete
Authors: Adekunle A. A. , Abimbola K. R. , Familusi A. O.
Published: November 2020

Ceramic wastes are found to be suitable for usage as substitution for fine and coarse aggregates in concrete production. This study is an investigation into the utilization of waste tiles as partial replacement for fine and coarse aggregates in concrete. The control mix and other mixes containing cement, water, granite and partial replacement for sand with crushed tiles (in 5%, 10%, 15% and 20% proportions) were cast, cubed, cured and crushed. Also, another mix containing cement, water, sand and partial replacement of granite with crushed tiles (in 25%, 50% and 75% proportions) were cast, cubed, cured and crushed. The specimens were tested for their respective compressive strengths using the Universal Testing Machine (UTM) on the 7th, 14th, 21st and 28th days of curing. At 28 days, the compressive strength value of 5% of fine-waste tiles replacement was 20.12 N/mm2 while that of 10%, 15% and 20% were 14.24 N/mm2, 11.04 N/mm2 and 10.12 N/mm2 respectively. Moreover, at 28 days, the compressive strength of 25% of coarse-waste tiles replacement shows an increase to 22.45 N/mm2 while that of 50% and 75% were 18.4 N/mm2 and 12.2 N/mm2 respectively. Thus it can be concluded that fine aggregates can be substituted at 5% waste tiles while coarse aggregates can be substituted at 25% waste tiles.>/p>
A Novel Approach for Arabic Text Steganography Based on the “BloodGroup” Text Hiding Method
Authors: Malalla S. , Shareef F. R.
Published: November 2020

Steganography is the science of hiding certain messages (data) in groups of irrelevant data possibly of other form. The purpose of steganography is covert communication to hide the existence of a message from an intermediary. Text Steganography is the process of embedding secret message (text) in another text (cover text) so that the existence of secret message cannot be detected by a third party. This paper presents a novel approach for text steganography using the Blood Group (BG) method based on the behavior of blood group. Experimentally it is found that the proposed method got good results in capacity, hiding capacity, time complexity, robustness, visibility, and similarity which shows its superiority as compared to most several existing methods.
Antecedents for the Success of the Adoption of Organizational ERP Among Higher Education Institutions and Competitive Advantage in Egypt
Authors: Soliman M. , Karia N.
Published: November 2020

Although the Enterprise Resource Planning (ERP) system has long been acknowledged in higher education institutions (HEIs) to improve their performance and efficiency, there are not many HEIs in Egypt that adopt ERP system and those that do are in an early stage. The research on ERP system in HEI is still limited and in the immature stage, hence little is known about the success factors for the adoption stage of ERP systems. Consequently, this article aims to understand what are the success factors for ERP adoption and further develop a conceptual model that explains the successful implementation of ERP in HEIs and its impact on competitive advantage. Based on previous studies, this paper identifies and conceptualizes success factors for ERP and further develops the proposed model for the adoption of ERP system in HEIs. This article contributes to the development of the theoretical framework of the successful implementation of the ERP system to explain the competitive advantage of HEI by merging information system (IS) success and diffusion of innovation (DOI) theories with the success factors for the adoption stage of ERP systems. The current study will provide recommendations and guidelines for both the potential adopters and the vendors on the successful ERP system adoption.
Dealing with Wormhole Attacks in Wireless Sensor Networks Through Discovering Separate Routes Between Nodes
Authors: Rezaei F. , Zahedi A.
Published: November 2020

One of the most common attacks against Wireless Sensor Networks is the wormhole attack. In this attack, the enemy deploys two malicious nodes in two different areas of the network and establishes a high-speed dedicated channel between these two. This will cause the normal nodes in two different areas wrongly think that they are two-hop neighbors. Therefore, this attack will greatly affect the routing algorithms. In this paper, a new distributed algorithm is provided to deal with the wormhole attack. The main idea of the proposed algorithm is to discover separate routes between pairs of two-hop neighboring nodes. The proposed algorithm was implemented and evaluated in terms of true and false detection rate by performing a series of experiments and the results were compared with the base algorithm. The test results showed that the proposed algorithm has desirable efficacy.
Spot Welding of 6061 Aluminum Alloy by Friction Stir Spot Welding Process
Authors: Tashkandi M. A. , Al-jarrah J. A. , Ibrahim M.
Published: November 2020

This study was focused on the effect of welding parameters on the lap-shear fracture load of the welded joints prepared by friction stir spot welding. Four different weld parameters were analyzed: rotational speed, dwell time, pin length and shoulder size of the welding tool. It was found that the lap-shear fracture load increases with an increase of the welding parameters to a limited value and decreases with further increase. The strong welded joints failed under nugget-pull out fracture.
QoS frameworks for Multimedia Traffic in Mobile Adhoc Networks: A Comparative Review
Authors: Soni S. , Shah J. S.
Published: November 2020

MANETs (Mobile Adhoc Networks) has gained an increased interest by the research community. Regular intelligent exchanges of multimedia will be typical in MANET, though the extended motivation on QoS (Quality of Service). However, various properties of the discussed QoS framework are provisioned for QoS as a challenging concern. Providing QoS provisioning is, to a great degree, challenging in MANETs in view of bouncing correspondences, center point movability and nonattendance of central coordination. Thus, most of the research has focused on giving QoS guarantees in MANETs coordinating traditions. Though huge numbers of QoS coordinating procedures have been proposed in composing, focusing on different QoS estimations yet none of the prescribed or discussed frameworks achieves a universal course of action. There exist several genuine necessary research areas of focus such as QoS metric assurance and cost limit layout, source level scheduling framework and QoS coordinating. In this paper, working and connecting of various QoS frameworks for MANETs is investigated throughout several veritable focus areas of research. After a comparative review, it is concluded that there is still a good scope of research for proposing a QoS framework for MANETs which could have cross-layer advantages, resource reservation, connection admission control, multi-constrained QoS parameters, hard QoS assurance, proactive routing advantages etc.
An Appraisal of Asia-Pacific Cities as Control and Command Centres Embedded in World City Network
Authors: Li Z. , Dawood S. R. S. , Zhang X.
Published: November 2020

Since the globalization trend is proliferating at a staggering rate, world cities have emerged as the most dominant vanguard incorporated into global economy. Control and command function is one of the robust integral parts of world city formation, which is closely associated with the corporate headquarter status of some dominant multinational companies. Previous research works on this topic tend to concentrate on the Western Europe and North American arenas neglecting the Asia-Pacific region. Hence, the objective of this paper is to explore control and command functions of Asia-Pacific cities with reference to headquarters’ locations of multinational companies. The methodology will utilize the Forbes global 2000 dataset from the seminal study of GaWC research group, and apply the control and command center model and the interlocking city network model to discover the control and command index, as well as network connectivity of Asia-Pacific cities. Based upon the empirical study of this research, we could identify the hierarchical structure and spatial structure of Asia-Pacific world cities to emerge as some control and command centers embedded in world city network.
Evaluation of Three Common Algorithms for Structure Active Control
Authors: Sareban M.
Published: November 2020

Recently active structure controllers were considered to deal with the impact of earthquake forces and the result of the investigations provided multiple algorithms to calculate force control and many different ways to apply these forces on the structure. In this study, the efficiency and effectiveness of three methods (linear quadratic regulator, fuzzy logic and pole assigning) are investigated. In addition, three buildings with different height classes with an active tuned mass damper (ATMD) on the top floor are considered to compare the active control methods. Examples with known mass and stiffness and with variable mass are considered. The results show that all three control methods used for the ATMD device reduce the structural response. The fuzzy control method, caused a sharp decline in relative displacement of building floors up to 80%. But in LQR and pole allocation procedures the applied force is limited. The best performance of fuzzy control is for high-rise buildings. The three different methods of control are stable in different masses and even under a random change of floor masses, their effectiveness can be trusted.
Direct Torque Control for Three-Level Neutral Point Clamped Inverter-Fed Induction Motor Drive
Authors: Sahu M. K. , Panda A. K. , Panigrahi B. P.
Published: November 2020

Direct torque control (DTC) is a control technique in AC drive systems to obtain high performance torque control. The classical DTC drive contains a pair of hysteresis comparators and suffers from variable switching frequency and high torque ripple. These problems can be solved by using space vector depending on the reference torque and flux. In this paper the space vector modulation technique is applied to the three-level Neutral Point Clamped (NPC) inverter control in the proposed DTC-based induction motor drive system, resulting to a significant reduce of torque ripple. Three-level neutral point clamped inverters have been widely used in medium voltage applications. This type of inverters have several advantages over standard two-level VSI, such as greater number of levels in the output voltage waveforms, less harmonic distortion in voltage and current waveforms and lower switching frequencies. This paper emphasizes the derivation of switching states using the Space Vector Pulse Width Modulation (SVPWM) technique. The control scheme is implemented using Matlab/Simulink. Experimental results using dSPACE validate the steady-state and the dynamic performance of the proposed control strategy.
Application of Time Recursive Processing for the Development of a Time/Phase Shifter
Authors: Perisic D. M. , Bojovic M.
Published: November 2020

This paper describes a powerful digital time and/or phase shifter of pulse rates, based on Time Recursive Processing. It can function either as a time shifter or as a phase shifter. The circuit can generate precise shifting for a pulse rate with a constant input period, but it is also capable to shift a pulse rate whose period is a ramp function. Besides that, the shifter can be used in tracking and prediction applications. The shifter is described by recursive equations as a linear discrete system. All mathematical analyses are made using the Z transform. Computer simulations are employed to prove the correctness of the mathematical analysis. The realization of the shifter is described and, to demonstrate the shifter functioning, actual oscilloscope screenshots are presented.
RETRACTED: Safety Index Evaluation and Calibration of Load and Resistance Factors for Concrete Beams Under the Simultaneous Effects of Bending, Shear and Torsion
Authors: Azhari A. , Mesbahi M. R.
Published: November 2020

This article has been retracted at the request of the Editor-in-Chief due to extended similarites with a previously published paper (in Persian).The previously published paper is:F. Jafari, J. Akbari, A. Jahanpur, "Evaluation of Safety Index and Calibration of Load and Resistance Factors for Reinforced Concrete Beams under Bending, Shear and Torsion Demands", Journal of Structural and Contruction Engineering, Article 5, Vol. 3, No. 4, pp. 49-64, 2017 (in Persian)The authors of this paper failed to provide any reasoning regarding the case.
Simulative Study into the Development of a Hybrid HVDC System Through a Comparative Research with HVAC: a Futuristic Approach
Authors: Narayan R. S. , Mohan S. , Sunitha K.
Published: November 2020

High Voltage Direct Current Transmission (HVDC) is considered a better solution for bulk long distance transmissions. The increased use of HVDC is a result of its advantages over the HVAC systems and especially of its fault stability nature. A better solution is proposed by using a Voltage Source Controlled–HVDC as one of the infeed for the Multi-Infeed HVDC (MIDC or MI-HVDC) systems. The main advantage with the VSC converter is its flexible power control which enhances the stability of the MIDC systems. In this paper, the behavior of an HVDC system is compared with that of an HVAC during faults. A Hybrid HVDC system that includes a LCC as a rectifier unit and a VSC converter as the inverter is being proposed. It is considered suitable for MIDC systems and particularly for supplying a weak AC system. The performance of the system during steady state and transient conditions for all the proposed topologies including HVDC, HVAC and Hybrid HVDC are studied in MATLAB/SIMULINK. All of the proposed control strategies are evaluated via a series of simulation case studies.
Geotechnical Characterization of Soils in the Eastern and Western Areas of Tehran
Authors: Razmyar A. , Eslami A.
Published: November 2020

Tehran is placed in a high seismic risk zone with specific natural hazards. The resources to deal effectively with a possible crisis are limited, so proper preparation is a necessity. Therefore, the identification of geotechnical design building features based on local and environmental conditions plays a fundamental role in improving the construction quality. Thus, given the increase of population in Tehran, the concentration in certain areas and the need to better identify soil characteristic for safer construction in these areas, a zoning study is performed in this study. The results showed that soils in regions 4 and 22 belong to B Tehran formation and are coarse. Because the soil is coarse-grained in these areas, earthquake liquefaction is not expected. Given the shear wave velocity in the 4 and 22 areas, the soil mass is characterized as dense or too dense.
Controller Design of DFIG Based Wind Turbine by Using Evolutionary Soft Computational Techniques
Authors: Bharti O. P. , Saket R. K. , Nagar S. K.
Published: November 2020

This manuscript illustrates the controller design for a doubly fed induction generator based variable speed wind turbine by using a bioinspired scheme. This methodology is based on exploiting two proficient swarm intelligence based evolutionary soft computational procedures. The particle swarm optimization (PSO) and bacterial foraging optimization (BFO) techniques are employed to design the controller intended for small damping plant of the DFIG. Wind energy overview and DFIG operating principle along with the equivalent circuit model is adequately discussed in this paper. The controller design for DFIG based WECS using PSO and BFO are described comparatively in detail. The responses of the DFIG system regarding terminal voltage, current, active-reactive power, and DC-Link voltage have slightly improved with the evolutionary soft computational procedure. Lastly, the obtained output is equated with a standard technique for performance improvement of DFIG based wind energy conversion system.
Ranking Tehran’s Stock Exchange Top Fifty Stocks Using Fundamental Indexes and Fuzzy TOPSIS
Authors: Saleh E. S. , Kimiagari A. M.
Published: November 2020

Investment through the purchase of securities, constitute an important part of countries economic exchange. Therefore, making decisions about investing in a particular stock has become one of the most controversial areas of economic and financial research and various institutions have began to rank companies stock and determine priorities of stock purchase to investment. The current research, with the determination of important required indexes for companies ranking based on their shares value on the Tehran stock exchange, can greatly help to the accurate ranking of fifty premier listed companies. Initial ranking indicators are extracted and then a decision-making group (exchange experts) with the use of the Delphi method and also non-parametric statistic methods, determines the final indexes. Then, by using Fuzzy ANP, weight criteria are obtained with taking into account their interaction with each other. Finally, using fuzzy TOPSIS and information extraction about the premier fifty listed companies of Tehran stock exchange in 2014 are ranked with the software "Rahavard Novin”. Sensitivity analysis to criteria weight and relevant analysis presentation was conducted at the end of the study procedures.
Critical Factors of E-Learning Adoption and Acceptance in Pakistan: A Literature Review
Authors: Kanwal F. , Rehman M. , Bashir K. , Qureshi U.
Published: November 2020

This review paper examines the prior studies on critical factors of e-learning adoption in Pakistan. The search terms identified 40 papers reporting 25 conceptual and qualitative and 15 quantitative evidence about the e-learning adoption and critical factors that may influence the adoption of e-learning in Pakistan. The findings revealed that modern paradigm shift requires the in-depth analysis of government policies, institutional and management role, students and faculty attitude, social norms, cultural values as well as technological advancement. These factors may directly or indirectly affect the intention of students towards e-learning adoption. The lack of quantitative evidences illustrate that policy makers, practitioners and researchers need to pay attention for further research of identifying and analyzing the critical factors which enhances the e-learning adoption in Pakistan.
The Effect of Measurement Error on X̃-R̃ Fuzzy Control Charts
Authors: Moameni M. , Saghaei A. , Ghorbani Salanghooch M.
Published: November 2020

Control charts are tools used for monitoring manufacturing processes. Fuzzy Set Theory has found its way in control charts and new types of fuzzy control charts, with different capabilities, has been introduced. In this paper, a process in which the result of the measuring of each piece is imprecise is studied, and a X̃-R̃ fuzzy control chart is used for monitoring. The aim is to study the effect of measurement error on the effectiveness of the fuzzy control chart to detect out of control situations. The model used in this research is a linear covariate model. ARL parameters are used to study the performance of the fuzzy control chart when the parameters of covariate model is increased or decreased.
A Novel Energy Efficient Clustering Algorithm for Wireless Sensor Networks
Authors: Singh S. P. , Sharma S. C.
Published: November 2020

Wireless sensor networks (WSNs) are composed of huge amount of tiny resource constrained devices known as sensors. The demand for an energy efficient structure is becoming gradually more essential in WSNs. Energy efficient clustering is a distinguished optimization problem which has been studied extensively to expand the life span of WSNs. In this manuscript, a new energy efficient clustering scheme for WSNs with the use of Particle Swarm Optimization (PSO) is proposed. The clustering algorithm is implemented with the goal of concurrently minimizing the intra-cluster distance along with optimizing the usage of network energy. The presented algorithm is tested widely and results are analyzed and compared with previous ones to show the supremacy in term of alive nodes, energy consumption, packet delivery ratio, and system throughput. Simulation results show that the proposed algorithm outperforms other existing algorithms.
Evaluation of Moving Average Window Technique as Low-pass Filter in Microprocessor-Based Protecting Relays
Authors: Khodabakhshi-Javinani N. , Askarian Abyaneh H.
Published: November 2020

Over the last decades, with the increase in the use of harmonic source devices, the filtering process has received more attention than ever before. Digital relays operate according to accurate thresholds and precise setting values. In signal flow graphs of relays, the low-pass filter plays a crucial role in pre-filtering and purifying waveforms performance estimating techniques to estimate the expected impedances, currents, voltage etc. The main process is conducted in the CPU through methods such as Man and Morrison, Fourier, Walsh-based techniques, least-square methods etc. To purify waveforms polluted with low-order harmonics, it is necessary to design and embed cutting frequency in a narrow band which would be costly. In this article, a technique is presented which is able to eliminate specified harmonics, noise and DC offset, attenuate whole harmonic order and hand low-pass filtered signals to CPU. The proposed method is evaluated by eight case studies and compared with first and second order low-pass filter.
Representing IT Projects Risk Management Best Practices as a Metamodel
Authors: El Yamami A. , Ahriz S. , Mansouri K. , Qbadou M. , Illoussamen E.
Published: November 2020

Although still relatively new, the field of IT Governance has its own bodies of knowledge that include various methodologies, frameworks and techniques supported by an increasing growing base of research. IT Project Risk Management has since emerged as its own field. Many frameworks and methodologies were proposed by both practitioners and researchers. A review of the literature about the subject shows that there is a divergence between the two. The practitioners propose a set of good practices from professional environment but the heaviness of the proposed guides does not allow its application and adoption by managers or it’s improvement by researchers. Thus it calls for specific focus on IT governance frameworks best practices modelling in order to reach fusion between practitioners and researchers contributions. In this paper, special attention is dedicated to Project Management Institute’s guides. The main objective is representing IT Project Risk Management best practices as a Metamodel in order to complement different areas of knowledge.
Improving Power System Stability Using Transfer Function: A Comparative Analysis
Authors: Shahgholian G. , Fattollahi A.
Published: November 2020

In this paper, a small-signal dynamic model of a single-machine infinite-bus (SMIB) power system that includes IEEE type-ST1 excitation system and PSS based on transfer function structure is presented. The changes in the operating condition of a power system on dynamic performance have been examined. The dynamic performance of the closed-loop system is analyzed base on its eigenvalues. The effectiveness of the parameters changes on dynamic stability is verified by simulation results. Three types of PSS have been considered for analysis: (a) the derivative PSS, (b) the lead-lag PSS or conventional PSS, and (c) the proportional-integral-derivative PSS. The objective function is formulated to increase the damping ratio of the electromechanical mode eigenvalues. Simulation results show that the PID-PSS performs better for less overshoot and less settling time compared with the CPSS and DPSS under different load operation and the significant system parameter variation conditions.
Considering FACTS in Optimal Transmission Expansion Planning
Authors: Soleimani K. , Mazloum J.
Published: November 2020

The expansion of power transmission systems is an important part of the expansion of power systems that requires enormous investment costs. Since the construction of new transmission lines is very expensive, it is necessary to choose the most efficient expansion plan that ensures system security with a minimal number of new lines. In this paper, the role of Flexible AC Transmission System (FACTS) devices in the effective operation and expansion planning of transmission systems is examined. Effort was taken to implement a method based on sensitivity analysis to select the optimal number and location of FACTS devices, lines and other elements of the transmission system. Using this method, the transmission expansion plan for a 9 and a 39 bus power system was performed with and without the presence of FACTS with the use of DPL environment in Digsilent software 15.1. Results show that the use of these devices reduces the need for new transmission lines and minimizes the investment cost.
A Hybrid Meta-Learner Technique for Credit Scoring of Banks’ Customers
Authors: Armaki A. G. , Fallah M. F. , Alborzi M. , Mohammadzadeh A.
Published: November 2020

Financial institutions are exposed to credit risk due to issuance of consumer loans. Thus, developing reliable credit scoring systems is very crucial for them. Since, machine learning techniques have demonstrated their applicability and merit, they have been extensively used in credit scoring literature. Recent studies concentrating on hybrid models through merging various machine learning algorithms have revealed compelling results. There are two types of hybridization methods namely traditional and ensemble methods. This study combines both of them and comes up with a hybrid meta-learner model. The structure of the model is based on the traditional hybrid model of ‘classification + clustering’ in which the stacking ensemble method is employed in the classification part. Moreover, this paper compares several versions of the proposed hybrid model by using various combinations of classification and clustering algorithms. Hence, it helps us to identify which hybrid model can achieve the best performance for credit scoring purposes. Using four real-life credit datasets, the experimental results show that the model of (KNN-NN-SVMPSO)-(DL)-(DBSCAN) delivers the highest prediction accuracy and the lowest error rates.
A Decision-Analytic Feasibility Study of Upgrading Machinery at a Tools Workshop
Authors: Chew Hernandez M. L. , Velazquez Hernandez E. K. , Leon Dominguez S.
Published: November 2020

This paper presents the evaluation, from a Decision Analysis point of view, of the feasibility of upgrading machinery at an existing metal-forming workshop. The Integral Decision Analysis (IDA) methodology is applied to clarify the decision and develop a decision model. One of the key advantages of the IDA is its careful selection of the problem frame, allowing a correct problem definition. While following most of the original IDA methodology, an addition to this methodology is proposed in this work, that of using the strategic Means-Ends Objective Network as a backbone for the development of the decision model. The constructed decision model uses influence diagrams to include factual operator and vendor expertise, simulation to evaluate the alternatives and a utility function to take into account the risk attitude of the decision maker. Three alternatives are considered: Base (no modification), CNC (installing an automatic lathe) and CF (installation of an automatic milling machine). The results are presented as a graph showing zones in which a particular alternative should be selected. The results show the potential of IDA to tackle technical decisions that are otherwise approached without the due care.
Optimization of Emulsion Liquid Membrane for Lead Separation from Aqueous Solutions
Authors: Fouad E. , Ahmad F. , Abdelrahman K.
Published: November 2020

This study focuses on evaluating the process parameters and their effects on extraction of lead as well as emulsion breaking. The Signal / Noise ratios have been used to study the performance characteristics. Six parameters affecting extraction by emulsion liquid membrane, namely, TOPO, Span80, and internal phase concentration, feed/emulsion ratio, agitation time and feed pH have been optimized with considerations to lead extraction and emulsion breaking. The standardized effects of the independent variables and their interactions were tested by the analysis of variance (ANOVA) with 95% confidence limits (α= 0.05) and Pareto chart. The use of the optimal values of these parameters has been proved useful in maximizing the extraction efficiency and minimizing the emulsion breakage. TOPO concentration of 0.1498 M, Span 80 concentration of 3.007 v%, Internal phase concentration of 0.183 M, Feed/emulsion volume ratio of 1.407, agitation time of 30 minutes, and feed pH of 5 are determined as the optimum parameters.
3D Centrifuge Modeling of the Effect of Twin Tunneling to an Existing Pile Group
Authors: Soomro M. A. , Keerio M. A. , Soomro M. A. , Bangwar D. K.
Published: November 2020

In densely built urban areas, it is inevitable that tunnels will be constructed near existing pile groups. The bearing capacity of a pile group depends on shear stress along the soil-pile interface and normal stress underneath the pile toe while the two would be adversely affected by the unloading process of tunneling. Although extensive studies have been conducted to investigate the effects of tunnel construction on existing single piles, the influence of twin tunnel advancement on an existing pile group is merely reported in the literature. In this study, a series of three-dimensional centrifuge tests were carried out to investigate the response of an existing pile group under working load subjected to twin tunneling at various locations in dry Toyoura sand. In each twin tunneling test, the first tunnel is constructed near the mid-depth of the pile shaft, while the second tunnel is subsequently constructed either next to, below or right underneath the pile toe (Tests G_ST, G_SB and G_SU, respectively). Among the three tests, the 2nd tunnel excavated near the pile toe (Test G_ST) results in the smallest settlement but the largest transverse tilting (0.2%) of pile group. Significant bending moment was induced at the pile head (1.4 times of its bending moment capacity) due to the 2nd tunnel T. On the contrary, tunneling right underneath the toe of pile (i.e., Test G_SU) results in the smallest tilting but largest settlement of the pile group (4.6% of pile diameter) and incremental mobilisation of shaft resistance (13%). Due to stress release by the twin tunneling, the axial force taken by the front piles close to tunnels was reduced and partially transferred to the rear piles. This load transfer can increase the axial force in rear piles by 24%.
Rectangular Strain-Rosette Method for Measuring the Mode I Stress-Intensity Factor KI and T-stress
Authors: Hamdi A. , Benseddiq N. , Mejni F.
Published: November 2020

In this paper, a new experimental technique for measuring Stress Intensity Factor (SIF) and T-stress under mode I loading is developed. The expressions of the normal and tangential strains close to the crack tip are given using the first five terms of the generalized Westergaard formulation. In order to accurately determine the SIF and T-stress, the method exploits the optimal positioning of a rectangular strain gage rosette near a crack tip in mode I. Thus, errors due to the higher order terms of the asymptotic expansion are eliminated. Finally, a comparison of the analytical results with a finite element calculations, for different specimen dimensions, is carried out.
Nanotechnological Developments in Structural Design: Load-Bearing Materials
Authors: Ilerisoy Z. Y. , Takva Y.
Published: November 2020

Nanotechnology has a wide field of possible applications that includes the design, manufacture and application of nanomaterials and nanostructures. The selection of materials is an issue of significant importance to the construction industry. Concrete, steel and wood materials are considered as the main load-bearing materials in building construction and due to nanotechnological developments advanced application possibilities have been provided. The aim of this study is to systematically examine the nanotechnological developments on concrete, steel and wood which are used as load-bearing materials. The materialsâ€™ properties and the steps that enable these properties are considered and the advantages brought by the use of nanotechnology are tabulated. The differences in the molecular level of materials exhibiting behaviors different from those of conventional scale equivalents are shown.
A Gain Programmable Analog Divider Circuit Based on a Data Converter
Authors: Asl S. N. , Tarkhan M. , Nia M. S.
Published: November 2020

Analog dividers are widely used in analog systems. Analog realization of such circuits suffer from limited dynamic range and non-linearity issues, therefore, extra circuitry should be required to compensate these types of shortcomings. In this paper a gain controllable, analog divider is proposed based on data converters. Our circuit can be implemented both in current and voltage mode by selecting proper architectures. The resolution, power consumption and operation speed can be controlled by proper selecting of components. Another advantage of our circuit is its gain programmability. Moreover, the gain can be adjusted independently based on the relationship between input signals. Our proposed method offers two different gain control abilities, one for situation that the numerator signal is bigger than the denominator, and another gain is applied when the denominator is larger than the numerator. As a result, no extra amplifier is required for signal amplification. Moreover, the input and output signal nature can be chosen arbitrarily in this circuit, i.e. input signal may be a voltage signal while the output signal is current. Simulation results from SPICE confirm the proper operation of the circuit.
Photoelastic Analysis of the Vertebral Fixation System Using Different Screws
Authors: Fakhouri S. F. , Shimano M. M. , Araujo C. A. , Defino H. L. , Shimano A. C.
Published: November 2020

The purpose of this study was to compare using photoelasticity, the internal stresses produced by two types of pedicular screws (Synthes™) with three different diameters, when submitted to different pullout strengths. The fringe orders were evaluated around the screws using the Tardy compensation method. In all the models analyzed, the shear stress was calculated. Results showed that, independently of the applied load, the screw of smaller outer diameter had larger values of shear stress. According to the analysis realized, we observed that the place of highest stress was in the last thread, close to the head of the screws.
Dynamic Power System Security Analysis Using a Hybrid PSO-APO Algorithm
Authors: Teeparthi K. , Vinod Kumar D. M.
Published: November 2020

In this paper, a novel hybrid particle swarm optimization and artificial physics optimization (HPSO-APO) algorithm is proposed to solve the dynamic security constrained optimal power flow (DSCOPF) problem for enhancing system security. The dynamic security assessment deals with contingency analysis which is carried out using a performance index. DSCOPF recommends preventive control actions like generator rescheduling to alleviate an existing credible contingency in the system while ensuring minimal operating cost. The OPF problem is a highly nonlinear differential one and becomes more complex when considering the rotor dynamics of the system. The APO algorithm has the capability to reach a near global optimum value. However, it suffers from convergence problem. On the other hand, PSO exhibits premature convergence characteristics, but it may get trapped at a local optima value. The proposed HPSO-APO algorithm combines both individual algorithm strengths, to get balance between global and local search capability. The proposed method has been evaluated on a standard IEEE six-generator, 30-bus system and a New England ten-generator, 39-bus test system. The proposed HPSO-APO algorithm gives an efficient and robust optimal solution of DSCOPF problem compared to standard PSO and APO methods.
Using Fuzzy Logic to Increase the Accuracy of E-Commerce Risk Assessment Based on an Expert System
Authors: Beheshti H. , Alborzi M.
Published: November 2020

Strong adaptive control can be exercised even without access to accurate data inputs. Such control is possible through fuzzy mathematics, which is a meta-collection of Boolean logic principles that imply relative accuracy. Fuzzy mathematics find applications in e-commerce, where different risk analysis methods are available for risk assessment and estimation. Such approaches can be quantitative or qualitative, depending on the type of examined data. Quantitative methods are grounded in statistics, whereas qualitative methods are based on expert judgments and fuzzy set theory. Given that qualitative methods are very subjective and deal with vague or inaccurate data, fuzzy logic can be used to extract useful information from data inaccuracies. In this study, a model based on the opinions of e-commerce security experts was designed and implemented by using fuzzy expert systems and MATLAB. A case study was conducted to validate the effectiveness of the Model.
Cloud Masking for Remotely Sensed Data Using Spectral and Principal Components Analysis
Authors: Ahmad A. , Quegan S.
Published: November 2020

Two methods of cloud masking tuned to tropical conditions have been developed, based on spectral analysis and Principal Components Analysis (PCA) of Moderate Resolution Imaging Spectroradiometer (MODIS) data. In the spectral approach, thresholds were applied to four reflective bands (1, 2, 3, and 4), three thermal bands (29, 31 and 32), the band 2/band 1 ratio, and the difference between band 29 and 31 in order to detect clouds. The PCA approach applied a threshold to the first principal component derived from the seven quantities used for spectral analysis. Cloud detections were compared with the standard MODIS cloud mask, and their accuracy was assessed using reference images and geographical information on the study area.
Using Combined One-Time Password for Prevention of Phishing Attacks
Authors: Nasiri S. , Tahghighi Sharabian M. , Aajami M.
Published: November 2020

Αs technologies and communications develop, more sabotaging attacks occur including phishing attacks which jeopardize users' security and critical information like their passwords and credentials. Several solutions have been proposed for existing dangers. One of which is the use of one-time passwords. This issue has remained as a main challenge and requires more extensive research. In this research, we have focused on one-time password combinations and we also have proposed solutions based on behavioral patterns which lead to significant optimizations while tending the simplicity for users. Efficiency of the proposed method has been measured through defining scenarios, modeling and simulations based on a prevention rate index. In addition, complexity coefficient of the proposed method showing the probability of unpredictability of passwords for attackers has been calculated. Ultimately, a descriptive comparison has shown that the proposed method is superior to some of the existing methods.
Development and Experimental Investigation on Delay Time Consistency of Modified Si/PbO/Pb3O4/FG Pyrotechnic Delay Composition
Authors: Khan Α. , Lodhi Z. H. , Malik A. Q.
Published: November 2020

In the present study, experimental investigation was carried out on the delay time consistency of modified Si/PbO/Pb3O4/FG pyrotechnic delay composition in a delay tube. Where Si is the fuel, PbO/Pb3O4 are oxidizers and Fish Glue (FG) is the binder. Ingredient mixing and loading pressure were studied. Results revealed that homogenous mixing of the delay composition is a very critical parameter for controlling the time consistency of pyrotechnic delay composition. The delay time accuracy was improved from 25% to about 7.42% by ensuring homogenous mixing of the ingredients. Results also show that loading pressure ranged from 30,000 to 65,000 psi did not affect much the delay time of this pyrotechnic composition and the burning rate.
Modeling and Parameter Optimization for Surface Roughness and Residual Stress in Dry Turning Process
Authors: El-Axir M. H. , Elkhabeery M. M. , Okasha M. M.
Published: November 2020

The influence of some turning variables and tool overhang on surface roughness parameters and residual stress induced due to machining 6061-T6 aluminum alloy is investigated in this paper. Four input parameters (cutting speed, feed rate, depth of cut and tool overhang) are considered. Tests are carried out by precision turning operation on a lathe. Design of experiment techniques, i.e. response surface methodology (RSM) and Taguchi's technique have been used to accomplish the objective of the experimental study. Surface roughness parameters are measured using a portable surface roughness device while residual stresses are measured employing deflection-etching technique using electrochemical analysis. The results obtained reveal that feed and rotational speed play significant role in determining the average surface roughness. Furthermore, the depth of cut and tool overhang are less significant parameters, whereas tool overhang interacts with feed rate. The best result of surface roughness was obtained using low or medium values of overhang with low speed and /or feed rate. Minimum maximum tensile residual stress can be obtained with a combination of tool overhang of 37 mm with very low depth of cut, low rotational speed and feed rate of 0.188 mm/rev.
An Enhanced Genetic Algorithm for the Generalized Traveling Salesman Problem
Authors: Jafarzadeh H. , Moradinasab N. , Elyasi M.
Published: November 2020

The generalized traveling salesman problem (GTSP) deals with finding the minimum-cost tour in a clustered set of cities. In this problem, the traveler is interested in finding the best path that goes through all clusters. As this problem is NP-hard, implementing a metaheuristic algorithm to solve the large scale problems is inevitable. The performance of these algorithms can be intensively promoted by other heuristic algorithms. In this study, a search method is developed that improves the quality of the solutions and competition time considerably in comparison with Genetic Algorithm. In the proposed algorithm, the genetic algorithms with the Nearest Neighbor Search (NNS) are combined and a heuristic mutation operator is applied. According to the experimental results on a set of standard test problems with symmetric distances, the proposed algorithm finds the best solutions in most cases with the least computational time. The proposed algorithm is highly competitive with the published until now algorithms in both solution quality and running time.
The Effect of Zinc Oxide Nanoparticles on Safflower Plant Growth and Physiology
Authors: Hafizi Z. , Nasr N.
Published: November 2020

In this paper, a study of the effect of ZnO nanoparticles on safflower growth and physiology was performed. Each of these elements plays a particular role in the plant life, the presence of these elements is necessary for plant’s life cycle and growth. Zinc deficiency causes the biggest problems in safflower’s production. Considering the importance of nanoparticles in today's world, this research investigated the effect of Zinc oxide nanoparticles on the concentration of guaiacol peroxidase, polypeptide oxidase, dehydrogenase and malondialdehyde in four plant sample groups in greenhouse and laboratory conditions. Results of showed that malondialdehyde enzyme increased with different treatments of various concentrations of Zinc oxide. The enzyme guaiacol oxidase increased at concentrations of 100 mg/L and polyphenol oxide at concentrations of 10 and 500 mg/L and dehydrogenase in 1000 mg/L and decreased in other treatments. In addition to showing the effect of nanoparticles in plants, these findings determine the beneficial concentrations of nanoparticles that have a positive effect on the level of enzymes in plants.
Fuzzy Predictive Force Control (FPFC) for Speed Sensorless Control of Single-side Linear Induction Motor
Authors: Masoumi Kazraji S. , Feyzi M. R. , Bannae Sharifian M. B. , Tohidi S.
Published: November 2020

In this paper a model fuzzy predictive force control (FPFC) for the speed sensorless control of a single-side linear induction motor (SLIM) is proposed. The main purpose of of predictive control is minimizing the difference between the future output and reference values. This control method has a lower force ripple and a higher convergence speed in comparison to conventional predictive force control (CPFC). In this paper, CPFC and FPFC are applied to a linear induction motor and their results are compared. The results show that this control method has better performance in comparison to the conventional predictive control method.
Designing a GA-Based Robust Controller For Load Frequency Control (LFC)
Authors: Soleimani K. , Mazloum J.
Published: November 2020

Power systems include multiple units linked together to produce constantly moving electric power flux. Stability is very important in power systems, so controller systems should be implemented in power plants to ensure power system stability either in normal conditions or after the events of unwanted inputs and disorder. Frequency and active power control are more important regarding stability. Our effort focused on designing and implementing robust PID and PI controllers based on genetic algorithm by changing the reference of generating units for faster damping of frequency oscillations. Implementation results are examined on two-area power system in the ideally state and in the case of parameter deviation. According to the results, the proposed controllers are resistant to deviation of power system parameters and governor uncertainties.
A Classification Study on the Development Stages of Construction Technologies in Turkey
Authors: Polat H. I.
Published: November 2020

Developmental stages of construction technologies in Turkey followed various methods and showed differences in practice up to 20th century when the first examples of early-period reinforced concrete structures was created. Following the late 18th century, when traditional construction techniques were applied to new masses and building types, the use of modern bricks in vertical carrier elements together with the means of the 19th century was followed by an increase in masonry construction types of building structures. The paper emphasizes in the effects of traditional construction techniques applied with brick, steel, concrete materials on construction technology in Turkey. Traditional construction techniques are classified and detailed evaluations are made on the design principles of the buildings with historical characteristics.
Random Valued Impulse Noise Removal Using Region Based Detection Approach
Authors: Banerjee S. , Bandyopadhyay A. , Mukherjee A. , Das A. , Bag R.
Published: November 2020

Removal of random valued noisy pixel is extremely challenging when the noise density is above 50%. The existing filters are generally not capable of eliminating such noise when density is above 70%. In this paper a region wise density based detection algorithm for random valued impulse noise has been proposed. On the basis of the intensity values, the pixels of a particular window are sorted and then stored into four regions. The higher density based region is considered for stepwise detection of noisy pixels. As a result of this detection scheme a maximum of 75% of noisy pixels can be detected. For this purpose this paper proposes a unique noise removal algorithm. It was experimentally proved that the proposed algorithm not only performs exceptionally when it comes to visual qualitative judgment of standard images but also this filter combination outsmarts the existing algorithm in terms of MSE, PSNR and SSIM comparison even up to 70% noise density level.