bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Carrier Phase on GPS Multipath Tracking Error
Authors: Mubarak O. M.
Published: November 2020

Multipath is one of the main sources of tracking error in GPS receivers. This tracking error has previously been analyzed against the relative delay of the Line Of Sight (LOS) and reflected signals. However, only carrier phase differences of 0 and π were used, since they give tracking error with maximum magnitude. This paper shows that tracking error does not change linearly with changing carrier phase difference. Tracking error plots against relative carrier phase difference of the LOS and reflected signals have been used to analyze the relationship between the two in various scenarios. While maximum positive and negative errors are found at carrier phase difference of 0 and π, a sharp increase in tracking error is found around the phase difference of π. There is a zero crossing in all plots but that point is dependent on relative amplitude, delay, and carrier phase difference of the two signals. The analysis has also been extended to narrow correlators receiver. Tracking error is significantly reduced in this case, however, similar characteristics have been observed when the tracking error is analyzed against the relative carrier phase difference. Moreover, the tracking error was found to be less dependent on the relative delay between the two signals when correlators spacing is reduced.
Socio-environmental Impacts Associated with Burning Alternative Fuels in Clinker Kilns
Authors: Mainier F. B. , Monteiro L. P. C. , Mainier R. J.
Published: November 2020

The pollutants found in emissions from cement plants depend on the processes used and the operation of the clinker kilns. Another crucial aspect concerns the characteristics of raw materials and fuels. The intensive use of fuels in rotary kilns of cement plants and the increasing fuel diversification, including fuels derived from coal and oil, from a multitude of industrial waste and from biomass, charcoal and agricultural waste (sugarcane bagasse, rice husk), is increasing the possibilities of combinations or mixtures of different fuels, known as blends. Thus, there are socio-environmental impacts associated with the burning of alternative fuels in clinker kilns. In view of the growing trend of entrepreneurs who want to target the waste produced in their unit and of the owners of the cement plants who want to reduce their production costs by burning a waste with lower cost than conventional fuels, it is necessary to warn that a minimum level of environmental care should be followed regarding these decisions. It is necessary to monitor the points of emission from cement kilns and in the wider area influenced by the plant, in order to improve environmental quality. Laboratory studies of burning vulcanised rubber contaminated with arsenic simulate the burning of used tires in cement clinker kilns producing SO2 and As2O3.
Overhead Transmission Line Easement and Right-of-Way Cases in Crete, Greece: A Statistical Analysis of 1220 Cases from 1974 to 2019
Authors: Pylarinos D.
Published: November 2020

Overhead Transmission Lines (OTLs) are used to carry High Voltage (HV) between HV substations, usually constructed at long distances from each other, thus spanning across numerous different properties. Easements, a legal term for nonpossessory rights, are essential to the utilities in order to maintain a Right-Of-Way (ROW) for construction and maintenance purposes in a corridor of land underneath the lines, and also to enforce certain restrictions within that corridor, in order to ensure the safety of both the OTLs and the public. The exact details of ROW corridors’ management vary between countries as the legislation and each utility’s approach may differ. This paper focuses on 1220 easements/ROW cases regarding the isolated HV Transmission System of the Greek island of Crete from 1974 to 2019. The various related factors are discussed and a statistical analysis of the records is performed.
Parametric Optimization of Biodiesel Fuelled Engine Noise using the Taguchi Method
Authors: Patil S. A. , Arakerimath R. R.
Published: November 2020

Biodiesel is a renewable, biodegradable, and efficient fuel that can be blended with petro-diesel in any proportion. The noise in the engine resulting from the combustion has a direct effect on the engine’s performance. Many studies have examined the engines’ vibration and noise when using diesel and biodiesel blends. This study examines the optimization of diesel blends, load, and compression ratio in the aspect of reducing noise on a Kirloskar single-cylinder diesel engine. Noise was measured at the engine and its exhaust on a computerized setup and for different loads. The experimental results showed that a blend with 15% biodiesel, at 7kg load, and 18 compression ratio produced the lowest noise. Moreover, the Taguchi method was utilized, and experimental results were validated by an ANN
Nonlinear Inelastic Analysis of 2D Steel Frames
Authors: Nguyen P. C. , Le-Van B. , Thanh S. D. T. V.
Published: November 2020

In this study, a new method for nonlinear analysis of 2D steel frames, by improving the conventional plastic hinge method, is presented. The beam-column element is established and formulated in detail using a fiber plastic hinge approach. Residual stresses of I-shape sections are declared at the two ends through fibers. Gradual yielding by residual stresses along the member length due to axial force is accounted for by the tangent elastic modulus concept. The P-δ effect is captured by stability functions, whereas the P-Δ effect is estimated by the geometric stiffness matrix. A nonlinear algorithm is established for solving nonlinear problems. The present study predicts the strength and behavior of 2D steel frames as efficiently and accurately as the plastic zone method did.
Solar Energy Potential and Feasibility Study of a 10MW Grid-connected Solar Plant in Libya
Authors: Kassem Y. , Camur H. , Abughinda O. A. M.
Published: November 2020

Libya is currently interested in utilizing renewable energy technologies to reduce the energy dependence on oil reserves and Greenhouse Gas (GHG) emissions. The objective of this study is to investigate the feasibility of a 10MW grid-connected PV power plant in Libya. NASA data are used to analyze the global horizontal irradiation, direct normal irradiation, and air temperature of 22 selected locations in Libya and to evaluate the potential of solar energy. RETScreen software is used to estimate the energy production, GHG emissions, and financial parameters for the 22 locations. Based on the solar atlas map, it is noticed that the highest global horizontal irradiation is in the southern part of Libya, which ranged from 2100 to 2500kWh/m2. These results indicate that Libya has a huge solar energy potential that can be used to ‎generate electricity. Moreover, based on techno-economic results, it is observed that the highest electricity generation of 22067.13MWh is recorded at Al Κufrah and the lowest at Al Jabal al Akhdar with a value of 17891.38MWh. Furthermore, Al Kufrah and Murzuq are the best locations for the future installation of PV power plants from annual energy and the economic parameters point of view. The maximum value of power that can be generated by the plant was estimated to be 22.06GW.
Contribution of Particles Size Ranges to Sand Friction
Authors: Mostefa Kara E. , Meghachou M. , Aboubekr N.
Published: November 2020

This work studies the correlation between certain physical properties of granular material such as the friction angle and the grain size distribution. In the laboratory, the determination of friction angle requires hard and expensive testing. Prediction of this parameter from the grading curve proves to be very interesting. Direct shear tests were performed on actual marine sand of Tergha (Algeria) and on seventeen different samples arranged from the same sand with various particle size ranges. Results showed that the friction angle of sand is a result of contribution of various constituent granular classes.
Source- and Site-Specific Earthquake Ground Motions
Authors: Nagao T. , Fukushima Y.
Published: November 2020

Seismic design is the preparation for earthquake ground motions considering the seismicity and seismic amplification properties of the ground at the target site. However, the effects of source, path, and site amplification characteristics are not sufficiently anticipated in seismic codes. Regarding the source and path characteristics, earthquakes that have the strongest influence on the target site should be considered specifically, and, concerning seismic amplification, the effects of not only a shallow subsurface but also a deep subsurface should be considered. This article takes the design spectra of Japanese highway bridges as an object and compares them with the spectra produced by a ground motion prediction equation and the source- and site-specific spectra evaluated using a state-of-the-art method. The results show that the spectra differ greatly. In this way, the necessity of the application of a state-of-the-art technique in the evaluation of source, path, and site amplification characteristics is demonstrated.
Influence of Squeezing Rate on Yield Stress and Viscosity of Fresh Mortar
Authors: Phan V. T. , Nguyen D. D.
Published: November 2020

In the present work, squeeze flow techniques were used to investigate the influence of squeezing rates on the yield stress of mortars in fresh state. The tested samples were prepared under similar conditions of room temperature and atmospheric pressure. The fresh mortars were tested at three squeezing rates (20 and 200mm/s) 15 minutes after mixing. The results show that the material’s yield stress increases with the increasing of the squeeze velocity. This increase is evident at low tensile speeds and is not obvious at high tack velocity. Elongational viscosity values increased as a result of the gap reduction for all the tested samples. However, when the squeeze speed was high, the strain rate increased because of the high displacement rates, a significant reduction in the mortar’s elongational viscosity was observed compared with those obtained when the squeeze speed was low. Despite that this behavior is associated with fluid-solid phase separation, which occurs for low displacement rates, these viscosity values actually represent the behavior of the material in practical situations when submitted to different velocities. The increase in the displacement rate of one order of magnitude caused a reduction in the viscosity of one order of magnitude.
Determination of Potential Tidal Power Sites at East Malaysia
Authors: Samo K. A. , Samo I. A. , Siyal Z. A. , Rigit A. R. H.
Published: November 2020

Tidal range energy is one of the most predictable and reliable sources of renewable energy. This study’s main aim is to determine potential sites for tidal range power in East Malaysia, by analyzing tidal range distributions and resources and the feasibility of constructing barrages. Investigation was conducted in 34 sites, estimating their potential energy outputs and studying their areas for constructing barrages. Only 18 sites were marked as appropriate for constructing a tidal range energy extraction barrage. The highest potential power was found in Tanjung Manis, and its maximum capacity was calculated as 50.7kW. The second highest potential of tidal power extraction was found in Kuching Barrage at Pending, where an energy harvester could produce electric power up to 33.1kW.
Identification of Oil-Gas Two Phase Flow in a Vertical Pipe using Advanced Measurement Techniques
Authors: Abdulkareem L. A.
Published: November 2020

The characteristics of flow configuration in pipes are very important in the oil industry due to its role in governing equipment design. In vertical risers, many flow configurations could be observed such as bubbly, slug, churn, and annular flow. In this project, two tomographic techniques have been applied simultaneously to the flow in a vertical riser: the Electrical Capacitance Tomography (ECT) technique and the Capacitance Wire Mesh Sensor (WMS) technique. The employed pipe diameter was 50mm and the superficial studied velocities were 0.06-3.0m/s for gas and 0.06-0.4m/s for oil. Several techniques have been used to analyze the output data of the two tomography techniques such as time series of cross-sectional averaged void fraction, Probability Density Function (PDF), image reconstruction, and liquid hold-up profile. The averaged void fractions were calculated from the output signal of the two measurement techniques and plotted as functions of the superficial velocity of the gas. The flow patterns were identified from the PDF of the averaged void fraction. In addition, it was found that both tomographic techniques are reliable in identifying the flow regimes in pipes.
Backstepping Control for Induction Motors with Input and Output Constrains
Authors: Nguyen T. L. , Vo T. H. , Le N. D.
Published: November 2020

In practice, the applied control voltage for an induction motor drive system fed by a voltage source inverter has a limit depending on the DC bus capacity. In certain operations such as accelerating, the motor might require an excessively high voltage value that the DC bus cannot supply. This paper presents a control solution for the bounded control input problem of the induction motor system by flexibly combining a hyperbolic tangent function in a backstepping control design procedure. In addition, the barrier Lyapunov function is also employed to force speed tracking error in a defined value. The closed-loop system stability is proven, and the proposed control is verified through numerical simulations.
An Experimental Study of Greenhouse Gas Concentration on the Maximum Power Point of Solar PV Panels
Authors: Patnaik B. , Swain S. C. , Rout U. K.
Published: November 2020

The energy demand increases along with demographic and development growth. India is the second-most populous country in the world and most of its population needs more energy as its human and energy development indices are rather low. So, the country depends on cheaper sources of energy which have ample effects on the environment. Many energy sources are polluting, but solar energy is pollution-free and its availability is abundant with zero cost. Solar Photo Voltaic (PV) technology is the best technology to harness electricity. The effect of varying environmental factors regulates the performance factors of this technology. Its efficiency mainly depends on the concentration of greenhouse gases (GHGs), ambient temperature, module temperature, incoming solar radiation intensity, and PV material composition. To understand the behavior of solar panels on maximum power point under various GHGs concentrations, three experiments were conducted. One in normal atmospheric CO2 concentration and two in higher CO2 concentration chambers.
Squeeze Flow of a Newtonian Fluid under Different Test Speeds
Authors: Pham H. S. , Vu X. H. , Phan V. T.
Published: November 2020

In this paper, the squeeze flow behavior of Newtonian fluid was investigated with a series of squeeze tack laboratory experiments. The Newtonian fluid was squeezed out radially between two parallel and circular plates. From the flow curves obtained in the squeeze tack experiments, rheological parameters such as yield stress in tension and in squeeze, have been investigated. The results indicate that the values of yield stress in squeeze and in tack of the testing material are relatively small. These values gradually decrease with increasing sample thickness. This shows that the squeezing and tacking process does not affect the testing material, glucose in this case. Although the experimental results are not much, a linear relationship can be found between tensile and squeeze stress of Newton fluid in the experiment. This is especially evident at low test speeds
Elaboration of a Wind Energy Potential Map in Morocco using GIS and Analytic Hierarchy Process
Authors: Elmahmoudi F. , Abra O. E. K. , Raihani A. , Serrar O. , Bahatti L.
Published: November 2020

The construction of a wind power generation center starts by the selection of a suitable wind farm location. The selection includes six factors, namely wind speed, slope, land use, distance from the power lines, distance from the roads, and distance from populated areas which have been integrated into QGIS by weights calculated using the Analytical Hierarchy Process (AHP) approach. As a result of this study, the areas having very high wind potentiality have been identified and a best wind farm location map has been prepared. The map, using the overlay function in GIS, exhibits the most and least suitable areas for the location of wind farms in Morocco. The approach could help identify suitable wind farm locations in other areas using their geographic information.
Simulation of Dissolved Oxygen and Dissolved Substrate for Hasel River
Authors: Khalifa W. M. A.
Published: November 2020

Hasel is considered a moderately polluted river in Germany. This study investigated its water quality, examining Dissolved Oxygen (DO) and dissolved substrate (COD) with the use of AQUASIM. The calibration procedure used observed data from various locations along the river. The model’s calibration was used to study the response of Hasel River to the effluents of wastewater treatment plants and sewer overflow emissions. Results revealed that high emissions from sewerage systems may reduce the oxygen concentration to low levels. Furthermore, joined sewer overflows may disrupt the oxygen levels for a long period. In addition, oxygen was over saturation in some periods of the calibration period. The proposed model can be utilized in future analyses, improving the functional understanding of ecological processes in rivers and the identification of ecological effective management strategies.
Surface Quality of Ti-6Al-4V Titanium Alloy Parts Machined by Laser Cutting
Authors: Boudjemline A. , Boujelbene M. , Bayraktar E.
Published: November 2020

This paper investigates high power CO2 laser cutting of 5mm-thick Ti-6Al-4V titanium alloy sheets, aiming to evaluate the effects of various laser cutting parameters on surface roughness. Using multiple linear regression, a mathematical model based on experimental data was proposed to predict the maximum height of the surface Sz as a function of two laser cutting parameters, namely cutting speed and assist-gas pressure. The adequacy of the proposed model was validated by Analysis Of Variance (ANOVA). Experimental data were compared with the model’s data to verify the capacity of the proposed model. The results indicated that for fixed laser power, cutting speed is the predominant cutting parameter that affects the maximum height of surface roughness.
Approaches on Mitigating Variation Orders in Road Construction Industry in Kenya: The Case of Kenya National Highways Authority (KeNHA)
Authors: Gatitu J. N. , Kabubo C. K. , Ajwang P.
Published: November 2020

Variation orders have been globally identified as a significant reason for poor performance of construction projects. Several variation orders have been identified in the Kenyan construction industry, however, there is a paucity of information on the approaches to minimize their occurrence. The aim of this study is to identify the practices for variation order mitigation in the public road construction sector in Kenya. This is a cross-sectional study that was carried out among the stakeholders (clients, consultants, and contractors) involved in road construction projects. The study used the purposive sampling technique whereby the data were collected with the use of distributed questionnaires among clients, consultants, and contractors’ staff with a technical background in civil engineering. The Relative Importance Index (RII) was used for data analysis. According to the findings of the study, the top five recommended approaches for minimizing variation orders include the provision of adequate planning before the initiation of road construction projects, understanding of the contract provisions by all the parties before project implementation, solving of land disputes before the project tender awards, provision of complete project designs, and provision of a brief project scope during the tendering process. This research, therefore, contributes to a pool of knowledge that will enable practitioners and researchers in the construction industry to develop effective models for minimizing variation orders.
A Single Phase Grid Connected PV System working in Different
Modes
Authors: Gotekar P. S. , Muley S. P. , Kothari D. P.
Published: November 2020

The current grid standards for the single-phase residential PV system expect
it to operate at Maximum Power Point Tracking (MPPT) mode under normal
operating conditions and to maintain the voltage profile whenever a grid
fault occurs. The proposed system supplies power to the load under stable
conditions and the PV system works in MPPT mode. When the fault occurs at
the Point of Common Coupling (PCC) and the voltage is reduced, the proposed
controller maintains the voltage profile by injecting the current fed by the
current controller at the PCC. The controller shifts from MPPT to the faulty
mode and maintains voltage as per grid requirements. During islanding
conditions, the PV system successfully caters to the requirements of the
load by shifting the control from MPPT to islanding mode. When the PV system
is in operation the power quality is enhanced
Compact Solid-State Marx Generator for Repetitive Applications
Authors: Pinjari N. , Bindu S.
Published: November 2020

The Marx generator plays a vital role in a pulsed power system. In this paper, a modified compact bipolar output pulse solid-state Marx generator topology is developed. A three-stage prototype is designed and tested, in which pulse width, polarity, and peak voltage of the output pulse are made variable. It is possible to generate either positive or negative pulses with less rise time. Various components which affect the repetitive frequency of the developed Marx generator are evaluated. Analysis reveals that the total time period TO is a function of capacitor charging time. This is been validated experimentally by operating the Marx generator for different pulse repetition frequencies. The type of charging method solely controls the charging time of the capacitor and hence the repetition frequency.
An Indirect Evaluation of Program Educational Objectives and Student Outcomes for Engineering Programs: A Case Study
Authors: Ghaly S. M. A.
Published: November 2020

Outcome and objective assessment is a method for determining whether students and graduates have learned, have retained, and can apply what they have been taught. Assessment plans have to include a statement of educational objectives, measurements of attainment of the objectives, and use of the assessment results for continuous improvement. In this paper, the experience of the Electrical Engineering program at Al-Imam Mohammad Ibn Saud Islamic University is used as an example of how an indirect assessment method is established and implemented. Many surveys have been used and contributed to the numerical analysis for the indirect assessment of the program outcomes and achievements. The indirect assessment results indicate that the target levels are achieved for all the seven program outcomes and the three objectives that have been considered.
Influence of Tack Speed on The Rheological Properties of Mortar in Fresh State
Authors: Phan V. T.
Published: November 2020

In the present work, the squeeze flow techniques were used to investigate the influence of tack speed to the rheological properties of mortar in fresh sate, including yield stress and extensional viscosity.Tested samples were prepared under similar conditions of room temperature and atmospheric pressure. Compositions of mortars were tested at two different squeezing rates (20 and 200 mm/s) 15 min after mixing. Results indicate that mortar’s yield stress increases with the increasing of the pulling speed. This increase is evident at low tensile speeds. At high speed of tack, this increase is not obvious, especially in case of high squeeze speed of 200 mm/s. It can be concluded that the optima speed for removing the mortar and the upper surface is lower than 20 mm/s. The extensional viscosity of fresh mortars significantly decrease as the tack speed increases. Elongational viscosity values decreased as a result of gap increasing. The increase of the gap during tack experiment stimulates different units (grains getting far apart to each other) causing the observed decrease of the mortars' elongational viscosity
Settlement Response of a Multi-Story Building
Authors: Bhutto A. H. , Bhurgri G. S. , Zardari S. , Zardari M. A. , Memon B. A. , Babar M. M.
Published: November 2020

The settlement calculation of a multi-story building is a challenging task due to the variation of soil properties and the use of an appropriate constitutive model for the reliable representation of soils’ stress-strain behaviors. In this study, the settlement response of a multi-story building was calculated with the simple Mohr-Coulomb Model (MCM) and the Hardening Soil Model (HSM). The effect of soil modulus of elasticity using both models was investigated on the overall settlement response of the building. Results indicated that MCM overestimated immediate settlement in a range of 50 to 65% compared to HSM. The settlement response of the building calculated with both models was within the allowable range. The results of this study can be helpful for geotechnical engineers working on reliable predictions of the settlement of multi-story buildings.
Real Time Speech Recognition based on PWP Thresholding and MFCC using SVM
Authors: Helali W. , Hajaiej Ζ. , Cherif A.
Published: November 2020

The real-time performance of Automatic Speech Recognition (ASR) is a big challenge and needs high computing capability and exhaustive memory consumption. Getting a robust performance against inevitable various difficult situations such as speaker variations, accents, and noise is a tedious task. It’s crucial to expand new and efficient approaches for speech signal extraction features and pre-processing. In order to fix the high dependency issue related to processing succeeding steps in ARS and enhance the extracted features’ quality, noise robustness can be solved within the ARS extraction block feature, removing implicitly the need for further additional specific compensation parameters or data collection. This paper proposes a new robust acoustic extraction approach development based on a hybrid technique consisting of Perceptual Wavelet Packet (PWP) and Mel Frequency Cepstral Coefficients (MFCCs). The proposed system was implemented on a Rasberry Pi board and its performance was checked in a clean environment, reaching 99% average accuracy. The recognition rate was improved (from 80% to 99%) for the majority of Signal-to-Noise Ratios (SNRs) under real noisy conditions for positive SNRs and considerably improved results especially for negative SNRs.
Simulation of the Optimized Structure of a Laterally Coupled Distributed Feedback (LC-DFB) Semiconductor Laser Above Threshold
Authors: Seifouri M. , Faraji A.
Published: November 2020

In this paper, the laterally coupled distributed feedback semiconductor laser is studied. In the simulations performed, variations of structural parameters such as the grating amplitude a, the ridge width W, the thickness of the active region d, and other structural properties are considered. It is concluded that for certain values ​​of structural parameters, the laser maintains the highest output power, the lowest distortion Bragg frequency δL and the smallest changes in the wavelength λ. Above threshold, output power more than 40mW and SMSR values greater than 50 dB were achieved.
Testing and Validating DeLone and MacLean IS Model: ERP System Success in Higher Education Institutions of Pakistan
Authors: Khand Z. H. , Kalhoro M. R.
Published: November 2020

The universities in Pakistan have recently started replacing their old legacy systems with ERP systems which are commonly used in business organizations to gain a competitive edge over competitors. The Higher Education Commission (HEC) has implemented ERPs systems at eight different Universities in Pakistan. HEC has invested a huge amount of money to facilitate the integration, customization, and implementation of ERP systems in these universities. Previous studies have mainly focused on Critical Success Factors (CSFs) and risk factors of ERP systems. This study intends to empirically measure the support of ERP systems in teaching processes. DeLone and McLean model of Information Systems (IS) success is one of the most commonly used models cited in IS literature. In this study, the DeLone and McLean model was applied at a University level analysis to access the impact of ERP in higher educational institutions and their support in the improvement of academic processes. Hypotheses were tested on the research model using empirical data collected from 230 respondents, including students and faculty at two selected universities, with the use of a questionnaire. The data were analyzed by structural equation modeling. The model was empirically tested and the findings showed that use and user satisfaction affected most net benefits. Information quality, system quality, and service quality accounted for 42.6% effect in use. Whereas, information quality, system quality, service quality, and use accounted for 46.5% variance in user satisfaction.
A Robust Frequency Controller based on Linear Matrix Inequality for a Parallel Islanded Microgrid
Authors: Pathan E. , Abu Bakar A. , Zulkifi S. A. , Khan M. H. , Arshad H. , Asad M.
Published: November 2020

This paper presents a robust H∞ control technique for an islanded microgrid in the presence of sudden changes in load conditions. The proposed microgrid scheme consists of a parallel connected inverter with distributed generations. When the load is suddenly changed the frequency deviates from its nominal value. The objective is to design a robust frequency droop controller in order to achieve the frequency at nominal values without using any secondary controller and communication systems while improving power sharing accuracy. Small signal modeling of the power system is designed for the formulation of the problem and the H∞ optimal linear matrix inequality technique is applied in order to achieve the objectives. The proposed controller has been tested with the MATLAB/ SimPowerSytem toolbox.
Farm-Based Environmental and Economic Impacts of the Drip Irrigation System
Authors: Khalifa W. M. A. , Gasmi H. , Butt T. A.
Published: November 2020

Drip irrigation has received considerable attention from policy makers, researchers, and economists for its ability to contribute significantly improvements to water resource development, agricultural productivity, economic growth, and environmental sustainability. In this paper, the impact of drip irrigation has been studied on a farming system in terms of environmental and economic conditions using the developed Trickle Irrigation System Design Modeling (TISD). The environmental conditions included soil type, land topography, climate zones, water sources, their quality, and the farm dimensions. The economic conditions comprised of real and nominal interest rates, raw land price, and the energy and labor escalation rates. The study considered only the Benefit-Cost Ratio (BCR) to indicate the impact of environmental and economic parameters on the use of the drip irrigation system. The study used tomato-sesame as a crop rotation (line-source) and citrus as a long-life tree (point-source). Some parameters such as soil type, land topography, and water quality had a significant impact on the BCR.
State of Quality Engineering Practices: The Pakistan Perspective
Authors: Khan M. N. A. , Mirza A. M. , Shahid M. , Wagan R. A. , Saleem I.
Published: November 2020

This study analyzes the state of quality engineering practices being exercised in the software industry of Pakistan. Statistics have been collected and analyzed to access important aspects of quality engineering including quality policy, review mechanism, quality assurance activities and practices, quality standards and models, and quality management systems. For this purpose, an elaborated questionnaire was prepared to pertain to various aspects of quality management and more than 30 software houses and software development organizations were surveyed in Islamabad and Rawalpindi. The survey results and a description of the concluding remarks are reported in this paper.
The Geometrical Effect on the Von Mises Stress on Ball and Socket Artificial Discs
Authors: Alnaimat F. A.
Published: November 2020

Wear has been considered as a major issue for ball and socket artificial discs. This paper studies the effects of ball radius and radial clearance of the artificial disc on the von Mises stresses. Different material combinations, used in artificial discs, are compared. FEA simulation using Solidworks has been conducted for different disk geometries. The highest von Mises stress was 714MPa for 10mm radius metal against metal design. The lowest von Mises stress was 14.8MPa for 16mm radius of the UHMWPE/CoCr material combination, which exhibited the lowest von Mises stresses for all the radii of the ball and socket articulation. Considering radial clearance, the lowest von Mises stress was 14.8MPa for 0.015mm clearance of the UHMWPE/CoCr combination. The highest von Mises stress of 100.8MPa with a radial clearance of 0.25mm was recorded for the same combination. There is a strong relation between the von Mises stress and the geometry of the ball and socket of the artificial disc.
Enhanced-PCA based Dimensionality Reduction and Feature Selection for Real-Time Network Threat Detection
Authors: More P. , Mishra P.
Published: November 2020

With the rise of the data amount being collected and exchanged over networks, the threat of cyber-attacks has also increased significantly. Timely and accurate detection of any intrusion activity in networks has become a crucial task in order to safeguard data and other valuable assets. While manual moderation and programmed logic have been used for this purpose, the use of machine learning algorithms for superior pattern mapping is desired. The system logs in a network tend to include many parameters, and not all of them provide indications of an impending network threat. The selection of the right features is thus important for achieving better results. There is a need for accurate mapping of high dimension features to low dimension intermediate representations while retaining crucial information. In this paper, an approach for feature reduction and selection when working on the task of network threat detection is proposed. This approach modifies the traditional Principal Component Analysis (PCA) algorithm by working on its shortcomings and by minimizing the false detection rates. Specifically, work has been done upon the calculation of symmetric uncertainty and subsequent sorting of features. The performance of the proposed approach is evaluated on four standard-sized datasets that are collected using the Microsoft SYSMON real-time log collection tool. The proposed method is found to be better than the standard PCA and FAST methods for data reduction. The proposed approach makes a strong case as a dimensionality reduction and feature selection technique for minimizing false detection rates when operating on real-time data.
Sentiment Aware Stock Price Forecasting using an SA-RNN-LBL Learning Model
Authors: Gurav U. P. , Kotrappa S.
Published: November 2020

Stock market historical information is often utilized in technical analyses for identifying and evaluating patterns that could be utilized to achieve profits in trading. Although technical analysis utilizing various measures has been proven to be helpful for forecasting and predicting price trends, its utilization in formulating trading orders and rules in an automated system is complex due to the indeterminate nature of the rules. Moreover, it is hard to define a specific combination of technical measures that identify better trading rules and points, since stocks might be affected by different external factors. Thus, it is important to incorporate investors’ sentiments in forecasting operations, considering dynamically the varying stock behavior. This paper presents a sentiment aware stock forecasting model using a Log BiLinear (LBL) model for learning short term stock market sentiment patterns, and a Recurrent Neural Network (RNN) for learning long-term stock market sentiment patterns. The Sentiment Aware Stock Price Forecasting (SASPF) model achieves a much superior performance compared to standard deep learning based stock price forecasting models.
80 kW Updraft Gasifier Performance Test using Biomass Residue Waste from Thailand Rural Areas
Authors: Sookramoon K.
Published: November 2020

This research presents the combustion test of Kanchanaburi’s residue waste used in an 80kW updraft gasifier as biomass fuel. Three types of selected biomass were considered: corncob, bagasee, and straw. The 80kW updraft gasifier was designed, fabricated, and experimentally studied. In the gasifier, a variable speed centrifugal fan acted as a forced convection unit, which was installed near the combustion chamber and transferred air volume to the updraft gasifier stove. The experimental results show the temperature in each zone of the thermochemical processes. The gasifier was evaluated by comparing the performance of the 3 different biomass fuels. The average producer gas from the burning of corncob, bagasee, and straw was 2.31m3/kg, 2.15m3/kg, and 2.11m3/kg respectively in the updraft gasifier. The recorded stove running times (h) for were 1.24, 1.2 and 1.05, respectively. The producer gas can be used to run a local cooking stove kiln with at normal rated heat generation successfully.
The “Stick-Slip” Phenomenon During the Active Earth Pressure Failure of a Granular Soil of Analogical Material
Authors: Daoud S. M. , Meghachou M. , Abbad H. , Vacher P.
Published: November 2020

The aim of this paper is to highlight the "stick-slip" phenomenon in the mechanisms of failure related to active earth pressure of an analogical material simulating a granular medium.  For this, a two-dimensional small-scale model was used and a phenomenological analysis of these mechanisms was conducted employing measurements of the fields of deformations using the method of digital image correlation. It was noted that a fluctuation in the response of the material occurs during the equal increments of displacements imposed on the mobile wall. This incremental response of the medium during the failure process related to active earth pressure explains the  "stick-slip" phenomenon
Influence of BCH and LDPC Code Parameters on the BER Characteristic of Satellite DVB Channels
Authors: Jordanova L. , Laskov L. , Dobrev D.
Published: November 2020

This article presents the results of a study on the noise immunity of DVB channels when higher-order M-ary APSK modulation schemes and concatenated BCH-LDPC codes are used. Dependencies to determine the probability at the decoder output are given taking into consideration the BCH and LDPC code parameters and the error probability in the communication channel. The influence of the BCH packets length, the BCH code rate, the number of maximum iteration and the parameters of LDPC parity-check matrix on the code efficiency is analyzed. Research of the influence of the concatenated LDPC-BCH code parameters on the radio channel noise immunity is conducted and dependencies to determine the required CNR at the input of the satellite receiver are given.
Modeling a Small Punch Testing Device
Authors: Habibi S. , Ziadi A. , Megueni A.
Published: November 2020

A small punch test of a sample in miniature is implemented in order to estimate the ultimate load of CrMoV ductile steel. The objective of this study is to model the ultimate tensile strength and ultimate load indentation according to the geometrical parameters of the SPT using experimental data. A comparison of the model obtained with the two models (European code of practice and method of Norris and Parker) allows the design and dimensioning of an indentation device that meets the practical constraints. Implemented as a Matlab program, allows the investigation of new combinations of test variables.
Discharges Classification using Genetic Algorithms and Feature Selection Algorithms on Time and Frequency Domain Data Extracted from Leakage Current Measurements
Authors: Pylarinos D. , Theofilatos K. , Siderakis K. , Thalassinakis E.
Published: November 2020

A number of 387 discharge portraying waveforms recorded on 18 different 150 kV post insulators installed at two different Substations in Crete, Greece are considered in this paper. Twenty different features are extracted from each waveform and two feature selection algorithms (t-test and mRMR) are employed. Genetic algorithms are used to classify waveforms in two different classes related to the portrayed discharges. Five different data sets are employed (1. the original feature vector, 2. time domain features, 3. frequency domain features, 4. t-test selected features 5. mRMR selected features). Results are discussed and compared with previous classification implementations on this particular data group.
Numerical Simulation of Tire Reinforced Sand behind Retaining Wall Under Earthquake Excitation
Authors: Lazizi A. , Trouzine H. , Asroun A. , Belabdelouhab F.
Published: November 2020

This paper studies the numerical simulations of retaining walls supporting tire reinforced sand subjected to El Centro earthquake excitation using finite element analysis. For this, four cases are studied: cantilever retaining wall supporting sand under static and dynamical excitation, and cantilever retaining wall supporting waste tire reinforced sand under static and dynamical excitation. Analytical external stability analyses of the selected retaining wall show that, for all four cases, the factors of safety for base sliding and overturning are less than default minimum values. Numerical analyses show that there are no large differences between the case of wall supporting waste tire reinforced sand and the case of wall supporting sand for static loading. Under seismic excitation, the higher value of Von Mises stress for the case of retaining wall supporting waste tire reinforced sand is 3.46 times lower compared to the case of retaining wall supporting sand. The variation of horizontal displacement (U1) and vertical displacement (U2) near the retaining wall, with depth, are also presented.
Seismic Assessment of an RC Building Using Pushover Analysis
Authors: Hakim R. A. , Alama M. S. A. , Ashour S. A.
Published: November 2020

Current research works and observations indicated that parts of the Kingdom of Saudi Arabia have low to moderate seismic regions. Major parts of buildings were designed only for gravity load and were poorly detailed to accommodate lateral loads. This study aims to investigate building performance on resisting expected seismic loadings. Two 3D frames were investigated using pushover analysis according to ATC-40. One was designed according to a design practice that considers only the gravity load and the other frame was designed according to the Saudi Building Code (SBC-301). Results showed that the building designed considering only the gravity load was found inadequate. On the other hand, the building designed according to SBC-301 satisfies the Immediate Occupancy (IO) acceptance criteria according to ATC-40.
A Research on the Synchronization of Two Novel Chaotic Systems Based on a Nonlinear Active Control Algorithm
Authors: Ahmad I. , Saaban A. , Ibrahin A. , Shahzad M.
Published: November 2020

The problem of chaos synchronization is to design a coupling between two chaotic systems (master-slave/drive-response systems configuration) such that the chaotic time evaluation becomes ideal and the output of the slave (response) system asymptotically follows the output of the master (drive) system. This paper has addressed the chaos synchronization problem of two chaotic systems using the Nonlinear Control Techniques, based on Lyapunov stability theory. It has been shown that the proposed schemes have outstanding transient performances and that analytically as well as graphically, synchronization is asymptotically globally stable. Suitable feedback controllers are designed to stabilize the closed-loop system at the origin. All simulation results are carried out to corroborate the effectiveness of the proposed methodologies by using Mathematica 9.
Numerical Study of the Effect of the Penetration of a Crack in the Matrix of a Composite
Authors: Nehari T. , Ziadi A. , Ouinas D. , Boutabout B.
Published: November 2020

In this numerical investigation, the effect of the penetration of a crack in a matrix reinforced by aluminum silicon carbide particles in a composite is studied in order to determine the thermo-mechanical behavior under the effect of different temperature gradients during cooling. To realize this, the thermal residual stresses are calculated by considering a wide range of cracks of different penetrations. The results of this investigation compared to a case without geometric discontinuity, have revealed no meaningful effect of the distribution of the stresses along a main direction perpendicular to the direction of the crack. On the other hand, regarding the distribution of the stresses along the plane of the crack and in vicinity of the particle, results show that the penetration of the crack in the matrix causes an asymmetry.
Physical and Mechanical Properties of the Muds of the Fergoug Dam
Authors: Benaissa A. , Aloui Z. , Ghembaza M. S. , Trouzine H. , Sebaibi Y.
Published: November 2020

Volumes of dredged sediments are rather considerable and are estimated approximately 600 million m3 per year worldwide. These can represent a very interesting source of raw materials, in particular for a sector consuming aggregates such as civil engineering. The work presented in this article is interested particularly in the valorization of the muds which come from the dam of Fergoug (Algeria), with an aim of improving their mechanical behavior using binders (cement, lime) in order to use them in road engineering. To this end, we carried out a series of physical, chemical, mechanical and mineralogical analyses presented in this paper.
Statistical Magnitude Analysis and Distance Determination of the Nearby F8V Stars
Authors: Dwidar H. R. , Sharaf A.
Published: November 2020

The present paper is of three folds. First, to provide some basic descriptive statistics parameters for the apparent and absolute magnitudes of the nearby stars of spectral type F8V stars. Second, to establish the frequency functions and of the absolute and apparent magnitudes for these stars. Third, to compute the distance r of these stars as a system assuming that they scatter around a mean absolute magnitude in a Gaussian distribution. The accuracy of the numerical results is satisfactory thus, the percentage error between r and the mean value is less than 0 .7%.
Effect of Cement and Compaction on the Physicochemical Behavior of a Material in the Region of Sidi Bel Abbes
Authors: Ikhlef N. S. , Ghembaza M. S. , Dadouch M.
Published: November 2020

Soil treatment describes the procedure under which a soil acquires certain characteristics that did not originally have. This paper is focused in the field of road earthworks and the treatment of a material found in the region of Sidi Bel Abbes, Algeria. This material has poor characteristics that do not meet the standards used in road geotechnics. To remedy this, firstly, the Proctor Standard characteristics of this material were improved using mechanical treatment that increased the compaction energy. Then a chemical treatment was employed, adding some cement dosages, and results show that the material classified in the A1h class, for an increased maximum dry density and a reduction in water content. A comparative study is made on the optimal properties of the material between the two modes of treatment. On the other hand, after treatment, one finds a decrease in the plasticity index and the methylene blue value. This material exhibits a change of class. Therefore, soil class CL turned into a soil class CL-ML (silt of low plasticity). This observation allows the material to be used as backfill or subgrade.