bluuebunny/crossref_metadata_2025 huggingface dataset:
Fuzzy Sliding Mode Control of DC-DC Boost Converter
Authors: Duranay Z. B. , Guldemir H. , Tuncer S.
Published: November 2020

A sliding mode fuzzy control method which combines sliding mode and fuzzy logic control for DC-DC boost converter is designed to achieve robustness and better performance. A fuzzy sliding mode controller in which sliding surface whose reference is obtained from the output of the outer voltage loop is used to control the inductor current. A linear PI controller is used for the outer voltage loop. The control system is simulated using Matlab/Simulink. The simulation results are presented for input voltage and load variations. Simulated results are given to show the effectiveness of the control system.
Developing A New Dimension of an Applied Exponential Model: Application in Biological Sciences
Authors: Ahmad W. M. A. W. , Rohim R. A. A. , Norhayati Y. , Aleng N. A. , Ali Z.
Published: November 2020

Modeling of exponential growth or decay is a nonlinear regression technique. In the real world, the exponential growth is often used to model population growth while the exponential decay is often used to a model declining population or a decreasing size. In this study, we try to improve the performance of exponential growth by adding bootstrap and fuzzy techniques. This gives us the option to perform analysis even when there is not enough data. The aim of the current work is to develop a new dimension of an applied exponential analysis with improved results. The suggested method was tested and applied to biological data. The gathered data was compared by measuring the average width of the predicted interval using least squares method and fuzzy method. The result shows that the average width of the predicted interval using least squares method was 0.522 while using fuzzy method was 0.082. This indicated the superiority of the fuzzy regression methodology. Besides that, this paper provides the algorithm for the prediction of cell growth and inferences.
Flexural Stress-Strain Behavior of RC Beams made with Partial Replacement of Coarse Aggregates with Coarse Aggregates from Old Concrete: Part-2: Rich Mix
Authors: Oad M. , Buller A. H. , Memon B. A. , Memon N. A. , Sohu S.
Published: November 2020

Crowded city centers pose serious problems of infrastructure and associated facilities. Construction industry is obliged to opt for vertical construction in place of short height structures in order to meet with the needs. This leads to the generation of huge quantities of demolishing waste whose management is a serious issue. One of its best uses is its utilization in new concrete. Concrete is widely used in construction industry. Normally 1:2:4 mix is used, but the use of rich mix is also common in columns and elsewhere. Therefore, this research work focuses on evaluating the flexural stress-strain behavior of rich concrete mix beams made with 50% replacement of natural coarse aggregates with coarse aggregates from old concrete. A total of 12 reinforced concrete beams 1:1.5:3 ratio mix and 0.54 w/c ratio are prepared in two batches in 0.9mx0.15mx0.15m beams. In the first batch, natural coarse aggregates are replaced in 50% with coarse aggregates from demolished concrete and the second batch contains beams made with all-natural coarse aggregates. To reinforce the beams, 2#4 deformed bars are used in compression and tension zone along with #3 stirrups at 15cm c/c all along the length of the beam. In each batch, half of the beams are cured for 7 days and half for 28 days. After curing, all beams are tested for load, deflection, and strain in a universal load testing machine. All parameters are recorded at regular intervals and cracking and failure patterns are monitored. From obtained results, it is analyzed that the beams presented 11.68% reduction in flexural capacity. Cracking pattern and failure mode of the beams is similar to those of the control specimen.
Implementation of Building Information Modeling (BIM) in Pakistan Construction Industry
Authors: Bhatti I. A. , Abdullah A. H. , Nagapan S. , Bhatti N. B. , Sohu S. , Jhatial A. A.
Published: November 2020

This paper examines the implementation of building information modeling (BIM) in construction industry. Various initiatives and approaches are used in different countries to promote the BIM implementation in their construction industries. The real implementation and use of BIM remains a major concern of the construction industry. This study investigates the implantation of BIM globally, in developed countries and the percentage of implementation of BIM in constriction industry of Sindh, Pakistan. This research demonstrates 131 responses from BIM users regarding BIM implementation whose collaboration aspects produce the highest positive impact. The adopted methodology is an online questionnaire survey and literature review which was conducted to find out the implementation of BIM in construction industries of developed countries. This research reveals that BIM implementation is increasing continuously over the past few years. A Number of developed countries are emerging successful BIM implementation strategies, United States, United Kingdom, Germany, France are generally leading the way. However, according to our study findings, only 11% of industries have implemented BIM in Sindh, Pakistan.
Enhanced Model For Evaluating Information System Success: Determining Critical Criteria
Authors: Daghouri A. , Mansouri K. , Qbadou M.
Published: November 2020

The purpose of this study is to enhance the DeLone and McLean information system success by adding a SERVQUAL instrument to evaluate the service quality dimension. An integrated model for evaluating the information system has been proposed. One of the most popular multi criteria decision making techniques, namely AHP was used to determine the weights of each criterion and sub-criterion of the model in order to identify the most influential criterion on information system’s evaluation. System quality dimension has a strong influence on information system success (0.39) followed by information quality (0.22). The proposed model could be used to enhance information system performance evaluation.
Forecasting Parameter Estimates: A Modeling Approach Using Exponential and Linear Regression
Authors: Ahmad W. M. A. W. , Rohim R. A. A. , Ismail N. H.
Published: November 2020

This paper supplies a calculation method for the parameter estimates of an exponential equation through SAS algorithm. The aim of this paper is to investigate the efficiency of the gained parameter estimates through the forecasting performance. The proposed calculation method can provide a very useful technique to develop an exponential equation with better accuracy performance. This research paper illustrates a sample of the data obtained from the established study, which characterize the proliferative capacity of mesenchymal stem cells. This paper also provides the specific algorithm for the parameter estimates.
Impact of a Single Spoiler on Scouring Depth Status Beneath a River Crossing Inclined Pipeline
Authors: Abbasi S. , Masoomi M. , Arjmandi S. A.
Published: November 2020

Deep river crossing pipelines utilized to carry fluids are often placed upon the sand bed. Placement of pipe on the non-smooth bed would result in the production of some local gaps beneath the pipe. Asymmetric scouring is one of the main reasons for pipe underwater failures which are significant in pipeline management. So, in designing pipelines, knowing the interaction between pipelines and bed, and predicting the scour depth with respect to the pipe distance from the bed is significant to ensure that the pipe will finally deposit on the bed. Numerical models have been developed for predicting the balance depth of scouring beneath the pipelines. In this paper, the impact of pipe orientation on maximum scour depth beneath the pipelines is investigated. To do this, a pipe is modeled with various angles with the flow. To manage the local scouring, some spoilers are placed and modeled upon some pipes too. Also, in order to know the effects of placement of a pipe at various distances from the bed, the impact of placement of each pipe at a distance of 0.2D, 0.4D and 0.6D is investigated as well. To model the pipe with and without a spoiler, the finite element model Flow-3D is utilized and the results show good accordance with previous experimental studies and proof the current model’s precision in predicting the scour depth. Results show that in the placement of the pipe in angles not investigated before and also with the installing of a spoiler, the scour process has a reverse ratio with the distance which would result in full deposition of the pipe on the bed. The least scour depth belongs to the condition in which the pipe has a 130° angle with the side wall.
Analysis of Mapping Techniques for Mountain Precipitation: A Case Study of Alpine Region, Austria
Authors: Laghari A. N. , Walasai G. D. , Bangwar D. K. , Memon A. H. , Shaikh A. H.
Published: November 2020

Truly representative precipitation map generation of mountain regions is a difficult task. Due to poor gauge representativity, complex topography and uneven density factors make the generation of representative precipitation maps a very difficult task. To generate representative precipitation maps, this study focused on analyzing four different mapping techniques: ordinary kriging, spline technique (SP), inverse distance weighting (IDW) and regression kriging (RK). The generated maps are assessed through cross-validation statistics, spatial cross-consistency test and by water balance approach. The largest prediction error is produced by techniques missing information on co-variables. The ME and RMSE values show that IDW and SP are the most biased techniques. The RK technique produced the best model results with 1.38mm and 72.36mm ME and RMSE values respectively. The comparative analysis proves that RK model can produce reasonably accurate values at poorly gauged areas, where geographical information compensated the poor availability of local data.
Effects of Climate Change on Mountain Waters: A Case Study of European Alps
Authors: Laghari A. N. , Walasai G. D. , Jatoi A. R. , Bangwar D. K. , Shaikh A. H.
Published: November 2020

The Alps play a vital role in the water supply of the region through the rivers Danube, Rhine, Po and Rhone while they are crucial to the ecosystem. Over the past two centuries, we witnessed the temperature to increase by +2 degrees, which is approximately three times higher than the global average. Under this study, the Alps are analyzed using regional climatic models for possible projections in order to understand the climatic changes impact on the water cycle, particularly on runoff. The scenario is based on assumptions of future greenhouse gases emissions. The regional model results show the consistent warming trend in the last 30-year span: temperature in winter may increase by 3 to 4.5°C and summers by 4 to 5.5°C. The precipitation regime may also be altered: increasing about 10-50% in winter and decreasing about 30-60% in summer. The changes in the amount of precipitation are not uninformed. Differences are observed particularly between the North West and South East part of the Alps. Due to the projected changes in alpine rainfall and temperature patterns, the seasonality of alpine flow regime will also be altered: massive rise will occur in winter and a significant reduction in summer. The typical low flow period during winter will also be shifted to late summer and autumn.
Assessment of Climate Driven Changes in Flow Series of Alpine Basin: A Case Study of Danube River Basin
Authors: Laghari A. N. , Rajper A. , Walasai G. D. , Jatoi A. R. , Jalbani N. B. , Soomro H.
Published: November 2020

This study was carried out in order to analyze the climate change driven influence on mean monthly flow series of Danube River and its tributaries during the last century. The study confirms some signs of climate driven alterations in monthly river flow series along with change in flow seasonality during the last century. In spite of this, man-made interference in the basin like i.e. groundwater extraction, irrigation, river regulation, land use alteration and urbanization, has significantly changed Danube flow regime in most areas of the catchment. The analysis of Achleiten station demonstrates that average annual flow regime is a little bit increased. Major increase is observed in winter and autumn months and decrease in summer months. These seasonal alterations clearly signal a future glimpse of reduced water availability in alpine basins. This will mainly occur due to the change in the form of precipitation in winter, from snow to rain and the consequent less snow accumulation, and the early melt of snow storage, less precipitation and high evaporation rate in summer.
Crude Oil Importation and Exportation in Nigeria: An Exploratory and Comparative Study
Authors: Oguntunde P. E. , Ojo O. O. , Oguntunde O. A. , Okagbue H. I.
Published: November 2020

Nigeria is an oil producing country and crude oil is an important asset to its economy. This research focuses on the analysis of importation and exportation of crude oil products (measured in million barrels). Comparisons between the total importation and exportation were made and descriptive analysis was performed on the crude oil components. Poisson regression was used to establish the relationship between total importation and the importation of the petroleum products under consideration. The results show that Nigeria makes more importation than exportation of these products.
Numerical Study of Natural Convective Heat and Mass Transfer in an Inclined Porous Media
Authors: Latreche A. , Djezzar M.
Published: November 2020

In this study, two dimensional natural convection heat and mass transfer generated in an inclined rectangular porous cavity filled with Newtonian fluid has been investigated numerically. The cavity is heated and cooled along horizontal walls while the solutal gradient is imposed horizontally. The physical model for the momentum conservation equation makes use of the Darcy model, and the set of coupled equations is solved using a finite volume approach. The successive-under-relaxation (SUR) method is used in the solution of the stream function equation. The results are presented graphically in terms of streamlines, isotherms and iso-concentrations. The heat and mass transfer rate in the cavity is measured in terms of the average Nusselt and Sherwood numbers for various non-dimensional parameters.
Photovoltaic Systems and Net Metering in Greece
Authors: Mavromatakis F. , Viskadouros G. , Haritaki H. , Xanthos G.
Published: November 2020

The latest measure for the development of photovoltaics in Greece utilizes the net-metering scheme. Under this scheme the energy produced by a PV system may be either consumed by the local loads or be injected to the grid. The final cost reported in an electricity bill depends upon the energy produced by the PV system, the energy absorbed from the grid and the energy injected to the grid. Consequently, the actual electricity consumption profile is important to estimate the benefit from the use of this renewable energy source. The state latest statistics in Greece for households reveal that the typical electrical consumption is 3750 kWh while 10244 kWh are consumed in the form of thermal energy. We adopt in our calculations the above amount of electrical energy but assume four different scenarios. These different hourly profiles are examined to study the effects of synchronization upon the final cost of energy. The above scenarios are applied to areas in different climate zones in Greece (Heraklion, Athens and Thessaloniki) to examine the dependence of the hourly profiles and the solar potential upon the financial data with respect to internal rate of return, payback times, net present value and the levelized cost of energy. These parameters are affected by the initial system cost and the financial parameters.
Modeling for Development of Simulation Tool: Impact of TCSC on Apparent Impedance Seen by Distance Relay
Authors: Khoa N. M. , Tung D. D.
Published: November 2020

The impact of thyristor controlled series capacitor (TCSC) on distance protection relays in transmission lines is analyzed in this paper. Voltage and current data are measured and collected at the relay locations to calculate the apparent impedance seen by distance protection relays in the different operating modes of the TCSC connected to the line. Short-circuit faults which occur at different locations on the power transmission line are considered in order to locate the fault for the purpose of evaluating the impact of TCSC on the distance protection relay. Matlab/Simulink simulation software is used to model the power transmission line with two sources at the two ends. Voltage source, transmission line, TCSC, voltage and current measurement, and discrete Fourier transform (DFT) blocks are integrated into the model. Simulation results show the impact of TCSC on the distance protection relay and determine the apparent impedance and fault location in the line.
The Effect of Multipath on Single Frequency C/A Code Based GPS Positioning
Authors: Dammalage T. L.
Published: November 2020

The differential GPS (DGPS) technique is one of the most popular and comparatively accurate techniques available to enhance the positioning accuracy by minimizing most of the common errors. However, the ultimate accuracy of the user location depends on the remaining non-common errors (multipath, receiver clock, and noise), which occur at the points of observation and reference. Out of these errors, multipath is the most dominant and challenging error to predict and minimize. Single frequency C/A code based GPS receivers are popular due to their comparatively low cost compared to dual frequency (L1/L2) GPS receivers. This paper focuses on evaluating the effect of multipath error on single frequency C/A code based GPS positioning. For the analysis, 72,000 continuous GPS observations with one-second interval under four different multipath environments were conducted by utilizing three geodetic GPS units. Accordingly, the observations with more than 5cm on the 2D positional error, created by the effected multipath, were always less than 25%. Here, an average of 16% of observations exceeded 20cm in 2D positional error. Further, it was noted that the presence of multipath introduces significantly higher and comparatively lower 3D positional errors on DGPS observations. This could be due to the compensation of negative and positive effects caused by the multipath and other remaining non-common mode errors at the reference and user stations. In addition, C/A code based single frequency GPS observations were significantly influenced by multipath, not only by the close-by reflectors but also by the ground surface. The effect of multipath was about 50% of the total 3D positional error for the four tested multipath environments.
Realization of a Single-Phase Multilevel Inverter for Grid-Connected Photovoltaic System
Authors: Nouaiti A. , Mesbahi A. , Saad A. , Khafallah M. , Reddak M.
Published: November 2020

This paper introduces the implementation of a single-phase multilevel inverter for a grid-connected photovoltaic system. The considered topology contains a full bridge converter tied to an auxiliary circuit made of two power switches. A proportional integral (PI) current controller is established with this inverter to inject a sinusoidal current into the grid with a power factor near to unity. The studied system is tested on Matlab/Simulink and verified by experiment through a test bench comprising of a fabricated prototype and a DSP TMS320F28379D. The obtained results prove the efficiency of the inverter to maintain a direct power flow from DC sources, such as solar panels, to the grid by respecting some normalized criteria for this operation.
Techno-Economic Feasibility Study of Investigation of Renewable Energy System for Rural Electrification in South Algeria
Authors: Chermat F. , Khemliche M. , Badoud A. E. , Latreche S.
Published: November 2020

This work aims to consider the combination of different technologies regarding energy production and management with four possible configurations. We present an energy management algorithm to detect the best design and the best configuration from the combination of different sources. This combination allows us to produce the necessary electrical energy for supplying habitation without interruption. A comparative study is conducted among the different combinations on the basis of the cost of energy, diesel consumption, diesel price, capital cost, replacement cost, operation, and maintenance cost and greenhouse gas emission. Sensitivity analysis is also performed.
Numerical Analysis for the Oxidation of Phenol with TiO2 in Wastewater Photocatalytic Reactors
Authors: Maddah H. A.
Published: November 2020

Phenolic compounds in wastewater (even at low levels) are found to be quite toxic to humans due to their carcinogenic effects. Photocatalysis has been widely studied for the removal of phenol from industrial wastewater. In this study, photocatalytic oxidation of phenol, under UV irradiation in the presence of TiO2, has been numerically investigated. Phenol mass balance and forward finite difference method (explicit) along with various assumed/calculated parameters, from previous works, were used to numerically plot phenol concertation profiles in water with different initial phenol concentrations. Phenol compounds were observed to be totally oxidized at the bottom of the reactor and the maximum conversion rates occur near the reactor walls. It was found that higher irradiation times increase phenol oxidation rates due to higher water hydrolysis. Oxidation rate of phenol (consumption) increases with the increase in initial phenol concentration.
Growth Mode Study of MgCl2 on Ti (0001) and SiO2 under Ultra High Vacuum by XPS
Authors: Karakalos S.
Published: November 2020

The growth mode of MgCl2 on Ti (0001) and on SiO2 grown on Si (100) was investigated by X-ray Photoelectron Spectroscopy (XPS) under UHV conditions. Magnesium chloride grows on both Ti (0001) single crystal and SiO2 following the Frank-van der Merve, (FM) growth mode.
Explaining the d-q Magnetic Couplings Theoretically in Saturated Smooth Air-Gap AC Machines
Authors: Khlifi M. A.
Published: November 2020

The current paper discusses the theoretically detailed physical analysis of the effects of main flux saturation in smooth air gap AC machines. For that purpose, three sections are presented. The first one deals for presenting equivalence saturation-air gap. The second presents the equivalence of inductances between saturation induction machines and a dismounted salient pole synchronous machine. The method analyzes the leakage inductances that properly represent the corresponding leakage fluxes. The third section treats the physical interpretation of the cross-saturation. It is possible to show that the equations and physical picture in a saturated smooth-air-gap machine are similar to the equations and physical picture in a non-saturated salient-pole machine, where mutual coupling exists between the direct and quadrature axes and the self-inductances are also different on the non-salient part of the machine due to the variation of the reluctance with the rotor angle.
Performance Evaluation of Locally-Produced Waste Cooking Oil Biodiesel with Conventional Diesel Fuel
Authors: Khaskheli A. A. , Walasai G. D. , Jamali A. S. , Jamali Q. B. , Siyal Z. A. , Mengal A.
Published: November 2020

Increasing environmental concerns forced us to look for cheaper, reliable and secure sources of energy. Fossil fuels like oil, coal, and natural gas are having limited supplies and are depleting fast. Both energy security and environmental concerns have resulted in inclination towards renewable energy sources. Biodiesel does not contain petroleum, but it can be blended with petro-diesel in various mix levels. This research investigated biodiesel produced by the use of cheap waste cooking oil, collected from the local market of Nawabshah, Pakistan. The collected waste oil was converted into biodiesel by trans-esterification process at PCSIR Laboratory, Karachi. The fuel samples were tested in a diesel engine test bed unit at the Thermodynamics Laboratory of Quaid-e-Awam University. Biodiesel blends were compared with the conventional diesel fuel. The comparative analysis of the performance parameters concluded that brake specific fuel consumption of B30 (biodiesel 30%+diesel 70%) mix was 6.9% higher than that of 100% diesel. The brake thermal efficiency of B30 decreased about 4.75% in comparison with conventional diesel.
Non Excusable Delays in Construction Industry: A Causal Study
Authors: Khahro S. H. , Memon Z. A.
Published: November 2020

Delays are one of the major problems construction industry faces. Delays can lead to many negative effects such as arbitration between owners and contractors, increased cost, loss of productivity and revenue, and contract termination. Various studies have been carried out to highlight the general causes of delays and suggest possible remedial measures to minimize the effect of delays on a project. This study aims to highlight the critical factors with specific reference to non-excusable delays (NEDs) only. It also suggests possible remedial measures to minimize the effects of contractor-oriented NEDs which is a significant type of delays in the construction industry. A qualitative study has been conducted for this research. Data have been collected by the use of a set of questionnaires on numerous construction project stakeholders. Relative importance index (RII) has been used for prioritizing the factors. Results show that slow material mobilization, subcontractor unreliability and shortage of labor and materials are the most critical NED causes. This paper aims to provide a prerequisite knowledge to practitioners to make a more informed decision in managing NED.
A Simple Square Rooting Circuit Based on Operational Amplifiers (OPAMPs)
Authors: Selvam K. C. , Latha S.
Published: November 2020

A simple circuit which accepts a negative voltage as input and provides an output voltage equal to the square root of the input voltage is described in this paper. The square rooting operation is dependent only on the ratio of two resistors and a DC voltage. Hence, the required accuracy can be obtained by employing precision resistors and a stable reference voltage. The feasibility of the circuit is examined by testing the results on a proto type.
RSW Junctions of Advanced Automotive Sheet Steel by Using Different Electrode Pressures
Authors: Alzahougi A. , Elitas M. , Demir B.
Published: November 2020

Based on this study, the effects of the different types of welding currents and electrode pressures on the tensile shear properties of the resistance spot welding (RSW) which are the joints of the commercial DP600 sheet steel are now been investigated. In addition to the fact that the electrode pressure is not much of a popular piece or topic of discussion in the literature, the expression of the mechanical properties of these commercial materials (most importantly in the DP and in the high strength steels). These factors that are known to be affecting the strength of the material are dispute. In the tensile shear tests of this welded joints; the tensile shear force and the maximum displacement were utilized to characterize the performance of the welding processes. The nugget diameter has been measured to create a clear definition of the RSW physical properties. The experimental results show that the tensile shear load bearing capacity is bond to increase as the electrode pressure increases based on a value in both the welding currents and the decrease at the higher values. The low current value at low and at the highest electrode pressures; during the high current value which could be at the middle of the electrode pressure values it can exhibit the superior mechanical properties. The effect of this electrode pressure on the tensile shear load bearing capacity is bond to increase as the welding current increases as well. This, also been assessed and examined based on the low carbon content.
A Multi-Criteria Decision Making Approach for Enhancing University Accreditation Process
Authors: Benmoussa N. , Elyamami A. , Mansouri K. , Qbadou M. , Illoussamen E.
Published: November 2020

This paper is an attempt to provide an accreditation training process model by the criteria established by the National Agency for Evaluation and Quality Assurance of Higher Education and Training. The aim is to minimize rejection returns or revisions of the training record. The main feature of our contribution is the use of multi-criteria decision making (MCDM) approaches for calculating the suitability of proposed courses. Therefore, our contribution will is concretized by the analysis of various decision support multi-criteria methods, the modeling of the general accreditation process of university courses, the development of a risk management matrix concerning the launch of new courses and the application of TOPSIS (technique for order of preference by similarity to ideal solution) on a sample of courses according to internal and external criteria, collected during interviews in Moroccan universities. Result analysis shows that the proposed model allows a better prioritization of training and thus avoids the abrupt closure of courses because of lack of material or human resources.
Implementation of MPPT Algorithm and Supervision of Shading on Photovoltaic Module
Authors: Latreche S. , Badoud A. E. , Khemliche M.
Published: November 2020

This paper presents an implementation of MPPT (maximum power point tracking) algorithm based on real-time measurements and on model-based simulation. For the supervision of a photovoltaic module, different cases of shading are used. Attention was given on advanced control for the supervision of a photovoltaic system according to the need to maximize energy output. Experimental results verified the performance and the feasibility of the proposed system.
An Efficient Power Control Technique for High-Frequency Resonant Inverter in Induction Heating System
Authors: Kumar A. , Sarkar D. , Sadhu P. K.
Published: November 2020

An efficacious and reliable power control technique has been developed which can be used to regulate the output power of a high-frequency full bridge series resonant inverter (HF-FBSRI) in an induction heating (IH) system. In this paper, a modified buck-boost converter is presented to control the DC link/bus voltage which maintains the IH system under resonant mode and optimizes the performance of the IH system. Controlled DC link/bus voltage has been applied to this HF- FBSRI to control the average output power in the IH system. Using this aimed control technique, a wide range of output powers has been controlled and consistent performance of the IH system has been achieved. ZVS switching technique has been used to reduce the switching losses. Varying average power has been obtained at different duty cycles ranging from 0.2 to 0.8 with variable DC link voltage and it has been corroborated using PSIM environment for an IH system rated at 5500W.
Investigating the Success and the Advantages of Using ERP System in KSA Context
Authors: Abdel-Haq M. S. , Chatti H. , Asfoura E.
Published: November 2020

Enterprise resource planning (ERP) is an important innovation, affecting the business world by generating improvements both tangible and intangible in large companies and small and medium enterprises (SME). This study focuses on the determinants of success and the advantages of the adoption of this technology. To address these points, a comprehensive literature survey was carried out in order to formulate an original research model for ERP success evaluation and provide a prospect for IT infrastructure and integration. The model, thus suggested and taken within the Kingdom of Saudi Arabia (KSA) context, examines in a systematic approach the relation between the ERP acceptance determinants, the effects of the process of ERP systems diffusion, and the impacts expected on organizational performance. Obtained results underline two key determinants of ERP projects success: First, the preponderance of information control and the improvement in the use of competences. The second factor is the quality of team projects, the definition of team’s mission, training, business processes reengineering, user acceptance, top management support and the selection of the ERP solution.
Transient Stability Analysis of Photovoltaic System with Experimental Shading Effects
Authors: Saidi A. S. , Ben Slimene M. , Khlifi M. A.
Published: November 2020

This paper presents the transient stability analysis of a photovoltaic (PV) system with account shading effects. Voltage and transient stability effect of PV system are assessed functions of an experimental study. The current advances in shading effect and temperature control of PV panels are studied. The study is performed on modeling and simulation of PV system with account shading effect. A shading effect system is introduced to reflect the transient response characteristics of PV generation model. An experimental setup is designed, constructed and assembled. The setup is provided with the necessary measuring instruments to carry out the required tests. A perspective on the other shading techniques for PV panels will be discussed in this paper.
Required Separation to Mitigate Pounding of Adjacent Building Blocks
Authors: Masmoum M. S. , Alama M. S. A.
Published: November 2020

This research discusses the feasibility of using the required minimum separation distance based on SBC 301-2007. Moment resistance frames were designed with expansion joints requiring 400mm separation distance. Nonlinear response history analysis was conducted with four ground motions selected and scaled to match the risk-targeted response spectrum of NEOM city based on ASCE 7-16 provisions. An equivalent spring constant value based on floor lateral stiffness was selected as a gap link stiffness. Finally, an evaluation for the pounding response of adjacent blocks is presented along with the conclusions.
Climate Change and Eutrophication: A Short Review
Authors: Nazari Sharabian M. , Ahmad S. , Karakouzian M.
Published: November 2020

Water resources are vital not only for human beings but essentially all ecosystems. Human health is at risk if clean drinking water becomes contaminated. Water is also essential for agriculture, manufacturing, energy production and other diverse uses. Therefore, a changing climate and its potential effects put more pressure on water resources. Climate change may cause increased water demand as a result of rising temperatures and evaporation while decreasing water availability. On the other hand, extreme events as a result of climate change can increase surface runoff and flooding, deteriorating water quality as well. One effect is water eutrophication, which occurs when high concentrations of nutrients, such as nitrogen and phosphorus, are present in the water. Nutrients come from different sources including agriculture, wastewater, stormwater, and fossil fuel combustion. Algal blooms can cause many problems, such as deoxygenation and water toxicity, ultimately disrupting normal ecosystem functioning. In this paper, we investigate the potential impacts of climatic factors affecting water eutrophication, how these factors are projected to change in the future, and what their projected potential impacts will be.
Monitoring Leachate Migration in Compacted Soil Using Digital Image Technique
Authors: Yamusa Y. B. , Sa’ari R. , Ahmad K. , Alias N. , Mustaffar M. , Foong L. K.
Published: November 2020

As leachate has been a source of groundwater contamination worldwide, this paper examines the phenomenon of leachate migration on different gradations of compacted laterite soil used as sanitary landfill liners. Three different soil gradations (30%, 40% and 50% with respect to fines content) used in this study were compacted in circular acrylic columns to provide a clear visualization of leachate migration into the soils. Digital image technique was used in capturing photos at successive time intervals to monitor the leachate migration. The captured digital images were fed into Matlab and converted into hue-saturation-intensity (HSI) format. Surfer software then read the HSI and generated 2D contour plots. The results of the experiments showed that the leachate moves downward faster in the soil gradation with the least fines content. Hydraulic conductivity values decrease with increase in time duration and equally with increase in fines content. The hydraulic conductivities of the leachate for 30%, 40% and 50% fines were 3.64×10-9m/s, 2.40×10-9m/s, and 1.24×10-9m/s respectively. This reveals that for tropical laterite soils, gradation containing 50% fines content provides better hydraulic conductivity. The use of noninvasive digital image technique can enable designers/engineers to monitor and visualize the leachate migration in compacted soils in waste containment application systems.
Retaining of Frequency in Micro-grid with Wind Turbine and Diesel Generator
Authors: Chung P. D.
Published: November 2020

This paper aims to compare the performance of frequency regulation with two control modes of controller including power control scheme and rotor speed control scheme. The frequency control in this research is based on the frequency droop control method but fuzzy logic is used to define the frequency droop coefficient. To compare the performance of these control modes, a simulation of a micro-grid with the existence of a group of doubly fed induction generator wind turbine system and a diesel generator is fulfilled in Matlab/Simulink. Simulation results indicated that the frequency in the micro-grid with two control schemes always remains in the operation range. With the power control scheme, the frequency in the micro-grid is smoother than that with the rotor speed control. Additionally, DFIG wind turbine with the power control scheme has a better performance in terms of electrical energy when compared to the rotor speed control scheme, and hence the cost of fuel used by diesel is less costly.
Modeling and Validation of 2-DOF Rail Vehicle Model Based on Electro–Mechanical Analogy Theory Using Theoretical and Experimental Methods
Authors: Pehlivan F. , Mizrak C. , Esen I.
Published: November 2020

This paper presents theoretical and experimental results on modeling and simulation of two degrees of freedom rail vehicle by using electro-mechanical similarity theory. In this study, the equations of motion were derived using Newton’s second law of motion and then mechanical and equivalent electrical circuits were obtained with the help of a free body diagram. A schema in Simulink allowing analyzing of the behavior of the primary and secondary suspension was created. In order to verify the electrical model, transfer function and schema were developed in Simulink. The simulation results were compared with the experimental data and the comparison showed that the results of the mechanical experiments were close to the simulation results, but the electrical results showed better periodic behavior.
Cognitive Radio Spectrum Sensing Mechanisms in TV White Spaces: A Survey
Authors: Kimani K. , Njiraine M.
Published: November 2020

Frequency spectrum is a limited resource and the increasing demand caused by emerging services, augmented number of wireless users along with the demand for high-quality multimedia applications have resulted in the overcrowding of the allocated spectrum bands. The overcrowding of spectrum bands has exacerbated by the current spectrum licensing policy which has emerged as a bottleneck to efficient spectrum utilization, due to its inflexibility, resulting in most of the licensed spectrum being severely under-utilized. However, the problem of scarcity of spectrum bands and the inefficient utilization of the already allocated radio spectrum can be smartly addressed through spectrum sharing by enabling opportunistic usage of the underutilized frequency bands. One of the most exciting ways of spectrum sharing is cognitive radio technology which allows a wireless node to sense the environment, detect the network changes, and then make intelligent decisions by dynamically changing its reception or transmission parameters to communicate while ensuring that no interference is affected to the licensed users. It thus improves the spectrum utilization by reusing the unused or underutilized spectrum owned by the incumbent systems (primary systems). In this paper, a comprehensive survey and review of recent research about the advances in cognitive radio technology will be carried out. We will also evaluate the various spectrum sensing techniques in a cognitive radio network in the UHF/VHF bands allocated for TV broadcasting.
Causes of Time Overrun in Construction of Building Projects in Pakistan
Authors: Soomro F. A. , Memon M. J. , Chandio A. F. , Sohu S. , Soomro R.
Published: November 2020

Time overrun in construction projects is a very serious issue in developed countries. The main object of this research is to find the main causes of time overrun in the construction of building project and its possible mitigation measures. Quantitative approach was adopted in this research to achieve object and RIW (relative importance weight) approach was used for collecting data. Financial issues faced by the contractor, contractor’s inexperience, weather impacts, late delivery of material, mistakes in design, shortage of skilled labor, incompetent subcontractor and mistakes in time estimation were identified as main causes of time overrun in construction projects and possible mitigation measures were also proposed from experts. This research will help in giving awareness to stakeholders to narrow down the factors of time overrun in construction projects in Pakistan.
Analyzing the Dynamic Characteristics of Milling Tool Using Finite Element Method and Receptance Coupling Method
Authors: Hung J. P. , Lin W. Z. , Wu K. D. , Shih W. C.
Published: November 2020

This study aims to investigate the dynamic characteristics of a milling machine with different head stocks by using finite element (FE) method and receptance coupling analysis (RCA). For this purpose, five full finite element machine models, including vertical column, reformed head stock and feeding mechanism were created. With these models, the tool point frequency response functions were directly predicted. Another approach was the application of the receptance coupling method, in which the frequency response of the assembly milling tool was calculated from the receptance components of the individual substructures through the coupling operation with the interfaces of the feeding mechanism. Results show that a whole machine model with reformed stock has superior dynamic behavior when compared with the original design, by an increment of 10% in the dynamic stiffness. The receptance coupling method was verified to show an accurate prediction of the frequency response functions of the spindle tool when compared with the results obtained from the full FE models. Overall, the proposed methodology can help the designer to efficiently and accurately develop the machine tool structure with excellent mechanical performance.
Estimate Outcome Value of Doubling Cell Growth Using Fuzzy Regression Method
Authors: Ahmad W. M. A. W. , Rohim R. A. A. , Ismail N. H.
Published: November 2020

In this paper, the fundamental concepts used in different disciplines are described and these concepts are written into one common theme: assessing crossness agreement of observation. Focus was given on continuous measurements and methodological approaches for expressing these methods mathematically, both for cases with and without reference. The build method was tested and applied to biological sciences data. The objective of the study was to determine the agreement between the two methods on microorganism data sets in order to determine if they can be used interchangeably and to estimate the fuzzy and bootstrap parameters of the models. The value of interclass correlation (ICC) by using a linear equation is 0.79661 (substantial agreement) and the value of ICC using fuzzy regression equation is 0.82692 (almost perfect agreement).
Chirplet Transform in Ultrasonic Non-Destructive Testing and Structural Health Monitoring: A Review
Authors: Mohammed M. S. , Ki-Seong K.
Published: November 2020

Ultrasonic non-destructive testing signal can be decomposed into a set of chirplet signals, which makes the chirplet transform a fitting ultrasonic signal analysis and processing method. Moreover, compared to wavelet transform, short-time Fourier transform and Gabor transform, chirplet transform is a comprehensive signal approximation method, nevertheless, the former methods gained more popularity in the ultrasonic signal processing research. In this paper, the principles of the chirplet transform are explained with a simplified presentation and the studies that used the transform in ultrasonic non-destructive testing and in structural health monitoring are reviewed to expose the existing applications and motivate the research in the potential ones.
Appraisal of Climatic Conditions for Potential Solar Energy Applications in Nawabshah and Quetta Cities
Authors: Jakhrani A. Q. , Jatoi A. R. , Jakhrani M. M. , Laghari A. N. , Kamboh S. A.
Published: November 2020

This study was conducted to appraise climatic conditions for potential applications of solar energy units in Nawabshah and Quetta cities. For that, twenty two annual monthly average data of insolation on horizontal surface, at various slopes on titled surface, air temperature, earth skin temperature was acquired and evaluated through the Statistical Package for the Social Sciences software. It is discovered from the study that Quetta is a more promising place for installation of solar energy applications as compared to Nawabshah as it receives more solar radiations and less air temperature.
Circuit Design for Thermal Compensation of Avalanche Photodiode
Authors: Chughtai M. T.
Published: November 2020

It has been observed that the breakdown voltage of the avalanche photodiode (APD) changes with the change in the ambient temperature. This situation may result in a poorer signal to noise ratio and sometimes to permanent damage to the APD. In order to overcome these problems, various considerations may be taken into account, including maintaining the temperature of the APD permanently or the design of a bias system, which would be self-adjusting according to any changes in the temperature. The latter technique was adopted and the design of a bias supply is presented in this article.
A Reflectance Model for Relatively Clear and Turbid Waters
Authors: Tiwari S. P. , Shanmugam P. , Ahn Y. H. , Ryu J. H.
Published: November 2020

Accurate modeling of spectral remote sensing reflectance (Rrs) is of great interest for ocean colour studies in highly turbid and relatively clear waters. In this work a semianalytical model that simulates the spectral curves of remote sensing reflectance of these waters is developed based on the inherent optical properties (IOPs) and f and Q factors. For accommodating differences in the optical properties of the water and accounting for their directional variations, IOPs and f and Q  factors are derived as a function of phytoplankton pigments, suspended sediments and solar zenith angle. Results of this model are compared with in-situ bio-optical data collected at 83 stations encompassing highly turbid/relatively cleared waters of the South Sea of Korea. Measured and modeled remote sensing reflectances agree favorably in both magnitude and spectral shape, with considerably low errors (mean relative error MRE -0.0327; root mean square error RMSE 0.205, bias -0.0727 and slope 1.15 and correlation coefficient R2 0.74). These results suggest that the new model has the ability to reproduce measured reflectance values and has potentially profound implications for remote sensing of complex waters in this region.