bluuebunny/crossref_metadata_2025 huggingface dataset:
Stochastic Sizing of Energy Storage Systems for Wind Integration
Authors: Le D. D. , Nguyen N. T. A.
Published: November 2020

In this paper, we present an optimal capacity decision model for energy storage systems (ESSs) in combined operation with wind energy in power systems. We use a two-stage stochastic programming approach to take into account both wind and load uncertainties. The planning problem is formulated as an AC optimal power flow (OPF) model with the objective of minimizing ESS installation cost and system operation cost. Stochastic wind and load inputs for the model are generated from historical data using clustering technique. The model is tested on the IEEE 39-bus system.
Effect Evaluation of Fault Resistance on the Operating Behavior of a Distance Relay
Authors: Le K. H. , Vu P. H.
Published: November 2020

This paper presents an application of a certain distance protection relay with a quadrilateral characteristic approach for the protection of the 110kV Duy Xuyen - Thang Binh transmission line in Vietnam using measured data from one terminal line. We propose the building process of a Matlab Simulink model for this relay that combines fault detection and classification block, apparent impedance calculation block for all types of faults and a trip logic block of three zone protection coordination. The proposed relay model is further tested using various fault scenarios on the transmission line. It is important to assess what happened, the actual conditions, the causes of mal-operation etc. Detailed explanation and results indicate that the proposed model behavior will help users to perform tests which correctly simulate real-world conditions besides that it properly interprets test results and troubleshoot distance function problems when results are not as expected.
Interface Microstructure Investigation of Babbitt-Carbon Steel Composite Using Flux with Glycerol and Petroleum Jelly Additives
Authors: Fathy N.
Published: November 2020

The influence of adding glycerol and petroleum jelly during the tinning process of steel shell base of Babbitt-steel bimetal is studied in this paper. The morphology of interface layer is changed from a discontinuous layer in case of using flux+tin to a continuous one by adding glycerol or petroleum jelly to the flux+tin mixture. Also, the nterface layer thickness and the unbonded interface layer area increase by adding glycerol or petroleum jelly to flux+tin mixture due to their physical properties.
Achieving Optimal Degrees of Freedom for an Interference Network with General Message Demand
Authors: Samadi Z. , Vakili V. T. , Haddadi F.
Published: November 2020

The concept of degrees of freedom (DoF) has been adopted to resolve the difficulty of studying the multi-user wireless network capacity regions. Interference alignment (IA) is an important technique developed recently for quantifying the DoF of such networks. In the present study, a single-hop interference network with K transmitters and N receivers is taken into account. Each transmitter emits an independent message and each receiver requests an arbitrary subset of the messages. Using the linear IA techniques, the optimal DoF assignment has been analyzed. Assuming generic channel coefficients, it has been shown that the perfect IA cannot be achieved for a broad class of interference networks. Analytical evaluation of DoF feasibility for general interference channels (IFCs) is complicated and not available yet. Iterative algorithm designed to minimize the leakage interference at each receiver is extended to work with general IFCs. This algorithm provides numerical insights into the feasibility of IA, which is not yet available in theory.
Energy Conversion Loops for Flux-Switching PM Machine Analysis
Authors: Ilhan E. , Motoasca T. E. , Paulides J. J. H. , Lomonova E. A.
Published: November 2020

Induction and synchronous machines have traditionally been the first choice of automotive manufacturers for electric/hybrid vehicles. However, these conventional machines are not able anymore to meet the increasing demands for a higher energy density due to space limitation in cars. Flux-switching PM (FSPM) machines with their high energy density are very suitable to answer this demand. In this paper, the energy conversion loop technique is implemented on FSPM for the first time. The energy conversion technique is a powerful tool for the visualization of machine characteristics, both linear and nonlinear. Further, the technique provides insight into the torque production mechanism. A stepwise explanation is given on how to create these loops for FSPM along with the machine operation.
Statistical Modeling via Bootstrapping and Weighted Techniques Based on Variances
Authors: Ahmad W. M. A. W. , Aleng N. A. , Ali Z. , Ibrahim M. S. M.
Published: November 2020

Multiple logistic regression is a methodology of handling dependent variables with a binary outcome. This method is becoming increasingly widespread as a statistical technique that represents a discrete probability model. Many studies have focused on the application but less on the methodology building. This study aims to provide an applied method for multiple logistic regression which is called modified Bayesian logistic regression modeling as an alternative technique for logistic regression analysis that focuses on a combination of the bootstrap method using SAS macro and weighted techniques based on variances using SAS algorithm. Data on oral cancer were applied to illustrate a real scenario of oral health data. This data will be applied to the multiple logistic regression algorithm and modified Bayesian logistic regression. Results from both cases are strongly supported by clinical studies. Through the proposed algorithm, the researcher will have an option whether to analyze the data with the usual or an alternative method. Final results indicate that the modified procedure can provide more efficient results especially for the case which involves statistical inferences.
Health and Safety Issues of Industry Workmen
Authors: Siddiqui F. , Akhund M. A. , Memon A. H. , Khoso A. R. , Imad H. U.
Published: November 2020

Flour milling is considered the oldest trade industry, initiated at least 6000 years ago. Like every other industry, numerous problems arise during functioning and maintenance operations. The production process involves the breakdown of grains to separate their outer covering and inner endosperm grinding to fine flour particles. Workers serving in the industry have been in an environment exposed to flour dust. After conducting several interviews and a questionnaire survey to the workers and sales managers of flour mills within Hyderabad in Pakistan, the workforce was found to be suffering from sensitization, occupational asthma, allergic rhinitis, obstructive lung diseases and eye infection. The core reason was the inhaled and swallowed flour dust. The majority of the respondents highlighted improper flour milling process including intake and final product collection systems as the main causes of these health problems. The other part of the research work revealed that the majority of safety issues emerged due to the unavailability, the failure to use and the unawareness of personal protective equipment. Regarding the suggestions received during the survey from respective stakeholders, the health and safety issues can be controlled by improving feeding and collection systems and by wearing personal protective equipment.
Outlining an Intelligent Tutoring System for a University Cooperation Information System
Authors: Laaziri M. , Khoulji S. , Benmoussa K. , Larbi K. M.
Published: November 2020

International opening of universities and research institutions is essential in the development of their research and innovation activities. Abdelmalek Essaadi University (AEU) attaches crucial importance to partnership and international cooperation, and actively participates in national and international cooperation and exchange programs. In order to manage the monitoring and evaluation of its cooperation activities as it evolves, the University has set up a system of information on the governance of university cooperation for proper management and managing better partnerships. When setting up a new information system, end-user training in this new management tool is a very important part of this process. For this reason, the University has adopted the idea of developing an intelligent tutoring system. This system will be based on the Moodle platform and will be fully automated and adaptable to the needs of each learner. This article presents the basic design of the intelligent tutoring system incorporated in the management information system of university cooperation SIMACoop of our university and shows the feasibility of the intelligent tutoring system around an information system.
Study of Physicochemical Properties of Commercial Drinking Bottled Water Brands
Authors: Jatoi A. R. , Jakhrani A. Q. , Mukwana K. C. , Laghari A. N. , Tunio M. M.
Published: November 2020

Drinking water quality is being affected by industrial effluents, pesticides and fertilizers, poor sanitation services and unhygienic practices. Thus, upper and middle-class people used to prefer bottled water for drinking instead of tap water. Increasing demand for bottled water leads to the presence of low quality branded waters in the market due to the high demand and improper quality checks. In this regard, this study is carried out to assess the physicochemical properties of various branded bottled waters. For that, ten different water brand samples, coded from S1 to S10, were collected from Safoora Goth, Karachi. Various physicochemical quality parameters of branded water samples were analyzed according to the set procedures of American Society for Testing and Materials. It was discovered that the pH levels of S9 and S8 bottled water brands were slightly less than World Health Organization guideline values. The physical and chemical quality parameters of S1, S2, S4, S5, S7, and S10 branded bottled water samples were found within standards.
Frequency Locked Loop Based on the Time Nonrecursive Processing
Authors: Perisic D. M. , Petrovic V. , Kovacevic B.
Published: November 2020

This paper describes one new approach to frequency locked loop (FLL), which is based on the time non-recursive processing of input periods. System parameters are defined by the ratio of frequencies. The conditions, under which the described system can have the properties of a FLL, are analyzed. All math analyses were made by the use of Z transform approach. It was shown that FLL is extremely fast and that it is suitable for usage in different predicting, tracking and modulation applications, for the measurements of frequency and for other applications. The FLL realization in the technique of standard integrated circuits is described. The oscilloscope picture, made on the realized 8 bit model, is presented. Analysis in frequency domain was made using Matlab tools.
Nonuniform C-Band Loop Antenna: A New Approach for Future UWB Applications
Authors: Shastri S. P. R. , Singh R. R. , Ajetrao K. V.
Published: November 2020

Antenna design becomes very difficult at very small wavelengths and a special lab is required to manufacture a small antenna which costs a lot. A new approach is proposed to enhance the bandwidth of the loop antenna which can be designed at very high frequency using conventional PCB design. The proposed antenna is a nonuniform loop and covers UWB frequency range. The nonuniform structure of the loop is designed using the concept of both thin and thick loop antenna together which leads to an improvement in the antenna bandwidth. The proposed nonuniform loop antenna covers a band of 91.4% which is higher than any existing printed loop antenna. The frequency ranges from 3.54GHz to 9.5GHz and the measured result is in agreement with the simulated result. This technique can be very helpful in designing UWB antennas in the range of Ku or higher than this.
Comparative Closed Vessel Firing-Ballistic Parameters Evaluation for Development of Base Bleed Composite Solid Propellant
Authors: Mukhtar A. , Nasir H.
Published: November 2020

Closed vessel test (CVT) is widely used for the measurement and comparison of ballistic and energetic properties of propellants by the ignition of a specific sample mass in a closed high-pressure vessel. In our research, comparative CVTs were performed in a vessel, where an internationally accepted composite propellant base bleed grain sample served as a reference (Ref) for recording the standard values of the under investigation propellant composition, in relation to which newly developed samples were characterized. These comparative CVT experiments were performed under chamber volume of 100cm3, sample mass of 10g for all samples and identical ignition system having 1.5g igniter bag of gunpowder. We used closed vessel with working pressure limit of 5000 bars for recording the ballistic parameters of various composite solid propellant samples with reference to a standard sample. It was found that the Ref sample at 50% propellant loading recorded mean maximum pressure (Pm) of 1040 bars in complete combustion time (tPm) of 120ms and vivacity of 0.038 (1/bar∙s). The measured mean Pm was taken as relative force (%) and measured mean vivacity was taken as relative vivacity (%). This data has been used to tune and study the ballistic parameters to develop Ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB) based composite solid propellant (CSP) base bleed grain for artillery projectile.
Effect of Improper Curing on the Properties of Normal Strength Concrete
Authors: Memon R. P. , Sam A. R. M. , Awang A. Z. , Memon U. I.
Published: November 2020

In real applications, 28 days are regarded as proper curing time for concrete. There is a self-evident need to minimize the duration of curing days. For this purpose, this research investigates 1 to 7 days of curing and compares it with concrete cured for 28 days. Three grades of normal concrete strength grade 30, grade 35 and grade 40 were made. After curing, two exposure conditions were applied to the concrete, inside laboratory-controlled environment and outside environment. Results indicate that slump increases with cement content in DOE method at constant water content. The concrete density in all grades reduces when the concrete is subject to inside exposure in comparison with outside exposure. Water loss from concrete reduces with increase in curing days in all concrete grades. Compression strength of all concrete grades increases with increase in curing days. For the uniformity of concrete, ultrasonic pulse velocity indicated that with an increase in curing days, concrete becomes denser and a bit void. Results showed that an increase in curing days also improves the surface quality of concrete. The significance point noticed is that there was not much difference in the concrete properties between 7 days of curing and 28 days of curing in all grades.
A Circuit for the Square Root of the Sum of Two Squared Voltages using an IC LM311 Open Collector Comparator
Authors: Selvam K. C.
Published: November 2020

A circuit which accepts two input dc voltages V1 and V2 and provides an output dc voltage VO equal to the square root of the sum of the two squared voltages of V1 and V2, using an LM311 open collector comparator based single quadrant time division multiplier is described in this paper.
FDREnet: Face Detection and Recognition Pipeline
Authors: Virmani D. , Girdhar P. , Jain P. , Bamdev P.
Published: November 2020

Face detection and recognition are being studied extensively for their vast applications in security, biometrics, healthcare, and marketing. As a step towards presenting an almost accurate solution to the problem in hand, this paper proposes a face detection and face recognition pipeline - face detection and recognition embedNet (FDREnet). The proposed FDREnet involves face detection through histogram of oriented gradients and uses Siamese technique and contrastive loss to train a deep learning architecture (EmbedNet). The approach allows the EmbedNet to learn how to distinguish facial features apart from recognizing them. This flexibility in learning due to contrastive loss accounts for better accuracy than using traditional deep learning losses. The dataset’s embeddings produced from the trained FDREnet result accuracy of 98.03%, 99.57% and 99.39% for face94, face95, and face96 datasets respectively through SVM clustering. Accuracy of 97.83%, 99.57%, and 99.39% was observed for face94, face95, and face96 datasets respectively through KNN clustering.
Model and Reduction of Inactive Times in a Maintenance Workshop Following a Diagnostic Error
Authors: Meva'a L. , Danwe R. , Beda T.
Published: November 2020

The majority of maintenance workshops in manufacturing factories are hierarchical. This arrangement permits quick response in advent of a breakdown. Reaction of the maintenance workshop is done by evaluating the characteristics of the breakdown. In effect, a diagnostic error at a given level of the process of decision making delays the restoration of normal operating state. The consequences are not just financial loses, but loss in customers’ satisfaction as well. The goal of this paper is to model the inactive time of a maintenance workshop in case that an unpredicted catalectic breakdown has occurred and a diagnostic error has also occurred at a certain level of decision-making, during the treatment process of the breakdown. We show that the expression for the inactive times obtained, is depended only on the characteristics of the workshop. Next, we propose a method to reduce the inactive times.
Influence of Temperature on Energetic and Rheological Characteristics of PLANTOHYD Bio Lubricants – a Study in the Laboratory
Authors: Kardjilova K. , Vozarova V. , Valah M.
Published: November 2020

This article presents the results of measuring the calorific value and the rheological characteristics of Plantohyd bio lubricants. Measurements were conducted under laboratory conditions with an IKA C5000 calorimeter and a DV-3P Anton Paar digital viscometer. Results are presented graphically. It is shown that the physical interpretation of energy values results ​​and the dependence of rheological properties on temperature can be used to assess the quality of lubricants.
Sanitary Landfill Siting Using GIS and AHP: A Case Study in Johor Bahru, Malaysia
Authors: Mohammed H. I. , Majid Z. , Yamusa Y. B. , Mohd Ariff M. F. , Idris K. M. , Darwin N.
Published: November 2020

One of the major problems affecting municipalities is solid waste management. There is a difficulty in selecting suitable sites for waste disposal as it involves different factors to be considered before site selection. Currently, waste generation in Johor Bahru has steadily increased over the last few years and the only existing sanitary landfill is reaching its capacity limits, which means that a new sanitary landfill site needs to be constructed. In this study, geographic information system (GIS) and analytical hierarchy process (AHP) methods were utilized with the integration of dynamic data such as future population and projection of waste production in order to provide suitable sites for the construction of a sanitary landfill in the study area. Thirteen criteria were considered for this study, namely water bodies, soil, geology, slope, elevation, residential areas, archeological sites, airports, population, road, railway, infrastructure, and land use. AHP was used to determine the weights for each criterion from the pairwise comparison matrix. Consistency index and consistency ratio were checked and confirmed to be suitable. The results obtained from AHP were assigned to each criterion in GIS environment using weighted overlay analysis tool. The final potential site map was produced, and the three most suitable potential landfill sites were identified.
Isolation of Crude Oil from Polluted Waters Using Biosurfactants Pseudomonas Bacteria: Assessment of Bacteria Concentration Effects
Authors: Khalifeh A. , Roozbehani B. , Moradi A. M. , Imani Moqadam S. , Mirdrikvand M.
Published: November 2020

Biological decomposition techniques and isolation of environmental pollutions using biosurfactants bacteria are effective methods of environmental protection. Surfactants are amphiphilic compounds that are produced by local microorganisms and are able to reduce the surface and the stresses between surfaces. As a result, they will increase solubility, biological activity, and environmental decomposition of organic compounds. This study analyzes the effects of biosurfactants on crude oil recovery and its isolation using pseudomonas sea bacteria species. Preparation of biosurfactants was done in glass flasks and laboratory conditions. Experiments were carried out to obtain the best concentration of biosurfactants for isolating oil from water and destroying oil-in-water or water-in-oil emulsions in two pH ranges and four saline solutions of different concentrations. The most effective results were gained when a concentration of 0.1% biosurfactants was applied.
Effects of Brick and Aerated Concrete Infill Walls on Buildings
Authors: Bilir Ozhan H. , Beklen C. , Cagatay I. H.
Published: November 2020

It has already been proved that infill walls have great impact on the behavior of the frame systems, especially under earthquake-like lateral loads. Infill walls are generally considered as partition members between spaces in concrete frame systems. They are generally included into calculations as dead loads exerted on beams, but they have various impacts on the behavior of frame-wall systems. Therefore, the well-known behavior of infill walls will have positive contributions. In the present study, a 10-story building was modeled with brick and aerated concrete infill walls. Window and door spaces were taken into consideration. Infill walls were modeled with the equivalent compression strut method. Changes in building rigidity, period, lateral displacement, base shear force and building behavior were investigated with relevant analyses.
A Study on the Effects of Cellular Mobile Networks on People in Tikrit City Based on Power Density Measurements and Calculations
Authors: Salih A. A. , Saeed A. T. , Saber Z. R.
Published: November 2020

In this paper, the emitted electromagnetic waves (EMW) from different cellular mobile base stations (BSs) have been measured and calculated in order to study their effects on public health. Moreover, a comparison between the effect of radiated power from the BSs on people who live near them and those who live away has been made by using OpenSignal software and calculated theoretically. The values of power density for different cells were also calculated to compare them with the maximum permissible exposure limit-the acceptable range values of power density. The measurements were done in Tikrit City considering ten cells and various locations and distances. The results show that most of the power density and EMV for the tested cells are within the acceptable range. However, power density and EMV for two of tested cells have hurtful effects in the long term for people who live near the BSs.
An Unified Framework for Measuring E-Service Quality
Authors: Alanezi M. A. , Sellami A.
Published: November 2020

Companies continually seek efficiency by utilizing the rapid advances in technology to improve their electronic services (e-services). A perusal of the literature shows varying approaches for measuring e-service quality; these approaches have found little consent among reviewers. Therefore, this study attempts to provide a new framework, a roadmap, as a useful model for researchers to measure user perception of e-service quality. For this model, an extensive study is carried and these study findings indicate that system functionality, procedure, content, user support, and manageability should be included in an empirical research model for measuring e-service quality.
Compact Hexagonal Monopole Antenna for Lower 5G Bands
Authors: Alsaif H.
Published: November 2020

This paper presents a compact planar antenna with extreme wide band. The antenna is designed to cover the entire lower 5th generation operating bands ranging from 2.32GHz to more than 12GHz. This band also covers the IEEE 802.11 a/b/g/n/ac. The patch geometry has been simulated using an industrial standard simulation software called CST MWS. The monopole is miniaturized with a total size of 23x24x1.2mm3. The radiator and the ground plane are printed on a substrate of Rogers Duriod RT 5880 with relative permittivity of 2.2 and loss tangent of 0.00009. The simulated reflection coefficient and radiation pattern results are presented. S11 parameter for the designed antenna is less that -10dB over the operating band, with lowest value of -32.5dB at 2.85GHz. The radiation pattern is presented at the two orthogonal planes, elevation (E plane) and azimuth (H plane). Simulated results show that the antenna is appropriate of lower 5G bands application and several other wireless systems.
Particle Crushing Effect on The Geotechnical Properties of Soil
Authors: Rind T. A. , Karira H. , Jhatial A. A. , Sohu S. , Sandhu A. R.
Published: November 2020

Foundations are considered as the backbone of a structure. Most of the times, the foundation is laid on the soil. For the foundation design of any structure, we need to know beforehand the soil conditions such as shear strength and permeability. These parameters help us determine the bearing capacity of the soil. The soil conditions are determined by performing various laboratory tests such as shear box test or tri-axial shear test. However, we cannot design the foundation considering these data as the ground conditions will change once the loads are applied to the soil as there are some soil particles with angularity or sharp edges will break. Once they will break, soil conditions will not remain the same as they were before since the gradation will change. This work is carried out in order to know the impact soil breakage brings to the soil (granular soil). For this purpose, actual ground conditions were simulated in the laboratory by applying one-dimensional compression to soil particles for about 45 minutes in a Universal Testing Machine (UTM). Different crushing loads to soil particles were applied and the change in the soil behavior was monitored. It was found that due to particle breakage of soil, the engineering properties of sand altered. This research work aims to analyze the effect of particle breakage only in the case of sand.
A Global Variational Filter for Restoring Noised Images with Gamma Multiplicative Noise
Authors: Diffellah N. , Baarir Z. E. , Derraz F. , Taleb-Ahmed A.
Published: November 2020

In this paper, we focus on a globally variational method to restore noisy images corrupted by multiplicative gamma noise. Our problem is assumed as a regularization problem in total variation (TV) framework with data fitting term which is deduced by maximizing the a-posteriori probability density (MAP estimation). We need to evaluate the proximal operator of a data fitting term then we numerically adapt the Douglas-Rachford (DR) splitting method to solve the problem. Our experiments use real images with different levels of noise. To validate the effectiveness of the proposed method, we compare the proposed method with other variational models. Our method shows effective suppression of noise, excellent edge preservation, and the measures of image quality such as PSNR (peak signal-to-noise ratio), VSNR (visual signal-to-noise ratio) and SSIM (structural similarity index) explain the proposed model΄s good performance.
Simulation of a Steel Wire Straightening Taking into Account Nonlinear Hardening of Material
Authors: Khromov I. , Kawalla R.
Published: November 2020

Straightening is used to ensure the straightness of a rod workpiece as well as to redistribute or reduce the residual stresses in a finished product. The accuracy of modeling the operation of this kind plays an important role when manufacturing high quality ropes and cables of a small diameter. The physical model of alternating wire bending in a straightener has been considered in the paper. Computer methodology has been developed to calculate deflected mode and internal bending moment in a cross section of a wire at the different stages of deformation, which allowed taking into account nonlinear hardening of the material.
Design of Two Optimized Controllers of a Hydraulic Actuator Semi-Active Suspension: A Comparison Study
Authors: Babesse S.
Published: November 2020

A parallel optimization of Proportional, Integral and Derivative (PID) controller and a sixth order phase lead-lag compensator of a high order naturally oscillatory hydraulic actuator are proposed in this paper. The PID controller parameters (proportional, integral and derivative) and the compensator parameters (gain, poles and zeros) are obtained by minimizing the Integral of Time Absolute Error (ITAE) criterion. The proposed methods are demonstrated through a realistic numerical synthesis example of a hydraulic actuator dedicated to a semi-active suspension modeled by an eighth order transfer function. A simulation comparison is investigated for both controllers to compare their performances.
Vibrating Reed Study of Superconducting Cuprates Fabricated by Superfast Melt Quenching in a Solar Furnace
Authors: Chigvinadze J. , Tavkhelidze V. , Mamniashvili G. , Donadze G. , Acrivos J. V. , Gulamova D.
Published: November 2020

In this study, the potential possibilities of the precision of the vibrating reed method for the evaluation of the Тс of superconducting precursors in an HTSC Bi-Pb-Sr-Cu-O system were investigated. A special technology for obtaining these samples by using solar energy for melting and following superfast melt quenching was applied to increase their internal inhomogeneity, allowing to receive high-quality textural ceramic samples of Bi1,7Pb0,3Sr2Can-1CunOy (n=2-30) showing critical temperatures of superconducting precursor transitions above bulk Тс. To determine critical temperatures of superconducting precursors above bulk Тс for the first time, the original vibrating reed method of studying these multiphase samples in an applied magnetic field was used. It was shown that this method has sensitivity to superconducting diamagnetism making possible to reveal new superconducting precursor phases above bulk Tc.
Enhancing Power Quality in PV-SOFC Microgrids Using Improved Particle Swarm Optimization
Authors: Prabhakaran V. V. , Singh A.
Published: November 2020

The concept of hybrid microgrid (MG) has attracted tremendous attention in modern electricity markets, owing to the enhanced efficiency and reliability it offers to the main electricity grid. Numerous meritorious aspects associated with hybrid MGs are the key features of future large scale renewable technologies. In this paper, a hybrid MG using PV-SOFC (PhotoVoltaic – Solid Oxide Fuel Cell) is connected to an infinite bus bar, in order to achieve an autonomous working mode. The dynamic and steady-state operation with control strategies for both PV and SOFC power systems are analyzed. The objective is to control the voltage and frequency of the MG when it is not connected to the main grid. Typically, an efficient control strategy must assess the power conversion system and its state, in the isolated MG. Moreover, it must reliably handle variant and intermittent type of loads. With this viewpoint, we propose a Voltage Source Inverter (VSI) based Proportional Integral (PI) controller, optimized by Improved Particle Swarm Optimization (IPSO) for the purpose of smooth power flow control improving power quality. The performance of PI-IPSO and PI technologies are evaluated, for the proposed MG, in MATLAB/Simulink. The results obtained verify the effectiveness of the modified PSO algorithm, in comparison to the conventional PI techniques, for the frequency and voltage control of the MG.
Experimental Investigation of Influence of Acoustic Wave on Vapour Precipitation Process
Authors: Vekteris V. , Tetsman I. , Moksin V.
Published: November 2020

The measurement results of acoustic field parameters above electroplating bath, in presence of water vapour, are analyzed in this work. Suction was created by means of side exhausters. It is obtained that the sound field generator generated a sound level of 130–140 dB at frequency interval between 1 and 10 kHz. It is shown that aerosol coagulation and precipitation processes are intensified under the mentioned conditions. The concentration of vapour and other aerosols in removal air decreases as a result, therefore air cleaning equipment costs can be reduced and cleaning efficiency increased.
AcSIS: Authentication System Based on Image Splicing
Authors: Hamid S. , Bawany N. Z. , Khan S.
Published: November 2020

Text-based passwords are widely used for the authentication of digital assets. Typically, password security and usability is a trade-off, i.e. easy-to-remember passwords have higher usability that makes them vulnerable to brute-force and dictionary attacks. Complex passwords have stronger security but poor usability. In order to strengthen the security in conjunction with the improved usability, we hereby propose a novel graphical authentication system. This system is a picture-based password scheme which comprises of the method of image splicing. Authentication data were collected from 33 different users. The usability of the method was evaluated via a comparison between the number of correct and incorrect authentication attempts and time taken. Additionally, a comparison was made between our proposed method and a complex text-based password authentication method using the authentication success rate. Authentication using image splicing proved to be resilient to brute-force attacks since the processing of images consumes a voluminous password space. The evaluation of the usability revealed that graphical passwords were easy-to-remember, resulting in a higher number of correct attempts. The proposed method produced 50% higher success rate compared to the text-based method. Findings motivate the use of the proposed method for securing digital assets.
Temperature Effect on Al/p-CuInS2/SnO2(F) Schottky Diodes
Authors: Ben Nasrallah T. , Mahboub D. , Jemai M. , Belgacem S.
Published: November 2020

In this paper, Schottky diodes (SDs) obtained by evaporated thin films of aluminum on pulverized p-CuInS2/SnO2:F have been studied using J-V-T characteristics in a temperature range of 200-340K. These characteristics show that aluminum acts as a rectifier metal-semiconductor contact. Characteristic variables of the Al/p-CuInS2/SnO2:F junctions, such as the current density, the serial resistance, the parallel conductance, the Schottky barrier height (SBH), and the ideality factor of the SD were obtained by fitting the J-V-T data using the Lambert function. Data analysis was conducted with the use of MATLAB. Results showed that n is greater than 1, which could be explained by the existence of inhomogeneities due to the grain boundaries in CuInS2. Through this analysis, one can see a good agreement between experimental and modeled data. The study has shown that the main contribution in the current conduction in such heterostructures is the thermionic emission (TE) supported by the recombination of the carriers. The last phenomenon appears mainly in the grain boundaries, which contain both intrinsic and extrinsic defects (secondary phases, segregated oxygen). An investigation of the J-V-T characteristics according to TE theory has demonstrated that the current density and the SBH increase while serial resistance, parallel conductance decrease with an increase in temperature. After an SBH inhomogeneity correction, the modified Richardson constant and the mean barrier height were found to be 120AK-2cm-2 and 1.29eV respectively. This kind of behavior has been observed in many metal-semiconductor contacts.
RETRACTED: An Efficient Metaheuristic Approach for the Multi-Period Technician Routing and Scheduling Problem
Authors: Khattara A. , Cherif-Khettaf W. R. , Mostefai M.
Published: November 2020

This article has been retracted at the request of the Editor-in-Chief and of co authors W. R. Cherif-Khettaf and M. Mostefai, as the article is largely based on work presented previously at an international conference by the same authors.

The conference paper is:

A. Khattara, W. R. Cherif-Khettaf and M. Mostefai, "Variable neighborhood search procedures for the multi-period technician routing and scheduling problem", 4th International Conference on Control, Decision and Information Technologies (CoDIT), Spain, April 5-7, 2017

and the corresponding author of this submission was unaware of the publication of this conference's proceedings at the time of submission and review/publication of this paper.
Controlling the Defects of Paint Shop using Seven Quality Control Tools in an Automotive Factory
Authors: Memon I. A. , Ali A. , Memon M. A. , Rajput U. A. , Abro S. A. K. , Memon A. A.
Published: November 2020

Seven quality control (7QC) tools are used for reducing defects during manufacturing. These tools are highly effective in productivity and quality improvement. In this case, the study of the 7QC tools was applied in an automotive factory in order to reduce paint shop defects. Within four months the production line was inspected, defects were categorized and the 7QC tools were successfully applied, reducing the overall defect rate by 70%. Although every tool was important, the cause and effect diagram was responsible for finding the root causes of the defects.
Understanding the Effect of Aluminum Addition on the Forming of Second Phase Particles on Grain Growth of Micro-Alloyed Steel
Authors: Abro S. H. , Moria H. A. , Chandio A. , Al-Khazaal A. Z.
Published: November 2020

The formation of second phase particles in the steel matrix during melting and casting plays an important role in controlling the grain size of steel. An attempt is made in the present work to find the role of nitrogen on forming nitride particles either with aluminum or titanium. Two steel samples with the same titanium and aluminum weight percent in their chemical composition were collected after the hot rolling process. Solution heat treatment at 1350°C for 60min holding time was used to dissolve the particles and then the steel samples were reheated at 800°C for 60min, water quenched and their microstructure was revealed by usual grinding and polishing process using 2% Nital. A transmission electron microscope connected with EDS was used to reveal the morphology of the second phase particles. The samples for TEM analysis were prepared by the replica extraction method in 5% Nital solution. The samples were then caught in 3mm copper grid for TEM analysis. TEM micrographs revealed the second phase particles in the matrix of steel. EDS peaks were studied and titanium peaks were found in both samples and surprisingly there was not any peak found for aluminum.
Transient Stability Analysis of the IEEE-9 Bus System under Multiple Contingencies
Authors: Anwar N. , Hanif A. H. , Khan H. F. , Ullah M. F.
Published: November 2020

The determination of the transient stability of an electric power system is a crucial step in power system analysis. This paper investigates the transient stability of an IEEE-9 bus system consisting of three generators and nine buses. At first, a load flow analysis is conducted in order to determine the pre-fault conditions. Secondly, fault analysis is performed to analyze post fault conditions like the fast fault clearing time and load switching in order to determine the system stability. For transient stability analysis, Euler and Runga methods are compared and applied on the frequency and rotor angle of the system to analyze the system variations under different fault conditions. The simulations were done on the Power World Simulator (PWS) software. It is concluded that Critical Fault Clearing Time (CFCT) is a very important factor in keeping the power system within the stability bounds. A slight increase in Clearing Time (CT) from the critical value causes un-synchronism.
Conformal Band-Notch UWB Monopole Antenna on Finite Cylindrical Substrates
Authors: Ahmed E. S.
Published: November 2020

A microstrip-fed new UWB monopole antenna with a band-notch characteristic mounted on the finite cylindrical surface is presented. The proposed antenna consists of a rectangular metal radiation patch fed by a 50 ohm microstrip line and a rectangular ground plane. To achieve ultra-wideband, three modifications are introduced. The first one is to blend the upper and lower corners of the radiating plates. The second one is to remove a circular section from the radiating metal. The third one is to blend the upper corners of the ground plane. The antenna is designed on a substrate with dielectric constant εr=3 and 1.6 mm height. The proposed antenna is conformed on finite cylindrical substrates of radiuses 4, 5 and 6 cm. The cylindrical structures were simulated through CST microwave studio finite element package. The simulation results, obtained via CST package on the return losses, VSWR and radiation pattern of the antenna are presented. For both planar and conformal antennas, results show that the impedance bandwidth of the designed antenna is from 2-18 GHz with a return loss less than -10 dB (VSWR<2) and a band rejection of 5-6 GHz for wireless LAN (WLAN), that includes the band 5.15-5.825 GHz limited by IEEE 802.11.a and HIPERLAN/2 with return loss greater than -10dB. The proposed simple shaped conformal antenna provides a good radiation pattern and  gain between 3.84 and 5.96 dBi over the entire frequency band excluding the rejected band.
Numerical Comparison of Triangular and Sinusoidal External Vibration Effects on the 3D Porous Drying Process
Authors: Ben Khedher N. , Ramzi R. , Alatawi I. A.
Published: November 2020

Drying is one of the most energy-intensive industrial processes. One of the techniques aiming to reduce energy consumption is the vibration technique which is generally employed to intensify the heat and mass transfer process. In this respect, this paper presents a three-dimensional numerical model to study the external vibration effects on the drying process of a porous medium. The model is based on a comparison of heat and mass transfer phenomena that arise during vibrating drying of unsaturated porous medium for two cases: triangular and sinusoidal external vibrations. The three-dimensional unstructured Control Volume Finite Element Method (CVFEM) is employed to simulate the vibrating drying. Numerical results of the time evolution of temperature, liquid saturation, pressure, and water content are compared and analyzed for the two cases.
Mobile-based Hospital Bed Management with Near Field Communication Technology
Authors: Lam M. C. , Ayob M. , Lee J. Y. , Abdullah N. , Hamzah F. A. , Zahir S. S. M.
Published: November 2020

Bed management is one of the most crucial tasks in a hospital. A desktop-based (PC) information technology system has been widely adopted to assist this operation. The fixed location and the limited amount of available PCs shared among staff for different routine tasks can cause delays in bed information updating and therefore delays to the bed management processes. With the penetration of smartphones, a mobile-based application becomes a reliable alternative solution for bed management to complement the existing system. Smartphones offer a few benefits, especially mobility because users can update the information from any place and at any time. Our aim was to study the applicability of a mobile-based application for assisting bed management operation. The application consisted of ward-based bed information visualization, bed information updating, and ward information updating modules. Observation and interviews with expert users were performed to outline the required functions of the application. On a Likert 1-5 scale, the mobile application achieved a mean score of 3.45 for usefulness, 3.40 for ease of use, and 3.42 for satisfaction. Meanwhile, the respondents were also concerned about the mobile data consumption of the app, which took up 45.8% of the negative feedback. On the positive side, the respondents agree that the mobile application helps them in the bed management operation.
Two-dimensional Numerical Estimation of Stress Intensity Factors and Crack Propagation in Linear Elastic Analysis
Authors: Boulenouar A. , Benseddiq N. , Mazari M.
Published: November 2020

When the loading or the geometry of a structure is not symmetrical about the crack axis, rupture occurs in mixed mode loading and the crack does not propagate in a straight line. It is then necessary to use kinking criteria to determine the new direction of crack propagation. The aim of this work is to present a numerical modeling of crack propagation under mixed mode loading conditions. This work is based on the implementation of the displacement extrapolation method in a FE code and the strain energy density theory in a finite element code. At each crack increment length, the kinking angle is evaluated as a function of stress intensity factors. In this paper, we analyzed the mechanical behavior of inclined cracks by evaluating the stress intensity factors. Then, we presented the examples of crack propagation in structures containing inclusions and cavities.
Supporting Scholarly Search by Query Expansion and Citation Analysis
Authors: Khalid S. , Wu S.
Published: November 2020

Published scholarly articles have increased exponentially in recent years. This growth has brought challenges for academic researchers in locating the most relevant papers in their fields of interest. The reasons for this vary. There is the fundamental problem of synonymy and polysemy, the query terms might be too short, thus making it difficult to distinguish between papers. Also, a new researcher has limited knowledge and often is not sure about what she is looking for until the results are displayed. These issues obstruct scholarly retrieval systems in locating highly relevant publications for a given search query. Researchers seek to tackle these issues. However, the user's intent cannot be addressed entirely by introducing a direct information retrieval technique. In this paper, a novel approach is proposed, which combines query expansion and citation analysis for supporting the scholarly search. It is a two-stage academic search process. Upon receiving the initial search query, in the first stage, the retrieval system provides a ranked list of results. In the second stage, the highest-scoring Term Frequency–Inverse Document Frequency (TF-IDF) terms are obtained from a few top-ranked papers for query expansion behind the scene. In both stages, citation analysis is used in further refining the quality of the academic search. The originality of the approach lies in the combined exploitation of both query expansion by pseudo relevance feedback and citation networks analysis that may bring the most relevant papers to the top of the search results list. The approach is evaluated on the ACL dataset. The experimental results reveal that the technique is effective and robust for locating relevant papers regarding normalized Discounted Cumulative Gain (nDCG), precision, and recall.
Fabrication of Cu4SnS4 Thin Films: Α Review
Authors: Ho S. M.
Published: November 2020

Ternary compounds such as Cu4SnS4 thin films can be deposited onto glass substrates by various deposition methods: electrodeposition, chemical bath deposition, successive ionic layer adsorption and reaction, and evaporation techniques. Cu4SnS4 films could be used in solar cell applications because of their suitable band gap and large absorption coefficient. This paper reviews previous researches on Cu4SnS4 thin films. X-ray diffraction showed that the obtained films are orthorhombic in structure and polycrystalline in nature. Cu4SnS4 films exhibited p-type electrical conductivity and indicated band gap values in the range of 0.93 to 1.84eV.