Psychosocial Factors and Musculoskeletal Disorders in the Construction Industry

Musculoskeletal disorders (MSDs) constitute more than half of the total injuries and illnesses within the construction industry. The aim of this study was to assess the prevalence of MSD among construction workers and identify the psychosocial and physical risk factors associated with their occurrence using an on-site survey instrument. One hundred forty seven construction workers (representing three trades) participated in the study. The 1-year prevalence of MSD was high with 61.2% reporting severe symptoms and 39.7% having some functional impairment due to MSD. Physical task requirement was the most important factor associated with MSD reflecting the physical nature of construction work. Economic and performance factors were the most stressful psychosocial factors reported and significantly increased the risk of reporting MSD. The findings of this research underscore the independent role that psychosocial factors play in the health and safety of construction workers. Understanding this role is imperative for practitioners and academics alike in the quest to make construction a safer work environment for all workers.     

Adaptive MRAC-based direct torque control with SVM for sensorless induction motor using adaptive observer

This paper presents an improved direct torque control (DTC) method for induction motor (IM) drive. The main drawback of the conventional DTC is the use of hysteresis comparators which leads to high torque and flux ripples. The improvement in this paper includes using the space vector modulation to preserve a constant switching frequency and to reduce totally flux and torque ripples. Besides, the torque and stator flux regulation will be done based on model reference adaptive control (MRAC) strategy to ensure a robust control against external disturbance and less sensitivity from machine parameter variation unlike the conventional proportional-integral (PI) controllers. Furthermore, a design of an adaptive observer based on Lyapunov stability is presented for speed/flux and load torque estimation. The observer can improve the control performances and decrease the cost and increase reliability of the global control system by reducing the number of sensors. The proposed strategy will be examined under simulation tests using Matlab/Simulink and experimental implementation with real-time interface (RTI) based on dSpace 1104 board.     

Dipper Throated Algorithm for Feature Selection and Classification in Electrocardiogram

Arrhythmia has been classified using a variety of methods. Because of the dynamic nature of electrocardiogram (ECG) data, traditional handcrafted approaches are difficult to execute, making the machine learning (ML) solutions more appealing. Patients with cardiac arrhythmias can benefit from competent monitoring to save their lives. Cardiac arrhythmia classification and prediction have greatly improved in recent years. Arrhythmias are a category of conditions in which the heart's electrical activity is abnormally rapid or sluggish. Every year, it is one of the main reasons of mortality for both men and women, worldwide. For the classification of arrhythmias, this work proposes a novel technique based on optimized feature selection and optimized K-nearest neighbors (KNN) classifier. The proposed method makes advantage of the UCI repository, which has a 279-attribute high-dimensional cardiac arrhythmia dataset. The proposed approach is based on dividing cardiac arrhythmia patients into 16 groups based on the electrocardiography dataset’s features. The purpose is to design an efficient intelligent system employing the dipper throated optimization method to categorize cardiac arrhythmia patients. This method of comprehensive arrhythmia classification outperforms earlier methods presented in the literature. The achieved classification accuracy using the proposed approach is 99.8%.     

A fair comparison of SAC-OCDMA system configurations based on two dimensional cyclic shift code and spectral direct detection

This paper investigates shortcomings that limit the performance of optical code division multiple access (OCDMA) systems including the low cardinality and data rate as well as the high power at reception. The main drawback for such systems known as multiple access interference accompanying by phase induced intensity noise is also investigated to effeciencly propose a novel two dimensional cyclic shift (2D-CS) code to be implemented in non-coherent OCDMA systems. The developed code is based on a one dimensional cyclic shift (1D-CS) code previously provided by research works processing spectral amplitude coding for optical code division multiple access (SAC-OCDMA) systems. Numerical results obtained by this study are therefore compared to previous studies employing different codes like two dimensional extended double weight (2D-EDW), two dimensional flexible cross correlation/modified double weight (2D-FCC/MDW), two dimensional perfect difference (2D-PD), two dimensional diluted perfect difference (2D-DPD), two dimensional multi service (2D-MS) and two dimensional zero cross correlation/multi diagonal (2D-ZCC/MD) codes. Accordingly, it is demonstrated that the proposed 2D-CS code outperforms all codes given previously in terms of system capacity where the small increasing percentage is about 40% compared to 2D-ZCC/MD and 2D-MS. Systems using 2D-CS code can support until 203 simultaneous users with a total code length equal to 171. System performance investigation leads to a BER and Q-Factor closely to1.0E?12 and 1.0E?27, and 6.6 dB and 10.6 dB at 20 km of single mode fiber length using white light source and Laser, respectively. Furthermore, such a code can be easily adopted by OCDMA systems for a long distance up to approximately 55 and 100 km.

     

Effect of Nickel Nitrate Concentration on the Size of Nickel Oxide Nanoparticles Bio-synthesized by Artemisia herba-alba Aqueous Leaves Extract and Improving Their Antioxidant Activities

Journal of Inorganic and Organometallic Polymers and Materials - This work aims to investigate the effect of nickel nitrate concentration on the size and antioxidant activity of nickel oxide...     

Fire tests of steel-to-timber connections with high fire resistance

This paper presents the results of twenty-one fire tests on unprotected steel-to-timber connections with dowel-type fasteners and one or two slotted-in steel plates. The experimental results of this type of connections available in existing studies have been mostly limited to a fire resistance duration of 60 min. The tests performed in this study target a significant increase of fire resistance to reach 90 and 120 min. Two configurations of connections with one and two slotted-in steel plates, i.e., two or four shear planes, were tested. The temperatures were measured at different locations in the wood members and along the steel plates. Two load levels for fire tests were determined on the basis of tests performed at ambient temperature. The experimental results show that the specimens proposed for steel-to-timber connections with dowel-type fasteners are suitable for achieving fire resistance of 90 and 120 min.     

A comprehensive optimized model for on‐board solar photovoltaic system for plug‐in electric vehicles: energy and economic impacts

Environmental concerns along with high energy demand in transportation are leading to major development in sustainable transportation technologies, not the least of which is the utilization of clean energy sources. Solar energy as an auxiliary power source of on‐board fuel has not been extensively investigated. This study focuses on the energy and economic aspects of optimizing and hybridizing, the conventional energy path of plug‐in electric vehicles (EVs) using solar energy by means of on‐board photovoltaic (PV) system as an auxiliary fuel source. This study is novel in that the authors (i) modeled the comprehensive on‐board PV system for plug‐in EV; (ii) optimized various design parameters for optimum well‐to‐tank efficiency (solar energy to battery bank); (iii) estimated hybrid solar plug‐in EVs energy generation and consumption, as well as pure solar PV daily range extender; and (iv) estimated the economic return of investment (ROI) value of adding on‐board PVs for plug‐in EVs under different cost scenarios, driving locations, and vehicle specifications. For this study, two months in two US cities were selected, which represent the extremities in terms of available solar energy; June in Phoenix, Arizona and December in Boston, Massachusetts to represent the driving conditions in all the US states at any time followed by assessment of the results worldwide. The results show that, by adding on‐board PVs to cover less than 50% (around 3.2 m²) of the projected horizontal surface area of a typical passenger EV, the daily driving range could be extended from 3.0 miles to 62.5 miles by solar energy based on vehicle specifications, locations, season, and total time the EV remains at Sun. In addition, the ROI of adding PVs on‐board with EV over its lifetime shows only small negative values (larger than ?45%) when the price of electricity remains below Environmental concerns along with high energy demand in transportation are leading to major development in sustainable transportation technologies, not the least of which is the utilization of clean energy sources. Solar energy as an auxiliary power source of on‐board fuel has not been extensively investigated. This study focuses on the energy and economic aspects of optimizing and hybridizing, the conventional energy path of plug‐in electric vehicles (EVs) using solar energy by means of on‐board photovoltaic (PV) system as an auxiliary fuel source. This study is novel in that the authors (i) modeled the comprehensive on‐board PV system for plug‐in EV; (ii) optimized various design parameters for optimum well‐to‐tank efficiency (solar energy to battery bank); (iii) estimated hybrid solar plug‐in EVs energy generation and consumption, as well as pure solar PV daily range extender; and (iv) estimated the economic return of investment (ROI) value of adding on‐board PVs for plug‐in EVs under different cost scenarios, driving locations, and vehicle specifications. For this study, two months in two US cities were selected, which represent the extremities in terms of available solar energy; June in Phoenix, Arizona and December in Boston, Massachusetts to represent the driving conditions in all the US states at any time followed by assessment of the results worldwide. The results show that, by adding on‐board PVs to cover less than 50% (around 3.2 m²) of the projected horizontal surface area of a typical passenger EV, the daily driving range could be extended from 3.0 miles to 62.5 miles by solar energy based on vehicle specifications, locations, season, and total time the EV remains at Sun. In addition, the ROI of adding PVs on‐board with EV over its lifetime shows only small negative values (larger than ?45%) when the price of electricity remains below $0.18/kWh and the vehicle is driven in low‐solar energy area (e.g. Massachusetts in the US and majority of Europe countries). The ROI is more than 148% if the vehicle is driven in high‐solar energy area (e.g. Arizona in the US, most Africa countries, Middle East, and Mumbai in India), even if the electricity price remains low. For high electricity price regions ($0.35/kWh), the ROI is positive and high under all driving scenarios (above 560%). Also, the reported system has the potential to reduce electricity consumption from grid by around 4.5 to 21.0 MWh per EV lifetime. A sensitivity analysis has been carried out, in order to study the impacts of the car parked in the shade on the results. Copyright © 2016 John Wiley & Sons, Ltd.     

Inter-vehicle communication of warning information: an experimental study

In this paper, we show experimentally the feasibility of intervehicle communication of warning information. Warning messages convey significant information that might improve the safety of drivers and passengers. Intervehicle communication can be achieved by the detection of important events through a vision-based detection module, and sharing them between vehicles using a transmission module. In this paper, we developed a testbed that considers both modules in order to detect, recognize and share relevant information, such as traffic signs. To the best of our knowledge, our architecture is the first that combines detection and transmission of messages in the same platform. We detect traffic signs as blobs using the Maximally Stable Extremal Regions (MSER) algorithm, and we recognize them using Random forest classifiers. In the transmission module, we used a simplied broadcasting mechanism that avoids the use of handshaking to establish a communication. In order to assess our system, a set of indoor and outdoor experiments are considered.     

Belief functions in telecommunications and network technologies: an overview

In the last few years, evidence theory, also known as Dempster-Shafer theory or belief functions theory, have received growing attention in many fields such as artificial intelligence, computer vision, telecommunications and networks, robotics, and finance. This is due to the fact that imperfect information permeates the real-world applications, and as a result, it must be incorporated into any information system that aims to provide a complete and accurate model of the real world. Although, it is in an early stage of development relative to classical probability theory, evidence theory has proved to be particularly useful to represent and reason with imperfect information in a wide range of real-world applications. In such cases, evidence theory provides a flexible framework for handling and mining uncertainty and imprecision as well as combining evidence obtained from multiple sources and modeling the conflict between them. The purpose of this paper is threefold. First, it introduces the basics of the belief functions theory with emphasis on the transferable belief model. Second, it provides a practical case study to show how the belief functions theory was used in a real network application, thereby providing guidelines for how the evidence theory may be used in telecommunications and networks. Lastly, it surveys and discusses a number of examples of applications of the evidence theory in telecommunications and network technologies.