Omar R. Paez  Ashraf M. Genaidy 《Theoretical Issues in Ergonomics Science》2017,18(3):241-265

In evaluating health and safety improvements for performance improvement, it is necessary to account for both the contributions of a healthy workforce and the resources required supporting it.

The Economic Assessment of the Work Environment (EAWE) is a financial framework that helps management forecast the financial benefits of health and safety implementations. The five-step process comprises (1) a health assessment to identify critical elements in the work environment, (2) an action plan to address gaps, (3) performance targets based on internal goals and external benchmarks, (4) transformation of the expected improvements in health and safety into expected performance outcomes, and (5) implementation in stages, starting from individual jobs to entire organisation.

EAWE offers a dynamic framework for corporate decision-makers when evaluating health and safety programmes. Further research should explore the bounds of EAWE across different types of organisations and the evolution of performance over time.  相似文献   

    

Remika Ngangbam  Ashraf Hossain  Alok Shukla 《International Journal of Electronics》2020,107(3):390-402

ABSTRACT

Wireless sensor networks (WSNs) play a vital role in present-day world, which are being used in different types of applications and occupy an important part in networking domain. The main objective of WSNs is to sense and collect the information from a given area of interest and provide the gathered data to the sink. WSN comprises of number of sensor nodes with batteries of limited energy for communication and computational activities, which are not possible to recharge the batteries after their deployment in the region of interest. Therefore, saving battery energy and utilising the limited power to the optimum level for extending network lifetime became the main factor of WSN. Hence, optimum cluster head (CH) selection will make the network to support longer lifetime and balanced energy consumption during its lifetime. Our proposed protocol selects the optimum CH and found out to be more efficient than the existing low energy adaptive clustering hierarchy. The simulated output shows better network lifetime and in some other performance metric.  相似文献   

    

M. Said Ashraf  A. M. Khalaf Ashraf 《International Journal of Adaptive Control and Signal Processing》2020,34(3):354-371

An electrocardiogram (ECG) signal is a record of the electrical activities of heart muscle and is used clinically to diagnose heart diseases. An ECG signal should be presented as clear as possible to support accurate decisions made by doctors. This article proposes different combinations of combined adaptive algorithms to derive different noise-cancelling structures to remove (denoise) different kinds of noise from ECG signals. The algorithms are applied to the following types of noise: power line interference, baseline wander, electrode motion artifact, and muscle artifacts. Moreover, the results of the suggested models and algorithms are compared with those of conventional denoising tools such as the discrete wavelet transform, an adaptive filter, and a multilayer neural network (NN) to ensure the superiority of the proposed combined structures and algorithms. Furthermore, the hybrid concept is based on dual, triple, and quadruple combinations of well-known algorithms that derive adaptive filters, such as the least mean squares, normalized least mean squares and recursive least squares algorithms. The combinations are formulated based on partial update, variable step-size (VSS), and second iterative VSS algorithms, which are considered in different combinations. In addition, biased NN and unbiased linear neural network (ULNN) structures are considered. The performance of the different structures and related algorithms are evaluated by measuring the post-signal-to-noise ratio, mean square error, and percentage root mean square difference.  相似文献   

    

Ashraf Mahmoud  Ahmad Abo Naser  Marwan Abu‐Amara  Tarek Sheltami  Nidal Nasser 《International Journal of Communication Systems》2018,31(1)

The evolved packet core (EPC) network is the mobile network standardized by the 3rd Generation Partnership Project and represents the recent evolution of mobile networks providing high‐speed data rates and on‐demand connectivity services. Software‐defined networking (SDN) is recently gaining momentum in network research as a new generation networking technique. An SDN‐based EPC is expected to introduce gains to the EPC control plane architecture in terms of simplified, and perhaps even software‐based, vendor independent infrastructure nodes. In this paper, we propose a novel SDN‐based EPC architecture along with the protocol‐level detailed implementation and provide a mechanism for identifying information fields exchanged between SDN‐EPC entities that maintains correct functionality with minimal impact on the conventional design. Furthermore, we present the first comprehensive network performance evaluation for the SDN‐based EPC versus the conventional EPC and provide a comparative analysis of 2 networks performances identifying potential bottlenecks and performance issues. The evaluation focuses on 2 network control operations, namely, the S1‐handover and registration operations, taking into account several factors, and assessing performance metrics such as end‐to‐end delay (E2ED) for completion of the respective control operation, and EPC nodes utilization figures.  相似文献   

    

Ashraf Q. J.  Prasad Reddy G. V.  Sandhya R.  Laha K.  Harmain G. A. 《Fatigue & Fracture of Engineering Materials & Structures》2018,41(2):336-347

Cyclic stress‐strain response of 316LN stainless steel subjected to low cycle fatigue at strain amplitude of ±0.4% and at 873 K is simulated using finite element analysis with non‐linear isotropic‐kinematic hardening Chaboche model. Four different approaches have been used in simulating cyclic stress response and hysteresis loops: 3 based on Chaboche model‐parameters and the fourth on direct experimental data (stabilized loop and cyclic stress‐strain curve [CSSC]). Among them, simulations performed with direct experimental data have not yielded expected initial cyclic response. The source of data used for evaluation of kinematic‐hardening (KH) parameters determined the extent of closeness between experimental results and Chaboche‐model predictions. KH parameters determined from first‐cycle loop and modified‐CSSC predicted the overall stress‐strain response (from initial to stabilized condition) with reasonable fit, compared with other approaches. All 4 approaches though predicted stabilized response, simulations based on “KH‐parameters from stabilized‐cycle” accurately described stabilized response with coefficient of determination (r²) 0.995.  相似文献   

    

M. Faheem  R. A. Butt  B. Raza  M. W. Ashraf  Seema Begum  Md. A. Ngadi  V. C. Gungor 《Transactions on Emerging Telecommunications Technologies》2019,30(8)

Recently, the advences of Industry 4.0 have paved the way for a systematical deployment of the smart grid (SG) to manage continuously growing energy demand of the 21st century. This even allows the fourth stage of the industrial revolution in the power sector, which is known as the smart grid industry (SGI) 4.0. In SGI 4.0, the industrial wireless sensor networks (WSNs) and the Internet of Things are envisioned as key promising communication technologies for monitoring various SG applications due to their large‐scale coverage, fault tolerance characteristics, and cost reduction. However, highly dynamic nature of the SG environments brings several unique challenges caused by systems and operating devices. This results in hampering the quality‐of‐service communication requirements for WSNs‐based SG applications. In SGI 4.0, the routing infrastructure not only requires a reliable but also fulfills the communication requirements of diverse SG applications. Thus, a sophisticated, reliable and QoS‐aware multi‐hop communications network architecture enabling a real‐time exchange of data for various WSNs‐based SG applications is essential in SGI 4.0. Hence, this paper proposes a novel bio‐inspired self‐optimized butterfly mating optimization‐based data gathering routing scheme called Self‐optimized Intelligent routing protocol (SIRP) for WSNs‐based SG applications. The extensive simulations reveal that the proposed scheme achieves its defined goals compared to existing routing schemes designed for WSNs‐based applications.  相似文献   

    

Magda Borhan El‐Arnaouty  Ashraf Maher Abdel Ghaffar  Ashraf Abdel Kareem Abdel Baky  Sayed Ahmed Shama 《乙烯基与添加剂工艺杂志》2019,25(Z1):E35-E43

Synthesis of carboxymethyl cellulose‐g‐methacrylic acid/acrylamide Poly(CMC/MAAc:AAm) hydrogel was carried out using direct radiation copolymerization technique at ambient temperature. The gel (%) increased with increasing the content of AAm till level off at Poly(CMC/MAAc:AAm) (1/50:50 wt%) hydrogel and the swelling behavior found to be increased with increasing MAAc content in the hydrogel composition up to Poly(CMC/MAAc:AAm) (1/60:40 wt%). The grafting yield, grafting ratio, swelling behavior, and the thermal stability of Poly(CMC/MAAc:AAm) binary system are higher than those reported in our previous study by the same author which described the individual grafting of acrylamide (AAm) and methacrylic acid (MAAc) with different concentration onto carboxymethyl cellulose (CMC) using direct radiation grafting technique. The swelling kinetics and diffusion mechanism indicate that the water penetration obey non‐Fickian transport mechanism. The characterization of the prepared hydrogel was evaluated using Fourier transform infrared, X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The analyses by different analytical tools confirmed the successful grafting of both MAAc and AAm onto CMC. The adsorption capacity of Poly(CMC/MAAc:AAm) (1/60:40 wt%) hydrogel toward metal ions such as Cu⁺² and Co⁺², dyes such as acid blue dye and methyl green have been investigated. J. VINYL ADDIT. TECHNOL., 25:E35–E43, 2019. © 2017 Society of Plastics Engineers  相似文献   

    

Abdul Rehman Yasin  Muhammad Ashraf  Aamer Iqbal Bhatti  Ali Arshad Uppal 《Asian journal of control》2019,21(4):2074-2086

The rising cost of fossil fuels, their high depleting rate and issues regarding environmental pollution have brought the attention of the researchers towards renewable energy technologies. Different renewable energy resources like wind turbines, fuel cells and solar cells are connected to DC micro grid through controllable power electronic converters. In presence of these diverse generation units, robust controllers are required to ensure good power quality and to regulate grid voltage. This paper presents a sliding mode control based methodology to address the above mentioned challenges. The proposed technique keeps the switching frequency constant so that electromagnetic compatibility (EMC) issues can be solved with conventional filter design. Parallel operation of converter in DC micro gird is considered. Chattering reduction and power quality improvement by harmonic cancellation is proposed. A scaled down hardware for unregulated 11.5 V to 17.5 V input and 24V output is designed and tested. The experimental results show good performance of the controller under different loads and uncertain input voltage conditions. Moreover, the results show the robustness of the closed loop system to sudden variations in load conditions. Furthermore, a significant improvement in power quality is achieved by harmonic cancellation of chattering in the output of the converters.  相似文献   

    

Mohammad Reza Barati  Ashraf M. Zenkour 《先进材料力学与结构力学》2019,26(6):503-511

This research is concerned with the analysis of post-buckling of a nano-composite beam reinforced by graphene plateletes (GPLs) having geometrical imperfection. GPLs are uniformly and nonuniformly distributed thorough the thickness direction. Different porosity distributions are considered. The elastic properties of the nanocomposite are obtained by employing Halpin-Tsai micromechanics model. The postbuckling load-deflection relation is obtained by solving the governing equations having cubic nonlinearity applying Galerkin's method needless of any iteration process. New results show the importance of porosity coefficient, porosity distribution, GPL distribution, GPL weight fraction, geometrical imperfection, and foundation parameters on nonlinear buckling behavior of porous nanoscale beams. Specially, porosities and GPL reinforcement have a great impact on postbuckling configuration of both ideal and imperfect nanocomposite beams.  相似文献   

    

Azeem Irshad  Shehzad Ashraf Chaudhry  Muhammad Shafiq  Muhammad Usman  Muhammad Asif  Anwar Ghani 《International Journal of Communication Systems》2019,32(14)

The mobile cloud computing (MCC) has enriched the quality of services that the clients access from remote cloud‐based servers. The growth in the number of wireless users for MCC has further augmented the requirement for a robust and efficient authenticated key agreement mechanism. Formerly, the users would access cloud services from various cloud‐based service providers and authenticate one another only after communicating with the trusted third party (TTP). This requirement for the clients to access the TTP during each mutual authentication session, in earlier schemes, contributes to the redundant latency overheads for the protocol. Recently, Tsai et al have presented a bilinear pairing based multi‐server authentication (MSA) protocol, to bypass the TTP, at least during mutual authentication. The scheme construction works fine, as far as the elimination of TTP involvement for authentication has been concerned. However, Tsai et al scheme has been found vulnerable to server spoofing attack and desynchronization attack, and lacks smart card‐based user verification, which renders the protocol inapt for practical implementation in different access networks. Hence, we have proposed an improved model designed with bilinear pairing operations, countering the identified threats as posed to Tsai scheme. Additionally, the proposed scheme is backed up by performance evaluation and formal security analysis.  相似文献