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An Enhanced Smith Predictor Based Control System Using Feedback-Feedforward Structure For Time-Delay Processes, M. Mohammadzaheri, R. Tafreshi Apr 2025

An Enhanced Smith Predictor Based Control System Using Feedback-Feedforward Structure For Time-Delay Processes, M. Mohammadzaheri, R. Tafreshi

The Journal of Engineering Research

This paper presents enhanced Smith predictor based control systems (SPBCSs) for processes with a time-varying or fixed time delay. This work focuses on improving the arrangement and asynchrony of SPBCS components rather than the design of the predictor and the feedback controller, which have been well discussed in the literature. The proposed control system advances SPBCS through implementation of two design recommendations: (i) replacing the classical feedback controller by a feedback-feedforward control system, and (ii) synchronizing the reference signal and the predicted output. As a result, common shortcomings of SPBCSs or control systems based on Pade approximation, i.e. the …

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Development Of A System Model For Determining Optimal Personnel Interaction Strategy In A Production Industry, B. Kareem, A. Adekiigbe Apr 2025

Development Of A System Model For Determining Optimal Personnel Interaction Strategy In A Production Industry, B. Kareem, A. Adekiigbe

The Journal of Engineering Research

Manufacturing organizations have become more complex in recent time as a result of technological advances. Communication among production workers operating in an environment marked by increased organizational complexity may require planning for the economically appropriate selection of network channels/media with enhanced productivity. This paper examines traditional and modern communication channels (media) and their comparative advantages over one another in their adoption in manufacturing organizations. In this framework, six media (human messengers, mobile-phones, intranet, fixed-internet, mobile-internet, and private branch exchange [PBX] phone systems) were subjected to analyses using five identified network patterns (all-channel, chain, Y, wheel, and circle) of interactions in …

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Performance Comparison Of Digital Circuits Using Subthreshold Leakage Power Reduction Techniques, B. Kalagadda, N. Muthyala, K.K. Korlapati Apr 2025

Performance Comparison Of Digital Circuits Using Subthreshold Leakage Power Reduction Techniques, B. Kalagadda, N. Muthyala, K.K. Korlapati

The Journal of Engineering Research

Complementary metal-oxide semiconductors (CMOS), stack, sleep and sleepy keeper techniques are used to control sub-threshold leakage. These effective low-power digital circuit design approaches reduce the overall power dissipation. In this paper, the characteristics of inverter, twoinput negative-AND (NAND) gate, and half adder digital circuits were analyzed and compared in 45nm, 120nm, 180nm technology nodes by applying several leakage power reduction methodologies to conventional CMOS designs. The sleepy keeper technique when compared to other techniques dissipates less static power. The advantage of the sleepy keeper technique is mainly its ability to preserve the logic state of a digital circuit while reducing …

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The Simulation Study Of A Restructured Residential Low-Voltage Distribution System Microgrid, L. Ramesh, Umamageswari Umamageswari Apr 2025

The Simulation Study Of A Restructured Residential Low-Voltage Distribution System Microgrid, L. Ramesh, Umamageswari Umamageswari

The Journal of Engineering Research

A primary and necessary focus in creating a greener environment is the conversion of existing power-generation sources to renewable power sources in the near future. Another important focus is to develop sustainable household power generation to a low-voltage electricity grid with a power purchase and selling facility. To help with achieving the above vision, the objective of this work is to critically analyze the existing low-voltage distribution system and make suggestions for restructuring it to the low-voltage interconnected microgrid (MG). The test was carried out in the Tamil Nadu Electricity Board (TNEB) 100kVA transformer feeder which was connected to supply …

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Single Cfta Based Current-Mode Universal Biquad Filter, S.V. Singh, R.S. Tomar, D.S. Chauhan Apr 2025

Single Cfta Based Current-Mode Universal Biquad Filter, S.V. Singh, R.S. Tomar, D.S. Chauhan

The Journal of Engineering Research

This paper introduces a new current-mode (CM) universal biquad filter structure with optimum number of active and passive elements. In the design, the proposed circuit uses a single active element namely, current follower trans-conductance amplifier (CFTA) and two grounded capacitors as passive elements. The main feature of the proposed circuit is that it can realize all five standard filtering functions such as low pass (LP), band pass (BP), high pass (HP), band stop (BS) and all pass (AP) responses across an explicit high impedance output terminal through the appropriate selection of three inputs. In addition, the same circuit is also …

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Sustainability In Small And Medium-Sized Manufacturing Enterprises: An Empirical Study, I. Garbie Apr 2025

Sustainability In Small And Medium-Sized Manufacturing Enterprises: An Empirical Study, I. Garbie

The Journal of Engineering Research

The main goal of this paper is to analyze and investigate sustainable practices in small and medium-sized manufacturing enterprises (SMEs). A comprehensive analysis and a mathematical framework are used to assess the sustainability indexes (SDIs) of each aspect/issue and pillar/dimension, and of the whole manufacturing enterprise. Sustainability in the whole manufacturing enterprise is represented by the sustainable development index (SDI). The results show that there is a significant difference in SDIs between aspects and dimensions, with economic sustainability representing the highest percentage in the SDI. Also, the results show that industrial companies are adopting sustainable practices and applying them to …

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Stochastic Allocation Of Transmit Power For Realistic Wireless Channel Models, N. G. Tarhuni, M. Elmusrati, M. Al-Nadabi Apr 2025

Stochastic Allocation Of Transmit Power For Realistic Wireless Channel Models, N. G. Tarhuni, M. Elmusrati, M. Al-Nadabi

The Journal of Engineering Research

Control of transmitted power is crucial for the successful operation of multi-user wireless channels communications. There are practical situations in which the transmitted power cannot be adjusted by feedback information; hence, only forward transmit power allocation can be applied, especially in situations where a feedback channel is not available in a wireless network or when wireless nodes are only transmit types. Conventionally, transmitted power can be fixed. Higher gain may be observed if the sensors’ transmitted power is randomized. In this work, random power allocation for a Nakagami-m distributed wireless channel model was investigated, and a number of random distributions …

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Optimization Of Process Design Problems Using Differential Evolution Algorithm, A.M. Gujarathia, G. Vakili-Nezhaad, M. Vatani Apr 2025

Optimization Of Process Design Problems Using Differential Evolution Algorithm, A.M. Gujarathia, G. Vakili-Nezhaad, M. Vatani

The Journal of Engineering Research

A modified differential evolution algorithm (MDE) has been used for solving different process related design problems (namely calculation of the NRTL and Two-Suffix Margules activity coefficient models parameters in 20 ternary extraction systems including different ionic liquids and reactor network design problem). The obtained results, in terms of root mean square deviations (rmsd) for these models are satisfactory, with the overall values of 0.0023 and 0.0170 for 169 tie-lines for NRTL and Two-Suffix Margules models, respectively. The results showed that the MDE algorithm results in better solutions compared to the previous work based on genetic algorithm (GA) for correlating liquid-liquid …

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Loss Reduction In Isolated Rural Area Distribution Network Using Photovoltaic System, M. H. Albadi, N.A. Al-Mashaikhi, S. Al-Hinai, R. S. Al-Abri, A.S. Al-Hinai, Q.K. Al-Aamri, A.A. Al-Mazidi, M.S. Al-Gafri Apr 2025

Loss Reduction In Isolated Rural Area Distribution Network Using Photovoltaic System, M. H. Albadi, N.A. Al-Mashaikhi, S. Al-Hinai, R. S. Al-Abri, A.S. Al-Hinai, Q.K. Al-Aamri, A.A. Al-Mazidi, M.S. Al-Gafri

The Journal of Engineering Research

This paper investigates the utilization of photovoltaic (PV) systems in a rural area electricity network. The Rural Area Electricity Company of Oman is planning to install a 304 kW PV system at the powerhouse of the Almazyonah network. Based on the available network data, a power flow model of the system under study was built and the system’s performance was studied. The location and installed capacity of the planned PV system were optimized based on loss reduction.

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Efficient Desalination Of Brackish Ground Water Via A Novel Capacitive Deionization Cell Using Nanoporous Activated Carbon Cloth Electrodes, K. Laxman, M.T.Z Myint, M. Al Abri, L. Al-Gharibi, B. Al Namani, H. Bourdoucen, J. Dutta Apr 2025

Efficient Desalination Of Brackish Ground Water Via A Novel Capacitive Deionization Cell Using Nanoporous Activated Carbon Cloth Electrodes, K. Laxman, M.T.Z Myint, M. Al Abri, L. Al-Gharibi, B. Al Namani, H. Bourdoucen, J. Dutta

The Journal of Engineering Research

Sea water intrusion in ground water sources has made brackish water desalination a necessity in Oman. The application of capacitive deionization (CDI) for the deionization of ground water samples from wells in Al-Musanaah Wilayat is proposed and demonstrated. A CDI cell is fabricated using nanoporous activated carbon cloth (ACC) as the electrodes and is shown to be power efficient for desalting ground water samples with total dissolved solids (TDS) of up to 4,000 mg/l. The CDI cell was able to remove up to 73% of the ionic scaling and fouling contaminants from brackish water samples. The power consumption for deionization …

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Overdesign Of Villa Structures In Oman, A.S. Alnuaimi, M. Al Mohsin, A. Hago, S. El Gamal Apr 2025

Overdesign Of Villa Structures In Oman, A.S. Alnuaimi, M. Al Mohsin, A. Hago, S. El Gamal

The Journal of Engineering Research

Residential projects represent the largest section of the construction industry in Oman. It is widely claimed that designers in Oman tend to unnecessarily overdesign structures, thereby aggravating construction costs. The aim of this research was to investigate the existence and extent of structural overdesign through the investigation of 31 villas which were approved by Muscat Municipality between 2000–2010. The specified villas were structurally redesigned based on the British Code of Practice using the same geometry and material strengths recorded in the drawings. The required reinforcement resulting from the redesign work was compared with the provided reinforcement as per the drawings. …

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Microwave-Assisted Adsorptive Desulfurization Of Model Diesel Fuel Using Synthesized Microporous Rare Earth Metal-Doped Zeolite Y, N. Salahudeen, A.S. Ahmed, A.H. Al-Muhtaseb, B.Y. Jibril, R. Al-Hajri, S. M. Waziri, M. Dauda, J. Al-Sabahi Apr 2025

Microwave-Assisted Adsorptive Desulfurization Of Model Diesel Fuel Using Synthesized Microporous Rare Earth Metal-Doped Zeolite Y, N. Salahudeen, A.S. Ahmed, A.H. Al-Muhtaseb, B.Y. Jibril, R. Al-Hajri, S. M. Waziri, M. Dauda, J. Al-Sabahi

The Journal of Engineering Research

The microwave-assisted adsorptive desulfurization of model fuel (thiophene in n-heptane) was investigated using a synthesized rare earth metal-doped zeolite Y (RE Y). Crystallinity of the synthesized zeolite was 89.5%, the silicon/aluminium (Si/Al) molar ratio was 5.2, the Brunauer–Emmett–Teller (BET) surface area was 980.9 m2/g, and the pore volume and diameter was 0.3494 cm3/g and 1.425 nm, respectively. The results showed that the microwave reactor could be used to enhance the adsorptive desulfurization process with best efficiency of 75% at reaction conditions of 100 °C and 15 minutes. The high desulfurization effect was likely due to the …

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Applying Interpretive Structural Modeling To Cost Overruns In Construction Projects In The Sultanate Of Oman, K. Alzebdeh, H.A. Bashir, S.K. Al Siyabi Apr 2025

Applying Interpretive Structural Modeling To Cost Overruns In Construction Projects In The Sultanate Of Oman, K. Alzebdeh, H.A. Bashir, S.K. Al Siyabi

The Journal of Engineering Research

Cost overruns in construction projects are a problem faced by project managers, engineers, and clients throughout the Middle East. Globally, several studies in the literature have focused on identifying the causes of these overruns and used statistical methods to rank them according to their impacts. None of these studies have considered the interactions among these factors. This paper examines interpretive structural modelling (ISM) as a viable technique for modelling complex interactions among factors responsible for cost overruns in construction projects in the Sultanate of Oman. In particular, thirteen interrelated factors associated with cost overruns were identified, along with their contextual …

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Experimental And Modeling Investigations Of The Viscosity Of Crude Oil Binary Blends: New Models Based On The Genetic Algorithm Method, R.S. Al-Maamari, G. Vakili-Nezhaada, M. Vatani Apr 2025

Experimental And Modeling Investigations Of The Viscosity Of Crude Oil Binary Blends: New Models Based On The Genetic Algorithm Method, R.S. Al-Maamari, G. Vakili-Nezhaada, M. Vatani

The Journal of Engineering Research

Achieving an estimation of viscosity in crude oil binary mixtures is often difficult because the relationship of viscosity, to the fraction of each crude oil, and many other parameters and constants is comply. This relationship can be expressed by mathematical models with different variables. Besides the known models for predicting the viscosity of crude oil mixtures, the petroleum industry demands other models which give accurate predictions. In this work, two new empirical models have been developed for the calculation of the viscosity of binary crude oil blends. Two techniques—least square (LS) and genetic algorithm (GA)—were used to determine the parameters …

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Electromagnetic Field Detector Circuit For Low- Frequency Energy Applications, M.M. Bait-Suwailam Apr 2025

Electromagnetic Field Detector Circuit For Low- Frequency Energy Applications, M.M. Bait-Suwailam

The Journal of Engineering Research

This study details an electromagnetic (EM) field radiation detector system that was developed for near-field low-frequency energy applications. The prototype constitutes the use of a dual-band monopole antenna system as a probe along with a detecting circuit. Furthermore, the prototype was equipped with a qualitative EM radiation strength display unit at its output stage. For proof of concept, the detecting probe was implemented on a printed-circuit board. Both numerical simulations were based on PSpice software (Cadence Design Systems, Inc., San Jose, California, USA) and measurements are presented and discussed. The EM field detector aimed to sense any potential sources of …

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M-Learning: The New Horizon Of Learning At Squ, Z. Al-Khanjari, K. Al-Kindi, A. Al-Zidi, Y. Baghdadi Apr 2025

M-Learning: The New Horizon Of Learning At Squ, Z. Al-Khanjari, K. Al-Kindi, A. Al-Zidi, Y. Baghdadi

The Journal of Engineering Research

M-learning extends the theory and practice of learning and mobility in converging technological environments. Developing a smart course in order to improve the standard of education at Sultan Qaboos University (SQU) is one of the main aims of the current authors. This proposal requires developing innovative applications for ubiquitous, mobile technologies for learning. This kind of development covers new educational and technological methods and concepts for supporting formal and informal learning. SQU is currently using Moodle as the open source e-learning management system to support and enhance traditional learning. Although elearning in SQU has proven its importance in enhancing traditional …

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On Sequence Lengths Of Some Special External Exclusive Or Type Lfsr Structures – Study And Analysis, A Ahmad, A Al Maashri Apr 2025

On Sequence Lengths Of Some Special External Exclusive Or Type Lfsr Structures – Study And Analysis, A Ahmad, A Al Maashri

The Journal of Engineering Research

The study of the length of pseudo-random binary sequences generated by Linear- Feedback Shift Registers (LFSRs) plays an important role in the design approaches of built-in selftest, cryptosystems, and other applications. However, certain LFSR structures might not be appropriate in some situations. Given that determining the length of generated pseudo-random binary sequence is a complex task, therefore, before using an LFSR structure, it is essential to investigate the length and the properties of the sequence. This paper investigates some conditions and LFSR’s structures, which restrict the pseudo-random binary sequences’ generation to a certain fixed length. The outcomes of this paper …

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A Basic Wind Speed Map For Oman, A.S. Alnuaimi, M.A. Mohsin, K.H. Al-Riyami Apr 2025

A Basic Wind Speed Map For Oman, A.S. Alnuaimi, M.A. Mohsin, K.H. Al-Riyami

The Journal of Engineering Research

The aim of this research was to develop the first basic wind speed map for Oman. Hourly mean wind speed records from 40 metrological stations were used in the calculation. The period of continuous records ranged from 4–37 years. The maximum monthly hourly mean and the maxima annual hourly mean wind speed data were analysed using the Gumbel and Gringorten methods. Both methods gave close results in determining basic wind speeds, with the Gumbel method giving slightly higher values. Due to a lack of long-term records in some regions of Oman, basic wind speeds were extrapolated for some stations with …

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Analysis And Design Of A New Dual Band Microstrip Patch Antenna Based On Slot Matching Y-Shaped, R. Wali, S. Ghnimi, A.G. Hand, T. Razban Apr 2025

Analysis And Design Of A New Dual Band Microstrip Patch Antenna Based On Slot Matching Y-Shaped, R. Wali, S. Ghnimi, A.G. Hand, T. Razban

The Journal of Engineering Research

A new compact microstrip slot antenna with Y-shaped coupling aperture is proposed. This antenna is based on a rectangular form with a microstrip fed line for excitation, and consists of slots on the edge of the radiation patch to provide dual-band operation. The design and simulation of the antenna were performed using CST Microwave Studio simulator. A prototype of the proposed antenna has been constructed and tested. In order to validate the return loss of the prototype antenna, the experimental results are presented. The results show two available bands with –10 dB band S at 2.7 GHz and band C …

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On Directed Edge-Disjoint Spanning Trees In Product Networks, An Algorithmic Approach, A.R. Touzene, K. Day Apr 2025

On Directed Edge-Disjoint Spanning Trees In Product Networks, An Algorithmic Approach, A.R. Touzene, K. Day

The Journal of Engineering Research

In (Ku et al. 2003), the authors have proposed a construction of edge-disjoint spanning trees EDSTs in undirected product networks. Their construction method focuses more on showing the existence of a maximum number (n1+n2-1) of EDSTs in product network of two graphs, where factor graphs have respectively n1 and n2 EDSTs. In this paper, we propose a new systematic and algorithmic approach to construct (n1+n2) directed routed EDST in the product networks. The direction of an edge is added to support bidirectional links in interconnection networks. Our EDSTs can be used straightforward to develop efficient collective communication algorithms for both …

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Mobility Assisted Sensor Node Self-Deployment For Maximizing The Coverage Of Wireless Sensor Networks Using A Genetic Algorithm, Vv Juli, J Raja Apr 2025

Mobility Assisted Sensor Node Self-Deployment For Maximizing The Coverage Of Wireless Sensor Networks Using A Genetic Algorithm, Vv Juli, J Raja

The Journal of Engineering Research

Wireless sensor networks extend the capability to monitor and control far-flung environments. However, sensor nodes must be deployed appropriately to reach an adequate coverage level for the successful acquisition of data. Modern sensing devices are able to move from one place to another for different purposes and constitute the mobile sensor network. This mobile sensor capability could be used to enhance the coverage of the sensor network. Since mobile sensor nodes have limited capabilities and power constraints, the algorithms which drive the sensors to optimal locations should extend the coverage. It should also reduce the power needed to move the …

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Simulation Study On Multipassed Welding Distortion Of Combined Joint Types Using Thermo-Elastic-Plastic Fem, Rn Lidam, Hpm Yupiter, Mr Redza, Mr Rahim, Ms Sulaiman, My Zakaria, G Tham, Sk Abasa, E Haruman, Cy Chau Apr 2025

Simulation Study On Multipassed Welding Distortion Of Combined Joint Types Using Thermo-Elastic-Plastic Fem, Rn Lidam, Hpm Yupiter, Mr Redza, Mr Rahim, Ms Sulaiman, My Zakaria, G Tham, Sk Abasa, E Haruman, Cy Chau

The Journal of Engineering Research

This paper investigates the angular distortion induced by the gas metal arc welding (GMAW) process on the combined butt and T-joint with a thickness of 9 mm. The material used in this study was low manganese carbon steel S355J2G3. A 2-D and 3-D thermo-elastic-plastic finite element (FE) analysis has been developed to simulate the induced distortion of multipassed welding. In this research, SYSWELD 2010 with its computation management tool, known as multipassed welding advisor (MPA), was applied to analyze the distortion behavior of combined joint types. To model the heat source of GMAW, Goldak's double ellipsoid representation, which is available …

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Optimizing Maintenance Planning In The Production Industry Using The Markovian Approach, B Kareem, Ha Owolabi Apr 2025

Optimizing Maintenance Planning In The Production Industry Using The Markovian Approach, B Kareem, Ha Owolabi

The Journal of Engineering Research

Maintenance is an essential activity in every manufacturing establishment, as manufacturing effectiveness counts on the functionality of production equipment and machinery in terms of their productivity and operational life. Maintenance cost minimization can be achieved by adopting an appropriate maintenance planning policy. This paper applies the Markovian approach to maintenance planning decision, thereby generating optimal maintenance policy from the identified alternatives over a specified period of time. Markov chains, transition matrices, decision processes, and dynamic programming models were formulated for the decision problem related to maintenance operations of a cable production company. Preventive and corrective maintenance data based on workloads …

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Thermal Performance Of Solar Hot Water Systems Using A Flat Plate Collector Of Accelerated Risers, Ke Amori, Ns Jabouri Apr 2025

Thermal Performance Of Solar Hot Water Systems Using A Flat Plate Collector Of Accelerated Risers, Ke Amori, Ns Jabouri

The Journal of Engineering Research

This study focuses on a comparison of the performance of two similar locally-fabricated solar water heaters. One of the collectors features a new design for accelerated absorber; its risers are made of converging ducts whose exit area is half that of the entrance. The other collector is a conventional absorber, with risers of the same cross sectional area along its length. Each collector is the primary part of an indirect thermosyphon circulation solar hot water system. Both collectors face south with a fixed tilt angle of 33.3

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Classification Of Static Security Status Using Multi-Class Support Vector Machines, S Kalyani, Ks Swarup Apr 2025

Classification Of Static Security Status Using Multi-Class Support Vector Machines, S Kalyani, Ks Swarup

The Journal of Engineering Research

This paper presents a Multi-class Support Vector Machine (SVM) based Pattern Recognition (PR) approach for static security assessment in power systems. The multi-class SVM classifier design is based on the calculation of a numeric index called the static security index. The proposed multi-class SVM based pattern recognition approach is tested on IEEE 57 Bus, 118 Bus and 300 Bus benchmark systems. The simulation results of the SVM classifier are compared to a Multilayer Perceptron (MLP) network and the Method of Least Squares (MLS). The SVM classifier was found to give high classification accuracy and a smaller misclassification rate compared to …

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Complexity Analysis Of Industrial Organizations Based On A Perspective Of Systems Engineering Analysts, I. H. Garbie, A. A. Shikdar Apr 2025

Complexity Analysis Of Industrial Organizations Based On A Perspective Of Systems Engineering Analysts, I. H. Garbie, A. A. Shikdar

The Journal of Engineering Research

Complexity in industrial organizations became more difficult and complex to be solved and it needs more attention from academicians and technicians. For these reasons, complexity in industrial organizations represents a new challenge in the next decades. Until now, analysis of industrial organizations complexity is still remaining a research topic of immense international interest and they require reduction in their complexity. In this paper, analysis of complexity in industrial organizations is shown based on the perspective of systems engineering analyst. In this perspective, analysis of complexity was divided into different levels and these levels were defined as complexity levels. A framework …

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Adaptive Compensator Of Single State Elastoplastic Friction Model, A. A. Abouelsoud, J. Abdo, R. Zaier Apr 2025

Adaptive Compensator Of Single State Elastoplastic Friction Model, A. A. Abouelsoud, J. Abdo, R. Zaier

The Journal of Engineering Research

A nonlinear friction is an unavoidable phenomenon frequently experienced in mechanical system between two contact surfaces. An adaptive compensator is designed to achieve tracking of a desired velocity trajectory in the presence of friction force described by a single state elastoplastic friction model. The adaptive compensator includes an adaptive observer and a computed force controller. The closed loop system is shown to be stable using Lyapunov second method. Simulation results show the effectiveness of the proposed compensator.

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Effective Flange Width For Composite Steel Beams, T. Salama, H.H. Nassif Apr 2025

Effective Flange Width For Composite Steel Beams, T. Salama, H.H. Nassif

The Journal of Engineering Research

The effective flange width is a concept proposed by various codes to simplify the computation of stress distribution across the width of composite beams. Questions have been raised as to the validity of the effective slab width provisions, since they have a direct effect on the computed ultimate moment as well as serviceability limit states such as deflection, fatigue, and overloading. The objective of this paper is to present results from an experimental and analytical investigation to determine the effective slab width in steel composite beams. The Finite Element Method (FEM) was employed for the analysis of composite steel-concrete beams …

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Class-E Amplifier Design Improvements For Gsm Frequencies, Z. Nadir, F. Touati Apr 2025

Class-E Amplifier Design Improvements For Gsm Frequencies, Z. Nadir, F. Touati

The Journal of Engineering Research

Efficient power amplifiers are essential in portable battery-operated systems such as mobile phones. Also, the power amplifier (PA) is the most power-consuming building block in the transmitter of a portable system. This paper investigates how the efficiency of the power amplifier (which is beneficial for multiple applications in communcation sector) can be improved by increasing the efficiency of switching mode class E power amplifiers for frequencies of 900 MHz and 1800 MHz. The paper tackles modeling, design improvements and verification through simulation for higher efficiencies. This is the continuation of previous work by the authors. These nonlinear power amplifiers can …

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A General Model For Describing The Performance Of Brushless Doubly-Fed Induction Machines, S. M. Allam, A. M. Azmy, M. A. El-Khazendar Apr 2025

A General Model For Describing The Performance Of Brushless Doubly-Fed Induction Machines, S. M. Allam, A. M. Azmy, M. A. El-Khazendar

The Journal of Engineering Research

This paper presents a generalized model, by which the dynamic and steady-state behaviour of the Brushless Doubly-Fed Induction Machine (BDFIM) can be precisely predicted. The investigated doubly-fed machine has two sets of three-phase stator windings with different pole numbers. The rotor is a squirrel-cage type with a simple modification in order to support the two air-gap rotating fields that are produced by the stator windings and have different pole numbers. The machine model is derived in the qdo-axis variables. The qdoaxes are attached to rotor and hence, it rotates at the rotor speed (

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