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Global challenges of climate change, environmental control, and energy conservation are persisting. In museum buildings, facing these challenges is prominent to achieve the sustainability of our cultural heritage. Controlling the microclimate of the indoor environment in exhibitions where artefacts are conserved, stored and exhibited is a critical challenge that faces museums not only in Egypt but worldwide as well. The aim of this paper is to analyze the main operational practices for rational environmental control that consider preservation and conservation requirements. In order to achieve the objective of this paper, a literature review of recent papers discussing this problem has been performed and analyzed. Then, a survey was conducted to analyze the operation practices in museums in Egypt. At last, environmental assessment criteria were suggested to manage the museum indoor environment to conserve energy and preserve artefacts. The findings of this paper could guide those involved in decision making and setting legislations in Egyptian museums.

The authors have attempted to summarize the evolution of research in Construction Productivity (CP) through a Systematic Literature Review (SLR) from the papers published from 2006 to 2017. The methodology adopted for the study is to use the systematic literature review for selecting the papers published in a few selected major journals of construction, built environment, and construction management fields. A total of eight journals selected for the SLR and 101 papers have been selected using the keyword “Construction Productivity in the title or the Keywords”. The findings of the study conclude that the studies in CP are focused in seven main areas are industry-level studies, the study of factors/attributes, measurement techniques, simulation and models, equipment and technology, issues and problems associated with CP, and improvement techniques and proposed frameworks. Keywords: Construction productivity, Construction management, Project, Construction industry, SLR (systematic literature review)

This paper presents a new improved Direct Torque Control of doubly fed induction motor using PI controller tuned using genetic algorithm. The classical DTC control of DFIM is well known and is widely used due to its simplicity and easy implementation. However, the performances of conventional DTC are often characterized by high torque and flux ripples as well as variable switching frequency. To overcome the previous drawbacks of the classical DTC control, a new combined DTC-GA method using PI controller optimized by genetic algorithm is presented. The GA selects PI parameters that optimize the performances of conventional DTC. The PI parameters are optimized in offline mode where several values have been tested; then the best PI gains are used in online mode. The proposed DTC-GA method applied to DFIM has been validated using Matlab/Simulink environment. Many improvements related to torque and flux ripples overshoot and response time have been demonstrated. Which torque and flux ripple have been reduced more than 64.44% and 50 % respectively. The speed overshoot and torque overshoot have been reduced about 90% and 86% respectively. In addition, more details are presented and discussed in this paper. Keywords: Double Feed Induction Machine, Genetic algorithm, PI controller, Direct Torque Control, Reducing of torque and flux ripples

This research paper performs symmetrical transient response analysis of FO4 inverter logic gate at 16-nm technology node. It is observed that symmetry is obtained at the aspect ratio (β) is equal to 3.52. With this β ratio, minimum energy point is investigated and found to be 0.15 V. At this minimum energy point, this research paper proposes an ultralow-power 10T 1-bit full adder circuit at 16-nm technology node in subthreshold region for energy constraint applications. It exhibits superior performance in terms of design metrics like propagation delay, average power, leakage power and energy at optimum supply voltage i.e., at 0.15 V. The proposed design achieves 1.81×, 3.39×, 2.25×, and 6.12× improvement in propagation delay, average power dissipation, leakage power dissipation and energy compared to conventional 1-bit full adder circuit. The proposed design exhibits 1.02× improvement in average power variability. Keywords: 1-bit full adder, Minimum energy point, Output voltage swing, Propagation delay, Power consumption, Ultralow power circuit

In this paper, an approach for optimal placement of D-STATCOM in mesh distribution systems using sensitivity approaches is proposed. The main contributions of the paper are as follows: (i) Optimal D-STATCOM placement based on the new voltage sensitivity index in mesh distribution system, (ii) optimal D-STATCOM size determination for seasonal loads with load growth scenario, (iii) comparison of D-STATCOM placement and size determination with the existing sensitivity methods, and (iv) impact of optimal D-STATCOM placement on voltage stability margin enhancement, energy loss reduction and cost of energy savings.The results of voltage profile improvement, reduction in power losses, reduction in cost of energy loss, improved voltage stability margin, cost of energy loss savings, installation cost of D-STATCOM and annual savings are obtained for UK 38 bus practical mesh distribution system. Keywords: Mesh distribution system, Load model, D-STATCOM, Sensitivity indices, Loss reduction, Annual energy savings

This paper presents differential search algorithm in order to solve reliability optimization problem of radial distribution network. Remote control switches have been optimally allocated to improve reliability at a compromised cost. A multi-objective problem has been formulated and solved using differential search algorithm. The test systems considered in this paper are an 8 bus radial distribution network and a 33 bus radial distribution network. Simulation results obtained using differential search algorithm when applied to the test cases, have been compared with those obtained by particle swarm optimization. Differential search algorithm has been found to provide superior results as compared to particle swarm optimization. Keywords: Differential search algorithm, Multi-objective function, Radial distribution system, Remote control switches, Repair time, Restoration time

This paper studies the power electronic converters for grid connection of axial flux permanent magnetic synchronous generators (AFPMSG) based variable speed wind turbine. In this paper, a new variable speed wind turbine with AFPMSG and Z-source inverter is proposed to improve number of switches and topology reliability. Besides, dynamic modeling of AFPMSG is presented to analyze grid connection of the proposed topology. The Z-source inverter controls maximum power point tracking (MPPT) and delivering power to the grid. Therefore other DC–DC chopper is not required to control the rectified output voltage of generator in view of MPPT. As a result, the proposed topology requires less power electronic switches and the suggested system is more reliable against short circuit. The ability of proposed energy conversion system with AFPMSG is validated with simulation results and experimental results using PCI-1716 data acquisition system.

Multi-core processors support all modern electronic devices nowadays. However, power management is one of the most critical issues in the design of today’s microprocessors. The goal of power management is to maximize performance within a given power budget. Power management techniques must balance between the demanding needs for higher performance/throughput and the impact of aggressive power consumption and negative thermal effects. Many techniques have been proposed in this area, and some of them have been implemented such as the well-known DVFS technique which is used in nearly all modern microprocessors. This paper explores the concepts of multi-core, trending research areas in the field of multi-core processors and then concentrates on power management issues in multi-core architectures. The main objective of this paper is to survey and discuss the current power management techniques. Moreover, it proposes a new technique for power management in multi-core processors based on that survey.

In this paper, a novel approach to determine the optimal location and sizing of Distribution Generation (DG) and Distribution STATic COMpensator (DSTATCOM) is analyzed, and the objective function is formulated for minimizing power loss, operational costs and voltage profile enhancement of the system subjected to equality and in equality constraints. Loss sensitivity factor (LSF) is used to pre-determine the optimal location of DG and DSTATCOM. The Bacterial Foraging Optimization Algorithm (BFOA) is proposed to determine the optimal size of the DG and DSTATCOM. In this paper, the DG and DSTATCOM are simultaneously allocated in radial distribution system and it is analyzed with different load models. To check the feasibility, the proposed method is tested on IEEE 33-bus and 119-bus radial distribution system and the results were compared with other existing technique.

Heterogeneous wireless networks are an integration of two different networks. For better performance, connections are to be exchanged among the different networks using seamless Vertical Handoff. The evolutionary algorithm of invasive weed optimization algorithm popularly known as the IWO has been used in this paper, to solve the Vertical Handoff (VHO) and Horizontal Handoff (HHO) problems. This integer coded algorithm is based on the colonizing behavior of weed plants and has been developed to optimize the system load and reduce the battery power consumption of the Mobile Node (MN). Constraints such as Receiver Signal Strength (RSS), battery lifetime, mobility, load and so on are taken into account. Individual as well as a combination of a number of factors are considered during decision process to make it more effective. This paper brings out the novel method of IWO algorithm for decision making during Vertical Handoff. Therefore the proposed VHO decision making algorithm is compared with the existing SSF and OPTG methods.

In this paper, an analytical threshold voltage model is proposed for a cylindrical gate-all-around (CGAA) MOSFET by solving the 2-D Poisson’s equation in the cylindrical coordinate system. A comparison is made for both the center and the surface potential model of CGAA MOSFET. This paper claims that the calculation of threshold voltage using center potential is more accurate rather than the calculation from surface potential. The effects of the device parameters like the drain bias ( V DS ) , oxide thickness ( t ox ) , channel thickness (r), etc., on the threshold voltage are also studied in this paper. The model is verified with 3D numerical device simulator Sentaurus from Synopsys Inc.

The ever increasing demand and depletion of fossil fuels had an adverse impact on environmental pollution. The selection of appropriate source of biodiesel and proper blending of biodiesel plays a major role in alternate energy production. This paper describes an application of hybrid Multi Criteria Decision Making (MCDM) technique for the selection of optimum fuel blend in fish oil biodiesel for the IC engine. The proposed model, Analytical Network Process (ANP) is integrated with Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) and VlseKriterijumska Optimizacija I Kompromisno Resenje (in Serbian) (VIKOR) to evaluate the optimum blend. Evaluation of suitable blend is based on the exploratory analysis of the performance, emission and combustion parameters of the single cylinder, constant speed direct injection diesel engine at different load conditions. Here the ANP is used to determine the relative weights of the criteria, whereas TOPSIS and VIKOR are used for obtaining the final ranking of alternative blends. An efficient pair-wise comparison process and ranking of alternatives can be achieved for optimum blend selection through the integration of ANP with TOPSIS and VIKOR. The obtained preference order of the blends for ANP-VIKOR and ANP-TOPSIS are B20 > Diesel > B40 > B60 > B80 > B100 and B20 > B40 > Diesel > B60 > B80 > B100 respectively. Hence by comparing both these methods, B20 is selected as the best blend to operate the internal combustion engines. This paper highlights a new insight into MCDM techniques to evaluate the best fuel blend for the decision makers such as engine manufactures and R& D engineers to meet the fuel economy and emission norms to empower the green revolution.

This paper presents a methodology based on graph theoretic approach (GTA) to design a new cogeneration cycle power plant (CGCPP), improvement of existing plant and comparison of two real life operating cogeneration cycle power plants. Different combinations may be suggested by a manufacturer to an organization for selecting or improving the efficiency of a power plant. This paper identifies various design parameters affecting cogeneration cycle power plant efficiency. All these parameters are interacting with each other by different amounts. An attempt has been made to develop a mathematical model of CGCPP from these interacting parameters using GTA. A CGCPP efficiency index is proposed which evaluates the influence power of these parameters.

Buildings' facades significantly impact human thermal comfort and the energy budget of buildings. It is estimated that 73% of heat losses or gains are immediately linked to the configuration and types of materials in the buildings' envelope. Building styles in the Kingdom of Saudi Arabia witnessed a large and growing expansion in curtain walls, glass facades, metal cladding, and precast concrete. It is striking that terracotta cladding is most often associated with school building facades, especially the government ones, with very limited applications in other building types. This paper investigates the energy-related budget of using Aluminum and terracotta cladding in an educational facility in KSA. The article follows the experimental approach. Data about both cladding materials' specifications were obtained and input into the virtual model building in DesignBuilder software for simulation and analysis. The comparative analysis of energy consumption during the building's operational phase in both cases revealed that more energy budget was needed in the case of Aluminum cladding to provide thermal comfort to the occupants. The study concludes that the efficiency of thermal insulation of Terracotta is better than the Aluminum sheets. On the other hand, and in the long run, the study underscores the preference of using Aluminum cladding for its extensive reuse and recycling potential. Brittleness of Terracotta limits its prospects for recycling; therefore, it might be more energy-consuming when frequently reproduced for new applications or maintenance purposes throughout the building life cycle.

This paper proposes a novel concept for ground faults locating on the basis of the traveling waves principles for EHV transmission systems. The transient surges generated due to single-pole breaker opening are localized in order to determine the accurate fault distance on the basis of single-end measurements. The proposed fault location concept is independent of the propagation speed. Also, the proposed strategy of creating traveling surges is exploited with synchronized double-end measurements. Time extraction of traveling surges is performed using the second derivative of the aerial mode voltage after breaker pole opening. The proposed algorithm is evaluated using transmission systems of multiple terminals. The results provide evidence the efficacy of the proposed fault location mechanism. Keywords: Earth fault location, Single-pole autoreclosure, Transient surges, Traveling waves

This paper presents the design and performance analysis of Flower Pollination Algorithm (FPA) based Proportional Integral Derivative (PID) controllers for Automatic Generation Control (AGC) of an interconnected power system. A two area thermal system with governor dead-band nonlinearity is considered for the design and analysis purpose. A different kind of approach is made to design a multi-objective function which contains weighted performance functions such as ISE, IAE, ISTE, ITAE. These weights are the functions of system response. It is noticed that the dynamic performance of new objective optimized PID controller is better than the others mentioned in the literature. The objective function also includes performance response for various percentage of loads, so that obtained gain parameters are optimal for dynamic load conditions. Keywords: Flower pollination, Weights, Dynamic loading, Automatic generation control, Two area thermal system, Governor dead-band nonlinearity

Renewable energy systems especially the wind energy grows worldwide continuously. Also, installations of the wind farms increase in remote area applications. The self-excited induction generator (SEIG) is an effective choice for using in these applications due to its merits. This paper presents a cuckoo search algorithm (CSA) optimizer for steady state analysis of the SEIG. The mathematical model of the SEIG is based on equivalent circuit loop impedance method. The target of optimization is to minimize the total equivalent circuit impedance of the generator in order to obtain the frequency and any other unknown parameter of the SEIG. In this study, the frequency and magnetizing reactance define the search space for the optimization problem. The MATLAB CSA optimization toolbox is used to solve optimization problem. The effectiveness of the proposed optimizer is evaluated on a 220 V, 0.75 kW induction generator for various operating conditions. The effectiveness of the CSA model is then compared with other conventional optimization models. The validity of the proposed optimizer is verified by experimental results. With this proposed CSA optimization technique, a faster and an accurate prediction for steady state analysis of the SEIG are achieved. Keywords: Cuckoo search algorithm, Optimization, Self-excited induction generator, Steady-state analysis, Wind energy

In Broadband Communications (BBC), terms like “Green Communication (GC)”, “Energy Efficiency (EE)”, and “Opportunistic Cognitive Radio (OCR)” are pursuing methods for saving energy consumption while accomplishing communications. Good implementations of these terms/concepts contribute in reducing pollution and preserve nature resources. Forthcoming mobile generations will face many tradeoffs between EE considerations versus system performance parameters especially throughput. In a multi-channel OCR system, the Secondary User (SU) senses some selected candidate primary channels based on a “belief” concept. This belief state represents the occupancy/vacancy state of the primary channel and is deduced via a Partial Observation Markov Decision Process (POMDP). Within the OCR transmission frame, a fixed time-period at the beginning of this frame is dedicated for sensing multi primary channels. The SU performs the sensing needed to explore the state of occupancy/vacancy/fading of primary channels -within the sensing period- by dedicating a sensing slot for sensing each primary channel, then, SU updates its channel state belief accordingly. SU may not find it necessary to continue sensing more channels -using more sensing slots- in case of “low belief”, “bad CSI”, “highly believed to be occupied”, or even “sleep” if no candidate channels exist. This will lead to residual (not used) sensing slots which will be a wasted time in the frame time interval. This paper proposes an enhanced algorithm (to a previous work Feng and Gan, 2015) where these unused sensing slots are utilized to enhance the system EE. This is done by manipulating extended variable time induced from using these residual slots to extend the available transmission time. This induced variable time will increase throughput while keeping sensing energy. The metric used in this work is the Normalized Energy Efficiency (NEE) which is in consistence with many research directions in this field. In Feng and Gan (2015), the obtained NEE results reached ∼93% after about 20 transmitted frames, as well as, when 20 primary channels exist in the system. This work proposed an enhanced optimum and approximate algorithms that obtain as high as ∼135% of NEE after about 20 transmitted frames, they also obtained ∼228% using the optimum algorithm, or, ∼138% using the approximate algorithm when 20 primary channels are available. Keywords: Green cellular, Energy efficiency, Cognitive radio, Partially observable Markov decision process, Heterogeneous wireless networks

The correct use of glass in office buildings plays a key role in the efficient use of energy especially with the application of nanotechnology. The main aim of this paper was to identify the capability of the different types of glass used in the building envelope to reduce energy consumption in office buildings. The chosen type will be combined with different Window to Wall Ratios (WWRs) and orientations to verify its efficiency. For this purpose, a simulation tool was used (Design Builder 3.1), then a comparison was done to test the performance of different types of glass and different orientations with the same glass thicknesses. The results are put into comparison in order to identify the best type of glass which can help in reducing the cost of energy consumption and how can it comply with the Egyptian energy code requirements for glass type which achieve energy efficiency. The results indicate that the use of glass treated with nanotechnology (Low-E) which have indices of (Solar Heat Gain Coefficient (SHGC) = 0.23), (Light Transmission (LT) = 0.42), (U Value (UV) = 1.55) reduces energy consumption by more than 20% compared to the standard 6 mm clear glass. Keywords: Nanotechnology, Energy saving, Thermal comfort, Low-E glass

Architecture, Engineering and Construction (AEC) industry is classified as a huge consumer of natural resources. It consumes 50% of natural material resources, 40% of energy and is responsible for 50% of total waste. Subsequently, different sustainability indices and environmental certifications have been introduced to AEC. As a result, most construction firms turn to green building designs and acquire different environmental certifications. Recently, the concept of lean management has been introduced to AEC after succeeding in manufacturing. This paper aims at examining the interaction between lean and sustainability principles on the management process of design and construction projects. Towards achieving this aim, two approaches were employed, namely literature review, and a correlation matrix to verify the area of interaction between both lean construction and sustainability principles. Findings took the form of guidelines for AEC companies to help in applying the integrated lean and sustainability principles on managing design and construction processes. Keywords: Sustainability, Lean, Architecture, Engineering and Construction

This paper proposes an improved fast dynamic system for controlling Matrix Converter (MC) based on modified hysteresis current controller using optimal tuning PI controller. An improved Bacterial Foraging Optimization (BFO) technique is employed for controlling the active and reactive current components of the Permanent Magnet Synchronous Generator (PMSG) to extract the maximum power from the wind. This proposed controller has the ability to supply the grid by both active and reactive power at normal and fault conditions. Dynamic limiter is employed with the proposed improved BFO controller to control the injected reactive power to the grid during Low Voltage Ride Through (LVRT) at a range limited by MC rated current to improve the system stability. The pitch angle controller with rate limiter was implemented in the proposed controller to protect WECS from mechanical damage. The simulation results prove the validity of the proposed controller under any conditions. Keywords: Wind energy, Permanent magnet synchronous generator, Hysteresis current control, Matrix converter, Bacterial foraging optimization, Low voltage ride through

Flood hazards to vehicle have become more frequent and noticeable in the recent years. Therefore, this paper aims at estimating the forces observed on a partially submerged vehicle in floodwater, namely frictional, buoyancy, lift and drag forces. An understanding of the relevant forces involved is necessary to attempt to characterize the instability thresholds of vehicles in floodwater flows. With that regards, a model vehicle with the scale ratio of 1:24 was used and a series of flume experiments were conducted. While determining the vertical pushing force, the influence of lift force was found insignificant due to sub-critical state of the flow. Moreover, the critical water depth at which the up-thrust force governed was observed when the water depth exceeded 0.042 m. Below critical depth, the vehicle stability governed unless the drag force imposed by the flowing water was lower than the frictional force between the tires and floodplain surface. Keywords: Hazard, Vehicle instability, Partially submerged vehicle, Floodwaters

Border Gateway Protocol (BGP) is the defecto standard routing protocol of the internet and has served as backbone technology for logical routing tasks to provide global connectivity in the world. Unfortunately, there are limitations on network performance factors such as latency or link utilization which are not used in BGP routing decisions. These limitations have a great effect on internet services, especially bandwidth sensitive application, where BGP does not automatically redistribute the traffic over different Multihomed links based on link utilization or latency. In this paper, a novel control mechanism for BGP (BGP-NCM) is proposed. BGP-NCM is a software controller which has been developed and injected in the Enterprise or internet service provider BGP multihomed network to force the traffic redistribution over the available links based on the link utilization or latency. The BGP-NCM has been developed using Python programming language and it consists of three modules which are Monitoring, Traffic Calculation and Configuration modules. BGP-NCM will keep an eye on link utilization by checking the monitoring tool log and when the link utilization reaches a predefined value, the BGP-NCM traffic calculation module will be triggered to determine the amount of traffic and corresponding IP prefix as well as the target link with available bandwidth to accommodate the redistributed traffic. Our results show that BGP-NCM solves the traffic redistribution problem without any change in both BGP protocol and running internet infrastructure. Keywords: Bandwidth, BGP, BGP-NCM, Utilization, Multihomed, Python, Quagga, SLA, SNMP

In this paper, a new optimization method is proposed to solve the optimal sizing and siting problem of distributed generation (DG) in a distribution system (DS). The optimization problem is solved using a new ant lion optimizer (ALO) with considering different objectives. These objectives are reduction of purchased energy cost from upstream network (due to DGs’ power generation), reliability improvement, reduction of DGs’ application cost, reduction of DS losses and reduction of buses’ voltage deviation. This problem is solved as a multi-objective optimization (MOO) in addition of a single-objective optimization (SOO). The proposed DGs optimal sizing and siting is implemented on 33 and 69-bus IEEE networks. The obtained results show that the ALO has the best performance in extracting the solution of DGs optimal sizing and siting problem in comparison to particle swarm optimization (PSO) and genetic algorithm (GA). Keywords: Optimal sizing and siting, Distributed generation, Ant lion optimizer, Reliability

This paper proposes a novel hybrid centralized and distributed control of hybrid renewable energy system consisting of AC/DC micro grids. An Interlinking Converter (IC) is used to connect both sides of the micro grid systems together. Improved Particle Swarm Optimization (IPSO) which acts as a master controller is used to control the power of the sources based on IC control. Also, there are different slave controllers for 100 kW photovoltaic, fuel cells and 100 kW wind, which are designed to supply continuous load power. Coordination between two grids is satisfied through droop control for both AC and DC micro grids to achieve power sharing process and control of renewable energy sources supplying different loads. The model has been implemented in MATLAB/SIMULINK. The proposed controller succeeded to manage energy between micro grids under different scenarios. The control technique using IPSO strategy improves the dynamics of the hybrid system connected to the grid. Keywords: Particle swarm optimization, Interlinking converter, AC/DC micro girds, Distributed generation, Control, grid fault

Muffling devices are essential parts of any vehicle/machine that uses internal combustion engines. From automotive manufacturers point of view, they contribute massive sheet metal processing and production time, especially mufflers that are produced at high rates for commercial vehicles. This paper is concerned with applying manufacturing procedures to reduce the production cost of any commercial automotive mufflers through theoretical studies and experimental measurements verification. Mufflers design parameters such as transmission loss, flow generated noise and pressure drop were selected for performance judgment, parameters were simulated and experimentally measured. The transfer matrix method was used to calculate the propagation of sound waves along the muffler. A commercial automotive muffler with a hybrid combination of dissipation and reflection was selected for application and a new design was proposed for this muffler with a reduced manufacturing cost. The manufacturing processes were reduced by 77.7% and consequently the cost relative to the original muffler. Keywords: Commercial vehicle, Vehicle economics, Perforated muffler, Dissipative muffler, Exhaust system manufacturing

One of the effective devices to eliminate voltage disturbances of sensitive loads in distribution systems is dynamic voltage restorer (DVR). In previous studies, the sinusoidal pulse width modulation (SPWM) method has been used as a switching method for DVR. However, a new switching approach called “one cycle control” (OCC) is presented in this paper for a three-phase DVR which has higher performance in dynamic and steady state operations compared to SPWM and is also simple and fixed in frequency. Moreover, this approach has few uncomplicated steps which make it suitable for practical implementation. In this study, the ability of the proposed approach is evaluated on two different types of DVR. The first DVR has fictitious dc link. In the second DVR, a battery is used in dc link. The proposed method can improve power quality disturbances such as voltage sag, voltage swell, and flicker. The ability of operating under changing parameters of load can show the robustness of the proposed approach. The simulation results obtained by OCC in six case studies were compared to the results obtained using the PWM method, revealing the higher efficiency of OCC than the PWM method. Keywords: DVR, OCC, PWM, Voltage disturbances, Voltage sag, Voltage swell

This paper presents an experimental and a FE analysis of the compressive behavior of slender section columns with and without stiffeners. A series of tests was performed on specimens with different overall heights and different number of stiffeners. A nonlinear three-dimensional FE model was developed using ANSYS program. The efficiency of the nonlinear FE model was verified and a parametric analysis was performed considering variation of number of stiffeners, values of web depth-to-thickness ratio, flange-to-thickness ratio, and slenderness ratio. The load carrying capacity of steel columns with large web-to-thickness ratio is noticeably enhanced up to 34% by increasing number of web stiffeners. Initial imperfection during fabrication should be well controlled and should be carefully considered in the FE modelling. Post local buckling strength of the sections is more sensitive to web width–thickness ratio than flange width–thickness ratio. Keywords: Slender sections, Local buckling, Stiffened I-column, Web stiffener, FE simulation, ANSYS

This paper presents heuristic modified group search optimization (MGSO) algorithm for solving multi-objective combined economic power and emission dispatch problem. Some modifications are applied on the conventional GSO method to improve its convergence characteristics. Simulations are carried out on IEEE 30 bus standard system in order to validate effectiveness of the proposed method. Simulation analyses are implemented for mentioned system with and without loss considering pure power, pure emission and combined economic power and emission dispatch. Numerical results indicate that, the proposed method has better performance and convergence time, in comparison with some recently published methods. Keywords: Multi-objective optimization, Environmental dispatch, Group search optimization, Combined power and emission dispatch

The increasing concern of power systems toward distributed generation enables modern power grids and energy management systems to focus their concentration to derive an optimal operational planning with regard to energy costs minimization of Micro-Grid and better utilization of Renewable Energy Sources in the presence of Battery Energy Storage. This paper presents Quasi-Oppositional Swine Influenza Model Based Optimization with Quarantine (SIMBO-Q) to minimize total operation cost of Micro-Grid considering optimal size of Battery Energy Storage. SIMBO-Q performs the optimization through quarantine and treatment loop based on probability. However SIMBO-Q algorithm takes large number of iterations to reach to the optimum solution if the system has large number of variables. To overcome this limitation and to improve computational efficiency, quasi-opposition based learning concept is introduced in basic SIMBO-Q algorithm. The proposed algorithm is tested on a typical Micro-Grid and simulation results establish that the proposed approach outperforms several existing optimization techniques.

In this paper, krill herd algorithm (KHA) technique is employed to solve the short-term hydrothermal scheduling (HTS) problem. In this article, the potentialities of DE are used in KHA technique to improve the convergence speed and robustness. The practical short-term HTS problem is solved here using KHA technique in which the crossover and mutation operation of differential evolution algorithm (DEA) is employed to efficiently control the local and global search, so that premature convergence may be avoided and global solutions can be achieved. The quality and usefulness of the proposed algorithm is demonstrated through its application to two standard test systems. The simulation results reveal that the current proposal is better in comparison with the other existing techniques in terms of computational time and the quality of the solutions obtained.

This paper analyses the acoustic conditions inside two lecture rooms in faculty of agriculture, Cairo University, based on field measurements and simulation technique. Ambient noise and reverberation time were measured in the unoccupied rooms. The measurement results were utilized for validating the results of CATT software that was used to estimate occupied reverberation time, STI and C 50 . These parameters were analysed in comparison with rooms’ properties, optimal reverberation time and maximum acceptable noise for learning spaces. The results demonstrated that acoustic design of the first room is far from the recommended values, whereas the second room includes many defects. For optimizing the rooms’ performance, acoustic treatments were proposed and explored. Results clarified that reducing the excessive reverberation to the optimal value, either by increasing room absorption or decreasing room volume, significantly optimizes speech intelligibility. The results also clarified that reforming the ceiling eliminated the shadow and increased the early reflections.

The dynamic plate loading test using the Light Falling Weight Deflectometer (LFWD) is an innovative and very simple method used for quick assessment of the field compaction quality. The basic outcome of the LFWD test is the dynamic resilience modulus of the tested soil. This paper concisely presents the state-of-the-art for the theory and applications of the LFWD test. Moreover, an attempt is made in this study to use the finite element method for simulating the LFWD test and investigating the consequent soil response. An axisymmetric model is established to simulate a realistic case study of in-situ LFWD test. Different soil models are examined for adequately simulating the soil performance, including linear elastic, Mohr–Coulomb and Hardening-Soil models. The finite element analysis is applied to investigate the factors that probably affect the LFWD results. Furthermore, an attempt to ascertain the influence depth of the LFWD is provided.

The high penetration of the wind energy in the power systems raises some issues such as ramping and mismatch between the wind power and power demand. One of the possible solutions to these issues is the demand side management (DSM). In this paper, dynamic economic dispatch (DED) incorporating different penetration levels of wind energy and utilizing the DSM is proposed to solve the issues related to high penetration of wind energy. The effect of utilizing the DSM on the operation cost with different test cases is discussed. The General Algebraic Modeling System (GAMS) using BARON as a solver and genetic algorithm (GA) with hybrid function are used to solve the proposed DED model and a comparison between them is assessed. The proposed model is applied to a six units’ generation system to test the effectiveness of the proposed model.

In this paper, a sensorless permanent magnet synchronous motor (PMSM) drive was presented based on direct power control (DPC) technique. To estimate the rotor’s position and speed of PMSM, a drastic sensorless strategy was developed according to artificial neural network (ANN) to reduce the cost of the drive and enhance the reliability. The proposed sensorless scheme was an innovative model reference adaptive system (MRAS) speed observer for DPC control PMSM drives. The suggested MRAS speed observer employed the current model as an adaptive model. The ANN was then designed and trained online by employing a back propagation network (BPN) algorithm. Performance of the proposed strategy was adopted using simulation analysis. The results showed the fast dynamic response, low ripples in motor’s currents, power, and electromagnetic torque, as well as good performance in tracking speed and power references.

In this paper, artificial neural networks (ANNs) modeling method with back propagation algorithm was employed to investigate the flow characteristics below vertical and inclined sluice gates for both free and submerged flow conditions. Two ANN models were developed yielding two generalized equations to predict the discharge coefficient (Cd) values for both modes of flow. The model network for free flow entailed four input variables, namely, dimensionless upstream water depth, Froude number, Reynolds number, and inclination angle, whereas, the Cd value represented the only single output variable. For submerged flow ANN model, a fifth input variable was added, which is the dimensionless tailwater depth. The two ANN models were trained and validated against 420 data sets collected from previous experimental studies. The results indicated that ANNs are powerful tools for modeling flow rates below both types of sluice gates within an accuracy of ±5%.

This paper suggests quinary asymmetric inverter with coupled inductors and transformer, and uses it in hybrid system including photovoltaic (PV) and wind. This inverter produces twenty-five-level voltage in addition to merits of multilevel inverter, has only one DC source. Then, it is adequate for hybrid systems, which prevents increasing DC-link and makes control of system easy. Proposed structure also provides isolation in the system and the switch numbers are reduced in this topology compared with other multilevel structures. In this system, battery is used as backup, where PV and wind have complementary nature. The performance of proposed inverter and hybrid system is validated with simulation results using MATLAB/SIMULINK software and experimental results based PCI-1716 data acquisition system.

Optimal reactive power dispatch (ORPD) problem has a significant influence on optimal operation of power systems. However, getting optimal solution of ORPD problem is a strenuous task for the researchers. The inclusion of flexible AC transmission system (FACTS) devices in the power system network for solving ORPD problem adds to its complexity. This paper presents the application of chemical reaction optimization (CRO) for optimal allocation of a static synchronous compensator (STATCOM) to minimize the transmission loss, improve the voltage profile and voltage stability in a power system. The proposed approach is carried out on IEEE 30-bus and IEEE 57-bus test systems and the simulation results are presented to validate the effectiveness of the proposed method. The results show that the proposed approach can converge to the optimum solution and obtains better solutions as compared to other methods reported in the literature.

In this paper, a hybrid method is proposed for reducing the amount of load shedding and voltage collapse. The hybrid method is the combination of Genetic Algorithm (GA) and Neural Network (NN). The GA is used by two stages, one is to frame the optimization model and other stage is to generate data set for developing the NN based intelligent load shedding model. The appropriate buses for load shedding are selected based on the sensitivity of minimum eigenvalue of load flow Jacobian with respect to the load shed. The proposed method is implemented in MATLAB working platform and the performance is tested with 6 bus and IEEE 14 bus bench mark system. The result of the proposed hybrid method is compared with the GA based optimization algorithm. The comparison shows that, the proposed method ensures voltage stability with minimum loading shedding.

Assessment of the reliability of wall-frame structures using simulation based method is often prohibited by the costly and lengthily computations. The present paper introduces a response surface based technique to quickly extract the reliability and safety information. The proposed method couples the finite element (FE) model of wall-frame structure, an improved response surface scheme and the second order reliability method (SORM). At the beginning, the large number of the random variables is reduced via preliminary sensitivity analysis. Then, the failure region is reached through a repetitive strategy integrated with recommended experimental designs. The efficiency and accuracy of the scheme are verified using Monte Carlo simulation. Moreover, both serviceability and flexural limit states are used in the verification. Tens of simulations are used instead of hundreds or thousands. The method is simple, efficient and can be easily implemented. For the considered example, the lateral load and the wall stiffness are the most important variables.

Thermal insulations over the building envelop reduce the heat gain due to solar radiation and may enhance good and uniform indoor thermal comfort for the occupants. In this paper, the insulation layer-wood wool is laid over the roof and exposed wall of an air-conditioned room and its performance on indoor thermal comfort is studied by computational fluid dynamics (CFD) technique. From this study, 3% of indoor thermal comfort index-predicted mean vote (PMV) is improved by providing wood wool layer. In addition, the optimum supply air temperature of air-conditioning unit for good thermal comfort is predicted as in the range of 299–300 K (26–27 °C).

Scour around bridge supports such as abutments can result in structural collapse and loss of life and property, so there is a need to control and minimize the local scour depth. In this paper, numerical and experimental studies were carried out to investigate the effect of different relative radii of the bridge abutment provided with collar on local scour depth. A 3-D numerical model is developed to simulate the scour at bridge abutment using SSIIM program. This model solves 3-D Navier–Stokes equations and a bed load conservation equation. The k–ε turbulence model is used to solve the Reynolds-stress term. It was found the curvature shape of bridge abutment provided with collar could share to reduce the local scour depth by more 95%. In addition, the results of simulation models agree well with the experimental data.

This paper aimed to monitor the different bus parameters in a substation from a centralized control room with the help of Zigbee enabled wireless sensor network (WSN). The parameters such as magnitude and phase angles of voltage and current, frequency, rate-of-change-of-frequency (ROCOF), active and reactive powers are measured using a state-of-the-art customized Zigbee enabled phasor measurement unit (ZPMU). The data from different ZPMUs at different bus nodes are acquired with the help of WSN system in order to have a centralized monitoring of different equipments load status. The coordination among different parameters for different buses and/or equipment is done from a centralized control room within the substation or plant with the help of substation management software and Zigbee networking. The data thus collected are utilized to study the power flow status of the different buses on real time basis and are stored within a server based database for future analysis purposes.

Ultrasonic machining (USM) is a mechanical material removal process used to erode holes and cavities in hard or brittle workpieces by using shaped tools, high-frequency mechanical motion and an abrasive slurry. Unlike other non-traditional machining processes, such as laser beam and electrical discharge machining, USM process does not thermally damage the workpiece or introduce significant levels of residual stress, which is important for survival of materials in service. For having enhanced machining performance and better machined job characteristics, it is often required to determine the optimal control parameter settings of an USM process. The earlier mathematical approaches for parametric optimization of USM processes have mostly yielded near optimal or sub-optimal solutions. In this paper, two almost unexplored non-conventional optimization techniques, i.e. gravitational search algorithm (GSA) and fireworks algorithm (FWA) are applied for parametric optimization of USM processes. The optimization performance of these two algorithms is compared with that of other popular population-based algorithms, and the effects of their algorithm parameters on the derived optimal solutions and computational speed are also investigated. It is observed that FWA provides the best optimal results for the considered USM processes.

The design and performance analysis of a Sugeno fuzzy logic (SFL) controller for an autonomous power system model is presented in this paper. In gravitational search algorithm (GSA), the searcher agents are collection of masses and their interactions are based on Newtonian laws of gravity and motion. The problem of obtaining the optimal tunable parameters of the studied model is formulated as an optimization problem and the same is solved by a novel opposition based GSA (OGSA). The proposed OGSA of the present work employs opposition-based learning for population initialization and also for generation jumping. In OGSA, opposite numbers are utilized to improve the convergence rate of the basic GSA. GSA and genetic algorithm are taken for the sake of comparison. Time-domain simulation reveals that the developed OGSA-SFL based on-line, off-nominal controller parameters for the studied model give real-time on-line terminal voltage response.

This paper presents a study on the seismic nonlinear performance of 86 multistory dual systems irregular in elevation and constructed from normal strength concrete (with fc = 25 MPa) and high-strength concrete (with fc = 75 MPa). The applicability of the Static Equivalent Lateral Force (SELF) method used by the seismic codes in Europe (Eurocode 8), in the United States (IBC-2012) and in Egypt (EC201-2008) when applied to dual systems irregular in elevation and con- structed from NSC and HSC is examined. In addition, the reliability of the criteria provided by the studied codes, in order to separate the regular from irregular dual systems is also verified. Records of two real earthquakes (El Centro and Parkfield) and one artificial earthquake, with wide ranges of frequency content have been selected as input ground motions. The results showed that the limits in IBC-2012 and EC201-2008 aimed to identify the lateral stiffness irregularity are satisfactory and can be relaxed by about 10%. 2013 Production and hosting by Elsevier B.V. on behalf of Ain Shams University.

This paper presents a Particle Swarm Optimization (PSO) technique and bacterial foraging (BF) technique for determining the optimal parameters of (PID) controller for speed control of a brushless DC motor (BLDC) where the (BLDC) motor is modeled in simulink in Matlab. The proposed technique was more efficient in improving the step response characteristics as well as reducing the steady-state error, rise time, settling time and maximum overshoot.

This research investigates the effect of implementing oriented groins on the scour and silting processes in a straight channel. Combined physical and numerical models were used. Twenty-seven (27) runs were conducted in which the geometry of scour and silting associated with model groins was evaluated. Groin models were angled at 60°, 90°, and 120° to the downstream channel side wall with contraction ratios of 0.10, 0.15 and 0.20. The main goals of this paper were to evaluate the effect of the three angles on the scour geometry on minimizing erosion adjacent to the stream banks. Results were analyzed and were graphically presented and the percentages of errors between the obtained results from the used models were reported to define the sufficient compatibility between the used models. Simple formulae were derived to evaluate the scour and silting parameters.

In this paper, we incorporate the idea of waveband switching in Mixed Line Rates (MLR) network design to address the problem of dynamic traffic grooming in waveband switching networks by investigating a cost function which take the effect of call holding time on the time slot assignment process of in WDM–TDM. Use has been made of Markov model in order to predict the wavelength congestion. A routing algorithm is developed based on the Markov modeling. The results are compared with existing routing algorithms – Available Shortest Path (ASP) and Online Traffic Grooming Algorithm (OTGA). Validation results have shown that the performance of the proposed system is significantly improved in terms of bandwidth blocking ratio, network utilization as well as port saving due to wavebanding.

There is an increasing trend of using space vector pulse-width modulation (SVPWM) schemes for driving voltage source inverters because of their easier digital realization and better DC bus utilization. This paper introduces an SVPWM technique based on a reduced computation method, which is much simpler and more executable than conventional means without lookup tables or complex logical judgments. The SVPWM scheme is modeled and simulated using MATLAB SIMULINK and experimentally implemented and verified on microchip PIC microcontroller 18F4431 platform. The experimental results are presented for three-phase two-level inverter followed by three-phase LC filter.