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Unraveling the nature of sensing in electrostatic MEMS gas sensors

Microsystems & Nanoengineering 2024年第3期10卷 109-117页

作者： Yasser S.Shama Sasan Rahmanian Hamza Mouharrar Rana Abdelrahman Alaaeldin Elhady Eihab M.Abdel-Rahman Systems Design Engineering University of Waterloo200 University Ave WWaterloo N2L 3G1 ONCanada Mechanical Engineering Benha Faculty of EngineeringBenha UniversityBenha 13511Egypt

This paper investigates the fundamental sensing mechanism of electrostatic MEMS gas *** compares among the responsivities of a set of MEMS isopropanol sensors before and after functionalization,and in the presence and absence of electrostatic fields when operated in static and dynamic detection *** the static mode,we found that the sensors do not exhibit a measurable change in displacement due to added *** the other hand,bare sensors showed a clear change in displacement in response to isopropanol *** the dynamic mode,functionalized sensors showed a measurable frequency shift due to the added mass of isopropanol *** the presence of strong electrostatic fields,the measured frequency shift was found to be threefold larger than that in their absence in response to the same concentration of isopropanol *** enhanced responsivity of dynamic detection allows the sensors to measure the vapor mass captured by the functional material,which is not the case for static *** detection of isopropanol by bare sensors in static mode shows that change in the medium permittivity is the primary sensing *** enhanced responsivity of dynamic mode sensors when operated in strong electrostatic fields shows that their sensing mechanism is a combination of a weaker added mass effect and a stronger permittivity *** findings show that electrostatic MEMS gas sensors are independent of the direction of the gravitational field and are,thus,robust to changes in *** is erroneous to refer to them as‘gravimetric’sensors.

关键词： mechanism electrostatic measurable

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Optimal material and geometry of 2D-FGM tapered microbeams under dynamic and static constraints

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Mechanics Based design of Structures and Machines 2024年第8期52卷 5227-5262页

作者： Abo-bakr, H.M. Abo-bakr, R.M. Shanab, R.A. Eltaher, M.A. Computers and Systems Engineering Department Faculty of Engineering Zagazig University Zagazig Egypt Mathematical Department Faculty of Science Zagazig University Zagazig Egypt Engineering Mathematics Department Faculty of Engineering Zagazig University Zagazig Egypt Mechanical Engineering Department Faculty of Engineering King Abdulaziz University Jeddah Saudi Arabia Mechanical Design and Production Department Faculty of Engineering Zagazig University Egypt

The present work applies meta-heuristic multi-objective particle swarm optimization (MOPSO) and non-dominated sorting genetic algorithm (NSGA)-II algorithms to predict optimal shape and material distribution of two-directional functionally graded tapered (2DFG-T) microbeams. The cross-section of the microbeam changes linearly along its length in both height and width directions. The rates of these changes are taken as the geometric design variables. Rather than the simple power law, two different trigonometric functions are introduced to provide various effective and flexible 2D- distributions of metal and ceramic phases. Using Hamilton’s principle, the mathematical model is derived based on the third order shear deformation theory (TSDT) and modified couple stress theory (MCST). Developing a computationally efficient and time saving semi-analytical approach, the governing set of variable-coefficients partial differential equations is solved for the frequency and critical buckling under different boundary conditions. Several constrained single- and multi-objective optimization problems are formulated and solved to determine optimal material and geometry parameters of 2DFG-T microbeams to achieve maximization of fundamental frequency and/or critical buckling load while minimizing the structural mass. Various optimization results demonstrate that including shape parameters in addition to material distribution parameters as design variables results in more economical and flexible profiles that is critical for the manufacture of 2DFG-T microbeams. The following model can be exploited in the optimum design of FG microscale nanobeams including their shapes and material distribution. © 2023 Taylor & Francis Group, LLC.

关键词： Multiobjective optimization

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Open-Gap Algorithm for Fast Reactive Collision Avoidance by Autonomous UAV using Sensor Array

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Journal of Aeronautics, Astronautics and Aviation 2025年第3期57卷 505-511页

作者： Butt, Muhammad Zohaib Nasir, Nazri Rashid, Rozeha A. Tang, Collin H.H. Department of Aeronautics Automotive and Ocean Engineering Faculty of Mechanical Engineering Universiti Teknologi Malaysia Malaysia UTM Aero Lab Institute for Vehicle Systems & Engineering Universiti Teknologi Malaysia Malaysia Department of Communication Engineering Faculty of Electrical Engineering Universiti Teknologi Malaysia Malaysia Department of Applied Mechanics and Design Faculty of Mechanical Engineering Universiti Teknologi Malaysia Malaysia

This paper presents a new local reactive collision avoidance strategy for autonomous unmanned aerial vehicles (UAVs) that operate in dynamic environments. Compared to ground robots, UAVs face greater challenges in terms of faster reaction time and encounter rapid environmental changes during low-flight operations due to their higher speed. Additionally, small UAVs have limited payload capacity, restricting their flight time, computational power, and sensing capabilities. For low-altitude autonomous flights, a fast and efficient computation approach is developed to avoid moving as well as stationary obstacles. Using a circular array of sensors onboard, the algorithm detects suitable open gaps within the circular proximity of the UAV. Then, to reach the designated target location, the algorithm chooses the most suitable gap. The proposed algorithm enhances the UAV’s ability at low-altitudes to perform collision-less navigation in unstructured environments without prior knowledge of the obstacle map. A simulated environment was used to test the proposed algorithm. © 2025 The Aeronautical and Astronautical Society of the Republic of China. All rights reserved.

关键词： Unmanned aerial vehicles (UAV)

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Remarks on an Optimal Predictive Control Using a Quaternion Neural Network-based Identifier

Remarks on an Optimal Predictive Control Using a Quaternion ...

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18th IEEE International Conference on Advanced Motion Control, AMC 2024

作者： Takahashi, Kazuhiko Aoki, Remi Kagamiishi, Eri Hashimoto, Masafumi Doshisha University Information Systems Design Faculty of Science and Engineering Kyoto Japan

ISBN: (纸本)9798350342819

This study explores the application of quaternion neural networks (QNNs) in control systems, specifically focusing on optimal predictive control. The approach introduces a model predictive control method for achieving optimal control of non-linear systems. In this method, a direct transfer function identifier is constructed using a QNN to estimate the future predicted output of the plant. The optimal control input is then determined by minimising the objective cost function which comprises the predictive control error and the increment of the control input. A derivative-free optimisation method is employed for this purpose. Computational experiments are conducted to assess the effectiveness of the optimal predictive control using the QNN-based identifier. These experiments are performed in the context of a tracking task involving a discrete-time non-linear plant. The simulation results demonstrate that the proposed method executes the control task with appropriate accuracy. Furthermore, the findings affirm the feasibility of employing QNNs for controlling non-linear systems. © 2024 IEEE.

关键词： Nonlinear systems

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STUDY ON MACHINE LEARNING-BASED PREDICTION OF INTENSITY FLUCTUATIONS IN HORIZONTAL OPTICAL PROPAGATION 41

STUDY ON MACHINE LEARNING-BASED PREDICTION OF INTENSITY FLUC...

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41st International Communications Satellite systems Conference, ICSSC 2024

作者： Takenaka, Hideki Ishii, Shoken Takayama, Yoshihisa Faculty of Systems Design Tokyo Metropolitan University Japan Department of Communication and Network Engineering Tokai University Japan

ISBN: (纸本)9781837242689

This study investigates the potential of machine learning to predict signal power fluctuations in free-space optical communications, impacted by atmospheric fluctuations. Conducted over a 600-meter terrestrial link, optical reception intensities were recorded at a sampling rate of 10 kHz, then averaged to 1 kHz to reduce the computational load for subsequent machine learning processes. The study employed 80% of this data for training and 20% for validation. It was demonstrated that within the spatial coherence time of atmospheric turbulence, the fluctuations in received signal intensity can be accurately predicted using machine learning. © The Institution of engineering & Technology 2024.

关键词： Adversarial machine learning

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Moral rhetoric in discrete choice models: a Natural Language Processing approach

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Quality and Quantity 2024年第1期58卷 179-206页

作者： Szép, Teodóra van Cranenburgh, Sander Chorus, Caspar Engineering Systems and Services Delft University of Technology Jaffalaan 5 Delft 2628 BX Netherlands Faculty of Industrial Design Engineering Delft University of Technology Delft Netherlands

This paper proposes a new method to combine choice- and text data to infer moral motivations from people’s actions. To do this, we rely on moral rhetoric, in other words, extracting moral values from verbal expressions with Natural Language Processing techniques. We use moral rhetoric based on a well-established moral, psychological theory called Moral Foundations Theory. We use moral rhetoric as input in Discrete Choice Models to gain insights into moral behaviour based on people’s words and actions. We test our method in a case study of voting and party defection in the European Parliament. Our results indicate that moral rhetoric have significant explanatory power in modelling voting behaviour. We interpret the results in the light of political science literature and propose ways for future investigations. © 2023, The Author(s).

关键词： Discrete choice models Moral Foundations Theory Moral rhetoric Natural Language Processing

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Analysis of the Impact of Prediction Accuracy on Search Performance in Surrogate-assisted Evolutionary Algorithms 13

Analysis of the Impact of Prediction Accuracy on Search Perf...

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13th IEEE Congress on Evolutionary Computation, CEC 2024

作者： Hanawa, Yuki Harada, Tomohiro Miura, Yukiya Graduate School of Systems Design Tokyo Metropolitan University Tokyo Japan Graduate School of Science and Engineering Saitama University Saitama Japan Tokyo Metropolitan University Faculty of Systems Design Tokyo Japan

ISBN: (纸本)9798350308365

When solving optimization problems with evolutionary algorithms (EAs), the optimization process can involve evaluating many solutions, which may lead to substantial computational time. To address this issue, surrogate-assisted evolutionary algorithms (SAEAs) have been proposed, utilizing solution evaluations predicted by a machine learning model (surrogate). However, previous studies have not analyzed the impact of prediction accuracy of a surrogate on the performance in SAEAs. This study aims at analyzing the impact of the surrogate model's prediction accuracy on search performance. For this purpose, the search performance of SAEAs is compared using pseudo-surrogate models whose accuracy can be adjusted. In the experiments, two types of SAEAs, the pre-selection strategy with classification-based surrogate (PS-CS) and the individualbased strategy with absolute fitness surrogate (IB-AFS), were addressed on solving the CEC2015 benchmark problems. EAs without surrogates were also compared as a baseline method. The results showed that, for PS-CS, the surrogate model with accuracy of 1.0 demonstrated the best search performance, and higher accuracy resulted in better search performance. At an accuracy of 50 %, the performance was equivalent to or lower than that of EAs without surrogates. On the other hand, for IB-AFS, using high accuracy surrogate models was still effective, but the trend of higher accuracy leading to better search performance was less observed than PS-CS. © 2024 IEEE.

关键词： Prediction models

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Impact of occupant autonomy on satisfaction and building energy efficiency

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Energy and Built Environment 2023年第4期4卷 377-385页

作者： Wipa Loengbudnark Kaveh Khalilpour Gnana Bharathy Alexey Voinov Leena Thomas Center on Persuasive Systems for Wise Adaptive Living Faculty of Engineering&ITUniversity of Technology SydneyNSW 2007Australia School of Architecture Faculty of DesignArchitecture and BuildingUniversity of Technology SydneyNSW 2007Australia Faculty of Engineering Technology University of Twentethe Netherlands

The philosophy of building energy management is going through a paradigm change from traditional,often inefficient,user-controlled systems to one that is centrally automated with the aid of IoT-enabled *** this context,occupants’perceived control and building automation may seem to be in *** inquiry of this study is rooted in a proposition that while building automation and centralized control systems are assumed to provide indoor comfort and conserve energy use,limiting occupants’control over their work environment may result in dissatisfaction,and in turn decrease *** assessing this hypothesis,data from the post-occupancy evaluation survey of a smart building in a university in Australia was used to analyze the relationships between perceived control,satisfaction,and perceived *** structural equation modeling,we have found a positive direct effect of occupants’perceived control on overall satisfaction with their working ***,perceived control exerts an influence on perceived productivity through ***,a field experiment conducted in the same building revealed the potential impact that occupant controllability can have on energy *** changed the default light settings from automatic on-and-offto manual-on and automatic-off,letting occupants choose themselves whether to switch the light on or ***,about half of the participants usually kept the lights off,preferring daylight in their *** also resulted in a reduction in lighting electricity use by 17.8%without any upfront investment and major technical *** findings emphasize the important role of perceived control on occupant satisfaction and productivity,as well as on the energy-saving potential of the user-in-the-loop automation of buildings.

关键词： Autonomy Occupant behavior Comfort preference Building energy management Human-in-the-loop automation

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Hybrid Model with Discrete-Event Simulation and Repeated Machine Learning Prediction-Based Quality Inspection of Inbound Distribution Center Deliveries

Hybrid Model with Discrete-Event Simulation and Repeated Mac...

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2023 Winter Simulation Conference, WSC 2023

作者： Remmmelts, Joost R. Hübl, Alexander University of Groningen Faculty of Science and Engineering Engineering Systems and Design Group Nijenborgh 4 Groningen9747 AG Netherlands

ISBN: (纸本)9798350369663

Business-to-business distributors deem it necessary to inspect the quality of inbound deliveries to their distribution centers. This paper observes a company that experiences an inefficient quality inspection and wishes to improve the process. The broader product-receiving process is under-researched in warehousing literature but possesses similarities with manufacturing quality control. Moreover, the paper aims to extend prediction-based quality inspection to the warehousing field. It applies a hybrid model, combining discrete-event simulation and machine learning multi-label classification to decrease the required inspection volume and evaluate its effects on the ability of the inspection and the workload and costs of distribution center operations. The results show that the inspection volume can drastically be decreased, reducing the workload and costs at the expense of the inspection capability of infrequently occurring delivery quality flaws in training data. The configuration of the classification model determines the degree of inspection volume reduction and wrongly predicted delivery quality flaws. © 2023 IEEE.

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Machining process parameters optimization using soft computing technique

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Journal of engineering and Applied Science 2023年第1期70卷 7页

作者： El Hossainy, Tarek M. Zeyada, Yasser Abdelkawy, Abdallah Mechanical Design and Production Department Faculty of Engineering Cairo University Giza12613 Egypt Industrial Systems Engineering Department Faculty of Engineering MSA University 6th of October City Egypt Projects and Services Europe & Africa Schneider Electric Cairo Egypt

This work introduces an approach for optimization machinability measures of power consumption, machining time, and the surface roughness (PMS). This approach is starting with market customer’s demands, passing by optimizing the machinability measures (PMS), and ending by the optimized cutting conditions. The fuzzy logic was used to define the weights of each of required machinability measurement using method through expert rules depending on factory requirements. Genetic algorithm was formulated for giving optimum output values based on the customer’s demands. A neural network was designed for controlling the input cutting conditions with the PMS output parameters. The proposed soft computing technique creates reasonable results compared to experimental results and gives rich investigations for optimizing the output parameters not only for increasing productivity and quality demands but also for saving power consumed. The variation of consumed power, machining time, and surface roughness was calculated based on different customer demand levels. When the machining time and power consumed importance increased, the proposed technique reduced them by about 20% and 10% for the testes case. © 2023, The Author(s).

关键词： Surface roughness

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