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41st IMAC, A Conference and Exposition on Structural Dynamics, 2023

作者： Thomas, Lauren Kernicky, Timothy Whelan, Matthew Park, Youngjin Cox, Robert Department of Civil and Environmental Engineering University of North Carolina at Charlotte CharlotteNC United States Department of Electrical and Computer Engineering University of North Carolina at Charlotte CharlotteNC United States

ISBN: (纸本)9783031366628

The application of digital twin technology offers the potential to significantly enhance the reliability and performance of structural health monitoring techniques by providing detailed information on, and measurements of, the as-built properties and performance of structures. In addition, a digital twin provides greater support for the application of probabilistic methods for prognostication and risk assessment following model updating and diagnostics provided by structural health monitoring. To date, digital twins have been predominantly applied in the advanced manufacturing space, although the increased use of modular and prefabricated construction has driven interest in the extension of digital twin technology to both civil and nuclear structures. This chapter details the implementation of a structural digital twin and investigates its influence on the performance of a Bayesian vibration-based structural health monitoring approach. In this chapter, a digital twin is developed throughout the construction of a model-scale steel-plate composite modular wall in a laboratory environment. Throughout the design, fabrication, and erection of the specimen, design calculations, numerical models, LiDAR point clouds, physical measurements of geometric features, and quality control inspection data are integrated into a digital twin framework to develop an as-built representation of the structural geometry, material properties, and condition throughout the stages of construction. The modular nature of the construction results in different effective section properties for wall modules as the early-age elastic properties of the structural concrete are developed. This time dependency of the section properties is leveraged to produce a series of datasets where structural parameters in the model evolve due to aging. Probabilistic model updating using modal parameters obtained from experimental modal analyses is used for structural identification of the as-built model. Static loadi

关键词： Modal analysis

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A Power Electronic Converters-Inspired Approach for Modeling PWM Switched-Based Nonlinear Hydraulic Servo Actuators

A Power Electronic Converters-Inspired Approach for Modeling...

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2023 IEEE International Conference on Systems, Man, and Cybernetics, SMC 2023

作者： Bozza, Augusto Cavone, Graziana Carli, Raffaele Dotoli, Mariagrazia The Department of Electrical and Information Engineering The Polytechnic of Bari Italy The Department of Civil Computer Science and Aeronautical Technologies Engineering The University Roma Tre Rome Italy

ISBN: (纸本)9798350337020

This paper investigates a novel approach for properly modeling Hydraulic Servo Actuators (HSAs) based on ON-OFF switching valves. HSAs represent very high efficiency and small size-to-power ratio hydraulic actuators. Their functioning is guaranteed by their control system that ensures the desired flow-rate, and consequently, the proper pressure, to be provided to the actuator's chambers. Nevertheless, achieving a good model of such HSAs for control purposes is non-trivial, due to their hybrid nature inherited from the switching between the different operating modes produced by valves. To overcome this limit, we propose an average equivalent discrete-time model of the chambers' pressure dynamics related to a single control input for the digital valves. The proposed model takes inspiration from the analogy existing between hydraulic systems and power electronic converters, and guarantees the same performance as the traditional model, with the advantage of greatly simplifying the control of the servo actuator. Finally, the consistency of the proposed model with respect to its nonlinear hybrid version is proved via numerical examples. © 2023 IEEE.

关键词： Electro-Hydraulic Analogy Hybrid Systems Hydraulic Servo Actuators Nonlinear Systems Pulse Width Modulation (PWM) Switching Systems

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Safety of Linear Systems under Severe Sensor Attacks 63

Safety of Linear Systems under Severe Sensor Attacks

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63rd IEEE Conference on Decision and Control, CDC 2024

作者： Tan, Xiao Ong, Pio Tabuada, Paulo Ames, Aaron D. California Institute of Technology Department of Mechanical and Civil Engineering PasadenaCA91125 United States University of California Department of Electrical and Computer Engineering Los AngelesCA90095 United States

ISBN: (纸本)9798350316339

Cyber-physical systems can be subject to sensor attacks, e.g., sensor spoofing, leading to unsafe behaviors. This paper addresses this problem in the context of linear systems when an omniscient attacker can spoof several system sensors at will. In this adversarial environment, existing results have derived necessary and sufficient conditions under which the state estimation problem has a unique solution. In this work, we consider a severe attacking scenario when such conditions do not hold. To deal with potential state estimation uncertainty, we derive an exact characterization of the set of all possible state estimates. Using the framework of control barrier functions, we propose design principles for system safety in offline and online phases. For the offline phase, we derive conditions on safe sets for all possible sensor attacks that may be encountered during system deployment. For the online phase, with past system measurements collected, a quadratic program-based safety filter is proposed to enforce system safety. A 2 D -vehicle example is used to illustrate the theoretical results. © 2024 IEEE.

关键词： State estimation

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Deep Learning Models for Future Occupancy Prediction in Residential Buildings 5th

Deep Learning Models for Future Occupancy Prediction in Resi...

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5th International Conference on Building Energy and Environment, COBEE 2022

作者： Esrafilian-Najafabadi, Mohammad Babahaji, Mina Haghighat, Fariborz Department of Building Civil and Environmental Engineering Concordia University MontrealQC Canada Department of Electrical and Computer Engineering Concordia University MontrealQC Canada

ISBN: (纸本)9789811998218

This paper contributes to the occupancy prediction problem by developing state-of-the-art deep learning models. The occupancy prediction problem is addressed from two different viewpoints: multi-label classification and a sequence-to-sequence time-series analysis using encoder-decoder architectures. The following deep learning algorithms are employed in this study to construct occupancy models: multi-layer perceptron (MLP), recurrent neural networks, long-short term memory (LSTM), gated recurrent units (GRU), and bidirectional LSTMs. The performance of these models is evaluated and compared in terms of accuracy and computational speed. The results demonstrate that addressing this problem using MLP models provides the best performance for short-term predictions, while for predictions more than 90 min ahead, GRU results in the highest accuracy. It is also demonstrated that the accuracy of the deep learning models can be approximated as a function of the occupancy index with an MAE of 0.014. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Multilayer neural networks

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Teaching the Equivalent Rectangular Stress Block

Teaching the Equivalent Rectangular Stress Block

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Best Practices and Lessons Learned for Teaching Concrete Materials and Reinforced Concrete 2021

作者： Carroll, J. Chris Dymond, Benjamin Z. Behrouzi, Anahid A. The Department of Civil Computer and Electrical Engineering The School of Science and Engineering Saint Louis University United States The Department of Civil Engineering Construction Management and Environmental Engineering Northern Arizona University United States California Polytechnic State University United States

ISBN: (纸本)9781641952361

The equivalent rectangular stress block is the basis for determining the flexural strength of reinforced concrete members. Instructors commonly present the concept in two dimensions, contrary to its three-dimensional nature. Unfortunately, this can be particularly difficult for students to understand and visualize, especially for students with visual learning style preferences. This paper presents an overview of the equivalent rectangular stress block, select active learning methods, and four specific examples used by the authors to introduce the equivalent rectangular stress block in an undergraduate reinforced concrete design course. The first method focuses on understanding the terms associated with the equivalent rectangular stress block using a visual, hands-on learning activity;the second focuses on visualizing the internal forces and couple moment within a beam;the third uses a virtual three-dimensional model to derive the depth of the equivalent rectangular stress block;and the fourth illustrates the various stress blocks used in reinforced concrete flexure theory via physical three-dimensional models. Each description includes detailed instructions to create the resources and how to facilitate the related activities within a course. The overall goal is to provide educators with several examples that will help students better visualize the three-dimensional concept. © 2023 American Concrete Institute. All rights reserved.

关键词： Students

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Smart Road Damage Survey System Using Machine Vision and IoT Technology 3

Smart Road Damage Survey System Using Machine Vision and IoT...

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3rd International Conference on Intelligent Cybernetics Technology and Applications, ICICyTA 2023

作者： Mutijarsa, Kusprasapta Alunjati, Figo Agil Hidayat, Fadhil Kurnia, Ranna Arsyad, Zulkifli School of Electrical Engineering and Informatics Bandung Indonesia National Institute of Technology Department of Civil Engineering Bandung Indonesia Bandung State Polytechnic Department of Computer and Informatics Engineering Bandung Indonesia

ISBN: (纸本)9798350394559

Road is an essential transportation infrastructure to move people and goods to support economic prosperity. The efficiency, safety, security, and comfort of people have significant consequences by damage and defects on the road surface. A good-condition road ensures the land traffic runs well. This research is a collaboration between the Bandung Institute of Technology and the Department of Public Works and Spatial Planning of West Java Province to develop a smart system for road damage surveys. The system was built by leveraging machine vision and IoT technologies to improve the performance of the road survey activities. The previous road damage detection, classification method, and pavement condition index (IKP) computation were performed semi-automatically. The proposed survey system developed in this work uses the Canny edge Detection algorithm and MobileNet V2 architecture to detect road defects automatically. The pavement condition index computation also improved by using the interpolation reduction factor. The system is designed into a four-layer architecture that consists of several functions and modules, i.e., the sensor system that includes a vision sensor, GPS and odometry, a hardware embedded system using a microcontroller, and machine learning to process the road condition image automatically, and a dashboard application to reveal the road condition on map. The performance resulted in accuracy, precision, recall, and F-score of the road damage detection are 54.5%, 24.2%, 78.9%, and 37%, respectively. © 2023 IEEE.

关键词： computer vision

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Mechanical properties prediction of metakaolin and fly ash - based geopolymer concrete using SVR

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Journal of Building Pathology and Rehabilitation 2024年第1期9卷 1-14页

作者： Pratap, Bheem Sharma, Sanjay Kumari, Pooja Raj, Sumit Department of Civil Engineering National Institute of Technology Jamshedpur Jharkhand Jamshedpur 831014 India Department of Electrical Engineering National Institute of Technology Jamshedpur Jharkhand Jamshedpur 831014 India Department of Computer Science and Engineering National Institute of Technology Jamshedpur Jharkhand Jamshedpur 831014 India

The field of construction materials and sustainable infrastructure has witnessed a significant shift towards environmentally friendly alternatives. Geopolymers, as an emerging class of materials, have gained substantial attention due to their eco-friendly nature and mechanical properties. One of the key ingredients in geopolymer formulations is metakaolin, a thermally activated aluminosilicate material derived from kaolin clay. This paper delves into an in-depth exploration of the diverse applications of fly ash and metakaolin in geopolymer concrete, highlighting its contributions to the construction industry, environmental sustainability, and technological advancements. In this investigation, the fly ash was substituted in varying proportions of 0%, 10%, 20%, 30%, and 40% across NaOH molar concentrations of 1 M, 3 M, 5 M, and 7 M. The objective was to assess the mechanical characteristics of the newly formulated geopolymer concrete. As consider the scenario where the concentration of NaOH was maintained at 5 M. In this case, the compressive strength of a geopolymer concrete (FM2), which comprised 20% metakaolin, demonstrated a maximum compressive strength of 55.28 MPa. Notably, the influence of metakaolin on bolstering compressive strength seems to be most noticeable when employed as a substitute at the 20% proportion. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.

关键词： Compressive strength Fly ash Geopolymer Metakaolin Sodium hydroxides

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A 1-Source 3- φ Boost Transformer-less Multilevel Inverter without Leakage Current 9

A 1-Source 3- φ Boost Transformer-less Multilevel Inverter ...

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9th International Conference on Technology and Energy Management, ICTEM 2024

作者： Ardashir, Jaber Fallah Ogly, Aydin Mohammad Ghadim, Hadi Vatankhah Sarhangzadeh, Mitra Azarbaijan, Hossein Khoun Jahan Shotorbani, Amin Mohammadpour Islamic Azad University Tabriz Department of Electrical Engineering Tabriz Branch Tabriz Iran University of Canterbury Department of Civil and Natural Resources Engineering Christchurch New Zealand Azarbaijan Regional Electric Company Tabriz Iran University of Tabriz Faculty of Electrical and Computer Engineering Tabriz Iran

ISBN: (纸本)9798350329797

This paper addresses the common issue of leakage current in transformer-less grid-tied inverters, rendering them unsuitable for photovoltaic (PV) system applications. To overcome this challenge, a 3- φ boost switched capacitor-based inverter is introduced, specifically designed for versatility. The innovative design employs a single dc power source, eliminating leakage current concerns. The paper conducts a thorough examination and discussion of the operational principles and theoretical analysis of the proposed topology. Notably, the inverter structure ensures a consistent dc source for all three phases, with each phase independently powered by a single dc source. This direct connection mitigates leakage current issues, enhancing the inverter's applicability across various scenarios. To achieve a 5-level output voltage in each phase and a 9 -level output voltage in the line voltage, the Sinusoidal Pulse Width Modulation (SPWM) method is employed. Simulation results, conducted in the MATLAB software environment, validate the efficacy of the proposed inverter design. The outcomes demonstrate successful voltage level generation and affirm the elimination of leakage current due to the direct connection of each phase to the dc source. The use of a single dc power source and direct connection to each phase provides a versatile, leakage-free solution for diverse applications, as validated by simulation results in the MATLAB environment. © 2024 IEEE.

关键词： MATLAB

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How Professional Networking Impacts Outcome Expectations and Choice Goals in a First-year engineering Course 14

How Professional Networking Impacts Outcome Expectations and...

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14th Annual First-Year engineering Experience Conference, FYEE 2023

作者： Walters, Evelyn Budischak, Cory Fagan, Shawn Temple University’s Department of Civil and Environmental Engineering United States Temple University The Department of Electrical and Computer Engineering United States The College of Engineering Temple University United States

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Ground Plane Projection for Improved Traffic Analytics at Intersections 27

Ground Plane Projection for Improved Traffic Analytics at In...

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27th IEEE International Conference on Intelligent Transportation Systems, ITSC 2024

作者： Pakdamansavoji, Sajjad Jha, Kumar Vaibhav Abdulhai, Baher Elder, James H. York University Department of Electrical Engineering and Computer Science 4700 Keele St TorontoON Canada University of Toronto Department of Civil and Mineral Engineering 27 King s College Cir TorontoON Canada

ISBN: (纸本)9798331505929

Accurate turning movement counts at intersections are important for signal control, traffic management and urban planning. computer vision systems for automatic turning movement counts typically rely on visual analysis in the image plane of an infrastructure camera. Here we explore potential advantages of back-projecting vehicles detected in one or more infrastructure cameras to the ground plane for analysis in real-world 3D coordinates. For single-camera systems we find that back-projection yields more accurate trajectory classification and turning movement counts. We further show that even higher accuracy can be achieved through weak fusion of back-projected detections from multiple cameras. These results suggeest that traffic should be analyzed on the ground plane, not the image plane. © 2024 IEEE.

关键词： Urban planning

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