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Mini-batch stochastic subgradient for functional constrained optimization

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arXiv 2024年

作者： Singh, Nitesh Kumar Necoara, Ion Kungurtsev, Vyacheslav Automatic Control and Systems Engineering Department University Politehnica Bucharest Spl. Independentei 313 Bucharest060042 Romania Gheorghe Mihoc-Caius Iacob Institute of Mathematical Statistics and Applied Mathematics The Romanian Academy Bucharest050711 Romania Computer Science Department Czech Technical University Karlovo Namesti 13 Prague12135 Czech Republic

In this paper we consider finite sum composite convex optimization problems with many functional constraints. The objective function is expressed as a finite sum of two terms, one of which admits easy computation of (sub)gradients while the other is amenable to proximal evaluations. We assume a generalized bounded gradient condition on the objective which allows us to simultaneously tackle both smooth and nonsmooth problems. We also consider the cases of both with and without a strong convexity property. Further, we assume that each constraint set is given as the level set of a convex but not necessarily differentiable function. We reformulate the constrained finite sum problem into a stochastic optimization problem for which the stochastic subgradient projection method from [17] specializes to a collection of mini-batch variants, with different mini-batch sizes for the objective function and functional constraints, respectively. More specifically, at each iteration, our algorithm takes a mini-batch stochastic proximal subgradient step aimed at minimizing the objective function and then a subsequent mini-batch subgradient projection step minimizing the feasibility violation. By specializing different mini-batching strategies, we derive exact expressions for the stepsizes as a function of the mini-batch size and in some cases we also derive insightful stepsize-switching rules which describe when one should switch from a constant to a decreasing stepsize regime. We also prove sublinear convergence rates for the mini-batch subgradient projection algorithm which depend explicitly on the mini-batch sizes and on the properties of the objective function. Numerical results also show a better performance of our mini-batch scheme over its single-batch counterpart. © 2024, CC BY.

关键词： Constrained optimization

A Novel Aerial-Aquatic Locomotion Robot with Variable Stiffness Propulsion Module

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arXiv 2024年

作者： Hu, Junzhe Chen, Pengyu Feng, Tianxiang Wen, Yuxuan Wu, Ke Dong, Janet The UC Center for Robotics Research College of Engineering and Applied Science University of Cincinnati CincinnatiOH United States The Robotics Institute School of Computer Science Carnegie Mellon University PittsburghPA United States Robotics department Mohamed bin Zayed University of Artificial Intelligence Masdar City Abu Dhabi United Arab Emirates

In recent years, the development of robots capable of operating in both aerial and aquatic environments has gained significant attention. This study presents the design and fabrication of a novel aerial-aquatic locomotion robot (AALR). Inspired by the diving beetle, the AALR incorporates a biomimetic propulsion mechanism with power and recovery strokes. The variable stiffness propulsion module (VSPM) uses low melting point alloy (LMPA) and variable stiffness joints (VSJ) to achieve efficient aquatic locomotion while reduce harm to marine life. The AALR's innovative design integrates the VSPM into the arms of a traditional quadrotor, allowing for effective aerial-aquatic locomotion. The VSPM adjusts joint stiffness through temperature control, meeting locomotion requirements in both aerial and aquatic modes. A dynamic model for the VSPM was developed, with optimized dimensional parameters to increase propulsion force. Experiments focused on aquatic mode analysis and demonstrated the AALR's swimming capability, achieving a maximum swimming speed of 77 mm/s underwater. The results confirm the AALR's effective performance in water environment, highlighting its potential for versatile, eco-friendly operations. Copyright © 2024, The Authors. All rights reserved.

关键词： Aircraft propulsion

Modeling of selected set of software requirements using UML class diagrams 17

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Modeling of selected set of software requirements using UML ...

17th IEEE India Council International Conference, INDICON 2020

作者： Arif, Mohd. Mohammad, Chaudhary Wali Sadiq, Mohd. Faculty of Engineering and Technology Computer Science and Technology Research Group Department of Applied Sciences and Humanities New Delhi110025 India Indian Institute of Science Department of Computer Science and Automation Bangalore560012 India

ISBN: (纸本)9781728169163

Unified Modeling Language (UML) is used to model and design the software requirements. Among various components of UML, class diagram is employed to model the software requirements in terms of objects organized in classes and relationships between them. In real life applications, it has been observed that a system may have several requirements and it is not possible to model each and every requirement because of time, budget, and other constraints of an organization. Based on our review, we found that, in literature less attention is given to the modeling of the software requirements from the selected set of the requirements using UML class diagrams. Therefore, to address this issue, in this paper we present a method for modeling of the selected set of the software requirements using UML class diagrams. The applicability of the proposed method is discussed with the help of the software requirements of an institute examination system. © 2020 IEEE.

关键词： Budget control

Dynamic control of 2D non-Hermitian photonic corner states in synthetic dimensions

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arXiv 2024年

作者： Zheng, Xinyuan Mehrabad, Mahmoud Jalali Vannucci, Jonathan Li, Kevin Dutt, Avik Hafezi, Mohammad Mittal, Sunil Waks, Edo Institute for Research in Electronics and Applied Physics University of Maryland College ParkMD20742 United States Joint Quantum Institute University of Maryland College ParkMD20742 United States Department of Mechanical Engineering Institute for Physical Science and Technology University of Maryland College ParkMD20742 United States Department of Electrical and Computer Engineering Northeastern University BostonMA United States

Non-Hermitian models describe the physics of ubiquitous open systems with gain and loss. One intriguing aspect of non-Hermitian models is their inherent topology that can produce intriguing boundary phenomena like resilient higher-order topological insulators (HOTIs) and non-Hermitian skin effects (NHSE). Recently, time-multiplexed lattices in synthetic dimensions have emerged as a versatile platform for the investigation of these effects free of geometric restrictions. Despite holding broad applications, studies of these effects have been limited to static cases so far, and full dynamical control over the non-Hermitian effects has remained elusive. Here, we demonstrate the emergence of topological non-Hermitian corner states with remarkable temporal controllability and robustness in a two-dimensional photonic synthetic time lattice. Specifically, we showcase various dynamic control mechanisms for light confinement and flow, including spatial mode tapering, sequential non-Hermiticity on-off switching, dynamical corner state relocation, and light steering. Moreover, we establish the corner state's robustness in the presence of intensity modulation randomness and quantitatively determine its breakdown regime. Our findings extend non-Hermitian and topological photonic effects into higher synthetic dimensions, offering remarkable flexibility and real-time control possibilities. This opens avenues for topological classification, quantum walk simulations of manybody dynamics, and robust Floquet engineering, free from the limitations of physical geometries. © 2024, CC BY.

关键词： Topology

Comparative Analysis of LR Parsers in Designing of Compilers

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Comparative Analysis of LR Parsers in Designing of Compilers

Augmented Intelligence and Sustainable Systems (ICAISS), International Conference on

作者： Milind Shah Nidhi Chitroda Safeya Dharmajwala Avani Vasant Department of Computer Science & Engineering Krishna School of Emerging Technology & Applied Research - Drs. Kiran & Pallavi Patel Global University (KPGU) Vadodara Gujarat India

ISBN: (纸本)9781665489638

Compiler development has been one of the leading computer research subjects. This field of study aims to understand the link between computer systems and computer languages. Compilers are used to translate code from a high-level programming language into machine code. This process consists of essentially six phases. Analysis of syntax is the second step of compilation. As input to a syntax analyzer, lexical analyzer-generated tokens are used. Syntax analyzers do parsing. Parsing is used to derive a string from a given grammar via the process of derivation. There are essentially two parsing algorithms, called top-down and bottom-up parsing. The four forms of bottom-up parsing LR (Left-To-Right) parsing strategies include Simple LR (SLR), Canonical LR (CLR), Look Ahead LR (LALR), and LR (1). In addition, LR Parsers are mostly used to parse a variety of context-free grammar. This approach is referred to as LR (k) parsing, where L stands for left-to-right input scanning, R stands for creating a reverse right-most derivation, and k is the number of look-ahead input symbols utilized to make parsing decisions. A bottom-up parser helps to reduce the number of top-level grammatical products by working from the leaves up. LR parsers are the most effective deterministic parsers in reality. This research aims to describe the compiler, its purpose, and LR parser algorithms, with the comparison to determine which LR parsing algorithms are efficient among all other LR parsers.

关键词： computer languages Codes Program processors Symbols Syntactics Grammar

Backward Radiation Reduction and Bandwidth Enhancement of Metamaterial Antenna for UWB Applications

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Backward Radiation Reduction and Bandwidth Enhancement of Me...

2021 Emerging Technology in Computing, Communication and Electronics, ETCCE 2021

作者： Uddin, M. Jasim Ullah, M. Habib Bentley, Barry L. Shakib, M.N. Islam, Syed Zahurul Rahman, Md Arafatur Cardiff Metropolitan University Cardiff School of Technologies Department of Applied Computing and Engineering United Kingdom University of Malaya Faculty of Engineering Department of Electrical Engineering Kuala Lumpur50603 Malaysia Cardiff Metropolitan University Cardiff School of Technologies Department of Computer Science United Kingdom Green University of Bangladesh Faculty of Science and Engineering Dept. of Electrical and Electronics Engineering Dhaka1207 Bangladesh University Tun Hussein Onn Malaysia Faculty of Electrical and Electronic Engineering Power Integration Systems Johor Malaysia Faculty of Science and Engineering University of Wolverhampton United Kingdom

ISBN: (纸本)9781665483643

A metamaterial inspired planar-patterned microstrip patch antenna, feeding on a Duroid substrate inset bottom ground soft-surface, is presented for ultra-wide band (UWB) applications. The present antenna is configured on a step-edge periodic unit-cell pattern, with a tiny air gap etched on the metal patch and finite ground plane. By employing these structures an ultra-wide band from 4 GHz ~ 16.2 GHz is achieved. The important advantage is retaining the suppression of back radiation while removing grounded edge metallic parts and replacing them with the finite cut-off square unit cell. The feeding ground plane and radiating patch are specially configured to develop artificial structures using series capacitance and shunt inductance. The efficiency of the proposed antenna is above 99.1%. To enhance gain and bandwidth, this antenna has etched Jerusalem crossed slots on the ground plane and star-slots on the patch, with the enhanced gain reaching a maximum of 8 dBi at 9.2 GHz. The antenna's overall dimensions exhibit 0.72λ × 0.83λ × 0.05λ at a 10.1 GHz cut-off frequency. The high absorption gain, directivity, and enhanced frequency bandwidth, verified by numerical modeling and experimentation, ensure the proposed antenna is well suited to any UWB application. © 2021 IEEE.

关键词： Metamaterial antennas

The Terms Estimation of S Robotics using MTRS as well as FEM

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The Terms Estimation of S Robotics using MTRS as well as FEM

Advance Computing and Innovative Technologies in engineering (ICACITE), International Conference on

作者： R. Gopal Mustafa Mudhafar Amjad Hashem Venkadeshan Ramalingam Dibyahash Bordoloi Muhammad Numan Ali Khan Myasar Mundher Adnan Zahraa N. Abdulhussain Assistant Professor Information and communication Engineering College of Engineering University of Buraimi Sultanate of Oman Department of Medical Physics Faculty of Medical Applied Sciences University of Kerbala Karbala Iraq Computer Engineer Department Al-kunooze University College Basra Iraq Network Computing College of Computing and Information Sciences University of Technology and Applied Sciences– Shinas Sultanate of Oman Dept of CSE Graphic Era Hill University Adjunct professor Graphic Era Deemed to be University Dehradun Uttarakhand Faculty – Network Computing College of Computing and Information Sciences University of Technology and Applied Sciences – Shinas Sultanate of Oman Department of computers Techniques engineering College of technical engineering The Islamic university Najaf Iraq College of Technical Engineering National University of Science and TechnologyDhi Qar Iraq

ISBN: (数字)9798350360165

ISBN: (纸本)9798350360172

This look at addresses the critical project of reaching dependable and precise proprioception in soft robots, it really is essential for his or her effective deployment in complicated environments. By integrating multi-tap resistive sensors in the robot’s form, our technique lets in for the distinct sensing of nearby deformations at various factors throughout the robotics’ frame, moving beyond traditional techniques that anticipate steady curvature. We beautify the decision of these deformations and couple the sensory facts with a strong finite detail technique (FEM) model. This included framework allows the correct estimation of the smooth robot’s form and the significance of outside forces applied to it, attaining a mean relative inaccuracy of about 4%. Additionally, our technique proves its software program in tender manipulation structures, in which it achieves thirteen% relative mistakes in external force estimation inside diverse zero to five N. The approach gives a promising direction for enhancing robotic interactions in sensitive and dynamic responsibilities, providing massive enhancements in robotic proprioception without reliance on outdoor monitoring generation.

关键词： Deformable models Deformation Force Estimation Soft robotics Robot sensing systems Software

Active Learning of Molecular Data for Task-Specific Objectives

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arXiv 2024年

作者： Ghosh, Kunal Todorović, Milica Vehtari, Aki Rinke, Patrick Department of Applied Physics Aalto University P.O. Box 11000 AaltoFI-00076 Finland Department of Computer Science Aalto University P.O. Box 15400 AaltoFI-00076 Finland Department of Mechanical and Materials Engineering University of Turku TurkuFI-20014 Finland Physics Department TUM School of Natural Sciences Technical University of Munich Garching Germany Atomistic Modelling Center Munich Data Science Institute Technical University of Munich Garching Germany

Active learning (AL) has shown promise for being a particularly data-efficient machine learning approach. Yet, its performance depends on the application and it is not clear when AL practitioners can expect computational savings. Here, we carry out a systematic AL performance assessment for three diverse molecular datasets and two common scientific tasks: compiling compact, informative datasets and targeted molecular searches. We implemented AL with Gaussian processes (GP) and used the many-body tensor as molecular representation. For the first task, we tested different data acquisition strategies, batch sizes and GP noise settings. AL was insensitive to the acquisition batch size and we observed the best AL performance for the acquisition strategy that combines uncertainty reduction with clustering to promote diversity. However, for optimal GP noise settings, AL did not outperform randomized selection of data points. Conversely, for targeted searches, AL outperformed random sampling and achieved data savings up to 64%. Our analysis provides insight into this task-specific performance difference in terms of target distributions and data collection strategies. We established that the performance of AL depends on the relative distribution of the target molecules in comparison to the total dataset distribution, with the largest computational savings achieved when their overlap is minimal. © 2024, CC BY-NC-ND.

关键词： Active learning

RETRACTED ARTICLE: Forecasting major impacts of COVID-19 pandemic on country-driven sectors: challenges, lessons, and future roadmap (Personal and Ubiquitous Computing, (2023), 27, 3, (807-830), 10.1007/s00779-021-01530-7)

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Personal and Ubiquitous Computing 2024年

作者： Kumar, Saket Viral, Rajkumar Deep, Vikas Sharma, Purushottam Kumar, Manoj Mahmud, Mufti Stephan, Thompson Amity School of Engineering and Technology Amity University Uttar Pradesh Noida India Dehradun Bidoli India Department of Computer Science Nottingham Trent University Clifton Campus Clifton NottinghamNG11 8NS United Kingdom Medical Technologies Innovation Facility Nottingham Trent University Clifton Campus Clifton NottinghamNG11 8NS United Kingdom Department of Computer Science and Engineering Faculty of Engineering and Technology M. S. Ramaiah University of Applied Sciences Karnataka Bangalore India

The Editor-in-Chief and the publisher have retracted this article. The article was submitted to be part of a guest-edited issue. An investigation by the publisher found a number of articles, including this one, with a number of concerns, including but not limited to compromised editorial handling and peer review process, inappropriate or irrelevant references or not being in scope of the journal or guest-edited issue. Based on the investigation's findings the Editor-in-Chief therefore no longer has confidence in the results and conclusions of this article. Manoj Kumar and Thompson Stephan disagree with this retraction. Mufti Mahmud has not explicitly stated whether they agree or disagree with the retraction. Rajkumar Viral and Vikas Deep have not responded to correspondence regarding this retraction. The Publisher has not been able to obtain a current email address for Saket Kumar and Purushottam Sharma. © The Author(s) 2024.

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