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International Conference on Intelligent systems Design and Applications (ISDA)

作者： Daniel M. Muñoz Arboleda Carlos H. Llanos Leandro dos_S. Coelho Mauricio Ayala-Rincón Department of Mechanical Engineering University of Brasilia Brasília Brazil Industrial and Systems Engineering Graduate Program Pontificial Catholic University of Paraná Curitiba Brazil Departments of Computer Science and Mathematics University of Brasilia Brasília Brazil

High computational cost for solving large engineering optimization problems point out the design of parallel optimization algorithms. Population based optimization algorithms provide parallel capabilities that can be explored by their implementations done directly in hardware. This paper presents a hardware implementation of particle swarm optimization algorithms using an efficient floating-point arithmetic which performs the computations with high precision. All the architectures are parameterizable by bit-width, allowing the designer to choose the suitable format according to the requirements of the optimization problem. Synthesis and simulation results demonstrate that the proposed architecture achieves satisfactory results obtaining a better performance in therms of elapsed time than conventional software implementations.

关键词： Hardware Particle swarm optimization Floating-point arithmetic Computer architecture Design optimization Computational efficiency Design engineering Algorithm design and analysis High performance computing Computational modeling

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Ship habitability - Preparing for the 21st century

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NAVAL ENGINEERS JOURNAL 1997年第6期109卷 21-27页

作者： Meere, EP Grieco, L Edward P. Meere:works in the Arrangements Division of the NavSea Systems Command (SEA 03H1) and has been the Navy Habitability Program Manager for the past three years. He received a Bachelor of Science in Engineering Science from Illinois Institute of Technology in 1966. He received a Masters of Business Administration from the American University in 1977. His experience to date includes: Mathematics teacher at Prince Georges Community College for 7 years 10 years as Branch Head for Carrier and Amphibious Arrangements Project Engineer for Underway Replenishment Equipment responsible for the concept and development of the One Man Control Station. Louis R. Grieco:is a Supervisory Mechanical Engineer in the Habitability Branch of the Hull and Deck Machinery Department at the Naval Surface Warfare Center Carderock Division Philadelphia where he has been employed since 1971. He received a Bachelor of Science in Mechanical Engineering degree from Drexel University in 1979. His experience to date includes trade design and combat systems assignments at Philadelphia Naval Shipyard from 1960 to 1971 In Service Engineering Section and Branch Head for cargo/ weapons elevators conveyors torpedo handling systems habitability equipment and underway replenishment equipment and Life Cycle Manager for habitability systems. He also serves as a member of the Industrial Advisory Board at Temple University Philadelphia PA.

This paper discusses the problems identified in a FY 1995 fleet habitability survey. The survey questioned the fleet on the quality of shipboard living and working conditions and identified shortfalls in berthing, sanitary spaces, and food service systems that influence crew morale, safety, and ultimately mission effectiveness. Existing habitability programs, new initiatives and responses to the survey problems, plus a few quality of life ideas for the 21st century, are outlined.

关键词： Warships

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Magnetoelastic coupling driven magnon gap in a honeycomb antiferromagnet

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Physical Review B 2024年第10期110卷 104419页

作者： Jeongheon Choe Andrey Baydin Gaihua Ye Bowen Ma Cynthia Nnokwe Martin Rodriguez-Vega David Lujan Swati Chaudhary Fuyang Tay Jiaming He Hiroyuki Nojiri Jianshi Zhou Gregory A. Fiete Junichiro Kono Rui He Xiaoqin Li Department of Physics Center of Complex Quantum Systems Center for Dynamics and Control of Materials Department of Electrical and Computer Engineering Smalley–Curl Institute Department of Physics Applied Physics Graduate Program Smalley–Curl Institute Department of Mechanical Engineering Institute for Materials Research Department of Physics and Astronomy Department of Materials Science and NanoEngineering

Cobalt titanate, CoTiO3, is a honeycomb antiferromagnet recently confirmed experimentally to host Dirac magnons, topological spin-orbit excitons, and chiral phonons. Here, we investigate a magnon gap at the zone center which calls for a refined spin Hamiltonian. We propose a microscopic model for the magnon gap and attribute it to a lattice-distortion (phonon)-induced higher-order spin interaction. Strong magnetoelastic coupling in CoTiO3 is also evident in Raman spectra, in which the magnetic order exerts a stronger influence on phonons corresponding to in-plane ionic motions than those with out-of-plane motions. We further examine the evolution of the zone-center magnons in a high magnetic field up to 18.5 T via THz absorption spectroscopy measurements. Based on this field dependence, we propose a spin Hamiltonian that not only agrees with magnon dispersion measured by inelastic neutron scattering but also includes fewer exchange constants and a realistic anisotropy term. Our work highlights the broad implications of magnetoelastic coupling in the study of topologically protected bosonic excitations.

关键词： Magnetism Magnons Topological materials Raman spectroscopy Terahertz spectroscopy

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Improvement of transmittance by fabricating broadband subwavelength anti-reflection structures for polycarbonate

Improvement of transmittance by fabricating broadband subwav...

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作者： Jang, H.S. Kim, J.H. Kim, K.S. Jung, G.Y. Lee, J.J. Kim, G.H. Division of Nano and Bio Technology Daegu-Gyeongbuk Institute of Science and Technology Dalseo-gu Daegu 704-230 Korea Republic of Department of Material Science and Engineering Program for Integrated Molecular System Gwangju Institute of Science and Technology Gwangju 500-712 Korea Republic of Nano-Mechanical Systems Research Division Korea Institute of Machinery and Materials Daejeon 305-343 Korea Republic of

We report on how to increase transmittance of a 0.2 mm thick polycarbonate (PC) film by periodic subwavelength anti-reflection structures in the visible spectral range. Subwavelength anti-reflection structures like moth-eyes are fabricated into the polycarbonate substrate itself by thermal nanoimprinting lithography (TH-NIL), which uses silicon stamps that have periodic structures such as gratings (lines and spaces) and pillared dots, and are fabricated by laser interference lithography (LIL) and transformer coupled plasma etching. To increase transmittance of a polycarbonate film, we control the periods and shapes of patterns, the number of patterned surfaces, and the overlapping direction of patterns that are fabricated into its surfaces. As a result of this, we show that average transmittance improves as the pattern period gets shorter and as both surfaces of the film are patterned. We also show that the spectrum range gets larger as the pattern period gets shorter and is determined by the longer pattern period in the case of designing a film to have different pattern period on its surfaces. The maximum average transmittance of a polycarbonate film increases up to approximately 6% compared to a bare sample in the 470-800 nm spectral range. Copyright © 2011 American Scientific Publishers All rights reserved.

关键词： Polycarbonates

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Modeling and simulation of the microalgae derived hydrogen process in compact photobioreactors

Modeling and simulation of the microalgae derived hydrogen p...

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IEEE Conference on Technologies for Sustainability

作者： J. V. C. Vargas D. A. Mitchell A. B. Mariano D. O. Correa J. C. Ordonez Graduate Program in Engineering and Materials Science PIPE and Sustainable Energy Research and Development Center NPDEAS Federal University of Parana Department of Mechanical Engineering Energy and Sustainability Center and Center for Advanced Power Systems Florida State University FSU

ISBN: (纸本)9781467346290

A general transient mathematical model for managing microalgae derived hydrogen production, with temperature dependence of the cultivation medium is developed. For that, the simplified physical model combines principles of classical thermodynamics, mass, species and heat transfer, resulting in a system of differential equations which are discretized in space using a three-dimensional cell-centered finite volume scheme. A Michaelis-Menten type expression is proposed for modeling the rate of H_2 production with dependence on O_2 inhibition. Tridimensional simulations are performed in order to determine the mass fractions distributions inside a compact photobioreactor (PBR), under different operating conditions. A relatively coarse mesh was used (6048 volume elements) to obtain converged results for a large compact PBR computational domain (5m×2m×8m). The largest computational time required for obtaining results was 560 s, i.e., less than 10 min. The numerical results for microalgal growth are validated by direct comparison to experimental measurements. Hydrogen production simulations are conducted to demonstrate PBR intermittent operation (aerobic and anaerobic stages) feasibility and adequate species evolution trends in an indirect biophotolysis approach. Therefore, after experimental validation for a particular H_2 production system, it is reasonable to state that the model could be used as an efficient tool for PBR systems thermal design, control and optimization for maximum H_2 production.

关键词： Chlamydomonas reinhardtii Scenedesmus sp. Photobioreactor architecture Early stage design tool

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Multi-Objective Grouped Grey Wolf Optimization of PID Controllers Applied to a Water Treatment Plant Model

Multi-Objective Grouped Grey Wolf Optimization of PID Contro...

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Congress on Evolutionary Computation

作者： Yan Lieven Souza Lúcio Viviana Cocco Mariani Leandro Dos Santos Coelho Electrical Engineering Graduate Program (PPGEE) Federal University of Parana (UFPR) Curitiba Parana Brazil Department of Electrical Engineering Mechanical Engineering Graduate Program (PPGEM) Pontifical Catholic University of Parana (PUCPR) and Federal University of Parana (UFPR) Curitiba Parana Brazil Department of Electrical Engineering Industrial and Systems Engineering Graduate Program (PPGEPS) Pontifical Catholic University of Parana (PUCPR) and Federal University of Parana (UFPR) Curitiba Parana Brazil

A comparison of proportional-integral-derivative (PID) controller tuning for a 2x2 Multiple-Input Multiple-Output (MIMO) water treatment plant model is presented. The PID tuning procedures are based on Multi-Objective Grey Wolf Optimizer (MOGWO) and Multi-Objective Grouped Grey Wolf Optimizer (MOGGWO) are performed under two different initial conditions. The tuning procedure is structured as a multi-objective optimization problem with four objective functions, the integral time-squared error is minimized in each output response, and the integral of the control actions is minimized in each input. MOGWO is a metaheuristic based on the hunting behavior of grey wolves, following the hierarchy and leadership procedures that these animals have, while the proposed MOGGWO is a new version proposed in this study with two different groups with different functionalities. The performance was analyzed by 50 runs based on statistical metrics. MOGGWO can find more local minima since its Pareto front is more dispersed than that found by MOGWO.

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End-to-End Reinforcement Learning for Torque Based Variable Height Hopping

End-to-End Reinforcement Learning for Torque Based Variable ...

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IEEE/RSJ International Conference on Intelligent Robots and systems (IROS)

作者： Raghav Soni Daniel Harnack Hauke Isermann Sotaro Fushimi Shivesh Kumar Frank Kirchner Department of Electronics Engineering Indian Institute of Technology (Banaras Hindu University) Varanasi India DFKI GmbH Robotic-s Innovation Center Bremen Germany Undergraduate Course Program of Mechanical and Systems Engineering Kyoto University Kyoto Japan

Legged locomotion is arguably the most suited and versatile mode to deal with natural or unstructured terrains. Intensive research into dynamic walking and running controllers has recently yielded great advances, both in the optimal control and reinforcement learning (RL) literature. Hopping is a challenging dynamic task involving a flight phase and has the potential to increase the traversability of legged robots. Model based control for hopping typically relies on accurate detection of different jump phases, such as lift-off or touch down, and using different controllers for each phase. In this paper, we present a end-to-end RL based torque controller that learns to implicitly detect the relevant jump phases, removing the need to provide manual heuristics for state detection. We also extend a method for simulation to reality transfer of the learned controller to contact rich dynamic tasks, resulting in successful deployment on the robot after training without parameter tuning.

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Developing a Floating Robot for mechanical Control of Water Hyacinth

Developing a Floating Robot for Mechanical Control of Water ...

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Mobile, Intelligent, and Ubiquitous Computing Conference (MIUCC), International

作者： Mostafa E.A. Elsayed Ahmed K.A. Mohamed Mahmoud Shaaban Mohamed A. Abdelrahman Mohamed E. A. E. Ahmed Mostafa R. Rashed Mechanical Engineering Department Automation and Energy Technology Lab. Shoubra Faculty of Engineering Benha University Cairo Egypt Department of Agricultural Engineering Agricultural Power and Machinery Faculty of Agriculture Benha University Kalubia Egypt Smart Engineering Systems Center. Mechanical Engineering Program. School of Engineering and Applied Sciences Nile University Giza Egypt Mechanical Engineering Department Combustion and Energy Technology Lab. shoubra Faculty of Engineering Benha University Cairo Egypt Mechanical Engineering Department Shoubra Faculty of Engineering Benha University Cairo Egypt Mechanical Engineering Department Faculty of Engineering Modern University for Technology and Information Cairo Egypt

Water hyacinth has become widespread in freshwater bodies in several countries, leading to various issues, particularly its substantial water consumption and the resulting need to control its growth. Among the different methods of controlling water hyacinth, mechanical control stands out as the most effective and environmentally friendly approach. A proposed harvester robot has been developed, capable of efficiently cutting and collecting water hyacinth from the water's surface. The robot boasts several advantages, including its ability to operate in narrow water paths and lakes, use clean energy sources to preserve the water ecology, employ a GPS module for safety and error detection, and generate maps for evaluating work and predicting annual growth. When compared to other technologies dealing with water hyacinth, this innovative water hyacinth harvesting robot presents a significantly lower cost of 0.01 $/kg, making it an optimal solution for addressing water hyacinth problems.

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Motion Measurement Methods for Nonlinear Analysis of Electrostatic MEMS Resonators

Motion Measurement Methods for Nonlinear Analysis of Electro...

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Eurocon

作者： Mehdi Ghommem Basil Alattar Michael Lherbette Alaaeldin Elhady Eihab Abdel-Rahman Department of Mechanical Engineering American University of Sharjah Sharjah UAE Mechatronics Graduate Program American University of Sharjah Sharjah UAE SmarAct Metrology Rohdenweg Oldenburg Germany Systems Design Engineering University of Waterloo Waterloo Ontario Canada

In this paper, we compare two measurement techniques to analyze the dynamic response of a MEMS resonator, made of a microcantilever beam, that is electrostatically actuated via a side electrode. The first method is based on a combination of Michelson interferometry, knife-edge analysis, and stroboscopic imaging, and is used to dissect the in-plane and out-of-plane motions of the resonator. The second approach follows the motion-induced current method and is based on a transduction mechanism that converts the movement of the resonator to a current signal. The third harmonic of said current is directly related to the in-plane motion of the resonator. Motion-induced current measurements enable the detection of the nonlinear dynamics associated with the motion of the resonator when actuated with high excitation voltages. The optical and electrical measurements show similar nonlinear features in terms of the location of the cyclic-fold bifurcation in the parameter space and the hysteretic region associated with it. These dynamic features can be exploited for sensing purposes.

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Corrosion resistant zirconia coated carbonyl iron particle-based magnetorheological fluid

Corrosion resistant zirconia coated carbonyl iron particle-b...

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Optical Fabrication and Testing, OFT 2010

作者： Shafrir, Shai N. Romanofsky, Henry J. Skarlinski, Michael Wang, Mimi Miao, Chunlin Salzman, Sivan Chartier, Taylor Mici, Joni Lambropoulos, John C. Shen, Rui Yang, Hong Jacobs, Stephen D. OptiPro Systems 6368 Dean Parkway Ontario NY 14519 United States Department of Mechanical Engineering University of Rochester Rochester NY 240 East River Road Rochester NY 14623 United States Laboratory for Laser Energetics University of Rochester Rochester NY 240 East River Road Rochester NY 14623 United States Department of Chemical Engineering University of Rochester Rochester NY 240 East River Road Rochester NY 14623 United States Materials Science Program Department of Mechanical Engineering University of Rochester Rochester NY 240 East River Road Rochester NY 14623 United States

Zirconia coated carbonyl iron particle-based magnetorheological fluid was developed for magnetorheological finishing. Particles were coated via sol-gel synthesis. Spot polishing tests were performed over 3 weeks with ... 详细信息

ISBN: (纸本)9781557528933

关键词： Iron

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