检索结果-内蒙古大学图书馆

IEEE Latin American Symposium on Circuits and Systems (LASCAS)

作者： Emmanuel K. M. Johnson Luis Victor N. Lima Pamela. R. A. N. Campagnucci Sandro A. P. Haddad Wellington A. Amaral Daniel M. Muñoz Department of Mechanical Engineering Mechatronics Graduate Program University of Brasilia Brasilia DF Brazil Faculty of Gama Electronics Engineering Undergraduate Program University of Brasilia Brasilia DF Brazil

ISBN: (数字)9798331522124

ISBN: (纸本)9798331522131

This paper presents a comparison between two LDOs (Low Dropout Regulators) developed for a PMIC (Power Management Integrated Circuit) responsible for powering a 32-bit microcontroller based on the RISC-V microarchitecture, designed in 22 nm technology. The microcontroller will be integrated with a radio frequency interface for IoT (Internet of Things) applications. Two LDOs were designed: one with external compensation and the other a capacitor-less LDO. Both operate with an input voltage of 2.5V, an output voltage of 0.8V, and a maximum current of 150mA. The externally compensated LDO exhibited greater stability in response to load variations and a higher PSRR (Power Supply Rejection Ratio), while the capacitor-less LDO demonstrated faster regulation speed and occupied a chip area similar to the externally compensated LDO.

关键词： Regulators Microcontrollers Power supplies Power system management Simulation Stability analysis Regulation Circuit stability Internet of Things Voltage control

来源：评论

学校读者我要写书评

暂无评论

Design and Performance Comparison of Low Dropout Regulators for a 32-bit Microcontroller Using 22nm Technology 16

Design and Performance Comparison of Low Dropout Regulators ...

引用

16th IEEE Latin American Symposium on Circuits and Systems, LASCAS 2025

作者： Johnson, Emmanuel K. M. Lima, Luis Victor N. Campagnucci, Pamela. R. A. N. Haddad, Sandro A. P. Amaral, Wellington A. Munoz, Daniel M. University of Brasilia Mechatronics Graduate Program Department of Mechanical Engineering DF Brasilia Brazil University of Brasilia Faculty of Gama Electronics Engineering Undergraduate Program DF Brasilia Brazil

ISBN: (纸本)9798331522124

关键词： Low power electronics

来源：评论

学校读者我要写书评

暂无评论

Performance of the multigrid method with time-stepping to solve 1D and 2D wave equations

引用

International Journal for Computational Methods in engineering Science and Mechanics 2022年第1期23卷 45-56页

作者： Malacarne, Maicon F. Pinto, Marcio A. V. Franco, Sebastião R. Graduate Program on Numerical Methods in Engineering–PPGMNE Federal University of Parana–UFPR PR Curitiba Brazil Department of Mechanical Engineering Federal University of Parana–UFPR PR Curitiba Brazil Department of Mathematics State University of Centro-Oeste–UNICENTRO PR Irati Brazil

This work aims to discuss a proposed solution for wave equations that utilize discretization by means of the finite difference method, weighted by a parameter η, with sweeping done according to the time-stepping method. The multigrid method is employed to speed up the convergence in obtaining the solution of the system of equations resulting from the discretization. To validate the proposed model, the discretization errors, effective and apparent orders, convergence factor, orders of complexity, and the computational time were assessed. A comparison between the singlegrid and multigrid methods was carried out in order to determine the most advantageous one. © 2021 Taylor & Francis Group, LLC.

关键词： Wave equations

来源：评论

学校读者我要写书评

暂无评论

Comparison between different internal cross-sections for pulmonary secretion suction catheters

引用

Research on Biomedical engineering 2022年第3期38卷 965-975页

作者： dos Santos Lima, Bruna Luiza Tadeu Las Casas, Marina Spyer de Oliveira, Patrícia Muniz Huebner, Rudolf Rodrigues-Machado, Maria da Glória de Las Casas, Estevam Barbosa Department of Structural Engineering Federal University of Minas Gerais Belo Horizonte Brazil Department of Mechanical Engineering Federal University of Minas Gerais Belo Horizonte Brazil Faculty of Medical Sciences of Minas Gerais Post-graduate Program in Health Sciences Belo Horizonte Brazil

Introduction: Endotracheal suctioning is a procedure to remove pulmonary secretions, which can lead to complications such as hypoxemia. To minimize this risk, a double-lumen pulmonary secretion suction device was developed at the Biomechanics Laboratory of the University of Minas Gerais. The aim of the study is to evaluate the flow of the removal of pulmonary secretions by reducing the cross-section for the passage of mucus, considering catheters with three new, distinct internal cross-sections (circular, semicircular, and curved). Methods: The study was divided into two stages: computer simulations in the software Ansys Fluent using three new internal cross-sections in order to assess the flow rate, secretion removal, and the preparation of solutions of mucus simulators (polyethylene glycol) in three concentrations (semi-liquid, intermediate, and semi-solid) to be aspirated by 12 Fr catheters and by a printed circular catheter in the bench test. Results: It was verified in a bench test that the relationship between shear stress and deformation rate of mucus simulator solutions is not linear and that a suction pressure of less than 300 mmHg, performed by a standard catheter, generates moderate rates of removal of thicker solutions. It is possible to verify, by computer simulations, higher flow rate levels when reducing the length of the circular catheter from 0.5 to 0.4 m. Semicircular catheter produces high flow rates when compared to other proposed catheters. Conclusion: Based on the results obtained, a dual-lumen semicircular catheter can be designed and validated by computer simulation. © 2022, Sociedade Brasileira de Engenharia Biomedica.

关键词： Catheters

来源：评论

学校读者我要写书评

暂无评论

Thermomechanical Characterization of Hot Surface Ignition Device Using Phenomenological Heat Flux Model

引用

JOURNAL OF PROPULSION AND POWER 2022年第4期38卷 656-670页

作者： Kang, Sang-Guk Ryu, Je Ir Motily, Austen H. Numkiatsakul, Prapassorn Lee, Tonghun Kriven, Waltraud M. Kim, Kenneth S. Kweon, Chol-Bum M. U.S. Army Research Laboratory Aberdeen Proving Ground MD 21005 Aerospace Engineer Weapons and Materials Research Directorate Postdoctoral Fellow Computational and Information Sciences Directorate University of Illinois at Urbana-Champaign Urbana IL 61801 Graduate Student Department of Mechanical Science and Engineering. Student Member AIAA Graduate Student Department of Materials Science and Engineering Professor Department of Mechanical Science and Engineering. Associate Fellow AIAA Professor Department of Materials Science and Engineering Mechanical Engineer Computational and Information Sciences Directorate. Member AIAA Program Manager Computational and Information Sciences Directorate. Member AIAA.

Modern aircraft compression ignition engines that seek to achieve fuel-flexible operation require ignition-assisting devices to perform reliably. Many military propulsion systems, and unmanned aircraft in particular, can use hot surface energy addition to improve engine performance. An analysis of the thermomechanical stress behavior of hot surface ignition devices is therefore critical to ensure that they can satisfy new operational requirements. In this paper, a phenomenological heat-flux model is proposed to simulate heat generation inside a heating element. Two finite element analysis models are established using the proposed heat-flux model in order to characterize the transient thermomechanical behavior of an ignition assistant: a two-dimensional (2-D) axisymmetric model with an equivalent cylindrical heating element and a three-dimensional (3-D) solid model with realistic heating element geometry. The transient behavior of the ignition assistant is investigated at standard conditions by characterizing the temperature and thermal stress inside the device for various input voltages. The effect of the nonaxisymmetric heating element geometry on the temperature and thermal stress distribution is assessed. Furthermore, the 3-D ignition assistant model is used to analyze the thermomechanical behavior of an ignition device subjected to a combustion event inside a rapid compression machine. Multiple circumferential orientations of the heating element plane relative to the spray axis are investigated. Results demonstrate that the observed maximum principal stress depends significantly on heating element orientation.

关键词： Heat Flux Stress Distribution Heat Generation Unmanned Aerial Vehicle Propulsion System Surface Energy Adaptive Mesh Refinement Fuel Injection CFD Simulation Fracture Toughness

来源：评论

学校读者我要写书评

暂无评论

ANALYSIS OF NITROGEN FLOW IN FOOD WASTE: A CASE STUDY OF THE UNIVERSITY RESTAURANT-UNB 32nd

ANALYSIS OF NITROGEN FLOW IN FOOD WASTE: A CASE STUDY OF THE...

引用

32nd European Biomass Conference and Exhibition, EUBCE 2024

作者： Ramos, Arthur Augusto Frasson De Brites, Eneida Campos Felipe Soares, Raquel Moraes Silveira, Edgar A. Contreras, Francisco University of Brasilia Department of Civil and Environmental Engineering DF Brasilia70910-900 Brazil University of Brasilia Graduate Program on Environmental Technology and Water Resources Department of Civil and Environmental Engineering DF Brasilia70910-900 Brazil Federal Institute of Education Science and Technology of Brasília Estrutural Campus DF Brasília71250-000 Brazil University of Brasília Mechanical Sciences Graduate Program Laboratory of Energy and Environment DF Brasilia70910-900 Brazil

With the projected global population reaching 9.7 billion by 2050, the production and consumption of food continue to escalate. Nitrogen is pivotal in this landscape due to its significance in living organisms and the environmental repercussions associated with nutrient-rich waste. Inappropriate disposal of such residues contributes to nitrogen release into the environment, impacting aquatic ecosystems and precipitating the generation of greenhouse gases. This study tackles the global challenge of effectively managing nitrogen in food waste by utilizing Material Flow Analysis (MFA) as a tool to comprehend this cycle. The analysis uncovered that vegetables, legumes, and fruits constitute the primary sources of waste generation, while meats, despite their lower mass, account for a substantial proportion of total nitrogen depletion. In the surveyed month of October 2023, 174,834 meals were served, resulting in an average food consumption N-footprint of 0.003 kg of nitrogen discarded per individual meal within the restaurant’s organic waste. These findings indicate that 65% of nitrogen is consumed in meal form, while 35% is discarded as organic solid waste. However, 53% of the nitrogen in the residues originates from food preparation processes, with food preparation responsible for over half of this figure. A deeper process analysis reveals that vegetables have low nitrogen concentrations, although they significantly contribute to waste at all stages. In contrast, meats and eggs, with higher nitrogen concentrations, emerge as noteworthy contributors to the overall nitrogen content in waste. Vegetables and meats contribute about 50% and 45% of the total nitrogen, respectively. These outcomes substantially enhance our comprehension of waste generation dynamics and nutrient utilization at the university restaurant, assisting with waste management, design of sustainable menus, reduction of food waste, and optimized resource utilization, contributing to sustainability and re

关键词： Effluent treatment

来源：评论

学校读者我要写书评

暂无评论

Effect of Cu addition on electrochemical activity of ribbons of Mg-Al-Ca anode materials for magnesium rechargeable batteries manufactured by rapid solidification method

引用

Keikinzoku/Journal of Japan Institute of Light Metals 2024年第1期74卷 14-17页

作者： Fukui, Shunsaku Tsukeda, Tadayoshi Aida, Tetsuo Tabata, Hironobu Kurihara, Hideki Suzuki, Mayumi Program of Materials Science and Engineering Studies in Science and Engineering Graduate School of Science and Engineering University of Toyama 3190 Gofuku Toyama-shi Toyama930-8555 Japan Faculty of Sustainable Design Academic Assembly University of Toyama Toyama-shi Toyama Japan CHUETSU METAL WORKS CO. LTD. Nakaniikawa-gun Toyama Japan Saitama Industrial Technology Center Kawaguchi Kawaguchi-shi Saitama Japan Department of Mechanical Systems Engineering Faculty of Engineering Toyama Prefectural University Imizu-shi Toyama Japan

The potential for magnesium storage batteries to become the next generation of rechargeable batteries is high. This is largely due to the abundance of magnesium metal resources and their high safety and electric capacity per volume. Our research team has been studying magnesium alloys as anode materials for these batteries. Specifically, we have been investigating the electrochemical activity and mechanism of adding copper to Mg-9mass%Al and Mg-9mass%Al-3mass%Ca. Our findings indicate that the electrochemical activity increased with the addition of 1mass%Cu, but decreased with the addition of 3mass%Cu. In addition, changes in lattice constant and basal orientation were also observed. These changes decreased with 1mass%Cu and increased with 3mass%Cu. SEM observations showed that the cell delimitation was indistinct for the 1%Cu addition. © 2024 The Japan Institute of Light Metals.

关键词： Secondary batteries

来源：评论

学校读者我要写书评

暂无评论

Hardware Implementation of a GMDH Controller for Mobile Robot Obstacle Following/Avoidance

Hardware Implementation of a GMDH Controller for Mobile Robo...

引用

IEEE Latin American Robotics Symposium, LARS

作者： M. A. Pastrana L. H. Oliveira M. S. Santana V. C. Oliveira Jose Mendoza-Peñaloza Daniel M. Muñoz Department of Mechanical Engineering Mechatronics Graduate Program Faculty of Gama Electronics Engineering Undergraduate Program University of Brasilia Brasilia DF Brazil

Proportional, integral, and derivative (PID) controllers have been widely adopted for industrial applications. However, these controllers are not very efficient for non-linear systems. Artificial neural networks (ANN) based on the Group Method of Data Handling (GMDH) have great potential to replace the PID controllers due to their polynomial structure, allowing complex non-linear systems to be controlled. This work presents a hardware architecture of a GMDH network applied to speed control of a mobile robot platform. The proposed GMDH controller was implemented using a 16-bit floating-point arithmetic representation and was mapped on a Zynq7020 device. A hardware-in-the-loop based on the Universal Direct Memory Access methodology was developed to validate the proposed circuits, allowing for performance comparisons between a classical PID and the GMDH controllers for different simulated scenarios.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Effect of Handshake in VR Environment via Robotic Arm on Psychological Distance

Effect of Handshake in VR Environment via Robotic Arm on Psy...

引用

IEEE International Workshop on Robot and Human Communication (ROMAN)

作者： Haruto Mukuno Daigo Misaki Graduate School of Engineering Mechanical Engineering Program Kogakuin University Tokyo Japan Faculty of Engineering Department of Mechanical Systems Engineering Kogakuin University Tokyo Japan

The COVID-19 pandemic has popularized telework using video chat tools. Although video chat tools allow people to communicate each other in remote locations, psychological distance is longer than face-to-face communication, which may lead to a lack of intimacy. Previous studies have shown that interfaces combining video chat, VR, and robots with handshakes can improve the sense of closeness. However, few studies have focused on the sense of closeness in interfaces combining VR and robots. In this study, we proposed a multimodal interface combining VR and a robotic arm and verified whether shaking hands with a remote partner in VR could shorten the psychological distance compared to video chat. The results showed that the psychological distance was predominantly shorter in VR communication than in video chat communication; however, a handshake using robotic arm did not shorten the psychological distance compared to a handshake without a robotic arm. These results indicate that spatial distance is shorter in VR than in video chat and that robotic arms must be made more human-like.

关键词：

来源：评论

学校读者我要写书评

暂无评论

High Order of Accuracy for Poisson Equation Obtained by Grouping of Repeated Richardson Extrapolation with Fourth Order Schemes

引用

Computer Modeling in engineering & Sciences 2021年第8期128卷 699-715页

作者： Luciano Pereira da Silva Bruno Benato Rutyna Aline Roberta Santos Righi Marcio Augusto Villela Pinto Graduate Program in Numerical Methods in Engineering Federal University of ParanaCuritiba81531-980Brazil Graduate Program in Space Sciences and Technologies Aeronautics Institute of TechnologySao Jose dos Campos12228-900Brazil Department of Mechanical Engineering Federal University of ParanaCuritiba81531-980Brazil

In this article,we improve the order of precision of the two-dimensional Poisson equation by combining extrapolation techniques with high order *** high order solutions obtained traditionally generate non-sparse matrices and the calculation time is very *** can obtain sparse matrices by applying compact *** this article,we compare compact and exponential finite difference schemes of fourth *** numerical solutions are calculated in quadruple precision(Real*16 or extended precision)in FORTRAN language,and iteratively obtained until reaching the round-off error magnitude around 1.0E−*** procedure is performed to ensure that there is no iteration *** Repeated Richardson Extrapolation(RRE)method combines numerical solutions in different grids,determining higher orders of *** main contribution of this work is based on a process that initializes with fourth order solutions combining with RRE in order to find solutions of sixth,eighth,and tenth order of *** multigrid Full Approximation Scheme(FAS)is also applied to accelerate the convergence and obtain the numerical solutions on the fine grids.

关键词： Tenth order accuracy RRE compact scheme exponential scheme multigrid finite difference

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：