检索结果-内蒙古大学图书馆

Kinematic Modelling and Structural Analysis of a Spherical Robot: BALL-E

IOP Conference Series: Materials Science and engineering 2021年第1期1132卷

作者： Satwik Tholapu A P Sudheer M L Joy Mechatronics/Robotics Lab Department of Mechanical Engineering National Institute of Technology Calicut Kerala India-673601

This paper presents a spherical mobile robot which is capable of executing rolling and walking motions. The proposed robot can also transform into a quadruped based on the terrain conditions. The advantage of combining these motions in the robot is that it improves the collision recovery and manoeuvrability over multiple terrains. Various conceptual designs are developed, and concept scoring is carried out to find the best design. The kinematic analysis is presented for the chosen design using the Denavit-Hartenberg (D-H) method. The inverse kinematics is solved using MATLAB and the corresponding robot configurations are plotted. The structural analysis of the robot is also completed using ANSYS Workbench.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Evaluation of mechanical properties, biodegradability and bioactivity of forsteritediopside scaffolds coated by polycaprolacton fumarate

Evaluation of mechanical properties, biodegradability and bi...

引用

Materials Science and Technology 2019, MS and T 2019

作者： Sadeghzade, Sorour Emadi, Rahmatollah Tavangarian, Fariborz Materials research Group Department of Materials engineering Isfahan University of Technology Isfahan84156-83111 Iran Mechanical Engineering Program School of Science Engineering and Technology Pennsylvania State University HarrisburgPA17057 United States

ISBN: (纸本)0873397703

One of the significant challenges in bone tissue engineering is the fabrication of highly porous scaffolds with interconnected pores and appropriate mechanical properties. Commonly available synthetic scaffolds are made of ceramic or polymer, but a better combination of properties can be achieved with a composite or multi-component structure. The aim of this study is to produce three-dimensional (forsterite-diopside) porous scaffolds using space holder technique in order to use in bone tissue engineering. Therefore, forsterite and Diopside nanopowders were synthesized via mechanical activation and sol-gel methods, respectively, and then were mixed with various ratios. After addition of sodium chloride as spacer with appropriate weight percentage, the powder mixture was compacted under the uniaxial compression. In order to remove sodium chloride and develop a porous structure, samples were sintered. After determination of the optimal scaffolds in terms of mechanical properties, the scaffolds were coated with 6 wt.% poly caprolactone fumarate solution and their mechanical, physical and biological properties was evaluated. The results showed that the addition of 10 wt.% diopside nanopowder altered the properties of the scaffolds such that compressive strength increased to 4.36 MPa compared to pure forsterite (3.45 MPa). Applying the polymer coating with cross-linked structure on the optimal scaffolds improved the compressive strength by 23%. Based on the results of Archimedes' principle and SEM micrographs, the addition of 10 wt.% diopside had a negligible effect on the porosity but improved the pores morphology. SEM micrographs of scaffolds after soaking in SBF depicted tiny agglomerated bone-like apatite particles. Considering the results obtained, it seems that, the produced scaffolds could be a good candidate for bone tissue engineering applications. Copyright © 2019 MS&T19®

关键词： Porosity

来源：评论

学校读者我要写书评

暂无评论

Evaluation of bioactivity and mechanical properties of silica-based ceramic for using in tissue engineering application

Evaluation of bioactivity and mechanical properties of silic...

引用

Materials Science and Technology 2019, MS and T 2019

作者： Tavangarian, Fariborz Sadeghzade, Sorour Emadi, Rahmatollah Mechanical Engineering Program School of Science Engineering and Technology Pennsylvania State University HarrisburgPA17057 United States Materials research Group Department of Materials engineering Isfahan University of Technology Isfahan84156-83111 Iran

ISBN: (纸本)0873397703

Bone engineering presents an alternative approach to repair and regenerate a damaged tissue. For bone repair and bone tissue engineering applications, bioactive materials with different degradation and mechanical properties are needed. Recently hardystonite bioceramic have received great attention for treatment of bone defects. In this study, a bioactive hardystonite (HT) - forstrite (FO) nanocomposite was fabricated by two step sintering method. The structure, morphology and bioactivity potential of the nanocomposite were examined using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The composite with optimized mechanical properties was HT-20wt.%Fo that had the compressive modulus and strength of 287 MPa and 149 MPa, respectively. The feasibility of the produced composite for bone tissue engineering application was evaluated using simulated body fluid (SBF). A range of characterization techniques was applied to confirm the deposition of Hydroxyl carbonated apatite (HCA) deposition on the surface of HT-20wt.%Fo composite following 7 days in SBF. Overall, results suggest that HT-20wt.%Fo composite with improved mechanical properties, and apatite formation ability can be a promising candidate for bone tissue engineering applications. Copyright © 2019 MS&T19®

关键词： Nanocomposites

来源：评论

学校读者我要写书评

暂无评论

HybrUR: A Hybrid Physical-Neural Solution for Unsupervised Underwater Image Restoration

arXiv

引用

arXiv 2021年

作者： Yan, Shuaizheng Chen, Xingyu Wu, Zhengxing Tan, Min Yu, Junzhi The Laboratory of Cognitive and Decision Intelligence for Complex System Institute of Automation Chinese Academy of Sciences Beijing100190 China The Department of Mechanical Engineering Fuzhou University Fuzhou350000 China The School of Artificial Intelligence University of Chinese Academy of Sciences Beijing100049 China Xiaobing.AI Beijing100080 China The State Key Laboratory for Turbulence and Complex Systems Department of Advanced Manufacturing and Robotics College of Engineering Peking University Beijing100871 China

Robust vision restoration of underwater images remains a challenge. Owing to the lack of well-matched underwater and in-air images, unsupervised methods based on the cyclic generative adversarial framework have been widely investigated in recent years. However, when using an end-to-end unsupervised approach with only unpaired image data, mode collapse could occur, and the color correction of the restored images is usually poor. In this paper, we propose a data- and physics-driven unsupervised architecture to perform underwater image restoration from unpaired underwater and in-air images. For effective color correction and quality enhancement, an underwater image degeneration model must be explicitly constructed based on the optically unambiguous physics law. Thus, we employ the Jaffe-McGlamery degeneration theory to design a generator and use neural networks to model the process of underwater visual degeneration. Furthermore, we impose physical constraints on the scene depth and degeneration factors for backscattering estimation to avoid the vanishing gradient problem during the training of the hybrid physical-neural model. Experimental results show that the proposed method can be used to perform high-quality restoration of unconstrained underwater images without supervision. On multiple benchmarks, the proposed method outperforms several state-of-the-art supervised and unsupervised approaches. We demonstrate that our method yields encouraging results in real-world applications. © 2021, CC BY-NC-ND.

关键词： Image reconstruction

来源：评论

学校读者我要写书评

暂无评论

Safe planning for self-driving via adaptive constrained ILQR

arXiv

引用

arXiv 2020年

作者： Pan, Yanjun Lin, Qin Shah, Het Dolan, John M. Department of Mechanical Engineering Carnegie Mellon University 5000 Forbes Ave PittsburghPA15213 United States Department of the Robotics Institute Carnegie Mellon University 5000 Forbes Ave PittsburghPA15213 United States Department of Mechanical Engineering Indian Institute of Technology Kharagpur Kharagpur West Bengal721302 India

Constrained Iterative Linear Quadratic Regulator (CILQR), a variant of ILQR, has been recently proposed for motion planning problems of autonomous vehicles to deal with constraints such as obstacle avoidance and reference tracking. However, the previous work considers either deterministic trajectories or persistent prediction for target dynamical obstacles. The other drawback is lack of generality - it requires manual weight tuning for different scenarios. In this paper, two significant improvements are achieved. Firstly, a twostage uncertainty-aware prediction is proposed. The short-term prediction with safety guarantee based on reachability analysis is responsible for dealing with extreme maneuvers conducted by target vehicles. The long-term prediction leveraging an adaptive least square filter preserves the long-term optimality of the planned trajectory since using reachability only for long-term prediction is too pessimistic and makes the planner over-conservative. Secondly, to allow a wider coverage over different scenarios and to avoid tedious parameter tuning case by case, this paper designs a scenario-based analytical function taking the states from the ego vehicle and the target vehicle as input, and carrying weights of a cost function as output. It allows the ego vehicle to execute multiple behaviors (such as lane-keeping and overtaking) under a single planner. We demonstrate safety, effectiveness, and real-time performance of the proposed planner in simulations. Copyright © 2020, The Authors. All rights reserved.

关键词： Vehicles

来源：评论

学校读者我要写书评

暂无评论

Corrections to: “The Soft Compiler: A Web-Based Tool for the Design of Modular Pneumatic Circuits for Soft Robots”

引用

IEEE robotics and Automation Letters 2022年第4期7卷 11474-11474页

作者： Savita V. Kendre Lauryn Whiteside Tian Y. Fan Jovanna A. Tracz Gus T. Teran Thomas C. Underwood Mohammed E. Sayed Haihui J. Jiang Adam A. Stokes Daniel J. Preston George M. Whitesides Markus P. Nemitz Department of Robotics Engineering Worcester Polytechnic Institute Worcester MA USA Eastern Virginia Medical School Norfolk VA USA Department of Aerospace Engineering and Engineering Mechanics University of Texas at Austin Austin TX USA School of Engineering University of Edinburgh Edinburgh U.K. Department of Chemistry and Chemical Biology Harvard University Cambridge MA USA Department of Mechanical Engineering Rice University Houston TX USA

In Section “I. Introduction” on page 6060 of our original article [1], we describe Rothemund et al.’s work on the soft bistable valve [2]. The corresponding reference to their work was cited incorrectly.

关键词： Soft robotics

来源：评论

学校读者我要写书评

暂无评论

Visual Servoing Approach for Autonomous UAV Landing on a Moving Vehicle

arXiv

引用

arXiv 2021年

作者： Keipour, Azarakhsh Pereira, Guilherme A.S. Bonatti, Rogerio Garg, Rohit Rastogi, Puru Dubey, Geetesh Scherer, Sebastian Robotics AI Amazon ArlingtonVA22202 United States Department of Mechanical and Aerospace Engineering West Virginia University MorgantownWV26506 United States Autonomous Systems Group Microsoft RedmondWA98052 United States Gather AI PittsburghPA15217 United States Mowito Bengaluru560091 India Robotics Institute Carnegie Mellon University PittsburghPA15213 United States

Many aerial robotic applications require the ability to land on moving platforms, such as delivery trucks and marine research boats. We present a method to autonomously land an Unmanned Aerial Vehicle on a moving vehicle. A visual servoing controller approaches the ground vehicle using velocity commands calculated directly in image space. The control laws generate velocity commands in all three dimensions, eliminating the need for a separate height controller. The method has shown the ability to approach and land on the moving deck in simulation, indoor and outdoor environments, and compared to the other available methods, it has provided the fastest landing approach. Unlike many existing methods for landing on fast-moving platforms, this method does not rely on additional external setups, such as RTK, motion capture system, ground station, offboard processing, or communication with the vehicle, and it requires only the minimal set of hardware and localization sensors. The videos and source codes are also provided. Copyright © 2021, The Authors. All rights reserved.

关键词： Visual servoing

来源：评论

学校读者我要写书评

暂无评论

Pump-free microfluidic system for cell culture under flow 23

Pump-free microfluidic system for cell culture under flow

引用

23rd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2019

作者： Paknahad, Mohammad Ghahremani, Morvarid F. Horst, Caleb Simmons, Craig A. Translational Biology and Engineering Program Ted Rogers Centre for Heart Research Toronto Canada Department of Mechanical and Industrial Engineering Institute of Biomaterials and Biomedical Engineering University of Toronto Toronto Canada CellScale Biomaterials Testing Toronto Canada

ISBN: (纸本)9781733419000

Most common method to perform microfluidic endothelial cell culture under physiological flow is to use a pump, which can be cumbersome and requires complex connections and a large fluid dead volume. To address these limitations, which hinder widespread adoption, we present here a pump-free, simple, low-cost microfluidic system as a meaningful alternative to traditional flow culture systems. © 2019 CBMS-0001.

关键词： Microfluidics

来源：评论

学校读者我要写书评

暂无评论

Effects of electrochemical synthetic conditions on surface property and photocatalytic performance of copper and iron-mixed p-type oxide electrodes

引用

Journal of Materials Science & Technology 2018年第9期34卷 1503-1510页

作者： Sun Hee Yoon Dong Suk Han Unseock Kang Seung Yo Choi Wubulikasimu Yiming Ahmed Abdel-Wahab Hyunwoong Park Chemical Engineering Program Texas A&M University at Qatar School of Energy Engineering Kyungpook National University Department of Mechanical Engineering Texas A&M University at Qatar

Earth-abundant copper and iron-mixed oxide（CuO/CuFeO_2; CFO） film electrodes are synthesized using an electrochemical deposition（ED） technique at two different ED potentials（-0.36 and-0.66 V vs saturated calomel electrode（SCE）; denoted as ED-1 and ED-2, respectively）. Then, their surface morphologies are compared, and the photo（electro）catalytic activities for the reduction of Cr（VI） are examined in aqueous solutions at pH 7 under simulated sunlight（AM 1.5 G; 100 mW cm（-2））. The degree of the electrical potential applied to the ED process significantly affects the thickness of the synthesized electrode film and the intensity ratio of the diffraction peaks of CuO（111） and CuFeO_2（012）. A 200 μm thick ED-2 sample with a distinct stacking of CuO on CuFeO_2 exhibits a larger broadband absorption spectrum than the 50-μm thick ED-1 with less separate stacking. Furthermore, the ED-2 sample has a higher intensity ratio of the diffraction peaks of CuO（111） and CuFe02（012） than ED-1. As-synthesized ED-2 samples produce larger photocurrents, leading to faster Cr（VI） reduction on the surface under given potential bias（-0.5 V vs SCE）or bias-free conditions. The energy levels（i.e., flatband potential） for the two samples are almost the same（only 10 mV difference）, presumably supposing that the enhanced photoactivity of the ED-2 sample for Cr（VI） reduction is due to the facilitated charge transfer. The time-resolved photoluminescence emission spectra analysis reveal that the lifetime（r） of the charge carriers in the ED-1 sample is 0.103 ns, which decreases to 0.0876 ns in the ED-2. The ED-2 sample synthesized at a high negative potential is expected to contribute greatly to the application of other solar-to-fuel energy conversion fields as a highly efficient electrode material.

关键词： Artificial photosynthesis Solar fuel Delafossites Morphology Charge transfer

来源：评论

学校读者我要写书评

暂无评论

mechanical Regulation of Endocytosis: New Insights and Recent Advances (vol 4, 1900278, 2020)

引用

ADVANCED BIOSYSTEMS 2020年第8期4卷 e2000155页

作者： Joseph, Jophin G. Liu, Allen P. Department of Mechanical Engineering University of Michigan Ann Arbor MI 48109 USA Department of Biomedical Engineering University of Michigan Ann Arbor MI 48109 USA Cellular and Molecular Biology Program University of Michigan Ann Arbor MI 48109 USA Department of Biophysics University of Michigan Ann Arbor MI 48109 USA

Endocytosis is a mechanosensitive process. It involves remodeling of the plasma membrane from a flat shape to a budded morphology, often at the sub-micrometer scale. This remodeling process is energy-intensive and is influenced by mechanical factors such as membrane tension, membrane rigidity, and physical properties of cargo and extracellular surroundings. The cellular responses to a variety of mechanical factors by distinct endocytic pathways are important for cells to counteract rapid and extreme disruptions in the mechanohomeostasis of cells. Recent advances in microscopy and mechanical manipulation at the cellular scale have led to new discoveries of mechanoregulation of endocytosis by the aforementioned factors. While factors such as membrane tension and membrane rigidity are generally shown to inhibit endocytosis, other mechanical stimuli have complex relationships with endocytic pathways. At this juncture, it is now possible to utilize experimental techniques to interrogate theoretical predictions on mechanoregulation of endocytosis in cells and even living organisms.

关键词： clathrin-mediated endocytosis endocytosis pathways mechanobiology mechanotargeting mechanotransduction

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：