检索结果-内蒙古大学图书馆

A Novel Hybrid Ureteroscope Tracking for Robotic-Assisted Retrograde Intrarenal Surgery via Recognition of Pathway With Lumen Identification

引用

IEEE Robotics and Automation Letters 2025年第6期10卷 6368-6375页

作者： Han, Jung-Min Kwon, Dong-Soo Kyung, Ki-Uk Korea Advanced Institute of Science and Technology Department of the Robotics Program Daejeon34141 Korea Republic of Roen Surgical Inc. Daejeon34051 Korea Republic of Korea Advanced Institute of Science and Technology Department of Mechanical Engineering Daejeon34141 Korea Republic of

Resolving disorientation of the surgeon caused by wrong recognition of scope's position, which often increases procedural time and workload, remains a significant challenge in robotic-assisted retrograde intrarenal surgery (RIRS). This letter introduces a novel hybrid ureteroscope tracking algorithm that integrates low-latency lumen identification with robotic motion data to enhance intrarenal navigation. The system estimates the ureteroscope's position on the centerline of the kidney by recognizing its pathway. In validation tests using a 3D-printed phantom, the proposed method achieved an average localization success rate of 89.2% for major calyx entry and 84.1% for minor calyx entry, with an average computation time of 0.26 seconds, ensuring low-latency operation. Usability testing with ten novice participants demonstrated a 44.5% reduction in cognitive workload (NASA-TLX), improved task success rates, and reduced manipulation effort. These results indicate that the proposed tracking algorithm significantly enhances ureteroscope navigation, improving efficiency and reducing the surgeon's cognitive load in robotic-assisted RIRS. © 2016 IEEE.

关键词： Medical robotics

来源：评论

学校读者我要写书评

暂无评论

Multiplexing B5G/6G Services Over Aerial VLC Networks: A Comprehensive Radio Resource Management Framework

引用

IEEE Internet of Things Journal 2025年第9期12卷 11600-11621页

作者： Zarini, Hosein Gholipoor, Narges Mili, Mohammad Robat Rasti, Mehdi Movaghar, Ali Choi, Jinho Chae, Chan-Byoung Sharif University of Technology Department of Computer Engineering Tehran11365-8639 Iran University of Oulu Center for Wireless Communications Oulu90570 Finland Pasargad Institute for Advanced Innovative Solutions Tehran1111111 Iran The University of Adelaide School of Electrical and Mechanical Engineering North Terrace AdelaideSA5005 Australia Yonsei University School of Integrated Technology BK21 Graduate Program in Intelligent Semiconductor Technology Seoul03722 Korea Republic of

Downlink transmission of a nonorthogonal visible light communication (VLC) system, empowered by autonomous aerial vehicles (AAVs), is studied for coexisting enhanced mobile broadband (eMBB), ultrareliable low-latency communication (URLLC), and massive machine-type communication (mMTC) services. A joint resource allocation problem involving user association, transmit power, and flight trajectory of AAVs is formulated, with the goal of characterizing a multiobjective tradeoff as a weighted sum of the power consumption of each AAV and the perceived Quality of Experience (QoE) of its associated eMBB users, while ensuring the service-specific requirements for eMBB, mMTC, and URLLC are met. Assuming the imperfection of channel state information (CSI), we invoke a generalized Benders decomposition (GBD) methodology, leveraging tools from convex optimization and multiagent deep reinforcement learning to address this problem. We further analytically derive the upper and lower bounds on the reward function for each AAV as a learning agent. Extensive simulations confirm that our proposed method outperforms the single-agent counterpart in the literature, with up to a 22% reduction in power consumption and a 13% gain in perceived QoE. Additionally, compared to the globally optimal brute-force method for AAV-user association, our proposed method experiences only a trivial performance loss in a small-scale scenario. © 2014 IEEE.

关键词： Convex optimization

来源：评论

学校读者我要写书评

暂无评论

Simulation study on mitigating manufacturing defects in vehicle steering knuckles

引用

International Journal of Advanced Manufacturing technology 2025年第3期138卷 1401-1411页

作者： Yang, Cheng-Jung Lien, Zih-An Huang, Liqi Chen, Po-Tuan Department of Mechanical and Electromechanical Engineering National Sun Yat-Sen University Kaohsiung Taiwan Technical and Vocational Program in Mechatronics National Taipei University of Technology Taipei Taiwan Co. Ltd. of Kunshan Jiangsu Kunshan China Department of Vehicle Engineering National Taipei University of Technology Taipei Taiwan

The application of aluminum alloy castings in vehicle structures demands exceptionally high dimensional accuracy and mechanical strength, particularly in critical load-bearing and control components such as steering knuckles. This study optimizes the casting process for specially shaped steering knuckle components by integrating computer-aided engineering technology to conduct numerical simulations and parameter adjustments, thereby minimizing casting defects and enhancing the quality of finished products. Cimatron software was employed for mold design and disassembly, while Pro CAST software was utilized for numerical analysis of the flow field and solidification behavior to assess the flow characteristics of aluminum melt, shrinkage cavity distribution, and the effects of thermal stress during solidification. By adjusting casting pressure, optimizing the mold flow channel design, and enhancing the cooling system, this study effectively reduces common casting defects such as shrinkage and porosity while improving filling uniformity and microstructural quality. The optimized process significantly enhances the mechanical properties and manufacturing stability of castings, ensuring that the final products meet the stringent strength and reliability standards required for vehicle structural components. This study not only presents an effective strategy for refining the steering knuckle casting process but also serves as a valuable technical reference for optimizing the manufacturing of high-precision aluminum alloy components. © The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature 2025.

关键词： Aluminum alloys

来源：评论

学校读者我要写书评

暂无评论

Comparison of Advanced Sample Preparation Techniques for High-Resolution Imaging of Sponge Spicule Cross-Sections

Comparison of Advanced Sample Preparation Techniques for Hig...

引用

Symposium on Natural Fibers and Biocomposites: A Sustainable Solution, 2025, held as part of the TMS Annual Meeting and Exhibition, TMS 2025

作者： Tavangarian, Fariborz Fani, Niloofar Monfared, Armaghan Hashemi Sadeghzade, Sorour Mechanical Engineering Program School of Science Engineering and Technology Pennsylvania State University Harrisburg MiddletownPA17057 United States Department of Biomedical Engineering Pennsylvania State University State College University ParkPA16802 United States School of Engineering Westlake University Hangzhou310024 China

ISBN: (纸本)9783031811890

This study comprehensively investigates the effectiveness of three advanced sample preparation techniques—ion milling, laser cuttingLaser-based techniques, and Focused Ion Beam (FIB) milling—for high-resolution imaging of Euplectella aspergillum sponge fibers called spicules. Primarily composed of silica layers with nanometer-scale organic interlayers, spicules possess complex hierarchical structures which are critical for their mechanical propertiesmechanical property. Accurate characterizationCharacterization of these structures requires advanced sample preparation to prevent artefacts and preserve structural integrity. Ion milling introduced significant surface degradation and uneven material removal in spicules. Despite its precision, laser cutting caused thermal damage and induced micro-cracks, compromising the microstructural integrity. In contrast, FIB milling provided superior results, producing smooth, artefact-free cross-sections with minimal thermal and mechanical stress. The real-time imaging capability of FIB milling further ensured optimal sample preparation, making it the most suitable technique for delicate biological materials like spicules. The findings of this study provide valuable insights into the preparation of biological samples for further research and analysis. © The Minerals, Metals & Materials Society 2025.

关键词： Milling (machining)

来源：评论

学校读者我要写书评

暂无评论

ANN-based analysis of thin film Maxwell fluid dynamics with electro-osmotic and nonlinear thermal effects

引用

Alexandria engineering Journal 2025年 127卷 392-410页

作者： Din, Irfan Saif Ud Siddique, Imran Zahid, Zohaib Nadeem, Muhammad Islam, S. Department of Mathematics University of Management and Technology Lahore54770 Pakistan Department of Mathematics University of Sargodha Sargodha40100 Pakistan Mathematics in Applied Sciences and Engineering Research Group Scientific Research Center Al-Ayen University Nasiriyah64001 Iraq Federal University of Technology Paran UTFPR Mechanical Engineering Department DAMEC Postgraduate Program in Mechanical and Materials Engineering PPGEM Research Center for Rheology and Non-Newtonian Fluids CERNN R. Deputado Heitor Alencar Furtado 5000 - Bloco N - Ecoville PR Curitiba81280-340 Brazil Department of Mechanical Engineering Prince Mohammad Bin Fahd University P.O Box 1664 Al Khobar31952 Saudi Arabia

An intelligent Levenberg-Marquardt Technique (LMT) with artificial neural network (ANN) backpropagation (BP) has been used to analyze the thermal heat and mass transfer of unsteady magnetohydrodynamics (MHD) thin film Maxwell fluid flow in a porous inclined sheet with an emphasis on the influence of electro-osmosis. The activation energy, chemical reaction, mixed convection, melting heat, joule heating, nonlinear thermal radiation, variable thermal conductivity and thermal source/sink effect are taken into account for transport expressions. Appropriate similarity transformations were used to translate partial differential equations (PDEs) into ordinary differential equations (ODEs). After that, the built-in MATLAB BVP4C method was used for a data set assessed using the LMT-ANN strategy to solve these ODEs. The physical significance of the designed parameters is thoroughly discussed in both tabular and graphical form. The observed R-squared value is 1, and the mean square error up to 10−15 demonstrates the LMT-ANN's precise and accurate computing capability. The model's validity is also confirmed by the strong agreement between the obtained predicted findings and numerical results, which shows a high degree of accuracy within the range of 10−8 to 10−11. It was revealed that radiative heat considerably increases surface heat energy through accumulation, improving heat transfer qualities, whereas fluid temperature is raised by Joule dissipation, variable thermal conductivity, and heat source. Electro-osmosis and magnetic fields reduce fluid velocity by generating opposing forces that resist the flow. This problem works best in microscale fluid transport systems and drilling operations, where magnetic and electro-osmotic control are crucial. These systems include micro-electromechanical systems, lab-on-a-chip devices, porous geological formations, and thin film coating technologies. © 2025 The Authors

关键词： Activation energy

来源：评论

学校读者我要写书评

暂无评论

Design and Performance Comparison of Current References for a 32-bit Microcontroller Using 22nm technology

Design and Performance Comparison of Current References for ...

引用

IEEE Latin American Symposium on Circuits and Systems (LASCAS)

作者： Eduardo A. Barcelos Pâmela R. A. N. Campagnucci Daniel M. Muñoz Wellington A. Amaral Sandro A. P. Haddad Department of Mechanical Engineering Faculty of Technology Mechatronics Graduate Program Faculty of Gama Electronics Engineering Undergraduate Program University of Brasilia Brasilia DF Brazil

ISBN: (数字)9798331522124

ISBN: (纸本)9798331522131

With the advancement of semiconductor technologies, the need for efficient power management solutions in integrated systems, such as RISC-V architecture-based microcontrollers, becomes increasingly critical. However, there is a lack of studies comparing current reference architectures in terms of performance and robustness, particularly in 22nm technologies. In this paper, we present a comparative analysis of two current reference designs implemented in the same technology-referred to as Reference Design A and Reference Design B. We focus on their approaches to thermal compensation, supply stability, and layout optimizations. Through simulations and experimental tests, we evaluate the performance of each design within a power management system that includes DC-DC converters and LDO regulators. Our results indicate that Design A exhibits superior power supply rejection with a PSRR of -85 dB, while Design B demonstrates enhanced energy efficiency and thermal stability, achieving a nominal current of 5.14 μA and a temperature coefficient of 16.21 ppm. These findings underscore the importance of balancing energy efficiency, thermal stability, and power supply variation rejection when selecting current references for low-power, high-reliability applications, such as those in the Internet of Things (IoT).

关键词： Resistance Microcontrollers Power system management Stability criteria Energy efficiency Robustness Circuit stability Thermal analysis Internet of Things Thermal stability

来源：评论

学校读者我要写书评

暂无评论

A 22nm CMOS PFM Buck Converter Used in a 32-Bit RISC-V Microcontroller for IoT Applications

A 22nm CMOS PFM Buck Converter Used in a 32-Bit RISC-V Micro...

引用

IEEE Latin American Symposium on Circuits and Systems (LASCAS)

作者： Luiz H. N. Oliveira Wellington A. Amaral Sandro A. P. Haddad Daniel M. Muñoz Eduardo A. Barcelos Vinícius V. M. Sotero Emmanuel K. M. Jonhson Pâmela R. A. N. Campagnucci Luis V. N. Lima Department of Mechanical Engineering Faculty of Technology Mechatronics Graduate Program University of Brasilia Brasilia DF Brazil Faculty of Gama Electronics Engineering Undergraduate Program

ISBN: (数字)9798331522124

ISBN: (纸本)9798331522131

The demand for efficient power management solutions in electronic devices has increased significantly, especially for microcontrollers operating in low-power modes. This article presents the design and implementation of a Pulse Frequency Modulation (PFM)-based buck converter for applications in 32-bit microcontrollers using 22nm CMOS technology. The methodology involves the development of a Constant On Time (COT) architecture that maintains a fixed duration for the activation of the high-side MOSFET, using a monostable multivibrator to generate the necessary timing signals. The converter's performance was simulated under various load conditions and process corners to evaluate its efficiency and output characteristics. The results show that the proposed buck converter achieves high efficiency, with peak values above 95%, while maintaining a low output ripple. Specifically, the converter exhibits an efficiency of 93.4% at a load of 1mA, with output ripple voltages as low as 2.20 mV under ideal conditions. The contributions of this work lie in the advancement of PFM converter technology for modern microcontroller applications, demonstrating the potential of 22nm CMOS processes to improve power efficiency and performance.

关键词： Semiconductor device modeling Performance evaluation MOSFET Buck converters Microcontrollers Power system management Multivibrators Timing Internet of Things Load modeling

来源：评论

学校读者我要写书评

暂无评论

Investigation of Operating Temperature as a Key Factor in Determining Photovoltaic Module Cooling Specifications 4

Investigation of Operating Temperature as a Key Factor in De...

引用

4th International Symposium on Advances and Innovation in mechanical engineering, ISAIME 2023

作者： Supriyono, Toto Omar, Ghazali Tamaldin, Noreffendy Ariantara, Bambang Yamin, Mohammad Sumartono, Muhammad Rizki Wati, Dian Anisa Rokhwah Faculty of Mechanical Technology and Engineering UTeM Melaka76100 Malaysia Program Studi Teknik Mesin Universitas Pasundan Bandung40153 Indonesia Program Studi Teknik Mesin Universitas Gunadarma Depok16424 Indonesia Progam Studi Teknik Mesin Universitas Hasyim Asy’ari Tebuireng Jombang Indonesia

Many studies have shown that the temperature of photovoltaic modules (PVM) significantly affects their performance. An effective thermal management system is required to maintain optimal efficiency. This investigation is part of an ongoing study on PVM thermal management that aims to maintain the PVM power output at high temperatures, that is, above 30oC. To design an efficient cooler, it is important to determine the operating temperature range of the PVM. This study focused on measuring the temperature of the back surface of a PVM with a capacity of 120 W using a thermocouple connected to a temperature data logger. Measurements were carried out in 3 (three) stages to improve the operating temperatures' accuracy, accuracy, and trend. The first phase was carried out in September, October, November 2020, July 2021, and June 2023, from 6:00 am to 6:00 pm. The measurement was in the parking area on the second floor of the Faculty of engineering, Pasundan University, Bandung. The results of the 3rd phase of the investigation revealed that the rear surface temperature ranged from 19°C in the morning at 06:00 to a peak of 64.5°C at 12:15 when the irradiance reached 535 W/m2. Then, the temperature gradually drops to approximately 30°C at 17:00 and drops back to approximately 24°C at sunset. Based on these findings, the optimal operating temperature range for PVM chillers is 30°C to 70°C, providing important data as a cooling design parameter. © 2025 Institute of Physics Publishing. All rights reserved.

关键词： Cooling systems

来源：评论

学校读者我要写书评

暂无评论

Insights into the role of metal dopant on ammonia decomposition over graphene-supported Ni6, Ni5Pt, and Ni5Rh clusters

引用

International Journal of Hydrogen Energy 2025年 130卷 168-175页

作者： Yusuf, Alfani Budiantono, Reva Juangsa, Firman Bagja Aziz, Muhammad Budiyanto, Muhammad Arif Saputro, Adhitya Gandaryus Mahyuddin, Muhammad Haris Graduate Program of Engineering Physics Faculty of Industrial Technology Institut Teknologi Bandung Jl. Ganesha 10 Bandung40132 Indonesia PLN Nusantara Power UMRO Jl. Pluit Karang Ayu Barat No. 1 Jakarta14450 Indonesia Thermal Science and Engineering Research Group Faculty of Mechanical and Aerospace Engineering Institut Teknologi Bandung Jl Ganesha 10 Bandung40132 Indonesia Institute of Industrial Science The University of Tokyo 4-6-1 Komaba Meguro-ku Tokyo153-8505 Japan Department of Mechanical Engineering Universitas Indonesia Depok16424 Indonesia Quantum and Nano Technology Research Group Faculty of Industrial Technology Institut Teknologi Bandung Jl. Ganesha 10 Bandung40132 Indonesia Research Center for Nanoscience and Nanotechnology Institut Teknologi Bandung Jl. Ganesha 10 Bandung40132 Indonesia

Ammonia (NH3) is a promising hydrogen (H2) carrier, owing to its high hydrogen content and ease of storage. However, efficient catalytic decomposition of NH3 to H2 remains challenging. This study investigates the catalytic activity of graphene-supported Ni6, Ni5Pt, and Ni5Rh clusters for NH3 decomposition to N2 and H2 using density functional theory (DFT) calculations. The results show that the addition of Pt and Rh dopants weakens the adsorption of intermediates formed during the NH3 dehydrogenation step and slightly increases the activation energies. Interestingly, however, this drawback becomes a key factor in enhancing the activity of the subsequent N–N association and H–H recombination steps, which are critical for the reaction to cycle. Our electronic structure analysis reveals that the decreased activity in the NH3 dehydrogenation step but increased activity in the N2 and H2 formation steps are due to the ligand effect exerted by Pt and Rh. Specifically, since the metal dopants have higher electronegativities than Ni, the number of electrons at the preferred Ni-edge site decreases and eventually weakens the adsorption. Furthermore, the spatially broad nature of the Pt-5d and Rh-4d orbitals delocalizes the cluster's electron distribution, which weakens the 2N and 2H adsorption and thus eases the N2 and H2 formation. This study provides insights into the role of noble metal dopants in optimizing Ni-based catalysts for NH3 decomposition, paving the way for efficient H2 utility technologies. © 2025 Hydrogen Energy Publications LLC

关键词： Dehydrogenation

来源：评论

学校读者我要写书评

暂无评论

Effect of Sn addition on electrochemical activity of ribbons of Mg-Al-Ca anode material for rechargeable magnesium batteries fabricated by rapid solidification

引用

Keikinzoku/Journal of Japan Institute of Light Metals 2025年第1期75卷 9-13页

作者： Fukuta, Yoshitaka Kikura, Kensei 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 Graduate School of Science and Engineering University of Toyama Toyama-shi Toyama Japan Faculty of Sustainable Design Academic Assembly University of Toyama Toyama-shi Toyama Japan CHUETSU METAL WORKS CO. LTD. Nakaniikawagun Toyama Japan Saitama Industrial technology Center Kawaguchi-shi Saitama Japan Department of Mechanical Systems Engineering Faculty of Engineering Toyama Prefectural University Imizu-shi Toyama Japan

Magnesium-based batteries are potential candidates for next-generation rechargeable batteries due to the divalent nature of magnesium cations and the natural abundance of magnesium resources. In this study, the electrochemical activity of Mg-6mass%Al-3mass%Ca anodes combined with Sn was investigated. Thin ribbons of the anode specimens were prepared by a single-roll rapid solidification method. The results showed that the electrochemical activity increased upon adding 1 mass% Sn, while it decreased for 3 mass% Sn. Based on the results of an X-ray diffraction analysis, the addition of Sn led to the formation of Mg2Sn and Ca2Sn phases, which increased the lattice distortion. Scanning electron microscopy observations indicated that these secondary phases were homogeneously distributed for 1 mass% Sn addition, while they were coarsely distributed for 3 mass% Sn. © 2025 The Japan Institute of Light Metals.

关键词： X ray diffraction analysis

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：