检索结果-内蒙古大学图书馆

arXiv 2019年

作者： Montero, Ral Murillo Del Barrio, Alberto A. Botella, Guillermo Department of Computer Architecture and Automation Complutense University of Madrid Madrid28040 Spain

The posit number system is arguably the most promising and discussed topic in Arithmetic nowadays. The recent breakthroughs claimed by the format proposed by John L. Gustafson have put posits in the spotlight. In this work, we first describe an algorithm for multiplying two posit numbers, even when the number of exponent bits is zero. This configuration, scarcely tackled in literature, is particularly interesting because it allows the deployment of a fast sigmoid function. The proposed multiplication algorithm is then integrated as a template into the well-known FloPoCo framework. Synthesis results are shown to compare with the floating point multiplication offered by FloPoCo as well. Second, the performance of posits is studied in the scenario of Neural Networks in both training and inference stages. To the best of our knowledge, this is the first time that training is done with posit format, achieving promising results for a binary classification problem even with reduced posit configurations. In the inference stage, 8-bit posits are as good as floating point when dealing with the MNIST dataset, but lose some accuracy with CIFAR-10. Copyright © 2019, The Authors. All rights reserved.

关键词： Numbering systems

来源：评论

学校读者我要写书评

暂无评论

Simulation, Optimization and Control of Trajectories of ASVS Performing HACBS Monitoring Missions in Lentic Waters 23

Simulation, Optimization and Control of Trajectories of ASVS...

引用

Proceedings of the Winter Simulation Conference

作者： Alfredo González-Calvin Lía García-Perez José L. Risco-Martín Eva Besada-Portas Department of Computer Architecture and Automation Universidad Complutense de Madrid Madrid SPAIN

ISBN: (纸本)9798350369663

Harmful Algaeand Cyanobacteria Blooms(HACBs)are dangerous dynamic processes for the users/inhabitants of the hydric resources. Their development and contingency plans can be anticipated by using Autonomous Surface Vehicles (ASVs) equipped with a self-driven system capable of deciding how to displace the ASV and its multi-parametric probe to take measurements in the 3D locations of the water body where the HACB is likely to occur. This paper presents a new self-driven system for that purpose, consistent on 1) an offline trajectory planner for the ASV that exploits the information provided by a commercial HACBs simulator to optimize, in turn, the ASV horizontal and probe vertical displacements; and 2) a guidance and control system specially designed for making the ASV follow the planned trajectories. The paper also presents a comprehensive set of simulations to evaluate our proposal's performance and adjust its parameters.

关键词：

来源：评论

学校读者我要写书评

暂无评论

PERCIVAL: Open-Source Posit RISC-V Core with Quire Capability

arXiv

引用

arXiv 2021年

作者： Mallasén, David Murillo, Raul Del Barrio, Alberto A. Botella, Guillermo Piñuel, Luis Prieto-Matias, Manuel The Department of Computer Architecture and Automation Complutense University of Madrid Madrid28040 Spain

The posit representation for real numbers is an alternative to the ubiquitous IEEE 754 floating-point standard. In this work, we present PERCIVAL, an application-level posit RISC-V core based on CVA6 that can execute all posit instructions, including the quire fused operations. This solves the obstacle encountered by previous works, which only included partial posit support or which had to emulate posits in software. In addition, Xposit, a RISC-V extension for posit instructions is incorporated into LLVM. Therefore, PERCIVAL is the first work that integrates the complete posit instruction set in hardware. These elements allow for the native execution of posit instructions as well as the standard floating-point ones, further permitting the comparison of these representations. FPGA and ASIC synthesis show the hardware cost of implementing 32-bit posits and highlight the significant overhead of including a quire accumulator. However, results show that the quire enables a more accurate execution of dot products. In general matrix multiplications, the accuracy error is reduced up to 4 orders of magnitude. Furthermore, performance comparisons show that these accuracy improvements do not hinder their execution, as posits run as fast as single-precision floats and exhibit better timing than double-precision floats, thus potentially providing an alternative representation. Copyright © 2021, The Authors. All rights reserved.

关键词： Digital arithmetic

来源：评论

学校读者我要写书评

暂无评论

Application migration in HPC - A driver of the exascale era? 14

Application migration in HPC - A driver of the exascale era?

引用

14th International Conference on High Performance Computing and Simulation, HPCS 2016

作者： Pickartz, Simon Lankes, Stefan Monti, Antonello Clauss, Carsten Breitbart, Jens Institute for Automation of Complex Power Systems RWTH Aachen University Aachen Germany ParTec Cluster Competence Center GmbH Munich Germany Department of Informatics Computer Architecture Technical University Munich Germany

ISBN: (纸本)9781509020881

Application migration is valuable for modern computing centers. Apart from a facilitation of the maintenance process, it enables dynamic load balancing for an improvement of the system's efficiency. Although, the concept is already wide-spread in cloud computing environments, it did not find huge adoption in HPC yet. As major challenges of future exascale systems are resiliency, concurrency, and locality, we expect migration of applications to be one means to cope with these challenges. In this paper we investigate its viability for HPC by deriving respective requirements for this specific field of application. In doing so, we sketch example scenarios demonstrating its potential benefits. Furthermore, we discuss challenges that result from the migration of OS-bypass networks and present a prototype migration mechanism enabling the seamless migration of MPI processes in HPC systems. © 2016 IEEE.

关键词： HPC Local Consistency MPI OS-bypass Networks Process Migration

来源：评论

学校读者我要写书评

暂无评论

Performance Evaluation of Multiple TCP connections in iSCSI

Performance Evaluation of Multiple TCP connections in iSCSI

引用

IEEE/NASA Goddard Conference on Mass Storage Systems and Technologies, (MSST)

作者： Bhargava K. Kancherla Ganesh M. Narayan K. Gopinath Computer Architecture and Systems Laboratory Department of Computer Science and Automation Indian Institute of Science Bangalore India

Storage area networks (SANs) based on fibre channel have been used extensively in the last decade while iSCSI is fast becoming a serious contender due to its reduced costs and unified infrastructure. This work examines the performance of iSCSI with multiple TCP connections. Multiple TCP connections are often used to realize higher bandwidth but there may be no fairness in how bandwidth is distributed. We propose a mechanism to share congestion information across multiple flows in "Fair-TCP" for improved performance. Our results show that Fair-TCP significantly improves the performance for I/O intensive workloads.

关键词： Throughput TCPIP Wide area networks Storage area networks Encapsulation Storage automation Bandwidth Transport protocols Optical fiber cables computer architecture

来源：评论

学校读者我要写书评

暂无评论

Simulation and implementation of a lowcost platform to improve the quality of biological images 49

Simulation and implementation of a lowcost platform to impro...

引用

49th Summer computer Simulation Conference, SCSC 2017, Part of the 2017 Summer Simulation Multi-Conference, SummerSim 2017

作者： Fabregat, Hermenegildo Del Barrio, Alberto A. Botella, Guillermo Computer Science Faculty Universidad Complutense de Madrid Prof. José García Santesmases 9 Madrid Spain Department of Computer Architecture and Automation Universidad Complutense de Madrid Prof. José García Santesmases 9 Madrid Spain

ISBN: (纸本)9781510838284

The development of fluorescence microscopy techniques has help advance in the understanding of molecular mechanisms present at biological systems, as the case of cell migration (Castillo-Lluva et al. 2010, Castillo- Lluva et al. 2013). These techniques allows studying the location, distribution as well as the movement of molecules that have been fluorescently tagged at a high resolution, even dealing with live cells (Rieckher 2017). In this paper a filtering and pattern recognition flow is simulated and implemented on a low-cost hardware platform in order to automate the detection of circular and ellipsoidal cells within the microscopic images. Results show that images keep a high quality after filtering and that 78.4% of the objects are properly recognized. © 2017 Society for Modeling & Simulation International (SCS).

关键词： Neural networks

来源：评论

学校读者我要写书评

暂无评论

Deep Learning For Predicting Cerebral Metabolism Changes Along The Alzheimer’s Disease Continuum 15

Deep Learning For Predicting Cerebral Metabolism Changes Alo...

引用

15th International Multi-Conference on Complexity, Informatics and Cybernetics, IMCIC 2024

作者： García-Gutiérrez, Fernando Hernández-Lorenzo, Laura Cabrera-Martín, María Nieves Matias-Guiu, Jordi A. Ayala, José L. Department of Computer Architecture and Automation Complutense University of Madrid Madrid28040 Spain Department of Nuclear Medicine Hospital Clinico San Carlos IdISSC Madrid28040 Spain Department of Neurology Hospital Clinico San Carlos IdISSC Madrid28040 Spain

ISBN: (纸本)9781950492787

In recent years, there has been a significant increase in the application of Artificial Intelligence (AI) techniques in Alzheimer’s disease (AD). However, current research primarily focuses on differentiating clinical phenotypes based on cross-sectional designs. In this study, we hypothesize that modeling additional aspects of the disease, such as variations in brain metabolism measured by [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET), is possible, and can provide valuable insights into AD progression. For this purpose, we first identified the brain regions with the most pronounced brain hypometabolism in AD. Subsequently, Deep Learning (DL) models, based on feed-forward networks (FFNs) and convolutional neural networks (CNNs), were used to model variations in brain metabolism. Our findings demonstrated the feasibility of predicting trends in brain metabolism along the AD continuum. Overall, this study introduces a novel dimension to predictive modeling in AD, highlighting the relevance of predicting variations in brain metabolism. © IMCIC 2024. All rights reserved.

关键词： Neuroimaging

来源：评论

学校读者我要写书评

暂无评论

Exploring brain networks via structured sparse representation of fMRI data 1

引用

1st International Workshop on Simulation and Synthesis in Medical Imaging, SASHIMI 2016 held in conjunction with 19th International Conference on Medical Image Computing and computer-Assisted Intervention, MICCAI 2016

作者： Zhao, Qinghua Lu, Jianfeng Lv, Jinglei Jiang, Xi Zhao, Shijie Liu, Tianming School of Computer Science and Engineering Nanjing University of Science and Technology Nanjing China School of Automation Northwestern Polytechnical University Xi’an China Cortical Architecture Imaging and Discovery Department of Computer Science and Bioimaging Research Center The University of Georgia AthensGA United States

ISBN: (数字)9783319467207

ISBN: (纸本)9783319467191

Investigating functional brain networks and activities using sparse representation of fMRI data has received significant interests in the neuroimaging field. It has been reported that sparse representation is effective in reconstructing concurrent and interactive functional brain networks. However,previous data-driven reconstruction approaches rarely simultaneously take consideration of anatomical structures,which are the substrate of brain function. Furthermore,it has been rarely explored whether structured sparse representation with anatomical guidance could facilitate functional networks reconstruction. To address this problem,in this paper,we propose to reconstruct brain networks using the anatomy-guided structured multi-task regression (AGSMR) in which 116 anatomical regions from the AAL template as prior knowledge are employed to guide the network reconstruction. Using the publicly available Human Connectome Project (HCP) Q1 dataset as a test bed,our method demonstrated that anatomical guided structure sparse representation is effective in reconstructing concurrent functional brain networks. © Springer International Publishing AG 2016.

关键词： Brain

来源：评论

学校读者我要写书评

暂无评论

Simulation of high-performance memory allocators

Simulation of high-performance memory allocators

引用

作者： Risco-Martín, José L. Colmenar, J.Manuel Atienza, David Hidalgo, J.Ignacio Department of Computer Architecture and Automation Universidad Complutense de Madrid 28040 Madrid Spain C.E.S. Felipe II Universidad Complutense de Madrid 28300 Aranjuez Spain 1015 Lausanne Switzerland

For the last 30 years, a large variety of memory allocators have been proposed. Since performance, memory usage and energy consumption of each memory allocator differs, software engineers often face difficult choices in selecting the most suitable approach for their applications. To this end, custom allocators are developed from scratch, which is a difficult and error-prone process. This issue has special impact in the field of portable consumer embedded systems, that must execute a limited amount of multimedia applications, demanding high performance and extensive memory usage at a low energy consumption. This paper presents a flexible and efficient simulator to study Dynamic Memory Managers (DMMs), a composition of one or more memory allocators. This novel approach allows programmers to simulate custom and general DMMs, which can be composed without incurring any additional runtime overhead or additional programming cost. We show that this infrastructure simplifies DMM construction, mainly because the target application does not need to be compiled every time a new DMM must be evaluated and because we propose a structured method to search and build DMMs in an object-oriented fashion. Within a search procedure, the system designer can choose the "best" allocator by simulation for a particular target application and embedded system. In our evaluation, we show that our scheme delivers better performance, less memory usage and less energy consumption than single memory allocators. © 2011 Elsevier B.V. All rights reserved.

关键词： Embedded systems

来源：评论

学校读者我要写书评

暂无评论

SIMULATION AND IMPLEMENTATION OF A LOW-COST PLATFORM TO IMPROVE THE QUALITY OF BIOLOGICAL IMAGES 17

SIMULATION AND IMPLEMENTATION OF A LOW-COST PLATFORM TO IMPR...

引用

computer Simulation Conference

作者： Hermenegildo Fabregat Alberto A. Del Barrio Guillermo Botella Computer Science Faculty Universidad Complutense de Madrid Department of Computer Architecture and Automation Universidad Complutense de Madrid

ISBN: (纸本)9781510838284

The development of fluorescence microscopy techniques has help advance in the understanding of molecular mechanisms present at biological systems, as the case of cell migration (Castillo-Lluva et al. 2010, Castillo-Lluva et al. 2013). These techniques allows studying the location, distribution as well as the movement of molecules that have been fluorescently tagged at a high resolution, even dealing with live cells (Rieckher 2017). In this paper a filtering and pattern recognition flow is simulated and implemented on a low-cost hardware platform in order to automate the detection of circular and ellipsoidal cells within the microscopic images. Results show that images keep a high quality after filtering and that 78.4% of the objects are properly recognized.

关键词： Microscopic images Filter Pattern recognition Neural network FiL

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：