检索结果-内蒙古大学图书馆

Proceedings of the 1999 IEEE/ACM international conference on Computer-aided design

作者： Jacob Avidan Abe Elfadel D. F. Wong Jacob White

ISBN: (纸本)9780780358324

A translator-level view of the circuit design has become of paramount importance for successful designs, especially in the very demanding context of high-performance microprocessor design in the deep-submicron regime. In this tutorial, such a transistor-level view will be adopted. The VLSI custom design problem will be approached from the three perspectives of transistor-level static timing analysis, fast transistor-level simulation, and transistor-level optimization process. Specifically, the first part of this tutorial will deal with the techniques used in transistor-level static timing, highlighting the differences between gate and transistor level techniques. It will also focus on how delay calculation, false path elimination and timing checks are performed at the transistor level for both combinational and sequential circuits. A fundamental ingredient of transistor-level static timing analyzers is a fast, event-driven transistor-level circuit simulator. The second part of this tutorial will present an important class of such simulators that uses simplified yet accurate transistor models. Simulators using piece-wise constant and piece-wise linear models will be described and contrasted. Methods for computing circuit sensitivities using these simulators will be covered. Finally, the third part will present some of the very recent advances in transistor-level circuit optimization. In particular, the timing-driven custom design problem will be rigorously formalized as a constrained, nonlinear optimization problem with respect to both the geometric and timing variables of the circuit. Although the resulting problems are large-scale, it will be shown how formal optimization algorithms can solve them efficiently. The tradeoffs between circuit size, device model accuracy, and algorithmic efficiency will be discussed, and generalizations of these techniques to simultaneous device and wire sizing will be considered.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Routing and capacity assignment for survivable WDM network based protected working capacity envelope concept

Routing and capacity assignment for survivable WDM network b...

引用

IFIP International conference on Wireless and Optical Communications Networks (WOCN)

作者： S.S.W. Lee Hong-Hsu Yen Department of Optical Communications/Networking Technologies Computer & Communications Research Laboratories ITRI Taiwan Department of Information Management Shih Hsin University Taiwan

Protected working capacity envelope concept has been proposed to simplify network management and operation in survivable WDM networks. Dynamic lightpath provisioning within working capacity envelope is only required to perform shortest path routing algorithm. Based on PWCE concept, we propose an efficient approximation approach, called Lagrangean relaxation with binary exponential reduction heuristics (LBER), aimed, to resolve the routing and capacity assignment (RCA) problem in survivable WDM networks to protect any single link failure. The task is first formulated as a mixed integer non-linear optimization problem in which the bottleneck link blocking probability for call setup is to be minimized. By sequentially solving a series of Lagrangean relaxation problems, the range of uncertainty of target blocking probability is reduced by half between the solutions of two adjacent problems such that the near optimal solution can be obtained in short time. We conduct a performance study on the proposed algorithms under different parameter settings. We further draw comparisons between LBER and a minimum working hop heuristic approach via experiments over two well known benchmark networks. Numerical results demonstrate that LBER outperforms minimum working hop approach for networks with both uniform and non-uniform demand distributions.

关键词： Routing WDM networks Protection Lagrangian functions Fiber nonlinear optics high speed optical techniques nonlinear optics Optical fiber networks Wavelength division multiplexing Optical fiber communication

来源：评论

学校读者我要写书评

暂无评论

A modified PSO algorithm for task scheduling optimization in cloud computing

引用

CONCURRENCY AND COMPUTATION-PRACTICE & EXPERIENCE 2018年第24期30卷 e4970.1-e4970.11页

作者： Zhou, Zhou Chang, Jian Hu, Zhigang Yu, Junyang Li, Fangmin Changsha Univ Sch Comp Engn & Appl Math Changsha 410081 Hunan Peoples R China Hunan Univ Dept Comp Sci Changsha 410082 Hunan Peoples R China Cent S Univ Sch Software Changsha 410083 Peoples R China Henan Univ Sch Software Kaifeng 475001 Peoples R China CERNET Ltd Co Beijing 100084 Peoples R China Beijing Univ Posts & Telecommun State Key Lab Networking & Switching Technol Beijing 100876 Peoples R China

With the increasing scale of tasks in cloud computing, the problem of high energy consumption becomes increasingly serious. To deal with the problem, we propose a cloud computing energy consumption model, which takes into account the execution and transmission cost of the processor. Then, based on this model, we put forward a task scheduling optimization algorithm named modified particle swarm optimization (M-PSO) to handle the local optimum and slow convergence problem. Different from the PSO, M-PSO can dynamically adjust the inertia weight coefficient to improve the speed of convergence according to the number of iterations. Finally, the performance of the proposed algorithm is evaluated through the CloudSim toolkit, and the experimental results show that the M-PSO can efficiently reduce total cost compared with other algorithms.

关键词： cloud computing inertia weight particle swarm optimization task scheduling

来源：评论

学校读者我要写书评

暂无评论

From Simulation to Reality: CFD-ML-Driven Structural optimization and Experimental Analysis of Thermal Plasma Reactors

From Simulation to Reality: CFD-ML-Driven Structural Optimiz...

引用

IEEE International conference on Plasma Science (ICOPS)

作者： H. Shi S. Wang P. Wang School of Mechanical and Power Engineering Shanghai Jiao Tong University Shanghai China

ISBN: (数字)9798350360912

ISBN: (纸本)9798350360929

Thermal plasma reactors offer an environment of high temperature, enthalpy, and reactivity, making them highly efficient for harmless solid waste treatment and promising for clean energy production from municipal and industrial waste. Optimal structural parameters of the reactor can enhance waste treatment and reactor performance. This study presents a comprehensive analysis of 11 key structural parameters of a thermal plasma reactor. Utilizing CFD Fluent software, numerical simulations were conducted to generate a dataset. Subsequently, a predictive model focusing on the average temperature in the core melt zone was developed using six machine learning algorithms. The Particle Swarm Optimisation (PSO) algorithm optimized the hyperparameters of the Gradient Booster (GBM) model, which was combined with a Genetic Algorithm (GA) to identify the reactor’s optimal structural parameters. A thermal plasma reactor system for solid waste treatment was thus established. The study also explored the effects of gasification coefficient, reaction temperature, and thermal plasma jet mode on system performance. Findings indicate that the PSO-GBM model achieved the highest prediction accuracy, with the temperature in the core reaction zone reaching 3620.76 K. The deviation between numerical simulations and machine learning predictions was a mere 1.3%. Enhancing syngas yield and energy efficiency is achievable by controlling reaction temperature and increasing the gasification coefficient. A laminar plasma jet mode, at equal power, provides a more effective reaction environment. The accuracy and reliability of the machine learning-driven regression model and optimization results are significant in guiding the optimal design of plasma reactors and advancing waste-to-energy conversion processes.

关键词： Plasma jets Predictive models Numerical simulation Plasmas Structural engineering Numerical models Thermal analysis

来源：评论

学校读者我要写书评

暂无评论

Fuzzy neural network simulation of vehicle yaw rate control based on PID

Fuzzy neural network simulation of vehicle yaw rate control ...

引用

World conference on Mechanical Engineering and Intelligent Manufacturing (WCMEIM)

作者： Hongtu Zhang Donglai Xu Yansheng Li Xudong Hu Beijing University of Technology Chaoyang District Beijing China

The core of driving force control strategy is the research core of electric vehicle driven by wheel motor. In order to give full play to the advantages of wheel motor drive system, a reasonable control strategy must be designed. In this paper, the stability of the vehicle is determined based on the sideslip angle of the center of mass of the vehicle. Through the speed and steering wheel angle, the actual yaw rate of the vehicle at a certain speed and the theoretical yaw rate at this speed are determined as the control objectives. The PID control is used to distribute the four-wheel brake pressure, generate additional yaw moment to adjust the vehicle attitude; and the traditional PID control is used to control the vehicle attitude. In contrast, fuzzy control using human expert control experience, for the control of nonlinear and complex objects shows the advantages of good robustness and high control performance. Therefore, on the basis of PID, through neural network learning, fuzzy neural network is used to optimize the output fuzzy rules and membership function to control the vehicle. The whole process is carried out with CarSim and Simulink Simulation is carried out to verify the control optimization process.

关键词： Fuzzy control PI control software packages Neural networks Wheels Process control Fuzzy neural networks

来源：评论

学校读者我要写书评

暂无评论

Selection of features for patient-independent detection of seizure events using scalp EEG signals

引用

COMPUTERS IN BIOLOGY AND MEDICINE 2020年 119卷 103671-000页

作者： Yang, Shuhan Li, Bo Zhang, Yinda Duan, Meiyu Liu, Shuai Zhang, Yexian Feng, Xin Tan, Renbo Huang, Lan Zhou, Fengfeng Jilin Univ Coll Comp Sci & Technol BioKnow Hlth Informat Lab Key Lab Symbol Computat & Knowledge EngnMinist E Changchun 130012 Jilin Peoples R China Jilin Inst Chem Technol Jilin 132000 Jilin Peoples R China Jilin Univ China Japan Union Hosp Canc Syst Biol Ctr Changchun 130033 Peoples R China Jilin Univ Coll Software BioKnow Hlth Informat Lab Key Lab Symbol Computat & Knowledge EngnMinist E Changchun 130012 Jilin Peoples R China

Epilepsy involves brain abnormalities that may cause sudden seizures or other uncontrollable body activities. Epilepsy may have substantial impacts on the patient's quality of life, and its detection heavily relies on tedious and time-consuming manual curation by experienced clinicians, based on EEG signals. Most existing EEG-based seizure detection algorithms are patient-dependent and train a detection model for each patient. A new patient can only be monitored effectively after several episodes of epileptic seizures. This study investigates the patientindependent detection of seizure events using the open dataset CHB-MIT Scalp EEG. First, a novel feature extraction algorithm called MinMaxHist is proposed to measure the topological patterns of the EEG signals. Following this, MinMaxHist and several other feature extraction algorithms are applied to parameterize the EEG signals. Next, a comprehensive series of feature screening and classification optimization experiments are conducted, and finally, an optimized EEG-based seizure detection model is presented that can achieve overall values for accuracy, sensitivity, specificity, Matthews correlation coefficient, and Kappa of 0.8627, 0.8032, 0.9222, 0.7504 and 0.7254, respectively, with only 30 features. The classification accuracy of the method with MinMaxHist features was 0.0464 higher than that without MinMaxHist features. Compared with existing methods, the proposed algorithm achieved higher accuracy and sensitivity, as shown in the experimental results.

关键词： EEG Epileptic seizure detection Time-domain feature extraction MinMaxHist nonlinear features Feature selection XGBoost

来源：评论

学校读者我要写书评

暂无评论

Facilitating Database Tuning with Hyper-Parameter optimization: A Comprehensive Experimental Evaluation

引用

PROCEEDINGS OF THE VLDB ENDOWMENT 2022年第9期15卷 1808-1821页

作者： Zhang, Xinyi Chang, Zhuo Li, Yang Wu, Hong Tan, Jian Li, Feifei Cui, Bin Peking Univ Sch CS Key Lab High Confidence Software Technol MOE Beijing Peoples R China Damo Acad Database & Storage Lab Alibaba Grp Hangzhou Peoples R China Peking Univ Ctr Data Sci Beijing Peoples R China Peking Univ Qingdao Inst Computat Social Sci Qingdao Peoples R China

Recently, using automatic configuration tuning to improve the performance of modern database management systems (DBMSs) has attracted increasing interest from the database community. This is embodied with a number of systems featuring advanced tuning capabilities being developed. However, it remains a challenge to select the best solution for database configuration tuning, considering the large body of algorithm choices. In addition, beyond the applications on database systems, we could find more potential algorithms designed for configuration tuning. To this end, this paper provides a comprehensive evaluation of configuration tuning techniques from a broader perspective, hoping to better benefit the database community. In particular, we summarize three key modules of database configuration tuning systems and conduct extensive ablation studies using various challenging cases. Our evaluation demonstrates that the hyper-parameter optimization algorithms can be borrowed to further enhance the database configuration tuning. Moreover, we identify the best algorithm choices for different modules. Beyond the comprehensive evaluations, we offer an efficient and unified database configuration tuning benchmark via surrogates that reduces the evaluation cost to a minimum, allowing for extensive runs and analysis of new techniques.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Balancing Revenue and Cache Partition Fairness for CDN Providers

Balancing Revenue and Cache Partition Fairness for CDN Provi...

引用

IEEE International conference on high performance Computing and Communications (HPCC)

作者： Xiaodong Dong Binlei Cai College of Computer Science Nankai University Tianjin China Shandong Computer Science Center Qilu University of Technology Jinan Shandong provience China

Nowadays, production CDNs hold a variety of content in shared caches, such as videos, software downloads, web pages, etc., which belongs to hundreds of content providers. Manage cache resources as a single un-partitioned cache and cache the most popular content maximizes cache hit ratio and the revenue of CDN providers. However, this causes some CPs' content files with low request rates never cached, which leads to performance degradation. Although the state-of-art works have focused on cache partitioning, a mechanism that can flexibly balance these two conflicting objectives is still missing. To fill this gap, in this paper, we propose a cache partition method to achieve flexible trade-offs between revenue and caching sharing fairness for CDN providers managing cache partition with LRU (least-recently-used) eviction algorithm. More specifically, our method achieves such flexible trade-offs by finding the Optimal Revenue Fairness Trade-off (ORJT) cache partition policies. It proves to be Pareto optimal by maximizing revenue while ensuring fairness is higher than a given threshold. However, a series of complex non-convex optimization problems get involved in obtaining RJT cache partition policies. Thus, we propose a simple but efficient heuristic algorithm called Landslide to eliminate this difficulty. Landslide simulates the natural landslide phenomenon, it converges to the ORJT cache partition policy by modifying an arbitrary feasible cache partition policy iteratively. Finally, experimental results show the proposed method can achieve flexible trade-offs between CDN provider's revenue and cache partition fairness.

关键词： Degradation Heuristic algorithms Web pages Production Pareto optimization Terrain factors software

来源：评论

学校读者我要写书评

暂无评论

high-precision online markerless stereo extrinsic calibration

High-precision online markerless stereo extrinsic calibratio...

引用

IEEE/RSJ International conference on Intelligent Robots and Systems

作者： Yonggen Ling Shaojie Shen Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology China

ISBN: (纸本)9781509037636

Stereo cameras and dense stereo matching algorithms are core components for many robotic applications due to their abilities to directly obtain dense depth measurements and their robustness against changes in lighting conditions. However, the performance of dense depth estimation relies heavily on accurate stereo extrinsic calibration. In this work, we present a real-time markerless approach for obtaining high-precision stereo extrinsic calibration using a novel 5-DOF (degrees-of-freedom) and nonlinear optimization on a manifold, which captures the observability property of vision-only stereo calibration. Our method minimizes epipolar errors between spatial per-frame sparse natural features. It does not require temporal feature correspondences, making it not only invariant to dynamic scenes and illumination changes, but also able to run significantly faster than standard bundle adjustment-based approaches. We introduce a principled method to determine if the calibration converges to the required level of accuracy, and show through online experiments that our approach achieves a level of accuracy that is comparable to offline marker-based calibration methods. Our method refines stereo extrinsic to the accuracy that is sufficient for block matching-based dense disparity computation. It provides a cost-effective way to improve the reliability of stereo vision systems for long-term autonomy.

关键词： Calibration Cameras Robot vision systems Real-time systems

来源：评论

学校读者我要写书评

暂无评论

Binary Bleed: Fast Distributed and Parallel Method for Automatic Model Selection

Binary Bleed: Fast Distributed and Parallel Method for Autom...

引用

IEEE conference on high performance Extreme Computing (HPEC)

作者： Ryan Barron Maksim E. Eren Manish Bhattarai Ismael Boureima Cynthia Matuszek Boian S. Alexandrov Theoretical Division Los Alamos National Laboratory Los Alamos USA Department of Computer Science and Electrical Engineering University of Maryland Baltimore County Maryland USA Advanced Research in Cyber Systems Los Alamos National Laboratory Los Alamos USA

ISBN: (数字)9798350387131

ISBN: (纸本)9798350387148

In several Machine Learning (ML) clustering and dimensionality reduction approaches, such as nonnegative matrix factorization (NMF), RESCAL, and K-Means clustering, users must select a hyper-parameter $k$ to define the number of clusters or components that yield an ideal separation of samples or clean clusters. This selection, while difficult, is crucial to avoid overfitting or underfitting the data. Several ML applications use scoring methods (e.g., Silhouette and Davies Boulding scores) to evaluate the cluster pattern stability for a specific $k$ . The score is calculated for different trials over a range of $k$ , and the ideal $k$ is heuristically selected as the value before the model starts overfitting, indicated by a drop or increase in the score resembling an elbow curve plot. While the grid-search method can be used to accurately find a good $k$ value, visiting a range of $k$ can become time-consuming and computationally resource-intensive. In this paper, we introduce the Binary Bleed method based on binary search, which significantly reduces the $k$ search space for these grid-search ML algorithms by truncating the target $k$ values from the search space using a heuristic with thresholding over the scores. Binary Bleed is designed to work with single-node serial, single-node multi-processing, and distributed computing resources. In our experiments, we demonstrate the reduced search space gain over a naive sequential search of the ideal $k$ and the accuracy of the Binary Bleed in identifying the correct $k$ for NMFk, K-Means pyDNMFk, and pyDRESCALk with Silhouette and Davies Boulding scores. We make our implementation of Binary Bleed for the NMF algorithm available on GitHub.

关键词： Instruction sets Computational modeling Heuristic algorithms Power system stability Stability analysis Elbow Distributed computing optimization Overfitting software development management

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：