检索结果-内蒙古大学图书馆

Corrosion 1997

作者： Kelly, R.G. Yuan, J. Jones, S.H. Blanke, W. Aylor, J.H. Wang, W. Batson, A.P. Wintenberg, A. Clemefla, G.G. Departments of Materials Science and Engineering Electrical Engineering Computer Science School of Engineering and Applied Science University of Virginia CharlottesvilleVA22903 United States Instrumentation and Control Division Oak Ridge National Laboratory Oak RidgeTN37831-6006 United States Virginia Transportation Research Council CharlottesvilleVA22903 United States

The design and development of an embeddable corrosion measurement microsystem which takes advantage of the increased availability of Application Specific Integrated Circuit (ASIC) development and Very Large Scale Integrated (VLSI) circuit manufacturing is described. Key elements of the system (micropotentiostat with zero resistance ammeter (ZRA) and analog-to-digital (A/D) and digital-to-analog (D/A) converters were tested electronically and found to perform satisfactorily. The micropotentiostat/ZRA combination was also tested on steel electrodes exposed to 0.6 M NaCl, saturated Ca(OH)2, and saturated Ca(OH)2 + 0.6 M NaCl. Comparisons of polarization resistance data generated by the micropotentiostat and commercially available systems demonstrated that the two systems performed equivalently. The 10-bit A/D and 6-bit D/A converters exhibited excellent linearity over a wide range of inputs. Future directions for the development of the embeddable corrosion measurement microsystem are also outlined. © 1997 by NACE International.

关键词： Corrosion rate

来源：评论

学校读者我要写书评

暂无评论

Stochastic differential dynamic programming

Stochastic differential dynamic programming

引用

作者： Theodorou, Evangelos Tassa, Yuval Todorov, Emo Departments of Computer Science and Neuroscience Computational Learning and Motor Control Lab. University of Southern California United States Interdisciplinary Center for Neural Computation Hebrew University Jerusalem Israel Department of Computer Science and Engineering University of Washington Seattle WA United States

ISBN: (纸本)9781424474264

Although there has been a significant amount of work in the area of stochastic optimal control theory towards the development of new algorithms, the problem of how to control a stochastic nonlinear system remains an open research topic. Recent iterative linear quadratic optimal control methods iLQG [1], [2] handle control and state multiplicative noise while they are derived based on first order approximation of dynamics. On the other hand, methods such as Differential Dynamic Programming expand the dynamics up to the second order but so far they can handle nonlinear systems with additive noise. In this work we present a generalization of the classic Differential Dynamic Programming algorithm. We assume the existence of state and control multiplicative process noise, and proceed to derive the second-order expansion of the cost-to-go. We find the correction terms that arise from the stochastic assumption. Despite having quartic and cubic terms in the initial expression, we show that these vanish, leaving us with the same quadratic structure as standard DDP. © 2010 AACC.

关键词： Additive noise

来源：评论

学校读者我要写书评

暂无评论

Power flow optimization using positive quadratic programming *

引用

IFAC Proceedings Volumes 2011年第1期44卷 10481-10486页

作者： Javad Lavei Anders Rantzer Stephen Low Department of Control and Dynamical Systems Caltech Automatic Control LTH Lund University Sweden Steven H. Low is with the Computer Science and Electrical Engineering Departments Caltech

Abstract The problem to minimize power losses in an electrical network subject to voltage and power constraints is in general hard to solve. However, it has recently been discovered that semidefinite programming relaxations in many cases enable exact computation of the global optimum. Here we point out a fundamental reason for the successful relaxations, namely that the passive network components give rise to matrices with nonnegative offdiagonal entries. Recent progress on quadratic programming with Metzler matrix structure can therefore be applied.

关键词： Power flow optimization relaxation analysis

来源：评论

学校读者我要写书评

暂无评论

User interface standards for control system design applications

User interface standards for control system design applicati...

引用

IEEE International Symposium on computer Aided control System Design (CACSD)

作者： H.A. Barker M. Chen I.T. Harvey P.W. Grant C.P. Jobling A. Parkman P. Townsend Control and Computer Aided Engineering Research Group Departments of Electrical and Electronic Engineering and Mathematics and Computer Science University College of Swansea University of Wales Swansea UK

Aspects of the design and specification of a generic graphical user interface for control system design and the emerging standards for user interface implementation that underlie it are discussed. The use of this interface in future design environments should permit the rapid development of novel design methods and at the same time, by enforcing a consistent look and feel across applications, make the transfer of new knowledge much simpler than is possible at present. A brief history of computer-aided control system design (CACSD) is given. Advantages of sophisticated graphical user interfaces and standards for user interface development are discussed. A description of how an existing CACSD package has been redesigned to take on board the latest user interface technology is included.< >

关键词： User interfaces control systems Packaging History Power engineering and energy computer graphics Workstations computer interfaces Application software Design engineering

来源：评论

学校读者我要写书评

暂无评论

Layering as Optimization Decomposition: Questions and Answers

Layering as Optimization Decomposition: Questions and Answer...

引用

MILCOM, Military Communications Conference

作者： Mung Chiang Steven H. Low A. Robert Calderbank John C. Doyle Electrical Engineering Department Princeton University USA Computer Science and Electrical Engineering Departments Caltech USA Electrical Engineering and Mathematics Departments Princeton University USA Control and Dynamic Systems Department Caltech USA

Network protocols in layered architectures have historically been obtained on an ad-hoc basis, and much of the recent cross-layer designs are conducted through piecemeal approaches. Network protocols may instead be holistically analyzed and systematically designed as distributed solutions to some global optimization problems in the form of generalized Network Utility Maximization (NUM), providing insight on what they optimize and on the structures of network protocol stacks. In the form of 10 Questions and Answers, this paper presents a short survey of the recent efforts towards a systematic understanding of "layering" as "optimization decomposition". The overall communication network is modeled by a generalized NUM problem, each layer corresponds to a decomposed subproblem, and the interfaces among layers are quantified as functions of the optimization variables coordinating the subproblems. Furthermore, there are many alternative decompositions, each leading to a different layering architecture. Industry adoption of this unifying framework has also started. Here we summarize the current status of horizontal decomposition into distributed computation and vertical decomposition into functional modules such as congestion control, routing, scheduling, random access, power control, and coding. We also discuss under-explored future research directions in this area. More importantly than proposing any particular crosslayer design, this framework is working towards a mathematical foundation of network architectures and the design process of modularization.

关键词： Protocols Design optimization computer architecture Cross layer design Utility programs Communication networks Distributed computing Routing Job shop scheduling Processor scheduling

来源：评论

学校读者我要写书评

暂无评论

Hardware-based parallel firefly algorithm for embedded applications

Hardware-based parallel firefly algorithm for embedded appli...

引用

2013 NASA/ESA Conference on Adaptive Hardware and Systems, AHS 2013

作者： Muñoz, Daniel M. Llanos, Carlos H. Dos Santos Coelho, Leandro Ayala-Rincón, Mauricio Electronics Engineering Graduate Program Faculty of Gama University of Brasilia Brasilia DF Brazil Department of Mechanical Engineering Automation and Control Group/GRACO University of Brasilia Brasilia DF Brazil Industrial and Systems Engineering Graduate Program LAS/PPGEPS Pontifical Catholic University of Parana Curitiba Parana Brazil Departments of Computer Science and Mathematics University of Brasilia Brasilia DF Brazil

ISBN: (纸本)9781467363839

The firefly algorithm (FA) is a new population-based metaheuristic bioinspired on the behavior of the flashing characteristics of fireflies. As a population-based algorithm, the FA suffers from large execution times specifically for embedded optimization problems with computational limitations. For reducing execution times we propose a hardware parallel architecture of the FA algorithm that facilitates the implementation in Field Programmable Gate Arrays (FPGAs). In addition, this work proposes the application of the opposition-based learning (OBL) approach to the FA algorithm. The respective hardware implementation (HPOFA) was mapped into a Virtex5 FPGA device and numerical experiments using four well-known benchmark problems demonstrate that the opposition-based approach allows the FA algorithm to improve its functionality, preserving the swarm diversity and avoiding the premature convergence problem. Synthesis results point out that the HPOFA architecture is effectively mapped in hardware and is suitable for embedded applications. © 2013 IEEE.

关键词： Parallel architectures

来源：评论

学校读者我要写书评

暂无评论

A predictive model of death from cerebrovascular diseases in intensive care units

引用

Intelligent Medicine 2023年第4期3卷 267-279页

作者： Mohammad Karimi Moridani Seyed Kamaledin Setarehdan Ali Motie Nasrabadi Esmaeil Hajinasrollah Department of Biomedical Engineering Faculty of HealthTehran Medical SciencesIslamic Azad UniversityTehranIran Control and Intelligent Processing Centre of Excellence School of Electrical and Computer EngineeringCollege of EngineeringUniversity of TehranTehranIran Departments of Biomedical Engineering Shahed UniversityTehranIran Loghman Medical Center Shahid Beheshti University of Medical SciencesTehranIran

Objective This study aimed to explore the mortality prediction of patients with cerebrovascular diseases inthe intensive care unit(ICU)by examining the important signals during different periods of admission in theICU,which is considered one of the new topics in the medical *** approaches have been proposed forprediction in this *** of these methods has been able to predict mortality somewhat,but many of thesetechniques require recording a large amount of data from the patients,where recording all data is not possiblein most cases;at the same time,this study focused only on heart rate variability(HRV)and systolic and diastolicblood *** The ICU data used for the challenge were extracted from the Multiparameter Intelligent Monitoring inIntensive Care II(MIMIC-II)Clinical *** proposed algorithm was evaluated using data from 88 cerebrovascular ICU patients,48 men and 40 women,during their first 48 hours of ICU *** electrocardiogram(ECG)signals are related to lead II,and the sampling frequency is 125 *** time of admission and time ofdeath are labeled in all *** this study,the mortality prediction in patients with cerebral ischemia is evaluated using the features extracted from the return map generated by the signal of HRV and blood *** the patient’s future condition,the combination of features extracted from the return mapping generatedby the HRV signal,such as angle(𝛼),area(A),and various parameters generated by systolic and diastolic bloodpressure,including DBPMax−Min SBPSD have been ***,to select the best feature combination,the geneticalgorithm(GA)and mutual information(MI)methods were *** sample t-test statistical analysis was usedto compare the results of two episodes(death and non-death episodes).The P-value for detecting the significancelevel was considered less than *** The results indicate that the new approach presented in this paper can be compared with other methodsor l

关键词： Death prediction Cerebrovascular diseases Intensive care unit Heart rate variability Systolic and diastolic blood pressure Return map

来源：评论

学校读者我要写书评

暂无评论

Optimal Charging of Plug-in Hybrid Electric Vehicles in Smart Grids

Optimal Charging of Plug-in Hybrid Electric Vehicles in Smar...

引用

IEEE Power and Energy Society General Meeting

作者： Somayeh Sojoudi Steven H. Low Department of Control and Dynamical Systems California Institute of Technology Computer Science and Electrical Engineering Departments California Institute of Technology

ISBN: (纸本)9781457710001

Plug-in hybrid electric vehicles (PHEVs) play an important role in making a greener future. Given a group of PHEVs distributed across a power network equipped with the smart grid technology (e.g. wireless communication devices), the objective of this paper is to study how to schedule the charging of the PHEV batteries. To this end, we assume that each battery must be fully charged by a pre-specified time, and that the charging rate can be time-varying at discrete-time instants. The scheduling problem for the PHEV charging can be augmented into the optimal power flow (OPF) problem to obtain a joint OPF-charging (dynamic) optimization. A solution to this highly nonconvex problem optimizes the network performance by minimizing the generation and charging costs while satisfying the network, physical and inelastic-load constraints. A global optimum to the joint OPF-charging optimization can be found efficiently in polynomial time by solving its convex dual problem whenever the duality gap is zero for the joint OPF-charging problem. It is shown in a recent work that the duality gap is expected to be zero for the classical OPF problem. We build on this result and prove that the duality gap is zero for the joint OPF-charging optimization if it is zero for the classical OPF problem. The results of this work are applied to the IEEE 14 bus system.

关键词： Smart grids optimal charging charging Polynomial time Power grids CHARGING(ACCOUNTTNG) Zero Joints Joints charging rate Batteries Hybrid electric vehicles

来源：评论

学校读者我要写书评

暂无评论

Congestion control Algorithms from Optimal control Perspective

Congestion Control Algorithms from Optimal Control Perspecti...

引用

Joint 48th IEEE Conference on Decision and control and 28th Chinese control Conference

作者： Javad Lavaei John C.Doyle Steven H.Low the Department of Control and Dynamical Systems California Institute of Technology Computer Science and Electrical Engineering Departments California Institute of Technology

This paper is concerned with understanding the connection between the existing Internet congestion control algorithms and the optimal control theory. The available resource allocation controllers are mainly devised to derive the state of the system to a desired equilibrium point and, therefore,they are oblivious to the transient behavior of the closed-loop system. This work aims to investigate what dynamical functions the existing algorithms maximize(minimize). In particular, it is shown that there exist meaningful cost functionals whose minimization leads to the celebrated primal and dual congestion algorithms. An implication of this result is that a real network problem may be solved by regarding it as an optimal control problem on which some practical constraints, such as a realtime link capacity constraint, are imposed.

关键词： Congestion control Algorithms from Optimal control Perspective

来源：评论

学校读者我要写书评

暂无评论

Design of explosive-driven ferroelectric pulse generators with outputs exceeding 200 kV

Design of explosive-driven ferroelectric pulse generators wi...

引用

2005 IEEE Pulsed Power Conference, PPC

作者： Holt, S. Dickens, J. Walter, J. Calico, S. Center for Pulsed Power and Power Electronics Research Departments of Electrical and Computer Engineering and Physics Texas Tech. University Lubbock TX 79409-3102 United States Lockheed Martin Missiles and Fire Control Dallas TX 75265-0003 United States

ISBN: (纸本)078039190X

The design and testing of explosive-driven ferroelectric generators (FEGs) with output voltages exceeding 200 kV is presented. The generator design is aimed at achieving high voltages in a compact device by explosively compressing stacks of ferroelectric ceramic discs. The ferroelectric used in this application is EC-64 lead zirconatetitanate (PZT), a hard ferroelectric ceramic with a high dielectric constant and a good piezoelectric coupling coefficient in the direction of polarization. The pressure impulse is generated by high explosive detonating cord and travels longitudinally along the polarization vector in the PZT. The effect of variations in the rise-time, width, and magnitude of the pressure pulse on the peak voltage has been experimentally studied by modifying the ferroelectric stack and explosive driver geometries. Different dielectric insulations are experimentally evaluated for good compatibility with the ferroelectrics and maximum hold-off voltage. © 2005 IEEE.

关键词： Ferroelectric ceramics

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：