检索结果-内蒙古大学图书馆

A PARALLEL OPTIMUM SEEKING TECHNIQUE - DYNOSTAT

IEEE TRANSACTIONS ON systemS SCIENCE AND CYBERNETICS 1970年第3期SSC6卷 197-&页

作者： GIBSON, JA COOMBES, GE Department of Electrical Engineering University of Canterbury Christchurch New Zealand

Dynostat is the name given to a system optimization technique employing both instantaneous and predictive optimum seeking strategies in parallel. Although it has both off-line and on-line capabilities of application this account is concerned mainly with an explanation of the essentials of the technique in the context of off-line optimization studies. A brief description of a successful application study of a practical problem in industry is also included. The technique is explained in a progressive manner by considering an example for which there is a requirement for an optimum schedule of alternative energy sources. As is well known, optimum scheduling using the dynamic programming technique is restricted in practice by limitations in computer storage and computing time to systems with few independent variables. However, in certain classes of multichannel systems some of these variables appear naturally, or by reasonable approximation can be made to appear, in a static section of the system, and it is shown that optimizing their values need consume only little computer time and storage. The remainder of the variables are in the dynamic section and their optimization makes a heavy demand on computational facilities. The Dynostat technique handles both types of variables in a single computer algorithm. An indication of a projected on-line configuration of Dynostat is presented in a statement of developments of the technique currently under study.

关键词： Nonlinear systems Control systems biological system modeling Controllability Biochemistry Optimal control Neutrons Process control biological control systems Job shop scheduling

来源：评论

学校读者我要写书评

暂无评论

ELASTIC-CONSTANTS MEASUREMENT WITH A DIGITAL ACOUSTIC MICROSCOPE

引用

IEEE TRANSACTIONS ON SONICS AND ULTRASONICS 1984年第4期31卷 271-278页

作者： SINCLAIR, DA SMITH, IR BENNETT, SD UNIV LONDON UNIV COLL DEPT ELECT ENGN LONDON WC1E 6BT ENGLAND VG SEMICON E GRINSTEAD W SUSSEX ENGLAND DATASONICS SUNNYVALE CA 94089 USA

A digitally controlled scanning acoustic microscope has been used for the characterization of human tissue. A theoretical treatment of the problem is presented, showing how simple measurements enable the calculation of the elastic constants of a specimen with fine spatial resolution. An error analysis is also presented. Details of the experimental equipment are given and preliminary results investigating diffuse tumors in human liver are presented. © 1984 IEEE

关键词： Acoustic measurements Microscopy Humans Lenses Transducers Liver Mechanical factors biological system modeling Digital control Spatial resolution

来源：评论

学校读者我要写书评

暂无评论

Cluster Synchronization as a Mechanism of Free Recall in Working Memory Networks

IEEE OPEN JOURNAL OF CONTROL SYSTEMS

引用

IEEE OPEN JOURNAL OF CONTROL systemS 2023年 2卷 454-463页

作者： Jafarian, Matin Huerta, David Chavez Villani, Gianluca Lansner, Anders Johansson, Karl H. Delft Univ Technol Delft Ctr Syst & Control RecalLab NL-2628 CD Delft Netherlands Univ Toronto Dept Elect & Comp Engn Toronto ON M5S 1A1 Canada KTH Royal Inst Technol Div Computat Sci & Technol S-11428 Stockholm Sweden Stockholm Univ S-11428 Stockholm Sweden KTH Royal Inst Technol Sch Elect Engn & Comp Sci Div Decis & Control Syst S-11428 Stockholm Sweden KTH Royal Inst Technol Digital Futures S-11428 Stockholm Sweden

This article studies free recall, i.e., the reactivation of stored memory items, namely patterns, in any order, of a model of working memory. Our free recall model is based on a biologically plausible modular neural network composed of H modules, namely hypercolumns, each of which is a bundle of M minicolumns. The coupling weights and constant bias values of the network are determined by a Hebbian plasticity rule. Using techniques from nonlinear stability theory, we show that cluster synchronization is the central mechanism governing free recall of orthogonally encoded patterns. Particularly, we show that free recall's cluster synchronization is the combination of two main mechanisms: simultaneous activities of minicolumns representing an encoded pattern, i.e., within-pattern synchronization, together with time-divided activities of minicolumns representing different patterns. We characterize the coupling and bias value conditions under which cluster synchronization emerges. We also discuss the role of heterogeneous coupling weights and bias values of minicolumns' dynamics in free recall. Specifically, we compare the behaviour of two H x 2 networks with identical and non-identical coupling weights and bias values. For these two networks, we obtain bounds on couplings and bias values under which both encoded patterns are recalled. Our analysis shows that having non-identical couplings and bias values for different patterns increases the possibility of their free recall. Numerical simulations are given to validate the theoretical analysis.

关键词： Synchronization Couplings biological system modeling Control systems biological information theory Task analysis Numerical stability Network analysis and control stability of nonlinear systems systems neuroscience

来源：评论

学校读者我要写书评

暂无评论

ANTHROPOMETRIC modeling PROGRAMS - A SURVEY

引用

IEEE COMPUTER GRAPHICS AND APPLICATIONS 1982年第9期2卷 17-&页

作者： DOOLEY, M Rockwell International United States

Some anhtropometric modeling programs focus on analytical and numerical data, but others provide mainly visual output for researchers to analyze.

关键词： Process design Human factors Design engineering Guidelines Workstations biological system modeling Anthropometry Personnel Computer graphics Military computing

来源：评论

学校读者我要写书评

暂无评论

Capacity and energy cost of information in biological and silicon photoreceptors

引用

PROCEEDINGS OF THE IEEE 2001年第7期89卷 1052-1064页

作者： Abshire, P Andreou, AG Johns Hopkins Univ Dept Elect & Comp Engn Baltimore MD 21218 USA

We outline a theoretical framework to analyze information processing in biological sensory organs and in engineered microsystems. We employ the mathematical tools of communication theory and model natural or synthetic physical structures as microscale communication networks, studying them under physical constraints at two different levels of abstraction. At the functional levels we examine the operational and task specification. while at the physical level, we examine the material specification and realization. Both levels of abstraction are characterized by Shannon's channel capacity as determined bi, the channel bandwidth, the signal power, and the noise power he link between the functional level and the physical level of abstraction is established through models for transformations on the signal, physical constraints on the system, and noise that degrades the signal. As a specific example, we present a comparative study of information capacity (in bits per second) versus energy cost of information (in joules per bit) in a biological and in a silicon adaptive photoreceptor The communication channel model for each of the two systems is a cascade of linear bandlimiting sections followed by additive noise. We model the filters and the noise from first principles whenever possible and phenomenologically otherwise. The parameters for the blowfly model are determined from biophysical data available in the literature. and the parameters of the silicon model are determined from our experimental data. This comparative study is a first step toward a fundamental and quantitative understanding of the tradeoffs between system performance and associated costs such as size, reliability, and energy requirements for natural and engineered sensory microsystems.

关键词： Costs Silicon biological system modeling Power engineering and energy Noise level Information analysis Information processing Biosensors Mathematical model Communication networks

来源：评论

学校读者我要写书评

暂无评论

ON THE STATUS OF STABILITY OF INTERCONNECTED systemS

引用

IEEE TRANSACTIONS ON CIRCUITS AND systemS 1983年第6期30卷 326-340页

作者： MICHEL, AN IOWA STATE UNIV SCI & TECHNOL IOWA AGR & HOME ECON EXPT STN ENGN RES INST AMES IA 50011 USA

In the present paper we report on the status of stability of complex dynamical systems. We consider those systems which may be viewed as an interconnection of lower order subsystems. We emphasize those types of results which are phrased in terms of the stability properties of the subsystems and in terms of the qualitative-properties of the system interconnecting structure. We consider both Lyapunov stability and input-output stability results. In our presentation, we concentrate on selected sample results and we show how some of these results are related. We then use these sample results to identify modifications, extensions, generalizations, and applications. In this way, we are able to provide a reasonably good picture of the entire subject on hand.

关键词： Stability Interconnected systems Integrated circuit interconnections Lyapunov method Large-scale systems Testing Lagrangian functions Control theory Stochastic systems biological system modeling

来源：评论

学校读者我要写书评

暂无评论

HEAT POTENTIAL DISTRIBUTION IN AN INHOMOGENEOUS SPHERICAL MODEL OF A CRANIAL STRUCTURE EXPOSED TO MICROWAVES DUE TO LOOP OR DIPOLE ANTENNAS

引用

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 1978年第8期26卷 607-612页

作者： HIZAL, A BAYKAL, YK NORTHWESTERN UNIV EVANSTONIL 60201

An inhomogeneous spherical model of a 3.3-cm radius cranial structure is assumed to be placed symmetically in the near field of a small loop antenna or an electrical dipole antenna at 3 GHz. The transitions between the layers are taken to be sharp but sinusoidal. Calculations of the heat potential are performed using a spherical wave expansion technique in which linear differential equations are solved for the unknown multipole coefficients. The results are also compared with the plane-wave excitations. It is seen that a more uniform distribution of the heat potential occurs for the dipole antenna excitation which is also similar to the E-plane distribution in the case of plane-wave excitation. For the loop excitation, a significant hot spot occurs near the center of the structure.

关键词： Cranial Electromagnetic heating Microwave antennas Dipole antennas Probes biological system modeling Electromagnetic fields Radio frequency Microwave theory and techniques

来源：评论

学校读者我要写书评

暂无评论

Computation of electric and magnetic stimulation in human head using the 3D impedance method

引用

IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 2003年第7期50卷 900-907页

作者： Nadeem, M Thorlin, T Gandhi, OP Persson, M Chalmers Dept Electromagnet S-41296 Gothenburg Sweden Gothenburg Univ Inst Clin Neurosci S-41345 Gothenburg Sweden Univ Utah Dept Elect Engn Salt Lake City UT 84112 USA

A comparative, computational study of the modeling of transcranial magnetic stimulation (TMS) and electroconvulsive therapy (ECT) is presented using a human head model. The magnetic fields from a typical TMS coil of figure-eight type is modeled using the Biot-Savart law. The TMS coil is placed in a position used clinically for treatment of depression. Induced current densities and electric field distributions are calculated in the model using the impedance method. The calculations are made using driving currents and wave forms typical in the clinical setting. The obtained results are compared and contrasted with the corresponding ECT results. In the ECT case, a uniform current density is injected on one side of the head and extracted from the equal area on the opposite side of the head. The area of the injected currents corresponds to the electrode placement used in the clinic. The currents and electric fields, thus, produced within the model are computed using the same three-dimensional impedance method as used for the TMS case. The ECT calculations are, made using. currents and wave forms typical in the clinic. The electrical tissue properties are obtained from a 4-Cole-Cole model. The numerical results obtained are shown on a two-dimenainnal cross section of the model. In this study, we find that the current densities and electric fields in the ECT case are stronger and deeper penetrating than the corresponding TMS quantities but both methods show biologically interesting current levels deep inside the brain.

关键词： Magnetic stimulation Humans Magnetic heads Impedance measurement Electrical capacitance tomography Current density Coils biological system modeling Medical treatment Magnetic fields

来源：评论

学校读者我要写书评

暂无评论

Deep Learning for Intradialytic Hypotension Prediction in Hemodialysis Patients

引用

IEEE ACCESS 2020年 8卷 82382-82390页

作者： Chen, Jin-Bor Wu, Kuo-Chuan Moi, Sin-Hua Chuang, Li-Yeh Yang, Cheng-Hong Kaohsiung Chang Gung Mem Hosp Dept Internal Med Div Nephrol Kaohsiung 83301 Taiwan Chang Gung Univ Coll Med Kaohsiung 83301 Taiwan Natl Kaohsiung Univ Sci & Technol Dept Elect Engn Kaohsiung 80778 Taiwan I Shou Univ Dept Chem Engn Kaohsiung 84001 Taiwan I Shou Univ Inst Biotechnol & Chem Engn Kaohsiung 84001 Taiwan Kaohsiung Med Univ PhD Program Biomed Engn Kaohsiung 80708 Taiwan Kaohsiung Med Univ Drug Dev & Value Creat Res Ctr Kaohsiung 80708 Taiwan

Intradialytic hypotension is a common problem during hemodialysis treatment. Despite several clinical variables have been authenticated for associations during dialysis session, the interaction effects between variables has not yet been presented. Our study aimed to investigate clinical factors associated with intradialytic hypotension by deep learning. A total of 279 participants with 780 hemodialysis sessions on an outpatient in a hospital-facilitated hemodialysis center were enrolled in March 2018. Associations between clinical factors and intradialytic hypotension were determined using linear regression method and deep neural network. A full-adjusted model indicated that intradialytic hypotension is positively associated with body mass index (Beta & x003D;0.17, $p =0.028$ ), hypertension comorbidity (Beta & x003D;0.17, $p =0.008$ ), and ultrafiltration amount (Beta & x003D;0.31, $p < 0.001$ ), and is inversely associated with the ultrafiltration rate in a hemodialysis session (Beta & x003D;& x2212;0.30, $p = 0.001$ ). The 4-factor locus obtained by the deep neural network reached the maximum performance metrics evaluation (accuracy & x003D;64.97 & x00B1;0.94;true positive rate & x003D;87.97 & x00B1;2.73;positive predictive value & x003D;66.74 & x00B1;0.98;Matthews correlation coefficient & x003D;0.19 & x00B1;0.03). The prediction model obtained by the deep learning scheme could be a potential tool for the management of intradialytic hypotension.

关键词： Machine learning Calcium Diseases Neural networks biological system modeling Predictive models Blood pressure Hemodialysis deep learning intradialytic hypotension

来源：评论

学校读者我要写书评

暂无评论

Some Effects of Weak Magnetic Fields on biological systems: RF fields can change radical concentrations and cancer cell growth rates

引用

IEEE Power Electronics Magazine 2016年第1期3卷 60-68页

作者： Barnes, Frank Greenebaum, Ben National Academy of Engineering University of Colorado Boulder United States Department of Physics University of Wisconsin-Parkside United States

Concerns have been raised about the possible biological effects of nonionizing radiation since at least the late 1950s with respect to radar, other radio, and microwave sources. More recent concerns have arisen about the potential effects of low-intensity fields, including lowfrequency fields from the electric power generating, transmission, and distribution system and the devices it energizes, as well as intermediate, radio-frequency (RF), and higher-frequency radiation from devices such as cell phones, broadcast antennas, Wi-Fi, security monitors, and so forth. These are concerns about the direct effects of radiation on humans or other organisms. They are distinct from the electromagnetic compatibility issues that concern interference by the fields from one device with the function of another, though human health can be indirectly affected by electromagnetic interference with the function of medical devices, including hospital equipment or pacemakers.

关键词： Magnetic fields Radio frequency Cancer biological system modeling Cellular phones biological systems Power electronics

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：