检索结果-内蒙古大学图书馆

International conference on Power Electronics and Drive Systems (PEDS)

作者： B. Singh S.S. Murthy S. Gupta Department of Electrical Engineering Indian Institute of Technology Delhi New-Delhi India

This paper presents a transient analysis of self-excited induction generator (SEIG) with electronic load controller (ELC) used in stand alone micro hydel power generation employing uncontrolled turbines. In view of the need to feed both 3-phase induction motor and static loads from such systems, the transient behaviour due to switching in of such loads is of interest and is carried out here. Combining the modelling of prime mover, SEIG, ELC and load has developed a composite mathematical model of the total system. Simulated results are compared with the experimental ones, obtained on a developed laboratory prototype of a SEIG-ELC system by starting a motor and switching in a resistive load. For the induction motor, a star/delta starter is used to avoid inrush current. Harmonic analysis is carried out to assess total harmonic distortion (THD) in the voltage and current to assess the power quality.

关键词： Transient analysis Induction generators Induction motors mathematical model Power generation Turbines Feeds Power system modeling Laboratories Virtual prototyping

来源：评论

学校读者我要写书评

暂无评论

A formal validation approach for holonic control system specifications

A formal validation approach for holonic control system spec...

引用

International conference on Emerging Technologies and Factory Automation (ETFA)

作者： P. Leitao A.W. Colombo F. Restivo Polytech. Inst. of Braganca Portugal Schneider Electric GmbH Seligensradt Germany Faculty of Engineering-University of Porto Porto Portugal

The holonic manufacturing paradigm allows a new approach to the emergent requirements faced by the manufacturing world, through the concepts of modularity, decentralisation, autonomy, re-use of control software components. The formal modelling and validation of the structural and behavioural specifications of holonic control systems assumes a critical role. This paper discusses the formal validation of the Petri Net models designed to represent the behaviour and specifications of the holon classes defined at ADACOR architecture.

关键词： Control systems Computer architecture Object oriented modeling Manufacturing systems Control system synthesis Agile manufacturing Flexible manufacturing systems mathematical model Performance analysis Globalization

来源：评论

学校读者我要写书评

暂无评论

Fuzzy modelling of human work efficiency in noisy environment

Fuzzy modelling of human work efficiency in noisy environmen...

引用

IEEE International conference on Fuzzy Systems (FUZZ-IEEE)

作者： Zaheeruddin G.V. Singh V.K. Jain Department of Electrical Engineering New Delhi India School of Computer & Systems Sciences Jawaharlal Nehru University New Delhi India School of Environmental Sciences Jawaharlal Nehru University New Delhi India

In this paper, an attempt has been made to develop a fuzzy model for determining the work efficiency of humans as a function of noise level, exposure time, and the type of task. The modelling technique is based on the concept of fuzzy logic, which offers a convenient way of representing the relationships between the inputs and outputs of a system in the form of IF-THEN rules. The model has been developed on the basis of literature surveys and implemented on Fuzzy Logic Toolbox of MATLAB/spl reg/. We have compared our model results with the deduction based on the criterion of Safe Exposure Limit recommended for general industrial workers.

关键词： humans Working environment noise Fuzzy logic mathematical model Fuzzy systems Noise level Inference algorithms Noise reduction Knowledge based systems Engines

来源：评论

学校读者我要写书评

暂无评论

Cardiovascular Dynamics — Multiple Time Scales, Oscillations and Noise

引用

AIP conference Proceedings 2003年第1期665卷 392-399页

作者： Aneta Stefanovska Andriy Bandrivskyy Peter V. E. McClintock *Group of Nonlinear Dynamics and Synergetics Faculty of Electrical Engineering University of Ljubljana Ljubljana Slovenia †Department of Physics Lancaster University Lancaster UK

modelling the cardiovascular system (CVS) presents a challenging and important problem. The CVS is a complex dynamical system that is vital to the function of the human organism, and it reflects numerous different states of health and disease. Its complexity lies in a combination of oscillatory modes spanning a wide frequency scale that can synchronize for short episodes of time, coupled with a strong stochastic contribution. Motivated by these properties, we discuss the problem of characterising dynamics when there is a combination of oscillatory components in the presence of strong noise and, in particular, where the characteristic frequencies and corresponding amplitudes vary in time. We show that, where there are several noisy oscillatory modes, the slower modes are difficult to characterise because the length of the recorded time series is inevitably limited in real measurements. We argue that, in the case of strong noise combined with a limited observation time, such oscillatory dynamics with several modes may appear to manifest as a 1/f‐like behaviour. We also show that methods of time‐frequency analysis can provide a basis for characterising noisy oscillations, but that a straightforward characterisation of multi‐scale oscillatory dynamics in the presence of strong noise still remains an unsolved problem.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A hybrid intelligent closed-loop model for exploration of cardiovascular interactions

A hybrid intelligent closed-loop model for exploration of ca...

引用

IEEE EMBS International conference on Information Technology Applications in Biomedicine (ITAB)

作者： E. Elsamahy M. Mahfouf D. Linkens Department of Automatic Control and Systems Engineering University of Sheffield Sheffield UK

Blood is a vital source for delivering oxygen and nutrients to trillions of cells in the body; this makes the function of the cardiovascular system essential to our existence. In the last few years, research interests have been directed to exploring its behaviour as well as its interactions with other systems in the human body under different types of stresses, i.e. mental and physical. In this study, we propose a closed-loop model built for the cardiovascular system, and analyse its interactions under physical-stress conditions. In this study, the signals of interest are: blood pressure, heart rate, temperature and respiration; our proposed model is based on the original Luczak model introduced in 1975. An intelligent system based modelling approach was used to represent the interactions between the cardiovascular system and the other control systems involved; based on the use of three neuro-fuzzy models for generating the blood pressure, heart rate, and temperature signals and a fuzzy-ARX model for generating the respiration signal. The interactions between the control systems that generate these signals are identified, and the estimated signals generated during simulation, for different patients, show good fits when compared with the actual measurements. The description of such complex interactions in patients will allow one to carry out diagnosis and prognosis in terms of the influence of stresses on systemic body functions.

关键词： Cardiology Signal generators Cardiovascular system Biological system modeling Blood pressure Heart rate Control system synthesis Signal processing Cells (biology) humans

来源：评论

学校读者我要写书评

暂无评论

Environment-based agent behaviour modelling

Environment-based agent behaviour modelling

引用

IEEE Canadian conference on Electrical and Computer engineering

作者： Martens, RJ Paranjape, RB Univ Regina TRLabs Regina Elect Syst Engn Regina SK S4S 0A2 Canada

ISBN: (纸本)0780375149

An understanding of how autonomous agents behave with respect to their environment is key for the deployment and management of agent systems. Relatively complex behaviour is seen to arise in mobile agents even when their behaviour is based on simple rules. The addition of more advanced forms of reasoning to mobile agents has been shown to benefit both the agent and the system that is hosting the agent. This paper discusses the work that has been done in studying how mobile software agents behave in economics based environments. The specific economic environment examined is a public goods threshold contribution game involving multiple players with multiple public goods to contribute towards. Models exist that predict or explain human behaviour in similar environments. We have developed a system so that we may compare these models with the trial results of mobile agent behaviour. The system developed consists of multiple mobile agents that play the threshold contribution game. By varying the reasoning system in the mobile agents, different behaviour patters emerged providing us with trial results for further analysis.

关键词： mobile software agents behaviour modelling economic games

来源：评论

学校读者我要写书评

暂无评论

Numerical modelling of free surface flows in metallurgical vessels

引用

APPLIED mathematical modelling 2002年第2期26卷 113-140页

作者： Liovic, P Rudman, M Liow, JL Univ Melbourne Dept Chem Engn GK Williams Cooperat Res Ctr Extract Met Parkville Vic 3010 Australia CSIRO Div Bldg Construct & Engn Highett Vic 3190 Australia James Cook Univ N Queensland Sch Engn Townsville Qld 4811 Australia

A numerical model for simulating the transient behaviour of multi-fluid problems defined in 2D rectangular and cylindrical geometries is presented. The model uses a piecewise linear volume tracking scheme, and maintains sharp interfaces and captures fine-scale flow phenomena such as fragmentation and coalescence. The numerical model was applied to four problems of pyrometallurgical relevance - entrainment of matte in the flow of slag during skimming operations, splash resulting from a drop impinging on a bath, bubble rise in a liquid bath, and top-submerged gas injection. The numerical predictions are in good agreement with the published experimental results. The simulation of top-submerged gas injection showed, in detail, the phenomena of bubble formation, bubble rise, and splash drop formation and recoalescence with the bath. Data useful for engineering purposes such as pressure traces and time-averaged flow fields were obtained, allowing assessment of splash behaviour for given gas injection conditions. The numerical model has been shown to be versatile in being able to adapt to a wide range of multi-phase flow problems. (C) 2002 Elsevier Science Inc. All rights reserved.

关键词： volume tracking gas injection entrainment splash bubble rise

来源：评论

学校读者我要写书评

暂无评论

modelling and Simulation of Offshore Crane Operations on a Floating Production Vessel

Modelling and Simulation of Offshore Crane Operations on a F...

引用

Proceedings of the Twelfth (2002) International Offshore and Polar engineering conference

作者： Than, Thuong Kim Langen, Ivar Birkeland, Oddvar Stavanger University College N-4068 Stavanger Norway Hydralift ASA N-4604 Kristiansand Norway

This present paper deals with mathematical modelling of the crane's mechanical, hydraulic, and control systems as well as the numerical simulation of offshore cranes performing sealift operations. The simulations are performed by FEDEM - a general non-linear dynamic analysis program for flexible multibody systems. The pedestal, the revolving crane superstructure called crane king, and the boom are flexible links modelled by shell finite elements and connected together by different joints. A mathematical model of the hydraulic system and a control system is implemented in the mechanism model, making it possible to realistically control the operation of the crane. The results from the dynamic simulations verify that the virtual crane gives a very good picture of the dynamic behaviour of the real crane in offshore environment. This study shows how dynamic amplification can be reduced by proper operation and design of the hydraulic and control system. Simulation examples are shown for sealift from supply vessel when both the supply vessel and the FPSO (Floating Production, Storage and Offloading vessel) are subjected to wave induced forces.

关键词： Floating cranes

来源：评论

学校读者我要写书评

暂无评论

Seismic analysis of MR steel frames based on refined hysteretic models of connections

引用

JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH 2002年第10期58卷 1331-1345页

作者： Della Corte, G De Matteis, G Landolfo, R Mazzolani, FM Univ Naples Federico II Dept Struct Anal & Design I-80125 Naples Italy Univ Chieti I-65127 Pescara Italy

Evaluation of seismic performance of moment-resisting (MR) steel frames is usually carried out assuming the elastic-perfectly-plastic type of hysteresis model for plastic zones (in particular for beam-to-column connections). This type of model is associated with a conventional available ductility, giving an indication of the maximum deformation beyond which strength degradation is likely to occur. This methodology leads to conservative results and the elastic-perfectly-plastic type of hysteresis model is certainly adequate in obtaining reliable information on deformation when the above ductility limits are not exceeded. However, the safety of the frame at 'collapse' remains unknown. The analyses presented in this paper show that safety margins against global collapse of the structure can be predicted only by considering more realistic hysteresis behaviour, i.e. using mathematical models able to take account of strength degradation and pinching phenomena. Moreover, it is shown that the design of conventional steel building systems according to the European seismic code may lead to over-resistant structures, due to the limitation on inter-storey drift angles-for non-structural damage control under frequent earthquakes. It is also noticed that this result is inevitable, owing to the indications provided by Eurocode 8 in terms of both prescribed inter-storey drift limits and assumed base shear-force demand under frequent earthquakes. (C) 2002 Elsevier Science Ltd. All rights reserved.

关键词： beam-to-column connections collapse damage modelling moment resisting frames seismic behaviour steel structures structural codes

来源：评论

学校读者我要写书评

暂无评论

Aspects of the mathematical modelling of rear impact car crash processes

Aspects of the mathematical modelling of rear impact car cra...

引用

International Body engineering conference and Exhibition and Automotive and Transportation Technology conference

作者： Abadjiev, Valentin Abadjiev, Emilia Bulgarian Academy of Sciences Institute of Mechanics Acad. G. Bonchev Str. 1113 Sofia Bulgaria

It is known that more than two thirds of road accidents between moving vehicles are car crashes, where the percentage of human casualties and direct societal losses is comparatively the highest one. Considering the expert-judicial practice the authors view is that the research effort should be put on the development of the mathematical models for an identification of the crash, aiming at the determination of the velocity characteristics of the involved vehicles as well and identification of the places of the passengers in the car before accidents. The study offers mathematical modelling of a car crash caused by a rear impact. It is based on the description of dynamic motion processes of multibody systems, which are configured after car collisions. The mathematical model is constructed for identification of the vehicle kinematic and dynamic characteristics of the running collision different stages. The common mathematical models include: a model of the event preceding the car crash;a model describing the impact process and a model of the events that take place after the crash. The algorithm created in this investigation is applied for solving the designated aspect in a real car crash for the necessity of the court. Copyright © 2002 Society of Automotive Engineers, Inc.

关键词： Highway accidents

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：