Analysis of parasitic quantum effects in classical CMOS circuits

In the mesoscopic regime, the MOS device performance is affected by gate‐induced quantization effects leading to a loss of transconductance and threshold voltage shift and gate leakage tunnelling currents degrading the overall device performance. We discuss the expected impact of quantum effects in highly down scaled CMOS circuits. Based on 1‐d numerical simulations for transport in mesoscopic systems, we set up Spice circuit models. The Spice models rebuild the influence of quantum effects; and the functionality of classical circuit concepts can be ‘tested’ in their robustness against these effects. A few circuit examples will be given. Copyright © 2005 John Wiley & Sons, Ltd.     

Improving Parsing of ‘BA’ Sentences for Machine Translation

The research on Chinese‐Japanese machine translation has been lasting for many years, and now this research field is increasingly thoroughly refined. In practical machine translation system, the processing of a simple and short Chinese sentence has somewhat good results. However, the translation of complex long Chinese sentence still has difficulties. For example, these systems are still unable to solve the translation problem of complex ‘BA’ sentences. In this article a new method of parsing of ‘BA’ sentence for machine translation based on valency theory is proposed. A ‘BA’ sentence is one that has a prepositional word ‘BA’. The structural character of a ‘BA’ sentence is that the original verb is behind the object word. The object word after the ‘BA’ preposition is used as an adverbial modifier of an active word. First, a large number of grammar items from Chinese grammar books are collected, and some elementary judgment rules are set by classifying and including the collected grammar items. Then, these judgment rules are put into use in actual Chinese language and are modified by checking their results instantly. Rules are checked and modified by using the statistical information from an actual corpus. Then, a five‐segment model used for ‘BA’ sentence translation is brought forward after the above mentioned analysis. Finally, we applied this proposed model into our developed machine translation system and evaluated the experimental results. It achieved a 91.3% rate of accuracy and the satisfying result verified effectiveness of our five‐segment model for ‘BA’ sentence translation. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

A Methodology for Quantitatively Introducing ‘Atomistic’ Fluctuations into Compact Device Models for Circuit Analysis

As device dimensions enter the decanano regime, ‘atomistic’ fluctuations will play an important role in device mismatch, and become one of the critical issues for high quality analogue and mixed signal IC design. In this paper, we present a two-stage extraction strategy to introduce ‘atomistic’ fluctuation effects into the industry standard compact model BSIM3v3, and integrate their effects into present circuit analysis and electronic design automation (EDA) tools. The methodology is illustrated by statistical parameter extraction for a typical 35 nm gate length nMOSFET, and performance of statistical simulations for a simple cascode current mirror circuit.     

Adaptive attenuation of unknown and time‐varying narrow band and broadband disturbances

In many classes of applications like active vibration control and active noise control, the disturbances can be characterized by their frequency content and their location in a specific region in the frequency domain. The disturbances can be of narrow band type (simple or multiple) or of broad band type. A model can be associated to these disturbances. The knowledge of this model allows to design an appropriate control system in order to attenuate (or to reject) their effect upon the system to be controlled. The attenuation of disturbances by feedback is limited by the Bode Integral and the ‘water bed’ effect upon the output sensitivity function. In such situations, the feedback approach has to be complemented by a ‘feedforward disturbance compensation’ requiring an additional transducer for obtaining information upon the disturbance. Unfortunately, in most of the situations, the disturbances are unknown and time‐varying and therefore an adaptive approach should be considered. The generic term for adaptive attenuation of unknown and time‐varying disturbances is ‘adaptive regulation’ (known plant model, unknown, and time‐varying disturbance model). The paper will review a number of recent developments for adaptive feedback compensation of multiple unknown and time‐varying narrow band disturbances and for adaptive feedforward compensation of broad band disturbances in the presence of the inherent internal positive feedback caused by the coupling between the compensator system and the measurement of the image of the disturbance. Some experimental results obtained on a relevant active vibration control system will illustrate the performance of the various algorithms presented. Some open research problems will be mentioned in the conclusion. Copyright © 2015 John Wiley & Sons, Ltd.     

基于IEC61850的配电网监视与控制功能的模型设计

为实现设备的互操作性,国际电工技术委员会发布了新的应用于变电站自动化的国际标准——IEC61850标准。分析了IEC 61850标准中各方面的优点,并介绍如何将这些优点应用在变电站自动化中。应用IEC61850标准建立配电系统模型,通过实验模型的搭建验证IEC61850所提出的通信方法,满足实时配电系统的控制和保护要求。     

Tools for semiphysical modelling

Semiphysical modelling is often interpreted as an application of system identification where physical insight into the application is used to come up with suitable non-linear transformations of the raw measurements so as to allow for a good model structure. This modelling procedure is less ‘ambitious’ than those used for traditional physical modelling in that no complete physical structure is sought, just suitable inputs and outputs that can be subjected to more or less standard model structures such as linear regressions. In this paper we discuss a semiphysical modelling procedure and various tools supporting it. These include constructive algorithms originating from commutative and differential algebra as well as more informal tools such as the programming environment.     

A network separation scheme for emergency control

During major system disturbances, uncontrolled splitting of the power system may take place, leading to further system deterioration and possibly a general system collapse. In order to avoid such developments, a controlled network separation scheme is proposed which will divide the system into stable, power-balanced ‘islands’. Methods for determining optimal ‘separation boundaries’ suitable for online computer implementation are outlined. The effectiveness of the scheme is illustrated by its application to a model power system.     

Transient bounds of dynamic certainty equivalent adaptive controllers

In this paper we show that the transient bounds of Morse's dynamic certainty equivalent adaptive controller established previously by us can be considerably strengthened. Specifically, we derive a computable bound on the ??_∞-norm of the tracking error which, in contrast with the local bound obtained previously by us, holds for all system initial conditions. Also, we add an ‘adaptation gain’ in the high-order estimator to prove that, by increasing this gain, the ??_∞-norm of the tracking error can be made arbitrarily small without increasing its ??_∞ norm. This is an improvement over the results obtained with backstepping designs, where these performance measures must be traded off in the selection of the adaptation speed.     

Methods for constructing physiologically motivated neuromorphic models in CNNs

We introduce a collection of techniques, which we propose to denote ‘neuromorphic CNN’, for applying cellular neural networks to the physiologically-detailed modelling of biological neural systems. Examples will be given of the application of these methods to the construction of highly biologically-faithful models of the vertebrate retina, and the utility of such models to neurobiological research will be discussed.     

园区型能源互联网的特征及其能量管理平台关键技术

为充分发挥园区型能源互联网在整合区域能源,实现横向多能互补,促进纵向"源-网-荷-储"协调运行方面的作用,文章在总结园区型能源互联网特征的基础上,研究了其能量管理关键技术。首先,阐述国内外能源互联网的产生背景、研究现状,分析能源市场环境下园区型能源互联网发展的必要性,并建立了能源互联网类型的细致划分模型;其次,立足能源领域供给侧改革和工业园区经济可持续发展的理念,强调了园区型能源互联网的概念,给出典型架构并分析了其相对于广义能源互联网的特征;最后分析了园区型能源互联网能量管理平台中信息感知、源-荷双端预测、多能源协调调度、高级应用服务等关键技术,并对园区型能源互联网的未来发展趋势提出了建议。     

Adaptive control of siso plants with unmodelled dynamics

In this paper we pursue a twofold aim. First we want to simplify the complexity of the classical Monopoli's scheme, the so-called ‘Augmented error signal control scheme’. Then we also wish to cope with the realistic situation in which the presence of unmodelled dynamics has to be taken into account. This latter problem has been faced in the literature by suitably modifying the adaptation mechanism in order to avoid undesired phenomena as well as to obtain an attractive stability region for the state trajectories starting from any point in a predefined initial condition set. In our case the necessity of introducing any sort of modification in the adaptation mechanism is completely avoided, but we still obtain asymptotic stability of the output error signal.     

CONCEPT OF BUILT-IN RELIABILITY IN THE DESIGN OF LARGE INDUCTION MOTORS

ABSTRACT

In recent years, the reliability study of the equipment has been given vital importance alongwith the other studies. In this paper, an attempt is made to construct the reliability model of a large induction motor in order to predict the reliability, with the knowledge of realistic failure data. Since the author is not aware of any failure data, the prediction is based on some realistic failure data. However, in this paper the basic concepts are laid down, to ensure reliability goal of each component in the design stage. It is also emphasised here, the effect of supply conditions, ambient and malfunctioning of accessories in induction motor on its reliability goal. The method of attack is based on Markov model, by judiciously choosing ‘Available’ states and ‘Failed’ states. This method affords better realisation of failure modes and possible decisions to improve the same. The theory of reliability is presented in short, in order to make the ideas presented in this paper, more clear. A numerical example is presented at the end, to elucidate the theory presented here.     

Reference model decomposition in direct adaptive control

This paper introduces the method of ‘reference model decomposition’ as a way to improve the robustness of model reference adaptive control systems (MRACs) with respect to unmodelled dynamics with a known structure. Such unmodelled dynamics occur when some of the nominal plant dynamics are purposely neglected in the controller design with the aim of keeping the controller order low. One of the effects of such ‘undermodelling’ of the controller is a violation of the perfect model-matching condition of the primary controller. The decomposition can be seen as a way to adjust the reference model output (and hence the control goal) to the actual model-matching capabilities. It is shown that the decomposition alleviates the negative effects unmodelled dynamics have on the error equation. Simulation examples illustrate the decomposition design steps and show the obtained improvements.     

Robust adaptive stabilization for time-varying systems with unmodelled dynamics and disturbances

In this paper, robust adaptive stabilization is discussed for time-varying discrete time systems with disturbances and unmodelled dynamics. Both bounded and unbounded stochastic disturbances are considered. It is assumed that the parameters of the nominal model belong to a bounded convex set and that the ‘frozen time’ nominal model is stabilizable for all possible parameter values. Requiring neither external excitation nor stable invertibility of the nominal model, an adaptive regulator is constructed on the basis of the solution to a finite time Riccati equation and a projected gradient estimator. It is shown that the closed-loop system is stable if both the time average of the parameter variations and the model error are sufficiently small.     

Forcing term discretization techniques in the external field‐to‐MTL coupling problems

In this paper, two, under certain conditions, equivalent models of electromagnetic plane wave coupling to multiconductor transmission lines (MTLs) are described. The ‘frequency‐to‐time domain’ (FTD) model incorporates the effect of the impinging electromagnetic waves by means of distributed voltage and current sources whose expressions are found through mathematical approximations made in the frequency domain followed by a transformation to the time domain. The approximations were made in order to gain an advantage in computation time in the discrete FTD (DFTD) model. In contrast to this approach, the same distributed sources of the ‘approximate analytic’ (AA) model are derived by directly evaluating the corresponding integral formulas. It is shown that, although the same second‐order‐accurate discretization technique has been employed to create both the DFTD and the discrete AA (DAA) models, the simulation results are not the same. In the case of the DFTD model, significant numerical error can be seen in the simulation results, whereas the DAA model does not show such a behaviour. It is shown that time averaging of the forcing terms in the DFTD model helps to reduce the numerical errors significantly at no extra computational cost. Copyright © 2001 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.     

Towards a robust BCI: error potentials and online learning.

Recent advances in the field of brain-computer interfaces (BCIs) have shown that BCIs have the potential to provide a powerful new channel of communication, completely independent of muscular and nervous systems. However, while there have been successful laboratory demonstrations, there are still issues that need to be addressed before BCIs can be used by nonexperts outside the laboratory. At IDIAP Research Institute, we have been investigating several areas that we believe will allow us to improve the robustness, flexibility, and reliability of BCIs. One area is recognition of cognitive error states, that is, identifying errors through the brain's reaction to mistakes. The production of these error potentials (ErrP) in reaction to an error made by the user is well established. We have extended this work by identifying a similar but distinct ErrP that is generated in response to an error made by the interface, (a misinterpretation of a command that the user has given). This ErrP can be satisfactorily identified in single trials and can be demonstrated to improve the theoretical performance of a BCI. A second area of research is online adaptation of the classifier. BCI signals change over time, both between sessions and within a single session, due to a number of factors. This means that a classifier trained on data from a previous session will probably not be optimal for a new session. In this paper, we present preliminary results from our investigations into supervised online learning that can be applied in the initial training phase. We also discuss the future direction of this research, including the combination of these two currently separate issues to create a potentially very powerful BCI.     

System identification of a class of Wiener systems with hysteretic nonlinearities

Existing works on Wiener system identification have essentially been focused on the case where the output nonlinearity is memoryless. When memory nonlinearities have been considered, the focus has been restricted to backlash like nonlinearities. In this paper, we are considering Wiener systems where the output nonlinearity is a general hysteresis operator captured by the well‐known Bouc–Wen model. The Wiener system identification problem is addressed by making use of a steady‐state property, obtained in periodic regime, referred to as ‘hysteretic loop assumption’. The complexity of this problem comes from the system nonlinearity as well as its unknown parameters that enter in a non‐affine way in the model. It is shown that the linear part of the system is accurately identified using a frequency method. Then, the nonlinear hysteretic subsystem is identified, on the basis of a parameterized representation, using a prediction‐error approach. Copyright © 2016 John Wiley & Sons, Ltd.     

Construction of a robust adaptive regulator for time-varying discrete time systems

A robust adaptive regulator is constructed for single-input/single-output discrete time systems modelled by a linear time-varying difference equation that includes an error term to incorporate model errors and/or disturbances. It is assumed that the parameters of the nominal model belong to a known bounded convex set and that the ‘frozen time’ nominal model is stabilizable for all possible parameter values. The estimation of the parameters of the nominal model is carried out using a standard gradient-type algorithm with a projection operation. An adaptive regulator is then constructed from the solution to a finite time Riccati equation. It is shown that the resulting closed-loop system is globally stable if the mean of the parameter time variations is sufficiently small and if the model error is sufficiently small, but where the disturbances applied to the plant may be arbitrarily large.     

Pumped-hydro in Bendigo: Room for wider reform?

As the world adjusts to a rapidly changing climate, interest in renewable energy technologies has increased. One disadvantage of renewables is that they’re only intermittently reliable; when the sun doesn’t shine, or the wind stops blowing the energy generation capacity of these infrastructures tapers off. In light of these changes there has been renewed interest in the creation of Pumped Hydro-Electricity Storage (‘PHES’), which acts as a ‘battery’ storing excess electricity generated when consumption of energy is at its lowest. In addition new technologies allow for legacy infrastructures, that would otherwise be a liability for the community, to now be used in a productive way for projects like PHES. Although there are many exciting opportunities the Bendigo PHES project presents, there is a dearth of regulatory issues for a small-medium scale project like this. This paper will explore the way in which such a project would fit within the national electricity market, as well as the limitations and barriers to implementation it might face before making some brief recommendations on changes that would benefit other such schemes in the future.     

Linear frequency networks with applications to ‘frequency set-on oscillators’ and ‘self-adaptive bandpass filters’

A ‘linear frequency network’ is a network system which consists of an arbitrary connection of devices, each of which performs a linear transformation on the instantaneous frequency of a signal. Thus a transfer function may be defined relating the output to input instantaneous frequency. Particular networks are investigated. the first is a basic section, producing a ‘self-adaptive bandpass filter’ which is then applied to a ‘frequency set-on oscillator’. Such an oscillator is a multimode oscillator where any mode will be stable when excited by a sample of an RF pulse adjacent to the mode. Cascading these basic sections results in an nth-degree ‘self-adaptive bandpass filter’ producing a bandpass characteristic which tracks a carrier frequency. Experimental devices in the 400-600 MHz band are shown to have excellent agreement with theory, and applications to digital RF memories, ESM receivers and frequency memory loops are discussed.