IEEE Transactions on Circuits and Systems I: Fundamental Theory and Applications
1558-1268
Cơ quản chủ quản: N/A
Các bài báo tiêu biểu
Variable gain amplifiers based on a new approximation method to realize the exponential function
Tập 49 Số 9 - Trang 1348-1354 - 2002
A new current mode variable-gain amplifier (VGA) is developed. The new circuit
is based on a novel approximation function that is very close to the ideal
exponential relation over a very wide range. Pspice simulations are provided
based on Mietec 0.5-/spl mu/m CMOS technology. The simulations show that the
dynamic range achieved is over 50 dB in a single stage. The proposed circuit
consumes averag...
#Approximation methods #Dynamic range #CMOS technology #Circuit simulation #Difference equations #Voltage #Gain control #Auditory system #Communication system control #Bipolar transistors
Using steady-state prior knowledge to constrain parameter estimates in nonlinear system identification
Tập 49 Số 9 - Trang 1376-1381 - 2002
This work investigates the use of prior knowledge in the parameter estimation of
NARMAX polynomial models. The problem of parameter estimation is then formulated
in such a way that the estimated models have specified features. This
formulation results in a constrained optimization problem, which is solved using
the ellipsoid algorithm. This technique is applied to a real DC-DC buck
converter. In t...
#Steady-state #Parameter estimation #Nonlinear systems #Polynomials #Stability #Constraint optimization #Ellipsoids #Buck converters #Least squares approximation #Yield estimation
A PWL circuit approach to the definition of a /spl epsiv/-approximation model of scalar static hysteresis
Tập 49 Số 9 - Trang 1290-1308 - 2002
A piecewise-linear (PWL) circuit model of hysteresis phenomena is presented. The
proposed model involves the use of parallel-connected simple PWL circuits. The
PWL characteristic of the model allows a direct determination of the condition
on a rate-independent hysteresis behavior. The basic features of the model are
discussed through proper demonstrations. In particular, it is shown that the
param...
#Hysteresis #Biological system modeling #Piecewise linear techniques #Nonlinear circuits #Mathematical model #Robustness #Arithmetic #Ferroelectric materials #Biological systems
Optimal digital redesign of hybrid cascaded input-delay systems under state and control constraints
Tập 49 Số 9 - Trang 1382-1392 - 2002
This paper presents a new multi-objective evolutionary programming (MOEP)-based
digital redesign scheme to find an optimal low-gain digital tracking controller
for hybrid control of multi-input, multi-output (MIMO) cascaded analog systems
with input time delays, having the constraints on the states and inputs. The
proposed global optimization searching technique enables one to find a high-gain
opt...
#Optimal control #Control systems #Digital control #MIMO #Delay effects #Pulse modulation #Genetic programming #Constraint optimization #Sampling methods #Amplitude modulation
Synchronized oscillators with the phase-negative feedback
Tập 49 Số 8 - Trang 1242-1245 - 2002
A novel idea, a phase-negative feedback for fundamentally injected LC
oscillators, is discussed, and a new method of linear approximation of their
shortened equations has been presented.
#Feedback #Injection-locked oscillators #Frequency synchronization #Signal processing #Circuits #Equations #Power harmonic filters #Linear approximation #Performance analysis #Technological innovation
A minimal integral nonlinearity criterion to optimize the design of a new tanh/sinh-type bipolar transconductor
Tập 49 Số 8 - Trang 1062-1070 - 2002
We report on the use of a simple design optimization criterion for obtaining
maximum static transfer function linearity. It is based on an analytic function
that corresponds to the integral nonlinearity of the circuit. The criterion may
be useful, either as an analytic tool to gain insight into the circuit's
behavior, or as an efficient computational alternative to calculating total
harmonic disto...
#Design optimization #Transconductors #Linearity #Transfer functions #Harmonic analysis #Circuit analysis computing #Total harmonic distortion #Circuit simulation #Transconductance #Voltage
Computation of limit cycle via higher order harmonic balance approximation and its application to a 3-bus power system
Tập 49 Số 9 - Trang 1360-1370 - 2002
This work reviews and elaborates a frequency domain approximate method of
estimating amplitude, frequency, and stability of the limit cycle near Hopf
bifurcations. A new iterative method and new criterion for ascertaining
stability are presented. The method and criterion are applied to a 3-bus dynamic
power system model to give the amplitude, frequency and stability at its Hopf
bifurcations. New a...
#Power system harmonics #Limit-cycles #Power system stability #Bifurcation #Power system modeling #Power system dynamics #Frequency estimation #Stability criteria #Frequency domain analysis #Amplitude estimation
The effects of generation redispatch on Hopf bifurcations in electric power systems
Tập 49 Số 8 - Trang 1180-1186 - 2002
In this paper, we examine how varying the generation redispatch can improve the
system stability margins with respect to Hopf bifurcations, as well as
robustness to uncertainties in load modeling and distribution. It is seen that
an optimal selection of load following units plays a key role in accomplishing
these objectives. An optimal redispatch strategy is proposed, and is verified
through a var...
#Power generation #Bifurcation #Power system modeling #Voltage #Load modeling #Eigenvalues and eigenfunctions #Robust stability #Power system stability #Differential equations #Power system dynamics
Controllability and observability of linear time-varying impulsive systems
Tập 49 Số 8 - Trang 1198-1208 - 2002
Many practical systems in physics, chemistry, biology, engineering, and
information science have impulsive dynamical behaviors due to abrupt changes at
certain instants during the dynamical processes. These complex dynamical
behaviors can be modeled by impulsive differential systems. This paper studies
the controllability and observability issues for a general time-varying
impulsive control system...
#Controllability #Observability #Time varying systems #Control systems #Biological system modeling #Systems biology #Information science #Aerospace electronics #Differential equations #Control engineering education
A modified Volterra series approach for nonlinear dynamic systems modeling
Tập 49 Số 8 - Trang 1118-1128 - 2002
This paper describes a modeling approach for nonlinear dynamic systems based on
a modified Volterra series; by comparing the truncation error of this series
with that of the classical Volterra one, we outlined that, under the assumption
of short-term nonlinear memory effects, the modified series enables a
single-fold nonlinear convolution integral to be adopted also in the presence of
strong nonli...
#Modeling #Nonlinear systems #Nonlinear dynamical systems #Finite wordlength effects #Convolution #Bandwidth #Microscopy #Signal processing #Transfer functions #Voltmeters