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This paper proposes a simple and novel method of designing and developing high-linearity linear variable differential transformer (LVDT)-based displacement sensing systems. Conventionally, precise adjustment of windings is made to enhance the linearity range of LVDTs. The tedious job of pitch adjustment of windings of LVDTs can be overcome by using the proposed method. A functional link artificial neural network has been successfully used in this paper for nonlinear compensation of the LVDT. The effectiveness of the proposed method is demonstrated through computer simulation with the experimental data of two different LVDT. The complete algorithm with the practical setup for the development of a linear LVDT is presented in this paper. [ABSTRACT FROM AUTHOR]

This paper presents results on fault simulation and response compaction on ISCAS 89 full scan sequential bench- mark circuits using HOPE—a fault simulator developed for synchronous sequential circuits that employs parallel fault simulation with heuristics to reduce simulation time in the context of designing space-efficient support hardware for built-in self-testing of very large-scale integrated circuits. The techniques realized in this paper take advantage of the basic ideas of sequence characterization previously developed and utilized by the authors for response data compaction in the case of ISCAS 85 combinational benchmark circuits, using simulation programs ATALANTA, FSIM, and COMPACTEST, under conditions of both stochastic independence and dependence of single and double line errors in the selection of specific gates for merger of a pair of output bit streams from a circuit under test (CUT). These concepts are then applied to designing efficient space compression networks in the case of full scan sequential benchmark circuits using the fault simulator HOPE. [ABSTRACT FROM AUTHOR]

Integrated Systems Health Management (ISHM) consists of processes managing erroneous conditions that systems may encounter during their operational life by either designing out failures early on or defending and mitigating any possible failures. A successful implementation of ISHM consists of the following four components: data sensors, computations, data sinks, and visualization modules. In this paper, we explore the use of virtual reality (VR) platforms as a candidate for developing ISHM visualization modules. VR allows for a complete and spatially accurate 3-D model of a system to be displayed in real time. It provides a medium for improved data assimilation and analysis through its core tenants of immersion, interaction, and navigation. Furthermore, VR allows for integrating graphical, functional, and measurement data in the same platform-providing for the development of subsequent risk-analysis modules. The research objectives of this paper are focused on creating a detailed visual model of a multisensor rocket engine test facility inside a VR platform and demonstrating the capability of the VR platform in integrating graphical, measurement, and health data in an immersive, navigable, and interactive manner. A human-based performance evaluation of the VR platform is also presented. These research objectives are addressed using an example of a multisensor rocket-engine portable test stand at the National Aeronautics and Space Administration (NASA) Stennis Space Center's E-3 test facility. [ABSTRACT FROM AUTHOR]

This paper presents research on the modeling of the design of measuring systems (MS) with time-limited data flow. A new method of describing the MS model based on Petri Nets (PNs) and the Colored PN Tools environment is proposed. This paper provides an overall description of the formal and informal methods that can be used while designing systems. [ABSTRACT FROM AUTHOR]

This paper proposes a multirate processing technique for obtaining integer and fractional derivatives of digital signals with an improved signal-to-quantization noise ratio. The technique consists of an oversampling analog-to-digital conversion unit with a dithering process and multistage down sampling process followed by an half-band finite impulse response (FIR) differentiator with high performance cascaded using a decimator with a factor of two. In the cascaded multistage processing, each stage contains a simple half-band low-pass FIR filter followed with decimation by two. The proposed technique uses an extremely small size for each half-band low-pass filter, hence requiring much less memory and computational complexity in comparison with the single-stage process. Computer simulations and experimental data processing demonstrate the effectiveness of the proposed method. [ABSTRACT FROM PUBLISHER]

The wavelet transform, the S-transform, the Gabor transform, and the Wigner distribution function are popular techniques for power quality (PQ) analysis in electrical power systems. They are mainly used to identify power harmonics and power disturbances and to estimate power quantities in the presence of nonstationary power components such as root-mean-square values and total harmonic distortions. Recently, the Hilbert–Huang transform has been also used in PQ analysis. These techniques have proven to be useful in PQ analysis; however, their performances depend on the types of PQ events. In this paper, a novel frequency-shifting wavelet decomposition via the Hilbert transform is introduced for PQ analysis. The proposed algorithm overcomes the spectra leakage problem in the discrete wavelet packet transform and can be used for estimating power quantities accurately and for detecting flickers. The effectiveness of the proposed algorithm was verified by computer simulations and experimental tests. [ABSTRACT FROM PUBLISHER]

In this paper, two novel voltage-mode (VM) single- input-three-output (SITO) second-order multifunction analog filters for simultaneously realizing low-pass, bandpass, and high-pass responses from the same topology are proposed. They employ a single dual-output differential voltage current conveyor (DVCC), two grounded capacitors, and three resistors. Both of the proposed filters offer the following two important features: the simultaneous realization of low-pass, bandpass, and high-pass responses and the use of a minimum number of grounded capacitors and a single DVCC. The nonideal gain effects of the developed structures are examined. To show the performance of the proposed VM filters, computer simulation results using the SPICE program, together with ideal ones, are drawn. [ABSTRACT FROM AUTHOR]

This paper presents a nuclear physics virtual laboratory that is focused on describing the core aspects and features of gamma radiation. Two simulated experiments are described. Each simulated experiment is programmed in full analogy with a real experiment performed in a real laboratory. The duration of each step is the same as in reality. The software used to carry out simulated experiment follows the assumption that all the results achieved during the virtual research were not the simulated results but, rather, the results achieved earlier in real-life experiments. [ABSTRACT FROM AUTHOR]

In this paper, the nonideality effects such as non- ideal gain and parasitic-impedance effects on the low-frequency performance of two new grounded inductor simulators are in- vestigated in great depth. In addition, some low-frequency- performance improvement methods for grounded inductor simulators are discussed. Both of the grounded simulated inductors derived from the previously published ones employ a minimum number of grounded passive components and plus-type second-generation current conveyors. Four second-order voltage- mode universal-filter topologies, three of which are novel, are derived from newly and previously developed simulated inductors as application examples. Computer simulations with SPICE program including ideal and experimental test results are drawn to verify theoretical ones. [ABSTRACT FROM AUTHOR]

In this paper, we present a method for calculating the attenuation factor and detecting the reflective and nonreflective events using the Kalman filter. For the part of the data whose signal-to-noise ratio is sufficiently high, we propose a second-order linear model by approximating the measurement data after the logarithm is applied; we design the optimal and suboptimal linear Kalman filters based on this model. Through a representative experiment, the proposed method is verified to precisely calculate the attenuation factor and detect the events with minimal computational resources. [ABSTRACT FROM AUTHOR]

This paper addresses the generation of accurate and efficient behavioral models of digital ICs. The proposed approach is based on the approximation of the device port characteristics by means of composite local linear state-space relations whose parameters can effectively be estimated from device port transient responses via well-established system identification techniques. The proposed models have been proven to overcome some inherent limitations of the state-of-the-art models used so far, and they can effectively be implemented in any commercial tool as Simulation Program with Integrated Circuit Emphasis (SPICE) subcircuits or VHDL-AMS hardware descriptions. A systematic study of the performances of the proposed state-space models is carried out on a synthetic test device. The effectiveness of the proposed approach has been demonstrated on a real application problem involving commercial devices and a data link of a mobile phone. [ABSTRACT FROM AUTHOR]

Disjoint top-view networked cameras are among the most commonly utilized networks in many applications. One of the open questions for these cameras' study is the computation of extrinsic parameters (positions and orientations), named extrinsic calibration or localization of cameras. Current approaches either rely on strict assumptions of the object motion for accurate results or fail to provide results of high accuracy without the requirement of the object motion. To address these shortcomings, we present a location-constrained maximum a posteriori (LMAP) approach by applying known locations in the surveillance area, some of which would be passed by the object opportunistically. The LMAP approach formulates the problem as a joint inference of the extrinsic parameters and object trajectory based on the cameras' observations and the known locations. In addition, a new task-oriented evaluation metric, named MABR (the Maximum value of All image points' Back-projected localization errors' L2 norms Relative to the area of field of view), is presented to assess the quality of the calibration results in an indoor object tracking context. Finally, results herein demonstrate the superior performance of the proposed method over the state-of-the-art algorithm based on the presented MABR and classical evaluation metric in simulations and real experiments. [ABSTRACT FROM AUTHOR]

Two simple discrete-time methods for unbiased estimation of the phase-shift between two real sinusoidal signals in white noise are proposed. The first estimator removes the bias of the recently proposed quadrature delay estimator (QDE) by utilizing all in-phase and quadrature-phase components of the received signals. The phase estimate of the second method is given by the phase difference of the discrete-time Fourier transforms (DTFTs) of two complex sinusoids derived from the real signals. In particular, we have derived the mean square phase-shift error of the DTFT-based estimator as well as the minimum achievable variance for phase-shift estimation, which are identical. Computer simulations show that the two proposed estimators are superior to the biased QDE and can attain optimum performance, although the second estimator has a larger signal-to-noise ratio operation range. [ABSTRACT FROM AUTHOR]

A newly developed resolver converter, providing a pseudolinear voltage proportional to the shaft angle, is presented. This converter is based on a new concept involving the absolute values of the demodulated sine and cosine resolver signals together with a dedicated linearization technique. The converter enables instantaneous determination of the mechanical angle with a theoretical error of nonlinearity below 0.0 11° over the 360° range. The practical performance of this converter is compared to that of a 105 pulses per revolution optical encoder arrangement. The theory of operation, computer simulation, full circuit details, and experimental results are given. [ABSTRACT FROM AUTHOR]