An adaptive procedure for categorical loudness scaling

In this study, an adaptive procedure for categorical loudness scaling is introduced and evaluated. The procedure adjusts the presentation levels to the subject's individual auditory dynamic range without employing any premeasurement and presents levels in randomized order. The procedure has been named "Oldenburg-ACALOS" (Oldenburg-Adaptive CAtegorical LOudness Scaling). It was evaluated using repeated measurements with ten subjects with normal hearing and ten subjects with sensorineural hearing impairment. The results of this investigation revealed that the adaptive procedure provides greater reliability, while being more time efficient than a reference procedure that uses constant stimuli.     

A restoration procedure for (non-stationary) signals from moving sources

Moving sources, such as trains, cars and airplanes, provide non-stationary sound and vibration signals in situations where the receiver is not moving with the source. For non-stationary signals there are strong limitations on the use of computerized analysis techniques based on Fourier transformation. For instance, it is not possible to compute reliably either power spectral density functions or coherence functions. A procedure has been developed, and is discussed in this paper, that restores non-stationary signals into stationary ones, thus enabling one to apply the analysis techniques mentioned above to moving source data with a reliable outcome.     

A computerised, unbiased method for epithelial measurement

OBJECTIVE: To develop and evaluate a standardised method for unbiased measurements of epithelial thickness taking the variability of the dermal papillae in consideration. METHODS: A computer-assisted measurement program suitable for haematoxylin and eosin routine stained specimens has been developed. RESULTS: The developed program was designed to measure four different distance parameters, taking the number, height and width of dermal papillae into account. The measurement program gave very accurate results compared with manual measurements. The measurement results can be presented as tables or star graphs, and the results can be further processed by multivariate analysis. CONCLUSION: The computer-assisted measurement program is considered to be a valuable and reliable tool for measurements of epithelial thickness, irrespectively of the variability of the epithelial morphology. Since length, size and number of the papillae may change with certain pathological conditions, age and also under hormonal influence, this method can be a helpful diagnostic tool.     

A simplified procedure for the estimation of (COP)R for heat pumps

A simplified procedure for estimating the Rankine coefficient of performance for vapor compression heat pumps is presented. This procedure ddoes not need detailed thermodynamic data. It requires only the liquid specific heat and the latent heat of vaporisation at the evaporating temperature. This procedure is tested by its application to eight potential heat pump working fluids for which exact (COP)_R values have been reported based on detailed thermodynamic data. Very wide ranges of evaporating and condensing temperatures are covered. The results indicate that the present procedures can predict (COP)_R values within 3–4%. Useful correlations for calculating the liquid specific heat and the latent heat of vaporisation for these working fluids are also presented, which cover temperature ranges of importance for heat pump applications.     

A novel robust proportional-integral （PI） adaptive observer design for chaos synchronization

In this paper, chaos synchronization in the presence of parameter uncertainty, observer gain perturbation and exogenous input disturbance is considered. A nonlinear non-fragile proportional-integral (PI) adaptive observer is designed for the synchronization of chaotic systems; its stability conditions based on the Lyapunov technique are derived. The observer proportional and integral gains, by converting the conditions into linear matrix inequality (LMI), are optimally selected from solutions that satisfy the observer stability conditions such that the effect of disturbance on the synchronization error becomes minimized. To show the effectiveness of the proposed method, simulation results for the synchronization of a Lorenz chaotic system with unknown parameters in the presence of an exogenous input disturbance and abrupt gain perturbation are reported.     

A procedure for testing the consistency of opacities with the oscillator strength sum rule

A simple method is derived and discussed for testing the degree of consistency between any opacity computer program and the Thomas-Reiche-Kuhn oscillator strength sum rule.     

Experimental testing of least-square procedure for determiningrailgun plasma current distribution

The plasma current distribution (initial length, velocity, amplitude versus x, and expansion rate) was determined by simultaneously fitting (using the method of least squares) the measured voltages of multiple B-dot probes to a function model. The model for the probe voltage was derived using the Biot-Savart equation and some simplifying assumptions, one of which was to divide the current into segments and then sum for the total voltage. The computer model contains selectable form functions which give the amplitude of the current for each segment. The procedure was tested by comparing multiple fits of symmetrically positioned probes on opposite sides of the bore, comparing fits using different form functions and different numbers of segments, comparing fits of different-size probes located at different distances from the bore, and comparing the fitted parameters of the plasma current distribution with other sensors. As far as could be determined, the current distribution determination gives meaningful data which correlate well with other measurements     

Measurements and calculations on the simple up-down adaptive procedure for speech-in-noise tests

The simple up-down adaptive procedure is a common method for measuring speech reception thresholds. It is used by the Dutch speech-in-noise telephone screening test [National Hearing test; Smits and Houtgast Ear Hear. 26, 89-95 (2005)]. The test uses digit triplets to measure the speech reception threshold in noise by telephone (SRTT(n)). About 66 000 people took this test within four months of its introduction and details were stored of all individual measurements. Analyses of this large volume of data have revealed that the standard deviation of SRTT(n) estimates increases with hearing loss. This paper presents a calculation model which--using an intelligibility function as input--can determine the standard deviation of SRTT(n) estimates and the bias for the simple up-down procedure. The effects of variations in the slope of the intelligibility function, the guess rate, the starting level, the heterogeneity of the speech material, and the possibilities of optimizing SRTT(n) measurements were all explored with this model. The predicted decrease in the standard deviation of SRTT(n) estimates as a result of optimizing the speech material was confirmed by measurements in 244 listeners. The paper concludes by discussing possibilities for optimizing the development of comparable tests.     

QuantumSU(2) andE(2) groups. Contraction procedure

In [3] it was shown (in the framework of deformed enveloping algebras) that quantumSU(2) andE(2) groups are related by the contraction procedure. We consider the same problem on theC ^*-level. As a result we find a number of formulae coupling the comultiplications in quantumSU(2) andE(2). In particular we show that the comultiplications in both groups are implemented by partial isometries. An unexpected feature of quantumE(2) is discovered and the corresponding strange behavior of quantumSU(2) is described.Supported by CNRS, France     

A numerical procedure for soliton generation

We present a simple method for obtaining stationary solutions to the perturbed nonlinear Schrödinger equation from a random input field. In particular, we propagate the initial field while both renormalizing to ensure that the maximum field value remains constant and absorbing the field at increasingly large distances from the centre of the computational window in position and wavevector space. Our algorithm, which results in near-perfect lowest-order solitons for a wide range of absorber and computational parameters, should be equally applicable to other nonlinear equations.     

自适应光学系统测试中大气湍流的时域模拟

建立了大气湍流模拟的时域模型,用于在自适应光学系统的测试中模拟大气湍流的时域变化。讨论了时域模型下随机相位屏平滑帧数和刷新频率与平均风速的关系。结果表明：对表征随机波前的随机相位屏进行时域平滑可使随机波前的变化更符合大气湍流对入射波前连续平滑渐变的影响;随机相位屏的平滑帧数仅与系统口径和大气相干长度相关,而与风速无关;随机相位屏的刷新频率与平均风速成正比,平滑后的刷新频率还与平滑帧数成正比。最后,构造了一套大气湍流模拟装置,应用功率谱分析法对时域模型的有效性进行了验证。     

A simple procedure for electroluminescent phosphor assessment

A simple assessment procedure is described which facilitates optimal selection of an electroluminescent phosphor based on the measurement of two optically deduced energies—absorption and emission. These two energies are used as input for an appraisal analysis based on a classical configuration-coordinate diagram model of the phosphor. A phosphor performance figure-of-merit is proposed as a consequence of the formulation of this assessment procedure. This procedure is then used to rationalize the relative performance of five electroluminescent phosphors (ZnS:Mn, BaAl₂S₄:Eu, SrS:Ce, SrGa₂S₄:Ce, CaGa₂S₄:Ce). Additionally, two cathodoluminescent phosphors (ZnS:Ag and ZnS:Cu) are appraised using this methodology, suggesting that this procedure may be of some utility in the evaluation of other types of phosphors.     

A programmable procedure for generating many-particle states

A procedure is described for generating the many-particle states belonging to an irreducible representation of the unitary group. A representation of this basis has been introduced which is appropriate in limited configuration interaction studies.     

A robust procedure for absolute phase measurement

A robust procedure for the measurement of absolute phase values with high accuracy is presented. This procedure is based on the derivation of a precision adapted sequence of grid orientations and the stepwise reconstruction of the continuous phase field without phase unwrapping. The determination of the angle sequence is oriented on the phase measuring accuracy and the known limits of the absolute phase. Similar results can be derived for the variation of the synthetic wavelength using contouring techniques where the object is illuminated with different wavelengths.     

A real-time procedure for acoustic-turbulence filtering ducts

A real-time procedure for acoustic-turbulence filtering in a duct is developed. The method consists of implementing a numerical recursive linear “optimal” filter (the Kalman filter) acting on the output signal of a microphone set inside the duct, via a preliminary identification of evolution models of the acoustic and turbulence processes in terms of arma (p,q) time series. Identification of models is carried out in the frequency domain by using an optimization method and a cross-spectrum technique, and this is also presented. As an example, the modelling, parameter identification, and filtering of a broadband acoustic noise produced by a rotating fan in a duct is considered. It is shown that a real-time filtering of the acoustic contribution from turbulent fluctuations should allow some improvement of broadband active sound cancellations systems at low frequencies.     

A new deconvolution procedure for ESR spectra

Quantitative determination of spin contents from complex spectra requires deconvolution of each peak. There are several ways to perform this task, the more common being the use of a non-linear fit such as the Marquardt–Levenberg algorithm (M–L). However this technique although very powerful and largely diffused fails when the initial set of parameters of the peaks are far from the true ones, i.e. when the sample composition is not a-priori completely known. In this case a new run with different initial values is required. This isn’t convenient for an automatic deconvolution procedure. Here a new procedure is presented, based on a genetic algorithm as a first step and a M–L method as the second step. The first step will always work regardless of the initial set of data but the accuracy obtainable is lower compared to the M–L technique. The accuracy is improved by using the parameter obtained in a subsequent algorithm employing the M–L method. However, due to the precision of the genetic algorithm presented here, the second step can sometimes be omitted. Results of some trials both on integral and differential spectra are reported and discussed here.     

Modelling the spontaneous combustion of coal: the adiabatic testing procedure

A general approach is described for modelling problems that involve heat and mass transfer in coal, such as spontaneous combustion. It is based on the TOUGH2 code, which is a general-purpose simulator for modelling multi-component, multi-phase, non-isothermal flow in a porous medium. An equation of state (EOS) module for TOUGH2 is developed, which includes accurate physical properties for all of the gases involved (N₂, oxygen and carbon dioxide). The new simulator is then used to model the adiabatic method for testing the reactivity of coal samples. An important part of the model development is the selection of the approximate representation of the reaction of coal with oxygen. The results show that (i) using dual Arrhenius parameters and (ii) representing the heat-release as an oxidation reaction rather than a purely thermal reaction both significantly improve the match of the model to the experimental data.     

Classification of audiograms by sequential testing using a dynamic Bayesian procedure

A new method for estimating audiograms using behavioral responses is presented. The method is based upon a modification of the Bayesian probability formula in which an outcome is predicted from a static set of events. In the new method, classification of audiograms by sequential testing (CAST), the probabilities of occurrence of audiogram patterns are dynamically updated according to the outcome of each test trial. Computer simulation using an infant response model suggests that the procedure is efficient, sensitive, and specific.     

An adaptive singular value decomposition (SVD) algorithm for analysis of wavelength modulation spectra

Optical interference fringes due to unwanted etalons are often the limiting uncertainty in diode laser spectroscopic trace gas measurements. Temporal variations in the fringe spacings, phases, and amplitudes introduce systematic baseline changes that limit useful signal averaging times to ∼1000 s, and constrain minimum detectable absorbances to between one and three orders of magnitude worse than the fundamental limiting noise sources (shot noise and/or detector thermal noise). We describe an adaptive numerical filtering method based on singular value decomposition (SVD) that shows, for the system studied, a fivefold reduction in baseline drift due to unwanted etalons over a one-week-measurement period. The adaptive algorithm is fast (<1 ms per computation), robust, and uses linear methods. It is computationally equivalent to principal component analysis (PCA). The test system was acetylene detected using a near-infrared telecommunications laser operating at 6541.96 cm^-1. The gas detection limit was 20 ppb (1σ) over the one-week measurement. PACS 07.05.Kf; 07.07.Df; 07.60.-j; 42.60.-v; 42.62.-b; 42.62.Fi