Smoothing vocal signal spectrum

Proposed was a method of smoothing the spectrum of vocal signal which is based on the histogram analysis of the peaks of the spectral envelope and represents a variety of the frequency analysis that is synchronous with the main tone. Its application was demonstrated by way of examples of the real vocal signals.     

A notation describing corrections in files

A simple, human-oriented notation enabling one to describe corrections in files is presented. The notation may be used as an input language for a program to produce a corrected file.     

Finger-vein recognition based on parametric-oriented corrections

The two key factors in a biometric identification system are its high identification rate and convenience of device usage. In a finger-vein identification task, these two problems often occur since the captured device of finger-vein image should accommodate the high identification rate as well as the easy-to-use device design. The finger-vein is visually invisible inside the human skin. This work develops a new finger-vein capturing device using Near-Infrared (NIR) LED light and proposes an efficient technique for finger-vein identification. The vein image may contain noise and shadows due to device lighting conditions. Parametric-Oriented Histogram Equalization (POHE) is utilized to enhance image contrast and reduce the noise effect. This work also discusses normalized issues related to the angle correction of the finger edge and Region of Interest (ROI) for width normalization. In the experimental result, the proposed method yields a clear finger-vein pattern with a superior identification rate in the recognition task compared to the state-of-the-art methods.

     

Dissimilarity computation through low rank corrections

Most of the energy of a multivariate feature is often contained in a low dimensional subspace. We exploit this property for the efficient computation of a dissimilarity measure between features using an approximation of the Bhattacharyya distance. We show that for normally distributed features the Bhattacharyya distance is a particular case of the Jensen–Shannon divergence, and thus evaluation of this distance is equivalent to a statistical test about the similarity of the two populations. The accuracy of the proposed approximation is tested for the task of texture retrieval.     

Limitations of visual gamma corrections in LCD displays

A method for estimating the non-linear gamma transfer function of liquid–crystal displays (LCDs) without the need of a photometric measurement device was described by Xiao et al. (2011) [1]. It relies on observer’s judgments of visual luminance by presenting eight half-tone patterns with luminances from 1/9 to 8/9 of the maximum value of each colour channel. These half-tone patterns were distributed over the screen both over the vertical and horizontal viewing axes. We conducted a series of photometric and psychophysical measurements (consisting in the simultaneous presentation of half-tone patterns in each trial) to evaluate whether the angular dependency of the light generated by three different LCD technologies would bias the results of these gamma transfer function estimations. Our results show that there are significant differences between the gamma transfer functions measured and produced by observers at different viewing angles. We suggest appropriate modifications to the Xiao et al. paradigm to counterbalance these artefacts which also have the advantage of shortening the amount of time spent in collecting the psychophysical measurements.     

Iterative learning of grasp adaptation through human corrections

In the context of object interaction and manipulation, one characteristic of a robust grasp is its ability to comply with external perturbations applied to the grasped object while still maintaining the grasp. In this work, we introduce an approach for grasp adaptation which learns a statistical model to adapt hand posture solely based on the perceived contact between the object and fingers. Using a multi-step learning procedure, the model dataset is built by first demonstrating an initial hand posture, which is then physically corrected by a human teacher pressing on the fingertips, exploiting compliance in the robot hand. The learner then replays the resulting sequence of hand postures, to generate a dataset of posture-contact pairs that are not influenced by the touch of the teacher. A key feature of this work is that the learned model may be further refined by repeating the correction-replay steps. Alternatively, the model may be reused in the development of new models, characterized by the contact signatures of a different object. Our approach is empirically validated on the iCub robot. We demonstrate grasp adaptation in response to changes in contact, and show successful model reuse and improved adaptation with additional rounds of model refinement.     

A new method of generating differential GPS corrections

In this paper, a simple method is proposed for calculating positions on the ground with a differential global positioning system that does not use conventional correction data. The method employs two low-cost GPS receivers, one of them being at a fixed location. In order to coordinate their operation, both receivers only use three of the highest satellites in sight. The precision obtained with this technique is similar to that calculated by more sophisticated methods.     

Parallelizing spectral deferred corrections across the method

In this paper we present two strategies to enable “parallelization across the method” for spectral deferred corrections (SDC). Using standard low-order time-stepping methods in an iterative fashion, SDC can be seen as preconditioned Picard iteration for the collocation problem. Typically, a serial Gauß–Seidel-like preconditioner is used, computing updates for each collocation node one by one. The goal of this paper is to show how this process can be parallelized, so that all collocation nodes are updated simultaneously. The first strategy aims at finding parallel preconditioners for the Picard iteration and we test three choices using four different test problems. For the second strategy we diagonalize the quadrature matrix of the collocation problem directly. In order to integrate non-linear problems we employ simplified and inexact Newton methods. Here, we estimate the speed of convergence depending on the time-step size and verify our results using a non-linear diffusion problem.

     

Speaker recognition using vocal source model

Speaker recognition is carried out in the space of the functional parameters of the area of the glottal cross-section, found by solving the inverse problem. This problem is solved in two stages: first, the signal obtained by inverse filtering is approximated using the vocal source model, and then the glottal area model parameters, which generate the calculated vocal source impulse, are computed. Speaker recognition is carried out on a database of Russian numerals from 0 to 9 separately for men (48 speakers) and women (37 speakers) at the segments of stressed vowels. Various methods of recognition are studied: the Gaussian mixture model (GMM), support vector machines (SVMs), discriminant analysis, naive Bayes classifier (NB), the method of classification trees (CTREE), and the Parzen window classifier. The best results were obtained using the method of SVMs and the Parzen method: the average total error of identification of men was 4.9% and 5.1%, and that of women—8.2% and 8.8%, respectively.     

Relativistic corrections in the laser ranging of spacecrafts

I construct a mathematical model for the laser ranging of spacecrafts, which includes the effects of general relativity. On the basis of numerical calculation I show that relativistic effects are revealed in the laser ranging of high-apogee spacecrafts. These effects must be included in the mathematical model of astrometric space missions.     

对一个代理签名方案的分析和更正

为了解决门限代理签名中谁是实际签名者的问题,Sun第1个提出了不可否认的门限代理签名方案,指出Sun方案的存在明显的错误,并对错误进行了更正,然后对更正后的方案进行了安全性分析,证明了更正后的方案容易受到内部攻击,原始签名者和可信中心完全可以伪造代理签名.     

Modeling of vocal tracts based on polynomials

A great problem in speech processing is to represent the shape and characteristics of the vocal tracts. This task is normally done by using an acoustics tube model, based on the calculation of the area function would be performed. The area function can be found from sagittal function determined by sagittal cub. In this paper, an optimization based method is presented to model the vocal tracts and their relationship with the fundamental frequencies of vowels and consonants. We present two models which are simple polynomials that need the minimum number of parameters. We will show that these models have good performance in experiments.     

化学软件的软件过程改进

针对国内化学软件开发的特点，以软件能力成熟度模型（Capability Maturity Model of Software,SW-CMM）为基础，介绍了由初始级到可重复级的软件过程改进方案，并提出了适合化学软件开发的软件过程模型。     

软件复用、软件合成与软件集成

软件复用被视为解决软件危机的一条现实可行的途径。在软件复用的科学研究与实践活动中,针对不同的应用领域,结合相关的计算机新兴技术,出现了许多解决软件危机的方法与途径,软件合成、软件集成就是软件复用的成功实践扩展和技术应用之一。简要地介绍了软件复用,分别给出了软件合成、软件集成的概念,归纳总结了二者实现所涉及的关键技术、适用领域和应用目的,详尽地对比了软件合成、软件集成的区别。     

Systematic corrections of AVHRR image composites for temporal studies

For quantitative studies of vegetation dynamics, satellite data need to be corrected for spurious effects. In this study, we have applied several changes to an earlier advanced very high resolution radiometer (AVHRR) processing methodology (ABC3; [Remote Sens. Environ. 60 (1997) 35; J. Geophys. Res.-Atmos. 102 (1997) 29625; Can. J. Remote Sens. 23 (1997) 163]), to better represent the various physical processes causing contamination of the AVHRR measurements. These included published recent estimates of the NOAA-11 and NOAA-14 AVHRR calibration trajectories for channels 1 and 2; the best available estimates for the water vapour, aerosol and ozone amounts at the time of AVHRR data acquisition; an improved bidirectional reflectance algorithm that also takes into consideration surface topography; and an improved image screening algorithm for contaminated pixels. Unlike the previous study that compared the composite images to a single-date AVHRR image, we employed coincident TM images to approximate the AVHRR pixel field of view during the data acquisition. Compared to ABC3, the modified procedure ABC3V2 was found to improve the accuracy of AVHRR pixel reflectance estimates, both in the sensitivity (slope) of the regression and in r². The improvements were especially significant in AVHRR channel 1. In comparison with reference values derived from two full TM scenes, the corrected AVHRR surface reflectance estimates had average standard errors values of ±0.009 for AVHRR C1, ±0.019 for C2, and ±0.04 for NDVI; the corresponding r² values were 0.55, 0.80, and 0.50, respectively. The changes in ABC3V2 were not able to completely remove interannual variability for land cover types with little or no vegetation cover, which would be expected to remain stable over time, and they increased the interannual variability of mixed forest and grassland. These results are attributed to a combination of increased sensitivity to interannual dynamics on one hand, and the inability to remove all sources of noise for barren or sparsely vegetated northern land cover types on the other.     

Algorithm for atmospheric corrections of aircraft and satellite imagery

Abstract

An algorithm is described for making fast atmospheric corrections. The required radiation parameters are stored in a lookup table. The procedure is to enter the lookup table with the measured radiance, wavelength, view and illumination directions, heights of observation and surface, and the aerosol and gaseous absorption optical thicknesses. The surface radiance, the irradiance incident on a surface, and surface reflectance are computed then. Alternately, the program will compute the upward radiances at specific altitudes for a given surface reflctance, view and illumination directions, and aerosol and gaseous absorption optical thicknesses.     

Orbital corrections of space vehicles while performing dynamic operations

The technical task of performing dynamic operations on orbit is considered. This problem is reduced to two basic problems: steering a space vehicle belonging to a group of vehicles to a prescribed region of space, and maneuvering within this region during the operational life. These technical statements of control problems and terminal requirements provide a basis for forming a mathematical statement of the problem, which is solved using the stochastic and minimax approaches, and for developing working algorithms.     

Implementation of an editing algorithm. Allowing repeating corrections

A research project on the application of computers of computers to typesetting, financed by the Ministry of Technology, has recently been concluded at the University of Newcastle upon Tyne. The design of one of the programs developed as part of this project is discussed in this paper. The program is an editor which runs in batch mode and which has been extensively used for the correction and maintenance of files of natural language text in preparation for computer typesetting. An important feature of the program is the handling of repeating corrections which allow consistent changes of notation over arbitrary parts of the file as well as the more usual local or non-repeating corrections. The internal representation of corrections which is used to implement this facility is described. An appendix gives some examples of corrections and illustrates some of the difficulties inherent in any such correction process.     

Entropy corrections to supersonic conical nonlinear potential flows

Entropy corrections are applied to full potential supersonic conical flows that have the how shock fit as a boundary. The entropy corrections require the implementation of the Rankine-Hugoniot shock relations instead of the isentropic shock conditions. In addition, the pressure must be corrected to account for the bow shock induced entropy variation. For high Mach number and/or large deflection angles, the correction to the potential pressures can be of the same order of magnitude as the Euler pressures. Considering the simplistic nature of the corrections, remarkably accurate results are achieved for circular and elliptic cones. Additional corrections account for embedded crossflow shocks.