A quantitative method for evaluating the performances of hyperspectral image fusion

Hyperspectral image fusion is a key technique of hyperspectral data processing. In recent years, many fusion methods have been proposed, but there is little work concerning evaluation of the performances of different image fusion methods. In this paper, a method called quantitative correlation analysis (QCA) is proposed, which provides a quantitative measure of the information transferred by an image fusion technique into the output image. Using the proposed method, the performances of different image fusion methods can be compared and analyzed directly based on the images of before and after performing the fusion. The correlation information entropy, based on the developed QCA, is also proposed and testified by numerical simulations. Typical hyperspectral data are applied to the proposed method. The results show that the method is effective, and its conclusions agree with the classification results in applications.     

A hierarchical method for evaluating products with quantitative and sensory characteristics

In some industries, such as food processing, product performance is assessed with multiple criteria including both quantitative measurements and subjective characteristics evaluated by a sensory panel. A sensory panel consists of trained individuals who compare products yielding data often in the form of matrices of paired comparisons. This paper presents a hierarchical method, based on the Analytic Hierarchy Process, for computing weights, or composite performance measures, for products of this type. The paper also presents a new method for collecting and analyzing sensory panel data. The proposed method enables comparison of alternative products taking into account multiple quantitative and sensory responses, their relative importance, and the experience and reliability of panel members.     

Full-field digital gradient sensing method for evaluating stress gradients in transparent solids

A full-field digital gradient sensing method is proposed for measuring small angular deflections of light rays due to local stresses in transparent planar solids. The working principle of the method is explained, and the governing equations are derived. The analysis shows that angular deflections of light rays can be linked to nonuniform changes in thickness and refractive index of the material. In mechanically loaded planar solids, the angular deflections can be further related to spatial gradients of first invariant of stresses under plane stress conditions. The proposed method is first demonstrated by capturing the angular deflection fields in two orthogonal directions for a thin plano-convex lens. The measured contours of constant angular deflection of light rays are in good agreement with the expected ones for a spherical wavefront. The method is also successfully implemented to study a stress concentration problem involving a line load acting on an edge of a large planar sheet. Again, the stress gradients, measured simultaneously along and perpendicular to the loading directions, are in good agreement with the analytical predictions. The measured stress gradients have also been used to estimate stresses in the load point vicinity where plane stress results hold.     

A method for evaluating shockwave propagation in snow

Shockwaves in snow are analyzed by developing and then solving a set of governing jump equations which are defined in terms of the jump in certain material parameters across the shockwave. This method represents an alternative means to studying shockwaves, since most previous solution techniques have involved direct integration of the governing differential wave equations. However, since this classical means is normally difficult, the use of jump equations represents a viable means of determining stress wave properties. The two methods are compared for propagation of plastic shockwaves in snow, and some comparison to data is made. The use of jump equations is shown to give results which are similar to those obtained with the direct method.     

Adaptive image interpolation for full-field digital x-ray mammography

Some full-field digital x-ray mammography systems use multiple abutted two-dimensional detectors. Gaps between adjacent detectors produce seams in the composite image. We develop an adaptive linear interpolation method for estimation of missing data in the seams. In this method, the interpolation path is determined on the basis of the similarity between adjacent subimage boundary profiles. In experiments with phantom images and clinical mammograms, the adaptive method performed significantly better than the conventional linear interpolation.     

A simple method for evaluating the maximum slip of anchorages

The analytical solutions to the bond problem for monotonically increasing loads are developed for a monomial exponential local bond stress-slip relationship (law) – “exact solution” –, a linear local law – “proposed solution” – and a constant bond stress distribution, such as that recommended by the Eurocode. The three solutions are thoroughly developed for the pull-out of a bar embedded in a cylindrical element, with longitudinal concrete in tension. For short anchorages, which undergo a rigid motion and whose “exact solution” requires a complex iterative procedure, the “proposed solution” explicitly provides very accurate bond stress distributions. On the basis of this accuracy, an approximate expression for the slip distribution is derived. The proposed approximate solution is the first one providing a direct slip expression for short anchorages. Approximate explicit expressions for the maximum bond stress and the maximum slip are also given. The comparison between the maximum slip values measured during experimental tests and the corresponding values obtained from the proposed approximate expression demonstrates the accuracy of the latter.     

Current challenges of full field digital mammography

Full field digital mammography (FFDM) has advantages over screen-film mammography (SFM), but some important challenges remain. The first challenge is related to the specific characteristics of FFDM. It remains unclear, which shape and limiting values of the modulation transfer function have the most influence on the performance of a detector, such as the effect of the image display on the overall image quality and the effect of processing on cancer detection. In order to assess the image quality of FFDM, we have set up a scoring system. The second challenge is related to screening mammography: is the quality of an image the same when it is viewed on different monitors and with different processing algorithms? Is Computer Aided Diagnosis necessary in a screening environment? In FFDM, the effect of different detectors, processing and display possibilities on the image and on cancer detection are not clearly investigated.     

A method for evaluating dynamic tensile damage of rock

This paper presents two evolution laws for dynamic tensile damage of brittle rock based on light gas gun (LGG) tests. By analyzing the attenuation of sound-wave propagation in the rock samples before and after impact tests, one evolution law for dynamic tensile damage of rock is introduced and incorporated into the finite element code LS-DYNA through a user-defined subroutine. The improved code is then applied to the simulation of the tensile damage and blast crater near free face of rock mass, and the resulting crater geometry is compared with empirical formula. In addition, based on the phenomenological point of view and the velocity–time histories recorded in LGG tests, another evolution law of tensile damage is proposed to consider the nucleation and growth of microflaws in rock. Parametric analyses are carried out with the self-developed finite difference code and an optimization procedure for the parameter determination is suggested.     

A method for evaluating Hunter whiteness of mixed powders

The Hunter whiteness (HW) is an important quality index of powder in agricultural, food and pigment industries. Relationship between HW of mixed powder and mass percent of each individual powder was investigated. We found a linear relationship expressed by a corresponding equation. According to this equation, the HW of mixed powder was only related to the HW and mass percent of each kind of individual power. Therefore, such equation can simply and rapidly evaluate HW of the mixed powder during the powder matching process.     

A dynamic approach for evaluating parameters in a numerical method

A new methodology for evaluating unknown parameters in a numerical method for solving a partial differential equation is developed. The main result is the identification of a functional form for the parameters which is derived by requiring the numerical method to yield ‘optimal’ solutions over a set of finite‐dimensional function spaces. The functional depends upon the numerical solution, the forcing function, the set of function spaces, and the definition of the optimal solution. It does not require exact or approximate analytical solutions of the continuous problem, and is derived from an extension of the variational Germano identity. This methodology is applied to the one‐dimensional, linear advection–diffusion problem to yield a non‐linear dynamic diffusivity method. It is found that this method yields results that are commensurate to the SUPG method. The same methodology is then used to evaluate the Smagorinsky eddy viscosity for the large eddy simulation of the decay of homogeneous isotropic turbulence in three dimensions. In this case the resulting method is found to be more accurate than the constant‐coefficient and the traditional dynamic versions of the Smagorinsky model. Copyright © 2004 John Wiley & Sons, Ltd.     

A digital coincidence method

A digital coincidence method is described in which the amplitude is digitized and the time of each pulse from the ionizing radiation detectors is recorded. The features of the processing of the digital amplitude-time measurement data are described in detail. It is shown that the digital coincidence method has a time resolution defined solely by the resolving power of the detectors.Translated from Izmeritelnaya Tekhnika, No. 12, pp. 53–58, December, 2004.This revised version was published online in April 2005 with a corrected cover date.     

A thermoelectric method of evaluating the purity of platinum for standard thermocouples

Conclusions Strict tolerances with respect to the stability of standard thermocouples require the checking of the value of W=R₁₀₀/R₀ of the electrode platinum. Direct measurements of R₁₀₀ and R₀ are complicated and require considerable expenditure of time. The thermoelectric method of indirect determination of R₁₀₀/R₀ provides a sufficiently accurate and speedy check of this characteristic of the platinum electrode.     

A survey of patient dose and clinical factors in a full-field digital mammography system

In this work, we analyse the dose to 5034 patients (20 137 images) who underwent mammographic examinations with a full-field digital mammography (FFDM) system over a 2-y period. The information relevant to this study has been extracted from the image Digital Imaging and Communications in Medicine (DICOM) headers. Entrance surface air-kerma (ESAK) without backscatter and average glandular dose (AGD) were estimated following the methodology proposed in the European Protocol on Dosimetry in Mammography. Mean values for patient age and compressed breast thickness were 56 +/- 11 y and 52 +/- 13 mm, respectively. The mean ESAK value was 8.1 mGy and the mean AGD was 1.9 mGy. In addition, the dose values from both FFDM and screening-film mammographic (SFM) examinations were compared. The third quartile (TQ) of the ESAK values delivered by the FFDM system was 33% lower and 32% higher than the TQ for SFM with slow and fast screen/film receptors. Differences between dose values for cranio-caudal (CC) and medio-lateral oblique (MLO) images (about 27% for SFM) decreased to 11% for FFDM.     

A new method for evaluating fracture toughness of brittle materials

A new testing procedure is suggested for measuring the fracture toughness of brittle materials as superconductors and ceramics. The idea is to perform a compression test on a subcompact square specimen which contains a central hole. The presence of the hole induces a tensile stress at a certain small region attached to the hole. In this region an artificial notch is introduced such that the fracture path satisfies a pure tensile opening mode (mode I) to which the linear fracture mechanics rules apply. The stress distribution on the fracture plane guarantees a certain amount of stable crack extension. The relationship between the critical compressive load and the stress intensity factor is formulated via an available Green function along with a numerical solution (FEM with ANSYS code). The testing procedure is demonstrated with specimens made of two types of tungsten carbide which differ by their grain size only. Test results are examined via fracture toughness and strength values produced by other conventional methods and the agreement is very good. The geometry and loading direction enable the fracture toughness results to be relatively insensitive to the notch tip radius and the crack length, thereby relaxing the requirements for accurate measurements.The small size of the suggested specimen (12.70mm×12.70mm×5mm) and the avoidance of gripping interfaces provide the major cost-wise advantages.     

基于潜艇声探测能力预测的感知行为决策方法

针对作战行为对潜艇作战结果的影响较大,且难以通过传统基于指标体系的方法来寻求战法创新的问题,提出了基于潜艇声探测能力预测的感知行为决策方法,用于目标搜索阶段的优化决策。首先分析了传播环境、平台特性及作战行为对声探测能力的影响;其次建立了声探测能力的形式化表达,并针对影响因素的特点建立了可实时修正的预测模型,实现行为驱动的声探测能力预测;然后建立了总体约束下的感知行为优化框架及具体优化流程;最后以要地搜反潜为例对所提方法进行了实验验证。实验结果表明,该方法可在目标搜索阶段为感知行为决策提供了有效优化。     

A method for evaluating functional content in mechatronic systems using optimisation

This paper presents a method to support designers and product planners in determining the functionalities that should be implemented in a product and those that should not. The proposed method identifies the set of customer functions and technical implementations that maximise the potential product profit. The customer functions represent the functionality of the product, and the technical implementations are the hardware and software components needed to realise these functions. For industrial applications, the numbers of possible combinations of customer functions and technical implementations are extremely large. We present a mathematical framework that handles this problem. Furthermore, optimisation is employed to find the set of customer functions that will maximise profit when subjected to a restricted development budget in order to find the best possible business case. The method was evaluated on an industrial case study of active safety systems performed at Volvo Cars. Based on this case study, the proposed method shows a substantial potential compared to the methods presently used.     

A method for evaluating personal dosemeters in workplace with neutron fields

Passive detectors, as albedo or track-etch, still dominate the field of neutron personal dosimetry, mainly due to their low-cost, high-reliability and elevated throughput. However, the recent appearance in the market of electronic personal dosemeters for neutrons presents a new option for personal dosimetry. In addition to passive detectors, electronic personal dosemeters necessitate correction factors, concerning their energy and angular response dependencies. This paper reports on the results of a method to evaluate personal dosemeters for workplace where neutrons are present. The approach here uses few instruments and does not necessitate a large mathematical workload. Qualitative information on the neutron energy spectrum is acquired using a simple spectrometer (Nprobe), reference values for H*(10) are derived from measurements with ambient detectors (Studsvik, Berthold and Harwell) and angular information is measured using personal dosemeters (electronic and bubbles dosemeters) disposed in different orientations on a slab phantom.