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21.
Constant improvements in digital cameras have made it possible to use these devices for colour acquisition and reproduction at an advanced level. It is known that a colour match for all observers when changing illumination can only be achieved by matching spectral data. Obtaining spectral data from digital camera RGB values could provide a new way of using the digital camera as a spectrophotometric tool or as a high‐quality colour‐capturing system that is required in more demanding applications. In the present study, two spectral reflectance estimation methods were examined – the Imai–Berns method (ImaiBerns) and the spectral‐sensitivity‐based method (SpecSens). The purpose of the research was to simplify the procedure of the SpecSens method by using a diffraction grating and a spectroradiometer instead of a monochromator, and to compare the results with those of the ImaiBerns approach. Obtained spectral reflectance estimates were evaluated using the root‐mean‐square error and ?E00 metrics. Results of the research show that the ImaiBerns method was superior to SpecSens, most likely because the former method does not require knowledge of the camera spectral sensitivities, which often introduces errors into reflectance estimation calculations. Both methods were successful in predicting black, brownish, and dark patches, as indicated by a low root‐mean‐square error, as well as unsaturated pastel, pink, or skin colours, which produced low ?E00 values. On the other hand, many of the patches with a low root‐mean‐square error also exhibited high ?E00 values, while bright, nearly‐white patches were characterised by a high root‐mean‐square error. 相似文献
22.
Many writers, using both experimental tests and complex numerical models, have examined the effect of vehicle velocity on a highway bridge’s dynamic amplification. Although these tests and models give valuable quantitative information on dynamic amplification, they give little insight into how amplification is affected by individual vehicle/bridge parameters. This paper uses relatively simple numerical models to investigate the effect of vehicle velocity on a bridge’s dynamic amplification. A single vehicle crossing a simply supported bridge is modeled as a constant point force. A set of critical velocities are determined associated with peaks of dynamic amplification for all beams. The reasons for these large amplifications are discussed. A more complex finite element model, validated with field tests, is used to test the applicability of the conclusions obtained from the simple models to a realistic bridge/vehicle system. 相似文献
23.
Gel chromatography in columns with Sephadex G-50 and biogel P-2 was used to separate a number of fractions formed in k-casein of cow's milk after short-term treatment with swine trypsin. These fractions, similar to beta-casomorphin, are capable of reducing the respiration and heart rates in rabbits after intravenous injection in a dose of 100 micrograms/kg, that suggests their capacity for interaction with opiate receptors. Some fractions injected subcutaneously induce in starving animals an electroencephalographic picture of satiation, similar to that observed after cholecystokinin injections. Correlation of amino acid composition and physiologic activity has evidenced that cholecystokinin and opioid effects are caused by different peptides. 相似文献
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The products of restricted proteolysis of kappa-casein were separated by gel filtration. Intravenous injection of high- and low-molecular fractions substantially reduced the pentagastrin-stimulated acid secretion in the anesthetized rat stomach. Intermediate fractions had lesser physiological activity. One of the active fractions administered intraintestinally inhibited acid secretion and reduced the pentagastrin-stimulated secretion in rat weanling isolated stomach. All the active fractions inhibited the stimulated secretion in rats with a ligated vagus. It is concluded that the nervous system does not play a crucial role in the mechanism by which gastric acid secretion is inhibited by the products of restricted proteolysis of kappa-casein. Decreasing acid secretion in the stomach, glycopeptide provides for the conditions favouring the efficacy of protein utilization at an early age. It is suggested that the effect of glycopeptide obtained from kappa-casein on the process of assimilation is mediated via peptide hormones. 相似文献
26.
A. Afshar Ebrahimi H. Ale Ebrahim E. Jamshidi 《Computers & Chemical Engineering》2008,32(8):1746-1759
In this work the solution of the coupled partial differential equations for noncatalytic gas–solid reactions has been considered by orthogonal collocation. First of all, by an integral transformation and then by applying the orthogonal collocation method, these partial differential equations are converted to the ordinary differential equations. Then the equations are solved and the conversion–time profiles are obtained. The solution of the equations for volume reaction model, grain model and grain model with product layer resistance, modified grain model, random pore model, nucleation model and reaction of two gas with one solid has been presented in this work. The orthogonal collocation is a rapid method for solving of these equations and shows a good accuracy with respect to other solution techniques in the literature. 相似文献
27.
Insect cuticular hydrocarbons (CHCs) were probed by matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry with a lithium 2,5-dihydroxybenzoate matrix. CHC profiles were obtained for 12 species of diverse insect taxa (termites, ants, a cockroach, and a flesh fly). MALDI spectra revealed the presence of high molecular weight CHCs on the insect cuticle. Hydrocarbons with more than 70 carbon atoms, both saturated and unsaturated, were detected. When compared with gas chromatography/mass spectrometry (GC/MS), MALDI-TOF covered a wider range of CHCs and enabled CHCs of considerably higher molecular weight to be detected. Good congruity between GC/MS and MALDI-TOF was observed in the overlapping region of molecular weights. Moreover, a number of previously undiscovered hydrocarbons were detected in the high mass range beyond the analytical capabilities of current GC/MS instruments. MALDI was shown to hold potential to become an alternative analytical method for insect CHC analyses. The ability of MALDI to discriminate among species varying in the degree of their relatedness was found to be similar to GC/MS. However, neither MALDI-MS nor GC/MS data were able to describe the phylogenetic relationships. 相似文献
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The hypothetical impact structure in the Saginaw Bay (Michigan, USA, Lake Huron) has been tested by the gravity data derived from the recent gravity field model EIGEN 6C4 (expanded to degree and order 2190, with ground resolution of ~9?km). The following gravity field aspects were used: the gravity disturbances/anomalies, second derivatives of the disturbing potential (Marussi tensor), two of three gravity invariants, their specific ratio (known as 2D factor), the strike angles, and the virtual deformations. These gravity aspects are sensitive in various ways to the underground density contrasts. For the Saginaw Bay area, we confirm that we do not see any typical impact crater in terms of gravity disturbance or the radial second order derivative, possibly because of the thick layer of the ice located at the place and time of the impact. But the “combed” strike angles (one type of the gravity aspects we use) disclose a trace of high pressure to the SE/S/SW of the Bay and may be due to an impacting body. Thus, we provide circumstantial evidence of the Younger Dryas impact hypothesis. 相似文献
30.
Ale??Popovi?Email authorView authors OrcID profile Ray?Hackney Rana?Tassabehji Mauro?Castelli 《Information Systems Frontiers》2018,20(2):209-222
Big Data Analytics (BDA) is an emerging phenomenon with the reported potential to transform how firms manage and enhance high value businesses performance. The purpose of our study is to investigate the impact of BDA on operations management in the manufacturing sector, which is an acknowledged infrequently researched context. Using an interpretive qualitative approach, this empirical study leverages a comparative case study of three manufacturing companies with varying levels of BDA usage (experimental, moderate and heavy). The information technology (IT) business value literature and a resource based view informed the development of our research propositions and the conceptual framework that illuminated the relationships between BDA capability and organizational readiness and design. Our findings indicate that BDA capability (in terms of data sourcing, access, integration, and delivery, analytical capabilities, and people’s expertise) along with organizational readiness and design factors (such as BDA strategy, top management support, financial resources, and employee engagement) facilitated better utilization of BDA in manufacturing decision making, and thus enhanced high value business performance. Our results also highlight important managerial implications related to the impact of BDA on empowerment of employees, and how BDA can be integrated into organizations to augment rather than replace management capabilities. Our research will be of benefit to academics and practitioners in further aiding our understanding of BDA utilization in transforming operations and production management. It adds to the body of limited empirically based knowledge by highlighting the real business value resulting from applying BDA in manufacturing firms and thus encouraging beneficial economic societal changes. 相似文献