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461.
Cost estimation of software projects is an important activity that continues to be a source of problems for practitioners despite improvement efforts. Most of the research on estimation has focused on methodological issues while the research focused on human factors primarily has targeted cognitive biases or perceived inhibitors. This paper focuses on the complex organizational context of estimation and investigates whether estimates may be distorted, i.e. intentionally changed for reasons beyond legitimate changes due to changing prerequisites such as requirements or scope. An exploratory study was conducted with 15 interviewees at six large companies that develop software-intensive products. The interviewees represent five stakeholder roles in estimation, with a majority being project or line managers. Document analysis was used to complement the interviews and provided additional context. The results show that both estimate increase and estimate decrease exist and that some of these changes can be explained as intentional distortions. The direction of the distortion depends on the context and the stakeholders involved. The paper underlines that it is critical to consider also human and organizational factors when addressing estimation problems and that intentional estimate distortions should be given more and direct attention. 相似文献
462.
Combarro Elías F. Vallecorsa Sofia Rodríguez-Muñiz Luis J. Aguilar-González Álvaro Ranilla José Di Meglio Alberto 《The Journal of supercomputing》2021,77(12):14436-14437
The Journal of Supercomputing - A correction to this paper has been published: https://doi.org/10.1007/s11227-021-03923-0 相似文献
463.
Dietary Fatty Acid Metabolism is Affected More by Lipid Level than Source in Senegalese Sole Juveniles: Interactions for Optimal Dietary Formulation 下载免费PDF全文
Kruno Bonacic Alicia Estévez Olga Bellot Marta Conde-Sieira Enric Gisbert Sofia Morais 《Lipids》2016,51(1):105-122
This study analyses the effects of dietary lipid level and source on lipid absorption and metabolism in Senegalese sole (Solea senegalensis). Juvenile fish were fed 4 experimental diets containing either 100 % fish oil (FO) or 25 % FO and 75 % vegetable oil (VO; rapeseed, linseed and soybean oils) at two lipid levels (~8 or ~18 %). Effects were assessed on fish performance, body proximate composition and lipid accumulation, activity of hepatic lipogenic and fatty acid oxidative enzymes and, finally, on the expression of genes related to lipid metabolism in liver and intestine, and to intestinal absorption, both pre‐ and postprandially. Increased dietary lipid level had no major effects on growth and feeding performance (FCR), although fish fed FO had marginally better growth. Nevertheless, diets induced significant changes in lipid accumulation and metabolism. Hepatic lipid deposits were higher in fish fed VO, associated to increased hepatic ATP citrate lyase activity and up‐regulated carnitine palmitoyltransferase 1 (cpt1) mRNA levels post‐prandially. However, lipid level had a larger effect on gene expression of metabolic (lipogenesis and β‐oxidation) genes than lipid source, mostly at fasting. High dietary lipid level down‐regulated fatty acid synthase expression in liver and intestine, and increased cpt1 mRNA in liver. Large lipid accumulations were observed in the enterocytes of fish fed high lipid diets. This was possibly a result of a poor capacity to adapt to high dietary lipid level, as most genes involved in intestinal absorption were not regulated in response to the diet. 相似文献
464.
Liliana Serrano Ana Cruz Sofia Sousa Zilda Morais 《European Food Research and Technology》2016,242(7):1041-1055
Though olive oil is a perishable product, there is not a European regulation for maximum consumption time after production, in part because its durability depends on the storage conditions. The main objectives of this study were to compare the influence of the type of storage on changes of Portuguese virgin olive oils and to verify whether the addition of Catostylus tagi could increase the oxidative stability of olive oil. Over 12 months, the conservation status of monovarietal and blended olive oils in four contexts possible to be used by the consumer was monitored. The analyzed parameters were chlorophyll content, free acidity, peroxide value, specific extinction coefficients at 232 and 270 nm and delta K. Spaced determinations of iodine index and total tocopherol contents complemented the study. Results showed that at Mediterranean temperatures and normal storage procedure, the mean time to reach maximum peroxides value was 12–13 months. At artificial light storage, C. tagi was effective in reducing peroxides evolution by 11 %. 相似文献
465.
Pierre Ineichen Carla Sofia Barroso Bernhard Geiger Rainer Hollmann Anne Marsouin Richard Mueller 《International journal of remote sensing》2013,34(21):5549-5571
Downward short- and longwave incoming irradiances play a key role in the radiation budget at the Earth's surface. Monitoring these parameters is essential for understanding the basic mechanisms involved in climate change, such as the greenhouse effect, global dimming, and changes in cloud cover and precipitation. Geostationary satellite observations are important in the retrieval of irradiance at the surface, providing excellent spatial and temporal coverage. Three decentralized Satellite Application Facilities (SAFs) are currently operational in the European Organisation for the Exploitation of Meteorological Satellites (Eumetsat), involved in retrieving surface solar irradiance (SSI) and downward longwave irradiance (DLI) from Meteosat images. This study presents a common validation of these radiation products against ground data from eight stations covering four months representative of the annual declination variation. The overall conclusion is that the products of the different SAFs are comparable in terms of bias and standard deviation. The SSI is retrieved with a standard deviation of 80–100 W m?2 and negligible bias, and the DLI with a standard deviation of 25 W m?2 with a slight site-dependent bias. 相似文献
466.
Melanie Häusler João M. N. Silva Sofia Cerasoli Gerardo López-Saldaña José M. C. Pereira 《International journal of remote sensing》2016,37(3):492-515
This study analyses the influence of vegetation structure (i.e. leaf area index and canopy cover) and seasonal background changes on moderate-resolution imaging spectrometer (MODIS)-simulated reflectance data in open woodland. Approximately monthly spectral reflectance and transmittance field measurements (May 2011 to October 2013) of cork oak tree leaves (Quercus suber) and of the herbaceous understorey were recorded in the region of Ribatejo, Portugal. The geometric-optical and radiative transfer (GORT) model was used to simulate MODIS response (red, near-infrared) and to calculate vegetation indices, investigating their response to changes in the structure of the overstorey vegetation and to seasonal changes in the understorey using scenarios corresponding to contrasting phenological status (dry season vs. wet season). The performance of normalized difference vegetation index (NDVI), soil-adjusted vegetation index (SAVI), and enhanced vegetation index (EVI) is discussed. Results showed that SAVI and EVI were very sensitive to the emergence of background vegetation in the wet season compared to NDVI and that shading effects lead to an opposing trend in the vegetation indices. The information provided by this research can be useful to improve our understanding of the temporal dynamic of vegetation, monitored by vegetation indices. 相似文献
467.
Sofia M. Morozova Tatiana G. Statsenko Egor O. Ryabchenko Albert Gevorkian Vahid Adibnia Maksim S. Lozhkin Alexey V. Kireynov Eugenia Kumacheva 《Advanced functional materials》2021,31(52):2105470
Nanocolloidal gels are emerging as a promising class of materials with applications as inks in 2D and 3D printing. Polymer nanoparticles (NPs) offer many advantages as potential building blocks of nanocolloidal gels, due to the ability to control NP dimensions, charge, surface chemistry, and functionality; however, their applications as inks in printing are yet to be explored. Here, functional nanocolloidal hydrogels formed by percolating oppositely charged latex NPs with different dimensions and charge densities are reported. The shear-thinning and self-healing properties of the nanocolloidal gels and the mechanical properties of the resulting printed films are examined. NP functionality is achieved by covalently labeling them with different fluorescent dyes that emit at two distinct wavelengths. Using these NPs, a facile route for 3D printing of multicolored fluorescence patterns is shown, with each color being visualized under a specific, well-defined excitation wavelength. 相似文献
468.
469.
Diniz C Leal S Logan K Rocha-Pereira C Soares AS Rocha E Gonçalves J Fresco P 《Microscopy research and technique》2007,70(8):677-681
Angiotensin II plays a crucial role in the control of blood pressure, acting at AT1 or AT2 receptors, and can act as a potent vasoconstrictor of the peripheral vasculature inducing hypertrophy, hyperplasia, or both, in resistance arteries. The aim of the present study was to investigate whether the pattern of distribution of angiotensin AT1 and AT2 receptors on mesenteric artery sections differs in spontaneously hypertensive rats (SHR) versus their respective controls (Wistar-Kyoto [WKY] rats). Immunohistochemistry using anti-AT1 or anti-AT2 antibodies was performed on perfused-fixed/paraffin-embedded mesenteric arteries from SHR and WKY rats. 3,3'-Diaminobenzidine tetrahydrochloride (DAB; activated by hydrogen peroxide) staining revealed distinct AT1 and AT2 labeling of all artery layers (adventitia, media and intima) from WKY rats, whereas in SHR an abundant AT1 labeling was found in both intima and adventitia and a sparser labeling in the media. There was a vast reduction of AT2 labeling throughout all layers. These results suggest a crucial role for AT2 receptors in the pathogenesis of hypertension. 相似文献
470.
The main objective of the present study was to examine the influence of culture (Sweden vs. Japan) and environmental attitude (urban vs. open-air person) on participants’ thermal, emotional and perceptual assessments of a park, within the physiological equivalent temperature (PET) comfortable interval of 18–23 °C. It was predicted that persons sharing different cultures and environmental attitudes might psychologically differently evaluate a Swedish and a Japanese park despite similar thermal conditions. Consistent with this prediction, Japanese were shown to evaluate the weather as warmer and less good for out-door activity than did Swedes, although and according to the PET index participants in both cultures experienced similar comfortable thermal conditions. Japanese were also shown to evaluate the park as more pleasant and warmer place than did Swedes. However, the Japanese felt emotionally less pleasant at the site than did Swedes. An interaction between culture and environmental attitude indicated tentatively a difference in environmental attitude (urban vs. open-air person) between the two countries as regards the place-related wind sensitivity. All these findings are discussed in terms of culture and environmental attitude suggesting that thermal, emotional and perceptual assessments of a physical place may be intertwined with psychological and cultural processes, rather than fixed by general thermal indices developed in line with the physiological heat balance models. 相似文献