Search results for "Variability"
showing 10 items of 904 documents
ISO Initiatives on Software Product Line Engineering: Vision and Current Status Invited Talk for Variability@ER2011
2011
Software product line engineering and management is still a relatively young discipline and its industrial diffusion is somewhat limited, partly due to the lack of international standards. It involves sub-disciplines that may not necessarily be mature enough yet for standardization. On the other hand, well-focused standardization efforts contribute to the diffusion of best product line practices and help raise the maturity of these practices. Careful roadmapping and execution of the standardization initiative is thus vital. This talk discusses the current roadmap for the international standardization initiative of software product line engineering and management methods and tools and the st…
An ecological dynamics framework for the acquisition of perceptual-motor skills in climbing
2016
Uncertainty in extreme sports performance environments, like rock and ice climbing, provides considerable psycho-emotional and physiological demands which challenge the acquisition of perceptual-motor skills. An ecological dynamics theoretical framework adopts concepts and tools of nonlinear dynamics and ecological psychology to investigate and model the relationships that emerge in extreme sports between athletes and their performance environments. In this relation, the interactions of athletes with key objects, surfaces, events and significant others during a sport like climbing emerge from interdependent personal, task and environmental constraints on performance. Performance behaviours …
A Mixed Approach for Determination of Initial Cable Forces in Cable-Stayed Bridges and the Parameters Variability
2015
The determination of initial cable forces in cable-stayed bridges is an important first step in design and analysis of the structure under external loads. Adjustments of stay forces are often required during construction in order to assure the requested behaviour of the bridge in terms of final geometrical configuration and internal force distribution. An accurate assessment of the stay tensioning system allows designers to obtain a good result at the end of construction, by considering the parameters involved as deterministic quantities, assuring the observance of the execution tolerances during works. Actual loads and their variations need instead a stochastic approach which can give usef…
Influence of material properties variability on springback and thinning in sheet stamping processes: a stochastic analysis
2010
A very critical issue for stamping operations is the improvement of process robustness. The reliability of final results, in fact, strongly depends on the intrinsic variability due to stochastic behavior of many parameters, namely, operative ones and material properties. A given process performance may undergo a variation around the value which would be obtained neglecting stochastic behaviors of the operative or material parameters (i.e., considering a deterministic parameters behavior). Such variation introduces a significant source of uncertainty within the process design: a possible consequence may be the rejection of some stamped parts. In this paper, reliability analyses aimed to evid…
Pattern recognition in cyclic and discrete skills performance from inertial measurement units
2014
The aim of this study is to compare and validate an Inertial Measurement Unit (IMU) relative to an optic system, and to propose methods for pattern recognition to capture behavioural dynamics during sport performance. IMU validation was conducted by comparing the motions of the two arms of a compass, which was equipped with IMUs and reflective landmarks detected by a multi-camera system. Spearman’s rank correlation tests showed good correlations between the IMU and multi-camera system, especially when the angles were normalized. Bland-Altman plot, root mean square and the normalized pairwise variability index showed low differences between the two systems, confirming the good accuracy level…
Benchmarking energy efficiency of water treatment plants: Effects of data variability
2019
This study evaluates, for the first time, the energy efficiency of a sample of drinking water treatment plants (DWTPs) using the data envelopment analysis (DEA) tolerance method, which is based on the simulation of scenarios to integrate data variations. The integration of data uncertainty in energy efficiency estimation changes drastically results for approximately one-third of the DWTPs evaluated. The results showed that, even in the best-case scenario, most of the DWTPs evaluated are inefficient and may therefore, be able to reduce the energy used to treat raw water. From a policy perspective, the findings of this study reveal that omitting data variability in benchmarking would involve …
Geostatistical Microscale Study of Magnetic Susceptibility in Soil Profile and Magnetic Indicators of Potential Soil Pollution
2015
Directional variograms, along the soil profile, can be useful and precise tool that can be used to increase the precision of the assessment of soil pollution. The detail analysis of spatial variability in the soil profile can be also an important part of the standardization of soil magnetometry as a screening method for an assessment of soil pollution related to the dust deposition. The goal of this study was to investigate the correlation between basic parameters of spatial correlations of magnetic susceptibility in the soil profile, such as a range of correlation and a sill, and selected magnetometric indicators of soil pollution. Magnetic indicators were an area under the curve of magnet…
Integrated satellite data fusion and mining for monitoring lake water quality status of the Albufera de Valencia in Spain
2015
Abstract Lake eutrophication is a critical issue in the interplay of water supply, environmental management, and ecosystem conservation. Integrated sensing, monitoring, and modeling for a holistic lake water quality assessment with respect to multiple constituents is in acute need. The aim of this paper is to develop an integrated algorithm for data fusion and mining of satellite remote sensing images to generate daily estimates of some water quality parameters of interest, such as chlorophyll a concentrations and water transparency, to be applied for the assessment of the hypertrophic Albufera de Valencia. The Albufera de Valencia is the largest freshwater lake in Spain, which can often pr…
Selection of biological and chemical parameters indicating or affecting the vitality of Norway spruce
1991
Abstract Thirty-two young and old Norway spruce trees ( Picea abies (L.) Karst.) showing different degrees of damage were investigated in a forest stand in the Taunus Mountains (FRG). The old trees showed visual symptoms of damage such as discolouration of the needles and needle loss. Over 70 biometric, physiological and chemical parameters were determined for needle and soil samples. Interrelationships between these variables were described by correlation analysis. The most discriminant variables between different groups of trees were found by Fisher weighing. This reduced data set was used for principal component analysis and for the classification of various parameters according to diffe…
Variation in spawning time promotes genetic variability in population responses to environmental change in a marine fish.
2015
Common-garden experiments suggest that the response of Atlantic cod larvae to temperature differs among populations that spawn at different times of year. Populations appear to be adapted to the temperatures experienced during the larval stage at a small spatial scale, despite a lack of physical barriers to gene flow.