2,022 research outputs found
Light-front model of the kaon electromagnetic current
The electromagnetic form factor is extracted from both components of the
electromagnetic current: J(plus) and J(minus) with a pseudo-scalar coupling of
the quarks to the kaon.
In the case of J(plus) there is no pair term contribution in the Drell-Yan
frame. However, J(minus) component of the electromagnetic current the pair term
contribution is different from zero and is necessary include it to preserve the
rotational symmetry of the current.Comment: 4 pages, 1 figure, uses World Scientific style file. To be published
by World Scientific in the proceedings of the "VIII International Workshop on
Hadron Physics,(HADRONS 2002)", Bento Goncalves, RS, Brazi
Bethe-Salpeter bound-state structure in Minkowski space
The quantitative investigation of the scalar Bethe-Salpeter equation in
Minkowski space, within the ladder-approximation framework, is extended to
include the excited states. This study has been carried out for an interacting
system composed by two massive bosons exchanging a massive scalar, by adopting
(i) the Nakanishi integral representation of the Bethe-Salpeter amplitude, and
(ii) the formally exact projection onto the null plane. Our analysis, on one
hand, confirms the reliability of the method already applied to the ground
state and, on the other one, extends the investigation from the valence
distribution in momentum space to the corresponding quantity in the
impact-parameter space, pointing out some relevant features, like (i) the
equivalence between Minkowski and Euclidean transverse-momentum amplitudes, and
(ii) the leading exponential fall-off of the valence wave function in the
impact-parameter space.Comment: 15 pages, 7 figure
Building lighting energy consumption modelling with hybrid neural-statistic approaches
"In the proposed work we aim at modelling building lighting energy consumption. We compared several classical methods to the latest Artificial Intelligence. modelling technique: Artificial Neural Networks Ensembling (ANNE). Therefore, in this study we show how we built the ANNE and a new hybrid model based on the. statistical-ANNE combination. Experimentation has been carried out over a three. months data set coming from a real office building located in the ENEA âCasacciaâ. Research Centre. Experimental results show that the proposed hybrid statistical-ANNE approach can get a remarkable improvement with respect to the best classical method(the statistical one).
An inter model distance for clustering utility function
Conjoint Analysis is one of the most widely used techniques in the assessment of the consumerâs behaviors. This method allows to estimate the partial utility coefficients according to a statistical model linking the overall note of preference with the attribute
levels describing the stimuli. Conjoint analysis results are useful in new-product positioning and market segmentation. In this paper a cluster-based segmentation strategy based on a new metric has been proposed. The introduced distance is based on a convex linear combination of two Euclidean distances em bedding information both on the estimated parameters and on the model fitting. Market segments can be then defined according to the
proximity of the part-worth coecients and to the explicative power of the estimated models
A sub-analysis of the SAGE study in Italy indicates good glycemic control in type 1 diabetes
Background and aims: Intensive glycemic control minimizes the risk of micro- and macrovascular complications in patients with type 1 diabetes (T1D). We report glycemic control in Italian participants (age groups: 26-44, 45-64, and â„65 years) of the global SAGE study. Methods and results: The primary endpoint was proportion of participants who achieved an HbA1c <7% in predefined age groups. In the 523 patients with T1D, mean age was 44.6 years and mean body mass index (BMI) was 25 kg/m2. Mean HbA1c was 7.5% and 29.4% had HbA1c <7.0%, with the highest percentage in those 26-45 years (31.7%) and the lowest in those â„65 years (20%). Altogether, 22.9% of patients achieved their physician-established individualized HbA1c target. Most patients had â„1 symptomatic hypoglycemic episode in the previous 3 months (â€70 mg/dL 82.5%; â€54 mg/dL 61%). Severe hypo- and hyperglycemia were experienced by 16.3% and 12% of patients, of which 7.1 and 9.5%, respectively, required hospitalization/emergency visits. More patients achieved HbA1c <7% with CSII (30%) than with multiple daily insulin injections (27.9%). In multivariate analysis, BMI (OR 0.94, 95% CI 0.89-0.99, p = 0.032) and adherence to diet (OR 0.36, 95% CI 0.18-0.70, p = 0.0028) were significantly associated with HbA1c <7.0%. Conclusions: Glycemic control can be considered good in the Italian SAGE cohort, especially in younger patients, who more frequently use pumps/continuous glucose monitoring. Greater patient education and use of technology may further support this achievement. Patients should be encouraged to maintain a low BMI and adhere to their diet
Seismic retrofit of an existing reinforced concrete building with buckling-restrained braces
Background: The seismic retrofitting of frame structures using hysteretic dampers is a very effective strategy to mitigate earthquake-induced risks. However, its application in current practice is rather limited since simple and efficient design methods are still lacking, and the more accurate time-history analysis is time-consuming and computationally demanding. Aims: This paper develops and applies a seismic retrofit design method to a complex real case study: An eight-story reinforced concrete residential building equipped with buckling-restrained braces. Methods: The design method permits the peak seismic response to be predicted, as well as the dampers to be added in the structure to obtain a uniform distribution of the ductility demand. For that purpose, a pushover analysis with the first mode load pattern is carried out. The corresponding story pushover curves are first idealized using a degrading trilinear model and then used to define the SDOF (Single Degree-of-Freedom) system equivalent to the RC frame. The SDOF system, equivalent to the damped braces, is designed to meet performance criteria based on a target drift angle. An optimal damper distribution rule is used to distribute the damped braces along the elevation to maximize the use of all dampers and obtain a uniform distribution of the ductility demand. Results: The effectiveness of the seismic retrofit is finally demonstrated by non-linear time-history analysis using a set of earthquake ground motions with various hazard levels. Conclusion: The results proved the design procedure is feasible and effective since it achieves the performance objectives of damage control in structural members and uniform ductility demand in dampers
The ethics of people analytics: risks, opportunities and recommendations
Purpose: This research analyzed the existing academic and grey literature concerning the technologies and practices of people analytics (PA), to understand how ethical considerations are being discussed by researchers, industry experts and practitioners, and to identify gaps, priorities and recommendations for ethical practice. Design/methodology/approach: An iterative âscoping reviewâ method was used to capture and synthesize relevant academic and grey literature. This is suited to emerging areas of innovation where formal research lags behind evidence from professional or technical sources. Findings: Although the grey literature contains a growing stream of publications aimed at helping PA practitioners to âbe ethical,â overall, research on ethical issues in PA is still at an early stage. Optimistic and technocentric perspectives dominate the PA discourse, although key themes seen in the wider literature on digital/data ethics are also evident. Risks and recommendations for PA projects concerned transparency and diverse stakeholder inclusion, respecting privacy rights, fair and proportionate use of data, fostering a systemic culture of ethical practice, delivering benefits for employees, including ethical outcomes in business models, ensuring legal compliance and using ethical charters. Research limitations/implications: This research adds to current debates over the future of work and employment in a digitized, algorithm-driven society. Practical implications: The research provides an accessible summary of the risks, opportunities, trade-offs and regulatory issues for PA, as well as a framework for integrating ethical strategies and practices. Originality/value: By using a scoping methodology to surface and analyze diverse literatures, this study fills a gap in existing knowledge on ethical aspects of PA. The findings can inform future academic research, organizations using or considering PA products, professional associations developing relevant guidelines and policymakers adapting regulations. It is also timely, given the increase in digital monitoring of employees working from home during the Covid-19 pandemic
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