262 research outputs found
Hybrid Software Development Approaches in Practice: A European Perspective
Agile and traditional development approaches are used in combination in todays software development. To improve the understanding and to provide better guidance for selecting appropriate development approaches, it is important to analyze such combinations in practice. Results obtained from an online survey strongly confirm that hybrid development approaches are widely used in industry. Our results show that hybrid development approaches: (i) have become reality for nearly all companies; (ii) are applied to specific projects even in the presence of company-wide policies for process usage; (iii) are neither planned nor designed but emerge from the evolution of different work practices; and, (iv) are consistently used regardless of company size or industry secto
Experimental growth law for bubbles in a "wet" 3D liquid foam
We used X-ray tomography to characterize the geometry of all bubbles in a
liquid foam of average liquid fraction and to follow their
evolution, measuring the normalized growth rate
for 7000 bubbles. While
does not depend only on the number of faces of a bubble, its average over
faced bubbles scales as for large s at all times. We
discuss the dispersion of and the influence of on
.Comment: 10 pages, submitted to PR
Computer-Assisted Proofs of Some Identities for Bessel Functions of Fractional Order
We employ computer algebra algorithms to prove a collection of identities
involving Bessel functions with half-integer orders and other special
functions. These identities appear in the famous Handbook of Mathematical
Functions, as well as in its successor, the DLMF, but their proofs were lost.
We use generating functions and symbolic summation techniques to produce new
proofs for them.Comment: Final version, some typos were corrected. 21 pages, uses svmult.cl
Catching up with Method and Process Practice: An Industry-Informed Baseline for Researchers
Software development methods are usually not applied by the book.companies are under pressure to continuously deploy software products that meet market needs and stakeholders\u27 requests. To implement efficient and effective development processes, companies utilize multiple frameworks, methods and practices, and combine these into hybrid methods. A common combination contains a rich management framework to organize and steer projects complemented with a number of smaller practices providing the development teams with tools to complete their tasks. In this paper, based on 732 data points collected through an international survey, we study the software development process use in practice. Our results show that 76.8% of the companies implement hybrid methods.company size as well as the strategy in devising and evolving hybrid methods affect the suitability of the chosen process to reach company or project goals. Our findings show that companies that combine planned improvement programs with process evolution can increase their process\u27 suitability by up to 5%
Non-smooth optimization methods for computation of the conditional value-at-risk and portfolio optimization
We examine numerical performance of various methods of calculation of the Conditional Value-at-risk (CVaR), and portfolio optimization with respect to this risk measure. We concentrate on the method proposed by Rockafellar and Uryasev in (Rockafellar, R.T. and Uryasev, S., 2000, Optimization of conditional value-at-risk. Journal of Risk, 2, 21-41), which converts this problem to that of convex optimization. We compare the use of linear programming techniques against a non-smooth optimization method of the discrete gradient, and establish the supremacy of the latter. We show that non-smooth optimization can be used efficiently for large portfolio optimization, and also examine parallel execution of this method on computer clusters.<br /
Quasisymmetric graphs and Zygmund functions
A quasisymmetric graph is a curve whose projection onto a line is a
quasisymmetric map. We show that this class of curves is related to solutions
of the reduced Beltrami equation and to a generalization of the Zygmund class
. This relation makes it possible to use the tools of harmonic
analysis to construct nontrivial examples of quasisymmetric graphs and of
quasiconformal maps.Comment: 21 pages, no figure
Distress, depression and coping in HLA-B27-associated anterior uveitis with focus on gender differences
Background/aims To evaluate depression, coping with
disease and stress, and the subjective impression of
distress and/or life events as triggers for recurrences in
HLA-B27-associated anterior uveitis (B27-AU), with
attention to gender-specific characteristics.
Methods 171 patients with a history of B27-AU
responded to a postal survey performed between
January 2006 and April 2008 using standardised
psychological questionnaires: Beck Depression Inventory,
Freiburg Questionnaire on Coping with Illness, and Stress
Coping Inventory.
Results Patients with B27-AU differed from healthy
controls showing more depressive symptoms (Beck
Depression Inventory, 31.6%), applying characteristic
disease coping as well as negative stress coping
strategies. Female B27-AU patients tended to react with
depression and male patients to use negative stress
coping strategies. 57.9% of patients believed that
psychological distress was a trigger for relapses, and
34.5% stated specific life events. Together, this group of
patients achieved higher depression scores and used
more negative disease and stress coping styles than
patients without perception of distress.
Conclusion Patients with B27-AU patients exhibited
significant psychopathology concerning depression and
disease coping. Distress and life events were
subjectively suspected to be a trigger. By imparting
knowledge to the patients on probable development of
depressive moods and the role of stress/life events as
trigger for relapses, as well as offering behaviour therapy
to optimise coping, may help patients to cope better
with B27-AU
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