1,109 research outputs found
Composition and Self-Adaptation of Service-Based Systems with Feature Models
The adoption of mechanisms for reusing software in pervasive systems has not yet become standard practice. This is because the use of pre-existing software requires the selection, composition and adaptation of prefabricated software parts, as well as the management of some complex problems such as guaranteeing high levels of efficiency and safety in critical domains. In addition to the wide variety of services, pervasive systems are composed of many networked heterogeneous devices with embedded software. In this work, we promote the safe reuse of services in service-based systems using two complementary technologies, Service-Oriented Architecture and Software Product Lines. In order to do this, we extend both the service discovery and composition processes defined in the DAMASCo framework, which currently does not deal with the service variability that constitutes pervasive systems. We use feature models to represent the variability and to self-adapt the services during the composition in a safe way taking context changes into consideration. We illustrate our proposal with a case study related to the driving domain of an Intelligent Transportation System, handling the context information of the environment.Work partially supported by the projects TIN2008-05932,
TIN2008-01942, TIN2012-35669, TIN2012-34840 and CSD2007-0004 funded by
Spanish Ministry of Economy and Competitiveness and FEDER; P09-TIC-05231 and
P11-TIC-7659 funded by Andalusian Government; and FP7-317731 funded by EU. Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tec
Internal brand co-creation: the experiential brand meaning cycle in higher education
Higher education (HE) institutions need to adapt to the global environment but the complex nature of HE highlights the role of marketing and the internal market in realizing the brand identity, creating a challenge for developing a shared brand meaning. This research explores how employees co-create brand meaning through their brand experiences and social interactions with management, colleagues and customers. Using a phenomenological approach, the findings highlight that brand meaning commences from historical, superficial brand interactions. Employees then develop brand meaning further through a series of brand interactions and social interactions. Bridging the internal branding and the co-creation literature, this study conceptualizes the evolving, co-created nature of employees' brand meaning in the experiential brand meaning cycle. This study extends Iglesias and Bonet's (2012) work and illustrates the function of employees as readers and authors of brand meaning, emphasizing the crucial role of brand co-creation in guiding employees' brand promise delivery
NMR microscopy of tissue in organic and mixed solvents
We propose to use organic and mixed solvents for nuclear magnetic resonance
microscopy of fixed tissue as a means for improving image information
content. NMR properties of some standard solvents (methanol, acetone, DMSO)
and solvents in use for tissue processing in pathology (xylenes, paraffin,
‘Clearify’) have been measured, reviewed, and analyzed. It was found that
DMSO and paraffin are very useful solvents that provide images of better
quality than those obtained in water (neutralized formalin buffer). This is
illustrated on the formalin fixed mouse brain sections imaged at 16.4 teslas
(700 MHz)
Forage Preferences of the European Beaver Castor fiber
By the beginning of the twentieth century, hunting and land use change had reduced the European beaver Castor fiber to a relict population of no more than 1200
individuals. In some European states, re introduction has successfully established viable populations, whilst other schemes have failed. Environmental, social and
economic issues associated with beaver reintroduction
have given rise to a range of information needs in relation to the species«SQ» ecology. In 2005, six European beavers were translocated from Bavaria to a reintroduction site in southern England. The following year, a 6 month study was undertaken to investigate which tree species and size classes were most frequently utilised by the beavers, and to determine if the utilised species and size classes reflected resource availability within the home range. These questions were answered by comparing the use and the availability of foraged tree species in two ways: (1) using a survey of tree stumps; and (2) as a food choice experiment. The results showed that the reintroduced beavers were highly selective in relation to both the species and the size of the trees they used i.e. the reintroduced beavers selected species in significantly different proportions to their availability. However, they selected similar size classes between the preferred tree species, and did not utilise human timber. The relevance of the study is discussed with respect to information needs associated with the reintroduction of a keystone species, overcoming negative perceptions, population viability, welfare and soft release strategies
Diffuse Ionized Gas in the Dwarf Irregular Galaxy DDO 53
The spectral characteristics throughout the dwarf irregular galaxy DDO 53 are
studied. The results are very similar to those for other irregular galaxies:
high excitation and low values of the [SII]/Halpha ratio. The most likely
ionization source is photon leakage from the classical HII regions, without any
other source, although the interstellar medium of the galaxy is quite
perturbed. Moreover, the physical conditions throughout the galaxy do not
change very much because both the photon leakage percentage and the ionization
temperature are very similar. In addition, the determined metal content for two
HII regions indicates that DDO 53 is a low-metallicity galaxy.Comment: 32 pages, 9 figures, 7 tables. AJ, in pres
Push-pull thiophene chromophores for electro-optic applications: from 1D linear to beta-branched structures
We report the synthesis and characterization of a novel series of push-pull chromophores bearing 1D linear and beta-branched thiophenes as pi-conjugated spacers between a 2, 2, 4, 7-tetramethyl-1, 2, 3, 4-tetrahydroquinoline electron donor unit and dicyano- and tricyanovinylene electron acceptor groups. The effect of the introduction of beta-thiophenes on the linear and nonlinear (NLO) optical properties as well as electrochemical and thermal data is studied in detail by performing a comparative study between the branched and 1D linear systems. In addition, a parallel DFT computational study is used to evaluate structure-property relationships. The non-linear optical behavior of the molecules both in solution and in solid state as electro-optic (EO) films using a guest-host approach shows very promising performance for electro-optic applications with high molecular first hyperpolarizabilities (mu beta) of 4840 x 10(-48) esu and electro-optic coefficients r(33) reaching 650 pm V-1. One highlight is that the electro-optic films of the beta-branched chromophores are superior in terms of thermal stability in device operation as measured by a transmissive modified reflective Teng-Man method. This work provides guidelines for the design of improved electro-optic materials including beta-branched chromophores which could be useful for practical EO applications, where both enhanced beta and r(33) values together with chemical and thermal stability are necessary
On Observability and Monitoring of Distributed Systems: An Industry Interview Study
Business success of companies heavily depends on the availability and
performance of their client applications. Due to modern development paradigms
such as DevOps and microservice architectural styles, applications are
decoupled into services with complex interactions and dependencies. Although
these paradigms enable individual development cycles with reduced delivery
times, they cause several challenges to manage the services in distributed
systems. One major challenge is to observe and monitor such distributed
systems. This paper provides a qualitative study to understand the challenges
and good practices in the field of observability and monitoring of distributed
systems. In 28 semi-structured interviews with software professionals we
discovered increasing complexity and dynamics in that field. Especially
observability becomes an essential prerequisite to ensure stable services and
further development of client applications. However, the participants mentioned
a discrepancy in the awareness regarding the importance of the topic, both from
the management as well as from the developer perspective. Besides technical
challenges, we identified a strong need for an organizational concept including
strategy, roles and responsibilities. Our results support practitioners in
developing and implementing systematic observability and monitoring for
distributed systems
Psychometric evaluation of the nine-item problematic Internet use questionnaire (PIUQ-9) in nine European samples of internet users
Objectives: The nine-item Problematic Internet Use Questionnaire (PIUQ-9) is a brief self-report screening instrument for problematic internet use. The main objective of the present study was to explore the psychometric properties of the PIUQ-9 among nine different language-based samples of European internet users (Italian, German, French, Polish, Turkish, Hungarian, English, and Greek). Methods: The total sample comprised 5,593 internet users (38.1% men), aged between 18 and 87 years (M = 25.81; SD = 8.61). Via online recruitment, participants completed the PIUQ-9, the Brief Symptom Inventory (BSI) and items about time spent online. Results: Confirmatory factor analysis demonstrated that the bifactor model with one general factor (i.e., general problem) and two-specific factors (i.e., obsession and neglect + control disorder) yielded acceptable or good fit indices in all subsamples except for one. The common variance index in the bifactor model indicated that the general problem factor explained from 57.0 to 76.5% of common variance, which supports the presence of a strong global factor. According to the multiple indicators multiple causes (MIMIC) model, psychiatric symptoms had a moderate-to-strong direct effect on the general problem factor in all subsamples, ranging from β = 0.28 to β = 0.52 supporting the construct validity of the scale. Furthermore, in a majority of the subsamples, time spent online during the weekend had considerably higher effect sizes on the general problem factor than time spent online during weekdays. Conclusion: The present study highlights the appropriate psychometric properties of the PIUQ-9 across a number of European languages and cultures
Galactic Evolution along the Hubble Sequence
A generalization of the multiphase chemical evolution model applied to a wide
set of theoretical galaxies is shown. This set of models has been computed by
using the so-called Universal Rotation Curve from Persic, Salucci & Steel to
calculate the radial mass distributions of each theoretical galaxy. By assuming
that the molecular cloud and star formation efficiencies depend on the
morphological type of each galaxy, we construct a bi-parametric grid of models
whose results are valid in principle for any spiral galaxy, of given maximum
rotation velocity or total mass, and morphological type.Comment: Proceedings of the Euroconference "The Evolution of Galaxies. III..."
(Kiel 2002
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