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581.
Zaccour (2008) analyses a marketing channel where firms invest in advertising to increase brand equity, showing that an exogenous two-part tariff cannot replicate the vertically integrated performance. I revisit the model proving that a multiplicity of efficient franchising contracts exists. I characterise an optimal two-part tariff specified as a linear function of the upstream firm’s advertising effort, performing this task both in the static and in the dynamic games. An analogous result emerges both in the static game, writing the fixed component of the two-part tariff as a non-linear function of the manufacturer’s advertising effort, and in the dynamic game, using a contract which is linear in the brand equity. 相似文献
582.
Luciano Baresi Elisabetta Di Nitto Carlo Ghezzi Sam Guinea 《Service Oriented Computing and Applications》2007,1(1):75-91
The basic paradigm of service-oriented architectures—publication, discovery, and use—can be interpreted in different ways.
Current technologies assume a static and rigid approach: UDDI was conceived with the idea of a centralized repository for
service publication and BPEL only supports design–time bindings between the orchestrated workflow and the external services.
The trend, however, is towards more flexibility and dynamism. The single centralized repository is being substituted by dedicated
repositories that cooperate and exchange information about stored services on demand. Design–time compositions are complemented
by mechanisms to allow for the selection and binding of services at runtime.
This paper presents the research results of our group in delivering a framework for the deployment of adaptable Web service
compositions. The publication infrastructure integrates existing heterogeneous repositories and makes them cooperate for service
discovery. The deployment infrastructure supports BPEL-like compositions that can select services dynamically, and also adjust
their behavior in response to detected changes and unforeseen events. The framework also provides a monitoring-based validation
of running compositions: we provide suitable probes to oversee the execution of deployed compositions. The various parts of
the framework are exemplified on a common case study taken from the automotive domain.
This research is partially supported by the European IST project SeCSE (Service Centric System Engineering) and the Italian FIRB project ARTDECO (Adaptive infRasTructures for DECentralized Organizations). 相似文献
583.
In real classification problems intrinsically vague information often coexist with conditions of “lack of specificity” originating from evidence not strong enough to induce knowledge, but only degrees of belief or credibility regarding class assignments. The problem has been addressed here by proposing a fuzzy Dempster–Shafer model (FDS) for multisource classification purposes. The salient aspect of the work is the definition of an empirical learning strategy for the automatic generation of fuzzy Dempster–Shafer classification rules from a set of exemplified training data. Dempster–Shafer measures of uncertainty are semantically related to conditions of ambiguity among the data and then automatically set during the learning process. Partial reduced beliefs in class assignments are then induced and explicitly represented when generating classification rules. The fuzzy deductive apparatus has been modified and extended to integrate the Dempster–Shafer propagation of evidence. The strategy has been applied to a standard classification problem in order to develop a sensitivity analysis in an easily controlled domain. A second experimental test has been conducted in the field of natural risk assessment, where vagueness and lack of specificity conditions are prevalent. These empirical tests show that classification benefits from the combination of the fuzzy and Dempster–Shafer models especially when conditions of lack of specifity among data are prevalent. ©1999 John Wiley & Sons, Inc. 相似文献
584.
Piek Vossen Laura Bloksma Antonietta Alonge Elisabetta Marinai Carol Peters Irene Castellon Antonia Marti German Rigau 《Computers and the Humanities》1998,32(2-3):153-184
This paper describes how the Euro WordNet project established a maximum level of consensus in the interpretation of relations, without loosing the possibility of encoding language-specific lexicalizations. Problematic cases arise due to the fact that each site re-used different resources and because the core vocabulary of the wordnets show complex properties. Many of these cases are discussed with respect to language internal and equivalence relations. Possible solutions are given in the form of additional criteria. 相似文献
585.
The transition from a planned economy to a market economy has caused considerable hardship for the people of Eastern Europe. One important aspect of the social costs of transition is access to, and the affordability of, basic services like electricity, heat and water, which under communism had been supplied fairly cheaply and abundantly. This paper provides evidence on this issue from the Ukraine Longitudinal Monitoring Survey (ULMS). The paper identifies considerable differences in both access and affordability between different localities in Ukraine. 相似文献
586.
Marco Faimali Elisabetta Chelossi Francesca Garaventa Christian Corrà Giuliano Greco Alfonso Mollica 《Electrochimica acta》2008,54(1):148-153
The aim of a series of works recently performed at ISMAR was to provide new useful information for a better understanding of the mechanisms by which bacteria settlement causes corrosion on Stainless Steels (SS) and similar active-passive alloys exposed to seawater. In this work, the evolutions of cathodic current, bacteria population, and electronic structure of the passive layer were investigated on SS samples polarised at fixed potentials during their exposure to natural seawater. It was found that, during the first phase of biofilm growth, cathodic current increase is proportional to the number of settled bacteria at each fixed potential. However, the proportionality factor between settled bacteria and cathodic current depends on imposed potential. In particular, the proportionality factor strongly decreases when the potential is increased above a critical value close to −150 mV Ag/AgCl. This effect seems to be correlated with the electronic structure of the passive layer. Indeed, the outer part of the passive layer on tested SS was found to behave like a conductor at potentials more active than −150 mV Ag/AgCl, and like an n-type semiconductor at more noble potentials. 相似文献
587.
588.
Development of a PCR Assay Targeting the rpoA Gene for the Screening of Vibrio Genus 总被引:1,自引:0,他引:1
Alessandra Dalmasso Fabio La Neve Elisabetta Suffredini Luciana Croci Laura Serracca Maria Teresa Bottero Tiziana Civera 《Food Analytical Methods》2009,2(4):317-324
A polymerase chain reaction (PCR) method based on the RNA polymerase alpha subunit (rpoA) gene was developed for the detection of the Vibrio genus. The specific primers were designed aligning the rpoA gene sequences available in GenBank of all Vibrio species. The specificity of the primers was tested against 35 Vibrio species. In addition, 12 species phylogenetically related to the Vibrio genus were used as negative control. Moreover, in order to eliminate any false-negative results, bacterium-specific primers
targeting the 16S rRNA gene were introduced in the test as a noncompetitive internal amplification control. The rpoA primers correctly amplified all the Vibrio species considered. No cross-reaction was observed when tested against closely related species. To estimate the applicability
of this method, 336 Vibrio wild-type strains isolated from Italian aquaculture products and from imported seafoods were tested. The sensitivity, tested
using serial dilutions of different pure cultures of certified strains, resulted to 103 colony-forming units per milliliter. The assay proved to be specific, rapid, and reliable. It can be proposed as a routine
screening technique for the confirmation of Vibrio genus in isolated colonies. 相似文献
589.
Amateur football game on artificial turf: Players’ perceptions 总被引:1,自引:0,他引:1
Elisabetta M. Zanetti 《Applied ergonomics》2009,40(3):485-490
The purpose of this study was to establish whether players’ perceptions in football competitions played on artificial turf can be influenced by the pitch under examination, the kind of infill material used, the weather conditions and by player's role in the team.A multifactorial statistical analysis was made of the results obtained from over 1600 U.E.F.A. questionnaires completed by amateur footballers.Pitch and weather factors were demonstrated to be relevant to the aspects investigated. Conversely, the players’ role and the infill material were significant for only a few aspects; for each variable, the analysis indicated the most favourable conditions. Overall, the analysis provided insight into amateur players’ favourable feelings about artificial turf, compared with its natural alternative (actually made of earth, without grass in the case of amateur players). 相似文献
590.
Luigi Angiolini Daniele Caretti Elisabetta Salatelli Laura Mazzocchetti Rudolph Willem Monique Biesemans 《Journal of Inorganic and Organometallic Polymers and Materials》2008,18(2):236-245
A novel trialkyltin carboxylate monomer, tributyltin 4-(p-styryl)-butanoate, characterized by the presence of a trimethylenic spacer linking the tin carboxylate moiety to the aromatic
group, has been prepared and submitted to radical homo- and copolymerization with styrene in order to obtain the corresponding
copolymers with variable contents of organometallic moiety. For the sake of comparison, tributyltin 4-(4-isopropylphenyl)-butanoate
has also been synthesized as the structural model of the repeating unit of the polymers. All the products prepared have been
characterized both in solution and in the solid state by spectroscopic and thermal techniques with the aim to establish the
coordination state of the tin atom, a feature which is of importance for future application of these derivatives. 相似文献