Toward Self-Organising Service Communities

This paper discusses a framework in which catalog service communities are built, linked for interaction, and constantly monitored and adapted over time. A catalog service community (represented as a peer node in a peer-to-peer network) in our system can be viewed as domain specific data integration mediators representing the domain knowledge and the registry information. The query routing among communities is performed to identify a set of data sources that are relevant to answering a given query. The system monitors the interactions between the communities to discover patterns that may lead to restructuring of the network (e.g., irrelevant peers removed, new relationships created, etc.)

Dynamic Trust Federation in Grids

Grids are becoming economically viable and productive tools. Grids provide a way of utilizing a vast array of linked resources such as computing systems, databases and services online within Virtual Organizations (VO). However, today’s Grid architectures are not capable of supporting dynamic, agile federation across multiple administrative domains and the main barrier, which hinders dynamic federation over short time scales is security. Federating security and trust is one of the most significant architectural issues in Grids. Existing relevant standards and specifications can be used to federate security services, but do not directly address the dynamic extension of business trust relationships into the digital domain. In this paper we describe an experiment in which we highlight those challenging architectural issues and we will further describe how the approach that combines dynamic trust federation and dynamic authorization mechanism can address dynamic security trust federation in Grids. The experiment made with the prototype described in this paper is used in the NextGRID project for the definition of requirements for next generation Grid architectures adapted to business application need

From service-oriented architecture to service-oriented enterprise

Service-Oriented Architecture (SOA) was originally motivated by enterprise demands for better business-technology alignment and higher flexibility and reuse. SOA evolved from an initial set of ideas and principles to Web services (WS) standards now widely accepted by industry. The next phase of SOA development is concerned with a scalable, reliable and secure infrastructure based on these standards, and guidelines, methods and techniques for developing and maintaining service delivery in dynamic enterprise settings. In this paper we discuss the principles and main elements of SOA. We then present an overview of WS standards. And finally we come back to the original motivation for SOA, and how these can be realized

Reinforced Video Captioning with Entailment Rewards

Sequence-to-sequence models have shown promising improvements on the temporal task of video captioning, but they optimize word-level cross-entropy loss during training. First, using policy gradient and mixed-loss methods for reinforcement learning, we directly optimize sentence-level task-based metrics (as rewards), achieving significant improvements over the baseline, based on both automatic metrics and human evaluation on multiple datasets. Next, we propose a novel entailment-enhanced reward (CIDEnt) that corrects phrase-matching based metrics (such as CIDEr) to only allow for logically-implied partial matches and avoid contradictions, achieving further significant improvements over the CIDEr-reward model. Overall, our CIDEnt-reward model achieves the new state-of-the-art on the MSR-VTT dataset.Comment: EMNLP 2017 (9 pages

Individual attitudes towards immigrants: welfare-state determinants across countries

This paper analyzes welfare-state determinants of individual attitudes towards immigrants - within and across countries - and their interaction with labor-market drivers of preferences. We consider two different mechanisms through which a redistributive welfare system might adjust as a result of immigration. Under the first scenario, immigration has a larger impact on individuals at the top of the income distribution, while under the second one it is low-income individuals who are most affected through this channel. Individual attitudes are consistent with the first welfare-state scenario and with labor-market determinants of immigration attitudes. In countries where natives are on average more skilled than immigrants, individual income is negatively correlated with pro-immigration preferences, while individual skill is positively correlated with them. These relationships have the opposite signs in economies characterized by skilled migration (relative to the native population). Such results are confirmed when we exploit international differences in the characteristics of destination countries' welfare state