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Construction safety and digital design: a review
As digital technologies become widely used in designing buildings and infrastructure, questions arise about
their impacts on construction safety. This review explores relationships between construction safety and
digital design practices with the aim of fostering and directing further research. It surveys state-of-the-art
research on databases, virtual reality, geographic information systems, 4D CAD, building information
modeling and sensing technologies, finding various digital tools for addressing safety issues in the
construction phase, but few tools to support design for construction safety. It also considers a literature on
safety critical, digital and design practices that raises a general concern about âmindlessnessâ in the use of
technologies, and has implications for the emerging research agenda around construction safety and digital
design. Bringing these strands of literature together suggests new kinds of interventions, such as the
development of tools and processes for using digital models to promote mindfulness through multi-party
collaboration on safet
State-of-the-art on evolution and reactivity
This report starts by, in Chapter 1, outlining aspects of querying and updating resources on
the Web and on the Semantic Web, including the development of query and update languages
to be carried out within the Rewerse project.
From this outline, it becomes clear that several existing research areas and topics are of
interest for this work in Rewerse. In the remainder of this report we further present state of
the art surveys in a selection of such areas and topics. More precisely: in Chapter 2 we give
an overview of logics for reasoning about state change and updates; Chapter 3 is devoted to briefly describing existing update languages for the Web, and also for updating logic programs;
in Chapter 4 event-condition-action rules, both in the context of active database systems and
in the context of semistructured data, are surveyed; in Chapter 5 we give an overview of some relevant rule-based agents frameworks
Middleware-based Database Replication: The Gaps between Theory and Practice
The need for high availability and performance in data management systems has
been fueling a long running interest in database replication from both academia
and industry. However, academic groups often attack replication problems in
isolation, overlooking the need for completeness in their solutions, while
commercial teams take a holistic approach that often misses opportunities for
fundamental innovation. This has created over time a gap between academic
research and industrial practice.
This paper aims to characterize the gap along three axes: performance,
availability, and administration. We build on our own experience developing and
deploying replication systems in commercial and academic settings, as well as
on a large body of prior related work. We sift through representative examples
from the last decade of open-source, academic, and commercial database
replication systems and combine this material with case studies from real
systems deployed at Fortune 500 customers. We propose two agendas, one for
academic research and one for industrial R&D, which we believe can bridge the
gap within 5-10 years. This way, we hope to both motivate and help researchers
in making the theory and practice of middleware-based database replication more
relevant to each other.Comment: 14 pages. Appears in Proc. ACM SIGMOD International Conference on
Management of Data, Vancouver, Canada, June 200
QueRIE: Collaborative Database Exploration
Interactive database exploration is a key task in information mining. However, users who lack SQL expertise or familiarity with the database schema face great difficulties in performing this task. To aid these users, we developed the QueRIE system for personalized query recommendations. QueRIE continuously monitors the userâs querying behavior and finds matching patterns in the systemâs query log, in an attempt to identify previous users with similar information needs. Subsequently, QueRIE uses these âsimilarâ users and their queries to recommend queries that the current user may find interesting. In this work we describe an instantiation of the QueRIE framework, where the active userâs session is represented by a set of query fragments. The recorded fragments are used to identify similar query fragments in the previously recorded sessions, which are in turn assembled in potentially interesting queries for the active user. We show through experimentation that the proposed method generates meaningful recommendations on real-life traces from the SkyServer database and propose a scalable design that enables the incremental update of similarities, making real-time computations on large amounts of data feasible. Finally, we compare this fragment-based instantiation with our previously proposed tuple-based instantiation discussing the advantages and disadvantages of each approach
Parallelizing Windowed Stream Joins in a Shared-Nothing Cluster
The availability of large number of processing nodes in a parallel and
distributed computing environment enables sophisticated real time processing
over high speed data streams, as required by many emerging applications.
Sliding window stream joins are among the most important operators in a stream
processing system. In this paper, we consider the issue of parallelizing a
sliding window stream join operator over a shared nothing cluster. We propose a
framework, based on fixed or predefined communication pattern, to distribute
the join processing loads over the shared-nothing cluster. We consider various
overheads while scaling over a large number of nodes, and propose solution
methodologies to cope with the issues. We implement the algorithm over a
cluster using a message passing system, and present the experimental results
showing the effectiveness of the join processing algorithm.Comment: 11 page
Structuring the process of integrity maintenance (extended version)
Two different approaches have been traditionally considered for dealing with the process of integrity constraints
enforcement: integrity checking and integrity maintenance. However, while previous research in the first approach has
mainly addressed efficiency issues, research in the second approach has been mainly concentrated in being able to
generate all possible repairs that falsify an integrity constraint violation. In this paper we address efficiency issues during
the process of integrity maintenance. In this sense, we propose a technique which improves efficiency of existing methods
by defining the order in which maintenance of integrity constraints should be performed. Moreover, we use also this
technique for being able to handle in an integrated way the integrity constraintsPostprint (published version
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