52,832 research outputs found
A review of the methodologies used in compiling owner-occupiers’ housing indices. ESRI Working Paper 651 January 2020
This paper examines the manner in which owner-occupiers housing costs are incorporated in the official inflation
index. In particular, the focus is on the net acquisitions and the payments approach, which are currently used by the Central
Statistics Office (CSO). The paper provides a detailed overview of the two approaches, along with some suggestion
for further refinement
Automatic Software Repair: a Bibliography
This article presents a survey on automatic software repair. Automatic
software repair consists of automatically finding a solution to software bugs
without human intervention. This article considers all kinds of repairs. First,
it discusses behavioral repair where test suites, contracts, models, and
crashing inputs are taken as oracle. Second, it discusses state repair, also
known as runtime repair or runtime recovery, with techniques such as checkpoint
and restart, reconfiguration, and invariant restoration. The uniqueness of this
article is that it spans the research communities that contribute to this body
of knowledge: software engineering, dependability, operating systems,
programming languages, and security. It provides a novel and structured
overview of the diversity of bug oracles and repair operators used in the
literature
Exchange-Repairs: Managing Inconsistency in Data Exchange
In a data exchange setting with target constraints, it is often the case that
a given source instance has no solutions. In such cases, the semantics of
target queries trivialize. The aim of this paper is to introduce and explore a
new framework that gives meaningful semantics in such cases by using the notion
of exchange-repairs. Informally, an exchange-repair of a source instance is
another source instance that differs minimally from the first, but has a
solution. Exchange-repairs give rise to a natural notion of exchange-repair
certain answers (XR-certain answers) for target queries. We show that for
schema mappings specified by source-to-target GAV dependencies and target
equality-generating dependencies (egds), the XR-certain answers of a target
conjunctive query can be rewritten as the consistent answers (in the sense of
standard database repairs) of a union of conjunctive queries over the source
schema with respect to a set of egds over the source schema, making it possible
to use a consistent query-answering system to compute XR-certain answers in
data exchange. We then examine the general case of schema mappings specified by
source-to-target GLAV constraints, a weakly acyclic set of target tgds and a
set of target egds. The main result asserts that, for such settings, the
XR-certain answers of conjunctive queries can be rewritten as the certain
answers of a union of conjunctive queries with respect to the stable models of
a disjunctive logic program over a suitable expansion of the source schema.Comment: 29 pages, 13 figures, submitted to the Journal on Data Semantic
Reactive point processes: A new approach to predicting power failures in underground electrical systems
Reactive point processes (RPPs) are a new statistical model designed for
predicting discrete events in time based on past history. RPPs were developed
to handle an important problem within the domain of electrical grid
reliability: short-term prediction of electrical grid failures ("manhole
events"), including outages, fires, explosions and smoking manholes, which can
cause threats to public safety and reliability of electrical service in cities.
RPPs incorporate self-exciting, self-regulating and saturating components. The
self-excitement occurs as a result of a past event, which causes a temporary
rise in vulner ability to future events. The self-regulation occurs as a result
of an external inspection which temporarily lowers vulnerability to future
events. RPPs can saturate when too many events or inspections occur close
together, which ensures that the probability of an event stays within a
realistic range. Two of the operational challenges for power companies are (i)
making continuous-time failure predictions, and (ii) cost/benefit analysis for
decision making and proactive maintenance. RPPs are naturally suited for
handling both of these challenges. We use the model to predict power-grid
failures in Manhattan over a short-term horizon, and to provide a cost/benefit
analysis of different proactive maintenance programs.Comment: Published at http://dx.doi.org/10.1214/14-AOAS789 in the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
The challenges facing road-side ‘m-Preneurs’ in leap-frogging the constraints of ICTs in DCs: A Nigerian case study
Studies have shown that the number of mobile telecommunications operators in Nigeria has been on the increase since the first Global System of Mobile Telecommunications (GSM) licence was granted to MTN (Mobile Telecommunications Network) in 2001.
With the increase in mobile telecommunications operators also has come an unprecedented increase in subscriptions. According to the Nigerian Communications Commission (NCC) data, between 2001 and 2006 for instance, mobile telephone subscribers in Nigeria jumped from 266, 461 to 32.3 million indicating an increase of 12, 030.18 %
A Review of integrity constraint maintenance and view updating techniques
Two interrelated problems may arise when updating a database. On one
hand, when an update is applied to the database, integrity constraints
may become violated. In such case, the integrity constraint maintenance
approach tries to obtain additional updates to keep integrity
constraints satisfied. On the other hand, when updates of derived or
view facts are requested, a view updating mechanism must be applied to
translate the update request into correct updates of the underlying base
facts.
This survey reviews the research performed on integrity constraint
maintenance and view updating. It is proposed a general framework to
classify and to compare methods that tackle integrity constraint
maintenance and/or view updating. Then, we analyze some of these methods
in more detail to identify their actual contribution and the main
limitations they may present.Postprint (published version
Milwaukee County-Funded Parks and Cultural Institutions
The Public Policy Forum's role in the Audit of Greater Milwaukee's Regional Cultural Assets was to examine the fiscal condition of those cultural assets owned and/or funded by Milwaukee County: the Milwaukee Public Museum, Marcus Center for the Performing Arts, Milwaukee County War Memorial Center, Milwaukee County Historical Society, Charles Allis Museum, Villa Terrace Decorative Art Museum, Milwaukee County Cultural Artistic and Musical Programming Advisory Council, Milwaukee County Zoo and Milwaukee County Parks
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