5,043 research outputs found
Controlling Risk of Web Question Answering
Web question answering (QA) has become an indispensable component in modern
search systems, which can significantly improve users' search experience by
providing a direct answer to users' information need. This could be achieved by
applying machine reading comprehension (MRC) models over the retrieved passages
to extract answers with respect to the search query. With the development of
deep learning techniques, state-of-the-art MRC performances have been achieved
by recent deep methods. However, existing studies on MRC seldom address the
predictive uncertainty issue, i.e., how likely the prediction of an MRC model
is wrong, leading to uncontrollable risks in real-world Web QA applications. In
this work, we first conduct an in-depth investigation over the risk of Web QA.
We then introduce a novel risk control framework, which consists of a qualify
model for uncertainty estimation using the probe idea, and a decision model for
selectively output. For evaluation, we introduce risk-related metrics, rather
than the traditional EM and F1 in MRC, for the evaluation of risk-aware Web QA.
The empirical results over both the real-world Web QA dataset and the academic
MRC benchmark collection demonstrate the effectiveness of our approach.Comment: 42nd International ACM SIGIR Conference on Research and Development
in Information Retrieva
Enhanced Integrated Scoring for Cleaning Dirty Texts
An increasing number of approaches for ontology engineering from text are
gearing towards the use of online sources such as company intranet and the
World Wide Web. Despite such rise, not much work can be found in aspects of
preprocessing and cleaning dirty texts from online sources. This paper presents
an enhancement of an Integrated Scoring for Spelling error correction,
Abbreviation expansion and Case restoration (ISSAC). ISSAC is implemented as
part of a text preprocessing phase in an ontology engineering system. New
evaluations performed on the enhanced ISSAC using 700 chat records reveal an
improved accuracy of 98% as compared to 96.5% and 71% based on the use of only
basic ISSAC and of Aspell, respectively.Comment: More information is available at
http://explorer.csse.uwa.edu.au/reference
THERMODYNAMICS OF DEVELOPMENT OF ENERGY SYSTEMS WITH APPLICATIONS TO THERMAL MACHINES AND LIVING ORGANISMS
We define and analyse thermodynamic limits for various traditional and
work-assisted processes of sequential development with finite rates
important in engineering and biology. The thermodynamic limits are expressed
in terms of classical exergy change and a residual minimum of dissipated
exergy, or some extension including time penalty. We consider processes with
heat and mass transfer that occur in a finite time and with equipment of
finite dimension. These processes include heat and separation operations and
are found in heat and mass exchangers, thermal networks, energy converters,
energy recovery units, storage systems, chemical reactors, and chemical
plants. Our analysis is based on the condition that in order to make the
results of thermodynamic analyses usable in engineering economics it is the
thermodynamic limit, not the maximum of thermodynamic efficiency, which must
be overcome for prescribed process requirements. A creative part of this
paper outlines a general approach to the construction of `Carnot variables´
as suitable controls. Finite-rate, endoreversible models include minimal
irreducible losses caused by thermal resistances to the classical exergy
potential. Functions of extremum work, which incorporate residual minimum
entropy production, are formulated in terms of initial and final states,
total duration and (in discrete processes) number of stages
Continuity and boundary conditions in thermodynamics: From Carnot's efficiency to efficiencies at maximum power
[...] By the beginning of the 20th century, the principles of thermodynamics
were summarized into the so-called four laws, which were, as it turns out,
definitive negative answers to the doomed quests for perpetual motion machines.
As a matter of fact, one result of Sadi Carnot's work was precisely that the
heat-to-work conversion process is fundamentally limited; as such, it is
considered as a first version of the second law of thermodynamics. Although it
was derived from Carnot's unrealistic model, the upper bound on the
thermodynamic conversion efficiency, known as the Carnot efficiency, became a
paradigm as the next target after the failure of the perpetual motion ideal. In
the 1950's, Jacques Yvon published a conference paper containing the necessary
ingredients for a new class of models, and even a formula, not so different
from that of Carnot's efficiency, which later would become the new efficiency
reference. Yvon's first analysis [...] went fairly unnoticed for twenty years,
until Frank Curzon and Boye Ahlborn published their pedagogical paper about the
effect of finite heat transfer on output power limitation and their derivation
of the efficiency at maximum power, now known as the Curzon-Ahlborn (CA)
efficiency. The notion of finite rate explicitly introduced time in
thermodynamics, and its significance cannot be overlooked as shown by the
wealth of works devoted to what is now known as finite-time thermodynamics
since the end of the 1970's. [...] The object of the article is thus to cover
some of the milestones of thermodynamics, and show through the illustrative
case of thermoelectric generators, our model heat engine, that the shift from
Carnot's efficiency to efficiencies at maximum power explains itself naturally
as one considers continuity and boundary conditions carefully [...]
Target Apps Selection: Towards a Unified Search Framework for Mobile Devices
With the recent growth of conversational systems and intelligent assistants
such as Apple Siri and Google Assistant, mobile devices are becoming even more
pervasive in our lives. As a consequence, users are getting engaged with the
mobile apps and frequently search for an information need in their apps.
However, users cannot search within their apps through their intelligent
assistants. This requires a unified mobile search framework that identifies the
target app(s) for the user's query, submits the query to the app(s), and
presents the results to the user. In this paper, we take the first step forward
towards developing unified mobile search. In more detail, we introduce and
study the task of target apps selection, which has various potential real-world
applications. To this aim, we analyze attributes of search queries as well as
user behaviors, while searching with different mobile apps. The analyses are
done based on thousands of queries that we collected through crowdsourcing. We
finally study the performance of state-of-the-art retrieval models for this
task and propose two simple yet effective neural models that significantly
outperform the baselines. Our neural approaches are based on learning
high-dimensional representations for mobile apps. Our analyses and experiments
suggest specific future directions in this research area.Comment: To appear at SIGIR 201
Object Detection in 20 Years: A Survey
Object detection, as of one the most fundamental and challenging problems in
computer vision, has received great attention in recent years. Its development
in the past two decades can be regarded as an epitome of computer vision
history. If we think of today's object detection as a technical aesthetics
under the power of deep learning, then turning back the clock 20 years we would
witness the wisdom of cold weapon era. This paper extensively reviews 400+
papers of object detection in the light of its technical evolution, spanning
over a quarter-century's time (from the 1990s to 2019). A number of topics have
been covered in this paper, including the milestone detectors in history,
detection datasets, metrics, fundamental building blocks of the detection
system, speed up techniques, and the recent state of the art detection methods.
This paper also reviews some important detection applications, such as
pedestrian detection, face detection, text detection, etc, and makes an in-deep
analysis of their challenges as well as technical improvements in recent years.Comment: This work has been submitted to the IEEE TPAMI for possible
publicatio
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