3,028 research outputs found
Improving the Scalability of DPWS-Based Networked Infrastructures
The Devices Profile for Web Services (DPWS) specification enables seamless
discovery, configuration, and interoperability of networked devices in various
settings, ranging from home automation and multimedia to manufacturing
equipment and data centers. Unfortunately, the sheer simplicity of event
notification mechanisms that makes it fit for resource-constrained devices,
makes it hard to scale to large infrastructures with more stringent
dependability requirements, ironically, where self-configuration would be most
useful. In this report, we address this challenge with a proposal to integrate
gossip-based dissemination in DPWS, thus maintaining compatibility with
original assumptions of the specification, and avoiding a centralized
configuration server or custom black-box middleware components. In detail, we
show how our approach provides an evolutionary and non-intrusive solution to
the scalability limitations of DPWS and experimentally evaluate it with an
implementation based on the the Web Services for Devices (WS4D) Java Multi
Edition DPWS Stack (JMEDS).Comment: 28 pages, Technical Repor
Heteroscedastic Gaussian processes for uncertainty modeling in large-scale crowdsourced traffic data
Accurately modeling traffic speeds is a fundamental part of efficient
intelligent transportation systems. Nowadays, with the widespread deployment of
GPS-enabled devices, it has become possible to crowdsource the collection of
speed information to road users (e.g. through mobile applications or dedicated
in-vehicle devices). Despite its rather wide spatial coverage, crowdsourced
speed data also brings very important challenges, such as the highly variable
measurement noise in the data due to a variety of driving behaviors and sample
sizes. When not properly accounted for, this noise can severely compromise any
application that relies on accurate traffic data. In this article, we propose
the use of heteroscedastic Gaussian processes (HGP) to model the time-varying
uncertainty in large-scale crowdsourced traffic data. Furthermore, we develop a
HGP conditioned on sample size and traffic regime (SRC-HGP), which makes use of
sample size information (probe vehicles per minute) as well as previous
observed speeds, in order to more accurately model the uncertainty in observed
speeds. Using 6 months of crowdsourced traffic data from Copenhagen, we
empirically show that the proposed heteroscedastic models produce significantly
better predictive distributions when compared to current state-of-the-art
methods for both speed imputation and short-term forecasting tasks.Comment: 22 pages, Transportation Research Part C: Emerging Technologies
(Elsevier
Industrial Illegitimacy and Negative Externalities: the Case of the Illinois Livestock Industry
An industry's legitimacy depends on stakeholders' perceptions and assessments of the appropriateness of its behavior across a wide array of settings. While products and services may be highly valued, and in some cases essential, business externalities serve as a powerful counterforce undermining legitimacy. The work draws on the theory of industrial legitimacy and employs a taxonomy of four different legitimacy sub components; pragmatic, regulative, normative, and cognitive. The paper identifies how externalities affect an industry's legitimacy and the relative contribution of each sub component. The research then empirically tests the theory using the case of the Illinois livestock industry.Livestock Production/Industries,
Multi-Output Gaussian Processes for Crowdsourced Traffic Data Imputation
Traffic speed data imputation is a fundamental challenge for data-driven
transport analysis. In recent years, with the ubiquity of GPS-enabled devices
and the widespread use of crowdsourcing alternatives for the collection of
traffic data, transportation professionals increasingly look to such
user-generated data for many analysis, planning, and decision support
applications. However, due to the mechanics of the data collection process,
crowdsourced traffic data such as probe-vehicle data is highly prone to missing
observations, making accurate imputation crucial for the success of any
application that makes use of that type of data. In this article, we propose
the use of multi-output Gaussian processes (GPs) to model the complex spatial
and temporal patterns in crowdsourced traffic data. While the Bayesian
nonparametric formalism of GPs allows us to model observation uncertainty, the
multi-output extension based on convolution processes effectively enables us to
capture complex spatial dependencies between nearby road segments. Using 6
months of crowdsourced traffic speed data or "probe vehicle data" for several
locations in Copenhagen, the proposed approach is empirically shown to
significantly outperform popular state-of-the-art imputation methods.Comment: 10 pages, IEEE Transactions on Intelligent Transportation Systems,
201
Epigenetic events underlying somatic cell reprogramming
Although differentiated cells normally retain cell-type-specific gene expression
patterns throughout their lifetime, cell identity can sometimes be modified or reversed
in vivo by transdifferentiation, or experimentally through cell fusion or by nuclear
transfer. Several studies have illustrated the importance of chromatin remodelling, DNA
demethylation and dominant transcriptional factor expression for changes in lineage
identity. Here the epigenetic mechanisms required to “reset” genome function were
investigated using experimental heterokaryons.
To examine the epigenetic changes that are required for the dominant
conversion of lymphocytes to muscle, I generated stable heterokaryons between
human B-lymphocytes and mouse C2C12 myotubes. I show that lymphocyte nuclei
adopt an architecture resembling that of muscle and initiate the expression of musclespecific
genes in the same temporal order as developing muscle. The establishment of
this novel gene expression program is coordinated with the shutdown of several
lymphocyte-associated genes. Interestingly, inhibition of histone deacetylase (HDAC)
activity during reprogramming selectively blocks the silencing of lymphocyte-specific
genes but does not prevent the establishment of muscle-specific gene expression.
In order to reprogram somatic cells to pluripotency, I fused human Blymphocytes
and mouse embryonic stem (ES) cells. The conversion of human cells is
initiated rapidly, occurring in heterokaryons before nuclear fusion. Reprogramming of
human lymphocytes by mouse ES cells elicits the expression of a human ES-specific
gene expression profile in which endogenous hSSEA4, hFgf receptors and ligands are
expressed while factors that are characteristic of mouse ES cells, such as Bmp4 and
Lif receptor are not. Using genetically engineered mouse ES cells I demonstrate that
successful reprogramming requires the expression of Oct4, but importantly, does not
require Sox2, a factor implicated as critical for the induction of pluripotency. Following
reprogramming, mOct4 becomes dispensable for maintaining the multi-potent state of
hybrid cells. Finally, I have examined the reprogramming potential of embryonic germ
(EG), embryonic carcinoma (EC) and ES cells deficient for the Polycomb repressive
complex 2 (PRC2) proteins Eed, Suz12 and Ezh2. While EC and EG cells share the
ability to reprogram human lymphocytes with ES cells, the lack of Polycomb proteins
abolishes reprogramming. Thus, the repressive chromatin mark (H3K27 methylation)
catalysed by PRC2 play a crucial role in keeping ES cells with full reprogramming
capacity. Collectively my results underscore the importance of chromatin events during
cell fate reprogramming
Avaliação da contaminação bacteriana de produtos oftálmicos em uso em consultórios e centDa Roscirúrgicos hospitalares.
Trabalho de ConclusĂŁo de Curso - Universidade Federal de Santa Catarina, Centro de CiĂŞncias da SaĂşde, Departamento de ClĂnica CirĂşrgica, Curso de Medicina, FlorianĂłpolis, 199
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