184 research outputs found
Tentative detection of ethylene glycol toward W51/e2 and G34.3+0.2
How complex organic - and potentially prebiotic - molecules are formed in
regions of low- and high-mass star-formation remains a central question in
astrochemistry. In particular, with just a few sources studied in detail, it is
unclear what role environment plays in complex molecule formation. In this
light, a comparison of relative abundances of related species between sources
might be useful to explain observed differences. We seek to measure the
relative abundance between three important complex organic molecules, ethylene
glycol ((CHOH)), glycolaldehyde (CHOHCHO) and methyl formate
(HCOOCH), toward high-mass protostars and thereby provide additional
constraints on their formation pathways. We use IRAM 30-m single dish
observations of the three species toward two high-mass star-forming regions -
W51/e2 and G34.3+0.2 - and report a tentative detection of (CH2OH)2 toward both
sources. Assuming that (CHOH), CHOHCHO and HCOOCH spatially
coexist, relative abundance ratios, HCOOCH/(CHOH), of 31 and 35 are
derived for G34.3+0.2 and W51/e2, respectively. CHOHCHO is not detected,
but the data provide lower limits to the HCOOCH/CHOHCHO abundance
ratios of 193 for G34.3+0.2 and 550 for W51/e2. A comparison of these
results to measurements from various sources in the literature indicates that
the source luminosities may be correlated with the HCOOCH/(CHOH)
and HCOOCH/CHOHCHO ratios. This apparent correlation may be a
consequence of the relative timescales each source spend at different
temperatures-ranges in their evolution. Furthermore, we obtain lower limits to
the ratio of (CHOH)/CH2OHCHO for G34.3+0.2 (6) and W51/e2
(16). This result confirms that a high (CHOH)/CHOHCHO
abundance ratio is not a specific property of comets, as previously speculated.Comment: Accepted for publication by A&
The Collaborative Business Intelligence Ontology (CBIOnt)
In the current era, many disciplines are seen devoted towards ontology
development for their domains with the intention of creating, disseminating and
managing resource descriptions of their domain knowledge into machine
understandable and processable manner. Ontology construction is a difficult
group activity that involves many people with the different expertise.
Generally, domain experts are not familiar with the ontology implementation
environments and implementation experts do not have all the domain knowledge.
We have designed Collaborative Business Intelligence Ontology (CBIOnt) for
BI4People project. In this paper, we present CBIOnt that is OWL 2 DL ontology
for the description of collaborative session between different collaborators
working together on the business intelligent platform. As the collaborative
session between various collaborators belongs to some collaborative form, phase
and research aspect, therefore CBIOnt captures this knowledge along with the
collaborative session content (comments, questions, answers, etc.) so that one
can inference various types of information stored on ontologies when required.
In addition, it stores the location and temporal-spatial information about the
collaboration held between collaborators. We believe CBIOnt serves as a formal
framework for dealing with the collaborative session taken place among
collaborators on the semantic Web
Evidence for DCO+ as a probe of ionization in the warm disk surface
In this Letter we model the chemistry of DCO in protoplanetary disks.
We find that the overall distribution of the DCO abundance is
qualitatively similar to that of CO but is dominated by thin layer located at
the inner disk surface. To understand its distribution, we investigate the
different key gas-phase deuteration pathways that can lead to the formation of
DCO. Our analysis shows that the recent update in the exothermicity of
the reaction involving CHD as a parent molecule of DCO favors
deuterium fractionation in warmer conditions. As a result the formation of
DCO is enhanced in the inner warm surface layers of the disk where X-ray
ionization occurs. Our analysis points out that DCO is not a reliable
tracer of the CO snow line as previously suggested. We thus predict that
DCO is a tracer of active deuterium and in particular X-ray ionization of
the inner disk.Comment: Accepted for publication in the Astrophysical Journal Letters (ApJL).
11 pages, 5 figure
A Reference Model for Collaborative Business Intelligence Virtual Assistants
Collaborative Business Analysis (CBA) is a methodology that involves bringing
together different stakeholders, including business users, analysts, and
technical specialists, to collaboratively analyze data and gain insights into
business operations. The primary objective of CBA is to encourage knowledge
sharing and collaboration between the different groups involved in business
analysis, as this can lead to a more comprehensive understanding of the data
and better decision-making. CBA typically involves a range of activities,
including data gathering and analysis, brainstorming, problem-solving,
decision-making and knowledge sharing. These activities may take place through
various channels, such as in-person meetings, virtual collaboration tools or
online forums. This paper deals with virtual collaboration tools as an
important part of Business Intelligence (BI) platform. Collaborative Business
Intelligence (CBI) tools are becoming more user-friendly, accessible, and
flexible, allowing users to customize their experience and adapt to their
specific needs. The goal of a virtual assistant is to make data exploration
more accessible to a wider range of users and to reduce the time and effort
required for data analysis. It describes the unified business intelligence
semantic model, coupled with a data warehouse and collaborative unit to employ
data mining technology. Moreover, we propose a virtual assistant for CBI and a
reference model of virtual tools for CBI, which consists of three components:
conversational, data exploration and recommendation agents. We believe that the
allocation of these three functional tasks allows you to structure the CBI
issue and apply relevant and productive models for human-like dialogue,
text-to-command transferring, and recommendations simultaneously. The complex
approach based on these three points gives the basis for virtual tool for
collaboration. CBI encourages people, processes, and technology to enable
everyone sharing and leveraging collective expertise, knowledge and data to
gain valuable insights for making better decisions. This allows to respond more
quickly and effectively to changes in the market or internal operations and
improve the progress
Data Lakes for Digital Humanities
Traditional data in Digital Humanities projects bear various formats
(structured, semi-structured, textual) and need substantial transformations
(encoding and tagging, stemming, lemmatization, etc.) to be managed and
analyzed. To fully master this process, we propose the use of data lakes as a
solution to data siloing and big data variety problems. We describe data lake
projects we currently run in close collaboration with researchers in humanities
and social sciences and discuss the lessons learned running these projects.Comment: Data and Digital Humanities Trac
Les quotas: levier ou frein au déroulement des carrières des femmes? Analyse suite à une enquête préliminaire dans le cas de l'enseignement supérieur et la recherche en France dans le domaine de l'informatique
This paper presents the preliminary results of a qualitative survey on the implementation of quotas policies, in the context of higher education and research in France, in the field of computer science specifically. Beyond the theoretical controversy over quotas, it is a question of diving into the heart of an environment that we can describe as specific (and of which we will draw some of the specificities), to collect the experience, the words of women, who are computer scientists in the academic environment, in relation to quotas. The main idea is to question the quotas implementation in order to study in which sense these quotas can indeed lead to more professional equality, but also to study the context in which they can slow down this professional equality
Infalling-Rotating Motion and Associated Chemical Change in the Envelope of IRAS 16293-2422 Source A Studied with ALMA
We have analyzed rotational spectral line emission of OCS, CH3OH, HCOOCH3,
and H2CS observed toward the low-mass Class 0 protostellar source IRAS
16293-2422 Source A at a sub-arcsecond resolution (~0".6 x 0".5) with ALMA.
Significant chemical differentiation is found at a 50 AU scale. The OCS line is
found to well trace the infalling-rotating envelope in this source. On the
other hand, the CH3OH and HCOOCH3 distributions are found to be concentrated
around the inner part of the infalling-rotating envelope. With a simple
ballistic model of the infalling-rotating envelope, the radius of the
centrifugal barrier (a half of the centrifugal radius) and the protostellar
mass are evaluated from the OCS data to be from 40 to 60 AU and from 0.5 to 1.0
Msun, respectively, assuming the inclination angle of the envelope/disk
structure to be 60 degrees (90 degrees for the edge-on configuration). Although
the protostellar mass is correlated with the inclination angle, the radius of
the centrifugal barrier is not. This is the first indication of the centrifugal
barrier of the infalling-rotating envelope in a hot corino source. CH3OH and
HCOOCH3 may be liberated from ice mantles due to weak accretion shocks around
the centrifugal barrier, and/or due to protostellar heating. The H2CS emission
seems to come from the disk component inside the centrifugal barrier in
addition to the envelope component. The centrifugal barrier plays a central
role not only in the formation of a rotationally-supported disk but also in the
chemical evolution from the envelope to the protoplanetary disk
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