10,789 research outputs found
Online Predictive Optimization Framework for Stochastic Demand-Responsive Transit Services
This study develops an online predictive optimization framework for
dynamically operating a transit service in an area of crowd movements. The
proposed framework integrates demand prediction and supply optimization to
periodically redesign the service routes based on recently observed demand. To
predict demand for the service, we use Quantile Regression to estimate the
marginal distribution of movement counts between each pair of serviced
locations. The framework then combines these marginals into a joint demand
distribution by constructing a Gaussian copula, which captures the structure of
correlation between the marginals. For supply optimization, we devise a linear
programming model, which simultaneously determines the route structure and the
service frequency according to the predicted demand. Importantly, our framework
both preserves the uncertainty structure of future demand and leverages this
for robust route optimization, while keeping both components decoupled. We
evaluate our framework using a real-world case study of autonomous mobility in
a university campus in Denmark. The results show that our framework often
obtains the ground truth optimal solution, and can outperform conventional
methods for route optimization, which do not leverage full predictive
distributions.Comment: 34 pages, 12 figures, 5 table
Missing Lensed Images and the Galaxy Disk Mass in CXOCY J220132.8-320144
The CXOCY J220132.8-320144 system consists of an edge-on spiral galaxy
lensing a background quasar into two bright images. Previous efforts to
constrain the mass distribution in the galaxy have suggested that at least one
additional image must be present (Castander et al. 2006). These extra images
may be hidden behind the disk which features a prominent dust lane. We present
and analyze Hubble Space Telescope (HST) observations of the system. We do not
detect any extra images, but the observations further narrow the observable
parameters of the lens system. We explore a range of models to describe the
mass distribution in the system and find that a variety of acceptable model
fits exist. All plausible models require 2 magnitudes of dust extinction in
order to obscure extra images from detection, and some models may require an
offset between the center of the galaxy and the center of the dark matter halo
of 1 kiloparsec. Currently unobserved images will be detectable by future James
Webb Space Telescope (JWST) observations and will provide strict constraints on
the fraction of mass in the disk.Comment: 10 pages, 8 figures, 6 tables. Minor changes, version accepted for
publication in Ap
Light trapping within the grooves of 1D diffraction gratings under monochromatic and sunlight illumination
The Rayleigh-Modal method is used to calculate the electromagnetic field
within the grooves of a perfectly conducting, rectangular-shaped 1D diffraction
grating. An \emph{enhancement coefficient} () is introduced in order to
quantify such an energy concentration. Accordingly, 1 means that the
amount of electromagnetic energy present within the grooves is larger than that
one will have, over the same volume, if the diffraction grating is replaced by
a perfectly reflecting mirror. The results in this paper show that can
be as large as several decades at certain, often narrow, ranges of wavelengths.
However, it reduces to approximately 20% under sunlight illumination. In this
latter case, such values are achieved when the \textit{optical spacing} between
the grooves is greater than 500 nm, where is the groove spacing and
is the refractive index of the substance within the grooves. For
smaller than 500 nm the enhancement coefficient turns negligibly small.Comment: This paper contains 11 pages and 4 figures, and will be published
elsewher
Design and Development of Inquiry-based Materials for Conducting Observational Astronomy Research at UTRGV
The purpose of this work is to develop instructional materials to enhance the expertise of students in conducting observational astronomy research. The designed instructional units aim to provide students with an adequate knowledge of astronomy and hone their skills necessary in conducting observations, collecting and analyzing data including processing of astronomical images.
The instructional design is anchored on the ADDIE model (Analyze, Design, Develop, Implement and Evaluate). The phases from ADDIE were used as a framework to accomplish the process of developing the instructional materials. After following the ADDIE, it was possible to define performance goals and tasks which were used to define a general structure of the material, composed of two instructional units: Observational Astronomy and Data Analysis, each one composed of two tasks and several subtasks.
Twelve inquiry-based activities were developed following the three phases of the Karplus’ learning cycle. These activities focus on developing specific knowledge of Astronomy and enhancing skills of the students, leading them to do real science at the observatory. In this paper, the development process and pilot-testing of the inquiry-based activities will be presented
Entity Identification Problem in Big and Open Data
Big and Open Data provide great opportunities to businesses to enhance their competitive advantages if
utilized properly. However, during past few years’ research in Big and Open Data process, we have
encountered big challenge in entity identification reconciliation, when trying to establish accurate
relationships between entities from different data sources. In this paper, we present our innovative Intelligent
Reconciliation Platform and Virtual Graphs solution that addresses this issue. With this solution, we are able
to efficiently extract Big and Open Data from heterogeneous source, and integrate them into a common
analysable format. Further enhanced with the Virtual Graphs technology, entity identification reconciliation
is processed dynamically to produce more accurate result at system runtime. Moreover, we believe that our
technology can be applied to a wide diversity of entity identification problems in several domains, e.g., e-
Health, cultural heritage, and company identities in financial world.Ministerio de Ciencia e Innovación TIN2013-46928-C3-3-
Avaliação da dor pós-operatória.
Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina. Curso de Medicina. Departamento de ClÃnica Médica
Determination of the influence of specific building regulations in smart buildings
The automation of domestic services began to be implemented in buildings since the late nineteenth century, and today we are used to terms like ‘intelligent buildings’, ‘digital home’ or ‘domotic buildings’. These concepts tell us about constructions which integrate
new technologies in order to improve comfort, optimize energy consumption or enhance the security of users. In conjunction, building regulations have been updated to suit the needs of society and to regulate these new facilities in such structures. However, we are not always
sure about how far, from the quantitative or qualitative point of view, legislation should
regulate certain aspects of the building activity. Consequently, content analysis is adopted in
this research to determine the influence of building regulations in the implementation of
new technologies in the construction process. This study includes the analysis of different
European regulations, the collection and documentation of such guidelines that have been
established and a study of the impact that all of these have had in the way we start thinking an architectural project. The achievements of the research could be explained in terms of the regulatory requirements that must be taken into account in order to achieve a successful implementation of a home automation system, and the key finding has been the confirmation of how the design of smart buildings may be promoted through specific regulatory requirements while other factors, such as the global economic situation, do not seem to affect directly the rate of penetration of home automation in construction
Improvement of AlGaN/GaN HEMTs Linearity Using Etched-Fin Gate Structure for Ka Band Applications
In this paper, AlGaN/GaN high electron mobility transistors (HEMTs) with etched-fin
gate structures fabricated to improve device linearity for Ka-band application are reported. Within
the proposed study of planar, one-etched-fin, four-etched-fin, and nine-etched-fin devices, which
have 50- m, 25- m, 10- m, and 5- m partial gate widths, respectively, the four-etched-fin gate
AlGaN/GaN HEMT devices have demonstrated optimized device linearity with respect to the
extrinsic transconductance (Gm) value, the output third order intercept point (OIP3), and the thirdorder
intermodulation output power (IMD3) level. The IMD3 is improved by 7 dB at 30 GHz for
the 4 50 m HEMT device. The OIP3 is found to reach a maximum value of 36.43 dBm with the
four-etched-fin device, which exhibits high potential for the advancement of wireless power amplifier
components for Ka band applications.Center for the Semiconductor Technology
ResearchFeatured Areas Research Center Program within the framework of the Higher
Education Sprout Project by the Ministry of Education (MOE) in TaiwanMinistry of Science and Technology, Taiwan, under Grants NSTC 111-2218-
E-A49-021NSTC 111-2634-F-A49-008NSTC 111-2221-E-A49 -173 -MY3NSTC 112-2622-8-A49
-013 –S
Fiber polytopes for the projections between cyclic polytopes
The cyclic polytope is the convex hull of any points on the
moment curve in . For , we
consider the fiber polytope (in the sense of Billera and Sturmfels) associated
to the natural projection of cyclic polytopes which
"forgets" the last coordinates. It is known that this fiber polytope has
face lattice indexed by the coherent polytopal subdivisions of which
are induced by the map . Our main result characterizes the triples
for which the fiber polytope is canonical in either of the following
two senses:
- all polytopal subdivisions induced by are coherent,
- the structure of the fiber polytope does not depend upon the choice of
points on the moment curve.
We also discuss a new instance with a positive answer to the Generalized
Baues Problem, namely that of a projection where has only
regular subdivisions and has two more vertices than its dimension.Comment: 28 pages with 1 postscript figur
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