69,449 research outputs found
Aplicación de la Teoría Situacional de los Públicos al primer proceso de voto en el exterior para Costa Rica: Lecciones para las relaciones públicas internacionales y la diplomacia pública
Using information gathered from 40 interviews with Costa Ricans who live abroad (some who decided to vote in the newly granted external voting right and others who did not vote in the Costa Rican National Elections of 2014), the variables that impacted the voting intention and/or behaviour of these Costa Rican diaspora members were categorized using the independent variables presented by the Situational Theory of Publics: problem recognition, constraint recognition (internal and external constraints), and level of involvement. This theory was used to better understand what is moving these potential external voters to vote or not, in order to suggest what kinds of efforts should the Costa Rican government undertake to increase the number of external voters. The implications for public diplomacy and international public relations are explored
Insights into thermonuclear supernovae from the incomplete silicon burning process
Type Ia supernova (SNIa) explosions synthesize a few tenths to several tenths
of a solar mass, whose composition is the result of incomplete silicon burning
that reaches peak temperatures of 4 GK to 5 GK. The elemental abundances are
sensitive to the physical conditions in the explosion, making their measurement
a promising clue to uncovering the properties of the progenitor star and of the
explosion itself. Using a parameterized description of the thermodynamic
history of matter undergoing incomplete silicon burning, we computed the final
composition for a range of parameters wide enough to encompass current models
of SNIa. Then, we searched for combinations of elemental abundances that trace
the parameters values and are potentially measurable. For this purpose, we
divide the present study into two epochs of SNIa, namely the optical epoch,
from a few weeks to several months after the explosion, and the X-ray epoch,
which refers to the time period in which the supernova remnant is young,
starting one or two hundred years age and ending a thousand years after the
event. During the optical epoch, the only SNIa property that can be extracted
from the detection of incomplete silicon burning elements is the neutron excess
of the progenitor white dwarf at thermal runaway, which can be determined
through measuring the ratio of the abundance of manganese to that of titanium,
chromium, or vanadium. Conversely, in the X-ray epoch, any abundance ratio
built using a couple of elements from titanium, vanadium, chromium, or
manganese may constrain the initial neutron excess. Furthermore, measuring the
ratio of the abundances of vanadium to manganese in the X-ray might shed light
on the timescale of the thermonuclear explosion.Comment: Accepted for Astronomy and Astrophysics (16 pages, 3 tables, 15
figures
New results on alpha_s and optimized scales
A summary of the latest alpha_s results at LEP1 and LEP2 from event-shape
predictions at Order(alpha2_s) + NLLA is presented. Later these are compared to
measurements obtained using the Experimentally Optimized Scale method. Finally
the alpha_s measurement from the 4-jet rate is discussed.Comment: 6 pages, 4 figures, talk presented at the 30th ISMD, Hungary, October
200
Program Evaluation in the Context of Debates in the Field: The Evaluation of PR-CETP
This paper rationalizes the selection of the concept of energy as the central theme of a new capstone course aimed at science education majors. It describes the goals of the course and the activities that preceded the course design and led to the selection of the topics, of the educational materials, and of the teaching methodologies. It presents a sequential description of the manner in which the conceptual knowledge of energy was to be developed. The specific experiments, interactive demonstrations and other educational materials utilized for the conceptual development of the concept of energy in context are described and referenced. The course objectives are described, as well as the instruments utilized to assess student learning. It also presents the activities utilized to assess the course, in addition to the modifications made to the course syllabus based on this assessment
Coincidences in generalized Lucas sequences
For an integer , let be the generalized
Lucas sequence which starts with ( terms) and each term
afterwards is the sum of the preceding terms. In this paper, we find all
the integers that appear in different generalized Lucas sequences; i.e., we
study the Diophantine equation in nonnegative integers
with . The proof of our main theorem uses lower
bounds for linear forms in logarithms of algebraic numbers and a version of the
Baker-Davenport reduction method. This paper is a continuation of the earlier
work [4].Comment: 14 page
An interior point algorithm for computing equilibria in economies with incomplete asset markets
Computing equilibria in general equilibria models with incomplete asset (GEI) markets is technically difficult. The standard numerical methods for computing these equilibria are based on homotopy methods. Despite recent advances in computational economics, much more can be done to enlarge the catalogue of techniques for computing GEI equilibria. This paper presents an interior-point algorithm that exploits the special structure of GEI markets. We prove that the algorithm converges globally at a quadratic rate, rendering it particularly effective in solving large-scale GEI economies. To illustrate its performance, we solve relevant examples of GEI market
Bridges of L\'{e}vy processes conditioned to stay positive
We consider Kallenberg's hypothesis on the characteristic function of a
L\'{e}vy process and show that it allows the construction of weakly continuous
bridges of the L\'{e}vy process conditioned to stay positive. We therefore
provide a notion of normalized excursions L\'{e}vy processes above their
cumulative minimum. Our main contribution is the construction of a continuous
version of the transition density of the L\'{e}vy process conditioned to stay
positive by using the weakly continuous bridges of the L\'{e}vy process itself.
For this, we rely on a method due to Hunt which had only been shown to provide
upper semi-continuous versions. Using the bridges of the conditioned L\'{e}vy
process, the Durrett-Iglehart theorem stating that the Brownian bridge from
to conditioned to remain above converges weakly to the
Brownian excursion as , is extended to L\'{e}vy processes. We
also extend the Denisov decomposition of Brownian motion to L\'{e}vy processes
and their bridges, as well as Vervaat's classical result stating the
equivalence in law of the Vervaat transform of a Brownian bridge and the
normalized Brownian excursion.Comment: Published in at http://dx.doi.org/10.3150/12-BEJ481 the Bernoulli
(http://isi.cbs.nl/bernoulli/) by the International Statistical
Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm
The falling appart of the tagged fragment and the asymptotic disintegration of the Brownian height fragmentation
We present a further analysis of the fragmentation at heights of the
normalized Brownian excursion. Specifically we study a representation for the
mass of a tagged fragment in terms of a Doob transformation of the 1/2-stable
subordinator and use it to study its jumps; this accounts for a description of
how a typical fragment falls apart. These results carry over to the height
fragmentation of the stable tree. Additionally, the sizes of the fragments in
the Brownian fragmentation when it is about to reduce to dust are described in
a limit theorem.Comment: 23 pages, 4 figures, AMSLaTeX (PDFLaTeX), accepted in Annales de
l'Institut Henri Poincar\'e (B
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