1,203 research outputs found
Looking for Simple Common Schemes to Design Recognizer P Systems with Active Membranes That Solve Numerical Decision Problems
Earlier solutions to decision problems by means of P systems
used many counter objects to control the synchronization of different
stages in a computation (usually as many counters as the stage must
last in the worst case). In this paper we propose a way to replace those
counters with some spacial objects for each stage. Furthermore, following
the ideas presented in [1], in order to have a common scheme to attack
numerical problems, all instances of a problem with the same size are
solved by the same P system (which depends on the size) given an input
which describes the corresponding instance of the problem. We illustrate
these ideas with a cellular solution to the Subset-Sum problem
Belmonte en Joselito
El gran novelista Joseph Conrad escribía a principios de siglo que él se imaginaba la sociedad ideal
como la exacta relación que se establece entre los
hombres de un barco bien ordenado. Una estructura
jerárquica donde los de abajo deben obediencia a los de arriba
y la totalidad constituye un organismo perfecto. Pues bien,
para los aficionados, críticos, toreros, ganaderos y estudiosos
de los toros en el siglo XIX y principios del XX, el desarrollo
de las corridas no debía diferenciarse mucho de la organización
aludida en el barco de Conrad. Los toros, las corridas·
de toros, eran un organismo perfecto, un barco bien ordenado,
y su capitán era Joselito el Gallo ... (Fig. n.0 35) y entonces
apareció Belmonte (Fig. n.0 36) y la nave entró en aguas
tormentosas
A pedagogical Approach to the Aharonov Bohm effect
Treball Final de Grau en Química. Codi: QU0943. Curs acadèmic: 2017/2018We carry out a pedagogical approach to the Aharonov Bohm effect. To this aim, we employ
the Comsol multiphysics program package to calculate the energy spectra of twodimensional quantum ring systems. We show that the Aharonov Bohm takes place when the
system has an “interior” (i.e., non-trivial topology) pierced by a magnetic field. In addition,
we show that the symmetry of the system affects the energy spectra but not the
presence/absence of the Aharonov Bohm effect. Finally, we demonstrate that it is the total
field flux and not the vector potential what influences the system
A New Strategy to Improve the Performance of PDP-Systems Simulators
One of the major challenges that current P systems simulators
have to deal with is to be as efficient as possible. A P system
is syntactically described as a membrane structure delimiting regions
where multisets of objects evolve by means of evolution rules. According
to that, on each computation step, the applicability of the rules for
the current P system configuration must be calculated. In this paper we
extend previous works that use Rete-based simulation algorithm in order
to improve the time consumed during the checking phase in the selection
of rules. A new approach is presented, oriented to the acceleration of
Population Dynamics P Systems simulations.Ministerio de Economía y Competitividad TIN2012- 3743
La pistola y el corazón. Conversaciones con Agustín Díaz Yanes
Sociedad de Derechos de Autor de Medios Audiovisuales (DAMA). Proyecto I+D+i “El cine y la televisión en la España de la post-Transición (1979-1992)”. Ministerio de Economía y Competitividad de España, Gobierno de España, CSO2012-31895
pTSA/[bmim][BF4] ionic liquid: a powerful recyclable catalytic system for the synthesis of a-2-deoxyglycosides
α-2-Deoxyglycosides were synthesized in ionic liquid ([bmim]BF 4)by stereoselective glycosylation of endo-glycals with various o-nucleophiles in the presence of catalytic amount of pTSAin 71-95 % yield. High yields, easy recovery of the products, and reusable reaction medium (pTSA/IL couple) with consistent activity makes this protocol efficient and environmentally benign.Fil: Díaz, Gisela. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química. Laboratorio de Estudio de Compuestos Orgánicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Ponzinibbio, Agustín. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química. Laboratorio de Estudio de Compuestos Orgánicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Bravo, Rodolfo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química. Laboratorio de Estudio de Compuestos Orgánicos; Argentin
Awake prone decubitus positioning in COVID-19 patients: a systematic review and metaanalysis
Review[Abstract] To date, recommendations for the implementation of awake prone positioning in patients with hypoxia secondary
to SARSCoV2 infection have been extrapolated from prior studies on respiratory distress. Thus, we carried out a systematic review and metaanalysis to evaluate the benefits of pronation on the oxygenation, need for endotracheal
intubation (ETI), and mortality of this group of patients. We carried out a systematic search in the PubMed and Embase databases between June 2020 and November 2021. A randomeffects metaanalysis was performed to evaluate
the impact of pronation on the ETI and mortality rates. A total of 213 articles were identified, 15 of which were finally
included in this review. A significant decrease in the mortality rate was observed in the group of pronated patients
(relative risk [RR] = 0.69; 95% confidence interval [CI]: 0.480.99; p = 0.044), but no significant effect was observed on
the need for ETI (RR = 0.79; 95% CI: 0.631.00; p = 0.051). However, a subgroup analysis of randomized clinical trials
(RCTs) did reveal a significant decrease in the need for this intervention (RR = 0.83; 95% CI: 0.710.97). Prone positioning was found to significantly reduce mortality, also diminishing the need for ETI, although this effect was statistically
significant only in the subgroup analysis of RCTs. Patients’ response to awake prone positioning could be greater
when this procedure is implemented early and in combination with noninvasive mechanical ventilation (NIMV) or
highflow nasal cannula (HFNC) therapy
An efficient confidentiality-preserving Proof of Ownership for deduplication
Data storage in the cloud is becoming widespread. Deduplication is a key mechanism to decrease the operating costs cloud providers face, due to the reduction of replicated data storage. Nonetheless, deduplication must deal with several security threats such as honest-but-curious servers or malicious users who may try to take ownership of files they are not entitled to. Unfortunately, state-of-the-art solutions present weaknesses such as not coping with honest-but-curious servers, deployment problems, or lacking a sound security analysis. In this paper we present a novel Proof of Ownership scheme that uses convergent encryption and requires neither trusted third parties nor complex key management. The experimental evaluation highlights the efficiency and feasibility of our proposal that is proven to be secure under the random oracle model in the bounded leakage setting. (C) 2015 Elsevier Ltd. All rights reserved
The Philosophy of Chemistry as an Epistemological Reference in the Construction of a ‘Nature of Science’ for Chemistry Teacher Education
En este trabajo pretendemos abordar la pregunta de qué referencia(s) epistemológica(s) puede(n) constituir la base para construir una imagen de la química y de los químicos que se adecue a los desarrollos actuales de la filosofía de la ciencia y al requerimiento contemporáneo de conseguir una educación científica de calidad para todos. Partiendo de la literatura acerca de la naturaleza de la ciencia, sostenemos la idea de que, si bien se pueden identificar algunos referentes epistemológicos generales, parece emerger la reciente filosofía de la química como un referente epistemológico que puede considerarse fructífero para la actual didáctica de la química. Este referente podría considerarse novedoso y a la vez cercano a la contemporánea “concepción semántica de las teorías científicas”.In this paper we intend to address the question of which epistemological reference(s) can constitute the basis to construct an image of chemistry and chemists that fits current developments in the philosophy of science and the contemporary requirement to achieve a quality science education for all. Based on the literature about the nature of science, we adhere to the idea that, although some general epistemological references can be identified, there also seems to emerge the recent philosophy of chemistry as an epistemological referent that can be considered fruitful for current didactics of chemistry. This reference could be considered new and at the same time close to the contemporary “semantic conception of scientific theories”.peerReviewe
Niveles de plomo en los individuos de la necrópolis tardorromana de la c/ Virgen de la Misericordia (Valencia)
El objetivo general de este estudio ha sido determinar los contenidos de plomo (Pb) en restos de huesos y suelos de la necrópolis de la c/ Virgen de la Misericordia (Valencia) para reconstruir el proceso de transición del elemento (desde el sedimento hacia los huesos y viceversa) debido a la acción de los procesos diagenéticos
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