A decision-supporting web model for integrating rural buildings with multi-criteria spatial planning

Este trabajo presenta un modelo web ideado para asesorar en la toma de decisiones en la integración de construcciones turísticas rurales en su entorno, mediante el intercambio de información y colaboración entre los agentes implicados. Se expone el uso de metodologías espaciales para la selección de localizaciones adecuadas a partir de la evaluación de criterios múltiples (ECM) en un marco web. Se emplean cuatro criterios para la evaluación, que se muestran en un mapa final global de idoneidad, basado en cuatro mapas intermedios parciales según los criterios de evaluación. Como resultado se utilizan tres niveles de información: página de información general, página para la toma de decisión espacial multi-criterio y una página con mapas de intercambio de conocimiento. El modelo propuesto, aplicado al caso práctico de ‘Hervás’, pretende conseguir una discusión esclarecedora entre distintas percepciones de integración de construcciones en su entorno, consi¬derando diferentes alternativas de decisión y posibles contribucionesThis paper presents an interoperable web-based model able to interchange information amongst different stakeholders and to use the information as a means of promoting collaborative activities to integrate rural tourism buildings into a landscape with a case study, Hervás (Spain). Preliminary results from a continuing research are explained with a spatial methodology for selecting the suitable locations of rural buildings, coupling multi-criteria evaluations (MCE) into a web framework. The aim of this methodology is to classify four evaluation criteria and then is to show a final composite suitability map based on the four intermediate maps. The model deals with three types of information: a general overview page; a multi-criteria spatial decision-supporting page; and, a knowledge sharing map page. Using the proposed model, the regional spatial planning is intended to discuss different perceptions of building integration with the surroundings from various decision alternatives and to elucidate this model’s contribution.-- Ministerio de Ciencia e Innovación (Proyecto BIA 2007-61166)peerReviewe

Single-bubble and multi-bubble cavitation in water triggered by laser-driven focusing shock waves

In this study a single laser pulse spatially shaped into a ring is focused into a thin water layer, creating an annular cavitation bubble and cylindrical shock waves: an outer shock that diverges away from the excitation laser ring and an inner shock that focuses towards the center. A few nanoseconds after the converging shock reaches the focus and diverges away from the center, a single bubble nucleates at the center. The inner diverging shock then reaches the surface of the annular laser-induced bubble and reflects at the boundary, initiating nucleation of a tertiary bubble cloud. In the present experiments, we have performed time-resolved imaging of shock propagation and bubble wall motion. Our experimental observations of single-bubble cavitation and collapse and appearance of ring-shaped bubble clouds are consistent with our numerical simulations that solve a one dimensional Euler equation in cylindrical coordinates. The numerical results agree qualitatively with the experimental observations of the appearance and growth of bubble clouds at the smallest laser excitation rings. Our technique of shock-driven bubble cavitation opens novel perspectives for the investigation of shock-induced single-bubble or multi-bubble cavitation phenomena in thin liquids

Far-infrared imaging of post-AGB stars and (proto)-planetary nebulae with the AKARI Far-Infrared Surveyor

By tracing the distribution of cool dust in the extended envelopes of post-AGB stars and (proto)-planetary nebulae ((P)PNe) we aim to recover, or constrain, the mass loss history experienced by these stars in their recent past. The Far-Infrared Surveyor (FIS) instrument on board the AKARI satellite was used to obtain far-infrared maps for a selected sample of post-AGB stars and (P)PNe. We derived flux densities (aperture photometry) for 13 post-AGB stars and (P)PNe at four far-infrared wavelengths (60, 90, 140, and 160 um). Radial (azimuthally averaged) profiles are used to investigate the presence of extended emission from cool dust. No (detached) extended emission is detected for any target in our sample at levels significant with respect to background and cirrus emission. Only IRAS 21046+4739 reveals tentative excess emission between 30 and 130". Estimates of the total dust and gas mass from the obtained maps indicate that the envelope masses of these stars should be large in order to be detected with the AKARI FIS. Imaging with higher sensitivity and higher spatial resolution is needed to detect and resolve, if present, any cool compact or extended emission associated with these evolved stars.Comment: accepted for publication in The Astronomical Journal (16 pages, 3 figures and 4 tables

Adam through a Second-Order Lens

Research into optimisation for deep learning is characterised by a tension between the computational efficiency of first-order, gradient-based methods (such as SGD and Adam) and the theoretical efficiency of second-order, curvature-based methods (such as quasi-Newton methods and K-FAC). We seek to combine the benefits of both approaches into a single computationally-efficient algorithm. Noting that second-order methods often depend on stabilising heuristics (such as Levenberg-Marquardt damping), we propose AdamQLR: an optimiser combining damping and learning rate selection techniques from K-FAC (Martens and Grosse, 2015) with the update directions proposed by Adam, inspired by considering Adam through a second-order lens. We evaluate AdamQLR on a range of regression and classification tasks at various scales, achieving competitive generalisation performance vs runtime.Comment: 28 pages, 15 figures, 4 tables. Submitted to ICLR 202

Dust discs around intermediate mass and Sun-like stars in the 16 Myr old NGC 1960 open cluster

We present an analysis of Spitzer IRAC (3.6--8um) and MIPS (24um) imaging of members of the 16(+10/-5)Myr old open cluster NGC 1960 (M36). Models of terrestrial planet formation indicate that rocky planets are likely to achieve their final masses at around 10-30Myr, and thus this cluster is at an interesting epoch for planet formation. We find 21 B-F5 type stars and 14 F6-K9 type stars which have 24um excess emission, and thus determine that >30% of B-F5 type stars and >23% of F6-K9 type stars in this cluster have 24um excess emission. These excess frequencies are similar to those observed in other clusters of similar age. Three early type stars have excesses at near-infrared wavelengths. Analysis of their SEDs confirms that these are true debris discs and not remnant primordial or transitional discs. None of the 61 sun-like stars have confirmed near-infrared excess, and we can place a limit on the frequency of 8um excess emission around sun-like stars of <7%. All of the detected excesses are consistent with emission from debris discs and are not primordial.Comment: 16 pages, 10 figures, accepted for publication in MNRAS (tables 1-4 will be available in full online in the electronic version of the paper

Variations on Debris Disks II. Icy Planet Formation as a Function of the Bulk Properties and Initial Sizes of Planetesimals

We describe comprehensive calculations of the formation of icy planets and debris disks at 30-150 AU around 1-3 solar mass stars. Disks composed of large, strong planetesimals produce more massive planets than disks composed of small, weak planetesimals. The maximum radius of icy planets ranges from roughly 1500 km to 11,500 km. The formation rate of 1000 km objects - `Plutos' - is a useful proxy for the efficiency of icy planet formation. Plutos form more efficiently in massive disks, in disks with small planetesimals, and in disks with a range of planetesimal sizes. Although Plutos form throughout massive disks, Pluto production is usually concentrated in the inner disk. Despite the large number of Plutos produced in many calculations, icy planet formation is inefficient. At the end of the main sequence lifetime of the central star, Plutos contain less than 10% of the initial mass in solid material. This conclusion is independent of the initial mass in the disk or the properties of planetesimals. Debris disk formation coincides with the formation of planetary systems containing Plutos. As Plutos form, they stir leftover planetesimals to large velocities. A cascade of collisions then grinds the leftovers to dust, forming an observable debris disk. In disks with small (< 1-10 km) planetesimals, collisional cascades produce luminous debris disks with maximum luminosity roughly 0.01 times the stellar luminosity. Disks with larger planetesimals produce much less luminous debris disks. Observations of debris disks around A-type and G-type stars strongly favor models with small planetesimals. In these models, our predictions for the time evolution and detection frequency of debris disks agree with published observations. We suggest several critical observations that can test key features of our calculations.Comment: 61 pages of text, 24 tables, and 34 figures; submitted to ApJS; comments welcome; revised version accepted to ApJS, changed text, modified tables, added references, no major changes to conclusion

A two-stage sodium thermal electrochemical converter: Parametric optimization and performance enhancement

[EN]An asymmetric two-stage sodium thermal electrochemical converter and its optimum performance are studied by means of an improved analytical model including the main losses in the overall system. Based on the study of a single-stage sodium thermal electrochemical converter, the inner process is divided into two stages including one at the 1300 K temperature (evaporator) and the other at the 800–1300 K intermediate temperature with the aim of improving efficiency. The parametric optimum selection criteria of a few main parameters of the two-stage device are provided and the coupling of the separate stages in an overall optimum system in terms of the appropriate intermediate temperature is particularly stressed. The maximum efficiency of the proposed overall system can attain 36.2%, which is 17.5% higher than that of the best performing single-stage device, and increase up to 34.1% and 24.8% over the existing two-stage devices designed by two research groups, respectively. The Pareto front obtained from numerical multiobjective and multiparametric methods endorses previous findings and visually presents the space of the states and the energetic properties of the overall arrangement compared with the corresponding data for the isolated first and second stages.China Scholarship Council under the State Scholarship Fund (No. 201906310095

Solar-driven sodium thermal electrochemical converter coupled to a Brayton heat engine: Parametric optimization

[EN]A novel high-efficiency device comprised of three subsystems, a solar collector, a sodium thermal electrochemical converter, and a non-recuperative Brayton heat engine, is modeled by taking into account the main internal and external irreversibility sources. The model extends previous works in which the heat waste of the electrochemical converter is used as heat input in a Brayton gas turbine to study its performance and feasibility when a solar energy input is added. The operative working temperatures of three subsystems are determined by energy balance equations. The dependence of the efficiency and power output of the overall system on the solar concentration ratio, the current density, the thickness of the electrolyte, and the adiabatic pressure ratio (or temperature ratio) of the Brayton cycle is discussed in detail. The maximum efficiencies and power output densities are calculated and the states of the maximum efficiency-power density are determined under different given solar concentration ratios. The parametric optimum selection criteria of a number of critical parameters of the overall system are provided and the matching problems of the three subsystems are properly addressed. It is found that under a solar concentration around 1350, the maximum efficiency and power output density of the proposed hybrid system can reach, respectively, 29.6% and 1:23 105 W/m2. These values amount approximately 32.7% and 156% compared to those of the solar-driven sodium thermal electrochemical converter system without the bottoming Brayton cycle. The Pareto front obtained from numerical multiobjective and multi-parametric methods endorses previous findings.China Scholarship Council under the State Scholarship Fund (No. 201806310020), People’s Republic of China

An assessment of web application with public participation in spatial planning and decision-making for rural building integrations

Se presenta una aplicación web que facilita la integración de construcciones turísticas rurales en su entorno mediante la participación ciudadana. El objetivo general ha sido examinar cómo la investigación puede contribuir a apoyar la toma de decisiones de los usuarios, así como su aplicación a un caso de estudio empírico en Hervás, España. A partir de los datos obtenidos de los participantes, agrupados en cuatro grupos diferentes, este estudio examinó la identificación de modelos espaciales para las distintas percepciones y el intercambio de conocimientos de los procesos de integración de construcciones en el entorno rural, la certificación del posible impacto en el turismo y la definición de una interfaz de usabilidad. Los resultados demostraron que esta web puede facilitar un consenso sobre las recomendaciones para la ordenación del territorio con la implementación de alternativas de decisión.This paper presents the final web implementation and statistical survey results from a continuing broad research project. In this work, a web spatial planning application with public participation was developed to support suitable rural tourism building integrations into a landscape. The general goal of this paper is to examine how research can contribute to support users’ decision-making, together with its application to an empirical case study in Hervás, Spain. With the participants’ data set grouped by four different clusters, this study examined the identification of spatial models for the different perceptions and knowledge sharing of building integrations into a rural landscape, the certification of the possible impact on tourism and the definition of interface usability. The results demonstrated the web could achieve consensus on recommendations for the spatial planning with the implementation of decision alternatives.Trabajo patrocinado por: Universidad de Extremadura. Contrato puente para becarios predoctorales para Jin Su JeongpeerReviewe