Multi-robot task allocation problem with multiple nonlinear criteria using branch and bound and genetic algorithms

The paper proposes the formulation of a single-task robot (ST), single-robot task (SR), time-extended assignment (TA), multi-robot task allocation (MRTA) problem with multiple, nonlinear criteria using discrete variables that drastically reduce the computation burden. Obtaining an allocation is addressed by a Branch and Bound (B&B) algorithm in low scale problems and by a genetic algorithm (GA) specifically developed for the proposed formulation in larger scale problems. The GA crossover and mutation strategies design ensure that the descendant allocations of each generation will maintain a certain level of feasibility, reducing greatly the range of possible descendants, and accelerating their convergence to a sub-optimal allocation. The proposed MRTA algorithms are simulated and analyzed in the context of a thermosolar power plant, for which the spatially distributed Direct Normal Irradiance (DNI) is estimated using a heterogeneous fleet composed of both aerial and ground unmanned vehicles. Three optimization criteria are simultaneously considered: distance traveled, time required to complete the task and energetic feasibility. Even though this paper uses a thermosolar power plant as a case study, the proposed algorithms can be applied to any MRTA problem that uses a multi-criteria and nonlinear cost function in an equivalent way. The performance and response of the proposed algorithms are compared for four different scenarios. The results show that the B&B algorithm can find the global optimal solution in a reasonable time for a case with four robots and six tasks. For larger problems, the genetic algorithm approaches the global optimal solution in much less computation time. Moreover, the trade-off between computation time and accuracy can be easily carried out by tuning the parameters of the genetic algorithm according to the available computational power.Unión Europea 789051Ministerio de Ciencia, Innovación y Universidades IJC2018-035395-

Overcoming the Necessity of γ-Substitution in δ-C(sp3)–H Arylation: Pd-Catalyzed Derivatization of α-Amino Acids

Despite the emergence of catalytic C(sp3 )−H arylation at the remote δ-position via challenging six-membered ring cyclometalation, the requirement of blocking the more reactive γ-position represents a restricting limitation. The use of the removable N-(2-pyridyl)sulfonyl directing group provides a viable solution to this challenge, expanding the scope of the Pd-catalyzed δ-C−H arylation of α-amino acid and amine derivatives with (hetero)aryl iodides. This method is compatible with complex, multifunctional structures at either reaction partner. Experimental and density functional theory studies provide insights about the underlying factors controlling site selectivityWe thank the Ministerio de Economía, Industria y Competitividad (MINECO) and Fondo Europeo de Desarrollo Regional (FEDER, UE) (Project CTQ2015-66954-P) and Ministerio de Ciencia e Innovación (MICINN)/FEDER, UE (Agencia Estatal de Investigación/Project PGC2018- 098660-B-I00) for the financial suppor

Observadores Distribuidos Garantistas para Sistemas en Red

En este art´ıculo se propone un observador distribuido garantista para sistemas en red, considerando de forma expl´ıcita el problema de los retardos variables en las comunicaciones. Se asume que la informacion intercambiada entre agentes llega siempre a ´ su destino, si bien las comunicaciones estan sujetas a retardos variables, cuyo valor m ´ aximo ´ se supone conocido. Cada observador trabaja con informacion parcial, y necesita comunicarse con observadores vecinos para llevar a cabo una estimaci ´ on del estado ´ completo del sistema. Para representar a los conjuntos garantistas, cuya funcion es acotar en tiempo real la regi ´ on en la que se ´ encuentra el estado del sistema, se ha optado por la utilizacion de zonotopos. Esto permite integrar de forma sencilla la informaci ´ on´ recibida por cada agente. Finalmente se presentan resultados de simulacion para validar el algoritmo propuesto.Ministerio de Economía y Competitividad DPI2013-44135-RMinisterio de Economía y Competitividad DPI2015-70973-RMinisterio de Economía y Competitividad TEC2016-80242-PUnión Europea TEC2016-80242-

Palladium-Catalyzed PIDA-Mediated δ-C(sp3 ) H Acetoxylation of amino acid derivatives: overriding competitive intramolecular amination

The selective δ-C(sp3)−H acetoxylation of N-(SO2Py)-protected amino acid derivatives has been accomplished by using palladium-catalysis and PhI(OAc)2 (PIDA) as both terminal oxidant and acetoxy source. The distinct structural and electronic features of the SO2Py compared to more traditional carbonyl-based directing groups is essential to override the otherwise more favourable competitive intramolecular C−H amination. The δ-site selectivity predominates over traditionally more favorable 5-membered cyclopalladation at competitive γ-CH2. Experimental and DFT mechanistic studies provide important insights about the mechanism and the underlying factors controlling the chemo- and regioselectivityWe thank the Ministerio de Ciencia e Innovación (MICINN) and Fondo Europeo de Desarrollo Regional (FEDER, UE) for financial support (Agencia Estatal de Investigación/Project PGC2018-098660-B-I00). M.M.-M. thanks MINECO for a FPI predoctoral fellowship and D.S.P. thanks Fonds der chemischen Industrie FCI (PhD fellowship) for financial suppor

Groundwater intensive use and mining in south-eastern peninsular Spain: Hydrogeological, economic and social aspects

Intensive groundwater development is a common circumstance in semiarid and arid areas. Often abstraction exceeds recharge, thus continuously depleting reserves. There is groundwater mining when the recovery of aquifer reserves needs more than 50 years. The MASE project has been carried out to compile what is known about Spain and specifically about the south-eastern Iberian Peninsula and the Canary Islands. The objective was the synthetic analysis of available data on the hydrological, economic, managerial, social, and ethical aspects of groundwater mining. Since the mid-20th century, intensive use of groundwater in south-eastern Spain allowed extending and securing the areas with traditional surface water irrigation of cash crops and their extension to former dry lands, taking advantage of good soils and climate. This fostered a huge economic and social development. Intensive agriculture is a main activity, although tourism plays currently an increasing economic role in the coasts. Many aquifers are relatively high yielding small carbonate units where the total groundwater level drawdown may currently exceed 300 m. Groundwater storage depletion is estimated about 15 km3. This volume is close to the total contribution of the Tagus-Segura water transfer, but without large investments paid for with public funds. Seawater desalination complements urban supply and part of cash crop cultivation. Reclaimed urban waste water is used for irrigation. Groundwater mining produces benefits but associated to sometimes serious economic, administrative, legal and environmental problems. The use of an exhaustible vital resource raises ethical concerns. It cannot continue under the current legal conditions. A progressive change of water use paradigm is the way out, but this is not in the mind of most water managers and politicians. The positive and negative results observed in south-eastern Spain may help to analyse other areas under similar hydrogeological conditions in a less advanced stage of water use evolution

Estimation of the Mass Concentration of Volcanic Ash Using Ceilometers: Study of Fresh and Transported Plumes from La Palma Volcano

This study presents a synergistic approach to the study of the aerosol optical and microphysical properties measured in La Palma, Spain, during the 2021 eruption of the Cumbre Vieja volcano (from 19 September to 13 December 2021). This study aims to characterize the different phases of the volcanic eruption using the spatio-temporal evolution of the event together with the mass concentration quantification of four different atmospheric layers. The impact of the plume’s pathway that reached the South of France is analyzed. Here, passive and active remote sensors were used, namely CL51 and CL61 ceilometers and AERONET sunphotometers. The attenuated backscattering ranged from 0.8 to 9.1 × 10−6 (msr)−1 and the volume depolarization ratio measured nearby the volcano was up to 0.3. The ash plume remained within the first 4 km agl, with intense episodes that reached mean aerosol optical depth values of up to 0.4. Thirteen study cases were selected where coarse mode was dominant over fine mode. For the data selection, the fine and coarse lidar ratios found were 3.9 ± 0.8 and 21.0 ± 3.8 sr in the north and 6.9 ± 1.8 and 30.1 ± 10.3 sr in the south. The ash mass concentration reached moderate levels with maximum values of up to 313.7 μgm−3.This work was financially supported by ONERA within the framework of the PROMETE project 2017–2021; the Spanish Ministry of Science and Innovation (PID2019-103886RB-I00\AEI\10.13039\501100011033); and the H2020 program from the European Union (GA no. 654109, 778349, 871115, 101008004 and 101086690)

From friends to foes: fungi could be emerging marine sponge pathogens under global change scenarios

Global change, experienced in the form of ocean warming and pollution by man-made goods and xenobiotics, is rapidly affecting reef ecosystems and could have devastating consequences for marine ecology. Due to their critical role in regulating marine food webs and trophic connections, sponges are an essential model for studying and forecasting the impact of global change on reef ecosystems. Microbes are regarded as major contributors to the health and survival of sponges in marine environments. While most culture-independent studies on sponge microbiome composition to date have focused on prokaryotic diversity, the importance of fungi in holobiont behavior has been largely overlooked. Studies focusing on the biology of sponge fungi are uncommon. Thus, our current understanding is quite limited regarding the interactions and “crosstalk” between sponges and their associated fungi. Anthropogenic activities and climate change may reveal sponge-associated fungi as novel emerging pathogens. Global change scenarios could trigger the expression of fungal virulence genes and unearth new opportunistic pathogens, posing a risk to the health of sponges and severely damaging reef ecosystems. Although ambitious, this hypothesis has not yet been proven. Here we also postulate as a pioneering hypothesis that manipulating sponge-associated fungal communities may be a new strategy to cope with the threats posed to sponge health by pathogens and pollutants. Additionally, we anticipate that sponge-derived fungi might be used as novel sponge health promoters and beneficial members of the resident sponge microbiome in order to increase the sponge's resistance to opportunistic fungal infections under a scenario of global change

Adaptation of a 1-D tool to study transient thermal in turbocharger bearing housing

[EN] The heat transfer model can be used in a one-dimensional (1-D) engine simulation. When the engine speed is reduced to zero, the codes have been upgraded to calculate transient turbocharger thermal conditions. The turbocharger model has been used as an external plugin. Analysis of the temperature evolution at different parts of the turbocharger is done by using a hot spot engine cycle. A turbocharger bypassing strategy is done by means of a 9 bypass valve system. By using this method, instabilities can be found in the binary on-off state of an engine. During engine hot-stops, the lack of oil flow inside the turbocharger makes the trapped oil in the bearings burnt as the turbine housing exchanges heat with the central housing. Coke formation can appear and produce big reductions in turbocharger endurance, as bearings clogged and damage the shaft. Several strategies can be used in order to minimize possibilities of coke formation, including an increase in the turbocharger cooling during normal operation and the use of electrically-driven pumps acting after the engine is shut down. These strategies can be simulated in acceptable calculation times thanks to modelling strategy proposed in this paper. The presented methodology allows a detailed study of the temperature rise of the central housing of an automotive turbocharger after a hot-stop process, simulating several combinations of cooling strategies in order to find the optimum one in terms of minimising extra energy consumption per K of housing temperature reduction.We thank Przemek Kmiec for his support in the language editing. This work has been partially supported by the Spanish Ministry of Economyand Competitiveness through [grant No. TRA2013-40853-R].Serrano, J.; Tiseira, A.; García-Cuevas González, LM.; Rodriguez-Usaquen, YT. (2018). Adaptation of a 1-D tool to study transient thermal in turbocharger bearing housing. Applied Thermal Engineering. 134:564-575. https://doi.org/10.1016/j.applthermaleng.2018.01.085S56457513

Veterinaria es calidad: Evaluación contínua y autoevaluación

El documento recoge los resultados del proyecto de Innova-Gestion UCM desarrollado durante los años 2016/2017 para la evaluación por rúbrica y online, formando, aplicando y analizando sus resultados. También se exponen los datos preliminares de la opinión de docentes y alumnos sobre su satisfacción con el actual Grado en Veterinaria. Estos resultados son, además, el punto de partida, para continuar mejorando la calidad de la docencia del centro