Rings whose class of projective modules is socle fine

A class C of modules over a unitary ring is said to be socle fine if whenever M, N ∈ C with Soc(M) ∼= Soc(N) then M ∼= N. In this work we characterize certain types of rings by requiring a suitable class of its modules to be socle fine. Then we study socle fine classes of quasi-injective, quasi-projective and quasicontinuous modules which we apply to find socle fine classes in special types of noetherian rings. We also initiate the study of those rings whose class of projective modules is socle fine

Reactivity and fate of secondary alkane sulfonates (SAS) in marine sediments

This research is focused on secondary alkane sulfonates (SAS), anionic surfactants widely used in household applications that access aquatic environments mainly via sewage discharges.We studied their sorption capacity and anaerobic degradation in marine sediments, providing the first data available on this topic. SAS partition coefficients increased towards those homologues having longer alkyl chains(from up to 141 L kg 1 for C14 to up to 1753 L kg 1 for C17), which were those less susceptible to undergo biodegradation. Overall, SAS removal percentages reached up to 98% after 166 days of incubation using anoxic sediments. The degradation pathway consisted on the formation of sulfocarboxylic acids after an initial fumarate attack of the alkyl chain and successive b-oxidations. This is the first study showing that SAS can be degraded in absence of oxygen, so this new information should be taken into account for future environmental risk assessments on these chemicals

Genuinely Distributed Byzantine Machine Learning

Machine Learning (ML) solutions are nowadays distributed, according to the so-called server/worker architecture. One server holds the model parameters while several workers train the model. Clearly, such architecture is prone to various types of component failures, which can be all encompassed within the spectrum of a Byzantine behavior. Several approaches have been proposed recently to tolerate Byzantine workers. Yet all require trusting a central parameter server. We initiate in this paper the study of the ``general'' Byzantine-resilient distributed machine learning problem where no individual component is trusted. We show that this problem can be solved in an asynchronous system, despite the presence of $\frac{1}{3}$ Byzantine parameter servers and $\frac{1}{3}$ Byzantine workers (which is optimal). We present a new algorithm, ByzSGD, which solves the general Byzantine-resilient distributed machine learning problem by relying on three major schemes. The first, Scatter/Gather, is a communication scheme whose goal is to bound the maximum drift among models on correct servers. The second, Distributed Median Contraction (DMC), leverages the geometric properties of the median in high dimensional spaces to bring parameters within the correct servers back close to each other, ensuring learning convergence. The third, Minimum-Diameter Averaging (MDA), is a statistically-robust gradient aggregation rule whose goal is to tolerate Byzantine workers. MDA requires loose bound on the variance of non-Byzantine gradient estimates, compared to existing alternatives (e.g., Krum). Interestingly, ByzSGD ensures Byzantine resilience without adding communication rounds (on a normal path), compared to vanilla non-Byzantine alternatives. ByzSGD requires, however, a larger number of messages which, we show, can be reduced if we assume synchrony.Comment: This is a merge of arXiv:1905.03853 and arXiv:1911.07537; arXiv:1911.07537 will be retracte

Determining the distribution of triclosan and methyl triclosan in estuarine settings

We have developed a method for the analysis of two sewage-derived contaminants: triclosan (TCS), an antibacterial agent, and methyl triclosan (MTCS), a TCS metabolite. For solid samples (4 g), extraction and cleanup were integrated into the same step using pressurized liquid extraction (PLE) with in-cell-clean-up (1 g of florisil). The extraction was performed using dichloromethane at 100 °C, 1500 psi and 3 static extraction cycles of 5 min each. For water samples (100 mL), stir bar sorptive extraction–liquid desorption (SBSE–LD) was used. Bars were stirred for 10 h and analytes were later desorbed using acetonitrile. Finally, MTCS and a silylated derivative of TCS were determined by gas chromatography–mass spectrometry (GC–MS). Recovery experiments in water and sediments were performed and the results ranged from 67% to 78%. Limits of detection (LODs) were 5 ng L−1 for TCS and 1 ng L−1 for MTCS, in water samples, and 0.1 ng g−1 for TCS and MTCS in solid samples. The method was applied then to determine the levels of these compounds in the estuary of Guadalete River (SW Spain). TCS and MTCS concentrations up to 9.6 ng g−1 in sediments and 310 ng L−1 in water were measured. Their distribution was strongly influenced by the presence of wastewater sources, treated and untreated, along the sampling area, where maximum concentrations were detected. Highest values were reached in the water column during low tides as the water volume in the estuary becomes lower

Spatio-temporal variability of surface air temperature in northeastern Spain

The present thesis examined changes in the annual and seasonal distribution of daily maximum and minimum temperatures for northeastern Spain. A better understanding of the ongoing changes in the temperature means and extremes was the primary objective. Further aims involved the analysis of large-scale atmospheric circulation patterns at different geopotential levels as well as the Mean Sea Level (MSL) pressure based on climate composites analysis and canonical variates in order to quantify the driving forces beyond the observed variability. Finally, this work aimed to assess future climate projections of seasonal temperature and their spatial variations to improve the understanding and prediction of the long-term trends of temperature means and extremes simulations. To achieve all these goals, it was necessary to develop a homogenous dataset with high spatial and temporal resolution. The next few paragraphs answer the main research questions raised during this work

The Late Quaternary tephrostratigraphy of annually laminated sediments from Meerfelder Maar, Germany

© 2015 Elsevier Ltd.The record of Late Quaternary environmental change within the sediments of Meerfelder Maar in the Eifel region of Germany is renowned for its high precision chronology, which is annually laminated throughout the Last Glacial to Interglacial transition (LGIT) and most of the Holocene. Two visible tephra layers are prominent within the floating varve chronology of Meerfelder Maar. An Early Holocene tephra layer, the Ulmener Maar Tephra (~11,000 varve years BP), provides a tie-line of the Meerfelder Maar record to the varved Holocene record of nearby Lake Holzmaar. The Laacher See Tephra provides another prominent time marker for the late Allerød, ~200 varve years before the transition into the Younger Dryas at 12,680 varve years BP. Further investigation has now shown that there are also 15 cryptotephra layers within the Meerfelder Maar LGIT-Holocene stratigraphy and these layers hold the potential to make direct comparisons between the Meerfelder Maar record and other palaeoenvironmental archives from across Europe and the North Atlantic. Most notable is the presence of the Vedde Ash, the most widespread Icelandic eruption known from the Late Quaternary, which occurred midway through the Younger Dryas. The Vedde Ash has also been found in the Greenland ice cores and can be used as an isochron around which the GICC05 and Meerfelder Maar annual chronologies can be compared. Near the base of the annual laminations in Meerfelder Maar a cryptotephra is found that correlates to the Neapolitan Yellow Tuff, erupted from Campi Flegrei in southern Italy, 1200km away. This is the furthest north that the Neapolitan Yellow Tuff has been found, highlighting its importance in the construction of a European-wide tephrostratigraphic framework. The co-location of cryptotephra layers from Italian, Icelandic and Eifel volcanic sources, within such a precise chronological record, makes Meerfelder Maar one of the most important tephrostratotype records for continental Europe during the Last Glacial to Interglacial transition

An assessment of the role of homogenization protocols in the performance of daily temperature series and trends: application to northeastern Spain

Ponencia presentada en: VII Congreso de la Asociación Española de Climatología: clima, ciudad y ecosistemas, celebrado en Madrid entre el 24 y 26 de noviembre de 2010.This paper details a full protocol applied to develop high resolution daily temperature dataset. Our methodology has been tested from a dataset of 1583 temperature observatories over the NE Spain. The raw dataset was initially tested for internal and external consistency and an algorithm was utilized to reconstruct the daily temperature series for selected candidate observatories. Discontinuities in the reconstructed series were determined by combining the results obtained by three homogeneity tests: the Standard Normal Homogeneity Test (SNHT), the Easterling and Peterson two-phased regression method and the Vincent test. To assess the role of data homogenization, a set of selected tests was applied to the temperature trends and the spatial and frequency properties of the series. Results show significant improvement in the spatial dependence of temperature trends at seasonal and annual scales after application of homogeneity correction. However, frequency statistics of the series evidenced no significant impact of the homogenization procedure. From the temporal and spatial perspectives, the new compiled dataset seems to be outstanding in a variety of meteorological, ecological, hydrological and agricultural research applications at local, regional and continental scales.This work has been supported by the research projects CGL2008-01189/BTE, CGL2006-11619/HID and CGL2008-1083/CLI financed by the Spanish Commission of Science and Technology and FEDER, EUROGEOSS (FP7-ENV-2008-1-226487) and ACQWA (FP7-ENV-2007-1- 212250) financed by the VII Framework Programme of the European Commissio

OptEEmAL: Decision-Support Tool for the Design of Energy Retrofitting Projects at District Level

Designing energy retrofitting actions poses an elevated number of problems, as the definition of the baseline, selection of indicators to measure performance, modelling, setting objectives, etc. This is time-consuming and it can result in a number of inaccuracies, leading to inadequate decisions. While these problems are present at building level, they are multiplied at district level, where there are complex interactions to analyse, simulate and improve. OptEEmAL proposes a solution as a decision-support tool for the design of energy retrofitting projects at district level. Based on specific input data (IFC(s), CityGML, etc.), the platform will automatically simulate the baseline scenario and launch an optimisation process where a series of Energy Conservation Measures (ECMs) will be applied to this scenario. Its performance will be evaluated through a holistic set of indicators to obtain the best combination of ECMs that complies with user's objectives. A great reduction in time and higher accuracy in the models are experienced, since they are automatically created and checked. A subjective problem is transformed into a mathematical problem; it simplifies it and ensures a more robust decision-making. This paper will present a case where the platform has been tested.This research work has been partially funded by the European Commission though the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 680676. All related information to the project is available at https://www.opteemal-project.eu

Gestión de Almacenes en una Empresa Comercial de Materiales Eléctricos e Iluminación

INDICE GENERAL -- Motivaciones -- Objetivos -- Metodología de Aplicación -- Alcances del trabajo -- Capitulo 1 – Marco general -- Conceptos básicos -- Definición de TPM -- Herramientas utilizadas por TPM -- Capítulo 2 – Aplicación en ELCON -- Materiales Eléctricos e Iluminación -- Definición del problema -- Análisis de las causas -- Plan de trabajo “5 eses” -- Capítulo 3 – Conclusiones -- Bibliografía -- Anexos.El presente trabajo está enfocado en la gestión de almacenes de una Pyme netamente comercial, de la Provincia de La Rioja, dedicada al rubro de comercialización de materiales eléctricos e iluminación hacia el consumidor final y venta al por mayor. No se aplica aún la distribución pero es un camino libre a incursionar para esta empresa.Fil: El Adi Quiroga, Martín Nicolas. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina