La formación de suelos sobre dunas costeras

[Resumen] Los suelos que se generan sobre las dunas de arena expresan la importancia relativa entre los procesos geomorfológicos y biológicos. Dependiendo del balance entre estos procesos podemos identificar distintos tipos de suelos.[Abstract] Sand dune express the relative importance of geomorfological an biological processes. Depending on the balance betwen these prosess we can identify different type of soils

Feasible database querying using a visual end-user approach

This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in Proceedings of the 2nd ACM SIGCHI symposium on Engineering interactive computing systems, http://dx.doi.org/10.1145/1822018.1822047Querying databases is a common daily task carried out by a great deal of end-users who do not have specific skills in SQL language. Today, most of the database interaction is achieved by means of query interfaces provided by the database environment. However, most of these interfaces suffer from expressive limitations, since they are mostly based on metaphors that drastically restrict the expressiveness of the SQL language that is generated and executed in the background. In this paper, we present a visual interaction language and tool focused on easily querying databases by end-users. We make no assumption on the level of the user's experience with query languages, as our visual metaphor is intended for querying databases by unskilled end-users and also leveraging the restriction on the expressiveness of the queries created by them. We also report on some late braking results obtained by an experiment carried out with real users.The work reported in this paper is being partially supported by the founded projects TIN2008-02081/TIN and S2009/TIC-1650

Facilitating the interaction with data warehouse schemas through a visual web-based approach

In most respects, there are implicit drawbacks concerning representation and interaction with data in relational-database applications. On the one hand, there is a lack of expressiveness and ease of use in the user interfaces that handle such data. On the other hand, there is an implicit need for interactive end-user visual tools to query data and avoid dependency on programming languages. The main aim of this work is to study the problem of database interaction and usability, comparing existing solutions and providing a new approach that overcomes existing problems. We propose a web-based tool that manipulates Data Warehouse schemas by using a visual language to represent the database structure and providing several visualization techniques that facilitate the interaction and creation of queries involving different levels of complexity. We based our research on an End-User Development approach that has been evaluated to obtain some initial usability indicators

Monitoring and forecasting usability indicators: a business intelligence approach for leveraging user-centered evaluation data

Monitoring performance indicators has become a main concern for most organizations today. While much attention has been paid to developing economic, bioinformatics, health, and social media dashboards, little or no attention has been devoted to monitoring and forecasting usability indicators. This can be of interest for analyzing the degree of perceived satisfaction and usability of interactive software products designed or just developed, being also useful as general strategic indicators in human-centered organizations. This paper presents an approach including main measures, Key Performance Indicators, trends, and forecasts to deal with usability information over time and produce new knowledge based on historical data. Also, an instance has been implemented, including data obtained from real software evaluations. Target users have evaluated the approach to validate its suitability, obtaining successful usability results that denote the adequacy of the approach presentedThis work was partially supported by the Spanish Research Agency [grant numbers TED2021-129381B-C21 and PID2021- 122270OB-I00

Pleba\'nski-Demia\'nski-like solutions in metric-affine gravity

We consider a (non--Riemannian) metric--affine gravity theory, in particular its nonmetricity--torsion sector ``isomorphic'' to the Einstein--Maxwell theory. We map certain Einstein--Maxwell electrovacuum solutions to it, namely the Pleba\'nski--Demia\'nski class of Petrov type D metrics.Comment: 12 pages of a LaTeX-fil

Weathering processes and mineral neoformation at serpentinite areas from Galicia (Spain)

[Resumen] Se realiza un estudio de muestreos en distintos grados de alteración, desde roca fresca a fracción arcilla de horizontes edáficos. El orden de movilidades geoquímicas es Mg > Si, Ca > Na»Al = Fe, en una primera etapa, y un mayor enriquecimiento en Fe en los estadios más avanzados. El grado de alteración aleanzado se encuentra en una posición intermedia al obtenido para este tipo de rocas en áreas mediterráneas y tropicales y siempre es mucho menor que el observado sobre otros materiales básicos de Galicia. A pesar de que termodinámicamente las soluciones de suelos y arroyos se sitúan en un campo intermedio entre filosilicatos 1/1 Y2/1, estos últimos en medios de peor drenaje, la escasez de Al inhibe la formación de arcillas de tipo caolinita, siendo los productos de neoformación típicos en los medios más evolucionados oxihidrósidos de Fe y precipitados silíceos.[Abstract] In a serpentinite area several samples with different degrees of weathering, ranging from fresh rock to clay fractions of soil horizons, were studied. During weathering, the geochemical mobility of the elements follows the order Mg > Si, Ca > Na» Al = Fe in the initial phases, showing a gre.ater aproach to Fe pole in more advanced stages. The intensity of weathering is intermediate between that obtained for serpentinites in mediterranean and tropical areas, and never reachs the high levels found in other basic rocks of Galicia. The composition of stream waters and soil solutions falls between the stability fields of 1/1 and 2/ llayer silicates, last ones mostly in poorly drained areas. In spite of this fact, the scarcity of Al inhibit the formation of kaolinite; iron oxihidroxides and precipitated silica being the most typical secondary products in the more envolved environments

Global design of analog cells using statistical optimization techniques

We present a methodology for automated sizing of analog cells using statistical optimization in a simulation based approach. This methodology enables us to design complex analog cells from scratch within reasonable CPU time. Three different specification types are covered: strong constraints on the electrical performance of the cells, weak constraints on this performance, and design objectives. A mathematical cost function is proposed and a bunch of heuristics is given to increase accuracy and reduce CPU time to minimize the cost function. A technique is also presented to yield designs with reduced variability in the performance parameters, under random variations of the transistor technological parameters. Several CMOS analog cells with complexity levels up to 48 transistors are designed for illustration. Measurements from fabricated prototypes demonstrate the suitability of the proposed methodology

Independent Component Analysis to Detect Clustered Microcalcification Breast Cancers

The presence of clustered microcalcifications is one of the earliest signs in breast cancer detection. Although there exist many studies broaching this problem, most of them are nonreproducible due to the use of proprietary image datasets. We use a known subset of the currently largest publicly available mammography database, the Digital Database for Screening Mammography (DDSM), to develop a computer-aided detection system that outperforms the current reproducible studies on the same mammogram set. This proposal is mainly based on the use of extracted image features obtained by independent component analysis, but we also study the inclusion of the patient's age as a nonimage feature which requires no human expertise. Our system achieves an average of 2.55 false positives per image at a sensitivity of 81.8% and 4.45 at a sensitivity of 91.8% in diagnosing the BCRP_CALC_1 subset of DDSM

Mineralogía de la fracción arcilla de suelos y sedimentos de la Cuenca de Maceda

[Resumen] Se estudia la mineralogía de la fracción arcilla de los sedimentos terciarios y cuaternarios que rellenan la depresión de Maceda,así como de las rocas que constituyen el marco y sus productos de alteración. Las rocas que rodean la cuenca están sometidas actual mente a un proceso de alteración de tipo hidrólisis ácida (caolinita, gibbsita y oxihidróxidos de hierro son los productos de alteración más significativos) Los sedimentos terciarios presentan en su fracción arcilla un filosilicato 1:1 dioctaédrico(haloisítico o caolinítico) como mineral más ahlndante, micas, micas degradadas, goethita y, ocasionalmente, hematita,observándose la presencia de vermiculitas de baja carga en las capas mas profundas. Los depósitos más recientes contienen abundante filo silicato 1:1 dioctaédrico de bajo grado de orden y gibbsita, micas degradadas en cantidades variables y goethita.[Abstract] The igneous and metamorphic rocks that surround the Maceda depressian are subjected to a weathering of acidic hydrolysis type (kaol inite, gibbsite and Fe-oxihydroxides are the more repl'esenta"LJ.ve weathering products). The tertiary sediments have as principal component a 1:1 diocthaedral phyllosilicate (halloysite or kaolini te) associated wi th micas, degradated micas, goethita-:occasionally hematite and in the deepest layers, low charge vermiculites • - The newest deposits have disordered 1:1 diocthaedral phyllosilicate and gibbsite, changing proportions of degradated micas and goethit