477 research outputs found
Modelling Bathymetric Uncertainty
Modelling depth measurement uncertainty during data collection and processing has become common practice since the release of S-44 4th Edition (IHO, 1998). Hydrographic Offices have also attempted to model uncertainty of legacy bathymetry in order to determine their fitness for various uses. Additional uncertainty can be introduced into representative bathymetry models by various gridding techniques that interpolate depths between measurements. This article reviews sources of measurement uncertainty, looks at methods for estimating uncertainty in legacy data sets and uncer-tainty that is introduced into bathymetry (digital elevation/depth) models (DEMs/DDMs) by gridding. Applications that could benefit from bathymetric/DEM/DDM uncertainty information include bridge risk management and tsunami inundation modelling.Keywords: bathymetry, uncertainty, digital elevation modelsLa modelización de la incertidumbre de las medidas de profundidad durante la recogida y el procesa-do de datos se ha convertido en una práctica común desde la publicación de la 4ª Edición de la S-44 (OHI, 1998). Los Servicios Hidrográficos han intentado también modelar la incertidumbre de la batimetrÃa tradicional para determinar su idoneidad para varios usos. Puede introducirse una incerti-dumbre adicional en modelos de batimetrÃa representativos mediante varias técnicas de reticulado que interpolan profundidades entre las medidas. Este artÃculo revisa las fuentes de incertidumbre en las medidas, estudia métodos para estimar la incertidumbre en las colecciones de datos tradicionales y la incertidumbre que se introduce en modelos de batimetrÃa (elevación digital/profundidad) (DEMs/DDMs) mediante el reticulado. Las aplicaciones que podrÃan beneficiar de información relativa a una incertidumbre batimétrica/DEM/DDM incluyen la gestión de los riesgos de puente y la modelización de las inundaciones causadas por los tsunamis.Palabras clave: batimetrÃa, incertidumbre, modelos de elevación digitales.La modélisation de l‘incertitude des mesures des profondeurs pendant la collecte et le traitement des données est devenue pratique commune depuis la publication de la 4ème Edition de la S-44 (OHI, 1998). Les Services hydrographiques se sont également efforcés de modéliser l’incertitude de la bathymétrie traditionnelle afin de déterminer leur aptitude à différentes utilisations. Une incertitude supplémentaire peut être introduite dans des modèles de bathymétrie représentatifs au moyen de différentes techniques de quadrillage qui interpolent les profondeurs entre les mesurages. Cet article passe en revue les sources d‘incertitude dans les mesurages, examine les méthodes d‘estimation de l‘incertitude dans les ensembles de données traditionnels et l‘incertitude introduite dans les modèles d‘élévation ou de profondeurs numériques (DEM/DDM) bathymétriques à l‘aide du quadrillage. Les applications qui pourraient bénéficier d‘informations sur l‘incertitude bathymétrique/DEM/DDM incluent la gestion des risques sur la passerelle et la modélisation des inondations en cas de tsunami.Mots clés : bathymétrie, incertitude, modèles d’élévation numérique
Dominance of grain size impacts on seasonal snow albedo at deforested sites in New Hampshire
Snow cover serves as a major control on the surface energy budget in temperate regions due to its high reflectivity compared to underlying surfaces. Winter in the northeastern United States has changed over the last several decades, resulting in shallower snowpacks, fewer days of snow cover, and increasing precipitation falling as rain in the winter. As these climatic changes occur, it is imperative that we understand current controls on the evolution of seasonal snow albedo in the region. Over three winter seasons between 2013 and 2015, snow characterization measurements were made at three open sites across New Hampshire. These near-daily measurements include spectral albedo, snow optical grain size determined through contact spectroscopy, snow depth, snow density, black carbon content, local meteorological parameters, and analysis of storm trajectories using the Hybrid Single-Particle Lagrangian Integrated Trajectory model. Using analysis of variance, we determine that land-based winter storms result in marginally higher albedo than coastal storms or storms from the Atlantic Ocean. Through multiple regression analysis, we determine that snow grain size is significantly more important in albedo reduction than black carbon content or snow density. And finally, we present a parameterization of albedo based on days since snowfall and temperature that accounts for 52% of variance in albedo over all three sites and years. Our improved understanding of current controls on snow albedo in the region will allow for better assessment of potential response of seasonal snow albedo and snow cover to changing climate
Research information management at ISCTE-IUL: the library’s role
ISCTE-IUL is a Portuguese public university with approximately 9000 students enrolled in undergraduate (46%) and postgraduate (54%) programs. The Repository of ISCTE-IUL is running since 2007 sustained by an Open Access Policy approved in the same year. In 2013, the current research information system – Ciência-IUL – became interoperable with the Repository bringing new challenges to SID, and allowing work collaboratively with other services to collect information, improve processes, and reduce duplication of efforts. SID seeks to support researchers throughout the research life cycle aiming to raise awareness of the academic community for Open Science best practices.info:eu-repo/semantics/publishedVersio
Avaliação de repositórios institucionais : análise comparativa
Só está disponÃvel o resumo.Esta comunicação tem como objetivo apresentar os resultados da monitorização de três repositórios institucionais de instituições do ensino superior, politécnico e universitário, numa perspetiva comparativa
La gestión directiva y su impacto en la calidad educativa: reflexiones a partir de la recuperación de una intervención en un centro educativo de la ZMG
Trabajo que expone el proyecto de intervención realizado en una escuela de Guadalajara que tuvo el objetivo de elevar la calidad educativa. En el diagnóstico que se realizó, se encontró que existÃa un grave problema de disciplina y respeto entre la comunidad escolar, por lo que se definió que era necesario crear un ambiente propicio para que se lograra en los alumnos un aprendizaje significativo. De igual forma, se planteó como objetivo implementar el trabajo colegiado entre los docentes y generar materiales de apoyo para propiciar el aprendizaje en los alumnos
Effective validation of chromatographic analytical methods: The illustrative case of androgenic steroids
Experimental and statistical protocol for the effective validation of chromatographic analytical methods
Optimization and validation of a GC–MS quantitative method for the determination of an extended estrogenic profile in human urine: Variability intervals in a population of healthy women
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