5,573 research outputs found
Random exams using Sweave
The adaptation of the Spanish University to the European Higher Education Area (EEES in Spanish) demands the integration of new tools and skills that would make the teaching- learning process easier. This adaptation involves a change in the evaluation methods, which goes from a system where the student was evaluated with a final exam, to a new system where we include a continuous evaluation in which the final exam may represent at most 50% in the vast majority of the Universities. Devising a new and fair continuous evaluation system is not an easy task to do. That would mean a studentâsâ learning process follow-up by the teachers, and as a consequence an additional workload on existing staff resources. Traditionally, the continuous evaluation is associated with the daily work of the student and a collection of the different marks partly or entirely based on the work they do during the academic year. Now, small groups of students and an attendance control are important aspects to take into account in order to get an adequate assessment of the students. However, most of the university degrees have groups with more than 70 students, and the attendance control is a complicated task to perform, mostly because it consumes significant amounts of staff time. Another problem found is that the attendance control would encourage not-interested students to be present at class, which might cause some troubles to their classmates. After a two year experience in the development of a continuous assessment in Statistics subjects in Social Science degrees, we think that individual and periodical tasks are the best way to assess results. These tasks or examinations must be done in classroom during regular lessons, so we need an efficient system to put together different and personal questions in order to prevent students from cheating. In this paper we provide an efficient and effective way to elaborate random examination papers by using Sweave, a tool that generates data, graphics and statistical calculus from the software R and shows results in PDF documents created by Latex. In this way, we will be able to design an exam template which could be compiled in order to generate as many PDF documents as it is required, and at the same time, solutions are provided to easily correct them
Discovering the Fine-Scale Morphology of the Gulf of CĂĄdiz: An Underwater Imaging Analysis
The dense and deep water flow that leaves the Mediterranean Sea to the Atlantic flows
through the upper and middle slope of the Gulf of CĂĄdiz as a powerful bottom stream that model sand interacts with bathymetry. The detailed analysis of underwater images,obtained with a photogrammetric sled in the central area of the upper and middle slope of the Gulf of CĂĄdiz, together with multibeam bathymetry and oceanographic and sediment types data, has allowed conducting a detailed study of the seafloor microtopography and the predominant oceanographic dynamics in the study area. Different fine-scale spatial bedforms were identified, such as ripples, dunes, burrows, mounds, obstacle marks, rock bottoms, and low-roughness bottoms using underwater images. Besides, a geostatistical study of the different video transects studied was carried out and allowed us to differentiate three types of bottoms depending on the processes that affect their microtopography.En prens
Aplicaciones diseĂąadas con Shiny: un recurso docente para la enseĂąanza de la estadĂstica
El departamento de MatemĂĄticas de la Facultad de Ciencias de la Universidad de Alicante imparte las asignaturas de EstadĂstica en los grados de CriminologĂa, Relaciones Laborales y Recursos Humanos y GestiĂłn y AdministraciĂłn PĂşblica, todos ellos adscritos a la Facultad de Derecho, y es consciente de la dificultad que presenta su aprendizaje para los estudiantes de estas titulaciones no tĂŠcnicas, aun siendo un ĂĄrea de gran importancia en el estudio de las Ciencias Sociales. Estas dificultades pueden ser subsanadas, en parte, proporcionando materiales bien organizados. Sin embargo, en muchas ocasiones, dichos materiales resultan insuficientes ante la necesidad de una mayor cantidad de ejercicios de naturaleza metodolĂłgica que permitan a los estudiantes un mayor entrenamiento. Recientemente, el software estadĂstico R ha incluido en su repositorio un paquete de instrucciones llamado Shiny que permite la creaciĂłn de aplicaciones web interactivas. En este trabajo, presentamos unos recursos docentes diseĂąados con Shiny que ponen al alcance de los alumnos tantos ejercicios como deseen, permitiĂŠndoles entrenar sus capacidades matemĂĄticas y estadĂsticas de manera individual desde su propia casa
Uso de Sweave para crear exĂĄmenes aleatorios
La adaptaciĂłn del sistema universitario espaĂąol al Espacio Europeo de EducaciĂłn Superior exige la inclusiĂłn de nuevos mĂŠtodos de evaluaciĂłn continua. Tradicionalmente, la evaluaciĂłn continua ha sido asociada con el trabajo diario del estudiante y una recopilaciĂłn de notas parciales que a dĂa de hoy resulta complicada debido al gran tamaĂąo de los grupos en los que se organizan las clases. Tras estos primeros aĂąos, creemos que la evaluaciĂłn mediante controles periĂłdicos es la mejor manera de valorar los resultados del proceso de aprendizaje diario. Sin embargo, la realizaciĂłn adecuada exige el diseĂąo de diferentes modelos de examen. En este trabajo, proponemos un sistema eficiente para confeccionar controles âaleatoriosâ a travĂŠs de Sweave, un paquete asociado al software libre R que proporciona datos, grĂĄficos y cĂĄlculos estadĂsticos y muestra los resultados en documentos PDF compilados en Latex. De esta forma, podremos generar tantos controles con diferentes datos como queramos siguiendo una estructura comĂşn, asĂ como las correspondientes soluciones para poder corregirlos con facilidad
Las asignaturas de Ălgebra Lineal y GeometrĂa Lineal en el Grado en MatemĂĄticas de la Universidad de Alicante
DespuĂŠs de varios aĂąos de implantaciĂłn del Grado en MatemĂĄticas de la Facultad de Ciencias de la Universidad de Alicante se plantea la necesidad de analizar el desarrollo de las asignaturas impartidas en el mismo y de abordar posibles mejoras. En esta red nos ocuparemos concretamente de las asignaturas correspondientes al Ălgebra Lineal y a la GeometrĂa Lineal. Estas asignaturas no han sido diseĂąadas por un Ăşnico profesor, sino que distintos profesores han participado en la elaboraciĂłn de las guĂas docentes y en la imparticiĂłn de las mismas. AsĂ pues, consideramos que resulta pertinente revisar de manera conjunta los contenidos para evitar solapamientos y, si procede, replantear alguno de los temas de manera que se puedan optimizar tanto los tiempos como los desarrollos teĂłrico-prĂĄcticos de las tres asignaturas revisadas. La red estĂĄ coordinada por la responsable de la asignatura GeometrĂa lineal hasta el curso 2014-2015 y constituida por los profesores que imparten las asignaturas Ălgebra Lineal I, Ălgebra Lineal II y GeometrĂa Lineal y por dos alumnos del Ăşltimo curso. Nuestro propĂłsito es detectar posibles lagunas, repeticiones o deficiencias y asĂ contribuir a la mejora de la docencia en estas asignaturas a partir de propuestas concretas
Dise?o, procura, construcci?n e implementaci?n de la torre de control para la nueva base aeronaval del Callao
Concebido por un equipo multidisciplinario, con diferentes visiones y experiencias para abordar los procesos de inicio y planificaci?n del proyecto ?Dise?o, procura, construcci?n e implementaci?n de la torre de control para la nueva base aeronaval del Callao?; permitiendo as? que la direcci?n de proyectos en sus diferentes fases de planeaci?n sea un proceso innovador, por medio de GISA, empresa de ingenier?a y construcci?n con una trayectoria de 20 a?os. El proyecto forma parte del megaproyecto de remodelaci?n de la base aeronaval del Callao para la Marina de Guerra del Per?. ?ste abarca la gesti?n, dise?o, procura construcci?n de una torre de control de medidas reglamentarias, implementaci?n de equipos de telecomunicaci?n de ?ltima generaci?n y capacitaci?n al personal usuario del cliente, hasta obtener la certificaci?n internacional. GISA ha establecido objetivos de eficiencia (2) alineados con la triple restricci?n, objetivos de producto (2) orientados a la conexi?n de los equipos de telecomunicaciones, as? como la obtenci?n de la certificaci?n aeron?utica internacional y satisfacci?n de stakeholders; para ello ha desarrollado los planes subsidiarios necesarios con plena conciencia de los factores pol?ticos, econ?micos, tecnol?gicos, ecol?gicos, legales y socioculturales presentes. El ?xito del proyecto posicionar? a GISA como un contratista preferente para el Estado
The ROSAT International X-ray/Optical Survey (RIXOS): source catalogue
We describe the ROSAT International X-ray/Optical Survey (RIXOS), a medium-sensitivity survey and optical identification of X-ray sources discovered in ROSAT high Galactic latitude fields (|b|>28°) and observed with the Position Sensitive Proportional Counter (PSPC) detector. The survey made use of the central 17 arcmin of each ROSAT field. A flux limit of 3Ă10â14 erg cmâ2 sâ1 (0.5â2 keV) was adopted for the survey, and a minimum exposure time of 8000 s was required for qualifying ROSAT observations. X-ray sources in the survey are therefore substantially above the detection threshold of each field used, and many contain enough counts to allow the X-ray spectral slope to be estimated.
Spectroscopic observations of potential counterparts were obtained of all sources down to the survey limit in 64 fields, totalling a sky area of 15.77 deg2. Positive optical identifications are made for 94 per cent of the 296 sources thus examined. A further 18 fields (4.44 deg2), containing 105 sources above the 3Ă10â14 erg cmâ2 sâ1 survey limit, are completely optically identified to a higher flux of 8Ă10â14 erg cmâ2 sâ1 (0.5â2 keV). Optical spectroscopic data are supplemented by deep CCD imaging of many sources to reveal the morphology of the optical counterparts, and objects too faint to register on Sky Survey plates. The faintest optical counterparts have Râź22.
This paper describes the survey method, and presents a catalogue of the RIXOS sources and their optical identifications. Finding charts based on Sky Survey data are given for each source, supplemented by CCD imaging where necessary
Precise measurement of the W-boson mass with the CDF II detector
We have measured the W-boson mass MW using data corresponding to 2.2/fb of
integrated luminosity collected in proton-antiproton collisions at 1.96 TeV
with the CDF II detector at the Fermilab Tevatron collider. Samples consisting
of 470126 W->enu candidates and 624708 W->munu candidates yield the measurement
MW = 80387 +- 12 (stat) +- 15 (syst) = 80387 +- 19 MeV. This is the most
precise measurement of the W-boson mass to date and significantly exceeds the
precision of all previous measurements combined
Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV
A search for new physics is presented based on an event signature of at least
three jets accompanied by large missing transverse momentum, using a data
sample corresponding to an integrated luminosity of 36 inverse picobarns
collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector
at the LHC. No excess of events is observed above the expected standard model
backgrounds, which are all estimated from the data. Exclusion limits are
presented for the constrained minimal supersymmetric extension of the standard
model. Cross section limits are also presented using simplified models with new
particles decaying to an undetected particle and one or two jets
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
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