3,249 research outputs found
Anchoring vignettes can they make adolescent self-reports of social-emotional skills more reliable, discriminant, and criterion-valid?
Individuals differ in the way they use rating scales to describe themselves, and these differences are particularly pronounced in children and early adolescents. One promising remedy is to correct (or "anchor'') an individual's responses according to the way they use the scale when they rate an anchoring vignette (a set of hypothetical targets differing on the attribute of interest). Studying adolescents' self-reports of their socio-emotional attributes, we compared traditional self-report scores with vignette-corrected scores in terms of reliability (internal consistency), discriminant validity (scale intercorrelations), and criterion validity (predicting achievement test scores in language and math). A large and representative sample of 12th grade Brazilian students (N = 8,582, 62% female, mean age 18.2) were administered a Portuguese-language self-report inventory assessing social-emotional skills related to the Big Five personality dimensions. Correcting scores according to vignette ratings led to increases in the reliability of scales measuring Conscientiousness and Openness, but discriminant validity and criterion validity increased only when each scale was corrected using its own corresponding vignette set. Moreover, accuracy in rating the vignettes was correlated with language achievement test scores, suggesting that verbal factors play a role in providing both normative vignette ratings of others and self-reports that are reliable and valid
MammoApplet: an interactive Java applet tool for manual annotation in medical imaging
Web-based applications in computational medicine have become increasingly important during the last years. The rapid growth of the World Wide Web supposes a new paradigm in the telemedicine and eHealth areas in order to assist and enhance the prevention, diagnosis and treatment of patients. Furthermore, training of radiologists and management of medical databases are also becoming increasingly important issues in the field. In this paper, we present MammoApplet , an interactive Java applet interface designed as a web-based tool. It aims to facilitate the diagnosis of new mammographic cases by providing a set of image processing tools that allow a better visualization of the images, and a set of drawing tools, used to annotate the suspicious regions. Each annotation allows including the attributes considered by the experts when issuing the final diagnosis. The overall set of overlays is stored in a database as XML files associated with the original images. The final goal is to obtain a database of already diagnosed cases for training and enhancing the performance of novice radiologistsPeer ReviewedPostprint (author's final draft
Texture descriptors applied to digital mammography
Breast cancer is the second cause of death among women cancers. Computer Aided Detection has been demon- strated an useful tool for early diagnosis, a crucial as- pect for a high survival rate. In this context, several re- search works have incorporated texture features in mam- mographic image segmentation and description such as Gray-Level co-occurrence matrices, Local Binary Pat- terns, and many others. This paper presents an approach for breast density classi¯cation based on segmentation and texture feature extraction techniques in order to clas- sify digital mammograms according to their internal tis- sue. The aim of this work is to compare di®erent texture descriptors on the same framework (same algorithms for segmentation and classi¯cation, as well as same images). Extensive results prove the feasibility of the proposed ap- proach.Postprint (published version
On the Use of XML in Medical Imaging Web-Based Applications
The rapid growth of digital technology in medical fields over recent years has increased the need for applications able to manage patient medical records, imaging data, and chart information. Web-based applications are implemented with the purpose to link digital databases, storage and transmission protocols, management of large volumes of data and security concepts, allowing the possibility to read, analyze, and even diagnose remotely from the medical center where the information was acquired. The objective of this paper is to analyze the use of the Extensible Markup Language (XML) language in web-based applications that aid in diagnosis or treatment of patients, considering how this protocol allows indexing and exchanging the huge amount of information associated with each medical case. The purpose of this paper is to point out the main advantages and drawbacks of the XML technology in order to provide key ideas for future web-based applicationsPeer ReviewedPostprint (author's final draft
Relación entre expectativas y percepciones de los pacientes con la atención en consulta externa en medicina interna
Objetivo: Determinar la relación entre expectativas y percepciones de los pacientes con la
atención en consulta externa en medicina interna en Hospital Belén de Trujillo, en el
periodo Enero - Febrero 2017.
Material y Métodos: Se llevó a cabo un estudio de tipo descriptivo, observacional,
transversal, descriptivo correlacional. La población de estudio estuvo constituida por 192
pacientes quienes se dividieron en 2 grupos: con percepción favorable o desfavorable; se
aplicó la prueba de chi cuadrado y el coeficiente de correlación de Pearson.
Resultados: No se apreciaron diferencias significativas en relación a las variables edad y
sexo entre los grupos con percepción favorable o desfavorable (p<0.05). La distribución de
los pacientes según expectativa global de atención fue: favorable (77%) y desfavorable
(23%). La distribución de los pacientes según percepción global de atención fue: favorable
(64%) y desfavorable (36%). Existe correlación entre las expectativas y las percepciones
de los pacientes atendidos en consulta externa de medicina interna, con un coeficiente de
Pearson de 0.76.
Conclusiones: Existe relación entre expectativas y percepciones de los pacientes con la
atención en consulta externa en medicina interna del Hospital Belén de Trujillo, en el
periodo Enero - Febrero 2017.Objective: To determine the relationship between expectations and perceptions of patients
with outpatient care in internal medicine at Hospital Belén de Trujillo, during the period
January - February 2017.
Material and Methods: A descriptive, observational, retrospective, correlational
descriptive study was carried out. The study population consisted of 192 patients who were
divided into 2 groups: with favorable or unfavorable perception; the chi square test and the
Pearson correlation coefficient were applied.
Results: There were no significant differences in relation to the variables age and sex
between the groups with favorable or unfavorable perception (p <0.05). The distribution of
patients according to the global expectation of care was favorable (77%) and unfavorable
(23%). The distribution of patients according to global perception of care was favorable
(64%) and unfavorable (36%). There is a correlation between the expectations and the
perceptions of the patients seen in an outpatient internal medicine, with a Pearson
coefficient of 0.76.
Conclusions: There is a relationship between expectations and perceptions of patients with
the outpatient care in internal medicine at Hospital Belén de Trujillo, in the period January
- February 2017.Tesi
RFID in the Cloud: A Service for High-Speed Data Access in Distributed Value Chains
Radio-Frequency Identification (RFID) is emerging as an important technology for exchanging information about physical objects along distributed value chains. The influential standardization organization EPCglobal has released standards for RFID-based data exchange that follow the data-on-network paradigm. Here, the business-relevant object data is provided by network services, whereas RFID tags are only used to carry a reference number for data retrieval via the Internet. However, as we show in this paper, this paradigm can result in long response times for data access. We present experiments that explore what factors impact the response times and identify obstacles in current architectures. Based on these analyses, we designed a cloud-based service that realizes high-speed data access for data-on-network solutions. We further present simulation experiments analyzing the benefits of our cloud-based concept with regards to fast RFID-data access and reduced infrastructure cost through scale effects
DESIGN AND OPTIMIZATION OF A FAST-NEUTRON, EXTERNALLY DRIVEN THORIUM-LITHIUM-BERYLLIUM FLUORIDE MOLTEN SALT SUBCRITICAL ASSEMBLY
An externally driven subcritical molten FLiBe-Thorium LiF-BeF2-ThF4 (52.8-27.2-20 mol%) salt assembly is being constructed at Texas A&M Nuclear Engineering and Science Center (NESC). The experiment is called the Thorium Engineering and Science Assembly (ThESA). The objective of ThESA was to be a separate effects test to isolate the phenomenon of thorium-232 fissioning in a FLiBe medium. ThESA was chosen to be driven with a deuteron-deuteron generator to ensure an unobscured fission neutron flux above the 3 MeV threshold. It was the objective of this thesis to support the design of ThESA to ensure the maximization of thorium fissioning in a FLiBe medium.
The thesis work was initiated with a comparison study between differing pin and pool assembly types. Multiple pins and pool type assemblies were analyzed using MCNP with either FLiBe-Th or a combination of FLiBe and ThO2 to measure the effective neutron multiplication factor (k-inf), neutron flux, and fission rates. The comparison study included each design's practicality, such as fuel heating, transportation, and glovebox physical restraints, as well as neutronics results. The results of the comparison study indicated that a pool-type would be the superior choice in producing the most thorium fissions in FLiBe. The pool-type assembly was also the most experimentally practical considering design and operational constraints. Following the final assembly choice, a parametric reflector study was performed on the pool type assembly. The reflector study results indicated that the ThESA objective would not benefit from a reflector, considering a large and heavy reflector's cost and complexity. After the mechanical team matured the design, a safety analysis was performed that included dose rates, criticality simulations, and an assessment to ensure no proliferation threats. The safety analyses revealed no significant hazards from ThESA. Then the addition of steel inserts in the pool intended for data gathering equipment was included in the MCNP model. The inclusion of the steel inserts was done to ensure that there would not be a significant reduction in the thorium fission rate. The analysis revealed that steel inserts would not induce a meaningful reduction in the assembly's fission rate. The final study goal was to capture the energy dependent neutron flux spectrum to capture the fraction of fission neutrons that, with certainty, would be differentiable from the source neutrons. The flux was subdivided into energy groups to observe the neutrons born from fission with energies above 3 MeV. The 3 MeV threshold was chosen due to the lack of source neutrons above this energy range. The total neutrons produced from fission above 3 MeV was 2.87E5 +/- 5.75E+01 neutrons per second. The work performed in this study did reveal that there was a substantial fission neutron population that could be differentiated from the source neutrons to be studied in an isolated effects test
Modelling Unmanned Vehicles Mission Planning problems as Constraint Satisfaction Problems
This Master Thesis provides a first analysis of mission planning for Unmanned Air Vehicles (UAVs), dealing with multiple UAVs that must perform one or more tasks in a set of waypoints and specific time windows. The solution plans obtained should fulfill all the constraints given by the different components and capabilities of the UAVs involved over the time periods given. Therefore a Temporal Constraint Satisfaction Problem (TCSP) representation is needed.
In a first approach, a temporal constraint model is implemented and tested by performing Backtracking
(BT) search in several missions. In this model, a set of resources and temporal constraints are designed to represent the main characteristics (task time, fuel consumption, ...) of this kind of aircrafts. On the other hand, BT algorithm is used to look through the whole
solutions space to measure the scalability of the problem.
In a second approach, we consider a Constraint Satisfaction Optimization Problem (CSOP) with an optimization function to minimize the fuel cost, the flight time and the number of UAVs
needed; and Branch & Bound (B&B) search is employed for solving this CSOP model. Finally, some experiments will be carried out to validate both the quality of the solutions found and the runtime spent to found them.El presente proyecto final de máster muestra un primer análisis sobre planificación de misiones para VehÃculos Aéreos no tripulados (UAVs), donde se trata con múltiples UAVs que deben realizar una o más tareas en un conjunto de puntos o waypoints y en una ventana temporal especÃfica. Los planes obtenidos como solución deben cumplir todas las restricciones dadas por los diferentes componentes y capacidades de los UAVs involucrados en un periodo de tiempo dado. Por tanto, se precisa de una representación del problema como un Problema de Satisfacción de Restricciones Temporales (TCSP).
En una primera aproximación, se implementa un modelo de restricciones temporales y se testea ejecutando una búsqueda Backtracking (BT) cronológico en varias misiones. En este modelo, se
diseñan un conjunto de restricciones temporales y de recursos para representar las principales caracterÃsticas (tiempo de la tarea, consumo de combustible, ...) de este tipo de aviones. Por
otro lado, el algoritmo BT es usado para examinar todo el espacio de soluciones para medir la escalabilidad del problema.
En una segunda aproximación, consideramos un Problema de Optimización de Satisfacción de Restricciones (CSOP) con una función de optimización que minimice el coste de combustible,
el tiempo de vuelo y el número de UAVs necesarios; y se utiliza Branch & Bound (B&B) para resolver este modelo de CSOP. Finalmente, se realizarán algunos experimentos para validar tanto
la calidad de las soluciones encontradas como el tiempo de ejecución gastado en su búsqueda
Diseño de la plaza de mercado ubicada en el sector sur oriental del municipio de Túquerres.
El trabajo de grado denominado diseño de la plaza de mercado ubicada en el sector
sur oriental del municipio de Túquerres, se enfoca en una propuesta de diseño por
medio de la cual se realiza una observación, análisis e investigación de las
condiciones actuales de las plazas de mercado y su incidencia sobre las
actividades de la ciudad, evaluando los impactos ambientales y el deterioro de los
usos educativo, y de movilidad con el fin de mejorar las condiciones actuales tanto
de la plaza de mercado como de la calidad de vida de los habitantes.
Con esta propuesta se plantea realizar una intervención que permita la reubicación
de la plaza de mercado central y un cambio de uso de la plaza Santa MarÃa, además
de una propuesta sistémica que mejore las condiciones ambientales, de movilidad,
de usos y equipamientos y espacio público.
La nueva plaza de mercado además de formar parte de un sistema de ciudad,
cumple con las condiciones para la comercialización de alimento como frutas,
verduras, carnes, mariscos, artesanÃas, graneros. Además cuanta con espacios
complementarios como bodegas, administración, restaurante, baterÃas sanitarias,
parqueaderos, parque infantil, zonas verdes, transporte público y ventas al aire
libre
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