Geometric calibration of Colour and Stereo Surface Imaging System of ESA's Trace Gas Orbiter

There are many geometric calibration methods for "standard" cameras. These methods, however, cannot be used for the calibration of telescopes with large focal lengths and complex off-axis optics. Moreover, specialized calibration methods for the telescopes are scarce in literature. We describe the calibration method that we developed for the Colour and Stereo Surface Imaging System (CaSSIS) telescope, on board of the ExoMars Trace Gas Orbiter (TGO). Although our method is described in the context of CaSSIS, with camera-specific experiments, it is general and can be applied to other telescopes. We further encourage re-use of the proposed method by making our calibration code and data available on-line.Comment: Submitted to Advances in Space Researc

A strategy for the employment of persons with disabilities

Please read the abstract in the section 00front of this document.Thesis (PhD)--University of Pretoria, 2011.Human Resource Managementunrestricte

Investigation of gamma-ray sensitivity of neutron detectors based on thin converter films

Currently, many detector technologies for thermal neutron detection are in development in order to lower the demand for the rare 3He gas. Gas detectors with solid thin film neutron converters readout by gas proportional counter method have been proposed as an appropriate choice for applications where large area coverage is necessary. In this paper, we investigate the probability for gamma-rays to generate a false count in a neutron measurement. Simulated results are compared to measurement with a 10B thin film prototype and a 3He detector. It is demonstrated that equal gamma-ray rejection to that of 3He tubes is achieved with the new technology. The arguments and results presented here are also applicable to gas detectors with converters other than solid 10B layers, such as 6Li layers and 10BF3 gas.Comment: Submitted to Journal of Instrumentatio

Online GIS services for mapping and sharing disease information

© 2008 Gao et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Towards Web-based representation and processing of health information

<p>Abstract</p> <p>Background</p> <p>There is great concern within health surveillance, on how to grapple with environmental degradation, rapid urbanization, population mobility and growth. The Internet has emerged as an efficient way to share health information, enabling users to access and understand data at their fingertips. Increasingly complex problems in the health field require increasingly sophisticated computer software, distributed computing power, and standardized data sharing. To address this need, Web-based mapping is now emerging as an important tool to enable health practitioners, policy makers, and the public to understand spatial health risks, population health trends and vulnerabilities. Today several web-based health applications generate dynamic maps; however, for people to fully interpret the maps they need data source description and the method used in the data analysis or statistical modeling. For the representation of health information through Web-mapping applications, there still lacks a standard format to accommodate all fixed (such as location) and variable (such as age, gender, health outcome, etc) indicators in the representation of health information. Furthermore, net-centric computing has not been adequately applied to support flexible health data processing and mapping online.</p> <p>Results</p> <p>The authors of this study designed a HEalth Representation XML (HERXML) schema that consists of the semantic (e.g., health activity description, the data sources description, the statistical methodology used for analysis), geometric, and cartographical representations of health data. A case study has been carried on the development of web application and services within the Canadian Geospatial Data Infrastructure (CGDI) framework for community health programs of the New Brunswick Lung Association. This study facilitated the online processing, mapping and sharing of health information, with the use of HERXML and Open Geospatial Consortium (OGC) services. It brought a new solution in better health data representation and initial exploration of the Web-based processing of health information.</p> <p>Conclusion</p> <p>The designed HERXML has been proven to be an appropriate solution in supporting the Web representation of health information. It can be used by health practitioners, policy makers, and the public in disease etiology, health planning, health resource management, health promotion and health education. The utilization of Web-based processing services in this study provides a flexible way for users to select and use certain processing functions for health data processing and mapping via the Web. This research provides easy access to geospatial and health data in understanding the trends of diseases, and promotes the growth and enrichment of the CGDI in the public health sector.</p

Tumor architecture exerts no bias on nuclear grading in breast cancer diagnosis

We recently reported that nuclear grading in prostate cancer is subject to a strong confirmation bias induced by the tumor architecture. We now wondered whether a similar bias governs nuclear grading in breast carcinoma. An unannounced test was performed at a pathology conference. Pathologists were asked to grade nuclei in a PowerPoint presentation. Circular high power fields of 27 invasive ductal carcinomas were shown, superimposed over low power background images of either tubule-rich or tubule-poor carcinomas. We found (a) that diagnostic reproducibility of nuclear grades was poor to moderate (weighed kappa values between 0.07 and 0.54, 27 cases, 44 graders), but (b) that nuclear grades were not affected by the tumor architecture. We speculate that the categorized grading in breast cancer, separating tubule formation, nuclear pleomorphism, and mitotic figure counts in a combined three tier score, prevents the bias that architecture exerts on nuclear grades in less well-controlled situation

Estudio geológico, geodinámica y geotécnico para la seguridad física del tramo carretero Puente Chaullay - Mesacancha, distrito de Vilcabamba -provincia La Convención - departamento Cusco

El "Estudio geológico. geodinámico, geotécnico para la seguridad física del tramo carretero Puente Chaullay - Mesacancha, distrito de Vilcabamba - provincia La Convención - departamento Cusco", es muy importante esta vía para la integración con los demás poblados del interior del país, lo que permitirá no solamente el abastecimiento de los poblados asentados a lo largo de la vía, sino también la salida de los productos agrícolas tropicales existentes en la zona de estudio; además de otros productos procesados en la capital de la Provincia de La Convención - Quillabamba, como son el café, cacao y otros que constituyen una de las más grandes actividades de esta parte de la Región del Cusco. Geomorfológicamente, el Tramo Carretero Puente Chaullay - Mesacancha, (área de estudio), se emplaza en la Cordillera Oriental y Valles Transversales, identificando localmente en la parte media e inferior de una zona de laderas de valle y vertientes montañosas. Superficialmente está cubierta por vegetación y material eluvial coluvial, depositado por acción gravitacional. Geológicamente, la zona de estudio está constituida por materiales que datan del Paleozoico al Cuaternario reciente, la Formación Málaga aflora al NE (inicio del tramo) de la zona en estudio y entre las progresivas Km 0+300 al Km 5+ 638Km, la acumulación de depósitos aluviales se encuentra entre las progresivas Km 6+250 al Km 6+ 750 y del Km 10+650 hasta el final del tramo carretero Km 12+040, principalmente; asi también aflora rocas instrusivas permo triásicas, entre las progresivas Km 7+725 al Km 7+ 920Km y del Km 8+635 al Km 8+790. El área de estudio se enmarca dentro de una zona con alta geodinámica y en un sector con deslizamientos continuos de materiales inestables y de rocas, los cuales ocasionan grandes movimientos de masa. Siendo evidentes todos los factores de riesgo, donde se incrementa la Vulnerabilidad por fenómenos de origen geodinámico. Los peligros naturales constituyen restricciones al uso del territorio, ya que son fenómenos naturales que por su origen y magnitud pueden escapar al control del hombre y generar desastres, no obstante que sus efectos pueden mitigarse. El conocimiento de estos temas permitirán la existencia y el origen de los problemas geodinámicos externos, el tipo de problema, estimar su persistencia en el tiempo, su amplitud, extensión y su evolución, así como la influencia en la estabilidad de la carretera, sobre esta información se definirá las alternativas de solución más adecuadas.Tesi