18 research outputs found
Toma de decisiones en el sector turismo mediante el uso de Sistemas de Información Geográfica e inteligencia de negocios
Currently, business intelligence is present in any process of data analysis, mainly due to the advantages that the moment of evaluation of market viability, inclusion of new products, and if any activity that requires knowing people's consumption habits has Within these activities, there is tourism, since, for this sector it is also important to be able to make decisions and focus on potentializing the regions according to the needs or interests of the people. In addition, by integrating business intelligence, aspects related to space, to determine proximity, or the displacement of people between regions, through the use of Geographic Information Systems (GIS) you can obtain a visual representation of the state of tourism in a region of interest and even evaluate the integration of the affected regions and offer planes together to have benefits and joint progress. In this sense, this article presents a systematic review of literature on the use of geographic information systems and business intelligence for decision-making supported in the tourism sector; for which articles published during the period 2015 to 2019 in the Scopus and IEEE databases will be analyzed. It was obtained as a result that during the last years (2015-2019) the trend in research related to the use of GIS in tourism has been increasing. It is concluded that thanks to technological advances, the use of, WebGIS, Open Source GIS, tourism business managers have built Tourist Resources Information systems.Actualmente, la inteligencia de negocios está presente en cualquier proceso de análisis de datos, principalmente, en casos en los que se evalúa la viabilidad de mercados, la inclusión de nuevos productos o la actividad que permite conocer los hábitos de consumo de las personas, lo cual muestra ventajas evidentes. El sector turístico tiene como fin proyectar y potencializar a las regiones, según las necesidades o intereses de las personas, por lo que los modelos de inteligencia de negocios son de fundamental utilidad para cumplir con dicho objetivo. Adicionalmente, al integrar a la inteligencia de negocios, aspectos relacionados con el espacio para determinar la cercanía o el desplazamiento de las personas entre regiones, mediante el uso de Sistemas de Información Geográfica (SIG), se puede obtener una representación visual del estado del turismo en una región de interés e incluso evaluar la integración de regiones cercanas y ofrecer planes en conjunto para tener beneficios y progreso conjunto. Este artículo presenta una revisión sistemática de literatura sobre el uso de sistemas de información geográfica y de inteligencia de negocios para la toma de decisiones apoyadas en el sector turismo; para lo cual se analizaron artículos publicados durante 2015-2019 en las bases de datos Scopus e IEEE. Se obtuvo como resultado que durante dicho periodo la tendencia en investigaciones relacionadas con la temática de uso de los GIS en turismo ha sido creciente. Se concluye que gracias a los avances tecnológicos con el uso de las WebGIS y Open Source GIS, los gerentes de empresas turísticas han podido construir sistemas de Información de Recursos Turísticos
Ontomastitis: ontología para la mastitis bovina
Mastitis is a cow disease caused by an infection in the mammary gland due to bacteria entering through the skin. This disease can have repercussions directly on the quality of the milk and thus, on the incomes of the producers. Therefore, the objective of this work was creating ontology with mastitis in order to provide a tool for veterinarians, which helps in the search of information related to different cases and treatments. Methontology and Protégé methodologies were respectively used in order to develop and formalize the ontology. As a result of the process, it was obtained an ontology integration model for mastitis, with an information system for medical diagnose
Characterization of protons accelerated from a 3 TW table-top laser system
[EN] We report on benchmark tests of a 3 TW/50 fs, table-top laser system specifically developed for proton acceleration with an intrinsic pump rate up to 100 Hz. In two series of single-shot measurements differing in pulse energy and contrast the successful operation of the diode pumped laser is demonstrated. Protons have been accelerated up to 1.6 MeV in interactions of laser pulses focused on aluminium and mylar foils between 0.8 and 25 mu m thickness. Their spectral distributions and maximum energies are consistent with former experiments under similar conditions. These results show the suitability of our system and provide a reference for studies of laser targets at high repetition rate and possible applications.This project has been funded by Centro para el Desarrollo Tecnologico Industrial (CDTI, Spain) within the INNPRONTA program, grant no. IPT-20111027, by EUROSTARS project E9113, and by the Spanish Ministry for Economy and Competitiveness within the Retos-Colaboracion 2015 initiative, ref. RTC-2015-3278-1.Bellido-Millán, PJ.; Lera, R.; Seimetz, M.; Ruiz-De La Cruz, A.; Torres Peiró, S.; Galán, M.; Mur, P.... (2017). Characterization of protons accelerated from a 3 TW table-top laser system. Journal of Instrumentation. 12:1-12. https://doi.org/10.1088/1748-0221/12/05/T05001S11212Daido, H., Nishiuchi, M., & Pirozhkov, A. S. (2012). Review of laser-driven ion sources and their applications. Reports on Progress in Physics, 75(5), 056401. doi:10.1088/0034-4885/75/5/056401Macchi, A., Borghesi, M., & Passoni, M. (2013). Ion acceleration by superintense laser-plasma interaction. Reviews of Modern Physics, 85(2), 751-793. doi:10.1103/revmodphys.85.751Ledingham, K., Bolton, P., Shikazono, N., & Ma, C.-M. (2014). Towards Laser Driven Hadron Cancer Radiotherapy: A Review of Progress. Applied Sciences, 4(3), 402-443. doi:10.3390/app4030402Kraft, S. D., Richter, C., Zeil, K., Baumann, M., Beyreuther, E., Bock, S., … Pawelke, J. (2010). Dose-dependent biological damage of tumour cells by laser-accelerated proton beams. New Journal of Physics, 12(8), 085003. doi:10.1088/1367-2630/12/8/085003Yogo, A., Sato, K., Nishikino, M., Mori, M., Teshima, T., Numasaki, H., … Daido, H. (2009). Application of laser-accelerated protons to the demonstration of DNA double-strand breaks in human cancer cells. Applied Physics Letters, 94(18), 181502. doi:10.1063/1.3126452Fritzler, S., Malka, V., Grillon, G., Rousseau, J. P., Burgy, F., Lefebvre, E., … Ledingham, K. W. D. (2003). Proton beams generated with high-intensity lasers: Applications to medical isotope production. Applied Physics Letters, 83(15), 3039-3041. doi:10.1063/1.1616661Kishimura, H., Morishita, H., Okano, Y. H., Okano, Y., Hironaka, Y., Kondo, K., … Nemoto, K. (2004). Enhanced generation of fast protons from a polymer-coated metal foil by a femtosecond intense laser field. Applied Physics Letters, 85(14), 2736-2738. doi:10.1063/1.1803915Nakamura, S., Iwashita, Y., Noda, A., Shirai, T., Tongu, H., Fukumi, A., … Wada, Y. (2006). Real-Time Optimization of Proton Production by Intense Short-Pulse Laser with Time-of-Flight Measurement. Japanese Journal of Applied Physics, 45(No. 34), L913-L916. doi:10.1143/jjap.45.l913Nishiuchi, M., Fukumi, A., Daido, H., Li, Z., Sagisaka, A., Ogura, K., … Nakamura, S. (2006). The laser proton acceleration in the strong charge separation regime. Physics Letters A, 357(4-5), 339-344. doi:10.1016/j.physleta.2006.04.053Yogo, A., Daido, H., Fukumi, A., Li, Z., Ogura, K., Sagisaka, A., … Itoh, A. (2007). Laser prepulse dependency of proton-energy distributions in ultraintense laser-foil interactions with an online time-of-flight technique. Physics of Plasmas, 14(4), 043104. doi:10.1063/1.2721066Robinson, A. P. L., Foster, P., Adams, D., Carroll, D. C., Dromey, B., Hawkes, S., … Neely, D. (2009). Spectral modification of laser-accelerated proton beams by self-generated magnetic fields. New Journal of Physics, 11(8), 083018. doi:10.1088/1367-2630/11/8/083018Nemoto, K., Maksimchuk, A., Banerjee, S., Flippo, K., Mourou, G., Umstadter, D., & Bychenkov, V. Y. (2001). Laser-triggered ion acceleration and table top isotope production. Applied Physics Letters, 78(5), 595-597. doi:10.1063/1.1343845Lee, K., Park, S. H., Cha, Y.-H., Lee, J. Y., Lee, Y. W., Yea, K.-H., & Jeong, Y. U. (2008). Generation of intense proton beams from plastic targets irradiated by an ultraintense laser pulse. Physical Review E, 78(5). doi:10.1103/physreve.78.056403Yogo, A., Daido, H., Bulanov, S. V., Nemoto, K., Oishi, Y., Nayuki, T., … Tajima, T. (2008). Laser ion acceleration via control of the near-critical density target. Physical Review E, 77(1). doi:10.1103/physreve.77.016401Lee, K., Lee, J. Y., Park, S. H., Cha, Y.-H., Lee, Y. W., Kim, K. N., & Jeong, Y. U. (2011). Dominant front-side acceleration of energetic proton beams from plastic targets irradiated by an ultraintense laser pulse. Physics of Plasmas, 18(1), 013101. doi:10.1063/1.3496058OKIHARA, S., SENTOKU, Y., SUEDA, K., SHIMIZU, S., SATO, F., MIYANAGA, N., … SAKABE, S. (2002). Energetic Proton Generation in a Thin Plastic Foil Irradiated by Intense Femtosecond Lasers. Journal of Nuclear Science and Technology, 39(1), 1-5. doi:10.1080/18811248.2002.9715150McKenna, P., Ledingham, K. W. D., Spencer, I., McCany, T., Singhal, R. P., Ziener, C., … Clark, E. L. (2002). Characterization of multiterawatt laser-solid interactions for proton acceleration. Review of Scientific Instruments, 73(12), 4176-4184. doi:10.1063/1.1516855Spencer, I., Ledingham, K. W. D., McKenna, P., McCanny, T., Singhal, R. P., Foster, P. S., … Davies, J. R. (2003). Experimental study of proton emission from 60-fs, 200-mJ high-repetition-rate tabletop-laser pulses interacting with solid targets. Physical Review E, 67(4). doi:10.1103/physreve.67.046402Kaluza, M., Schreiber, J., Santala, M. I. K., Tsakiris, G. D., Eidmann, K., Meyer-ter-Vehn, J., & Witte, K. J. (2004). Influence of the Laser Prepulse on Proton Acceleration in Thin-Foil Experiments. Physical Review Letters, 93(4). doi:10.1103/physrevlett.93.045003Ceccotti, T., Lévy, A., Popescu, H., Réau, F., D’Oliveira, P., Monot, P., … Martin, P. (2007). Proton Acceleration with High-Intensity Ultrahigh-Contrast Laser Pulses. Physical Review Letters, 99(18). doi:10.1103/physrevlett.99.185002Neely, D., Foster, P., Robinson, A., Lindau, F., Lundh, O., Persson, A., … McKenna, P. (2006). Enhanced proton beams from ultrathin targets driven by high contrast laser pulses. Applied Physics Letters, 89(2), 021502. doi:10.1063/1.2220011Steinke, S., Henig, A., Schnürer, M., Sokollik, T., Nickles, P. V., Jung, D., … Habs, D. (2010). Efficient ion acceleration by collective laser-driven electron dynamics with ultra-thin foil targets. Laser and Particle Beams, 28(1), 215-221. doi:10.1017/s0263034610000157Strickland, D., & Mourou, G. (1985). Compression of amplified chirped optical pulses. Optics Communications, 56(3), 219-221. doi:10.1016/0030-4018(85)90120-8Yogo, A., Kondo, K., Mori, M., Kiriyama, H., Ogura, K., Shimomura, T., … Bolton, P. R. (2014). Insertable pulse cleaning module with a saturable absorber pair and a compensating amplifier for high-intensity ultrashort-pulse lasers. Optics Express, 22(2), 2060. doi:10.1364/oe.22.002060Trisorio, A., Grabielle, S., Divall, M., Forget, N., & Hauri, C. P. (2012). Self-referenced spectral interferometry for ultrashort infrared pulse characterization. Optics Letters, 37(14), 2892. doi:10.1364/ol.37.002892Seimetz, M., Bellido, P., Soriano, A., Garcia Lopez, J., Jimenez-Ramos, M. C., Fernandez, B., … Benlloch, J. M. (2015). Calibration and Performance Tests of Detectors for Laser-Accelerated Protons. IEEE Transactions on Nuclear Science, 62(6), 3216-3224. doi:10.1109/tns.2015.2480682Nürnberg, F., Schollmeier, M., Brambrink, E., Blažević, A., Carroll, D. C., Flippo, K., … Roth, M. (2009). Radiochromic film imaging spectroscopy of laser-accelerated proton beams. Review of Scientific Instruments, 80(3), 033301. doi:10.1063/1.3086424Oishi, Y., Nayuki, T., Fujii, T., Takizawa, Y., Wang, X., Yamazaki, T., … Andreev, A. A. (2005). Dependence on laser intensity and pulse duration in proton acceleration by irradiation of ultrashort laser pulses on a Cu foil target. Physics of Plasmas, 12(7), 073102. doi:10.1063/1.1943436Nishiuchi, M., Daito, I., Ikegami, M., Daido, H., Mori, M., Orimo, S., … Yoshiyuki, T. (2009). Focusing and spectral enhancement of a repetition-rated, laser-driven, divergent multi-MeV proton beam using permanent quadrupole magnets. Applied Physics Letters, 94(6), 061107. doi:10.1063/1.3078291Antici, P., Fuchs, J., d’ Humières, E., Lefebvre, E., Borghesi, M., Brambrink, E., … Pépin, H. (2007). Energetic protons generated by ultrahigh contrast laser pulses interacting with ultrathin targets. Physics of Plasmas, 14(3), 030701. doi:10.1063/1.2480610Green, J. S., Carroll, D. C., Brenner, C., Dromey, B., Foster, P. S., Kar, S., … Zepf, M. (2010). Enhanced proton flux in the MeV range by defocused laser irradiation. New Journal of Physics, 12(8), 085012. doi:10.1088/1367-2630/12/8/085012Zeil, K., Kraft, S. D., Bock, S., Bussmann, M., Cowan, T. E., Kluge, T., … Schramm, U. (2010). The scaling of proton energies in ultrashort pulse laser plasma acceleration. New Journal of Physics, 12(4), 045015. doi:10.1088/1367-2630/12/4/045015Nishiuchi, M., Daido, H., Yogo, A., Orimo, S., Ogura, K., Ma, J., … Azuma, H. (2008). Efficient production of a collimated MeV proton beam from a polyimide target driven by an intense femtosecond laser pulse. Physics of Plasmas, 15(5), 053104. doi:10.1063/1.2928161Macchi, A., Sgattoni, A., Sinigardi, S., Borghesi, M., & Passoni, M. (2013). Advanced strategies for ion acceleration using high-power lasers. Plasma Physics and Controlled Fusion, 55(12), 124020. doi:10.1088/0741-3335/55/12/124020Fuchs, J., Antici, P., d’ Humières, E., Lefebvre, E., Borghesi, M., Brambrink, E., … Audebert, P. (2005). Laser-driven proton scaling laws and new paths towards energy increase. Nature Physics, 2(1), 48-54. doi:10.1038/nphys199Schwoerer, H., Pfotenhauer, S., Jäckel, O., Amthor, K.-U., Liesfeld, B., Ziegler, W., … Esirkepov, T. (2006). Laser-plasma acceleration of quasi-monoenergetic protons from microstructured targets. Nature, 439(7075), 445-448. doi:10.1038/nature04492Margarone, D., Klimo, O., Kim, I. J., Prokůpek, J., Limpouch, J., Jeong, T. M., … Korn, G. (2012). Laser-Driven Proton Acceleration Enhancement by Nanostructured Foils. Physical Review Letters, 109(23). doi:10.1103/physrevlett.109.234801Flippo, K. A., d’ Humières, E., Gaillard, S. A., Rassuchine, J., Gautier, D. C., Schollmeier, M., … Hegelich, B. M. (2008). Increased efficiency of short-pulse laser-generated proton beams from novel flat-top cone targets. Physics of Plasmas, 15(5), 056709. doi:10.1063/1.291812
Calibration and Performance Tests of Detectors for Laser-Accelerated Protons
“©2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”We present the calibration and performance tests carried out with two detectors for intense proton pulses accelerated by lasers. Most of the procedures were realized with proton beams of 0.46-5.60 MeV from a tandem accelerator. One approach made use of radiochromic films, for which we calibrated the relation between optical density and energy deposition over more than three orders of magnitude. The validity of these results and of our analysis algorithms has been confirmed by controlled irradiation of film stacks and reconstruction of the total beam charge for strongly non-uniform beam profiles. For the spectral analysis of protons from repeated laser shots, we have designed an online monitor based on a plastic scintillator. The resulting signal from a photomultiplier directly measured on a fast oscilloscope is especially useful for time-of-flight applications. Variable optical filters allow for suppression of saturation and an extension of the dynamic range. With pulsed proton beams we have tested the detector response to a wide range of beam intensities from single particles 3 x 10(5) to protons per 100 ns time interval.Project funded by the Spanish Ministry of Economy and Competitiveness and co-funded with FEDER's funds within the INNPACTO 2011 program under Grant No. IPT-2011-0862-900000. This work was supported by the Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I+D+i) under Grant No. TEC 2013-48036-C3-1-R and the Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013. The work of A. J. Gonzalez is financed by CSIC with a JAE-Doc contract under Junta de Ampliacion de Estudios program, cofinanced by the European Social Fund.Seimetz, M.; Bellido, P.; Soriano Asensi, A.; García López, J.; Jiménez-Ramos, M.; Fernández, B.; Conde Castellanos, PE.... (2015). Calibration and Performance Tests of Detectors for Laser-Accelerated Protons. IEEE Transactions on Nuclear Science. 62(6):3216-3224. https://doi.org/10.1109/TNS.2015.2480682S3216322462
The Caldera. No. 23
La pandemia, sin lugar a dudas, nos ha cambiado la vida a todos; un viernes nos fuimos para nuestros hogares, en el marco de una educación presencial; al lunes siguiente, después de dos días, estábamos iniciando el camino hacia una educación remota, una educación virtual, que se ha convertido en una gran alternativa para seguir contribuyendo con la formación de nuestros niños y jóvenes caldistas y al mejoramiento de nuestra calidad de vida que halla, en la educación, nuevamente la respuesta; han sido meses de cambios drásticos, inimaginables pero, cambios positivos que nos han permitido crecer como individuos, como familia, como escuela y como sociedad.Especial pandemia. Una generación Resiliente por promoción DINASTIA…06
VII Concurso Intercolegiado departamental de Oratoria. Ulibro 2020…51
Deporte en el Caldas…64
Expresiones Caldistas…71
Celebremos la palabra…93
Nuestros Maestros…102
Galería de Imágenes…107The pandemic, without a doubt, has changed the lives of all of us; One Friday we went to our homes, as part of a face-to-face education; The following Monday, after two days, we were starting the path towards a remote education, a virtual education, which has become a great alternative to continue contributing to the training of our children and young Caldistas and to the improvement of our quality of life. that finds, in education, the answer again; They have been months of drastic changes, unimaginable but positive changes that have allowed us to grow as individuals, as a family, as a school and as a society
Propuesta de mejora del SG-SST en Ovante S.A.S. enfocado en la satisfacción, el cumplimiento normativo y la adherencia de sus colaboradores
Propuesta de mejora enfocada en incrementar la satisfacción, adherencia y participación de los colaboradores en el SG-SST que se encuentra implementado en la empresa Ovante S.A.S., ubicada en la ciudad de Bogotá D.C.Tabla de contenido 1. Problema de investigación 4 1.1. Descripción del problema 4 1.1.1. Enunciado del problema 6 1.1.2. Delimitación o alcance del problema 6 1.2. Formulación del problema 7 2. Objetivos 7 3.1. Objetivo General 7 3.2. Objetivos Específicos 7 4. Justificación y delimitación 8 4.1. Justificación 8 4.2. Delimitación 10 4.2.1. Temporal 10 4.2.2. Espacial 10 4.2.3. Operacional 10 4.3. Limitaciones 11 5. Marcos de referencia 11 5.1. Estado del arte 11 5.1.1.1. Tesis Nacionales 11 5.1.2. Tesis Internacionales 15 5.2. Marco teórico 18 5.2.1. Marco teórico Nacional 18 5.2.2. Marco teórico Internacional 22 5.3. Marco Legal 23 6. Marco Metodológico de la Investigación 25 6.1. Paradigma 25 6.2. Método 26 6.3. Tipo de investigación 26 6.4. Fases del estudio 26 6.5. Diagrama de Gantt 28 6.6. Recolección de la información 28 6.6.1. Fuentes primarias 28 6.6.2. Fuentes secundarias 29 6.6.3. Población 29 6.6.4. Materiales 30 6.7. Diseño de instrumentos y consentimientos 30 6.8. Recolección de los datos 30 6.9. Análisis de la información 31 6.10. Propuesta de solución 32 7. Resultados y/o Propuesta de solución (análisis de los resultados y la discusión.) 32 5 7.1. Resultados 32 7.1.1. Lista de chequeo estándares mínimos según la resolución 0312 de 2019 del SGSST 32 7.1.2. Lista de chequeo de decreto único reglamentario del sector trabajo 1072 de 2015 36 7.1.3. Encuesta para medición de satisfacción del SG-SST de OVANTE SAS 38 7.1.3.1. Comunicación en el SG-SST 38 7.1.3.2. Rol dentro del SG-SST 40 7.1.3.3. Compromiso organizacional frente al SG-SST 42 7.1.3.4. Liderazgo en el SG-SST 44 7.1.3.5. Formación y desarrollo del SG-SST 47 7.2. Propuesta de solución 50 7.2.1. Propuestas de mejora 50 8. Análisis Financiero (costo-beneficio) 54 9. Conclusiones y recomendaciones 54 9.1. Conclusiones 54 9.2. Recomendaciones 55 10. Referencias bibliográficas y webgrafía.EspecializaciónEspecialista en Gerencia de la Seguridad y Salud en el TrabajoEspecialización en Gerencia de la Seguridad y Salud en el Trabaj
the Machine learning model for the classification of municipalities by illicit crops in Colombia from 2010 to 2020: Machine learning model for the classification of municipalities by illicit crops in Colombia from 2010 to 2020
For the United Nations Office on Drugs and Crime (UNODC), Colombia is one of the top countries where drug trafficking and crime jeopardize security, peace and development opportunities of citizens. Initially, an account of the history of coca crops in Colombia will be developed. Starting with the period known as “bonanza marimbera” in the 60s, it will be described how the country transformed from a marijuana producer to being one of the main cocaine producers in the world. Multiple sources of information are crossed, such as the number of hectares of coca per municipality, seizures, destroyed laboratories, manual eradication and fumigation monitored by the national institutions, crossed with socio-economic variables and performance of the municipalities that have coca crops in Colombia in the period from 2010 to 2020. Data mining algorithms were used to identify correlations and patterns that allowed the classification of municipalities with coca and starting from the classification it was possible to analyze the scenarios of each category found, to find scenarios that shed light on the dynamics of the territories that suffer from this scourge.La Oficina de las Naciones Unidas contra la Droga y el Delito (UNODC) clasifica a Colombia como uno de los países donde el narcotráfico y el delito ponen en riesgo la seguridad, la paz y las oportunidades de desarrollo de los ciudadanos. Objetivo: Este artículo presenta la aplicación del algoritmo de clasificación no supervisado K-means para categorizar los municipios que tienen presencia de cultivos de coca en Colombia. Metodología: Se hizo uso de la metodología CRISP-DM, propia de la minería de datos, y para la correlación de variables se utilizó el algoritmo PCA (Análisis de componentes principales). Resultados: Se utilizaron múltiples fuentes de información como: el número de hectáreas de coca por municipio, incautaciones, laboratorios destruidos, erradicación manual y fumigación, monitoreadas por la institucionalidad nacional, con el fin de realizar cruces con variables socioeconómicas y de desempeño de los municipios que tienen cultivos de coca en el periodo de 2010 a 2020. Partiendo de la clasificación, se analizaron los escenarios de cada categoría para hallar escenarios que permitan dilucidar las dinámicas de los territorios que sufren este flagelo. Conclusiones: Se encontró que el comportamiento de los municipios productores de coca responde principalmente a 4 grupos. También se encuentra que el municipio de Tumaco en Nariño no encaja en ninguna categoría ya que excede la producción respecto a los demás municipios
Detector block performance based on a monolithic LYSO crystal using a novel signal multiplexing method
[EN] Organ dedicated PET devices provide improved imaging performance when compared to whole body systems. The present study summarizes the test carried out to study a new detector block designed for an organ dedicated PET system. This block includes three novel components namely the scintillator geometry and a retroreflector layer coupled to the entrance face, the photosensor and the readout electronics. We used arrays of 12 x 12 SiPM photosensors with 3 x 3 mm(2) active area each and a pitch of 4.2 mm. We are proposing a new readout electronics that permits to reduce the 12 row and columns signals to only 8 without significant detector performance degradation. This approach also allows for resolving radioactive sources in the whole volume of the proposed crystal, significantly reducing the edge effect that typically rejects these events.
An overall spatial resolution of about 1.8 mm FWHM is obtained for the whole scintillation volume, with an average energy resolution of 13% FWHM and a photon depth of interaction resolution (FWHM) of 3.7 mm. (C) 2018 Elsevier B.V. All rights reserved.This work was supported by the Spanish Ministerio de Economía, Industria y Competitividad under Grant Nos. FIS2014-62341-EXP and TEC2016-79884-C2-1-R. This project has also received funding from the European Union s Horizon 2020 research and innovation programme under grant agreement No. 711323. This project has received funding from the European Research Council (ERC) under the European Union s Horizon 2020 research and innovation programme (grant agreement No. 695536).González, A.; Sánchez, F.; Martí, R.; Hernández Hernández, L.; Aguilar-Talens, A.; Barbera Ballester, J.; Catret Mascarell, JV.... (2018). Detector block performance based on a monolithic LYSO crystal using a novel signal multiplexing method. Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment. 912:372-377. https://doi.org/10.1016/j.nima.2017.10.098S37237791
Noise Analysis in Computed Tomography (CT) Image Reconstruction using QR-Decomposition Algorithm
“©2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”In this paper, the noise of 3D computed tomography
(CT) image reconstruction using QR-Decomposition is analyzed.
There are several types of image noise that can interfere with the
interpretation of an image. Here, the noise introduced by the reconstruction
process is studied. In this analysis, condition numbers
are calculated with different CT model parameters, three dimensional
(3D) CT image reconstruction with simulated and real data
are performed, image noise analysis is performed through various
image quality parameters and the condition number of the linear
system is related with the image quality parameters. Results show
the condition number’s dependence on the CT model. Image reconstructions
with simulated data show errors significantly below
the condition number theoretical bound and image reconstructions
with real data show that quality improvements depend strongly on
the condition number. This allows a reduction on the number of
projections without compromising image quality and places this
reconstruction method as a strong candidate for low-dose 3D CT
imaging reconstruction.This work was supported in part by the Spanish Goverment grant RTC-2014-2065-2 and the Valencian Local Government grants PROMETEOII/2013/010 and ISIC 2011/013.Iborra Carreres, A.; Rodríguez Álvarez, MJ.; Soriano Asensi, A.; Sanchez, F.; Bellido, P.; Conde Castellanos, PE.; Crespo Navarro, E.... (2015). Noise Analysis in Computed Tomography (CT) Image Reconstruction using QR-Decomposition Algorithm. IEEE Transactions on Nuclear Science. 62(3):869-875. doi:10.1109/TNS.2015.2422213S86987562
Analysis of the Statistical Moments of the Scintillation Light Distribution With dSiPMs
“©2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”In gamma-ray detectors, monolithic scintillation crystals offer the possibility of preserving the scintillation light distribution especially when painted black. The statistical moments of this distribution provide accurate information on the three photon impact coordinates, including their depth of interaction (DOI). Digital SiPMs (dSiPMs) return digital information based on pixels about the collected light distribution, since the signal is a digital sum of the trigger bins. In this work we present, for the first time, an accurate analysis of the statistical moments of the light distribution using monolithic painted black crystals and state-of-the-art dSiPMs. Two 32.6 x 32.6 mm(2) monolithic LYSO crystals covering the entire photodetectors area have been used in coincidence with 10 mm in thickness. The photosensor tiles were kept at a stable temperature of T = 20 degrees C. Energy resolution of about 18% was reached in relation to the zeroth moment. The first moment, related to the impact position, determined a spatial resolution of about 3 mm near the crystal center, but quadratically degrading towards the crystal borders. The DOI resolution, measured by means of the second moment, was found to be nearing 4 mm in the crystal center region. The third order moment, the so-called skewness, is related to the degree of truncation and once calibrated minimizes the compression effects. A corrected spatial resolution of about 3 mm was then measured for the entire crystal surface. DOI resolution improved at the crystal's center, reaching 3.5 mm, but a degradation towards the borders remained due to truncation of the scintillation light distribution.This work was supported in part by the Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I+D+I) under Grant FIS2010-21216-CO2-01 and in part by the Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013.Conde Castellanos, PE.; González Martínez, AJ.; Gonzalez, A.; Hernández Hernández, L.; Bellido, P.; Crespo Navarro, E.; Iborra Carreres, A.... (2015). Analysis of the Statistical Moments of the Scintillation Light Distribution With dSiPMs. IEEE Transactions on Nuclear Science. 62(5):1981-1988. https://doi.org/10.1109/TNS.2015.2473695S1981198862