A Meta-Review of Indoor Positioning Systems.

An accurate and reliable Indoor Positioning System (IPS) applicable to most indoor scenarios has been sought for many years. The number of technologies, techniques, and approaches in general used in IPS proposals is remarkable. Such diversity, coupled with the lack of strict and verifiable evaluations, leads to difficulties for appreciating the true value of most proposals. This paper provides a meta-review that performed a comprehensive compilation of 62 survey papers in the area of indoor positioning. The paper provides the reader with an introduction to IPS and the different technologies, techniques, and some methods commonly employed. The introduction is supported by consensus found in the selected surveys and referenced using them. Thus, the meta-review allows the reader to inspect the IPS current state at a glance and serve as a guide for the reader to easily find further details on each technology used in IPS. The analyses of the meta-review contributed with insights on the abundance and academic significance of published IPS proposals using the criterion of the number of citations. Moreover, 75 works are identified as relevant works in the research topic from a selection of about 4000 works cited in the analyzed surveys.

Revisión del proceso de separación de fases del gas natural a alta presión en la industria Oil&Gas / Review of the natural gas phases separation process at high pressure in the Oil&Gas industry / Revisão do processo de separação de fases do gás natural para alta pressão na indústria de Oil&Gas

Resumen La separación física de líquidos y gases es una de las operaciones de producción, procesamiento y tratamiento en la industria petrolera, necesaria para prevenir daños en equipos rotativos, evitar corrosión en tuberías y cumplir con las especificaciones de calidad del gas natural para uso doméstico. Cuando la presión de operación aumenta, la diferencia de densidades entre las fases disminuye, lo cual dificulta el proceso de separación. Se realiza la revisión del estado del arte, desde los años 90 hasta el presente, de las diferentes metodologías para separar las fases líquida y gaseosa del gas natural, así como las variables de diseño con aplicación a sistemas que operan a alta presión; prestando especial énfasis en los avances encontrados utilizando Dinámica de Fluidos Computacional. Los resultados muestran que, aunque los separadores centrífugos y los separadores supersónicos son más compactos y de fácil mantenimiento comparados con los separadores gravitacionales, éstos últimos continúan siendo la estrategia más favorable cuando se combinan alta presión y baja cantidad de líquido (menos del 4% vol), como es el caso del gas natural. Conclusión adjudicada, en parte, a la falta de estudios experimentales/numéricos que involucren al gas natural en equipos alternativos al separador gravitacional

Abstract The Physical separation of liquids and gases is one of the main operations of production, processing and treatment in the oil industry; it is necessary to prevent damage to rotating equipment, to avoid corrosion in pipes and to achieve with the natural gas quality specifications for domestic use. When the operating pressure increases, the density difference between the phases decreases, which makes the separation process difficult or in some cases impossible. In this work, the state of the art of the different methodologies to separate the liquid and gaseous phases of natural gas is reviewed , as well as the design variables applied to systems that operate at high pressure from the 90's to the present; with special emphasis on the advances found using Computational Fluid Dynamics. The results show that, although both centrifugal and supersonic separators are more compact and easy to maintain compared to gravitational separators, gravitational separators remain the most favorable strategy when combining high pressure and low liquid load (less than 4%vol), as is the case of natural gas. Conclusion awarded, in part, to the lack of experimental/numerical studies involving natural gas in alternative equipment to the gravitational separator

Resumo A separação física de líquidos e gases é uma das principais operações de produção, processamento e tratamento na indústria do petróleo, necessária para evitar danos ao equipamento rotativo, para evitar a corrosão nos tubos e para cumprir as especificações de qualidade do gás natural para uso doméstico. Quando a pressão de operação aumenta, a diferença de densidade entre as fases diminui, o que torna o processo de separação difícil ou, em alguns casos, impossível. Neste trabalho, é realizada a avaliação do estado da arte de diferentes metodologias para separar as fases líquida e gasosa do gás natural e as variáveis de design com aplicação para sistemas que operam a alta pressão a partir dos anos 90 até a data atual; com ênfase especial nos avanços encontrados usando a Dinâmica dos Fluidos Computacional. Os resultados mostram que, embora ambos os separadores centrífugos e supersónicos são mais compactos e de fácil manutenção comparado com separadores gravitacionais, o último continua a ser a estratégia favorecida quando a alta pressão e de baixa quantidade de líquido são combinados (menos de 4% vol), como é o caso do gás natural; Conclusão concedida, em parte, à falta de estudos experimentais/numéricos envolvendo gás natural em equipamentos alternativos ao separador gravitacional

Off-Line Evaluation of Mobile-Centric Indoor Positioning Systems: The Experiences from the 2017 IPIN Competition.

The development of indoor positioning solutions using smartphones is a growing activity with an enormous potential for everyday life and professional applications. The research activities on this topic concentrate on the development of new positioning solutions that are tested in specific environments under their own evaluation metrics. To explore the real positioning quality of smartphone-based solutions and their capabilities for seamlessly adapting to different scenarios, it is needed to find fair evaluation frameworks. The design of competitions using extensive pre-recorded datasets is a valid way to generate open data for comparing the different solutions created by research teams. In this paper, we discuss the details of the 2017 IPIN indoor localization competition, the different datasets created, the teams participating in the event, and the results they obtained. We compare these results with other competition-based approaches (Microsoft and Perf-loc) and on-line evaluation web sites. The lessons learned by organising these competitions and the benefits for the community are addressed along the paper. Our analysis paves the way for future developments on the standardization of evaluations and for creating a widely-adopted benchmark strategy for researchers and companies in the field.

Comparing the Performance of Indoor Localization Systems through the EvAAL Framework.

In recent years, indoor localization systems have been the object of significant research activity and of growing interest for their great expected social impact and their impressive business potential. Application areas include tracking and navigation, activity monitoring, personalized advertising, Active and Assisted Living (AAL), traceability, Internet of Things (IoT) networks, and Home-land Security. In spite of the numerous research advances and the great industrial interest, no canned solutions have yet been defined. The diversity and heterogeneity of applications, scenarios, sensor and user requirements, make it difficult to create uniform solutions. From that diverse reality, a main problem is derived that consists in the lack of a consensus both in terms of the metrics and the procedures used to measure the performance of the different indoor localization and navigation proposals. This paper introduces the general lines of the EvAAL benchmarking framework, which is aimed at a fair comparison of indoor positioning systems through a challenging competition under complex, realistic conditions. To evaluate the framework capabilities, we show how it was used in the 2016 Indoor Positioning and Indoor Navigation (IPIN) Competition. The 2016 IPIN competition considered three different scenario dimensions, with a variety of use cases: (1) pedestrian versus robotic navigation, (2) smartphones versus custom hardware usage and (3) real-time positioning versus off-line post-processing. A total of four competition tracks were evaluated under the same EvAAL benchmark framework in order to validate its potential to become a standard for evaluating indoor localization solutions. The experience gained during the competition and feedback from track organizers and competitors showed that the EvAAL framework is flexible enough to successfully fit the very different tracks and appears adequate to compare indoor positioning systems.

The Smartphone-Based Offline Indoor Location Competition at IPIN 2016: Analysis and Future Work.

This paper presents the analysis and discussion of the off-site localization competition track, which took place during the Seventh International Conference on Indoor Positioning and Indoor Navigation (IPIN 2016). Five international teams proposed different strategies for smartphone-based indoor positioning using the same reference data. The competitors were provided with several smartphone-collected signal datasets, some of which were used for training (known trajectories), and others for evaluating (unknown trajectories). The competition permits a coherent evaluation method of the competitors' estimations, where inside information to fine-tune their systems is not offered, and thus provides, in our opinion, a good starting point to introduce a fair comparison between the smartphone-based systems found in the literature. The methodology, experience, feedback from competitors and future working lines are described.

Enfermedades reumáticas pediátricas

Se presenta el caso de un niño de cinco años de edad que consulta por primera vez por edema y dolor en maléolo interno izquierdo presentando posteriormente hematuria en el que se estudia una enfermedad reumática de origen autoinmune.

Uso de la membrana amniótica en los pacientes con abdomen abierto como método de prevención y tratamiento de las fístulas intestinales / Use of amniotic membrana in patients with open abdomen as a preventive method and treatment of intestinal fístulae

En la actualidad, la técnica operatoria que implica dejar temporalmente el abdomen abierto con múltiples lavados quirúrgicos, es parte fundamental del tratamiento de la peritonitis generalizada difusa y es la única que ha demostrado algún grado de eficacia. Sin embargo, predispone la aparición de una serie de complicaciones entre las cuales las fístulas intestinales, con una incidencia aparentemente baja, representan un alto índice de estancia Hospitalaria, morbilidad, mortalidad y costos. Con base en esto diseñamos, en la escuela Colombiana de medicina un estudio de prevención y tratamiento de fístulas intestinales utilizando membrana amniótica como apósito bológico en pacientes tratados con laparostomía buscando reducir el proceso adherencial, factor predisponerte paso a la formación de fístulas y favorecer la cicatrización de fístulas establecidas. Desarrollamos inicialmente una primera fase experimental en curies encaminada a establecer el efecto local de la membrana sobre las asas intestinales y determinar su comportamiento en la cavidad abdominal. Observamos que la colocación de un parche de membrana amniótica en forma homóloga cubriendo un segmento intestinal en el abdomen del cury no genera respuesta inflamatoria que sugiera rechazo. De igual forma no estimula la reacción adherencial. El parche heterólogo de membrana amniótica humana estimula una marcada respuesta de rechazo y formación de adherencias. En ningún caso observamos signos de infección.