Pervasive Data Access in Wireless and Mobile Computing Environments

The rapid advance of wireless and portable computing technology has brought a lot of research interests and momentum to the area of mobile computing. One of the research focus is on pervasive data access. with wireless connections, users can access information at any place at any time. However, various constraints such as limited client capability, limited bandwidth, weak connectivity, and client mobility impose many challenging technical issues. In the past years, tremendous research efforts have been put forth to address the issues related to pervasive data access. A number of interesting research results were reported in the literature. This survey paper reviews important works in two important dimensions of pervasive data access: data broadcast and client caching. In addition, data access techniques aiming at various application requirements (such as time, location, semantics and reliability) are covered

SoK: Cryptographically Protected Database Search

Protected database search systems cryptographically isolate the roles of reading from, writing to, and administering the database. This separation limits unnecessary administrator access and protects data in the case of system breaches. Since protected search was introduced in 2000, the area has grown rapidly; systems are offered by academia, start-ups, and established companies. However, there is no best protected search system or set of techniques. Design of such systems is a balancing act between security, functionality, performance, and usability. This challenge is made more difficult by ongoing database specialization, as some users will want the functionality of SQL, NoSQL, or NewSQL databases. This database evolution will continue, and the protected search community should be able to quickly provide functionality consistent with newly invented databases. At the same time, the community must accurately and clearly characterize the tradeoffs between different approaches. To address these challenges, we provide the following contributions: 1) An identification of the important primitive operations across database paradigms. We find there are a small number of base operations that can be used and combined to support a large number of database paradigms. 2) An evaluation of the current state of protected search systems in implementing these base operations. This evaluation describes the main approaches and tradeoffs for each base operation. Furthermore, it puts protected search in the context of unprotected search, identifying key gaps in functionality. 3) An analysis of attacks against protected search for different base queries. 4) A roadmap and tools for transforming a protected search system into a protected database, including an open-source performance evaluation platform and initial user opinions of protected search.Comment: 20 pages, to appear to IEEE Security and Privac

Collaborative geographic visualization

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia do Ambiente, perfil Gestão e Sistemas AmbientaisThe present document is a revision of essential references to take into account when developing ubiquitous Geographical Information Systems (GIS) with collaborative visualization purposes. Its chapters focus, respectively, on general principles of GIS, its multimedia components and ubiquitous practices; geo-referenced information visualization and its graphical components of virtual and augmented reality; collaborative environments, its technological requirements, architectural specificities, and models for collective information management; and some final considerations about the future and challenges of collaborative visualization of GIS in ubiquitous environment

NASA space station automation: AI-based technology review

Research and Development projects in automation for the Space Station are discussed. Artificial Intelligence (AI) based automation technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics. AI technology will also be developed for the servicing of satellites at the Space Station, system monitoring and diagnosis, space manufacturing, and the assembly of large space structures

Getting the point: tracing worked examples enhances learning

Embodied cognition perspectives suggest that pointing and tracing with the index finger may support learning, with basic laboratory research indicating such gestures have considerable effects on information processing in working memory. The present thesis examined whether tracing worked examples could enhance learning through decreased intrinsic cognitive load. In Experiment 1, 56 Year 6 students (mean age = 11.20, SD = .44) were presented with either tracing or no-tracing instructions on parallel lines relationships. The tracing group solved more acquisition phase practice questions and made fewer test phase errors, but otherwise test results were limited by ceiling effects. 42 Year 5 students (mean age = 10.50, SD = .51) were recruited in Experiment 2 to better align the materials with students’ knowledge levels. The tracing group outperformed the non-tracing group at the test and reported lower levels of test difficulty, interpreted as lower levels of intrinsic cognitive load. Experiment 3 recruited 52 Year 6 and Year 7 students (mean age = 12.04, SD = .59) presented with materials on angle relationships of a triangle; the tracing effect was replicated on test scores and errors, but not test difficulty. Experiment 4 used the parallel lines materials to test hypothesized gradients across experimental conditions with 72 Year 5 students (mean age = 9.94, SD = .33), predicting the tracing on the paper group would outperform the tracing above the paper group, who in turn would outperform the non-tracing group. The hypothesized gradient was established across practice questions correctly answered, practice question errors, test questions correctly answered, test question time to solution, and test difficulty self-reports. The results establish that incorporating the haptic input into worked example-based instruction design enhances the worked example effect and that tracing worked examples is a natural, simple yet effective way to enhance novices’ mathematics learning

Intelligent Radio Spectrum Monitoring

[EN] Spectrum monitoring is an important part of the radio spectrum management process, providing feedback on the workflow that allows for our current wirelessly interconnected lifestyle. The constantly increasing number of users and uses of wireless technologies is pushing the limits and capabilities of the existing infrastructure, demanding new alternatives to manage and analyse the extremely large volume of data produced by existing spectrum monitoring networks. This study addresses this problem by proposing an information management system architecture able to increase the analytical level of a spectrum monitoring measurement network. This proposal includes an alternative to manage the data produced by such network, methods to analyse the spectrum data and to automate the data gathering process. The study was conducted employing system requirements from the Brazilian National Telecommunications Agency and related functional concepts were aggregated from the reviewed scientific literature and publications from the International Telecommunication Union. The proposed solution employs microservice architecture to manage the data, including tasks such as format conversion, analysis, optimization and automation. To enable efficient data exchange between services, we proposed the use of a hierarchical structure created using the HDF5 format. The suggested architecture was partially implemented as a pilot project, which allowed to demonstrate the viability of presented ideas and perform an initial refinement of the proposed data format and analytical algorithms. The results pointed to the potential of the solution to solve some of the limitations of the existing spectrum monitoring workflow. The proposed system may play a crucial role in the integration of the spectrum monitoring activities into open data initiatives, promoting transparency and data reusability for this important public service.[ES] El control y análisis de uso del espectro electromagnético, un servicio conocido como comprobación técnica del espectro, es una parte importante del proceso de gestión del espectro de radiofrecuencias, ya que proporciona la información necesaria al flujo de trabajo que permite nuestro estilo de vida actual, interconectado e inalámbrico. El número cada vez más grande de usuarios y el creciente uso de las tecnologías inalámbricas amplían las demandas sobre la infraestructura existente, exigiendo nuevas alternativas para administrar y analizar el gran volumen de datos producidos por las estaciones de medición del espectro. Este estudio aborda este problema al proponer una arquitectura de sistema para la gestión de información capaz de aumentar la capacidad de análisis de una red de equipos de medición dedicados a la comprobación técnica del espectro. Esta propuesta incluye una alternativa para administrar los datos producidos por dicha red, métodos para analizar los datos recolectados, así como una propuesta para automatizar el proceso de recopilación. El estudio se realizó teniendo como referencia los requisitos de la Agencia Nacional de Telecomunicaciones de Brasil, siendo considerados adicionalmente requisitos funcionales relacionados descritos en la literatura científica y en las publicaciones de la Unión Internacional de Telecomunicaciones. La solución propuesta emplea una arquitectura de microservicios para la administración de datos, incluyendo tareas como la conversión de formatos, análisis, optimización y automatización. Para permitir el intercambio eficiente de datos entre servicios, sugerimos el uso de una estructura jerárquica creada usando el formato HDF5. Esta arquitectura se implementó parcialmente dentro de un proyecto piloto, que permitió demostrar la viabilidad de las ideas presentadas, realizar mejoras en el formato de datos propuesto y en los algoritmos analíticos. Los resultados señalaron el potencial de la solución para resolver algunas de las limitaciones del tradicional flujo de trabajo de comprobación técnica del espectro. La utilización del sistema propuesto puede mejorar la integración de las actividades e impulsar iniciativas de datos abiertos, promoviendo la transparencia y la reutilización de datos generados por este importante servicio público[CA] El control i anàlisi d'ús de l'espectre electromagnètic, un servei conegut com a comprovació tècnica de l'espectre, és una part important del procés de gestió de l'espectre de radiofreqüències, ja que proporciona la informació necessària al flux de treball que permet el nostre estil de vida actual, interconnectat i sense fils. El número cada vegada més gran d'usuaris i el creixent ús de les tecnologies sense fils amplien la demanda sobre la infraestructura existent, exigint noves alternatives per a administrar i analitzar el gran volum de dades produïdes per les xarxes d'estacions de mesurament. Aquest estudi aborda aquest problema en proposar una arquitectura de sistema per a la gestió d'informació capaç d’augmentar la capacitat d’anàlisi d'una xarxa d'equips de mesurament dedicats a la comprovació tècnica de l'espectre. Aquesta proposta inclou una alternativa per a administrar les dades produïdes per aquesta xarxa, mètodes per a analitzar les dades recol·lectades, així com una proposta per a automatitzar el procés de recopilació. L'estudi es va realitzar tenint com a referència els requisits de l'Agència Nacional de Telecomunicacions del Brasil, sent considerats addicionalment requisits funcionals relacionats descrits en la literatura científica i en les publicacions de la Unió Internacional de Telecomunicacions. La solució proposada empra una arquitectura de microserveis per a l'administració de dades, incloent tasques com la conversió de formats, anàlisi, optimització i automatització. Per a permetre l'intercanvi eficient de dades entre serveis, suggerim l'ús d'una estructura jeràrquica creada usant el format HDF5. Aquesta arquitectura es va implementar parcialment dins d'un projecte pilot, que va permetre demostrar la viabilitat de les idees presentades, realitzar millores en el format de dades proposat i en els algorismes analítics. Els resultats van assenyalar el potencial de la solució per a resoldre algunes de les limitacions del tradicional flux de treball de comprovació tècnica de l'espectre. La utilització del sistema proposat pot millorar la integració de les activitats i impulsar iniciatives de dades obertes, promovent la transparència i la reutilització de dades generades per aquest important servei públicSantos Lobão, F. (2019). Intelligent Radio Spectrum Monitoring. http://hdl.handle.net/10251/128850TFG

Proceedings of the NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications

The proceedings of the National Space Science Data Center Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications held July 23 through 25, 1991 at the NASA/Goddard Space Flight Center are presented. The program includes a keynote address, invited technical papers, and selected technical presentations to provide a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include magnetic disk and tape technologies, optical disk and tape, software storage and file management systems, and experiences with the use of a large, distributed storage system. The technical presentations describe integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's

Peer-to-peer systems for simple and flexible information sharing

Includes abstract.Includes bibliographical references (leaves 76-80).Peer to peer computing (P2P) is an architecture that enables applications to access shared resources, with peers having similar capabilities and responsibilities. The ubiquity of P2P computing and its increasing adoption for a decentralized data sharing mechanism have fueled my research interests. P2P networks are useful for sharing content files containing audio, video, and data. This research aims to address the problem of simple and flexible access to data from a variety of data sources across peers with different operating systems, databases and hardware. The proposed architecture makes use of SQL queries, web services, heterogeneous database servers and XML data transformation for the peer to peer data sharing prototype. SQL queries and web services provide a data sharing mechanism that allows both simple and flexible data access