80 research outputs found

    Efficient data representation for XML in peer-based systems

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    Purpose - New directions in the provision of end-user computing experiences mean that the best way to share data between small mobile computing devices needs to be determined. Partitioning large structures so that they can be shared efficiently provides a basis for data-intensive applications on such platforms. The partitioned structure can be compressed using dictionary-based approaches and then directly queried without firstly decompressing the whole structure. Design/methodology/approach - The paper describes an architecture for partitioning XML into structural and dictionary elements and the subsequent manipulation of the dictionary elements to make the best use of available space. Findings - The results indicate that considerable savings are available by removing duplicate dictionaries. The paper also identifies the most effective strategy for defining dictionary scope. Research limitations/implications - This evaluation is based on a range of benchmark XML structures and the approach to minimising dictionary size shows benefit in the majority of these. Where structures are small and regular, the benefits of efficient dictionary representation are lost. The authors' future research now focuses on heuristics for further partitioning of structural elements. Practical implications - Mobile applications that need access to large data collections will benefit from the findings of this research. Traditional client/server architectures are not suited to dealing with high volume demands from a multitude of small mobile devices. Peer data sharing provides a more scalable solution and the experiments that the paper describes demonstrate the most effective way of sharing data in this context. Social implications - Many services are available via smartphone devices but users are wary of exploiting the full potential because of the need to conserve battery power. The approach mitigates this challenge and consequently expands the potential for users to benefit from mobile information systems. This will have impact in areas such as advertising, entertainment and education but will depend on the acceptability of file sharing being extended from the desktop to the mobile environment. Originality/value - The original work characterises the most effective way of sharing large data sets between small mobile devices. This will save battery power on devices such as smartphones, thus providing benefits to users of such devices

    08261 Abstracts Collection -- Structure-Based Compression of Complex Massive Data

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    From June 22, 2008 to June 27, 2008 the Dagstuhl Seminar 08261 ``Structure-Based Compression of Complex Massive Data\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

    Text books untuk mata kuliah pemrograman web

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    .HTML.And.Web.Design.Tips.And.Techniques.Jan.2002.ISBN.0072228253.pd

    Compressed self-indexed XML representation with efficient XPath evaluation

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    [Abstract] The popularity of the eXtensible Markup Language (XML) has been continuously growing since its first introduction, being today acknowledged as the de facto standard for semi-structured data representation and data exchange on the World Wide Web. In this scenario, several query languages were proposed to exploit the expressiveness of XML data, as well as systems to provide an eficient support. At the same time, as research in compression became more and more relevant, works also focused their efforts on studying new approaches to provide eficient solutions, using the minimum amount of space. Today, however, there is a lack of practical available tools that join both eficient query support, and minimum space requirements. In this thesis we address this problem, and propose a new approach for storing, processing and querying XML documents in time and space eficient way, by specially focusing on XPath queries. We have developed a new compressed selfindexed representation of XML documents that obtains compression ratios about 30%-40%, over which a query module providing eficient XPath query evaluation has also been developed. As a whole, both parts make up a complete system, we called XXS, for the eficient evaluation of XPath queries over compressed self-indexed XML documents. Experimental results show the outstanding performance of our proposal, which can successfully compete with some of the best-known solutions, and that largely outperforms them in terms of space.[Resumo] A popularidade do eXtensible Markup Language (XML) non fixo máis que medrar dende a súa introdución inicial, sendo recoñecido hoxe en día como o estándar de facto para a representación de datos semi-estruturados e o intercambio de datos na Rede. Baixo este escenario, son varias as linguaxes de consulta que se propuxeron para explotar a expresividade dos datos en formato XML, así como sistemas que proporcionasen un soporte eficiente a eles. Ó mesmo tempo, e conforme a investigación en compresión se fixo cada vez máis relevante, os esforzos tamén foron dirixidos a estudiar novas aproximacións que ofrecesen solucións eficientes, pero usando ademáis a menor cantidade de espacio posible. Actualmente, sen embargo, existe unha clara ausencia de ferramentas prácticas dispoñibles que agrupen ambas características: un soporte á realización de consultas eficiente, xunto con requisitos de espacio mínimos. Nesta tese abordamos ese problema, e propoñemos unha nova solución para o almacenamento, procesamento e consulta de documentos XML, eficiente tanto en tempo como en espacio, centrándonos, en particular, na linguaxe de consulta XPath. Así, desenvolvimos unha nova representación comprimida e auto-indexada de documentos XML, que obtén ratios de compresión en torno ó 30%-40%, e sobre a cal se creou tamén un módulo de consulta para a eficiente evaluación de consultas XPath. En conxunto, ambas contribucións conforman un sistema completo, que chamamos XXS, para a evaluación eficiente de consultas XPath sobre documentos XML comprimidos e auto-indexados. Os resultados experimentais amosan o destacado comportamento da nosa ferramenta, que é capaz de competir exitosamente con algunhas das solucións máis coñecidas, ás que ademáis supera claramente en termos de espacio.[Resumen] La popularidad del eXtensible Markup Language (XML) no ha hecho sino más que ir en aumento desde su introducción inicial, siendo hoy día reconocido como el estándar de facto para la representación de datos semi-estructurados, y el intercambio de datos en Internet. Bajo este escenario, son varios los lenguajes de consulta que se han venido proponiendo para explotar la expresividad de los datos en formato XML, así como sistemas que proporcionasen un soporte eficiente a ellos. Al mismo tiempo, y conforme la investigación en compresión se ha hecho cada vez más relevante, los esfuerzos se han dirigido también a estudiar nuevas aproximaciones que ofreciesen soluciones eficientes, pero usando además la menor cantidad de espacio posible. Actualmente, sin embargo, existe una clara ausencia de herramientas prácticas disponibles que aúnen ambas características: un soporte a la realización de consultas eficiente, con requisitos de espacio mínimos. En esta tesis abordamos ese problema, y proponemos una nueva solución para el almacenamiento, procesamiento y consulta de documentos XML, eficiente en tiempo y en espacio, centrándonos, en particular, en el lenguaje de consulta XPath. Así, hemos desarrollado una nueva representación comprimida y auto-indexada de documentos XML, que obtiene ratios de compresión del 30%-40%, y sobre la cual se ha creado un módulo de consulta para la eficiente evaluación de consultas XPath. En conjunto, ambas contribuciones conforman un sistema completo, que hemos dado en llamar XXS, para la evaluación eficiente de consultas XPath sobre documentos XML comprimidos y auto-indexados. Los resultados experimentales evidencian el destacado comportamiento de nuestra herramienta, que es capaz de competir exitosamente con algunas de las soluciones más conocidas, a las que además supera claramente en términos de espacio

    An XML Messaging Service for Mobile Devices

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    In recent years, XML has been accepted as the format of messages for several applications. Prominent examples include SOAP for Web services, XMPP for instant messaging, and RSS and Atom for content syndication. This XML usage is understandable, as the format itself is a well-accepted standard for structured data, and it has excellent support for many popular programming languages, so inventing an application-specific format no longer seems worth the effort. Simultaneously with this XML's rise to prominence there has been an upsurge in the number and capabilities of various mobile devices. These devices are connected through various wireless technologies to larger networks, and a goal of current research is to integrate them seamlessly into these networks. These two developments seem to be at odds with each other. XML as a fully text-based format takes up more processing power and network bandwidth than binary formats would, whereas the battery-powered nature of mobile devices dictates that energy, both in processing and transmitting, be utilized efficiently. This thesis presents the work we have performed to reconcile these two worlds. We present a message transfer service that we have developed to address what we have identified as the three key issues: XML processing at the application level, a more efficient XML serialization format, and the protocol used to transfer messages. Our presentation includes both a high-level architectural view of the whole message transfer service, as well as detailed descriptions of the three new components. These components consist of an API, and an associated data model, for XML processing designed for messaging applications, a binary serialization format for the data model of the API, and a message transfer protocol providing two-way messaging capability with support for client mobility. We also present relevant performance measurements for the service and its components. As a result of this work, we do not consider XML to be inherently incompatible with mobile devices. As the fixed networking world moves toward XML for interoperable data representation, so should the wireless world also do to provide a better-integrated networking infrastructure. However, the problems that XML adoption has touch all of the higher layers of application programming, so instead of concentrating simply on the serialization format we conclude that improvements need to be made in an integrated fashion in all of these layers

    DescribeX: A Framework for Exploring and Querying XML Web Collections

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    This thesis introduces DescribeX, a powerful framework that is capable of describing arbitrarily complex XML summaries of web collections, providing support for more efficient evaluation of XPath workloads. DescribeX permits the declarative description of document structure using all axes and language constructs in XPath, and generalizes many of the XML indexing and summarization approaches in the literature. DescribeX supports the construction of heterogeneous summaries where different document elements sharing a common structure can be declaratively defined and refined by means of path regular expressions on axes, or axis path regular expression (AxPREs). DescribeX can significantly help in the understanding of both the structure of complex, heterogeneous XML collections and the behaviour of XPath queries evaluated on them. Experimental results demonstrate the scalability of DescribeX summary refinements and stabilizations (the key enablers for tailoring summaries) with multi-gigabyte web collections. A comparative study suggests that using a DescribeX summary created from a given workload can produce query evaluation times orders of magnitude better than using existing summaries. DescribeX's light-weight approach of combining summaries with a file-at-a-time XPath processor can be a very competitive alternative, in terms of performance, to conventional fully-fledged XML query engines that provide DB-like functionality such as security, transaction processing, and native storage.Comment: PhD thesis, University of Toronto, 2008, 163 page

    Reduction of mobile phone interference in tele-ECG monitoring.

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    by Hung King Fai Kevin.Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.Includes bibliographical references (leaves 82-85 (2nd gp.)).Abstracts in English and Chinese.ACKNOWLEDGEMENT --- p.iiABSTRACT --- p.iii摘要 --- p.vTABLE OF CONTENTS --- p.viChapter CHAPTER 1 --- INTRODUCTION --- p.1Chapter 1.1 --- OBJECTIVES --- p.1Chapter 1.2 --- NEED FOR PATIENT-MONITORING SYSTEM --- p.1Chapter 1.2.1 --- Aging Population --- p.1Chapter 1.2.2 --- Increasing Population with Heart Diseases --- p.2Chapter 1.3 --- ECG BASICS --- p.3Chapter 1.4 --- EXISITING ECG-MONITORING TECHNOLOGIES --- p.4Chapter 1.5 --- CHALLENGES IN PATIENT-MONITORING --- p.5Chapter 1.6 --- DEVELOPMENT OF AN ECG-MONITORING SYSTEM --- p.6Chapter 1.6.1 --- Overall Structure --- p.6Chapter 1.6.2 --- Considerations --- p.7Chapter CHAPTER 2 --- EMI FILTERS IN ECG ACQUISITION CIRCUIT --- p.8Chapter 2.1 --- OVERVIEW OF NOISE SOURCES IN ECG ACQUISITION --- p.8Chapter 2.1.1 --- Other Biopotentials --- p.8Chapter 2.1.2 --- Motion Artifact --- p.8Chapter 2.1.3 --- Power-line Interference --- p.10Chapter 2.1.4 --- High-Frequency Electromagnetic Interference --- p.15Chapter 2.2 --- EMI FILTERS --- p.16Chapter 2.2.1 --- Introduction to EMI Filters --- p.16Chapter 2.2.2 --- Types of EMI Filter --- p.17Chapter 2.2.3 --- EMI Filters in ECG Monitoring --- p.21Chapter 2.3 --- MODELING OF INTERFERENCE IN ECG-MONITORING SYSTEM --- p.22Chapter 2.3.1 --- Model and Parameters --- p.22Chapter 2.3.2 --- Method --- p.24Chapter 2.3.2 --- Results --- p.27Chapter 2.3.3 --- Discussion --- p.30Chapter 2.4 --- BUILDING AN ECG ACQUISITION CIRCUIT WITH EMI FILTERS --- p.30Chapter 2.4.1 --- Purpose --- p.30Chapter 2.4.2 --- Experimental Setup and Method --- p.30Chapter 2.4.3 --- Results --- p.32Chapter 2.4.4 --- Discussion --- p.46Chapter CHAPTER 3 --- ADAPTIVE FILTER --- p.48Chapter 3.1 --- OBJECTIVE --- p.48Chapter 3.2 --- INTRODUCTION TO ADAPTIVE FILTER --- p.48Chapter 3.3 --- METHOD --- p.50Chapter 3.4 --- RESULTS --- p.52Chapter 3.5 --- DISCUSSION --- p.57Chapter CHAPTER 4 --- WAP-BASED TELEMEDICINE APPLICATIONS --- p.59Chapter 4.1 --- INTRODUCTION TO TELEMEDICINE --- p.59Chapter 4.2 --- INTRODUCTION TO WAP --- p.59Chapter 4.3 --- WAP APPLICATIONS --- p.60Chapter 4.4 --- SYSTEM IMPLEMENTATION --- p.63Chapter 4.4.1 --- Overall Structure --- p.63Chapter 4.4.2 --- Relational Database --- p.63Chapter 4.4.3 --- Program Flow --- p.64Chapter 4.4.4 --- ECG Browsing and Feature Extraction --- p.70Chapter 4.5 --- EMULATION --- p.72Chapter 4.6 --- EXPERIENCE WITH WAP PHONE --- p.74Chapter 4.7 --- DISCUSSION AND CONCLUSION --- p.75Chapter CHAPTER 5: --- CONCLUSION AND FUTURE WORK --- p.77Chapter 5.1 --- CONCLUSION --- p.77Chapter 5.2 --- FUTURE WORK --- p.77Chapter 5.3 --- MARKET ANALYSIS --- p.79BIBLIOGRAPHY --- p.8

    Automated Spectral Identification of Materials Using Spectral Identity Mapping

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    With increased use of Raman spectroscopic instrumentation for material analysis there has also been an increase in the amount of acquired Raman spectral data. Because of this, there is a clear need to develop and implement advanced spectral analysis techniques. This is especially true in cases where limited reference data may be available and large data sets need to be interpreted. Raman spectral analysis and standardization techniques, along with a foundation for a comprehensive repository of Raman spectral data, will be described in this thesis. The main focus will be automated analysis and standardization of Raman spectral data using spectral identity mapping (SIM). In addition, details on how to promote widespread access to the analyzed data and SIM techniques will be given. SIM, a statistical spectral analysis method, is useful as either a stand-alone data classification method or as a factor analysis step that precedes other multivariate approaches. SIM for calibrating spectra utilizes multivariate processing algorithms that can differentiate spectra according to the intrinsic nature of their spectral shapes. SIM also enables spectral identity mapping to be performed on unknown samples by calculating a set of scores giving the most likely match for given set of spectral information. A SIM database of calibrated spectra and a proposal to utilize SIM matching algorithms via the internet was developed. There are currently few searchable databases available for Raman spectral data. Also, while there are many internet platforms available to publish spectra, some can be difficult to implement and most do not provide data to users in a way that is educational, engaging and fully oriented to the Raman community. The software libraries given here provide a set of tools for data-basing, searching and interpreting spectral data while encouraging user/client participation in order to grow the spectral libraries. The hope is that the SIM results and the database developed here will promote SIM for more exten

    Automated Spectral Identification of Materials Using Spectral Identity Mapping

    Get PDF
    With increased use of Raman spectroscopic instrumentation for material analysis there has also been an increase in the amount of acquired Raman spectral data. Because of this, there is a clear need to develop and implement advanced spectral analysis techniques. This is especially true in cases where limited reference data may be available and large data sets need to be interpreted. Raman spectral analysis and standardization techniques, along with a foundation for a comprehensive repository of Raman spectral data, will be described in this thesis. The main focus will be automated analysis and standardization of Raman spectral data using spectral identity mapping (SIM). In addition, details on how to promote widespread access to the analyzed data and SIM techniques will be given. SIM, a statistical spectral analysis method, is useful as either a stand-alone data classification method or as a factor analysis step that precedes other multivariate approaches. SIM for calibrating spectra utilizes multivariate processing algorithms that can differentiate spectra according to the intrinsic nature of their spectral shapes. SIM also enables spectral identity mapping to be performed on unknown samples by calculating a set of scores giving the most likely match for given set of spectral information. A SIM database of calibrated spectra and a proposal to utilize SIM matching algorithms via the internet was developed. There are currently few searchable databases available for Raman spectral data. Also, while there are many internet platforms available to publish spectra, some can be difficult to implement and most do not provide data to users in a way that is educational, engaging and fully oriented to the Raman community. The software libraries given here provide a set of tools for data-basing, searching and interpreting spectral data while encouraging user/client participation in order to grow the spectral libraries. The hope is that the SIM results and the database developed here will promote SIM for more exten
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