Retrieval Server Research Articles

Recuperação da informação e a consulta à base de dados no processo de busca do Mecanismo Online para Referências

Os dados das organizações crescem, exponencialmente, a cada ano e têm trazido aos administradores e gerentes incremento para tomada de decisão à qual são diariamente submetidos. Para a gestão destes dados, bem como, para descoberta de informações neles contidas, surgiram os Sistemas de Recuperação da Informação - largamente empregados no ambiente organizacional, atualmente. A Recuperação da Informação foi desenvolvida com a finalidade precípua de fornecer, rapidamente, aos usuários a informação que procuram. A avaliação de um Sistema de Recuperação da Informação é focada em seu motor de busca, medindo o quão rápido ele pode responder a uma consulta, ou o nível de relevância da informação recuperada. Este trabalho tem como objetivo verificar o impacto da utilização de motores de busca, baseados no Apache Solr® , no processo de recuperação da informação contida na base de dados do Mecanismo Online para Referências. Assim, buscaram-se na bibliografia, fundamentos para conceituar a Recuperação da Informação e tratar sobre as peculiaridades que se coadunam com o escopo desta pesquisa. Abordam-se as principais características do servidor de recuperação da informação Apache Solr® e do protótipo desenvolvido para os propósitos deste trabalho. Cabe esclarecer que o Apache Solr® foi configurado para ordenar os resultados pelo nível de relevância, sendo o Modelo de Espaço Vetorial utilizado no cálculo do grau de similaridade. Na sequência, os dados colhidos são tabulados, apresentados e analisados. Concluise que a utilização de motores de busca, baseados no Apache Solr® , impacta, positivamente, no processo de recuperação da informação contida na base de dados do Mecanismo Online para Referências.

A generic content-based image retrieval framework for mobile devices

Multimedia mobile devices have created new possibilities for developing and accessing a variety of multimedia items such as images, audio and video clips. Personal multimedia items are, nowadays, being consumed at an enormous rate. Therefore, the management of these media items has become a pressing problem. In this paper, a client-server content-based image retrieval framework for mobile platforms is developed, which provides the capability of content-based query and browsing from mobile devices. The proposed framework provides an adaptive user interface and a generic structure, which supports a wide range of mobile devices. In this framework, a client requests the server for retrieval of particular images with a particular content. The server performs a content-based retrieval of images from a selected database and streams the retrieved results back to the client in an efficient way. The query results are transmitted over a wireless network and a certain number of similar images are rendered on the mobile device screen using thumbnail sizes. The proposed framework serves as a basis of content-based image retrieval on mobile devices. It addresses several important challenges such as hardware and software limitations as well as efficient use of the available network bandwidth.

Bubble-sensing: Binding sensing tasks to the physical world

We propose bubble-sensing, a new sensor network abstraction that allows mobile phone users to create a binding between sensing tasks and the physical world at locations of interest, that remains active for a duration set by the user. We envision mobile phones being able to affix sensing task bubbles at places of interest and then receive sensed data as it becomes available in a delay-tolerant fashion, in essence, creating a living documentary of places of interest in the physical world. The system relies on other mobile phones that opportunistically pass through bubble-sensing locations to acquire tasks and do the sensing on behalf of the initiator, and deliver the data to the bubble-sensing server for retrieval by the user who initiated the task. We describe an implementation of the bubble-sensing system using sensor-enabled mobile phones, specifically, Nokia’s N80 and N95 (with GPS, accelerometers, microphone, camera). Task bubbles are maintained at locations through the interaction of “bubble carriers”, which carry the sensing task into the area of interest, and “bubble anchors”, which maintain the task bubble in the area when the bubble carrier is no longer present. In our implementation, bubble carriers and bubble anchors implement a number of simple mobile phone based protocols that refresh the task bubble state as new mobile phones move through the area. Phones communicate using the local Ad-Hoc 802.11g radio to transfer task state and maintain the task in the region of interest. This task bubble state is ephemeral and times out when no bubble carriers or bubble anchors are in the area. Our design is resilient to periods when no mobiles pass through the bubble area and is capable of “reloading” the task into the bubble region. In this paper, we describe the bubble-sensing system and a simple proof-of-concept experiment.

Taxonomic information exchange and copyright: the Plazi approach.

BackgroundA large part of our knowledge on the world's species is recorded in the corpus of biodiversity literature with well over hundred million pages, and is represented in natural history collections estimated at 2 – 3 billion specimens. But this body of knowledge is almost entirely in paper-print form and is not directly accessible through the Internet. For the digitization of this literature, new territories have to be chartered in the fields of technical, legal and social issues that presently impede its advance. The taxonomic literature seems especially destined for such a transformation.DiscussionPlazi was founded as an association with the primary goal of transforming both the printed and, more recently, "born-digital" taxonomic literature into semantically enabled, enhanced documents. This includes the creation of a test body of literature, an XML schema modeling its logic content (TaxonX), the development of a mark-up editor (GoldenGATE) allowing also the enhancement of documents with links to external resources via Life Science Identifiers (LSID), a repository for publications and issuance of bibliographic identifiers, a dedicated server to serve the marked up content (the Plazi Search and Retrieval Server, SRS) and semantic tools to mine information. Plazi's workflow is designed to respect copyright protection and achieves extraction by observing exceptions and limitations existent in international copyright law.ConclusionThe information found in Plazi's databases – taxonomic treatments as well as the metadata of the publications – are in the public domain and can therefore be used for further scientific research without any restriction, whether or not contained in copyrighted publications.

Result merging methods in distributed information retrieval with overlapping databases

In distributed information retrieval systems, document overlaps occur frequently among different component databases. This paper presents an experimental investigation and evaluation of a group of result merging methods including the shadow document method and the multi-evidence method in the environment of overlapping databases. We assume, with the exception of resultant document lists (either with rankings or scores), no extra information about retrieval servers and text databases is available, which is the usual case for many applications on the Internet and the Web. The experimental results show that the shadow document method and the multi-evidence method are the two best methods when overlap is high, while Round-robin is the best for low overlap. The experiments also show that [0,1] linear normalization is a better option than linear regression normalization for result merging in a heterogeneous environment.

A content-based parallel image retrieval system on cluster architectures

We propose a content-based parallel image retrieval system to achieve high responding ability. Our system is developed on cluster architectures. It has several retrieval. servers to supply the service of content-based image retrieval. It adopts the Browser/Server (B/S) mode. The users could visit our system though web pages. It uses the symmetrical color-spatial features (SCSF) to represent the content of an image. The SCSF is effective and efficient for image matching because it is independent of image distortion such as rotation and flip as well as it increases the matching accuracy. The SCSF was organized by M-tree, which could speedup the searching procedure. Our experiments show that the image matching is quickly and efficiently with the use of SCSF. And with the support of several retrieval servers, the system could respond to many users at mean time.