Denis Shestakov

On building a search interface discovery system

A huge portion of the Web known as the deep Web is accessible via search interfaces to myriads of databases on the Web. While relatively good approaches for querying the contents of web databases have been recently proposed, one cannot fully utilize them having most search interfaces unlocated. Thus, the automatic recognition of search interfaces to online databases is crucial for any application accessing the deep Web. This paper describes the architecture of the I-Crawler, a system for finding and classifying search interfaces. The I-Crawler is intentionally designed to be used in the deep web characterization surveys and for constructing directories of deep web resources.

Terabyte-scale image similarity search: Experience and best practice

While the past decade has witnessed an unprecedented growth of data generated and collected all over the world, existing data management approaches lack the ability to address the challenges of Big Data. One of the most promising tools for Big Data processing is the MapReduce paradigm. Although it has its limitations, the MapReduce programming model has laid the foundations for answering some of the Big Data challenges. In this paper, we focus on Hadoop, the open-source implementation of the MapReduce paradigm. Using as case-study a Hadoop-based application, i.e., image similarity search, we present our experiences with the Hadoop framework when processing terabytes of data. The scale of the data and the application workload allowed us to test the limits of Hadoop and the efficiency of the tools it provides. We present a wide collection of experiments and the practical lessons we have drawn from our experience with the Hadoop environment. Our findings can be shared as best practices and recommendations to the Big Data researchers and practioners.

Databases on the web: national web domain survey

The deep Web, the part of the Web consisting of web pages filled with information from myriads of online databases, is to date relatively unexplored. Even its basic characteristics such as, for instance, the number of searchable databases on the Web are disputable. In this paper, we address the problem of accurate estimation of the deep Web by sampling one national web domain. We report some of our results obtained when surveying the Russian Web. The survey findings, namely the size estimates of the deep Web, could be useful for further studies to handle data in the deep Web.

Toward Unified Web Application Development

Web application development in the context of the conventional three-tier architecture is complex, typically requiring a team of experts. Recent Web application architectures and frameworks simplify the development process, potentially turning tier-specific experts into one-person developer teams.

Leveraging declarative languages in web application development

Web Applications have become an omnipresent part of our daily lives. They are easy to use, but hard to develop. WYSIWYG editors, form builders, mashup editors, and markup authoring tools ease the development of Web Applications. However, more advanced Web Applications require servers-side programming, which is beyond the skills of end-user developers. In this paper, we discuss how declarative languages can simplify Web Application development and empower end-users as Web developers. We first identify nine end-user Web Application development levels ranging from simple visual customization to advanced three-tier programming. Then, we propose expanding the presentation tier to support all aspects of Web Application development. We introduce a unified XForms-based framework—called XFormsDB—that supports both client-side and server-side Web Application development. Furthermore, we make a language extension proposal—called XFormsRTC—for adding true real-time communication capabilities to XForms. We also present XFormsDB Integrated Development Environment (XIDE), which assists end-users in authoring highly interactive data-driven Web Applications. XIDE supports all Web Application development levels and, especially, promotes the transition from markup authoring and snippet programming to single and unified language programming.

Current challenges in web crawling

Web crawling, a process of collecting web pages in an automated manner, is the primary and ubiquitous operation used by a large number of web systems and agents starting from a simple program for website backup to a major web search engine. Due to an astronomical amount of data already published on the Web and ongoing exponential growth of web content, any party that want to take advantage of massive-scale web data faces a high barrier to entry. In this tutorial, we will introduce the audience to five topics: architecture and implementation of high-performance web crawler, collaborative web crawling, crawling the deep Web, crawling multimedia content and future directions in web crawling research.

Extending XForms with server-side functionality

Most Web applications are based on a conventional three-tier architecture, in which the presentation, application logic, and data management are developed and maintained in separate tiers. The main disadvantage of this architecture is that it requires expertise in multiple programming languages, programming paradigms, and data models used in each tier. A single expert rarely masters all technologies involved. In this paper, we introduce a framework that allows users---namely, Web designers---to implement entire Web applications using only markup languages. In addition, all application development is performed on the client side, simplifying both development and maintenance work. The proposed framework is based on the XForms markup language and its server-side extension proposed in this paper. We derive the extension requirements from the literature and depict its function using a simple Web-based blog application. We also show how the extension can be implemented as part of a comprehensive Web application development framework called XFormsDB. Our conclusion is that expanding the presentation tier to define both application logic and data management functionality makes both the development and maintenance of small- and medium-sized Web applications easier.

Web services for DNA sequence analysis

The standardized interface to sequence analysis tools is highly desirable to integrate bioinformatics applications. Currently existing software packages and programming toolkits (BioPerl, BioJava, etc.) used by bioinformaticians for DNA sequence analysis have limited support for exchanging and reusing data. To solve these issues, we propose the Web services approach and discuss how to apply the Web services technology for nucleotide sequence analysis workflow. In this work, we present a program-friendly interface to DNA sequence analysis tools using Web services. All data including query requests to the Web services are managed in XML-formats. The Web services responsible for statistical analysis provide an interface to the R statistical environment and can perform analysis using several statistical methods (including correspondence analysis and principal component analysis). Output of the Web services is in XML-format and, thus, can be stored in local XML databases.

XFormsDB: a declarative web application framework

Most Web applications utilize a three-tier architecture, in which the presentation, application logic, and data management are implemented as separate tiers. The disadvantage of this popular approach is that it usually requires expertise in multiple programming languages and paradigms as well as data models used in each tier. A single expert rarely masters all the technologies involved. In this demonstration, we give an overview of the XFormsDB framework that allows developers to implement entire Web applications using only markup languages. The framework is based on the XForms markup language and our server-side extensions. We demonstrate the functionality of the framework using a simple blog application as an example.

XFormsDB: an extensible web application framework built upon declarative W3C standards

Most Web applications are based on a conventional three-tier architecture, in which the presentation, application logic, and data management are developed and maintained in separate tiers. The main disadvantage of this architecture is that it requires expertise in multiple programming languages, programming paradigms, and data models used in each tier. A single expert rarely masters all the technologies and concepts involved. In this paper, we introduce a tier-expanding architectural approach that unifies the client-side (presentation tier) and server-side (logic and data tiers) programming under a single model. We base our approach on a W3C-standardized client-side markup language, XForms, and its server-side extension proposed in this paper. We derive the extension requirements from the literature and use cases, and demonstrate their functionality on the example of a blog Web application. We also show how the extension can be implemented as part of a comprehensive Web application framework called XFormsDB. The XFormsDB framework is an extensible Web application framework built upon declarative W3C standards. It has four major advantages: (1) one programming language, (2) one data model, (3) based on W3C-standardized declarative markup, and (4) extensibility in all tiers. Our conclusion is that expanding the presentation tier to cover both application logic and data management functionality makes both the development and maintenance of small- and medium-sized Web applications easier.