OpenRaiser/Intern-Atlas huggingface dataset:
Multimedia meets computer graphics in SMIL2.0: a time model for the web
Authors: Patrick Schmitz
Venue: WWW
Year: 2002

Multimedia scheduling models provide a rich variety of tools for managing the synchronization of media like video and audio, but generally have an inflexible model for time itself. In contrast, modern animation models in the computer graphics community generally lack tools for synchronization and structural time, but allow for a flexible concept of time, including variable pacing, acceleration and deceleration and other tools useful for controlling and adapting animation behaviors. Multimedia authors have been forced to choose one set of features over the others, limiting the range of presentations they can create. Some programming models addressed some of these problems, but provided no declarative means for authors and authoring tools to leverage the functionality. This paper describes a new model incorporated into SMIL 2.0 that combines the strengths of scheduling models with the flexible time manipulations of animation models. The implications of this integration are discussed with respect to scheduling and structured time, drawing upon experience with SMIL 2.0 timing and synchronization, and the integration with XHTML.
Hunter gatherer: interaction support for the creation and management of within-web-page collections
Authors: Monica M. C. Schraefel, Yuxiang Zhu, David Modjeska, Daniel Wigdor, Shengdong Zhao
Venue: WWW
Year: 2002

Hunter Gatherer is an interface that lets Web users carry out three main tasks: (1) collect components from within Web pages; (2) represent those components in a collection; (3) edit those component collections. Our research shows that while the practice of making collections of content from within Web pages is common, it is not frequent, due in large part to poor interaction support in existing tools. We engaged with users in task analysis as well as iterative design reviews in order to understand the interaction issues that are part of within-Web-page collection making and to design an interaction that would support that process.We report here on that design development, as well as on the evaluations of the tool that evolved from that process, and the future work stemming from these results, in which our critical question is: what happens to users perceptions and expectations of web-based information (their web-based information management practices) when they can treat this information as harvestable, recontextualizable data, rather than as fixed pages?
Abstracting application-level web security
Authors: David J. Scott, Richard Sharp
Venue: WWW
Year: 2002

Application-level web security refers to vulnerabilities inherent in the code of a web-application itself (irrespective of the technologies in which it is implemented or the security of the web-server/back-end database on which it is built). In the last few months application-level vulnerabilities have been exploited with serious consequences: hackers have tricked e-commerce sites into shipping goods for no charge, user-names and passwords have been harvested and condential information (such as addresses and credit-card numbers) has been leaked.In this paper we investigate new tools and techniques which address the problem of application-level web security. We (i) describe a scalable structuring mechanism facilitating the abstraction of security policies from large web-applications developed in heterogenous multi-platform environments; (ii) present a tool which assists programmers develop secure applications which are resilient to a wide range of common attacks; and (iii) report results and experience arising from our implementation of these techniques.
A web middleware architecture for dynamic customization of content for wireless clients
Authors: Jesse Steinberg, Joseph Pasquale
Venue: WWW
Year: 2002

We present a new Web middleware architecture that allows users to customize their view of the Web for optimal interaction and system operation when using non-traditional resource-limited client machines such as wireless PDAs (personal digital assistants). Web Stream Customizers (WSC) are dynamically deployable software modules and can be strategically located between client and server to achieve improvements in performance, reliability, or security. An important design feature is that Customizers provide two points of control in the communication path between client and server, supporting adaptive system-based and content-based customization. Our architecture exploits HTTP&apos;s proxy capabilities, allowing Customizers to be seamlessly integrated with the basic Web transaction model. We describe the WSC architecture and implementation, and illustrate its use with three non-trivial, adaptive Customizer applications that we have built. We show that the overhead in our implementation is small and tolerable, and is outweighed by the benefits that Customizers provide.
Model checking cobweb protocols for verification of HTML frames behavior
Authors: P. David Stotts, Jaime Navon
Venue: WWW
Year: 2002

HTML documents composed of frames can be difficult to write correctly. We demonstrate a technique that can be used by authors manually creating HTML documents (or by document editors) to verify that complex frame construction exhibits the intended behavior when browsed. The method is based on model checking (an automated program verification technique), and on temporal logic specifications of expected frames behavior. We show how to model the HTML frames source as a CobWeb protocol, related to the Trellis model of hypermedia documents. We show how to convert the CobWeb protocol to input for a model checker, and discuss several ways for authors to create the necessary behavior specifications. Our solution allows Web documents to be built containing a large number of frames and content pages interacting in complex ways. We expect such Web structures to be more useful in "literary" hypermedia than for Web "sites" used as interfaces to organizational information or databases.
Profiles for the situated web
Authors: Lalitha Suryanarayana, Johan Hjelm
Venue: WWW
Year: 2002

The World Wide Web is evolving into a medium that will soon make it possible for conceiving and implementing situation-aware services. A situation-aware or situated web application is one that renders the user with an experience (content, interaction and presentation) that is so tailored to his/her current situation. This requires the facts and opinions regarding the context to be communicated to the server by means of a profile, which is then applied against the description of the application objects at the server in order to generate the required experience. This paper discusses a profiles view of the situated web architecture and analyzes the key technologies and capabilities that enable them. We conclude that trusted frameworks wherein rich vocabularies describing users and their context, applications and documents, along with rules for processing them, are critical elements of such architectures.
Semantic web support for the business-to-business e-commerce lifecycle
Authors: David Trastour, Claudio Bartolini, Chris Preist
Venue: WWW
Year: 2002

If an e-services approach to electronic commerce is to become widespread, standardisation of ontologies, message content and message protocols will be necessary. In this paper, we present a lifecycle of a business-to-business e-commerce interaction, and show how the Semantic Web can support a service description language that can be used throughout this lifecycle. By using DAML, we develop a service description language sufficiently expressive and flexible to be used not only in advertisements, but also in matchmaking queries, negotiation proposals and agreements. We also identify which operations must be carried out on this description language if the B2B lifecycle is to be fully supported. We do not propose specific standard protocols, but instead argue that our operators are able to support a wide variety of interaction protocols, and so will be fundamental irrespective of which protocols are finally adopted.
An incremental XSLT transformation processor for XML document manipulation
Authors: Lionel Villard, Nabil Layaïda
Venue: WWW
Year: 2002

In this paper, we present an incremental transformation framework called incXSLT. This framework has been experimented for the XSLT language defined at the World Wide Web Consortium. For the currently available tools, designing the XML content and the transformation sheets is an inefficient, a tedious and an error prone experience. Incremental transformation processors such as incXSLT represent a better alternative to help in the design of both the content and the transformation sheets. We believe that such frameworks are a first step toward fully interactive transformation-based authoring environments.
Optimal crawling strategies for web search engines
Authors: Joel L. Wolf, Mark S. Squillante, Philip S. Yu, Jay Sethuraman, L. Ozsen
Venue: WWW
Year: 2002

Web Search Engines employ multiple so-called crawlers to maintain local copies of web pages. But these web pages are frequently updated by their owners, and therefore the crawlers must regularly revisit the web pages to maintain the freshness of their local copies. In this paper, we propose a two-part scheme to optimize this crawling process. One goal might be the minimization of the average level of staleness over all web pages, and the scheme we propose can solve this problem. Alternatively, the same basic scheme could be used to minimize a possibly more important search engine embarrassment level metric: The frequency with which a client makes a search engine query and then clicks on a returned url only to find that the result is incorrect. The first part our scheme determines the (nearly) optimal crawling frequencies, as well as the theoretically optimal times to crawl each web page. It does so within an extremely general stochastic framework, one which supports a wide range of complex update patterns found in practice. It uses techniques from probability theory and the theory of resource allocation problems which are highly computationally efficient -- crucial for practicality because the size of the problem in the web environment is immense. The second part employs these crawling frequencies and ideal crawl times as input, and creates an optimal achievable schedule for the crawlers. Our solution, based on network flow theory, is exact as well as highly efficient. An analysis of the update patterns from a highly accessed and highly dynamic web site is used to gain some insights into the properties of page updates in practice. Then, based on this analysis, we perform a set of detailed simulation experiments to demonstrate the quality and speed of our approach.
OCTOPUS: aggressive search of multi-modality data using multifaceted knowledge base
Authors: Jun Yang, Qing Li, Yueting Zhuang
Venue: WWW
Year: 2002

An important trend in Web information processing is the support of multimedia retrieval. However, the most prevailing paradigm for multimedia retrieval, content-based retrieval (CBR), is a rather conservative one whose performance depends on a set of specifically defined low-level features and a carefully chosen sample object. In this paper, an aggressive search mechanism called Octopus is proposed which addresses the retrieval of multi-modality data using multifaceted knowledge. In particular, Octopus promotes a novel scenario in which the user supplies seed objects of arbitrary modality as the hint of his information need, and receives a set of multi-modality objects satisfying his need. The foundation of Octopus is a multifaceted knowledge base constructed on a layered graph model (LGM), which describes the relevance between media objects from various perspectives. Link analysis based retrieval algorithm is proposed based on the LGM. A unique relevance feedback technique is developed to update the knowledge base by learning from user behaviors, and to enhance the retrieval performance in a progressive manner. A prototype implementing the proposed approach has been developed to demonstrate its feasibility and capability through illustrative examples.
Mobile streaming media CDN enabled by dynamic SMIL
Authors: Takeshi Yoshimura, Yoshifumi Yonemoto, Tomoyuki Ohya, Minoru Etoh, Susie J. Wee
Venue: WWW
Year: 2002

In this paper, we present a mobile streaming media CDN (Content Delivery Network) architecture in which content segmentation, request routing, pre-fetch scheduling, and session handoff are controlled by SMIL (Synchronized Multimedia Integrated Language) modification. In this architecture, mobile clients simply follow modified SMIL files downloaded from a streaming portal server; these modifications enable multimedia content to be delivered to the mobile clients from the best surrogates in the CDN. The key components of this architecture are 1) content segmentation with SMIL modification, 2) on-demand rewriting of URLs in SMIL, 3) pre-fetch scheduling based on timing information derived from SMIL, 4) SMIL updates by SOAP (Simple Object Access Protocol) messaging for session handoffs due to clients mobility. We also introduce QoS control with a network called an RTP monitoring agent to enable appropriate control of media quality based on both network congestion and radio link conditions. The current status of our prototyping on a mobile QoS testbed MOBIQ is reported in this paper. We are currently designing the SOAP-based APIs (Application Programmable Interfaces) needed for the mobile streaming media CDN and building the CDN over the current testbed.
Adaptive on-line page importance computation
Authors: Serge Abiteboul, Mihai Preda, Gregory Cobena
Venue: WWW
Year: 2003

The computation of page importance in a huge dynamic graph has recently attracted a lot of attention because of the web. Page importance, or page rank is defined as the fixpoint of a matrix equation. Previous algorithms compute it off-line and require the use of a lot of extra CPU as well as disk resources (e.g. to store, maintain and read the link matrix). We introduce a new algorithm OPIC that works on-line, and uses much less resources. In particular, it does not require storing the link matrix. It is on-line in that it continuously refines its estimate of page importance while the web/graph is visited. Thus it can be used to focus crawling to the most interesting pages. We prove the correctness of OPIC. We present Adaptive OPIC that also works on-line but adapts dynamically to changes of the web. A variant of this algorithm is now used by Xyleme.We report on experiments with synthetic data. In particular, we study the convergence and adaptiveness of the algorithms for various scheduling strategies for the pages to visit. We also report on experiments based on crawls of significant portions of the web.
An SPath-based preference language for P3P
Authors: Rakesh Agrawal, Jerry Kiernan, Ramakrishnan Srikant, Yirong Xu
Venue: WWW
Year: 2003

The Platform for Privacy Preferences (P3P) is the most significant effort currently underway to enable web users to gain control over their private information. The designers of P3P simultaneously designed a preference language called APPEL to allow users to express their privacy preferences, thus enabling automatic matching of privacy preferences against P3P policies. Unfortunately subtle interactions between P3P and APPEL result in serious problems when using APPEL: Users can only directly specify what is unacceptable in a policy, not what is acceptable; simple preferences are hard to express; and writing APPEL preferences is error prone. We show that these problems follow from a fundamental design choice made by APPEL, and cannot be solved without completely redesigning the language. Therefore we explore alternatives to APPEL that can overcome these problems. In particular, we show that XPath serves quite nicely as a preference language and solves all the above problems. We identify the minimal subset of XPath that is needed, thus allowing matching programs to potentially use a smaller memory footprint. We also give an APPEL to XPath translator that shows that XPath is as expressive as APPEL.
?-Queries: enabling querying for semantic associations on the semantic web
Authors: Kemafor Anyanwu, Amit P. Sheth
Venue: WWW
Year: 2003

This paper presents the notion of Semantic Associations as complex relationships between resource entities. These relationships capture both a connectivity of entities as well as similarity of entities based on a specific notion of similarity called r-isomorphism. It formalizes these notions for the RDF data model, by introducing a notion of a Property Sequence as a type. In the context of a graph model such as that for RDF, Semantic Associations amount to specific certain graph signatures. Specifically, they refer to sequences (i.e. directed paths) here called Property Sequences, between entities, networks of Property Sequences (i.e. undirected paths), or subgraphs of r-isomorphic Property Sequences.The ability to query about the existence of such relationships is fundamental to tasks in analytical domains such as national security and business intelligence, where tasks often focus on finding complex yet meaningful and obscured relationships between entities. However, support for such queries is lacking in contemporary query systems, including those for RDF.
Sensor-enhanced mobile web clients: an XForms approach
Authors: John J. Barton, Tim Kindberg, Hui Dai, Nissanka Bodhi Priyantha, Fahd Al-Bin-Ali
Venue: WWW
Year: 2003

This paper describes methods for service selection and service access for mobile, sensor-enhanced web clients such as wireless cameras or wireless PDAs with sensor devices attached. The clients announce their data-creating capabilities in "Produce" headers sent to servers; servers respond with forms that match these capabilities. Clients fill in these forms with sensor data as well as text or file data. The resultant system enables clients to access dynamically discovered services spontaneously, as their users engage in everyday nomadic activities.
Make it fresh, make it quick: searching a network of personal webservers
Authors: Mayank Bawa, Roberto J. Bayardo Jr., Sridhar Rajagopalan, Eugene J. Shekita
Venue: WWW
Year: 2003

Personal webservers have proven to be a popular means of sharing files and peer collaboration. Unfortunately, the transient availability and rapidly evolving content on such hosts render centralized, crawl-based search indices stale and incomplete. To address this problem, we propose YouSearch, a distributed search application for personal webservers operating within a shared context (e.g., a corporate intranet). With YouSearch, search results are always fast, fresh and complete -- properties we show arise from an architecture that exploits both the extensive distributed resources available at the peer webservers in addition to a centralized repository of summarized network state. YouSearch extends the concept of a shared context within web communities by enabling peers to aggregate into groups and users to search over specific groups. In this paper, we describe the challenges, design, implementation and experiences with a successful intranet deployment of YouSearch.
Efficient URL caching for world wide web crawling
Authors: Andrei Z. Broder, Marc Najork, Janet L. Wiener
Venue: WWW
Year: 2003

Crawling the web is deceptively simple: the basic algorithm is (a) Fetch a page (b) Parse it to extract all linked URLs (c) For all the URLs not seen before, repeat (a)-(c). However, the size of the web (estimated at over 4 billion pages) and its rate of change (estimated at 7% per week) move this plan from a trivial programming exercise to a serious algorithmic and system design challenge. Indeed, these two factors alone imply that for a reasonably fresh and complete crawl of the web, step (a) must be executed about a thousand times per second, and thus the membership test (c) must be done well over ten thousand times per second against a set too large to store in main memory. This requires a distributed architecture, which further complicates the membership test.A crucial way to speed up the test is to cache, that is, to store in main memory a (dynamic) subset of the "seen" URLs. The main goal of this paper is to carefully investigate several URL caching techniques for web crawling. We consider both practical algorithms: random replacement, static cache, LRU, and CLOCK, and theoretical limits: clairvoyant caching and infinite cache. We performed about 1,800 simulations using these algorithms with various cache sizes, using actual log data extracted from a massive 33 day web crawl that issued over one billion HTTP requests.Our main conclusion is that caching is very effective - in our setup, a cache of roughly 50,000 entries can achieve a hit rate of almost 80%. Interestingly, this cache size falls at a critical point: a substantially smaller cache is much less effective while a substantially larger cache brings little additional benefit. We conjecture that such critical points are inherent to our problem and venture an explanation for this phenomenon.
Content extraction signatures using XML digital signatures and custom transforms on-demand
Authors: Laurence Bull, Peter Stañski, David Squire
Venue: WWW
Year: 2003

Content Extraction Signatures (CES) enable selective disclosure of verifiable content, provide privacy for blinded content, and enable the signer to specify the content the document owner is allowed to extract or blind. Combined, these properties give what we call CES functionality. In this paper we describe our work in developing custom transform algorithms to expand the functionality of an XML Signature to include CES functionality in XML Signature Core Validation.We also describe a custom revocation mechanism and our implementation for non-XML content where the custom transforms are dynamically loaded demonstrating that custom signing and verification is not constrained to a 'closed system'. Through the use of dynamic loading we show that a verifier can still verify an XML Signature-compliant signature even though a custom signature was produced.