Modelling dynamic web data

We introduce Xd¼, a peer-to-peer model for reasoning about the dynamic behaviour of web data. It is based on an idealised model of semistructured data, and an extension of the ¼-calculus with process mobility and with operations for interacting with data. Our model can be used to reason about behaviour found in, for example, dynamic web page programming, applet interaction, and service orchestration. We study behavioural equivalences for Xd¼, motivated by examples

Distributed XQuery

XQuery is increasingly being used for ad-hoc integration of heterogeneous data sources that are logically mapped to XML. For example, scientists need to query multiple scientific databases, which are distributed over a large geographic area, and it is possible to use XQuery for that. However, the language currently supports only the data shipping query evaluation model (through the document() function): it fetches all data sources to a single server, then runs the query there. This is a major limitation for many applications, especially when some data sources are very large, or when a data source is only a virtual XML view over some other logical data model. We propose here a simple extension to XQuery that allows query shipping to be expressed in the language, in addition to data shipping

A Framework for XML-based Integration of Data, Visualization and Analysis in a Biomedical Domain

Biomedical data are becoming increasingly complex and heterogeneous in nature. The data are stored in distributed information systems, using a variety of data models, and are processed by increasingly more complex tools that analyze and visualize them. We present in this paper our framework for integrating biomedical research data and tools into a unique Web front end. Our framework is applied to the University of Washington’s Human Brain Project. Specifically, we present solutions to four integration tasks: definition of complex mappings from relational sources to XML, distributed XQuery processing, generation of heterogeneous output formats, and the integration of heterogeneous data visualization and analysis tools

Combining behavioural types with security analysis

Today's software systems are highly distributed and interconnected, and they increasingly rely on communication to achieve their goals; due to their societal importance, security and trustworthiness are crucial aspects for the correctness of these systems. Behavioural types, which extend data types by describing also the structured behaviour of programs, are a widely studied approach to the enforcement of correctness properties in communicating systems. This paper offers a unified overview of proposals based on behavioural types which are aimed at the analysis of security properties

V for Virtual

AbstractOperating system virtualization has been available on commodity hardware for a few years, and today attracts considerable commercial and research interest. Virtualization allows one or more virtual machines (VMs) to run on a single physical machine, and to interact via virtual devices, such as virtual hard discs or virtual network cards. To model basic virtualization operations, we propose a process calculus, V, with primitives to start and stop VMs, and to read and write data in a hierarchical store. Formalisms such as V may be useful for programming and reasoning about various applications of virtualization, such as VM-based trusted computing or VM-based computational grids

Tipski sistemi za kontrolu memorije i prava pristupa

Three issues will be elaborated and disussed in the proposed thesis. The first is administration and control of data access rights in networks with XML data, with emphasis on data security. The second is the administration and control of access rights to data in computer networks with RDF data, with emphasis on data privacy. The third is prevention of errors and memory leaks, as well as communication errors, generated by programs written in Sing # language in the presence of exceptions. For all three issues, there will be presented formal models with corresponding type systems and showed the absence of undesired behavior i.e. errors in networks or programs.У тези су разматрана три проблема. Први је администрација и контрола права приступа података у рачунарској мрежи са XML подацима, са нагласком на безбедости посматраних података. Други је администрација и котрола права приступа подацима у рачунарској мрежи са RDF подацима, са нагласком на приватности посматраних података. Трећи је превенција грешака и цурења меморије, као и грешака у комуникацији генерисаним програмима написаних на језику Sing# у којима су присутни изузеци. За сва три проблема биће предложени формални модели и одговарајући типски системи помоћу којих се показује одсуство неповољних понашања тј. грешака у мрежама односно програмима.U tezi su razmatrana tri problema. Prvi je administracija i kontrola prava pristupa podataka u računarskoj mreži sa XML podacima, sa naglaskom na bezbedosti posmatranih podataka. Drugi je administracija i kotrola prava pristupa podacima u računarskoj mreži sa RDF podacima, sa naglaskom na privatnosti posmatranih podataka. Treći je prevencija grešaka i curenja memorije, kao i grešaka u komunikaciji generisanim programima napisanih na jeziku Sing# u kojima su prisutni izuzeci. Za sva tri problema biće predloženi formalni modeli i odgovarajući tipski sistemi pomoću kojih se pokazuje odsustvo nepovoljnih ponašanja tj. grešaka u mrežama odnosno programima

Tipski sistemi za kontrolu memorije i prava pristupa

Three issues will be elaborated and disussed in the proposed thesis. The first is administration and control of data access rights in networks with XML data, with emphasis on data security. The second is the administration and control of access rights to data in computer networks with RDF data, with emphasis on data privacy. The third is prevention of errors and memory leaks, as well as communication errors, generated by programs written in Sing # language in the presence of exceptions. For all three issues, there will be presented formal models with corresponding type systems and showed the absence of undesired behavior i.e. errors in networks or programs.У тези су разматрана три проблема. Први је администрација и контрола права приступа података у рачунарској мрежи са XML подацима, са нагласком на безбедости посматраних података. Други је администрација и котрола права приступа подацима у рачунарској мрежи са RDF подацима, са нагласком на приватности посматраних података. Трећи је превенција грешака и цурења меморије, као и грешака у комуникацији генерисаним програмима написаних на језику Sing# у којима су присутни изузеци. За сва три проблема биће предложени формални модели и одговарајући типски системи помоћу којих се показује одсуство неповољних понашања тј. грешака у мрежама односно програмима.U tezi su razmatrana tri problema. Prvi je administracija i kontrola prava pristupa podataka u računarskoj mreži sa XML podacima, sa naglaskom na bezbedosti posmatranih podataka. Drugi je administracija i kotrola prava pristupa podacima u računarskoj mreži sa RDF podacima, sa naglaskom na privatnosti posmatranih podataka. Treći je prevencija grešaka i curenja memorije, kao i grešaka u komunikaciji generisanim programima napisanih na jeziku Sing# u kojima su prisutni izuzeci. Za sva tri problema biće predloženi formalni modeli i odgovarajući tipski sistemi pomoću kojih se pokazuje odsustvo nepovoljnih ponašanja tj. grešaka u mrežama odnosno programima