University of Leicester

informatics

Computer Science Internal Seminars

The Internal Seminar Series is a relaxed forum for members of the Department to present their current research and discuss ideas of interest. Invited speakers are also welcome, in particular for presentations that might be to specialised for a general computer science audience as on the Friday's seminar.

Semester 2

Seminar programme


Seminar details

ICT for Saudi Health System Development

Ahmad Khudair (Loughborough University)
Friday June 1, 14:30 in Ben LT5

The health infrastructure of Saudi Arabia and its diagnostic, therapeutic and health prevention services have made important and increasing progress during the past decades. The Kingdom's medical colleges and hospitals provide specialist diagnostic and therapeutic services and medical education and training programmes, while they also conduct health research in collaboration with other research centres. However, Saudi health care is facing some challenges. A factor that affects the sustainability of Saudi healthcare is that hospitals are established individually and independently with no consideration for co-operation and co-ordination. The existing cooperative research is aimed to study and develop the role of Information and Communica-tion Technologies (ICTs) in Saudi health systems. A literature search and document analysis related to the development of the Saudi healthcare system is presented, in conjunction, non-participant observation and interviews are used to provided deep understanding. In practice, Saudi health is the least fortunate sector in utilising ICTs and most hospitals have a poor information infrastructure. In particular, the rate of use and adoption of Electronic Health System (EHR) is low and small health practice organisations appear to lag behind larger ones in adopting EHR systems. A model for health system sustainability in Saudi Arabia is proposed that is a framework for developing e-health services in Saudi Arabia. It has been concluded that development and technological advancement will not reach their full potential if there is continued lack of investment in management. A holistic view of the current health system may be adopted to utilise ICT as a driver for improved health system sustainability.

The Protection of Software Development - some interesting issues arising from EU v Microsoft

Ann Walsh
May 17, 10:30 in Benett LT10

The Microsoft case provides a fascinating set of new circumstances within the established tensions surrounding intellectual property and competition law.

The main aim of this talk is to give a brief introduction to some of the main issues arising in the Microsoft case. It will also attempt to highlight some of the particular difficulties which software brings to this area of law, and try to stimulate discussion on how the development of software should be protected.

Hong Qing Yu
tba, 10:30 in Benett LT10


Ossama El-Hassam
March 29, 10:30 in Benett LT10


Reversing CCS with SimCCSK

Gavin Cox
March 22, 10:30 in Benett LT10

Reversible computation has a growing number of potential application areas such as debugging, testing and the modeling of biochemical systems. To look in the possible use of reversibility in such areas some form of computer aided simulation would be of great advantage. With this in mind I have created a prototype simulator SimCCSK for CCSK a reversible version of CCS with communication keys by Phillips and Ulidowski.

Migrating Legacy Systems to Service-Oriented Architectures

Carlos Matos
March 15, 10:30 in Benett LT10

This presentation focuses on the issues that involve the transformation of legacy systems towards Service-Oriented Architectures. First a motivation for the problem will be given, followed by an explanation of the strategy that is being used in the context of Leg2Net project. This consists of the separation of the problem in two levels of complexity: technical and functional. An approach to address the latter is then presented, as well as some ideias for its implementation.

Semi-automatic Software Reengineering: Migrating Legacy Systems to Layered Architectures

Rui Correia
March 8, 10:30 in Benett LT10

In this presentation we put forward a methodology for migrating legacy systems towards new architectural styles. Based on a metamodel for both source and target style, the approach consists in (1) categorizing the source code according to the different elements of the target architecture they shall be mapped to, (2) obtaining a metamodel-based representation of the code, (3) transforming it into the target architectural style, and (4) generating the target code. The categorization is carried out through an iteration of manual code annotation and automated deduction. The result of the categorization determines the level of detail required for the metamodel-based representation which enables the use of graph transformation rules on metamodel instances to describe the transformation. Our approach follows that by Mens et al in which refactoring is formalized as graph transformation, except that:

* we aim at fully automated transformation, controlled by the code categorization.

* our transformations are not always semantics-preserving

We will also discuss issues of the implementation of the approach based on existing program and model transformation tools and report on a small case study, the transformation of a two-tier application in Java into a three-tier one.

Mentality Patterns: Capturing and Dealing Explicitly With Recurring Turns of Mind in Software Development

Georgios Koutsoukos
March 1, 10:30 in Benett LT10

The increasing adoption of agile software development methods is amplifying the message that people are one of the most critical success factors of any software project. As A. Cockburn, one of the pioneers of agile methods, states:

"People's characteristics are a first-order success driver, not a second-order one. [...] Most of my experiences can be accounted for from just a few characteristics of people. Applying these on recent projects, I have had much greater success at predicting results and making successful recommendations. I believe the time has come to, formally and officially, put a research emphasis on what are the characteristics of people that affect software development, and what are their implications on methodology design"

In this presentation we describe a means to make certain people characteristics a first-class concern in software development projects. In particular, we present a systematic way of capturing, communicating, reasoning and making such human characteristics explicit through an abstraction and representation primitive that we call mentality pattern. In a second stage, we use this primitive to define what we call the Mentality Innovation Sub-Process - an organized way to supplement and enhance software development methods and processes in order to "manage" explicitly such human-related factors and improve the effectiveness of individual work and the way teams blend together.

UML for \lambda_{req}

Carlo Montangero, Dipartemento di Informatica, University of Pisa
Feb 22, 10:30 in Benett LT10

\lambda_{req} is a core language for service orchestration, developed inside SENSORIA by Bartoletti, Degano and Ferrari to explore how the call-by-contract mechanism may be exploited to define services that abide by explicitely stated safety and liveness policies.

In the spirit of SENSORIA, we are defininig and implementing a UML front-end, to facilitate and standardize the exploitation of the language. We will discuss both the problems related to the proper utilization/extension of UML to express the relevant concepts, and the VIATRA2-based graph-transformational approach taken to implement the front-end.

Towards a Web-Service based Implementation for Architectural Management Laws

Ahmed Al-Ghamdi
Feb 15, 10:30 in Benett LT10

Web-Service applications require a clear approach to management in order to be efficiently and optimally deployed. For that purpose, Service Level Agreements (SLAs) have been proposed as management contracts between customers and service providers, using different implementation technologies (what are called IT-SLAs). However, the modelling of SLAs at the business level remains largely unexplored despite the many benefits that they may provide in addition to IT-SLAs. In this work, we propose to leverage Web-Service management to this business level by putting forward adequate conceptual primitives based on software architectural techniques.The main advantage of our approach is the ability to distribute rules across web services, which enables powerful ways of executing and separating business rules.

Compressed Prefix Sums

O.N. Delpratt
Feb 8, 10:30 in Benett LT10

This is joint work with Naila Rahman and Rajeev Raman

We consider the PrefixSum problem: Given a sequence of positive integers k=( n_1,...,n_k), the prefixsums for the sequence are (d_1,...,d_k), where d_1=n_1, d_2=n_1+n_2,...,d_k=n_1+...+n_k, such that m=d_1+d_2+..+d_k. We wish to support the operation sum(k,j), which returns d_j=n_1+..+n_j. Our interests is in minimising the space required for storing k, where minimum space is defined according to some compressibility criteria, while supporting sum as rapidly as possible.

We are motivated by several applications such as Inverted lists in the information retrieval (IR) community, String collections: web databases and XML documents where we often achieve good text compression, but a large overhead for string offsets. The main application is XML DOM.

We demonstrate a close connection between a succinct compressilibity measure and (IR) data-aware measure that is the best in practice. We give theoretical solutions that use space close to other data-aware compressibility measures (often within o(n) bits), and support sum in doubly-logarithmic (or better) time, and experimental evaluations of practical variants thereof.

A bit-vector is a data structure that supports 'rank/select' on a bit-string, and is fundamental to succinct and compressed data structures. We describe a new bit-vector that is robust and efficient.

Organization-Oriented Measurement and Evaluation Framework for Software and Web Engineering Projects

Hernan Molina (GIDIS Web, National University of La Pampa, Argentina)
1 Feb, 10:30 in Benett LT10

Quality assurance is one of the most important activities in every software and web organization. Through the use of measurement and evaluation processes it is possible to keep an updated view of the engineering activities providing useful mechanisms to improve the quality of processes and products as well. In this sense, a framework that defines sound specifications of the information used in measurement and evaluation activities in the organization, can provide more consistent and comparable solutions among the organization's projects.

In this presentation we describe a measurement and evaluation framework called INCAMI, which is based on an ontology describing the main concepts involved in this activities, and also in the WebQEM (Web Quality Evaluation Method) methodology. This framework is goal-oriented, since all activities are performed to satisfy a stated information need; and it is organization-focused, considering consistency issues among all organization's projects. A current research work is evolving this framework to make it context-aware, in order to be able to use the information relative to the relevant context to help in the design activities of measurement and evaluation.

A Categorical Model of Computation for Graph Transformation: True Concurrency and Logic, Part II

Reiko Heckel (Leicester)
31 Jan, 10:00 in G4

See Jan 25

A Categorical Model of Computation for Graph Transformation: True Concurrency and Logic

Reiko Heckel (Leicester)
25 Jan, 10:30 in Benett LT10

Categories with algebraic structure are well-known as models of concurrent computations for, e.g., formal grammars, Petri nets, and term rewriting. The approach, of obtaining concurrent computations by means of an algebraic construction from a set of rules, can be generalised to graph transformation systems. The resulting computational model, a free double category with finite horizontal colimits, captures the established notion of concurrency of DPO graph transformation.

Such a construction exposes the intrinsic structure of concurrency in graph transformations and provides the basis for defining a temporal logic for concurrent computations. The logic represents a specialisation of van Benthem's arrow logic to categories, extended by spatial connectives like a concurrent composition of computations.

The talk will present the basics of the categorical model and discuss the definition of the logic, its semantics, deduction rules, and potential applications.

Semester 1

Seminar programme


Seminar details

Bioinformatics: Simulation (Computational methods)

Krishna Bandaru (Leicester)
14 Dec, 10:30 in Benett LT3

I am going to cover below topics.

Importance of the role of computers and computer science in investigations and applications of biological data.

Convince you that bioinformatics will have a positive effect on our understanding of life and improving human health.

Computation of the Electrostatic Component of Solvation Energy using Poisson-Boltzmann Equation: Comparison of Krylov Subspace Methods.

Software process engineering in the filed: "Doing the thing right" and "Doing the right thing"

James Byles (BSc, MRPharmS), Michael Isherwood (BSc) from Accenture (accenture.com)
7 Dec, 10:30 in Benett LT3 (Host: Mohammad El-Ramly for CO7206)


A type-based approach to service interaction (and sessions)

Emilio Tuosto
30 Nov, 10:30 in Benett LT3

Service Oriented Computing (SOC) promotes the metaphor of computation as service composition where (basic) services are (somehow) composed to form more complex services. Services interact by invoking each other.

In this talk I'll describe a very ongoing work where a type-based approach to service coordination is presented. The proposed type system has been designed on the Signal Calculus (SC), a process calculus based on an event notification paradigm where services are modeled as components which expose reactions (i.e., interfaces) triggered by signals.

An emergent issue in SOC is the formalisation of sessions within computations. Sessions are indeed widely used in practice but, at the best of our knowledge, they have not been very much studied. Only recently there has been some research on this topic. We will show how the proposed type system can suitably be used to model general notion of sessions.

This work has been jointly done with Roberto Guanciale and Daniele Strollo during their visit to our department.

BIP Language Framework for Modeling Systems Integration from Heterogenous Real-Time Components

Simon Biludze (VERIMAG lab, Grenoble, France)
23 Nov, 10:30 in Benett LT3 (Host: Jose Fiadeiro)

A central idea in systems engineering is that complex systems are built by assembling components. System designers deal with a large variety of components, each having different characteristics, from a large variety of viewpoints, each highlighting different dimensions of a system. A central problem is the meaningful composition of heterogeneous components to ensure their correct inter-operation.

We present a methodology for modeling heterogeneous real-time components. Components are obtained as the superposition of three layers: Behaviour, specified as a set of transitions; Interactions between transitions of the behavior; and Priorities, used to choose amongst possible interactions. A parameterised binary composition operator is used to compose components layer by layer.

We present also the BIP language for the description and composition of layered components as well as associated tools for executing and analysing components on a dedicated platform. The language provides a powerful mechanism for structuring interactions involving rendezvous and broadcast. We show that synchronous and timed systems are particular classes of components. Finally, we provide examples and compare the BIP framework to existing ones for heterogeneous component-based modeling.

Abstract Model Theory meets Computational Logic

Balder ten Cate (Amsterdam)
16 Nov, 16:30 in G4 (Host: Alexander Kurz)

JSCL: a middleware for service coordination

Daniele Strollo (IMT Lucca, Italy)
16 Nov, 10:30 in Benett LT3

The main goal of the Service Oriented Architectures (SOAs) is to define software components which are (i) developed in a language and architecture-independent way and (ii) distributed in the web. Most of the current methodologies are focused on composition of such services and several programming languages have been recently proposed for describing aggregated services. However, it is not infrequent that such languages have drawbacks. In fact, constructs are often informally specified which usually leads to ambiguities or redundancy. In this talk the prototype implementation of Java Signal Core Layer (JSCL) will be described. Basically, JSCL is a coordination language of distributed services based on an event notification paradigm and has been inspired (and its implementation driven) by the Signal Calculus, a formally defined process calculus.

General Reversibility

Pawel Sobocinski (Cambridge, UK)
2 Nov, 10:30 in Benett LT3 (Host: Reiko Heckel)

Reversible CCS was introduced in order to model concurrent computations where certain actions are allowed to be reversed. In fact, the core of the construction can be analysed at an abstract level, yielding a theorem of pure category theory which underlies the previous results. This opens the way to several new examples; in particular we shall demonstrate an immediate concrete application to Petri nets.

Signal Calculus: A formal approach to service coordination

Roberto Guanciale (IMT Lucca, Italy)
26 Oct, 10:30 in Benett LT3

Signal Calculus (SC) is a process calculus specifically designed to describe coordination policies of services distributed over a network. The formal specification driven and inspired the design and the implementation of a middleware for service coordination (JSCL). We present the formal specification remarking the analogies with the programming middleware.

Policy Support for Business-oriented Web Service Management

Stephen Gorton (The University of Leicester, UK)
19 Oct, 10:30 in Benett LT3

Policies have been adopted for many reasons within Web Services and Service-oriented Architecture in general. However, while they are a favoured method of management, this only occurs at the service level and in the software domain. Policies already exist in a narrow variety more focussed on service properties such as authorisation. As a significant number of web services become available, more emphasis needs to be placed on management of services in the business domain. In this presentation, we propose a policy framework that can be used to express business requirements for web services, at a business level that is more abstract than the current high-level composition and orchestration technologies. This is joint work with Stephan Reiff-Marganiec in the Sensoria project.

Author: Alexander Kurz (kurz mcs le ac uk), T: 0116 252 5356.
© University of Leicester . Last modified: 30th August 2007, 13:23:36.
Informatics Web Maintainer. This document has been approved by the Head of Department.