18 research outputs found
Semantic web-services or semantic-web services?
The emergence of the Semantic Web together with the promise of Web Services, a new level of service on top of the current web is envisaged as the new silver bullet and considered as the next great cure-all for IT’s ill. However, in order to employ their full potential, appropriate description techniques for such services need to be developed, and even though the future looks bright, promising and interesting, one should proceed with caution as potential pitfalls lie ahead. In this paper a brief overview of how to best ensue such issues is given, together with a personal clarification to which this paper is entitled.peer-reviewe
Distributed application reliability on unstable, dynamic, P2P-based platforms
Application developers are used to a homogeneous, reliable and easily manageable platform on which to deploy their applications. Increasingly however, the need for a highly scalable distributed environment is becoming prevalent. Just as TCP/IP offers reliability over unreliable links, we aim at providing a simple API to hide an underlying unstable, dynamic, P2P platform and present a consistent, reliable view to the applications requesting it. The API should provide robustness and features found in present Grid-systems, which have similar objectives but numerous inherent and logistical differences. Applications would be able to run in a distributed manner over such a platform.peer-reviewe
Automatic document clustering using topic analysis
Web users are demanding more out of current search engines. This can be noticed by the behaviour of users when interacting with search engines [12, 28]. Besides traditional query/results interactions, other tools are springing up on the web. An example of such tools includes web document clustering systems. The idea is for the user to interact with the system by navigating through an organised hierarchy of topics. Document clustering is ideal for unspecified search goals or for the exploration of a topic by the inexpert [21]. Document clustering is there to transform the current interactions of searching through a large amount of links into an efficient interaction where the interaction is navigation through hierarchies. This report will give an overview of the major work in this area, we will also propose our current work, progress and pitfalls which are being tackled.peer-reviewe
Matrix decomposition algorithms for feature extraction
Clinical decision support software is a delicate system which, can potentially be the physician’s closest friend. The aim of such systems is to be able to cleverly recommend a list of treatment options which closely matches the patient. We envisage a system which learns from experts without ever needing to ask them for feedback, and thus one which learns from past patient encounters. The system needs to be adaptive as well as dynamic, since all patients are different even if they may exhibit very similar symptoms. This paper proposes using matrices to capture such data, and algorithms using Singular Value Decomposition to predict treatments.peer-reviewe
Reading between the lines of code : visualising a program’s lifetime
Visual representations of systems or processes are rife in all fields of science and engineering due to the concise yet effusive descriptions such representations convey. Humans’ pervasive tendency to visualise has led to various methods being evolved through the years to represent different aspects of software. However visualising running software has been fraught with the challenges of providing a meaningful representation of a process which is stripped of meaningful cues and reduced to manipulating values and the field has consequently evolved very slowly. Visualising running software is particularly useful for analysing the behaviour of software (e.g. software written to make use of late binding) and to gain a better understanding of the ever-important assessment of how well the final product is fulfilling the initial request. This paper discusses the significance of gaining improved insight into a program’s lifetime and demonstrates how attributing a geometric sense to the design of computer languages can serve to make it easier to visualise the execution of software by shifting the focus of semantics towards the spatial organisation of program parts.peer-reviewe
Corpus-driven bilingual lexicon extraction
This paper introduces some key aspects of machine translation in order to situate the role of the bilingual lexicon in transfer-based systems. It then discusses the data-driven approach to extracting bilingual knowledge automatically from bilingual texts, tracing the processes of alignment at different levels of granularity. The paper concludes with some suggestions for future work.peer-reviewe
Forecasting using non-linear techniques in time series analysis : an overview of techniques and main issues
The development of techniques in non linear time series analysis has emerged from its time series background and developed over the last few decades into a range of techniques which aim to fill a gap in the ability to model and forecast certain types of data sets such a chaotic determinate systems. These systems are found in many diverse areas of natural and human spheres. This study outlines the background within which these techniques developed, the fundamental elements on which they are based and details some of the predictive techniques. This study aims to provide some insight into their mechanisms and their potential.peer-reviewe
Simulo Tempestas : a simulation tool for hydrological modelling
Man’s existence has clearly interfered with nature. Ever since man appeared on the face of our planet, the landscape was adapted to make it a more habitable environment. Although early humans transformed land to accommodate their dwellings and livestock, land was changed only to a certain extent. However, modern man has altered his surroundings beyond recognition through the building of road networks, sprawling cities, industrial zones, so on and so forth. This project studies the natural flow of water over the terrain through the use of a simulation tool, with particular focus on the Maltese Islands. Such a tool would help engineers plan better the assignment of construction zones as it allows proper analysis of the effects of land development on the flow of storm water before making any commitment that would change the landscape irreversibly. Different weather scenarios, based either on past statistics or completely fictitious ones, could be fed to the tool and its effects studied in the quest of finding the best solutions to avoid man-made catastrophes.peer-reviewe
Low-latency message passing over gigabit ethernet clusters
As Ethernet hardware bandwidth increased to Gigabit speeds it became evident that it was difficult for conventional messaging protocols to deliver this performance to the application layer. Kernel based protocols such as TCP/IP impose a significant load on the host processor in order to service incoming packets and pass them to the application layer. Under heavy loads this problem can also lead to the host processor being completely used up for processing incoming messages, thus starving host applications of CPU resources. Another problem suffered by inter-process communication using small messages is the latency imposed by memory-to-memory copying in layered protocols as well as the slow context switching times in kernel-level schedulers required for servicing incoming interrupts. All this has put pressure on messaging software which led to the development of several lower latency userlevel protocols specifically adapted to high-performance networks (see U-Net[18], EMP[16], VIA[3], QsNET[15], Active Messages[19], GM[13], FM[14]). The aim of this paper is to investigate the issues involved in building high performance cluster messaging systems. We will also review some of the more prominent work in the area as well as propose a low-overhead low-latency messaging system to be used by a cluster of commodity platforms running over Gigabit Ethernet. We propose to use the programmable Netgear GA620-T NICs and modify their firmware to design a lightweight reliable OS-bypass protocol for message passing. We propose the use of zero-copy and polling techniques in order to keep host CPU utilization to a minimum whilst obtaining the maximum bandwidth possible.peer-reviewe
The use of model-checking for the verification of concurrent algorithms
The design of concurrent algorithms tends to be a long and difficult process. Increasing the number of concurrent entities to realistic numbers makes manual verification of these algorithms almost impossible. Designers normally resort to running these algorithms exhaustively yet can never be guaranteed of their correctness. In this report, we propose the use of a model-checker (SMV) as a machine-automated tool for the verification of these algorithms. We present methods how this tool can be used to encode algorithms and allow properties to be guaranteed for uni-processor machines running a scheduler or SMP machines. We also present a language-generator allowing the designer to use a description language that is then automatically converted to the model-checker’s native language. We show how this approach was successful in encoding a concurrent algorithm and is able to verify the desired properties.peer-reviewe