37459114
Cluster Analysis of Named Entities
This paper presents a statistics-based and language independent unsupervised approach for clustering possible named entities. We describe and motivate the features and statistical filters used by our clustering process. Using the Model-Based Clustering Analysis software we obtained different clusters of named entities. The method was applied to Bulgarian and English. For some clusters, precision is close to 100%; this helps human validation and saves time. Other clusters still need further refinement.
15739638
Identification of Document Language is Not yet a Completely Solved Problem
Existing Language Identification (LID) approaches do reach 100% precision, in most common situations, when dealing with documents written in just one language, and when those documents are large enough. However, LID approaches do not provide a reliable solution for some situations: when there is need to discriminate the correct variant of the language used in a text, for example, European or Brazilian variants of Portuguese, UK or USA English variants, or any other language variants. Another hard context occur with small touristic advertisements on the web, addressing foreigners but using local language to name most local entities. In this paper, we present a fully statistics- based LID approach which learns the most discriminant information according to each context, and identifies the correct language or language variant a text is written in. This methodology is shown to be correct for normal texts and maintains its robustness in hard LID contexts.
35428904
Portable checkpointing and recovery
This paper presents a checkpointing scheme that was implemented in a parallel library that runs on top of CHIMP/MPI. The main goals of the checkpointing mechanism are portability and efficiency. It runs on every platform supported by MPI in a machine-independent way. The scheme allows the migration of checkpoints and offers a flexible recovery mechanism based on data-reconfiguration. Some performance results will be presented at the end of the paper together with some techniques that can be used to increase the efficiency of the checkpointing mechanism.
38588422
Merging Web-Based with Cluster-Based Computing
This paper presents a Java-based software infrastructure that allows the merging of Web-based metacomputing with cluster-based parallel computing. We briefly compare the two approaches and we describe the implementation of a software bridge that supports the execution of metaapplications: some processes of the application may run over the Internet as Java applets while other processes of the same application can execute on a dedicated cluster of machines running PVM or MPI. We present some performance results that show the effectiveness of our approach.
206855912
An algorithm to compare OO-conceptual schemas
In this paper, an algorithmic study of how to compare object-oriented conceptual schemas in a data migration context is carried out. An algorithm is presented based on the tree-comparison technique that compares conceptual schemas. The algorithm uses semantic information in order to optimize efficiency. A template of the equivalences and differences between two schemas is generated in an automatic way. The template shows the results in terms of insertions, updates and deletions. This work is the first phase in a tool which performs the automatic migration of databases starting from the differences detected.
42069370
An Experimental Evaluation of Coordinated Checkpointing in a Parallel Machine
Coordinated checkpointing represents a very effective solution to assure the continuity of distributed and parallel applications in the occurrence of failures. In previous studies it has been proved that this approach achieved better results than independent checkpointing and message logging. However, we need to know more about the real overhead of coordinated checkpointing and get sustained insights about the best way to implement this technique of fault-tolerance. This paper presents an experimental evaluation of coordinated checkpointing in a parallel machine. It describes some optimization techniques and presents some performance results.
206853964
A Java Interface for WMPI
Traditionally, parallel programs have been developed in Fortran and C. However, the extraordinary success of the Java language has raised an impressive hype among the community of software programmers, in such a way that it seems quite promising that parallel programmers could also use Java in their applications.