Search results for "computer.software_genre"
showing 10 items of 3858 documents
Testing Grammars for Parsability
1990
In the preceding chapters we have studied in detail the major methods of deterministic context-free parsing: strong LL(k) parsing (Chapter 5), simple precedence parsing (Chapter 5), canonical LR(k) parsing, LALR(k) parsing, and SLR(k) parsing (Chapters 6 and 7), and canonical LL(k) parsing (Chapter 8). Each of these methods induces a class of grammars that are “parsable” using that method, that is, a class of grammars for which a deterministic parser employing that method can be constructed. For example, the LL(k) grammars constitute the class of grammars parsable by the LL(k) parsing method. By definition, a context-free grammar is an LL(k) grammar if and only if its canonical LL(k) parser…
On the use of relational expressions in the design of efficient algorithms
2005
Relational expressions have finite binary relations as arguments and the operations are composition (·), closure (*), inverse (−1), and union (U). The efficient computation of the relation denoted by a relational expression is considered, and a tight bound is established on the complexity of the algorithm suggested by Hunt, Szymanski and Ullman. The result implies a unified method for deriving efficient algorithms for many problems in parsing. For example, optimal algorithms are derived for strong LL(1) and strong LL(2) parser construction and an efficient polynomialtime algorithm is derived for determining the inessential error entries in an LR(1) parsing table.
Numerical approximation of mixed models for digital integrated circuits
1991
To analyse an electrical network many CAD (Computer Aided Design) circuit simulators are available today. The most well-known is probably SPICE -Nagel [1975]. Although this type of simulator is able to precisely compute the transient performances (as delay time), the usage of complete models of devices implies an extremely high time consumption. So, the circuit simulators are unappropriate for the initial stage of VLSI design where a high speed timing analyser (“timing simulator”) is required. To this goal, alternative approaches using either simpler device models or simpler numerical algorithms or easily computable formulae for delay time approximation, have been developed in the past deca…
Developing and Integrating Advanced Movement Features Improves Automated Classification of Ciliate Species
2015
Recent advances in tracking technologies such as GPS or video tracking systems describe the movement paths of individuals in unprecedented details and are increasingly used in different fields, including ecology. However, extracting information from raw movement data requires advanced analysis techniques, for instance to infer behaviors expressed during a certain period of the recorded trajectory, or gender or species identity in case data is obtained from remote tracking. In this paper, we address how different movement features affect the ability to automatically classify the species identity, using a dataset of unicellular microbes (i.e., ciliates). Previously, morphological attributes a…
A Metric for Automatic Word categorization
2008
This paper presents a metric to be used by the working prototype WIH (Web Intelligent Handler). This metric (referred here as po) is designed to reflect main topic words and discriminate certain text profiles through word weightings. The actual version is designed only for Spanish web texts. Statistical analyses show that it is possible to differentiate text profiles upon po behavior. A poll is presented also, showing that it is a good main words discriminator. This paper is posted here as a new algorithm useful for Spanish text processing.
Semantics for Managing Systems in Heterogeneous and Distributed Environment
2002
The problem of legacy systems collaboration is being solved. Particularly we look at the collaboration as workflow in a distributed and heterogeneous environment. Attention is paid to the description of semantics for workflow process definition languages. There are many solutions how semantics can be decomposed into logical fragments, but the problem of obtaining reusable components that are easy to compile into desired specific semantics still remains. We evolve the division of semantics by semantic aspects whose description is based on abstract data types (pre-built components) and connectors (meta-programs to produce the glue code) between them. This paper offers a way in which semantic …
Collaborative Assessment of Information Provider's Reliability and Expertise Using Subjective Logic
2011
QA each user can individually estimate the expertise and the reliability of her peers using her direct interactions with them and our framework. The online SN (OSN), which can be considered as a distributed database, performs continuous data aggregation for users expertise and reliability assessment in order to reach a consensus. We emulate a Q&A SN to examine various performance aspects of our algorithm (e.g., convergence time, responsiveness etc.). Our evaluations indicate that it can accurately assess the reliability and the expertise of a user with a small number of samples and can successfully react to the latter's behavior change, provided that the cognitive traits hold in practice.
Accelerating data queries on Hadoop framework by using compact data formats
2016
There are massive amounts of data generated from IoT, online transactions, click streams, emails, logs, posts, social networking interactions, sensors, mobile phones and their applications etc. The question is where and how to store these data in order to provide faster data access. Understanding and handling Big Data is a big challenge. The research direction in Big Data projects using Hadoop Technology, MapReduce kind of framework and compact data formats such as RCFile, SequenceFile, ORC, Avro, Parquet shows that only two data formats (Avro and Parquet) support schema evolution and compression in order to utilize less storage space. In this paper, file formats like Avro and Parquet are c…
Memory Resource Management for Real-Time Systems
2007
Dynamic memory storage has been widely used for years in computer science. However, its use in real-time systems has not been considered as an important issue, and memory management has not receive much consideration, whereas today's real-time applications are often characterized by highly fluctuating memory requirements. In this paper we present an approach to dynamic memory management for real-time systems. In response to application behavior and requests, the underlying memory management system adjusts resources to meet changing demands and user needs. The architectural framework that realizes this approach allows adaptive allocation of memory resources to applications involving both per…
Pharmacological distribution diagrams: a tool for de novo drug design.
1996
Abstract Discriminant analysis applied to SAR studies using topological descriptors allows us to plot frequency distribution diagrams: a function of the number of drugs within an interval of values of discriminant function vs. these values. We make use of these representations, pharmacological distribution diagrams (PDDs), in structurally heterogeneous groups where generally they adopt skewed Gaussian shapes or present several maxima. The maxima afford intervals of discrimianant function in which exists a good expectancy to find new active drugs. A set of β-blockers with contrasted activity has been selected to test the ability of PDDs as a visualizing technique, for the identification of n…