On power of p systems using sequential and parallel rewriting

A new class of distributed computing models inspired from biology, that of P Systems, was recently introduced by Gh. P[acaron]un. Several variants of P Systems were already shown to be computationally universal, equal in power to Turing Machines. We investigate in this paper the power of computability of P Systems based on rewriting, with cooperation, priorities and external output. It is established that rewriting P Systems with priorities and two membranes is computationally universal, thereby making an improvement in the existing result that RE?RP ₃(Pri). We give a new model in P Systems stressing the importance of parallelism. The power of computability of such models is investigated by comparing them with classic mechanisms in L-Systems: TOL, EOL and ETOL Systems     

Restarted Gmres Augmented With Eigenvectors For Shifted Linear Systems * Supported by the National Natural Science Foundation of China and the Science and Technology Developing Foundation of University in Shanghai of China

Shifted matrices, which differ by a multiple of the identity only, generate the same Krylov subspaces with respect to any fixed vector. Frommer and Glassner [5] develop a variant of the restarted GMRES method for such shifted systems at the expense of only one matrix-vector multiplication per iteration. However, restarting slows down the convergence, even stagnation. We present a variant of the restarted GMRES augmented with some eigenvectors for the shifted systems. The convergence can be much faster at little extra expense. Numerical experiments show its efficiency.     

Spatial distribution of thorium fission rate in a fast spallation and fission neutron field: An experimental and Monte Carlo study

The Energy plus Transmutation (EpT) set-up of the Joint Institute for Nuclear Research (JINR), Dubna, Russia is composed of a lead spallation target surrounded by a blanket of natural uranium. The resultant neutron spectrum is a combination of spallation and fission spectra, modified by a reflective external layer of polyethylene and an internal absorbing layer of cadmium. The EpT set-up was irradiated with a beam of 4 GeV deuterons from the Nuclotron Accelerator at JINR. The spatial distribution of thorium fission rate within the assembly was determined experimentally, using a fission track detector technique, and compared with Monte Carlo predictions of the MCNPX code. Contributions of neutrons, protons, deuterons, photons and pions to total fission were taken into account. Close agreement between the experimental and calculated results was found.     

On the transformation of symmetric sparse matrices to the triple diagonal form

The problem of minimizing the number of zero elements that become non-zero during the computation when a sparse symmetric matrix is reduced to a triple diagonal form, either by Givens' or Householder's method, is discussed. Algorithms for minimizing the growth of such non-zero elements are given.     

Knowledge-based temporal interpolation

Temporal interpolation is the task of bridging gaps between time-oriented concepts in a context-sensitive manner. It is a subtask important for solving the temporal-abstraction task-abstraction of interval-based, higher-level concepts from time-stamped data. We present a knowledge-based approach to the temporal-interpolation task and discuss in detail the precise knowledge required by that approach, its theoretical foundations, and the implications of the approach. The temporal-interpolation computational mechanism we discuss relies, among other knowledge types, on a temporal-persistence model. The temporal-persistence model employs local temporal-persistence functions that are temporally bidirectional (i.e. extend a belief measure in a predicate both into the future and into the past) and global, maximal-gap temporal-persistence functions that bridge gaps between interval-based predicates. We investigate the quantitative and qualitative properties implied by both types of persistence functions. We have implemented our approach in the RÉSUMÉ program and evaluated it in several different medical and engineering domains. We discuss the implications of our conceptual and computational methodology for acquisition, maintenance, reuse, and sharing of temporal-abstraction knowledge.     

Outlier detection in audit logs for application systems

An outlier is defined as an observation that is significantly different from the other data in its set. An auditor will employ many techniques, processes and tools to identify these entries, and data mining is one such medium through which the auditor can analyze information. The enormous amount of information contained within transactional processing systems׳ logs means that auditors must employ automated systems for anomalous data detection. Several data mining algorithms have been tested, especially those that deal specifically with classification and outlier detection. A group of these previously described algorithms was selected for use in designing and developing a process to assist the auditor in anomalous data detection within audit logs. We have been successful in creating and ratifying an outlier detection process that works in the alphanumeric fields of the audit logs from an information system, thus constituting a useful tool for system auditors performing data analysis tasks.     

The effects of geography lessons with geospatial technologies on the development of high school students' relational thinking

Geospatial technologies offer access to geospatial information via digital representations, such as digital maps, and tools for interaction with those representations. The question is whether geography lessons with geospatial technologies really contribute to the development of students' geospatial thinking, in particular geospatial relational thinking, as is suggested in the literature about geospatial technologies in secondary education. This paper reports about the outcomes of a quasi-experimental research project, in which a geography lesson series with geospatial technologies was compared with a conventional geography lesson series that had the same content. Although the lesson series covered only three lessons, the data showed that the lesson series with geospatial technologies contributed significantly more to the development of students' geospatial relational thinking than the conventional lesson series. The effect size was ‘medium large’.     

An ontology-based approach to conflict resolution in Home and Building Automation Systems

Ambient intelligent systems such as Home and Building Automation Systems (HBAS) are becoming evermore accepted and capable of actuating automatically on behalf of users to fulfil their requests or enable activities. However, when multiple users interact with such systems, the requirements of activities often interfere resulting in conflicting actuations which HBAS ought to automatically detect and resolve. Yet, despite recent advances in HBAS, no ambient intelligent solution has been reported that is adequately grounded on knowledge analysis.The contributions of this article are twofold. First, it reviews relevant literature on Ambient Intelligence, conflict detection, conflict resolution and knowledge representation in HBAS. Second, it proposes and validates an ontological framework for conflict detection and resolution backed by knowledge-based analysis. Effectively, the proposed solution performs automatic environment actuations maximizing users comfort and energy efficiency.     

Thermodynamic analysis of non-isothermal mixing's influence on the energy target of water-using networks

In this paper, a thermodynamic analysis of non-isothermal mixing's influence on the energy target of water-using network is presented. Firstly, water streams in the network are divided into two categories, and then based on the classification all the non-isothermal mixing patterns between two streams are defined. Through thermodynamic analysis from energy composite curve of hot and cold water streams, the influences of non-isothermal mixing on the energy target of water-using network are explored and some mixing rules are obtained, which can be used to simplify the heat exchanger network of a given water-using system and improve the system's energy performance through identifying the beneficial non-isothermal mixings. The applicability of these rules is illustrated by an example in the paper and the result is very encouraging.     

Mental maps compared to actual spatial behavior using GPS data: A new method for investigating segregation in cities

This article examines the relationship between perceived territorial boundaries and actual spatial activity. The methodology used includes a combination of mental maps and interviews for examining perceptions of territorial boundaries, with tracking technology (GPS) and activity diaries to track the actual use of space. This methodology was implemented in a pilot study with a sample of 18 women living in Jerusalem, including secular Jews, ultra-orthodox Jews, and Palestinian Muslims.The study found a very strong relationship between perceived personal territory and actual spatial activity. However, while the secular Jewish women appeared to be completely segregated within their territory, the ultra-orthodox Jewish women and the Palestinian Muslim women were both very active within the secular Jewish territory, but avoided each other’s territories. The analysis of mental maps and actual spatial patterns of residential daily activities challenges prevailing notions about the spatial structure of Jerusalem and the internal power relations between the populations that inhabit it. More generally, it provides a new methodological approach for investigating segregation in cities.