Local closed world reasoning with description logics under the well-founded semantics

An important question for the upcoming Semantic Web is how to best combine open world ontology languages, such as the OWL-based ones, with closed world rule-based languages. One of the most mature proposals for this combination is known as hybrid MKNF knowledge bases (Motik and Rosati, 2010 [52]), and it is based on an adaptation of the Stable Model Semantics to knowledge bases consisting of ontology axioms and rules. In this paper we propose a well-founded semantics for nondisjunctive hybrid MKNF knowledge bases that promises to provide better efficiency of reasoning, and that is compatible with both the OWL-based semantics and the traditional Well-Founded Semantics for logic programs. Moreover, our proposal allows for the detection of inconsistencies, possibly occurring in tightly integrated ontology axioms and rules, with only little additional effort. We also identify tractable fragments of the resulting language.     

An Analysis of Edge Detection by Using the Jensen-Shannon Divergence

This work constitutes a theoretical study of the edge-detection method by means of the Jensen-Shannon divergence, as proposed by the authors. The overall aim is to establish formally the suitability of the procedure of edge detection in digital images, as a step prior to segmentation. In specific, an analysis is made not only of the properties of the divergence used, but also of the method's sensitivity to the spatial variation, as well as the detection-error risk associated with the operating conditions due to the randomness of the spatial configuration of the pixels. Although the paper deals with the procedure based on the Jensen-Shannon divergence, some problems are also related to other methods based on local detection with a sliding window, and part of the study is focused to noisy and textured images.     

Ab initio determination of heavy oxide perovskite related structures from precession electron diffraction data

Two complex perovskite-related structures were solved by ab initio from precession electron diffraction intensities. Structure models were firstly derived from HREM images and than have been confirmed independently using two and three-dimensional sets of precession intensities. Patterson techniques prove to be effective for ab initio structure resolution, specially in case of projections with no overlapping atoms. Quality of precession intensity data may be suitable enough to resolve unknown heavy oxide structures.     

Male response to natural sex pheromone ofMigdolus fryanus westwood (Coleoptera: Cerambycidae) females as affected by daily climatic factors

Males of the sugarcane borer,Migdolus fryanus (Coleoptera: Cerambycidae), are attracted to females by means of a sex pheromone. Mating usually occurs during a few days from October to March under field conditions in São Paulo State, Brazil. This work reports on mating of this species as affected by daily climatic factors, during a single nuptial flight. Maximum male capture by the natural sex pheromone occurred from 1000 to 1100 AM at air and soil temperatures of 30.0°C and relative humidity of 57.0%. As these temperatures increased, females burrowed into the soil, as they are more sensitive to heat than males. Thus, it was concluded that sex pheromone-mediated mating in this cerambycid is directly affected by temperatures of air and soil.     

QoS and energy management with Petri nets: A self-adaptive framework

Energy use is becoming a key design consideration in computing infrastructures and services. In this paper we focus on service-based applications and we propose an adaptation framework that can be used to reduce power consumption according to the observed workload. The adaptation guarantees a trade-off between energy consumption and system performance. The approach is based on the principle of proportional energy consumption obtained by scaling down energy for unused resources, considering both the number of servers switched on and their operating frequencies. Stochastic Petri nets are proposed for the modeling of the framework concerns, their analyses give results about the trade-offs. The application of the approach to a simple case study shows its usefulness and practical applicability. Finally, different types of workloads are analyzed with validation purposes.     

Methodological design and comparative evaluation of a MAS providing AmI

Researches on Ambient Intelligent and Ubiquitous Computing using wireless technologies have increased in the last years. In this work, we review several scenarios to define a multi-agent architecture that support the information needs of these new technologies, for heterogeneous domain. Our contribution consists of designing in a methodological way a Context Aware System (involving location services) using agents that can be used in very different domains. We describe all the steps followed in the design of the agent system. We apply a hybridizing methodology between GAIA and AUML. Additionally we propose a way to compare different agent architectures for Context Aware System using agent interactions. So, in this paper, we describe the assignment of weight values to agents interaction in two different MAS architectures for Context Aware problems solving different scenarios inspired in FIPA standard negotiation protocols.     

Linking Organizational Resources and Work Engagement to Employee Performance and Customer Loyalty: The Mediation of Service Climate.

This study examined the mediating role of service climate in the prediction of employee performance and customer loyalty. Contact employees (N=342) from 114 service units (58 hotel front desks and 56 restaurants) provided information about organizational resources, engagement, and service climate. Furthermore, customers (N=1,140) from these units provided information on employee performance and customer loyalty. Structural equation modeling analyses were consistent with a full mediation model in which organizational resources and work engagement predict service climate, which in turn predicts employee performance and then customer loyalty. Further analyses revealed a potential reciprocal effect between service climate and customer loyalty. Implications of the study are discussed, together with limitations and suggestions for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The W-Process for Software Product Evaluation: A Method for Goal-Oriented Implementation of the ISO 14598 Standard

The importance of software product evaluations will grow with the awareness of the need for better software quality. The process to conduct such evaluations is crucial to get evaluation results that can be applied and meet customers' expectations. This paper reviews a well-known evaluation process: the ISO 14598 standard. The review focuses on the difficulties in selecting and evaluating the appropriate evaluation techniques. The review shows that the standard has problems in applying evaluation processes in practice due to insufficient attention to goal definition and to relationships between activities being implicit. Also, the standard ignores the trade-off between goals and resources and pays insufficient attention to feedback. To address these deficiencies, the W-process is proposed. It extends the standard through an improved process structure and additional guidelines.     

Exciton storage by Mn(2+) in colloidal Mn(2+)-doped CdSe quantum dots

Colloidal Mn (2+)-doped CdSe quantum dots showing long excitonic photoluminescence decay times of up to tau exc = 15 mus at temperatures over 100 K are described. These decay times exceed those of undoped CdSe quantum dots by approximately 10 (3) and are shown to arise from the creation of excitons by back energy transfer from excited Mn (2+) dopant ions. A kinetic model describing thermal equilibrium between Mn (2+ 4)T 1 and CdSe excitonic excited states reproduces the experimental observations and reveals that, for some quantum dots, excitons can emit with near unity probability despite being approximately 100 meV above the Mn (2+ 4)T 1 state. The effect of Mn (2+) doping on CdSe quantum dot luminescence at high temperatures is thus completely opposite from that at low temperatures described previously.