Measuring eccentricity in binary black-hole initial data

Initial data for evolving black-hole binaries can be constructed via many techniques, and can represent a wide range of physical scenarios. However, because of the way that different schemes parameterize the physical aspects of a configuration, it is not alway clear what a given set of initial data actually represents. This is especially important for quasiequilibrium data constructed using the conformal thin-sandwich approach. Most initial-data studies have focused on identifying data sets that represent binaries in quasi-circular orbits. In this paper, we consider initial-data sets representing equal-mass black holes binaries in eccentric orbits. We will show that effective-potential techniques can be used to calibrate initial data for black-hole binaries in eccentric orbits. We will also examine several different approaches, including post-Newtonian diagnostics, for measuring the eccentricity of an orbit. Finally, we propose the use of the ``Komar-mass difference'' as a useful, invariant means of parameterizing the eccentricity of relativistic orbits.Comment: 12 pages, 11 figures, submitted to Physical Review D, revtex

Ontological approach to development of computing with words based systems

AbstractComputing with words introduced by Zadeh becomes a very important concept in processing of knowledge represented in the form of propositions. Two aspects of this concept – approximation and personalization – are essential to the process of building intelligent systems for human-centric computing.For the last several years, Artificial Intelligence community has used ontology as a means for representing knowledge. Recently, the development of a new Internet paradigm – the Semantic Web – has led to introduction of another form of ontology. It allows for defining concepts, identifying relationships among these concepts, and representing concrete information. In other words, an ontology has become a very powerful way of representing not only information but also its semantics.The paper proposes an application of ontology, in the sense of the Semantic Web, for development of computing with words based systems capable of performing operations on propositions including their semantics. The ontology-based approach is very flexible and provides a rich environment for expressing different types of information including perceptions. It also provides a simple way of personalization of propositions. An architecture of computing with words based system is proposed. A prototype of such a system is described

Infrastructure Interdependencies: Opportunities from Complexity

Infrastructure networks, such as those for energy, transportation, and telecommunications, perform key functions for society. Although such systems have largely been developed and managed in isolation, infrastructure now functions as a system of systems, exhibiting complex interdependencies that can leave critical functions vulnerable to cascade failure. Consequently, research efforts and management strategies have focused on risks and negative aspects of complexity. This paper explores how interdependencies can be seen positively, representing opportunities to increase organizational resilience and sustainability. A typology is presented for classifying positive interdependencies, drawing on fundamental principles in ecology and validated using case studies. Understanding opportunities that arise from interdependency will enable better understanding and management of infrastructure complexity, which in turn will allow the use of such complexity to the advantage of society. Integrative thinking is necessary not only for mitigating risk but also for identifying innovations to make systems and organizations more sustainable and resilient

Infrastructure interdependencies : opportunities from complexity

Infrastructure networks, such as those for energy, transportation, and telecommunications, perform key functions for society. Although such systems have largely been developed and managed in isolation, infrastructure now functions as a system of systems, exhibiting complex interdependencies that can leave critical functions vulnerable to cascade failure. Consequently, research efforts and management strategies have focused on risks and negative aspects of complexity. This paper explores how interdependencies can be seen positively, representing opportunities to increase organizational resilience and sustainability. A typology is presented for classifying positive interdependencies, drawing on fundamental principles in ecology and validated using case studies. Understanding opportunities that arise from interdependency will enable better understanding and management of infrastructure complexity, which in turn will allow the use of such complexity to the advantage of society. Integrative thinking is necessary not only for mitigating risk but also for identifying innovations to make systems and organizations more sustainable and resilient

Neural mechanisms of goal-directed behavior: outcome-based response selection is associated with increased functional coupling of the angular gyrus

Goal-directed behavior is based on representations of contingencies between a certain situation (S), a certain (re)action (R) and a certain outcome (O). These S-R-O representations enable flexible response selection in different situations according to the currently pursued goal. Importantly however, the successful formation of such representations is a necessary but not sufficient precondition for goal-directed behavior which additionally requires the actual usage of the contingency information for action control. The present fMRI study aimed at identifying the neural basis of each of these two aspects: representing vs. explicitly using experienced S-R-O contingencies. To this end, we created three experimental conditions: S-R-O contingency present and used for outcome-based response selection, S-R-O contingency present but not used, and S-R-O contingency absent. The comparison between conditions with and without S-R-O contingency revealed that the angular gyrus is relevant for representing S-R-O contingencies. The explicit usage of learnt S-R-O representations in turn was associated with increased functional coupling between angular gyrus and several subcortical (hippocampus, caudate head), prefrontal (lateral orbitofrontal cortex (OFC), rostrolateral prefrontal cortex (RLPFC)) and cerebellar areas, which we suggest represent different explicit and implicit processes of goal-directed action control. Hence, we ascribe a central role to the angular gyrus in associating actions to their sensory outcomes which is used to guide behavior through coupling of the angular gyrus with multiple areas related to different aspects of action control

AN IMPORTANCE PERFORMANCE-PERFORMANCE ANALYSIS OF AFRICAN STUDENTS’PERCEPTION ON ENROLLING AT THAI UNIVERSITIES

This study focuses on African students’ perception on enrolling at Thai Universities using the Importance-Performance Analysis (IPA), so the objectives are set to describe the African students’ perception of their university experience upon studying in Thailand and identifying the extent to which these perceptions can lead to what Thai universities services for them. The reason behind the need to study on perception on enrolling at Thai Universities is that these universities are no exception when it comes to marketing on international studies as such there has been an influx of students from all over the world who study at Thai universities, so in order to understand what makes international students leave their home countries to study in Thailand, that alone signifies the importance of Thai universities to international education, thereby bringing more reasons to understand the perceptions of enrolling students to these universities. The researcher distributed the questionnaire to five universities within the greater Bangkok metropolitan, including Salaya sub-district in Nakhon Pathom province and Pathum Thani province. The universities engaged in this study are Assumption university, Mahidol university, Rangsit university, Ramkhamhaeng university and Kasem Bundit university. Out of the 400 enrolling African students respondents from these five universities 207 respondents were male, representing 51.8%, while 193 respondents were females, representing 48.3%. Thus the majority of enrolling African students in Thai universities within Bangkok metropolitan and surrounding provinces are male. The IPA in this study is based on five elements which include: academic aspects, access, administrative support, programs issues, reputation and 30 attributes of the students’ perception of the five elements and 6 attributes on demographics. There in total five hypotheses tested using paired sample t-test and the results indicate that four out of five hypotheses have the significant difference at the level of p>0.05 except academic aspects