On Bisimulations for Description Logics

We study bisimulations for useful description logics. The simplest among the considered logics is $\mathcal{ALC}_{reg}$ (a variant of PDL). The others extend that logic with inverse roles, nominals, quantified number restrictions, the universal role, and/or the concept constructor for expressing the local reflexivity of a role. They also allow role axioms. We give results about invariance of concepts, TBoxes and ABoxes, preservation of RBoxes and knowledge bases, and the Hennessy-Milner property w.r.t. bisimulations in the considered description logics. Using the invariance results we compare the expressiveness of the considered description logics w.r.t. concepts, TBoxes and ABoxes. Our results about separating the expressiveness of description logics are naturally extended to the case when instead of $\mathcal{ALC}_{reg}$ we have any sublogic of $\mathcal{ALC}_{reg}$ that extends $\mathcal{ALC}$. We also provide results on the largest auto-bisimulations and quotient interpretations w.r.t. such equivalence relations. Such results are useful for minimizing interpretations and concept learning in description logics. To deal with minimizing interpretations for the case when the considered logic allows quantified number restrictions and/or the constructor for the local reflexivity of a role, we introduce a new notion called QS-interpretation, which is needed for obtaining expected results. By adapting Hopcroft's automaton minimization algorithm and the Paige-Tarjan algorithm, we give efficient algorithms for computing the partition corresponding to the largest auto-bisimulation of a finite interpretation.Comment: 42 page

Complex evolutionary dynamics of massively expanded chemosensory receptor families in an extreme generalist chelicerate herbivore

While mechanisms to detoxify plant produced, anti-herbivore compounds have been associated with plant host use by herbivores, less is known about the role of chemosensory perception in their life histories. This is especially true for generalists, including chelicerate herbivores that evolved herbivory independently from the more studied insect lineages. To shed light on chemosensory perception in a generalist herbivore, we characterized the chemosensory receptors (CRs) of the chelicerate two-spotted spider mite, Tetranychus urticae, an extreme generalist. Strikingly, T. urticae has more CRs than reported in any other arthropod to date. Including pseudogenes, 689 gustatory receptors were identified, as were 136 degenerin/Epithelial Na+ Channels (ENaCs) that have also been implicated as CRs in insects. The genomic distribution of T. urticae gustatory receptors indicates recurring bursts of lineage-specific proliferations, with the extent of receptor clusters reminiscent of those observed in the CR-rich genomes of vertebrates or C. elegans. Although pseudogenization of many gustatory receptors within clusters suggests relaxed selection, a subset of receptors is expressed. Consistent with functions as CRs, the genomic distribution and expression of ENaCs in lineage-specific T. urticae expansions mirrors that observed for gustatory receptors. The expansion of ENaCs in T. urticae to > 3-fold that reported in other animals was unexpected, raising the possibility that ENaCs in T. urticae have been co-opted to fulfill a major role performed by unrelated CRs in other animals. More broadly, our findings suggest an elaborate role for chemosensory perception in generalist herbivores that are of key ecological and agricultural importance

The process of developing professional capacity for teachers

The primary aim of Vietnam's new educational program is to enhance students' knowledge and skills through practical learning experiences, enabling them to tackle academic and real-world challenges. However, teachers in Dong Thap province face limitations in their professional competencies. Thus, this study aims to address these issues by examining different models for developing teachers' professional competencies. 1,116 participants participated in this study (258 managers and 868 teachers from high schools and preschools) who completed two questionnaires assessing their professional competence and the perceived importance of professional development. The findings reveal that teachers lack subject knowledge, interdisciplinary understanding   and skills in teaching design and assessment. Both school managers and teachers recognize the necessity of professional competence development. A three-step process for enhancing teachers' professional competence is proposed for implementing professional development activities based on these findings

Wear and friction of Y-TZP spheres reciprocating against various Sialon plates

The friction and wear characteristics of various Y2O3-stabilized tetragonal ZrO2 polycrystal (Y-TZP)-Sialon sliding systems were examd. These systems consisted of a Y-TZP sphere reciprocating against various Sialon plates. The Sialons differed in phase content and compn. They range from a-Sialons to b-Sialons and include a-b composites. The length of the wear tracks was 10 mm, the loads used were 2 and 8 N, the frequencies 1, 4 and 8 Hz and the humidity was controlled by flushing with dry nitrogen. The tests were continued for 8, 24 and 72 h at room temp. The total vertical displacement and the friction coeff. were measured continuously and sampled. Various addnl. measurements were performed after each test and the worn surfaces were obsd. microscopically. It was concluded that the a-b composites show less wear than the single-phase a- and b-Sialons. It was also concluded that the amt. of wear increases approx. linearly with increasing load and increases significantly more than linearly with increasing frequency. A wear mechanism was derived incorporating the measured data and the observations. [on SciFinder (R)

Collective multipole excitations in a microscopic relativistic approach

A relativistic mean field description of collective excitations of atomic nuclei is studied in the framework of a fully self-consistent relativistic random phase approximation (RRPA). In particular, results of RRPA calculations of multipole giant resonances and of low-lying collective states in spherical nuclei are analyzed. By using effective Lagrangians which, in the mean-field approximation, provide an accurate description of ground-state properties, an excellent agreement with experimental data is also found for the excitation energies of low-lying collective states and of giant resonances. Two points are essential for the successful application of the RRPA in the description of dynamical properties of finite nuclei: (i) the use of effective Lagrangians with non-linear terms in the meson sector, and (ii) the fully consistent treatment of the Dirac sea of negative energy states.Comment: 10 figures, submitted to Nucl.Phys.

Modelling household residential location choice and travel behaviour and its relationship with public transport accessibility

Cities are seeking to reduce the growth of car-based travel by developing public transport networks. Much research asserts that the correct arrangement of built environment will result in the enhancement of public transport utilization. There is, however, debate that this approach results only in ‘self-selection’, that is that only residents willing to travel by public transport will locate in these places with resultant minimal impact on car -user households. If policy solutions towards public transport are to be effective, it is necessary to understand the multi-dimensional relationship between location behavior and travel patterns of residents living in proximity to public transport. This research seeks to model the relationship between residential location and mode choice within a behavioral analysis framework. At this early stage of in the research this paper focuses on the methodological framework

Emission of photon echoes in a strongly scattering medium

We observe the two- and three-pulse photon echo emission from a scattering powder, obtained by grinding a Pr$^{3+}$:Y$_2$SiO$_5$ rare earth doped single crystal. We show that the collective emission is coherently constructed over several grains. A well defined atomic coherence can therefore be created between randomly placed particles. Observation of photon echo on powders as opposed to bulk materials opens the way to faster material development. More generally, time-domain resonant four-wave mixing offers an attractive approach to investigate coherent propagation in scattering media