A novel approach to controlled query evaluation in DL-Lite

In Controlled Query Evaluation (CQE) confidential data are protected through a declarative policy and a (optimal) censor, which guarantees that answers to queries are maximized without disclosing secrets. In this paper we consider CQE over Description Logic ontologies and study query answering over all optimal censors. We establish data complexity of the problem for ontologies specified in DL-LiteR and for variants of the censor language, which is the language used by the censor to enforce the policy. In our investigation we also analyze the relationship between CQE and the problem of Consistent Query Answering

POLITICAL PARTIES IN MODERN DEMOCRACY - TERM AND ELEMENTS

Političke stranke su neophodan činilac demokratskih sistema. Autor u radu definiše pojam i osnovne elemente pojma političkih stranaka imajući u vidu političku i javnopravnu dimenziju. Autor analizira pet osnovnih elemenata koje su klasični i moderniji autori razmatrali prilikom definisanja političkih stranaka: ideologiju, izražavanje interesa socijalnih grupa, ostvarivanje državnog (nacionalnog) interesa, predlaganje kandidata na izborima za javnopolitičke funkcije, vršenje vlasti i stalnost. Prilikom razmatranja su posebno u obzir uzete društvene promene koje su uticale na promenu političkih stranaka, ali i celokupnog političkog sistema. Tako su određeni elementi koje su klasični teoretičari političkih stranaka smatrali suštinom nekadašnjih partija, poput ideologije i zastupanja interesa određenih socijalnih grupa, postali više simboličkog i lako promenljivog karaktera. U radu se otuda daje definicija koja sadrži nužne, konstitutivne elemente. Političke stranke se određuju kao postojana (stalna) organizacija koja isticanjem kandidata na izborima omogućava vršenje političke vlasti i sprovođenje određene politike koja se želi sprovesti kroz pravno obavezujuće odluke i norme.Political parties are a necessary component of democratic systems. In the paper, the author defines the concept and basic elements of the concept of political parties, keeping in mind the political and public legal dimension. The paper analyzes five basic elements that classical and more modern authors considered when defining political parties. These are: ideology, expression of interests of social groups, realization of state (national) interest, nomination of candidates in elections for public-political positions, exercise of power and permanence. During the discussion, the change of the political party, and therefore the entire political scene with the changes that took place in society through the development of the economy, consumer society and mass media, were taken into account. Thus, certain elements that classical theorists of political parties considered the essence of former parties, such as ideology and representation of the interests of certain social groups, became more symbolic and easily changeable. The paper therefore gives one definition containing the necessary, constitutive elements. Hence, political parties are defined as permanent (permanent) organizations that, by nominating candidates in elections, enable the exercise of political power and the implementation of certain policies that are to be implemented through legally binding decisions and norms

Lower bounds for nodal sets of Dirichlet and Neumann eigenfunctions

Let \phi\ be a Dirichlet or Neumann eigenfunction of the Laplace-Beltrami operator on a compact Riemannian manifold with boundary. We prove lower bounds for the size of the nodal set {\phi=0}.Comment: 7 page

Post-stroke depression increases disability more than 15% in ischemic stroke survivors: a case-control study

We performed a retrospective, case-control study in consecutive ischemic stroke patients admitted to our stroke rehabilitation unit. Patients were matched for severity of neurological impairment (evaluated with the Canadian Neurological Scale, CNS), age (difference within 1 year), and onset admission interval (difference within 3 days). Participants were divided into two subgroups according to the presence or absence of PSD. Aim was to assess the specific influence of post-stroke depression (PSD) and antidepressant treatment on both basal functional status and rehabilitation outcomes. All PSD patients were treated primarily with serotoninergic antidepressants (AD). The final sample included 280 patients with depression (out of 320 found in a whole case series of 993 ischemic patients, i.e., 32.25%) and 280 without depression. Forty patients with depression were excluded because they had a history of severe psychiatric illness or aphasia, with a severe comprehension deficit. On one hand, PSD patients obtained lower Barthel Index (BI) and Rivermead Mobility Index (RMI) scores at both admission and discharge, with minor effectiveness of rehabilitative treatment and longer length of stay; on the other hand, this group had a lower percentage of dropouts. Lastly, PSD patients showed a different functional outcome, based on their response to antidepressant therapy, that was significantly better in responders than in non-responders (13.13%). Our results confirm the unfavorable influence of PSD on functional outcome, despite pharmacological treatment

Cooperative field localization and excitation eigenmodes in disordered metamaterials

We investigate numerically and experimentally the near-field response of disordered arrays comprising asymmetrically split ring resonators that exhibit a strong cooperative response. Our simulations treat the unit cell split-ring resonators as discrete pointlike oscillators with associated electric and magnetic point dipole radiation, while the strong cooperative radiative coupling between the different split rings is fully included at all orders. The methods allow us to calculate local field and Purcell factor enhancement arising from the collective electric and magnetic excitations. We find substantially increased standard deviation of the Purcell enhancement with disorder, making it increasingly likely to find collective excitation eigenmodes with very high Purcell factors that are also stronger for magnetic than electric excitations. We show that disorder can dramatically modify the cooperative response of the metamaterial even in the presence of strong dissipation losses, as is the case for plasmonic systems. Our analysis in terms of collective eigenmodes paves the way for controlled engineering of electromagnetic device functionalities based on strongly interacting metamaterial arrays

Strong interactions and subradiance in disordered metamaterials

We provide detailed comparisons between experimental findings and numerical simulations of large coopera- tively interacting, spatially disordered metamaterial arrays, consisting of asymmetrically split rings. Simulation methods fully incorporate strong field-mediated inter-meta-atom interactions between discrete resonators and statistical properties of disorder, while approximating the resonators’ internal structure. Despite the large system size, we find a qualitative agreement between the simulations and experiments and characterize the microscopic origins of the observed disorder response. Our microscopic description of macroscopic electrodynamics reveals how the response of disordered arrays with strong field-mediated interactions is inherently linked to their cooperative response to electromagnetic waves where the multiple scattering induces strong correlations between the excitations of individual resonators. Whereas for a regular array the response can be overwhelmingly dominated by a spatially extended collective eigenmode with subradiant characteristics, a gradual increase of the positional disorder rapidly leads to a spatial localization of both the electric and magnetic dipolar excitation profile of this eigenmode. We show how the effects of disorder and cooperative interactions are mapped onto the transmission resonance in the far field spectrum and measure the “cooperative Lamb shift” of the resonance that is shifting toward the red as the disorder increases. The interplay between the disorder and interactions generally is most dramatic in the microwave arrays, but we find that in suitable regimes the strong disorder effects can be achieved also for plasmonic optical systems

Hybrid photonic-bandgap accelerating cavities

In a recent investigation, we studied two-dimensional point-defected photonic bandgap cavities composed of dielectric rods arranged according to various representative periodic and aperiodic lattices, with special emphasis on possible applications to particle acceleration (along the longitudinal axis). In this paper, we present a new study aimed at highlighting the possible advantages of using hybrid structures based on the above dielectric configurations, but featuring metallic rods in the outermost regions, for the design of extremely-high quality factor, bandgap-based, accelerating resonators. In this framework, we consider diverse configurations, with different (periodic and aperiodic) lattice geometries, sizes, and dielectric/metal fractions. Moreover, we also explore possible improvements attainable via the use of superconducting plates to confine the electromagnetic field in the longitudinal direction. Results from our comparative studies, based on numerical full-wave simulations backed by experimental validations (at room and cryogenic temperatures) in the microwave region, identify the candidate parametric configurations capable of yielding the highest quality factor.Comment: 13 pages, 5 figures, 3 tables. One figure and one reference added; minor changes in the tex

Sadržaj magnezijuma u zemljištu i krmivu u zavisnosti od tipa zemljišta i krmnog useva

The aim of this study is to examine the effects of soil type and forage crops on the content of magnesium in soil and roughages, as well as forage quality regarding Mg content for the prevention of animal disease ‘tetany’. The trial was carried out on chernozem and humogley under alfalfa and red clover. Samples for determination of Mg content in plant and total Mg content in soil were digested using the apparatus Milestone Ethos 1. The content of Mg was determined using the apparatus ICP-OES Vista Pro -Axial Varian. The average total Mg content in soil of the tested sites was 0.64%. Total Mg content in chernozem was higher than in humogley. A higher total Mg content was in the deeper horizon. A significant positive correlation was found between total Mg content in soil and soil pH as well as the content of CaCO3. The average Mg content in forage crops was 0.28%. A higher Mg content in the dry matter was observed in crops grown on humogley. Mg content was significantly higher in red clover. There was no risk for the occurrence of animal disease ‘tetany’ regarding Mg content in crops, because the ratio K/(Ca+Mg) was below 2.2, and K and Mg content in the dry matter of crops was below the critical value.Cilj rada je da prikaže uticaj tipa zemljišta i krmnog useva na sadržaj magnezijuma u zemljištu i krmnim biljkama, kao i obezbeđenost krmiva magnezijumom sa aspekta prevencije bolesti “tetanije” kod životinja. Ispitivanja su izvedena na poljoprivrednim površinama černozema i humogleja, na kojima su zasnovane proizvodnje lucerke i crvene deteline. Za određivanje sadržaja Mg u biljnom materijalu, kao i ukupnog sadržaja u zemljištu primenjena je digestija uzoraka u zatvorenom mikrotalasnom sistemu pod visokim pritiskom na aparatu Milestone Ethos 1 i determinacija na aparatu ICP-OES Vista Pro-Axial Varian. Prosečan ukupan sadržaj Mg u zemljištu ispitivanih lokaliteta iznosio je 0,64%. Ukupan sadržaj Mg u černozmu je bio viši u odnosu na humoglej. Sadržaj ukupnog Mg je rastao sa dubinom zemljišta. Konstatovana je značajna pozitivna korelaciona veza između ukupnog sadržaja Mg u zemljištu i pH vrednosti zemljišta, kao i sadržaja CaCO3. Prosečna vrednost sadržaja Mg u ispitivanim krmnim usevima iznosila je 0,28%. Viši sadržaj Mg u suvoj materiji biljaka je konstatovan na humogleju. Crvena detelina je, u proseku, imala značajno veći sadržaj Mg. Sa aspekta obezbeđenosti biljaka magnezijumom, može se smatrati da ne postoji potencijalna opasnost od pojave bolesti “tetanije” kod životinja, jer je odnos K/(Ca+Mg) ispod 2,2, a sadržaj K i Mg u suvoj materiji biljaka izvan kritičnih vrednosti

Brownian bridges to submanifolds

We introduce and study Brownian bridges to submanifolds. Our method involves proving a general formula for the integral over a submanifold of the minimal heat kernel on a complete Riemannian manifold. We use the formula to derive lower bounds, an asymptotic relation and derivative estimates. We also see a connection to hypersurface local time. This work is motivated by the desire to extend the analysis of path and loop spaces to measures on paths which terminate on a submanifold