967 research outputs found
Web ontology representation and reasoning via fragments of set theory
In this paper we use results from Computable Set Theory as a means to
represent and reason about description logics and rule languages for the
semantic web.
Specifically, we introduce the description logic \mathcal{DL}\langle
4LQS^R\rangle(\D)--admitting features such as min/max cardinality constructs
on the left-hand/right-hand side of inclusion axioms, role chain axioms, and
datatypes--which turns out to be quite expressive if compared with
\mathcal{SROIQ}(\D), the description logic underpinning the Web Ontology
Language OWL. Then we show that the consistency problem for
\mathcal{DL}\langle 4LQS^R\rangle(\D)-knowledge bases is decidable by
reducing it, through a suitable translation process, to the satisfiability
problem of the stratified fragment of set theory, involving variables
of four sorts and a restricted form of quantification. We prove also that,
under suitable not very restrictive constraints, the consistency problem for
\mathcal{DL}\langle 4LQS^R\rangle(\D)-knowledge bases is
\textbf{NP}-complete. Finally, we provide a -translation of rules
belonging to the Semantic Web Rule Language (SWRL)
“Do You Hear What I Hear?”: Empirical Research on Earwitness Testimony
Despite recurring empirical interest in eyewitness research, legal scholars have conducted far less research exploring the significance and limitations of earwitness testimony. Nevertheless, earwitness expert testimony serves an important purpose, which dates back many centuries. This Article analyzes empirical studies regarding earwitness testimony and places them into a recognized legal framework regarding admission of expert testimony. The result of this analysis demonstrates that, if courts believe that eyewitness testimony meets the restrictions on junk science employed by both Daubert v. Merrell Dow Pharmaceuticals, Inc. and the Federal Rules of Evidence, then the courts should also admit earwitness testimony under the same rationale. This Article, however, recognizes the many methodological issues in the study of earwitness testimony and addresses both the limitations in earwitness expert testimony and the hurdles it must face to meet the evidential standards of admissibility
A simplified pneumatic model for air brake of passenger trains
Braking system performance is relevant for both railway safety and network optimization. Most trains employ air brake systems; air brake systems of freight trains mostly cannot achieve a synchronous application of brake forces, which is usually customary for passenger trains. The paper generalizes a previous air brake pneumatic model to passenger trains and describes the needed modifications. Among them, the way the pressure reduces in the brake pipe is generalized. Moreover, this paper reports an analytical bi-dimensional function for calculating the nozzle diameter equivalent to the electro-pneumatic (EP) or the electronically controlled pneumatic (ECP) brake valve as a function of the wagon length and the time to vent the brake pipe locally. The numerical results of the new model are compared against several experimental tests of high-speed passenger trains of Trenitalia, namely ETR500 and ETR1000. The model is suitable to be integrated into the UIC software TrainDy, aiming to extend its computational field to passenger trains and to simulate the safety of trains during a recovery
Justice Stevens and Securities Law
In this Article, we tell the overlooked story of Justice Stevens\u27s important role in Supreme Court securities law decisions. In Part I, where we briefly highlight Stevens\u27s career before his 1975 appointment to the Supreme Court, we observe that we can identify no evident interest in or connection to federal securities law or the securities industry, making his contributions all the more remarkable. The only foreshadowing of his prolific opinion-writing on the subject of securities law was his voluminous writing of opinions, in general, while serving on the Seventh Circuit Court of Appeals. This commitment to authoring opinions stemmed, in turn, from Stevens\u27s unforgettable experience as general counsel to a special commission that investigated bribery on the Illinois Supreme Court in the late 1960s, as Part I relates
Fine Morphological Study of the Myrmecina graminicola (Latreille, 1802) Male, With First Description of External Genitalia in the Genus (Hymenoptera: Formicidae: Myrmecinae)
Te genus Myrmecina was described basing on males of M. graminicola. Tough representing the caste type, males were sufciently described in only two out of 105 species known in the genus. However, the morphology of the male external genitalia remained undescribed. Re-examining by SEM the male of M. graminicola, we describe and illustrate in detail for the frst time the external genitalia, redefning and updating the morphological male diagnosis of the genus. We also analyze the overall mor- phology, illustrating additional peculiar characters of this species as follows: (i) a very distinctive stipital groove in the dorsolateral stipes; (ii) a developed uncinate-shaped mesoscutellar arm; (iii) the antennal cleaning; and (iv) the absence of meso- and metatibial spurs. Tis morphological study will be useful as a base for further morphological descriptions of the males in other species of the same genus to support correct taxonomic identifcation
An Empirical Evaluation of Proposed Civil Rules for Multidistrict Litigation
The Civil Rules Committee of the Judicial Conference of theUnited States recently began considering the need for specificrules regarding multidistrict litigation (MDL) proceedings. Thepossibility of creating rules specifically for MDL originates withrecently proposed legislation prompted by groups typically tiedto the defense bar. One area the Civil Rules Committee isconsidering concerns the use of fact sheets in MDL proceedings.These party-negotiated questionnaires—directed at bothparties to the case—inform judges and attorneys about thescope of the proceeding. Understanding whether these casemanagement tools are currently being used and how they workwith other tools, such as bellwether trials, in MDL proceedingswill help inform a discussion of the need for specific MDL rules.Despite their importance, very little published, empirical worklooks at fact sheets in MDL proceedings. This is the firstcomprehensive study of the use of fact sheets.Using a sample of 116 mass tort proceedings—typicallyinvolving products liability—centralized through MDLbetween 2008 and 2018, we examine when fact sheets wereordered, what the procedures for complying with the casemanagement order were, what information was collected, andwhat effect fact sheets had on the termination of theproceedings. The proceedings ranged between 3 and 40,533actions and were open a minimum of 118 days and a maximumof 3811 days. Actions terminated within the proceeding at least
98% of the time, but little available information existsregarding how the actions terminated. These proceedings werecentralized in forty districts. We find that fact sheets wereordered more than half the time and were most likely to be usedin the largest proceedings. The information in fact sheets wasused in proceedings in several ways, including to identify casesfor bellwether trials and winnowing cases. Using fact sheets,moreover, led to quicker termination of the proceeding, all elsebeing equal. Our sample of proceedings suggests judges use factsheets to organize products liability proceedings when judgesperceive they are merited, after considering the size of theproceeding or the nature of the litigation. The frequency withwhich judges already employ fact sheets and the variation inuses call into question both the need for a rule and how to writeone without tying the hands of transferee judges. Many issuesregarding how fact sheets are used remain to be studied morein-depth. We encourage future studies regarding how factsheets are used across MDL proceedings
Sequence searching allowing for non-overlapping adjacent unbalanced translocations
Unbalanced translocations are among the most frequent chromosomal alterations, accounted for 30% of all losses of heterozygosity, a major genetic event causing inactivation of tumor suppressor genes. Despite of their central role in genomic sequence analysis, little attention has been devoted to the problem of matching sequences allowing for this kind of chromosomal alteration.
In this paper we investigate the approximate string matching problem when the edit operations are non-overlapping unbalanced translocations of adjacent factors. In particular, we first present a O(nm3)-time and O(m2)-space algorithm based on the dynamic-programming approach. Then we improve our first result by designing a second solution which makes use of the Directed Acyclic Word Graph of the pattern. In particular, we show that under the assumptions of equiprobability and independence of characters, our algorithm has a O(n log2σ m) average time complexity, for an alphabet of size σ, still maintaining the O(nm3)-time and the O(m2)-space complexity in the worst case. To the best of our knowledge this is the first solution in literature for the approximate string matching problem allowing for unbalanced translocations of factors
Decidability results for classes of purely universal formulae and quantifiers elimination in Set Theory
A general mechanism to extend decision algorithms to deal with additional predicates is described. The only conditions imposed on the predicates is stability with respect to some transitive relations
Decision procedures for elementary sublanguages of set theory. V. Multilevel syllogistic extended by the general union operator
The Automation of Syllogistic II. Optimization and Complexity Issues
In the first paper of this series it was shown that any unquantified formula p in the collection MLSSF (multilevel syllogistic extended with the singleton operator and the predicate Finite) can be decomposed as a disjunction of set-theoretic formulae called syllogistic schemes. The syllogistic schemes are satisfiable and no two of them have a model in common, therefore the previous result already implied the decidability of the class MLSSF by simply checking if the set of syllogistic schemes associated with the given formula is empty. In the first section of this paper a new and improved searching algorithm for syllogistic schemes is introduced, based on a proof of existence of a 'minimum effort' scheme for any given satisfiable formula in MLSF. The algorithm addressed above can be piloted quite effectively even though it involves backtracking. In the second part of the paper, complexity issues are studied by showing that the class of ( 00)o1-simple prenex formulae (an extension of MLS) has a decision problem which is NP-complete. The decision algorithm that proves the membership of this decision problem to NP can be seen as a different decision algorithm for ML
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