Population Firm Interaction and the Dynamics of Assimilation Gap

The paper shows that the interaction between population and firm knowledge produces a non-monotonic change in the assimilation gap. The assimilation gap follows a convex curve experiencing an upward slope driven by imitation and the downward slope by knowledge spillovers. Changes in the characteristics of innovation shift its peak across time. The relative advantage and compatibility shift the peak towards the left and the complexity shifts it to the right. The model is tested in a simulated environment and offers insights into the differences in temporal trajectories of the various adopter groups

TEMPOS: A Platform for Developing Temporal Applications on Top of Object DBMS

This paper presents TEMPOS: a set of models and languages supporting the manipulation of temporal data on top of object DBMS. The proposed models exploit object-oriented technology to meet some important, yet traditionally neglected design criteria related to legacy code migration and representation independence. Two complementary ways for accessing temporal data are offered: a query language and a visual browser. The query language, namely TempOQL, is an extension of OQL supporting the manipulation of histories regardless of their representations, through fully composable functional operators. The visual browser offers operators that facilitate several time-related interactive navigation tasks, such as studying a snapshot of a collection of objects at a given instant, or detecting and examining changes within temporal attributes and relationships. TEMPOS models and languages have been formalized both at the syntactical and the semantical level and have been implemented on top of an object DBMS. The suitability of the proposals with regard to applications' requirements has been validated through concrete case studies

Covering various Needs in Temporal Annotation: a Proposal of Extension of ISO TimeML that Preserves Upward Compatibility

International audienceThis paper reports a critical analysis of the ISO TimeML standard, in the light of several experiences of temporal annotation that were conducted on spoken French. It shows that the norm suffers from weaknesses that should be corrected to fit a larger variety of needs in NLP and in corpus linguistics. We present our proposition of some improvements of the norm before it will be revised by the ISO Committee in 2017. These modifications concern mainly (1) Enrichments of well identified features of the norm: temporal function of TIMEX time expressions, additional types for TLINK temporal relations; (2) Deeper modifications concerning the units or features annotated: clarification between time and tense for EVENT units, coherence of representation between temporal signals (the SIGNAL unit) and TIMEX modifiers (the MOD feature); (3) A recommendation to perform temporal annotation on top of a syntactic (rather than lexical) layer (temporal annotation on a treebank)

SOWL QL: Querying Spatio - Temporal Ontologies in OWL

We introduce SOWL QL, a query language for spatio-temporal information in ontologies. Buildingupon SOWL (Spatio-Temporal OWL), an ontology for handling spatio-temporal information in OWL, SOWL QL supports querying over qualitative spatio-temporal information (expressed using natural language expressions such as “before”, “after”, “north of”, “south of”) rather than merely quantitative information (exact dates, times, locations). SOWL QL extends SPARQL with a powerful set of temporal and spatial operators, including temporal Allen topological, spatial directional and topological operations or combinations of the above. SOWL QL maintains simplicity of expression and also, upward and downward compatibility with SPARQL. Query translation in SOWL QL yields SPARQL queries implying that, querying spatio-temporal ontologies using SPARQL is still feasible but suffers from several drawbacks the most important of them being that, queries in SPARQL become particularly complicated and users must be familiar with the underlying spatio-temporal representation (the “N-ary relations” or the “4D-fluents” approach in this work). Finally, querying in SOWL QL is supported by the SOWL reasoner which is not part of the standard SPARQL translation. The run-time performance of SOWL QL has been assessed experimentally in a real data setting. A critical analysis of its performance is also presented

Geochemical Consequences of Melt Percolation: The Upper Mantle as a Chromatographic Column

As magmas rise toward the surface, they traverse regions of the mantle and crust with which they are not in equilibrium; to the extent that time and the intimacy of their physical contact permit, the melts and country rocks will interact chemically. We have modeled aspects of these chemical interactions in terms of ion-exchange processes similar to those operating in simple chromatographic columns. The implications for trace element systematics are straightforward: the composition of melt emerging from the top of the column evolves from close to that of the incipient melt of the column matrix toward that of the melt introduced into the base of the column. The rate of evolution is faster in the incompatible than the compatible elements and, as a result, the abundance ratios of elements of different compatibilities can vary considerably with time. If diffusion and other dispersive processes in the melt are negligible and if exchange between melt and solid rock is rapid, extreme fractionations may occur, and the change from initial to final concentration for each element can be through an abrupt concentration front. Integration and mixing of the column output in a magma chamber or dispersive processes within the column, in particular the incomplete equilibration between matrix and fluid due to the slow diffusion in the solid phases, may lead to diffuse fronts and smooth trace element abundance patterns in the column output. If the matrix material is not replenished, the chromatographic process is a transient phenomenon. In some geological situations (e.g., under island arcs and oceanic islands), fresh matrix may be fed continuously into the column, leading to the evolution of a steady state. Aspects of the geochemistry of ultramafic rocks, island arc lavas, and comagmatic alkaline and tholeiitic magmas may be explained by the operation of chromatographic columns

Alternating register automata on finite words and trees

We study alternating register automata on data words and data trees in relation to logics. A data word (resp. data tree) is a word (resp. tree) whose every position carries a label from a finite alphabet and a data value from an infinite domain. We investigate one-way automata with alternating control over data words or trees, with one register for storing data and comparing them for equality. This is a continuation of the study started by Demri, Lazic and Jurdzinski. From the standpoint of register automata models, this work aims at two objectives: (1) simplifying the existent decidability proofs for the emptiness problem for alternating register automata; and (2) exhibiting decidable extensions for these models. From the logical perspective, we show that (a) in the case of data words, satisfiability of LTL with one register and quantification over data values is decidable; and (b) the satisfiability problem for the so-called forward fragment of XPath on XML documents is decidable, even in the presence of DTDs and even of key constraints. The decidability is obtained through a reduction to the automata model introduced. This fragment contains the child, descendant, next-sibling and following-sibling axes, as well as data equality and inequality tests

Blazar origin of some IceCube events

Recently ANTARES collaboration presented a time dependent analysis to a selected number of flaring blazars to look for upward going muon events produced from the charge current interaction of the muon neutrinos. We use the same list of flaring blazars to look for possible positional correlation with the IceCube neutrino events. In the context of photohadronic model we propose that the neutrinos are produced within the nuclear region of the blazar where Fermi accelerated high energy protons interact with the background synchrotron/SSC photons. Although we found that some objects from the ANTARES list are within the error circles of few IceCube events, the statistical analysis shows that none of these sources have a significant correlation.Comment: Latex file, 6 pages, two columns, 1 Figur

Temporal Data Modeling and Reasoning for Information Systems

Temporal knowledge representation and reasoning is a major research field in Artificial Intelligence, in Database Systems, and in Web and Semantic Web research. The ability to model and process time and calendar data is essential for many applications like appointment scheduling, planning, Web services, temporal and active database systems, adaptive Web applications, and mobile computing applications. This article aims at three complementary goals. First, to provide with a general background in temporal data modeling and reasoning approaches. Second, to serve as an orientation guide for further specific reading. Third, to point to new application fields and research perspectives on temporal knowledge representation and reasoning in the Web and Semantic Web

Deriving time discounting correction factors for TTO tariffs

The Time Tradeoff (TTO) method is a popular method for valuing health state utilities and is frequently used in economic evaluations. However, this method produces utilities that are distorted by several biases. One important bias entails the failure to incorporate time discounting. This paper aims to measure time discounting for health outcomes in a sample representative for the general population. In particular, we estimate TTO scores alongside time discounting in order to derive a set of correction factors that can be employed to correct raw TTO scores for the downward bias caused by time discounting. We find substantial positive correction factors, which are increasing with the severity of the health state. Furthermore, higher discounting is found when using more severe health states in the discounting elicitation task. More research is needed to further develop discount rate elicitation procedures and test their validity, especially in general public samples. Moreover, future research should investigate the correction of TTO score for other biases as well, such as loss aversion, and to develop a criterion to test the external validity of TTO scores.Discounting; QALY model; Time Tradeoff; Utility Measurement