Interning Ground Terms in XSB

This paper presents an implementation of interning of ground terms in the XSB Tabled Prolog system. This is related to the idea of hash-consing. I describe the concept of interning atoms and discuss the issues around interning ground structured terms, motivating why tabling Prolog systems may change the cost-benefit tradeoffs from those of traditional Prolog systems. I describe the details of the implementation of interning ground terms in the XSB Tabled Prolog System and show some of its performance properties. This implementation achieves the effects of that of Zhou and Have but is tuned for XSB's representations and is arguably simpler.Comment: Proceedings of the 13th International Colloquium on Implementation of Constraint LOgic Programming Systems (CICLOPS 2013), Istanbul, Turkey, August 25, 201

Score Reliability and Factor Similarity of the Sociocultural Attitudes towards Appearance Questionnaire-3 (SATAQ-3) Among Four Ethnic Groups

Background:This study evaluated the score reliability and equivalence of factor structure of the Sociocultural Attitudes towards Appearance Questionnaire-3 (SATAQ-3) [1] in a sample of female college students from the four largest ethnic groups in the USA.Methods:Participants were 1245 women who self-identified as European American/White (n = 543), African American/Black (n = 137), Asian American (n = 317), or Latina/Hispanic (n = 248). All completed the SATAQ-3 and a demographic questionnaire. To test the factor similarity and score reliability across groups, we used exploratory factor analysis and calculated Cronbach’s alphas (respectively).Results:Score reliability was high for all groups. Tests of factor equivalence suggested that the four pre-established factors of the SATAQ-3 (i.e., knowledge, perceived pressure, thin-ideal internalization, athletic-ideal internalization) were similar for women of all ethnic groups. Only two items (20 and 27) did not consistently load on the previously identified scale across all four groups. When scored, African Americans reported significantly less perceived pressure and internalization than all other groups.Conclusions:Results support the use of the SATAQ-3 in female college students of these four ethnicities

Dynamic Relationships Among Selected U.S. Commodity-Based, Value Added Markets: Applying Directed Acyclic Graphs to a Time Series Model

This paper demonstrates the application of a recently developed methodology, the combination of directed acyclic graphs (DAGs) with Bernanke structural vector autoregression (VAR) models, to model a system of U.S. commodity-related and value-added markets. As an example, the paper applies this methodology to a quarterly system of U.S. markets: the wheat market and a set of downstream milling and bakery markets that use wheat as an input. Analyses of the model's impulse response simulations and forecast error variance decompositions provide updated estimates of market elasticity parameters that drive these markets, and updated policy-relevant information on how these quarterly markets run and dynamically interact. Results suggest that movements in commodity-based markets strongly influence each other, although most of these effects occur in the long run beyond a single crop cycle. The paper illuminates how important U.S. food prices respond to wheat farm market shocks in price and quantity.Bernanke structural VARs, directed acyclic graphs, quarterly wheat-related markets, Industrial Organization, Marketing, Research Methods/ Statistical Methods,

FORMAL SEMANTICS FOR TIME IN DATABASES

The concept of an historical database is introduced as a tool for modelling the dynamic nature of some part of the real world. Just as first-order logic has been shown to be a useful formalism for expressing and understanding the underlying semantics of the relational database model, intensional logic is presented as an analogous formalism for expressing and understanding the temporal semantics involved in an historical database. The various components of the relational model, as extended to include historical relations, are discussed in terms of the model theory for the logic ILs, a variation of the logic IL formulated by Richard Montague. The modal concepts of intensional and extensional data constraints and queries are introduced and contrasted. Finally, the potential application of these ideas to the problem of Natural Language Database Querying is discussed.Information Systems Working Papers Serie