Inference of monotonicity constraints in Datalog programs

Datalog (i.e., function-free logic) programs with monotonicity constraints on extensional predicates are considered. A monotonicity constraint states that one argument of a predicate or a constant is always less than another argument or a constant, according to some strict partial order. Relations of an extensional database are required to satisfy the monotonicity constraints imposed on their predicates. More specifically, a strict partial order is defined on the domain (i.e., set of constants) of the database, and every tuple of each relation satisfies the monotonicity constraints imposed on its predicate. This paper focuses on the problem of entailment of monotonicity constraints in the intensional database from monotonicity constraints in the extensional database. The entailment problem is proven to be decidable, based on a suggested algorithm for computing sound and complete disjunctions of monotonicity and equality constraints that hold in the intentional database. It is also shown that the entailment of monotonicity constraints in programs is a complete problem for exponential time. For linear programs, this problem is complete for polynomial space. This revised version was published online in June 2006 with corrections to the Cover Date.     

Object features, object locations, and object files: Which does selective attention activate and when?

The representation within which attention operates was investigated in 3 experiments. The task was similar to that of R. Egly, J. Driver, and R. D. Rafal (1994). Participants had to detect the presence of a target at 1 of 4 ends of 2 shapes, differing in color and form. A precue appeared at 1 of the 4 possible corners. The 2 shapes occupied either the same or different locations in the cuing and target displays. The results showed that the cued object location was attended whether or not space was task relevant, whereas the cued object features (color and form) were attended only when these were task relevant. Moreover, when object file continuity was maintained through continuous movement, attention was found to follow the cued object file as it moved while also accruing to the cued location. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stoichiometric dye-binding procedure for the determination of the reactive lysine content of soya bean protein

A new analytical method has been developed for the determination of the reactive lysine content of soya bean protein. The method is based on the reaction of the free basic groups of the protein with 1-phenylazo-2 naphthol-6,8 disulphonic acid. With regard to the stoichiometry of the procedure, it has been proved, contrary to earlier reports, that the basic amino acids, histidine, arginine and lysine, each combine with one mole of the dye. After acylation with propionic anhydride lysine alone loses its dye reactivity. The usefulness of the proposed method has been demonstrated by the determination of the reactive lysine content of several untreated, heat-treated and acid-treated soya bean samples. The results show that heat damage of about 5% in reactive lysine content can be measured in 1·5 h with good reproducibility.     

Evaluation and application of a semantic network partition

Semantic networks (SNs) are excellent knowledge representation structures. However, large semantic networks are difficult to comprehend. To overcome this difficulty, several methods of partitioning have been developed that rely on different mixes of structural and semantic methods. However, little has appeared in the literature concerning the question whether a partition of a semantic network creates subnetworks that agree with human insight. We address this issue by presenting a comparison between the results of an algorithmic partitioning method and a partition created by a group of experts. Subsequently, we show how a network partition can be used to generate various partial views of a semantic network, which facilitate user orientation. Examples from the Unified Medical Language System (UMLS) SN are used to demonstrate partial views     

Something completely different: Informatik und Sport

Ohne Zusammenfassung     

Grid-connected vehicles as the core of future land-based transport systems

Grid-connected vehicles (GCVs)—e.g., electric trains, metros, trams, and trolley buses—are propelled by electric motors directly connected to remote power sources. Their low at-vehicle energy consumption and ability to use a wide range of renewable energy sources make them strong contenders for urban and interurban transport systems in an era of energy constraints that favours use of renewable fuels, which may lie ahead. Needs for autonomous motorised mobility could be acceptably met in large measure by deployment of personal GCVs, also known as personal rapid transit (PRT). Alternatives, including fuel-cell vehicles and dual-drive vehicles fuelled with ethanol, will be less feasible. The ‘car of the future’ may not be an automobile so much as a PRT element of a comprehensive GCV-based system that offers at least as much utility and convenience as today's transport systems.     

Heat transfer efficiency in a fliuidized bed

The equilibrium stage concept used in staged contacting operations was adopted as a measure of heat transfer efficiency for a fluidized bed. A simple model was developed which postulates that solids flow through the bed can be by perfect mixing, plug flow and short-circuiting. Efficiencies were determined experimentally in a 150 mm diameter fluidized bed with air as the fluidizing medium and sand as the solid. Heat transfer efficiencies greater than 100% were obtained indicating that small diameter, low aspect ratio fluidized beds do not behave as perfect mixers. The results indicate that heat transfer measurements can be used to develop information on solids flow behavior.