This paper solves the known problem of elimination of unnecessary internal element construction as well as variable elimination in XML processing with (a subset of) XQuery without ignoring the issues of document order. The semantics of XQuery is context sensitive and requires preservation of document order. In this paper, we propose, as far as we are aware, the first XQuery fusion that can deal with both the document order and the context of XQuery expressions. More specifically, we carefully design a context representation of XQuery expressions based on the Dewey order encoding, develop a context-preserving XQuery fusion for ordered trees by static emulation of the XML store, and prove that our fusion is correct. Our XQuery fusion has been implemented, and all the examples in this paper have passed through the system.

This paper introduces a smart office chair, Owens Luis, whose pronunciation has a meaning of “an encouraging chair (****)” in Japanese. For most of the people, office environments are the place where they spend the longest time while awake. To improve the quality of life (QoL) in the office, Owens Luis monitors an office worker's mental and physiological states such as sleepiness and concentration, and controls the working environment by multi-modal displays including a motion chair, a variable color-temperature LED light and a hypersonic directional speaker.

We propose a smart office system that recognizes office workers' mental and physiological states to improve their quality of life at office. We integrated our systems into a single smart office environment. In this article we show the implementation of the smart office system and the details of each of its components such as I/O devices.

This paper discusses temporal reasoning with respect to constraints on two concurrent sequences of events. If two given sequences of events can be mapped into one sequence that satisfies a given constraint, then the constraint is said to be consistent. First, we mention that the consistency of such constraints is NP-complete. Then we introduce the notion of graph representations of constraints. If a graph representation of a given constraint c can be constructed in polynomial time, then the consistency of c is decidable in polynomial time. However, it is shown that the graph representability of a given c is coNP-complete. Next, we propose a subclass CDC$^{\neq} of constraints such that for each constraint c in CDC$^{\neq}$, a graph representation of c can be constructed in polynomial time. The expressive power of CDC$^{\neq}$ is incomparable to any other subclasses of constraints for which the consistency problem is known to be tractable.

A method of translating natural language specifications of communication protocols into algebraic specifications is presented. Such a natural language specification specifies action sequences performed by the protocol machine (program). Usually, a sentence implicitly specifies the state of the protocol machine in which the described actions should be performed. A method of analyzing the implicitly specified states of the protocol machine is proposed, taking the OSI session protocol specification as an example. The method uses the following properties: (a) syntactic properties of a natural language; (b) syntactic properties introduced by the target algebraic specifications, e.g., subtype relations; and (c) properties of a data type, e.g., properties of timer. The results of applying this method to the main part of the OSI session protocol specification is shown.>