On Constructing Constrained Tree Automata Recognizing Ground Instances of Constrained Terms

An inductive theorem proving method for constrained term rewriting systems, which is based on rewriting induction, needs a decision procedure for reduction-completeness of constrained terms. In addition, the sufficient complete property of constrained term rewriting systems enables us to relax the side conditions of some inference rules in the proving method. These two properties can be reduced to intersection emptiness problems related to sets of ground instances for constrained terms. This paper proposes a method to construct deterministic, complete, and constraint-complete constrained tree automata recognizing ground instances of constrained terms.Comment: In Proceedings TTATT 2013, arXiv:1311.505

Hydrogen-assisted fabrication of spherical gold nanoparticles through sonochemical reduction of tetrachloride gold(III) ions in water

Spherical gold nanoparticles (AuNPs) were selectively synthesized through sonochemical reduction of tetrachloride gold(III) ions ([AuCl4](-)) in an aqueous solution of hydrogen tetrachloroaurate(III) tetrahydrate (HAuCl4.H2O) with the aid of hydrogen (H-2) gas in the absence of any additional capping agents. On the other hand, various shaped-AuNPs such as spherical nanoparticles, triangular and hexagonal plates were formed from sonochemical reduction of [AuCl4](-) in argon (Ar)-, nitrogen (N-2)- or oxygen (O-2)-purged aqueous [AuCl4](-) solutions. The selective fabrication of spherical AuNPs assisted by H-2 gas is most likely attributed to the generation of hydrogen radicals (H center dot) promoted by the reaction of H-2 introduced and hydrogen oxide radicals (center dot OH) produced by sonolysis of water.ArticleULTRASONICS SONOCHEMISTRY. 21(3):946-950 (2014)journal articl

Soundness of Unravelings for Deterministic Conditional Term Rewriting Systems via Ultra-Properties Related to Linearity

Unravelings are transformations from a conditional term rewriting system (CTRS, for short) over an original signature into an unconditional term rewriting systems (TRS, for short) over an extended signature. They are not sound for every CTRS w.r.t. reduction, while they are complete w.r.t. reduction. Here, soundness w.r.t. reduction means that every reduction sequence of the corresponding unraveled TRS, of which the initial and end terms are over the original signature, can be simulated by the reduction of the original CTRS. In this paper, we show that an optimized variant of Ohlebusch\u27s unraveling for deterministic CTRSs is sound w.r.t. reduction if the corresponding unraveled TRSs are left-linear or both right-linear and non-erasing. We also show that soundness of the variant implies that of Ohlebusch\u27s unraveling

Surfactant- and reducer-free synthesis of gold nanoparticles in aqueous solutions

We report here the surfactant- and reducer-free synthesis of gold nanoparticles from an aqueous hydrogen tetrachloroaurate (III) tetrahydrate (HAuCl(4)center dot 4H(2)O) solution using a high-frequency (950 kHz) ultrasound (in the absence of any stabilizing, capping and reducing agents). In particular, size, shape and stability of gold nanoparticles prepared by the 950 kHz ultrasound irradiation (sonication) for 8 min in the surfactant-free aqueous solutions were examined in terms of AuCl(4)(-) concentration (in the range of 0.01-0.1 mM), additional salts (NaCl, HCl and NaOH) and temperature (in the range of 4-60 degrees C). We found that higher AuCl(4)(-) concentration promoted particle growth (size increase) and plate formation. In addition, the plate formation was enhanced with the addition of NaCl or HCl (but not NaOH). This is most likely due to the AuCl(4)(-) reduction on a certain crystal facets (e.g. (1 1 0) facets) caused by the adsorption of Cl(-) ions on specific crystal facets (e.g. (1 1 1) facets). Furthermore, we revealed that the temperature elevated above 50 degrees C led to the formation of spherical gold nanoparticles with the diameter of 20-60 nm from a 0.1 mM AuCl(4)(-) aqueous solution while triangular plates formed coexisting with spherical nanoparticles below 50 degrees C.ArticleCOLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS. 347(1-3):18-26 (2009)journal articl

Inverse Unfold Problem and Its Heuristic Solving

Unfold/fold transformations have been widely studied in various programming paradigms and are used in program transformations, theorem proving, and so on. This paper, by using an example, show that restoring an one-step unfolding is not easy, i.e., a challenging task, since some rules used by unfolding may be lost. We formalize this problem by regarding one-step program transformation as a relation. Next we discuss some issues on a specific framework, called pure-constructor systems, which constitute a subclass of conditional term rewriting systems. We show that the inverse of T preserves rewrite relations if T preserves rewrite relations and the signature. We propose a heuristic procedure to solve the problem, and show its successful examples. We improve the procedure, and show examples for which the improvement takes effect