We call a CNF formula linear if any two clauses have at most one variable in common. Let Linear k-SAT be the problem of deciding whether a given linear k-CNF formula is satisfiable. Here, a k-CNF formula is a CNF formula in which every clause has size exactly k. It was known that for k ≥ 3, Linear k-SAT is NP-complete if and only if an unsatisfiable linear k-CNF formula exists, and that they do...

Quantified Boolean Formula (QBF) solvers that utilize nonCNF representations are able to reason dually about conflicts and solutions by accessing structural information contained in the non-CNF representation. This structure is not as easily accessed from a CNF representation, hence CNF based solvers are not able to perform the same kind of reasoning. Recent work has shown how this additional s...

We use a novel balanced experimental design to specifically investigate brain mechanisms underlying the modulating effect of expected pain intensity on afferent nociceptive processing and pain perception. We used two visual cues, each conditioned to one of two noxious thermal stimuli [ approximately 48 degrees C (high) or 47 degrees C (low)]. The visual cues were presented just before and durin...

Modern SAT solvers are proficient at solving Boolean satisfiability problems in Conjunctive Normal Form (CNF). However, these problems mostly arise from general Boolean circuits that are then translated to CNF. We outline a simple and expressive data structure for describing arbitrary circuits, as well as an algorithm for converting circuits to CNF. Our experimental results over a large benchma...

The reaction of three types of carbon nanofibers (CNFs; platelet: CNF-P, tubular: CNF-T, herringbone: CNF-H) with [Ru3(CO)12] in toluene heated at reflux provided the corresponding CNF-supported ruthenium nanoparticles, Ru/CNFs (Ru content = 1.1-3.8 wt %). TEM studies of these Ru/CNFs revealed that size-controlled Ru nanoparticles (2-4 nm) exist on the CNFs, and that their location was dependen...

Stochastic local search techniques have been successful in solving propositional satisfiability (SAT) problems encoded in conjunctive normal form (CNF). Recently complete solvers have shown that there are advantages to tackling propositional satisfiability problems in a more expressive natural representation, since the conversion to CNF can lose problem structure and introduce significantly mor...

In this paper, we propose a new encoding of the cardinality constraint ∑i=1 xi > b. It makes an original use of the general formulation of the Pigeon-Hole principle to derive a formula in conjunctive normal form (CNF). Our Pigeon-Hole based CNF encoding can be seen as a nice and simple way to express the semantic of the cardinality constraint, that can be defined as how to put b pigeons into n ...

Hierarchically mesoporous CuO/carbon nanofiber coaxial shell-core nanowires (CuO/CNF) as anodes for lithium ion batteries were prepared by coating the Cu2(NO3)(OH)3 on the surface of conductive and elastic CNF via electrophoretic deposition (EPD), followed by thermal treatment in air. The CuO shell stacked with nanoparticles grows radially toward the CNF core, which forms hierarchically mesopor...

Introduction: The antinociceptive effect of morphine is, in part, mediated through the activation of a descending pathway. One of the major components of this pathway is the nucleus raphe magnus (NRM). Our previous study demonstrated the involvement of NRM in the analgesic effect of morphine microinjected into the nucleus cuneiformis (NCF) in a descending manner. The aim of the current study...

BACKGROUND Laparoscopic Nissen fundoplication (LNF) has essentially replaced its conventional open counterpart (CNF). An economic evaluation of LNF compared with CNF based on prospective data with adequate follow-up is lacking. METHODS Data from two consecutive studies (a randomized clinical trial (RCT) of 57 patients undergoing LNF and 46 undergoing CNF that was terminated prematurely, and a...