857 research outputs found
Balancing Scalability and Uniformity in SAT Witness Generator
Constrained-random simulation is the predominant approach used in the
industry for functional verification of complex digital designs. The
effectiveness of this approach depends on two key factors: the quality of
constraints used to generate test vectors, and the randomness of solutions
generated from a given set of constraints. In this paper, we focus on the
second problem, and present an algorithm that significantly improves the
state-of-the-art of (almost-)uniform generation of solutions of large Boolean
constraints. Our algorithm provides strong theoretical guarantees on the
uniformity of generated solutions and scales to problems involving hundreds of
thousands of variables.Comment: This is a full version of DAC 2014 pape
Orthogonal Ramanujan Sums, its properties and Applications in Multiresolution Analysis
Signal processing community has recently shown interest in Ramanujan sums
which was defined by S.Ramanujan in 1918. In this paper we have proposed
Orthog- onal Ramanujan Sums (ORS) based on Ramanujan sums. In this paper we
present two novel application of ORS. Firstly a new representation of a finite
length signal is given using ORS which is defined as Orthogonal Ramanujan
Periodic Transform.Secondly ORS has been applied to multiresolution analysis
and it is shown that Haar transform is a spe- cial case
Sampling Techniques for Boolean Satisfiability
Boolean satisfiability ({\SAT}) has played a key role in diverse areas
spanning testing, formal verification, planning, optimization, inferencing and
the like. Apart from the classical problem of checking boolean satisfiability,
the problems of generating satisfying uniformly at random, and of counting the
total number of satisfying assignments have also attracted significant
theoretical and practical interest over the years. Prior work offered heuristic
approaches with very weak or no guarantee of performance, and theoretical
approaches with proven guarantees, but poor performance in practice.
We propose a novel approach based on limited-independence hashing that allows
us to design algorithms for both problems, with strong theoretical guarantees
and scalability extending to thousands of variables. Based on this approach, we
present two practical algorithms, {\UniformWitness}: a near uniform generator
and {\approxMC}: the first scalable approximate model counter, along with
reference implementations. Our algorithms work by issuing polynomial calls to
{\SAT} solver. We demonstrate scalability of our algorithms over a large set of
benchmarks arising from different application domains.Comment: MS Thesis submitted to Rice Universit
Recent advances in periodontal drug delivery systems.
Periodontitis, a disease involving supportive structures of the teeth prevails in all groups, ethnicities, races and both genders. The relationship between bacterial plaque and the development of periodontal disease and caries is well established. Antibacterial agents have been used effectively in the management of periodontal infection. The effectiveness of mechanical debridement of plaque and repeated topical and systemic administration of antibacterial agents are limited due to the lack of accessibility to periodontopathic organisms in the periodontal pocket. Systemic administration of drugs leads to therapeutic concentrations at the site of infection, but for short periods of time, forcing repeated dosing for longer periods. Local delivery of antimicrobials has been investigated for the possibility of overcoming the limitations of conventional therapy. The use of sustained release formulations to deliver antibacterials to the site of infection (periodontal pocket) has recently gained interest. These products provide a long-term, effective treatment at the site of infection at much smaller doses. Biodegradable polymers are extensively employed in periodontal drug delivery devices because of their abundant source, lack of toxicity, and high tissue compatibility. A major advantage of natural polymers is that they do not affect periodontal tissue regeneration. Amongst various natural polymers, chitosan, a deacetylated product of chitin is widely used in drug delivery devices. Since it exhibits favourable biological properties such as non-toxicity, biocompatibility, biodegradability and wound healing traits, it has attracted great attention in the pharmaceutical and biomedical fields. The conventional treatment consists of tooth surface mechanical cleaning and root planning, associated or not to the systemic use of high concentrations of antibiotics, but with reduced effectiveness, and adverse effects. The patient compliance to the therapeutic is committed too. In the last decades, the treatment has been optimized for the use of drug delivery systems to the periodontal pocket, with the advantage of delivering the drug in the specific site, sustaining and/or controlling the drug concentration. Recently, the use of new drug delivery systems has been receiving great interest. This review approaches the main delivery systems for the administration of drugs to the periodontal pocket, their usefulness, as well as the advancement of these systems effectiveness in the periodontal therapy. Keywords : Periodontal diseases; Periodontal pocket; Delivery systems; Periodontal pocket deliver
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