1,088 research outputs found
A Spectrum of Applications of Automated Reasoning
The likelihood of an automated reasoning program being of substantial
assistance for a wide spectrum of applications rests with the nature of the
options and parameters it offers on which to base needed strategies and
methodologies. This article focuses on such a spectrum, featuring W. McCune's
program OTTER, discussing widely varied successes in answering open questions,
and touching on some of the strategies and methodologies that played a key
role. The applications include finding a first proof, discovering single
axioms, locating improved axiom systems, and simplifying existing proofs. The
last application is directly pertinent to the recently found (by R. Thiele)
Hilbert's twenty-fourth problem--which is extremely amenable to attack with the
appropriate automated reasoning program--a problem concerned with proof
simplification. The methodologies include those for seeking shorter proofs and
for finding proofs that avoid unwanted lemmas or classes of term, a specific
option for seeking proofs with smaller equational or formula complexity, and a
different option to address the variable richness of a proof. The type of proof
one obtains with the use of OTTER is Hilbert-style axiomatic, including details
that permit one sometimes to gain new insights. We include questions still open
and challenges that merit consideration.Comment: 13 page
Double-Negation Elimination in Some Propositional Logics
This article answers two questions (posed in the literature), each concerning
the guaranteed existence of proofs free of double negation. A proof is free of
double negation if none of its deduced steps contains a term of the form
n(n(t)) for some term t, where n denotes negation. The first question asks for
conditions on the hypotheses that, if satisfied, guarantee the existence of a
double-negation-free proof when the conclusion is free of double negation. The
second question asks about the existence of an axiom system for classical
propositional calculus whose use, for theorems with a conclusion free of double
negation, guarantees the existence of a double-negation-free proof. After
giving conditions that answer the first question, we answer the second question
by focusing on the Lukasiewicz three-axiom system. We then extend our studies
to infinite-valued sentential calculus and to intuitionistic logic and
generalize the notion of being double-negation free. The double-negation proofs
of interest rely exclusively on the inference rule condensed detachment, a rule
that combines modus ponens with an appropriately general rule of substitution.
The automated reasoning program OTTER played an indispensable role in this
study.Comment: 32 pages, no figure
USA reaktsioon globaalsele AIDSi-kriisile
Töötades noore arstina 1980. aastatel AIDSi-patsientidega, ei teadnud ei mina ega mu kolleegid, mis laadi haigusega on tegemist. Me ei teadnud, milliseid ettevaatusabinõusid tarvitusele võtta, puudusid kohased ravivõimalused. 1980ndate lõpul ja 1990ndate algul, kui aina enam inimesi suri HIV/AIDS tagajärjel ja meie, arstid, saime rohkem teadmisi selle haiguse kohta, kasvas ühiskonna teadlikkus nii USAs kui ka teistes riikides. Samas aga Aafrikas ja mujal arengumaades haigust peamiselt ignoreeriti, vaatamata sellele et see levis kui kulutuli
Populations of doubled haploids for genetic mapping in hexaploid winter triticale.
To create a framework for genetic dissection of hexaploid triticale, six populations of doubled haploid (DH) lines were developed from pairwise hybrids of high-yielding winter triticale cultivars. The six populations comprise between 97 and 231 genotyped DH lines each, totaling 957 DH lines. A consensus genetic map spans 4593.9 cM is composed of 1576 unique DArT markers. The maps reveal several structural rearrangements in triticale genomes. In preliminary tests of the populations and maps, markers specific to wheat segments of the engineered rye chromosome 1R (RM1B) were identified. Example QTL mapping of days to heading in cv. Krakowiak revealed loci on chromosomes 2BL and 2R responsible for extended vernalization requirement, and candidate genes were identified. The material is available to all parties interested in triticale genetics
Effects of gender differences on the subjective perceived intensity of steering wheel rotational vibration based on a multivariate regression model
This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2009 ElsevierThe aims of this study were to determine equal sensation curves for hand-arm steering wheel rotational vibration and to investigate the effect of gender on the subjective perceived intensity of steering wheel hand-arm vibration. Psychophysical response tests of 40 participants (20 mates and 20 females) were performed using a steering wheel rotational vibration simulator using the category-ratio Borg CR10 scale procedure for direct estimation of perceived intensity. The test stimuli were sinusoidal vibrations at 22 third octave band centre frequencies in the range from 3 to 400 Hz, with acceleration amplitudes in the range from 0.04 to 27 m/s(2) r.m.s. Multivariate regression procedures were applied to the experimentally acquired data in order to establish a regression model expressing the Borg CR10 perceived intensity values as a function of the two independent parameters of the frequency and amplitude of vibration. The equal sensation curves suggested a non-linear dependency of the subjective perceived intensity on both frequency and amplitude. Females were found to provide higher Borg CR10 perceived intensity values than males (p < 0.05), particularly at the higher intensity levels above approximately 1.0 m/s(2) r.m.s and at the higher frequencies above approximately 20 Hz.Relevance to industry: For the manufacturers of steering systems and of other automobile components this study provides vibration perception curves and identifies the possible importance of gender towards the perception of vibration which arrives at the steering wheel. (C) 2009 Elsevier B.V. All rights reserved
Recommended from our members
A Rare Oncologic Emergency: Spontaneous Tumor Lysis Syndrome in Metastatic Colon Adenocarcinoma
Tumor lysis syndrome is an oncologic emergency that can present with variable symptoms and is truly a laboratory-based diagnosis without pathognomonic clinical findings. The classical teaching is to consider this diagnosis in cancer patients undergoing chemotherapy. We present the case of a 66-year-old female with newly diagnosed metastatic liver adenocarcinoma, not on chemotherapy, who was diagnosed with spontaneous tumor lysis syndrome. Cognizance of this syndrome and associated laboratory findings are paramount to diagnosis and rapid intervention
Immunodepletion in xenotransplantation
Xenograft transplantation is perhaps the most immunologically difficult problem in transplantation today. An overwhelming hyperacute rejection reaction (HAR) occurs within minutes of organ implantation. Preformed antibodies are thought to initiate this process. We used a pig-to-dog renal xenograft transplant model and investigated methods of decreasing the severity of hyperacute rejection. Female pigs weighing 15-20 kg were used as donors. Recipients were mongrel dogs weighing 15-25 kg. Experimental dogs were all given a number of treatments of IgG depletion using an antibody removal system (Dupont-Excorim). This machine immunoadsorbs plasma against a column containing immobilized staphylococcal protein A, which is known to bind the IgG Fc receptor. An 84% reduction in the IgG levels and a 71% reduction in IgM levels was achieved. Postoperative assessment was made of urine output, time to onset of HAR, and histopathological examination of the rejected kidneys. Although cross-matches between donor lymphocytes and recipient sera remained strongly positive in the treated dogs, there was a two- to fourfold reduction in the titers. The time to onset of HAR was prolonged in the experimental group, and the urine output was increased slightly. The histopathologic changes in the experimental group generally showed signs of HAR, but of less intensity than in the nonimmunodepleted control group. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted
Superposition as a logical glue
The typical mathematical language systematically exploits notational and
logical abuses whose resolution requires not just the knowledge of domain
specific notation and conventions, but not trivial skills in the given
mathematical discipline. A large part of this background knowledge is expressed
in form of equalities and isomorphisms, allowing mathematicians to freely move
between different incarnations of the same entity without even mentioning the
transformation. Providing ITP-systems with similar capabilities seems to be a
major way to improve their intelligence, and to ease the communication between
the user and the machine. The present paper discusses our experience of
integration of a superposition calculus within the Matita interactive prover,
providing in particular a very flexible, "smart" application tactic, and a
simple, innovative approach to automation.Comment: In Proceedings TYPES 2009, arXiv:1103.311
- …
