173,836 research outputs found
Couplings in F-theory and non-commutative geometry
No full textA shifted view of fundamental physics / Michael Atiyah and Gregory W. Moore -- Subgroups of depth three / Sebastian Burciu and Lars Kadison -- Yukawa couplings in F-theory and non-commutative geometry / Sergio Cecotti, et. al. -- Spin structures and superstrings / Jacques Distler, et. al. -- Operator traces and holography / Michael R. Douglas -- A loop of SU(2) gauge fileds stable under the Yang-Mills flow / Daniel Friedan -- Automorphisms of graded super symplectic manifolds / Joshua Leslie -- The signature of the Seiberg-Witten surface / Andreas Malmendier -- Eta forms and the odd pseudodifferential families index / Richard Melrose and Frederic Rochon -- Anomaly constraints and string/F-theory geormetry in 6D quantum gravity / Washington Taylor -- A new look at the path integral of quantum mechanics / Edward Witten -- Quasi-local mass in general relativity / Shing-Tung Yau
Cooperazione e competizione nello sfruttamento di una risorsa rinnovabile
No full textIn this paper we propose a static model describing the commercial exploitation of a common property renewable resource by a population of agents. Players can cooperate or compete; cooperators maximize the utility of their group while defectors maximize their own profit. Agents aren't assumed to be divided into the two groups from the beginning; by solving the static game we obtained the best response function of i-th player without making other agents positions. Then, the Nash equilibria we calculated point out how different strategies - all the players cooperate, all the players compete or players can be divided into cooperators and defectors - can coexist.Resource Exploitation, Game theory
Determinazione di strategie nello sfruttamento di una risorsa rinnovabile
No full textIn this paper we propose a static model describing the commercial exploitation of a common property renewable resource by a population of agents. Players can cooperate or compete; cooperators maximize the utility of their group while defectors maximize their own profit. The model provide for one utility function which can be used for every kind of player. Agents aren't assumed to be divided into the two groups from the beginning; by solving the static game we obtained the best response function of i-th player without making other agents positions. Then, the Nash equilibria we calculated point out how different strategies - all the players cooperate, all the players compete or players can be divided into cooperators and defectors - can coexist. In any case we have analyzed, it's possible to observe how the total harvest depend on renewable resource stock, and how it influences agents' positions. Keywords Resource Exploitation, Game Theory
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Determination of sediment oxygen demand in Shing-mun River
No full textA lab-scale set-up has been developed for studying the effects of boundary flow velocity and temperature on the sediment oxygen demand (SOD) of Shing-Mun River. The set-up was installed with upstream baffles to obtain even flow environment in the experimental study. It has been found that the correlation of the SOD with the flow velocity is approximately linear in the flow range of 0.035 m/s ~0.104 m/s at different temperature, while temperature effect on SOD rate is expressed as an exponential function of temperature in the range of 11°C to 35°C at different flow velocity. Therefore, temperature has a greater influence on the SOD than the flow velocity. A model for estimating the SOD rate has been developed in this study: SOD(gO2 / m2 / d) = 9.96Use0.076Twhere : Us = boundary flow velocity (m/s) T = temperature (degree C) The above model was generated from experimental data obtained under the following specific operation conditions: 1) flow velocity = 0.035 m/s ~ 0.104 m/s; 2) temperature = 11°C ~ 35°C; 3) initial DO concentration in overlying water = 6.4 ~ 7.0 mg/L; 4) COD concentration in overlying water = 23 ~ 28 mg/L 5) sediment thickness = 5 cm 6) organic content of sediment = 6 ~ 11% Through the overall mechanism study, it has been found that 62% of the SOD is from biological oxygen consumption within the sediment. Experimental data also implies that SOD should be mainly knited by oxygen mass transfer rate from the overlyingg water into the sediment.Keywords: sediment oxygen demand, boundary flow velocity, temperature, Shing-Mun River</p
Estudo dinâmico e térmico do escoamento laminar em duplo tubo aletado
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-graduação em Engenharia Mecânica
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
