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Compacting the Penn Treebank Grammar  [PDF]
Alexander Krotov,Mark Hepple,Robert Gaizauskas,Yorick Wilks
Computer Science , 1999,
Abstract: Treebanks, such as the Penn Treebank (PTB), offer a simple approach to obtaining a broad coverage grammar: one can simply read the grammar off the parse trees in the treebank. While such a grammar is easy to obtain, a square-root rate of growth of the rule set with corpus size suggests that the derived grammar is far from complete and that much more treebanked text would be required to obtain a complete grammar, if one exists at some limit. However, we offer an alternative explanation in terms of the underspecification of structures within the treebank. This hypothesis is explored by applying an algorithm to compact the derived grammar by eliminating redundant rules -- rules whose right hand sides can be parsed by other rules. The size of the resulting compacted grammar, which is significantly less than that of the full treebank grammar, is shown to approach a limit. However, such a compacted grammar does not yield very good performance figures. A version of the compaction algorithm taking rule probabilities into account is proposed, which is argued to be more linguistically motivated. Combined with simple thresholding, this method can be used to give a 58% reduction in grammar size without significant change in parsing performance, and can produce a 69% reduction with some gain in recall, but a loss in precision.
Semiconductor dielectric function, excitons and the Penn model  [PDF]
Diego Julio Cirilo-Lombardo
Physics , 2015,
Abstract: Improved computation of the dielectric function considering excitonic effects and long wavelength is performed and compared with the nearly free electron band approximation, similarly with the Penn's model case. New expressions for the real and imaginary part of the dielectric function are presented and the real part compared with the Penn's result. The obtained functions satisfy the Kramers-Kr\"onig relations, in contrast with earlier results in the literature. In addition, our improved dielectric function presents a coeficient of 2/3 for small gap approximation (different from the value of 1 in the original Penn model) is very close to the value 0.62 obtained in [Can. J. Phys.53,(1975) p.2549] from pure numerical procedures. The obtained dielectric function also is used in a rough and stimative analysis of the metal-insulator transition in molecular hydrogen being the critical densities determined near the experimental values for the hydrogen coming from other approach. The approximated expressions and critical values are given and the usefulness of the rough methods involved in the determination of the critical points briefly discussed.
Attribution and its annotation in the Penn Discourse TreeBank  [PDF]
Rashmi Prasad,Nikhil Dinesh,Alan Lee,Aravind Joshi
Traitement Automatique des Langues , 2007,
Abstract: In this paper, we describe an annotation scheme for the attribution of abstract objects (propositions, facts, and eventualities) associated with discourse relations and their arguments annotated in the Penn Discourse TreeBank. The scheme aims to capture both the source and degrees of factuality of the abstract objects through the annotation of text spans signalling the attribution, and of features recording the source, type, scopal polarity, and determinacy of attribution.
Teresa Cristina Lara Lanza de Sá e Melo Marques,Janice Guedes de Carvalho,Mariluza Pinto Coelho Lacerda,Paulo Emílio Ferreira da Mota
CERNE , 2004,
Abstract: Macronutrients concentrations in leave, stem, and root tissues of Schizolobium amazonicum Herb. were determined under greenhouse conditions using the missing element technique. The experimental design was a completely randomized block with four replications and 13 treatments. Seedlings 0.05–0.10 -m high were planted into 3 L pots filled with nutritive solution. Based on the concentrations of macronutrients in the leaves of the complete and the deficient treatments, suitable and deficient levels (g kg-1) of macronutrients for S. amazonicum are: a) suitable: 4 for P; 15 for K; 40 for Ca; 4 for Mg; and 3 for S; 33of B; 5 of Cu; 540 of Fe, 88 of Mn; and 71 of Zn; b) critical: 1 for P; 4 for K; 8 for Ca; 1 for Mg; and 2 for S; 31 of B; 4 of Cu; 140 of Fe; 38 of Mn; and 24 of Zn
Chemical study of leaves of Chrysophyllum marginatum (Hook. & Arn.) Radlk (Sapotaceae)
Silva, Viviane Candida da;Lopes, Márcia Nasser;Bolzani, Vanderlan da Silva;
Química Nova , 2006, DOI: 10.1590/S0100-40422006000300016
Abstract: the fractionation of the antioxidant ethyl acetate extract obtained from the dried leaves of chrysophyllum marginatum afforded six substances identified as: a-amirin, gallic acid, myricitrin, quercitrin, (-)-epigallocatechin and (-)-epigallocatechin-3-o-gallate. this study contributes to the knowledge of the secondary metabolites produced by one more species of the brazilian flora, until now not investigated. moreover, this study allowed the identification of three substances with antioxidant activity previously detected in this species.
Chemical study of leaves of Chrysophyllum marginatum (Hook. & Arn.) Radlk (Sapotaceae)  [cached]
Silva Viviane Candida da,Lopes Márcia Nasser,Bolzani Vanderlan da Silva
Química Nova , 2006,
Abstract: The fractionation of the antioxidant ethyl acetate extract obtained from the dried leaves of Chrysophyllum marginatum afforded six substances identified as: alpha-amirin, gallic acid, myricitrin, quercitrin, (-)-epigallocatechin and (-)-epigallocatechin-3-O-gallate. This study contributes to the knowledge of the secondary metabolites produced by one more species of the Brazilian Flora, until now not investigated. Moreover, this study allowed the identification of three substances with antioxidant activity previously detected in this species.
Reproductive cycle of Macrobrachium amazonicum females (Crustacea, Palaemonidae)
Sampaio, CMS.;Silva, RR.;Santos, JA.;Sales, SP.;
Brazilian Journal of Biology , 2007, DOI: 10.1590/S1519-69842007000300022
Abstract: macrobrachium amazonicum is considered a favorite brazilian species of freshwater prawn for cultivation as a result of its quick development and because it is easy to maintain in captivity. the aim of this work is to describe the sexual cycle stages and determine maturation age of the female m. amazonicum, which was collected monthly from june, 2002 to may, 2003 in the jaguaribe river, itai?aba, ceará. a monthly sample of water was also collected to determine the following parameters: temperature, dissolved oxygen, ph and salinity. a monthly sample of females was selected among the individuals caught, to determine the total weight (wt), carapace length (lc) and abdomen+telson length (la+t) and to register the number of non-ovigerous females (nof) and ovigerous females (of). determining ovarian maturation stages of m. amazonicum was done in a laboratory by observing macroscopic characters such as coloring, size, location and appearance of ovarians examined by transparent carapace. the first maturation age was determined from the relative frequency of the total length (lt) of young and adult females. the environmental parameters of the jaguaribe river did not hold any influence in the number of individuals collected. a total of 1,337 prawns were sampled, 513 males (38.4%) and 824 females (61.6%). the proportion between males and females in the studied population was of 1:1.6. among the collected females, 492 (50.7%) did not carry eggs in their abdomens (nof) and 332 (40.3%) carried eggs in their abdomens (of). there was no record of intact females. non-ovigerous females with mature ovaries were recorded throughout all the months of collection. the female ovaries were classified as immature (im), rudimentary (ru), intermediary (in) and mature (m). m. amazonicum females reach their first sexual maturity between 4.5 and 5.5 cm of total length.
Fecundity and fertility of Macrobrachium amazonicum (Crustacea, Palaemonidae)
da Silva, R. R.;Sampaio, C. M. S.;Santos, J. A.;
Brazilian Journal of Biology , 2004, DOI: 10.1590/S1519-69842004000300012
Abstract: in brazil, studies with native freshwater prawn species were discontinued due to great importance of macrobrachium rosenbergii. therefore, it is necessary to continue investigations about our species, in order to develop technology adequate to our reality and in a future allow prawn farmers to culture other species. the aim of this study was to determine the fecundity and fertility of macrobrachium amazonicum captured monthly from june 1999 to june 2001 from jaguaribe river, itai?aba, ceará, brazil. prawns were collected using fishing net and transferred at biological science laboratory, ceará state university (fortaleza, ceará, brazil). among the ovigerous m. amazonicum females, 60 were randomly selected to determine fecundity. the eggs adhered to the pleopods were taken out and they were then placed in a gilson solution, and then stored in alcohol 70%. individual fecundity was determined from the total egg counting, using a stereoscopic microscope. to determine fertility, ovigerous m. amazonicum females were stored in individual 10 l-glass tanks maintained under strong aeration. after the hatching, the larvae were siphoned and counted. the data referring to total length and weight of all the females, storage date, coloration and number of eggs, weight and coloration of gonad and number of hatched larvae were noted. with respect to average fecundity (f) by length classes, the lowest and highest number of eggs observed was 696 and 1,554, respectively. as for fecundity by weight classes, the lowest number of eggs observed was 760 and the highest, 1,690. the highest number of eggs observed individually per hatching was 2,193. average fecundity/total length (l) and average fecundity/total weight (w) may be expressed by a linear relationship. the adjusted equations are: f = -411.6 + 203.1 l (p < 0.0001) and f = 566.4 + 157.3 w (p < 0.0001), respectively. in the analysis of average fertility (n) per length classes, the lowest and highest number of larvae observed was 374
Respostas de plantas de Schizolobium amazonicum [S. parahyba var. amazonicum] e Schizolobium parahyba [Schizolobium parahybum] à deficiência hídrica
Carvalho, Cláudio José Reis de;
Revista árvore , 2005, DOI: 10.1590/S0100-67622005000600009
Abstract: juvenile plants of s. amazonicum (paricá) and s. parahyba (guapuruvu) were subjected to two cycles of water stress in greenhouse conditions. the water deficit induced the increase in total soluble amino acids, proline, total soluble sugars and k+ contents in the leaf tissues, lowering osmotic potential values in both species. however, the analysis of the pressure-volume curve results suggests that the species respond differently to water stress, and that s. amazonicum presents greater capacity of osmotic adaptation than s. parahyba.
Nutrient Values of Chrysophyllum Albidum Linn African Star Apple as a Domestic Income Plantation Species
U.N Ureigho, B.A Ekeke
African Research Review , 2010,
Abstract: This study analyzed the nutritive composition of Chrysophyllum albidum Linn. It was necessitated by the need towards creating awareness that this species can provide nutrient supplements for the larger percentage of the population in the rural and peri-urban communities. Chrysophyllum albidum locally called “Udara” is one of the 80 species of Chrysophyllum Linn, a pan-tropical genus. Market Survey was done to collect data from three major markets in Rivers State known for assorted fruits business. Eight to ten of morphologically differing types were characterized and further identified into types. Nine fruit types were morphologically identified and comprehensively analyzed in Food Science and Technology Laboratory, Rivers State University of Science and Technology for nutrient content. The analysis has shown that Chrysophyllum albidum has an approximation of carbohydrate (11%), crude fibre (4%), Lipids (3%), protein (7%), Calcium (17.11ppm), Iron (< Ippm), phosphorus (9.92ppm), vitamin C (25.03ppb), A (10.74ppb), B1 and B2 (< 1ppb). It is recommended that the awareness of the nutritive value of this species be created so as to increase it’s consumption as food supplement to the larger population and expand its utilization.
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