11,254 research outputs found
PFTijah: text search in an XML database system
This paper introduces the PFTijah system, a text search system that is integrated with an XML/XQuery database management system. We present examples of its use, we explain some of the system internals, and discuss plans for future work. PFTijah is part of the open source release of MonetDB/XQuery
Earnings and wealth inequality and income taxation: quantifying the tradeoffs of switching to a proportional income tax in the U.S.
This paper quantifies the steady-state aggregate, distributional, and mobility effects of switching the U.S. to a proportional income tax system.Income tax
Common DNA markers can account for more than half of the genetic influence on cognitive abilities
For nearly a century, twin and adoption studies have yielded substantial estimates of heritability for cognitive abilities, although it has proved difficult for genomewide-association studies to identify the genetic variants that account for this heritability (i.e., the missing-heritability problem). However, a new approach, genomewide complex-trait analysis (GCTA), forgoes the identification of individual variants to estimate the total heritability captured by common DNA markers on genotyping arrays. In the same sample of 3,154 pairs of 12-year-old twins, we directly compared twin-study heritability estimates for cognitive abilities (language, verbal, nonverbal, and general) with GCTA estimates captured by 1.7 million DNA markers. We found that DNA markers tagged by the array accounted for .66 of the estimated heritability, reaffirming that cognitive abilities are heritable. Larger sample sizes alone will be sufficient to identify many of the genetic variants that influence cognitive abilities
Emotional Strategies as Catalysts for Cooperation in Signed Networks
The evolution of unconditional cooperation is one of the fundamental problems
in science. A new solution is proposed to solve this puzzle. We treat this
issue with an evolutionary model in which agents play the Prisoner's Dilemma on
signed networks. The topology is allowed to co-evolve with relational signs as
well as with agent strategies. We introduce a strategy that is conditional on
the emotional content embedded in network signs. We show that this strategy
acts as a catalyst and creates favorable conditions for the spread of
unconditional cooperation. In line with the literature, we found evidence that
the evolution of cooperation most likely occurs in networks with relatively
high chances of rewiring and with low likelihood of strategy adoption. While a
low likelihood of rewiring enhances cooperation, a very high likelihood seems
to limit its diffusion. Furthermore, unlike in non-signed networks, cooperation
becomes more prevalent in denser topologies.Comment: 24 pages, Accepted for publication in Advances in Complex System
Urban tree classification using discrete-return LiDAR and an object-level local binary pattern algorithm
© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group. Urban trees have the potential to mitigate some of the harm brought about by rapid urbanization and population growth, as well as serious environmental degradation (e.g. soil erosion, carbon pollution and species extirpation), in cities. This paper presents a novel urban tree extraction modelling approach that uses discrete laser scanning point clouds and object-based textural analysis to (1) develop a model characterised by four sub-models, including (a) height-based split segmentation, (b) feature extraction, (c) texture analysis and (d) classification, and (2) apply this model to classify urban trees. The canopy height model is integrated with the object-level local binary pattern algorithm (LBP) to achieve high classification accuracy. The results of each sub-model reveal that the classification of urban trees based on the height at 47.14 (high) and 2.12 m (low), respectively, while based on crown widths were highest and lowest at 22.5 and 2.55 m, respectively. Results also indicate that the proposed algorithm of urban tree modelling is effective for practical use
Financial analysis ("Sell-Side"): CISCO Systems, Inc.
Cisco Systems, Inc. es una empresa estadounidense que cotiza en el mercado de valores NASDAQ y est? incluida en los ?ndices S&P 500, DJIA y NASDAQ-100. La empresa se constituy? en California en 1984 y opera en el sector de las tecnolog?as de la informaci?n (tambi?n denominado "TI"), compitiendo principalmente en el mercado de los equipos de redes y comunicaciones. El sector en el que opera Cisco es el de las redes inform?ticas, un sector afectado por la pandemia, dada la necesidad de redise?ar forzosamente la forma de trabajar de las empresas, pasando del trabajo de oficina al teletrabajo. De esta manera, se reduce la necesidad de hardware y software necesario en las oficinas para comunicarse con el personal y todo se desarrolla a distancia. El an?lisis del valor de las acciones de la empresa se ha realizado mediante dos m?todos: el m?todo del flujo de caja descontado y el m?todo de los m?ltiplos. El resultado de estos modelos indica que el valor de la acci?n de la empresa deber?a estar entre 40,83 y 45,12 d?lares, valores que comparados con el valor actual de la acci?n (abr-2021) 51,50 d?lares, indicar?an que el mercado est? pagando una prima por tener la acci?n de la empresa, lo que indica que es una acci?n sobrevalorada y deber?a ser vendida
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