5,813 research outputs found

    Kantorovich-Rubinstein Distance and Barycenter for Finitely Supported Measures: Foundations and Algorithms

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    The purpose of this paper is to provide a systematic discussion of a generalized barycenter based on a variant of unbalanced optimal transport (UOT) that defines a distance between general non-negative, finitely supported measures by allowing for mass creation and destruction modeled by some cost parameter. They are denoted as Kantorovich–Rubinstein (KR) barycenter and distance. In particular, we detail the influence of the cost parameter to structural properties of the KR barycenter and the KR distance. For the latter we highlight a closed form solution on ultra-metric trees. The support of such KR barycenters of finitely supported measures turns out to be finite in general and its structure to be explicitly specified by the support of the input measures. Additionally, we prove the existence of sparse KR barycenters and discuss potential computational approaches. The performance of the KR barycenter is compared to the OT barycenter on a multitude of synthetic datasets. We also consider barycenters based on the recently introduced Gaussian Hellinger–Kantorovich and Wasserstein–Fisher–Rao distances

    Study of a twisted ATLAS SCT Barrel deformation as revealed by a photogrammetric survey

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    A photogrammetry survey on the SCT barrels was performed as an engineering check on the structure of the ATLAS Semiconductor Tracker (SCT) shortly after construction. Analysis of the data obtained revealed small scale elliptical deformation as well as a twist of the structure. The results of the survey are presented as well as interpolation of the measured targets to the module positions and a comparison with track based alignment measurements

    Respostas adaptativas de três parentais de arroz de terras altas à deficiência hídrica.

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    Esse estudo teve como objetivo avaliar as respostas adaptativas de três diferentes parentais de arroz de terras altas (Douradão, BRS Primavera e BRS Soberana) à deficiência hídrica

    Caracteres morfológicos do crescimento e desenvolvimento de quatro cultivares de arroz de terras altas.

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    Esse estudo teve como objetivo identificar e comparar os principais processos morfológicos relacionados ao desenvolvimento e crescimento de quatro diferentes cultivares de arroz de terras altas na fase vegetativa.bitstream/CNPAF-2009-09/27968/1/doc_229.pd

    Riscos climáticos para a consorciação feijão e milho no Estado de Goiás.

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    Os estudos de sistemas e arranjos para cultivos consorciados devem basear-se em observações de campo, respeitando as características regionais. Entende-se que o delineamento de áreas e períodos mais apropriados ao cultivo da consorciação feijão e milho é, também, uma linha de pesquisa importante para ser explorada. Utilizando-se o modelo de balanço hídrico SARRA (Sistema de Análise Regional dos Riscos Agroclimáticos) considerando-se precipitação pluvial, evapotranspiração potencial, coeficiente de cultura e fases fenológicas do consórcio, foram definidos os riscos climáticos que as plantas estarão expostas em função da relação ETr/ETm. Para a espacialização do risco climático foi utilizado o software SPRING 5.1.5. Baseado nos resultados obtidos nesse estudo pode-se concluir que, para o pior cenário, 30mm de água disponível no solo, a semeadura poderá ser realizada até 10 de fevereiro. Após esta data, as culturas estarão expostas a um alto risco climático. Para um solo com 50 mm de água disponível no solo, a semeadura desse sistema pode se estender até 20 de fevereiro. Entretanto, quanto mais precoce este procedimento for realizado maior será a probabilidade de sucesso

    Prognostic and therapeutic significance of carbohydrate antigen 19-9 as tumor marker in patients with pancreatic cancer

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    In pancreatic cancer ( PC) accurate determination of treatment response by imaging often remains difficult. Various efforts have been undertaken to investigate new factors which may serve as more appropriate surrogate parameters of treatment efficacy. This review focuses on the role of carbohydrate antigen 19- 9 ( CA 19- 9) as a prognostic tumor marker in PC and summarizes its contribution to monitoring treatment efficacy. We undertook a Medline/ PubMed literature search to identify relevant trials that had analyzed the prognostic impact of CA 19- 9 in patients treated with surgery, chemoradiotherapy and chemotherapy for PC. Additionally, relevant abstract publications from scientific meetings were included. In advanced PC, pretreatment CA 19- 9 levels have a prognostic impact regarding overall survival. Also a CA 19- 9 decline under chemotherapy can provide prognostic information for median survival. A 20% reduction of CA 19- 9 baseline levels within the first 8 weeks of chemotherapy appears to be sufficient to define a prognostic relevant subgroup of patients ('CA 19- 9 responder'). It still remains to be defined whether the CA 19- 9 response is a more reliable method for evaluating treatment efficacy compared to conventional imaging. Copyright (c) 2006 S. Karger AG, Basel

    Mapping the potential yield of upland rice in Rondonia State.

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    The rice farming has a high socioeconomical importance for Brazilian population, and represents since the 1970?s, it is the main crop for agricultural borders opening. Aiming characterize the potential yield and to define the regions most favorable for growth upland rice, it was simulated the potential grain yield (PGY), potential evapotranspiration (ETP) and maximum transpiration (TRC) by anoriented process crop model. The simulations were based on cultivar BRSPrimavera, considering eight planting dates (Nov 1st, 10th, 20th, Dec 1st, 10th, 20th, 30th and Jan 9th), for 33 years of data weather (1980-2013), in seven locations at Rondônia state: Ariquemes, Cacoal, Guajara-Mirim, Ji-Paraná, Machadinho do Oeste, Porto Velho and Vilhena. The upland rice crop cycle ranged from 95 days from emergence (DAE) in Ariquemes to 99 DAE in Machadinho do Oeste. The PGY, ETP and TRC data set were spatialized for the region. Rondônia showed an average and standard deviation potential yield of 4393 and 477 kg ha-1. The average ETP was 584,8 mm/cycle, with variance of 1259.9 mm/cycle. Maximum and minimum values of ETP was found for Guajara-Mirim and Vilhena, planting dates of Nov 1st and Jan 9th, respectively. The spatialization of results demonstrated a trend of PGY reduction as the sowing date is delayed. The highest potential yield were found at Vilhena (4952.7 kg/ha) and Ariquemes (4461.4 kg/ha)
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