619 research outputs found
Education alignment
This essay reviews recent developments in embedding data
management and curation skills into information technology,
library and information science, and research-based
postgraduate courses in various national contexts. The essay
also investigates means of joining up formal education with
professional development training opportunities more
coherently. The potential for using professional internships as a
means of improving communication and understanding between
disciplines is also explored. A key aim of this essay is to identify
what level of complementarity is needed across various
disciplines to most effectively and efficiently support the entire
data curation lifecycle
Issues in digital preservation: towards a new research agenda
Digital Preservation has evolved into a specialized, interdisciplinary research discipline of its own, seeing significant increases in terms of research capacity, results, but also challenges. However, with this specialization and subsequent formation of a dedicated subgroup of researchers active in this field, limitations of the challenges addressed can be observed. Digital preservation research may seem to react to problems arising, fixing problems that exist now, rather than proactively researching new solutions that may be applicable only after a few years of maturing. Recognising the benefits of bringing together researchers and practitioners with various professional backgrounds related to digital preservation, a seminar was organized in Schloss Dagstuhl, at the Leibniz Center for Informatics (18-23 July 2010), with the aim of addressing the current digital preservation challenges, with a specific focus on the automation aspects in this field. The main goal of the seminar was to outline some research challenges in digital preservation, providing a number of "research questions" that could be immediately tackled, e.g. in Doctoral Thesis. The seminar intended also to highlight the need for the digital preservation community to reach out to IT research and other research communities outside the immediate digital preservation domain, in order to jointly develop solutions
Integrated methods and scenario development for urban groundwater management and protection during tunnel road construction: a case study of urban hydrogeology in the city of Basel, Switzerland
In the northwestern area of Basel, Switzerland, a tunnel highway connects the French highway A35 (Mulhouse-Basel) with the Swiss A2 (Basel-Gotthard-Milano). The subsurface highway construction was associated with significant impacts on the urban groundwater system. Parts of this area were formerly contaminated by industrial wastes, and groundwater resources are extensively used by industry. During some construction phases, considerable groundwater drawdown was necessary, leading to major changes in the groundwater flow regime. Sufficient groundwater supply for industrial users and possible groundwater pollution due to interactions with contaminated areas had to be taken into account. A groundwater management system is presented, comprising extensive groundwater monitoring, high-resolution numerical groundwater modeling, and the development and evaluation of different scenarios. This integrated approach facilitated the evaluation of the sum of impacts, and their interaction in time and space with changing hydrological boundary conditions. For all project phases, changes of the groundwater system had to be evaluated in terms of the various goals and requirements. Although the results of this study are case-specific, the overall conceptual approach and methodologies applied may be directly transferred to other urban area
Reinforcement Learning in Sparse-Reward Environments with Hindsight Policy Gradients
A reinforcement learning agent that needs to pursue different goals across episodes requires a goal-conditional policy. In addition to their potential to generalize desirable behavior to unseen goals, such policies may also enable higher-level planning based on subgoals. In sparse-reward environments, the capacity to exploit information about the degree to which an arbitrary goal has been achieved while another goal was intended appears crucial to enabling sample efficient learning. However, reinforcement learning agents have only recently been endowed with such capacity for hindsight. In this letter, we demonstrate how hindsight can be introduced to policy gradient methods, generalizing this idea to a broad class of successful algorithms. Our experiments on a diverse selection of sparse-reward environments show that hindsight leads to a remarkable increase in sample efficiency
Recurrent Neural-Linear Posterior Sampling for Nonstationary Contextual Bandits
An agent in a nonstationary contextual bandit problem should balance between
exploration and the exploitation of (periodic or structured) patterns present
in its previous experiences. Handcrafting an appropriate historical context is
an attractive alternative to transform a nonstationary problem into a
stationary problem that can be solved efficiently. However, even a carefully
designed historical context may introduce spurious relationships or lack a
convenient representation of crucial information. In order to address these
issues, we propose an approach that learns to represent the relevant context
for a decision based solely on the raw history of interactions between the
agent and the environment. This approach relies on a combination of features
extracted by recurrent neural networks with a contextual linear bandit
algorithm based on posterior sampling. Our experiments on a diverse selection
of contextual and noncontextual nonstationary problems show that our recurrent
approach consistently outperforms its feedforward counterpart, which requires
handcrafted historical contexts, while being more widely applicable than
conventional nonstationary bandit algorithms. Although it is very difficult to
provide theoretical performance guarantees for our new approach, we also prove
a novel regret bound for linear posterior sampling with measurement error that
may serve as a foundation for future theoretical work
Hindsight policy gradients
A reinforcement learning agent that needs to pursue different goals across
episodes requires a goal-conditional policy. In addition to their potential to
generalize desirable behavior to unseen goals, such policies may also enable
higher-level planning based on subgoals. In sparse-reward environments, the
capacity to exploit information about the degree to which an arbitrary goal has
been achieved while another goal was intended appears crucial to enable sample
efficient learning. However, reinforcement learning agents have only recently
been endowed with such capacity for hindsight. In this paper, we demonstrate
how hindsight can be introduced to policy gradient methods, generalizing this
idea to a broad class of successful algorithms. Our experiments on a diverse
selection of sparse-reward environments show that hindsight leads to a
remarkable increase in sample efficiency.Comment: Accepted to ICLR 201
Sunset-calc: An R Shiny Application for Processing Thermo-Optical Analysis Data from Atmospheric Aerosol Measurements
Atmospheric aerosols are harmful to human health and affect the climate. We use radiocarbon for the source apportionment of carbonaceous aerosols to unequivocally separate fossil form non-fossil sources. We use thermal-optical analysis (TOA) for radiocarbon measurement of the organic carbon (OC) and elemental carbon (EC) fractions, which requires physical OC/EC separation. TOA relies on the changes in the optical behaviour of carbon when OC is thermally separated from EC. Thermal-optical OC/EC separation leads to partial EC-loss and the conversion of some OC to EC (charring). EC-loss and charring are artifacts which falsify the results of the quantification and must be corrected for. Furthermore, quantifications with custom TOA protocols are not supported with the provided device software. These calculations were previously performed with various spreadsheet style templates and other tools. With Sunset-calc, we aimed to bundle the data processing and develop an extendable and simple web application. With R Shiny, we found a powerful and simple language also for people with little prior programming skills to build rich web applications. We have deployed Sunset-calc on an on-premises R server (14c.unibe.ch/sunsetcalc), which is publicly accessible and particularly useful for our collaborators outside of the University. Sunset-calc is available on GitHub (github.com/martin-rauber/sunset-calc)
Spatial and temporal distribution of supercooled cloud liquid water during wintertime storms over the northern Colorado Rockies, The
August 1984.Includes bibliographical references (page 58).Sponsored by National Science Foundation ATM-78-19260.Sponsored by National Science Foundation ATM-81-09890
Influ?ncia do ?cido giber?lico sobre a germina??o de sementes de milho
Maize (Zea mays L.) is widely cultivated and consumed in Brazil, as well as in other
countries. This culture has great adaptability in different growing environments, so
when sowing is carried out, it is preferable that fast germination occur, because the
seeds are exposed to pest attack, and can accelerate the deterioration process. The
objective of the present work was to evaluate the germination process of maize seeds
submitted to different concentrations of gibberellic acid, in order to visualize their
influence on the germination of the seeds of this crop. The experiment was carried out
at the Laboratory of Plant Physiology of the Federal University of the Southern Frontier
- UFSS, Cerro Largo campus. In order to conduct the experiments, we used 7-
treatments that refer to different concentrations of gibberellic acid, which vary between
0, 10, 50, 100, 200, 500 and 1000 ppm, with a completely randomized design (DIC).
four replicates of 50 seeds, totaling 28 experimental units. The evaluated parameters
were percentage of germination, of normal seedlings, abnormal seedlings and dead
seeds, also the germination speed index test was performed. The results were
submitted to analysis of variance (ANOVA), using the SASM-agri program, posterior,
submitted to regression analysis. With the results obtained, it was observed that, in
corn seeds, the application of gibberellic acid resulted in the reduction of germination
percentage and normal seedlings, increase of abnormal seedlings and dead seeds.
For the germination rate index (IVG), the higher the concentration of gibberellic acid
the lower the IVG, therefore, it is concluded that the results found do not positively
influence the application of gibberellic acid in maize seeds.O milho (Zea mays L.) ? amplamente cultivado e consumido no Brasil, assim como, em
outros pa?ses. Essa cultura possui grande adaptabilidade em diferentes ambientes de
cultivo, desse modo quando realizada a semeadura, ? prefer?vel que ocorra a r?pida
germina??o, pois as sementes est?o expostas ao ataque de pragas, podendo acelerar
o processo de deteriora??o das mesmas. Com isso, o objetivo do presente trabalho foi
avaliar o processo germinativo de sementes de milho submetidas a diferentes
concentra??es de ?cido giber?lico, buscando visualizar sua influ?ncia sobre a
germina??o das sementes dessa cultura. O experimento foi realizado no Laborat?rio
de Fisiologia Vegetal da Universidade Federal da Fronteira Sul ? UFSS, campus Cerro
Largo. Para a condu??o dos experimentos, utilizou-se o Delineamento Inteiramente
Casualizado (DIC), foram utilizados 7 tratamentos que referem a diferentes
concentra??es de ?cido giber?lico, as quais variam entre 0, 10, 50, 100, 200, 500 e
1000 ppm, com quatro repeti??es de 50 sementes, totalizando 28 unidades
experimentais. Os par?metros avaliados foram porcentagem de germina??o, de
pl?ntulas normais, pl?ntulas anormais e sementes mortas, realizou-se tamb?m o teste
de ?ndice de velocidade de germina??o. Os resultados obtidos foram submetidos a
an?lise de vari?ncia (ANOVA), utilizando o programa SASM-agri, posterior, submetidas
a an?lise de regress?o. Com os resultados alcan?ados, observou-se que em sementes
de milho, a aplica??o de ?cido giber?lico resultou, na redu??o da porcentagem de
germina??o e de pl?ntulas normais, aumento de pl?ntulas anormais e sementes
mortas. Para o ?ndice de velocidade de germina??o (IVG), quanto maior a
concentra??o de ?cido giber?lico menor o IVG, portanto, conclui-se que os resultados
encontrados n?o influenciam positivamente a aplica??o de ?cido giber?lico em
sementes de milho
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