3,371 research outputs found
EAGLE—A Scalable Query Processing Engine for Linked Sensor Data
Recently, many approaches have been proposed to manage sensor data using semantic web technologies for effective heterogeneous data integration. However, our empirical observations revealed that these solutions primarily focused on semantic relationships and unfortunately paid less attention to spatio–temporal correlations. Most semantic approaches do not have spatio–temporal support. Some of them have attempted to provide full spatio–temporal support, but have poor performance for complex spatio–temporal aggregate queries. In addition, while the volume of sensor data is rapidly growing, the challenge of querying and managing the massive volumes of data generated by sensing devices still remains unsolved. In this article, we introduce EAGLE, a spatio–temporal query engine for querying sensor data based on the linked data model. The ultimate goal of EAGLE is to provide an elastic and scalable system which allows fast searching and analysis with respect to the relationships of space, time and semantics in sensor data. We also extend SPARQL with a set of new query operators in order to support spatio–temporal computing in the linked sensor data context.EC/H2020/732679/EU/ACTivating InnoVative IoT smart living environments for AGEing well/ACTIVAGEEC/H2020/661180/EU/A Scalable and Elastic Platform for Near-Realtime Analytics for The Graph of Everything/SMARTE
Reexamining the monetarist critique of interest rate rules
Monetarist economists argued long ago that central bank interest rate rules exacerbate macroeconomic fluctuations, essentially by not allowing the interest rate to respond promptly to shifts in the supply and demand for loans. To support this critique, they pointed to the procyclicality of the money stock. Yet, when there are real shocks and a real business cycle, modern macroeconomic models imply that some procyclicality of money is desirable, to stabilize the price level. A simple interest rate rule illustrates that the monetarist critique can be valid within this model, since the rule exacerbates the response of real activity to real shocks. Other interest rate rules instead limit the macro economy's response to real shocks. But, while these interest rate rules have diverse effects on real activity, there is an important common implication: By smoothing the nominal interest rate in the short run, the rules all lead to increases in the longer-run variability in inflation and nominal interest rates.Interest rates ; Macroeconomics
Li spectrum from Li fragmentation
A recently developed time dependent model for the excitation of a nucleon
from a bound state to a continuum resonant state in the system n+core is
applied to the study of the population of the low energy continuum of the
unbound Li system obtained from Li fragmentation. Comparison of
the model results to new data from the GSI laboratory suggests that the
reaction mechanism is dominated by final state effects rather than by the
sudden process, but for the population of the l=0 virtual state, in which case
the two mechanisms give almost identical results. There is also, for the first
time, a clear evidence for the population of a d resonance in
Li.Comment: 15 pages, 4 figures, 3 tables. Accepted for publication in
Nucl.Phys.
Ecohydrological Modeling in Agroecosystems: Examples and Challenges
Human societies are increasingly altering the water and biogeochemical cycles to both improve ecosystem productivity and reduce risks associated with the unpredictable variability of climatic drivers. These alterations, however, often cause large negative environmental consequences, raising the question as to how societies can ensure a sustainable use of natural resources for the future. Here we discuss how ecohydrological modeling may address these broad questions with special attention to agroecosystems. The challenges related to modeling the two‐way interaction between society and environment are illustrated by means of a dynamical model in which soil and water quality supports the growth of human society but is also degraded by excessive pressure, leading to critical transitions and sustained societal growth‐collapse cycles. We then focus on the coupled dynamics of soil water and solutes (nutrients or contaminants), emphasizing the modeling challenges, presented by the strong nonlinearities in the soil and plant system and the unpredictable hydroclimatic forcing, that need to be overcome to quantitatively analyze problems of soil water sustainability in both natural and agricultural ecosystems. We discuss applications of this framework to problems of irrigation, soil salinization, and fertilization and emphasize how optimal solutions for large‐scale, long‐term planning of soil and water resources in agroecosystems under uncertainty could be provided by methods from stochastic control, informed by physically and mathematically sound descriptions of ecohydrological and biogeochemical interactions
Particle-particle random phase approximation applied to Beryllium isotopes
This work is dedicated to the study of even-even 8-14 Be isotopes using the
particle-particle Random Phase Approximation that accounts for two-body
correlations in the core nucleus. A better description of energies and
two-particle amplitudes is obtained in comparison with models assuming a
neutron closed-shell (or subshell) core. A Wood-Saxon potential corrected by a
phenomenological particle-vibration coupling term has been used for the
neutron-core interaction and the D1S Gogny force for the neutron-neutron
interaction. Calculated ground state properties as well as excited state ones
are discussed and compared to experimental data. In particular, results suggest
the same 2s_1/2-1p_1/2 shell inversion in 13Be as in 11Be.Comment: to appear in Phys. Rev.
Response function beyond mean field of neutron-rich nuclei
The damping of single-particle and collective motion in exotic isotopes is a
new topic and its study may shed light on basic problems of nuclear dynamics.
For instance, it is known that nuclear structure calculations are not able, as
a rule, to account completely for the empirical single-particle damping. In
this contribution, we present calculations of the single-particle self-energy
in the case of the neutron-rich light nucleus O, by taking proper care
of the continuum, and we show that there are important differences with the
case of nuclei along the valley of stability.Comment: 9 pages, 4 figures. To appear in: Proceedings of the Topical
Conference on Giant Resonances, Varenna, May 11-16, 1997 (Nucl. Phys. A, to
be published
Non-minimal Einstein-Yang-Mills-Higgs theory: Associated, color and color-acoustic metrics for the Wu-Yang monopole model
We discuss a non-minimal Einstein-Yang-Mills-Higgs model with uniaxial
anisotropy in the group space associated with the Higgs field. We apply this
theory to the problem of propagation of color and color-acoustic waves in the
gravitational background related to the non-minimal regular Wu-Yang monopole.Comment: 14 pages, no figure
Unbound exotic nuclei studied by transfer to the continuum reactions
In this paper we show that the theory of transfer reactions from bound to
continuum states is well suited to extract structure information from data
obtained by performing "spectroscopy in the continuum". The low energy unbound
states of nuclei such as Li and He can be analyzed and the
neutron-core interaction, necessary to describe the corresponding borromean
nuclei Li and He can be determined in a semi-phenomenological way.
An application to the study of Li is then discussed and it is shown that
the scattering length for s-states at threshold can be obtained from the ratio
of experimental and theoretical cross sections. The scattering single particle
states of the system n+Li are obtained in a potential model. The
corresponding S-matrix is used to calculate the transfer cross section as a
function of the neutron continuum energy with respect to Li. Three
different reactions are calculated ,
, , to check the
sensitivity of the results to the target used and in particular to the transfer
matching conditions. Thus the sensitivity of the structure information
extracted from experimental data on the reaction mechanism is assessed.Comment: 21 pages, 5 ps figures, accepted for publication on Nucl. Phys.
PENGEMBANGAN MANAJEMEN SISTEM INFORMASI DI UNIT PELAKSANA TEKNIS LABORATORIUM LAHAN KERING KEPULAUAN UNIVERSITAS NUSA CENDANA
Kemajuan teknologi informasi yang sangat cepat telah memacu perubahan berbagai aspek kehidupan. Perkembangan teknologi ini sangat berdampak salah satunya pada bidang pendidikan yang ditandai dengan teknologi pembelajaran berbasis online, mobile, multimedia, sarana informasi, interaksi, hingga media promosi. Perkembangan teknologi ini tidak terlepas dari kemudahan akses terhadap berbagai informasi dan tidak dibatasi oleh ruang dan waktu. Teknologi informasi telah dimanfaatkan berbagai lembaga untuk perbaikan kualitas pengelolaan dan kinerja lembaga. Unit Pelaksana Teknis (UPT) Laboratorium Lahan kering Kepulauan (LLKK) Universitas Nusa Cendana (Undana) merupakan salah satu laboratorium pendukung kegiatan Tri-Dharma civitas Undana melalui sistem kerjasama dan memiliki lahan yang menghasilkan produk-produk hasil pertanian, peternakan, dan perikanan. Kegiatan pengabdian masyarakat ini bertujuan untuk membentuk berbagai platform media sosial lembaga UPT. LLKK sebagai sistem informasi dan mengembangkan pengelolaan website sebagai sistem informasi. Metode yang digunakan berupa pengelolaan media sebagai sistem informasi untuk meningkatkan kinerja UPT. LLKK dengan pembentukan platform media sosial, pengelolaan website, penerapan, dan tahap evaluasi. Pembuatan berbagai platform media sosial UPT. LLKK diantaranya facebook, youtube, dan instagram. Media sosial ini akan menjadi wadah informatif sehingga lembaga dapat memberikan berbagai macam informasi yang dapat diakses oleh masyarakat luas dengan mudah. Platform media sosial yang sudah terbentuk lalu diintegrasikan dalam website UPT. LLKK agar keseluruhan media dapat menjadi satu kesatuan sistem infromasi. Pengelolaan website UPT. LLKK yang terintegrasi dengan media sosial akan meningkatkan efisiensi penyebaran informasi karena masyarakat semakin mudah untuk mengakses hanya dengan bantu kata kunci dalam mesin pencari internet. Perkembangan media sosial dan website dinilai sangat relevan dengan kondisi saat ini, sehingga perlu dilakukan pengelolaan pada sistem informasi tersebut untuk pengembangan kinerja UPT. LLKK
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