On the impact of time scales on tail behavior of long-range dependent internet traffic

Abstract. Many fields, such as drought-risk assessment or reservoir management, can benefit from long-range streamflow forecasts. Climatology has long been used in long-range streamflow forecasting. Conditioning methods have been proposed to select or weight relevant historical time series from climatology. They are often based on general circulation model (GCM) outputs that are specific to the forecast date due to the initialisation of GCMs on current conditions. This study investigates the impact of conditioning methods on the performance of seasonal streamflow forecasts. Four conditioning statistics based on seasonal forecasts of cumulative precipitation and the standardised precipitation index were used to select relevant traces within historical streamflows and precipitation respectively. This resulted in eight conditioned streamflow forecast scenarios. These scenarios were compared to the climatology of historical streamflows, the ensemble streamflow prediction approach and the streamflow forecasts obtained from ECMWF System 4 precipitation forecasts. The impact of conditioning was assessed in terms of forecast sharpness (spread), reliability, overall performance and low-flow event detection. Results showed that conditioning past observations on seasonal precipitation indices generally improves forecast sharpness, but may reduce reliability, with respect to climatology. Conversely, conditioned ensembles were more reliable but less sharp than streamflow forecasts derived from System 4 precipitation. Forecast attributes from conditioned and unconditioned ensembles are illustrated for a case of drought-risk forecasting: the 2003 drought in France. In the case of low-flow forecasting, conditioning results in ensembles that can better assess weekly deficit volumes and durations over a wider range of lead times.

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GNSS-to-GNSS time offsets: study on the broadcast of a common reference time

GPS Solutions ◽

10.1007/s10291-020-01082-y ◽

2021 ◽

Vol 25 (2) ◽

Author(s):

Ilaria Sesia ◽

Giovanna Signorile ◽

Tung Thanh Thai ◽

Pascale Defraigne ◽

Patrizia Tavella

Keyword(s):

Time Scales ◽

Time Scale ◽

Reference Time ◽

Single Time ◽

Common Reference ◽

Prediction Quality ◽

Common Time ◽

Time Offset ◽

The Impact ◽

Low Uncertainty

AbstractWe present two different approaches to broadcasting information to retrieve the GNSS-to-GNSS time offsets needed by users of multi-GNSS signals. Both approaches rely on the broadcast of a single time offset of each GNSS time versus one common time scale instead of broadcasting the time offsets between each of the constellation pairs. The first common time scale is the average of the GNSS time scales, and the second time scale is the prediction of UTC already broadcast by the different systems. We show that the average GNSS time scale allows the estimation of the GNSS-to-GNSS time offset at the user level with the very low uncertainty of a few nanoseconds when the receivers at both the provider and user levels are fully calibrated. The use of broadcast UTC prediction as a common time scale has a slightly larger uncertainty, which depends on the broadcast UTC prediction quality, which could be improved in the future. This study focuses on the evaluation of two different common time scales, not considering the impact of receiver calibration, at the user and provider levels, which can nevertheless have an important impact on GNSS-to-GNSS time offset estimation.

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On the impact of long-range-dependent traffic in dimensioning ATM network buffer

Proceedings. IEEE INFOCOM '98, the Conference on Computer Communications. Seventeenth Annual Joint Conference of the IEEE Computer and Communications Societies. Gateway to the 21st Century (Cat. No.98CH36169) ◽

10.1109/infcom.1998.662947 ◽

2002 ◽

Author(s):

G.C. Lin ◽

T. Suda

Keyword(s):

Long Range ◽

Atm Network ◽

The Impact ◽

Network Buffer

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Strictly linear trinuclear Dy–Ca/Mg–Dy single-molecule magnets: the impact of long-range f–f ferromagnetic interactions on suppressing quantum tunnelling of magnetization leading to slow magnetic relaxation

Dalton Transactions ◽

10.1039/c7dt01395g ◽

2017 ◽

Vol 46 (25) ◽

pp. 8259-8268 ◽

Cited By ~ 6

Author(s):

Wan-Ying Zhang ◽

Yong-Mei Tian ◽

Hong-Feng Li ◽

Peng Chen ◽

Yi-Quan Zhang ◽

...

Keyword(s):

Long Range ◽

Single Molecule ◽

Magnetic Relaxation ◽

Single Molecule Magnets ◽

Quantum Tunnelling ◽

Trinuclear Complexes ◽

Slow Magnetic Relaxation ◽

Ferromagnetic Interactions ◽

The Impact

A series of linear trinuclear complexes Ln2M(OQ)8 [Ln(iii) = Dy and Er, M(ii) = Ca and Mg] were structurally and magnetically investigated.

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The impact of North American anthropogenic emissions and lightning on long-range transport of trace gases and their export from the continent during summers 2002 and 2004

Journal of Geophysical Research Atmospheres ◽

10.1029/2010jd014305 ◽

2011 ◽

Vol 116 (D7) ◽

Cited By ~ 15

Author(s):

Matus Martini ◽

Dale J. Allen ◽

Kenneth E. Pickering ◽

Georgiy L. Stenchikov ◽

Andreas Richter ◽

...

Keyword(s):

Long Range ◽

North American ◽

Trace Gases ◽

Long Range Transport ◽

Anthropogenic Emissions ◽

Range Transport ◽

The Impact

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Effects of Solar UV Radiation on Morphology and Photosynthesis of Filamentous Cyanobacterium Arthrospira platensis

Applied and Environmental Microbiology ◽

10.1128/aem.71.9.5004-5013.2005 ◽

2005 ◽

Vol 71 (9) ◽

pp. 5004-5013 ◽

Cited By ~ 105

Author(s):

Hongyan Wu ◽

Kunshan Gao ◽

Virginia E. Villafañe ◽

Teruo Watanabe ◽

E. Walter Helbling

Keyword(s):

Solar Radiation ◽

Cell Density ◽

Uv Radiation ◽

Time Scales ◽

Morphological Development ◽

Filamentous Cyanobacterium ◽

Solar Uv Radiation ◽

Solar Uv ◽

Adaptive Time ◽

The Impact

ABSTRACT To study the impact of solar UV radiation (UVR) (280 to 400 nm) on the filamentous cyanobacterium Arthrospira (Spirulina) platensis, we examined the morphological changes and photosynthetic performance using an indoor-grown strain (which had not been exposed to sunlight for decades) and an outdoor-grown strain (which had been grown under sunlight for decades) while they were cultured with three solar radiation treatments: PAB (photosynthetically active radiation [PAR] plus UVR; 280 to 700 nm), PA (PAR plus UV-A; 320 to 700 nm), and P (PAR only; 400 to 700 nm). Solar UVR broke the spiral filaments of A. platensis exposed to full solar radiation in short-term low-cell-density cultures. This breakage was observed after 2 h for the indoor strain but after 4 to 6 h for the outdoor strain. Filament breakage also occurred in the cultures exposed to PAR alone; however, the extent of breakage was less than that observed for filaments exposed to full solar radiation. The spiral filaments broke and compressed when high-cell-density cultures were exposed to full solar radiation during long-term experiments. When UV-B was screened off, the filaments initially broke, but they elongated and became loosely arranged later (i.e., there were fewer spirals per unit of filament length). When UVR was filtered out, the spiral structure hardly broke or became looser. Photosynthetic O2 evolution in the presence of UVR was significantly suppressed in the indoor strain compared to the outdoor strain. UVR-induced inhibition increased with exposure time, and it was significantly lower in the outdoor strain. The concentration of UV-absorbing compounds was low in both strains, and there was no significant change in the amount regardless of the radiation treatment, suggesting that these compounds were not effectively used as protection against solar UVR. Self-shading, on the other hand, produced by compression of the spirals over adaptive time scales, seems to play an important role in protecting this species against deleterious UVR. Our findings suggest that the increase in UV-B irradiance due to ozone depletion not only might affect photosynthesis but also might alter the morphological development of filamentous cyanobacteria during acclimation or over adaptive time scales.

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An Assessment on the Impact of the Solar Spectrum on Different PV Materials in Sunny Sites by Using Different Time Scales

Renewable Energy in the Service of Mankind Vol II ◽

10.1007/978-3-319-18215-5_42 ◽

2015 ◽

pp. 477-481

Author(s):

G. Nofuentes ◽

M. Alonso-Abella ◽

M. Torres-Ramírez ◽

F. Chenlo

Keyword(s):

Time Scales ◽

Solar Spectrum ◽

The Impact ◽

Different Time Scales

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Long-range Transport Impacts on Surface Aerosol Concentrations and the Contributions to Haze Events in China: an HTAP2 Multi-Model Study

10.5194/acp-2018-91 ◽

2018 ◽

Cited By ~ 1

Author(s):

Xinyi Dong ◽

Joshua S. Fu ◽

Qingzhao Zhu ◽

Jian Sun ◽

Jiani Tan ◽

...

Keyword(s):

East Asia ◽

Long Range ◽

Source Region ◽

Long Range Transport ◽

Special Focus ◽

Anthropogenic Emission ◽

Multiple Model ◽

Aerosol Mass Concentration ◽

Range Transport ◽

The Impact

Abstract. Haze has been severely affecting the densely populated areas in China during recent years. While many of the pilot studies have been devoted to investigate the contributions from local anthropogenic emission, limited attention has been paid to the influence from long-range transport. In this study, we use simulations from 6 participating models supplied through the Task Force on Hemispheric Transport of Air Pollution Phase 2 (HTAP2) exercise to investigate the long-range transport impact of Europe and Russia/Belarussia/Ukraine on the surface air quality in East Asia, with special focus on their contributions during the haze episodes over China. The impact of 20 % anthropogenic emission perturbation from the source region is extrapolated by a factor of 5 to estimate the full impact. We find that the full impacts from EUR and RBU are 0.99 µg/m3 (3.1 %) and 1.32 µg/m3 (4.1 %) respectively during haze episodes, while the annual averaged full impacts are only 0.35 µg m3 (1.7 %) and 0.53 µg/m3 (2.6 %) respectively. By estimating the aerosol response within and above the planetary boundary layer (PBL), we find that long-range transport within the PBL contributes to 22–38 % of the total column density of aerosol response. Comparison with the HTAP Phase 1 (HTAP1) assessment reveals that from 2000 to 2010, the long-range transport from Europe to East Asia has decreased significantly by a factor of 2–10 for surface aerosol mass concentration due to the simultaneous emission reduction in source region and emission increase in the receptor region. By investigating the visibility response, we find that the long-range transport from the Europe and RBU region increases the number of haze events in China by 0.15 % and 0.11 % respectively, and the North China Plain and southeast China receives 1–3 extra haze days. This study is the first investigation into the contribution of long-range transport to haze in China with multiple model experiments.

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Time-scale dependent mechanism of atmospheric CO2 concentration drivers of watershed water-energy balance

10.5194/egusphere-egu21-8128 ◽

2021 ◽

Author(s):

Jing Zhao

Keyword(s):

Energy Balance ◽

River Basin ◽

Time Scales ◽

Time Scale ◽

Hydrological Processes ◽

Multiple Time Scales ◽

Multiple Time ◽

The Wei River Basin ◽

Balance Dynamics ◽

The Impact

The elevated atmospheric carbon dioxide concentration (CO2), as a key variable linking human activities and climate change, seriously affects the watershed hydrological processes. However, whether and how atmospheric CO2 influences the watershed water-energy balance dynamics at multiple time scales have not been revealed. Based on long-term hydrometeorological data, the variation of non-stationary parameter n series in the Choudhury's equation in the mainstream of the Wei River Basin (WRB), the Jing River Basin (JRB) and Beiluo River Basin (BLRB), three typical Loess Plateau regions in China, was examined. Subsequently, the Empirical Mode Decomposition method was applied to explore the impact of CO2 on watershed water-energy balance dynamics at multiple time scales. Results indicate that (1) in the context of warming and drying condition, annual n series in the WRB displays a significantly increasing trend, while that in the JRB and BLRB presents non-significantly decreasing trends; (2) the non-stationary n series was divided into 3-, 7-, 18-, exceeding 18-year time scale oscillations and a trend residual. In the WRB and BLRB, the overall variation of n was dominated by the residual, whereas in the JRB it was dominated by the 7-year time scale oscillation; (3) the relationship between CO2&#160;concentration and n series was significant in the WRB except for 3-year time scale. In the JRB, CO2&#160;concentration and n series were significantly correlated on the 7- and exceeding 7-year time scales, while in the BLRB, such a significant relationship existed only on the 18- and exceeding 18-year time scales. (4) CO2-driven temperature rise and vegetation greening elevated the aridity index and evaporation ratio, thus impacting watershed water-energy balance dynamics. This study provided a deeper explanation for the possible impact of CO2 concentration on the watershed hydrological processes.

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