scholarly journals Gear-Type Glide-Meter as an Instrument For Forecasting Full-Depth Avalanches

1980 ◽  
Vol 26 (94) ◽  
pp. 521-521
Author(s):  
Yutaka Yamada
Keyword(s):  
Relative Frequency ◽  
Field Measurements ◽  
Short Term ◽  
Term Variation ◽  
Long Term Variations ◽  
Angle Of Rotation

AbstractThis paper is concerned with the variation of snow glide and its predictability in full-depth avalanches. From field measurements of snow glide using a newly developed gear-type glide-meter which is fixed to the ground and which measures the amount of glide as the angle of rotation of a gear, the following characteristics are deduced: (1) the variation of gliding rate is composed of both short-term and long-term variations, and (2) the existence of correlation between the short-term variation and the relative frequency of avalanches is recognized.

scholarly journals Gear-Type Glide-Meter as an Instrument For Forecasting Full-Depth Avalanches

1980 ◽  
Vol 26 (94) ◽  
pp. 521
Author(s):  
Yutaka Yamada
Keyword(s):  
Relative Frequency ◽  
Field Measurements ◽  
Short Term ◽  
Term Variation ◽  
Long Term Variations ◽  
Angle Of Rotation

Abstract This paper is concerned with the variation of snow glide and its predictability in full-depth avalanches. From field measurements of snow glide using a newly developed gear-type glide-meter which is fixed to the ground and which measures the amount of glide as the angle of rotation of a gear, the following characteristics are deduced: (1) the variation of gliding rate is composed of both short-term and long-term variations, and (2) the existence of correlation between the short-term variation and the relative frequency of avalanches is recognized.

scholarly journals Satellites, Self-reports, and Submersion: Exposure to Floods in Bangladesh

2015 ◽  
Vol 105 (5) ◽  
pp. 232-236 ◽  
Author(s):  
Raymond Guiteras ◽  
Amir Jina ◽  
A. Mushfiq Mobarak
Keyword(s):  
Climate Change ◽  
Economic Activity ◽  
Climate Change Impacts ◽  
Objective Data ◽  
Short Term ◽  
Temperature And Precipitation ◽  
Flood Exposure ◽  
Self Reports ◽  
Term Variation

A burgeoning “Climate-Economy” literature has uncovered many effects of changes in temperature and precipitation on economic activity, but has made considerably less progress in modeling the effects of other associated phenomena, like natural disasters. We develop new, objective data on floods, focusing on Bangladesh. We show that rainfall and self-reported exposure are weak proxies for true flood exposure. These data allow us to study adaptation, giving accurate measures of both long-term averages and short term variation in exposure. This is important in studying climate change impacts, as people will not only experience new exposures, but also experience them differently.

Radial Velocity Variability of K Giants

1991 ◽  
Vol 130 ◽  
pp. 386-388
Author(s):  
Artie P. Hatzes ◽  
William D. Cochran
Keyword(s):  
Radial Velocity ◽  
Active Regions ◽  
Peak Amplitude ◽  
Short Term ◽  
Rotational Modulation ◽  
Surface Active ◽  
Radial Velocity Data ◽  
Long Term Variations ◽  
K Giants

AbstractAt McDonald Observatory we have been monitoring the relative radial velocities of a sample of K giants. The technique employed uses the telluric O2 lines near 6300 Å as a reference for measuring the stellar line shifts. We demonstrate that precisions of 10 m s−1 are possible with this technique. We present radial velocity data covering a 2 year time span for α Boo, α Tau, and β Gem. All of these stars show both long term variations (~ several hundred days) with a peak-to-peak amplitude of about 400 m s−1 and short term variations (~ few days) with a peak-to-peak amplitude of about 100 m s−1. The long term variations may be due to the rotational modulation of surface active regions whereas the short term variations may be indicative of pulsations.

scholarly journals The Long-term Variation in the RV Tauri Star U Mon

1995 ◽  
Vol 155 ◽  
pp. 409-410 ◽  
Author(s):  
Karen R. Pollard ◽  
P. L. Cottrell
Keyword(s):  
High Resolution ◽  
Light Curve ◽  
Radial Velocity ◽  
Tauri Star ◽  
Short Term ◽  
Instability Strip ◽  
Term Variation ◽  
Velocity Variations

The RV Tauri stars are semiregular pulsating variables located in the brightest part of the Cepheid II instability strip. They have a characteristic light curve of alternating deep and shallow minima. A subset of the RV Tauri stars (the RVb subclass) exhibit long-term (500 to 2600 day) light and radial velocity variations. Although it is well established that the short-term variations are due to pulsations, the long-term behaviour is not well understood.BVRI photometry and high-resolution spectra of U Mon (the brightest member of the RVb subclass) were obtained at the Mt John University Observatory (MJUO) between 1990 Aug and 1994 May. The light and colour curves obtained clearly show the long-term variation in U Mon (Fig. 1(a) and (b)). The reddest colours occur slightly later than the long-term minimum in the light curve. The short-term light and colour variations are ‘damped’ at the long-term minimum.

A LRFD Code Format for Accounting Long-Term Variation of Multiple Load Effects

2002 ◽  
Author(s):  
Paulo Mauricio Videiro ◽  
Luis Volnei Sudati Sagrilo ◽  
Edison Castro Prates de Lima
Keyword(s):  
Extreme Value ◽  
Structural Components ◽  
Short Term ◽  
Resistance Factors ◽  
Term Variation ◽  
Load And Resistance Factors ◽  
Load Effects ◽  
Code Format ◽  
Multiple Load

This paper proposes a Load and Resistance Factors Design (LRFD) code format for structural components of offshore structures under multiple load effects. This code format accounts for the long-term variation of seastate and the actual correlation between dynamic load effects due to environmental actions. Ultimate limit states are formulated in terms of an Interaction Ratio (IR) random variable, such that the long-term extreme value of IR greater than unity means component failure. The long-term distribution of IR is obtained by combining the distribution of each short-term seastate. The short-term response of the generally nonlinear IR is determined by time domain simulation, taking into account partial load and resistance factors. The IR short-term distribution may be fitted, for instance, by using Rayleigh or Weibull distribution. The main advantages of the proposed code format are: • This code format accounts implicitly and correctly for the actual correlation among all dynamic environmental load processes. • Structural designers have used interaction ratios for a long time. Hence, it is straightforward to evolve from a deterministic stage of looking for IR < 1, as in old Working Stress Design codes, to a code format where the aim is to design structural components with long term IR extreme value < 1. The feasibility of the proposed code format is demonstrated by calibrating partial factors for beam-column cylindrical members based on components of a Floating Production System Semi-submersible hull.

scholarly journals Temporal and spatial analysis of ozone concentrations in Europe based on time scale decomposition and a multi-clustering approach

2019 ◽  
Author(s):  
Eirini Boleti ◽  
Christoph Hueglin ◽  
Stuart K. Grange ◽  
André S. H. Prévôt ◽  
Satoshi Takahama
Keyword(s):  
Time Scale ◽  
Seasonal Cycle ◽  
Clustering Algorithm ◽  
Short Term ◽  
Ozone Concentrations ◽  
Time Period ◽  
Term Variation ◽  
Long Term Trends ◽  
Time Scale Decomposition

Abstract. Air quality measures that were implemented in Europe in the 1990s resulted in reductions of ozone precursors concentrations. In this study, the effect of these reductions on ozone is investigated by analyzing surface measurements of ozone for the time period between 2000 and 2015. Using a non-parametric time scale decomposition methodology, the long-term, seasonal and short-term variation of ozone observations were extracted. A clustering algorithm was applied to the different time scale variations, leading to a classification of sites across Europe based on the temporal characteristics of ozone. The clustering based on the long-term variation resulted in a site type classification, while a regional classification was obtained based on the seasonal and short-term variations. Long-term trends of de-seasonalized mean and meteo-adjusted peak ozone concentrations were calculated across large parts of Europe for the time period 2000–2015. A multi-dimensional scheme was used for a detailed trend analysis, based on the identified clusters, which reflect precursor emissions and meteorological influence either on the inter-annual or the short-term time scale. Decreasing mean ozone concentrations at rural sites and increasing or stabilizing at urban sites were observed. At the same time downward trends for peak ozone concentrations were detected for all site types. The effect of hemispheric transport of ozone can be seen either in regions affected by synoptic patterns in the northern Atlantic or at sites located at remote high altitude locations. In addition, a reduction of the amplitude in the seasonal cycle of ozone was observed, and a shift in the occurrence of the seasonal maximum towards earlier time of the year. Finally, a reduced sensitivity of ozone to temperature was identified. It was concluded that long-term trends of mean and peak ozone concentrations are mostly controlled by precursors emissions changes, while seasonal cycle trends and changes in the sensitivity of ozone to temperature are driven by regional climatic conditions.

Empirical Procedures for Long-Term Prediction of Fatigue Damage for an Instrumented Marine Riser

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
C. Shi ◽  
L. Manuel ◽  
M. A. Tognarelli
Keyword(s):  
Fatigue Damage ◽  
Field Measurements ◽  
Damage Estimation ◽  
Current Profile ◽  
Short Term ◽  
Response Characteristics ◽  
Damage Rate ◽  
Using Data ◽  
Analytical Approaches

Slender marine risers used in deepwater applications can experience vortex-induced vibration (VIV). It is becoming increasingly common for field monitoring campaigns to be undertaken wherein data loggers such as strain sensors and/or accelerometers are installed on such risers to aid in VIV-related fatigue damage estimation. Such damage estimation relies on the application of empirical procedures that make use of the collected data. This type of damage estimation can be undertaken for different current profiles encountered. The empirical techniques employed make direct use of the measurements and key components in the analyszes (such as participating riser modes selected for use in damage estimation) are intrinsically dependent on the actual current profiles. Fatigue damage predicted in this manner is in contrast to analytical approaches that rely on simplifying assumptions on both the flow conditions and the response characteristics. Empirical fatigue damage estimates conditional on current profile type can account explicitly even for complex response characteristics, participating riser modes, etc. With significant amounts of data, it is possible to establish “short-term” fatigue damage rate distributions conditional on current type. If the relative frequency of different current types is known from metocean studies, the short-term fatigue distributions can be combined with the current distributions to yield integrated “long-term” fatigue damage rate distributions. Such a study is carried out using data from the Norwegian Deepwater Programme (NDP) model riser subject to several sheared and uniform current profiles and with assumed probabilities for different current conditions. From this study, we seek to demonstrate the effectiveness of empirical techniques utilized in combination with field measurements to predict the long-term fatigue damage and the fatigue failure probability.

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