scholarly journals DESIGN WAVES AND THEIR PROBABILITY DENSITY FUNCTIONS

1988 ◽  
Vol 1 (21) ◽  
pp. 61 ◽  
Author(s):  
J. Rossouw
Keyword(s):  
Probability Distributions ◽  
Confidence Bands ◽  
Data Uncertainty ◽  
Data Set ◽  
Wave Heights ◽  
Period Wave ◽  
Best Fit ◽  
Selection Of ◽  
Made In

Design wave heights were estimated from measured data using a virtually continuous data set consisting of 8 years of waverider data. Evidence is given which shows that waveriders tend to malfunction during storms. Special care was taken to select independant and identically distributed samples from the data before fitting a number of probability distributions to the selected wave heights. Bootstrap techniques were used to select the models that give the best fit to the data as well as to determine the confidence bands for the predicted design wave heights. It is shown that once the model for the long term distribution of wave height is chosen, relatively narrow confidence bands can be obtained for the most probable value of up to the 100 year return period wave if maximum use is made of the available data. Uncertainty about the selection of the model and the representativeness of the measurements however reduces the usefulness of these confidence bands. A plea is also made in the paper to stop using the concept of a wave with a certain recurrence interval but rather to specify a wave with a given risk of being exceeded within the design life of the structure.

A soot prediction for a taxi cycle of a diesel engine

2008 ◽  
Vol 222 (10) ◽  
pp. 1879-1881
Author(s):  
A A Stotsky
Keyword(s):  
Steady State ◽  
Diesel Engine ◽  
Accumulation Rate ◽  
New Method ◽  
Engine Test ◽  
Data Set ◽  
Model Based ◽  
Selection Of ◽  
Made In

The time and cost associated with running long-term tests to acquire data on the soot percentage in the oil of a diesel engine necessitate the development of a new method for a model-based prediction of the soot accumulation performance. A new method for a model-based prediction of the soot percentage for a vehicle that sequentially executes a number of taxi cycles is proposed. The method is based on the steady-state soot accumulation rate measurements that are made in the engine test cell, and is used for a relative soot percentage judgement and selection of the most suitable data set among several candidates. The method provides significant savings with respect to the direct long-term soot percentage measurements on a vehicle.

scholarly journals Validation of the GRAPE single view aerosol retrieval for ATSR-2 and insights into the long term global AOD trend over the ocean

2010 ◽  
Vol 10 (10) ◽  
pp. 4849-4866 ◽  
Author(s):  
G. E. Thomas ◽  
C. A. Poulsen ◽  
R. Siddans ◽  
A. M. Sayer ◽  
E. Carboni ◽  
...  
Keyword(s):  
Data Set ◽  
Single View ◽  
Cloud Parameters ◽  
Aerosol Retrieval ◽  
Time Period ◽  
Orbital Drift ◽  
Along Track ◽  
Best Fit ◽  
Good Agreement

Abstract. The Global Retrieval of ATSR Cloud Parameters and Evaluation (GRAPE) project has produced a global data-set of cloud and aerosol properties from the Along Track Scanning Radiometer-2 (ATSR-2) instrument, covering the time period 1995–2001. This paper presents the validation of aerosol optical depths (AODs) over the ocean from this product against AERONET sun-photometer measurements, as well as a comparison to the Advanced Very High Resolution Radiometer (AVHRR) optical depth product produced by the Global Aerosol Climatology Project (GACP). The GRAPE AOD over ocean is found to be in good agreement with AERONET measurements, with a Pearson's correlation coefficient of 0.79 and a best-fit slope of 1.0±0.1, but with a positive bias of 0.08±0.04. Although the GRAPE and GACP datasets show reasonable agreement, there are significant differences. These discrepancies are explored, and suggest that the downward trend in AOD reported by GACP may arise from changes in sampling due to the orbital drift of the AVHRR instruments.

scholarly journals A SMARTPHONE-BASED 3D PIPELINE FOR THE CREATIVE INDUSTRY – THE REPLICATE EU PROJECT

2017 ◽  
Vol XLII-2/W3 ◽  
pp. 535-541 ◽  
Author(s):  
E. Nocerino ◽  
F. Lago ◽  
D. Morabito ◽  
F. Remondino ◽  
L. Porzi ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Point Clouds ◽  
First Year ◽  
Automated Generation ◽  
Dense Point ◽  
Modelling Techniques ◽  
Eu Project ◽  
Selection Of ◽  
Made In

During the last two decades we have witnessed great improvements in ICT hardware and software technologies. Three-dimensional content is starting to become commonplace now in many applications. Although for many years 3D technologies have been used in the generation of assets by researchers and experts, nowadays these tools are starting to become commercially available to every citizen. This is especially the case for smartphones, that are powerful enough and sufficiently widespread to perform a huge variety of activities (e.g. paying, calling, communication, photography, navigation, localization, etc.), including just very recently the possibility of running 3D reconstruction pipelines. The REPLICATE project is tackling this particular issue, and it has an ambitious vision to enable ubiquitous 3D creativity via the development of tools for mobile 3D-assets generation on smartphones/tablets. This article presents the REPLICATE project’s concept and some of the ongoing activities, with particular attention being paid to advances made in the first year of work. Thus the article focuses on the system architecture definition, selection of optimal frames for 3D cloud reconstruction, automated generation of sparse and dense point clouds, mesh modelling techniques and post-processing actions. Experiments so far were concentrated on indoor objects and some simple heritage artefacts, however, in the long term we will be targeting a larger variety of scenarios and communities.

Pipeline Maintenance in Geotechnically Unstable Areas: A Case Study

2000 ◽  
Author(s):  
Michelle L. Sorensen
Keyword(s):  
Risk Mitigation ◽  
Probability Distributions ◽  
Slope Instability ◽  
Ground Movement ◽  
Data Uncertainty ◽  
Strain Gauges ◽  
Mitigation Options ◽  
Soil Movement ◽  
Fort Mcmurray

The 22″ Alberta Oilsands Pipeline transports synthetic crude oil from Syncrude Canada Limited in Fort McMurray to Edmonton, Alberta. The pipeline crosses the House River approximately 100 kilometers south of Fort McMurray. The slope has been monitored since 1991 by three slope indicators. A finite element stress analysis indicated that total ground movement since installation in 1977 could correspond to pipeline compressive strains in excess of 0.32%, a level of risk unacceptable to the pipeline owner. A probability-based model was developed to determine cost and benefit of risk mitigation options. Parameters such as soil movement and pipe strain were input as probability distributions. The mitigation options included: reduce slope instability; reduce pipe stress; reduce pipe-to-soil interaction; implement long term monitoring; determine current pipe strain level (to decrease data uncertainty); do nothing. A Monte Carlo simulation was used to establish probability of failure and probable cost distributions for each option. The results were presented as a combined cost of failure and mitigation over 10 years. The analysis indicated that the optimum solution was to remove the existing soil traction loading on the pipe and mitigate long-term slope movement. The decision was made to relieve the pipe strain by excavating. Current pipe strain was measured in situ using residual strain measurement. Long term strain gauges were installed. Slope mitigation was deferred until the strain gauges indicate total pipeline strain levels approaching 0.32%.

scholarly journals EXTREME WAVE PREDICTION USING DIRECTIONAL DATA

1986 ◽  
Vol 1 (20) ◽  
pp. 11
Author(s):  
M.C. Deo ◽  
R. Burrows
Keyword(s):  
Directional Data ◽  
Irish Sea ◽  
Data Set ◽  
Wave Data ◽  
The North ◽  
Wave Heights ◽  
Directional Wave ◽  
The Irish Sea ◽  
Height Predictions

Potential inconsistencies in the predictions of long term wave heights can be experienced as a result of different methods of analysis possible when using directional wave data. This paper attempts to illustrate some of them. It involves analysis of two sets of directional wave data - one froa a coastal location in the Irish Sea and another from an offshore location in the North Sea. An attempt is made to eliminate the discrepancies between the long term return-value wave height predictions based upon the conditional height distributions associa ted with different direction sectors and those derived from the oonl-directional data set.

scholarly journals REALITA AND THE VILLAGE FUNDS IN INDONESIA

2020 ◽  
Vol 3 (12) ◽  
pp. 158-164
Author(s):  
Farid Th. Musa ◽  
Yudianto R. Takuloe
Keyword(s):  
Rural Communities ◽  
Community Involvement ◽  
Daily Lives ◽  
Negative Effect ◽  
The Subject ◽  
The Republic ◽  
The Village ◽  
Selection Of ◽  
Made In

Village funds are a form of the Republic of Indonesia's government program which launched the concept of Building Indonesia from Pingiran. This program is closely related to the empowerment of rural communities to improve community welfare. The budget, which has been launched in the amount of billions of rupiah for rural communities, is expected to bring changes in their daily lives. Community involvement in this program is intended so that the community is no longer the object of development but becomes the subject of development. On the other hand, village funds also have a negative effect, namely misuse of these funds by village officials. To explore the reality of this village fund, data on the use of funds has been used since its inception until now. To reveal this phenomenon, a study is needed to reveal the usage. This research was conducted in Gorontalo Regency which has 18 Districts, 191 Villages, which quantitatively has the largest number of villages in Gorontalo Province. Another thing about the selection of Gorontalo District as a research location is based on the consideration of having a coastal village and an agricultural village. The existence of these two villages is interesting to conduct research on village funds. In this study using qualitative methods with data collection stages, namely: initial observation, interviews and documents. The data analysis used was Huberman and Miles. The choice of the analysis method is based on the consideration of uncovering a phenomenon and nomena, which requires the researcher to directly associate and live with the community to be studied.Efforts made in the use of village funds are oriented towards long-term needs

scholarly journals Magmatic Processes at La Soufrière de Guadeloupe: Insights From Crystal Studies and Diffusion Timescales for Eruption Onset

2021 ◽  
Vol 9 ◽  
Author(s):  
Abigail Metcalfe ◽  
Séverine Moune ◽  
Jean-Christophe Komorowski ◽  
Geoff Kilgour ◽  
David E. Jessop ◽  
...  
Keyword(s):  
Large Scale ◽  
Probability Distributions ◽  
Crisis Response ◽  
Data Set ◽  
Eruption Style ◽  
Magmatic Processes ◽  
Backscattered Electron ◽  
And Diffusion ◽  
Magmatic Timescales

Signals of volcanic unrest do not usually provide insights into the timing, size and style of future eruptions, but detailed analysis of past eruptions may uncover patterns that can be used to understand future eruptive behavior. Here, we examine basaltic-andesitic to andesitic eruption deposits from La Soufrière de Guadeloupe, covering a range of eruption styles, ages and magnitudes. Our work is timely given unrest at La Soufrière de Guadeloupe has increased over the last 25 years. We constrain the timescales of magmatic processes preceding four eruptions: 1657 Cal. CE (Vulcanian), 1010 Cal. CE (Plinian), ∼341 Cal. CE (Strombolian) and 5680 Cal. BCE (La Soufrière de Guadeloupe’s first known Plinian eruption). Using crystal-specific analyses of diffusion in orthopyroxenes, we calculate the timescale occurring between the last recharge/mixing event in the magma reservoir and the eruption. We use backscattered electron images, coupled with EMPA of the outermost crystal rim, to derive magmatic timescales. We model the timescale populations as random processes whose probability distributions provide expected (“mean”) timescales and the associated standard errors for each eruption. This provides a new statistical method for comparing magmatic timescales between disparate eruptions. From this, we obtain timescales of magma storage at La Soufrière de Guadeloupe ranging from 34.8 ± 0.4 days to 847 ± 0.4 days, with no clear distinction between eruption style/size and timescales observed. Based on these data, magmatic interaction timescales are a poor predictor of eruption style/size. This study shows that magmatic processes prior to eruption can occur on relatively short timescales at La Soufrière de Guadeloupe. Further to this basaltic-andesitic to andesitic volcanoes can rapidly produce large-scale eruptions on short timescales. These relatively short timescales calculated for volcanic processes at this system constitute a critical new data set and warrant an urgency in enhancing modeling and interpretation capabilities for near-real time monitoring data. These integrated efforts will improve early warning, eruption forecasting and crisis response management for different scenarios, as well as planning for long-term risk reduction.

scholarly journals Further study of fOF2 and M(3000)F2 in different solar cycles

1994 ◽  
Vol 37 (2) ◽  
Author(s):  
P. A. Bradley
Keyword(s):  
Sunspot Number ◽  
Solar Cycles ◽  
Long Term Effects ◽  
Best Fit ◽  
Selection Of

Measured monthly median fOF2 and M(3000)F2 for Slough over six solar cycles from 1932 onwards are examined for a selection of hours and months. Data are shown as a function of twelve-monthly smoothed sunspot number. Comparisons are made for the different solar cycles and for the rising and falling halves of each cycle. Measurements for individual cycles are compared with best-fit parabolic regression lines over all cycles to investigate possible systematic long-term effects.

scholarly journals Modelling the spatial demography of Atlantic cod (Gadus morhua) on the European continental shelf

2006 ◽  
Vol 63 (5) ◽  
pp. 1027-1048 ◽  
Author(s):  
Jessica M Andrews ◽  
William SC Gurney ◽  
Michael R Heath ◽  
Alejandro Gallego ◽  
Carl M O'Brien ◽  
...  
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Statistical Tests ◽  
Data Set ◽  
Spatial Demography ◽  
Trawl Fishery ◽  
The North ◽  
European Shelf ◽  
Best Fit

Atlantic cod (Gadus morhua) stocks across the North Atlantic have been subject to intense fishing pressure during the 20th century, and some stocks have suffered well-documented collapses. On the European shelf, cod are widely but heterogeneously distributed and are caught as part of a multispecies trawl fishery. There is a growing body of evidence that this stock is composed of substocks with potentially distinct demographic properties. As a first step towards the development of management methodologies that reflect this spatial and biological complexity, we present a spatially and physiologically explicit model describing the demography and distribution of cod on the European shelf. The computational efficiency of our implementation enables numerical parameter optimization, thus facilitating formal statistical tests of structural hypotheses. We use these methods to fit model variants embodying a variety of hypotheses about the movements of settled fish to a data set including spatial distribution information derived from International Bottom Trawl Surveys. The best-fit model emerging from this study is then used to investigate the potential effects of long-term application of a series of regional fishing closure policies.

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