scholarly journals The Cross-Dike Failure Probability by Wave Overtopping over Grass-Covered and Damaged Dikes

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 690
Author(s):  
Vera M. van Bergeijk ◽  
Vincent A. Verdonk ◽  
Jord J. Warmink ◽  
Suzanne J. M. H. Hulscher
Keyword(s):  
Failure Probability ◽  
Probability Distributions ◽  
Grass Cover ◽  
Wave Overtopping ◽  
Erosion Depth ◽  
Strength Failure ◽  
Slope Change ◽  
The Cross ◽  
Dike Failure

A probabilistic framework is developed to calculate the cross-dike failure probability by overtopping waves on grass-covered dikes. The cross-dike failure probability of dike profiles including transitions and damages can be computed to find the most likely location of failure and quantify the decrease in the failure probability when this location is strengthened. The erosion depth along the dike profile is calculated using probability distributions for the water level, wind speed and dike cover strength. Failure is defined as the exceedance of 20 cm erosion depth when the topsoil of the grass cover is eroded. The cross-dike failure probability shows that the landward toe is the most vulnerable location for wave overtopping. Herein, the quality of the grass cover significantly affects the failure probability up to a factor 1000. Next, the failure probability for different types of damages on the landward slope are calculated. In case of a damage where the grass cover is still intact and strong, the dike is most likely to fail at the landward toe due to high flow velocity and additional load due to the slope change. However, when the grass cover is also damaged, the probability of failure at the damage is between 4 and 125 times higher than for a regular dike profile.

scholarly journals DESTRUCTIVE WAVE OVERTOPPING TESTS ON GRASS COVERED LANDWARD SLOPES OF DIKES AND TRANSITIONS TO BERMS

2011 ◽  
Vol 1 (32) ◽  
pp. 8 ◽  
Author(s):  
Gosse Jan Steendam ◽  
Jentsje W. Van der Meer ◽  
Bianca Hardeman ◽  
André Van Hoven
Keyword(s):  
The Netherlands ◽  
Grass Cover ◽  
Wave Overtopping ◽  
Sand Core ◽  
Boulder Clay ◽  
River Dike

In 2009 tests have been performed at the Afsluitdijk, the closure dike of Lake IJssel in the Netherlands. This dike has a sand core covered by layers of clay and boulder clay, and a grass cover. In 2010 succeeding tests were performed at a river dike near Zwolle. This dike was a sand dike with a grass cover. In all of these tests research was performed on the behaviour of the grass cover on the landward slope of the dikes. Furthermore, the influence on erodibility of the grass cover caused by damage of the grass cover by mice, moles or other influences like tractor tracks were investigated. Also the influence of obstacles or other elements, which may be present at dikes, was part of the investigations (tree, stairs, fence, maintenance road). It was observed that all of these influences are to some extent contributing to a decrease of the resistance against failure.

Pacific Salmon Environmental and Life History Models: Advancing Science for Sustainable Salmon in the Future

2009 ◽  
Keyword(s):  
Model Uncertainty ◽  
Pacific Salmon ◽  
Probability Distributions ◽  
Cultural Resources ◽  
Policy Makers ◽  
Recovery Planning ◽  
Habitat Recovery ◽  
Alternative Scenarios ◽  
The One

<em>Abstract.</em>—Natural resource management requires difficult decisions, broad societal costs, and sacrifices from private landowners and public agencies. With so many financial, ecological and cultural resources at stake, policy-makers, managers, and citizens need scientific predictions that can help resolve conflicts and balance the often competing needs of ecosystems and communities. Modeled information is essential for meeting this need. The words “model uncertainty” are often misinterpreted as describing a lack of knowledge about model output. In fact, they describe knowledge, not only of the one most likely modeled estimate, but also of all the other possible estimates that the model might have provided, and their likelihood. We present six case studies, from salmon habitat recovery planning, illustrating how scientists can provide more useful products by describing distributions of possible outcomes as formal probability distributions, as confidence intervals, or as descriptions of alternative scenarios. In terms of management effectiveness, the communication and use of model uncertainty can be at least as important as the quality of the original model.

A Relative Fractal Dimension Spectrum for a Perceptual Complexity Measure

2011 ◽  
pp. 381-395
Author(s):  
W. Kinsner ◽  
R. Dansereau
Keyword(s):  
Fractal Dimension ◽  
Probability Distributions ◽  
Objective Measure ◽  
Mean Opinion Score ◽  
Perceptual Quality ◽  
Dimension Spectrum ◽  
Opinion Score ◽  
Single Scale ◽  
Scale Measure

This article presents a derivation of a new relative fractal dimension spectrum, DRq, to measure the dis-similarity between two finite probability distributions originating from various signals. This measure is an extension of the Kullback-Leibler (KL) distance and the Rényi fractal dimension spectrum, Dq. Like the KL distance, DRq determines the dissimilarity between two probability distibutions X and Y of the same size, but does it at different scales, while the scalar KL distance is a single-scale measure. Like the Rényi fractal dimension spectrum, the DRq is also a bounded vectorial measure obtained at different scales and for different moment orders, q. However, unlike the Dq, all the elements of the new DRq become zero when X and Y are the same. Experimental results show that this objective measure is consistent with the subjective mean-opinion-score (MOS) when evaluating the perceptual quality of images reconstructed after their compression. Thus, it could also be used in other areas of cognitive informatics.

Bayesian Reliability Sampling Plans under the Conditions of Rayleigh-Inverse-Rayleigh Distribution

2014 ◽  
Vol 0 (0) ◽  
Author(s):  
S. Kalaiselvi ◽  
A. Loganathan ◽  
R. Vijayaraghavan
Keyword(s):  
Probability Distributions ◽  
Rayleigh Distribution ◽  
Predictive Distribution ◽  
Life Testing ◽  
Sampling Plans ◽  
Sampling Inspection ◽  
Single Sampling Plan ◽  
Reliability Sampling Plans ◽  
Quality Of Products

AbstractReliability sampling plans are used to take decisions on the disposition of lots based on life testing of products. Such plans are developed taking into the consideration of relevant probability distributions of the lifetimes of the products under testing. When the quality of products varies over lots, then a predictive distribution of the lifetime should be used to design sampling plans. In this paper, designing of reliability single sampling plan based on the predictive distribution of the lifetime is considered. It is assumed that sampling inspection is carried out through life testing of products with hybrid censoring. The predictive distribution is obtained assuming that the probability distribution of the lifetime of the product is Rayleigh and the process parameter has an inverse-Rayleigh prior. Plan parameters are determined using hypergeometric, binomial and Poisson probabilities, providing protection to both producer as well as consumer.

Are Color Categories Innate or Internalized? Hypotheses and Implications

2005 ◽  
Vol 5 (3-4) ◽  
pp. 265-292 ◽  
Author(s):  
David Bimler
Keyword(s):  
Historical Development ◽  
Color Categories ◽  
The Cross ◽  
Special Circumstances ◽  
Cross Language ◽  
Experiential Quality ◽  
The Way

AbstractThe considerable agreement across languages in the way they categorize the color domain, despite independent historical development, demands an explanation. One option is to postulate a universal innate representation of the color categories, 'hardwired' into each observer's brain. An alternative is that observers internalize their color categories through a process of cultural (linguistic) transmission, constrained by some kind of 'optimality hypothesis' to account for the cross-language agreement. A number of optimality hypotheses are reviewed. It is tempting to believe that the vivid experiential quality of the categories can only be explained if they are determined by innate representations rather than by linguistic imprinting. However, linguistic transmission of color categories – perturbed from their optimal boundaries by special circumstances – fits best with the experience of dichromats. Even for the 'primary hue' categories, where the case for innate representations should be strongest, the evidence is far from convincing.

scholarly journals Many hepatitis C reinfections that spontaneously clear may be undetected: Markov-chain Monte Carlo analysis of observational study data

2015 ◽  
Vol 12 (104) ◽  
pp. 20141197 ◽  
Author(s):  
Rachel Sacks-Davis ◽  
Emma McBryde ◽  
Jason Grebely ◽  
Margaret Hellard ◽  
Peter Vickerman
Keyword(s):  
Hepatitis C ◽  
Bayesian Model ◽  
Prior Probability ◽  
Probability Distributions ◽  
Monte Carlo Analysis ◽  
Study Data ◽  
Spontaneous Clearance ◽  
Simulation Studies ◽  
Reinfection Rate

Hepatitis C virus (HCV) reinfection rates are probably underestimated due to reinfection episodes occurring between study visits. A Markov model of HCV reinfection and spontaneous clearance was fitted to empirical data. Bayesian post-estimation was used to project reinfection rates, reinfection spontaneous clearance probability and duration of reinfection. Uniform prior probability distributions were assumed for reinfection rate (more than 0), spontaneous clearance probability (0–1) and duration (0.25–6.00 months). Model estimates were 104 per 100 person-years (95% CrI: 21–344), 0.84 (95% CrI: 0.59–0.98) and 1.3 months (95% CrI: 0.3–4.1) for reinfection rate, spontaneous clearance probability and duration, respectively. Simulation studies were used to assess model validity, demonstrating that the Bayesian model estimates provided useful information about the possible sources and magnitude of bias in epidemiological estimates of reinfection rates, probability of reinfection clearance and duration or reinfection. The quality of the Bayesian estimates improved for larger samples and shorter test intervals. Uncertainty in model estimates notwithstanding, findings suggest that HCV reinfections frequently and quickly result in spontaneous clearance, with many reinfection events going unobserved.

Dynamic Stability and Failure Probability Analysis of Dome Structures Under Stochastic Seismic Excitation

2014 ◽  
Vol 14 (05) ◽  
pp. 1440001 ◽  
Author(s):  
Jie Li ◽  
Jun Xu
Keyword(s):  
Dynamic Stability ◽  
Failure Probability ◽  
Stochastic System ◽  
Dynamic Instability ◽  
Seismic Excitation ◽  
Stochastic Dynamic ◽  
Deterministic System ◽  
Density Evolution ◽  
Stochastic Response ◽  
Strength Failure

The intrinsic relationship between deterministic system and stochastic system is profoundly revealed by the probability density evolution method (PDEM) with introduction of physical law into the stochastic system. On this basis, stochastic dynamic stability analysis of single-layer dome structures under stochastic seismic excitation is firstly studied via incorporating an energetic physical criterion for identification of dynamic instability of dome structures into PDEM, which yields to sample stability (stable reliability). However, dynamic instability is not identical to structural failure definitely, where strength failure can be experienced not only in the stable structure but also when the structure is out of dynamic stability. It is practically feasible to decouple the stochastic dynamic response of dome structures to be a stable one and an unstable one according to the generalized density evolution equation (GDEE). Consequently, the global failure probability can be investigated separately based on the corresponding independent stochastic response. For unstable failure probability assessment, the failure probability is the unstable probability if the dome's failure is attributed to instability, whereas inverse absorbing is firstly implemented to get rid of the stochastic response before instability and a complementary process is filled in the safe domain immediately to finally assess the probability of strength failure after dynamic instability.

Flexibility Analysis of the Cross Axis and Furcated Frame in the Spatial 4-Bar Linkage Weft Insertion Mechanism

2012 ◽  
Vol 627 ◽  
pp. 435-438 ◽  
Author(s):  
Lei Zhang ◽  
Ke Long Yu
Keyword(s):  
High Speed ◽  
Component Material ◽  
Insertion Mechanism ◽  
The Cross ◽  
Cross Axis ◽  
Map Analysis ◽  
Four Bar Linkage ◽  
Relationship Of ◽  
The Impact

In this paper, the flexibility of the cross axis and furcated frame of high speed rapier loom was considered through the change of the two components’ material. Corresponding neutral documents were generated in ANSYS, then with the ANSYS-ADAMS co-simulation, those neutral documents were imported into ADAMS. The motion curves of sword belt were received. Through the map analysis and comparison, the relationship of changing the two components’ material and the motion curves of sword belt were found. The simulation results show that, in consideration of the flexible components, rational selection of the component material can greatly reduce the impact on Spatial four bar linkage weft insertion mechanism, thereby enhance the quality of the fabric.

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