scholarly journals Application of Envelope Curve Method for Quantitative Definition of Extreme Drought Conditions

2019 ◽  
Vol 19 (5) ◽  
pp. 245-251
Author(s):  
Chan Wook Lee ◽  
Donghwi Jung ◽  
Moo Jong Park ◽  
Do Guen Yoo
Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3366
Author(s):  
Daniel Suchet ◽  
Adrien Jeantet ◽  
Thomas Elghozi ◽  
Zacharie Jehl

The lack of a systematic definition of intermittency in the power sector blurs the use of this term in the public debate: the same power source can be described as stable or intermittent, depending on the standpoint of the authors. This work tackles a quantitative definition of intermittency adapted to the power sector, linked to the nature of the source, and not to the current state of the energy mix or the production predictive capacity. A quantitative indicator is devised, discussed and graphically depicted. A case study is illustrated by the analysis of the 2018 production data in France and then developed further to evaluate the impact of two methods often considered to reduce intermittency: aggregation and complementarity between wind and solar productions.


2021 ◽  
Vol 9 ◽  
Author(s):  
Ted Sichelman

Many scholars have employed the term “entropy” in the context of law and legal systems to roughly refer to the amount of “uncertainty” present in a given law, doctrine, or legal system. Just a few of these scholars have attempted to formulate a quantitative definition of legal entropy, and none have provided a precise formula usable across a variety of legal contexts. Here, relying upon Claude Shannon's definition of entropy in the context of information theory, I provide a quantitative formalization of entropy in delineating, interpreting, and applying the law. In addition to offering a precise quantification of uncertainty and the information content of the law, the approach offered here provides other benefits. For example, it offers a more comprehensive account of the uses and limits of “modularity” in the law—namely, using the terminology of Henry Smith, the use of legal “boundaries” (be they spatial or intangible) that “economize on information costs” by “hiding” classes of information “behind” those boundaries. In general, much of the “work” performed by the legal system is to reduce legal entropy by delineating, interpreting, and applying the law, a process that can in principle be quantified.


2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
E. L. Rex ◽  
J. Werle ◽  
B. C. Burkart ◽  
J. R. MacKenzie ◽  
K. D. Johnston ◽  
...  

Geometry of the patella (kneecap) remains poorly understood yet is highly relevant to performing the correct patellar cut to reduce pain and to improve function and satisfaction after knee replacement surgery. Although studies routinely refer to “parallel to the anterior surface” and “the patellar horizon,” a quantitative definition of these is lacking and significant variability exists between observers for this irregularly-shaped bone. A 2D-3D shape analysis technique was developed to determine the optimal device configuration for contacting the patellar surface. Axial and sagittal pseudo-X-rays were created from 18 computed tomography (CT) scans of cadaveric knees. Four expert surgeons reviewed three repetitions of the X-rays in randomized order, marking their desired cut plane and their estimate of the anterior surface. These 2D results were related back to the 3D model to create the desired plane. There was considerable variability in perceptions, with intra- and intersurgeon repeatability (standard deviations) ranging from 1.3° to 2.4°. The best configuration of contact points to achieve the desired cutting plane was three pegs centred on the patellar surface, two superior and one inferior, forming a 16 mm equilateral triangle. This configuration achieved predicted cut planes within 1° of the surgeon ranges on all 18 patellae. Implementing this, as was done in a subsequent prototype surgical device, should help improve the success and satisfaction of knee replacement surgery.


2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
P Bartko ◽  
H Arfsten ◽  
G Heitzinger ◽  
N Pavo ◽  
A Toma ◽  
...  

Abstract Background Diverging guideline definitions for the quantitative assessment of severe secondary mitral regurgitation (sMR) reflect the lacking link of the sMR spectrum to mortality and has introduced a source of uncertainty and continuing debate. Objectives The current study aimed to define improved risk-thresholds specifically tailored to the complex nature of sMR that provide a unifying solution to the ongoing guideline-controversy. Methods We enrolled 423 heart failure patients under guideline directed medical therapy and assessed sMR by effective regurgitant orifice area (EROA), regurgitant volume (RegVol) and regurgitant fraction (RegFrac). Results Measures of sMR severity were consistently associated with 5-year mortality with a HR for a 1-SD increase of 1.42 (95%CI 1.25-1.63, P < 0.001) for EROA, 1.37 (95%CI 1.20-1.56, P < 0.001) for RegVol and 1.50 (95%CI 1.30-1.73, P < 0.001) for RegFrac. Results remained statistically significant after bootstrap- or clinical confounder-based adjustment. Spline-curve analyses (Figure 1A-C) showed a linearly increasing risk enabling to stratify in low-risk (EROA < 20mm2 and RegVol < 30ml), intermediate-risk (EROA 20-30mm2 and RegVol 30-45ml) and, high-risk (EROA≥30mm2 and RegVol≥45ml). In the intermediate-risk group, a RegFrac ≥50% as indicator for hemodynamic severe sMR was associated with poor outcome (P = 0.017). A unifying concept based on combined assessment of the EROA, the RegVol, and the RegFrac (Figure 1D) showed a significantly better discrimination compared to the currently established algorithms (Table 1). Conclusions Risk-based thresholds tailored to the pathophysiological concept of sMR provide a unifying solution to the ongoing guideline controversy. An algorithm based on the combined assessment of the unifying cut-offs for EROA, RegVol and RegFrac improves risk prediction compared to currently established grading. Table 1 Definition of severe sMR Cox regression analysis ROC analysis IDI analysis HR (95%CI) P-Value ROC P-Value-for-comparison IDI P-Value Unifying concept 3.76 (2.71-5.23) <0.001 0.63 –- –- –- ACC/AHA definition 3.20 (2.14-4.78) <0.001 0.57 <0.001 0.06 <0.001 ESC/EACTS definition 1.52 (1.10-2.09) 0.01 0.55 <0.001 0.13 <0.001 ACC/ASE expert consensus 1.89 (1.40-2.56) <0.001 0.59 0.04 0.08 <0.001 Comparison of the unifying concept with the ACC/AHA, ESC/EACTS and ACC/ASE expert consensus definitions of sMR by Cox regression, ROC, and IDI demonstrated the most powerfull prediction by the unifying concept with significantly higher ROC area under the curve and better discriminatory power by IDI. Abstract P1764 Figure 1 A-D


2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Michelle Murti ◽  
Ellen Yard ◽  
Rachel Kramer ◽  
Dirk Haselow ◽  
Mike Mettler ◽  
...  

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 581
Author(s):  
Chan Wook Lee ◽  
Moo Jong Park ◽  
Do Guen Yoo

Recently, the signs of extreme droughts, which were thought of as exceptional and unlikely, are being detected worldwide. It is necessary to prepare countermeasures against extreme droughts; however, current definitions of extreme drought are just used as only one or two indicators to represent the status or severity of a drought. More representative drought factors, which can show the status and severity that are relevant to extreme drought, need to be considered depending on the characteristics of the drought and comprehensive evaluation of various indices. Therefore, this study attempted to quantitatively define regional extreme droughts using more acceptable factors. The methodology comprises five factors that are indicative of extreme drought. The five factors are (1) duration (days), (2) number of consecutive years (years), (3) water availability, (4) return period, and (5) regional experience. The results were analyzed by applying the procedure to droughts that took place in 2014–2015 in South Korea. The results showed that the applied historical event did not enter the status of extreme drought, which is proposed in this study; however, the proposed methodology is applicable because it uses acceptable and reasonable factors to judge extreme drought, but it can also take into account the past regional experience of extreme drought.


2014 ◽  
Vol 15 (2) ◽  
pp. 157-160 ◽  
Author(s):  
Alison Van Eenennaam ◽  
Holly Neibergs ◽  
Christopher Seabury ◽  
Jeremy Taylor ◽  
Zeping Wang ◽  
...  

AbstractThe Bovine Respiratory Disease Coordinated Agricultural Project (BRD CAP) is a 5-year project funded by the United States Department of Agriculture (USDA), with an overriding objective to use the tools of modern genomics to identify cattle that are less susceptible to BRD. To do this, two large genome wide association studies (GWAS) were conducted using a case:control design on preweaned Holstein dairy heifers and beef feedlot cattle. A health scoring system was used to identify BRD cases and controls. Heritability estimates for BRD susceptibility ranged from 19 to 21% in dairy calves to 29.2% in beef cattle when using numerical scores as a semi-quantitative definition of BRD. A GWAS analysis conducted on the dairy calf data showed that single nucleotide polymorphism (SNP) effects explained 20% of the variation in BRD incidence and 17–20% of the variation in clinical signs. These results represent a preliminary analysis of ongoing work to identify loci associated with BRD. Future work includes validation of the chromosomal regions and SNPs that have been identified as important for BRD susceptibility, fine mapping of chromosomes to identify causal SNPs, and integration of predictive markers for BRD susceptibility into genetic tests and national cattle genetic evaluations.


1996 ◽  
Vol 113-114 ◽  
pp. 349-378
Author(s):  
Marc Bourdeau ◽  
Jean-Pierre Tubach

Abstract We describe a statistical methodology that provides a quantitative definition of the concept of phonological space that has been used for a long time as a purely qualitative description of languages. We apply this description to five corpora : four of French language, and one of Polish language. We obtain cartesian planes where the speakers are represented as points. We show that we can discriminate the five corpora. We end by pointing to applications to the learning and destruction of phonological capabilities.


2008 ◽  
Vol 122 (3) ◽  
pp. 267 ◽  
Author(s):  
Erin E. Fraser ◽  
Johnston F. Miller

We report the first record of Hairy-tailed Moles (Parascalops breweri) moving above ground during the day and suggest that the four individuals observed were young-of-the-year dispersing from their natal territories. Extreme drought conditions may also have driven these animals to move above ground.


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