scholarly journals Differential Evolution with Estimation of Distribution for Worst-Case Scenario Optimization

Mathematics ◽  
2021 ◽  
Vol 9 (17) ◽  
pp. 2137
Author(s):  
Margarita Antoniou ◽  
Gregor Papa
Keyword(s):  
Differential Evolution ◽  
Computational Cost ◽  
Benchmark Problems ◽  
Initial Population ◽  
Maximum Output ◽  
Case Scenario ◽  
Worst Case ◽  
Worst Case Scenario ◽  
Scenario Optimization ◽  
Estimation Of Distribution

Worst-case scenario optimization deals with the minimization of the maximum output in all scenarios of a problem, and it is usually formulated as a min-max problem. Employing nested evolutionary algorithms to solve the problem requires numerous function evaluations. This work proposes a differential evolution with an estimation of distribution algorithm. The algorithm has a nested form, where a differential evolution is applied for both the design and scenario space optimization. To reduce the computational cost, we estimate the distribution of the best worst solution for the best solutions found so far. The probabilistic model is used to sample part of the initial population of the scenario space differential evolution, using a priori knowledge of the previous generations. The method is compared with a state-of-the-art algorithm on both benchmark problems and an engineering application, and the related results are reported.

The Limits of Estimation of Distribution Algorithms

2014 ◽  
Vol 926-930 ◽  
pp. 3294-3297
Author(s):  
Cai Chang Ding ◽  
Wen Xiu Peng ◽  
Wei Ming Wang
Keyword(s):  
Bayesian Networks ◽  
Probabilistic Model ◽  
Estimation Of Distribution Algorithms ◽  
Case Scenario ◽  
Learning Methods ◽  
Worst Case ◽  
Worst Case Scenario ◽  
Estimation Of Distribution ◽  
Distribution Algorithms

In this paper, we study the ability limit of EDAs to effectively solve problems in relation to the number of interactions among the variables. More in particular, we numerically analyze the learning limits that different EDA implementations encounter to solve problems on a sequence of additively decomposable functions (ADFs) in which new sub-functions are progressively added. The study is carried out in a worst-case scenario where the sub-functions are defined as deceptive functions. We argue that the limits for this type of algorithm are mainly imposed by the probabilistic model they rely on. Beyond the limitations of the approximate learning methods, the results suggest that, in general, the use of bayesian networks can entail strong computational restrictions to overcome the limits of applicability.

Reducing Probabilistic Weather Forecasts to the Worst Case Scenario: Anchoring Effects

2008 ◽  
Author(s):  
Sonia Savelli ◽  
Susan Joslyn ◽  
Limor Nadav-Greenberg ◽  
Queena Chen
Keyword(s):  
Case Scenario ◽  
Worst Case ◽  
Weather Forecasts ◽  
Worst Case Scenario ◽  
Anchoring Effects

scholarly journals A Comparison of Match Demands Using Ball-in-Play versus Whole Match Data in Professional Soccer Players of the English Championship

Sports ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 76
Author(s):  
Dylan Mernagh ◽  
Anthony Weldon ◽  
Josh Wass ◽  
John Phillips ◽  
Nimai Parmar ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Soccer Players ◽  
Training Methods ◽  
Case Scenario ◽  
Worst Case ◽  
Repeated Measures Design ◽  
Worst Case Scenario ◽  
Professional Soccer ◽  
Peak Match ◽  
Playing Time

This is the first study to report the whole match, ball-in-play (BiP), ball-out-of-play (BoP), and Max BiP (worst case scenario phases of play) demands of professional soccer players competing in the English Championship. Effective playing time per soccer game is typically <60 min. When the ball is out of play, players spend time repositioning themselves, which is likely less physically demanding. Consequently, reporting whole match demands may under-report the physical requirements of soccer players. Twenty professional soccer players, categorized by position (defenders, midfielders, and forwards), participated in this study. A repeated measures design was used to collect Global Positioning System (GPS) data over eight professional soccer matches in the English Championship. Data were divided into whole match and BiP data, and BiP data were further sub-divided into different time points (30–60 s, 60–90 s, and >90 s), providing peak match demands. Whole match demands recorded were compared to BiP and Max BiP, with BiP data excluding all match stoppages, providing a more precise analysis of match demands. Whole match metrics were significantly lower than BiP metrics (p < 0.05), and Max BiP for 30–60 s was significantly higher than periods between 60–90 s and >90 s. No significant differences were found between positions. BiP analysis allows for a more accurate representation of the game and physical demands imposed on professional soccer players. Through having a clearer understanding of maximum game demands in professional soccer, practitioners can design more specific training methods to better prepare players for worst case scenario passages of play.

Legal adaptability in Elbonia

2006 ◽  
Vol 2 (4) ◽  
pp. 393-408 ◽  
Author(s):  
Mathias M. Siems
Keyword(s):  
Empirical Data ◽  
Baltic States ◽  
Case Scenario ◽  
Worst Case ◽  
Worst Case Scenario ◽  
The Law

Law has to be able to respond to new or changing circumstances. This ‘legal adaptability’ may be more important than details in the ‘law as such’. However, its meaning and its significance have not yet been analysed in detail. Thus, legal adaptability will be examined in this article. It looks at the worst case scenario by discussing a fictional country (Elbonia) where legal adaptability is poor, and identifies the main adaptability criteria. By using empirical data from the three Baltic States (Lithuania, Latvia, Estonia), it also provides an example of how to ascertain the degree of legal adaptability of particular countries.

Discussion of the Worst Case Scenario of FLD0

2000 ◽  
Author(s):  
Naji Arwashan
Keyword(s):  
Simple Formula ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Vertical Position ◽  
Engineering Practice ◽  
Case Scenario ◽  
Worst Case ◽  
Grid Analysis ◽  
Worst Case Scenario ◽  
Minimum Value

Abstract The Forming Limit Diagram is used in circle grid analysis to check the safety of a formed panel. The shape of the Forming Limit Diagram for steel is always the same, it is only the vertical position of the diagram that varies depending on the value of FLD0. For steel, FLD0 is widely accepted to be dependent on the thickness and n value which are both inherently indeterministic, and can exhibit variations, small or large, depending on the manufacturing process. To account for this variability in determining the safety of a formed panel, the engineering practice in many companies is to use a minimum value for FLD0 called Worst Case Scenario, because it is calculated using minimum values for both t and n. This paper presents a different and better approach to calculate the minimum value of FLD0. The approach is based on probabilistic concepts, and allows the calculation of a minimum value for FLD0 that is related to a certain probability of occurrence. The derivation technique used in the paper is borrowed from Reliability Analysis and tailored to solve our problem. The derivation leads to a simple formula that can be easily used. The minimum value of FLD0 calculated according to the paper is more accurate than the Worst Case Scenario, and provides better cost saving since it is always greater than the Worst Case Scenario value.

Genetic Family Histories: An Aid to Social Work Assessment

1993 ◽  
Vol 74 (4) ◽  
pp. 195-206 ◽  
Author(s):  
Barbara Bernhardt ◽  
Julia B. Rauch
Keyword(s):  
Social Work ◽  
Genetic Services ◽  
Case Scenario ◽  
Worst Case ◽  
Worst Case Scenario ◽  
Family Histories ◽  
Work Assessment ◽  
Focus Depth ◽  
Service Training ◽  
Agency Design

The focus, depth, and use of genetic family histories vary depending on the agency purpose and the client's presenting problem. Failure to obtain genetic family histories can result in inaccurate assessment and incomplete or misdirected services. In the worst-case scenario, failure to obtain such information and to advise clients of available genetic services are potential grounds for malpractice and wrongful-adoption suits. The authors discuss approaches to obtaining and recording genetic family histories and present criteria for referral to genetic services. The authors recommend that agency administrators consider consulting with a genetic professional to determine the appropriate focus of genetic family histories within the agency, design a protocol, and arrange in-service training in use of the protocol.

scholarly journals Vertical Head Velocity During Worst-Case Scenario Swim Starts

2013 ◽  
Vol 7 (3) ◽  
Author(s):  
Joel M. Stager ◽  
Andrew C. Cornett ◽  
Hiroki Naganobori
Keyword(s):  
Case Scenario ◽  
Worst Case ◽  
Head Velocity ◽  
Worst Case Scenario
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