scholarly journals Biomorpher: Interactive evolution for parametric design

2018 ◽  
Vol 16 (2) ◽  
pp. 144-163 ◽  
Author(s):  
John Harding ◽  
Cecilie Brandt-Olsen
Keyword(s):  
Parametric Design ◽  
Performance Criteria ◽  
Evolutionary Design ◽  
Parametric Modelling ◽  
Small Populations ◽  
Design Exploration ◽  
Wide Range ◽  
Large Populations ◽  
Modelling Environment ◽  
User Motivation

Combining graph-based parametric design with metaheuristic solvers has to date focused solely on performance-based criteria and solving clearly defined objectives. In this article, we outline a new method for combining a parametric modelling environment with an interactive Cluster-Orientated Genetic Algorithm. In addition to performance criteria, evolutionary design exploration can be guided through choice alone, with user motivation that cannot be easily defined. As well as numeric parameters forming a genotype, the evolution of whole parametric definitions is discussed through the use of genetic programming. Visualisation techniques that enable mixing small populations for interactive evolution with large populations for performance-based optimisation are discussed, with examples from both academia and industry showing a wide range of applications.

Design Exploration Using A Shape Grammar With A Genetic Algorithm

2007 ◽  
Vol 32 (2) ◽  
pp. 26-35
Author(s):  
Orestes Chouchoulas ◽  
Alan Day
Keyword(s):  
Genetic Algorithm ◽  
Genetic Material ◽  
Performance Criteria ◽  
Shape Grammar ◽  
Shape Evolution ◽  
Design Exploration ◽  
Wide Range ◽  
Design Generation ◽  
Conventional Manner ◽  
Crossover And Mutation

Although the idea of linking a shape grammar to a genetic algorithm is not new, this paper proposes a novel way of combining these two elements in order to provide a tool that can be used for design exploration. Using a shape grammar for design generation provides a way of creating a range of potential solutions to a design problem which fit with the designer's stylistic agenda. A genetic algorithm can then be used to take these designs and develop them into a much richer set of solutions which can still be recognised as part of the same family. By setting quantifiable targets for design performance, the genetic algorithm can evolve new designs which exhibit the best features of previous generations. The designer is then presented with a wide range of high scoring solutions and can choose which of these to take forward and develop in the conventional manner. The novelty of the proposed approach is in the use of a shape code, which describes the steps that the shape grammar has taken to create each design. The genetic algorithm works on this shape code by applying crossover and mutation in order to create a range of designs that can be tested. The fittest are then selected in order to provide the genetic material for the next generation. A prototype version of such a program, called Shape Evolution, has been developed. In order to test Shape Evolution it has been used to design a range of apartment buildings which are required to meet certain performance criteria.

scholarly journals Parametric Design and Comfort Optimization of Dynamic Shading Structures

2021 ◽  
Vol 13 (14) ◽  
pp. 7670
Author(s):  
Doris A. Chi ◽  
Edwin González M. ◽  
Renato Valdivia ◽  
Eduardo Gutiérrez J.
Keyword(s):  
Thermal Comfort ◽  
Social Dynamics ◽  
Parametric Design ◽  
Environmental Parameters ◽  
Outdoor Thermal Comfort ◽  
Climate Index ◽  
Parametric Modelling ◽  
The Social ◽  
Thermal Climate ◽  
Dynamic Time

This work implements parametric tools to optimize the environmental design of urban adaptive shadings through multiobjective evolutionary algorithms that look for solutions of dynamic (time-changing) structures used in open public spaces. The proposal is located in Malecon Cancun Tajamar in the southeast part of Mexico, and the main objective is to enhance the thermal comfort of users as well as to become part of the social dynamics of the place reinforcing identity through appropriation. The proposed workflow includes four steps: (1) geometric modelling by parametric modelling tools; (2) simulation of environmental parameters by using BPS tools; (3) shape optimization by using an evolutionary algorithm; and (4) environmental verification of the results. The Universal Thermal Climate Index (UTCI) was used to assess the outdoor thermal comfort derived from the dynamic shadings. The results showed a significant improvement in the thermal comfort with absolute UTCI differences of 3.9, 7.4, and 3.1 °C at 8, 12, and 16 h, respectively, during the summer; and absolute differences of 1.4, 3.5, and 2 °C at 8, 12, and 16 h, respectively, during the winter. The proposed workflow can help to guide the early design process of dynamic shadings by finding optimal solutions that enhance outdoor thermal comfort.

scholarly journals Performance Criteria for Testosterone Measurements Based on Biological Variation in Adult Males: Recommendations from the Partnership for the Accurate Testing of Hormones

2012 ◽  
Vol 58 (12) ◽  
pp. 1703-1710 ◽  
Author(s):  
Yeo-Min Yun ◽  
Julianne Cook Botelho ◽  
Donald W Chandler ◽  
Alex Katayev ◽  
William L Roberts ◽  
...  
Keyword(s):  
Total Error ◽  
Full Range ◽  
Biological Variation ◽  
Analytical Performance ◽  
Performance Criteria ◽  
Performance Goals ◽  
Adult Males ◽  
Large Variability ◽  
Wide Range ◽  
Variation Data

BACKGROUND Testosterone measurements that are accurate, reliable, and comparable across methodologies are crucial to improving public health. Current US Food and Drug Administration–cleared testosterone assays have important limitations. We sought to develop assay performance requirements on the basis of biological variation that allow physiologic changes to be distinguished from assay analytical errors. METHODS From literature review, the technical advisory subcommittee of the Partnership for the Accurate Testing of Hormones compiled a database of articles regarding analytical and biological variability of testosterone. These data, mostly from direct immunoassay-based methodologies, were used to specify analytical performance goals derived from within- and between-person variability of testosterone. RESULTS The allowable limits of desirable imprecision and bias on the basis of currently available biological variation data were 5.3% and 6.4%, respectively. The total error goal was 16.7%. From recent College of American Pathologists proficiency survey data, most currently available testosterone assays missed these analytical performance goals by wide margins. Data from the recently established CDC Hormone Standardization program showed that although the overall mean bias of selected certified assays was within 6.4%, individual sample measurements could show large variability in terms of precision, bias, and total error. CONCLUSIONS Because accurate measurement of testosterone across a wide range of concentrations [approximately 2–2000 ng/dL (0.069–69.4 nmol/L)] is important, we recommend using available data on biological variation to calculate performance criteria across the full range of expected values. Additional studies should be conducted to obtain biological variation data on testosterone from women and children, and revisions should be made to the analytical goals for these patient populations.

Prescreening in large populations as a tool for identifying elevated CO2-responsive genotypes in plants

2019 ◽  
Vol 46 (1) ◽  
pp. 1 ◽  
Author(s):  
Hiroyuki Shimono ◽  
Graham Farquhar ◽  
Matthew Brookhouse ◽  
Florian A. Busch ◽  
Anthony O'Grady ◽  
...  
Keyword(s):  
Genetic Selection ◽  
Co2 Concentration ◽  
Elevated Atmospheric Co2 ◽  
High Performing ◽  
Active Selection ◽  
Wide Range ◽  
Large Populations ◽  
Increase Productivity ◽  
The Cost ◽  
Selection Of

Elevated atmospheric CO2 concentration (e[CO2]) can stimulate the photosynthesis and productivity of C3 species including food and forest crops. Intraspecific variation in responsiveness to e[CO2] can be exploited to increase productivity under e[CO2]. However, active selection of genotypes to increase productivity under e[CO2] is rarely performed across a wide range of germplasm, because of constraints of space and the cost of CO2 fumigation facilities. If we are to capitalise on recent advances in whole genome sequencing, approaches are required to help overcome these issues of space and cost. Here, we discuss the advantage of applying prescreening as a tool in large genome×e[CO2] experiments, where a surrogate for e[CO2] was used to select cultivars for more detailed analysis under e[CO2] conditions. We discuss why phenotypic prescreening in population-wide screening for e[CO2] responsiveness is necessary, what approaches could be used for prescreening for e[CO2] responsiveness, and how the data can be used to improve genetic selection of high-performing cultivars. We do this within the framework of understanding the strengths and limitations of genotype–phenotype mapping.

Surface bypass as a means of protecting downstream-migrating fish: lack of standardised evaluation criteria complicates evaluation of efficacy

2018 ◽  
Vol 69 (12) ◽  
pp. 1882 ◽  
Author(s):  
Elena-Maria Klopries ◽  
Zhiqun Daniel Deng ◽  
Theresa U. Lachmann ◽  
Holger Schüttrumpf ◽  
Bradly A. Trumbo
Keyword(s):  
Performance Studies ◽  
Pearson Correlation ◽  
Evaluation Criteria ◽  
Fish Passage ◽  
Performance Criteria ◽  
Design Criteria ◽  
Good Surface ◽  
Wide Range ◽  
Student’S T ◽  
Meta Analyses

Surface bypasses are downstream migration structures that can help reduce hydropower-induced damage to migrating fish. However, no comprehensive design concept that facilitates good surface bypass performance for a wide range of sites and species is available. This is why fish-passage efficiencies at recently built bypass structures vary widely between 0% and up to 97%. We reviewed 50 surface bypass performance studies and existing guidelines for salmonids, eels and potamodromous species to identify crucial design criteria for surface bypasses employed in North America, Europe and Australia. Two-tailed Pearson correlation of bypass efficiency and bypass design criteria shows that bypass entrance area (r=0.3300, P=0.0036) and proportion of inflow to the bypass (r=0.3741, P=0.0032) are the most influential parameters on bypass efficiency. However, other parameters such as guiding structures (P=0.2181, ordinary Student’s t-test) and trash-rack spacing (r=–0.1483, P=0.3951, Spearman correlation), although not statistically significant, have been shown to have an effect on efficiency in some studies. The use of different performance criteria and efficiency definitions for bypass evaluation hampers direct comparison of studies and, therefore, deduction of design criteria. To enable meta-analyses and improve bypass design considerations, we suggest a list of standardised performance parameters for bypasses that should be considered in future bypass-performance studies.

scholarly journals Nematodes in relation to plant growth, IV. Pratylenchus penetrans (Cobb) on orchard trees.

1962 ◽  
Vol 10 (4) ◽  
pp. 286-296 ◽  
Author(s):  
H. Hoestra ◽  
M. Oostenbrink
Keyword(s):  
Plant Growth ◽  
Shoot Growth ◽  
Sandy Soils ◽  
Good Evidence ◽  
Small Populations ◽  
Pratylenchus Penetrans ◽  
Experimental Conditions ◽  
Nematode Density ◽  
Large Populations ◽  
Considerable Damage

The damage caused by Pratylenchus penetrans in orchards is discussed. In 2 experimental fields containing 4 varieties of apple, there was good evidence of a decrease in yield with increased nematode density before apple seedlings were planted. Heavy nematode infestations reduced shoot growth by more than 50%. A concentration of 100 nematodes per 300 ml. of soil may cause considerable damage. The process of infestation and symptoms of nematode attack under field and experimental conditions are discussed. In clean cultivated orchards on light sandy soils there are often large populations in the roots and very small populations in the soil but on heavier soils, the converse is true. Hoestra & Oostenbrink conclude without doubt that P. penetrans is an important cause of replant problems in orchards. H.R. W. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Towards motivation-based adaptation of difficulty in e-learning programs

2012 ◽  
Vol 28 (7) ◽  
Author(s):  
Anke Endler ◽  
Gunter Daniel Rey ◽  
Martin V. Butz
Keyword(s):  
Adaptation Strategies ◽  
Future Research ◽  
Proximal Development ◽  
Real World Data ◽  
Learning Classifier System ◽  
Wide Range ◽  
Learning Programs ◽  
Reported Study ◽  
E Learning ◽  
User Motivation

<span>The objective of this study was to investigate if an e-learning environment may use measurements of the user's current motivation to adapt the level of task difficulty for more effective learning. In the reported study, motivation-based adaptation was applied randomly to collect a wide range of data for different adaptations in a variety of motivational states. This data was then utilised to extract rules for an adequate motivation-based adaptation to maximise expected learning success. A learning classifier system was used for the data analysis, generating rules for suitable and unsuitable adaptations based on current user motivation data. We extracted a set of twelve rules which suggest particular adaptation strategies based on real-world data. These rules could generally be embedded into existing psychological theories, namely the Zone of Proximal Development and the Yerkes-Dodson Law. In future research, we intend to evaluate these rules on further studies and develop concrete sets of adaptation strategies based on user motivation measurements.</span>

scholarly journals Unexpected heterozygosity in an island mouflon population founded by a single pair of individuals

2006 ◽  
Vol 274 (1609) ◽  
pp. 527-533 ◽  
Author(s):  
Renaud Kaeuffer ◽  
David W Coltman ◽  
Jean-Louis Chapuis ◽  
Dominique Pontier ◽  
Denis Réale
Keyword(s):  
Genetic Diversity ◽  
Wild Population ◽  
Ovis Aries ◽  
Stochastic Simulations ◽  
Single Pair ◽  
Small Populations ◽  
Short Period ◽  
Large Populations ◽  
History Of ◽  
Over Time

In population and conservation genetics, there is an overwhelming body of evidence that genetic diversity is lost over time in small populations. This idea has been supported by comparative studies showing that small populations have lower diversity than large populations. However, longitudinal studies reporting a decline in genetic diversity throughout the whole history of a given wild population are much less common. Here, we analysed changes in heterozygosity over time in an insular mouflon ( Ovis aries ) population founded by two individuals in 1957 and located on one of the most isolated locations in the world: the Kerguelen Sub-Antarctic archipelago. Heterozygosity measured using 25 microsatellite markers has actually increased over 46 years since the introduction, and exceeds the range predicted by neutral genetic models and stochastic simulations. Given the complete isolation of the population and the short period of time since the introduction, changes in genetic variation cannot be attributed to mutation or migration. Several lines of evidence suggest that the increase in heterozygosity with time may be attributable to selection. This study shows the importance of longitudinal genetic surveys for understanding the mechanisms that regulate genetic diversity in wild populations.

Unequal Voting

2019 ◽  
pp. 175-192
Author(s):  
James Lindley Wilson
Keyword(s):  
Electoral College ◽  
Small Populations ◽  
Political Equality ◽  
Voting Power ◽  
Political Inequality ◽  
The Us ◽  
Large Populations ◽  
Us Senate

This chapter assesses how the inequalities in voting power involved in the US Senate and in the Electoral College used to elect the president violate the requirements of political equality. The Senate comprises two senators from each state. States with large populations get the same number of votes in the Senate as do states with small populations. Because the states vary considerably in population, there are large inequalities in how many citizens are represented by a senate delegation. This unequal representation of individuals in the Senate constitutes objectionable political inequality. The Senate is thus unjustifiably undemocratic. This conclusion has implications for the election of the US president, as the Electoral College process for such election tracks what the chapter argues is the malapportionment of the Senate. This inequality, too, is objectionable, and it should be eliminated. The reasons for a more egalitarian election of the president are all the more urgent given that the inequalities in the Senate are much more constitutionally entrenched, and thus likely to remain. The election of the president should mitigate that inequality rather than exaggerate it.

Optioneering of long viaducts via parametric design

2021 ◽  
Author(s):  
Paul M. Sobota
Keyword(s):  
Design Process ◽  
Performance Indicators ◽  
Parametric Design ◽  
Design Stage ◽  
Parametric Modelling ◽  
Parametric Approach ◽  
Early Design Stage ◽  
Main Challenge ◽  
Suitable Approximation

<p><br clear="none"/></p><p>During the optioneering phase, engineers face the challenge of choosing between myriads of possible designs, while, simultaneously, several sorts of constraints have to be considered. We show in a case study of a 380 m long viaduct how parametric modelling can facilitate the design process. The main challenge was to satisfy the constraints imposed by several different stakeholders. In order to identify sustainable, aesthetic, economic as well as structurally efficient options, we assessed several key performance indicators in real time. By automatically estimating steel and concrete volumes, a simple, yet suitable approximation of the embodied carbon (considering 85-95%) can be obtained at a very early design stage. In summary, our parametric approach allowed us to consider a wider range of parameters and to react more flexibly to changing conditions during the project.</p><p><br clear="none"/></p>

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