Deductive Sort and Climbing Sort: New Methods for Non-Dominated Sorting

2012 ◽  
Vol 20 (1) ◽  
pp. 1-26 ◽  
Author(s):  
Kent McClymont ◽  
Ed Keedwell
Keyword(s):  
Computational Complexity ◽  
Evolutionary Algorithms ◽  
Real World ◽  
Future Generations ◽  
Nsga Ii ◽  
New Methods ◽  
Research Fields ◽  
Dominance Relationships ◽  
Large Populations ◽  
Novel Methods

In recent years an increasing number of real-world many-dimensional optimisation problems have been identified across the spectrum of research fields. Many popular evolutionary algorithms use non-dominance as a measure for selecting solutions for future generations. The process of sorting populations into non-dominated fronts is usually the controlling order of computational complexity and can be expensive for large populations or for a high number of objectives. This paper presents two novel methods for non-dominated sorting: deductive sort and climbing sort. The two new methods are compared to the fast non-dominated sort of NSGA-II and the non-dominated rank sort of the omni-optimizer. The results demonstrate the improved efficiencies of the deductive sort and the reductions in comparisons that can be made when applying inferred dominance relationships defined in this paper.

scholarly journals Visualisation of the combinatorial effects within evolutionary algorithms: the compass plot

2020 ◽  
Author(s):  
Qi Wang ◽  
Miaoting Guan ◽  
Wen Huang ◽  
Libing Wang ◽  
Zhihong Wang ◽  
...  
Keyword(s):  
Evolutionary Algorithms ◽  
Real World ◽  
Distribution System ◽  
Water Distribution ◽  
Cost Effective ◽  
Considerable Change ◽  
Nsga Ii ◽  
Effective Decision ◽  
Effective Decision Making ◽  
Real World Problems

Abstract Applications of evolutionary algorithms (EAs) to real-world problems are usually hindered due to parameterisation issues and computational efficiency. This paper shows how the combinatorial effects related to the parameterisation issues of EAs can be visualised and extracted by the so-called compass plot. This new plot is inspired by the traditional Chinese compass used for navigation and geomantic detection. We demonstrate the value of the proposed compass plot in two scenarios with application to the optimal design of the Hanoi water distribution system. One is to identify the dominant parameters in the well-known NSGA-II. The other is to seek the efficient combinations of search operators embedded in Borg, which uses an ensemble of search operators by auto-adapting their use at runtime to fit an optimisation problem. As such, the implicit and vital interdependency among parameters and search operators can be intuitively demonstrated and identified. In particular, the compass plot revealed some counter-intuitive relationships among the algorithm parameters that led to a considerable change in performance. The information extracted, in turn, facilitates a deeper understanding of EAs and better practices for real-world cases, which eventually leads to more cost-effective decision-making.

Evolutionary Computing

2009 ◽  
pp. 131-142
Author(s):  
Thomas E. Potok ◽  
Xiaohui Cui ◽  
Yu Jiao
Keyword(s):  
Neural Networks ◽  
Evolutionary Algorithms ◽  
Swarm Intelligence ◽  
Real World ◽  
Artificial Life ◽  
Evolutionary Computing ◽  
New Paradigm ◽  
New Methods ◽  
Nature Inspired Computing ◽  
Real World Problems

The rate at which information overwhelms humans is significantly more than the rate at which humans have learned to process, analyze, and leverage this information. To overcome this challenge, new methods of computing must be formulated, and scientist and engineers have looked to nature for inspiration in developing these new methods. Consequently, evolutionary computing has emerged as new paradigm for computing, and has rapidly demonstrated its ability to solve real-world problems where traditional techniques have failed. This field of work has now become quite broad and encompasses areas ranging from artificial life to neural networks. This chapter specifically focuses on two sub-areas of nature-inspired computing: Evolutionary Algorithms and Swarm Intelligence.

scholarly journals Difficulty Adjustable and Scalable Constrained Multiobjective Test Problem Toolkit

2020 ◽  
Vol 28 (3) ◽  
pp. 339-378 ◽  
Author(s):  
Zhun Fan ◽  
Wenji Li ◽  
Xinye Cai ◽  
Hui Li ◽  
Caimin Wei ◽  
...  
Keyword(s):  
Evolutionary Algorithms ◽  
Multiobjective Optimization ◽  
Real World ◽  
Optimization Problems ◽  
Test Problems ◽  
Nsga Ii ◽  
Multiobjective Problems ◽  
Multiobjective Optimization Problems ◽  
Dominance Principle ◽  
Constrained Multiobjective Optimization

Multiobjective evolutionary algorithms (MOEAs) have progressed significantly in recent decades, but most of them are designed to solve unconstrained multiobjective optimization problems. In fact, many real-world multiobjective problems contain a number of constraints. To promote research on constrained multiobjective optimization, we first propose a problem classification scheme with three primary types of difficulty, which reflect various types of challenges presented by real-world optimization problems, in order to characterize the constraint functions in constrained multiobjective optimization problems (CMOPs). These are feasibility-hardness, convergence-hardness, and diversity-hardness. We then develop a general toolkit to construct difficulty adjustable and scalable CMOPs (DAS-CMOPs, or DAS-CMaOPs when the number of objectives is greater than three) with three types of parameterized constraint functions developed to capture the three proposed types of difficulty. In fact, the combination of the three primary constraint functions with different parameters allows the construction of a large variety of CMOPs, with difficulty that can be defined by a triplet, with each of its parameters specifying the level of one of the types of primary difficulty. Furthermore, the number of objectives in this toolkit can be scaled beyond three. Based on this toolkit, we suggest nine difficulty adjustable and scalable CMOPs and nine CMaOPs, to be called DAS-CMOP1-9 and DAS-CMaOP1-9, respectively. To evaluate the proposed test problems, two popular CMOEAs—MOEA/D-CDP (MOEA/D with constraint dominance principle) and NSGA-II-CDP (NSGA-II with constraint dominance principle) and two popular constrained many-objective evolutionary algorithms (CMaOEAs)—C-MOEA/DD and C-NSGA-III—are used to compare performance on DAS-CMOP1-9 and DAS-CMaOP1-9 with a variety of difficulty triplets, respectively. The experimental results reveal that mechanisms in MOEA/D-CDP may be more effective in solving convergence-hard DAS-CMOPs, while mechanisms of NSGA-II-CDP may be more effective in solving DAS-CMOPs with simultaneous diversity-, feasibility-, and convergence-hardness. Mechanisms in C-NSGA-III may be more effective in solving feasibility-hard CMaOPs, while mechanisms of C-MOEA/DD may be more effective in solving CMaOPs with convergence-hardness. In addition, none of them can solve these problems efficiently, which stimulates us to continue to develop new CMOEAs and CMaOEAs to solve the suggested DAS-CMOPs and DAS-CMaOPs.

scholarly journals Electronic Phenomena of Transition Metal Oxides

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 256
Author(s):  
Christian Rodenbücher ◽  
Kristof Szot
Keyword(s):  
Solid State ◽  
Transition Metal ◽  
Metal Oxides ◽  
Real World ◽  
Transition Metal Oxides ◽  
Major Research ◽  
Research Fields ◽  
Real World Applications

Transition metal oxides with ABO3 or BO2 structures have become one of the major research fields in solid state science, as they exhibit an impressive variety of unusual and exotic phenomena with potential for their exploitation in real-world applications [...]

scholarly journals Change the Narrative

2018 ◽  
Vol 5 ◽  
pp. 24-38
Author(s):  
Tynan Drake
Keyword(s):  
Young Adult ◽  
Real World ◽  
Future Generations ◽  
Empathic Understanding ◽  
Young Adult Novel ◽  
Fiction Writers ◽  
Personal Level

In post-apocalyptic fiction, the concept of empathy often is depicted as a weakness that the characters cannot afford if they hope to survive. This depiction leads to harmful perceptions on the value of empathy and its ability to avert apocalyptic catastrophes. By examining David Clement-Davies young adult novel The Sight through theories of narrative empathy and through James Berger’s theories of post-apocalyptic representation, this essay argues that by representing empathic understanding, fiction writers have the power to influence positive changes in real world situations. By representing the need to teach empathy for all people, regardless of their differences, and the harm a lack of empathy can cause on both a personal level and on a large societal scale, this novel encourages future generations to seek peaceful and empathic solutions instead of repeating the cataclysmic mistakes of their forebearers.

scholarly journals Practical Recognition System for Text Printed on Clear Reflected Material

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Khader Mohammad ◽  
Sos Agaian
Keyword(s):  
Processing Time ◽  
Recognition Rate ◽  
Recognition System ◽  
Experimental Results ◽  
Research Fields ◽  
Average Recognition Rate ◽  
Clear Plastic ◽  
Novel Methods ◽  
Processor Speed ◽  
Background Contrast

Text embedded in an image contains useful information for applications in the medical, industrial, commercial, and research fields. While many systems have been designed to correctly identify text in images, no work addressing the recognition of degraded text on clear plastic has been found. This paper posits novel methods and an apparatus for extracting text from an image with the practical assumption: (a) poor background contrast, (b) white, curved, and/or differing fonts or character width between sets of images, (c) dotted text printed on curved reflective material, and/or (d) touching characters. Methods were evaluated using a total of 100 unique test images containing a variety of texts captured from water bottles. These tests averaged a processing time of ~10 seconds (using MATLAB R2008A on an HP 8510 W with 4 G of RAM and 2.3 GHz of processor speed), and experimental results yielded an average recognition rate of 90 to 93% using customized systems generated by the proposed development.

scholarly journals Using the Generative Adversarial Network to Generate Recommendations

2020 ◽  
Author(s):  
A.V. Prosvetov
Keyword(s):  
Real World ◽  
Recommendation System ◽  
Generative Adversarial Networks ◽  
Generative Adversarial Network ◽  
Theoretical Comparison ◽  
New Methods ◽  
Adversarial Network ◽  
Adversarial Networks ◽  
Recommendation Algorithms ◽  
Cold Start Problem

Widely used recommendation systems do not meet all industry requirements, so the search for more advanced methods for creating recommendations continues. The proposed new methods based on Generative Adversarial Networks (GAN) have a theoretical comparison with other recommendation algorithms; however, real-world comparisons are needed to introduce new methods in the industry. In our work, we compare recommendations from the Generative Adversarial Network with recommendation from the Deep Semantic Similarity Model (DSSM) on real-world case of airflight tickets. We found a way to train the GAN so that users receive appropriate recommendations, and during A/B testing, we noted that the GAN-based recommendation system can successfully compete with other neural networks in generating recommendations. One of the advantages of the proposed approach is that the GAN training process avoids a negative sampling, which causes a number of distortions in the final ratings of recommendations. Due to the ability of the GAN to generate new objects from the distribution of the training set, we assume that the Conditional GAN is able to solve the cold start problem.

scholarly journals A Real-World Comparison of SARS-CoV-2 Rapid Antigen vs. Polymerase Chain Reaction Testing in Florida

2021 ◽  
Author(s):  
Lao-Tzu Allan-Blitz ◽  
Jeffrey D. Klausner
Keyword(s):  
Polymerase Chain Reaction ◽  
Real World ◽  
Threshold Value ◽  
Test Results ◽  
Chain Reaction ◽  
Cycle Threshold ◽  
Large Populations ◽  
Symptom Status ◽  
Polymerase Chain ◽  
Antigen Tests

Background The reported sensitivity of rapid, antigen-based diagnostics for SARS-CoV-2 infection varies. Few studies have evaluated rapid antigen tests in real-world settings or among large populations. Methods Beginning October 2020, Florida offered individuals presenting for SARS-CoV-2 testing polymerase chain reaction (PCR) testing if they tested positive by the Abbott BinaxNOW TM COVID-19 Ag Card, were symptomatic, or required or requested PCR testing. We compared test results among individuals who received both types of tests at four publicly-accessible testing sites across Florida. We calculated the positive percent agreement (PPA) between the two test types by symptom status. Subsequently, we evaluated the PPA among individuals regardless of symptoms with lower cycle threshold values (<30). Results Overall, 18,457 individuals were tested via both methods, of which 3,153 (17.1%) were positive by PCR. The PPA for the Abbott BinaxNOW TM COVID-19 Ag Card using the PCR comparator was 49.2% (95% CI 47.4%-50.9%). That performance was moderately improved among symptomatic individuals (51.9%; 95% CI 49.7%-54.0%). When restricted to positive PCR tests with a cycle threshold value <30, regardless of symptom status, the PPA was 75.3% (95% CI 72.8%-77.6%). Conclusion The PPA of the Abbott BinaxNOW TM COVID-19 Ag Card with PCR was lower than among previous reports. Our findings may reflect the performance of the BinaxNOW TM antigen test in real-world settings.

scholarly journals Risk of Liver Injury Associated with Intravenous Lipid Emulsions: A Prescription Sequence Symmetry Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiao-xiao Li ◽  
Yin-chu Cheng ◽  
Suo-di Zhai ◽  
Peng Yao ◽  
Si-yan Zhan ◽  
...  
Keyword(s):  
Liver Injury ◽  
Real World ◽  
Time Windows ◽  
Strong Association ◽  
Female Gender ◽  
Symmetry Analysis ◽  
Lipid Emulsions ◽  
Real World Setting ◽  
Large Populations ◽  
Using Data

Aims: To determine the risk of liver injury associated with the use of different intravenous lipid emulsions (LEs) in large populations in a real-world setting in China.Methods: A prescription sequence symmetry analysis was performed using data from 2015 Chinese Basic Health Insurance for Urban Employees. Patients newly prescribed both intravenous LEs and hepatic protectors within time windows of 7, 14, 28, 42, and 60 days of each other were included. The washout period was set to one month according to the waiting-time distribution. After adjusting prescribing time trends, we quantify the deviation from symmetry of patients initiating LEs first and those initiating hepatic protectors first, by calculating adjusted sequence ratios (ASRs) and relevant 95% confidence intervals. Analyses were further stratified by age, gender, and different generations of LEs developed.Results: In total, 416, 997, 1,697, 2,072, and 2,342 patients filled their first prescriptions with both drugs within 7, 14, 28, 42, and 60 days, respectively. Significantly increased risks of liver injury were found across all time windows, and the strongest effect was observed in the first 2 weeks [ASR 6.97 (5.77–8.42) ∼ 7.87 (6.04–10.61)] in overall patients. In subgroup analyses, female gender, age more than 60 years, and soybean oil-based and alternative-LEs showed higher ASRs in almost all time windows. Specially, a lower risk for liver injury was observed in the first 14 days following FO-LEs administration (ASR, 3.42; 95% CI, 0.81–14.47), but the risk started to rise in longer time windows.Conclusion: A strong association was found between LEs use and liver injury through prescription sequence symmetry analysis in a real-world setting, which aligns with trial evidence and clinical experience. Differences revealed in the risks of liver injury among various LEs need further evaluation.

scholarly journals Participatory Budgeting with Project Interactions

2020 ◽  
Author(s):  
Pallavi Jain ◽  
Krzysztof Sornat ◽  
Nimrod Talmon
Keyword(s):  
Computational Complexity ◽  
Standard Model ◽  
Real World ◽  
Participatory Budgeting ◽  
Aggregation Methods ◽  
The Standard Model ◽  
Public Money ◽  
Complementarity Effects

Participatory budgeting systems allow city residents to jointly decide on projects they wish to fund using public money, by letting residents vote on such projects. While participatory budgeting is gaining popularity, existing aggregation methods do not take into account the natural possibility of project interactions, such as substitution and complementarity effects. Here we take a step towards fixing this issue: First, we augment the standard model of participatory budgeting by introducing a partition over the projects and model the type and extent of project interactions within each part using certain functions. We study the computational complexity of finding bundles that maximize voter utility, as defined with respect to such functions. Motivated by the desire to incorporate project interactions in real-world participatory budgeting systems, we identify certain cases that admit efficient aggregation in the presence of such project interactions.

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