problem structure
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2021 ◽  
pp. 1-20
Author(s):  
Shusaku Egami ◽  
Takahiro Kawamura ◽  
Kouji Kozaki ◽  
Akihiko Ohsuga

Abstract Urban areas have many problems, including homelessness, graffiti, and littering. These problems are influenced by various factors and are linked to each other; thus, an understanding of the problem structure is required in order to detect and solve the root problems that generate vicious cycles. Moreover, before implementing action plans to solve these problems, local governments need to estimate cost-effectiveness when the plans are carried out. Therefore, this paper proposes constructing an urban problem knowledge graph that would include urban problems' causality and the related cost information in budget sheets. In addition, this paper proposes a method for detecting vicious cycles of urban problems using SPARQL queries with inference rules from the knowledge graph. Finally, several root problems that led to vicious cycles were detected. Urban-problem experts evaluated the extracted causal relations.


2021 ◽  
pp. 1-21
Author(s):  
Chloe M. Barnes ◽  
Abida Ghouri ◽  
Peter R. Lewis

Abstract Understanding how evolutionary agents behave in complex environments is a challenging problem. Agents can be faced with complex fitness landscapes derived from multi-stage tasks, interaction with others, and limited environmental feedback. Agents that evolve to overcome these can sometimes access greater fitness, as a result of factors such as cooperation and tool use. However, it is often difficult to explain why evolutionary agents behave in certain ways, and what specific elements of the environment or task may influence the ability of evolution to find goal-achieving behaviours; even seemingly simple environments or tasks may contain features that affect agent evolution in unexpected ways. We explore principled simplification of evolutionary agent-based models, as a possible route to aiding their explainability. Using the River Crossing Task (RCT) as a case study, we draw on analysis in the Minimal River Crossing (RC-) Task testbed, which was designed to simplify the original task while keeping its key features. Using this method, we present new analysis concerning when agents evolve to successfully complete the RCT. We demonstrate that the RC- environment can be used to understand the effect that a cost to movement has on agent evolution, and that these findings can be generalised back to the original RCT. Then, we present new insight into the use of principled simplification in understanding evolutionary agents. We find evidence that behaviour dependent on features that survive simplification, such as problem structure, are amenable to prediction; while predicting behaviour dependent on features that are typically reduced in simplification, such as scale, can be invalid.


2021 ◽  
Author(s):  
Waranya Mahanan ◽  
W. Art Chaovalitwongse ◽  
Juggapong Natwichai

AbstractWith growing concern of data privacy violations, privacy preservation processes become more intense. The k-anonymity method, a widely applied technique, transforms the data such that the publishing datasets must have at least k tuples to have the same link-able attribute, quasi-identifiers, values. From the observations, we found that, in a certain domain, all quasi-identifiers of the datasets, can have the same data type. This type of attribute is considered as an Identical Generalization Hierarchy (IGH) data. An IGH data has a particular set of characteristics that could utilize for enhancing the efficiency of heuristic privacy preservation algorithms. In this paper, we propose a data privacy preservation heuristic algorithm on IGH data. The algorithm is developed from the observations on the anonymous property of the problem structure that can eliminate the privacy constraints consideration. The experiment results are presented that the proposed algorithm could effectively preserve data privacy and also reduce the number of visited nodes for ensuring the privacy protection, which is the most time-consuming process, compared to the most efficient existing algorithm by at most 21%.


2021 ◽  
Vol 1 (2) ◽  
pp. 1-23
Author(s):  
Arkadiy Dushatskiy ◽  
Tanja Alderliesten ◽  
Peter A. N. Bosman

Surrogate-assisted evolutionary algorithms have the potential to be of high value for real-world optimization problems when fitness evaluations are expensive, limiting the number of evaluations that can be performed. In this article, we consider the domain of pseudo-Boolean functions in a black-box setting. Moreover, instead of using a surrogate model as an approximation of a fitness function, we propose to precisely learn the coefficients of the Walsh decomposition of a fitness function and use the Walsh decomposition as a surrogate. If the coefficients are learned correctly, then the Walsh decomposition values perfectly match with the fitness function, and, thus, the optimal solution to the problem can be found by optimizing the surrogate without any additional evaluations of the original fitness function. It is known that the Walsh coefficients can be efficiently learned for pseudo-Boolean functions with k -bounded epistasis and known problem structure. We propose to learn dependencies between variables first and, therefore, substantially reduce the number of Walsh coefficients to be calculated. After the accurate Walsh decomposition is obtained, the surrogate model is optimized using GOMEA, which is considered to be a state-of-the-art binary optimization algorithm. We compare the proposed approach with standard GOMEA and two other Walsh decomposition-based algorithms. The benchmark functions in the experiments are well-known trap functions, NK-landscapes, MaxCut, and MAX3SAT problems. The experimental results demonstrate that the proposed approach is scalable at the supposed complexity of O (ℓ log ℓ) function evaluations when the number of subfunctions is O (ℓ) and all subfunctions are k -bounded, outperforming all considered algorithms.


Covid-19 pandemic has created unprecedented interruption for the global business industry management. The world economy already facing a turbulent phase experienced the worst scenario in the view of this pandemic. Business management strategists and policymakers have been making an impact assessment to understand the problem structure of this worst possible pandemic situation. The present article tries to develop a viewpoint on Covid-19 impact on business industries and management. Further authors attempt to develop a problem-solving structure by discussing the best possible solutions to mitigate the fact on the one hand and facilitating the business process in various sectors such as business Industry, Marketing, finance, and health industries on the other.


Author(s):  
Yihong Dong ◽  
Lunchen Xie ◽  
Qingjiang Shi

The rotation averaging problem is a fundamental task in computer vision applications. It is generally very difficult to solve due to the nonconvex rotation constraints. While a sufficient optimality condition is available in the literature, there is a lack of a fast convergent algorithm to achieve stationary points. In this paper, by exploring the problem structure, we first propose a block coordinate descent (BCD)-based rotation averaging algorithm with guaranteed convergence to stationary points. Afterwards, we further propose an alternative rotation averaging algorithm by applying successive upper-bound minimization (SUM) method. The SUM-based rotation averaging algorithm can be implemented in parallel and thus is more suitable for addressing large-scale rotation averaging problems. Numerical examples verify that the proposed rotation averaging algorithms have superior convergence performance as compared to the state-of-the-art algorithm. Moreover, by checking the sufficient optimality condition, we find from extensive numerical experiments that the proposed two algorithms can achieve globally optimal solutions.


Global Policy ◽  
2021 ◽  
Vol 12 (S1) ◽  
pp. 8-19
Author(s):  
Sikina Jinnah ◽  
David Morrow ◽  
Simon Nicholson

2021 ◽  
Vol 13 (2) ◽  
pp. 985
Author(s):  
Adem Pınar ◽  
Rouyendegh Babak Daneshvar ◽  
Yavuz Selim Özdemir

Supply chain management is to improve competitive stress. In today’s world, competitive terms and customer sense have altered in favor of an environmentalist manner. As a result of this, green supplier selection has become a very important topic. In the green supplier selection approach, agility, lean process, sustainability, environmental sensitivity, and durability are pointed. Like the classical supplier selection problems, environmental criteria generally emphasize green supplier selection. However, these two problem approaches are different from each other in terms of carbon footprint, water consumption, environmental and recycling applications. Due to the problem structure, a resolution is defined that includes an algorithm based on q-Rung Orthopair Fuzzy (q-ROF) TOPSIS method. Brief information about q-ROF sets is given before the methodology of the q-ROF model is introduced. By using the proposed method and q-ROF sets, an application was made with today’s uncertain conditions. In the conclusion part, a comparison is made with classical TOPSIS, Intuitionistic Fuzzy TOPSIS and q-ROF TOPSIS methodology. As a result, more stable and accurate results are obtained with q-ROF TOPSIS.


Author(s):  
Aitalina Akhmetovna Kuzmina

This article is dedicated to the creation of a folklore subcorpus of the national corpus of Yakut language. The need for creating a folklore subcorpus is substantiated by fact that it illustrates the initial, historical path of development of a particular language, cultural and linguistic richness, and folk traditions. Language corpora are considered incomplete if not contain folklore texts. The development of such subcorpus has a number of theoretical and technological difficulties, which defines the relevance of this work. The object of this research is the folklore subcorpus of the national corpus of Yakut language. The subject is articulation of the problem, structure, and technique of creating this subcorpus. Attention is focused on the problematic of creation of a folklore subcorpus. The scientific novelty lies in the fact that this article is first to develop the concept of creation of the Yakut folklore corpus and determine the cognate problems, structure and technique of its formation. It is revealed that the structure of folklore subcorpus must reflect the genre differences, forms of record, authenticity, various databases that characterize a folklore text, its performer or register.  The author determines the work stages and preparation technique of the folklore subcorpus. The conclusion is made that the folklore subcorpus can serve as a method for solution of fundamental and applied tasks of Yakut philology, as well as one of the ways to preserve folklore heritage of the Sakha people.


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