scholarly journals Complexity Analysis in Maintenance Systems

Author(s):  
Sareh Shafiei Monfared

Complexity is a very broad subject that applies to project management, engineering design and manufacturing, arithmetic, software, statistics, etc. In maintenance systems, complexity can be defined based on technical and managerial aspects of a maintenance project. Because relative complexity between two projects can be used as a yardstick for resource allocation between them, quantifying the complexity becomes important. To quantify the complexity of maintenance projects, this thesis reports two models. In uncertain situations, a fuzzy graph-based model is developed that determines relative complexities of maintenance projects based on experts‟ opinions with respect to technical and managerial aspects. These aspects may not be measured precisely due to uncertain situations. The model uses an aggregation operator to mitigate conflict of experts‟ opinions on complexity relations. Using a fuzzy relation matrix representing the degrees of membership of relative complexities, the model maps the fuzzy graph into a scaled Cartesian diagram. Also, complexity of a maintenance project can be investigated through time to repair (TTR). Performing statistical analysis shows that human cognition and project complexity have significant influence on TTR. These influential factors can be studied by a learning curve. Due to the nature of maintenance calls for repairs, a learning curve model made up of two segments is proposed. A project complexity can be derived from the learning curve at the breakpoint time. Taking into account human cognitive abilities, the breakpoint indicates the required number of trials in order to reach mastery level for performing certain tasks unsupervised.

2021 ◽  
Author(s):  
Sareh Shafiei Monfared

Complexity is a very broad subject that applies to project management, engineering design and manufacturing, arithmetic, software, statistics, etc. In maintenance systems, complexity can be defined based on technical and managerial aspects of a maintenance project. Because relative complexity between two projects can be used as a yardstick for resource allocation between them, quantifying the complexity becomes important. To quantify the complexity of maintenance projects, this thesis reports two models. In uncertain situations, a fuzzy graph-based model is developed that determines relative complexities of maintenance projects based on experts‟ opinions with respect to technical and managerial aspects. These aspects may not be measured precisely due to uncertain situations. The model uses an aggregation operator to mitigate conflict of experts‟ opinions on complexity relations. Using a fuzzy relation matrix representing the degrees of membership of relative complexities, the model maps the fuzzy graph into a scaled Cartesian diagram. Also, complexity of a maintenance project can be investigated through time to repair (TTR). Performing statistical analysis shows that human cognition and project complexity have significant influence on TTR. These influential factors can be studied by a learning curve. Due to the nature of maintenance calls for repairs, a learning curve model made up of two segments is proposed. A project complexity can be derived from the learning curve at the breakpoint time. Taking into account human cognitive abilities, the breakpoint indicates the required number of trials in order to reach mastery level for performing certain tasks unsupervised.


2020 ◽  
Vol 375 (1803) ◽  
pp. 20190495 ◽  
Author(s):  
Natalie Uomini ◽  
Joanna Fairlie ◽  
Russell D. Gray ◽  
Michael Griesser

Traditional attempts to understand the evolution of human cognition compare humans with other primates. This research showed that relative brain size covaries with cognitive skills, while adaptations that buffer the developmental and energetic costs of large brains (e.g. allomaternal care), and ecological or social benefits of cognitive abilities, are critical for their evolution. To understand the drivers of cognitive adaptations, it is profitable to consider distant lineages with convergently evolved cognitions. Here, we examine the facilitators of cognitive evolution in corvid birds, where some species display cultural learning, with an emphasis on family life. We propose that extended parenting (protracted parent–offspring association) is pivotal in the evolution of cognition: it combines critical life-history, social and ecological conditions allowing for the development and maintenance of cognitive skillsets that confer fitness benefits to individuals. This novel hypothesis complements the extended childhood idea by considering the parents' role in juvenile development. Using phylogenetic comparative analyses, we show that corvids have larger body sizes, longer development times, extended parenting and larger relative brain sizes than other passerines. Case studies from two corvid species with different ecologies and social systems highlight the critical role of life-history features on juveniles’ cognitive development: extended parenting provides a safe haven, access to tolerant role models, reliable learning opportunities and food, resulting in higher survival. The benefits of extended juvenile learning periods, over evolutionary time, lead to selection for expanded cognitive skillsets. Similarly, in our ancestors, cooperative breeding and increased group sizes facilitated learning and teaching. Our analyses highlight the critical role of life-history, ecological and social factors that underlie both extended parenting and expanded cognitive skillsets. This article is part of the theme issue ‘Life history and learning: how childhood, caregiving and old age shape cognition and culture in humans and other animals’.


2013 ◽  
Vol 357-360 ◽  
pp. 2353-2357 ◽  
Author(s):  
Xu Dong He ◽  
Yuan Li Wang ◽  
Yuan Yuan Zhang

We attempt to study the participants behavioral risks of the complex project based on the theory of complexity analysis in this paper. First of all, through the review of literature we put forward the research contents of the complexity theory. Then, discuss the complexity characteristics of the project management; focus on the definition of the project complexity, the nonlinear characteristics of the project organization, the emergence and uncertainty characteristics of the complex project, etc. Finally, we point out that both from the perspective of theoretical research and project practice, the complexity analysis of project management has a positive significance.


2011 ◽  
Vol 54 (4) ◽  
pp. 93-109
Author(s):  
Miljana Milojevic

The aim of this paper is to show how a new outlook on human cognitive abilities, and in accordance with this a different view of rationality, can influence semantics and one of the most prominent debates in this field, namely, conflict between Fregeans and non Fregean anti-indiviidualists. This new account of rationality will help us difuse some of the main motivators for Fregean view of semantics and it will help us in justifying non-Fregean anti-individualism but also in eliminating some of the apparent contradictions in Fregean anti-individualism of, e.g. Campbell and Evans. In this attempt of bringing together some of the latest insights into human cognition and semantics I will be dealing mainly with Jessica Brown's outlook on motivation for Fregean sense and Ruth Millikan's embedded view on rationality.


Anthropology ◽  
2020 ◽  
Author(s):  
Frederick L. Coolidge ◽  
Thomas Wynn

Cognitive archaeology may be divided into two branches. Evolutionary cognitive archaeology (ECA) is the discipline of prehistoric archaeology that studies the evolution of human cognition. Practitioners are united by a methodological commitment to the idea that archaeological traces of past activity provide access to the minds of the agents responsible. The second branch, ideational cognitive archaeology, encompasses archaeologists who strive to discover the meaning of symbolic system, primarily through the analysis of iconography. This approach differs from ECA in its epistemology, historical roots, and citation universes, and focuses on comparatively recent time periods (after 10,000 years ago). Evolutionary cognitive archaeologists are concerned with the nature of cognition itself, and its evolutionary development from the time of the last common ancestor with chimpanzees to the final ascendancy of modern humans at the end of the Pleistocene. Although ECA methods are primarily archaeological, its theoretical grounding is in the cognitive sciences, including cognitive psychology, neuropsychology, and cognitive neuroscience. It is by its nature interdisciplinary. ECA differs from the allied discipline of evolutionary psychology in several important respects. Methodologically, ECA is a macroevolutionary science that studies physical evidence of past human cognition, including archaeological and fossil remains. Evolutionary psychology relies heavily on reverse engineering from controlled experiments on living humans. Theoretically, ECA is more eclectic, drawing on a variety of cognitive and evolutionary models; evolutionary psychology is committed to a neo-Darwinian, selectionist understanding of evolutionary change. The two approaches tend to study different components of human mental life, but are not inherently contradictory. ECA practitioners reconstruct prehistoric activities using well-established archaeological methods and techniques, including morphological analysis of artifacts to identify action sequences and decision patterns, functional analyses (e.g., microwear) to identify use patterns, and spatial patterns within sites to recognize activity loci (e.g., hearths). An increasingly important method is the actualistic recreation of prehistoric technologies to identify features not preserved in the archaeological remains. Neuroarchaeologists enhance such actualistic research by imaging the brains of the participants (most typically using fMRI), an approach that also contributes directly to cognitive science’s understanding of the neural basis of technical cognition. ECA practitioners take two non-mutually exclusive approaches to documenting human cognitive evolution. The first approach enriches the understanding of specific hominin taxa (i.e., Homo sapiens and their direct ancestors since 6 million years ago) by providing accounts of their cognitive life worlds, or by contrasting two taxa with one another. This approach is famously exemplified by attempts to contrast the abilities of Neandertals with those of modern humans. The second approach traces the evolution of specific cognitive abilities from the first appearance of stone tools 3.3 million years ago to the emergence of city-states 5,000 years ago. The range of accessible cognitive abilities is limited by the nature of archaeological remains, but evolutionary cognitive archaeologists have been able to trace developments in spatial cognition, memory, cognitive control, technical expertise, theory of mind, aesthetic cognition, symbolism, language, and numeracy.


2012 ◽  
Vol 367 (1599) ◽  
pp. 2091-2096 ◽  
Author(s):  
Cecilia Heyes

Humans are animals that specialize in thinking and knowing, and our extraordinary cognitive abilities have transformed every aspect of our lives. In contrast to our chimpanzee cousins and Stone Age ancestors, we are complex political, economic, scientific and artistic creatures, living in a vast range of habitats, many of which are our own creation. Research on the evolution of human cognition asks what types of thinking make us such peculiar animals, and how they have been generated by evolutionary processes. New research in this field looks deeper into the evolutionary history of human cognition, and adopts a more multi-disciplinary approach than earlier ‘Evolutionary Psychology’. It is informed by comparisons between humans and a range of primate and non-primate species, and integrates findings from anthropology, archaeology, economics, evolutionary biology, neuroscience, philosophy and psychology. Using these methods, recent research reveals profound commonalities, as well striking differences, between human and non-human minds, and suggests that the evolution of human cognition has been much more gradual and incremental than previously assumed. It accords crucial roles to cultural evolution, techno-social co-evolution and gene–culture co-evolution. These have produced domain-general developmental processes with extraordinary power—power that makes human cognition, and human lives, unique.


Author(s):  
Lambros Malafouris ◽  
Chris Gosden

The study of material culture is changing the way we perceive and study the past, as well as how we understand the process of human becoming. This chapter proposes that a focus on the phenomenon of material engagement provides a productive means to situate and integrate evolutionary, historical, and developmental processes. The material engagement approach brings with it a relational conceptualization of human cognition as profoundly embodied, enacted, extended, and distributed. This conceptualisation opens the way to, on the one hand, reanimate the importance of history and development in the study of human cognitive evolution, and on the other hand, allow a new approach to historical analysis, one in which minds and things play a more central role. Specifically, we explore some of the implications of the view that humans and things coconstitute each other for understanding the processes by which human cognitive abilities develop and change in different cultural and historical contexts.


2019 ◽  
Author(s):  
Julian Baur ◽  
Jean d’Amour ◽  
David Berger

Abstract“The mating mind hypothesis”, originally aimed at explaining human cognition, holds that the socio-sexual environment shapes cognitive abilities among animals. Similarly, general sexual selection theory predicts that mate competition should benefit individuals carrying “good genes” with beneficial pleiotropic effects on general cognitive ability. However, few experimental studies have evaluated these related hypotheses due to difficulties of performing direct tests in most taxa. Here we harnessed the empirical potential of the seed beetle study system to investigate the role of sexual selection and mating system in the evolution of cognition. We evolved replicate lines of beetle under enforced monogamy (eliminating sexual selection) or polygamy for 35 generations and then challenged them to locate and discriminate among mating partners (male assays) or host seeds (female assays). To assess learning, the same beetles performed the task in three consecutive rounds. All lines learned the task, improving both within and between trails. Moreover, polygamous males outperformed monogamous males. However, there were no differences in the rate of learning between males of the two regimes, and polygamous females showed no improvement in host search, and even signs of reduced learning. Hence, while sexual selection was a potent factor that increased cognitive performance in mate search, it did not lead to the general increase in cognitive abilities expected under the “mating mind” hypothesis or general “good genes” theory. Our results highlight sexually antagonistic (balancing) selection as a potential force maintaining genetic variation in cognitive traits.


2017 ◽  
Author(s):  
A. Coutrot ◽  
R. Silva ◽  
E. Manley ◽  
W. de Cothi ◽  
S. Sami ◽  
...  

SummaryCountries vary in their geographical and cultural properties. Only a few studies have explored how such variations influence how humans navigate or reason about space [1–7]. We predicted that these variations impact human cognition, resulting in an organized spatial distribution of cognition at a planetary-wide scale. To test this hypothesis we developed a mobile-app-based cognitive task, measuring non-verbal spatial navigation ability in more than 2.5 million people, sampling populations in every nation state. We focused on spatial navigation due to its universal requirement across cultures. Using a clustering approach, we find that navigation ability is clustered into five distinct, yet geographically related, groups of countries. Specifically, the economic wealth of a nation was predictive of the average navigation ability of its inhabitants, and gender inequality was predictive of the size of performance difference between males and females. Thus, cognitive abilities, at least for spatial navigation, are clustered according to economic wealth and gender inequalities globally, which has significant implications for cross-cultural studies and multi-centre clinical trials using cognitive testing.


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