Multi-objective community detection applied to social and COVID-19 constructed networks

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University LondonCommunity Detection plays an integral part in network analysis, as it facilitates understanding the structures and functional characteristics of the network. Communities organize real-world networks into densely connected groups of nodes. This thesis provides a critical analysis of the Community Detection and highlights the main areas including algorithms, evaluation metrics, applications, and datasets in social networks. After defining the research gap, this thesis proposes two Attribute-Based Label Propagation algorithms that maximizes both Modularity and homogeneity. Homogeneity is considered as an objective function one time, and as a constraint another time. To better capture the homogeneity of real-world networks, a new Penalized Homogeneity degree (PHd) is proposed, that can be easily personalized based on the network characteristics. For the first time, COVID-19 tracing data are utilized to form two dataset networks: one is based on the virus transition between the world countries. While the second dataset is an attributed network based on the virus transition among the contact-tracing in the Kingdom of Bahrain. This type of networks that is concerned in tracking a disease was not formed based on COVID-19 virus and has never been studied as a community detection problem. The proposed datasets are validated and tested in several experiments. The proposed Penalized Homogeneity measure is personalized and used to evaluate the proposed attributed network. Extensive experiments and analysis are carried out to evaluate the proposed methods and benchmark the results with other well-known algorithms. The results are compared in terms of Modularity, proposed PHd, and accuracy measures. The proposed methods have achieved maximum performance among other methods, with 26.6% better performance in Modularity, and 33.96% in PHd on the proposed dataset, as well as noteworthy results on benchmarking datasets with improvement in Modularity measures of 7.24%, and 4.96% respectively, and proposed PHd values 27% and 81.9%

Attributed-Based Label Propagation Method for Balanced Modularity and Homogeneity Community Detection

Community Detection is an expanding field of interest in many scopes, e.g., social science, bibliometrics, marketing and recommendations, biology etc. Various community detection tools and methods have been proposed in the last years. This research is to develop an improved Label Propagation algorithm (Attribute-Based Label Propagation ABLP) that considers the nodes’ attributes to achieve a fair Homogeneity value, while maintaining high Modularity measure. It also formulates an adaptive Homogeneity measure, with penalty and weight modulation, that can be utilized in consonance with the user’s requirements. Based on the literature review, a research gap of employing Homogeneity in Community Detection was identified, and accordingly, Homogeneity as a constraint in Modularity based methods is investigated. In addition, a novel dataset constructed on COVID-19 contact tracing in the Kingdom of Bahrain is proposed, to help identify communities of infected persons and study their attributes’ values. The implementation of proposed algorithm performed high Modularity and Homogeneity measures compared with other algorithms

Link Prediction in Complex Networks: A Survey

Link prediction in complex networks has attracted increasing attention from both physical and computer science communities. The algorithms can be used to extract missing information, identify spurious interactions, evaluate network evolving mechanisms, and so on. This article summaries recent progress about link prediction algorithms, emphasizing on the contributions from physical perspectives and approaches, such as the random-walk-based methods and the maximum likelihood methods. We also introduce three typical applications: reconstruction of networks, evaluation of network evolving mechanism and classification of partially labelled networks. Finally, we introduce some applications and outline future challenges of link prediction algorithms.Comment: 44 pages, 5 figure

Maori facial tattoo (Ta Moko): implications for face recognition processes.

Ta Moko is the art of the Maori tattoo. It was an integral aspect of Maori society and is currently seeing resurgence in popularity. In particular it is linked with ancestry and a sense of “Maori” pride. Ta Moko is traditionally worn by Maori males on the buttocks and on the face, while Maori women wear it on the chin and lips. With curvilinear lines and spiral patterns applied to the face with a dark pigment, the full facial Moko creates a striking appearance. Given our reliance on efficiently encoding faces this transformation could potentially interfere with how viewers normally process and recognise the human face (e.g. configural information). The pattern’s effects on recognising identity, expression, race, speech, and gender are considered, and implications are drawn, which could help wearers and viewers of Ta Moko understand why sustained attention (staring) is drawn to such especially unique faces

Effigy Mounds, Social Identity, and Ceramic Technology: Decorative Style, Clay Composition, and Petrography of Wisconsin Late Woodland Vessels

This ceramic analysis is focused on a combination of technical and decorative analyses involving energy dispersive X-ray fluorescence (EDXRF) and petrographic data unused by or unavailable to previous researchers. The ceramics used in this study are non-collared forms of Late Woodland (AD 700 - 1200) types found across southern Wisconsin. Ceramic attributes from these data sets are analyzed using multi-variate statistical methods and the resulting clusters are plotted geographically. Results indicate regionalization of particular attributes with a major east-west trend noted in some cases. However, geographical plotting shows broad overlap among river valleys and locales. Importantly, EDXRF data demonstrates that ceramics or clays were transported across the landscape. The results are used to assess three models commonly used to explain Late Woodland group spatial distribution and interaction: Monolithic, Low-level Territorial, and High-level Territorial. However, while it is argued the Low-level Territorial model best respresents the data, the ceramic attributes indicate that multiple types of social organizations were practiced over space and time during the Late Woodland and that multiple territorial models are necessary to fully understand the social interactions occurring during this period. Finally, it is hypothesized that these results are best approached from a performance perspective where the social organization provides a contextual basis for investigating the daily performance of pottery making. Pottery manufacture is used to assess the constant making and re-making of social relationships at multiple levels of interaction in an egalitarian setting. It is hypothesized that different suites of attributes reflect different levels of group membership and that potters are consciously selecting attributes to negotiate these nested relationships through the practice of pottery construction

Pottery Making and Communities During the 5th Millennium BCE in Fars Province, Southwestern Iran

This book explores pottery making and communities during the Bakun period (c. 5000 – 4000 BCE) in the Kur River Basin, Fars province, southwestern Iran, through the analysis of ceramic materials collected at Tall-e Jari A, Tall-e Gap, and Tall-e Bakun A & B. Firstly, it reconsiders the stratigraphy and radiocarbon dates of the four sites by reviewing the descriptions of excavation trenches, then presents a new chronological relationship between the sites. The book sets out diachronic changes in the the Bakun pottery quantitatively, namely the increase of black-on-buff ware and the gradual shift of vessel forms. It also presents analyses of pottery-making techniques, painting skills, petrography, and geochemistry and clarifies minor changes in the chaînes opératoires and major changes in painting skill. Finally, the book discusses the organisation of pottery production from a relational perspective. It concludes that the more fixed community of pottery making imposed longer apprenticeship periods and that social inequality also increased