Ulrik Brandes
Dados Biográficos
| ID | 635642 |
|---|---|
| NOME | Ulrik Brandes |
| PRENOMES | Ulrik |
| SOBRENOME | Brandes |
| ASSINATURA | BRANDES U |
| AFILIAÇÕES | University of Konstanz |
| ORCID | 0000-0002-1520-0430 |
| VERIFICADO | Sim |
| TOTAL DE OBRAS | 30 |
| TOTAL DE CITAÇÕES | 293 |
| TOTAL COMO AUTOR | 29 |
| TOTAL COMO EDITOR | 1 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 1999 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2026 |
| ÍNDICE H | 7 |
Centrality in directed networks
The identification of important nodes in a network is a pervasive task in a variety of disciplines from sociology and bibliometry to geography and chemistry, and an ever growing number of centrality indices is proposed for this purpose. While such indices are often ad-hoc, preservation of the vicinal preorder has been identified as the core axiom shared by centrality rankings on undirected graphs. We extend this idea to directed graphs by definin…
Influence, inertia, and independence
In this work, we propose a di usion model for temporal social networks and relate it to other well-known models of social in uence by investigating its formal properties. The model establishes dyadic in uence weights based on two antagonistic components: the susceptibility to be in uenced (or, conversely, inertia with respect to the status quo) and becoming independent of prior in uence. The proposed model generalizes the Friedkin-Johnsen model b…
Coaching legacies
We study the lineage network of coaches in the Australian Football League (AFL) using a novel process of influence propagation through temporal social networks. Coaching and being coached are considered major opportunities for learning, and the vast majority of AFL coaches are former AFL players. We, therefore, establish influence via two antagonistic components: as players, future coaches are influenced by their coaches, and later liberate thems…
A holistic provenance and microwear study of pre-colonial jade objects from the Virgin Islands
Pre-colonial Caribbean jade objects from the National Museum of Denmark Hatt Collection were subjected to a provenance and microwear analysis. Thirty-nine jade celts and bodily ornaments from the US Virgin Islands, i.e., St. Croix, St. Thomas, St. John, and five celts from the West Indies of unknown location, St. Vincent, Cuba and the Dominican Republic were analysed. A comprehensive in-depth examination of jade adornments from St. Croix, combini…
The evolution of roles
We propose a novel formalization of roles in social networks that unifies the most commonly used definitions of role equivalence. As one consequence, we obtain a single, straightforward proof that role equivalences form lattices. Our formalization focuses on the evolution of roles from arbitrary initial conditions and thereby generalizes notions of relative and iterated roles that have been suggested previously. In addition to the unified structu…
Trace-elemental and multi-isotopic (Sr-Nd-Pb) discrimination of jade in the circum-Caribbean
Dense and strong, hydrothermal-metasomatic jadeitite and jadeite-omphacite rocks were used as tools and adornments throughout the wider Caribbean since initial inhabitation. Regionally, rich sources of jadeitite and jadeite-omphacite jade are known only in Guatemala (north and south of the Motagua Fault Zone), eastern Cuba and the northern Dominican Republic, establishing that humans transported jadeitic material over vast distances. This study v…
Plainware and Polychrome
A common problem when classifying archaeological objects is a potential cultural bias of the person deciding on the classification system. These are existing concerns within archaeology and anthropology and have previously been discussed as an emic/etic divide, “folk” classifications, or objective versus subjective approaches. But who gets to decide what is objective is often a subjective endeavour. To examine if and how cultural perceptions bias…
A Framework for Reconstructing Archaeological Networks Using Exponential Random Graph Models
Reconstructing ties between archaeological contexts may contribute to explain and describe a variety of past social phenomena. Several models have been formulated to infer the structure of such archaeological networks. The applicability of these models in diverse archaeological contexts is limited by the restricted set of assumptions that fully determine the mathematical formulation of the models and are often articulated on a dyadic basis. Here,…
Social networks and similarity of site assemblages
Reconstructing Archaeological Networks with Structural Holes
Model-based reconstruction is an approach to infer network structures where they cannot be observed. For archaeological networks, several models based on assumptions concerning distance among sites, site size, or costs and benefits have been proposed to infer missing ties. Since these assumptions are formulated at a dyadic level, they do not provide means to express dependencies among ties and therefore include less plausible network scenarios. I…
Exploring Transformations in Caribbean Indigenous Social Networks through Visibility Studies
This paper presents a study of the visual properties of natural and Amerindian cultural landscapes in late pre-colonial East-Guadeloupe and of how these visual properties affected social interactions. Through a review of descriptive and formal visibility studies in Caribbean archaeology, it reveals that the ability of visual properties to affect past human behaviour is frequently evoked but the more complex of these hypotheses are rarely studied …
Correlations among centrality indices and a class of uniquely ranked graphs
Social network analysis in sport research
While network analysis is a major methodological approach in many disciplines of the social and natural sciences, it has only recently come into the focus of sport researchers. This article assesses the utility of network analysis to analyze sport phenomena. We begin with an overview of social network analysis (SNA) and related concepts. To explore research topics and approaches, we conduct a systematic review of empirical literature of SNA and i…
Investigating Link Inference in Partially Observable Networks
While privacy preserving mechanisms, such as hiding one's friends list, may be available to withhold personal information on online social networking sites, it is not obvious whether to which degree a user's social behavior renders such an attempt futile. In this paper, we study the impact of additional interaction information on the inference of links between nodes in partially covert networks. This investigation is based on the assumption that …
Maintaining the duality of closeness and betweenness centrality
On graphical representations of similarity in geo-temporal frequency data
Its focus on dependencies and patterns in relational data makes network science a promising addition to the analytic toolbox in archaeology. Despite its tradition in a number of other fields, however, the methodology of network science is only in development and its scope and proper usage are subject to debate. We argue that the historical linkage with graph theory and limitations in commonly available software form an obstacle to leveraging the …
Network positions
A formal definition of position in networks is proposed. Based on the conceptualization of networks as data on intersecting dyads, it leads to integrated means of analysis for various kinds of relational and attribute data and to a simultaneous unification and generalization of a wide range of network-analytic methods. In fact, by defining network positions explicitly, various methods can be broken down into sequences of generic steps that are mo…
Social Network Algorithms and Software
Smallest graphs with distinct singleton centers
An incredible number of centrality indices has been proposed to date (Todeschini & Consonni, 2009). Four of them, however, can be considered prototypical because they operationalize distinct concepts of centrality and together cover the bulk of analyses and empirical uses: degree, closeness, betweenness, and eigenvector centrality
Relative importance of effects in stochastic actor-oriented models
A measure of relative importance of network effects in the stochastic actor-oriented model (SAOM) is proposed. The SAOM is a parametric model for statistical inference in longitudinal social networks. The complexity of the model makes the interpretation of inferred results difficult. So far, the focus is on significance tests while the relative importance of effects is usually ignored. Indeed, there is no established measure to determine the rela…
What is network science
This is the beginning of Network Science . The journal has been created because network science is exploding. As is typical for a field in formation, the discussions about its scope, contents, and foundations are intense. On these first few pages of the first issue of our new journal, we would like to share our own vision of the emerging science of networks
Modeling Open, Web-Based Collaboration Networks
Visualization methods for longitudinal social networks and stochastic actor-oriented modeling
Explorative Visualization of Citation Patterns in Social Network Research
We propose a visual representation of bibliographic data based on shared references. Our method employs a distance metric that is derived from bibliographic coupling and then subjected to fast approximate multidimensional scaling. Its utility is demonstrated by an explorative analysis of social network publications that, most notably, depicts the genesis of an area now commonly referred to as network science. However, the example also illustrates…
Longitudinal analysis of personal networks. The case of Argentinean migrants in Spain
A faster algorithm for betweenness centrality
Motivated by the fast‐growing need to compute centrality indices on large, yet very sparse, networks, new algorithms for betweenness are introduced in this paper. They require O(n + m) space and run in O(nm) and O(nm + n2 log n) time on unweighted and weighted networks, respectively, where m is the number of links. Experimental evidence is provided that this substantially increases the range of networks for which centrality analysis is feasible. …
What is network science
This is the beginning of Network Science . The journal has been created because network science is exploding. As is typical for a field in formation, the discussions about its scope, contents, and foundations are intense. On these first few pages of the first issue of our new journal, we would like to share our own vision of the emerging science of networks
On variants of shortest-path betweenness centrality and their generic computation
Relative importance of effects in stochastic actor-oriented models
A measure of relative importance of network effects in the stochastic actor-oriented model (SAOM) is proposed. The SAOM is a parametric model for statistical inference in longitudinal social networks. The complexity of the model makes the interpretation of inferred results difficult. So far, the focus is on significance tests while the relative importance of effects is usually ignored. Indeed, there is no established measure to determine the rela…
Social networks and similarity of site assemblages
Social network analysis in sport research
While network analysis is a major methodological approach in many disciplines of the social and natural sciences, it has only recently come into the focus of sport researchers. This article assesses the utility of network analysis to analyze sport phenomena. We begin with an overview of social network analysis (SNA) and related concepts. To explore research topics and approaches, we conduct a systematic review of empirical literature of SNA and i…
Explorations into the Visualization of Policy Networks
Visualization is an important aspect of both exploration and communication of categorical as well as relational data. Graphical displays of policy networks are particularly attractive, since they enable authors to display in a compact way the relevant actors in a network, how they are related to each other, and what the overall structure looks like. Sociograms were early companions of social network analysis, but have received surprisingly little…
Correlations among centrality indices and a class of uniquely ranked graphs
Network positions
A formal definition of position in networks is proposed. Based on the conceptualization of networks as data on intersecting dyads, it leads to integrated means of analysis for various kinds of relational and attribute data and to a simultaneous unification and generalization of a wide range of network-analytic methods. In fact, by defining network positions explicitly, various methods can be broken down into sequences of generic steps that are mo…
On graphical representations of similarity in geo-temporal frequency data
Its focus on dependencies and patterns in relational data makes network science a promising addition to the analytic toolbox in archaeology. Despite its tradition in a number of other fields, however, the methodology of network science is only in development and its scope and proper usage are subject to debate. We argue that the historical linkage with graph theory and limitations in commonly available software form an obstacle to leveraging the …
Trace-elemental and multi-isotopic (Sr-Nd-Pb) discrimination of jade in the circum-Caribbean
Dense and strong, hydrothermal-metasomatic jadeitite and jadeite-omphacite rocks were used as tools and adornments throughout the wider Caribbean since initial inhabitation. Regionally, rich sources of jadeitite and jadeite-omphacite jade are known only in Guatemala (north and south of the Motagua Fault Zone), eastern Cuba and the northern Dominican Republic, establishing that humans transported jadeitic material over vast distances. This study v…
Exploring Transformations in Caribbean Indigenous Social Networks through Visibility Studies
This paper presents a study of the visual properties of natural and Amerindian cultural landscapes in late pre-colonial East-Guadeloupe and of how these visual properties affected social interactions. Through a review of descriptive and formal visibility studies in Caribbean archaeology, it reveals that the ability of visual properties to affect past human behaviour is frequently evoked but the more complex of these hypotheses are rarely studied …
Reconstructing Archaeological Networks with Structural Holes
Model-based reconstruction is an approach to infer network structures where they cannot be observed. For archaeological networks, several models based on assumptions concerning distance among sites, site size, or costs and benefits have been proposed to infer missing ties. Since these assumptions are formulated at a dyadic level, they do not provide means to express dependencies among ties and therefore include less plausible network scenarios. I…
A Framework for Reconstructing Archaeological Networks Using Exponential Random Graph Models
Reconstructing ties between archaeological contexts may contribute to explain and describe a variety of past social phenomena. Several models have been formulated to infer the structure of such archaeological networks. The applicability of these models in diverse archaeological contexts is limited by the restricted set of assumptions that fully determine the mathematical formulation of the models and are often articulated on a dyadic basis. Here,…
Explorative Visualization of Citation Patterns in Social Network Research
We propose a visual representation of bibliographic data based on shared references. Our method employs a distance metric that is derived from bibliographic coupling and then subjected to fast approximate multidimensional scaling. Its utility is demonstrated by an explorative analysis of social network publications that, most notably, depicts the genesis of an area now commonly referred to as network science. However, the example also illustrates…
Explorations into the Visualization of Policy Networks
Visualization is an important aspect of both exploration and communication of categorical as well as relational data. Graphical displays of policy networks are particularly attractive, since they enable authors to display in a compact way the relevant actors in a network, how they are related to each other, and what the overall structure looks like. Sociograms were early companions of social network analysis, but have received surprisingly little…
A faster algorithm for betweenness centrality
Motivated by the fast‐growing need to compute centrality indices on large, yet very sparse, networks, new algorithms for betweenness are introduced in this paper. They require O(n + m) space and run in O(nm) and O(nm + n2 log n) time on unweighted and weighted networks, respectively, where m is the number of links. Experimental evidence is provided that this substantially increases the range of networks for which centrality analysis is feasible. …
Analysis and Visualization of Social Networks
Network Analysis
On variants of shortest-path betweenness centrality and their generic computation
Longitudinal analysis of personal networks. The case of Argentinean migrants in Spain
Explorative Visualization of Citation Patterns in Social Network Research
We propose a visual representation of bibliographic data based on shared references. Our method employs a distance metric that is derived from bibliographic coupling and then subjected to fast approximate multidimensional scaling. Its utility is demonstrated by an explorative analysis of social network publications that, most notably, depicts the genesis of an area now commonly referred to as network science. However, the example also illustrates…
Modeling Open, Web-Based Collaboration Networks
Visualization methods for longitudinal social networks and stochastic actor-oriented modeling
Relative importance of effects in stochastic actor-oriented models
A measure of relative importance of network effects in the stochastic actor-oriented model (SAOM) is proposed. The SAOM is a parametric model for statistical inference in longitudinal social networks. The complexity of the model makes the interpretation of inferred results difficult. So far, the focus is on significance tests while the relative importance of effects is usually ignored. Indeed, there is no established measure to determine the rela…
What is network science
This is the beginning of Network Science . The journal has been created because network science is exploding. As is typical for a field in formation, the discussions about its scope, contents, and foundations are intense. On these first few pages of the first issue of our new journal, we would like to share our own vision of the emerging science of networks
Smallest graphs with distinct singleton centers
An incredible number of centrality indices has been proposed to date (Todeschini & Consonni, 2009). Four of them, however, can be considered prototypical because they operationalize distinct concepts of centrality and together cover the bulk of analyses and empirical uses: degree, closeness, betweenness, and eigenvector centrality
Social Network Algorithms and Software
Investigating Link Inference in Partially Observable Networks
While privacy preserving mechanisms, such as hiding one's friends list, may be available to withhold personal information on online social networking sites, it is not obvious whether to which degree a user's social behavior renders such an attempt futile. In this paper, we study the impact of additional interaction information on the inference of links between nodes in partially covert networks. This investigation is based on the assumption that …
Maintaining the duality of closeness and betweenness centrality
On graphical representations of similarity in geo-temporal frequency data
Its focus on dependencies and patterns in relational data makes network science a promising addition to the analytic toolbox in archaeology. Despite its tradition in a number of other fields, however, the methodology of network science is only in development and its scope and proper usage are subject to debate. We argue that the historical linkage with graph theory and limitations in commonly available software form an obstacle to leveraging the …
Network positions
A formal definition of position in networks is proposed. Based on the conceptualization of networks as data on intersecting dyads, it leads to integrated means of analysis for various kinds of relational and attribute data and to a simultaneous unification and generalization of a wide range of network-analytic methods. In fact, by defining network positions explicitly, various methods can be broken down into sequences of generic steps that are mo…
Reconstructing Archaeological Networks with Structural Holes
Model-based reconstruction is an approach to infer network structures where they cannot be observed. For archaeological networks, several models based on assumptions concerning distance among sites, site size, or costs and benefits have been proposed to infer missing ties. Since these assumptions are formulated at a dyadic level, they do not provide means to express dependencies among ties and therefore include less plausible network scenarios. I…
Exploring Transformations in Caribbean Indigenous Social Networks through Visibility Studies
This paper presents a study of the visual properties of natural and Amerindian cultural landscapes in late pre-colonial East-Guadeloupe and of how these visual properties affected social interactions. Through a review of descriptive and formal visibility studies in Caribbean archaeology, it reveals that the ability of visual properties to affect past human behaviour is frequently evoked but the more complex of these hypotheses are rarely studied …
Correlations among centrality indices and a class of uniquely ranked graphs
Social network analysis in sport research
While network analysis is a major methodological approach in many disciplines of the social and natural sciences, it has only recently come into the focus of sport researchers. This article assesses the utility of network analysis to analyze sport phenomena. We begin with an overview of social network analysis (SNA) and related concepts. To explore research topics and approaches, we conduct a systematic review of empirical literature of SNA and i…
Social networks and similarity of site assemblages
A Framework for Reconstructing Archaeological Networks Using Exponential Random Graph Models
Reconstructing ties between archaeological contexts may contribute to explain and describe a variety of past social phenomena. Several models have been formulated to infer the structure of such archaeological networks. The applicability of these models in diverse archaeological contexts is limited by the restricted set of assumptions that fully determine the mathematical formulation of the models and are often articulated on a dyadic basis. Here,…
Plainware and Polychrome
A common problem when classifying archaeological objects is a potential cultural bias of the person deciding on the classification system. These are existing concerns within archaeology and anthropology and have previously been discussed as an emic/etic divide, “folk” classifications, or objective versus subjective approaches. But who gets to decide what is objective is often a subjective endeavour. To examine if and how cultural perceptions bias…
The evolution of roles
We propose a novel formalization of roles in social networks that unifies the most commonly used definitions of role equivalence. As one consequence, we obtain a single, straightforward proof that role equivalences form lattices. Our formalization focuses on the evolution of roles from arbitrary initial conditions and thereby generalizes notions of relative and iterated roles that have been suggested previously. In addition to the unified structu…
Computer Science (25 obras) · Complex Network Analysis Techniques (20 obras) · Mathematics (14 obras) · Theoretical Computer Science (10 obras) · World Wide Web (9 obras) · Artificial Intelligence (8 obras) · Data mining (8 obras) · Data science (8 obras) · Opinion Dynamics and Social Influence (7 obras) · Psychology (7 obras)