CiteULike: RafG's library [244 articles]

Scholarly research and information practices: a domain analytic approach

J Fry — 2007-09-04T16:22:05-00:00

Information Processing & Management, Vol. 42, No. 1. (January 2006), pp. 299-316.

This paper deals with information needs, seeking, searching, and uses within scholarly communities by introducing theory from the field of science and technology studies. In particular it contributes to the domain-analytic approach in information science by showing that Whitley's theory of `mutual dependence' and `task uncertainty' can be used as an explanatory framework in understanding similarity and difference in information practices across intellectual fields. Based on qualitative case studies of three specialist scholarly communities across the physical sciences, applied sciences, social sciences and arts and humanities, this paper extends Whitley's theory into the realm of information communication technologies. The paper adopts a holistic approach to information practices by recognising the interrelationship between the traditions of informal and formal scientific communication and how it shapes digital outcomes across intellectual fields. The findings show that communities inhabiting fields with a high degree of `mutual dependence' coupled with a low degree of `task uncertainty' are adept at coordinating and controlling channels of communication and will readily co-produce field-based digital information resources, whereas communities that inhabit fields characterised by the opposite cultural configuration, a low degree of `mutual dependence' coupled with a high degree of `task uncertainty', are less successful in commanding control over channels of communication and are less concerned with co-producing field-based digital resources and integrating them into their epistemic and social structures. These findings have implications for the culturally sensitive development and provision of academic digital resources such as digital libraries and web-based subject portals.

Finding scientific gems with Google's PageRank algorithm

P Chen — 2008-04-21T06:02:28-00:00

Journal of Informetrics, Vol. 1, No. 1. (January 2007), pp. 8-15.

We apply the Google PageRank algorithm to assess the relative importance of all publications in the Physical Review family of journals from 1893 to 2003. While the Google number and the number of citations for each publication are positively correlated, outliers from this linear relation identify some exceptional papers or "gems" that are universally familiar to physicists.

The anatomy of a large-scale hypertextual Web search engine

Sergey Brin — 2004-11-22T17:49:28-00:00

Computer Networks and ISDN Systems, Vol. 30, No. 1--7. (1998), pp. 107-117.

In this paper, we present Google, a prototype of a large-scale search engine which makes heavy use of the structure present in hypertext. Google is designed to crawl and index the Web efficiently and produce much more satisfying search results than existing systems. The prototype with a full text and hyperlink database of at least 24 million pages is available at

Hirsch's h-index: A stochastic model

Quentin Burrell — 2008-06-06T13:58:49-00:00

Journal of Informetrics, Vol. 1, No. 1. (January 2007), pp. 16-25.

We propose a simple stochastic model for an author's production/citation process in order to investigate the recently proposed h-index for measuring an author's research output and its impact. The parametric model distinguishes between an author's publication process and the subsequent citation processes of the published papers. This allows us to investigate different scenarios such as varying the production/publication rates and citation rates as well as the researcher's career length. We are able to draw tentative results regarding the dependence of Hirsch's h-index on each of these fundamental parameters. We conjecture that the h-index is, according to this model, (approximately) linear in career length, log publication rate and log citation rate, at least for moderate citation rates.

Definitions of time series in citation analysis with special attention to the h-index

Yuxian Liu — 2008-05-14T12:36:44-00:00

Journal of Informetrics (2008)

Does the h index have predictive power?

JE Hirsch — 2007-11-28T00:17:55-00:00

Proceedings of the National Academy of Sciences, Vol. 104, No. 49. (26 November 2007), pp. 19193-19198.

Bibliometric measures of individual scientific achievement are of particular interest if they can be used to predict future achievement. Here we report results of an empirical study of the predictive power of the h index compared with other indicators. Our findings indicate that the h index is better than other indicators considered (total citation count, citations per paper, and total paper count) in predicting future scientific achievement. We discuss reasons for the superiority of the h index. 10.1073/pnas.0707962104

Toward a Social Semantic Web

Alexander Mikroyannidis — 2007-12-12T19:51:41-00:00

Computer, Vol. 40, No. 11. (2007), pp. 113-115.

The Semantic Web and Social Web are essentially compatible.

On variants of shortest-path betweenness centrality and their generic computation

Ulrik Brandes — 2008-04-23T11:01:10-00:00

Social Networks, Vol. 30, No. 2. (May 2008), pp. 136-145.

Betweenness centrality based on shortest paths is a standard measure of control utilized in numerous studies and implemented in all relevant software tools for network analysis. In this paper, a number of variants are reviewed, placed into context, and shown to be computable with simple variants of the algorithm commonly used for the standard case.

Hirsch index or Hirsch rate? Some thoughts arising from Liang’s data

Quentin Burrell — 2008-04-11T13:00:05-00:00

Scientometrics, Vol. 73, No. 1. (22 October 2007), pp. 19-28.

Abstract Hirsch’s h-index gives a single number that in some sense summarizes an author’s research output and its impact. Since an individual author’s h-index will be time-dependent, we propose instead the h-rate which, according to theory, is (almost) constant. We re-analyse a previously published data set (Liang, 2006) which, although not of the precise form to properly test our model, reveals that in many cases we do not have a constant h-rate. On the other hand this then suggests ways in which deeper scientometric investigations could be carried out. This work should be viewed as complementary to that of Liang (2006).

H-index sequence and h-index matrix: Constructions and applications

Liming Liang — 2008-04-11T12:38:46-00:00

Scientometrics, Vol. 69, No. 1. (12 April 2006), pp. 153-159.

Summary The calculation of Hirsch's h-index is a detail-ignoring way, therefore, single h-index could not reflect the difference of time spans for scientists to accumulate their papers and citations. In this study the h-index sequence and the h-index matrix are constructed, which complement the absent details of single h-index, reveal different increasing manner and the increasing mechanism of the h-index, and make the scientists at different scientific age comparable.

A case study: Evolution of JASIS' Hirsch index

Ronald Rousseau — 2008-04-11T12:35:46-00:00

(2006)

The evolution of the Hirsch index of the Journal of the American Society of Information Science over the period 1991-2000 is studied using a variable citation window. A relative h-index is introduced.

Collective dynamics of 'small-world' networks.

DJ Watts — 2004-11-22T00:17:30-00:00

Nature, Vol. 393, No. 6684. (4 June 1998), pp. 440-442.

Networks of coupled dynamical systems have been used to model biological oscillators, Josephson junction arrays, excitable media, neural networks, spatial games, genetic control networks and many other self-organizing systems. Ordinarily, the connection topology is assumed to be either completely regular or completely random. But many biological, technological and social networks lie somewhere between these two extremes. Here we explore simple models of networks that can be tuned through this middle ground: regular networks 'rewired' to introduce increasing amounts of disorder. We find that these systems can be highly clustered, like regular lattices, yet have small characteristic path lengths, like random graphs. We call them 'small-world' networks, by analogy with the small-world phenomenon (popularly known as six degrees of separation. The neural network of the worm Caenorhabditis elegans, the power grid of the western United States, and the collaboration graph of film actors are shown to be small-world networks. Models of dynamical systems with small-world coupling display enhanced signal-propagation speed, computational power, and synchronizability. In particular, infectious diseases spread more easily in small-world networks than in regular lattices.

'Mini small worlds' of shortest link paths crossing domain boundaries in an academic Web space

Lennart Björneborn — 2008-03-31T18:43:07-00:00

Scientometrics, Vol. 68, No. 3. (26 December 2006), pp. 395-414.

Summary Combining webometric and social network analytic approaches, this study developed a methodology to sample and identify Web links, pages, and sites that function as small-world connectors affecting short link distances along link paths between different topical domains in an academic Web space. The data set comprised 7669 subsites harvested from 109 UK universities. A novel corona-shaped Web graph model revealed reachability structures among the investigated subsites. Shortest link path netsfunctioned as investigable small-world link structures - 'mini small worlds' - generated by deliberate juxtaposition of topically dissimilar subsites. Indicative findings suggest that personal Web page authors and computer science subsites may be important small-world connectors across sites and topics in an academic Web space. Such connectors may counteract balkanization of the Web into insularities of disconnected and unreachable subpopulations.

Using RDF to Model the Structure and Process of Systems

Marko Rodriguez — 2008-03-28T15:52:26-00:00

(15 Oct 2007)

Many systems can be described in terms of networks of discrete elements and their various relationships to one another. A semantic network, or multi-relational network, is a directed labeled graph consisting of a heterogeneous set of entities connected by a heterogeneous set of relationships. Semantic networks serve as a promising general-purpose modeling substrate for complex systems. Various standardized formats and tools are now available to support practical, large-scale semantic network models. First, the Resource Description Framework (RDF) offers a standardized semantic network data model that can be further formalized by ontology modeling languages such as RDF Schema (RDFS) and the Web Ontology Language (OWL). Second, the recent introduction of highly performant triple-stores (i.e. semantic network databases) allows semantic network models on the order of $10^9$ edges to be efficiently stored and manipulated. RDF and its related technologies are currently used extensively in the domains of computer science, digital library science, and the biological sciences. This article will provide an introduction to RDF/RDFS/OWL and an examination of its suitability to model discrete element complex systems.

The RDF virtual machine

Marko Rodriguez — 2008-03-28T15:48:48-00:00

(2008)

A Multi-Relational Network to Support the Scholarly Communication Process

Marko Rodriguez — 2007-05-22T23:44:11-00:00

International Journal of Public Information Systems, No. 1. (21 May 2007)

The general pupose of the scholarly communication process is to support the creation and dissemination of ideas within the scientific community. At a finer granularity, there exists multiple stages which, when confronted by a member of the community, have different requirements and therefore different solutions. In order to take a researcher's idea from an initial inspiration to a community resource, the scholarly communication infrastructure may be required to 1) provide a scientist initial seed ideas; 2) form a team of well suited collaborators; 3) located the most appropriate venue to publish the formalized idea; 4) determine the most appropriate peers to review the manuscript; and 5) disseminate the end product to the most interested members of the community. Through the various delinieations of this process, the requirements of each stage are tied soley to the multi-functional resources of the community: its researchers, its journals, and its manuscritps. It is within the collection of these resources and their inherent relationships that the solutions to scholarly communication are to be found. This paper describes an associative network composed of multiple scholarly artifacts that can be used as a medium for supporting the scholarly communication process.

Hierarchical modularity of nested bow-ties in metabolic networks

Jing Zhao — 2006-08-18T08:28:18-00:00

BMC Bioinformatics, Vol. 7 (18 August 2006), 386.

Rational (successive) h -indices: An application to economics in the Republic of Ireland

Frances Ruane — 2008-03-28T14:46:47-00:00

Scientometrics

Abstract We rank economics departments in the Republic of Ireland according to the number of publications, number of citations, and successive h-index of research-active staff. We increase the discriminatory power of the h 1-index by introducing three generalizations, each of which is a rational number. The first (h 1 +) measures the excess over the actual h-index, while the other two (h 1*, h 1 Δ) measures the distance to the next h-index. At the individual level, h* and h Δ coincide while h + is undefined.

Fish oil, Raynaud's syndrome, and undiscovered public knowledge.

DR Swanson — 2007-05-06T16:01:49-00:00

Perspect Biol Med, Vol. 30, No. 1. (1986), pp. 7-18.

Graph structure in the Web

A Broder — 2005-12-17T15:50:11-00:00

Computer Networks, Vol. 33, No. 1. (June 2000), pp. 309-320.

The study of the Web as a graph is not only fascinating in its own right, but also yields valuable insight into Web algorithms for crawling, searching and community discovery, and the sociological phenomena which characterize its evolution. We report on experiments on local and global properties of the Web graph using two AltaVista crawls each with over 200 million pages and 1.5 billion links. Our study indicates that the macroscopic structure of the Web is considerably more intricate than suggested by earlier experiments on a smaller scale.

Architectural styles and the design of network-based software architectures

Roy Fielding — 2007-09-20T20:09:11-00:00

(2000)

Chair-Richard N. Taylor

The semantic Web

Tim Lee — 2008-02-26T15:00:31-00:00

Scientific American, Vol. 284, No. 5. (2001), pp. 28-37.

An index to quantify an individual's scientific research output

Jorge Hirsch — 2008-02-26T13:18:18-00:00

Proceedings of the National Academy of Sciences, Vol. 102, No. 46. (2005), pp. 16569-16572.

Brocade, de nieuwe bibliotheeksoftware van Anet

Richard Philips — 2008-02-26T09:58:25-00:00

Bibliotheek- en archiefgids, Vol. 75, No. 5. (1999), pp. 207-213.

Agrippa, van literaire databank tot gestructureerde archievenbank

Isabel Rotthier — 2008-02-26T09:57:21-00:00

Bibliotheek- en archiefgids, Vol. 81, No. 5. (2005), pp. 8-14.

Efficient Algorithms for Citation Network Analysis

Vladimir Batagelj — 2006-10-26T18:17:33-00:00

(14 Sep 2003)

In the paper very efficient, linear in number of arcs, algorithms for determining Hummon and Doreian's arc weights SPLC and SPNP in citation network are proposed, and some theoretical properties of these weights are presented. The nonacyclicity problem in citation networks is discussed. An approach to identify on the basis of arc weights an important small subnetwork is proposed and illustrated on the citation networks of SOM (self organizing maps) literature and US patents.

Social Information Processing in News Aggregation

Kristina Lerman — 2007-11-22T18:32:25-00:00

IEEE Internet Computing, Vol. 11, No. 6. (2007), pp. 16-28.

Social media sites underscore the Web's transformation to a participatory medium in which users collaboratively create, evaluate, and distribute information. Innovations in social media have led to social information processing, a new paradigm for interacting with data. The social news aggregator Digg exploits social information processing for the purpose of document recommendation and rating. Additionally, via mathematical modeling it's possible to describe how collaborative document rating emerges from the independent decisions users make. Using such a model, the author reproduces observed ratings that actual stories on Digg have received.

Social Bookmarking for Scholarly Digital Libraries

Umer Farooq — 2007-11-09T19:13:26-00:00

IEEE Internet Computing, Vol. 11, No. 6. (2007), pp. 29-35.

Social bookmarking services have recently gained popularity among Web users. Whereas numerous studies provide a historical account of tagging systems, the authors use their analysis of a domain-specific social bookmarking service called CiteULike to reflect on two metrics for evaluating tagging behavior: tag growth and tag reuse. They examine the relationship between these two metrics and articulate design implications for enhancing social bookmarking services. The authors also briefly reflect on their own work on developing a social bookmarking service for CiteSeer, an online scholarly digital library for computer science.

The Future of Social Networks on the Internet: The Need for Semantics

J Breslin — 2008-02-22T09:47:47-00:00

Internet Computing, IEEE, Vol. 11, No. 6. (2007), pp. 86-90.

Everyone on the Internet knows the buzzword social networking. Social networking services (SNS) usually offer the same basic functionalities: network of friends listings, person surfing, private messaging etc. With such features, SNSs demonstrate how the Internet continues to better connect people for various social and professional purposes. The fundamental problems with today's SNSs block their potential to access the full range of available content and networked people online. A possible solution is to build semantic social networking into the fabric of the next-generation Internet itself-interconnecting both content and people in meaningful ways. The semantic Web is a useful platform for linking and for performing operations on diverse person-and object-related data gathered from heterogeneous social networking sites. In the other direction, object-centered networks can serve as rich data sources for semantic Web applications.

Serendipitous Reuse

Steve Vinoski — 2008-02-22T09:44:24-00:00

Internet Computing, IEEE, Vol. 12, No. 1. (2008), pp. 84-87.

The word "serendipity" speaks volumes about the nature of the Web and why it's become such an indispensable tool within our daily lives. Of course, by definition, we can't plan for serendipity, but it might be possible to make a given situation more amenable to it. The question becomes: Is it feasible to arrange the primary elements of an area such as enterprise integration in a way that encourages the development of beneficial applications that the enterprise architects never dreamed of?

Graph Farming

D Ayers — 2008-02-22T09:43:08-00:00

Internet Computing, IEEE, Vol. 12, No. 1. (2008), pp. 80-83.

The Giant Global Graph is an excellent perspective on how we can consider diverse pieces of Web infrastructure as a conceptual whole. The Web, when augmented with RDF's graph model, provides an interconnected system. The resources on the semantic Web are interconnected through logical predicates, but this layer exists on top of the coupling offered by the link, as built into the Web since day one. Resources can be identified with URIs designed for HTTP, and the primary Web mechanism is that of using HTTP to get representations of those resources.

Theory and practise of the g-index

Leo Egghe — 2008-02-21T10:22:39-00:00

Scientometrics, Vol. 69, No. 1. (12 April 2006), pp. 131-152.

Without Abstract

Cognitive semantics, complexity and scale-free networks

Joseph Derosa — 2008-02-21T10:14:13-00:00

(2004)

Werner Kuhn’s paper claims that “...cognitive linguistics is both more relevant and more useful to information science than traditional (i.e. Chomskian) linguistics when it comes to dealing with semantics.” An understanding of the ways in which cognitive linguistics is more relevant and useful to information systems, I consider three information system viewpoints: 1. Conceptual spaces 2. Complexity Theory 3. Scale-free networks These ideas are not well-formed, but my intuition tells me there is perhaps some gain to be made by the different viewpoints – if only by stimulating other related ideas within the workshop.

Is Semantic Web Technology Taking the Wrong Turn?

C Bussler — 2008-02-20T13:00:33-00:00

Internet Computing, IEEE, Vol. 12, No. 1. (2008), pp. 75-79.

Developers create semantic Web technologies (SWTs) not only to overcome the syntactic, semantic data heterogeneity problem at design time but also to support uniform agreements on the meaning of data and processes at run time. As defined in the landmark article in the space, the greatest promises of the semantic Web and SWTs are: seamless interactions among agents (people and services) based on reliable communications and uniform data and process semantics; a solution to the heterogeneity and interoperability problem in data and processes via dynamic and automatic discovery and integration; and semantic correctness and dependability (including trust and explanation of reasoning results).

Informetrics at the beginning of the 21st century--A review

Judit Bar-Ilan — 2008-02-18T14:41:13-00:00

Journal of Informetrics, Vol. 2, No. 1. (January 2008), pp. 1-52.

This paper reviews developments in informetrics between 2000 and 2006. At the beginning of the 21st century we witness considerable growth in webometrics, mapping and visualization and open access. A new topic is comparison between citation databases, as a result of the introduction of two new citation databases Scopus and Google Scholar. There is renewed interest in indicators as a result of the introduction of the h-index. Traditional topics like citation analysis and informetric theory also continue to develop. The impact factor debate, especially outside the informetric literature continues to thrive. Ranked lists (of journal, highly cited papers or of educational institutions) are of great public interest.

Libraries and the Long Tail: Some Thoughts about Libraries in a Network Age

Lorcan Dempsey — 2006-04-19T16:20:56-00:00

D-Lib Magazine, Vol. 12, No. 4. (2006)

Discussions of the long tail that I have seen or heard in the library community strike me as somewhat partial. Much of that discussion is about how libraries contain deep and rich collections, and about how their system-wide aggregation represents a very long tail of scholarly and cultural materials (a system may be at the level of a consortium, or a state, or a country). However, I am not sure that we have absorbed the real relevance of the long tail argument, which is about how well supply and demand are matched in a network environment. It is not enough for materials to be present within the system: they have to be readily accessible ('every reader his or her book', in Ranganathan's terms), potentially interested readers have to be aware of them ('every book its reader'), and the system for matching supply and demand has to be efficient ('save the time of the user').

Coming together around Library 2.0: A focus for discussion and a call to arms

Paul Miller — 2007-12-07T22:16:49-00:00

D-Lib Magazine, Vol. 12, No. 4. (2006)

Measuring and extracting proximity in networks

Yehuda Koren — 2008-01-29T15:24:47-00:00

(2006), pp. 245-255.

Author productivity and geodesic distance in bibliographic co-authorship networks, and visibility on the Web

Hildrun Kretschmer — 2008-02-07T14:19:26-00:00

Scientometrics, Vol. 60, No. 3. (2004), pp. 409-420.

Abstract The increasing cooperation in science, which has led to larger co-authorship networks, requires the application of new methods of analysis of social networks in bibliographic co-authorship networks as well as in networks visible on the Web. In this context, a number of interesting papers on the “Erdős Number”, which gives the shortest path (geodesic distance) between an author and the well-known Hungarian mathematician Erdős in a co-authorship network, have been published recently. This paper develops new methods concerning the position of highly productive authors in the network. Thus a relationship of distribution of these authors among the clusters in the co-authorship network could be proved to be dependent upon the size of the clusters. Highly productive authors have, on average, low geodesic distances and thus shorter length of paths to all the other authors of a specialism compared to low productive authors, whereas the influencing possibility of highly productive scientists gets distributed amongst others in the development of the specialism. A theory on the stratification in science with respect to the over random similarity of scientists collaborating with one another, previously covered with other empirical methods, could also be confirmed by the application of geodesic distances. The paper proposes that the newly developed methodology may also be applied to visible networks in future studies on the Web. Further investigation is warranted into whether co-authorship and web networks have similar structures with regards to author productivity and geodesic distances.

Using graph concepts to understand the organization of complex systems

Claire Christensen — 2008-01-30T13:29:40-00:00

(7 Nov 2006)

Complex networks are universal, arising in fields as disparate as sociology, physics, and biology. In the past decade, extensive research into the properties and behaviors of complex systems has uncovered surprising commonalities among the topologies of different systems. Attempts to explain these similarities have led to the ongoing development and refinement of network models and graph-theoretical analysis techniques with which to characterize and understand complexity. In this tutorial, we demonstrate through illustrative examples, how network measures and models have contributed to the elucidation of the organization of complex systems.

Percolation as a Model for Informetric Distributions: Fragment Size Distribution Characterised by Bradford Curves

Jan Bogaert — 2008-01-30T10:50:07-00:00

Scientometrics, Vol. 47, No. 2. (26 February 2000), pp. 195-206.

Abstract It is shown how Bradford curves, i.e. cumulative rank-frequency functions, as used in informetrics, can describe the fragment size distribution of percolation models. This interesting fact is explained by arguing that some aspects of percolation can be interpreted as a model for the success-breeds-success or cumulative advantage phenomenon. We claim, moreover, that the percolation model can be used as a model to study (generalised) bibliographies. This article shows how ideas and techniques studied and developed in informetrics and scientometrics can successfully be applied in other fields of science, and vice versa.

Grammar-based random walkers in semantic networks

MA Rodriguez — 2008-01-22T13:18:04-00:00

Los Alamos National Laboratory, Tech. Rep. LA-UR-06-7791 (2007)

The R- and AR-indices: Complementing the h-index

Bihui Jin — 2008-01-22T12:50:59-00:00

Chinese Science Bulletin, Vol. 52, No. 6. (17 March 2007), pp. 855-863.

Abstract Based on the foundation laid by the h-index we introduce and study the R- and AR-indices. These new indices eliminate some of the disadvantages of the h-index, especially when they are used in combination with the h-index. The R-index measures the h-core’s citation intensity, while AR goes one step further and takes the age of publications into account. This allows for an index that can actually increase and decrease over time. We propose the pair (h, AR) as a meaningful indicator for research evaluation. We further prove a relation characterizing the h-index in the power law model.

Analyzing trails in complex networks.

L da Fontoura Costa — 2007-11-21T08:15:04-00:00

Phys Rev E Stat Nonlin Soft Matter Phys, Vol. 76, No. 4 Pt 2. (October 2007)

Even more interesting than the intricate organization of complex networks is the dynamical behavior of systems underlain by such structures. Among the many types of dynamics, one particularly interesting category involves the evolution of trails left by moving agents progressing through random walks and dilating processes in a complex network. The emergence of trails is present in many dynamical process, such as pedestrian traffic, information flow, and metabolic pathways. Important problems related to trails include the reconstruction of the trail and the identification of its source, when complete knowledge of the trail is missing. In addition, the following of trails in multiagent systems represents a particularly interesting situation related to pedestrian dynamics and swarming intelligence. The present work addresses these three issues while taking into account permanent and transient marks left in the visited nodes. Different topologies are considered for trail reconstruction and trail source identification, including four complex network models and four real networks, namely, the Internet, the U.S. airlines network, an email network, and the scientific collaboration network of complex network researchers. Our results show that the topology of the network influences trail reconstruction, source identification, and agent dynamics.

Graph theoretical analysis of complex networks in the brain

CJ Stam — 2007-10-10T22:41:06-00:00

Nonlinear Biomed Phys, Vol. 1, No. 1. (2007)

ABSTRACT: Since the discovery of small-world and scale-free networks the study of complex systems from a network perspective has taken an enormous flight. In recent years many important properties of complex networks have been delineated. In particular, significant progress has been made in understanding the relationship between the structural properties of networks and the nature of dynamics taking place on these networks. For instance, the 'synchronizability' of complex networks of coupled oscillators can be determined by graph spectral analysis. These developments in the theory of complex networks have inspired new applications in the field of neuroscience. Graph analysis has been used in the study of models of neural networks, anatomical connectivity, and functional connectivity based upon fMRI, EEG and MEG. These studies suggest that the human brain can be modelled as a complex network, and may have a small-world structure both at the level of anatomical as well as functional connectivity. This small-world structure is hypothesized to reflect an optimal situation associated with rapid synchronization and information transfer, minimal wiring costs, as well as a balance between local processing and global integration. The topological structure of functional networks is probably restrained by genetic and anatomical factors, but can be modified during tasks. There is also increasing evidence that various types of brain disease such as Alzheimer's disease, schizophrenia, brain tumours and epilepsy may be associated with deviations of the functional network topology from the optimal small-world pattern.

An information-theoretic framework for resolving community structure in complex networks

Martin Rosvall — 2006-12-07T00:10:07-00:00

(5 Dec 2006)

This paper develops a rigorous foundation for the concept of modularity in networks. We present an explicit method to best partition a complex network by finding an optimal compression of its topology, capitalizing on regularities in its structure. To illustrate the power of our approach, we partition a number of real-world and model networks and explain why our results outperform other methods.

BRS-compactness in networks: Theoretical considerations related to cohesion in citation graphs, collaboration networks and the internet

Leo Egghe — 2008-01-08T14:20:45-00:00

Mathematical and Computer Modelling, Vol. 37, No. 7-8. (2003), pp. 879-899.

Compactness as introduced by Botafogo, Rivlin and Shneiderman, in short: BRS-compactness, is studied in general, as it can be used to describe the cohesion of parts of the internet or collaboration networks, and in the particular case of a unidirectional network, such as a citation graph. It is shown that the connection coefficient is an upper bound for the BRS-compactness value of a network. During our investigations, we derive an upper bound for the generalized Wiener index of a directed graph. Several networks are constructed and their BRS-compactness values are calculated.

Structural holes and good ideas

Ronald Burt — 2008-01-08T13:58:18-00:00

American Journal of Sociology, Vol. 110, No. 2. (2004), pp. 349-399.

This article outlines the mechanism by which brokerage provides social capital. Opinion and behavior are more homogeneous within than between groups, so people connected across groups are more familiar with alternative ways of thinking and behaving. Brokerage across the structural holes between groups provides a vision of options otherwise unseen, which is the mechanism by which brokerage becomes social capital. I review evidence consistent with the hypothesis, then look at the networks around managers in a large American electronics company. The organization is rife with structural holes, and brokerage has its expected correlates. Compensation, positive performance evaluations, promotions, and good ideas are disproportionately in the hands of people whose networks span structural holes. The between‐group brokers are more likely to express ideas, less likely to have ideas dismissed, and more likely to have ideas evaluated as valuable. I close with implications for creativity and structural change.

A note on structural holes theory and niche overlap

Jeroen Bruggeman — 2007-01-11T13:20:57-00:00

Social Networks, Vol. 25, No. 1. (January 2003), pp. 97-101.

Diffuse competition due to niche overlap between actors without (direct) ties with each other, constrains their structural autonomy. This is not dealt with in Burt's mathematical model of his well-known structural holes theory. We fix his model by introducing a network measure of niche overlap.

Uniform SPARQL access to interlinked (digital library) sources

Bernhard Haslhofer — 2008-01-08T13:42:53-00:00

(2007)