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Displaying 1-50 out of 124 total
Cultivating Twitter
Found in: eLearn
By Kay Lehmann, Lisa Chamberlin, Kay Lehmann, Lisa Chamberlin
Issue Date:August 2010
pp. 444-445
In a recent article ("Finding a Place for Twitter in Higher Education," May 20, 2010,, Hend Suliman Al-Khalifa reported some of the findings in a Faculty Focus 2009 survey, "Twitter in Higher Education: Usage Habits and Trends of Today's Col...
Combinatorial auctions with decreasing marginal utilities
Found in: Proceedings of the 3rd ACM conference on Electronic Commerce (EC '01)
By Benny Lehmann, Daniel Lehmann, Noam Nisan
Issue Date:October 2001
pp. 18-28
In most of microeconomic theory, consumers are assumed to exhibit decreasing marginal utilities. This paper considers combinatorial auctions among such buyers. The valuations of such buyers are placed within a hierarchy of valuations that exhibit no comple...
Orthographic Star Coordinates
Found in: IEEE Transactions on Visualization and Computer Graphics
By Dirk J. Lehmann,Holger Theisel
Issue Date:December 2013
pp. 2615-2624
Star coordinates is a popular projection technique from an nD data space to a 2D/3D visualization domain. It is defined by setting n coordinate axes in the visualization domain. Since it generally defines an affine projection, strong distortions can occur:...
Orthographic Star Coordinates
Found in: IEEE Transactions on Visualization and Computer Graphics
By Dirk J. Lehmann,Holger Theisel
Issue Date:December 2013
pp. 2615-2624
Star coordinates is a popular projection technique from an nD data space to a 2D/3D visualization domain. It is defined by setting n coordinate axes in the visualization domain. Since it generally defines an affine projection, strong distortions can occur:...
Networked user engagement
Found in: Proceedings of the 1st workshop on User engagement optimization (UEO '13)
By Janette Lehmann, Elad Yom-Tov, Mounia Lalmas, Ricardo Baeza-Yates
Issue Date:November 2013
pp. 7-10
Online providers frequently offer a variety of services, ranging from news to mail. These providers endeavour to keep users accessing and interacting with the sites offering these services, that is to engage users by spending time on these sites and return...
Online multitasking and user engagement
Found in: Proceedings of the 22nd ACM international conference on Conference on information & knowledge management (CIKM '13)
By Georges Dupret, Ricardo Baeza-Yates, Janette Lehmann, Mounia Lalmas
Issue Date:October 2013
pp. 519-528
Users often access and re-access more than one site during an online session, effectively engaging in multitasking. In this paper, we study the effect of online multitasking on two widely used engagement metrics designed to capture users browsing behavior ...
Integration of a Highly Scalable, Multi-FPGA-Based Hardware Accelerator in Common Cluster Infrastructures
Found in: 2013 42nd International Conference on Parallel Processing (ICPP)
By Oliver Knodel,Andy Georgi,Patrick Lehmann,Wolfgang E. Nagel,Rainer G. Spallek
Issue Date:October 2013
pp. 893-900
Heterogeneous systems consisting of general-purpose processors and different types of hardware accelerators are becoming more and more common in HPC systems. Especially Field Programmable Gate Arrays (FPGAs) provide an energy-efficient way to achieve high ...
A mobile personal informatics system with interactive visualizations of mobility and social interactions
Found in: Proceedings of the 1st ACM international workshop on Personal data meets distributed multimedia (PDM '13)
By Andrea Cuttone, Jakob Eg Larsen, Sune Lehmann
Issue Date:October 2013
pp. 27-30
We describe a personal informatics system for Android smartphones that provides personal data on mobility and social interactions through interactive visualization interfaces. The mobile app has been made available to N=136 first year university students a...
Towards Transfer Learning of Link Specifications
Found in: 2013 IEEE Seventh International Conference on Semantic Computing (ICSC)
By Axel-Cyrille Ngonga Ngomo,Jens Lehmann,Mofeed Hassan
Issue Date:September 2013
pp. 202-205
Over the last years, link discovery frameworks have been employed successfully to create links between knowledge bases. Consequently, repositories of high-quality link specifications have been created and made available on the Web. The basic question under...
Keyword Query Expansion on Linked Data Using Linguistic and Semantic Features
Found in: 2013 IEEE Seventh International Conference on Semantic Computing (ICSC)
By Saeedeh Shekarpour,Konrad Hoffner,Jens Lehmann,Soren Auer
Issue Date:September 2013
pp. 191-197
Effective search in structured information based on textual user input is of high importance in thousands of applications. Query expansion methods augment the original query of a user with alternative query elements with similar meaning to increase the cha...
Tracking Visitor Engagement in the Blogosphere for Leveraging Rankings
Found in: 2013 International Conference on Social Computing (SocialCom)
By Patrick Hennig,Philipp Berger,Christoph Meinel,Maria Graber,Jens Hildebrandt,Stefan Lehmann,Cathleen Ramson
Issue Date:September 2013
pp. 365-372
Current blog search engines use rankings, such as BIImpact or B2Rank, focusing on the link structure and thereat criteria externally extracted for blogs. A good, but due to the unavailability, not often used criteria is the visitor engagement. This metric ...
Can We Create Better Links by Playing Games?
Found in: 2013 IEEE Seventh International Conference on Semantic Computing (ICSC)
By Jens Lehmann,Tri Quan Nguyen,Timofey Ermilov
Issue Date:September 2013
pp. 322-329
Just like links are the backbone of the traditional World Wide Web, they are an equally important element in the Data Web. There exist a variety of automated tools, which are able to create a high number of links between RDF resources by using heuristics. ...
User-driven quality evaluation of DBpedia
Found in: Proceedings of the 9th International Conference on Semantic Systems (I-SEMANTICS '13)
By Amrapali Zaveri, Dimitris Kontokostas, Jens Lehmann, Lorenz Bühmann, Mohamed A. Sherif, Mohamed Morsey, Sören Auer
Issue Date:September 2013
pp. 97-104
Linked Open Data (LOD) comprises of an unprecedented volume of structured datasets on the Web. However, these datasets are of varying quality ranging from extensively curated datasets to crowdsourced and even extracted data of relatively low quality. We pr...
Turning the OpenMobileNetwork into a live crowdsourcing platform for semantic context-aware services
Found in: Proceedings of the 9th International Conference on Semantic Systems (I-SEMANTICS '13)
By Abdulbaki Uzun, Axel Küpper, Lorenz Lehmann, Thilo Geismar
Issue Date:September 2013
pp. 89-96
The OpenMobileNetwork is a semantic model for mobile network topologies created by following the principles of Linked Data. By correlating data in the Linking Open Data Cloud with the OpenMobileNetwork, innovative Semantic Context-aware Services (CAS) can ...
Techno-economic Balance of Load-Adaptive Telecommunication Network Operation for Energy Efficiency Improvements
Found in: 2013 24th International Workshop on Database and Expert Systems Applications (DEXA)
By Christoph Lange,Heiko Lehmann
Issue Date:August 2013
pp. 249-253
Load-adaptive telecommunication network operation has crystallized as a promising option for improving the network energy efficiency. On the one hand significant energy savings are expected when the network capacity follows the traffic load, on the other h...
Annotating 3D content in interactive, virtual worlds
Found in: Proceedings of the 18th International Conference on 3D Web Technology (Web3D '13)
By Christine Lehmann, Jürgen Döllner
Issue Date:June 2013
pp. 67-70
Labeling or annotating 3D content is an essential task for interactive environments such as digital 3D cities or indoor models, to enable target-oriented exploration and navigation. The seamless integration of text information into the perspective view of ...
Automatic Detection and Visualization of Qualitative Hemodynamic Characteristics in Cerebral Aneurysms
Found in: IEEE Transactions on Visualization and Computer Graphics
By R. Gasteiger,D. J. Lehmann,R. van Pelt,G. Janiga,O. Beuing,A. Vilanova,H. Theisel,B. Preim
Issue Date:December 2012
pp. 2178-2187
Cerebral aneurysms are a pathological vessel dilatation that bear a high risk of rupture. For the understanding and evaluation of the risk of rupture, the analysis of hemodynamic information plays an important role. Besides quantitative hemodynamic informa...
A DCC pipeline for native 3D graphics in browsers
Found in: Proceedings of the 17th International Conference on 3D Web Technology (Web3D '12)
By Christian Ulbrich, Claus Lehmann
Issue Date:August 2012
pp. 175-178
Current consumer hardware has become quite powerful. Off-the-shelf computers are today capable of displaying 3D in realtime. With the advent of the Apple iPhone and the Smartphone revolution, mobile devices are becoming ubiquitous, yet they are equipped wi...
Exploiting single-user web applications for shared editing: a generic transformation approach
Found in: Proceedings of the 21st international conference on World Wide Web (WWW '12)
By Matthias Heinrich, Thomas Springer, Franz Lehmann, Martin Gaedke
Issue Date:April 2012
pp. 1057-1066
In the light of the Web 2.0 movement, web-based collaboration tools such as Google Docs have become mainstream and in the meantime serve millions of users. Apart from established collaborative web applications, numerous web editors lack multi-user support ...
Template-based question answering over RDF data
Found in: Proceedings of the 21st international conference on World Wide Web (WWW '12)
By Christina Unger, Daniel Gerber, Philipp Cimiano, Axel-Cyrille Ngonga Ngomo, Jens Lehmann, Lorenz Buhmann
Issue Date:April 2012
pp. 639-648
As an increasing amount of RDF data is published as Linked Data, intuitive ways of accessing this data become more and more important. Question answering approaches have been proposed as a good compromise between intuitiveness and expressivity. Most questi...
Dynamical classes of collective attention in twitter
Found in: Proceedings of the 21st international conference on World Wide Web (WWW '12)
By Bruno Goncalves, Janette Lehmann, Jose J. Ramasco, Ciro Cattuto
Issue Date:April 2012
pp. 251-260
Micro-blogging systems such as Twitter expose digital traces of social discourse with an unprecedented degree of resolution of individual behaviors. They offer an opportunity to investigate how a large-scale social system responds to exogenous or endogenou...
Gaze in HRI: from modeling to communication
Found in: Proceedings of the seventh annual ACM/IEEE international conference on Human-Robot Interaction (HRI '12)
By Yukiko Nakano, Bilge Mutlu, Frank Broz, Hagen Lehmann
Issue Date:March 2012
pp. 491-492
The purpose of this half-day workshop is to explore the role of social gaze in human-robot interaction, both how to measure social gaze behavior by humans and how to implement it in robots that interact with them. Gaze directed at an interaction partner ha...
Sustainable instrumentation of everyday commodities -- Concepts and tools
Found in: Pervasive Computing and Communications Workshops, IEEE International Conference on
By Boris Brandherm,Alexander Kroner,Jens Haupert,Michael Schmitz,Frank Lehmann,Ralf Gampfer
Issue Date:March 2012
pp. 467-470
Many research activities are currently exploring the use of digital object memories. But outside research activities even nowadays still most of the everyday commodities and convenience goods are even not equipped with an RFID tag due to the inefficient co...
Electronic Identities Need Private Credentials
Found in: IEEE Security and Privacy
By Jan Camenisch,Anja Lehmann,Gregory Neven
Issue Date:January 2012
pp. 80-83
For transactions on the Internet, user authentication typically involves usernames and passwords. When creating an account, users often must provide additional personal information. Usually, this is a list of self-claimed attributes such as name, address, ...
A serious game prototype for education of medical doctors and students on insulin management for treatment of diabetes mellitus
Found in: Serious Games and Applications for Health, International Conference on
By Leandro A. Diehl,Eldon Lehmann,Rodrigo M. Souza,Juliano B. Alves,Roberto Z. Esteves,Pedro A. Gordan
Issue Date:November 2011
pp. 1-4
This paper describes the construction of a serious game prototype for training doctors and medical students about insulin management for the treatment of diabetes mellitus (DM). There are a few simulators that are educationally useful for this aim, but the...
Features in Continuous Parallel Coordinates
Found in: IEEE Transactions on Visualization and Computer Graphics
By Dirk J. Lehmann,Holger Theisel
Issue Date:December 2011
pp. 1912-1921
Continuous Parallel Coordinates (CPC) are a contemporary visualization technique in order to combine several scalar fields, given over a common domain. They facilitate a continuous view for parallel coordinates by considering a smooth scalar field instead ...
ReDD-Observatory: Using the Web of Data for Evaluating the Research-Disease Disparity
Found in: Web Intelligence and Intelligent Agent Technology, IEEE/WIC/ACM International Conference on
By Amrapali Zaveri,Ricardo Pietrobon,Sören Auer,Jens Lehmann,Michael Martin,Timofey Ermilov
Issue Date:August 2011
pp. 178-185
It is widely accepted that there is a large disparity between the availability of treatment options and the prevalence of diseases all over the world, thus placing individuals in danger. This disparity is partially caused by the restricted access to inform...
Enterprise Architecture for Addressing Business Transformation Challenges: The Case of Embedded Mobile Provisioning Process in the Telecommunications Industry
Found in: Enterprise Distributed Object Computing Conference, IEEE International
By Marcos Tong,Harald Bender,Mikko Kolehmainen,Janne Parantainen,Gerald Lehmann
Issue Date:September 2011
pp. 35-43
The present is a report of an exploratory case study about using an Enterprise Architecture method for addressing the business transformation challenges of embedded mobile provisioning in the telecommunications industry. The study focused on the analysis o...
Improving performance and retention in computer science courses using a virtual game show
Found in: Proceedings of the 49th Annual Southeast Regional Conference (ACM-SE '11)
By Carl Arrington, Dale-Marie Wilson, Lorrie Lehmann
Issue Date:March 2011
pp. 320-321
One of the many factors that contribute to the decline in Computer Science retention is poor performance in foundation programming courses. In the Introduction to Programming course here at UNC Charlotte, it has been observed that poor assessment performan...
Found in: ACM SIGGRAPH ASIA 2010 Computer Animation Festival (SA '10)
By Alexander Lehmann
Issue Date:December 2010
pp. 1-2
Exodus is my Graduation film. I started this project in 2006 and finished it in 2010 as my graduation film. It was my goal to create a shortfilm based on music. I wanted to perfectly adjust picture and music so it would conceal what was first, the sound or...
Linking open government data: what journalists wish they had known
Found in: Proceedings of the 6th International Conference on Semantic Systems (I-SEMANTICS '10)
By Andrina Mascher, Christoph Bohm, Claudia Lehmann, Felix Naumann, Markus Freitag, Martin Koppelmann, Norman Hofler, Stefan George, Tobias Schmidt
Issue Date:September 2010
pp. 1-4
Many government organizations publish a variety of data on the web to facilitate transparency. The multitude of sources has resulted in heterogeneous structures and formats as well as varying quality of such data. We report on a project dubbed GovWild (<...
Discontinuities in Continuous Scatter Plots
Found in: IEEE Transactions on Visualization and Computer Graphics
By Dirk J. Lehmann, Holger Theisel
Issue Date:November 2010
pp. 1291-1300
The concept of continuous scatterplot (CSP) is a modern visualization technique. The idea is to define a scalar density value based on the map between an n-dimensional spatial domain and an m-dimensional data domain, which describe the CSP space. Usually t...
Detecting Social Situations from Interaction Geometry
Found in: Social Computing / IEEE International Conference on Privacy, Security, Risk and Trust, 2010 IEEE International Conference on
By Georg Groh, Alexander Lehmann, Jonas Reimers, Marc René Frieß, Loren Schwarz
Issue Date:August 2010
pp. 1-8
A novel method for quantitatively measuring social interactions on small temporal and spatial scales on the basis of interaction geometry (reduced to the parameters interpersonal distance and relative body orientation) with the help of infrared (IR) tracki...
Development of context-adaptive applications on the basis of runtime user interface models
Found in: Proceedings of the 2nd ACM SIGCHI symposium on Engineering interactive computing systems (EICS '10)
By Grzegorz Lehmann, Marco Blumendorf, Sahin Albayrak
Issue Date:June 2010
pp. 309-314
One of the challenges faced by developers of applications for smart environments is the diversity of contexts of use. Applications in smart environments must cope with continuously changing context of use, so the developers need to prepare them for a possi...
Bridging models and systems at runtime to build adaptive user interfaces
Found in: Proceedings of the 2nd ACM SIGCHI symposium on Engineering interactive computing systems (EICS '10)
By Grzegorz Lehmann, Marco Blumendorf, Sahin Albayrak
Issue Date:June 2010
pp. 9-18
Adapting applications and user interfaces at runtime requires a deeper understanding of the underlying design. Models formalize this design, express the underlying concepts and make them accessible to machines. In our work we utilize runtime models to refl...
Grounding Mobility Research
Found in: Mobile Business / Global Mobility Roundtable, International Conference on
By Hans Lehmann, Eusebio Scornavacca
Issue Date:June 2010
pp. 410-415
Research into mobile business has grown significantly over the last decade, but seemingly in a haphazard and not always rigorous fashion. This was first observed in 2003 and then borne out by an in-depth analysis of hundreds of m-business research publicat...
Turbo Segmentation of Textured Images
Found in: IEEE Transactions on Pattern Analysis and Machine Intelligence
By Frederic Lehmann
Issue Date:January 2011
pp. 16-29
We consider the problem of semi-supervised segmentation of textured images. Existing model-based approaches model the intensity field of textured images as a Gauss-Markov random field to take into account the local spatial dependencies between the pixels. ...
Bipartite networks of Wikipedia's articles and authors: a meso-level approach
Found in: Proceedings of the 5th International Symposium on Wikis and Open Collaboration (WikiSym '09)
By Martin Schwartz, Rut Jesus, Sune Lehmann
Issue Date:October 2009
pp. 1-10
This exploratory study investigates the bipartite network of articles linked by common editors in Wikipedia, 'The Free Encyclopedia that Anyone Can Edit'. We use the articles in the categories (to depth three) of Physics and Philosophy and extract and focu...
A Composite Calculation for Author Activity in Wikis: Accuracy Needed
Found in: Web Intelligence and Intelligent Agent Technology, IEEE/WIC/ACM International Conference on
By Claudia Müller-Birn, Janette Lehmann, Sabina Jeschke
Issue Date:September 2009
pp. 84-91
Researchers of computer science and social science are increasingly interested in the Social Web and its applications. To improve existing infrastructures, to evaluate the success of available services, and to build new virtual communities and their applic...
Testing of Image Processing Algorithms on Synthetic Data
Found in: Software Engineering Advances, International Conference on
By Kilian von Neumann-Cosel, Erwin Roth, Daniel Lehmann, Johannes Speth, Alois Knoll
Issue Date:September 2009
pp. 169-172
In this paper, it is shown that synthetic images can be used to test specific use cases of a lane tracking algorithm which has been developed by Audi AG. This was achieved by setting up a highly configurable and extendable simulation framework “Virtual Tes...
Foundations of non-commutative probability theory
Found in: Proceedings of the 11th Conference on Theoretical Aspects of Rationality and Knowledge (TARK '09)
By Daniel Lehmann
Issue Date:July 2009
pp. 1-29
Kolmogorov's setting for probability theory is given an original generalization to account for probabilities arising from Quantum Mechanics. The sample space has a central role in this presentation and random variables, i.e., observables, are defined in a ...
TeamCom: A Service Creation Platform for Next Generation Networks
Found in: Internet and Web Applications and Services, International Conference on
By A. Lehmann, T. Eichelmann, U. Trick, R. Lasch, B. Ricks, R. Tönjes
Issue Date:May 2009
pp. 12-17
The development of value added services is currently still very time and cost consuming. The need for specific user generated and in particular business-to-business services demands for efficient service development methods. This paper presents a service c...
Triplify: light-weight linked data publication from relational databases
Found in: Proceedings of the 18th international conference on World wide web (WWW '09)
By David Aumueller, Jens Lehmann, Soren Auer, Sebastian Dietzold, Sebastian Hellmann
Issue Date:April 2009
pp. 66-66
In this paper we present Triplify - a simplistic but effective approach to publish Linked Data from relational databases. Triplify is based on mapping HTTP-URI requests onto relational database queries. Triplify transforms the resulting relations into RDF ...
Blind soft-output equalization of block-oriented wireless communications
Found in: Acoustics, Speech, and Signal Processing, IEEE International Conference on
By Frederic Lehmann
Issue Date:April 2009
pp. 2801-2804
We consider blind equalization for block transmissions over the frequency selective Rayleigh fading channel. In the absence of pilot symbols, the receiver must be able to perform joint equalization and blind channel identification. Relying on a mixed discr...
Flash-Based Tool for Earthquake Epicenter Identification
Found in: Computer Science and Information Engineering, World Congress on
By Youwen Ouyang, Matthew Lehmann, Katherine Hayden, Debi Kilb
Issue Date:April 2009
pp. 389-393
Previously, the methods used by scientists to locate an earthquake epicenter were so cumbersome, even for scientists, that the epicenter location methodology needed to be simplified before it was presented to K-12 students. Today, because of the advances i...
Wavelet Image Two-Line Coder for Wireless Sensor Node with Extremely Little RAM
Found in: Data Compression Conference
By Stephan Rein, Stephan Lehmann, Clemens Gühmann
Issue Date:March 2009
pp. 252-261
This paper gives a novel wavelet image two-line (Wi2l) coder that is designed to fulfill the memory constraints of a typical wireless sensor node. The algorithm operates line-wisely on picture data stored on the sensor's flash memory card while it requires...
Poster: Design and evaluation of 3D content with wind output
Found in: 3D User Interfaces
By Anke Lehmann, Christian Geiger, Bjorn Woldecke, Jorg Stocklein
Issue Date:March 2009
pp. 151-152
In this paper we discuss the effect of two different wind output devices and compare head mounted wind with stationary wind, i.e., wind output of fix mounted fans on a rack. By means of a simple interactive 3D application we evaluated the subjects' feeling...
HorseIO - virtual riding lessons with a low-cost tangible horse interface
Found in: Proceedings of the 3rd International Conference on Tangible and Embedded Interaction (TEI '09)
By Andrea Wegstein, Anke Lehmann, Christian Geiger, Gundula Dorries
Issue Date:February 2009
pp. 118-125
We describe the implementation of a playful multi-user virtual riding lesson for beginners. Our work focused on the integration of a wooden horse, equipped with real snaffle and saddle, which is used as input interface to navigate in a 3D environment. With...
Protecting BitTorrent: Design and Evaluation of Effective Countermeasures against DoS Attacks
Found in: Reliable Distributed Systems, IEEE Symposium on
By Marinho P. Barcellos, Daniel Bauermann, Henrique Sant'anna, Matheus Lehmann, Rodrigo Mansilha
Issue Date:October 2008
pp. 73-82
BitTorrent is a P2P file-sharing protocol that can be used to efficiently distribute files such as software updates and digital content to very large numbers of users. In a previous paper, we have shown that vulnerabilities can be exploited to launch Denia...
Adapting the IS success model for mobile technology in health: a New Zealand example
Found in: Proceedings of the 10th international conference on Electronic commerce (ICEC '08)
By Eusebio Scornavacca, Hans Lehmann, Mishul Prasad
Issue Date:August 2008
pp. 1-30
Many healthcare providers throughout the world are starting to take advantage of mobile technologies as part of their key initiatives to provide better quality service. Given that the benefits of Information Technology (IT) in the health sector is still in...
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