University of Leipzig

Displaying 1-14 of 14 results

  • White Papers // Nov 2014

    SAFE: Policy Aware SPARQL Query Federation Over RDF Data Cubes

    Several query federation engines have been proposed for accessing public Linked Open Data (LOD) sources. However, in many domains, resources are sensitive and access to these resources is tightly controlled by stakeholders; consequently, privacy is a major concern when federating queries over such datasets. In this paper, the authors present...

    Provided By University of Leipzig

  • White Papers // Aug 2014

    Test-Driven Evaluation of Linked Data Quality

    Linked Open Data (LOD) comprises of an unprecedented volume of structured data on the Web. However, these datasets are of varying quality ranging from extensively curated datasets to crowd-sourced or extracted data of often relatively low quality. The authors present a methodology for test-driven quality assessment of linked data, which...

    Provided By University of Leipzig

  • White Papers // Nov 2012

    Mqr-Tree: A 2-Dimensional Spatial Access Method

    In this paper, the authors propose the mqr-tree, a two-dimensional spatial access method that organizes spatial objects in a two-dimensional node and based on their spatial relationships. Previously proposed spatial access methods that attempt to maintain spatial relationships between objects in their structures are limited in their incorporation of existing...

    Provided By University of Leipzig

  • White Papers // Jun 2011

    Was The Worldwide Asymmetry In Current Accounts Caused By The Macroeconomic Policy Of The Global Economy's Leader?

    Some authors sketch the causal chain that produced the current account surplus in China and the current account deficit of the US (as a part of global imbalances) as follows: declining interest rates in the US cause a redirection of capital flows into the periphery, rising capital inflows into China...

    Provided By University of Leipzig

  • White Papers // Apr 2011

    Analyzing the Effective Throughput in Multi-Hop IEEE 802.11n Networks

    In this paper, the authors characterize the effective throughput for multi-hop paths in IEEE 802.11n based wireless mesh networks. They derive an analytical model capturing the effects of frame aggregation and block acknowledgements, features found in the new IEEE 802.11n standard. They describe the throughput at MAC layer as a...

    Provided By University of Leipzig

  • White Papers // Mar 2011

    Understanding IEEE 802.11n Multi-Hop Communication in Wireless Networks

    In this paper, the authors present a measurement study of the multi-hop behavior of the new IEEE 802.11n standard in an indoor mesh testbed. As main contribution, they quantitatively describe characteristics of IEEE 802.11n on multi-hop paths like throughput, aggregate size and utilized MIMO features. Furthermore, they show how to...

    Provided By University of Leipzig

  • White Papers // Feb 2011

    Quantile Hedging For Multiple Assets Derivatives

    The problem of quantile hedging for multiple assets derivatives in the Black-Scholes model with correlation is considered. Explicit formulas for the probability maximizing function and the cost reduction function are derived. Applicability of the results for the widely traded derivatives as digital, quantos, outperformance and spread options is shown. As...

    Provided By University of Leipzig

  • White Papers // Oct 2010

    An Accurate and Analytically Tractable Model for Human Inter-Contact Times

    The authors present an analytically tractable mathematical approach for accurately modeling the distribution of inter-contact times between mobile devices carried by users. The contribution of this paper is two-fold: they show how to employ a MarkovModulated Poisson process (MMPP) for characterizing long-term dependencies in the mobility behavior, and they propose...

    Provided By University of Leipzig

  • White Papers // May 2010

    Evolution of the Linux Kernel Variability Model

    Understanding the challenges faced by real projects in evolving variability models, is a prerequisite for providing adequate support for such undertakings. The authors study the evolution of a model describing features and configurations in a large product line - the Linux kernel variability model. They analyze this evolution quantitatively and...

    Provided By University of Leipzig

  • White Papers // Apr 2010

    The Theory Of Optimum Currency Areas And Growth In Emerging Markets

    The authors test for the impact of exchange rate volatility on growth in emerging market economies based on the theory of optimum currency areas. The findings provide evidence for a positive impact of exchange rate stability on growth. The 1997/98 Asian crisis and the obligation of 12 new EU member...

    Provided By University of Leipzig

  • White Papers // Mar 2010

    A Scalable Dual-Radio Wireless Testbed for Emulating Mesh Networks

    In this paper, the authors introduce and evaluate ScaleMesh, a scalable miniaturized dual-radio wireless mesh testbed based on IEEE 802.11b/g technology. ScaleMesh can emulate large-scale mesh networks within a miniaturized experimentation area by adaptively shrinking the transmission range of mesh nodes by means of variable signal attenuators. To this end,...

    Provided By University of Leipzig

  • White Papers // Mar 2010

    LESS - Template-Based Syndication and Presentation of Linked Data

    Recently, the publishing of structured, semantic information as linked data has gained quite some momentum. For ordinary users on the Internet, however, this information is not yet very visible and (re-) usable. With LESS the authors present an end-to-end approach for the syndication and use of linked data based on...

    Provided By University of Leipzig

  • White Papers // Oct 2009

    CrossTrace: Cross-Layer Measurement for IEEE 802.11 Wireless Testbeds

    In this paper, the authors introduce and evaluate CrossTrace, a framework for performing cross-layer measurements in IEEE 802.11 based wireless networks. CrossTrace allows tracing of parameters at MAC-layer, routing and transport layer in a controlled environment and in a repeatable manner. Using CrossTrace, they conduct a comprehensive measurement study in...

    Provided By University of Leipzig

  • White Papers // Aug 2009

    Enhancing Customer Relationship Management Using Enterprise Information Integration With Topic Maps

    In most companies the landscape of used computer software is very heterogeneous; this causes a need for data integration. This is especially difficult to achieve for small and mid-sized enterprises, as they face the problem of relatively high costs for the existing standard solutions spread only on a small scale....

    Provided By University of Leipzig

  • White Papers // Aug 2009

    Enhancing Customer Relationship Management Using Enterprise Information Integration With Topic Maps

    In most companies the landscape of used computer software is very heterogeneous; this causes a need for data integration. This is especially difficult to achieve for small and mid-sized enterprises, as they face the problem of relatively high costs for the existing standard solutions spread only on a small scale....

    Provided By University of Leipzig

  • White Papers // Mar 2010

    LESS - Template-Based Syndication and Presentation of Linked Data

    Recently, the publishing of structured, semantic information as linked data has gained quite some momentum. For ordinary users on the Internet, however, this information is not yet very visible and (re-) usable. With LESS the authors present an end-to-end approach for the syndication and use of linked data based on...

    Provided By University of Leipzig

  • White Papers // Nov 2012

    Mqr-Tree: A 2-Dimensional Spatial Access Method

    In this paper, the authors propose the mqr-tree, a two-dimensional spatial access method that organizes spatial objects in a two-dimensional node and based on their spatial relationships. Previously proposed spatial access methods that attempt to maintain spatial relationships between objects in their structures are limited in their incorporation of existing...

    Provided By University of Leipzig

  • White Papers // Feb 2011

    Quantile Hedging For Multiple Assets Derivatives

    The problem of quantile hedging for multiple assets derivatives in the Black-Scholes model with correlation is considered. Explicit formulas for the probability maximizing function and the cost reduction function are derived. Applicability of the results for the widely traded derivatives as digital, quantos, outperformance and spread options is shown. As...

    Provided By University of Leipzig

  • White Papers // Apr 2010

    The Theory Of Optimum Currency Areas And Growth In Emerging Markets

    The authors test for the impact of exchange rate volatility on growth in emerging market economies based on the theory of optimum currency areas. The findings provide evidence for a positive impact of exchange rate stability on growth. The 1997/98 Asian crisis and the obligation of 12 new EU member...

    Provided By University of Leipzig

  • White Papers // Jun 2011

    Was The Worldwide Asymmetry In Current Accounts Caused By The Macroeconomic Policy Of The Global Economy's Leader?

    Some authors sketch the causal chain that produced the current account surplus in China and the current account deficit of the US (as a part of global imbalances) as follows: declining interest rates in the US cause a redirection of capital flows into the periphery, rising capital inflows into China...

    Provided By University of Leipzig

  • White Papers // Mar 2010

    A Scalable Dual-Radio Wireless Testbed for Emulating Mesh Networks

    In this paper, the authors introduce and evaluate ScaleMesh, a scalable miniaturized dual-radio wireless mesh testbed based on IEEE 802.11b/g technology. ScaleMesh can emulate large-scale mesh networks within a miniaturized experimentation area by adaptively shrinking the transmission range of mesh nodes by means of variable signal attenuators. To this end,...

    Provided By University of Leipzig

  • White Papers // Apr 2011

    Analyzing the Effective Throughput in Multi-Hop IEEE 802.11n Networks

    In this paper, the authors characterize the effective throughput for multi-hop paths in IEEE 802.11n based wireless mesh networks. They derive an analytical model capturing the effects of frame aggregation and block acknowledgements, features found in the new IEEE 802.11n standard. They describe the throughput at MAC layer as a...

    Provided By University of Leipzig

  • White Papers // Mar 2011

    Understanding IEEE 802.11n Multi-Hop Communication in Wireless Networks

    In this paper, the authors present a measurement study of the multi-hop behavior of the new IEEE 802.11n standard in an indoor mesh testbed. As main contribution, they quantitatively describe characteristics of IEEE 802.11n on multi-hop paths like throughput, aggregate size and utilized MIMO features. Furthermore, they show how to...

    Provided By University of Leipzig

  • White Papers // Oct 2010

    An Accurate and Analytically Tractable Model for Human Inter-Contact Times

    The authors present an analytically tractable mathematical approach for accurately modeling the distribution of inter-contact times between mobile devices carried by users. The contribution of this paper is two-fold: they show how to employ a MarkovModulated Poisson process (MMPP) for characterizing long-term dependencies in the mobility behavior, and they propose...

    Provided By University of Leipzig

  • White Papers // Oct 2009

    CrossTrace: Cross-Layer Measurement for IEEE 802.11 Wireless Testbeds

    In this paper, the authors introduce and evaluate CrossTrace, a framework for performing cross-layer measurements in IEEE 802.11 based wireless networks. CrossTrace allows tracing of parameters at MAC-layer, routing and transport layer in a controlled environment and in a repeatable manner. Using CrossTrace, they conduct a comprehensive measurement study in...

    Provided By University of Leipzig

  • White Papers // Nov 2014

    SAFE: Policy Aware SPARQL Query Federation Over RDF Data Cubes

    Several query federation engines have been proposed for accessing public Linked Open Data (LOD) sources. However, in many domains, resources are sensitive and access to these resources is tightly controlled by stakeholders; consequently, privacy is a major concern when federating queries over such datasets. In this paper, the authors present...

    Provided By University of Leipzig

  • White Papers // May 2010

    Evolution of the Linux Kernel Variability Model

    Understanding the challenges faced by real projects in evolving variability models, is a prerequisite for providing adequate support for such undertakings. The authors study the evolution of a model describing features and configurations in a large product line - the Linux kernel variability model. They analyze this evolution quantitatively and...

    Provided By University of Leipzig

  • White Papers // Aug 2014

    Test-Driven Evaluation of Linked Data Quality

    Linked Open Data (LOD) comprises of an unprecedented volume of structured data on the Web. However, these datasets are of varying quality ranging from extensively curated datasets to crowd-sourced or extracted data of often relatively low quality. The authors present a methodology for test-driven quality assessment of linked data, which...

    Provided By University of Leipzig