University of Frankfurt

Displaying 1-27 of 27 results

  • White Papers // Sep 2013

    Pleasantly Consuming Linked Data With RDF Data Descriptions

    Although the intention of RDF is to provide an open, minimally constraining way for representing information, there exist an increasing number of applications for which guarantees on the structure and values of an RDF data set become desirable if not essential. What is missing in this respect are mechanisms to...

    Provided By University of Frankfurt

  • White Papers // Aug 2013

    PigSPARQL: A SPARQL Query Processing Baseline for Big Data

    In this paper, the authors discuss PigSPARQL, a competitive yet easy to use SPARQL query processing system on MapReduce that allows ad-hoc SPARQL query processing on large RDF graphs out of the box. Instead of a direct mapping, PigSPARQL uses the query language of Pig, a data analysis platform on...

    Provided By University of Frankfurt

  • White Papers // Aug 2013

    On Process Rewriting for Business Process Security

    In this paper, the author reports on ongoing work towards a framework to automatically rewrite business process models and, thereby, correctively enforce adherence to regulatory compliance and security policies. Specifically, the paper first motivates the need for rewriting mechanisms as a means to enforce a particular class of properties. Second,...

    Provided By University of Frankfurt

  • White Papers // May 2013

    Online Load Analysis for Automated Request-Quota Controlling in Clouds

    The importance of efficient use of IT infrastructure capacities increases, as the growing amount of deployed IT systems increasingly requires resources. On the one hand, companies can outsource their IT demands to Cloud providers in order to only pay for the very amount of required computational power. On the other...

    Provided By University of Frankfurt

  • White Papers // May 2013

    Preventive Inference Control in Data-centric Business Models

    Inference control is a modern topic in data usage management, especially in the context of data-centric business models. However, it is generally not well understood how protection mechanisms could be designed to protect the users. The contributions of this paper are threefold: firstly, it describes the inference problem and relate...

    Provided By University of Frankfurt

  • White Papers // Mar 2013

    On Active Information Storage in Input-Driven Systems

    Information theory and the framework of information dynamics have been used to provide tools to characterize complex systems. In particular, the authors are interested in quantifying information storage, information modification and information transfer as characteristic elements of computation. Although these quantities are defined for autonomous dynamical systems, information dynamics can...

    Provided By University of Frankfurt

  • White Papers // Oct 2012

    From a Barrier to a Bridge: Data-Privacy in Deregulated Smart Grids

    The introduction of so-called smart meters involves detailed consumption data. While this data plays a key role in integrating volatile renewable energy sources, a side effect is that it can reveal sensitive personal information. Concerns and protests led to a stopped smart meter rollout yet. In deregulated electricity markets, data-privacy...

    Provided By University of Frankfurt

  • White Papers // Jul 2012

    Automatic Information Flow Analysis of Business Process Models

    The authors present an automated and efficient approach for the verification of information flow control for business process models. Building on the concept of Place-based Non-Interference, the novelty is that Petri net reachability is employed to detect places in which information leaks occur. They show that the approach is sound...

    Provided By University of Frankfurt

  • White Papers // Mar 2012

    An Approach to Data-Driven Detective Internal Controls for Process-Aware Information Systems

    This paper argues for an approach for the well-founded, scalable detective internal controls to assist controllers in swiftly and reliably identifying violations of control objectives in business process executions. Considering the usual internal control setting, in which controllers have a process and policy specification (target state) and the corresponding event...

    Provided By University of Frankfurt

  • White Papers // Nov 2011

    MXQuery With Hardware Acceleration

    From a language perspective, XML-based data and query processing has been unprecedentedly successful, penetrating virtually all application areas that had been dominated by domain-specific solutions and languages previously. System makers, however, are scared by significant costs that are often associated with the versatile data model. Parsing and memory overheads often...

    Provided By University of Frankfurt

  • White Papers // Apr 2011

    RDFPath: Path Query Processing on Large RDF Graphs with MapReduce

    The MapReduce programming model has gained traction in different application areas in recent years, ranging from the analysis of log les to the computation of the RDFS closure. Yet, for most users the MapReduce abstraction is too low-level since even simple computations have to be expressed as Map and Reduce...

    Provided By University of Frankfurt

  • White Papers // Sep 2010

    ComCert: Automated Certification of Cloud-Based Business Processes

    Reliable Cloud Computing must provide control over business process compliance. The central task to this end is certifying business processes for their adherence to regulations. However, due to the dynamics of Clouds, current manual audits for compliance certification, such as SAS-70 or SAS-117, are hard to apply in this setting....

    Provided By University of Frankfurt

  • White Papers // Sep 2010

    A Parallel SPH Implementation on Multi-Core CPUs

    In this paper, the authors present a parallel framework for simulating fluids with the Smoothed Particle Hydrodynamics (SPH) method. For low computational costs per simulation step, efficient parallel neighborhood queries are proposed and compared. To further minimize the computing time for entire simulation sequences, strategies for maximizing the time step...

    Provided By University of Frankfurt

  • White Papers // Aug 2010

    FORTES: Forensic Information Flow Analysis of Business Processes

    This extended paper outlines the FORTES project for the forensic analysis of information flow properties. FORTES claims that information flow control can be made usable as a core of an audit-control system. For this purpose, it reconstructs work flow models from secure log files (i.e. execution traces) and, applying security...

    Provided By University of Frankfurt

  • White Papers // Oct 2009

    Incentive Compensation, Valuation, And Capital Market Access

    In this paper, the authors consider linear sharing rules for incentive compensation, when principal and agent are potentially restricted from short sales. They derive subjective valuation lines for performance shares, based on graphical analyses, and present results with respect to implementing effort and investment incentives. When the agent is restricted...

    Provided By University of Frankfurt

  • White Papers // Jul 2009

    Financial Constraints And The Decision To Lease - Evidence From German SME

    The objective of this paper is to test the hypothesis that in particular financially constrained firms lease a higher share of their assets to mitigate problems of asymmetric information. The assumptions are tested under a GMM framework which simultaneously controls for endogeneity problems and firms' fixed effects. The authors find...

    Provided By University of Frankfurt

  • White Papers // Jun 2009

    On The Real Effects Of Bank Bailouts: Micro-Evidence From Japan

    Exploiting the Japanese banking crisis as a laboratory, the authors provide novel firm-level evidence on the real effects of different government interventions for resolving a systemic banking crisis. Their results show that government recapitalizations of weak banks result in significantly positive abnormal returns for those banks' clients. After recapitalizations, banks...

    Provided By University of Frankfurt

  • White Papers // Apr 2009

    Does Size Matter?: Economies Of Scale In The German Mutual Fund Industry

    In this paper, the authors analyze economies of scale for German mutual fund complexes. Using 2002-2005 data of 41 investment management companies, they specify a hedonic translog cost function. Applying a fixed effects regression on a one-way error component model there is clear evidence of significant overall economies of scale....

    Provided By University of Frankfurt

  • White Papers // Apr 2009

    Gauging Risk With Higher Moments: Handrails In Measuring And Optimising Conditional Value At Risk

    The aim of the paper is to study empirically the influence of higher moments of the return distribution on Conditional Value at Risk (CVaR). To be more exact, the authors attempt to reveal the extent to which the risk given by CVaR can be estimated when relying on the mean,...

    Provided By University of Frankfurt

  • White Papers // Mar 2009

    Investment, Income, Incompleteness

    The utility-maximizing consumption and investment strategy of an individual investor receiving an unspanned labor income stream seems impossible to find in closed form and very difficult to find using numerical solution techniques. The authors suggest an easy procedure for finding a specific, simple, and admissible consumption and investment strategy, which...

    Provided By University of Frankfurt

  • White Papers // Feb 2009

    Optimal Housing, Consumption, And Investment Decisions Over The Life-Cycle

    The authors provide explicit solutions to life-cycle utility maximization problems simultaneously involving dynamic decisions on investments in stocks and bonds, consumption of perishable goods, and the rental and the ownership of residential real estate. House prices, stock prices, interest rates, and the labor income of the decision-maker follow correlated stochastic...

    Provided By University of Frankfurt

  • White Papers // Nov 2008

    The Effects Of Bank Mergers On Small Business Lending In Germany

    In this paper, the authors examine the impact of mergers among German savings banks on the extent to which these savings banks engage in small business lending. The ongoing consolidation in the banking industry has sparked concerns about the continuous availability of credit to small businesses which has been further...

    Provided By University of Frankfurt

  • White Papers // Nov 2008

    Dyssynergies Of Mergers Among Local Banks

    In this paper, the authors investigate how bank mergers affect bank revenues and present empirical evidence that mergers among banks have a substantial and persistent negative impact on merging banks' revenues. The authors refer to merger related negative effects on banks' revenues as dissynergies and suggest that they are a...

    Provided By University of Frankfurt

  • White Papers // Nov 2008

    The Quiet Life Hypothesis In Banking - Evidence From German Savings Banks

    The Quiet Life Hypothesis (QLH)' posits that banks enjoy the advantages of market power in terms of foregone revenues or cost savings. The authors suggest a unified approach to measure competition and efficiency simultaneously to test this hypothesis. They estimate bank-specific Lerner indices as measures of competition and test if...

    Provided By University of Frankfurt

  • White Papers // Nov 2008

    The Effects Of Size On Local Banks' Funding Costs

    Motivated by the recent discussion of the declining importance of deposits as banks' major source of funding the authors investigate which factors determine funding costs at local banks. Using a panel data set of more than 800 German local savings and cooperative banks for the period from 1998 to 2004...

    Provided By University of Frankfurt

  • White Papers // Mar 2008

    The SME Way of Adopting Rfid Technology - Empirical Findings From a German Cross-Sectoral Study

    More than 98 per cent of all European companies are Small or Medium-sized Enterprises (SMEs). Even though their structural characteristics are well known, neither academia nor politics have paid much attention to SMEs' experiences in using RFID technology. Consequently, SMEs that deal with an implementation have so far only few...

    Provided By University of Frankfurt

  • White Papers // May 2006

    Difference in Security Policies for Dynamic Systems

    Advances in three aspects of computing, namely reachability, pervasiveness, and autonomy, lead to highly dynamic systems, whose components increasingly manage themselves. However, their security and trustworthiness must always be evaluated in the user's context and in tight association with his personal goals and current preferences. Therefore, this paper defines an...

    Provided By University of Frankfurt

  • White Papers // Feb 2009

    Optimal Housing, Consumption, And Investment Decisions Over The Life-Cycle

    The authors provide explicit solutions to life-cycle utility maximization problems simultaneously involving dynamic decisions on investments in stocks and bonds, consumption of perishable goods, and the rental and the ownership of residential real estate. House prices, stock prices, interest rates, and the labor income of the decision-maker follow correlated stochastic...

    Provided By University of Frankfurt

  • White Papers // Jul 2009

    Financial Constraints And The Decision To Lease - Evidence From German SME

    The objective of this paper is to test the hypothesis that in particular financially constrained firms lease a higher share of their assets to mitigate problems of asymmetric information. The assumptions are tested under a GMM framework which simultaneously controls for endogeneity problems and firms' fixed effects. The authors find...

    Provided By University of Frankfurt

  • White Papers // Mar 2009

    Investment, Income, Incompleteness

    The utility-maximizing consumption and investment strategy of an individual investor receiving an unspanned labor income stream seems impossible to find in closed form and very difficult to find using numerical solution techniques. The authors suggest an easy procedure for finding a specific, simple, and admissible consumption and investment strategy, which...

    Provided By University of Frankfurt

  • White Papers // Apr 2009

    Does Size Matter?: Economies Of Scale In The German Mutual Fund Industry

    In this paper, the authors analyze economies of scale for German mutual fund complexes. Using 2002-2005 data of 41 investment management companies, they specify a hedonic translog cost function. Applying a fixed effects regression on a one-way error component model there is clear evidence of significant overall economies of scale....

    Provided By University of Frankfurt

  • White Papers // Apr 2009

    Gauging Risk With Higher Moments: Handrails In Measuring And Optimising Conditional Value At Risk

    The aim of the paper is to study empirically the influence of higher moments of the return distribution on Conditional Value at Risk (CVaR). To be more exact, the authors attempt to reveal the extent to which the risk given by CVaR can be estimated when relying on the mean,...

    Provided By University of Frankfurt

  • White Papers // Nov 2008

    The Effects Of Bank Mergers On Small Business Lending In Germany

    In this paper, the authors examine the impact of mergers among German savings banks on the extent to which these savings banks engage in small business lending. The ongoing consolidation in the banking industry has sparked concerns about the continuous availability of credit to small businesses which has been further...

    Provided By University of Frankfurt

  • White Papers // Nov 2008

    Dyssynergies Of Mergers Among Local Banks

    In this paper, the authors investigate how bank mergers affect bank revenues and present empirical evidence that mergers among banks have a substantial and persistent negative impact on merging banks' revenues. The authors refer to merger related negative effects on banks' revenues as dissynergies and suggest that they are a...

    Provided By University of Frankfurt

  • White Papers // Nov 2008

    The Quiet Life Hypothesis In Banking - Evidence From German Savings Banks

    The Quiet Life Hypothesis (QLH)' posits that banks enjoy the advantages of market power in terms of foregone revenues or cost savings. The authors suggest a unified approach to measure competition and efficiency simultaneously to test this hypothesis. They estimate bank-specific Lerner indices as measures of competition and test if...

    Provided By University of Frankfurt

  • White Papers // Nov 2008

    The Effects Of Size On Local Banks' Funding Costs

    Motivated by the recent discussion of the declining importance of deposits as banks' major source of funding the authors investigate which factors determine funding costs at local banks. Using a panel data set of more than 800 German local savings and cooperative banks for the period from 1998 to 2004...

    Provided By University of Frankfurt

  • White Papers // Oct 2009

    Incentive Compensation, Valuation, And Capital Market Access

    In this paper, the authors consider linear sharing rules for incentive compensation, when principal and agent are potentially restricted from short sales. They derive subjective valuation lines for performance shares, based on graphical analyses, and present results with respect to implementing effort and investment incentives. When the agent is restricted...

    Provided By University of Frankfurt

  • White Papers // Jun 2009

    On The Real Effects Of Bank Bailouts: Micro-Evidence From Japan

    Exploiting the Japanese banking crisis as a laboratory, the authors provide novel firm-level evidence on the real effects of different government interventions for resolving a systemic banking crisis. Their results show that government recapitalizations of weak banks result in significantly positive abnormal returns for those banks' clients. After recapitalizations, banks...

    Provided By University of Frankfurt

  • White Papers // May 2013

    Online Load Analysis for Automated Request-Quota Controlling in Clouds

    The importance of efficient use of IT infrastructure capacities increases, as the growing amount of deployed IT systems increasingly requires resources. On the one hand, companies can outsource their IT demands to Cloud providers in order to only pay for the very amount of required computational power. On the other...

    Provided By University of Frankfurt

  • White Papers // Mar 2013

    On Active Information Storage in Input-Driven Systems

    Information theory and the framework of information dynamics have been used to provide tools to characterize complex systems. In particular, the authors are interested in quantifying information storage, information modification and information transfer as characteristic elements of computation. Although these quantities are defined for autonomous dynamical systems, information dynamics can...

    Provided By University of Frankfurt

  • White Papers // Nov 2011

    MXQuery With Hardware Acceleration

    From a language perspective, XML-based data and query processing has been unprecedentedly successful, penetrating virtually all application areas that had been dominated by domain-specific solutions and languages previously. System makers, however, are scared by significant costs that are often associated with the versatile data model. Parsing and memory overheads often...

    Provided By University of Frankfurt

  • White Papers // Mar 2008

    The SME Way of Adopting Rfid Technology - Empirical Findings From a German Cross-Sectoral Study

    More than 98 per cent of all European companies are Small or Medium-sized Enterprises (SMEs). Even though their structural characteristics are well known, neither academia nor politics have paid much attention to SMEs' experiences in using RFID technology. Consequently, SMEs that deal with an implementation have so far only few...

    Provided By University of Frankfurt

  • White Papers // Aug 2013

    On Process Rewriting for Business Process Security

    In this paper, the author reports on ongoing work towards a framework to automatically rewrite business process models and, thereby, correctively enforce adherence to regulatory compliance and security policies. Specifically, the paper first motivates the need for rewriting mechanisms as a means to enforce a particular class of properties. Second,...

    Provided By University of Frankfurt

  • White Papers // May 2006

    Difference in Security Policies for Dynamic Systems

    Advances in three aspects of computing, namely reachability, pervasiveness, and autonomy, lead to highly dynamic systems, whose components increasingly manage themselves. However, their security and trustworthiness must always be evaluated in the user's context and in tight association with his personal goals and current preferences. Therefore, this paper defines an...

    Provided By University of Frankfurt

  • White Papers // Sep 2013

    Pleasantly Consuming Linked Data With RDF Data Descriptions

    Although the intention of RDF is to provide an open, minimally constraining way for representing information, there exist an increasing number of applications for which guarantees on the structure and values of an RDF data set become desirable if not essential. What is missing in this respect are mechanisms to...

    Provided By University of Frankfurt

  • White Papers // Aug 2013

    PigSPARQL: A SPARQL Query Processing Baseline for Big Data

    In this paper, the authors discuss PigSPARQL, a competitive yet easy to use SPARQL query processing system on MapReduce that allows ad-hoc SPARQL query processing on large RDF graphs out of the box. Instead of a direct mapping, PigSPARQL uses the query language of Pig, a data analysis platform on...

    Provided By University of Frankfurt

  • White Papers // Oct 2012

    From a Barrier to a Bridge: Data-Privacy in Deregulated Smart Grids

    The introduction of so-called smart meters involves detailed consumption data. While this data plays a key role in integrating volatile renewable energy sources, a side effect is that it can reveal sensitive personal information. Concerns and protests led to a stopped smart meter rollout yet. In deregulated electricity markets, data-privacy...

    Provided By University of Frankfurt

  • White Papers // Apr 2011

    RDFPath: Path Query Processing on Large RDF Graphs with MapReduce

    The MapReduce programming model has gained traction in different application areas in recent years, ranging from the analysis of log les to the computation of the RDFS closure. Yet, for most users the MapReduce abstraction is too low-level since even simple computations have to be expressed as Map and Reduce...

    Provided By University of Frankfurt

  • White Papers // Mar 2012

    An Approach to Data-Driven Detective Internal Controls for Process-Aware Information Systems

    This paper argues for an approach for the well-founded, scalable detective internal controls to assist controllers in swiftly and reliably identifying violations of control objectives in business process executions. Considering the usual internal control setting, in which controllers have a process and policy specification (target state) and the corresponding event...

    Provided By University of Frankfurt

  • White Papers // Aug 2010

    FORTES: Forensic Information Flow Analysis of Business Processes

    This extended paper outlines the FORTES project for the forensic analysis of information flow properties. FORTES claims that information flow control can be made usable as a core of an audit-control system. For this purpose, it reconstructs work flow models from secure log files (i.e. execution traces) and, applying security...

    Provided By University of Frankfurt

  • White Papers // Sep 2010

    ComCert: Automated Certification of Cloud-Based Business Processes

    Reliable Cloud Computing must provide control over business process compliance. The central task to this end is certifying business processes for their adherence to regulations. However, due to the dynamics of Clouds, current manual audits for compliance certification, such as SAS-70 or SAS-117, are hard to apply in this setting....

    Provided By University of Frankfurt

  • White Papers // Jul 2012

    Automatic Information Flow Analysis of Business Process Models

    The authors present an automated and efficient approach for the verification of information flow control for business process models. Building on the concept of Place-based Non-Interference, the novelty is that Petri net reachability is employed to detect places in which information leaks occur. They show that the approach is sound...

    Provided By University of Frankfurt

  • White Papers // Sep 2010

    A Parallel SPH Implementation on Multi-Core CPUs

    In this paper, the authors present a parallel framework for simulating fluids with the Smoothed Particle Hydrodynamics (SPH) method. For low computational costs per simulation step, efficient parallel neighborhood queries are proposed and compared. To further minimize the computing time for entire simulation sequences, strategies for maximizing the time step...

    Provided By University of Frankfurt

  • White Papers // May 2013

    Preventive Inference Control in Data-centric Business Models

    Inference control is a modern topic in data usage management, especially in the context of data-centric business models. However, it is generally not well understood how protection mechanisms could be designed to protect the users. The contributions of this paper are threefold: firstly, it describes the inference problem and relate...

    Provided By University of Frankfurt