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Knittl S.,Msg Systems Ag | Schmitz D.,Leibniz Supercomputing Center
Proceedings of the 2013 IFIP/IEEE International Symposium on Integrated Network Management, IM 2013 | Year: 2013

IT services are more and more offered by a combination of on- and off-premises or even cloud services. While for internally provided IT services guidelines and standards for the IT management exist, the IT management must be further supported by integrating management aspects of external IT services. Based on our previous concept of the inter-organizational Configuration Management Database, in this article, we concentrate on an ontology-based solution for the problem of heterogeneity issues caused by the autonomy in modeling CMDB contents in each of the observed IT service provider organizations. Our concept delivers a stepwise approach to handle semantic mismatches and is based on a hybrid Ontology mapping. Besides solving the heterogeneity of the service providers' management information systems and offering a holistic view of the overall IT infrastructure to the IT management, semantic mechanisms additionally allow to retrieve knowledge in an automated manner. © 2013 IFIP.

Gong J.,Ludwig Maximilians University of Munich | Wei T.,Ludwig Maximilians University of Munich | Stark R.W.,Ludwig Maximilians University of Munich | Jamitzky F.,Ludwig Maximilians University of Munich | And 6 more authors.
Journal of Structural Biology | Year: 2010

Toll-like receptors (TLRs) belong to the Toll-like receptor/interleukin-1 receptor (TLR/IL-1R) superfamily which is defined by a common cytoplasmic Toll/interleukin-1 receptor (TIR) domain. TLRs recognize pathogen-associated molecular patterns and initiate an intracellular kinase cascade to trigger an immediate defensive response. SIGIRR (single immunoglobulin interleukin-1 receptor-related molecule), another member of the TLR/IL-1R superfamily, acts as a negative regulator of MyD88-dependent TLR signaling. It attenuates the recruitment of MyD88 adaptors to the receptors with its intracellular TIR domain. Thus, SIGIRR is a highly important molecule for the therapy of autoimmune diseases caused by TLRs. So far, the structural mechanism of interactions between SIGIRR, TLRs and adaptor molecules is unclear. To develop a working hypothesis for this interaction, we constructed three-dimensional models for the TIR domains of TLR4, TLR7, MyD88 and SIGIRR based on computational modeling. Through protein-protein docking analysis, we developed models of essential complexes involved in the TLR4 and 7 signaling and the SIGIRR inhibiting processes. We suggest that SIGIRR may exert its inhibitory effect through blocking the molecular interface of TLR4, TLR7 and the MyD88 adaptor mainly via its BB-loop region. © 2009 Elsevier Inc. All rights reserved.

Fritz W.,Leibniz Supercomputing Center | Hanka O.,Ludwig Maximilians University of Munich
9th International Conference on Networks, ICN 2010 | Year: 2010

Security is an essential business requirement towards communication networks and will play a major role in future internet concepts. Many researchers see security functionality as an integral part of a new architecture, which should be thought of as soon as the conceptional phase of any proposal. In this paper we discuss suggested security mechanisms for the so called Locator/Identifier-Split and outline problematic issues found in those concepts. Based on these observations, we propose a security architecture using smart cards, which allows for lifelong assigned identifiers and is able to handle key replacement and revocation. Furthermore, we discuss the aspect of initial bootstrap and how to integrate devices with very low computational power like sensors. © 2010 IEEE.

Bernau C.,Leibniz Supercomputing Center | Riester M.,Dana-Farber Cancer Institute | Riester M.,Harvard University | Boulesteix A.-L.,Biometry and Epidemiology | And 6 more authors.
Bioinformatics | Year: 2014

Motivation: Numerous competing algorithms for prediction in high-dimensional settings have been developed in the statistical and machine-learning literature. Learning algorithms and the prediction models they generate are typically evaluated on the basis of cross-validation error estimates in a few exemplary datasets. However, in most applications, the ultimate goal of prediction modeling is to provide accurate predictions for independent samples obtained in different settings. Cross-validation within exemplary datasets may not adequately reflect performance in the broader application context. Methods: We develop and implement a systematic approach to 'cross-study validation', to replace or supplement conventional cross-validation when evaluating high-dimensional prediction models in independent datasets. We illustrate it via simulations and in a collection of eight estrogen-receptor positive breast cancer microarray gene-expression datasets, where the objective is predicting distant metastasis-free survival (DMFS). We computed the C-index for all pairwise combinations of training and validation datasets. We evaluate several alternatives for summarizing the pairwise validation statistics, and compare these to conventional cross-validation. Results: Our data-driven simulations and our application to survival prediction with eight breast cancer microarray datasets, suggest that standard cross-validation produces inflated discrimination accuracy for all algorithms considered, when compared to cross-study validation. Furthermore, the ranking of learning algorithms differs, suggesting that algorithms performing best in cross-validation may be suboptimal when evaluated through independent validation. © 2014 The Author. Published by Oxford University Press. All rights reserved.

Pohn D.,Leibniz Supercomputing Center
ICISSP 2016 - Proceedings of the 2nd International Conference on Information Systems Security and Privacy | Year: 2016

Inter-organizational acceb to IT services based on the predominant standard of Federated Identity Management (FIM), the Security Abertion Markup Language (SAML), suffers from scalability ibues related to metadata exchange. In order to overcome these ibues, an approach for automated metadata exchange between Identity Provider (IDP) and Service Provider (SP) via a Trusted Third Party (TTP) is presented in this article. Based on the architecture, risk management with threats and counter measures is applied by using a risk management template. Special emphasis is put on the secure design of the automated metadata exchange. Copyright © 2016 by SCITEPRESS - Science and Technology Publications, Lda.

Leong S.H.,Leibniz Supercomputing Center | Frank A.,Leibniz Supercomputing Center | Kranzlmuller D.,Leibniz Supercomputing Center | Kranzlmuller D.,Ludwig Maximilians University of Munich
Procedia Computer Science | Year: 2013

Urgent computing enables responsible authorities to make educated decisions by supporting the computations of simulated predictions of time critical events. Unfortunately, most domains of science cannot afford dedicated resources for their urgent computing problems. As a solution, exploiting existing e-Infrastructures is invaluable for many problems if the wide array of available resources in today's e-Infrastructures can be utilised. In this paper, we focus on rarely occurring events that are best suited for urgent computations on existing HPC, Grid and Cloud e-Infrastructures. Since e-Infrastructures are meant to serve more than just one community of users, they have inherent characteristics that have to be modified or adapted in order to enable them effectively for urgent computing. We hope to demonstrate that there are many existing and on-going developments that can be leveraged to prepare existing e-Infrastructures for urgent computing. © 2013 The Authors. Published by Elsevier B.V.

Metzger S.,Leibniz Supercomputing Center | Hommel W.,Leibniz Supercomputing Center | Reiser H.,Leibniz Supercomputing Center
Proceedings - 6th International Conference on IT Security Incident Management and IT Forensics, IMF 2011 | Year: 2011

We present a holistic, process-oriented approach to ISO/IEC 27001 compliant security incident management that integrates multiple state-of-the-art security tools and has been applied to a real-world scenario very successfully for one year so far. The computer security incident response team, CSIRT, is enabled to correlate IT security related events across multiple communication channels and thus to classify any incidents consistently. Depending on an incident's classification, manual intervention or even fully automated reaction steps can be triggered, this starts with simple email notifications of system and network administrators, and scales up to quarantining compromised systems and sub networks automatically. A formally specified security incident response (SIR) process serves as the basis that clearly defines responsibilities, workflows, and interfaces. It has been designed to enable quick reactions to IT security events in a very resource-conserving manner. © 2011 IEEE.

Jamitzky F.,Leibniz Supercomputing Center | Stark R.W.,Ludwig Maximilians University of Munich
Ultramicroscopy | Year: 2010

From a mathematical point of view, the atomic force microscope (AFM) belongs to a special class of continuous time dynamical systems with intermittent impact collisions. Discontinuities of the velocity result from the collisions of the tip with the surface. Transition to chaos in non-linear systems can occur via the following four routes: bifurcation cascade, crisis, quasi-periodicity, and intermittency. For the AFM period doubling and period-adding cascades are well established. Other routes into chaos, however, also may play an important role. Time series data of a dynamic AFM experiment indicates a chaotic mode that is related to the intermittency route into chaos. The observed intermittency is characterized as a type III intermittency. Understanding the dynamics of the system will help improve the overall system performance by keeping the operation parameters of dynamic AFM in a range, where chaos can be avoided or at least controlled. © 2010 Elsevier B.V.

Bode A.,Leibniz Supercomputing Center | Bode A.,TU Munich
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

For a long period in the development of computers and computing efficient applications were only characterized by computational - and memory complexity or in more practical terms elapsed computing time and required main memory capacity. The history of Euro-Par and its predecessor-organizations stands for research on the development of ever more powerful computer architectures that shorten the compute time both by faster clocking and by parallel execution as well as the development of algorithms that can exhibit these parallel architectural features. The success of enhancing architectures and algorithms is best described by exponential curves regarding the peak computing power of architectures and the efficiency of algorithms. As microprocessor parts get more and more power hungry and electricity gets more and more expensive, "energy to solution" is a new optimization criterion for large applications. This calls for energy aware solutions. © 2013 Springer-Verlag.

Heinecke A.,TU Munich | Klemm M.,Intel Corporation | Bungartz H.-J.,Leibniz Supercomputing Center
Computing in Science and Engineering | Year: 2012

Comparing the architectures and performance levels of an Nvidia Fermi accelerator with an Intel MIC Architecture coprocessor demonstrates the benefit of the coprocessor for bringing highly parallel applications into, or even beyond, GPGPU performance regions. © 2006 IEEE.

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