Karlsruhe Institute of Technology

Displaying 1-40 of 93 results

  • White Papers // Sep 2014

    Energy-Aware Cloud Management Through Progressive SLA Specification

    Novel energy-aware cloud management methods dynamically reallocate computation across geographically distributed data centers to leverage regional electricity price and temperature differences. As a result, a managed Virtual Machine (VM) may suffer occasional downtimes. Current cloud providers only offer high availability VMs, without enough flexibility to apply such energy-aware management. In...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jan 2014

    Scalable Business Process Execution in the Cloud

    Business processes orchestrate service requests in a structured fashion. Process knowledge, however, has rarely been used to predict and decide about cloud infrastructure resource usage. In this paper, the authors present an approach for BPM-aware cloud computing that builds on process knowledge to improve the timeliness and quality of resource...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jan 2014

    Interacting with Statistical Linked Data via OLAP Operations

    On-Line Analytical Processing (OLAP) promises an interface to analyze Linked Data containing statistics going beyond other interaction paradigms such as follow-your-nose browsers, faceted-search interfaces and query builders. As a new way to interact with statistical Linked Data the authors define common OLAP operations on data cubes modelled in RDF and...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Nov 2013

    Scalable and Live Trace Processing with Kieker Utilizing Cloud Computing

    Knowledge of the internal behavior of applications often gets lost over the years. This paper can arise, for example, from missing documentation. Application-level monitoring, e.g., provided by the researcher, can help with the comprehension of such internal behavior. However, it can have large impact on the performance of the monitored...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Oct 2013

    Future Challenges for Linked APIs

    A number of approaches combine the principles and technologies of linked data and RESTful services. Services and APIs are thus enriched by, and contribute to, the web of data. These resource-centric approaches, referred to as linked APIs, focus on flexibility and the integration capabilities of linked data. The authors use...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Oct 2013

    Knowledge Discovery meets Linked APIs

    Knowledge Discovery and Data Mining (KDD) is a very well-established research field with useful techniques that explore patterns and regularities in large relational, structured and unstructured datasets. Theoretical and practical development in this field have led to useful and scalable solutions for the tasks of pattern mining, clustering, graph mining,...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Sep 2013

    Towards Online Performance Model Extraction in Virtualized Environments

    Virtualization increases the complexity and dynamics of modern software architectures making it a major challenge to manage the end-to-end performance of applications. Architecture-level performance models can help here as they provide the modeling power and analysis flexibility to predict the performance behavior of applications under varying workloads and configurations. However,...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Sep 2013

    Model-Based Throughput Prediction in Data Center Networks

    In this paper, the authors address the problem of performance analysis in computer networks. They present a new meta-model designed for the performance modeling of network infrastructures in modern data centers. Instances of their meta-model can be automatically transformed into stochastic simulation models for performance prediction. They evaluate the approach...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Aug 2013

    LoGV: Low-overhead GPGPU Virtualization

    Over the last few years, running high performance computing applications in the cloud has become feasible. At the same time, GPGPUs are delivering unprecedented performance for HPC applications. Cloud providers thus face the challenge to integrate GPGPUs into their virtualized platforms, which has proven difficult for current virtualization stacks. In...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jul 2013

    Vectorizing Database Column Scans with Complex Predicates

    The performance of the full table scan is critical for the overall performance of column-store database systems such as the SAP HANA database. Compressing the underlying column data format is both an advantage and a challenge, because it reduces the data volume involved in a scan on one hand and...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2013

    Elasticity in Cloud Computing: What It Is, and What It Is Not

    Originating from the field of physics and economics, the term elasticity is nowadays heavily used in the context of cloud computing. In this context, elasticity is commonly understood as the ability of a system to automatically provision and deprovision computing resources on demand as workloads change. However, elasticity still lacks...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2013

    A Method for Simulating Cloud Business Models: A Case Study on Platform as a Service

    Cloud computing has changed how software is produced, distributed, consumed, and priced. The cloud paradigm has had a disruptive effect on existing business models and elicited a need for more thoroughly defined business models as well as the tools to represent and compare business models. In this paper, the authors...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Apr 2013

    Cross-Layer Dependability Modeling and Abstraction in System on Chip

    The Resilience Articulation Point (RAP) model aims at provisioning researchers and developers with a probabilistic fault abstraction and error propagation framework covering all hardware/software layers of a system on chip. RAP assumes that physically induced faults at the technology or CMOS device layer will eventually manifest themselves as a single...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Dec 2012

    Towards Truthful Resource Reservation in Cloud Computing

    Prudent capacity planning to meet their clients future computational needs is one of the major issues cloud computing providers face today. By offering resource reservations in advance, providers gain insight into the projected demand of their customers and can act accordingly. However, customers need to be given an incentive, e.g....

    Provided By Karlsruhe Institute of Technology

  • White Papers // Dec 2012

    Decentralized Control Based on Globally Optimal Estimation

    A new method for globally optimal estimation in decentralized sensor-networks is applied to the decentralized control problem. The resulting approach is proven to be optimal when the nodes have access to all information in the network. More precisely, the authors utilize an algorithm for optimal distributed estimation in order to...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Nov 2012

    A Social Content Delivery Network for Scientific Cooperation: Vision, Design, and Architecture

    Data volumes have increased so significantly that the authors need to carefully consider how they interact with, share, and analyze data to avoid bottlenecks. In contexts such as e-Science and scientific computing, a large emphasis is placed on collaboration, resulting in many well-known challenges in ensuring that data is in...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Oct 2012

    A Flexible Approach for Compiling Scilab to Reconfigurable Multi-Core Embedded Systems

    The mapping process of high performance embedded applications to today's reconfigurable Multi-Processor System-on-Chip (MPSoC) devices suffers from a complex tool-chain and programming process. Thus, the efficient programming of such architectures in terms of achievable performance and power consumption is limited to experts only. Enabling them to non-experts requires a simplified...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Oct 2012

    Network Virtualization for QoS-Aware Resource Management in Cloud Data Centers: A Survey

    The increasing popularity of Cloud Computing is leading to the emergence of large virtualized data centers hosting increasingly complex and dynamic IT systems and services. Over the past decade, the efficient sharing of computational resources through virtualization has been subject to intensive research, while network management in cloud data centers...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Sep 2012

    Optimal Point Estimates for Multi-Target States Based on Kernel Distances

    Almost all multi-target tracking systems have to generate point estimates for the targets, e.g., for displaying the tracks. The novel idea in this paper is to consider point estimates for multi-target states that are optimal according to a kernel distance measure. Because the kernel distance is a metric on point...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Sep 2012

    Stochastic Nonlinear Model Predictive Control Based on Progressive Density Simplification

    Increasing demand for nonlinear model predictive control with the ability to handle highly noise-corrupted systems has recently given rise to stochastic control approaches. Besides providing high-quality results within a noisy environment, these approaches have one problem in common, namely a high computational demand and, as a consequence, generally a short...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Sep 2012

    Sequence-Based Control for Networked Control Systems Based on Virtual Control Inputs

    In this paper, the authors address the problem of controlling a system over an unreliable UDP-like network that is affected by time-varying delays and randomly occurring packet losses. A major challenge of this setup is that the controller just has uncertain information about the control inputs actually applied by the...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Sep 2012

    Optimal Kalman Gains for Combined Stochastic and Set-Membership State Estimation

    In state estimation theory, two directions are mainly followed in order to model disturbances and errors. Either uncertainties are modeled as stochastic quantities or they are characterized by their membership to a set. Both approaches have distinct advantages and disadvantages making each one inherently better suited to model different sources...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Aug 2012

    A Conceptual Framework for Simulating Autonomic Cloud Markets

    One of the major challenges facing the Cloud paradigm is the emergence of suitable economic platforms for the trading of Cloud services. Today, many researchers investigate how specific Cloud market platforms can be conceived and in some cases implemented. However, such endeavours consider only specific types of actors, business models,...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jul 2012

    Control Over Unreliable Networks Based on Control Input Densities

    Time delays and data losses arising from an unreliable communication between the components of a control loop decrease the quality of control and thus, have to be incorporated explicitly in the control decision. In this paper, a novel concept, the so-called virtual control inputs, is presented, which extends the well-established...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jul 2012

    Combined Stochastic and Set-Membership Information Filtering in Multisensor Systems

    In state estimation theory, stochastic and set membership approaches are generally considered separately from each other. Both concepts have distinct advantages and disadvantages making each one inherently better suited to model different sources of estimation uncertainty. In order to better utilize the potentials of both concepts, the core element of...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jun 2012

    Tightly Secure Signatures and Public-Key Encryption

    The authors construct the first public-key encryption scheme whose chosen-ciphertext (i.e., INDCCA) security can be proved under a standard assumption and does not degrade in either the number of users or the number of ciphertexts. In particular, their scheme can be safely deployed in unknown settings in which no a-priori...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jun 2012

    Spectral Estimation-Based OFDM Radar Algorithms for IEEE 802.11a Signals

    Recently, OFDM radar has gained attention as new algorithms for range and Doppler estimation specific to OFDM signals have been developed. The major advantage of OFDM is that it is both well-suited for radar processing as well as being suitable for communication. In previous work, the authors have proposed parametrizations...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jun 2012

    Collision-Balancing Frequency Hopping in Single-Hop Mobile Ad Hoc Networks

    The authors consider a single-hop Frequency Hopping (FH) Mobile Ad hoc NETwork (MANET). To increase throughput Orthogonal FH (O-FH) with hop-synchronous hopping can be used, thereby allowing collision-free transmissions under certain circumstances. However, as the MANET grows, hopping sequences must be re-used. As a result, nodes sharing the same sequence...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    Hopping Strategies for Adaptive FH-CDMA Ad Hoc Networks Under External Interference

    The authors discuss the performance of an adaptive FHCDMA ad hoc network under the influence of external interference where node positions are modeled by a homogeneous Poisson point process. The optimum channel assignment that balances internal network interference due to spatial reuse and external interference is derived analytically for a...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    Adaptive Frequency Hopping in Ad Hoc Networks With Rayleigh Fading and Imperfect Sensing

    A probabilistic model for Adaptive Frequency Hopping (AFH) based wireless ad hoc networks with Rayleigh fading, where interference is due to self - and to slow-varying external interference, is proposed. Different AFH sensing techniques are studied in terms of Area Spectral Efficiency (ASE) and it is shown that self-interference can...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    Increasing the One-Hop Progress of Nearest Neighbor Forwarding

    Wireless networks have recently gained much attraction due to several reasons: research on hardware has achieved considerable advances in the development of small and inexpensive communications devices. A fundamental property of these networks is that communication does not rely on a wired backbone. Hence, nodes additionally have to function as...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    Tracking 3D Shapes in Noisy Point Clouds With Random Hypersurface Models

    State of the art depth-sensors such as range cameras (time-of-flight, structured light, stereo) or laser rangefinder obtain three-dimensional point cloud data of a given real-world scene. Recently, multi-sensor setups have received increasing attention. Point clouds have become highly relevant for many real world applications, such as surveillance, target tracking, 3D...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    Interference and Throughput in Aloha-based Ad Hoc Networks With Isotropic Node Distribution

    The authors study the interference and outage statistics in a slotted Aloha ad hoc network, where the spatial distribution of nodes is non-stationary and isotropic. In such a network, outage probability and local throughput depend on both the particular location in the network and the shape of the spatial distribution....

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    Modeling the Target Extent With Multiplicative Noise

    Extended target tracking deals with simultaneously tracking the shape and the kinematic parameters of a target. In this paper, the authors formulate the extended target tracking problem as a state estimation problem with both multiplicative and additive measurement noise. In case of extended targets with known orientation, they show that...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    State Estimation in Networked Control Systems

    The authors consider the problem of state estimation in a Networked Control System, where measurements and control inputs are transmitted via a communication network. The network is subject to time-varying delays and stochastic data losses and does not provide acknowledgments of successfully transmitted data packets. A challenge that arises in...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    A Robust Computational Test for Overlap of Two Arbitrary-Dimensional Ellipsoids in Fault-Detection of Kalman Filters

    On-line fault-detection in uncertain measurement and estimation systems is of particular interest in many applications. In certain systems based on the Kalman filter, this test can be performed by checking whether hyper-ellipsoids overlap. This test can be applied to detecting failure in the system itself or in the sensors used...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    Recursive Bayesian Calibration of Depth Sensors With Non-Overlapping Views

    Setting up a network of multiple depth sensors introduces several issues that need to be addressed. For example, the popular Microsoft Kinect TM device acquires depth information using an active measurement system which projects an infrared pattern. This has important consequences in setups with overlapping fields of view, where the...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    On Optimal Distributed Kalman Filtering in Non-Ideal Situations

    The distributed processing of measurements and the subsequent data fusion is called Track-to-Track fusion. Although a solution for the Track-to-Track fusion that is equivalent to a central processing scheme has been proposed, this algorithm suffers from strict requirements regarding the local availability of knowledge about utilized models of the remote...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    Group Activity Recognition Using Mobile Devices

    Group activities are more than the sum of the activities of the individuals in them, but are rather generated by those activities and interactions between group members. This paper proposes Group Activity Recognition (GAR) using collaborative mobile user devices for sensing, processing and recognition. The contribution is a thorough evaluation...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Apr 2012

    CloudGenius: Decision Support for Web Server Cloud Migration

    Cloud computing is the latest computing paradigm that delivers hardware and software resources as virtualized services in which users are free from the burden of worrying about the low-level system administration details. Migrating Web applications to Cloud services and integrating Cloud services into existing computing infrastructures is non-trivial. It leads...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Apr 2012

    CloudGenius: Decision Support for Web Server Cloud Migration

    Cloud computing is the latest computing paradigm that delivers hardware and software resources as virtualized services in which users are free from the burden of worrying about the low-level system administration details. Migrating Web applications to Cloud services and integrating Cloud services into existing computing infrastructures is non-trivial. It leads...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    Hopping Strategies for Adaptive FH-CDMA Ad Hoc Networks Under External Interference

    The authors discuss the performance of an adaptive FHCDMA ad hoc network under the influence of external interference where node positions are modeled by a homogeneous Poisson point process. The optimum channel assignment that balances internal network interference due to spatial reuse and external interference is derived analytically for a...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Mar 2012

    ECO/ee: Energy-Aware Collaborative Organic Execution Environment for Wireless Sensor Networks

    This paper presents an energy-aware execution environment, called Energy-aware Collaborative Organic Execution Environment (ECO/ee), for Wireless Sensor Networks (WSN). ECO/ee provides an energy-aware and autonomous data routing scheme. It can dynamically adapt to the user's queries and efficiently determine the energy-abundant delivery paths. The fundamental concepts are inspired by the...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Oct 2012

    Network Virtualization for QoS-Aware Resource Management in Cloud Data Centers: A Survey

    The increasing popularity of Cloud Computing is leading to the emergence of large virtualized data centers hosting increasingly complex and dynamic IT systems and services. Over the past decade, the efficient sharing of computational resources through virtualization has been subject to intensive research, while network management in cloud data centers...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Dec 2012

    Towards Truthful Resource Reservation in Cloud Computing

    Prudent capacity planning to meet their clients future computational needs is one of the major issues cloud computing providers face today. By offering resource reservations in advance, providers gain insight into the projected demand of their customers and can act accordingly. However, customers need to be given an incentive, e.g....

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2013

    Elasticity in Cloud Computing: What It Is, and What It Is Not

    Originating from the field of physics and economics, the term elasticity is nowadays heavily used in the context of cloud computing. In this context, elasticity is commonly understood as the ability of a system to automatically provision and deprovision computing resources on demand as workloads change. However, elasticity still lacks...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Nov 2012

    A Social Content Delivery Network for Scientific Cooperation: Vision, Design, and Architecture

    Data volumes have increased so significantly that the authors need to carefully consider how they interact with, share, and analyze data to avoid bottlenecks. In contexts such as e-Science and scientific computing, a large emphasis is placed on collaboration, resulting in many well-known challenges in ensuring that data is in...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    Recursive Bayesian Calibration of Depth Sensors With Non-Overlapping Views

    Setting up a network of multiple depth sensors introduces several issues that need to be addressed. For example, the popular Microsoft Kinect TM device acquires depth information using an active measurement system which projects an infrared pattern. This has important consequences in setups with overlapping fields of view, where the...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jul 2012

    Combined Stochastic and Set-Membership Information Filtering in Multisensor Systems

    In state estimation theory, stochastic and set membership approaches are generally considered separately from each other. Both concepts have distinct advantages and disadvantages making each one inherently better suited to model different sources of estimation uncertainty. In order to better utilize the potentials of both concepts, the core element of...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    On Optimal Distributed Kalman Filtering in Non-Ideal Situations

    The distributed processing of measurements and the subsequent data fusion is called Track-to-Track fusion. Although a solution for the Track-to-Track fusion that is equivalent to a central processing scheme has been proposed, this algorithm suffers from strict requirements regarding the local availability of knowledge about utilized models of the remote...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jul 2011

    Fitting Conics to Noisy Data Using Stochastic Linearization

    Fitting conic sections, e.g., ellipses or circles, to noisy data points is a fundamental sensor data processing problem, which frequently arises in robotics. In this paper, the authors introduce a new procedure for deriving a recursive Gaussian state estimator for fitting conics to data corrupted by additive Gaussian noise. For...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Sep 2012

    Stochastic Nonlinear Model Predictive Control Based on Progressive Density Simplification

    Increasing demand for nonlinear model predictive control with the ability to handle highly noise-corrupted systems has recently given rise to stochastic control approaches. Besides providing high-quality results within a noisy environment, these approaches have one problem in common, namely a high computational demand and, as a consequence, generally a short...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Sep 2012

    Optimal Point Estimates for Multi-Target States Based on Kernel Distances

    Almost all multi-target tracking systems have to generate point estimates for the targets, e.g., for displaying the tracks. The novel idea in this paper is to consider point estimates for multi-target states that are optimal according to a kernel distance measure. Because the kernel distance is a metric on point...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Sep 2012

    Sequence-Based Control for Networked Control Systems Based on Virtual Control Inputs

    In this paper, the authors address the problem of controlling a system over an unreliable UDP-like network that is affected by time-varying delays and randomly occurring packet losses. A major challenge of this setup is that the controller just has uncertain information about the control inputs actually applied by the...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Sep 2012

    Optimal Kalman Gains for Combined Stochastic and Set-Membership State Estimation

    In state estimation theory, two directions are mainly followed in order to model disturbances and errors. Either uncertainties are modeled as stochastic quantities or they are characterized by their membership to a set. Both approaches have distinct advantages and disadvantages making each one inherently better suited to model different sources...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Dec 2012

    Decentralized Control Based on Globally Optimal Estimation

    A new method for globally optimal estimation in decentralized sensor-networks is applied to the decentralized control problem. The resulting approach is proven to be optimal when the nodes have access to all information in the network. More precisely, the authors utilize an algorithm for optimal distributed estimation in order to...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    Modeling the Target Extent With Multiplicative Noise

    Extended target tracking deals with simultaneously tracking the shape and the kinematic parameters of a target. In this paper, the authors formulate the extended target tracking problem as a state estimation problem with both multiplicative and additive measurement noise. In case of extended targets with known orientation, they show that...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    State Estimation in Networked Control Systems

    The authors consider the problem of state estimation in a Networked Control System, where measurements and control inputs are transmitted via a communication network. The network is subject to time-varying delays and stochastic data losses and does not provide acknowledgments of successfully transmitted data packets. A challenge that arises in...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    A Robust Computational Test for Overlap of Two Arbitrary-Dimensional Ellipsoids in Fault-Detection of Kalman Filters

    On-line fault-detection in uncertain measurement and estimation systems is of particular interest in many applications. In certain systems based on the Kalman filter, this test can be performed by checking whether hyper-ellipsoids overlap. This test can be applied to detecting failure in the system itself or in the sensors used...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jul 2012

    Control Over Unreliable Networks Based on Control Input Densities

    Time delays and data losses arising from an unreliable communication between the components of a control loop decrease the quality of control and thus, have to be incorporated explicitly in the control decision. In this paper, a novel concept, the so-called virtual control inputs, is presented, which extends the well-established...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2012

    Tracking 3D Shapes in Noisy Point Clouds With Random Hypersurface Models

    State of the art depth-sensors such as range cameras (time-of-flight, structured light, stereo) or laser rangefinder obtain three-dimensional point cloud data of a given real-world scene. Recently, multi-sensor setups have received increasing attention. Point clouds have become highly relevant for many real world applications, such as surveillance, target tracking, 3D...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Feb 2012

    Towards Large-Scale Network Virtualization

    Most existing Virtual Network (VN) provisioning approaches assume a single administrative domain and therefore, VN deployments are limited to the geographic footprint of the substrate provider. To enable wide-area VN provisioning, network virtualization architectures need to address the intricacies of inter-domain aspects, i.e., how to provision VNs with limited control...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2013

    A Method for Simulating Cloud Business Models: A Case Study on Platform as a Service

    Cloud computing has changed how software is produced, distributed, consumed, and priced. The cloud paradigm has had a disruptive effect on existing business models and elicited a need for more thoroughly defined business models as well as the tools to represent and compare business models. In this paper, the authors...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Feb 2011

    Implementing Trust in Cloud Infrastructures

    Today's cloud computing infrastructures usually require customers who transfer data into the cloud to trust the providers of the cloud infrastructure. Not every customer is willing to grant this trust without justification. It should be possible to detect that at least the configuration of the cloud infrastructure - as provided...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Aug 2012

    A Conceptual Framework for Simulating Autonomic Cloud Markets

    One of the major challenges facing the Cloud paradigm is the emergence of suitable economic platforms for the trading of Cloud services. Today, many researchers investigate how specific Cloud market platforms can be conceived and in some cases implemented. However, such endeavours consider only specific types of actors, business models,...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Apr 2012

    The KeY Approach for the Cryptographic Verification of JAVA Programs: A Case Study

    In this paper, the authors report on an ongoing case study in which they use the KeY tool, a theorem prover for checking functional correctness and noninterference properties of JAVA programs, to establish computational indistinguishability for a simple JAVA program that involves clients sending encrypted messages over an untrusted network...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jun 2012

    Tightly Secure Signatures and Public-Key Encryption

    The authors construct the first public-key encryption scheme whose chosen-ciphertext (i.e., INDCCA) security can be proved under a standard assumption and does not degrade in either the number of users or the number of ciphertexts. In particular, their scheme can be safely deployed in unknown settings in which no a-priori...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Mar 2012

    Secure Information Flow for Java a Dynamic Logic Approach

    In this paper, the authors discuss and define an information flow property for sequential Java that takes into account information leakage through objects (as opposed to primitive values). They present proof rules for compositional reasoning over information-flow in Java programs. Their calculus rules apply at Java code-level (not at an...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Feb 2012

    Dynamic Logic With Trace Semantics

    Dynamic Logic (DL) is an established instrument for program verification and for reasoning about the semantics of programs and programming languages. In this paper, the authors define an extension of dynamic logic, called Dynamic Logic with Trace Semantics (DLTS), which combines the expressiveness of program logics such as DL with...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Feb 2012

    Model-Based Techniques for Performance Engineering of Business Information Systems

    With the increasing adoption of virtualization and the transition towards Cloud Computing platforms, modern business information systems are becoming increasingly complex and dynamic. This raises the challenge of guaranteeing system performance and scalability while at the same time ensuring efficient resource usage. In this paper, the authors present a historical...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Mar 2012

    Architectural Concerns in Multi-Tenant SaaS Applications

    Multi-tenant applications serve different customers with one application instance. This architectural style leverages sharing and economies of scale to provide cost efficient hosting. As multi-tenancy is a new concept, a common definition of the word and related concepts is not yet established and the architectural concerns are not fully understood....

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jun 2012

    Collision-Balancing Frequency Hopping in Single-Hop Mobile Ad Hoc Networks

    The authors consider a single-hop Frequency Hopping (FH) Mobile Ad hoc NETwork (MANET). To increase throughput Orthogonal FH (O-FH) with hop-synchronous hopping can be used, thereby allowing collision-free transmissions under certain circumstances. However, as the MANET grows, hopping sequences must be re-used. As a result, nodes sharing the same sequence...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jun 2012

    Spectral Estimation-Based OFDM Radar Algorithms for IEEE 802.11a Signals

    Recently, OFDM radar has gained attention as new algorithms for range and Doppler estimation specific to OFDM signals have been developed. The major advantage of OFDM is that it is both well-suited for radar processing as well as being suitable for communication. In previous work, the authors have proposed parametrizations...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Oct 2009

    Wireless Networks In-the-Loop: Software Radio as the Enabler

    A software architecture to rapidly develop and test radio networks in real and physical environments is proposed. Radio network terminals are developed in software and run on generic hardware to maximize re-configurability. Due to the software nature of the radio terminals, radio networks can be simulated in a virtual environment,...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jan 2010

    Maximum Likelihood Speed and Distance Estimation for OFDM Radar

    A distance and speed estimation algorithm for OFDM based radar is analyzed statistically. The maximum likelihood estimator is derived and compared to previous results. A connection to spectral analysis is drawn, simplifying the analysis of the estimator in question. Finally, a method to evaluate the performance of the algorithm is...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Feb 2010

    Wideband Receiver for a Spaceborne Software Radio Application

    Software Defined Radio (SDR), thanks to the recent technological advancements, has become one of the valuable solutions to achieve flexibility in a regenerative communication payload on board the satellite. However, in order to take advantage of all its potentialities much work needs still to be done to overcome the related...

    Provided By Karlsruhe Institute of Technology

  • White Papers // May 2010

    Wireless Networks In-the-Loop: Emulating an RF Front-End in GNU

    The objective of this paper is to emulate the behavior of the Universal Software Radio Peripheral as an example of an RF front-end hardware for software radios. The model includes digital and analog signal processing. The emulator is implemented in GNU Radio and is intended to be used as part...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Mar 2010

    A Simple Stochastic Channel Simulator for Car-to-Car Communication at 24 GHz

    A channel model, based on stochastics and Ray tracing, is described for a communication system, in which moving participants communicate in the 24 GHz band. A realistic behaviour of propagation effects, both short-term and long-term, is modeled. This allows to simulate and design future vehicle-to-vehicle systems. Due to the increasing...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Nov 2009

    Software Defined Radio in Public and Governmental Security Systems

    Radio communication is crucial for Public and Governmental Security (P&GS) systems. No matter if a police officer waits for a radio message to get to his next scene or a firefighter needs to contact the operator, there will always be the need for a reliable, secure and fast radio communication...

    Provided By Karlsruhe Institute of Technology

  • White Papers // Jan 2011

    Lowering Outage Probability in Ad Hoc Networks by Nearest Neighbor FDMA Scheduling

    This paper investigates the performance of a wireless ad hoc network capable of dynamically coordinating a set of orthogonal frequency channels such that every receiver and its nearest interferer operate in different channels. The distribution of the ratio of the interference powers of the second and first interferer is derived...

    Provided By Karlsruhe Institute of Technology