University of Asmara

Displaying 1-24 of 24 results

  • White Papers // Jul 2014

    Time-Constrained Live VM Migration in Share-Nothing IaaS-Clouds

    Both economic reasons and interoperation requirements necessitate the deployment of Infrastructure as a Service (IaaS)-clouds based on share-nothing architecture. Here, live Virtual Machine (VM) migration becomes a major impediment to achieving cloud-wide load balancing via selective and timely VM migrations. The authors approach is based on copying virtual disk images...

    Provided By University of Asmara

  • White Papers // Sep 2013

    Adaptive Live VM Migration in Share-Nothing IaaS-Clouds With LiveFS

    Live migration is a versatile option when it comes to attain load-balancing in Infrastructure as a Service (IaaS)-cloud architectures. Liveness, reliability and conformance to Service Level Agreements (SLAs) may all be achieved by moving a Virtual Machine (VM) that creates excessive work from its current Physical Machine (PM) to a...

    Provided By University of Asmara

  • White Papers // Aug 2013

    Exploiting Network-Topology Awareness for VM Placement in IaaS Clouds

    In contemporary Infrastructure as a Service (IaaS) configurations, resources are distributed to users primarily through the assignment of Virtual Machines (VMs) to Physical Nodes (PMs). This resource allocation is typically done in a way that does not consider user preferences and is unaware of the underlying network layout. The latter...

    Provided By University of Asmara

  • White Papers // Apr 2013

    Distributed Query Processing on the Cloud: the Optique Point of View

    The optique european project aims at providing an end-to-end solution for scalable access to big data integration, where end users will formulate queries based on a familiar conceptualization of the underlying domain. From the users' queries the optique platform will automatically generate appropriate queries over the underlying integrated data, optimize...

    Provided By University of Asmara

  • White Papers // Apr 2013

    Addressing Streaming and Historical Data in OBDA Systems: Optique's Approach

    In large companies such as Siemens and Statoil monitoring tasks are of great importance, e.g., Siemens does monitoring of turbines and Statoil of oil behavior in wells. This paper brings up importance of both streaming and historical (temporal) data in the Big Data challenge for industries. The authors present the...

    Provided By University of Asmara

  • White Papers // Dec 2012

    Incomplete Information in RDF

    Incomplete information has been studied in-depth in relational databases and knowledge representation. It is also an important issue in Semantic Web frameworks such as RDF, description logics, and OWL 2 especially given that all these systems rely on the Open World Assumption (OWA). Making the OWA means that the authors...

    Provided By University of Asmara

  • White Papers // Oct 2012

    MAPCloud: Mobile Applications on an Elastic and Scalable 2-Tier Cloud Architecture

    The rise in popularity of mobile applications creates a growing demand to deliver richer functionality to users executing on mobile devices with limited resources. The availability of cloud computing platforms has made available unlimited and scalable resource pools of computation and storage that can be used to enhance service quality...

    Provided By University of Asmara

  • White Papers // Jun 2012

    A Privacy-Aware Access Control Model for Distributed Network Monitoring

    Despite the usefulness of network monitoring for the operation, maintenance, control and protection of communication networks, as well as law enforcement, network monitoring activities are surrounded by serious privacy implications. Their inherent leakage-proneness is harshened due to the increasing complexity of the monitoring procedures and infrastructures that may include multiple...

    Provided By University of Asmara

  • White Papers // Jun 2012

    I Forgot Your Password: Randomness Attacks Against PHP Applications

    The authors provide a number of practical techniques and algorithms for exploiting randomness vulnerabilities in PHP applications. They focus on the predictability of password reset tokens and demonstrate how an attacker can take over user accounts in a web application via predicting or algorithmically de-randomizing the PHP core randomness generators....

    Provided By University of Asmara

  • White Papers // May 2012

    A Novel Handover Decision Policy for Reducing Power Transmissions in the Two-Tier LTE Network

    Femtocells are attracting a fast increasing interest nowadays, as a promising solution to improve indoor coverage, enhance system capacity, and lower transmit power. Technical challenges still remain, however, mainly including interference, security and mobility management, intercepting wide deployment and adoption from mobile operators and end users. This paper describes a...

    Provided By University of Asmara

  • White Papers // Feb 2012

    Malware Characteristics and Threats on the Internet Ecosystem

    Malware encyclopedias now play a vital role in disseminating information about security threats. Coupled with categorization and generalization capabilities, such encyclopedias might help better defend against both isolated and clustered specimens. In this paper, the authors present Malware Evaluator, a classification framework that treats malware categorization as a supervised learning...

    Provided By University of Asmara

  • White Papers // Oct 2011

    A Business Resolution Engine for Cloud Marketplaces

    Now-a-days cloud computing can be considered as a key element of modern ICT systems, changing the technological and architectural aspects that these systems are designed and managed. The number and variety of applications, exploiting the advantages of this new computing paradigm, is increasing, emerging a new market of services and...

    Provided By University of Asmara

  • White Papers // Sep 2011

    Data Warehouse Process Management

    Previous research has provided metadata models that enable the capturing of the static components of a data warehouse architecture, along with information on different quality factors over these components. This paper complements this work with the modeling of the dynamic parts of the data warehouse. The proposed meta-model of data...

    Provided By University of Asmara

  • White Papers // Aug 2010

    Adaptive MMSE Rake Receiver for WCDMA

    Several types of Rake Receivers like A-Rake, S-Rake, P-Rake, Adaptive frequency Rake, Time frequency Rake, Conventional MMSE Rake and Adaptive MMSE Rake are used for WCDMA. In this paper, the authors observed that the BER performance of the Adaptive MMSE Rake receiver gives better result in WCDMA. The comparative analysis...

    Provided By University of Asmara

  • White Papers // Jun 2010

    Software and Middleware Technologies Based on Open APIs and Protocols for Modern Service Provision in Telecoms

    The presence of software and middleware technologies based on open APIs and protocols for advanced service provision in telecoms is the main subject of this paper. Specifically, the role and the trade-off between open APIs and Protocols, i.e. OSA/Parlay APIs, JAIN APIs and SIP, in modern telecoms are addressed. The...

    Provided By University of Asmara

  • White Papers // Jun 2010

    Bit Error and Outage Probability of Serial Relaying Communication Systems

    In this paper, a study on the end-to-end performance of multi-hop non-regenerative relaying over independent and identical generalized-gamma fading channels is presented. Novel closed-form bounds for the cumulative distribution function, the moments, and the Moment Generating Function (MGF) of the end-to-end signal-to-noise ratio are presented. Using the MGF-based approach, closed-form...

    Provided By University of Asmara

  • White Papers // May 2010

    Towards Self-Adaptable, Scalable, Dependable and Energy Efficient Networks: The Self-Growing Concept

    In next generation systems and networks, the incorporation of mechanisms achieving robust, predictable and self-adaptive behavior with minimum cost will be a key requirement. Towards this goal, the authors introduce the notion of the "Self-growing network". The latter, in its initial deployment stage, is limited to a single dedicated purpose...

    Provided By University of Asmara

  • White Papers // Feb 2010

    Dual-Hop Transmissions With Fixed-Gain Relays Over Generalized-Gamma Fading Channels

    In this paper, a study on the end-to-end performance of dual-hop wireless communication systems equipped with fixed-gain relays and operating over Generalized-Gamma (GG) fading channels is presented. A novel closed form expression for the moments of the end-to-end Signal-to-Noise Ratio (SNR) is derived. The average bit error probability for coherent...

    Provided By University of Asmara

  • White Papers // Feb 2010

    A Rake Receiver Model for Filtering White Nose Presence in the Receiving Signals

    The third-generation universal mobile telecommunications system uses the high signal bandwidth for the WCDMA system (5 MHz) allows the received signal to be split into distinct multipath with high resolution. The rake receiver combines the received signals from different paths into a composite signal with substantially better characteristics for demodulation...

    Provided By University of Asmara

  • White Papers // Jul 2009

    FlexFS: Transparent Resilience for GRID Storage Resources

    Existing GRID infrastructures rely on explicit user instructions in order to replicate files for the purposes of resiliency. This human-intensive process is inefficient, error prone and, more importantly, makes file replication in GRIDs a cumbersome task. To address this problem, the authors introduce FlexFS - a fully automated file-system framework...

    Provided By University of Asmara

  • White Papers // Aug 2007

    Continuous RDF Query Processing over DHTs

    The authors study the continuous evaluation of conjunctive triple pattern queries over RDF data stored in distributed hash tables. In a continuous query scenario network nodes subscribe with long-standing queries and receive answers whenever RDF triples satisfying their queries are published. They present two novel query processing algorithms for this...

    Provided By University of Asmara

  • White Papers // Jun 2007

    A Security Binding for Efficient Authentication in 3G-WLAN Heterogeneous Networks

    The security architecture of the 3G-WLAN heterogeneous networks, which is proposed in 3GPP 33.234, specifies that a WLAN user, in order to get access to the 3G packet switched services or the public internet through the 3G Public Land Mobile Network (PLMN), they must follow a two-pass EAP-AKA authentication procedure....

    Provided By University of Asmara

  • White Papers // Jun 2007

    Vulnerabilities and Possible Attacks Against the GPRS Backbone Network

    This paper presents the security weaknesses and the possible attacks, which threaten the GPRS backbone network and the data that either reside at the network or are transferred through it. These attacks may be performed by malicious third parties, mobile users, network operators or network operator personnel, which exploit the...

    Provided By University of Asmara

  • White Papers // Jun 2007

    Security Issues in an Established Autonomous Wireless Network

    Athens Wireless Metropolitan Network (AWMN) is a wireless community that started forming in 2002. Currently there are 1700 active nodes in the Attica area, while 2500 more have shown interest in connecting to the network and are awaiting its expansion. This paper describes the nature, architecture and functionality of one...

    Provided By University of Asmara

  • White Papers // May 2010

    Towards Self-Adaptable, Scalable, Dependable and Energy Efficient Networks: The Self-Growing Concept

    In next generation systems and networks, the incorporation of mechanisms achieving robust, predictable and self-adaptive behavior with minimum cost will be a key requirement. Towards this goal, the authors introduce the notion of the "Self-growing network". The latter, in its initial deployment stage, is limited to a single dedicated purpose...

    Provided By University of Asmara

  • White Papers // Oct 2012

    MAPCloud: Mobile Applications on an Elastic and Scalable 2-Tier Cloud Architecture

    The rise in popularity of mobile applications creates a growing demand to deliver richer functionality to users executing on mobile devices with limited resources. The availability of cloud computing platforms has made available unlimited and scalable resource pools of computation and storage that can be used to enhance service quality...

    Provided By University of Asmara

  • White Papers // Feb 2010

    Dual-Hop Transmissions With Fixed-Gain Relays Over Generalized-Gamma Fading Channels

    In this paper, a study on the end-to-end performance of dual-hop wireless communication systems equipped with fixed-gain relays and operating over Generalized-Gamma (GG) fading channels is presented. A novel closed form expression for the moments of the end-to-end Signal-to-Noise Ratio (SNR) is derived. The average bit error probability for coherent...

    Provided By University of Asmara

  • White Papers // Jun 2010

    Bit Error and Outage Probability of Serial Relaying Communication Systems

    In this paper, a study on the end-to-end performance of multi-hop non-regenerative relaying over independent and identical generalized-gamma fading channels is presented. Novel closed-form bounds for the cumulative distribution function, the moments, and the Moment Generating Function (MGF) of the end-to-end signal-to-noise ratio are presented. Using the MGF-based approach, closed-form...

    Provided By University of Asmara

  • White Papers // Jun 2010

    Software and Middleware Technologies Based on Open APIs and Protocols for Modern Service Provision in Telecoms

    The presence of software and middleware technologies based on open APIs and protocols for advanced service provision in telecoms is the main subject of this paper. Specifically, the role and the trade-off between open APIs and Protocols, i.e. OSA/Parlay APIs, JAIN APIs and SIP, in modern telecoms are addressed. The...

    Provided By University of Asmara

  • White Papers // Feb 2010

    A Rake Receiver Model for Filtering White Nose Presence in the Receiving Signals

    The third-generation universal mobile telecommunications system uses the high signal bandwidth for the WCDMA system (5 MHz) allows the received signal to be split into distinct multipath with high resolution. The rake receiver combines the received signals from different paths into a composite signal with substantially better characteristics for demodulation...

    Provided By University of Asmara

  • White Papers // Aug 2010

    Adaptive MMSE Rake Receiver for WCDMA

    Several types of Rake Receivers like A-Rake, S-Rake, P-Rake, Adaptive frequency Rake, Time frequency Rake, Conventional MMSE Rake and Adaptive MMSE Rake are used for WCDMA. In this paper, the authors observed that the BER performance of the Adaptive MMSE Rake receiver gives better result in WCDMA. The comparative analysis...

    Provided By University of Asmara

  • White Papers // May 2012

    A Novel Handover Decision Policy for Reducing Power Transmissions in the Two-Tier LTE Network

    Femtocells are attracting a fast increasing interest nowadays, as a promising solution to improve indoor coverage, enhance system capacity, and lower transmit power. Technical challenges still remain, however, mainly including interference, security and mobility management, intercepting wide deployment and adoption from mobile operators and end users. This paper describes a...

    Provided By University of Asmara

  • White Papers // Dec 2012

    Incomplete Information in RDF

    Incomplete information has been studied in-depth in relational databases and knowledge representation. It is also an important issue in Semantic Web frameworks such as RDF, description logics, and OWL 2 especially given that all these systems rely on the Open World Assumption (OWA). Making the OWA means that the authors...

    Provided By University of Asmara

  • White Papers // Jun 2012

    I Forgot Your Password: Randomness Attacks Against PHP Applications

    The authors provide a number of practical techniques and algorithms for exploiting randomness vulnerabilities in PHP applications. They focus on the predictability of password reset tokens and demonstrate how an attacker can take over user accounts in a web application via predicting or algorithmically de-randomizing the PHP core randomness generators....

    Provided By University of Asmara

  • White Papers // Jun 2012

    A Privacy-Aware Access Control Model for Distributed Network Monitoring

    Despite the usefulness of network monitoring for the operation, maintenance, control and protection of communication networks, as well as law enforcement, network monitoring activities are surrounded by serious privacy implications. Their inherent leakage-proneness is harshened due to the increasing complexity of the monitoring procedures and infrastructures that may include multiple...

    Provided By University of Asmara

  • White Papers // Oct 2011

    A Business Resolution Engine for Cloud Marketplaces

    Now-a-days cloud computing can be considered as a key element of modern ICT systems, changing the technological and architectural aspects that these systems are designed and managed. The number and variety of applications, exploiting the advantages of this new computing paradigm, is increasing, emerging a new market of services and...

    Provided By University of Asmara

  • White Papers // Jun 2007

    A Security Binding for Efficient Authentication in 3G-WLAN Heterogeneous Networks

    The security architecture of the 3G-WLAN heterogeneous networks, which is proposed in 3GPP 33.234, specifies that a WLAN user, in order to get access to the 3G packet switched services or the public internet through the 3G Public Land Mobile Network (PLMN), they must follow a two-pass EAP-AKA authentication procedure....

    Provided By University of Asmara

  • White Papers // Aug 2007

    Continuous RDF Query Processing over DHTs

    The authors study the continuous evaluation of conjunctive triple pattern queries over RDF data stored in distributed hash tables. In a continuous query scenario network nodes subscribe with long-standing queries and receive answers whenever RDF triples satisfying their queries are published. They present two novel query processing algorithms for this...

    Provided By University of Asmara

  • White Papers // Jun 2007

    Security Issues in an Established Autonomous Wireless Network

    Athens Wireless Metropolitan Network (AWMN) is a wireless community that started forming in 2002. Currently there are 1700 active nodes in the Attica area, while 2500 more have shown interest in connecting to the network and are awaiting its expansion. This paper describes the nature, architecture and functionality of one...

    Provided By University of Asmara

  • White Papers // Apr 2013

    Distributed Query Processing on the Cloud: the Optique Point of View

    The optique european project aims at providing an end-to-end solution for scalable access to big data integration, where end users will formulate queries based on a familiar conceptualization of the underlying domain. From the users' queries the optique platform will automatically generate appropriate queries over the underlying integrated data, optimize...

    Provided By University of Asmara

  • White Papers // Jul 2009

    FlexFS: Transparent Resilience for GRID Storage Resources

    Existing GRID infrastructures rely on explicit user instructions in order to replicate files for the purposes of resiliency. This human-intensive process is inefficient, error prone and, more importantly, makes file replication in GRIDs a cumbersome task. To address this problem, the authors introduce FlexFS - a fully automated file-system framework...

    Provided By University of Asmara

  • White Papers // Sep 2013

    Adaptive Live VM Migration in Share-Nothing IaaS-Clouds With LiveFS

    Live migration is a versatile option when it comes to attain load-balancing in Infrastructure as a Service (IaaS)-cloud architectures. Liveness, reliability and conformance to Service Level Agreements (SLAs) may all be achieved by moving a Virtual Machine (VM) that creates excessive work from its current Physical Machine (PM) to a...

    Provided By University of Asmara

  • White Papers // Aug 2013

    Exploiting Network-Topology Awareness for VM Placement in IaaS Clouds

    In contemporary Infrastructure as a Service (IaaS) configurations, resources are distributed to users primarily through the assignment of Virtual Machines (VMs) to Physical Nodes (PMs). This resource allocation is typically done in a way that does not consider user preferences and is unaware of the underlying network layout. The latter...

    Provided By University of Asmara

  • White Papers // Jul 2014

    Time-Constrained Live VM Migration in Share-Nothing IaaS-Clouds

    Both economic reasons and interoperation requirements necessitate the deployment of Infrastructure as a Service (IaaS)-clouds based on share-nothing architecture. Here, live Virtual Machine (VM) migration becomes a major impediment to achieving cloud-wide load balancing via selective and timely VM migrations. The authors approach is based on copying virtual disk images...

    Provided By University of Asmara

  • White Papers // Apr 2013

    Addressing Streaming and Historical Data in OBDA Systems: Optique's Approach

    In large companies such as Siemens and Statoil monitoring tasks are of great importance, e.g., Siemens does monitoring of turbines and Statoil of oil behavior in wells. This paper brings up importance of both streaming and historical (temporal) data in the Big Data challenge for industries. The authors present the...

    Provided By University of Asmara

  • White Papers // Feb 2012

    Malware Characteristics and Threats on the Internet Ecosystem

    Malware encyclopedias now play a vital role in disseminating information about security threats. Coupled with categorization and generalization capabilities, such encyclopedias might help better defend against both isolated and clustered specimens. In this paper, the authors present Malware Evaluator, a classification framework that treats malware categorization as a supervised learning...

    Provided By University of Asmara

  • White Papers // Jun 2007

    Vulnerabilities and Possible Attacks Against the GPRS Backbone Network

    This paper presents the security weaknesses and the possible attacks, which threaten the GPRS backbone network and the data that either reside at the network or are transferred through it. These attacks may be performed by malicious third parties, mobile users, network operators or network operator personnel, which exploit the...

    Provided By University of Asmara

  • White Papers // Sep 2011

    Data Warehouse Process Management

    Previous research has provided metadata models that enable the capturing of the static components of a data warehouse architecture, along with information on different quality factors over these components. This paper complements this work with the modeling of the dynamic parts of the data warehouse. The proposed meta-model of data...

    Provided By University of Asmara