Search results for "DDR"
showing 10 items of 108 documents
Multicast access control concept for xDSL-customers
2006
Multicast is a tempting possibility for many broad- band services. It makes possible to deliver one data-stream to several receivers simultaneously. IP-Multicast is based on an open group concept. This means that it is possible for all the users to join the group and thus receive the data. The open concept is also the main reason why multicast has not been taken in wider use. There is two different solution to solve this problem, group access control and multicast data encryption. Group access control mechanisms focuses on restricting the group membership at the users edge device. Traffic encryption scheme relies on end-to-end encryption, so a key management architecture is also needed. We …
Quality of Service Multicasting over Differentiated Services Networks
2003
This paper proposes a solution to support real-time multicast traffic with Quality of Service (QoS) constraints over Differentiated Services (DiffServ) IP networks. Our solution allows multicast users to dynamically join and leave the multicast tree. Moreover, it allows a multicast user which has negotiated a best-effort session to upgrade to a QoS-enabled session. Our solution is backward compatible with the Protocol Independent Multicast (PIM) scheme. It combines two ideas. First, resource availability along a new QoS path is verified via a probe-based approach. Second, QoS is maintained by marking replicated packets with a special DSCP value, before forwarding them on the QoS path.
UPC++ for bioinformatics: A case study using genome-wide association studies
2014
Modern genotyping technologies are able to obtain up to a few million genetic markers (such as SNPs) of an individual within a few minutes of time. Detecting epistasis, such as SNP-SNP interactions, in Genome-Wide Association Studies is an important but time-consuming operation since statistical computations have to be performed for each pair of measured markers. Therefore, a variety of HPC architectures have been used to accelerate these studies. In this work we present a parallel approach for multi-core clusters, which is implemented with UPC++ and takes advantage of the features available in the Partitioned Global Address Space and Object Oriented Programming models. Our solution is base…
Unified Parallel C++
2018
Abstract Although MPI is commonly used for parallel programming on distributed-memory systems, Partitioned Global Address Space (PGAS) approaches are gaining attention for programming modern multi-core CPU clusters. They feature a hybrid memory abstraction: distributed memory is viewed as a shared memory that is partitioned among nodes in order to simplify programming. In this chapter you will learn about Unified Parallel C++ (UPC++), a library-based extension of C++ that gathers the advantages of both PGAS and Object Oriented paradigms. The examples included in this chapter will help you to understand the main features of PGAS languages and how they can simplify the task of programming par…
Cultural institutions as agents of urban and community regeneration in the (post-)pandemic city. The case of the «Laboratorio Zen Insieme» in Palermo
2022
Although all cities in the world have been affected by the COVID-19 pandemic, its impacts on the territories, yet to be understood, are unevenly distributed, revealing extremely varied imbalances depending on the places. However, it is clear that the virus and its variants have aggravated pre-existing socio-spatial inequalities, creating new ones and bringing attention back to those implications between space, planning, public health and citizenship that are at the origins of contemporary urbanism. In a reference framework in which the crisis is globalized but unequal and in the absence of a welfare system capable of responding to the urgencies of the most marginalized social contexts and g…
A secure architecture for P2PSIP-based communication systems
2009
Today, Peer-to-Peer SIP based communication systems have attracted much attention from both academia and industry. The decentralized nature of P2P might provide the distributed peer-to-peer communication system without help of the traditional SIP server. However, it comes to the cost of reduced manageability and therefore causes security problems, e.g. distrust, privacy leaks, unpredictable availability, etc. In this paper, we investigate on P2PSIP security issues and propose a proxy-based system architecture that improves security during P2PSIP session initiation. The main issues considered in this architecture include Source inter-working, Encryption & Decryption, Policy Management, Desti…
Associative Memory Based on Double-Gating of Molecularly Linked Nanosystem Arrays: A Theoretical Scheme
2008
We discuss theoretically the properties of an associative memory (a system that can retrieve a stored pattern that is similar to the input pattern) based on the ideal conductive properties of a molecularly linked nanosystem array. Two schemes are considered for the memory based on the gate potential modulation of the drain-source current through the array. In the first scheme, the basic units of the electric circuit are nanosystems (e.g., nanoparticles) arranged in a series array. Each nanosystem is assumed to have two states of conductances, GM and Gm (GM ≫ Gm), that can be tuned externally by the gate and backgate potentials. The bit sequence associated with a given pattern is stored as t…
Heavy Ion Sensitivity of 16/32-Gbit NAND-Flash and 4-Gbit DDR3 SDRAM
2012
16/32-Gbit NAND-Flash and 4-Gbit DDR3 SDRAM memories have been tested under heavy ion irradiation. At high LET, 25nm NAND-Flash show MBUs at normal incidence. Techniques for SEFI mitigation in DDR3 SDRAM are studied.
SEA presidential address: Group connectivity and cooperation
2011
A model-free methodology is used for the first time to estimate a daily volatility index (VIBEX-NEW) for the Spanish financial market.We use a public data set of daily option prices to compute this index and showthat daily changes in VIBEXNEW display a negative, tight contemporaneous relationship with IBEX daily returns, contrary to other common volatility indicators, as an implied volatility indicator or a GARCH(1,1) conditional volatility model. This relationship is approximately symmetric to the sign on VIBEX-NEW changes and asymmetric to the IBEX-35 returns sign, which make it clearly a suitable volatility index for the Spanish stock market. We also examine the relationship between curr…
The law and the risks of stability and integrity for financial institutions
2011
Purpose – There are ever growing relations and mutual influences between law and global economic context: so, there arises the need for them to be investigated in a legal perspective, which is the aim of this paper.Design/methodology/approach – The method used tries to combine the empirical observation of the legal and economic reality in today's world and a few essential theoretical foundations such as the freedom to dispose of one's rights by wave of contractual instrument.Findings – The dramatic crisis that the global world has had to face over the past few years compels legal scholars to revisiting process of traditional categories in order to adapt them to society's changing problems.R…