86 research outputs found
Proxy dynamic delegation in grid gateway
Nowadays one of the main obstacles the research comes up against is the
difficulty in accessing the required computational resources. Grid is able to
offer the user a wide set of resources, even if they are often too hard to
exploit for non expert end user. Use simplification has today become a common
practice in the access and utilization of Cloud, Grid, and data center
resources. With the launch of L-GRID gateway, we introduced a new way to deal
with Grid portals. L-GRID is an extremely light portal developed in order to
access the EGI Grid infrastructure via Web, allowing users to submit their jobs
from whatever Web browser in a few minutes, without any knowledge about the
underlying Grid infrastructure.Comment: 6 page
A new job migration algorithm to improve data center efficiency
The under exploitation of the available resources risks to be one of the main
problems for a computing center. The growing demand of computational power
necessarily entails more complex approaches in the management of the computing
resources, with particular attention to the batch queue system scheduler. In a
heterogeneous batch queue system, available for both serial single core
processes and parallel multi core jobs, it may happen that one or more
computational nodes composing the cluster are not fully occupied, running a
number of jobs lower than their actual capability. A typical case is
represented by more single core jobs running each one over a different multi
core server, while more parallel jobs - requiring all the available cores of a
host - are queued. A job rearrangement executed at runtime is able to free
extra resources, in order to host new processes. We present an efficient method
to improve the computing resources exploitation.Comment: 7 page
High availability using virtualization
High availability has always been one of the main problems for a data center.
Till now high availability was achieved by host per host redundancy, a highly
expensive method in terms of hardware and human costs. A new approach to the
problem can be offered by virtualization. Using virtualization, it is possible
to achieve a redundancy system for all the services running on a data center.
This new approach to high availability allows to share the running virtual
machines over the servers up and running, by exploiting the features of the
virtualization layer: start, stop and move virtual machines between physical
hosts. The system (3RC) is based on a finite state machine with hysteresis,
providing the possibility to restart each virtual machine over any physical
host, or reinstall it from scratch. A complete infrastructure has been
developed to install operating system and middleware in a few minutes. To
virtualize the main servers of a data center, a new procedure has been
developed to migrate physical to virtual hosts. The whole Grid data center
SNS-PISA is running at the moment in virtual environment under the high
availability system. As extension of the 3RC architecture, several storage
solutions have been tested to store and centralize all the virtual disks, from
NAS to SAN, to grant data safety and access from everywhere. Exploiting
virtualization and ability to automatically reinstall a host, we provide a sort
of host on-demand, where the action on a virtual machine is performed only when
a disaster occurs.Comment: PhD Thesis in Information Technology Engineering: Electronics,
Computer Science, Telecommunications, pp. 94, University of Pisa [Italy
High availability using virtualization - 3RC
High availability has always been one of the main problems for a data center.
Till now high availability was achieved by host per host redundancy, a highly
expensive method in terms of hardware and human costs. A new approach to the
problem can be offered by virtualization. Using virtualization, it is possible
to achieve a redundancy system for all the services running on a data center.
This new approach to high availability allows the running virtual machines to
be distributed over a small number of servers, by exploiting the features of
the virtualization layer: start, stop and move virtual machines between
physical hosts. The 3RC system is based on a finite state machine, providing
the possibility to restart each virtual machine over any physical host, or
reinstall it from scratch. A complete infrastructure has been developed to
install operating system and middleware in a few minutes. To virtualize the
main servers of a data center, a new procedure has been developed to migrate
physical to virtual hosts. The whole Grid data center SNS-PISA is running at
the moment in virtual environment under the high availability system.Comment: 10 page
CP Violation and K0 decays revelation: study and simulation of neutral Trigger in NA48 experiment -- Violazione di CP e rivelazione dei decadimenti del K0: studio e simulazione del Trigger neutro nell'esperimento NA48
At the INFN laboratory in Pisa I have prepared my dissertation, which
essentially concerned Montecarlo simulation of subnuclear particles decays and
investigation of low-noise electronic devices for analyzing high-frequency
signals. The team-work was part of NA48/EPSI experiment jointly carried out
with European Organization for Nuclear Research CERN, Geneva.
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Nell'ambito dell'esperimento NA48 in corso al CERN Super Proton Syncrothon
(SPS) finalizzato a misurare la violazione diretta di CP in sistemi di
particelle K0 attraverso il doppio rapporto R =
[N(K_L->Pi0Pi0)]/[N(K_S->Pi0Pi0)] / [N(K_L->Pi+Pi-)]/[N(K_S->Pi+Pi-)] = 1 - 6
Re(e1/e) con una precisione di Re(e1/e) superiore a 2 * 10^-4, il lavoro di
tesi si propone di effettuare una simulazione per la rivelazione dei
decadimenti neutri dei K0 ed una successiva analisi dei dati raffrontando
l'evento fisico generato con metodo Montecarlo e quello ricostruito. Per la
misura di e1/e occorre isolare tra i vari modi di decadimento dei K quelli
K_S->Pi0Pi0, K_S->Pi+Pi-, e quelli K_L->Pi0Pi0, K_L->Pi+Pi-.Comment: 69 Pages, in Italia
Geomorphic signal of active faulting at the northern edge of Lut Block. Insights on the kinematic scenario of Central Iran
Recent works documented Neogene to Quaternary dextral strike-slip tectonics along the Kuh-e-Sarhangi and Kuh-e-Faghan intraplate strike-slip faults at the northern edge of the Lut Block of Central Iran, previously thought to be dominated by sinistral strike-slip deformation. This work focuses on the evidence of Quaternary activity of one of these fault systems, in order to provide new spatio-temporal constraints on their role in the active regional kinematic scenario. Through geomorphological and structural investigation, integrated with Optically Stimulated Luminescence (OSL) dating of three generations of alluvial fans and fluvial terraces (at ~53, ~25 and ~6 ka), this study documents (i) the topographic inheritance of the long-term (Myr) punctuated history of fault nucleation, propagation, and exhumation along the northern edge of Lut Block; (ii) the tectonic control on drainage network evolution, pediment formation, fluvial terraces, and alluvial-fan architecture; (iii) the minimum Holocene age of Quaternary dextral strike-slip faulting; and (iv) the evidence of Late Quaternary fault-related uplift localized along the different fault strands. The documented spatial and temporal constraints on the active dextral strike-slip tectonics at the northern edge of Lut Block provided new insights on the kinematic model for active faulting in Central Iran, which has been reinterpreted in an escape tectonic scenario
Contextualizing Microcredit in Bosnia-Herzegovina and Hungary: A Focus Group Exploration
Microfinance is gaining importance as a tool to reduce poverty and promote financial and social inclusion. The main goal of the paper is to analyze the role of microcredit in solving the problem of credit access to vulnerable people. The paper focuses on the direct experience of people who have used microcredit living in Bosnia-Herzegovina and Hungary to analyze the use of microcredit in these areas. From the methodological point of view, the research uses focus groups to investigate customer relations with the banking system, microcredit, social and financial exclusion, and possible alternatives to microcredit. In this way, it is possible to analyze the mechanism through which involvement in microcredit operations results in positive(and negative) effects on people's lives. Results show that microcredit is a great opportunity to facilitate employment, create jobs, increase productivity, improve living conditions promote social integration. Results show that services of mentoring and coaching improve entrepreneurship skills or vocational(technical) know-how. These services help to improve access to finance for vulnerable individuals and to support better living conditions. We identify current good practices among microfinance services to understand the future potential role of microcredit proposes concrete in particular areas
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