3,792 research outputs found
How much does it cost? The LIFE Project - costing models for digital curation and preservation
Digital preservation is concerned with the long-term safekeeping of electronic resources. How can we be confident of their permanence, if we do not know the cost of preservation? The LIFE (Lifecycle Information
for E-Literature) Project has made a major step forward in understanding the long-term costs in this complex area. The LIFE Project has developed a methodology to model the digital lifecycle and to calculate the costs of preserving digital information for the next 5, 10 or 100 years. National and higher education (HE) libraries can now apply this process and plan effectively for the preservation of their digital collections. Based on previous work undertaken on the lifecycles of paper-based materials, the LIFE Project created a lifecycle model and applied it to real-life digital collections across a diverse subject range. Three case studies examined the everyday operations, processes and costs involved in their respective activities. The results were then used to calculate the direct costs for each element of the digital lifecycle. The Project has made major advances in costing preservation activities, as well as making detailed costs of real digital preservation activities available. The second phase of LIFE (LIFE2), which recently started, aims to refine the lifecycle methodology and to add a greater range and breadth to the project with additional exemplar case studies
The LIFE Model v1.1
Extract: This document draws together feedback, discussion and review of the LIFE Model from a number of sources:
1. The LIFE and LIFE2 Project Teams, and the staff of their institutions
2. Feedback from review by independent economics expert
3. The LIFE Project Conference
4. Early adopters of the Life Model (particularly the Royal Danish Library, State Archives and the State and University Library, Denmark)
The result is a revision of the LIFE Model which was first published in 2006 by the LIFE Project .
In line with the objectives of the LIFE2 Project, this revision aims to:
1. fix outstanding anomalies or omissions in the Model
2. scope and define the Model and its components more precisely
3. facilitate useful and repeatable mapping and costing of digital lifecycles
Influence of tensile overload on crack growth in 316L stainless-steel - including high strain & low stress interactions in 316l stainless steel, mild steel and aluminium alloy 6060-T5
The fatigue crack growth behaviour of 316L stainless steel (Batch A} following a tensile overload has been observed. Micrographs and compliance measurements have also been taken. Results indicated that strain hardening may be the primary contributor toward retardation of crack growth. High strain - low stress interactions were observed in 316L stainless steel (Batch B and C), mild steel (C1020 and AS1214) and aluminium alloy (6060-T5). This was done as plasticity-induced crack closure is largely removed by using tensile specimens. Pre-training of 316L (Batch B) by low cycle fatigue (LCF) showed an increase in the fatigue life while pre-training of 316L (Batch C) showed a retardation of fatigue crack initiation and growth. Pre-training of the other materials showed little effect or a decrease in the fatigue life.
The conclusions of this thesis are as follows:
1. Fatigue crack growth occurs by a process of damage accumulation in the material in front of the crack tip.
2. Tensile overload creates a plastic deformation zone ahead of the crack tip. The material within this zone is strain hardened and also causes plasticity-induced crack closure (PICC). It has been found that retardation of post-overload fatigue crack growth is mainly a result of the increased fatigue resistance of the· strain-hardened material within the overload plastic zone.
3. A tensile overload enhances the fatigue damage ahead of the crack tip.· This results in a transient acceleration in the fatigue crack growth following overload.
4. 316L Stainless Steel (Batch B} displayed ail enhancement of fatigue life with LCF · pre-training. Crack initiation and propagation was retarded in 316L (Batch C) by similar LCF pre-training. This behaviour was not observed in mild steel (C1020 and AS1214) or aluminium alloy (6060-T5). A martensitic strain induced transformation was found to be not responsible for the observed behaviour of 316L (Batch B). It is suggested that this behaviour supports the findings of fatigue crack growth experiments of 316L stainless steel (Batch A), i.e. that strain hardening is primarily responsible for fatigue crack growth retardation following tensile overload
Improved mirror position estimation using resonant quantum smoothing
Quantum parameter estimation, the ability to precisely obtain a classical
value in a quantum system, is very important to many key quantum technologies.
Many of these technologies rely on an optical probe, either coherent or
squeezed states to make a precise measurement of a parameter ultimately limited
by quantum mechanics. We use this technique to theoretically model, simulate
and validate by experiment the measurement and precise estimation of the
position of a cavity mirror. In non-resonant systems, the achieved estimation
enhancement from quantum smoothing over optimal filtering has not exceeded a
factor two, even when squeezed state probes were used. Using a coherent state
probe, we show that using quantum smoothing on a mechanically resonant
structure driven by a resonant forcing function can result significantly
greater improvement in parameter estimation than with non-resonant systems. In
this work, we show that it is possible to achieve a smoothing improvement by a
factor in excess of three times over optimal filtering. By using intra-cavity
light as the probe we obtain finer precision than has been achieved with the
equivalent quantum resources in free-space.Comment: 14 pages, 9 figures and 1 tabl
Lifecycle information for E-literature: an introduction to the second phase of the LIFE project
Introduction: The first phase of LIFE (Lifecycle Information For E-Literature) made a major contribution to
understanding the long-term costs of digital preservation; an essential step in helping institutions
plan for the future. The LIFE work models the digital lifecycle and calculates the costs of
preserving digital information for future years. Organisations can apply this process in order
to understand costs and plan effectively for the preservation of their digital collections
The second phase of the LIFE Project, LIFE2, has refined the LIFE Model adding three new
exemplar Case Studies to further build upon LIFE1. LIFE2 is an 18-month JISC-funded project
between UCL (University College London) and The British Library (BL), supported by the
LIBER Access and Preservation Divisions. LIFE1 was completed in April 2006. LIFE2 started
in March 2007, and was completed in August 2008.
This summary aims to give an overview of the LIFE Project, summarising some of the key outputs.
There are four main areas discussed:
1 From LIFE1 to LIFE2 outlines some of the key findings from the first phase of the project
as well as summarising the motivation behind this second phase.
2 The LIFE Model describes the current version of the model (version 2) which has been
thoroughly updated from the first phase.
3 LIFE2 Case Studies describes the three new Case Studies for LIFE2. It does not include the
results from the Case Studies (these are available in the overall LIFE2 Report), but offers
some background on each of the studies as well as discussion of why they were chosen.
4 Findings and Conclusions outlines all of the findings and outputs from the entire project
Utilizing weak pump depletion to stabilize squeezed vacuum states
We propose and demonstrate a pump-phase locking technique that makes use of
weak pump depletion (WPD) - an unavoidable effect that is usually neglected -
in a sub-threshold optical parametric oscillator (OPO). We show that the phase
difference between seed and pump beam is imprinted on both light fields by the
non-linear interaction in the crystal and can be read out without disturbing
the squeezed output. Our new locking technique allows for the first
experimental realization of a pump-phase lock by reading out the pre-existing
phase information in the pump field. There is no degradation of the detected
squeezed states required to implement this scheme.Comment: 11 pages, 7 figure
The LIFE2 final project report
Executive summary: The first phase of LIFE (Lifecycle Information For E-Literature) made a major contribution to
understanding the long-term costs of digital preservation; an essential step in helping
institutions plan for the future. The LIFE work models the digital lifecycle and calculates the
costs of preserving digital information for future years. Organisations can apply this process
in order to understand costs and plan effectively for the preservation of their digital
collections
The second phase of the LIFE Project, LIFE2, has refined the LIFE Model adding three new
exemplar Case Studies to further build upon LIFE1. LIFE2 is an 18-month JISC-funded
project between UCL (University College London) and The British Library (BL), supported
by the LIBER Access and Preservation Divisions. LIFE2 began in March 2007, and
completed in August 2008.
The LIFE approach has been validated by a full independent economic review and has
successfully produced an updated lifecycle costing model (LIFE Model v2) and digital
preservation costing model (GPM v1.1). The LIFE Model has been tested with three further
Case Studies including institutional repositories (SHERPA-LEAP), digital preservation
services (SHERPA DP) and a comparison of analogue and digital collections (British Library
Newspapers). These Case Studies were useful for scenario building and have fed back into
both the LIFE Model and the LIFE Methodology.
The experiences of implementing the Case Studies indicated that enhancements made to the
LIFE Methodology, Model and associated tools have simplified the costing process. Mapping
a specific lifecycle to the LIFE Model isn’t always a straightforward process. The revised and
more detailed Model has reduced ambiguity. The costing templates, which were refined
throughout the process of developing the Case Studies, ensure clear articulation of both
working and cost figures, and facilitate comparative analysis between different lifecycles.
The LIFE work has been successfully disseminated throughout the digital preservation and
HE communities. Early adopters of the work include the Royal Danish Library, State
Archives and the State and University Library, Denmark as well as the LIFE2 Project partners.
Furthermore, interest in the LIFE work has not been limited to these sectors, with interest in
LIFE expressed by local government, records offices, and private industry. LIFE has also
provided input into the LC-JISC Blue Ribbon Task Force on the Economic Sustainability of
Digital Preservation.
Moving forward our ability to cost the digital preservation lifecycle will require further
investment in costing tools and models. Developments in estimative models will be needed to
support planning activities, both at a collection management level and at a later preservation
planning level once a collection has been acquired. In order to support these developments a
greater volume of raw cost data will be required to inform and test new cost models. This
volume of data cannot be supported via the Case Study approach, and the LIFE team would
suggest that a software tool would provide the volume of costing data necessary to provide a
truly accurate predictive model
The Use of a Multi-modal Interface to Integrate In-Vehicle Information Presentation
The car of the future will have many new information sources— including telematics systems, navigation systems and Advanced Driver Assistance Systems (ADAS)—that will compete for a driver’s limited cognitive attention. If they are implemented as completely separate systems then cognitive overload and driver distraction are inevitable outcomes. However, if they are implemented as an integrated intelligent system with a multi-modal interface, then the benefits of such functionality will be achieved with much less impact on driving safety. Such a system will support the task of safe driving by filtering and mediating information in response to real-world driving demands. This paper outlines the Human Factors research program being undertaken by Motorola Labs to evaluate key elements of such a multi-modal interface as well as the key human factors issues involved in a multi-modal interface
Characterization of entangling properties of quantum measurement via two-mode quantum detector tomography using coherent state probes
Entangled measurement is a crucial tool in quantum technology. We propose a
new entanglement measure of multi-mode detection, which estimates the amount of
entanglement that can be created in a measurement. To illustrate the proposed
measure, we perform quantum tomography of a two-mode detector that is comprised
of two superconducting nanowire single photon detectors. Our method utilizes
coherent states as probe states, which can be easily prepared with accuracy.
Our work shows that a separable state such as a coherent state is enough to
characterize a potentially entangled detector. We investigate the entangling
capability of the detector in various settings. Our proposed measure verifies
that the detector makes an entangled measurement under certain conditions, and
reveals the nature of the entangling properties of the detector. Since the
precise characterization of a detector is essential for applications in quantum
information technology, the experimental reconstruction of detector properties
along with the proposed measure will be key features in future quantum
information processing.Comment: 18 pages, 6 figure
Adaptive Optical Phase Estimation Using Time-Symmetric Quantum Smoothing
Quantum parameter estimation has many applications, from gravitational wave
detection to quantum key distribution. We present the first experimental
demonstration of the time-symmetric technique of quantum smoothing. We consider
both adaptive and non-adaptive quantum smoothing, and show that both are better
than their well-known time-asymmetric counterparts (quantum filtering). For the
problem of estimating a stochastically varying phase shift on a coherent beam,
our theory predicts that adaptive quantum smoothing (the best scheme) gives an
estimate with a mean-square error up to times smaller than that
from non-adaptive quantum filtering (the standard quantum limit). The
experimentally measured improvement is
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