131,678 research outputs found
Enabling electronic prognostics using thermal data
Prognostics is a process of assessing the extent of deviation or degradation
of a product from its expected normal operating condition, and then, based on
continuous monitoring, predicting the future reliability of the product. By
being able to determine when a product will fail, procedures can be developed
to provide advanced warning of failures, optimize maintenance, reduce life
cycle costs, and improve the design, qualification and logistical support of
fielded and future systems. In the case of electronics, the reliability is
often influenced by thermal loads, in the form of steady-state temperatures,
power cycles, temperature gradients, ramp rates, and dwell times. If one can
continuously monitor the thermal loads, in-situ, this data can be used in
conjunction with precursor reasoning algorithms and stress-and-damage models to
enable prognostics. This paper discusses approaches to enable electronic
prognostics and provides a case study of prognostics using thermal data.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Expert Elicitation for Reliable System Design
This paper reviews the role of expert judgement to support reliability
assessments within the systems engineering design process. Generic design
processes are described to give the context and a discussion is given about the
nature of the reliability assessments required in the different systems
engineering phases. It is argued that, as far as meeting reliability
requirements is concerned, the whole design process is more akin to a
statistical control process than to a straightforward statistical problem of
assessing an unknown distribution. This leads to features of the expert
judgement problem in the design context which are substantially different from
those seen, for example, in risk assessment. In particular, the role of experts
in problem structuring and in developing failure mitigation options is much
more prominent, and there is a need to take into account the reliability
potential for future mitigation measures downstream in the system life cycle.
An overview is given of the stakeholders typically involved in large scale
systems engineering design projects, and this is used to argue the need for
methods that expose potential judgemental biases in order to generate analyses
that can be said to provide rational consensus about uncertainties. Finally, a
number of key points are developed with the aim of moving toward a framework
that provides a holistic method for tracking reliability assessment through the
design process.Comment: This paper commented in: [arXiv:0708.0285], [arXiv:0708.0287],
[arXiv:0708.0288]. Rejoinder in [arXiv:0708.0293]. Published at
http://dx.doi.org/10.1214/088342306000000510 in the Statistical Science
(http://www.imstat.org/sts/) by the Institute of Mathematical Statistics
(http://www.imstat.org
Toward a Systematic Evidence-Base for Science in Out-of-School Time: The Role of Assessment
Analyzes the tools used in assessments of afterschool and summer science programs, explores the need for comprehensive tools for comparisons across programs, and discusses the most effective structure and format for such a tool. Includes recommendations
Managing Well Integrity using Reliability Based Models
Imperial Users onl
SciTech News Volume 70, No. 4 (2016)
Columns and Reports
From the Editor 3
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SLA Annual Meeting 2016 Report (S. Kirk Cabeen Travel Stipend Award recipient) 6
Reflections on SLA Annual Meeting (Diane K. Foster International Student Travel Award recipient) 8
SLA Annual Meeting Report (Bonnie Hilditch International Librarian Award recipient)10
Chemistry Division 12
Engineering Division 15
Reflections from the 2016 SLA Conference (SPIE Digital Library Student Travel Stipend recipient)15
Fundamentals of Knowledge Management and Knowledge Services (IEEE Continuing Education Stipend recipient) 17
Makerspaces in Libraries: The Big Table, the Art Studio or Something Else? (by Jeremy Cusker) 19
Aerospace Section of the Engineering Division 21
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Occupational screening
Medical screening of workers is one of the tools often used to assess suitability for work and to attempt to reduce worker ill-health. This article outlines the objectives of the screening process and the basic criteria to be followed in developing a quality programme. It describes the different types of medical examination used in this setting. Screening programmes should be related to hazards specific to the work place as well as to the physical and mental requirements of the job. The guiding principle in the prevention of occupational disease should always be the control of hazardous exposure to prevent harmful effects occurring rather than early detection of harmful effects after they have occurred. The importance of being aware of and abiding by these principles is particularly applicable in the local context.peer-reviewe
Post-failure evolution analysis of a rainfall-triggered landslide by multi-temporal interferometry SAR approaches integrated with geotechnical analysis
Persistent Scatterers Interferometry (PSI) represents one of the most powerful techniques for Earth's surface deformation processes' monitoring, especially for long-term evolution phenomena. In this work, a dataset of 34 TerraSAR-X StripMap images (October 2013–October 2014) has been processed by two PSI techniques - Coherent Pixel Technique-Temporal Sublook Coherence (CPT-TSC) and Small Baseline Subset (SBAS) - in order to study the evolution of a slow-moving landslide which occurred on February 23, 2012 in the Papanice hamlet (Crotone municipality, southern Italy) and induced by a significant rainfall event (185 mm in three days). The mass movement caused structural damage (buildings' collapse), and destruction of utility lines (gas, water and electricity) and roads. The results showed analogous displacement rates (30–40 mm/yr along the Line of Sight – LOS-of the satellite) with respect to the pre-failure phase (2008–2010) analyzed in previous works. Both approaches allowed detect the landslide-affected area, however the higher density of targets identified by means of CPT-TSC enabled to analyze in detail the slope behavior in order to design possible mitigation interventions. For this aim, a slope stability analysis has been carried out, considering the comparison between groundwater oscillations and time-series of displacement. Hence, the crucial role of the interaction between rainfall and groundwater level has been inferred for the landslide triggering. In conclusion, we showed that the integration of geotechnical and remote sensing approaches can be seen as the best practice to support stakeholders to design remedial works.Peer ReviewedPostprint (author's final draft
Highlights of 1980 activities
Progress in the Space Transportation System is reported. A review of the Voyager 1 mission is presented along with a summary of facts gathered on its Saturn encounter. Research and development in energy technology, space tracking, and data systems is described
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