898 research outputs found
Making evaluations matter: a practical guide for evaluators
This guide is primarily for evaluators working in the international development sector. It is also useful for commissioner of evaluations, evaluation managers and M&E officers. The guide explains how to make evaluations more useful. It helps to better understand conceptual issues and appreciate how evaluations can contribute to changing mindsets and empowering stakeholders. On a practical level, the guide presents core guiding principles and pointers on how to design and facilitate evaluations that matter. Furthermore, it shows how to get primary intended users and other key stakeholders to contribute effectively to the evaluation proces
Differentially Private Billing with Rebates
A number of established and novel business models are based on fine grained billing, including pay-per-view, mobile messaging, voice calls, pay-as-you-drive insurance, smart metering for utility provision, private computing clouds and hosted services. These models apply fine-grained tariffs dependent on time-of-use or place of-use to readings to compute a bill. We extend previously proposed billing protocols to strengthen their privacy in two key ways. First, we study the monetary amount a customer should add to their bill in order to provably hide their activities, within the differential privacy framework. Second, we propose a cryptographic protocol for oblivious billing that ensures any additional expenditure, aimed at protecting privacy, can be tracked and reclaimed in the future, thus minimising its cost. Our proposals can be used together or separately and are backed by provable guarantees of security. © 2011 Springer-Verlag
Using local and historical data to enhance understanding of spatial and temporal rainfall patterns
Farmers face uncertainty in their businesses from many factors, but rainfall is a key determinant of both the nature of the production system and variation in financial returns. Currently, various weather forecasting services are available from the Australian Bureau of Meteorology (BoM) based on about 7000 stations covering all of Australia. Seasonal Climate Forecasts are seen as another tool that can help to improve farm productivity. It is well known that many farmers keep their own rainfall records, and likely that the farmers have a high degree of confidence in their own records. Australian Bureau of Statistics figures indicate that there were possibly 7000 grain related âagricultural businessesâ in NSW alone in 2009/10 indicating that there is the potential to increase data density by up to an order of magnitude. This project is part of a broader study to improve rainfall predictions for grain farmers using data collected locally to the users (crowd sourcing). The data is collected directly on farm, and from other sources which may be available. The focus is on the historical data, its collection and analysis, in terms of discerning patterns in time and space which may help provide a local framework, within which coarser scale forecasts can be interpreted and understood. Data will be stored on secure database systems at the University of Sydney. Results indicate that farm data does provide more local detail, temporally and spatially. Deficit and surplus analysis demonstrates the predictive capacity of the local temporal data, despite limited data precluding the definition of ideal criteria and parameters for predictive âsimilar yearâ selection. The spatial data demonstrates quantifiable site specific differences from institutional data. Testing across more climate types may allow these differences to be defined within and across regions. Tests for an indicator time period show that farm rainfall in the early part of the growing season (April and May) may indeed be indicative of seasonal condtions, while more data is needed to confirm this. The use of southern oscillation life cycle information to select appropriate years considerably improved the relationships revealed, with a doubling of relationship strength across all climatic types, although the strength of the relationships differed across the climatic types, and the strongest relationships were split between the months of April and May. More extensive analysis, with more data across more BoM districts (and therefore climate classes) will be required to confirm this conclusion, but it appears that farm rainfall records and SOI information can provide an indicator time period to help farmers interpret, refine and utilise seasonal forecasts
Dynamical Landau-de Gennes Theory for Electrically-Responsive Liquid Crystal Networks
Liquid crystal networks combine the orientational order of liquid crystals
with the elastic properties of polymer networks, leading to a vast application
potential in the field of responsive coatings, e.g., for haptic feedback,
self-cleaning surfaces and static and dynamic pattern formation. Recent
experimental work has further paved the way toward such applications by
realizing the fast and reversible surface modulation of a liquid crystal
network coating upon in-plane actuation with an AC electric field. Here, we
construct a Landau-type theory for electrically-responsive liquid crystal
networks and perform Molecular Dynamics simulations to explain the findings of
these experiments and inform on rational design strategies. Qualitatively, the
theory agrees with our simulations and reproduces the salient experimental
features. We also provide a set of testable predictions: the aspect ratio of
the nematogens, their initial orientational order when cross-linked into the
polymer network and the cross-linking fraction of the network all increase the
plasticization time required for the film to macroscopically deform. We
demonstrate that the dynamic response to oscillating electric fields is
characterized by two resonances, which can likewise be influenced by varying
these parameters, providing an experimental handle to fine-tune device design
Double Exchange Alone Does Not Explain the Resistivity of
The system with has
traditionally been modelled with a ``double exchange'' Hamiltonian, in which it
is assumed that the only relevant physics is the tendency of carrier hopping to
line up neighboring spins. We present a solution of the double exchange model,
show it is incompatible with many aspects of the resistivity data, and propose
that a strong electron-phonon interaction arising from a Jahn-Teller splitting
of the outer Mn d-level plays a crucial role.Comment: Figure available via concentional mail. Contact
[email protected]
Expression profiling of immune inhibitory Siglecs and their ligands in patients with glioma
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The use of a real-time computer-aided detection system for visible lesions in the Barrett's esophagus during live endoscopic procedures:a pilot study (with video)
Background and aims: This pilot study evaluated the performance of a recently developed computer-aided detection (CADe) system for Barrett's neoplasia during live endoscopic procedures. Methods: Fifteen patients with a visible lesion and 15 without were included in this study. A CAD-assisted workflow was used that included a slow pullback video recording of the entire Barrett's segment with live CADe assistance, followed by CADe-assisted level-based video recordings every 2 cm of the Barrett's segment. Outcomes were per-patient and per-level diagnostic accuracy of the CAD-assisted workflow, in which the primary outcome was per-patient in vivo CADe sensitivity. Results: In the per-patient analyses, the CADe system detected all visible lesions (sensitivity 100%). Per-patient CADe specificity was 53%. Per-level sensitivity and specificity of the CADe assisted workflow were 100% and 73%, respectively. Conclusions: In this pilot study, detection by the CADe system of all potentially neoplastic lesions in Barrett's esophagus was comparable to that of an expert endoscopist. Continued refinement of the system may improve specificity. External validation in larger multicenter studies is planned. (Clinical trial registration number: NCT05628441.)</p
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