259,140 research outputs found
Integrating Learning And Visualization Technologies In Orthopaedics:- Establishing The Virtual Orthopaedic European University
Digital technologies offer a working environment for familiarisation with new surgical procedures and management of clinical case audit. Our aim is to provide a novel route for access to educational material that more closely resembles the working practice of the arthroscopist. This is to support higher surgical training and life long learning. The proof of concept has been the development of a shoulder arthroscopy simulation model as an interface for the surgical trainee to access multimedia based educational orthopaedic modules. This demonstrates a human-computer interface that more closely resembles the process of factual knowledge association during clinical procedures, moving toward the ultimate goal of seamless integration of knowledge repositories with clinical intervention operative video information, integrating the structured surgical course model with the multimedia educational orthopaedic modules, generated for the learning of shoulder surgery
Adaptive Compressed Sensing for Support Recovery of Structured Sparse Sets
This paper investigates the problem of recovering the support of structured
signals via adaptive compressive sensing. We examine several classes of
structured support sets, and characterize the fundamental limits of accurately
recovering such sets through compressive measurements, while simultaneously
providing adaptive support recovery protocols that perform near optimally for
these classes. We show that by adaptively designing the sensing matrix we can
attain significant performance gains over non-adaptive protocols. These gains
arise from the fact that adaptive sensing can: (i) better mitigate the effects
of noise, and (ii) better capitalize on the structure of the support sets.Comment: to appear in IEEE Transactions on Information Theor
Beyond Good and Evil: Formalizing the Security Guarantees of Compartmentalizing Compilation
Compartmentalization is good security-engineering practice. By breaking a
large software system into mutually distrustful components that run with
minimal privileges, restricting their interactions to conform to well-defined
interfaces, we can limit the damage caused by low-level attacks such as
control-flow hijacking. When used to defend against such attacks,
compartmentalization is often implemented cooperatively by a compiler and a
low-level compartmentalization mechanism. However, the formal guarantees
provided by such compartmentalizing compilation have seen surprisingly little
investigation.
We propose a new security property, secure compartmentalizing compilation
(SCC), that formally characterizes the guarantees provided by
compartmentalizing compilation and clarifies its attacker model. We reconstruct
our property by starting from the well-established notion of fully abstract
compilation, then identifying and lifting three important limitations that make
standard full abstraction unsuitable for compartmentalization. The connection
to full abstraction allows us to prove SCC by adapting established proof
techniques; we illustrate this with a compiler from a simple unsafe imperative
language with procedures to a compartmentalized abstract machine.Comment: Nit
Corrupted Sensing with Sub-Gaussian Measurements
This paper studies the problem of accurately recovering a structured signal
from a small number of corrupted sub-Gaussian measurements. We consider three
different procedures to reconstruct signal and corruption when different kinds
of prior knowledge are available. In each case, we provide conditions for
stable signal recovery from structured corruption with added unstructured
noise. The key ingredient in our analysis is an extended matrix deviation
inequality for isotropic sub-Gaussian matrices.Comment: To appear in Proceedings of IEEE International Symposium on
Information Theory 201
Branch-coverage testability transformation for unstructured programs
Test data generation by hand is a tedious, expensive and error-prone activity, yet testing is a vital part of the development process. Several techniques have been proposed to automate the generation of test data, but all of these are hindered by the presence of unstructured control flow. This paper addresses the problem using testability transformation. Testability transformation does not preserve the traditional meaning of the program, rather it deals with preserving test-adequate sets of input data. This requires new equivalence relations which, in turn, entail novel proof obligations. The paper illustrates this using the branch coverage adequacy criterion and develops a branch adequacy equivalence relation and a testability transformation for restructuring. It then presents a proof that the transformation preserves branch adequacy
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