Abstract: Biba model can protect information integrity but might
deny various non-malicious access requests of the subjects, thereby
decreasing the availability in the system. Therefore, a mechanism that
allows exceptional access control is needed. Break the Glass (BTG)
strategies refer an efficient means for extending the access rights of
users in exceptional cases. These strategies help to prevent a system
from stagnation. An approach is presented in this work for integrating
Break the Glass strategies into the Biba model. This research proposes
a model, BTG-Biba, which provides both an original Biba model used
in normal situations and a mechanism used in emergency situations.
The proposed model is context aware, can implement a fine-grained
type of access control and primarily solves cross-domain access
problems. Finally, the flexibility and availability improvement with
the use of the proposed model is illustrated.
Abstract: Currently, resource sharing and system security are
critical issues. This paper proposes a POL module composed of
PRIV ILEGE attribute (PA), obligation and log which improves
attribute based access control (ABAC) model in dynamically granting
authorizations and revoking authorizations. The following describes
the new model termed PABAC in terms of the POL module
structure, attribute definitions, policy formulation and authorization
architecture, which demonstrate the advantages of it. The POL
module addresses the problems which are not predicted before and
not described by access control policy. It can be one of the subject
attributes or resource attributes according to the practical application,
which enhances the flexibility of the model compared with ABAC.
A scenario that illustrates how this model is applied to the real world
is provided.
Abstract: Digital image correlation (DIC) is a contactless fullfield
displacement and strain reconstruction technique commonly
used in the field of experimental mechanics. Comparing with
physical measuring devices, such as strain gauges, which only
provide very restricted coverage and are expensive to deploy widely,
the DIC technique provides the result with full-field coverage and
relative high accuracy using an inexpensive and simple experimental
setup. It is very important to study the natural patterns effect on the
DIC technique because the preparation of the artificial patterns is
time consuming and hectic process. The objective of this research is
to study the effect of using images having natural pattern on the
performance of DIC. A systematical simulation method is used to
build simulated deformed images used in DIC. A parameter (subset
size) used in DIC can have an effect on the processing and accuracy
of DIC and even cause DIC to failure. Regarding to the picture
parameters (correlation coefficient), the higher similarity of two
subset can lead the DIC process to fail and make the result more
inaccurate. The pictures with good and bad quality for DIC methods
have been presented and more importantly, it is a systematic way to
evaluate the quality of the picture with natural patterns before they
install the measurement devices.