1,610 research outputs found
A Max-Plus Model of Asynchronous Cellular Automata
This paper presents a new framework for asynchrony. This has its origins in
our attempts to better harness the internal decision making process of cellular
automata (CA). Thus, we show that a max-plus algebraic model of asynchrony
arises naturally from the CA requirement that a cell receives the state of each
neighbour before updating. The significant result is the existence of a
bijective mapping between the asynchronous system and the synchronous system
classically used to update cellular automata. Consequently, although the CA
outputs look qualitatively different, when surveyed on "contours" of real time,
the asynchronous CA replicates the synchronous CA. Moreover, this type of
asynchrony is simple - it is characterised by the underlying network structure
of the cells, and long-term behaviour is deterministic and periodic due to the
linearity of max-plus algebra. The findings lead us to proffer max-plus algebra
as: (i) a more accurate and efficient underlying timing mechanism for models of
patterns seen in nature, and (ii) a foundation for promising extensions and
applications.Comment: in Complex Systems (Complex Systems Publications Inc), Volume 23,
Issue 4, 201
Averaging t-structures and extension closure of aisles
We ask when a finite set of t-structures in a triangulated category can be
`averaged' into one t-structure or, equivalently, when the extension closure of
a finite set of aisles is again an aisle. There is a straightforward, positive
answer for a finite set of compactly generated t-structures in a big
triangulated category. For piecewise tame hereditary categories, we give a
criterion for when averaging is possible, and an algorithm that computes
truncation triangles in this case. A finite group action on a triangulated
category gives a natural way of producing a finite set of t-structures out of a
given one. If averaging is possible, there is an induced t-structure on the
equivariant triangulated category.Comment: 26 pages, 11 figures. v2: fixed minor mistakes, improved
presentation. Comments still welcome
Event tracking for real-time unaware sensitivity analysis (EventTracker)
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.This paper introduces a platform for online Sensitivity Analysis (SA) that is applicable in large scale real-time data acquisition (DAQ) systems. Here we use the term real-time in the context of a system that has to respond to externally generated input stimuli within a finite and specified period. Complex industrial systems such as manufacturing, healthcare, transport, and finance require high quality information on which to base timely responses to events occurring in their volatile environments. The motivation for the proposed EventTracker platform is the assumption that modern industrial systems are able to capture data in real-time and have the necessary technological flexibility to adjust to changing system requirements. The flexibility to adapt can only be assured if data is succinctly interpreted and translated into corrective actions in a timely manner. An important factor that facilitates data interpretation and information modelling is an appreciation of the affect system inputs have on each output at the time of occurrence. Many existing sensitivity analysis methods appear to hamper efficient and timely analysis due to a reliance on historical data, or sluggishness in providing a timely solution that would be of use in real-time applications. This inefficiency is further compounded by computational limitations and the complexity of some existing models. In dealing with real-time event driven systems, the underpinning logic of the proposed method is based on the assumption that in the vast majority of cases changes in input variables will trigger events. Every single or combination of events could subsequently result in a change to the system state. The proposed event tracking sensitivity analysis method describes variables and the system state as a collection of events. The higher the numeric occurrence of an input variable at the trigger level during an event monitoring interval, the greater is its impact on the final analysis of the system state. Experiments were designed to compare the proposed event tracking sensitivity analysis method with a comparable method (that of Entropy). An improvement of 10% in computational efficiency without loss in accuracy was observed. The comparison also showed that the time taken to perform the sensitivity analysis was 0.5% of that required when using the comparable Entropy based method.EPSR
The influence of the nature of children's disabilities on societal reactions experienced by their parents
This paper details a qualitative study which examined the influence of the nature of children's disabilities on stigmatisation experienced by their parents. To explore stigmatisation, semi-structured interviews were conducted with 22 parents of children with a range of disabilities. Findings highlighted that differential treatment was experienced by all parents, regardless of the nature of their children's disabilities. However, the types of reactions from others were influenced by three key factors; visibility of the child's disability, evidence of behaviour deemed to be socially inappropriate, and perceived controllability of the disability. Parents of children with behavioural, emotional and social difficulties experienced intensely negative reactions from others, whilst other parents experienced much pity. The implications of these findings for policy and practice are considered, indicating that parents may be encountering stigma solely based on the nature of their children's disabilities. The paper concludes by stressing the importance of support outlets for parents. © 2018 NASE
Partially ample line bundles on toric varieties
In this note we study properties of partially ample line bundles on
simplicial projective toric varieties. We prove that the cone of q-ample line
bundles is a union of rational polyhedral cones, and calculate these cones in
examples. We prove a restriction theorem for big q-ample line bundles, and
deduce that q-ampleness of the anticanonical bundle is not invariant under
flips. Finally we prove a Kodaira-type vanishing theorem for q-ample line
bundles.Comment: 12 pages, 2 figures; v.2: proofs simplified, lots of material added,
new autho
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