Cancer disease: integrative modelling approaches

Cancer is a complex disease in which a variety of phenomena interact over a wide range of spatial and temporal scales. In this article a theoretical framework will be introduced that is capable of linking together such processes to produce a detailed model of vascular tumour growth. The model is formulated as a hybrid cellular automaton and contains submodels that describe subcellular, cellular and tissue level features. Model simulations will be presented to illustrate the effect that coupling between these different elements has on the tumour's evolution and its response to chemotherapy

Ontological Approaches to Modelling Narrative

We outline a simple taxonomy of approaches to modelling narrative, explain how these might be realised ontologically, and describe our continuing work to apply these techniques to the problem of Memories for Life

3d Modelling with Linear Approaches Using Geometric Primitives

In this paper, we study linear approaches for 3D model acquisition from non-calibrated images. First, the intrinsic andextrinsic camera calibration is taken into consideration. In particular, we study the use of a specific calibrationprimitive: the parallelepiped. Parallelepipeds are frequently present in man-made environments and naturally encode theaffine structure of the scene. Any information about their euclidean structure (angles or ratios of edge lengths), possiblycombined with information about camera parameters is useful to obtain the euclidean reconstruction. We propose anelegant formalism to incorporate such information, in which camera parameters are dual to parallelepiped parameters,i.e. any knowledge about one entity provides constraints on the parameters of the others. Consequently, an image aparallelepiped with known Euclidean structure allows to compute the intrinsic camera parameters, and reciprocally, acalibrated image of a parallelepiped allows to recover its euclidean shape (up to size). On the conceptual level, thisduality can be seen as an alternative way to understand camera calibration: usually, calibration is considered to beequivalent to localizing the absolute conic or quadric in an image, whereas here we show that other primitives, such ascanonic parallelepipeds, can be used as well. While the main contributions of this work concern the estimation ofcamera and parallelepiped parameters. The complete system allows both calibration and 3D model acquisition from asmall number of arbitrary images with a reasonable amount of user interaction

On approaches to modelling lattice dislocations

By proposing a sinusoidal relationship between slip discontinuity and the associated mismatch force, Peierls and Nabarro famously developed a dislocation model that eliminates the stress singularity from the Volterra dislocation model. Recently, Lubarda and Markenscoff (Appl. Phys. Lett. 89:151923, 2006) developed a model in which the Burgers vector of the dislocation is applied over some finite distance, , described as the ‘core radius’. They found that the shear stress on the glide-plane predicted in the Lubarda-Markenscoff model is identical to that predicted by the Peierls-Nabarro model. In this paper, we investigate generalisations of both the Lubarda-Markenscoff and Peierls-Nabarro models, demonstrating that different distributions of infinitesimal dislocations in a generalised Lubarda-Markenscoff model can be associated with different expressions for the misalignment force in a generalised Peierls-Nabarro model. Our results indicate that the generalised Lubarda-Markenscoff framework is a versatile and useful method for modelling the core of a dislocation that neatly complements the well established Peierls-Nabarro framework

Cyber Security Threat Modelling:Classical Approaches Survey – An Insight

Threat modeling provides a systematic way to identify cybersecurity threats. It is an essential part of the Cybersecurity Risk Management Process. It defines countermeasures to prevent or mitigate the effects of threats to the system. Every software system today faces a range of threats, and it is increasing constantly as technology rapidly changes. Increasing use of mobiles and IoT devices also increases the threat landscape. Threats can emanate from inside/outside of organizations, and their impact has the potential to be devastating. Systems could be stopped from working entirely or sensitive information could be leaked, which would impact consumer faith. To avoid threats from taking benefit of system flaws, threat modeling methods can be used to think defensively. Though there are numerous types of frameworks for security architectures available, not a single framework is complete and totally secure. In this paper we analyzed some of the commonly used thereat modelling approaches

Interactive situation modelling in knowledge intensive domains

Interactive Situation Modelling (ISM) method, a semi-methodological approach, is proposed to tackle issues associated with modelling complex knowledge intensive domains, which cannot be easily modelled using traditional approaches. This paper presents the background and implementation of ISM within a complex domain, where synthesizing knowledge from various sources is critical, and is based on the principles of ethnography within a constructivist framework. Although the motivation for the reported work comes from the application presented in the paper, the actual scope of the paper covers a wide range of issues related to modelling complex systems. The author firstly reviews approaches used for modelling knowledge intensive domains, preceded by a brief discussion about two main issues: symmetry of ignorance and system behaviour, which are often confronted when applying modelling approaches to business domains. The ISM process is then characterized and critiqued with lessons from an exemplar presented to illustrate its effectiveness

A comparative study on mean value modelling of two-stroke marine diesel engine

In the present paper, two mean value modelling approaches of varying complexity, capable of simulating two-stroke marine Diesel engines, are presented. Both approaches were implemented in the computational environment of MATLAB Simulink®. Simulation runs of transient operation cases of a large two-stroke marine Diesel engine were performed. The derived results were validated against previously published data are used for comparing the two modelling approaches and discussing the advantages and drawbacks of each

Modelling Hybrid Stars in Quark-Hadron Approaches

The density in the core of neutron stars can reach values of about 5 to 10 times nuclear matter saturation density. It is, therefore, a natural assumption that hadrons may have dissolved into quarks under such conditions, forming a hybrid star. This star will have an outer region of hadronic matter and a core of quark matter or even a mixed state of hadrons and quarks. In order to investigate such phases, we discuss different model approaches that can be used in the study of compact stars as well as being applicable to a wider range of temperatures and densities. One major model ingredient, the role of quark interactions in the stability of massive hybrid stars is discussed. In this context, possible conflicts with lattice QCD simulations are investigated.Comment: Contribution to the EPJA Topical Issue on "Exotic Matter in Neutron Stars