Parametric CAD model based shape optimization using adjoint functions

Adjoint methods have proven to be an efficient way of calculating the gradient of an objective function with respect to a shape parameter for optimisation, with a computational cost nearly independent of the number of the design variables [1]. The approach in this paper links the adjoint surface sensitivities (gradient of objective function with respect to the surface movement) with the parametric design velocities (movement of the surface due to a CAD parameter perturbation) in order to compute the gradient of the objective function with respect to CAD variables.
For a successful implementation of shape optimization strategies in practical industrial cases, the choice of design variables or parameterisation scheme used for the model to be optimized plays a vital role. Where the goal is to base the optimization on a CAD model the choices are to use a NURBS geometry generated from CAD modelling software, where the position of the NURBS control points are the optimisation variables [2] or to use the feature based CAD model with all of the construction history to preserve the design intent [3]. The main advantage of using the feature based model is that the optimized model produced can be directly used for the downstream applications including manufacturing and process planning.
This paper presents an approach for optimization based on the feature based CAD model, which uses CAD parameters defining the features in the model geometry as the design variables. In order to capture the CAD surface movement with respect to the change in design variable, the “Parametric Design Velocity” is calculated, which is defined as the movement of the CAD model boundary in the normal direction due to a change in the parameter value.
The approach presented here for calculating the design velocities represents an advancement in terms of capability and robustness of that described by Robinson et al. [3]. The process can be easily integrated to most industrial optimisation workflows and is immune to the topology and labelling issues highlighted by other CAD based optimisation processes. It considers every continuous (“real value”) parameter type as an optimisation variable, and it can be adapted to work with any CAD modelling software, as long as it has an API which provides access to the values of the parameters which control the model shape and allows the model geometry to be exported. To calculate the movement of the boundary the methodology employs finite differences on the shape of the 3D CAD models before and after the parameter perturbation. The implementation procedure includes calculating the geometrical movement along a normal direction between two discrete representations of the original and perturbed geometry respectively. Parametric design velocities can then be directly linked with adjoint surface sensitivities to extract the gradients to use in a gradient-based optimization algorithm.
The optimisation of a flow optimisation problem is presented, in which the power dissipation of the flow in an automotive air duct is to be reduced by changing the parameters of the CAD geometry created in CATIA V5. The flow sensitivities are computed with the continuous adjoint method for a laminar and turbulent flow [4] and are combined with the parametric design velocities to compute the cost function gradients. A line-search algorithm is then used to update the design variables and proceed further with optimisation process.

Point-and-shoot: rapid quantitative detection methods for on-site food fraud analysis – moving out of the laboratory and into the food supply chain

Major food adulteration and contamination events occur with alarming regularity and are known to be episodic, with the question being not if but when another large-scale food safety/integrity incident will occur. Indeed, the challenges of maintaining food security are now internationally recognised. The ever increasing scale and complexity of food supply networks can lead to them becoming significantly more vulnerable to fraud and contamination, and potentially dysfunctional. This can make the task of deciding which analytical methods are more suitable to collect and analyse (bio)chemical data within complex food supply chains, at targeted points of vulnerability, that much more challenging. It is evident that those working within and associated with the food industry are seeking rapid, user-friendly methods to detect food fraud and contamination, and rapid/high-throughput screening methods for the analysis of food in general. In addition to being robust and reproducible, these methods should be portable and ideally handheld and/or remote sensor devices, that can be taken to or be positioned on/at-line at points of vulnerability along complex food supply networks and require a minimum amount of background training to acquire information rich data rapidly (ergo point-and-shoot). Here we briefly discuss a range of spectrometry and spectroscopy based approaches, many of which are commercially available, as well as other methods currently under development. We discuss a future perspective of how this range of detection methods in the growing sensor portfolio, along with developments in computational and information sciences such as predictive computing and the Internet of Things, will together form systems- and technology-based approaches that significantly reduce the areas of vulnerability to food crime within food supply chains. As food fraud is a problem of systems and therefore requires systems level solutions and thinking.

The U.N. convention on the rights of the child: Relevance and application to pediatric clinical bioethics

This article provides an overview of the relevance and import of the U.N. Convention on the Rights of the Child (CRC) to child health practice and pediatric bioethics. We discuss the four general principles of the CRC that apply to the implementation of all rights contained in the document, the right to health articulated in Article 24, and the important position ascribed to parents in fulfilling the rights of their children. We then examine how the CRC is implemented and monitored in law and practice. The CRC and associated principles of child rights provide strategies for rights-based approaches to clinical practice and health systems, as well as to policy design, professional training, and health services research. In light of the relevance of the CRC and principles of child rights to children’s health and child health practice, it follows that there is an intersection between child rights and pediatric bioethics. Pediatric bioethicists and child rights advocates should work together to define this intersection in all domains of pediatric practice.

The Reintegration of Sexual Offenders

This paper, presented as the 9th Martin Tansey Memorial Lecture in April 2016, considers current and future approaches to sex offender reintegration. It critically examines the core models of reintegration in terms of risk-based and strengths-based approaches in the criminal justice context as well as barriers to reintegration, chiefly in terms of the community and negative public attitudes. It also presents an overview of new findings from recent empirical research on sex offender desistance, generally referred to the as the process of slowing down or ceasing of criminal behaviour. Finally, the paper presents an optimum vision in terms of re-thinking sex offender reintegration, and what I term ‘inverting the risk paradigm’, drawing out the key challenges and implications for criminal justice as well as society more broadly.

Dynalog: an automated dynamic analysis framework for characterizing android applications

Android is becoming ubiquitous and currently has the largest share of the mobile OS market with billions of application downloads from the official app market. It has also become the platform most targeted by mobile malware that are becoming more sophisticated to evade state-of-the-art detection approaches. Many Android malware families employ obfuscation techniques in order to avoid detection and this may defeat static analysis based approaches. Dynamic analysis on the other hand may be used to overcome this limitation. Hence in this paper we propose DynaLog, a dynamic analysis based framework for characterizing Android applications. The framework provides the capability to analyse the behaviour of applications based on an extensive number of dynamic features. It provides an automated platform for mass analysis and characterization of apps that is useful for quickly identifying and isolating malicious applications. The DynaLog framework leverages existing open source tools to extract and log high level behaviours, API calls, and critical events that can be used to explore the characteristics of an application, thus providing an extensible dynamic analysis platform for detecting Android malware. DynaLog is evaluated using real malware samples and clean applications demonstrating its capabilities for effective analysis and detection of malicious applications.

From Crisis to Opportunity: Turnaround Strategies of Large Irish Construction Contractors During the Period 2007-2015.

The sudden change in environmental munificence level in the construction sector
during the period 2007 – 2015 provides a natural experiment to investigate strategic
and operating actions of firms, particularly during an environmental jolt. Statistics on
business failures corroborate that neither academics nor practitioners have succeeded
in guiding strategic action during periods of environmental jolt. Despite the recent
increase of turnaround research in the general management domain, its use in the
construction management realm remains underexplored. To address this research
gap, five exploratory case studies of an ongoing PhD study were used to examine the
turnaround strategies of construction contractors during a period of economic
contraction and growth. The findings show that, although retrenchment is often
considered to be a short-term strategy, this is clearly not the case; with the majority of
contractors maintaining the strategy for 6-7 years. During the same period,
internationalization became critical, with the turnaround process shifting towards
strategic reorientation that altered the firms' market domain. The case studies further
suggest that strategic and operational actions resonate quite well with contemporary
practice-based approaches to strategy making. The findings provide valuable
assistance for construction contractors in dealing with organisational decline and in
developing a successful turnaround response.

Policing, Terrorism and the Conundrum of 'Community': A Northern Ireland Perspective

The book chapter examines the conundrums and contradictions for PSNI in delivering their community policing agenda within a post-conflict environment which simultaneously demands the delivery of counter-terrorism policing in view of the current dissident terrorist threat.