Development of an automated aircraft subsystem architecture generation and analysis tool

Purpose – The purpose of this paper is to present a new computational framework to address future preliminary design needs for aircraft subsystems. The ability to investigate multiple candidate technologies forming subsystem architectures is enabled with the provision of automated architecture generation, analysis and optimization. Main focus lies with a demonstration of the frameworks workings, as well as the optimizers performance with a typical form of application problem. Design/methodology/approach – The core aspects involve a functional decomposition, coupled with a synergistic mission performance analysis on the aircraft, architecture and component levels. This may be followed by a complete enumeration of architectures, combined with a user defined technology filtering and concept ranking procedure. In addition, a hybrid heuristic optimizer, based on ant systems optimization and a genetic algorithm, is employed to produce optimal architectures in both component composition and design parameters. The optimizer is tested on a generic architecture design problem combined with modified Griewank and parabolic functions for the continuous space. Findings – Insights from the generalized application problem show consistent rediscovery of the optimal architectures with the optimizer, as compared to a full problem enumeration. In addition multi-objective optimization reveals a Pareto front with differences in component composition as well as continuous parameters. Research limitations/implications – This paper demonstrates the frameworks application on a generalized test problem only. Further publication will consider real engineering design problems. Originality/value – The paper addresses the need for future conceptual design methods of complex systems to consider a mixed concept space of both discrete and continuous nature via automated methods

Experimental investigation into aircraft system manual assembly performance under varying structural component orientations

Installation of aircraft wing systems is a bottleneck in the assembly process. This phase is typically composed of many work packages, taking hundreds of man-hours per wing. In addition to this volume of work, tasks are specialized and completed in a difficult environment in terms of access and visibility. In current industrial practice, the wing is mounted horizontally on a transport trolley, which exposes the workforce to prolonged periods of overhead working. Future wing designs may consider a pre-equipping build philosophy, where systems are installed to major structure assemblies before the wing box is assembled. This allows for a change in the orientation and position of the major structure and provides new freedoms in assembly station design and layout. This research presents results of experiments to investigate manual assembly performance of aircraft wing systems, under varying wing structure orientation. A mock-up of a section of an A320 aircraft wing front spar, mounted on a rotation device, functions as the testbed. Manual installation activities are then conducted to emulate real aircraft system equipping for electric harnesses, raceways and hot air ducts. The results show a best-case assembly performance change of 36% for electric system installation activities of cable harnesses and raceway housing components. Tilted and horizontal orientations of the structure show the highest time reductions, with the vertical orientation either non-conclusive or increasing the assembly time. The outcomes of this study are intended to aid in effective trade-off decision making for future wing systems and assembly station layouts from the perspective of structural orientation and assembly task interaction

Application of an automated aircraft architecture generation and analysis tool to unmanned aerial vehicle subsystem design

The work presents the application of a new computational framework, addressing future preliminary design needs for aircraft subsystems. The ability to investigate multiple candidate technologies forming subsystem architectures is enabled with the provision of automated architecture generation, analysis and optimisation. The core aspects involve a functional decomposition, coupled with a synergistic mission performance analysis on the aircraft, architecture and component level. This may be followed by a complete enumeration of architectures combined with a user-defined technology filtering and concept ranking procedure. In addition, a novel hybrid heuristic optimiser, based on ant colony optimisation and a genetic algorithm, is employed to produce optimal architectures in both component composition and design parameters. The framework is applied to the design of a regenerative energy system for a long endurance high altitude unmanned aerial vehicle, considering various emerging technologies. A comparison with the traditional design processes and certification requirements is made as well as technology trends summarised and substantiated

Assistive Technology for Independent Living with Dementia: Stylized Facts and Research Gaps

Background: Demographic change and continuously increasing spending on public health have intensified the public debate as well as deliberations on the development and deployment of new assistive technologies; particularly for dementia patients as it affects a large and increasing number of people, not only causing massive social distress, but also great economic losses. Recent advancement in assistive technologies (AT) have therefore fueled the debate on new, IT-reliant ways of providing cure and care of dementia. Still the impact on practice has been little. With this paper, we want to find out to which extent current studies have discussed the impacts of AT for dementia. Methods: We conduct a scoping review of the literature. We identified n=539 unique articles, out of which n=36 reported on impacts of AT use in the context of dementia. Based on this subset, we extracted a list of original statements, which was then further aggregated to 6 stylized facts. Results: The identified stylized facts describe common findings that can be observed in most studies reporting on IT-reliant assistive tools for dementia patients although applying different methods, focusing on different technologies, or working in different contexts. Conclusions: While the identified stylized facts indicate how much evidence behind certain common assumptions is, we additionally found that studies in the area of AT for dementia often neglect the socio-economic and ethical dimension. These are important research gaps for future work

Europa: Velika iluzija

Prevela: Silva Mežnarić

Novel parvoviruses in reptiles and genome sequence of a lizard parvovirus shed light on Dependoparvovirus genus evolution.

Here, we report the detection and partial genome characterization of two novel reptilian parvoviruses derived from a short-tailed pygmy chameleon (Rampholeon brevicaudatus) and a corn snake (Pantherophis guttatus) along with the complete genome analysis of the first lizard parvovirus, obtained from four bearded dragons (Pogona vitticeps). Both homology searches and phylogenetic tree reconstructions demonstrated that all are members of the Dependoparvovirus genus. Even though most dependoparvoviruses replicate efficiently only in co-infections with large DNA viruses, no such agents could be detected in one of the bearded dragon samples, hence the possibility of autonomous replication was explored. The alternative ORF encoding the full assembly-activating protein (AAP), typical for the genus, could be obtained from reptilian parvoviruses for the first time, with a structure that appears to be more ancient than that of avian and mammalian parvoviruses. All three viruses were found to harbor short introns as previously observed for snake adeno-associated virus (SAAV), shorter than that of any non-reptilian dependoparvovirus. According to the phylogenetic calculations based on full non-structural protein (Rep) and AAP sequences, the monophyletic cluster of reptilian parvoviruses seems to be the most basal out of all lineages of genus Dependoparvovirus. The suspected ability for autonomous replication, results of phylogenetic tree reconstruction, intron lengths and the structure of the AAP, suggested that a single Squamata origin instead of the earlier assumed diapsid (common avian-reptilian) origin is more likely for the genus Dependoparvovirus of the Parvoviridae family

Effects of more electric systems on fuel tank thermal behaviour

With the advent of more electric airframe systems and ultra-high bypass ratio turbofan engines, there is growing interest in the associated thermal implications. In this research project, an aircraft level model that is appropriate to enable investigations into novel thermal management solution on future aircraft is developed. In this paper, an investigation into the effects of more electric systems on the thermal behaviour of fuel tanks in civil transport aircraft is presented.Specifically, the influence of the heat generated by conventional and more electric systems on the fuel tank was modelled and simulated. A fuel thermal model was developed, which consists of a tank geometry representation, coupled to a module that calculates remaining mission fuel mass. The systems architectures are represented by connected thermal component models. Standard approaches were then employed to estimate convection and conduction heat transfer coefficients at the tank interfaces. The model solves 1-D transient heat equations, coupling heat transfer and material heat capacity via heat flux balances. The thermal and systems models were integrated into a baseline aircraft performance model, which was used to dynamically simulate the tank thermal behaviour during representative missions. The initial results indicate that switching to more electric environmental control and iceprotection systems likely have negligible thermal impact on the bulk fuel temperature. However, some benefits may be obtained regarding safety and certification, but this requires further study