1,085 research outputs found
Enabling technologies for precise aerial manufacturing with unmanned aerial vehicles
The construction industry is currently experiencing a revolution with automation techniques
such as additive manufacturing and robot-enabled construction. Additive Manufacturing (AM)
is a key technology that can o er productivity improvement in the construction industry by
means of o -site prefabrication and on-site construction with automated systems. The key
bene t is that building elements can be fabricated with less materials and higher design freedom
compared to traditional manual methods.
O -site prefabrication with AM has been investigated for some time already, but it has limitations
in terms of logistical issues of components transportation and due to its lack of design
exibility on-site. On-site construction with automated systems, such as static gantry systems
and mobile ground robots performing AM tasks, can o er additional bene ts over o -site
prefabrication, but it needs further research before it will become practical and economical.
Ground-based automated construction systems also have the limitation that they cannot extend
the construction envelope beyond their physical size. The solution of using aerial robots
to liberate the process from the constrained construction envelope has been suggested, albeit
with technological challenges including precision of operation, uncertainty in environmental
interaction and energy e ciency.
This thesis investigates methods of precise manufacturing with aerial robots. In particular,
this work focuses on stabilisation mechanisms and origami-based structural elements that allow
aerial robots to operate in challenging environments. An integrated aerial self-aligning delta
manipulator has been utilised to increase the positioning accuracy of the aerial robots, and
a Material Extrusion (ME) process has been developed for Aerial Additive Manufacturing
(AAM). A 28-layer tower has been additively manufactured by aerial robots to demonstrate the
feasibility of AAM. Rotorigami and a bioinspired landing mechanism demonstrate their abilities
to overcome uncertainty in environmental interaction with impact protection capabilities and
improved robustness for UAV. Design principles using tensile anchoring methods have been
explored, enabling low-power operation and explores possibility of low-power aerial stabilisation.
The results demonstrate that precise aerial manufacturing needs to consider not only just the
robotic aspects, such as
ight control algorithms and mechatronics, but also material behaviour
and environmental interaction as factors for its success.Open Acces
Third International Symposium on Space Mission Operations and Ground Data Systems, part 2
Under the theme of 'Opportunities in Ground Data Systems for High Efficiency Operations of Space Missions,' the SpaceOps '94 symposium included presentations of more than 150 technical papers spanning five topic areas: Mission Management, Operations, Data Management, System Development, and Systems Engineering. The symposium papers focus on improvements in the efficiency, effectiveness, and quality of data acquisition, ground systems, and mission operations. New technology, methods, and human systems are discussed. Accomplishments are also reported in the application of information systems to improve data retrieval, reporting, and archiving; the management of human factors; the use of telescience and teleoperations; and the design and implementation of logistics support for mission operations. This volume covers expert systems, systems development tools and approaches, and systems engineering issues
DNA-based communication in populations of synthetic protocells
Developing molecular communication platforms based on orthogonal communication channels is a crucial step towards engineering artificial multicellular systems. Here, we present a general and scalable platform entitled ‘biomolecular implementation of protocellular communication’ (BIO-PC) to engineer distributed multichannel molecular communication between populations of non-lipid semipermeable microcapsules. Our method leverages the modularity and scalability of enzyme-free DNA strand-displacement circuits to develop protocellular consortia that can sense, process and respond to DNA-based messages. We engineer a rich variety of biochemical communication devices capable of cascaded amplification, bidirectional communication and distributed computational operations. Encapsulating DNA strand-displacement circuits further allows their use in concentrated serum where non-compartmentalized DNA circuits cannot operate. BIO-PC enables reliable execution of distributed DNA-based molecular programs in biologically relevant environments and opens new directions in DNA computing and minimal cell technology
UAS in the Airspace: A Review on Integration, Simulation, Optimization, and Open Challenges
Air transportation is essential for society, and it is increasing gradually
due to its importance. To improve the airspace operation, new technologies are
under development, such as Unmanned Aircraft Systems (UAS). In fact, in the
past few years, there has been a growth in UAS numbers in segregated airspace.
However, there is an interest in integrating these aircraft into the National
Airspace System (NAS). The UAS is vital to different industries due to its
advantages brought to the airspace (e.g., efficiency). Conversely, the
relationship between UAS and Air Traffic Control (ATC) needs to be well-defined
due to the impacts on ATC capacity these aircraft may present. Throughout the
years, this impact may be lower than it is nowadays because the current lack of
familiarity in this relationship contributes to higher workload levels.
Thereupon, the primary goal of this research is to present a comprehensive
review of the advancements in the integration of UAS in the National Airspace
System (NAS) from different perspectives. We consider the challenges regarding
simulation, final approach, and optimization of problems related to the
interoperability of such systems in the airspace. Finally, we identify several
open challenges in the field based on the existing state-of-the-art proposals
Optimizing Communication for Massively Parallel Processing
The current trends in high performance computing show that large machines with tens of thousands of processors will soon be readily available. The IBM Bluegene-L machine with 128k processors (which is currently being deployed) is an important step in this direction. In this scenario, it is going to be a significant burden for the programmer to manually scale his applications. This task of scaling involves addressing issues like load-imbalance and communication overhead. In this thesis, we explore several communication optimizations to help parallel applications to easily scale on a large number of processors. We also present automatic runtime techniques to relieve the programmer from the burden of optimizing communication in his applications.
This thesis explores processor virtualization to improve communication performance in applications. With processor virtualization, the computation is mapped to virtual processors (VPs). After one VP has finished computation and is waiting for responses to its messages, another VP can compute, thus overlapping communication with computation. This overlap is only effective if the processor overhead of the communication operation is a small fraction of the total communication time. Fortunately, with network interfaces having co-processors, this happens to be true and processor virtualization has a natural advantage on such interconnects.
The communication optimizations we present in this thesis, are motivated by applications such as NAMD (a classical molecular dynamics application) and CPAIMD (a quantum chemistry application). Applications like NAMD and CPAIMD consume a fair share of the time available on supercomputers. So, improving their performance would be of great value. We have successfully scaled NAMD to 1TF of peak performance on 3000 processors of PSC Lemieux, using the techniques presented in this thesis.
We study both point-to-point communication and collective communication (specifically all-to-all communication). On a large number of processors all-to-all communication can take several milli-seconds to finish. With synchronous collectives defined in MPI, the processor idles while the collective messages are in flight. Therefore, we demonstrate an asynchronous collective communication framework, to let the CPU compute while the all-to-all messages are in flight. We also show that the best strategy for all-to-all communication depends on the message size, number of processors and other dynamic parameters. This suggests that these parameters can be observed at runtime and used to choose the optimal strategy for all-to-all communication. In this thesis, we demonstrate adaptive strategy switching for all-to-all communication.
The communication optimization framework presented in this thesis, has been designed to optimize communication in the context of processor virtualization and dynamic migrating objects. We present the streaming strategy to optimize fine grained object-to-object communication.
In this thesis, we motivate the need for hardware collectives, as processor based collectives can be delayed by intermediate that processors busy with computation. We explore a next generation interconnect that supports collectives in the switching hardware. We show the performance gains of hardware collectives through synthetic benchmarks
Supporting families managing childhood eczema:Developing and optimising Eczema Care Online using qualitative research
Background: childhood eczema is often poorly controlled due to under-use of emollients and topical corticosteroids. Parents/carers report practical and psychosocial barriers to managing their child’s eczema, including child resistance. Online interventions could potentially support parents/carers; however, rigorous research developing such interventions has been limited. Aim: to develop an online behavioural intervention to help parents/carers manage and co-manage their child’s eczema. Design and setting: Intervention development using a theory-, evidence- and Person-Based Approach with qualitative research. Methods: a systematic review and qualitative synthesis (32 studies) and interviews with parents/carers (N=30) were used to identify barriers and facilitators to effective eczema management, and a prototype intervention was developed. Think-aloud interviews with parents/carers (N=25) were then used to optimise the intervention to increase its acceptability and feasibility. Results: qualitative research identified that parents/carers had concerns about using emollients and topical corticosteroids; incomplete knowledge and skills around managing eczema; and reluctance to transitioning to co-managing eczema with their child. Think-aloud interviews highlighted that while experienced parents/carers felt they knew how to manage eczema, some information about how to use treatments was still new. Techniques for addressing barriers included: providing a rationale explaining how emollients and topical corticosteroids work; demonstrating how to use treatments; and highlighting that the intervention provided new, up-to-date information. Conclusions: parents/carers need support in effectively managing and co-managing their child’s eczema. The key output of this research is Eczema Care Online (ECO) for Families; an online intervention for parents/carers of children with eczema, which is being evaluated in a randomised trial
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