scholarly journals A Comprehensive Approach to On-board Autonomy Verification and Validation

2021 ◽  
Vol 12 (4) ◽  
pp. 1-29
Author(s):  
Marco Bozzano ◽  
Alessandro Cimatti ◽  
Marco Roveri
Keyword(s):  
Formal Model ◽  
Comprehensive Approach ◽  
Space Systems ◽  
Symbolic Manipulation ◽  
Plan Generation ◽  
Future Space ◽  
Communication Links ◽  
On Line ◽  
And Performance ◽  
Scientific Return

Deep space missions are characterized by severely constrained communication links. To meet the needs of future missions and increase their scientific return, future space systems will require an increased level of autonomy on-board. In this work, we propose a comprehensive approach to on-board autonomy. We rely on model-based reasoning, and we consider many important (on-line and off-line) reasoning capabilities such as plan generation, validation, execution and monitoring, runtime diagnosis, and fault detection, identification, and recovery. The controlled platform is represented symbolically, and the reasoning capabilities are seen as symbolic manipulation of such formal model. We have developed a prototype of our framework, and we have integrated it within an on-board Autonomous Reasoning Engine. Finally, we have evaluated our approach on three case-studies inspired by real-world projects and characterized it in terms of reliability, availability, and performance.

scholarly journals The influence of chemical parameters on the in-situ metal carbonyl complex formation studied with the fast on-line reaction apparatus (FORA)

2021 ◽  
Vol 109 (4) ◽  
pp. 243-260 ◽  
Author(s):  
Yves Wittwer ◽  
Robert Eichler ◽  
Dominik Herrmann ◽  
Andreas Türler
Keyword(s):  
Metal Carbonyl ◽  
Ambient Air ◽  
Single Atom ◽  
Carbonyl Complex ◽  
Carbonyl Complexes ◽  
On Line ◽  
Carrier Gases ◽  
And Performance ◽  
Atom Chemistry

Abstract A new setup named Fast On-line Reaction Apparatus (FORA) is presented which allows for the efficient investigation and optimization of metal carbonyl complex (MCC) formation reactions under various reaction conditions. The setup contains a 252Cf-source producing short-lived Mo, Tc, Ru and Rh isotopes at a rate of a few atoms per second by its 3% spontaneous fission decay branch. Those atoms are transformed within FORA in-situ into volatile metal carbonyl complexes (MCCs) by using CO-containing carrier gases. Here, the design, operation and performance of FORA is discussed, revealing it as a suitable setup for performing single-atom chemistry studies. The influence of various gas-additives, such as CO2, CH4, H2, Ar, O2, H2O and ambient air, on the formation and transport of MCCs was investigated. O2, H2O and air were found to harm the formation and transport of MCCs in FORA, with H2O being the most severe. An exception is Tc, for which about 130 ppmv of H2O caused an increased production and transport of volatile compounds. The other gas-additives were not influencing the formation and transport efficiency of MCCs. Using an older setup called Miss Piggy based on a similar working principle as FORA, it was additionally investigated if gas-additives are mostly affecting the formation or only the transport stability of MCCs. It was found that mostly formation is impacted, as MCCs appear to be much less sensitive to reacting with gas-additives in comparison to the bare Mo, Tc, Ru and Rh atoms.

scholarly journals Interactive effects of incentive value and valence on the performance of discrete action sequences

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tyler J. Adkins ◽  
Bradley S. Gary ◽  
Taraz G. Lee
Keyword(s):  
Motor Learning ◽  
Large Body ◽  
Interactive Effects ◽  
Motor Tasks ◽  
Skill Retention ◽  
Incentive Value ◽  
Discrete Action ◽  
On Line ◽  
And Performance ◽  
Gains And Losses

AbstractIncentives can be used to increase motivation, leading to better learning and performance on skilled motor tasks. Prior work has shown that monetary punishments enhance on-line performance while equivalent monetary rewards enhance off-line skill retention. However, a large body of literature on loss aversion has shown that losses are treated as larger than equivalent gains. The divergence between the effects of punishments and reward on motor learning could be due to perceived differences in incentive value rather than valence per se. We test this hypothesis by manipulating incentive value and valence while participants trained to perform motor sequences. Consistent with our hypothesis, we found that large reward enhanced on-line performance but impaired the ability to retain the level of performance achieved during training. However, we also found that on-line performance was better with reward than punishment and that the effect of increasing incentive value was more linear with reward (small, medium, large) while the effect of value was more binary with punishment (large vs not large). These results suggest that there are differential effects of punishment and reward on motor learning and that these effects of valence are unlikely to be driven by differences in the subjective magnitude of gains and losses.

Generalized Evidential Processing in Multiple Simultaneous Threat Detection in UNIX

2012 ◽  
pp. 104-120
Author(s):  
Zafar Sultan ◽  
Paul Kwan
Keyword(s):  
Data Fusion ◽  
Detection System ◽  
Set Cover ◽  
Threat Detection ◽  
Fusion Model ◽  
Detection Systems ◽  
Size Groups ◽  
On Line ◽  
And Performance ◽  
Statistical Data Fusion

In this paper, a hybrid identity fusion model at decision level is proposed for Simultaneous Threat Detection Systems. The hybrid model is comprised of mathematical and statistical data fusion engines; Dempster Shafer, Extended Dempster and Generalized Evidential Processing (GEP). Simultaneous Threat Detection Systems improve threat detection rate by 39%. In terms of efficiency and performance, the comparison of 3 inference engines of the Simultaneous Threat Detection Systems showed that GEP is the better data fusion model. GEP increased precision of threat detection from 56% to 95%. Furthermore, set cover packing was used as a middle tier data fusion tool to discover the reduced size groups of threat data. Set cover provided significant improvement and reduced threat population from 2272 to 295, which helped in minimizing the processing complexity of evidential processing cost and time in determining the combined probability mass of proposed Multiple Simultaneous Threat Detection System. This technique is particularly relevant to on-line and Internet dependent applications including portals.

scholarly journals Pilot Project for the Establishment of a Development Process for Future Space Systems at INPE

2002 ◽  
Author(s):  
Luciana S. C. Gonçalves ◽  
Paula E. Cardoso ◽  
Ana M. Ambrosio
Keyword(s):  
Development Process ◽  
Pilot Project ◽  
Space Systems ◽  
Future Space

On-line Monitoring of Gas Turbines to Improve Their Availability, Reliability, and Performance Using Both Process and Vibration Data

2012 ◽  
pp. 334-343 ◽  
Author(s):  
Osama Ashour ◽  
Abdurrahman Khalidi ◽  
Ever Fadlun ◽  
Nicola Giannini ◽  
Marco Pieri ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Vibration Data ◽  
On Line ◽  
And Performance

CONTRACTOR SAFETY

1997 ◽  
Vol 37 (1) ◽  
pp. 682
Author(s):  
M.A. Thackray
Keyword(s):  
Performance Indicators ◽  
Best Practice ◽  
Safety Management ◽  
Hazard Analysis ◽  
Business Plan ◽  
Safety Performance ◽  
Communication Links ◽  
The Status ◽  
And Performance

This paper deals with the efforts and results of a Management driven campaign to improve contractor safety performance in WAPET's operations.WAPET Management identified Contractor safety performance as one of four key safety focus areas in their 1995 Business Plan. The other focus areas were Hazard Analysis, Training and Audit and Review.Strategies adopted for achieving improvements in contractor safety included:aligning Contractor Goals and Objectives with WAPET's by involving major contractors in 'Best Practices' workshops. The workshops specifically addressed the Business Plan focus areas and the identification and measurement of performance indicators. The workshops provided contractors with an open forum to express their views and efforts in these areas;holding follow-up meetings with individual contractors and contractor groups with common areas of work. Both contractors and WAPET management detailed the status and efforts being put into these areas. These meetings identified improvement opportunities and opened up communication links both with WAPET personnel and between contractors; andimplementing the results of the workshop and meetings by upgrading WAPET's Safety Management System particularly in the areas of pre-qualification, contracting philosophies and contractor management philosophies.Feedback on each stage of the 1995 program was used to determine the strategies for the 1996 program. The workshops and meetings highlighted process improvement opportunities particularly in areas of industry standardisation, development of contractor Safety Management Systems, lines of communication/accountability, employee involvement and performance indicators. These opportunities were documented in a 'Contractor Best Practice* manual of which over 350 have been distributed.Conventional safety measures indicate a 50 per cent improvement in both LTI and Total Reportable frequency rates for WAPET's contractors in the past 12 months. The success of the program was also demonstrated by other indicators such as greater openness in communications, greater participation in safety meetings and a closer working relationship with WAPET.

scholarly journals Proposal for space-borne quantum memories for global quantum networking

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Mustafa Gündoğan ◽  
Jasminder S. Sidhu ◽  
Victoria Henderson ◽  
Luca Mazzarella ◽  
Janik Wolters ◽  
...  
Keyword(s):  
Quantum Communication ◽  
Global Scale ◽  
Space Systems ◽  
Quantum Communications ◽  
Communication Links ◽  
Probabilistic Detection ◽  
Entanglement Distribution ◽  
Near Term ◽  
Quantum Internet ◽  
Memory Characteristics

AbstractGlobal-scale quantum communication links will form the backbone of the quantum internet. However, exponential loss in optical fibres precludes any realistic application beyond few hundred kilometres. Quantum repeaters and space-based systems offer solutions to overcome this limitation. Here, we analyse the use of quantum memory (QM)-equipped satellites for quantum communication focussing on global range repeaters and memory-assisted (MA-) QKD, where QMs help increase the key rate by synchronising otherwise probabilistic detection events. We demonstrate that satellites equipped with QMs provide three orders of magnitude faster entanglement distribution rates than existing protocols based on fibre-based repeaters or space systems without QMs. We analyse how entanglement distribution performance depends on memory characteristics, determine benchmarks to assess the performance of different tasks and propose various architectures for light-matter interfaces. Our work provides a roadmap to realise unconditionally secure quantum communications over global distances with near-term technologies.

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