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UKAEA-RACE-CP(23)092023
When transferring a Deep Reinforcement Learning (DRL) model from simulation to the real world, the performance could be unsatisfactory since the simulation cannot imitate the real world well in many circumstances. This results in a long period of fine-tuning in the real world. This paper proposes a self-supervised vision-based DRL method that al…
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UKAEA-RACE-CP(23)082023
Many complex domains would benefit from the services of Large-scale, Safety-verified, Always-on (LSA) robotic systems. However, existing large-scale solutions often forego the complex reasoning required for safety verification and prescient reasoning in favour of scalability. We propose a method of partitioning the task domain to enable scalabil…
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UKAEA-RACE-CP(23)072023
We consider planning problems where a robot must visit a large set of locations to complete a task at each one. Our focus is problems where the difficulty of each task, and thus its duration, can be predicted, but not fully known in advance. We propose a general Markov decision process (MDP) model for difficulty-aware problems, and propose varia…
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UKAEA-RACE-CP(23)062023
Sim-and-real training is a promising alternative to sim-to-real training for robot manipulations. However, the current sim-and-real training is neither efficient, i.e., slow convergence to the optimal policy, nor effective, i.e., sizeable real-world robot data. Given limited time and hardware budgets, the performance of sim-and-real training is …
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UKAEA-RACE-PR(23)052023
ITER In-Vessel Components (IVCs) will have limited lifetimes and need to be maintained and/or replaced during the operational life of ITER. IVCs are attached to the plant cooling water system via pipework to enable active cooling of the components during plasma operations. When maintenance is required, Remote Handling Systems (RHS) will be used …
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UKAEA-CCFE-CP(23)592022
Investigations were undertaken into the thermal treatment of beryllium and tungsten to see if these materials can be detritiated in the Material Detritiation Facility (MDF) at UKAEA, allowing for the declassification of intermediate level waste (ILW) to low level waste (LLW). When heated in oxygen, both tungsten and beryllium readily oxidise, wi…
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UKAEA-CCFE-PR(23)1402023
We investigated the athermal irradiation-induced swelling and creep in iron subjecting to the application of external uniaxial stress. We studied this through atomic scale simulations using the creation-relaxation algorithm. We also calculated the defect relaxation volume density tensors (or eigenstrain) as a function of external uniaxial stress. B…
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UKAEA-CCFE-PR(23)1392023
Refractory high-entropy alloys (RHEAs) with high melting points and low neutron absorption cross-section are sought for generation-IV fission and fusion reactors. A high throughput computational screening tool, Alloy Search and Predict (ASAP), was used to identify promising RHEA candidates from over 1 million four-element equimolar combinations. Th…
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UKAEA-CCFE-PR(23)1282022
Predictions of the impact of charge-exchange (CX) reactions on beam ions in the MAST Upgrade spherical tokamak have been compared to measurements carried out with a fission chamber (neutron fluxes) and a Fast Ion Deuterium-Alpha (FIDA) diagnostic. A simple model was developed to reconstruct the outer-midplane neutral density based on Thomson sca…
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UKAEA-CCFE-PR(23)1262023
Scanning electron microscopy-based is now an established technique, providing full-field strain and displacement measurement at the microscale. Techniques for generating speckle patterns for sub-micron strain mapping are highly substrate dependent but typically rely on applying aggressive conditions which may alter the microstructure of interest…
Showing 481 - 490 of 2581 UKAEA Paper Results