Incremental acquisition of behaviors and signs based on a reinforcement learning schemata model and a spike timing-dependent plasticity network

A novel integrative learning architecture based on a reinforcement learning schemata model (RLSM) with a spike timing-dependent plasticity (STDP) network is described. This architecture models operant conditioning with discriminative stimuli in an autonomous agent engaged in multiple reinforcement learning tasks. The architecture consists of two constitutional learning architectures: RLSM and STDP. RLSM is an incremental modular reinforcement learning architecture, and it makes an autonomous agent acquire several behavioral concepts incrementally through continuous interactions with its environment and/or caregivers. STDP is a learning rule of neuronal plasticity found in cerebral cortices and the hippocampus of the human brain. STDP is a temporally asymmetric learning rule that contrasts with the Hebbian learning rule. We found that STDP enabled an autonomous robot to associate auditory input with its acquired behaviors and to select reinforcement learning modules more effectively. Auditory signals interpreted based on the acquired behaviors were revealed to correspond to 'signs' of required behaviors and incoming situations. This integrative learning architecture was evaluated in the context of on-line modular learning.     

Melt conditioning by advanced shear technology (MCAST) for refining solidification microstructures

Abstract

MCAST (melt conditioning by advanced shear technology) is a novel processing technology developed recently for conditioning liquid metal prior to solidification processing. The MCAST process uses a twin screw mechanism to impose a high shear rate and a high intensity of turbulence on the liquid metal, so that the conditioned liquid metal has uniform temperature, uniform chemical composition and well-dispersed and completely wetted oxide particles with a fine size and a narrow size distribution. The microstructural refinement is achieved through an enhanced heterogeneous nucleation rate and an increased nuclei survival rate during the subsequent solidification processing. In this paper we present the MCAST process and its applications for microstructural refinement in both shape casting and continuous casting of light alloys.     

33—THE CSIRO CONDITIONING OVEN

The CSIRO Conditioning Oven has been developed for use in conditioning houses and testing laboratories that are concerned with the accurate determination of the invoice weight of consignments of wool. The primary objective of the oven design is to achieve a high degree of accuracy and reliability in accordance with the conditioning regulations of the International Wool Textile Organization (IWTO). For this reason, considerable care has been taken in the design of the oven chamber to ensure isothermal conditions during weighing and in the temperature control to ensure that the sample is dried at 105 ± 2°C. In addition, a fast drying rate is obtained by compressing the sample into a uniform bed and forcing the heated air through the sample under pressure.

Samples of scoured wool weighing up to 800 g can be dried in 10–15 min to a state corresponding to that laid down in the IWTO regulations.

A prototype oven has given satisfactory service in two years of operation by the Australian Wool Testing Authority.