3 research outputs found
Data_Sheet_1_Brain-inspired Predictive Coding Improves the Performance of Machine Challenging Tasks.PDF
Backpropagation has been regarded as the most favorable algorithm for training artificial neural networks. However, it has been criticized for its biological implausibility because its learning mechanism contradicts the human brain. Although backpropagation has achieved super-human performance in various machine learning applications, it often shows limited performance in specific tasks. We collectively referred to such tasks as machine-challenging tasks (MCTs) and aimed to investigate methods to enhance machine learning for MCTs. Specifically, we start with a natural question: Can a learning mechanism that mimics the human brain lead to the improvement of MCT performances? We hypothesized that a learning mechanism replicating the human brain is effective for tasks where machine intelligence is difficult. Multiple experiments corresponding to specific types of MCTs where machine intelligence has room to improve performance were performed using predictive coding, a more biologically plausible learning algorithm than backpropagation. This study regarded incremental learning, long-tailed, and few-shot recognition as representative MCTs. With extensive experiments, we examined the effectiveness of predictive coding that robustly outperformed backpropagation-trained networks for the MCTs. We demonstrated that predictive coding-based incremental learning alleviates the effect of catastrophic forgetting. Next, predictive coding-based learning mitigates the classification bias in long-tailed recognition. Finally, we verified that the network trained with predictive coding could correctly predict corresponding targets with few samples. We analyzed the experimental result by drawing analogies between the properties of predictive coding networks and those of the human brain and discussing the potential of predictive coding networks in general machine learning.</p
Forward Osmosis Membranes under Null-Pressure Condition: Do Hydraulic and Osmotic Pressures Have Identical Nature?
Forward osmosis (FO) membranes fall
into the category of nonporous
membranes, based on the assumption that water and solute transport
occur solely based on diffusion. The solution-diffusion (S-D) model
has been widely used in predicting their performances in the coexistence
of hydraulic and osmotic driving forces, a model that postulates the
hydraulic and osmotic driving forces have identical nature. It was
suggested, however, such membranes may have pores and mass transport
could occur both by convection (i.e., volumetric flow) as well as
by diffusion assuming that the dense active layer of the membranes
is composed of a nonporous structure with defects which induce volumetric
flow through the membranes. In addition, the positron annihilation
technique has revealed that the active layers can involve relatively
uniform porous structures. As such, the assumption of a nonporous
active layer in association with hydraulic pressure is questionable.
To validate this assumption, we have tested FO membranes under the
conditions where hydraulic and osmotic pressures are equivalent yet
in opposite directions for water transport, namely the null-pressure
condition. We have also established a practically valid characterization
method which quantifies the vulnerability of the FO membranes to hydraulic
pressure
Rice bran supplement prevents UVB-induced skin photoaging <i>in vivo</i>
<p>Although rice bran consumption is reportedly has numerous beneficial effects on human health, the relationship between rice bran and the prevention of photoaging has not been investigated in detail. We sought to investigate whether consumption of rice bran supplement (RBS) can elicit preventive effects against UVB-induced photoaging <i>in vivo</i>. Dorsal skin sections of hairless mice were exposed to UVB over 16Â weeks. RBS consumption suppressed UVB-induced wrinkle formation and inhibited the loss of water content and epidermal thickening in the mouse skin. Western blot and immunohistochemical analyses revealed that repeated exposure to UVB upregulated matrix metalloproteinase-13 (MMP-13) and cyclooxygenase-2 (COX-2) expression, while consumption of RBS suppressed MMP-13 and COX-2 expression, as well as mitogen-activated protein kinase (MAPK) signaling pathways. These findings suggest that RBS could be a potential bioactive ingredient in nutricosmetics to inhibit wrinkle formation and water content loss via the suppression of COX-2 and MMP-13 expression.</p> <p>Effect of RBS on UVB-irradiated COX-2 and MMP-13 expression in SKH-1 hairless mouse skin.</p