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A biologically inspired model based on a multi-scale spatial representation for goal-directed navigation

( Weilong Li ),( Dewei Wu ),( Jia Du ),( Yang Zhou ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.3
- 원문보기 2
  ScienceON
  
  KISS
Inspired by the multi-scale nature of hippocampal place cells, a biologically inspired model based on a multi-scale spatial representation for goal-directed navigation is proposed in order to achieve robotic spatial cognition and autonomous navigation. First, a map of the place cells is constructed in different scales, which is used for encoding the spatial environment. Then, the firing rate of the place cells in each layer is calculated by the Gaussian function as the input of the Q-learning process. The robot decides on its next direction for movement through several candidate actions according to the rules of action selection. After several training trials, the robot can accumulate experiential knowledge and thus learn an appropriate navigation policy to find its goal. The results in simulation show that, in contrast to the other two methods(G-Q, S-Q), the multi-scale model presented in this paper is not only in line with the multi-scale nature of place cells, but also has a faster learning potential to find the optimized path to the goal. Additionally, this method also has a good ability to complete the goal-directed navigation task in large space and in the environments with obstacles.
2
Mimicking synaptic plasticity and learning behaviours in solution processed SnO2 memristor

Pan, Ying,Wan, Tao,Du, Haiwei,Qu, Bo,Wang, Danyang,Ha, Tae-Jun,Chu, Dewei Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.757 No.-
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Abstract In this study, a transparent memristor with a configuration of Au/SnO2/FTO is fabricated by a simple solution process at low temperature and further utilized to mimic biological synapses. A series of significant synaptic functions, including nonlinear transmission characteristics, spike-rate-dependent plasticity (SRDP), short-term plasticity (STP) and long-term plasticity (LTP) are emulated. The transition from short-term to long-term plasticity is also investigated in the device by repeated stimulation. The nonlinear rectification characteristic in the current memristor is attributed to the Schottky barrier at the Au/SnO2 interface. By controlling the oxygen vacancy migration induced under electrical input, the barrier at the interface can be modified, giving rise to the different synaptic functions. These results suggest that the proposed Au/SnO2/FTO memristor in this study is a promising synaptic device for artificial neural network applications. Highlights <UL> <LI> Synaptic electronic based on Au/SnO2/FTO memristor was fabricated through a simple solution process at low temperature. </LI> <LI> Synaptic plasticity including SRDP, STP, LTP and STP-to-LTP transition were demonstrated in the synaptic device. </LI> <LI> Different synaptic functions were realised by controlling oxygen vacancy migration induced by electrical input. </LI> </UL> Graphical abstract [DISPLAY OMISSION]
3
Long-term and stable correction of uremic anemia by intramuscular injection of plasmids containing hypoxia-regulated system of erythropoietin expression

Jifeng Sun,Yarong Wang,Jie Yang,Dewei Du,Zhanting Li,Junxia Wei,Angang Yang 생화학분자생물학회 2012 Experimental and molecular medicine Vol.44 No.11
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 ScienceON
 
 KCI
Relative deficiency in production of glycoprotein hormone erythropoietin (Epo) is a major cause of renal anemia. This study planned to investigate whether the hypoxia-regulated system of Epo expression, constructed by fusing Epo gene to the chimeric phosphoglycerate kinase (PGK) hypoxia response elements (HRE) in combination with cytomegalovirus immediate-early (CMV IE) basal gene promoter and delivered by plasmid intramuscular injection, might provide a long-term physiologically regulated Epo secretion expression to correct the anemia in adenine-induced uremic rats. Plasmid vectors (pHRE-Epo) were synthesized by fusing human Epo cDNA to the HRE/CMV promoter. Hypoxia-inducible activity of this promoter was evaluated first in vitro and then in vivo in healthy and uremic rats (n = 30 per group). The vectors (pCMV-Epo) in which Epo expression was directed by a constitutive CMV gene promoter served as control. ANOVA and Student’s t-test were used to analyze between-group differences. A high-level expression of Epo was induced by hypoxia in vitro and in vivo. Though both pHRE-Epo and pCMV-Epo corrected anemia,the hematocrit of the pCMV-Epo-treated rats exceeded the normal (P < 0.05), but that of the pHRE-Epo-treated rats didn’t. Hypoxia-regulated system of Epo gene expression constructed by fusing Epo to the HRE/CMV promoter and delivered by plasmid intramuscular injection may provide a long-term and stable Epo expression and secretion in vivo to correct the anemia in adenine-induced uremic rats.