Thesis - Department of Electronic & Computer Engineering

More documents

Recommendations

Info

3. Output-phase execute OutputFunction for all neurons:U ˙ i ( n)=max( v i ( n) , 0)emit spike, if U i( n)exceeds threshold4. Arbitration-phase execute ArbitrationFunction for all events:set s i( n)according to arbitration schemeThese phases represent a way of structuring the computation of a new state of thenetwork. They will be used in the following sections when describing the simulationprocedures.4.2.1 Non-arbiteredTo model the non-arbitered communication scheme proposed by Mortara[12], weassume that as long as the address code on the bus is valid, the decoder can decode itcorrectly, as shown in Fig. 4.4. The overlapping part of each colliding pulse is ignored,while the rest of them can go through.In digital simulation, suppose TS time steps of a network with N neurons shouldbe simulated. First, the inputs and all the state variables are initialized; For each timestep in TS, we calculate the new state of the network: for each neuron in N,we updateall the variables and detect the potential spikes; If there is no potential spike, no spikeis encoded, if there is only one potential spike, it is encoded. Otherwise, collision is30
detected, all the potential spikes involved are discarded. The flow chart is given in Fig.4.5.Address code on the busDecoded signal at the receiverCollision betweenandFig. 4.4 The non-arbitered communication schemeInitializationFor each timestep ε inTSFor each neuron in NInputFunction()UpdateFunction()OutputFunction()Collision?YSet all s i zeroNSet s i A for the firing neuronSet s i zero for the non-firing neuronsFig. 4.5 Flow chart for the simulation of the non-arbitered scheme31
Page 3 and 4: the system level. Our results show
Page 5: activities. The basin of attraction
Page 9 and 10: It is interesting to note that whic
Page 11 and 12: Although there is no saturation in
Page 13 and 14: • Response time of the system;As
Page 15 and 16: e verified by computer simulation (
Page 17 and 18: inhibition. Due to the fact that ea
Page 19 and 20: tion. Thus the power consumption is
Page 21 and 22: Let∆be the minimum time necessary
Page 23 and 24: The sender initiates the sequence b
Page 25 and 26: Here in Table 1 is the comparison o
Page 27 and 28: source cell will be broadcast on th
Page 29: At this point, it seems appropriate
Page 33 and 34: InitializationFor each timestep ε
Page 35 and 36: global inhibition BusActivity to fr
Page 37 and 38: Spikes from the winnerATpTTT n T n+
Page 39 and 40: the network will either work at WTA
Page 41 and 42: The computer simulation results for
Page 43 and 44: 5.5 Steady State AnalysisAs demonst
Page 45 and 46: all the losers. To ensure that all
Page 47 and 48: 10090θ=θ mThe necessary condition
Page 49 and 50: 100Necessary conditions to exhibit
Page 51 and 52: The response time is estimated in t
Page 53 and 54: 5.6.2 Further study on the non-arbi
Page 55 and 56: 100Response time V.S. equivalent ga
Page 57 and 58: cell will never collide with each o
Page 59 and 60: ps ( i) = ( 1 - ϕ i)δ( s)for s =
Page 61 and 62: These results show that the collisi
Page 63 and 64: 5.7.4 SummaryCompared with the Pois
Page 65 and 66: 6. ConclusionsIn this thesis, a cla
Page 67 and 68: In this thesis, we consider only a
Page 69 and 70: v i() t≤I i----------- ( 1 - e1 -
Page 71 and 72: If a+ b - 1≥0, then τ---- d [ v
Page 73 and 74: If a+ b - 1 > 0, since v i() t > 0
Page 75 and 76: whereV ˙ i () t=max( v i ()0 t , )
Page 77 and 78: θ t s Nf f wp ct(%) p cl(%) p cw(%
Page 79 and 80: 10. “WTA networks with lateral ex

Thesis - Department of Electronic & Computer Engineering

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?