---
# System prepended metadata

title: 2020/10/20 group meeting

---

# 2020/10/20 group meeting

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1. Past work
2. Noise re:result
3. Decision make;關係 of recurrent & noise
4. probability of Decision exchange 
5. Inverse spikes intervel

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## past work

1. EMA & firingrate
![](https://i.imgur.com/l82yFUZ.png)
2. noise test
`noisevalue = noise * (rand() / (RAND_MAX + 1.0)) - noise / 2`
![](https://i.imgur.com/CEWRwCg.png)

---

## noise re:result
1. 加了種子進去 like this
```
#include <iostream>
#include <stdio.h>
#include <random>

using namespace std;

int main(void)
 {
     unsigned seed;
     seed = (unsigned)time(NULL);
     srand(seed);
     int i;
     float noisevalue;
     FILE*fp;
     float noise;
     noise = 1.0;
     fp = fopen("noisetest.txt","w");
     for(i = 0; i < 1000000; i++)
 {
     noisevalue = noise * float(rand() / (RAND_MAX + 1.0)) + noise / 2;
     fprintf(fp,"%f\n",noisevalue);
 }
     fclose(fp);
     return 0;
 }
```
2. result
10W
![](https://i.imgur.com/rvDzqL1.png)
100W
![](https://i.imgur.com/Jcd54Fp.png)

---

## Decision make;關係 of recurrent & noise
要在關閉input後保留current like this
![](https://i.imgur.com/irIgvxK.png)
放大decision部份後長這樣，約300units -> 1/5sec
![](https://i.imgur.com/WMDBMgq.png)

if noise upup -> recurrent have to upup too
如此才能維持那一小段decision time

---

## probability of Decision exchange 

| time | neuron | inputstr |
| ---- | ------ | -------- |
| 3000 | 0      | 6        |
| 3000 | 1      | 5        |
| next | next   | next     |
| var  | 0      | 0        |
| var  | 1      | 5        |
| next | next   | next     |
| 3000 | 0      | 6        |
| 3000 | 1      | 5        |

every test run 1000 times,like this
![](https://i.imgur.com/oFZ7qQ1.png)
and this is their probability


| var  | exchange probability |
| ---- | -------------------- |
| 300  | 0                    |
| 400  | 0                    |
| 500  | .2                   |
| 600  | .48                  |
| 700  | .68                  |
| 800  | .8                   |
| 900  | .83                  |
| 1000 | .85                  |
| 1100 | .88                  |
| 1200 | .88                  |
| 1300 | 1                    |

---

## inverse spikes interval

不知道算法對不對
參照上課講義
![](https://i.imgur.com/CSgO78s.png)

```
    Epu = (external_current / -_g) + _rest;
    Z = (_threshold - _reset) / (Epu - _threshold);
    ISI = (1 / ((1 / -_g) * log(1 + Z)));
```



