请用json格式输出你昨天做了什么。
user
```json
{
  "activities": [
    {
      "time": "Morning",
      "activity": "Reviewed and responded to user queries"
    },
    {
      "time": "Afternoon",
      "activity": "Continued model training and improvement"
    },
    {
      "time": "Evening",
      "activity": "Monitored performance metrics and data analysis"
    }
  ]
}
```
assistant