# Detection and Classification of Human Activity for Emergency Response in Smart Factory Shop Floor
## 2 Related Works and Background Information
### Smart Factory and IIoT Technologies  
IoT refers to the interconnection of devices (known as things) over the internet with identifiable internet protocols (IPs). The application of IoT to the industry is loosely called IIoT since it involves the connections of industrial components (devices or things with IPs). The Smart factories are an important part of the IoT. Meanwhile, the IIoT refers specifically to the impact of this innovation on industrial applications. Smart factories are not necessarily a \"factory without people\" [13]. It is in the understanding that smart factory also refer to the integration of shop floor decisions and insights with the rest of the supply chain and broader enterprise through an interconnected Information technology/operational technology landscape [26].  
Both IoT/IIoT technologies together create \"smart\" networks. One great example is the wireless technologies of a smart home, which connect homeowners to almost anything in the house, ranging from their entrance door to their refrigerator, and enable remote access via smart phone. In the same vein, a smart factory provides plant managers with remote access to wirelessly-connected machines, as well as access to a wealth of data on the operation of those machines, by automating the communication between industrial automation equipment and systems [26]. Data availability is one of the hallmarks of IIoT because it allows businesses to leverage data more meaningfully, including enabling predictive maintenance for machines. Smart sensors, including those with wireless and IO-Link capabilities, play a key role in making the smart factory a reality. Putting the benefits of smart factory in proper perspective, the authors of Reference [27] listed the advantages of smart factories to include: increased process efficiency, reduction in operational cost, improved product quality and increase in safety and sustainability. The focus of our work is on safety of persons in a smart factory.  
Basically, the three critical IIoT capabilities of the smart factory are: remote monitoring, predictive maintenance, and process optimization [28]. With ML, these three can be improved for overall industry benefit and availability of human and machines [29]. In the smart factory, the shop floor is highly computerized such that it is capable of continuously collection of data, as well as sharing among the connected devices, machines, and production systems [30]. To attain the full potential of industry 4.0 beyond the hype, the authors in Reference [31] opined that \"collaborative industry 4.0\" made possible by the exploitation of the available heterogenous data and leveraging on ML capabilities could help in optimizing smart factories for intelligence and shared situation awareness. Moreover, data gathering alone does not bring about the complete benefit of the smart factory. Rather, the highest level of benefit lies in the use of ML for actionable solutions to issues that are identified from the data [32]. The use of ML is one example of such actionable solutions in the emergency detection system which allows for remedy or counter actions should issues arise that are a deviation from the normal.