# Intelligent Educational Environments: Recent Trends, Modeling, and Applications
## 5 Results
### Conceptual Model of an Intelligent Educational Environment
The reason for introducing these categories is that environmental management is relatively low-speed and usually does not need too much precision, while interactions tend to require a fast speed of both sensor measurements and actuator responses with a high degree of accuracy. In addition, environmental control is a traditional research area with many existing mature technologies, devices, and service providers. The topic of interaction is much more colorful and may incorporate a variety of different technologies often adapted from other sectors--e.g., industrial, automotive, or military technologies. The system management of the intelligent educational system is tasked with the overall management of all sensor data and IoT device interactions. The _Environment_ and _Interaction_ classes are tasked with keeping track of the past, present, and desired future states of the environment and the interactions, respectively. The communication with the devices takes place via specialized communication hardware (class _IoTGateway_), which provides a communication bridge between the IoT device networks and the intelligent educational system. An IoT device data storage capability (class _IoTDataStorage_) is also envisioned to support analytics and decision-making. The intelligent educational environment is technology-packed and, like any technical environment, must consider dependability and information security aspects, as well. Dependability is a concept usually associated with high-reliability and safety-critical systems [48; 49; 50], where the consequences of system failure could be catastrophic. Therefore, they are designed and built to resist external and internal faults. The high-reliability requirement brings additional costs, and a trade-off has to be made between dependability and expenses. The educational environment does not impose heavy fault-tolerance requirements on the applied technical solutions. Some dependability concepts and approaches, however, are applicable in modern intelligent educational environments. Continuous and flawless operation can be achieved by replicating the most valuable system assets, applying error detection and recovery of the data, and using fault-tolerance techniques for real-timeoperations. For example, the IoT gateways and device data storages may be replicated to enhance the reliability and availability of their functionality (represented by the attribute Replicas in classes _IoTGateway_, _IoTDeviceDataStorage_, and _DigitalRepository_). Error detection techniques may be applied to the data acquired from the sensors. Some vital IES subsystems, such as data repositories, system management, and IoT device control, must be fault-tolerant. Their reliability can be achieved by hardware or software redundancy, design diversity, error detection, etc. Assets and functions associated with real-time (like online examination) should envision techniques such as encryption, signature monitoring, duplication, etc. Fault-tolerance approaches, in combination with information security measures, can assure information protection and continuous functioning of the IEE. Information security is a significant aspect that should be taken into account in the IEE. Information security techniques are essential in data creation, storage, management, and transfer [51]. Techniques for data protection, authorized access to information, availability of the needed learning resources, protection of sensitive data, prevention of tampering with data, and the theft of sensitive information are some of the security measures needed. They include methods such as encryption, anonymization, data erasure, and data backup. For example, control of access rights and conformity to the GDPR act [52] are included in the class _SignIn_. Security techniques should be incorporated during the design of the IEE and comply with security policy [53]. Dependability and information security need special attention in the context of an IEE. They permeate almost every element of the proposed UML model without being a single class.