# SCM-IoT: An Approach for Internet of Things Services Integration and Coordination
## 4 Case Study
### Platform Dependent Computational Model
#### 4.3.2 Definition of Notification Conditions for Actuators  
Notification conditions for actuators are classified into two parts, comfort and safety. Comfort and energy-saving conditions. Among the comfort conditions that the system allows to guarantee is to ensure that the temperature of a room is pleasant for those who occupy it. The above conditions are described as logical expressions in the SCM-IoT model as follows:  
$ update/Temperature = 'LOW' and  
$ update/presence = 'YES' and  
$ update/heater = 'NO'  
$ update/fan = 'NO'  
In previous expressions, \"$ update\" designates the variable that represents the last update of the notebook and that, therefore, contains the most recent information available on the temperature of the room, the presence of a resident in it, and the state of the heater or fan (air conditioning) installed in a room.  
The above conditions are established as follows:  
$ room/Temperature = 'VERY HIGH' and  
$ room/smoke = 'YES' and  
$ room/mexico expense = 'YES' and  
$ Fire = 'NO'  
The variable \"$ room\" contains a copy of the records recorded in the main book and consequently corresponds to the most recent readings reported by the sensors. The presented case study describes the scope of SCM-IoT as established in the contributions provided by this model. The following is a more detailed description of the contributions:  
1. The SCM-IoT model introduces a coordination mechanism where storage, production, and notification services are performed on the original data provided by the content producers. By providing these services, the editor may generate new data following application-defined rules. The editor coordinates participant activities through requests for direct modification of the table content (by update services) and subscriptions for relevant data notifications (by notify and collect services). The editor offers clients a mediated interaction driven by their interest in relevant data detection and notification. The centralization of data processing and pattern recognition may simplify the design of IoT applications characterized by sensors and actuators with insufficient computational resources. 2. SCM-IoT is a table-oriented coordination language instead of tuple-oriented as in the Linda coordination model [20; 21]. In SCM-IoT, tables, table entries, and entry fields are also called notebooks, pages, and topics, respectively. The table model establishes a fixed number of table entries, each sharing the same fixed number and type of fields. On the contrary, in the Linda model, tuples can have a distinct and arbitrary structure and even introduce new ones dynamically during execution. Nonetheless, the SCM-IoT restriction on the table structure can considerably improve the efficiency of the representation and processing of the data space used as a coordination medium. However, this does not limit the expressiveness of the model since several tables can be simultaneously allocated, each one with its structure and managed by its corresponding editor. The edition rules determine the type of editor that manages the table contents. Data production and subscription dependencies can form data flows among tables in more complex applications. Moreover, to increase the model efficiency, additional editors of the same type can be introduced for the same table as long as they do not interfere with each other acting on the same data. 3. As in Linda, in SCM-IoT the content of the data space is accessed and modified by a reduced set of primitive operations. However, by establishing the data space with a fixed structure, the SCM-IoT coordination primitives differ from the Linda primitives in that they do not use the availability principle as a coordination mechanism. In Linda, the out() operation makes available a new tuple in the data space, while the blocking in() operation waits for an available tuple matching the description specified by the operation.