3.1. Formal Formulation of the Evaluation Problem
Students’ ATCo
is tested using a device to measure reaction time and relative error rate in multitasking tasks. The developed measuring device is designed to assess the efficiency of student pilots and air traffic controllers during multitasking tasks. It consists of hardware and software components that together provide data collection and analysis of students’ reactions to various stimuli during training sessions. The device allows measuring both qualitative and quantitative performance indicators, including reaction time to visual and acoustic signals as well as the number of errors during task performance. Specialized sensors and software are used to collect and process data. Measuring reaction time in multitasking conditions allows assessment of the speed and accuracy of students’ task performance, which is an important aspect of their training. Such a device was proposed by the authors and a useful model was obtained for it [
27]. This device generates 50 instructions
from 6 problems
within one test. As a result, the student ATCo must answer 300 tasks focused on visual and acoustic perception. Tasks 1–3 focus on visual stimuli to which the subject responds in the manipulation zone. Their purpose is to assess the predisposition to the profession and to determine the speed and accuracy of reactions to visual stimuli under a standard load. Additionally, the ability to respond to visual stimuli with different wavelengths is assessed, which indicates the correction of color vision. Tasks 4–5 also focus on visual stimuli, to which the subject responds in the population zone. The main purpose is to determine the predisposition to the profession and to assess the speed and accuracy of reactions to visual stimuli under a standard load. Additionally, the ability to use both hemispheres of the brain is studied. Task 6 focuses on acoustic stimuli in the manipulation zone. The purpose is to assess the predisposition to the profession and to determine the speed and accuracy of reactions to acoustic stimuli. The ability to perform several types of tasks simultaneously is also tested. A detailed description of the functions is given in the work [
16].
The construction of artificial intelligence technology to assess the level of practical knowledge of ATCo students is possible only with enough test data. Such data are needed for training neural networks, which make it possible to detect complex and non-linear dependencies in the data. To conduct the research, it is necessary to have data on the level of practical knowledge of student ATCo Ps, who are called the research respondents. This level is expressed in a hundred-point scale and is denoted by .
The level of practical knowledge from the teacher is determined taking into account two aspects:
Evaluation of reaction time and accuracy of responses: Quantification of the level of practical knowledge of ATCo student pilots is carried out by assessing their average reaction times to visual and acoustic signals as well as the number of errors in performing tasks. Reaction time and error rate in multitasking conditions show the effectiveness of task performance and the level of preparation for work in real situations.
Multitasking and adaptability: This assesses students’ ability to perform multiple tasks simultaneously, including measuring the number of correct answers when multitasking and the level of errors under stress or changing circumstances. Also determined is the stability of task performance and the ability to adapt to change, which is important for assessing students’ practical knowledge in real-world work environments.
Also, the number of mistakes made ( and the reaction time (t) to perform the assigned task are considered for each ATCo student. Testing for each student is carried out several times, denoted by , and determines the repetition of the exercise within the testing. An information model for processing the data of ATCo student reactions in multitasking situations is proposed: to process the input data. Based on the processed input data, a neuro-fuzzy model for assessing the level of practical knowledge of ATCo students, , is built.
Neural fuzzy models combine the advantages of neural networks and fuzzy logic, allowing you to work with inaccurate, incomplete, or contradictory data, which is important for assessing students’ cognitive and emotional reactions. This allows the model to adapt to different levels of task complexity and take into account the individual characteristics of students, which increases the accuracy and reliability of the results.
Definition 1. Artificial intelligence technology is a system that uses machine learning algorithms and neural networks to analyze students’ reactions to multitasking situations, assessing their speed, accuracy, and efficiency. It allows you to automatically assess the level of practical knowledge of students based on their reactions to visual and acoustic stimuli as well as their ability to perform several tasks simultaneously.
The artificial intelligence technology for assessing the level of practical knowledge of ATCo students based on their reactions in multitasking situations is presented in the form of a theoretical multiple model system, as follows:
Based on the input data, a technology is built that enables ATCo students, , after passing their testing on the device, to receive an initial quantitative assessment of their level of practical knowledge, Y.
For the development of artificial intelligence technology, the following subjects are defined: the respondents are ATCo students who will be trained in a neuro-fuzzy model based on the number of mistakes made, reaction time to perform the task, and assessment of the level of practical knowledge; a system analyst is a person who configures all the management processes of the artificial intelligence technology; the decision-making person (DM) is the instructor of the student ATCo, who is responsible for the level of training and, based on the initial evaluations, makes a decision to approve the received assessment of the level of practical knowledge of the ATCo based on their reactions in multitasking situations.
An illustration of the processes of artificial intelligence technology for assessing the level of practical knowledge of ATCo students is shown in
Figure 1.
Figure 1 shows the structural scheme of the artificial intelligence technology for assessing the level of practical knowledge of ATCo students based on their reactions in multitasking situations. The input data are divided into two types: test input data, which is the input data of the student ATCo respondents (
), and input data of the evaluated student pilots (
). There are two blocks at the input: “Input Test Data” and “Input Data”. Student ATCos are tested using a device to measure the reaction time and relative error rate by generating 50 instructions (
) from 6 tasks (
). This testing is repeated 15 times (
. Also, the level of practical knowledge (
is considered for student ATCo respondents. The “Measuring Device” block is responsible for this. After that, the data on the reactions of the ATCo students in multitasking situations are processed using the information model—
. The “Information Model—
” block is responsible for this. The results of the data obtained from the pilot student respondents form the “database” block of the study. After that, the data are entered into the neuro-fuzzy model to assess students’ level of practical knowledge at ATCo—
(block “Neuro-fuzzy model—
”). Based on the data from student ATCo respondents, the neural network is trained to determine the synaptic weights. The knowledge gained forms the “knowledge base” block of the study. The acquired knowledge forms the research knowledge base. Based on the input data, a student ATCo’s practical knowledge is evaluated based on their reactions in multitasking situations using the calculation of the neuro-fuzzy model
. Next, the assessment of the level of practical knowledge is derived using the knowledge base of the study. After that, the final evaluation of the DM is determined. After that, the result goes to the block “Determination of the final assessment of the DM”.
3.2. An Information Model for Processing the Data of ATCo Student Reactions in Multitasking Situations—
Student ATCo
is tested using a device to measure reaction time and relative error rate in multitasking tasks. The number of mistakes made and the reaction time to perform the tasks,
,
…
, are considered for each task. As a result, a data set is obtained for each student
,
:
In general, the set of data received from the device for measuring reaction time and relative error rate in multitasking tasks will look like , where is the student number ; is the instruction number ; and is the number of the given problem The information model for processing student ATCo reaction data in multitasking situations is presented as a step-by-step algorithm.
First step. In the first step, the error data and reaction time for the performance of the given task are fuzzified.
Since the obtained data take different values and have different semantic contents, it is suggested that the theory of fuzzy sets and one-dimensional membership functions be used to compare them. The greater the number of mistakes made in the task, the worse the level of skill acquisition, which indicates the need for additional training or retraining. Similarly, the longer the task time, the worse the response, which may indicate uncertainty in decision making. It may also indicate a lack of experience in dealing with similar situations. Long reaction times can be critical in stressful and multitasking environments, requiring additional training to improve decision-making speed and accuracy in real-world flight conditions. Given this, in both cases, the “small amount” type is uncertain. Membership functions of this type are described by Z-like membership functions: quadratic Z-spline, harmonic Z-spline, Z-sigmoid, and Z-linear. To construct the membership function, it is necessary to determine the parameters of the lower and upper limits. Membership functions are constructed based on accurate data from the students’ training [
28]. For example, a quadratic Z-spline given by the following analytical formula is proposed for the number of errors:
, and the larger the value, the fewer errors the student makes. The quadratic Z-spline will have the form for the reaction time to perform the assigned task:
, and the value goes to 1 when the reaction time is the minimum possible.
Thus, the obtained values , are normalized and comparative, ; ;
Second step. In the second step, the aggregated level of performance of the assigned task is obtained.
Aggregation of values
,
is carried out within the limits of
problems by modeling the uncertainty of the “average value” form based on multidimensional membership functions. For example, such modeling can be naturally performed using a cone-shaped membership function. Putting the value of the center of the base of the cone as a unit vector, the scaling according to the coordinates of the vector
will be
:
where
.
;
;
The obtained values of characterize the aggregated level of performance of the assigned task by the student ATCo regarding the mistakes made and the reaction time to perform the assigned task. When the value goes to 1, it means the best result, accompanied by a quick reaction and error-free task execution.
Third step. In the third step, a generalized assessment of the performance of the assigned task is obtained within 50 instructions.
The transition to the generalized evaluation in terms of the set tasks
is calculated using the following formula:
where
is one normalized assessment of the performance of the given task
within 50 instructions in a section by student
,
. The obtained normalized scores
determine the level of performance of the given task.
Fourth step. This step considers the repetition of the performance exercise within the limits of testing.
It is estimated that each student ATCo must perform the test 15 times to assess their level of practical knowledge of reactions in multitasking situations. Of course, when the number of repetitions of the exercises within the testing framework is increased, the result in terms of reaction time and the number of errors improves. This needs to be considered, as the improvement in performance with time and the number of repetitions is a consequence of the learning effect. When a student ATCo repeats the exercise several times, they remember the sequence of actions better and begin to react faster and more accurately. Such a factor can give a false impression of the level of their basic skills since the improvement in results is due to habituation to a specific task and does not always reflect the ATCo’s real ability to adapt to new or unexpected situations. Such exercises are denoted by
and characterize the number of repetitions. Normalized values are required to consider the repeatability of exercises and compare data. From the above logic, it is proposed to use the Z-linear membership function:
The obtained values are called the coefficients of repetition of the exercise within the testing limits by the student ATCo. As the number of repetitions of the exercise increases, the coefficient will approach zero.
The instructor also evaluates the student ATCo and gives an assessment of the level of practical knowledge on a one-hundred-point scale .
Thus, based on the information model of data processing of student ATCo reactions in multitasking situations, a set of input data was obtained separately for exercises
(
),
Table 1.
Where is the normalized assessment of the performance of the assigned task by the student ATCo ; is the coefficient of repetition of the exercise within the testing limits; and is the evaluation of the level of practical knowledge, .
3.3. A Neuro-Fuzzy Model for Assessing the Level of Practical Knowledge of Student ATCos,
Let the input of the neuro-fuzzy model be supplied with normalized assessments of the performance of the given task by the student (), the evaluation of the level of practical knowledge (), and the coefficient of repetition of the exercise within the limits of testing (). Then, the object of the form д is considered, for which the relationship “inputs —output ” is presented as production rules of a fuzzy knowledge base. Then, you need to build a base of vague knowledge, which consists of systems of logical statements: “If–Then, Else”. They associate the values of the input data with one possible assessment of the level of practical knowledge :
IF (with weight ) and (with weight ) … and (with weight ) and (with weight ) THEN ELSE …
is a student ATCo based on which the level of practical knowledge is determined, . are the synaptic weights of the neuro-fuzzy model. Synaptic weights are obtained in the process of learning a neuro-fuzzy network.
The derivation of levels of practical knowledge can be illustrated in the form of a four-layer neuro-fuzzy network (
Figure 2). Where the following notations are used, the input is data on student
, for which an assessment is made on 6 tasks
in exercises, which characterizes the number of repetitions
. Next is the calculation in terms of four layers: First layer: {
is normalized assessments of the performance of the corresponding tasks
is the repetition coefficient of the exercise within the limits of data fuzzification testing. Second layer:
is the value of the excitation level of neurons that form input signals with synaptic weights. Third layer:
is the postsynaptic potential of neurons of the third layer. Fourth layer:
is the level of practical knowledge of the student.
Below are the formalized steps performed at each layer of the neuro-fuzzy model.
First layer: Fuzzification of input data
In the neurons of the first layer, a data fuzzification operation is performed to obtain normalized and comparative data. Fuzzification is carried out with the help of the developed information model of data processing of student ATCo reactions in multitasking situations, . The formalization of error data and the reaction time for the performance of the given task is carried out according to Formulas (3) and (4), after which the data are aggregated according to Formula (5), and a generalized assessment of the performance of the given task is obtained within 50 instructions, according to Formula (6). Further, Formula (7) considers the performance exercise’s repetition within the testing limits.
Second layer: Combining values of activation conditions
At the second layer, the functions of the postsynaptic potential are aggregated according to the tasks set by the student ATCo and the repetition of the performance exercise within the testing framework. The second layer contains seven neurons, and the synaptic weights
and are obtained in the process of learning the neuro-fuzzy model. For this, the authors suggest, but are not limited to, the method of backpropagation of the error. It is said that input signals with synaptic weights form the values of the neurons’ excitation level
. In this case, the functions of the postsynaptic potential of neurons of the second layer are determined by the following formula:
As a result, the output neurons of the second layer , , …, are obtained, and this process is repeated separately for exercises ().
Third layer: Adjustment of neurons of the second layer
On the third layer, the neurons of the second layer are adjusted to the importance of a given task and the repetition of the exercise. For this, the DM enters the synaptic weights
, respectively, from some interval
. Calculation of the postsynaptic potential of neurons of the third layer is carried out as follows:
Here, the output neurons of the third layer are and is some student ATCo for whom the level of practical knowledge is determined, .
Fourth layer: Output layer
At the fourth layer, the data are defuzzified to derive the levels of practical knowledge
. For this, the activation function is used in the output neuron:
The obtained assessment of the level of practical knowledge is on a 100-point scale
, which is substituted according to the accepted classification levels [
28]: “A” is excellent if 91–100; “B” is very good if 81–90; “C” is good if 71–80; “D” is satisfactory if 61–70; “E” is sufficient if 51–60; “FX” is not enough if 0–50. The student completes practical training on reactions in multitasking situations if his or her results are rated no lower than 75.
Synaptic weights () in a neuro-fuzzy model determine the influence of each of the input parameters () on the output result (, the level of practical knowledge of the pilot student). They provide the flexibility of the model and the accuracy of its estimates, adapting to the specifics and significance of each parameter. The role of the weights is to weigh the influence of the input data. That is, each parameter receives its weight, which determines its significance. Also, in the learning process, the synaptic weights are adjusted, which allows the model to adapt to the characteristics of each student () and consider different conditions. The weights adjust the “If–Then” rules, determining the influence of the variables () on the result.
Also, in the study, the mechanism of synaptic weighting coefficients is used to adjust the importance of the neurons in the third layer of the neuro-fuzzy network. These coefficients determine the relative influence of parameters such as the level of performance of the task or the repetition of the exercise on the calculation of the postsynaptic potential. The coefficients allow setting a different significance for each parameter depending on the conditions. Thus, the model achieves high accuracy, considering all aspects of practical knowledge.
The artificial intelligence technology for assessing the level of practical knowledge of student ATCos based on their reactions in multitasking situations is presented. The result is a standardized assessment of the level of practical knowledge based on testing with a device for measuring reaction time and the relative frequency of errors in multitasking tasks. The automation of the process of obtaining a standardized assessment was made possible owing to the available sample of real data on which the neuro-fuzzy model was trained. Of course, the training process of ATCo students cannot be completely automated. Therefore, the obtained assessment of the level of practical knowledge based on artificial intelligence technology is an auxiliary tool for the DM in determining the final evaluation. Such an assessment allows for a more objective assessment of the ATCo student’s reactions to the various stressful situations and multitasking conditions. Still, the final decision always requires the participation of an instructor or an expert who considers all other factors that can affect the training of the ATCo, including their psychological readiness and real experience.