# Data Classification of Mental Health and Personality Evaluation Based on Network Deep Learning

Authors: Lin Zhou; Wenjun An
Journal: Mobile Information Systems
 (2022)

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## Abstract

In real life, people are at a risk of encountering various negative emotions all the time, and in the case of long-term negative emotions, it is easy to fall into a state of depression. However, in the current mental health system, the diagnosis of the depressive state of a client usually requires a doctor or a consultant to conduct face-to-face or video consultation with the client, which is time consuming and labor intensive. Therefore, it is necessary to adopt IT for mental health monitoring and personality data analysis. In order to achieve better results in identifying the students’ mental health problems, this paper attempts to use multiple data sources, proposes an algorithm for identifying mental health problems based on multiple data sources, and uses the data on students’ mental states provided in psychology as labels to improve the shortcomings brought about by the questionnaire approach. To further optimise the model identification results, this paper proposes a mental health problem identification algorithm based on the DeepPsy model. A 2D-CNN was used to extract the online pattern of a day, an LSTM network was used to capture the temporal dependency between days, and a deep learning network was designed to combine the underlying features with the online trajectory pattern. Experiments showed an accuracy of 0.71, a recall of 0.75, and an F1-Measure of 0.72, and were able to identify 75% of students with mental health problems.


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## Body

## 1. Introduction

In traditional mental health diagnosis, it is usually necessary to diagnose whether the client has psychological problems through assessment, interview, etc. This method is more labor intensive and not conducive to the discovery and intervention of early psychological problems. However, many previous studies have shown that people’s various habits and traces in their lives project psychological states. Although at present, the accuracy of traditional mental health diagnosis is better than diagnosis through multi-dimensional machine learning, diagnosis through machine learning also has its own advantages. The intelligent system constructed by big data can diagnose and analyze a large number of users at the same time, saving time and labor costs, and can monitor the psychological state of users 24 hours a day, which is conducive to the discovery and prevention of early bad psychological states. These are things that traditional mental health diagnostic methods cannot do. Therefore, traditional mental health diagnosis and big data mental health diagnosis can complement each other. Since the diagnosis accuracy of big data system is not as good as that of traditional health diagnosis, in practical application, the model can be optimised by methods to achieve lenient entry and strict exit. That is, users who are suspected of psychological well-being (PWB) problems are discovered, reminded, and recalled through the big data system, and then further diagnosis and intervention are carried out through traditional mental health diagnosis methods.Mental health and personality evaluation are becoming more and more important, and Day C develops specific parenting interventions for some special parents. These parents generally have severe personality disorders and mental health problems, because parents’ psychological problems are likely to be infected by their children. The aim of devising a pragmatic mixed methods design is to develop and pilot specialized parenting interventions [1]. Family education greatly affects the mental health of adolescents. Chen analyzed the impact of family cumulative risk on the growth and development of adolescents from different perspectives, and put forward corresponding family education methods on this basis, mainly to provide certain guidelines for children’s mental health education and personality issues [2]. Mamsharifi et al. investigated social support and personality traits to predict mental health problems and performed regression analysis on the data [3]. The relationship between racial discrimination and negative mental health outcomes has been questioned, and Mekawi et al. used bivariate relationships and hierarchical regression analysis methods to determine whether racial discrimination contributes to depression, anxiety, and post-traumatic stress symptoms that affect the role of personality [4]. Shirazi and Omidvar studied the role of critical thinking and dynamic personality in predicting job self-efficacy and performed regression analysis on the data [5]. In general, the diagnosis of depression in the traditional PWB diagnosis system mainly relies on psychiatric interviews, which is time consuming and labor intensive, and will lead to more serious conditions, which is not conducive to the prevention and treatment of depression.How to extract emotional information from big data becomes extremely important. Gong Y’s research found that different personalities, emotional states, and external stimuli will have different effects on emotional semantic analysis. The process characteristics describing emotional evolution were more comprehensively predicted starting from the description and calculation of emotional dynamic characteristics [6]. Adamopoulos et al. investigated whether the underlying personality traits of online users affect the effectiveness of the platform, using machine learning methods combined with econometric techniques [7]. Ammannato and Chiesi studied and investigated information on game players’ behavior and reaction patterns to assess the likelihood of personality traits. It was found that in five of the six personality dimensions, the probability of correctly identifying a player’s trait level is higher than chance by using deep learning for training deep neural networks [8]. To address mental stress health in the framework of smart medical care, Rachakonda et al. proposed a novel deep learning-based system that can monitor a person’s stress level through body temperature, movement speed, and sweat during physical activity [9]. Psychological research models how people learn features and categories, but deep neural networks learn representations of real-world stimuli through the network that might be used to capture the mental representations. Peterson et al. had found that simple transformations that correct for these differences can be obtained by convex optimization, extending the scope of psychological experiments and computational modeling [10]. Although there is a strong relationship between behavior and PWB problems in the above studies, the obtained labels may be inaccurate by using questionnaires to obtain and the relationship between behavioral single data source and PWB cannot accurately assess the PWB status.


## 2. PWB and Personality Evaluation of Deep Learning

### 2.1. Application of Artificial Intelligence Technology in PWB State Prediction

Advances in intelligent technology merge into the psychological realm. For example, there are artificial intelligence assistants that can chat with users, evaluate the user’s PWB, and recommend suitable solutions to users [11]. There are also related technology companies that have developed devices using AR and VR technologies. Users can wear these devices and watch VR and AR video images for psychotherapy.The development of the Internet, big data, and artificial intelligence technology provides new methods and opportunities for the study of psychology. Through social media content, sensors (including various wearable devices and cameras) and smartphones, a large amount of data can be obtained from people’s daily lives. The PWB big data is summarized and classified as shown in Figure1.Figure 1
PWB big data.As shown in Figure1, the big data at the PWB level is divided into emotional, cognitive, behavioral, social, and biological levels. These big data at the PWB level will project people’s PWB status. For example, at the level of social big data, when people feel sad or happy, they will let their relatives and friends know their current emotions by sending a circle of friends [12]. At the level of biological big data, people’s sleep quality will be affected by mental health conditions, so collecting people’s sleep data through wearable devices such as sleep bracelets can also conduct research on mental health conditions. In short, people’s emotions and PWB status can be known by analyzing these PWB big data. The character classification is shown in Figure 2.Figure 2
Character classification.As shown in Figure2, personality theory refers to the description of a person’s personality mainly covered by five traits, including openness, conscientiousness, extraversion, agreeableness, and neuroticism [13].Although the current level of artificial intelligence technology has not reached the point where it can truly replace human psychological counselors, the development of artificial intelligence technology has brought a huge impact on traditional psychological counseling work. Some high-cost and low-efficiency psychological counseling will be replaced by artificial intelligence, and artificial intelligence technology will play a role in promoting and advancing the entire PWB industry [14].


### 2.2. Network Deep Learning to Evaluate PWB

#### 2.2.1. Decision Tree Algorithm

The most critical technique in the construction of a decision tree is the selection of split attributes, and the dataset often contains many attributes. For some high-dimensional datasets, there may even be thousands of attributes. How to choose the best attribute is the focus of decision tree research, that is, among several attributes, which attribute is preferentially selected for splitting [15]. The calculation of information entropy is shown in Formula (1):(1)EntropyE=−∑m=1ifilog2fi.Among them,i represents the number of categories in the dataset E, and the smaller the Entropy (E) value, the higher the purity of E. The information gain of the sample set E is shown in Formula (2):(2)GainE,b=EntropyE−∑n=1NDnDEntropyDn.The attribute selection has the highest gain, and the C4.5 algorithm is shown in Formula (3):(3)Gini_ratioE,b=GiniE,bISb.Among them:(4)ISb=−∑​log2DnD.The CART algorithm outperforms the former in speed. The calculation is shown in Formula (5):(5)GiniE=1−∑n=1ifn2.Decision tree algorithms are not data sensitive. Both nominal data and numerical data can be processed, and features without correlation can also be processed [16].


#### 2.2.2. Gradient Boosting Tree

The base classifier of the Gradient Boosting Decision Tree (GBDT) algorithm is also a decision tree, and it is a CART decision tree, like random forests [17]. It is difficult to achieve both accuracy and diversity by using only one decision tree classifier, and a single decision tree classifier is prone to overfitting and unstable classification results in classification problems. The gradient boosting tree algorithm solves these shortcomings of decision trees [18]. The basic idea of gradient boosted trees is to reduce the loss by accumulating weak classifiers. The initialized base classifier is shown in Formula (6):(6)f0y=argminλ∑​n=1NLxn,λ.Each base classifier needs to do:The negative gradient calculation result is used as the residual value, and the process is shown in Formula (7).(7)ϕnm=−∂Lxn,fyn∂,fyn.For fitting a regression tree, for leaf nodes, the calculation is shown in Formula (8):(8)amj=argmina∑yn∈RmjLxn,fm−1yn+a.The output gradient boosting tree is shown in Formula (9):(9)f^n=fMn.The difference between a gradient boosted tree and a random forest is that each tree in a random forest is built independently of other trees, while a gradient boosted tree is built based on the results of the previous trees. The latter can ensure the continuity of features, and there are many nonlinear transformations, which are helpful for feature transformation and high-dimensional feature generation [19]. In addition, gradient boosting trees, like random forests, overcome the problem that decision trees are prone to overfitting and are not sensitive to outliers.


#### 2.2.3. Neural Network

A classifier with the lowest current error rate was selected as the first base classifier, and the accuracy of the classifier was calculated as shown in Formula (10):(10)ulaz=1,bz=flz,−1,bz≠flz.Among themflz represents the actual output class of the first base classifier relative to input az. Calculate the error of the base classifier on distribution dl as shown in Formula (11):(11)rl=∑z=1Zdlzulaz.The weight of the base classifier in the final classifier is calculated as shown in Formula (12):(12)rl=pIn1+rl1−rl,p∈0,1.The weight distribution of the updated training samples is shown in Formula (13):(13)dl+1z=dlzexp−γlulaz∑​z=1Zdlzexp−γlulaz.Then, return to the second step until the classification effect reaches the preset accuracy or the pre-given base classifier has been used up.(14)HA=argmaxo∑l=1MγlHloA.Among them,HloA represents the direct output of the first base classifier.


### 2.3. Identification Algorithm of Students’ PWB Based on Multisource Data

The overall framework of the multisource data-based student PWB problem identification algorithm is shown in Figure3.Figure 3
Algorithm framework for student PWB problem identification based on multisource data.As shown in Figure3, the accuracy rate (Precision) was higher than the recall rate (Recall), and the highest recall rate (Recall) can only reach 0.58, indicating that there are relatively few samples that can be correctly identified. Secondly, the comprehensive performance of the decision tree was the best, especially the recall rate (Recall) was improved more. Therefore, the decision tree was selected as the classifier of the PWB identification algorithm based on multisource data. The results of five classification algorithms in identifying students with PWB are shown in Table 1.Table 1
Results of five classification algorithms for identifying students with PWB.
Classification algorithmPrecisionRecallF1-MeasureRT0.680.530.65GBDT0.660.520.62NB0.620.500.60NN0.650.500.63DT0.680.580.69The experimental results are as follows, as stated in Table1: Precision is 0.68, Recall is 0.56, and F1-Measure is 0.67. The algorithm using multisource data was able to identify 56% of pupils with PWB difficulties, as per the experimental findings of the test set.


### 2.4. Identification Algorithm of Students’ Mental Health Problems Based on DeepPsy

In this recognition algorithm, the algorithm uses data such as student consumption, access control, network, and grades to analyze students’ behavior in school, and can identify students with mental health problems to a certain extent. But through in-depth analysis, it is found that the algorithm has shortcomings.


#### 2.4.1. Weaknesses of Algorithms

For the identification algorithm of students’ mental health problems based on multisource data, students with mental health problems can be identified to a certain extent, but the results of the experiment are not ideal. Through further analysis of the whole method framework, it is found that there are two deficiencies. First, due to the large difference in the length of the online behavior sequences, there are a large number of vacancies. For a shorter sequence, it may not be possible to extract the students’ online patterns. Secondly, the online mode has been trained twice, and each training will generate a certain loss. The process of extracting surfing patterns using a one-dimensional convolutional neural network (ID-CNN) incurs one loss, and another loss when training with a classification algorithm [20, 21].To this end, an online trajectory matrix is constructed, and a network is designed to obtain an improved identification algorithm for students’ mental health problems.


#### 2.4.2. Construction of Students’ Online Trajectory Matrix

The time granularity of the data in the network log is accurate to the second. The length of the sequence obtained by directly establishing the behavior sequence according to the order of time varies. Usually, students’ online behavior is time-periodic, and even the purpose of Internet access in different periods is generally different. For example, more web pages related to the study are browsed during the day, and more web pages related to entertainment and shopping are browsed at night [22]. If the categories of web pages accessed by students are calculated by time period, then the purpose of the students’ Internet access in each time period can be known. It was divided each day into 24 time periods, that is, each period is 1 hour. In this way, students’ daily surfing trajectory can be transformed into a two-dimensional matrix C∗H of time and behavior (web browsing category). Among them, C represents the number of types of web pages, H represents the number of time periods, and the value in the matrix is the number of visits to the web page. If there is no access record within the time period, it is filled with 0. For feature extraction of a two-dimensional matrix, the commonly used method is to use two-dimensional convolutional neural network (2D-CNN). The frame is shown in Figure 4.Figure 4
Mental health problem identification framework based on DeepPsy model.As shown in Figure4, the model is mainly divided into two modules. The first module designs a joint model of 2D-CNN and LSTM with the input of the student’s online trajectory matrix, which is responsible for extracting the hidden patterns of the students’ online behavior trajectory. The second module uses the basic features (including abnormal scores) extracted from the four data sources as input to establish a fully connected neural network, which is responsible for building the impact of students’ basic features on the identification of mental health problems. Then, the outputs of the two modules are connected, and finally a fully connected layer neural network is used. All parameters in this model are connected. When training the model, the back-propagated loss is applied to both the first module and the second module. At the same time, the online behavior trajectory module will make corresponding adjustments according to the feedback of the students’ basic feature module, and the students’ basic feature module will also be affected by the characteristics of the students’ online behavior trajectory [23].


#### 2.4.3. Network Architecture Design

A total of eight neural network layers are built in the 2D-CNN part of the online behavior trajectory module. The first and fourth layers of the neural network layer are convolutional layers, and the same convolution is used at the same time, that is, the edge of the matrix is filled with 0, so that the dimension of the matrix will not change after the convolution operation.(15)xni=f∑m∈Nmxni−1∗kmni+bni.The second and fifth layers of the neural network layer use a batch normalization layer. What it does is batch normalize the output of the previous convolutional layer. Its operation is shown in (16).(16)x^ni=fWmidownxni+bni.To combine the features output by the convolutional and pooling layers, the extracted feature matrix is first flattened into a vector before the fully connected layer. The function of the Dropout network layer is to randomly hide some neuron nodes, which can prevent overfitting during training and improve the generalization ability of the model. Therefore, the eighth layer uses a Dropout network layer. For each student, the output for each day is a vector feature for a total ofT vectors.After the 2D-CNN part, the daily surfing behavior characteristics of each student are extracted. In the ninth hidden layer to obtain the time dependence, the calculation is as Formulas (17) and (18).(17)Ok=δW9∗hk−1,xk+b9,(18)hk=Ok∗tanhCk.A long short-term memory network has an output at each moment. Only output the value of the last moment, and then input this value into the tenth layer fully connected neural network, and the result obtained is the output of the online behavior trajectory module, as shown in Formula (19).(19)stra=fW10+hT+b10.The basic feature module uses a fully connected neural network, and then the outputs of the two modules are connected together as the input of the next layer of fully connected neural network, and the connection operation is shown in Formula (20).(20)sconcat=fW11conxatstra,sbase+b11.In this study, the target is a binary classification problem, using the sigmoid function to convert the output into a number between 0 and 1, which represents the probability that the sample belongs to “1,” and then output the class result.


## 2.1. Application of Artificial Intelligence Technology in PWB State Prediction

Advances in intelligent technology merge into the psychological realm. For example, there are artificial intelligence assistants that can chat with users, evaluate the user’s PWB, and recommend suitable solutions to users [11]. There are also related technology companies that have developed devices using AR and VR technologies. Users can wear these devices and watch VR and AR video images for psychotherapy.The development of the Internet, big data, and artificial intelligence technology provides new methods and opportunities for the study of psychology. Through social media content, sensors (including various wearable devices and cameras) and smartphones, a large amount of data can be obtained from people’s daily lives. The PWB big data is summarized and classified as shown in Figure1.Figure 1
PWB big data.As shown in Figure1, the big data at the PWB level is divided into emotional, cognitive, behavioral, social, and biological levels. These big data at the PWB level will project people’s PWB status. For example, at the level of social big data, when people feel sad or happy, they will let their relatives and friends know their current emotions by sending a circle of friends [12]. At the level of biological big data, people’s sleep quality will be affected by mental health conditions, so collecting people’s sleep data through wearable devices such as sleep bracelets can also conduct research on mental health conditions. In short, people’s emotions and PWB status can be known by analyzing these PWB big data. The character classification is shown in Figure 2.Figure 2
Character classification.As shown in Figure2, personality theory refers to the description of a person’s personality mainly covered by five traits, including openness, conscientiousness, extraversion, agreeableness, and neuroticism [13].Although the current level of artificial intelligence technology has not reached the point where it can truly replace human psychological counselors, the development of artificial intelligence technology has brought a huge impact on traditional psychological counseling work. Some high-cost and low-efficiency psychological counseling will be replaced by artificial intelligence, and artificial intelligence technology will play a role in promoting and advancing the entire PWB industry [14].


## 2.2. Network Deep Learning to Evaluate PWB

### 2.2.1. Decision Tree Algorithm

The most critical technique in the construction of a decision tree is the selection of split attributes, and the dataset often contains many attributes. For some high-dimensional datasets, there may even be thousands of attributes. How to choose the best attribute is the focus of decision tree research, that is, among several attributes, which attribute is preferentially selected for splitting [15]. The calculation of information entropy is shown in Formula (1):(1)EntropyE=−∑m=1ifilog2fi.Among them,i represents the number of categories in the dataset E, and the smaller the Entropy (E) value, the higher the purity of E. The information gain of the sample set E is shown in Formula (2):(2)GainE,b=EntropyE−∑n=1NDnDEntropyDn.The attribute selection has the highest gain, and the C4.5 algorithm is shown in Formula (3):(3)Gini_ratioE,b=GiniE,bISb.Among them:(4)ISb=−∑​log2DnD.The CART algorithm outperforms the former in speed. The calculation is shown in Formula (5):(5)GiniE=1−∑n=1ifn2.Decision tree algorithms are not data sensitive. Both nominal data and numerical data can be processed, and features without correlation can also be processed [16].


### 2.2.2. Gradient Boosting Tree

The base classifier of the Gradient Boosting Decision Tree (GBDT) algorithm is also a decision tree, and it is a CART decision tree, like random forests [17]. It is difficult to achieve both accuracy and diversity by using only one decision tree classifier, and a single decision tree classifier is prone to overfitting and unstable classification results in classification problems. The gradient boosting tree algorithm solves these shortcomings of decision trees [18]. The basic idea of gradient boosted trees is to reduce the loss by accumulating weak classifiers. The initialized base classifier is shown in Formula (6):(6)f0y=argminλ∑​n=1NLxn,λ.Each base classifier needs to do:The negative gradient calculation result is used as the residual value, and the process is shown in Formula (7).(7)ϕnm=−∂Lxn,fyn∂,fyn.For fitting a regression tree, for leaf nodes, the calculation is shown in Formula (8):(8)amj=argmina∑yn∈RmjLxn,fm−1yn+a.The output gradient boosting tree is shown in Formula (9):(9)f^n=fMn.The difference between a gradient boosted tree and a random forest is that each tree in a random forest is built independently of other trees, while a gradient boosted tree is built based on the results of the previous trees. The latter can ensure the continuity of features, and there are many nonlinear transformations, which are helpful for feature transformation and high-dimensional feature generation [19]. In addition, gradient boosting trees, like random forests, overcome the problem that decision trees are prone to overfitting and are not sensitive to outliers.


### 2.2.3. Neural Network

A classifier with the lowest current error rate was selected as the first base classifier, and the accuracy of the classifier was calculated as shown in Formula (10):(10)ulaz=1,bz=flz,−1,bz≠flz.Among themflz represents the actual output class of the first base classifier relative to input az. Calculate the error of the base classifier on distribution dl as shown in Formula (11):(11)rl=∑z=1Zdlzulaz.The weight of the base classifier in the final classifier is calculated as shown in Formula (12):(12)rl=pIn1+rl1−rl,p∈0,1.The weight distribution of the updated training samples is shown in Formula (13):(13)dl+1z=dlzexp−γlulaz∑​z=1Zdlzexp−γlulaz.Then, return to the second step until the classification effect reaches the preset accuracy or the pre-given base classifier has been used up.(14)HA=argmaxo∑l=1MγlHloA.Among them,HloA represents the direct output of the first base classifier.


## 2.2.1. Decision Tree Algorithm

The most critical technique in the construction of a decision tree is the selection of split attributes, and the dataset often contains many attributes. For some high-dimensional datasets, there may even be thousands of attributes. How to choose the best attribute is the focus of decision tree research, that is, among several attributes, which attribute is preferentially selected for splitting [15]. The calculation of information entropy is shown in Formula (1):(1)EntropyE=−∑m=1ifilog2fi.Among them,i represents the number of categories in the dataset E, and the smaller the Entropy (E) value, the higher the purity of E. The information gain of the sample set E is shown in Formula (2):(2)GainE,b=EntropyE−∑n=1NDnDEntropyDn.The attribute selection has the highest gain, and the C4.5 algorithm is shown in Formula (3):(3)Gini_ratioE,b=GiniE,bISb.Among them:(4)ISb=−∑​log2DnD.The CART algorithm outperforms the former in speed. The calculation is shown in Formula (5):(5)GiniE=1−∑n=1ifn2.Decision tree algorithms are not data sensitive. Both nominal data and numerical data can be processed, and features without correlation can also be processed [16].


## 2.2.2. Gradient Boosting Tree

The base classifier of the Gradient Boosting Decision Tree (GBDT) algorithm is also a decision tree, and it is a CART decision tree, like random forests [17]. It is difficult to achieve both accuracy and diversity by using only one decision tree classifier, and a single decision tree classifier is prone to overfitting and unstable classification results in classification problems. The gradient boosting tree algorithm solves these shortcomings of decision trees [18]. The basic idea of gradient boosted trees is to reduce the loss by accumulating weak classifiers. The initialized base classifier is shown in Formula (6):(6)f0y=argminλ∑​n=1NLxn,λ.Each base classifier needs to do:The negative gradient calculation result is used as the residual value, and the process is shown in Formula (7).(7)ϕnm=−∂Lxn,fyn∂,fyn.For fitting a regression tree, for leaf nodes, the calculation is shown in Formula (8):(8)amj=argmina∑yn∈RmjLxn,fm−1yn+a.The output gradient boosting tree is shown in Formula (9):(9)f^n=fMn.The difference between a gradient boosted tree and a random forest is that each tree in a random forest is built independently of other trees, while a gradient boosted tree is built based on the results of the previous trees. The latter can ensure the continuity of features, and there are many nonlinear transformations, which are helpful for feature transformation and high-dimensional feature generation [19]. In addition, gradient boosting trees, like random forests, overcome the problem that decision trees are prone to overfitting and are not sensitive to outliers.


## 2.2.3. Neural Network

A classifier with the lowest current error rate was selected as the first base classifier, and the accuracy of the classifier was calculated as shown in Formula (10):(10)ulaz=1,bz=flz,−1,bz≠flz.Among themflz represents the actual output class of the first base classifier relative to input az. Calculate the error of the base classifier on distribution dl as shown in Formula (11):(11)rl=∑z=1Zdlzulaz.The weight of the base classifier in the final classifier is calculated as shown in Formula (12):(12)rl=pIn1+rl1−rl,p∈0,1.The weight distribution of the updated training samples is shown in Formula (13):(13)dl+1z=dlzexp−γlulaz∑​z=1Zdlzexp−γlulaz.Then, return to the second step until the classification effect reaches the preset accuracy or the pre-given base classifier has been used up.(14)HA=argmaxo∑l=1MγlHloA.Among them,HloA represents the direct output of the first base classifier.


## 2.3. Identification Algorithm of Students’ PWB Based on Multisource Data

The overall framework of the multisource data-based student PWB problem identification algorithm is shown in Figure3.Figure 3
Algorithm framework for student PWB problem identification based on multisource data.As shown in Figure3, the accuracy rate (Precision) was higher than the recall rate (Recall), and the highest recall rate (Recall) can only reach 0.58, indicating that there are relatively few samples that can be correctly identified. Secondly, the comprehensive performance of the decision tree was the best, especially the recall rate (Recall) was improved more. Therefore, the decision tree was selected as the classifier of the PWB identification algorithm based on multisource data. The results of five classification algorithms in identifying students with PWB are shown in Table 1.Table 1
Results of five classification algorithms for identifying students with PWB.
Classification algorithmPrecisionRecallF1-MeasureRT0.680.530.65GBDT0.660.520.62NB0.620.500.60NN0.650.500.63DT0.680.580.69The experimental results are as follows, as stated in Table1: Precision is 0.68, Recall is 0.56, and F1-Measure is 0.67. The algorithm using multisource data was able to identify 56% of pupils with PWB difficulties, as per the experimental findings of the test set.


## 2.4. Identification Algorithm of Students’ Mental Health Problems Based on DeepPsy

In this recognition algorithm, the algorithm uses data such as student consumption, access control, network, and grades to analyze students’ behavior in school, and can identify students with mental health problems to a certain extent. But through in-depth analysis, it is found that the algorithm has shortcomings.


### 2.4.1. Weaknesses of Algorithms

For the identification algorithm of students’ mental health problems based on multisource data, students with mental health problems can be identified to a certain extent, but the results of the experiment are not ideal. Through further analysis of the whole method framework, it is found that there are two deficiencies. First, due to the large difference in the length of the online behavior sequences, there are a large number of vacancies. For a shorter sequence, it may not be possible to extract the students’ online patterns. Secondly, the online mode has been trained twice, and each training will generate a certain loss. The process of extracting surfing patterns using a one-dimensional convolutional neural network (ID-CNN) incurs one loss, and another loss when training with a classification algorithm [20, 21].To this end, an online trajectory matrix is constructed, and a network is designed to obtain an improved identification algorithm for students’ mental health problems.


### 2.4.2. Construction of Students’ Online Trajectory Matrix

The time granularity of the data in the network log is accurate to the second. The length of the sequence obtained by directly establishing the behavior sequence according to the order of time varies. Usually, students’ online behavior is time-periodic, and even the purpose of Internet access in different periods is generally different. For example, more web pages related to the study are browsed during the day, and more web pages related to entertainment and shopping are browsed at night [22]. If the categories of web pages accessed by students are calculated by time period, then the purpose of the students’ Internet access in each time period can be known. It was divided each day into 24 time periods, that is, each period is 1 hour. In this way, students’ daily surfing trajectory can be transformed into a two-dimensional matrix C∗H of time and behavior (web browsing category). Among them, C represents the number of types of web pages, H represents the number of time periods, and the value in the matrix is the number of visits to the web page. If there is no access record within the time period, it is filled with 0. For feature extraction of a two-dimensional matrix, the commonly used method is to use two-dimensional convolutional neural network (2D-CNN). The frame is shown in Figure 4.Figure 4
Mental health problem identification framework based on DeepPsy model.As shown in Figure4, the model is mainly divided into two modules. The first module designs a joint model of 2D-CNN and LSTM with the input of the student’s online trajectory matrix, which is responsible for extracting the hidden patterns of the students’ online behavior trajectory. The second module uses the basic features (including abnormal scores) extracted from the four data sources as input to establish a fully connected neural network, which is responsible for building the impact of students’ basic features on the identification of mental health problems. Then, the outputs of the two modules are connected, and finally a fully connected layer neural network is used. All parameters in this model are connected. When training the model, the back-propagated loss is applied to both the first module and the second module. At the same time, the online behavior trajectory module will make corresponding adjustments according to the feedback of the students’ basic feature module, and the students’ basic feature module will also be affected by the characteristics of the students’ online behavior trajectory [23].


### 2.4.3. Network Architecture Design

A total of eight neural network layers are built in the 2D-CNN part of the online behavior trajectory module. The first and fourth layers of the neural network layer are convolutional layers, and the same convolution is used at the same time, that is, the edge of the matrix is filled with 0, so that the dimension of the matrix will not change after the convolution operation.(15)xni=f∑m∈Nmxni−1∗kmni+bni.The second and fifth layers of the neural network layer use a batch normalization layer. What it does is batch normalize the output of the previous convolutional layer. Its operation is shown in (16).(16)x^ni=fWmidownxni+bni.To combine the features output by the convolutional and pooling layers, the extracted feature matrix is first flattened into a vector before the fully connected layer. The function of the Dropout network layer is to randomly hide some neuron nodes, which can prevent overfitting during training and improve the generalization ability of the model. Therefore, the eighth layer uses a Dropout network layer. For each student, the output for each day is a vector feature for a total ofT vectors.After the 2D-CNN part, the daily surfing behavior characteristics of each student are extracted. In the ninth hidden layer to obtain the time dependence, the calculation is as Formulas (17) and (18).(17)Ok=δW9∗hk−1,xk+b9,(18)hk=Ok∗tanhCk.A long short-term memory network has an output at each moment. Only output the value of the last moment, and then input this value into the tenth layer fully connected neural network, and the result obtained is the output of the online behavior trajectory module, as shown in Formula (19).(19)stra=fW10+hT+b10.The basic feature module uses a fully connected neural network, and then the outputs of the two modules are connected together as the input of the next layer of fully connected neural network, and the connection operation is shown in Formula (20).(20)sconcat=fW11conxatstra,sbase+b11.In this study, the target is a binary classification problem, using the sigmoid function to convert the output into a number between 0 and 1, which represents the probability that the sample belongs to “1,” and then output the class result.


## 2.4.1. Weaknesses of Algorithms

For the identification algorithm of students’ mental health problems based on multisource data, students with mental health problems can be identified to a certain extent, but the results of the experiment are not ideal. Through further analysis of the whole method framework, it is found that there are two deficiencies. First, due to the large difference in the length of the online behavior sequences, there are a large number of vacancies. For a shorter sequence, it may not be possible to extract the students’ online patterns. Secondly, the online mode has been trained twice, and each training will generate a certain loss. The process of extracting surfing patterns using a one-dimensional convolutional neural network (ID-CNN) incurs one loss, and another loss when training with a classification algorithm [20, 21].To this end, an online trajectory matrix is constructed, and a network is designed to obtain an improved identification algorithm for students’ mental health problems.


## 2.4.2. Construction of Students’ Online Trajectory Matrix

The time granularity of the data in the network log is accurate to the second. The length of the sequence obtained by directly establishing the behavior sequence according to the order of time varies. Usually, students’ online behavior is time-periodic, and even the purpose of Internet access in different periods is generally different. For example, more web pages related to the study are browsed during the day, and more web pages related to entertainment and shopping are browsed at night [22]. If the categories of web pages accessed by students are calculated by time period, then the purpose of the students’ Internet access in each time period can be known. It was divided each day into 24 time periods, that is, each period is 1 hour. In this way, students’ daily surfing trajectory can be transformed into a two-dimensional matrix C∗H of time and behavior (web browsing category). Among them, C represents the number of types of web pages, H represents the number of time periods, and the value in the matrix is the number of visits to the web page. If there is no access record within the time period, it is filled with 0. For feature extraction of a two-dimensional matrix, the commonly used method is to use two-dimensional convolutional neural network (2D-CNN). The frame is shown in Figure 4.Figure 4
Mental health problem identification framework based on DeepPsy model.As shown in Figure4, the model is mainly divided into two modules. The first module designs a joint model of 2D-CNN and LSTM with the input of the student’s online trajectory matrix, which is responsible for extracting the hidden patterns of the students’ online behavior trajectory. The second module uses the basic features (including abnormal scores) extracted from the four data sources as input to establish a fully connected neural network, which is responsible for building the impact of students’ basic features on the identification of mental health problems. Then, the outputs of the two modules are connected, and finally a fully connected layer neural network is used. All parameters in this model are connected. When training the model, the back-propagated loss is applied to both the first module and the second module. At the same time, the online behavior trajectory module will make corresponding adjustments according to the feedback of the students’ basic feature module, and the students’ basic feature module will also be affected by the characteristics of the students’ online behavior trajectory [23].


## 2.4.3. Network Architecture Design

A total of eight neural network layers are built in the 2D-CNN part of the online behavior trajectory module. The first and fourth layers of the neural network layer are convolutional layers, and the same convolution is used at the same time, that is, the edge of the matrix is filled with 0, so that the dimension of the matrix will not change after the convolution operation.(15)xni=f∑m∈Nmxni−1∗kmni+bni.The second and fifth layers of the neural network layer use a batch normalization layer. What it does is batch normalize the output of the previous convolutional layer. Its operation is shown in (16).(16)x^ni=fWmidownxni+bni.To combine the features output by the convolutional and pooling layers, the extracted feature matrix is first flattened into a vector before the fully connected layer. The function of the Dropout network layer is to randomly hide some neuron nodes, which can prevent overfitting during training and improve the generalization ability of the model. Therefore, the eighth layer uses a Dropout network layer. For each student, the output for each day is a vector feature for a total ofT vectors.After the 2D-CNN part, the daily surfing behavior characteristics of each student are extracted. In the ninth hidden layer to obtain the time dependence, the calculation is as Formulas (17) and (18).(17)Ok=δW9∗hk−1,xk+b9,(18)hk=Ok∗tanhCk.A long short-term memory network has an output at each moment. Only output the value of the last moment, and then input this value into the tenth layer fully connected neural network, and the result obtained is the output of the online behavior trajectory module, as shown in Formula (19).(19)stra=fW10+hT+b10.The basic feature module uses a fully connected neural network, and then the outputs of the two modules are connected together as the input of the next layer of fully connected neural network, and the connection operation is shown in Formula (20).(20)sconcat=fW11conxatstra,sbase+b11.In this study, the target is a binary classification problem, using the sigmoid function to convert the output into a number between 0 and 1, which represents the probability that the sample belongs to “1,” and then output the class result.


## 3. PWB and Personality Data Experiments

### 3.1. Personality Evaluation and Prediction Based on Social Network

Through repeated training of the SVM algorithm, that is, the classic SVM-REF algorithm, the features corresponding to the optimal model are screened out, and 5 personality prediction models are constructed using these features. The experiment still used the scikit-learn library to improve the feature selection process. While calling its RFE interface, grid search is used to determine the optimal hyperparameters of the linear SVM during each round of training, and tenfold cross-validation is used in the training process. In the personality classification task of this experiment, there are a total of 42 image features. That is to say, a total of 42 models were constructed in the first round of the algorithm, and one feature would be removed at the end of one round of training. These 42 models are trained under the basic settings of grid search optimal hyperparameters and tenfold cross-validation. This allows the algorithm to obtain the optimal model under the current feature set for each round of execution. Finally, after the iteration of the SVM-RFE algorithm, an optimal model will be obtained, and the corresponding features of the model are the features after the feature selection operation. Next, the extracted features are applied to the experimental process, and there are only differences in the feature extraction stage, and other settings remain unchanged.


#### 3.1.1. Experimental Results of Openness and Extraversion

It is worth noting that 18 of the 20 image style features extracted by the deep convolutional neural network appear in the above 30 features. It showed that the stylistic features of the avatar are more important to the openness model than the facial features of the avatar. When experimenting separately on face features and style features, the model built with style features is stronger than the model built with face features in both accuracy and F1 score. A comparison of the predictive effects of openness and extraversion is shown in Figure5.Figure 5
Comparison of predictive effects of openness and extraversion. (a). Comparison of predictive effects of openness. (b). Comparison of predictive effects of extraversion.
(a)(b)As shown in Figure5, after the improvement, the average accuracy of the four open prediction models increased from 66.0% to 70.6%, and the average F1 increased from 66.2% to 68.1%. After the improvement, the average accuracy of the four extraversion prediction models increased from 56.3% to 59.6%, and the F1 average increased from 56.8% to 59.0%, and the overall model performance continued to improve. The accuracy and F1 value of the naive Bayesian and k-nearest neighbor classification models have improved significantly, the SVM classification model with Gaussian kernel has a small improvement in accuracy, while the accuracy of CART has hardly changed, and the F1 value has even declined. By using SVM-RFE to improve the feature selection method, the classification algorithm’s prediction of openness personality reached the highest accuracy rate of 78.4% and the highest F1 value of 77.8%. It is proved that the proposed method of using avatar style and facial features to predict user’s openness personality is effective. The experimental results of the openness prediction of multiple images published by users daily are analyzed. The openness experimental results are shown in Table 2.Table 2
Open experiment results.
Classification algorithmBased on user avatarBased on daily multiple imagesAccuracyF1AccuracyF1RBF SVM0.6930.6130.8260.789Naive bayes0.6920.7020.7500.733k-NN0.7840.7780.8330.829CART0.6540.6320.7120.627As shown in Table2, the overall performance of the classification model improved when inferring openness using multiple images posted daily by users, and when inferring user personality based on multiple images posted daily by users. The average accuracy of the four open prediction models increased from 70.6% to 78.0%, and the F1 average increased from 68.1% to 74.5%. Only the F1 value of the CART classification model decreased, by only 0.05. Among them, the accuracy and F1 value of the k-nearest neighbor algorithm was as high as 83.3% and 82.9%, which are the optimal performance indicators under the open prediction task. The performance improvement of Gaussian kernel SVM was the most obvious, the accuracy rate was increased by 0.133, and the F1 value was increased by 0.176. This not only proved the feasibility and effectiveness of using users’ daily posted images to predict users’ openness characteristics, but also further confirmed that when multiple images are used to predict users’ openness, the performance of the model will be enhanced. The results of the extraversion experiment are shown in Table 3.Table 3
Extraversion test results.
Classification algorithmBased on user avatarBased on daily multiple imagesAccuracyF1AccuracyF1RBF SVM0.6110.5820.7130.756Naive bayes0.5770.5720.7210.709k-NN0.5690.560.7150.703CART0.6270.6470.7000.670As shown in Table3, the average value of F1 increased from 59.0% to 71.0%, and the overall model performance kept improving. The accuracy of all classification models exceeded 70.0%, the highest was 72.1% obtained by the Naive Bayes classification model, and the highest F1 value was 75.6% obtained by the Gaussian kernel SVM. Among them, the F1 value of the Gaussian kernel SVM increased by 0.174 before and after, and the accuracy of the k-nearest neighbor model increased by 0.146 before and after, and the improvement effect is the most obvious in the two evaluation standards.


#### 3.1.2. Conscientiousness Test Results

When experimenting on conscientiousness through SVM-RFE, a total of 19 image features were screened out, and the comparison of the conscientiousness prediction effect is shown in Figure6.Figure 6
Comparison of the predicted effects of conscientiousness.As shown in Figure6, the features with the absolute value of the Pearson correlation coefficient greater than 0.1 were selected to participate in the training process of the conscientious personality classification model, and finally only 8 facial features were obtained. While using the SVM-RFE method to extract the coincident 5 facial features, 11 image style features were also extracted. While compared with the multisource experimental results, the average accuracy of the four improved conscientious prediction models increased from 63.5.0% to 65.3%, and the F1 average increased from 63.7% to 64.0%, and the overall performance of the model improved. The accuracy and F1 value of the Gaussian kernel SVM and the Naive Bayes classification model have improved, but the two evaluation indicators of the k-nearest neighbor model have both decreased. By changing the feature selection method, the highest prediction accuracy for conscientiousness was improved to 69.2% and the F1 value to 70.2%.When using the image predictions published by users daily, due to the increase in the number of images, the two evaluation indicators of the four classification models of conscientiousness have all improved, and the same model has the same prediction effect in the two types of images. Among them, consistent with the results of experiments using avatars, the k-nearest neighbor model is still the worst performing classification model in the conscientious prediction task. The Naive Bayes classification model maintains the best classification effect in both methods, and the results of the conscientiousness experiment are shown in Table4.Table 4
Conscientiousness experiment results.
Classification algorithmBased on user avatarBased on daily multiple imagesAccuracyF1AccuracyF1RBF SVM0.6470.6460.7810.742Naive bayes0.6920.7020.8000.792k-NN0.5940.5960.6360.630CART0.680.6160.7140.755As shown in Table4, when inferring conscientiousness using images posted by users daily, the accuracy of the Naive Bayes classification model was 80.0%, and the F1 value was 79.2%, both of which were the optimal values for this task. The Gaussian kernel SVM has the highest accuracy improvement at 0.134. The F1 value of the CART classification algorithm has the most obvious improvement, with an increase of 0.139. Through this part of the experiment, it is found that when using multiple images published by users to predict conscientiousness, the classification models have excellent performance, and are better than when only one user image was used. The effectiveness of the experimental method and image features was verified. However, the highest prediction accuracy rate was only 80.0%, which also showed that although the features considered in the experiment are effective, they also have the problem of imperfect features.


### 3.2. Identification Results of Students’ PWB Problems

Through each network layer in the DeepPsy model, the parameters of each layer would be described next. During model training, the number of iterations is 60, the batch_size is set to 4, and the optimization algorithm adopts Adam optimization. The experimental results of the DeepPsy model were compared. In order to facilitate the intuitive comparison, the two sets of results were displayed visually. The comparison effect between the DeepPsy model and the multisource data model is shown in Figure7.Figure 7
Comparison of DeepPsy model and multisource data model.As shown in Figure7, it can be seen that the DeepPsy model is higher than the multisource model in all the three evaluation indicators. In particular, the Recall indicator has the most obvious improvement. The goal is to identify students with PWB issues, hopefully identifying as many of these students as possible and giving them more attention. According to the definition of recall, this represents the proportion of positive samples that predicted students to positive samples that were actually positive. The Recall value of the model was been paid more attention to. The Recall of the DeepPsy model reached 0.75, which was 19% higher than that of the multisource algorithm, which meant that the model can identify 75% of students with PWB problems.It is not known how the features affect the results. This paper uses these feature sets to train the model:The feature types included in feature set I are: network feature, achievement feature, consumption feature, and access control feature. Feature set II removes network features on the basis of feature set I, including: performance features, consumption features, and access control features. Feature set II removes the achievement features on the basis of feature set II, including: consumption features, access control features. Feature set IV excludes consumption features on the basis of feature set II, and only includes access control features. The visualization of the experimental results of four different feature combination sets is shown in Figure8.Figure 8
Visualization of experimental results for four different feature combination sets.As shown in Figure8, the experimental result of feature set I is the best, and the experimental effect gradually deteriorates with the reduction of feature types, especially the decline of feature set IV is larger. This is because the number of consumption features is large, which greatly affects the results. The number of iterations was seated to 60, for the parameter batch_size, if other parameters remain unchanged, also take n = 1, 2, 3, 4, 5, as shown in Figure 9.Figure 9
Experimental results. (a). Experimental results of different number of convolution kernels. (b). Experimental results of different batch_size.
(a)(b)Figure9 illustrates how the number of convolution kernels is typically set to 2 when all other parameters are left unchanged. The five sets of experimental data are compared in Figure 9(a). Precision, Recall, and F1-Measure fluctuation ranges are, respectively, 4 percent, 6 percent, and 3 percent, showing that the number of convolution kernels in the first convolutional layer has no impact on the experimental outcomes. The five groups of experimental data are compared in Figure 9(b). Precision, Recall, and F1-Measure fluctuation ranges are 5 percent, 7 percent, and 5 percent, respectively. The outcomes of the experiment are slightly more affected by batch size than by the quantity of convolution kernels in the first convolutional layer.


## 3.1. Personality Evaluation and Prediction Based on Social Network

Through repeated training of the SVM algorithm, that is, the classic SVM-REF algorithm, the features corresponding to the optimal model are screened out, and 5 personality prediction models are constructed using these features. The experiment still used the scikit-learn library to improve the feature selection process. While calling its RFE interface, grid search is used to determine the optimal hyperparameters of the linear SVM during each round of training, and tenfold cross-validation is used in the training process. In the personality classification task of this experiment, there are a total of 42 image features. That is to say, a total of 42 models were constructed in the first round of the algorithm, and one feature would be removed at the end of one round of training. These 42 models are trained under the basic settings of grid search optimal hyperparameters and tenfold cross-validation. This allows the algorithm to obtain the optimal model under the current feature set for each round of execution. Finally, after the iteration of the SVM-RFE algorithm, an optimal model will be obtained, and the corresponding features of the model are the features after the feature selection operation. Next, the extracted features are applied to the experimental process, and there are only differences in the feature extraction stage, and other settings remain unchanged.


### 3.1.1. Experimental Results of Openness and Extraversion

It is worth noting that 18 of the 20 image style features extracted by the deep convolutional neural network appear in the above 30 features. It showed that the stylistic features of the avatar are more important to the openness model than the facial features of the avatar. When experimenting separately on face features and style features, the model built with style features is stronger than the model built with face features in both accuracy and F1 score. A comparison of the predictive effects of openness and extraversion is shown in Figure5.Figure 5
Comparison of predictive effects of openness and extraversion. (a). Comparison of predictive effects of openness. (b). Comparison of predictive effects of extraversion.
(a)(b)As shown in Figure5, after the improvement, the average accuracy of the four open prediction models increased from 66.0% to 70.6%, and the average F1 increased from 66.2% to 68.1%. After the improvement, the average accuracy of the four extraversion prediction models increased from 56.3% to 59.6%, and the F1 average increased from 56.8% to 59.0%, and the overall model performance continued to improve. The accuracy and F1 value of the naive Bayesian and k-nearest neighbor classification models have improved significantly, the SVM classification model with Gaussian kernel has a small improvement in accuracy, while the accuracy of CART has hardly changed, and the F1 value has even declined. By using SVM-RFE to improve the feature selection method, the classification algorithm’s prediction of openness personality reached the highest accuracy rate of 78.4% and the highest F1 value of 77.8%. It is proved that the proposed method of using avatar style and facial features to predict user’s openness personality is effective. The experimental results of the openness prediction of multiple images published by users daily are analyzed. The openness experimental results are shown in Table 2.Table 2
Open experiment results.
Classification algorithmBased on user avatarBased on daily multiple imagesAccuracyF1AccuracyF1RBF SVM0.6930.6130.8260.789Naive bayes0.6920.7020.7500.733k-NN0.7840.7780.8330.829CART0.6540.6320.7120.627As shown in Table2, the overall performance of the classification model improved when inferring openness using multiple images posted daily by users, and when inferring user personality based on multiple images posted daily by users. The average accuracy of the four open prediction models increased from 70.6% to 78.0%, and the F1 average increased from 68.1% to 74.5%. Only the F1 value of the CART classification model decreased, by only 0.05. Among them, the accuracy and F1 value of the k-nearest neighbor algorithm was as high as 83.3% and 82.9%, which are the optimal performance indicators under the open prediction task. The performance improvement of Gaussian kernel SVM was the most obvious, the accuracy rate was increased by 0.133, and the F1 value was increased by 0.176. This not only proved the feasibility and effectiveness of using users’ daily posted images to predict users’ openness characteristics, but also further confirmed that when multiple images are used to predict users’ openness, the performance of the model will be enhanced. The results of the extraversion experiment are shown in Table 3.Table 3
Extraversion test results.
Classification algorithmBased on user avatarBased on daily multiple imagesAccuracyF1AccuracyF1RBF SVM0.6110.5820.7130.756Naive bayes0.5770.5720.7210.709k-NN0.5690.560.7150.703CART0.6270.6470.7000.670As shown in Table3, the average value of F1 increased from 59.0% to 71.0%, and the overall model performance kept improving. The accuracy of all classification models exceeded 70.0%, the highest was 72.1% obtained by the Naive Bayes classification model, and the highest F1 value was 75.6% obtained by the Gaussian kernel SVM. Among them, the F1 value of the Gaussian kernel SVM increased by 0.174 before and after, and the accuracy of the k-nearest neighbor model increased by 0.146 before and after, and the improvement effect is the most obvious in the two evaluation standards.


### 3.1.2. Conscientiousness Test Results

When experimenting on conscientiousness through SVM-RFE, a total of 19 image features were screened out, and the comparison of the conscientiousness prediction effect is shown in Figure6.Figure 6
Comparison of the predicted effects of conscientiousness.As shown in Figure6, the features with the absolute value of the Pearson correlation coefficient greater than 0.1 were selected to participate in the training process of the conscientious personality classification model, and finally only 8 facial features were obtained. While using the SVM-RFE method to extract the coincident 5 facial features, 11 image style features were also extracted. While compared with the multisource experimental results, the average accuracy of the four improved conscientious prediction models increased from 63.5.0% to 65.3%, and the F1 average increased from 63.7% to 64.0%, and the overall performance of the model improved. The accuracy and F1 value of the Gaussian kernel SVM and the Naive Bayes classification model have improved, but the two evaluation indicators of the k-nearest neighbor model have both decreased. By changing the feature selection method, the highest prediction accuracy for conscientiousness was improved to 69.2% and the F1 value to 70.2%.When using the image predictions published by users daily, due to the increase in the number of images, the two evaluation indicators of the four classification models of conscientiousness have all improved, and the same model has the same prediction effect in the two types of images. Among them, consistent with the results of experiments using avatars, the k-nearest neighbor model is still the worst performing classification model in the conscientious prediction task. The Naive Bayes classification model maintains the best classification effect in both methods, and the results of the conscientiousness experiment are shown in Table4.Table 4
Conscientiousness experiment results.
Classification algorithmBased on user avatarBased on daily multiple imagesAccuracyF1AccuracyF1RBF SVM0.6470.6460.7810.742Naive bayes0.6920.7020.8000.792k-NN0.5940.5960.6360.630CART0.680.6160.7140.755As shown in Table4, when inferring conscientiousness using images posted by users daily, the accuracy of the Naive Bayes classification model was 80.0%, and the F1 value was 79.2%, both of which were the optimal values for this task. The Gaussian kernel SVM has the highest accuracy improvement at 0.134. The F1 value of the CART classification algorithm has the most obvious improvement, with an increase of 0.139. Through this part of the experiment, it is found that when using multiple images published by users to predict conscientiousness, the classification models have excellent performance, and are better than when only one user image was used. The effectiveness of the experimental method and image features was verified. However, the highest prediction accuracy rate was only 80.0%, which also showed that although the features considered in the experiment are effective, they also have the problem of imperfect features.


## 3.1.1. Experimental Results of Openness and Extraversion

It is worth noting that 18 of the 20 image style features extracted by the deep convolutional neural network appear in the above 30 features. It showed that the stylistic features of the avatar are more important to the openness model than the facial features of the avatar. When experimenting separately on face features and style features, the model built with style features is stronger than the model built with face features in both accuracy and F1 score. A comparison of the predictive effects of openness and extraversion is shown in Figure5.Figure 5
Comparison of predictive effects of openness and extraversion. (a). Comparison of predictive effects of openness. (b). Comparison of predictive effects of extraversion.
(a)(b)As shown in Figure5, after the improvement, the average accuracy of the four open prediction models increased from 66.0% to 70.6%, and the average F1 increased from 66.2% to 68.1%. After the improvement, the average accuracy of the four extraversion prediction models increased from 56.3% to 59.6%, and the F1 average increased from 56.8% to 59.0%, and the overall model performance continued to improve. The accuracy and F1 value of the naive Bayesian and k-nearest neighbor classification models have improved significantly, the SVM classification model with Gaussian kernel has a small improvement in accuracy, while the accuracy of CART has hardly changed, and the F1 value has even declined. By using SVM-RFE to improve the feature selection method, the classification algorithm’s prediction of openness personality reached the highest accuracy rate of 78.4% and the highest F1 value of 77.8%. It is proved that the proposed method of using avatar style and facial features to predict user’s openness personality is effective. The experimental results of the openness prediction of multiple images published by users daily are analyzed. The openness experimental results are shown in Table 2.Table 2
Open experiment results.
Classification algorithmBased on user avatarBased on daily multiple imagesAccuracyF1AccuracyF1RBF SVM0.6930.6130.8260.789Naive bayes0.6920.7020.7500.733k-NN0.7840.7780.8330.829CART0.6540.6320.7120.627As shown in Table2, the overall performance of the classification model improved when inferring openness using multiple images posted daily by users, and when inferring user personality based on multiple images posted daily by users. The average accuracy of the four open prediction models increased from 70.6% to 78.0%, and the F1 average increased from 68.1% to 74.5%. Only the F1 value of the CART classification model decreased, by only 0.05. Among them, the accuracy and F1 value of the k-nearest neighbor algorithm was as high as 83.3% and 82.9%, which are the optimal performance indicators under the open prediction task. The performance improvement of Gaussian kernel SVM was the most obvious, the accuracy rate was increased by 0.133, and the F1 value was increased by 0.176. This not only proved the feasibility and effectiveness of using users’ daily posted images to predict users’ openness characteristics, but also further confirmed that when multiple images are used to predict users’ openness, the performance of the model will be enhanced. The results of the extraversion experiment are shown in Table 3.Table 3
Extraversion test results.
Classification algorithmBased on user avatarBased on daily multiple imagesAccuracyF1AccuracyF1RBF SVM0.6110.5820.7130.756Naive bayes0.5770.5720.7210.709k-NN0.5690.560.7150.703CART0.6270.6470.7000.670As shown in Table3, the average value of F1 increased from 59.0% to 71.0%, and the overall model performance kept improving. The accuracy of all classification models exceeded 70.0%, the highest was 72.1% obtained by the Naive Bayes classification model, and the highest F1 value was 75.6% obtained by the Gaussian kernel SVM. Among them, the F1 value of the Gaussian kernel SVM increased by 0.174 before and after, and the accuracy of the k-nearest neighbor model increased by 0.146 before and after, and the improvement effect is the most obvious in the two evaluation standards.


## 3.1.2. Conscientiousness Test Results

When experimenting on conscientiousness through SVM-RFE, a total of 19 image features were screened out, and the comparison of the conscientiousness prediction effect is shown in Figure6.Figure 6
Comparison of the predicted effects of conscientiousness.As shown in Figure6, the features with the absolute value of the Pearson correlation coefficient greater than 0.1 were selected to participate in the training process of the conscientious personality classification model, and finally only 8 facial features were obtained. While using the SVM-RFE method to extract the coincident 5 facial features, 11 image style features were also extracted. While compared with the multisource experimental results, the average accuracy of the four improved conscientious prediction models increased from 63.5.0% to 65.3%, and the F1 average increased from 63.7% to 64.0%, and the overall performance of the model improved. The accuracy and F1 value of the Gaussian kernel SVM and the Naive Bayes classification model have improved, but the two evaluation indicators of the k-nearest neighbor model have both decreased. By changing the feature selection method, the highest prediction accuracy for conscientiousness was improved to 69.2% and the F1 value to 70.2%.When using the image predictions published by users daily, due to the increase in the number of images, the two evaluation indicators of the four classification models of conscientiousness have all improved, and the same model has the same prediction effect in the two types of images. Among them, consistent with the results of experiments using avatars, the k-nearest neighbor model is still the worst performing classification model in the conscientious prediction task. The Naive Bayes classification model maintains the best classification effect in both methods, and the results of the conscientiousness experiment are shown in Table4.Table 4
Conscientiousness experiment results.
Classification algorithmBased on user avatarBased on daily multiple imagesAccuracyF1AccuracyF1RBF SVM0.6470.6460.7810.742Naive bayes0.6920.7020.8000.792k-NN0.5940.5960.6360.630CART0.680.6160.7140.755As shown in Table4, when inferring conscientiousness using images posted by users daily, the accuracy of the Naive Bayes classification model was 80.0%, and the F1 value was 79.2%, both of which were the optimal values for this task. The Gaussian kernel SVM has the highest accuracy improvement at 0.134. The F1 value of the CART classification algorithm has the most obvious improvement, with an increase of 0.139. Through this part of the experiment, it is found that when using multiple images published by users to predict conscientiousness, the classification models have excellent performance, and are better than when only one user image was used. The effectiveness of the experimental method and image features was verified. However, the highest prediction accuracy rate was only 80.0%, which also showed that although the features considered in the experiment are effective, they also have the problem of imperfect features.


## 3.2. Identification Results of Students’ PWB Problems

Through each network layer in the DeepPsy model, the parameters of each layer would be described next. During model training, the number of iterations is 60, the batch_size is set to 4, and the optimization algorithm adopts Adam optimization. The experimental results of the DeepPsy model were compared. In order to facilitate the intuitive comparison, the two sets of results were displayed visually. The comparison effect between the DeepPsy model and the multisource data model is shown in Figure7.Figure 7
Comparison of DeepPsy model and multisource data model.As shown in Figure7, it can be seen that the DeepPsy model is higher than the multisource model in all the three evaluation indicators. In particular, the Recall indicator has the most obvious improvement. The goal is to identify students with PWB issues, hopefully identifying as many of these students as possible and giving them more attention. According to the definition of recall, this represents the proportion of positive samples that predicted students to positive samples that were actually positive. The Recall value of the model was been paid more attention to. The Recall of the DeepPsy model reached 0.75, which was 19% higher than that of the multisource algorithm, which meant that the model can identify 75% of students with PWB problems.It is not known how the features affect the results. This paper uses these feature sets to train the model:The feature types included in feature set I are: network feature, achievement feature, consumption feature, and access control feature. Feature set II removes network features on the basis of feature set I, including: performance features, consumption features, and access control features. Feature set II removes the achievement features on the basis of feature set II, including: consumption features, access control features. Feature set IV excludes consumption features on the basis of feature set II, and only includes access control features. The visualization of the experimental results of four different feature combination sets is shown in Figure8.Figure 8
Visualization of experimental results for four different feature combination sets.As shown in Figure8, the experimental result of feature set I is the best, and the experimental effect gradually deteriorates with the reduction of feature types, especially the decline of feature set IV is larger. This is because the number of consumption features is large, which greatly affects the results. The number of iterations was seated to 60, for the parameter batch_size, if other parameters remain unchanged, also take n = 1, 2, 3, 4, 5, as shown in Figure 9.Figure 9
Experimental results. (a). Experimental results of different number of convolution kernels. (b). Experimental results of different batch_size.
(a)(b)Figure9 illustrates how the number of convolution kernels is typically set to 2 when all other parameters are left unchanged. The five sets of experimental data are compared in Figure 9(a). Precision, Recall, and F1-Measure fluctuation ranges are, respectively, 4 percent, 6 percent, and 3 percent, showing that the number of convolution kernels in the first convolutional layer has no impact on the experimental outcomes. The five groups of experimental data are compared in Figure 9(b). Precision, Recall, and F1-Measure fluctuation ranges are 5 percent, 7 percent, and 5 percent, respectively. The outcomes of the experiment are slightly more affected by batch size than by the quantity of convolution kernels in the first convolutional layer.


## 4. Conclusions

The traditional questionnaires on PWB problems have problems that are easy to conceal and small in scale. In recent years, methods for identifying PWB problems based on Internet logs have emerged. This method makes up for the shortcomings of the questionnaire survey method, but the students have various behaviors on campus, and online behavior is only a part of it, which is not enough to reflect all the psychological activities of students. At the same time, the method of identifying PWB problems based on Internet logs still uses questionnaires to obtain labels, so the labels are still unreliable. This paper uses multisource data to identify the PWB problems of college students, and proposes a PWB problem identification algorithm based on the DeepPsy model. Then, use user avatars for character data analysis to design a deep learning network that combines basic functions and online trajectory patterns. The experimental results showed that the proposed algorithm has higher practicability. The algorithm proposed in this paper identified those students with undiscovered PWB problems and personality defects, and can provide timely psychological counseling to these students to prevent further deterioration. In future work, it is hoped to be able to predict the severity of students’ mental health problems.



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*Source: 9251598-2022-09-02.xml*