# Mobile Education Resource Sharing Method for Wireless Broadband Connection

Authors: Zihang Jia; Jiasai Zhang; Kenan Yi
Journal: Security and Communication Networks
 (2021)

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## Abstract

The recall rate and precision rate of current mobile education resource sharing methods are low, and the resource sharing time is long, so a mobile education resource sharing method based on wireless broadband connection is proposed. Ant colony algorithm was used to optimize the focused crawler, the optimized crawler was used to capture the data of mobile education resources and extract the semantic features of the captured data, and the K-means clustering algorithm was used to cluster all the data. Based on the calculation results of network centrality and network density, a wireless broadband connection is used to schedule mobile education resources to complete the sharing of mobile education resources. The experimental results show that the proposed method’s recall rate and precision rate are above 95% and 96%, and the average resource sharing time is 0.63 s. The comprehensive performance of the proposed method is better.


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## Body

## 1. Introduction

With the advancement and deepening of reform and opening up, China's education industry is in an international environment of openness, competition, participation, and sharing, which not only brings opportunities for China's educational development, but also brings external pressure and challenges. Facing China's educational development, schools are also inevitable in the tide of competition, and reform has become the main driving force for the development of education [1]. Only by realizing interuniversity cooperation and sharing of educational resources can sustainable development of education be realized [2]. In addition, with the continuous development of information technology, mobile education resources show a trend of massive growth. Therefore, to make rational use of educational resources and fully tap the potential for mobile education resources, it has become a problem that the education field must think about to seek survival and development in today’s open competition environment [3].Current for mobile education resource sharing research progress has been made; for example, [4] proposed a method of digital teaching resource sharing based on blockchain, building the public chain based on teachers and students in colleges and universities and based on the internal departments of colleges and universities and private chain based on the alliance of alliance chain teaching resource coconstruction and sharing of the overall architecture. By the distributed architecture of blockchain mechanism, incentive mechanism, consensus, and intelligence for the underlying support contract design the user management module, virtual currency trading module, resource management module, resource creation and copyright management module, and five function modules, so as to arouse the enthusiasm of the construction of the participants shared and meet the personalized needs of college teachers and students. However, this method has the problem of low accuracy, and the practical application effect is not good. Reference [5] proposed a method of sharing online education course resources based on a cloud platform and designed an online education course resource sharing platform based on a cloud platform, which is composed of the cloud infrastructure layer, cloud system service layer, cloud application layer, and cloud client layer. Among them, the purpose of the business in the cloud system service layer management system is to achieve the business logic of the platform. The platform in accordance with the user permission differences will divide user functionality into two function modules. The teachers and students use teacher function modules to manage students, team, curriculum and live, editing, generation, and examination and approval of the examination paper, to finish creating student assignments, arrangement, and statistics, and to upload content such as teaching resources. The functions of teaching resource downloading, online homework, online examination, and discussion and communication can be realized by using the student function module, but the problem of resource sharing time is long, and there is a big gap with the ideal application effect. Reference [6] proposed a learning resource sharing platform design method based on Hadoop and cluster analysis. This method first adopts the Hadoop framework to build the entire platform. It introduces a clustering analysis algorithm to complete the classification of different learning documents according to the efficiency of SOA to improve the efficiency of the entire resource retrieval. On this basis, an ontology-based resource retrieval model is proposed, and the retrieval content is sorted according to semantic similarity. Finally, according to the above ideas, a partial interface is given in order to promote the sharing of learning resources and expand the source channels of students’ knowledge. However, this method has the problem of low recall and precision, and the practical application effect is not good. In order to solve the problems of the above methods as the research goal, this paper proposes a mobile education resource sharing method based on a wireless broadband connection, and experiments verify the effectiveness of the method.In some learning communities, there is often a need to share and exchange learning materials and resources, such as in the same office, the same classroom, and the same university dormitory. The data shared is of the same type and requires high timeliness, and sharing using cloud computing and blockchain can be time-consuming in an environment with high immediacy. At this point, this paper proposes a sharing method based on wireless broadband links, which plays a great advantage in the above application scenario:(1)
There is high transmission efficiency, located in the same LAN because there are few data transmission nodes(2)
It is based on a wireless broadband link, with no streaming restrictions and no charges(3)
In the same network of mobile devices, users can independently form their own network and share resources


## 2. Design of Mobile Education Resource Sharing Method

### 2.1. Data Capture of Mobile Education Resources

Unlike web crawlers, focused crawlers have a more complex workflow, which needs to filter the links unrelated to the topic according to a certain web page analysis algorithm, retain the useful links, and put them into the URL queue waiting to be captured. Then, it will select the web page URL to be captured in the next step from the queue according to a certain search strategy and repeat the above process until it stops when a certain condition of the system is reached. The workflow of the focusing crawler is shown in Figure1.Figure 1
Workflow of focused crawler.Compared with general crawlers, the search content of focused crawlers is limited to specific topics or specialized fields, so the width-first or depth-first algorithms widely used by general web crawlers are no longer applicable. At present, focused web crawlers usually adopt a heuristic search strategy, which selects the “most valuable” link with priority access each time. However, such a strategy is prone to fall into local optimization too early and lack of global features, resulting in a low overall return rate of focused crawlers. Ant colony algorithm is introduced into the URL selection strategy of focused crawlers in order to improve the accuracy of the crawler system to capture mobile educational resource data [7].The core problem of the focusing crawler system is how to effectively optimize the priority order for URL queue so that the corresponding page of the URL that is crawled priority has high topic relevance. A good focused crawler system must accurately predict the value of URLs and pay attention to both short-term and long-term returns. Therefore, the calculation of URL values and the selection of crawling strategy are particularly important, which determines the search efficiency and quality of the focused crawler [8].This section proposes a search strategy ACO-FC that uses an ANT colony algorithm to guide the focusing crawler on the basis of the ant colony algorithm. Its basic idea is as follows. There are hypertext pageswi and wj on the web page. If there is a link in wi that points to wj, then the ant in wi will decide whether to move from wi to wj according to certain conditions. Each sequence of links represents a possible ant route. Information is transmitted between individual ants through pheromones as they move. Pheromones evaporate over time as an ant crawls. The crawling of ants between pages is divided into several cycles. In each cycle, an ant makes a series of moves between web pages until it finds the target resource and returns to the source point. Every time a crawling cycle is completed, the ant colony updates the amount of pheromone on each route [9].To be sure, we will choose a pheromone in ant colony foraging process high routes, thus forming an information positive feedback phenomenon. This positive feedback has also side effects. However, when too many ants have chosen the same route, the route of the pheromone amount will increase rapidly, so as to make the ant more focused on a particular route, caused by a blockage and stagnation phenomenon. When using the ant colony algorithm to solve problems, it is easy to lead to precocious and local convergence. In order to solve the problem of “precocity” and “local convergence” of the ant colony algorithm, dynamic adaptive adjustment pheromone is utilized [10].Assuming thatV represents the entire set of pages and E represents the set of paths made up of links, web pages (links) constitute a directed figure G=V,E. Because the ant must consider its topic relevance when selecting the next web page, we can refer to the Page Rank algorithm formula for the topic relevance value of the page Pk in the directed figure G. For the convenience of expression, this paper intends to define it as follows.RPk is the topic relevance value of the page, and its calculation formula is(1)RPk=1−d+d∑i=1kRTiCi.Among them,d refers to the regulating factor, which is generally valued at 0.8, Ti refers to the set of pages linked to Pk, Ci refers to the link to the degree of Ti, and k is the number of links from 1 to other pages.dij represents the distance between page wi and page wj, which can be calculated by the following formula:(2)dij=C∑i=1kRPi.Among them,C is a coordination factor constant, and Pi refers to the collection of pages passed from i toj.Δτij represents the number of pheromones left on path ei,j in this cycle. Δτijk represents the amount of pheromone left by the k-th ant on path ei,j in this cycle:(3)Δτijk=QLk,if the kth ant passes ij in this cycle,0,other,where Q is a constant and Lk represents the length of the path traveled by the k-th ant in this cycle, which can be expressed as(4)Lk=∑i=1n∑j=1ndij,where n represents the number of web nodes n≤N that ant k travels in this cycle.Suppose that the number of nodes on the web page isn and the number of ants is m, then bit represents the number of ants on page wj at timet, and the number is m=∑i=1nbit. At the initial time, the amount of pheromones in each path is equal. Set τij0=c, c as a constant, usually 0. In the movement process, ant ki=1,2,…,m determines the next path according to the pheromone intensity on each path. The probability Pijkt of ant k moving from position i to j at time t is expressed as follows:(5)Pijkt=τijtα⋅ηijtβ∑li,j∈Eτltα⋅ηltβ,j∈V,0,other.In the formula,ηij represents the expected degree of moving from position i to j, α represents the role of the pheromone accumulated by the ant in its path selection, and β is a parameter representing the importance of pheromone or the importance of heuristic information. li,j∈E indicate that a link from wi to wj exists on a given page Pi. In order to avoid loop crawling with the ant colony and restrain ants to explore page increment, each ant stores a tabu table tabu to record the links visited. If wj belongs totabu, the path probability value Pijkt from wi to wj is 0, thus prohibiting ant k from exploring this link. At the end of each cycle, the table tabu is cleared.Pheromone intensityτij imbalance over time will fade. Set the pheromone retention coefficient to ρ0<ρ<1, which reflects the persistence of pheromone intensity. And 1−ρ is the degree of pheromone loss. When the limited number of moves per cycle is reached, the pheromone quantity of each path should be updated according to the following formula:(6)τijt+1=ρτijt+Δτij,Δτij=∑k=1mΔτijk.However, in order to avoid the “precocity” and “local convergence” problems of the ant colony algorithm, this paper adopts the following formula to adjust the pheromone quantity of each path according to the paper.Whenτ>τmax, the following relationship exists:(7)τijt+1=ρ1+φn⋅τijt+Δτij.Whenτ<τmax, the following relationship exists:(8)τijt+1=ρ1−φn⋅τijt+Δτij.In the formula,φn is a function proportional to the number of convergence n; the more the number of convergence n is, the greater the value of φn is:(9)φn=nc.Here,c is a constant. In this way, the pheromone quantity is updated adaptively according to the distribution of solutions, so as to adjust the intensity of pheromone quantity of each path dynamically, so that ants are neither too concentrated nor too dispersed, thus avoiding precocious and local convergence and improving the global search energy. At the end of a cycle, the optimal path is output, and the optimized crawler is used to grab the data of mobile education resources.


### 2.2. Data Clustering of Mobile Education Resources

Clustering has been widely used in the clustering research of mobile educational resource data, and the commonly used method is to determine the clustering of educational resources according to the judgment method of similarity [11]. This method can narrow the range of clustering and improve the accuracy of clustering.The traditional educational resource clustering process mainly involves the extraction of semantic features, and the commonly used methods are VSM. Here, VSM is also used for feature extraction in this paper [12]. VSM maps the text content of the resource to a feature vector Vd=t1,w1d;t2,w2d;…;tn,wnd, where tii=1,2,…,n is different entries and wid is the weight of d. The most commonly used weight calculation method is TF-IDF. Table 1 intuitively shows the mapping relationship between text, feature words, and weight in VSM.Table 1
Mapping table between text and VSM.
The text point of viewVSM perspectiveTextPoint in spaceKeywordsA dimension in spaceText setsA set of points in spaceWeight of feature wordsThe value of a point in space in some dimensionIn this paper, TF-IDF weight is used to measure the feature frequency of feature items appearing in the document. Tf-IDF, proposed by Salton in 1988, is a feature weight calculation method, which has been widely used in the field of data mining and achieved good results. The formula for TF-IDF is as follows:(10)TF−IDFt=TFt,Di×logNDFt+0.01.Among them,TF (Term Frequency) refers to the word Frequency, indicating the occurrence frequency of entry t into text Di. N represents the total number of documents, and DF represents the number of documents containing feature word t, that is, the document frequency of feature word t. The second part on the right of the formula represents the inverse document frequency of the feature word IDF.Considering the length of the text, the weight of the feature terms is normalized, and the formula is as follows:(11)TF−IDFt=TFt,Di×logN/DFt+0.01∑i=1mTFt,Di×logN/DFt+0.012.At the current stage, the K-means algorithm [13] is a clustering algorithm that uses mean clustering data points. There are now many evolved versions of the K-means algorithm, such as K-means ++ [14], and we will use the original K-means algorithm here because it has many advantages; for example, the algorithm guarantees better scalability when dealing with large data sets and the algorithm is of low complexity, where K represents the number of categories and means represents the mean [15]. Similar data points are then divided by default category and selection of the initialized center of mass. The advantage of the K-means algorithm lies in its simplicity and fast speed. It only needs to calculate the distance between the point and the center of the group. Suppose that a resource is a sample point to be clustered, and the goal is to cluster the sample points into multiple categories. For each point, we calculate the nearest central point among all the central points, and this point can be defined as its same cluster. After an iteration, we recalculate the center point of each clan and then find the center point closest to itself for each point. In this way, the loop continues until the two iterations of the cluster class no longer change [16]. The algorithm process is as follows:Step 1: selectk categories to be clustered (for example, k=3 categories), and select k center points. The selection of the cluster center is shown in Figure 2.Step 2: look for the sample points closest to the central point and classify them. All the points closest to the same central point represent a class. In this way, clustering is completed. The primary clustering process is shown in Figure3.Step 3: judge whether the categories of sample points before and after clustering are the same. If they are the same, the algorithm will terminate; otherwise, go to Step 4.Step 4: for the sample points in each category, calculate the central points of these sample points as the new central points of the class, and continue with Step 2. Center point judgment is shown in Figure4.Step 5: obtainK clusters until the clustering result does not change. The clustering results are shown in Figure 5.Figure 2
Selection of cluster center.Figure 3
Primary clustering process.Figure 4
Center point judgment.Figure 5
Clustering results.The smaller the distance between K-means algorithm data is, the more similar sampleA is to sample B, and the smaller the difference degree is. The larger the distance is, the less similar samples A and B are, and the greater the degree of difference is. According to the length of the distance, we cluster the sample points into the specified category number K, which lays the data foundation for the next intelligent push [17]. The common Euclidean distance formula is(12)dxi,yi=∑k=1dxik−xjk2.


### 2.3. Resource Sharing Based on Wireless Broadband Connection

With the continuous promotion of Wireless Fidelity (WiFi), the network coverage and Internet access speed continue to improve, and more and more users favor this kind of access without charge and unlimited traffic. According to the relevant statistical report, with the rapid popularization of various portable devices, the use of mobile Internet devices further grows. These smart mobile terminals are equipped with powerful network access technologies, such as Bluetooth and WiFi, to facilitate independent networking among devices. Users can share resources through physical contact with these devices [18].In the virtual learning community, the user relationship graph is formed by the friends between users. After community division, there will be many subcommunities. The similarity between two users in the subcommunity is calculated, and the learning resources are recommended to the friends of the users according to the similarity from high to low. Although learners in a virtual learning community form a social circle, there are intimate relationships among people in the social circle. If two people have different numbers of mutual friends, the likelihood of them becoming friends is different even if they are in the same social circle. Therefore, the affinity relationship between learners can be obtained through similarity, and recommendations can be generated. Learners in the mobile learning community can connect with each other in the wired virtual community and communicate offline through mobile devices with a wireless broadband connection. Some social networking software, for example, has the ability to find people nearby. In this way, they have a high probability of becoming friends and thus can share mobile education resources in a wider range.In this paper, the contact strength between nodes is used to describe the similarity between nodes. LetCu,v represent the contact strength between node u and nodev, which includes the following three parts.


#### 2.3.1. Update Components

The formula for updating components is as follows:(13)Cu,v=Cu,vold+1−Cu,vold×Ci,where Cu,vold represents the contact strength between node u and node v at the last contact and Ci is an initial value, generally 0.75.


#### 2.3.2. Decay Component

The formula for the decay component is as follows:(14)Cu,v=Cu,vold×αt.In the formula,t represents the interval between two contacts and α represents the declining index.


#### 2.3.3. Transfer Components

The specific formula for the delivery component is as follows:(15)Cu,v=Cu,wold+1−Cu,wold×Cu,v×Cu,w×β.In the formula,β represents the dependency between nodes, generally 0.25.Network centrality is a basic concept used to distinguish the status of community members in the network. It can be studied from two aspects: one is the individual centrality; the second is the central potential. The degree of personal centrality refers to the degree of the relationship between an individual and its members in the community. The higher the degree of personal centrality, the closer the relationship with other members of the community. If a member is directly related to the majority of other members, the actor is central and thus has greater power. This shows that it is an important node in the process of community information transmission and plays a core and bridge role in interpersonal relationships, resource possession, knowledge dissemination, and sharing. On the contrary, if a member is at the edge of the network, he may obtain a lot of information, but he cannot play an important role in information transmission, and his position is not conducive to his contribution to the construction of the group knowledge. The central potential is a quantification of the local group's position in the community, indicating the overall integration or consistency of the graph.The PageRank algorithm is used to calculate the centrality of the node. Assume thatPu represents the centrality of nodeu; then, Pu can be expressed as(16)Pu=1−dn+d∑v=1NuPvNv.In the formula,d represents the decay factor and Nu represents the number of neighbors of node u.The entire algorithm steps are as follows: Algorithm1Algorithm 1: The PageRank algorithm.
Step 1: assumptionNu≥0;Step 2:Pu=0;Step 3: when nodeu encounters node v;Step 4: ifv is u‘s neighbor;Step 5: sendNv,Pv;Step 6: receiveNv,Pv;Step 7: update (P (u));Step 8: end ifStep 9: end whileNetwork density indicates the degree of interaction among members of the community. High density means more connections among members, while low density means less connections among members. The possible value of the network density is between 0 and 1. If there is a direct relationship between each pair of members in the network community, the maximum value of the network density is 1, but in most cases, the network density value cannot reach 1. The network density is the ratio of the actual number of connections to the possible number of connections. The calculation formula for the density of the directed graph is(17)D=nNN−1,where n is the actual number of connections and N is the number of actors. Density D shows how interconnected the nodes are and can be used to measure the speed of information exchange.According to the degree of network center and network density of mobile education resource scheduling, hypothesisxjt said mobile education resources data in t times of the j-th distribution location of network nodes, and ljt said t times of the j-th mutual information of network node characteristics, combined with wireless broadband connection method. The adaptive scheduling formula of mobile education resource sharing is as follows:(18)xit=xit−1+sPuxjt−1−xit−1Dxjt−1−xit−1.The resource sharing mode based on wireless broadband connection is shown in Figure6.Figure 6
Resource sharing mode based on a wireless broadband connection.The user first submits the request to the central scheduling node, and the central scheduling node queries the metadata database and redirects the request to the corresponding service site. Finally, the redirected service site provides services for user resource sharing.


## 2.1. Data Capture of Mobile Education Resources

Unlike web crawlers, focused crawlers have a more complex workflow, which needs to filter the links unrelated to the topic according to a certain web page analysis algorithm, retain the useful links, and put them into the URL queue waiting to be captured. Then, it will select the web page URL to be captured in the next step from the queue according to a certain search strategy and repeat the above process until it stops when a certain condition of the system is reached. The workflow of the focusing crawler is shown in Figure1.Figure 1
Workflow of focused crawler.Compared with general crawlers, the search content of focused crawlers is limited to specific topics or specialized fields, so the width-first or depth-first algorithms widely used by general web crawlers are no longer applicable. At present, focused web crawlers usually adopt a heuristic search strategy, which selects the “most valuable” link with priority access each time. However, such a strategy is prone to fall into local optimization too early and lack of global features, resulting in a low overall return rate of focused crawlers. Ant colony algorithm is introduced into the URL selection strategy of focused crawlers in order to improve the accuracy of the crawler system to capture mobile educational resource data [7].The core problem of the focusing crawler system is how to effectively optimize the priority order for URL queue so that the corresponding page of the URL that is crawled priority has high topic relevance. A good focused crawler system must accurately predict the value of URLs and pay attention to both short-term and long-term returns. Therefore, the calculation of URL values and the selection of crawling strategy are particularly important, which determines the search efficiency and quality of the focused crawler [8].This section proposes a search strategy ACO-FC that uses an ANT colony algorithm to guide the focusing crawler on the basis of the ant colony algorithm. Its basic idea is as follows. There are hypertext pageswi and wj on the web page. If there is a link in wi that points to wj, then the ant in wi will decide whether to move from wi to wj according to certain conditions. Each sequence of links represents a possible ant route. Information is transmitted between individual ants through pheromones as they move. Pheromones evaporate over time as an ant crawls. The crawling of ants between pages is divided into several cycles. In each cycle, an ant makes a series of moves between web pages until it finds the target resource and returns to the source point. Every time a crawling cycle is completed, the ant colony updates the amount of pheromone on each route [9].To be sure, we will choose a pheromone in ant colony foraging process high routes, thus forming an information positive feedback phenomenon. This positive feedback has also side effects. However, when too many ants have chosen the same route, the route of the pheromone amount will increase rapidly, so as to make the ant more focused on a particular route, caused by a blockage and stagnation phenomenon. When using the ant colony algorithm to solve problems, it is easy to lead to precocious and local convergence. In order to solve the problem of “precocity” and “local convergence” of the ant colony algorithm, dynamic adaptive adjustment pheromone is utilized [10].Assuming thatV represents the entire set of pages and E represents the set of paths made up of links, web pages (links) constitute a directed figure G=V,E. Because the ant must consider its topic relevance when selecting the next web page, we can refer to the Page Rank algorithm formula for the topic relevance value of the page Pk in the directed figure G. For the convenience of expression, this paper intends to define it as follows.RPk is the topic relevance value of the page, and its calculation formula is(1)RPk=1−d+d∑i=1kRTiCi.Among them,d refers to the regulating factor, which is generally valued at 0.8, Ti refers to the set of pages linked to Pk, Ci refers to the link to the degree of Ti, and k is the number of links from 1 to other pages.dij represents the distance between page wi and page wj, which can be calculated by the following formula:(2)dij=C∑i=1kRPi.Among them,C is a coordination factor constant, and Pi refers to the collection of pages passed from i toj.Δτij represents the number of pheromones left on path ei,j in this cycle. Δτijk represents the amount of pheromone left by the k-th ant on path ei,j in this cycle:(3)Δτijk=QLk,if the kth ant passes ij in this cycle,0,other,where Q is a constant and Lk represents the length of the path traveled by the k-th ant in this cycle, which can be expressed as(4)Lk=∑i=1n∑j=1ndij,where n represents the number of web nodes n≤N that ant k travels in this cycle.Suppose that the number of nodes on the web page isn and the number of ants is m, then bit represents the number of ants on page wj at timet, and the number is m=∑i=1nbit. At the initial time, the amount of pheromones in each path is equal. Set τij0=c, c as a constant, usually 0. In the movement process, ant ki=1,2,…,m determines the next path according to the pheromone intensity on each path. The probability Pijkt of ant k moving from position i to j at time t is expressed as follows:(5)Pijkt=τijtα⋅ηijtβ∑li,j∈Eτltα⋅ηltβ,j∈V,0,other.In the formula,ηij represents the expected degree of moving from position i to j, α represents the role of the pheromone accumulated by the ant in its path selection, and β is a parameter representing the importance of pheromone or the importance of heuristic information. li,j∈E indicate that a link from wi to wj exists on a given page Pi. In order to avoid loop crawling with the ant colony and restrain ants to explore page increment, each ant stores a tabu table tabu to record the links visited. If wj belongs totabu, the path probability value Pijkt from wi to wj is 0, thus prohibiting ant k from exploring this link. At the end of each cycle, the table tabu is cleared.Pheromone intensityτij imbalance over time will fade. Set the pheromone retention coefficient to ρ0<ρ<1, which reflects the persistence of pheromone intensity. And 1−ρ is the degree of pheromone loss. When the limited number of moves per cycle is reached, the pheromone quantity of each path should be updated according to the following formula:(6)τijt+1=ρτijt+Δτij,Δτij=∑k=1mΔτijk.However, in order to avoid the “precocity” and “local convergence” problems of the ant colony algorithm, this paper adopts the following formula to adjust the pheromone quantity of each path according to the paper.Whenτ>τmax, the following relationship exists:(7)τijt+1=ρ1+φn⋅τijt+Δτij.Whenτ<τmax, the following relationship exists:(8)τijt+1=ρ1−φn⋅τijt+Δτij.In the formula,φn is a function proportional to the number of convergence n; the more the number of convergence n is, the greater the value of φn is:(9)φn=nc.Here,c is a constant. In this way, the pheromone quantity is updated adaptively according to the distribution of solutions, so as to adjust the intensity of pheromone quantity of each path dynamically, so that ants are neither too concentrated nor too dispersed, thus avoiding precocious and local convergence and improving the global search energy. At the end of a cycle, the optimal path is output, and the optimized crawler is used to grab the data of mobile education resources.


## 2.2. Data Clustering of Mobile Education Resources

Clustering has been widely used in the clustering research of mobile educational resource data, and the commonly used method is to determine the clustering of educational resources according to the judgment method of similarity [11]. This method can narrow the range of clustering and improve the accuracy of clustering.The traditional educational resource clustering process mainly involves the extraction of semantic features, and the commonly used methods are VSM. Here, VSM is also used for feature extraction in this paper [12]. VSM maps the text content of the resource to a feature vector Vd=t1,w1d;t2,w2d;…;tn,wnd, where tii=1,2,…,n is different entries and wid is the weight of d. The most commonly used weight calculation method is TF-IDF. Table 1 intuitively shows the mapping relationship between text, feature words, and weight in VSM.Table 1
Mapping table between text and VSM.
The text point of viewVSM perspectiveTextPoint in spaceKeywordsA dimension in spaceText setsA set of points in spaceWeight of feature wordsThe value of a point in space in some dimensionIn this paper, TF-IDF weight is used to measure the feature frequency of feature items appearing in the document. Tf-IDF, proposed by Salton in 1988, is a feature weight calculation method, which has been widely used in the field of data mining and achieved good results. The formula for TF-IDF is as follows:(10)TF−IDFt=TFt,Di×logNDFt+0.01.Among them,TF (Term Frequency) refers to the word Frequency, indicating the occurrence frequency of entry t into text Di. N represents the total number of documents, and DF represents the number of documents containing feature word t, that is, the document frequency of feature word t. The second part on the right of the formula represents the inverse document frequency of the feature word IDF.Considering the length of the text, the weight of the feature terms is normalized, and the formula is as follows:(11)TF−IDFt=TFt,Di×logN/DFt+0.01∑i=1mTFt,Di×logN/DFt+0.012.At the current stage, the K-means algorithm [13] is a clustering algorithm that uses mean clustering data points. There are now many evolved versions of the K-means algorithm, such as K-means ++ [14], and we will use the original K-means algorithm here because it has many advantages; for example, the algorithm guarantees better scalability when dealing with large data sets and the algorithm is of low complexity, where K represents the number of categories and means represents the mean [15]. Similar data points are then divided by default category and selection of the initialized center of mass. The advantage of the K-means algorithm lies in its simplicity and fast speed. It only needs to calculate the distance between the point and the center of the group. Suppose that a resource is a sample point to be clustered, and the goal is to cluster the sample points into multiple categories. For each point, we calculate the nearest central point among all the central points, and this point can be defined as its same cluster. After an iteration, we recalculate the center point of each clan and then find the center point closest to itself for each point. In this way, the loop continues until the two iterations of the cluster class no longer change [16]. The algorithm process is as follows:Step 1: selectk categories to be clustered (for example, k=3 categories), and select k center points. The selection of the cluster center is shown in Figure 2.Step 2: look for the sample points closest to the central point and classify them. All the points closest to the same central point represent a class. In this way, clustering is completed. The primary clustering process is shown in Figure3.Step 3: judge whether the categories of sample points before and after clustering are the same. If they are the same, the algorithm will terminate; otherwise, go to Step 4.Step 4: for the sample points in each category, calculate the central points of these sample points as the new central points of the class, and continue with Step 2. Center point judgment is shown in Figure4.Step 5: obtainK clusters until the clustering result does not change. The clustering results are shown in Figure 5.Figure 2
Selection of cluster center.Figure 3
Primary clustering process.Figure 4
Center point judgment.Figure 5
Clustering results.The smaller the distance between K-means algorithm data is, the more similar sampleA is to sample B, and the smaller the difference degree is. The larger the distance is, the less similar samples A and B are, and the greater the degree of difference is. According to the length of the distance, we cluster the sample points into the specified category number K, which lays the data foundation for the next intelligent push [17]. The common Euclidean distance formula is(12)dxi,yi=∑k=1dxik−xjk2.


## 2.3. Resource Sharing Based on Wireless Broadband Connection

With the continuous promotion of Wireless Fidelity (WiFi), the network coverage and Internet access speed continue to improve, and more and more users favor this kind of access without charge and unlimited traffic. According to the relevant statistical report, with the rapid popularization of various portable devices, the use of mobile Internet devices further grows. These smart mobile terminals are equipped with powerful network access technologies, such as Bluetooth and WiFi, to facilitate independent networking among devices. Users can share resources through physical contact with these devices [18].In the virtual learning community, the user relationship graph is formed by the friends between users. After community division, there will be many subcommunities. The similarity between two users in the subcommunity is calculated, and the learning resources are recommended to the friends of the users according to the similarity from high to low. Although learners in a virtual learning community form a social circle, there are intimate relationships among people in the social circle. If two people have different numbers of mutual friends, the likelihood of them becoming friends is different even if they are in the same social circle. Therefore, the affinity relationship between learners can be obtained through similarity, and recommendations can be generated. Learners in the mobile learning community can connect with each other in the wired virtual community and communicate offline through mobile devices with a wireless broadband connection. Some social networking software, for example, has the ability to find people nearby. In this way, they have a high probability of becoming friends and thus can share mobile education resources in a wider range.In this paper, the contact strength between nodes is used to describe the similarity between nodes. LetCu,v represent the contact strength between node u and nodev, which includes the following three parts.


### 2.3.1. Update Components

The formula for updating components is as follows:(13)Cu,v=Cu,vold+1−Cu,vold×Ci,where Cu,vold represents the contact strength between node u and node v at the last contact and Ci is an initial value, generally 0.75.


### 2.3.2. Decay Component

The formula for the decay component is as follows:(14)Cu,v=Cu,vold×αt.In the formula,t represents the interval between two contacts and α represents the declining index.


### 2.3.3. Transfer Components

The specific formula for the delivery component is as follows:(15)Cu,v=Cu,wold+1−Cu,wold×Cu,v×Cu,w×β.In the formula,β represents the dependency between nodes, generally 0.25.Network centrality is a basic concept used to distinguish the status of community members in the network. It can be studied from two aspects: one is the individual centrality; the second is the central potential. The degree of personal centrality refers to the degree of the relationship between an individual and its members in the community. The higher the degree of personal centrality, the closer the relationship with other members of the community. If a member is directly related to the majority of other members, the actor is central and thus has greater power. This shows that it is an important node in the process of community information transmission and plays a core and bridge role in interpersonal relationships, resource possession, knowledge dissemination, and sharing. On the contrary, if a member is at the edge of the network, he may obtain a lot of information, but he cannot play an important role in information transmission, and his position is not conducive to his contribution to the construction of the group knowledge. The central potential is a quantification of the local group's position in the community, indicating the overall integration or consistency of the graph.The PageRank algorithm is used to calculate the centrality of the node. Assume thatPu represents the centrality of nodeu; then, Pu can be expressed as(16)Pu=1−dn+d∑v=1NuPvNv.In the formula,d represents the decay factor and Nu represents the number of neighbors of node u.The entire algorithm steps are as follows: Algorithm1Algorithm 1: The PageRank algorithm.
Step 1: assumptionNu≥0;Step 2:Pu=0;Step 3: when nodeu encounters node v;Step 4: ifv is u‘s neighbor;Step 5: sendNv,Pv;Step 6: receiveNv,Pv;Step 7: update (P (u));Step 8: end ifStep 9: end whileNetwork density indicates the degree of interaction among members of the community. High density means more connections among members, while low density means less connections among members. The possible value of the network density is between 0 and 1. If there is a direct relationship between each pair of members in the network community, the maximum value of the network density is 1, but in most cases, the network density value cannot reach 1. The network density is the ratio of the actual number of connections to the possible number of connections. The calculation formula for the density of the directed graph is(17)D=nNN−1,where n is the actual number of connections and N is the number of actors. Density D shows how interconnected the nodes are and can be used to measure the speed of information exchange.According to the degree of network center and network density of mobile education resource scheduling, hypothesisxjt said mobile education resources data in t times of the j-th distribution location of network nodes, and ljt said t times of the j-th mutual information of network node characteristics, combined with wireless broadband connection method. The adaptive scheduling formula of mobile education resource sharing is as follows:(18)xit=xit−1+sPuxjt−1−xit−1Dxjt−1−xit−1.The resource sharing mode based on wireless broadband connection is shown in Figure6.Figure 6
Resource sharing mode based on a wireless broadband connection.The user first submits the request to the central scheduling node, and the central scheduling node queries the metadata database and redirects the request to the corresponding service site. Finally, the redirected service site provides services for user resource sharing.


## 2.3.1. Update Components

The formula for updating components is as follows:(13)Cu,v=Cu,vold+1−Cu,vold×Ci,where Cu,vold represents the contact strength between node u and node v at the last contact and Ci is an initial value, generally 0.75.


## 2.3.2. Decay Component

The formula for the decay component is as follows:(14)Cu,v=Cu,vold×αt.In the formula,t represents the interval between two contacts and α represents the declining index.


## 2.3.3. Transfer Components

The specific formula for the delivery component is as follows:(15)Cu,v=Cu,wold+1−Cu,wold×Cu,v×Cu,w×β.In the formula,β represents the dependency between nodes, generally 0.25.Network centrality is a basic concept used to distinguish the status of community members in the network. It can be studied from two aspects: one is the individual centrality; the second is the central potential. The degree of personal centrality refers to the degree of the relationship between an individual and its members in the community. The higher the degree of personal centrality, the closer the relationship with other members of the community. If a member is directly related to the majority of other members, the actor is central and thus has greater power. This shows that it is an important node in the process of community information transmission and plays a core and bridge role in interpersonal relationships, resource possession, knowledge dissemination, and sharing. On the contrary, if a member is at the edge of the network, he may obtain a lot of information, but he cannot play an important role in information transmission, and his position is not conducive to his contribution to the construction of the group knowledge. The central potential is a quantification of the local group's position in the community, indicating the overall integration or consistency of the graph.The PageRank algorithm is used to calculate the centrality of the node. Assume thatPu represents the centrality of nodeu; then, Pu can be expressed as(16)Pu=1−dn+d∑v=1NuPvNv.In the formula,d represents the decay factor and Nu represents the number of neighbors of node u.The entire algorithm steps are as follows: Algorithm1Algorithm 1: The PageRank algorithm.
Step 1: assumptionNu≥0;Step 2:Pu=0;Step 3: when nodeu encounters node v;Step 4: ifv is u‘s neighbor;Step 5: sendNv,Pv;Step 6: receiveNv,Pv;Step 7: update (P (u));Step 8: end ifStep 9: end whileNetwork density indicates the degree of interaction among members of the community. High density means more connections among members, while low density means less connections among members. The possible value of the network density is between 0 and 1. If there is a direct relationship between each pair of members in the network community, the maximum value of the network density is 1, but in most cases, the network density value cannot reach 1. The network density is the ratio of the actual number of connections to the possible number of connections. The calculation formula for the density of the directed graph is(17)D=nNN−1,where n is the actual number of connections and N is the number of actors. Density D shows how interconnected the nodes are and can be used to measure the speed of information exchange.According to the degree of network center and network density of mobile education resource scheduling, hypothesisxjt said mobile education resources data in t times of the j-th distribution location of network nodes, and ljt said t times of the j-th mutual information of network node characteristics, combined with wireless broadband connection method. The adaptive scheduling formula of mobile education resource sharing is as follows:(18)xit=xit−1+sPuxjt−1−xit−1Dxjt−1−xit−1.The resource sharing mode based on wireless broadband connection is shown in Figure6.Figure 6
Resource sharing mode based on a wireless broadband connection.The user first submits the request to the central scheduling node, and the central scheduling node queries the metadata database and redirects the request to the corresponding service site. Finally, the redirected service site provides services for user resource sharing.


## 3. Experimental Design

In order to verify the effectiveness of the mobile education resource sharing method based on a wireless broadband connection designed in this paper, experimental design is needed. In order to ensure the scientific and credibility of the experimental results, it is necessary to ensure that the experiment is carried out in the same environment.We used an open-source dataset provided by the Korean Academy of Sciences [19]. The dataset collected the trajectories of 34 students over a period of almost two years, generating 92 files, each containing a few hundred to several thousand individual system logs. The dataset contains information about the location of each student at different times. The format is as follows: time of the stop, position (x, y). Here, x and y are the coordinates.The real platform built in this paper consists of three roles: client, controller, and compute node. The client can be built by any physical host in the LAN segment of the laboratory. The controller consists of Nova and Glance. They can be deployed on one physical host or on different physical hosts. Due to the limited laboratory environment, the first deployment method is adopted. Compute nodes consist of three physical hosts that run virtual instances and provide computing services. The experimental hardware environment is shown in Table2.Table 2
Experimental hardware environment.
EquipmentTypeCPUMemory (GB)Network bandwidth (Mbps)The controllerDELL optiplex330Intel (R) Core (TM) 2 CPU6420@ 2.13 GHz3100Compute node 1HPL1908wIntel Core2 Duo 2.53 GHz2100Compute node 2HPL1908wIntel Core2 Duo 2.53 GHz2100Compute node 3HPL1908wIntel Core2 Duo 2.53 GHz2100The clientHPL1908wIntel Core2 Duo 2.53 GHz2100The experimental software environment is as follows:(1)
The operating system of the controller node is Ubuntu 12.04.1 server, and the kernel version is Linux version 3.2.0–35-generic-pae(2)
The Open Stack project, a Folsom version, was released in February 2012. The Open Stack component must be installed on the controller and compute nodes(3)
Deployment of application services: the Java EE container used for mobile education resource sharing is apache-tomcat-6.0.32, the database is Oracle11g, and other configurations include JDK 1.6, Python 2.7.3, My SQL 5.0, etc.The specific experimental environment is shown in Figure7.Figure 7
Experimental environment.Based on the above hardware equipment conditions, we added a network stress test, we set different numbers of people networked, and the number of people is 10, 50, 100, and 500, using the “Kolai network analysis system” real-time monitoring network. We use the “Kolai network analysis system” to monitor the network transmission data in real time, providing a comprehensive overview of the dynamic information of the entire network. In addition to real-time detection of each computer’s Internet access, resource sharing, and network traffic, it also detects the packet decoding analysis function, diagnoses network errors, and detects security hazards. We found that, with the same network bandwidth, the transmission rate decreases as the number of people increases. In practice, we are not able to reach the maximum number of people for the stress test, so our method is perfectly suited to practical applications.The resource sharing method based on a blockchain, the resource sharing method based on a cloud platform, and the resource sharing method based on a wireless broadband connection are taken as the experimental comparison method, and the application effect of different methods is verified by comparing the recall rate, precision rate, and information sharing time of the information sharing results of different methods.


### 3.1. Recall Ratio Comparison of Different Methods

According to the above experimental design, the recall rates of resource sharing method based on blockchain, resource sharing method based on a cloud platform, and resource sharing method based on a wireless broadband connection are compared, and the comparison results are shown in Figure8.Figure 8
Recall ratio comparison.From the analysis of the data in Figure8, it can be seen that the recall rate of the resource sharing method based on blockchain varies between 73% and 93%, and that of the resource sharing method based on cloud platform varies between 72% and 89%, while the recall rate of the resource sharing method based on wireless broadband connection always stays above 95%, indicating that the recall rate of the sharing result of this method is higher. The practical application results are better.


### 3.2. Precision Ratio Comparison of Different Methods

Then, the precision ratio of resource sharing methods based on blockchain, cloud platform, and the wireless broadband connection is compared, and the comparison results are shown in Figure9.Figure 9
Comparison of precision ratio.From the analysis of the data in Figure9, it can be seen that the precision rate of the resource sharing method based on blockchain varies between 73% and 87%, and that of the resource sharing method based on cloud platform varies between 70% and 92%, while the precision rate of the resource sharing method based on wireless broadband connection always stays above 96%, indicating that the recall rate of the sharing result of this method is higher. The practical application results are better.


### 3.3. Comparison of Resource Sharing Time between Different Methods

Resource sharing time is an important index to test the efficiency of different methods. Therefore, the resource sharing time of resource sharing methods based on blockchain, cloud platform, and the wireless broadband connection is compared. The comparison results are shown in Table3.Table 3
Resource sharing time (unit: s).
Number of experimentsResource sharing method based on blockchainResource sharing method based on a cloud platformResource sharing method based on a wireless broadband connection101.521.870.58201.843.650.69301.362.470.74401.472.580.52501.852.690.75601.884.170.68701.741.540.57801.961.630.48902.141.470.661002.331.250.59Average1.812.330.63According to the analysis in Table3, the average resource sharing time of the blockchain-based resource sharing method is 1.81 s, the average resource sharing time of the cloud platform based resource sharing method is 2.33 s, and the average resource sharing time of the wireless broadband connection based resource sharing method is 0.63 s. Compared with the experimental comparison method, in this paper, the sharing time of mobile education resources is shorter and the efficiency is higher.


## 3.1. Recall Ratio Comparison of Different Methods

According to the above experimental design, the recall rates of resource sharing method based on blockchain, resource sharing method based on a cloud platform, and resource sharing method based on a wireless broadband connection are compared, and the comparison results are shown in Figure8.Figure 8
Recall ratio comparison.From the analysis of the data in Figure8, it can be seen that the recall rate of the resource sharing method based on blockchain varies between 73% and 93%, and that of the resource sharing method based on cloud platform varies between 72% and 89%, while the recall rate of the resource sharing method based on wireless broadband connection always stays above 95%, indicating that the recall rate of the sharing result of this method is higher. The practical application results are better.


## 3.2. Precision Ratio Comparison of Different Methods

Then, the precision ratio of resource sharing methods based on blockchain, cloud platform, and the wireless broadband connection is compared, and the comparison results are shown in Figure9.Figure 9
Comparison of precision ratio.From the analysis of the data in Figure9, it can be seen that the precision rate of the resource sharing method based on blockchain varies between 73% and 87%, and that of the resource sharing method based on cloud platform varies between 70% and 92%, while the precision rate of the resource sharing method based on wireless broadband connection always stays above 96%, indicating that the recall rate of the sharing result of this method is higher. The practical application results are better.


## 3.3. Comparison of Resource Sharing Time between Different Methods

Resource sharing time is an important index to test the efficiency of different methods. Therefore, the resource sharing time of resource sharing methods based on blockchain, cloud platform, and the wireless broadband connection is compared. The comparison results are shown in Table3.Table 3
Resource sharing time (unit: s).
Number of experimentsResource sharing method based on blockchainResource sharing method based on a cloud platformResource sharing method based on a wireless broadband connection101.521.870.58201.843.650.69301.362.470.74401.472.580.52501.852.690.75601.884.170.68701.741.540.57801.961.630.48902.141.470.661002.331.250.59Average1.812.330.63According to the analysis in Table3, the average resource sharing time of the blockchain-based resource sharing method is 1.81 s, the average resource sharing time of the cloud platform based resource sharing method is 2.33 s, and the average resource sharing time of the wireless broadband connection based resource sharing method is 0.63 s. Compared with the experimental comparison method, in this paper, the sharing time of mobile education resources is shorter and the efficiency is higher.


## 4. Conclusion

The rapid development of information technology is having a profound and long-term impact on all areas of human life, including education. The rapid development of mobile education has promoted the informationization of education and played an important role in promoting the popularization of higher education, building the national education system and learning-oriented social services, and building the lifelong education system. The construction of learning resources is the core and foundation of distance education activities. It is an urgent task to care about the construction of learning resources and strengthen the management of learning resources. Although the number of mobile learning resources is growing rapidly, the quality is uneven, the phenomenon of repeated construction is serious, and the resources lack effective organization and management. Learning resources are highly dispersed and disordered, which reduces the utilization rate of resources and affects the effective sharing of resources, which has become the main challenge faced by the information construction of learning resources. Therefore, this paper proposes a mobile education resource sharing method based on a wireless broadband connection. Experimental results show that the method has higher recall and precision, shorter resource sharing time, and better practical application effect.The mobile education resource sharing method based on wireless broadband connection proposed in this paper is well researched in terms of devices and transmission rates, but it is lacking in terms of education resource integration and education resource data classification and sharing. Later work will focus on the unification of data resources and the mining of data features to improve sharing efficiency and experience.



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*Source: 6008149-2021-10-22.xml*