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Intellicise communication system: model-driven semantic communications
Zhang Ping, Xu Xiaodong, Dong Chen, Han Shujun, Wang Bizhu
The Journal of China Universities of Posts and Telecommunications    2022, 29 (1): 2-12.   DOI: 10.19682/j.cnki.1005-8885.2022.2002
Abstract1742)            Save
As one of the critical technologies for the 6th generation mobile communication system (6G) mobile communication systems, artificial intelligence (AI) technology will provide complete automation for connecting the virtual and physical worlds. In order to construct the future ubiquitous intelligent network, people are beginning to rethink how mobile communication systems transmit and exploit intelligent information. This paper proposes a new communication paradigm, called the Intellicise communication system: model-driven semantic communication. Intellicise communication system is built on top of the traditional communication system and innovatively adds a new feature dimension on top of the traditional source coding, which enables the communication system to evolve from the traditional transmission of bit to the transmission of  model . Like the semantic base (Seb) for semantic communication, the model is considered as the new feature obtained from the joint source-channel coding. The sink node can re-construct the original signal based on the received model and the encoded sequence. In addition, the performance evaluation metrics and the implementation details of the Intellicise communication system are discussed in this paper. Finally, preliminary results of model-driven image transmission in the Intellicise communication system are presented.
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User association and resource allocation in green mobile edge networks using deep reinforcement learning
The Journal of China Universities of Posts and Telecommunications    2021, 28 (3): 1-10.   DOI: 10.19682/j.cnki.1005-8885.2021.0016
Abstract970)      PDF(pc) (1989KB)(132)       Save

In order to meet the emerging requirements for high computational complexity, low delay and energy consumption of the 5th generation wireless systems (5G) network, ultra-dense networks (UDNs) combined with multi-access edge computing ( MEC) can further improve network capacity and computing capability. In addition, the integration of green energy can effectively reduce the on-grid energy consumption of system and realize green computation. This paper studies the joint optimization of user association (UA) and resource allocation (RA) in MEC enabled UDNs under the green energy supply pattern, users need to perceive the green energy status of base stations (BSs) and choose the one with abundant resources to associate. To minimize the computation cost for all users, the optimization problem is formulated as a mixed integer nonlinear programming (MINLP) which is NP-hard. In order to solve the problem, a deep reinforcement learning ( DRL)-based association and optimized allocation (DAOA) scheme is designed to solve it in two stages. The simulation results show that the proposed scheme has good performance in terms of  computationcost and time out ratio, as well achieve load balancing potentially.

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Native intelligence for 6G mobile network: technical challenges, architecture and key features
Liu Guangyi, Deng Juan, Zheng Qingbi, Li Gang, Sun Xin, Huang Yuhong
The Journal of China Universities of Posts and Telecommunications    2022, 29 (1): 27-40.   DOI: 10.19682/j.cnki.1005-8885.2022.2004
Abstract803)            Save
The application of the artificial intelligence (AI) technology in the 5th generation mobile communication system (5G) networks promotes the development of the mobile communication network and its application in vertical industries, however, the application models of "patching" and "plug-in" have hindered the effect of AI applications. Meanwhile, the application of AI in all walks of life puts forward requirements for new capabilities of the future network, such as distributed training, real-time collaborative inference, local data processing, etc. , which require "native intelligence design” in future networks. This paper discusses the requirements of native intelligence in the 6th generation mobile communication system (6G) networks from the perspectives of 5G intelligent network challenges and the  ubiquitous intelligence  vision of 6G, and analyzes the technical challenges of the AI workflows in its lifecycle and the AI as a service (AIaaS) in cloud network. The progress and deficiencies of the current research on AI functional architecture in various industry organizations are summarized. The end-to-end functional architecture for native AI for 6G network and its three key technical characteristics are proposed: quality of AI services (QoAIS) based AI service orchestration for its full lifecycle, deep integration of native AI computing and communication, and integration of native AI and digital twin network. The directions of future research are also prospected.
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Behavioral finance between the spot and futures markets based on multilayer network
Zhang Sicong, Dai Jianzhuo, Huang Wenjing, Mi Xinping
The Journal of China Universities of Posts and Telecommunications    2023, 30 (6): 82-88.   DOI: 10.19682/j.cnki.1005-8885.2023.1013
Abstract798)      PDF(pc) (3117KB)(52)       Save
In order to study the financial behavior of investors in the spot market, the transmission process of futures prices to spot prices is analyzed. Firstly, a coarse-graining method is proposed to construct a dual-layer coupled complex network of spot price and futures price. Then, to characterize the financial behavior of investors in the spot market, a price coupling strength indicator is introduced to capture investors' overreaction and underreaction behavior. The simulation results show that, despite the focus of researchers on arbitrage opportunities between futures and spot markets, investors in the spot market will not overreact or delay when the acceptance level of price fluctuations remains unchanged. On the contrary, when the stable coefficient of the price difference between the futures and spot markets remains unchanged, investors undergo a nonlinear process of overreaction followed by underreaction as their acceptance level of price fluctuations increases.
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Shared experiences across multiple devices: a new digital interactive experience method for cultural heritage based on mixed reality
Lu Zhichao, Zhao Haiying
The Journal of China Universities of Posts and Telecommunications    2022, 29 (2): 1-12.   DOI: 10. 19682/ j. cnki. 1005-8885. 2022. 0011
Abstract694)      PDF       Save

In order to study the role of the new technological concept of shared experiences in the digital interactive experience of cultural heritage and apply it to the digital interactive experience of cultural heritage to solve the current problems in this field, starting from the mixed reality (MR) technology that the shared experiences rely on, proper software and hardware platforms were investigated and selected, a universal shared experiences solution was designed, and an experimental project based on the proposed solution was made to verify its feasibility. In the end, a proven and workable shared experiences solution was obtained. This solution included a proposed MR spatial alignment method, and it integrated the existing MR content production process and standard network synchronization functions. Furthermore, it is concluded that the introduction and reasonable use of new technologies can help the development of the digital interactive experience of cultural heritage. The shared experiences solution for the digital interactive experience of cultural heritage balances investment issues in the exhibition, display effect, and user experience. It can speed up the promotion of cultural heritage and bring the vitality of MR technology to relevant projects.

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Research on cross-chain and interoperability for blockchain system

李鸣 邱鸿霖 徐泉清 宋文鹏 Liu Baixiang
The Journal of China Universities of Posts and Telecommunications    2021, 28 (5): 1-17.   DOI: 10.19682/j.cnki.1005-8885.2021.0029
Abstract687)      PDF(pc) (3984KB)(269)       Save

At present, there is an urgent need for blockchain interoperability technology to realize interconnection between various blockchains, data communication and value transfer between blockchains, so as to break the ‘ value silo’ phenomenon of each blockchain. Firstly, it lists what people understand about the concept of interoperability. Secondly, it gives the key technical issues of cross-chain, including cross-chain mechanism, interoperability, eventual consistency, and universality. Then, the implementation of each cross-chain key technology is analyzed, including Hash-locking, two-way peg, notary schemes, relay chain scheme, cross-chain protocol, and global identity system. Immediately after that, five typical cross-chain systems are introduced and comparative analysis is made. In addition, two examples of cross-chain programmability and their analysis are given. Finally, the current state of cross-chain technology is summarized from two aspects: key technology implementation and cross-chain application enforcement. The cross-chain technology as a whole has formed a centralized fixed mechanism, as well as a trend of modular design, and some of the solutions to mature applications were established in the relevant standards organizations, and the cross-chain technology architecture tends to be unified, which is expected to accelerate the evolution of the open cross-chain network that supports the real needs of the interconnection of all chains.



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Modulation classification based on the collaboration of dual-channel CNN-LSTM and residual network
Li Hui, Li Shanshan, Zou Borong, Chen Yannan
The Journal of China Universities of Posts and Telecommunications    2022, 29 (1): 113-124.   DOI: 10.19682/j.cnki.1005-8885.2022.2012
Abstract652)            Save
Deep learning has recently been progressively introduced into the field of modulation classification due to its wide application in image, vision, and other areas. Modulation classification is not only the priority of cognitive radio and spectrum sensing, but also the link during signal demodulation. Combining the advantages of convolutional neural network (CNN), long short-term memory (LSTM), and residual network (ResNet), a modulation classification method based on dual-channel CNN-LSTM and ResNet is proposed to automatically classify the modulation signal more accurately. Specifically, CNN and LSTM are initially used to form a dual-channel structure to effectively explore the spatial and temporal features of the original complex signal. It solves the problem of only focusing on temporal or spatial aspects, and increases the diversity of features. Secondly, the features extracted from CNN and LSTM are fused, making the extracted features richer and conducive to signal classification. In addition, a convolutional layer is added within the residual unit to deepen the network depth. As a result, more representative features are extracted, improving the classification performance. Finally, simulation results on the radio machine learning (RadioML) 2018.01A dataset signify that the network's classification performance is superior to many classifiers in the literature.
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Aerial edge computing for 6G
Mao Sun, Zhang Yan
The Journal of China Universities of Posts and Telecommunications    2022, 29 (1): 50-63.   DOI: 10.19682/j.cnki.1005-8885.2022.2006
Abstract625)            Save
In the 6th generation mobile communication system (6G) era, a large number of delay-sensitive and computation-intensive applications impose great pressure on resource-constrained Internet of things (IoT) devices. Aerial edge computing is envisioned as a promising and cost-effective solution, especially in hostile environments without terrestrial infrastructures. Therefore, this paper focuses on integrating aerial edge computing into 6G for providing ubiquitous computing services for IoT devices. This paper first presents the layered network architecture of aerial edge computing for 6G. The benefits, potential applications, and design challenges are also discussed in detail. Next, several key techniques like unmanned aerial vehicle (UAV) deployment, operation mode, offloading mode, caching policy, and resource management are highlighted to present how to integrated aerial edge computing into 6G. Then, the joint UAV deployment optimization and computation offloading method is designed to minimize the computing delay for a typical aerial edge computing network. Numerical results reveal the significant delay reduction of the proposed method compared with the other benchmark methods. Finally, several open issues for aerial edge computing in 6G are elaborated to provide some guidance for future research.
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Stability and Hopf bifurcation analysis in DCTCP congestion control
Cheng Zunshui, Jiang Jingna, Sun Dongsheng
The Journal of China Universities of Posts and Telecommunications    2023, 30 (6): 30-37.   DOI: 10.19682/j.cnki.1005-8885.2023.1015
Abstract621)      PDF(pc) (3657KB)(61)       Save
Traditional loss-based transports cannot meet the strict requirements of low latency and high throughput in data center networks (DCNs). Thus data center transmission control protocol (DCTCP) is proposed to better manage the congestion control in DCNs. To provide insight into improving the stability of the DCN, this paper focuses on the Hopf bifurcation analysis of a fluid model of DCTCP, and investigates the stability of the network. The round-trip time (RTT), being an effective congestion signal, is selected as the bifurcation parameter. And the network turns unstable and generates periodic solutions when the parameter is larger than the given critical value, which is given by explicit algorithms. The analytical results reveal the existence of Hopf bifurcation. Numerical simulations are performed to make a comparative analysis between the fluid model and the simplified model of DCTCP. The influence of other parameters on the DCN stability is also discussed.
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Real-time hand tracking based on YOLOv4 model and Kalman filter
The Journal of China Universities of Posts and Telecommunications    2021, 28 (3): 86-94.   DOI: 10.19682/j.cnki.1005-8885.2021.0011
Abstract612)      PDF(pc) (6638KB)(188)       Save

Aiming at the shortcomings of current gesture tracking methods in accuracy and speed, based on deep learning You Only Look Once version 4 (YOLOv4) model, a new YOLOv4 model combined with Kalman filter rea-time hand tracking method was proposed. The new algorithm can address some problems existing in hand tracking technology such as detection speed, accuracy and stability. The convolutional neural network (CNN) model YOLOv4 is used to detect the target of current frame tracking and Kalman filter is applied to predict the next position and bounding box size of the target according to its current position. The detected target is tracked by comparing the estimated result with the detected target in the next frame and, finally, the real-time hand movement track is displayed. The experimental results validate the proposed algorithm with the overall success rate of 99.43%

at speed of 41.822 frame/ s, achieving superior results than other algorithms. 

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Dynamic event-triggered leader-follower consensus of nonlinear multi-agent systems under directed weighted topology
Wu Yue, Chen Xiangyong, Qiu Jianlong, Hu Shunwei, Zhao Feng
The Journal of China Universities of Posts and Telecommunications    2023, 30 (6): 3-10.   DOI: 10.19682/j.cnki.1005-8885.2023.1019
Abstract606)      PDF(pc) (1536KB)(197)       Save
This paper studies the dynamic event-triggered leader-follower consensus of nonlinear multi-agent systems (MASs) under directed weighted graph containing a directed spanning tree, and also considers the effects of disturbances and leader of non-zero control inputs in the system. Firstly, a novel distributed control protocol is designed for uncertain disturbances and leader of non-zero control inputs in MASs. Secondly, a novel dynamic event-triggered control ( DETC) strategy is proposed, which eliminates the need for continuous communication between agents and reduces communication resources between agents. By introducing dynamic thresholds, the complexity of excluding Zeno behavior within the system is reduced. Finally, the effectiveness of the proposed theory is validated through numerical simulation.
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Linear-quadratic optimal control for time-varying descriptor systems via space decompositions
Lv Pengchao, Huang Junjie, Liu Bo
The Journal of China Universities of Posts and Telecommunications    2023, 30 (6): 38-48.   DOI: 10.19682/j.cnki.1005-8885.2023.1011
Abstract588)      PDF(pc) (1663KB)(57)       Save
This paper aims at solving the linear-quadratic optimal control problems ( LQOCP) for time-varying descriptor systems in a real Hilbert space. By using the Moore-Penrose inverse theory and space decomposition technique, the descriptor system can be rewritten as a new differential-algebraic equation (DAE), and then some novel sufficient conditions for the solvability of LQOCP are obtained. Especially, the methods proposed in this work are simpler and easier to verify and compute, and can solve LQOCP without the range inclusion condition. In addition, some  numerical examples are shown to verify the results obtained.
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RB-SLAM: visual SLAM based on rotated BEBLID feature point description
Fan Xinyue, Wu Kai, Chen Shuai
The Journal of China Universities of Posts and Telecommunications    2023, 30 (3): 1-13.   DOI: 10.19682/j.cnki.1005-8885.2023.1002
Abstract586)            Save
The extraction and description of image features are very important for visual simultaneous localization and mapping (V-SLAM). A rotated boosted efficient binary local image descriptor ( BEBLID) SLAM ( RB-SLAM) algorithm based on improved oriented fast and rotated brief (ORB) feature description is proposed in this paper, which can solve the problems of low localization accuracy and time efficiency of the current ORB-SLAM3 algorithm. Firstly, it uses the BEBLID to replace the feature point description algorithm of the original ORB to enhance the expressiveness and description efficiency of the image. Secondly, it adds rotational invariance to the BEBLID using the orientation information of the feature points. It also selects the rotationally stable bits in the BEBLID to further enhance the rotational invariance of the BEBLID. Finally, it retrains the binary visual dictionary based on the BEBLID to reduce the cumulative error of V-SLAM and improve the loading speed of the visual dictionary. Experiments show that the dictionary loading efficiency is improved by more than 10 times. The RB-SLAM algorithm improves the trajectory accuracy by 24.75% on the TUM dataset and 26.25% on the EuRoC dataset compared to the ORB-SLAM3 algorithm.
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Back in time: digital restoration techniques for the millennium Dunhuang murals
The Journal of China Universities of Posts and Telecommunications    2022, 29 (2): 13-23.   DOI: 10. 19682/ j. cnki. 1005-8885. 2022. 0012
Abstract560)      PDF       Save

In the long history of more than 1 500 years, Dunhuang murals suffered from various deteriorations causing irreversible damage such as falling off, fading, and so on. However, the existing Dunhuang mural restoration methods are time-consuming and not feasible to facilitate cultural issemination and permanent inheritance. Inspired by cultural computing using artificial intelligence, gated-convolution-based dehaze net (GD-Net) was proposed for Dunhuang mural refurbishment and comprehensive protection. First, a neural network with gated convolution was applied to restore the falling off areas of the mural to ensure the integrity of the mural content. Second, a dehaze network was applied to enhance image quality to cope with the fading of the mural. Besides, a Dunhuang mural dataset was presented to meet the needs of deep learning approach, containing 1 180 images from the Cave 290 and Cave 112 of the Mogao Grottoes. The  experimental results demonstrate the effectiveness and superiority of GD-Net.

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Mainlobe interference suppression and beam pattern optimization methods
Du Xiaojuan, Tian Bin
The Journal of China Universities of Posts and Telecommunications    2023, 30 (2): 1-7.   DOI: 10.19682/j.cnki.1005-8885.2022.0024
Abstract559)      PDF(pc) (1575KB)(20)       Save

When the power of the mainlobe interference received by the receiver is at the same level as the power of the sidelobe interference power, the traditional eigen-projection interference suppression method has the problems of severe beam deformation and peak shift. Aiming at these problems, a beam pattern optimization method (BPOM) was proposed, which can suppress the interference well even when the mainlobe interference power is approximately equal to the sidelobe interference power. In the method, the mainlobe interference eigenvectors are firstly determined according to the correlation criterion. Then through the eigenvalue comparison, the sidelobe interference eigenvectors whose eigenvalues are approximately equal to the mainlobe interference eigenvalues are judged. After that, a projection matrix is constructed to filter out the mainlobe and sidelobe interference. Finally, the covariance matrix is reconstructed and the weight vector for beamforming is obtained. Simulation shows that BPOM has a better output performance than the existing algorithms in case that the power of the mainlobe interference is close to that of the sidelobe interference.

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Adaptive TTI bundling with self-healing scheme for 5G
Sun Junshuai, Zhu Xinghui, Xiao Yeqiu, Cheng Ke, Zhao Shuangrui
The Journal of China Universities of Posts and Telecommunications    2022, 29 (1): 64-70.   DOI: 10.19682/j.cnki.1005-8885.2022.2007
Abstract557)            Save
The flexibility of the media access control (MAC) layer has always been an important concern in the existing communication architecture. To meet the more stringent requirements under large-scale connections, the MAC layer structure needs to be optimized carefully. This paper proposes a new architecture of the MAC layer to optimize the complex communication backhaul link structure, which will increase the flexibility of the system and decrease the transmission delay. Moreover, an adaptive transmission time interval (TTI) bundling with self-healing scheme is proposed to further decrease the transmission delay and improve the quality of service (QoS). The simulation results show that the average transmission delay is greatly reduced with our proposed scheme. The bit error rate (BER) and the block error rate are also improved even if the channel changes drastically.
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Node interdependent percolation of multiplex hypergraph with weak interdependence
Zhang Junjie, Liu Caixia, Liu Shuxin, Zang Weifei, Li Qian
The Journal of China Universities of Posts and Telecommunications    2023, 30 (6): 49-59.   DOI: 10.19682/j.cnki.1005-8885.2023.1016
Abstract557)      PDF(pc) (3049KB)(65)       Save
In recent years, there has been considerable attention and research on the higher-order interactions that are prevalent in various real-world networks. Hypergraphs, especially in the study of complex systems, are proved effective in capturing these interactions. To better characterize the model in reality, this paper proposes a theoretical model of node interdependent percolation in multiplex hypergraphs, considering “ weak ” interdependence. The proposed model includes pairwise and higher-order interactions, where the removal of nodes triggers cascading failures. However, interdependent nodes connected to failed nodes experience partial loss of connections due to “ weak” interdependence, reflecting the self-sustaining capabilities of real-world systems. Percolation theory is applied to the analysis to investigate the properties of the percolation threshold and phase transition. Both analysis and simulation results show that as the strength of interdependence between nodes weakens, the network transitions from a discontinuous to a continuous phase, thereby increasing its robustness.
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Fairness optimization and power allocation in cognitive NOMA / OMA V2V network with imperfect SIC
Liang Xiaolin, Liu Qianlong, Cao Wangbin, Liu Shuaiqi, Zhao Shuhuan, Zhao Xiongwen
The Journal of China Universities of Posts and Telecommunications    2023, 30 (6): 68-81.   DOI: 10.19682/j.cnki.1005-8885.2023.1020
Abstract544)      PDF(pc) (4592KB)(62)       Save
In order to improve the reliability and resource utilization efficiency of vehicle-to-vehicle (V2V) communication system, in this paper, the fairness optimization and power allocation for the cognitive V2V network that takes into account the realistic three-dimensional (3D) channel are investigated. Large-scale and small-scale fading are considered in the proposed channel model. An adaptive non-orthogonal multiple access ( NOMA) / orthogonal multiple access (OMA) scheme is proposed to reduce the complexity of successive-interference-cancellation (SIC) in decoding and improve spectrum utilization. Also, a fairness index that takes into account each user’s requirements is proposed to indicate the optimal point clearly. In the imperfect SIC, the optimization problem of maximizing user fairness is formulated. Then, a subgradient descent method is proposed to solve the optimization problem with customizable precision. And the computational complexity of the proposed method is analyzed. The achievable rate, outage probability and user fairness are analyzed. The results show that the proposed adaptive NOMA / OMA (A-NOMA / OMA) outperforms both NOMA and OMA. The simulation results are compared with validated analysis to confirm the theoretical analysis.
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Liveness detection of occluded face based on dual-modality convolutional neural network
Ming Yue, Li Wenmin, Xu Siya, Gao Lifang, Zhang Hua, Shao Sujie, Yang Huifeng
The Journal of China Universities of Posts and Telecommunications    2021, 28 (4): 1-12.   DOI: 10.19682/j.cnki.1005-8885.2021.2001
Abstract527)      PDF(pc) (3096KB)(118)       Save
Facial recognition has become the most common identity authentication technologies. However, problems such as  uneven light and occluded faces have increased the hardness of liveness detection. Nevertheless, there are a few  pieces of research on face liveness detection under occlusion conditions. This paper designs a face recognition  technique suitable for different degrees of facial occlusion, which employs the facial datasets of near-infrared (NIR)  images and visible (VIS) light images to examine the single-modality detection accuracy rate (experimental control  group) and the corresponding high-dimensional features through the residual network (ResNet). Based on the idea  of data fusion, we propose two feature fusion methods. The two methods extract and fuse the data of one and two  convolutional layers from two single-modality detectors respectively. The fusion of high-dimensional features apply a  new ResNet to get the dual-modality detection accuracy. And then, a new ResNet is applied to test the accuracy of  dual-modality detection. The experimental results show that the dual-modality face liveness detection model  improves face live detection accuracy and robustness compared with the single-modality. The fusion of two-layer  features from the single-modality detector can also improve face detection accuracy by utilizing the above-mentioned  dual-modality detector, and it doesn't increase the algorithm's complexity.
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Research on sentiment terms extraction and visualization of character sentimental interactions in A Dream of Red Mansions
The Journal of China Universities of Posts and Telecommunications    2022, 29 (2): 24-32.   DOI: 10. 19682/ j. cnki. 1005-8885. 2022. 0013
Abstract521)      PDF       Save

In the context of interdisciplinary research, using computer technology to further mine keywords in cultural texts and carry out semantic analysis can deepen the understanding of texts, and provide quantitative support and evidence for humanistic studies. Based on the novel A Dream of Red Mansions, the automatic extraction and classification of those sentiment terms in it were realized, and detailed analysis of large-scale sentiment terms was carried out. Bidirectional encoder representation from transformers (BERT) pretraining and fine-tuning model was used to construct the sentiment classifier of A Dream of Red Mansions. Sentiment terms of A Dream of Red Mansions are divided into eight sentimental categories, and the relevant people in sentences are extracted according to specific rules. It also tries to visually display the sentimental interactions between Twelve Girls of Jinling and Jia Baoyu along with the development of the episode. The overall F1 score of BERT-based sentiment classifier reached 84-89%. The best single sentiment score reached 91-15%. Experimental results show that the classifier can satisfactorily classify the text of A Dream of Red  Mansions, and the text classification and interactional analysis results can be mutually verified with the text interpretation of A dream of Red Mansions by literature experts.

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