ISSN 
2022 Vol. 51, No. 6
column
2022, 51(6): 802-811.
doi: 10.12178/1001-0548.2022178
Abstract:
In the big data scenario, data security is as important as identity security. The identity blindness deserves additional attention. In order to meet the needs of quantum entrusted computing in the blockchain scenario, this paper proposes an anonymous quantum entrusted computing protocol which considering both data security and identity security. In our protocol, the user participates in the delegated computing protocol anonymously, and can send the delegation and receive the results without displaying the identity information. The protocol can achieve the above objectives without a trusted third party. When sending the calculation delegation, Alice uses the ring network to confuse the identity to hide the specific sender. Bob uses controlled quantum teleportation to transmit quantum states safely and anonymously in the process of feeding back the entrusted calculation results. The protocol introduces blockchain technology for Charlie, the third party, to anonymous payment and anonymous approval. The blockchain and quantum technology used in the protocol have been basically realized, so the protocol has high feasibility. Furthermore, we propose an improved protocol for users to verify the results of delegated calculations by comparing the results of multiple principals. The protocol proposed is a practical protocol framework for big data environment and has good portability
In the big data scenario, data security is as important as identity security. The identity blindness deserves additional attention. In order to meet the needs of quantum entrusted computing in the blockchain scenario, this paper proposes an anonymous quantum entrusted computing protocol which considering both data security and identity security. In our protocol, the user participates in the delegated computing protocol anonymously, and can send the delegation and receive the results without displaying the identity information. The protocol can achieve the above objectives without a trusted third party. When sending the calculation delegation, Alice uses the ring network to confuse the identity to hide the specific sender. Bob uses controlled quantum teleportation to transmit quantum states safely and anonymously in the process of feeding back the entrusted calculation results. The protocol introduces blockchain technology for Charlie, the third party, to anonymous payment and anonymous approval. The blockchain and quantum technology used in the protocol have been basically realized, so the protocol has high feasibility. Furthermore, we propose an improved protocol for users to verify the results of delegated calculations by comparing the results of multiple principals. The protocol proposed is a practical protocol framework for big data environment and has good portability
2022, 51(6): 812-818.
doi: 10.12178/1001-0548.2022033
Abstract:
The S-box is an important nonlinear component in SM4 block cipher algorithm. In this paper, Toffoli gates, CNOT gates and NOT gates are used to construct the quantum circuit of the S-box. Based on the algebraic expression of the S-box, the inverse operation in finite field\begin{document}${\rm{GF}}({2^8})$\end{document} ![]()
![]()
\begin{document}${\rm{GF}}({({2^4})^2})$\end{document} ![]()
![]()
\begin{document}${\rm{ GF}}({2^4})$\end{document} ![]()
![]()
The S-box is an important nonlinear component in SM4 block cipher algorithm. In this paper, Toffoli gates, CNOT gates and NOT gates are used to construct the quantum circuit of the S-box. Based on the algebraic expression of the S-box, the inverse operation in finite field
2022, 51(6): 820-829.
doi: 10.12178/1001-0548.2022132
Abstract:
Artificial intelligence accurately predicted the three-dimensional structure of proteins for the first time, which was selected as one of the top ten scientific breakthroughs in 2020 by "Science" magazine, and became a frontier direction in the field of structural bioinformatics. Most single-chain proteins in nature contain multiple domains. In a biological sense, inter-domain association and cooperation are crucial to achieve multiple related functions. This paper firstly introduces the development of protein structure prediction and the critical assessment of structure prediction (CASP); Secondly, some representative methods are briefly described in three parts: single-domain protein structure prediction methods, multi-domain protein structure assembly methods and end-to-end protein structure prediction methods; The commonly used databases and model quality evaluation indicators in protein structure prediction are then demonstrated, and the performances of the representative prediction methods are compared. Finally, we conclude with a brief overview of the future challenges and outstanding questions in the field.
Artificial intelligence accurately predicted the three-dimensional structure of proteins for the first time, which was selected as one of the top ten scientific breakthroughs in 2020 by "Science" magazine, and became a frontier direction in the field of structural bioinformatics. Most single-chain proteins in nature contain multiple domains. In a biological sense, inter-domain association and cooperation are crucial to achieve multiple related functions. This paper firstly introduces the development of protein structure prediction and the critical assessment of structure prediction (CASP); Secondly, some representative methods are briefly described in three parts: single-domain protein structure prediction methods, multi-domain protein structure assembly methods and end-to-end protein structure prediction methods; The commonly used databases and model quality evaluation indicators in protein structure prediction are then demonstrated, and the performances of the representative prediction methods are compared. Finally, we conclude with a brief overview of the future challenges and outstanding questions in the field.
2022, 51(6): 830-840.
doi: 10.12178/1001-0548.2022188
Abstract:
The traditional methods for the identification of antimicrobial peptides are experimental means, which is inefficient and consumes a lot of manpower and material resources. The latest ways to identify antimicrobial peptides combine computer technology, bioinformatics, and machine learning methods together. Based on big data mining and analysis, antimicrobial peptides can be predicted from a large amount of peptide sequence data. The identification of antimicrobial peptides thereby could be accelerated. This paper classifies and analyzes the main literatures of the computer-aided antimicrobial peptide recognition in the recent 10 years, sorts out the main antimicrobial peptides data resources, the characteristic engineering of antimicrobial peptide recognitions, the machine learning prediction algorithms of antimicrobial peptides, the regression analysis methods of antimicrobial peptides. In the meanwhile, this paper reviews the model performance evaluation methods of machine learning algorithms, summarizes the existing shortcomings, and prospects the future development directions.
The traditional methods for the identification of antimicrobial peptides are experimental means, which is inefficient and consumes a lot of manpower and material resources. The latest ways to identify antimicrobial peptides combine computer technology, bioinformatics, and machine learning methods together. Based on big data mining and analysis, antimicrobial peptides can be predicted from a large amount of peptide sequence data. The identification of antimicrobial peptides thereby could be accelerated. This paper classifies and analyzes the main literatures of the computer-aided antimicrobial peptide recognition in the recent 10 years, sorts out the main antimicrobial peptides data resources, the characteristic engineering of antimicrobial peptide recognitions, the machine learning prediction algorithms of antimicrobial peptides, the regression analysis methods of antimicrobial peptides. In the meanwhile, this paper reviews the model performance evaluation methods of machine learning algorithms, summarizes the existing shortcomings, and prospects the future development directions.
2022, 51(6): 841-846.
doi: 10.12178/1001-0548.2022179
Abstract:
In the tracking task of distributed radar networks, low signal-to-noise ratio will lead to detection probability of the target less than 1, which may lead to the interruption of target track. This paper proposes a power allocation algorithm for distributed radar networks to track stably for a long track. The track continuity and the tracking performance of the system are both guaranteed by optimizing the power allocation for radar nodes. First, signal and measurement models of distributed radar are established. Then, the Bayesian Cramér-Rao lower bound (BCRLB) under uncertainty measurements is derived, and a mathematical model of the power allocation problem is established. To efficiently solve the optimization problem which contains complex non-convex constraints, a self-constrained power allocation (SCPA) algorithm based on convex optimization is proposed. The simulation results show that the proposed SCPA algorithm can ensure that all target tracks are not interrupted in the whole tracking process, while keeping good tracking performance.
In the tracking task of distributed radar networks, low signal-to-noise ratio will lead to detection probability of the target less than 1, which may lead to the interruption of target track. This paper proposes a power allocation algorithm for distributed radar networks to track stably for a long track. The track continuity and the tracking performance of the system are both guaranteed by optimizing the power allocation for radar nodes. First, signal and measurement models of distributed radar are established. Then, the Bayesian Cramér-Rao lower bound (BCRLB) under uncertainty measurements is derived, and a mathematical model of the power allocation problem is established. To efficiently solve the optimization problem which contains complex non-convex constraints, a self-constrained power allocation (SCPA) algorithm based on convex optimization is proposed. The simulation results show that the proposed SCPA algorithm can ensure that all target tracks are not interrupted in the whole tracking process, while keeping good tracking performance.
2022, 51(6): 847-855.
doi: 10.12178/1001-0548.2022299
Abstract:
With the development of wireless communication 5G/6G technology, a variety of new services based on the fusion of communications and radar (RadCom) technology continue to emerge. In order to implement RadCom based on 5G new radio (NR), many different deployment scenarios covered by the latest 5G NR wireless communication standard defined by 3GPP need to be considered. However, radar detection performance is limited by 5G NR numerology in different scenarios. Therefore, it is necessary to explore the radar detection performance with different 5G NR numerology in specific scenes. This paper takes the radar detection requirements of internet of vehicle (IoV) scenes and the calculation criteria of basic radar performance parameters as constraints, and presents the simulation analysis of radar detection performance under different 5G NR numerology. Some instructive suggestions are given for the designs and optimizations of RadCom systems based on 5G NR standard and deployment scenarios in the future.
With the development of wireless communication 5G/6G technology, a variety of new services based on the fusion of communications and radar (RadCom) technology continue to emerge. In order to implement RadCom based on 5G new radio (NR), many different deployment scenarios covered by the latest 5G NR wireless communication standard defined by 3GPP need to be considered. However, radar detection performance is limited by 5G NR numerology in different scenarios. Therefore, it is necessary to explore the radar detection performance with different 5G NR numerology in specific scenes. This paper takes the radar detection requirements of internet of vehicle (IoV) scenes and the calculation criteria of basic radar performance parameters as constraints, and presents the simulation analysis of radar detection performance under different 5G NR numerology. Some instructive suggestions are given for the designs and optimizations of RadCom systems based on 5G NR standard and deployment scenarios in the future.
2022, 51(6): 856-861.
doi: 10.12178/1001-0548.2022037
Abstract:
Most of the existing locally repairable codes can meet the boundary condition of minimum distance, but it is difficult to construct the locally repairable codes with optimal dimension under the condition of minimum distance optimization. To solve this problems, this paper proposes a construction method of optimal locally repairable codes based on Hadamard matrix. By expanding Hadamard matrix, the check matrix of the optimal locally repairable code can be obtained. Specifically, the parity matrix of locally repairable codes is constructed using Hadamard matrix, and the minimum distance of the locally repairable codes constructed by the parity matrix can reach the optimal boundary, but its dimension does not reach the optimal dimension boundary condition. In order to improve the dimension, the element 0 and element 1 of the incidence matrix in the check matrix are exchanged to obtain a new incidence matrix. By cascading with the new incidence matrix, the constructed extended locally repairable code can not only achieve the minimum distance optimization, but also achieve the boundary condition of the optimal dimension. Compared with the existing locally repairable codes, the extended locally repairable code based on Hadamard matrix constructed in this paper is the optimal locally repairable code with minimum distance and dimension, and its code rate is closer to the boundary of the optimal code rate of locally repairable codes.
Most of the existing locally repairable codes can meet the boundary condition of minimum distance, but it is difficult to construct the locally repairable codes with optimal dimension under the condition of minimum distance optimization. To solve this problems, this paper proposes a construction method of optimal locally repairable codes based on Hadamard matrix. By expanding Hadamard matrix, the check matrix of the optimal locally repairable code can be obtained. Specifically, the parity matrix of locally repairable codes is constructed using Hadamard matrix, and the minimum distance of the locally repairable codes constructed by the parity matrix can reach the optimal boundary, but its dimension does not reach the optimal dimension boundary condition. In order to improve the dimension, the element 0 and element 1 of the incidence matrix in the check matrix are exchanged to obtain a new incidence matrix. By cascading with the new incidence matrix, the constructed extended locally repairable code can not only achieve the minimum distance optimization, but also achieve the boundary condition of the optimal dimension. Compared with the existing locally repairable codes, the extended locally repairable code based on Hadamard matrix constructed in this paper is the optimal locally repairable code with minimum distance and dimension, and its code rate is closer to the boundary of the optimal code rate of locally repairable codes.
2022, 51(6): 862-865.
doi: 10.12178/1001-0548.2022098
Abstract:
The special-shaped section waveguide has special mode transmission characteristics. In theory, it can expand the existing mode conversion technology and promote the development of multi-frequency point, broadband and compact mode converter. However, due to its complex structure, it is difficult to directly obtain the analytical expression to accurately describe the mode coupling process through mathematical methods, which inhibits the development of this kind of technology. Based on Maxwell's equations, the coupled wave equations of curved waveguide and the expression of coupling coefficient based on vector waveform function are deduced and given. Combined with the numerical solution of vector waveform function, the optimization problem of special-shaped waveguide mode converter can be solved. In order to verify the effectiveness of this technical approach, this paper attempts to design an elliptical waveguide TM01-TE11 mode converter working in X-band. The simulation and numerical results show that the mode conversion efficiency of this mode converter is higher than 95%, the bandwidth is 10%, and the maximum conversion efficiency is higher than 99%. It has better performance than classical circular waveguide mode converters.
The special-shaped section waveguide has special mode transmission characteristics. In theory, it can expand the existing mode conversion technology and promote the development of multi-frequency point, broadband and compact mode converter. However, due to its complex structure, it is difficult to directly obtain the analytical expression to accurately describe the mode coupling process through mathematical methods, which inhibits the development of this kind of technology. Based on Maxwell's equations, the coupled wave equations of curved waveguide and the expression of coupling coefficient based on vector waveform function are deduced and given. Combined with the numerical solution of vector waveform function, the optimization problem of special-shaped waveguide mode converter can be solved. In order to verify the effectiveness of this technical approach, this paper attempts to design an elliptical waveguide TM01-TE11 mode converter working in X-band. The simulation and numerical results show that the mode conversion efficiency of this mode converter is higher than 95%, the bandwidth is 10%, and the maximum conversion efficiency is higher than 99%. It has better performance than classical circular waveguide mode converters.
2022, 51(6): 866-874.
doi: 10.12178/1001-0548.2022032
Abstract:
In the complex actual combat environment, the uncertainty of the prior information of the radar makes it difficult to meet the performance requirements, and the interference is more intelligent, which further reduces the detection performance of the radar in actual warfare. In order to improve the detection performance of electronic warfare radars, a radar game waveform design method based on mutual information and signal-to-interference-plus-noise ratio weighting criterion is proposed. First, weighting criterion for mutual information and signal-to-interference-plus-noise ratio is established, and then the radar and jamming game model based on the above criterion is designed. Finally, the maximum marginal reallocation algorithm is proposed to solve the repeated game dilemma and refine the Nash equilibrium. Simulation experiments verify the effectiveness of the proposed method.
In the complex actual combat environment, the uncertainty of the prior information of the radar makes it difficult to meet the performance requirements, and the interference is more intelligent, which further reduces the detection performance of the radar in actual warfare. In order to improve the detection performance of electronic warfare radars, a radar game waveform design method based on mutual information and signal-to-interference-plus-noise ratio weighting criterion is proposed. First, weighting criterion for mutual information and signal-to-interference-plus-noise ratio is established, and then the radar and jamming game model based on the above criterion is designed. Finally, the maximum marginal reallocation algorithm is proposed to solve the repeated game dilemma and refine the Nash equilibrium. Simulation experiments verify the effectiveness of the proposed method.
2022, 51(6): 875-883.
doi: 10.12178/1001-0548.2021379
Abstract:
Aiming at the problem that the radar data in the well is difficult to extract effective data due to factors such as pollution in the complex environment, this paper proposes a two-dimensional modal empirical decomposition method (BEMD) based on the empirical mode decomposition method (EMD). The time-frequency domain decomposition algorithm of radar signal preprocessing is analyzed, and the two-dimensional radar signals in wells can be processed effectively by extending the signals to high dimensions. The simulation results show that the proposed BEMD can effectively eliminate the interference of high frequency and low frequency and achieves a great improvement compared with the one-dimensional modal empirical decomposition, which verifies that the method has the potential to be applied to the processing of radar data in Wells..
Aiming at the problem that the radar data in the well is difficult to extract effective data due to factors such as pollution in the complex environment, this paper proposes a two-dimensional modal empirical decomposition method (BEMD) based on the empirical mode decomposition method (EMD). The time-frequency domain decomposition algorithm of radar signal preprocessing is analyzed, and the two-dimensional radar signals in wells can be processed effectively by extending the signals to high dimensions. The simulation results show that the proposed BEMD can effectively eliminate the interference of high frequency and low frequency and achieves a great improvement compared with the one-dimensional modal empirical decomposition, which verifies that the method has the potential to be applied to the processing of radar data in Wells..
2022, 51(6): 884-889.
doi: 10.12178/1001-0548.2020307
Abstract:
The traditional matching network can only achieve the ideal matching at one certain frequency through the series inductor, which limits the antenna bandwidth. In this paper, the broadband matching problem of electrically small antenna is studied, and a negative-impedance matching network is realized by using the active non-foster circuit, which breaks the limitation of the electrically small antenna quality factor and can cancel the capacitance of the electrically small antenna in a very wide frequency band. Based on the above principle, a negative resistance matching network for handheld devices terminal antenna is designed and processed in this paper. When the height of the monopole antenna is only 1/10 wavelength, no structure is attached, the VSWR is less than 2.5 in the 400 MHz to 700 MHz band, and the antenna radiation efficiency is greater than 75%.
The traditional matching network can only achieve the ideal matching at one certain frequency through the series inductor, which limits the antenna bandwidth. In this paper, the broadband matching problem of electrically small antenna is studied, and a negative-impedance matching network is realized by using the active non-foster circuit, which breaks the limitation of the electrically small antenna quality factor and can cancel the capacitance of the electrically small antenna in a very wide frequency band. Based on the above principle, a negative resistance matching network for handheld devices terminal antenna is designed and processed in this paper. When the height of the monopole antenna is only 1/10 wavelength, no structure is attached, the VSWR is less than 2.5 in the 400 MHz to 700 MHz band, and the antenna radiation efficiency is greater than 75%.
2022, 51(6): 890-903.
doi: 10.12178/1001-0548.2021308
Abstract:
Based on the large objective function value imbalance problem of selection, crossover and mutation in hormone-regulation based genetic algorithm, an adaptive genetic algorithm based on improved hormone concentration calculation method (referred to as IHCCM-IAGA) is proposed. IHCCM-IAGA adopts the coding method based on the arrangement of work pieces, and uses the reverse learning method to initialize the population, which improves the quality of the initial solution. Aiming at the problems of high redundancy and low efficiency in the two-points crossover (TPX) operator, an improved TPX (improved two-points crossover, ITPX) is proposed, and the introduction of excellent gene pool and immune factors realizes two crossover methods and monitors the entire evolution process, avoiding the loss of high-quality chromosomes. A variety of perturbations are designed to maintain a rich diversity structure and related local search algorithms are combined into a mutation operator. A population annihilation operator is established and an annihilation factor is set to guide the local search in the mutation operator. IHCCM-IAGA is applied to the permutation flow shop scheduling problem, and various tests of the standard calculation example of the problem are performed. The results show that IHCCM-IAGA is effective.
Based on the large objective function value imbalance problem of selection, crossover and mutation in hormone-regulation based genetic algorithm, an adaptive genetic algorithm based on improved hormone concentration calculation method (referred to as IHCCM-IAGA) is proposed. IHCCM-IAGA adopts the coding method based on the arrangement of work pieces, and uses the reverse learning method to initialize the population, which improves the quality of the initial solution. Aiming at the problems of high redundancy and low efficiency in the two-points crossover (TPX) operator, an improved TPX (improved two-points crossover, ITPX) is proposed, and the introduction of excellent gene pool and immune factors realizes two crossover methods and monitors the entire evolution process, avoiding the loss of high-quality chromosomes. A variety of perturbations are designed to maintain a rich diversity structure and related local search algorithms are combined into a mutation operator. A population annihilation operator is established and an annihilation factor is set to guide the local search in the mutation operator. IHCCM-IAGA is applied to the permutation flow shop scheduling problem, and various tests of the standard calculation example of the problem are performed. The results show that IHCCM-IAGA is effective.
2022, 51(6): 904-912.
doi: 10.12178/1001-0548.2021393
Abstract:
K-means clustering algorithm is a classic algorithm in academic and industrial fields. However, it has two most obvious defeats: one is that the number of clusters needs to be known in advance; the other is that it is very sensitive to the random initialization of the algorithm. In order to solve these problems, this paper summarizes the basic step of K-means algorithm and analyzes the clustering validity. Then, based on the Euclidean distance of the data points, the sum of centroid distances between classes and the sum of distances within cluster with the number of clusters k as the independent variable are defined, and the cluster validity evaluation function is constructed. Finally, according to the empirical rules, the optimal number of clusters in the data set is determined by solving the minimum value of the cluster validity evaluation function within the possible range of number of clusters. The simulation results of the three UCI datasets Iris, Seeds, and Wine shows that the proposed cluster validity evaluation function can not only accurately reflect the true cluster structure of the data, but also effectively suppress the sensitivity of the algorithm to random initialization. The multiple runs of the K-means algorithm also verify the robustness of the cluster validity evaluation function.
K-means clustering algorithm is a classic algorithm in academic and industrial fields. However, it has two most obvious defeats: one is that the number of clusters needs to be known in advance; the other is that it is very sensitive to the random initialization of the algorithm. In order to solve these problems, this paper summarizes the basic step of K-means algorithm and analyzes the clustering validity. Then, based on the Euclidean distance of the data points, the sum of centroid distances between classes and the sum of distances within cluster with the number of clusters k as the independent variable are defined, and the cluster validity evaluation function is constructed. Finally, according to the empirical rules, the optimal number of clusters in the data set is determined by solving the minimum value of the cluster validity evaluation function within the possible range of number of clusters. The simulation results of the three UCI datasets Iris, Seeds, and Wine shows that the proposed cluster validity evaluation function can not only accurately reflect the true cluster structure of the data, but also effectively suppress the sensitivity of the algorithm to random initialization. The multiple runs of the K-means algorithm also verify the robustness of the cluster validity evaluation function.
2022, 51(6): 913-920.
doi: 10.12178/1001-0548.2022007
Abstract:
Identity-based encryption (IBE) is very attractive because it does not have certificate management issues. However, the IBEs based on the bilinear Diffie-Hellman problem cannot resist quantum attacks. In order to ensure security under quantum attacks, lattice-based IBE is proposed. However, the existing lattice-based IBEs usually not only have a large ciphertext size but also can only encrypt a few bits of plaintext information in one ciphertext. In this paper, we propose a new lattice-based IBE scheme based on learning with errors (LWE) and its ring version. For the setting\begin{document}$ l=n $\end{document} ![]()
![]()
Identity-based encryption (IBE) is very attractive because it does not have certificate management issues. However, the IBEs based on the bilinear Diffie-Hellman problem cannot resist quantum attacks. In order to ensure security under quantum attacks, lattice-based IBE is proposed. However, the existing lattice-based IBEs usually not only have a large ciphertext size but also can only encrypt a few bits of plaintext information in one ciphertext. In this paper, we propose a new lattice-based IBE scheme based on learning with errors (LWE) and its ring version. For the setting
2022, 51(6): 921-927.
doi: 10.12178/1001-0548.2021385
Abstract:
In this paper, based on the noise reduction capability and feature extraction capability of deep residual shrinkage networks with channel-wise thresholds (DRSNCW) module, combined with long short-term memory network (LSTM) and attention mechanism module, an end-to-end vibration signal-based bearing fault diagnosis model, named DRSNCW-LSTM, is proposed. In this model, LSTM module makes good use of the time-series characteristics of the signal to sufficiently extract the internal time-domain features of the vibration signal. Moreover, the introduction of attention mechanism enables the model to automatically extract important time-domain features for follow-up fault type recognition. The effectiveness of the proposed model is validated on the authoritative case Western Reserve University (CWRU) dataset, and experiments show that the proposed method can achieve more accurate bearing fault diagnosis than the state-of-the-art multi-scale convolutional neural network-LSTM (MCNN-LSTM) model without noise reduction processing. In particular, in the case of insufficient training data, the proposed method still achieves rather good bearing fault diagnosis with an average accuracy of 98.16%, which is an average improvement of 2.62% over the MCNN-LSTM.
In this paper, based on the noise reduction capability and feature extraction capability of deep residual shrinkage networks with channel-wise thresholds (DRSNCW) module, combined with long short-term memory network (LSTM) and attention mechanism module, an end-to-end vibration signal-based bearing fault diagnosis model, named DRSNCW-LSTM, is proposed. In this model, LSTM module makes good use of the time-series characteristics of the signal to sufficiently extract the internal time-domain features of the vibration signal. Moreover, the introduction of attention mechanism enables the model to automatically extract important time-domain features for follow-up fault type recognition. The effectiveness of the proposed model is validated on the authoritative case Western Reserve University (CWRU) dataset, and experiments show that the proposed method can achieve more accurate bearing fault diagnosis than the state-of-the-art multi-scale convolutional neural network-LSTM (MCNN-LSTM) model without noise reduction processing. In particular, in the case of insufficient training data, the proposed method still achieves rather good bearing fault diagnosis with an average accuracy of 98.16%, which is an average improvement of 2.62% over the MCNN-LSTM.
2022, 51(6): 928-936.
doi: 10.12178/1001-0548.2021378
Abstract:
The research uses the network collaborative construction theory to construct a national scientific cooperation network during the COVID-19 epidemic period, aiming to describe the evolution patterns of scientific research cooperation and the impact on the cooperation during the epidemic period. From the perspective of the cooperation network, the research calculates the network features to investigate the evolution patterns of the scientific research cooperation network. The present work also calculates the national cooperation freshness to investigate the dynamic evolution of the cooperation center. Finally, the regression discontinuity design is used to estimate the impact of the epidemic on national scientific research cooperation. The results show that the outbreak of the epidemic strengthens the scientific research cooperation. Furthermore, China played an important role in the epidemic, especially in the early stage. Although the cooperation center has gradually shifted with the change of the affected areas, China is still an important collaborator. Finally, our work studies the cooperative behavior of countries during the epidemic through regression discontinuity design and finds that the epidemic has been promoting people's ability to cooperate in fighting against disasters.
The research uses the network collaborative construction theory to construct a national scientific cooperation network during the COVID-19 epidemic period, aiming to describe the evolution patterns of scientific research cooperation and the impact on the cooperation during the epidemic period. From the perspective of the cooperation network, the research calculates the network features to investigate the evolution patterns of the scientific research cooperation network. The present work also calculates the national cooperation freshness to investigate the dynamic evolution of the cooperation center. Finally, the regression discontinuity design is used to estimate the impact of the epidemic on national scientific research cooperation. The results show that the outbreak of the epidemic strengthens the scientific research cooperation. Furthermore, China played an important role in the epidemic, especially in the early stage. Although the cooperation center has gradually shifted with the change of the affected areas, China is still an important collaborator. Finally, our work studies the cooperative behavior of countries during the epidemic through regression discontinuity design and finds that the epidemic has been promoting people's ability to cooperate in fighting against disasters.
2022, 51(6): 937-946.
doi: 10.12178/1001-0548.2021352
Abstract:
This paper assesses the potential risks of epidemic situation and public opinion during the Beijing Winter Olympic Games by analyzing the epidemic situation and public opinion of the Tokyo Olympic Games. The results show that there is a strong time-lag correlation between the COVID-19 epidemic and the public opinion of the Tokyo Olympics. For the epidemic situation, the multi-agent modeling method is used at the city level to simulate the possible spread of diseases in the city where the event was held. At the Olympic village level, the modified the SEIR transmission model is modified to simulate the virus transmission in the Olympic Village during the Beijing Winter Olympic Games. At the end, the risk analysis of the Beijing Winter Olympic Games is carried out based on the time series prediction model.
This paper assesses the potential risks of epidemic situation and public opinion during the Beijing Winter Olympic Games by analyzing the epidemic situation and public opinion of the Tokyo Olympic Games. The results show that there is a strong time-lag correlation between the COVID-19 epidemic and the public opinion of the Tokyo Olympics. For the epidemic situation, the multi-agent modeling method is used at the city level to simulate the possible spread of diseases in the city where the event was held. At the Olympic village level, the modified the SEIR transmission model is modified to simulate the virus transmission in the Olympic Village during the Beijing Winter Olympic Games. At the end, the risk analysis of the Beijing Winter Olympic Games is carried out based on the time series prediction model.
2022, 51(6): 947-952.
doi: 10.12178/1001-0548.2021368
Abstract:
The H-gate SOI (silicon on insulator) PMOS plays an important role in SOI-technology circuit design because of its strong anti-radiation ability and good symmetry. However, since its transconductance has an obvious bimodal effect, the general BSIMSOI model cannot predict this type of device accurately. Such an effect brings new challenges to the simulation and prediction of device characteristics. To solve this problem, this work establishes a SPICE model of the H-gate PMOS devices by defining two parallel transistor channels in the sub-circuits based on the BSIMSOI simulation model. This model can effectively represent the bimodal effect of the transconductance of PMOS devices under the SOI process. Compared with BSIMSOI, the experimental results show the RMS value of the proposed model is reduced from 6.91% to 1.91%. At the same time, after using the bin parameters of BSIMSOI, the RMS value with a smaller size of W is reduced by more than 60%. The proposed model can be used in H-gate PMOS structure modeling and circuit design in the SOI process.
The H-gate SOI (silicon on insulator) PMOS plays an important role in SOI-technology circuit design because of its strong anti-radiation ability and good symmetry. However, since its transconductance has an obvious bimodal effect, the general BSIMSOI model cannot predict this type of device accurately. Such an effect brings new challenges to the simulation and prediction of device characteristics. To solve this problem, this work establishes a SPICE model of the H-gate PMOS devices by defining two parallel transistor channels in the sub-circuits based on the BSIMSOI simulation model. This model can effectively represent the bimodal effect of the transconductance of PMOS devices under the SOI process. Compared with BSIMSOI, the experimental results show the RMS value of the proposed model is reduced from 6.91% to 1.91%. At the same time, after using the bin parameters of BSIMSOI, the RMS value with a smaller size of W is reduced by more than 60%. The proposed model can be used in H-gate PMOS structure modeling and circuit design in the SOI process.
2022, 51(6): 953-960.
doi: 10.12178/1001-0548.2022065
Abstract:
The predesigned position activation of printed circuit board (PCB) substrates is the key process for manufacturing circuits by selective electroless copper plating. A compatible Cu2+ solution for epoxy resin (EP) substrate was designed with copper acetate monohydrate as a catalyst precursor, thiourea as a complexing agent, bisphenol A diglycidyl ether as a prepolymer of EP, reagent 593 as a curing agent, and 1-methoxy-2-propanol as a solvent. The compatible Cu2+ solution was printed on EP substrate surface by an inkjet printer. Copper circuits were additively fabricated by selective electroless copper plating. Based on quantum chemistry density functional theory, the complexation reactions between thiourea molecules and copper ions were simulated in the compatible Cu2+ solution. The special functional groups in the compatible Cu2+ solution were characterized by infrared spectroscopy and Raman spectroscopy. The results show that the resistivity of copper circuits is as low as 2.62×10−6 Ω·cm attributing to the good crystallization and dense accumulation of copper grains. The adhesion between copper circuit and EP substrate is up to 5B level with the help of the modified layer. Therefore, compatible modification EP substrate to catalyze copper circuits deposition has the advantages of simple process, economic and environmental-friendly, which provides a valuable reference for compatible modification on other common resin substrates in additive manufacturing of PCB.
The predesigned position activation of printed circuit board (PCB) substrates is the key process for manufacturing circuits by selective electroless copper plating. A compatible Cu2+ solution for epoxy resin (EP) substrate was designed with copper acetate monohydrate as a catalyst precursor, thiourea as a complexing agent, bisphenol A diglycidyl ether as a prepolymer of EP, reagent 593 as a curing agent, and 1-methoxy-2-propanol as a solvent. The compatible Cu2+ solution was printed on EP substrate surface by an inkjet printer. Copper circuits were additively fabricated by selective electroless copper plating. Based on quantum chemistry density functional theory, the complexation reactions between thiourea molecules and copper ions were simulated in the compatible Cu2+ solution. The special functional groups in the compatible Cu2+ solution were characterized by infrared spectroscopy and Raman spectroscopy. The results show that the resistivity of copper circuits is as low as 2.62×10−6 Ω·cm attributing to the good crystallization and dense accumulation of copper grains. The adhesion between copper circuit and EP substrate is up to 5B level with the help of the modified layer. Therefore, compatible modification EP substrate to catalyze copper circuits deposition has the advantages of simple process, economic and environmental-friendly, which provides a valuable reference for compatible modification on other common resin substrates in additive manufacturing of PCB.
