In clinics, especially in the emergency department, carbon dioxide (CO2) is considered as the sixth vital sign in evaluating a patient's medical status. However, its wide applications in developing countries are d...In clinics, especially in the emergency department, carbon dioxide (CO2) is considered as the sixth vital sign in evaluating a patient's medical status. However, its wide applications in developing countries are dissatisfactory due to their high cost compared to their economic growth. In order to develop a practical system for concentration detection of human exhaled CO2 gas for our own, we studied the detection principle based upon the non-dispersive infrared (NDIR) measuring technique and related Lambert-Beer's equation carefully, gave out our functional circuit design of the system, and provided the corresponding graphical user interface (GUI) for CO2 detection. Finally, the experiment shows that it may be a practical system, and will give benefits for the development of our medical care in the future.展开更多
Aiming at the spatial pattern phenomenon in biochemical reactions,an enzyme-reaction Sporns-Seelig model with cross-diffusion is chosen as study object.Applying the central manifold theory,normal form method,local Hop...Aiming at the spatial pattern phenomenon in biochemical reactions,an enzyme-reaction Sporns-Seelig model with cross-diffusion is chosen as study object.Applying the central manifold theory,normal form method,local Hopf bifurcation theorem and perturbation theory,we study Turing instability of the spatially homogeneous Hopf bifurcation periodic solutions.At last,the theoretical results are verified by numerical simulations.展开更多
In this paper,we consider the long-term sustainability of the northeast Korean pine.We propose a class of natural Korean pine population system with time delay and diffusion term.First,by analyzing the roots distribut...In this paper,we consider the long-term sustainability of the northeast Korean pine.We propose a class of natural Korean pine population system with time delay and diffusion term.First,by analyzing the roots distribution of the characteristic equation,we study the stability of the model system with diffusion terms and prove the occurrence of Hopf bifurcation.Second,we introduce lactation time delay into a population model with a diffusion term,based on stability theory of ordinary differential equation,norm form methods and center manifold theorem,the stability of bifurcating periodic solutions and the relevant formula for the direction of Hopf bifurcation are given.Finally,some numerical simulations are given.展开更多
This paper proposes an image encryption algorithm LQBPNN(logistic quantum and back propagation neural network)based on chaotic sequences incorporating quantum keys. Firstly, the improved one-dimensional logistic cha...This paper proposes an image encryption algorithm LQBPNN(logistic quantum and back propagation neural network)based on chaotic sequences incorporating quantum keys. Firstly, the improved one-dimensional logistic chaotic sequence is used as the basic key sequence. After the quantum key is introduced, the quantum key is incorporated into the chaotic sequence by nonlinear operation. Then the pixel confused process is completed by the neural network. Finally, two sets of different mixed secret key sequences are used to perform two rounds of diffusion encryption on the confusing image. The experimental results show that the randomness and uniformity of the key sequence are effectively enhanced. The algorithm has a secret key space greater than 2182. The adjacent pixel correlation of the encrypted image is close to 0, and the information entropy is close to 8. The ciphertext image can resist several common attacks such as typical attacks, statistical analysis attacks and differential attacks.展开更多
The aim of this paper is the study of a double phase problems involving superlinear nonlinearities with a growth that need not satisfy the Ambrosetti-Rabinowitz condition.Using variational tools together with suitable...The aim of this paper is the study of a double phase problems involving superlinear nonlinearities with a growth that need not satisfy the Ambrosetti-Rabinowitz condition.Using variational tools together with suitable truncation and minimax techniques with Morse theory,the authors prove the existence of one and three nontrivial weak solutions,respectively.展开更多
A novel approach based on the upper bound theory is proposed to assess the stability of excavated slopes with spatially variable clay in undrained conditions.The proposed random limit analysis is a combination of the ...A novel approach based on the upper bound theory is proposed to assess the stability of excavated slopes with spatially variable clay in undrained conditions.The proposed random limit analysis is a combination of the deterministic slope stability limit analysis together with random field theory and Monte Carlo simulation.A series of analyses is conducted to verify the potential application of the proposed method and to investigate the effects of the soil undrained shear strength gradient and the spatial correlation length on slope stability.Three groups of potential sliding surfaces are identified and the occurrence probability of each sort of failure mechanism is quantified for various slope ratios.The proposed method is found to be feasible for evaluating slope reliability.The obtained results are helpful in understanding the slope failure mechanism from a quantitative point of view.The paper could provide guidance for slope targeted local reinforcement.展开更多
The problem of recommending new items to users(often referred to as item cold-start recommendation)remains a challenge due to the absence of users’past preferences for these items.Item features from side information ...The problem of recommending new items to users(often referred to as item cold-start recommendation)remains a challenge due to the absence of users’past preferences for these items.Item features from side information are typically leveraged to tackle the problem.Existing methods formulate regression methods,taking item features as input and user ratings as output.These methods are confronted with the issue of overfitting when item features are high-dimensional,which greatly impedes the recommendation experience.Availing of high-dimensional item features,in this work,we opt for feature selection to solve the problem of recommending top-N new items.Existing feature selection methods find a common set of features for all users,which fails to differentiate users1 preferences over item features.To personalize feature selection,we propose to select item features discriminately for different users.We study the personalization of feature selection at the level of the user or user group.We fulfill the task by proposing two embedded feature selection models.The process of personalized feature selection filters out the dimensions that are irrelevant to recommendations or unappealing to users.Experimental results on real-life datasets with high-dimensional side information reveal that the proposed method is effective in singling out features that are crucial to top-N recommendation and hence improving performance.展开更多
文摘In clinics, especially in the emergency department, carbon dioxide (CO2) is considered as the sixth vital sign in evaluating a patient's medical status. However, its wide applications in developing countries are dissatisfactory due to their high cost compared to their economic growth. In order to develop a practical system for concentration detection of human exhaled CO2 gas for our own, we studied the detection principle based upon the non-dispersive infrared (NDIR) measuring technique and related Lambert-Beer's equation carefully, gave out our functional circuit design of the system, and provided the corresponding graphical user interface (GUI) for CO2 detection. Finally, the experiment shows that it may be a practical system, and will give benefits for the development of our medical care in the future.
基金supported by Scientific Research and Innovation Fund for PhD Student:Research on the bifurcation problems of diffusive oncolytic virotherapy system(No.3072022CFJ2401).
文摘Aiming at the spatial pattern phenomenon in biochemical reactions,an enzyme-reaction Sporns-Seelig model with cross-diffusion is chosen as study object.Applying the central manifold theory,normal form method,local Hopf bifurcation theorem and perturbation theory,we study Turing instability of the spatially homogeneous Hopf bifurcation periodic solutions.At last,the theoretical results are verified by numerical simulations.
基金supported by the National Natural Science Foundation of China(No.11201095)the Fundamental Research Funds for the Central Universities(No.3072022TS2402)+1 种基金the Postdoctoral research startup foundation of Heilongjiang(No.LBH-Q14044)the Science Research Funds for Overseas Returned Chinese Scholars of Heilongjiang Province(No.LC201502).
文摘In this paper,we consider the long-term sustainability of the northeast Korean pine.We propose a class of natural Korean pine population system with time delay and diffusion term.First,by analyzing the roots distribution of the characteristic equation,we study the stability of the model system with diffusion terms and prove the occurrence of Hopf bifurcation.Second,we introduce lactation time delay into a population model with a diffusion term,based on stability theory of ordinary differential equation,norm form methods and center manifold theorem,the stability of bifurcating periodic solutions and the relevant formula for the direction of Hopf bifurcation are given.Finally,some numerical simulations are given.
基金supported by National Natural Science Foundation of China (No. 61402012)Doctor Foundation of Anhui University of Science and Technology
文摘This paper proposes an image encryption algorithm LQBPNN(logistic quantum and back propagation neural network)based on chaotic sequences incorporating quantum keys. Firstly, the improved one-dimensional logistic chaotic sequence is used as the basic key sequence. After the quantum key is introduced, the quantum key is incorporated into the chaotic sequence by nonlinear operation. Then the pixel confused process is completed by the neural network. Finally, two sets of different mixed secret key sequences are used to perform two rounds of diffusion encryption on the confusing image. The experimental results show that the randomness and uniformity of the key sequence are effectively enhanced. The algorithm has a secret key space greater than 2182. The adjacent pixel correlation of the encrypted image is close to 0, and the information entropy is close to 8. The ciphertext image can resist several common attacks such as typical attacks, statistical analysis attacks and differential attacks.
基金supported by the National Natural Science Foundation of China (No. 11201095)the Fundamental Research Funds for the Central Universities (No. 3072022TS2402)+1 种基金the Postdoctoral research startup foundation of Heilongjiang (No. LBH-Q14044)the Science Research Funds for Overseas Returned Chinese Scholars of Heilongjiang Province (No. LC201502)
文摘The aim of this paper is the study of a double phase problems involving superlinear nonlinearities with a growth that need not satisfy the Ambrosetti-Rabinowitz condition.Using variational tools together with suitable truncation and minimax techniques with Morse theory,the authors prove the existence of one and three nontrivial weak solutions,respectively.
基金the National Natural Science Foundation of China(Grant No.52322808)the QingLan Project of Jiangsu Province of China.
文摘A novel approach based on the upper bound theory is proposed to assess the stability of excavated slopes with spatially variable clay in undrained conditions.The proposed random limit analysis is a combination of the deterministic slope stability limit analysis together with random field theory and Monte Carlo simulation.A series of analyses is conducted to verify the potential application of the proposed method and to investigate the effects of the soil undrained shear strength gradient and the spatial correlation length on slope stability.Three groups of potential sliding surfaces are identified and the occurrence probability of each sort of failure mechanism is quantified for various slope ratios.The proposed method is found to be feasible for evaluating slope reliability.The obtained results are helpful in understanding the slope failure mechanism from a quantitative point of view.The paper could provide guidance for slope targeted local reinforcement.
基金supported by the National Natural Science Foundation of China under Grant Nos.61872446,61902417,71690233,and 71971212the Natural Science Foundation of Hunan Province of China under Grant No.2019JJ20024.
文摘The problem of recommending new items to users(often referred to as item cold-start recommendation)remains a challenge due to the absence of users’past preferences for these items.Item features from side information are typically leveraged to tackle the problem.Existing methods formulate regression methods,taking item features as input and user ratings as output.These methods are confronted with the issue of overfitting when item features are high-dimensional,which greatly impedes the recommendation experience.Availing of high-dimensional item features,in this work,we opt for feature selection to solve the problem of recommending top-N new items.Existing feature selection methods find a common set of features for all users,which fails to differentiate users1 preferences over item features.To personalize feature selection,we propose to select item features discriminately for different users.We study the personalization of feature selection at the level of the user or user group.We fulfill the task by proposing two embedded feature selection models.The process of personalized feature selection filters out the dimensions that are irrelevant to recommendations or unappealing to users.Experimental results on real-life datasets with high-dimensional side information reveal that the proposed method is effective in singling out features that are crucial to top-N recommendation and hence improving performance.