ISSN 0253-2778

CN 34-1054/N

2020 Vol. 50, No. 2

Display Method:
Original Paper
Characterizing isolated singularities of conformal hyperbolic metrics
FENG Yu, SHI Yiqian, XU Bin
2020, 50(2): 87-93. doi: 10.3969/j.issn.0253-2778.2020.02.001
The explicit local models were classified for isolated singularities of complex one-dimensional hyperbolic metrics by complex analysis, which is interesting in its own way and could potentially be extended to higher dimensional cases.
On 2-extra edge connectivity of folded crossed cube
CAI Xuepeng, YANG Wei
2020, 50(2): 94-99. doi: 10.3969/j.issn.0253-2778.2020.02.002
The g-extra edge connectivity is an important parameter in measuring the reliability and fault tolerance of large interconnection networks. Let G be a connected graph and an integer g≥0, the g-extra edge connectivity of G, denoted by λg(G), is the minimum cardinality of a set of edges of G, if it exists, whose deletion disconnects G and leaves each remaining component to have at least g+1 vertices.
Sufficient conditions for a graph to be Hamilton-connected and traceable from every vertex
WANG Lixiang, YU Guidong, XU Yi
2020, 50(2): 100-105. doi: 10.3969/j.issn.0253-2778.2020.02.003
A path passing through all the vertices of
Positive solutions to boundary value problems for fractional differential equations with time delays
HU Xiulin, ZHANG Yongjun
2020, 50(2): 106-114. doi: 10.3969/j.issn.0253-2778.2020.02.004
The existence of positive solutions for a class of
The shock solution to a class of nonlinear singularly perturbed boundary value problems with time delay
ZHU Hongbao, CHEN Songlin, DU Yajie
2020, 50(2): 115-119. doi: 10.3969/j.issn.0253-2778.2020.02.005
The shock solution for a class of singularly perturbed time delay nonlinear problem were studied .The solution was obtained by using the matching asymptotic expansion,and the uniform validity of the shock solution of the problem was proved by the theory of differential inequalities .Finally, an example was given to verify the existence of the shock solution.
Resonance rogue wave prediction
2020, 50(2): 120-127. doi: 10.3969/j.issn.0253-2778.2020.02.006
Rogue wave is a kind of local wave with very steep distribution, very short existence time, and whose peak value is much higher than the surrounding waves. Therefore, taking the (2+1)-dimensional SK equation as an example, the Hirota bilinear method was used to explore a new type of rogue wave(resonance rogue wave), whose formation is closely related to the lump-type soliton. When the lump-type soliton is under the influence of a double-striped soliton, it will appear only momentarily and then disappear immediately, so it becomes a rogue wave. And the characteristic quantities such as the movement track, the existence time, the area and the volume of the strange wave were obtained by the method of theoretical calculation and the combination of number and shape.
X-strongly Gorenstein modules
HU Yue, ZHOU Jun, ZHAO Zhibing
2020, 50(2): 128-131. doi: 10.3969/j.issn.0253-2778.2020.02.007
The notion of X-strongly Gorenstein projective module was defined. It was proved that a module is X-Gorenstein projective if and only if it is a direct summand of some X-strongly Gorenstein projective module. Furthermore, some basic properties of X-strongly Gorenstein modules were obtained. And some results about strongly Gorenstein modules were generalized or strengthened.
A multi-stage infectious disease model on the complete graph
FU Shunan, LIAO Hongyi, NIE Jiaxin
2020, 50(2): 132-139. doi: 10.3969/j.issn.0253-2778.2020.02.008
The classical contact process is an interactive particle system model based on the complete graph Cn of n points. This is a continuous-time Markov process with state space{0,1}Cn, which explores the survival of two-stage disease spread at a certain rate on the graph. However, particles in the model may have more than two states. To this end, a multi-stage infectious disease model with a propagation rate of λn(λ>0) was considered, its future trends under long-term effects was studied. And the critical value λc(λc>0) was explored, so that when λ>λc, the infectious disease survives with a high probability within the exponential time eCn; when λ<λc, the infectious disease extincts with a high probability within the logarithmic time Clnn.
Repairing multiple failures for algebraic geometry codes
HU Wanbao, HU Shuai, CHEN Wenwen, CUI Liangwu
2020, 50(2): 140-145. doi: 10.3969/j.issn.0253-2778.2020.02.009
Minimum storage regenerating codes have minimum storage of data in each node and therefore are maximal distance separable codes.Thus,the number of nodes is upper-bounded by 2b,where b is the bits of data stored in each node.From both theoretical and practical points of view,it is natural to consider regenerating codes that nearly have minimum storage of data,and meanwhile,the number of nodes is unbounded.Aiming at the problem,Jin et al.constructed the regenerating codes by algebraic geometry codes,which generalized the repairing algorithm of Reed-Solomon codes by Guruswami and Wotters.This paper mainly gives a construction to repair multiple failures for algebraic geometry codes,which extends the framework of repairing one failure for the regenerating codes. The results generalize some quite recent results in which regenerating codes,for instance,Reed-Solomon codes and scalar codes with multiple erasures.
Continuous-time contracting problems with one-sided limited commitment under Knightian uncertainty
FEI Weiyin, YANG Shanshan, LIANG Yong
2020, 50(2): 146-155. doi: 10.3969/j.issn.0253-2778.2020.02.010
The optimal contract design problem with one-sided limited commitment under Knightian uncertainty was studied.First,based on the agent’s endowment process and the consumption returned by the principal under Knightian uncertainty,the contract model was established with the agent’s one-side limited commitment which characterizes the maximization of the principal expected profit under the agent’s expected utility (the agent’s continuation value) being not lower than the agent’s outside option value (keeping the participation constraint).By using the dynamic programming principle under Peng’s sublinear expectation theory, the Hamilton-Jacobi-Bellman (HJB) equation of the principal’s value function on her maximal expected utility was derived.Next,using the sublinear theory, the weak and strong dual theorems and the verification theorem of optimal strategy were obtained.Finally,for an example of consumption,the numerical simulation for results and the corresponding economic analysis were provided.
Complete moment convergence for weighted sums of extended negatively dependent random variables
LI Xiang, SHEN Aiting
2020, 50(2): 156-162. doi: 10.3969/j.issn.0253-2778.2020.02.011
The complete convergence and complete moment convergence for weighted sums of extended negatively dependent (END) random variables was studied by using the Rosenthal type moment inequality and truncation method of random variables.The obtained results extend some corresponding ones for independent random variables and negatively associated (NA) random variables in the existing literature.
Reduced rank regression based on hard-thresholding singular value penalization
XU Hongming
2020, 50(2): 163-175. doi: 10.3969/j.issn.0253-2778.2020.02.012
Reduced rank estimation using penalty functions to restrict ranks of variety matrices is often used for solving the multi-collinearity of high-dimensional multivariate regression. Here a hard-thresholding singular value penalization was considered to get more efficient results. Through local linear approximate method, non-convex models were converted to computable ones. This model is computationally efficient, and the resulting solution path is continuous. Experiment results from simulation and public datasets show that this kind of reduced rank regression has better accuracy than some frequently-used ones in most situations.
Dynamic systematic tail risk measurement based on tail index regression
YE Wuyi, LI Yiwei, WU Zun
2020, 50(2): 176-184. doi: 10.3969/j.issn.0253-2778.2020.02.013
The impact of the (volatility index,VIX) on the tail index was considered based on the regression model. The relationship between the tail index and the systematic tail risk coefficient was studied and a time-varying dynamic systematic tail risk coefficient model was established. Based on the model, the CVaR and the time-varying tail systematic tail risk coefficient of typical stock indices of eight countries were studied. The results show that during the financial crisis, the tail risk of the global market had increased significantly. The systematic tail risks of typical stock indices of China, Japan, Russia, India, France, and England were less than those of the global market, while those of the United States and Germany were higher.
Impact of the expansion of inter-bank certificates of deposit on the costs of corporate debt of financing of China
WANG Xiangning, WANG Zhihao
2020, 50(2): 185-196. doi: 10.3969/j.issn.0253-2778.2020.02.014
Since the release at the end of 2013, the development of the domestic inter-bank certificates of deposit(CDs) market has been rapid, and inter-bank CDs has become the most important currency market tool. However, at present, there are still few systematic studies on inter-bank CDs and its impact on China’s financial markets, and there is a lack of quantitative research. At the same time, the majority of small and medium-sized enterprises in China now face the problems of financing difficulties and expensive financing. In this regard, it was studied that how inter-bank CDs effect the cost of corporate debt financing in China from both macro and micro perspectives.At the macro level, daily data of inter-bank CDs and various types of bonds in the bond market of China from August 2015 to July 2017 were used to study the process of expansion of inter-bank CDs and the mechanism of influence of it to bond market. At the micro level, quarterly unbalanced panel data of 865 non-ST and non-financial listed SMEs from October 2014 to September 2017 were used. The empirical results show that the expansion of inter-bank CDs can significantly increase the debt financing cost of small and medium-sized listed enterprises to a certain extent. After further verification by industry and scale, it was found that the results are not affected by the industry in which the enterprise is located, but will be significantly affected by the enterprise scale (using operating income as an indicator).
Influence of entrepreneurs’ negative behavior on corporate image: Mediated by consumer psychological reasoning strategies
ZHANG Shengliang, XIA Fengyan, LI Xiaodong
2020, 50(2): 197-207. doi: 10.3969/j.issn.0253-2778.2020.02.015
A mediation mechanism of consumer psychological reasoning strategies was proposed, which elucidate the influence of entrepreneurs’ negative behavior on corporate image. The negative behavior was classified as feeling-hurting behavior and law-violating behavior, and their influences were presented under the mediation paths of three kinds of consumer psychological reasoning strategies (separation, rationalization, and combination). Through the scenario simulation and questionnaire, 564 samples were collected for analysis. The results show that separation and combination play a partial mediating role in the relationship between severity of the negative behavior of entrepreneurs and corporate image. Meanwhile, the type of the negative behavior has moderate effects on the relationships between severity of negative behavior and the psychological reasoning strategies.
Population aging, technological progress and economic growth:A research based on the PSTR model
HE Jun, ZHANG Yue, TANG Shuyi
2020, 50(2): 208-219. doi: 10.3969/j.issn.0253-2778.2020.02.016
Using an endogenous growth framework containing the R&D sector, a theoretical model of population aging and technological progress acting on economic growth was constructed. The results of numerical simulation show that aging has a non-linear inhibitory effect on economic growth. Aiming at reflecting the dynamic influence of aging on economic growth, provincial panel data of China from 2005 to 2015 was used to carry out empirical tests with panel smooth transition regression(PSTR) model. The results show that with technological progress as a conversion variable, the negative impact of aging rate on economic growth is smoothed with the improvement of technological progress level, which is characterized as a gradual weakening of nonlinear inhibition. In order to improve the robustness of the conclusion, the elderly dependency ratio was taken as an alternative variable of the aging rate, the robustness test still supports the benchmark test results. In order to eliminate the effect of bidirectional causality between economic growth and population aging, the joint equation model was constructed and the test results are consistent with those of the PSTR model.
Shared-use lane assignment and signal timing optimization at intersections with waiting area
ZHOU Yaping, ZHOU Qiaoqi, ZHUANG Hongbin, ZHENG Jianxin, ZHANG Yanyan
2020, 50(2): 220-235. doi: 10.3969/j.issn.0253-2778.2020.02.017
Based on the shared-use lane control method of intersection with left-turn waiting area configuration, a comprehensive optimization model with lane allocation and signal timing optimization was proposed to obtain the optimal design of shared-use lane assignment and signal timing, which is a mixed integer nonlinear programming model. A feasible directions method was hence introduced to solve the mixed integer non-linear programming. The research result shows that the improved control method and optimization model effectively improve the traffic efficiency of the intersections and minimize the average delay of the intersection. The comparison between the shared-use configuration with waiting area and the conventional configuration was presented and the result verifies that the former shows better performance than the latter. Besides, the sensitivities of the optimized average delay were investigated, which include the length of waiting area and the arrival rates. The optimal results proposed by the integrated model may enrich the design of signalized intersections with waiting area.
Simulation of the implantation of slow positron beams into metallic materials based on Geant4
MENG Fei, PAN Ziwen, YE Bangjiao
2020, 50(2): 236-242. doi: 10.3969/j.issn.0253-2778.2020.02.018
The processes of slow positron beam implantation into metals were studied by employing the Geant4 software. The backscattering coefficients of two patterns (i.e. normal incidence and oblique incidence) were calculated, and the distribution curves of positron implantation depth at oblique incidence and the relations between the backscattering coefficient and the incident angle were obtained. Further analysis of lateral diffusions of positrons at different angles was conducted. Simulations indicate that the lateral diffusions of slow positrons become more significant obliquely implanting into metals with smaller atomic numbers. The simulation can provide some useful referential data for the research of metals using slow positron beam technology.