The distribution of continuous service time in call centers is investigated.A non-Maxwellian collision kernel combining two different value functions in the interaction rule are used to describe the evolution of conti...The distribution of continuous service time in call centers is investigated.A non-Maxwellian collision kernel combining two different value functions in the interaction rule are used to describe the evolution of continuous service time,respectively.Using the statistical mechanical and asymptotic limit methods,Fokker–Planck equations are derived from the corresponding Boltzmann-type equations with non-Maxwellian collision kernels.The steady-state solutions of the Fokker–Planck equation are obtained in exact form.Numerical experiments are provided to support our results under different parameters.展开更多
The new generation of the times is the latest requirement for young people in the new era,and it is the latest training goal for young people put forward by the Party and the country in the face of the second centenni...The new generation of the times is the latest requirement for young people in the new era,and it is the latest training goal for young people put forward by the Party and the country in the face of the second centennial goal.At the 19th National Congress,it was put forward by the country that the concept of“new generation of the times”for the first time,indicating the training direction and theoretical guidance for the new generation of the times.The new age requires young people to have firm ideals and beliefs,excellent skills,and a great spirit of responsibility.The proposition of cultivating a new generation of the times is a deep exploration and summary of Marx’s theory of“all-round human development,”Lenin’s youth view and the education view of excellent traditional Chinese culture,and the proposition needs to strengthen the leadership of the Party,give play to the leading role of socialist core values,and the youth themselves should actively act to realize the transformation of theoretical and practical results.展开更多
"People-oriented" is the core of the scientific concept of development, it is to carry out and implement the scientific concept of development which is reflected in the field of education, ideological and political ..."People-oriented" is the core of the scientific concept of development, it is to carry out and implement the scientific concept of development which is reflected in the field of education, ideological and political education is to improve the effectiveness of a powerful guarantee. In this paper, in-depth analysis and in view of the meaning of ideological and political education of people text, we combine with the particularity of the ideological and political education, and propose practical measures to promote the stable development of the ideological and political education.展开更多
By establishing equivalent fixed point theorem, the boundary value problems of p Laplace equations with finite time delay are studied. It’s the first time that the functional differential equation is discussed w...By establishing equivalent fixed point theorem, the boundary value problems of p Laplace equations with finite time delay are studied. It’s the first time that the functional differential equation is discussed with p Laplacian. The topological degree and fixed point theorem on cone are used to prove the existence of solution and positive solution. The conditions are all easy to check.展开更多
Qu Qiubai is a Marxist,proletarian revolutionist,great thinker and theorist who was never afraid of conducting creative thinking.It is creative thinking that have helped Qu Qiubai to accurately feel the pulse of the t...Qu Qiubai is a Marxist,proletarian revolutionist,great thinker and theorist who was never afraid of conducting creative thinking.It is creative thinking that have helped Qu Qiubai to accurately feel the pulse of the times,to timely respond to the requirement of the times and to scientifically answer the realist question raised by times in carrying out the China’s revolutionary theory into practice.In a word,creative thinking gave full demonstration to Qu Qiu bai’s time value by following the general trend and requirements of history and keeping up with the times.展开更多
In order to assess the meat quality under different storage time and conditions, the pH value, TBA value, glycogen and lactic acid content in muscle of Landrace and Yorkshire were measured. The results showed that wit...In order to assess the meat quality under different storage time and conditions, the pH value, TBA value, glycogen and lactic acid content in muscle of Landrace and Yorkshire were measured. The results showed that within 10 h post slaughtering, post slaughtering time had extremely significant influence on pH value and lactic acid content of Landrace, but had no significant influence on glycogen content and TBA value. On the other hand, post slaughtering time had extremely significant influence on pH value of Yorkshire, but had no significant influence on glycogen, lactic acid content and TBA value. The pH values of Yorkshire at 3, 5 and 10 h post slaughtering were 5.21% ( P 〈 0.01 ), 5.64% ( P 〈 0.05 ) and 5.59% ( P 〈 0.05 ) higher than those of Landrace, respectively ; the lactic acid content in muscle of Landrace at 10 h post slaughtering was 56.04% (P 〈0.05) higher than that of Yorkshire; the TBA value in muscle of Yorkshire at 10 h post slaughtering was 89. 19% (P 〈 0.01 ) higher than that of Landrace; there was no significant difference in glycogen content between Yorkshire and Landrace. When pork stored at 4℃, storage time had no significant influence on pH value and glycogen content in muscle of Landrace, but had significant influence on drip loss, lactic acid content and TBA value ; storage time had no significant influence on pH value, glycogen content and TBA value in muscle of Yorkshire, but extremely significant influence on drip loss and significant influence on lactic acid content. The pH value in muscle of Yorkshire at 24 h post storage at 4℃ was 6.56% (P 〈0.05) higher than that of Landrace; the glycogen contents in muscle of Landrace at 24, 48, 72, 96, 120 and 144 h post storage at 4℃ were 84.90% (P〈0.05),78.40% (P〈0.01), 101.87% (P〈0.05), 83.80% (P〈0.05), 83.59% (P〈 0.05)and67.25% (P〈0.01)higher than those of York-shire, respectively; the drip loss of Landrace at 72 h post storage and TBA value at 144 h post storage were 55.70% ( P 〈 0.05 ) and 141.33 % ( P 〈 0.01 ) higher than those of Yorkshire, respectively; there was no significant difference in glycogen content between Yorkshire and Landrace. When pork stored at -20℃, storage time had significant influence on TBA value in muscle of Landrace, but had no significant influence on pH value, thawing water loss rate, glycogen and lactic acid content; storage time had no significant impact on pH value, thawing water loss rate, glycogen content and TBA value in muscle of Yorkshire, and had significant influence on lactic acid content. The pH value in muscle of Yorkshire at 24 h post storage at - 20℃ was 5.43 % ( P 〈 0.05 ) higher than that of I.andrace ; the glycogen contents in muscle of Landrace at 24, 48, 72, 96, 120 h post storage at - 20℃ were 85.08% ( P 〈0. 05 ), 108.66% ( P 〈 0.01 ), 72.69% ( P 〈 0.05 ), 90.31% ( P 〈 0.01 ), 70.38% ( P 〉 0.05 ) higher than those of Yorkshire, respectively ; the thawing water loss rates of Landrace at 24 and 72 h were 160.14% ( P 〈 0.05 ) and 74.32% ( P 〈 0.05 ) higher than those of Yorkshire, respectively ; there was no significant difference in lactic acid content and TBA value at the same time point between Yorkshire and Landrace.展开更多
In this paper, we investigate the existence of positive solutions of a class higher order boundary value problems on time scales. The class of boundary value problems educes a four-point (or three-point or two-point...In this paper, we investigate the existence of positive solutions of a class higher order boundary value problems on time scales. The class of boundary value problems educes a four-point (or three-point or two-point) boundary value problems, for which some similar results are established. Our approach relies on the Krasnosel'skii fixed point theorem. The result of this paper is new and extends previously known results.展开更多
The correlation between the initial time value of transient iterative parameters and the blowing pressure in the numerical simulation process of blowing balloon is investigated by POLYFLOW. The results show that: 1) A...The correlation between the initial time value of transient iterative parameters and the blowing pressure in the numerical simulation process of blowing balloon is investigated by POLYFLOW. The results show that: 1) As the blow molding pressure increases, the boundary value of the iterative time step decreases rapidly at first and then slowly. At the end of the first step of iterative calculation for each boundary value, the balloon parison is in the mold core cavity. 2) If the initial time value of transient iterative parameters is smaller than the boundary value of the iterative time step, the balloon parison is still in the mold core cavity at the end of the first iteration. However, if the iterative calculation continues, the calculation process may be interrupted when the time step is smaller than the initial time value of the transient iterative parameters, which makes the blow molding simulation of balloon unable to continue. 3) It is suggested that the initial time value of transient iterative parameters is one order of magnitude smaller than the boundary value of the iterative time step to complete smoothly the simulation of blow molding balloon.展开更多
Time series analysis is a key technology for medical diagnosis,weather forecasting and financial prediction systems.However,missing data frequently occur during data recording,posing a great challenge to data mining t...Time series analysis is a key technology for medical diagnosis,weather forecasting and financial prediction systems.However,missing data frequently occur during data recording,posing a great challenge to data mining tasks.In this study,we propose a novel time series data representation-based denoising autoencoder(DAE)for the reconstruction of missing values.Two data representation methods,namely,recurrence plot(RP)and Gramian angular field(GAF),are used to transform the raw time series to a 2D matrix for establishing the temporal correlations between different time intervals and extracting the structural patterns from the time series.Then an improved DAE is proposed to reconstruct the missing values from the 2D representation of time series.A comprehensive comparison is conducted amongst the different representations on standard datasets.Results show that the 2D representations have a lower reconstruction error than the raw time series,and the RP representation provides the best outcome.This work provides useful insights into the better reconstruction of missing values in time series analysis to considerably improve the reliability of timevarying system.展开更多
Marx's theory of scientific and technological progress and utilization of natural resources is an indispensable and important part of Marx's economic theory.To realize the harmonious unification of man and nat...Marx's theory of scientific and technological progress and utilization of natural resources is an indispensable and important part of Marx's economic theory.To realize the harmonious unification of man and nature,man must correctly understand the effect of scientific and technological progress on the use of natural resources,fundamentally solve the problem that scientific and technological progress cannot replace the position of natural resources in economic development,and objectively evaluate the relationship between human power and the power of nature.Grasping and comprehending the scientific connotation of Marx's theory of scientific and technological progress and utilization of natural resources has a very important theoretical value and practical significance for saving and effectively using natural resources and building an environment-friendly society.展开更多
To take the seismic zone that includes the great shock with M S8.5 as the statistical unit of estimating b value can often lead to more large variance, because the seismogenic zone of the great shock with M...To take the seismic zone that includes the great shock with M S8.5 as the statistical unit of estimating b value can often lead to more large variance, because the seismogenic zone of the great shock with M S8.5 are larger than that delineated in general seismic zone. Two-level statistical units are considered in this paper. The seismic province is the first level unit that is suitable for group of earthquakes including the great shock of M S8.5. A seismic province can be divided into several seismic zones. They can be taken as the second level unit for group of quakes in which the super magnitude of the greatest shock do not exceed 8. Because of the nonstationarity in time of seismic activity, the unbalancedness of data and differential of seismic temporal series feature in different areas need to be considered when we select the time period for estimating b value. According to local conditions, the time period is selected at one′s discretion in order to reflect seismicity level of this statistical unit in future 100 years.展开更多
Let W be a standard Brownian motion,and define Y(t) =∫t 0 ds W(s) as Cauchy' s principal value related to the local time of W.We study some limitresults on lag increments of Y(t) and obtain various results all...Let W be a standard Brownian motion,and define Y(t) =∫t 0 ds W(s) as Cauchy' s principal value related to the local time of W.We study some limitresults on lag increments of Y(t) and obtain various results all of which are related to earlier work by Hanson and Russo in 1 983展开更多
We consider the nth order nonlinear differential equation on time scales subject to the right focal type two-point boundary conditions We establish a criterion for the existence of at least one positive solution by ut...We consider the nth order nonlinear differential equation on time scales subject to the right focal type two-point boundary conditions We establish a criterion for the existence of at least one positive solution by utilizing Krasnosel’skii fixed point theorem. And then, we establish the existence of at least three positive solutions by utilizing Leggett-Williams fixed point theorem.展开更多
The accuracy and time scale invariance of value-at-risk (VaR) measurement methods for different stock indices and at different confidence levels are tested. Extreme value theory (EVT) is applied to model the extre...The accuracy and time scale invariance of value-at-risk (VaR) measurement methods for different stock indices and at different confidence levels are tested. Extreme value theory (EVT) is applied to model the extreme tail of standardized residual series of daily/weekly indices losses, and parametric and nonparametric methods are used to estimate parameters of the general Pareto distribution (GPD), and dynamic VaR for indices of three stock markets in China. The accuracy and time scale invariance of risk measurement methods through back-testing approach are also examined. Results show that not all the indices accept time scale invariance; there are some differences in accuracy between different indices at various confidence levels. The most powerful dynamic VaR estimation methods are EVT-GJR-Hill at 97.5% level for weekly loss to Shanghai stock market, and EVT-GARCH-MLE (Hill) at 99.0% level for weekly loss to Taiwan and Hong Kong stock markets, respectively.展开更多
This paper introduces the theory of utility maximization ofNested Logit model,the establishment of selective limbs and its probability expressions;the basic calculation formula of time value. Investigate the travel ro...This paper introduces the theory of utility maximization ofNested Logit model,the establishment of selective limbs and its probability expressions;the basic calculation formula of time value. Investigate the travel routes and travel mode choices of residents from Suzhou to Shanghai,consider different impact variables in the survey,and divide their travel lines into two travel days on weekdays due to commuting to Shanghai, and free travel to Shanghai on weekdays.The data of the survey were analyzed and analyzed,and the parameters of the established Nested Logit model were calibrated by ST AT A software.The selection model and time value of the travel route and travel mode of residents under different scenarios and different influence variables were obtained Analyze.展开更多
Time-spectral solution of ordinary and partial differential equations is often regarded as an inefficient approach. The associated extension of the time domain, as compared to finite difference methods, is believed to...Time-spectral solution of ordinary and partial differential equations is often regarded as an inefficient approach. The associated extension of the time domain, as compared to finite difference methods, is believed to result in uncomfortably many numerical operations and high memory requirements. It is shown in this work that performance is substantially enhanced by the introduction of algorithms for temporal and spatial subdomains in combination with sparse matrix methods. The accuracy and efficiency of the recently developed time spectral, generalized weighted residual method (GWRM) are compared to that of the explicit Lax-Wendroff and implicit Crank-Nicolson methods. Three initial-value PDEs are employed as model problems;the 1D Burger equation, a forced 1D wave equation and a coupled system of 14 linearized ideal magnetohydrodynamic (MHD) equations. It is found that the GWRM is more efficient than the time-stepping methods at high accuracies. The advantageous scalings Nt<sup style="margin-left:-6px;">1.0Ns<sup style="margin-left:-6px;">1.43 and Nt<sup style="margin-left:-6px;">0.0Ns<sup style="margin-left:-6px;">1.08 were obtained for CPU time and memory requirements, respectively, with Nt and Ns denoting the number of temporal and spatial subdomains. For time-averaged solution of the two-time-scales forced wave equation, GWRM performance exceeds that of the finite difference methods by an order of magnitude both in terms of CPU time and memory requirement. Favorable subdomain scaling is demonstrated for the MHD equations, indicating a potential for efficient solution of advanced initial-value problems in, for example, fluid mechanics and MHD.展开更多
In this note, the expectation value of time based on quantum mechanics formalism is derived. It is found that the expectation value of time does not depend on space.
The article deals with an economic order quantity (EOQ) inventory model for deteriorating items in which the supplier provides the purchaser a permissible delay in payment. This is so when deterioration of units in th...The article deals with an economic order quantity (EOQ) inventory model for deteriorating items in which the supplier provides the purchaser a permissible delay in payment. This is so when deterioration of units in the inventory is subject to constant deterioration rate, demand rate is quadratic function of time and salvage value is associated with the deteriorated units. Shortages in the system are not allowed to occur. A mathematical formulation is developed when the supplier offers a permissible delay period to the customers under two circumstances: 1) when delay period is less than the cycle of time;and 2) when delay period is greater than the cycle of time. The method is suitable for the items like state-of-the-art aircrafts, super computers, laptops, android mobiles, seasonal items and machines and their spare parts. A solution procedure algorithm is given for finding the optimal order quantity which minimizes the total cost of an inventory system. The article includes numerical examples to support the effectiveness of the developed model. Finally, sensitivity analysis on some parameters on optimal solution is provided.展开更多
With the increased number of PMUs in the power grid, effective high speed, realtime methods to ascertain relevant data for situational awareness are needed. Several techniques have used data from PMUs in conjunction w...With the increased number of PMUs in the power grid, effective high speed, realtime methods to ascertain relevant data for situational awareness are needed. Several techniques have used data from PMUs in conjunction with state estimation to assess system stability and event detection. However, these techniques require system topology and a large computational time. This paper presents a novel approach that uses real-time PMU data streams without the need of system connectivity or additional state estimation. The new development is based on the approximation of the eigenvalues related to the decoupled discreet-time power flow Jacobian matrix using direct openPDC data in real-time. Results are compared with other methods, such as Prony’s method, which can be too slow to handle big data. The newly developed Discreet-Time Jacobian Eigenvalue Approximation (DDJEA) method not only proves its accuracy, but also shows its effectiveness with minimal computational time: an essential element when considering situational awareness.展开更多
Temporal and spatial subdomain techniques are proposed for a time-spectral method for solution of initial-value problems. The spectral method, called the generalised weighted residual method (GWRM), is a generalisatio...Temporal and spatial subdomain techniques are proposed for a time-spectral method for solution of initial-value problems. The spectral method, called the generalised weighted residual method (GWRM), is a generalisation of weighted residual methods to the time and parameter domains [1]. A semi-analytical Chebyshev polynomial ansatz is employed, and the problem reduces to determine the coefficients of the ansatz from linear or nonlinear algebraic systems of equations. In order to avoid large memory storage and computational cost, it is preferable to subdivide the temporal and spatial domains into subdomains. Methods and examples of this article demonstrate how this can be achieved.展开更多
基金the Special Project of Yili Normal University(to improve comprehensive strength of disciplines)(Grant No.22XKZZ18)Yili Normal University Scientific Research Innovation Team Plan Project(Grant No.CXZK2021015)Yili Science and Technology Planning Project(Grant No.YZ2022B036).
文摘The distribution of continuous service time in call centers is investigated.A non-Maxwellian collision kernel combining two different value functions in the interaction rule are used to describe the evolution of continuous service time,respectively.Using the statistical mechanical and asymptotic limit methods,Fokker–Planck equations are derived from the corresponding Boltzmann-type equations with non-Maxwellian collision kernels.The steady-state solutions of the Fokker–Planck equation are obtained in exact form.Numerical experiments are provided to support our results under different parameters.
文摘The new generation of the times is the latest requirement for young people in the new era,and it is the latest training goal for young people put forward by the Party and the country in the face of the second centennial goal.At the 19th National Congress,it was put forward by the country that the concept of“new generation of the times”for the first time,indicating the training direction and theoretical guidance for the new generation of the times.The new age requires young people to have firm ideals and beliefs,excellent skills,and a great spirit of responsibility.The proposition of cultivating a new generation of the times is a deep exploration and summary of Marx’s theory of“all-round human development,”Lenin’s youth view and the education view of excellent traditional Chinese culture,and the proposition needs to strengthen the leadership of the Party,give play to the leading role of socialist core values,and the youth themselves should actively act to realize the transformation of theoretical and practical results.
文摘"People-oriented" is the core of the scientific concept of development, it is to carry out and implement the scientific concept of development which is reflected in the field of education, ideological and political education is to improve the effectiveness of a powerful guarantee. In this paper, in-depth analysis and in view of the meaning of ideological and political education of people text, we combine with the particularity of the ideological and political education, and propose practical measures to promote the stable development of the ideological and political education.
文摘By establishing equivalent fixed point theorem, the boundary value problems of p Laplace equations with finite time delay are studied. It’s the first time that the functional differential equation is discussed with p Laplacian. The topological degree and fixed point theorem on cone are used to prove the existence of solution and positive solution. The conditions are all easy to check.
文摘Qu Qiubai is a Marxist,proletarian revolutionist,great thinker and theorist who was never afraid of conducting creative thinking.It is creative thinking that have helped Qu Qiubai to accurately feel the pulse of the times,to timely respond to the requirement of the times and to scientifically answer the realist question raised by times in carrying out the China’s revolutionary theory into practice.In a word,creative thinking gave full demonstration to Qu Qiu bai’s time value by following the general trend and requirements of history and keeping up with the times.
基金Supported by Shandong Swine Industry Technology System Innovation(SDAIT-08-03)Agricultural Improved Variety Project of Shandong Province(2011LZ013-01)National Swine Industry Technology System Innovation(CARS-36-09B)
文摘In order to assess the meat quality under different storage time and conditions, the pH value, TBA value, glycogen and lactic acid content in muscle of Landrace and Yorkshire were measured. The results showed that within 10 h post slaughtering, post slaughtering time had extremely significant influence on pH value and lactic acid content of Landrace, but had no significant influence on glycogen content and TBA value. On the other hand, post slaughtering time had extremely significant influence on pH value of Yorkshire, but had no significant influence on glycogen, lactic acid content and TBA value. The pH values of Yorkshire at 3, 5 and 10 h post slaughtering were 5.21% ( P 〈 0.01 ), 5.64% ( P 〈 0.05 ) and 5.59% ( P 〈 0.05 ) higher than those of Landrace, respectively ; the lactic acid content in muscle of Landrace at 10 h post slaughtering was 56.04% (P 〈0.05) higher than that of Yorkshire; the TBA value in muscle of Yorkshire at 10 h post slaughtering was 89. 19% (P 〈 0.01 ) higher than that of Landrace; there was no significant difference in glycogen content between Yorkshire and Landrace. When pork stored at 4℃, storage time had no significant influence on pH value and glycogen content in muscle of Landrace, but had significant influence on drip loss, lactic acid content and TBA value ; storage time had no significant influence on pH value, glycogen content and TBA value in muscle of Yorkshire, but extremely significant influence on drip loss and significant influence on lactic acid content. The pH value in muscle of Yorkshire at 24 h post storage at 4℃ was 6.56% (P 〈0.05) higher than that of Landrace; the glycogen contents in muscle of Landrace at 24, 48, 72, 96, 120 and 144 h post storage at 4℃ were 84.90% (P〈0.05),78.40% (P〈0.01), 101.87% (P〈0.05), 83.80% (P〈0.05), 83.59% (P〈 0.05)and67.25% (P〈0.01)higher than those of York-shire, respectively; the drip loss of Landrace at 72 h post storage and TBA value at 144 h post storage were 55.70% ( P 〈 0.05 ) and 141.33 % ( P 〈 0.01 ) higher than those of Yorkshire, respectively; there was no significant difference in glycogen content between Yorkshire and Landrace. When pork stored at -20℃, storage time had significant influence on TBA value in muscle of Landrace, but had no significant influence on pH value, thawing water loss rate, glycogen and lactic acid content; storage time had no significant impact on pH value, thawing water loss rate, glycogen content and TBA value in muscle of Yorkshire, and had significant influence on lactic acid content. The pH value in muscle of Yorkshire at 24 h post storage at - 20℃ was 5.43 % ( P 〈 0.05 ) higher than that of I.andrace ; the glycogen contents in muscle of Landrace at 24, 48, 72, 96, 120 h post storage at - 20℃ were 85.08% ( P 〈0. 05 ), 108.66% ( P 〈 0.01 ), 72.69% ( P 〈 0.05 ), 90.31% ( P 〈 0.01 ), 70.38% ( P 〉 0.05 ) higher than those of Yorkshire, respectively ; the thawing water loss rates of Landrace at 24 and 72 h were 160.14% ( P 〈 0.05 ) and 74.32% ( P 〈 0.05 ) higher than those of Yorkshire, respectively ; there was no significant difference in lactic acid content and TBA value at the same time point between Yorkshire and Landrace.
基金The NSF (11201109) of Chinathe NSF (10040606Q50) of Anhui Province+1 种基金Excellent Talents Foundation (2012SQRL165) of University of Anhui Provincethe NSF (2012kj09) of Heifei Normal University
文摘In this paper, we investigate the existence of positive solutions of a class higher order boundary value problems on time scales. The class of boundary value problems educes a four-point (or three-point or two-point) boundary value problems, for which some similar results are established. Our approach relies on the Krasnosel'skii fixed point theorem. The result of this paper is new and extends previously known results.
文摘The correlation between the initial time value of transient iterative parameters and the blowing pressure in the numerical simulation process of blowing balloon is investigated by POLYFLOW. The results show that: 1) As the blow molding pressure increases, the boundary value of the iterative time step decreases rapidly at first and then slowly. At the end of the first step of iterative calculation for each boundary value, the balloon parison is in the mold core cavity. 2) If the initial time value of transient iterative parameters is smaller than the boundary value of the iterative time step, the balloon parison is still in the mold core cavity at the end of the first iteration. However, if the iterative calculation continues, the calculation process may be interrupted when the time step is smaller than the initial time value of the transient iterative parameters, which makes the blow molding simulation of balloon unable to continue. 3) It is suggested that the initial time value of transient iterative parameters is one order of magnitude smaller than the boundary value of the iterative time step to complete smoothly the simulation of blow molding balloon.
文摘Time series analysis is a key technology for medical diagnosis,weather forecasting and financial prediction systems.However,missing data frequently occur during data recording,posing a great challenge to data mining tasks.In this study,we propose a novel time series data representation-based denoising autoencoder(DAE)for the reconstruction of missing values.Two data representation methods,namely,recurrence plot(RP)and Gramian angular field(GAF),are used to transform the raw time series to a 2D matrix for establishing the temporal correlations between different time intervals and extracting the structural patterns from the time series.Then an improved DAE is proposed to reconstruct the missing values from the 2D representation of time series.A comprehensive comparison is conducted amongst the different representations on standard datasets.Results show that the 2D representations have a lower reconstruction error than the raw time series,and the RP representation provides the best outcome.This work provides useful insights into the better reconstruction of missing values in time series analysis to considerably improve the reliability of timevarying system.
文摘Marx's theory of scientific and technological progress and utilization of natural resources is an indispensable and important part of Marx's economic theory.To realize the harmonious unification of man and nature,man must correctly understand the effect of scientific and technological progress on the use of natural resources,fundamentally solve the problem that scientific and technological progress cannot replace the position of natural resources in economic development,and objectively evaluate the relationship between human power and the power of nature.Grasping and comprehending the scientific connotation of Marx's theory of scientific and technological progress and utilization of natural resources has a very important theoretical value and practical significance for saving and effectively using natural resources and building an environment-friendly society.
文摘To take the seismic zone that includes the great shock with M S8.5 as the statistical unit of estimating b value can often lead to more large variance, because the seismogenic zone of the great shock with M S8.5 are larger than that delineated in general seismic zone. Two-level statistical units are considered in this paper. The seismic province is the first level unit that is suitable for group of earthquakes including the great shock of M S8.5. A seismic province can be divided into several seismic zones. They can be taken as the second level unit for group of quakes in which the super magnitude of the greatest shock do not exceed 8. Because of the nonstationarity in time of seismic activity, the unbalancedness of data and differential of seismic temporal series feature in different areas need to be considered when we select the time period for estimating b value. According to local conditions, the time period is selected at one′s discretion in order to reflect seismicity level of this statistical unit in future 100 years.
文摘Let W be a standard Brownian motion,and define Y(t) =∫t 0 ds W(s) as Cauchy' s principal value related to the local time of W.We study some limitresults on lag increments of Y(t) and obtain various results all of which are related to earlier work by Hanson and Russo in 1 983
文摘We consider the nth order nonlinear differential equation on time scales subject to the right focal type two-point boundary conditions We establish a criterion for the existence of at least one positive solution by utilizing Krasnosel’skii fixed point theorem. And then, we establish the existence of at least three positive solutions by utilizing Leggett-Williams fixed point theorem.
基金The National Natural Science Foundation of China (No70501025 & 70572089)
文摘The accuracy and time scale invariance of value-at-risk (VaR) measurement methods for different stock indices and at different confidence levels are tested. Extreme value theory (EVT) is applied to model the extreme tail of standardized residual series of daily/weekly indices losses, and parametric and nonparametric methods are used to estimate parameters of the general Pareto distribution (GPD), and dynamic VaR for indices of three stock markets in China. The accuracy and time scale invariance of risk measurement methods through back-testing approach are also examined. Results show that not all the indices accept time scale invariance; there are some differences in accuracy between different indices at various confidence levels. The most powerful dynamic VaR estimation methods are EVT-GJR-Hill at 97.5% level for weekly loss to Shanghai stock market, and EVT-GARCH-MLE (Hill) at 99.0% level for weekly loss to Taiwan and Hong Kong stock markets, respectively.
基金the National Natural Science Foundation of China (71601110)the National Research and Development Program of China (2017YFC0804900).
文摘This paper introduces the theory of utility maximization ofNested Logit model,the establishment of selective limbs and its probability expressions;the basic calculation formula of time value. Investigate the travel routes and travel mode choices of residents from Suzhou to Shanghai,consider different impact variables in the survey,and divide their travel lines into two travel days on weekdays due to commuting to Shanghai, and free travel to Shanghai on weekdays.The data of the survey were analyzed and analyzed,and the parameters of the established Nested Logit model were calibrated by ST AT A software.The selection model and time value of the travel route and travel mode of residents under different scenarios and different influence variables were obtained Analyze.
文摘Time-spectral solution of ordinary and partial differential equations is often regarded as an inefficient approach. The associated extension of the time domain, as compared to finite difference methods, is believed to result in uncomfortably many numerical operations and high memory requirements. It is shown in this work that performance is substantially enhanced by the introduction of algorithms for temporal and spatial subdomains in combination with sparse matrix methods. The accuracy and efficiency of the recently developed time spectral, generalized weighted residual method (GWRM) are compared to that of the explicit Lax-Wendroff and implicit Crank-Nicolson methods. Three initial-value PDEs are employed as model problems;the 1D Burger equation, a forced 1D wave equation and a coupled system of 14 linearized ideal magnetohydrodynamic (MHD) equations. It is found that the GWRM is more efficient than the time-stepping methods at high accuracies. The advantageous scalings Nt<sup style="margin-left:-6px;">1.0Ns<sup style="margin-left:-6px;">1.43 and Nt<sup style="margin-left:-6px;">0.0Ns<sup style="margin-left:-6px;">1.08 were obtained for CPU time and memory requirements, respectively, with Nt and Ns denoting the number of temporal and spatial subdomains. For time-averaged solution of the two-time-scales forced wave equation, GWRM performance exceeds that of the finite difference methods by an order of magnitude both in terms of CPU time and memory requirement. Favorable subdomain scaling is demonstrated for the MHD equations, indicating a potential for efficient solution of advanced initial-value problems in, for example, fluid mechanics and MHD.
文摘In this note, the expectation value of time based on quantum mechanics formalism is derived. It is found that the expectation value of time does not depend on space.
文摘The article deals with an economic order quantity (EOQ) inventory model for deteriorating items in which the supplier provides the purchaser a permissible delay in payment. This is so when deterioration of units in the inventory is subject to constant deterioration rate, demand rate is quadratic function of time and salvage value is associated with the deteriorated units. Shortages in the system are not allowed to occur. A mathematical formulation is developed when the supplier offers a permissible delay period to the customers under two circumstances: 1) when delay period is less than the cycle of time;and 2) when delay period is greater than the cycle of time. The method is suitable for the items like state-of-the-art aircrafts, super computers, laptops, android mobiles, seasonal items and machines and their spare parts. A solution procedure algorithm is given for finding the optimal order quantity which minimizes the total cost of an inventory system. The article includes numerical examples to support the effectiveness of the developed model. Finally, sensitivity analysis on some parameters on optimal solution is provided.
文摘With the increased number of PMUs in the power grid, effective high speed, realtime methods to ascertain relevant data for situational awareness are needed. Several techniques have used data from PMUs in conjunction with state estimation to assess system stability and event detection. However, these techniques require system topology and a large computational time. This paper presents a novel approach that uses real-time PMU data streams without the need of system connectivity or additional state estimation. The new development is based on the approximation of the eigenvalues related to the decoupled discreet-time power flow Jacobian matrix using direct openPDC data in real-time. Results are compared with other methods, such as Prony’s method, which can be too slow to handle big data. The newly developed Discreet-Time Jacobian Eigenvalue Approximation (DDJEA) method not only proves its accuracy, but also shows its effectiveness with minimal computational time: an essential element when considering situational awareness.
文摘Temporal and spatial subdomain techniques are proposed for a time-spectral method for solution of initial-value problems. The spectral method, called the generalised weighted residual method (GWRM), is a generalisation of weighted residual methods to the time and parameter domains [1]. A semi-analytical Chebyshev polynomial ansatz is employed, and the problem reduces to determine the coefficients of the ansatz from linear or nonlinear algebraic systems of equations. In order to avoid large memory storage and computational cost, it is preferable to subdivide the temporal and spatial domains into subdomains. Methods and examples of this article demonstrate how this can be achieved.