To establish the empirical capacity model of an on- ramp merging section, the Erlang distribution is first selected to define the time headway distribution, and then the gap acceptance theory is applied to develop the...To establish the empirical capacity model of an on- ramp merging section, the Erlang distribution is first selected to define the time headway distribution, and then the gap acceptance theory is applied to develop the basic capacity model of the on-ramp merging section. Since not all the time headways on the shoulder lane can be made full use of by on- ramp vehicles, a modified capacity model is developed, which takes the usage probability of time headway into consideration. Then, a model of capacity discount coefficient ~: is developed. Finally, based on the modified capacity model and the model of capacity discount coefficient, an empirical merge capacity model which contains the shoulder lane volume, critical gap, and the distance from nose to merging point, is constructed. Results show that, compared with other models, the proposed model is more reasonable since it takes merging section geometry into consideration, and it is easy to apply. The merge capacity varies with the shoulder lane volume, the critical gap, the distance between the nose and the merging point, and the design velocity of the shoulder lane and ramp.展开更多
A households′production behavior directly influences the quality of the environment and determines the successful development of nature reserves.Meanwhile,the households′production behaviors are complicated by inter...A households′production behavior directly influences the quality of the environment and determines the successful development of nature reserves.Meanwhile,the households′production behaviors are complicated by interrelated factors,such as protection attitudes,resource endowment,and family wealth.This research evaluated households near the Crested Ibis National Nature Reserve in Shaanxi Province,acquiring data from 436 households around Yang County and Ningshan County in the south slope of Qinling Mountains,China.Based on the collected data,we developed a structural equation model to evaluate the coupling relationships among households′ protection attitudes,production behaviors,resource endowment,and family wealth.The results showed that:1) households with great resource endowment had more negative attitudes,probably due to their greater protection costs;2) the households with higher education levels had worse protection attitudes;3) the households with more family wealth were likely to use fewer fertilizers,pesticides,and firewood;4) the households with more resource endowment showed less production and management behaviors;5) the enhancement of households' attitudes improved production behaviors to protection the environment,but the effects were not statistically significant.Our results provide a basis for the government's protection policy making,exploring the effective management measures that are beneficial for both nature reserve management and community development.展开更多
The rapid development of multimodal transportation system prompts travellers to choose multiple transportation modes, such as private vehicles or taxi, transit(subways or buses), or park-and-ride combinations for urba...The rapid development of multimodal transportation system prompts travellers to choose multiple transportation modes, such as private vehicles or taxi, transit(subways or buses), or park-and-ride combinations for urban trips. Traffic corridor is a major scenario that supports travellers to commute from suburban residential areas to central working areas. Studying their modal choice behaviour is receiving more and more interests. On one hand, it will guide the travellers to rationally choose their most economic and beneficial mode for urban trips. On the other hand, it will help traffic operators to make more appropriate policies to enhance the share of public transit in order to alleviate the traffic congestion and produce more economic and social benefits. To analyze the travel modal choice, a generalized cost model for three typical modes is first established to evaluate each different travel alternative. Then, random utility theory(RUT) and decision field theory(DFT) are introduced to describe the decision-making process how travellers make their mode choices. Further, some important factors that may influence the modal choice behaviour are discussed as well. To test the feasibility of the proposed model, a field test in Beijing was conducted to collect the real-time data and estimate the model parameters. The improvements in the test results and analysis show new advances in the development of travel mode choice on multimodal transportation networks.展开更多
In recent years, the bridge safety monitoring has been paid more attention in engineering field. How- ever, the financial and material resources as well as human resources were costly for the traditional monitoring me...In recent years, the bridge safety monitoring has been paid more attention in engineering field. How- ever, the financial and material resources as well as human resources were costly for the traditional monitoring means. Besides, the traditional means of monitoring were low in accuracy. From an engineering example, based on neural network method and historical data of the bridge monitoring to construct the BP neural network model with dual hidden layer strueture, the bridge temperature field and its effect on the behavior of bridge deflection are forecasted. The fact indicates that the predicted biggest error is 3.06% of the bridge temperature field and the bridge deflection behavior under temperature field affected is 2. 17% by the method of the BP neural net-work, which fully meet the precision requirements of the construction with practical value.展开更多
The classical Kermack-McKendrick homogeneous SIR (susceptible, infected and removed) model is well known, Its general solution is a function of the unique parameter (the reproduction number) that is equal to a mea...The classical Kermack-McKendrick homogeneous SIR (susceptible, infected and removed) model is well known, Its general solution is a function of the unique parameter (the reproduction number) that is equal to a mean number of secondary cases produced by a typical infected individual in a completely susceptible population. If the reproduction number is more than one (the threshold value) its value describes an epidemic scope: larger values correspond to more severe epidemics. In the more complex compartment SIR models the population is divided into several non-overlapping groups. It allows us to partly remove assumptions of the classical model. It is well known that for this kind of models, just as for the classical model there is the threshold parameter R0. Usually it is called by the same name--the reproduction number--though the physical meaning of this parameter has changed. The main purpose of the paper is to show that this new parameter is a not unique measure of an epidemic severity for any compartment SIR model. In particular it means that for such models comparison of the severity of two epidemics by simple comparing values of their reproduction numbers is incorrect. For compartment models these statements were proved with the help of the corresponding ODEs analysis. Very popular now individual-based models (IBMs) are more complex in comparison with the compartment ones since they use overlapping groups (school children are members of families also, for example). In such a case Diekmann's calculation method for the reproduction number used in many papers is inapplicable as well as a presentation the simulation results obtained as functions of this parameter.展开更多
Varying-coefficient models are a useful extension of classical linear model. They are widely applied to economics, biomedicine, epidemiology, and so on. There are extensive studies on them in the latest three decade y...Varying-coefficient models are a useful extension of classical linear model. They are widely applied to economics, biomedicine, epidemiology, and so on. There are extensive studies on them in the latest three decade years. In this paper, many of models related to varying-coefficient models are gathered up. All kinds of the estimation procedures and theory of hypothesis test on the varying-coefficients model are summarized. Prom my opinion, some aspects waiting to study are proposed.展开更多
The threats concerning financial stability seriously affect the overall functioning of the economy at a local, regional, national, and continental level instead of a global level, and therefore, the emphasis is laid o...The threats concerning financial stability seriously affect the overall functioning of the economy at a local, regional, national, and continental level instead of a global level, and therefore, the emphasis is laid on analyzing the causes and effects of such threats. Financial crises in the current decade, as well as those in the past have shown that a major cause of instability in the global market is the so-called financial contagion. This leads to a natural question: whether similar authorities could specify and mitigate these shocks through efficient calculation followed by stability measures taken by banking networks. To answer this question, an empirical research was conducted by analyzing the degree of contagion induced by markets in Central and Eastern Europe, based on an econometric model, involving over 17 European countries, from January 2006 to January 2013.展开更多
The nuclear industry needs of prediction of behavior and life-time, for a wide range of normal, off-normal and accident conditions for safe and economic operation. Among different thermo-mechanical properties that can...The nuclear industry needs of prediction of behavior and life-time, for a wide range of normal, off-normal and accident conditions for safe and economic operation. Among different thermo-mechanical properties that can be predictable, the knowledge on the radial temperature distribution of the UO2 (uranium dioxide) nuclear fuel during the operation of nuclear reactors is essential for safety as different mechanical and thermal-hydraulic thresholds should be respected. One of the attributes of the Brazilian CNEN (Nuclear Energy Commission) is to assess the performance of the fuel rods used in these reactors in high-bumup regimes. The effective removal of the heat generated in the fuel rods constitutes one of the primary points to consider in the design of nuclear reactors. One of the important physical parameters in the study of heat conduction from the nuclear fuel to the coolant in a PWR (pressurized water reactor) is its thermal conductivity. It is therefore desirable that the empirical models, updated for the calculation of thermal conductivity in the fuel region be developed from new sets of experimental data from the irradiated fuel rods in controlled environments This paper presents the obtained results of implementing of a new model for thermal conductivity of the UO2 in the FRAPCON code.展开更多
The dynamical behavior in the cortical brain network of macaque is studied by modeling each cortical area with a subnetwork of interacting excitable neurons. We characterize the system by studying how to perform the t...The dynamical behavior in the cortical brain network of macaque is studied by modeling each cortical area with a subnetwork of interacting excitable neurons. We characterize the system by studying how to perform the transition, which is now topology-dependent, from the active state to that with no activity. This could be a naive model for the wakening and sleeping of a brain-like system, i.e., a multi-component system with two different dynamical behavior.展开更多
The scheduling utility plays a fundamental role in addressing the commuting travel behaviours. A new scheduling utility,termed as DMRD-SU, was suggested based on some recent research findings in behavioural economics....The scheduling utility plays a fundamental role in addressing the commuting travel behaviours. A new scheduling utility,termed as DMRD-SU, was suggested based on some recent research findings in behavioural economics. DMRD-SU admitted the existence of positive arrival-caused utility. In addition, besides the travel-time-caused utility and arrival-caused utility, DMRD-SU firstly took the departure utility into account. The necessity of the departure utility in trip scheduling was analyzed comprehensively,and the corresponding individual trip scheduling model was presented. Based on a simple network, an analytical example was executed to characterize DMRD-SU. It can be found from the analytical example that: 1) DMRD-SU can predict the accumulation departure behaviors at NDT, which explains the formation of daily serious short-peak-hours in reality, while MRD-SU cannot; 2)Compared with MRD-SU, DMRD-SU predicts that people tend to depart later and its gross utility also decreases faster. Therefore,the departure utility should be considered to describe the traveler's scheduling behaviors better.展开更多
Econometric models have not been widely used for thorough analysis of the statistics published by banks. The paper presents the results of analyses of Estonian Banking, made by the authors during the last seven years....Econometric models have not been widely used for thorough analysis of the statistics published by banks. The paper presents the results of analyses of Estonian Banking, made by the authors during the last seven years. Earlier results have been published in a number of collections of research articles and have been reported on international conferences worldwide (in Mexico, South Africa, Egypt, Poland, Check Republic, Chile, China, and USA, etc.). From econometric models, the Cobb-Douglas production function with income-earning assets, equity, liabilities and fixed assets as inputs was selected. The time period chosen is from the first quarter of 1995 to the fourth quarter of 2008 that is a total of 56 periods. The balance sheets and income statements published quarterly by the banks were used as the empirical base of analysis.展开更多
Objective It has been reported that D-galactose (D-gal) can model subacute aging, and aluminum (AI) acts as a neurotoxin, but combined effects of them have not been reported. The present work aimed to reveal the e...Objective It has been reported that D-galactose (D-gal) can model subacute aging, and aluminum (AI) acts as a neurotoxin, but combined effects of them have not been reported. The present work aimed to reveal the effect of combined administration of D-gal and A1 in mice and compare the effect of D-gal treatment with that of A1 treatment. Meth- ods A1 was intragastricaHy administered and D-gal was subcutaneously injected into Kunming mice for 10 consecutive weeks. Learning and memory, eholinergic systems, as well as protein levels of amyloid β (Aβ) and hyperphosphorylated tau were determined using Morri water maze test, biochemical assays and immunohistochemical staining, respectively. Results The mice with combined treatment had obvious learning and memory deficits, and showed decreases in brain ace- tylcholine (ACh) level and in activities of choline acetyltransferase (CHAT) and acetyleholinesterase (ACHE). Formation of senile plaque (SP)-like and neurofibrillary tangle (NFT)-like structures was also observed. The behavioral and pathologi- cal changes persisted for at least 6 weeks after withdrawal of D-gal and A1. Conclusion Combined use of D-gal and A1 is an effective way to establish the non-transgenic Alzheimer's disease (AD) animal model, and is useful for studies of AD pathogenesis and therapeutic evaluation.展开更多
This paper presents an Euler discretized inertial delayed neuron model, and its bifurcation dynamical behaviors are discussed. By using the associated characteristic model, center manifold theorem and the normal form ...This paper presents an Euler discretized inertial delayed neuron model, and its bifurcation dynamical behaviors are discussed. By using the associated characteristic model, center manifold theorem and the normal form method, it is shown that the model not only undergoes codimension one(flip, Neimark-Sacker) bifurcation, but also undergoes cusp and resonance bifurcation(1:1 and 1:2) of codimension two. Further, it is found that the parity of delay has some effect on bifurcation behaviors. Finally, some numerical simulations are given to support the analytic results and explore complex dynamics, such as periodic orbits near homoclinic orbits, quasiperiodic orbits, and chaotic orbits.展开更多
We consider a behavioural model of an animal choosing between two activities, based on positive feedback, and exa- mine the effect of introducing cross inhibition between the motivations for the two activities. While ...We consider a behavioural model of an animal choosing between two activities, based on positive feedback, and exa- mine the effect of introducing cross inhibition between the motivations for the two activities. While cross-inhibition has pre- viously been included in models of decision making, the question of what benefit it may provide to an animal's activity selection behaviour has not previously been studied. In neuroscience and in collective behaviour cross-inhibition, and other equivalent means of coupling evidence-accumulating pathways, have been shown to approximate statistically-optimal decision-making and to adaptively break deadlock, thereby improving decision performance. Switching between activities is an ongoing decision process yet here we also find that cross-inhibition robustly improves its efficiency, by reducing the frequency of costly switches between behaviours .展开更多
In this study, the role of melanopsin-expressing retinal ganglion cells (mRGCs) in the glaucoma-induced depressive behavioral response pattern was investigated. The CFP-D2 transgenic glaucoma animal model from five ...In this study, the role of melanopsin-expressing retinal ganglion cells (mRGCs) in the glaucoma-induced depressive behavioral response pattern was investigated. The CFP-D2 transgenic glaucoma animal model from five age groups was used in this study. Immunohistochemical labeling, quantitative analysis of mRGC morphology, open field test (OFT), and statistical analysis were used. In comparison with C57 BL/6 mice, the age-matched CFP-D2 mice had significantly elevated intraocular pressure (lOP). We observed parallel morphological changes in the retina, including a reduction in the density of cyan fluorescent protein- (CFP) expressing cells (cells mm^-2 at 2 months of age, 1309±26; 14 months, 878±30, P〈0.001), mRGCs (2 months, 48_+3; 14 months, 19±4, P〈0.001), Brn3b-expressing RGCs (2 months, 1283±80; 14 months, 950±31, P〈0.001), Brn-3b expressing mRGCs (5 months, 50.17%±5.5%; 14 months, 12.61%±3.8%, P〈0.001), and reduction in the dendritic field size of mRGCs (mm^2 at 2 months, 0.077±0.015; 14 months, 0.065±0.015, P〈0.05). CFP-D2 mice had hyperactive locomotor activity patterns based on OFT findings of the total distance traveled, number of entries into the center, and time spent in the center of the testing apparatus. The glaucoma induced hyperactive response pattern could be associated with dysfunctional mRGCs, most likely Brn-3b-positive mRGCs in CFP-D2 mice.展开更多
Alzheimer's disease(AD) is a progressive and age-related irreversible neurodegenerative disease. When AD occurs, the relevant amount of zinc ions in brain considerably changes. In this contribution, we have explor...Alzheimer's disease(AD) is a progressive and age-related irreversible neurodegenerative disease. When AD occurs, the relevant amount of zinc ions in brain considerably changes. In this contribution, we have explored the possibility of in vivo rapid fluorescence imaging of AD through accurate targeting biomarker of zinc gluconate. By using the 3- and 6-month-old Alzheimer's model mice(AD-1) as the experimental models, our observations demonstrate that zinc gluconate molecules could pass through the blood–brain barrier and then produce hippocampus region-specific accumulation of fluorescent zinc nanoclusters in vivo, thus allowing kinetically controlled selective imaging of AD by fluorescence bioimaging.展开更多
Clinical medicine and experiments have shown that electrophysiological activities on neuronal disease systems such as the epilepsy and Parkinson can exhibit the evolutions of complex dynamical behaviors and their tran...Clinical medicine and experiments have shown that electrophysiological activities on neuronal disease systems such as the epilepsy and Parkinson can exhibit the evolutions of complex dynamical behaviors and their transitions, which are closely related to the generation mechanism of neuronal diseases. Traditionally, electrophysiological activities have been analyzed from the statistical methods. Although some ideal results have been obtained, mechanisms of complex electrophysiological activities in neuronal systems cannot yet be disclosed. Dynamics modelling can help researchers to explore the mechanisms of electro- physiological activities of neuronal disease systems. By constructing reasonable physiological dynamical model, inner relation between the dynamics model and representation behaviors of the neuronal disease systems can be further studied. In addition, based on the constructed network model, we can also explore mechanisms of the evolutions of dynamical behaviors and their transitions of the initiation, propagation and termination of different kinds of the seizures. Finally, we can design the feasible control method to regulate dynamics behaviors of the seizures so as to realize the healthy neuronal firings.展开更多
基金The National Natural Science Foundation of China(No.51278520 51278220)the Science and Technology Development Project of Jilin Province(No.20130206093SF)
文摘To establish the empirical capacity model of an on- ramp merging section, the Erlang distribution is first selected to define the time headway distribution, and then the gap acceptance theory is applied to develop the basic capacity model of the on-ramp merging section. Since not all the time headways on the shoulder lane can be made full use of by on- ramp vehicles, a modified capacity model is developed, which takes the usage probability of time headway into consideration. Then, a model of capacity discount coefficient ~: is developed. Finally, based on the modified capacity model and the model of capacity discount coefficient, an empirical merge capacity model which contains the shoulder lane volume, critical gap, and the distance from nose to merging point, is constructed. Results show that, compared with other models, the proposed model is more reasonable since it takes merging section geometry into consideration, and it is easy to apply. The merge capacity varies with the shoulder lane volume, the critical gap, the distance between the nose and the merging point, and the design velocity of the shoulder lane and ramp.
基金Under the auspices of Forestry Industry Research Special Funds for Public Welfare Projects(No.201004008)National Natural Science Foundation of China(No.71003007)Research Program of Food and Agriculture Organization(No.CHN/2011/077/LOA)
文摘A households′production behavior directly influences the quality of the environment and determines the successful development of nature reserves.Meanwhile,the households′production behaviors are complicated by interrelated factors,such as protection attitudes,resource endowment,and family wealth.This research evaluated households near the Crested Ibis National Nature Reserve in Shaanxi Province,acquiring data from 436 households around Yang County and Ningshan County in the south slope of Qinling Mountains,China.Based on the collected data,we developed a structural equation model to evaluate the coupling relationships among households′ protection attitudes,production behaviors,resource endowment,and family wealth.The results showed that:1) households with great resource endowment had more negative attitudes,probably due to their greater protection costs;2) the households with higher education levels had worse protection attitudes;3) the households with more family wealth were likely to use fewer fertilizers,pesticides,and firewood;4) the households with more resource endowment showed less production and management behaviors;5) the enhancement of households' attitudes improved production behaviors to protection the environment,but the effects were not statistically significant.Our results provide a basis for the government's protection policy making,exploring the effective management measures that are beneficial for both nature reserve management and community development.
基金Project(2012CB725405)supported in part by National Basic Research Program of ChinaProject(2014BAG03B01)supported by the National Science and Technology Support Program,China+1 种基金Project(71301083)supported by the National Natural Science Foundation of ChinaProject(20131089307)supported by the Project Supported by Tsinghua University,China
文摘The rapid development of multimodal transportation system prompts travellers to choose multiple transportation modes, such as private vehicles or taxi, transit(subways or buses), or park-and-ride combinations for urban trips. Traffic corridor is a major scenario that supports travellers to commute from suburban residential areas to central working areas. Studying their modal choice behaviour is receiving more and more interests. On one hand, it will guide the travellers to rationally choose their most economic and beneficial mode for urban trips. On the other hand, it will help traffic operators to make more appropriate policies to enhance the share of public transit in order to alleviate the traffic congestion and produce more economic and social benefits. To analyze the travel modal choice, a generalized cost model for three typical modes is first established to evaluate each different travel alternative. Then, random utility theory(RUT) and decision field theory(DFT) are introduced to describe the decision-making process how travellers make their mode choices. Further, some important factors that may influence the modal choice behaviour are discussed as well. To test the feasibility of the proposed model, a field test in Beijing was conducted to collect the real-time data and estimate the model parameters. The improvements in the test results and analysis show new advances in the development of travel mode choice on multimodal transportation networks.
文摘In recent years, the bridge safety monitoring has been paid more attention in engineering field. How- ever, the financial and material resources as well as human resources were costly for the traditional monitoring means. Besides, the traditional means of monitoring were low in accuracy. From an engineering example, based on neural network method and historical data of the bridge monitoring to construct the BP neural network model with dual hidden layer strueture, the bridge temperature field and its effect on the behavior of bridge deflection are forecasted. The fact indicates that the predicted biggest error is 3.06% of the bridge temperature field and the bridge deflection behavior under temperature field affected is 2. 17% by the method of the BP neural net-work, which fully meet the precision requirements of the construction with practical value.
基金Acknowledgements This work was assisted through participation in "Optimal Control and Optimization for Individual- based and Agent-based Models" Investigative Workshop at the National Institute for Mathematical and Biological Synthesis, sponsored by the National Science Foundation, the U.S. Department of Homeland Security, and the U.S. Department of Agriculture through NSF Award #EF-0832858, with additional support from The University of Tennessee, Knoxville.
文摘The classical Kermack-McKendrick homogeneous SIR (susceptible, infected and removed) model is well known, Its general solution is a function of the unique parameter (the reproduction number) that is equal to a mean number of secondary cases produced by a typical infected individual in a completely susceptible population. If the reproduction number is more than one (the threshold value) its value describes an epidemic scope: larger values correspond to more severe epidemics. In the more complex compartment SIR models the population is divided into several non-overlapping groups. It allows us to partly remove assumptions of the classical model. It is well known that for this kind of models, just as for the classical model there is the threshold parameter R0. Usually it is called by the same name--the reproduction number--though the physical meaning of this parameter has changed. The main purpose of the paper is to show that this new parameter is a not unique measure of an epidemic severity for any compartment SIR model. In particular it means that for such models comparison of the severity of two epidemics by simple comparing values of their reproduction numbers is incorrect. For compartment models these statements were proved with the help of the corresponding ODEs analysis. Very popular now individual-based models (IBMs) are more complex in comparison with the compartment ones since they use overlapping groups (school children are members of families also, for example). In such a case Diekmann's calculation method for the reproduction number used in many papers is inapplicable as well as a presentation the simulation results obtained as functions of this parameter.
基金Foundation item: Supported by the National Natural Science Foundation of China(10501053) Acknowledgement I would like to thank Henan Society of Applied Statistics for which give me a chance to declare my opinion about the varying-coefficient model.
文摘Varying-coefficient models are a useful extension of classical linear model. They are widely applied to economics, biomedicine, epidemiology, and so on. There are extensive studies on them in the latest three decade years. In this paper, many of models related to varying-coefficient models are gathered up. All kinds of the estimation procedures and theory of hypothesis test on the varying-coefficients model are summarized. Prom my opinion, some aspects waiting to study are proposed.
文摘The threats concerning financial stability seriously affect the overall functioning of the economy at a local, regional, national, and continental level instead of a global level, and therefore, the emphasis is laid on analyzing the causes and effects of such threats. Financial crises in the current decade, as well as those in the past have shown that a major cause of instability in the global market is the so-called financial contagion. This leads to a natural question: whether similar authorities could specify and mitigate these shocks through efficient calculation followed by stability measures taken by banking networks. To answer this question, an empirical research was conducted by analyzing the degree of contagion induced by markets in Central and Eastern Europe, based on an econometric model, involving over 17 European countries, from January 2006 to January 2013.
文摘The nuclear industry needs of prediction of behavior and life-time, for a wide range of normal, off-normal and accident conditions for safe and economic operation. Among different thermo-mechanical properties that can be predictable, the knowledge on the radial temperature distribution of the UO2 (uranium dioxide) nuclear fuel during the operation of nuclear reactors is essential for safety as different mechanical and thermal-hydraulic thresholds should be respected. One of the attributes of the Brazilian CNEN (Nuclear Energy Commission) is to assess the performance of the fuel rods used in these reactors in high-bumup regimes. The effective removal of the heat generated in the fuel rods constitutes one of the primary points to consider in the design of nuclear reactors. One of the important physical parameters in the study of heat conduction from the nuclear fuel to the coolant in a PWR (pressurized water reactor) is its thermal conductivity. It is therefore desirable that the empirical models, updated for the calculation of thermal conductivity in the fuel region be developed from new sets of experimental data from the irradiated fuel rods in controlled environments This paper presents the obtained results of implementing of a new model for thermal conductivity of the UO2 in the FRAPCON code.
基金supported by National Natural Science Foundation of China under Grant No. 10675060
文摘The dynamical behavior in the cortical brain network of macaque is studied by modeling each cortical area with a subnetwork of interacting excitable neurons. We characterize the system by studying how to perform the transition, which is now topology-dependent, from the active state to that with no activity. This could be a naive model for the wakening and sleeping of a brain-like system, i.e., a multi-component system with two different dynamical behavior.
基金Projects(71131001,71271023,71471014)supported by National Natural Science Foundation of ChinaProject(2012CB725403)supported by National Basic Research Program of ChinaProject(2011AA110303)supported by National High Technology Research and Development Program of China
文摘The scheduling utility plays a fundamental role in addressing the commuting travel behaviours. A new scheduling utility,termed as DMRD-SU, was suggested based on some recent research findings in behavioural economics. DMRD-SU admitted the existence of positive arrival-caused utility. In addition, besides the travel-time-caused utility and arrival-caused utility, DMRD-SU firstly took the departure utility into account. The necessity of the departure utility in trip scheduling was analyzed comprehensively,and the corresponding individual trip scheduling model was presented. Based on a simple network, an analytical example was executed to characterize DMRD-SU. It can be found from the analytical example that: 1) DMRD-SU can predict the accumulation departure behaviors at NDT, which explains the formation of daily serious short-peak-hours in reality, while MRD-SU cannot; 2)Compared with MRD-SU, DMRD-SU predicts that people tend to depart later and its gross utility also decreases faster. Therefore,the departure utility should be considered to describe the traveler's scheduling behaviors better.
文摘Econometric models have not been widely used for thorough analysis of the statistics published by banks. The paper presents the results of analyses of Estonian Banking, made by the authors during the last seven years. Earlier results have been published in a number of collections of research articles and have been reported on international conferences worldwide (in Mexico, South Africa, Egypt, Poland, Check Republic, Chile, China, and USA, etc.). From econometric models, the Cobb-Douglas production function with income-earning assets, equity, liabilities and fixed assets as inputs was selected. The time period chosen is from the first quarter of 1995 to the fourth quarter of 2008 that is a total of 56 periods. The balance sheets and income statements published quarterly by the banks were used as the empirical base of analysis.
基金supported by National Natural Science Foundation of China (No. 30271502)
文摘Objective It has been reported that D-galactose (D-gal) can model subacute aging, and aluminum (AI) acts as a neurotoxin, but combined effects of them have not been reported. The present work aimed to reveal the effect of combined administration of D-gal and A1 in mice and compare the effect of D-gal treatment with that of A1 treatment. Meth- ods A1 was intragastricaHy administered and D-gal was subcutaneously injected into Kunming mice for 10 consecutive weeks. Learning and memory, eholinergic systems, as well as protein levels of amyloid β (Aβ) and hyperphosphorylated tau were determined using Morri water maze test, biochemical assays and immunohistochemical staining, respectively. Results The mice with combined treatment had obvious learning and memory deficits, and showed decreases in brain ace- tylcholine (ACh) level and in activities of choline acetyltransferase (CHAT) and acetyleholinesterase (ACHE). Formation of senile plaque (SP)-like and neurofibrillary tangle (NFT)-like structures was also observed. The behavioral and pathologi- cal changes persisted for at least 6 weeks after withdrawal of D-gal and A1. Conclusion Combined use of D-gal and A1 is an effective way to establish the non-transgenic Alzheimer's disease (AD) animal model, and is useful for studies of AD pathogenesis and therapeutic evaluation.
基金supported by the National Priorities Research Program through the Qatar National Research Funda member of Qatar Foundation(Grant No.NPRP 4-1162-1-181)+2 种基金the Natural Science Foundation of China(Grant Nos.6140331361374078&61375102)the Natural Science Foundation Project of Chongqing CSTC(Grant No.cstc2014jcyj A40014)
文摘This paper presents an Euler discretized inertial delayed neuron model, and its bifurcation dynamical behaviors are discussed. By using the associated characteristic model, center manifold theorem and the normal form method, it is shown that the model not only undergoes codimension one(flip, Neimark-Sacker) bifurcation, but also undergoes cusp and resonance bifurcation(1:1 and 1:2) of codimension two. Further, it is found that the parity of delay has some effect on bifurcation behaviors. Finally, some numerical simulations are given to support the analytic results and explore complex dynamics, such as periodic orbits near homoclinic orbits, quasiperiodic orbits, and chaotic orbits.
文摘We consider a behavioural model of an animal choosing between two activities, based on positive feedback, and exa- mine the effect of introducing cross inhibition between the motivations for the two activities. While cross-inhibition has pre- viously been included in models of decision making, the question of what benefit it may provide to an animal's activity selection behaviour has not previously been studied. In neuroscience and in collective behaviour cross-inhibition, and other equivalent means of coupling evidence-accumulating pathways, have been shown to approximate statistically-optimal decision-making and to adaptively break deadlock, thereby improving decision performance. Switching between activities is an ongoing decision process yet here we also find that cross-inhibition robustly improves its efficiency, by reducing the frequency of costly switches between behaviours .
基金supported by the National Basic Research Program of China (2009CB320900 to Pu MingLiang,2011CB510206 to Pu MingLiangand Gao Jie)National Natural Science Foundation of China(30831160516 to Pu MingLiang)+2 种基金NIH EY04067 (N.C. Brecha)VAMerit Review (N.C. Brecha).supported by a summer fellowship from the PKU-UCLA Joint Research Institute
文摘In this study, the role of melanopsin-expressing retinal ganglion cells (mRGCs) in the glaucoma-induced depressive behavioral response pattern was investigated. The CFP-D2 transgenic glaucoma animal model from five age groups was used in this study. Immunohistochemical labeling, quantitative analysis of mRGC morphology, open field test (OFT), and statistical analysis were used. In comparison with C57 BL/6 mice, the age-matched CFP-D2 mice had significantly elevated intraocular pressure (lOP). We observed parallel morphological changes in the retina, including a reduction in the density of cyan fluorescent protein- (CFP) expressing cells (cells mm^-2 at 2 months of age, 1309±26; 14 months, 878±30, P〈0.001), mRGCs (2 months, 48_+3; 14 months, 19±4, P〈0.001), Brn3b-expressing RGCs (2 months, 1283±80; 14 months, 950±31, P〈0.001), Brn-3b expressing mRGCs (5 months, 50.17%±5.5%; 14 months, 12.61%±3.8%, P〈0.001), and reduction in the dendritic field size of mRGCs (mm^2 at 2 months, 0.077±0.015; 14 months, 0.065±0.015, P〈0.05). CFP-D2 mice had hyperactive locomotor activity patterns based on OFT findings of the total distance traveled, number of entries into the center, and time spent in the center of the testing apparatus. The glaucoma induced hyperactive response pattern could be associated with dysfunctional mRGCs, most likely Brn-3b-positive mRGCs in CFP-D2 mice.
基金supported by the National Natural Science Foundation of China(81325011)the National High Technology Research and Development Program of China(2015AA020502,2012AA022703)the Major Science and Technology Project of Suzhou(ZXY2012028)
文摘Alzheimer's disease(AD) is a progressive and age-related irreversible neurodegenerative disease. When AD occurs, the relevant amount of zinc ions in brain considerably changes. In this contribution, we have explored the possibility of in vivo rapid fluorescence imaging of AD through accurate targeting biomarker of zinc gluconate. By using the 3- and 6-month-old Alzheimer's model mice(AD-1) as the experimental models, our observations demonstrate that zinc gluconate molecules could pass through the blood–brain barrier and then produce hippocampus region-specific accumulation of fluorescent zinc nanoclusters in vivo, thus allowing kinetically controlled selective imaging of AD by fluorescence bioimaging.
文摘Clinical medicine and experiments have shown that electrophysiological activities on neuronal disease systems such as the epilepsy and Parkinson can exhibit the evolutions of complex dynamical behaviors and their transitions, which are closely related to the generation mechanism of neuronal diseases. Traditionally, electrophysiological activities have been analyzed from the statistical methods. Although some ideal results have been obtained, mechanisms of complex electrophysiological activities in neuronal systems cannot yet be disclosed. Dynamics modelling can help researchers to explore the mechanisms of electro- physiological activities of neuronal disease systems. By constructing reasonable physiological dynamical model, inner relation between the dynamics model and representation behaviors of the neuronal disease systems can be further studied. In addition, based on the constructed network model, we can also explore mechanisms of the evolutions of dynamical behaviors and their transitions of the initiation, propagation and termination of different kinds of the seizures. Finally, we can design the feasible control method to regulate dynamics behaviors of the seizures so as to realize the healthy neuronal firings.