Falling weight deflectometer （FWD） testing has been used to evaluate structural condition of pavements to predict the layer moduli using backcalculation process. However, the predicted pavement layer moduli sometime...Falling weight deflectometer （FWD） testing has been used to evaluate structural condition of pavements to predict the layer moduli using backcalculation process. However, the predicted pavement layer moduli sometimes may not be accurate even if computed and measured deflection basin has fulfilled the standard and is in concurrence with certain tolerable limits. The characteristics of pavement structure, including pavement layer thickness condition and temperature variation, affect the predicted pavement structural capacity and back calculated layer modulus. The main objective of this study is to analyze the FVc＇D test results of flexible pavement in Western Australia to predict the pavement structural capacity. Collected data includes, in addition to FWD measurements, core data and pavement distress surveys. Results showed that the dynamic analysis of falling weight deflectometer test and prediction for the strength of character of flexible pavement layer moduli have been achieved, and algorithms for interpretation of the deflection basin have been improved. The variations of moduli of all layers along the length of sections for majority of the projects are accurate and consistent with measured and computed pre- diction. However, some of the projects had some inconsistent with modulus values along the length of the sections. Results are reasonable but consideration should be taken to fix varied pavement layers moduli sections.展开更多
Dynamic simulation plays a fundamental role in security evaluation of distribution networks(DNs).However,the strong stiffness and non-linearity of distributed generation(DG)models in DNs bring about burdensome computa...Dynamic simulation plays a fundamental role in security evaluation of distribution networks(DNs).However,the strong stiffness and non-linearity of distributed generation(DG)models in DNs bring about burdensome computation and noteworthy instability on traditional methods which hampers the rapid response of simulation tool.Thus,a novel L-stable approximate analytical method with high accuracy is proposed to handle these problems.The method referred to as multistage discontinuous Galerkin method(MDGM),first derives approximate analytical solutions(AASs)of state variables which are explicit symbolic expressions concerning system states.Then,in each time window,it substitutes values for symbolic variables and trajectories of state variables are obtained subsequently.This paper applies MDGM to DG models to derive AASs.Local-truncation-error-based variable step size strategy is also developed to further improve simulation efficiency.In addition,this paper establishes detailed MDGM-based dynamic simulation procedure.From case studies on a numerical problem,a modified 33-bus system and a practical large-scale DN,it can be seen that proposed method demonstrates fast and dependable performance compared with the traditional trapezoidal method.展开更多
In this paper,we propose an analytical stochastic dynamic programming(SDP)algorithm to address the optimal management problem of price-maker community energy storage.As a price-maker,energy storage smooths price diffe...In this paper,we propose an analytical stochastic dynamic programming(SDP)algorithm to address the optimal management problem of price-maker community energy storage.As a price-maker,energy storage smooths price differences,thus decreasing energy arbitrage value.However,this price-smoothing effect can result in significant external welfare changes by reduc-ing consumer costs and producer revenues,which is not negligible for the community with energy storage systems.As such,we formulate community storage management as an SDP that aims to maximize both energy arbitrage and community welfare.To incorporate market interaction into the SDP format,we propose a framework that derives partial but sufficient market information to approximate impact of storage operations on market prices.Then we present an analytical SDP algorithm that does not require state discretization.Apart from computational efficiency,another advantage of the analytical algorithm is to guide energy storage to charge/discharge by directly comparing its current marginal value with expected future marginal value.Case studies indicate community-owned energy storage that maximizes both arbitrage and welfare value gains more benefits than storage that maximizes only arbitrage.The proposed algorithm ensures optimality and largely reduces the computational complexity of the standard SDP.Index Terms-Analytical stochastic dynamic programming,energy management,energy storage,price-maker,social welfare.展开更多
The sloshing in a group of rigid cylindrical tanks with baffles and on soil foundation under horizontal excitation is studied analytically.The solutions for the velocity potential are derived out by the liquid subdoma...The sloshing in a group of rigid cylindrical tanks with baffles and on soil foundation under horizontal excitation is studied analytically.The solutions for the velocity potential are derived out by the liquid subdomain method.Equivalent models with mass-spring oscillators are established to replace continuous fluid.Combined with the least square technique,Chebyshev polynomials are employed to fit horizontal,rocking and horizontal-rocking coupling impedances of soil,respectively.A lumped parameter model for impedance is presented to describe the effects of soil on tank structures.A mechanical model for the soil-foundation-tank-liquid-baffle system with small amount of calculation and high accuracy is proposed using the substructure technique.The analytical solutions are in comparison with data from reported literature and numerical codes to validate the effectiveness and correctness of the model.Detailed dynamic properties and seismic responses of the soil-tank system are given for the baffle number,size and location as well as soil parameter.展开更多
The aggregation ofα-synuclein(α-syn)is strongly influenced by membrane interfaces,but the mechanism of transition from monomers to oligomers at early aggregation stage is not clear.Here,we investigate the adsorption...The aggregation ofα-synuclein(α-syn)is strongly influenced by membrane interfaces,but the mechanism of transition from monomers to oligomers at early aggregation stage is not clear.Here,we investigate the adsorption and structure changes ofα-syn on oppositely charged aromatic interfaces through in-situ surface-enhanced infrared absorption(SEIRA)spectroscopy and nano-IR technique.The results show that the synergy of electrostatic and hydrophobic interactions leads to a“fast-slow”two-step aggregation pathway on negatively charged interface.Surface adsorption induces the formation of an extended helix structure and subsequently partial helix unwinding in NAC region,which enables the hydrophobic stacking between nearby NAC regions.Stable antiparallel β-sheet rich aggregates are gradually emerging as further interactions of monomers with the fast formed“first layer”.Monomers electrostatically adsorb on positively charged interface by C-terminus with NAC region and N-terminus stretched in solvent,which serve as an aggregation core and induce further adsorption and gradual formation of aggregates with C-terminus exposure.Our results demonstrate the modulation of surface charge and synergy of electrostatic and hydrophobic interactions on the interaction modes and aggregation pathways,which provide insights into dynamic conformation changes ofα-syn at early aggregation stage and imply the important role of spatial-temporal heterogeneity of membranes inα-synucleinopathies.展开更多
基金financial support by Australia GovernmentCurtin University
文摘Falling weight deflectometer （FWD） testing has been used to evaluate structural condition of pavements to predict the layer moduli using backcalculation process. However, the predicted pavement layer moduli sometimes may not be accurate even if computed and measured deflection basin has fulfilled the standard and is in concurrence with certain tolerable limits. The characteristics of pavement structure, including pavement layer thickness condition and temperature variation, affect the predicted pavement structural capacity and back calculated layer modulus. The main objective of this study is to analyze the FVc＇D test results of flexible pavement in Western Australia to predict the pavement structural capacity. Collected data includes, in addition to FWD measurements, core data and pavement distress surveys. Results showed that the dynamic analysis of falling weight deflectometer test and prediction for the strength of character of flexible pavement layer moduli have been achieved, and algorithms for interpretation of the deflection basin have been improved. The variations of moduli of all layers along the length of sections for majority of the projects are accurate and consistent with measured and computed pre- diction. However, some of the projects had some inconsistent with modulus values along the length of the sections. Results are reasonable but consideration should be taken to fix varied pavement layers moduli sections.
文摘Dynamic simulation plays a fundamental role in security evaluation of distribution networks(DNs).However,the strong stiffness and non-linearity of distributed generation(DG)models in DNs bring about burdensome computation and noteworthy instability on traditional methods which hampers the rapid response of simulation tool.Thus,a novel L-stable approximate analytical method with high accuracy is proposed to handle these problems.The method referred to as multistage discontinuous Galerkin method(MDGM),first derives approximate analytical solutions(AASs)of state variables which are explicit symbolic expressions concerning system states.Then,in each time window,it substitutes values for symbolic variables and trajectories of state variables are obtained subsequently.This paper applies MDGM to DG models to derive AASs.Local-truncation-error-based variable step size strategy is also developed to further improve simulation efficiency.In addition,this paper establishes detailed MDGM-based dynamic simulation procedure.From case studies on a numerical problem,a modified 33-bus system and a practical large-scale DN,it can be seen that proposed method demonstrates fast and dependable performance compared with the traditional trapezoidal method.
基金supported in part by the Joint Funds of the National Natural Science Foundation of China(U2066214)in part by Shanghai Sailing Program(22YF1414500)in part by the Project(SKLD22KM19)funded by State Key Laboratory of Power System Operation and Control.
文摘In this paper,we propose an analytical stochastic dynamic programming(SDP)algorithm to address the optimal management problem of price-maker community energy storage.As a price-maker,energy storage smooths price differences,thus decreasing energy arbitrage value.However,this price-smoothing effect can result in significant external welfare changes by reduc-ing consumer costs and producer revenues,which is not negligible for the community with energy storage systems.As such,we formulate community storage management as an SDP that aims to maximize both energy arbitrage and community welfare.To incorporate market interaction into the SDP format,we propose a framework that derives partial but sufficient market information to approximate impact of storage operations on market prices.Then we present an analytical SDP algorithm that does not require state discretization.Apart from computational efficiency,another advantage of the analytical algorithm is to guide energy storage to charge/discharge by directly comparing its current marginal value with expected future marginal value.Case studies indicate community-owned energy storage that maximizes both arbitrage and welfare value gains more benefits than storage that maximizes only arbitrage.The proposed algorithm ensures optimality and largely reduces the computational complexity of the standard SDP.Index Terms-Analytical stochastic dynamic programming,energy management,energy storage,price-maker,social welfare.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51978336 and 11702117)the Science and Technology Plan Project of Department of Communications of Zhejiang Province(Grant No.2021051)Nantong City Social Livelihood Science and Technology Project(Grant No.MS22022067).
文摘The sloshing in a group of rigid cylindrical tanks with baffles and on soil foundation under horizontal excitation is studied analytically.The solutions for the velocity potential are derived out by the liquid subdomain method.Equivalent models with mass-spring oscillators are established to replace continuous fluid.Combined with the least square technique,Chebyshev polynomials are employed to fit horizontal,rocking and horizontal-rocking coupling impedances of soil,respectively.A lumped parameter model for impedance is presented to describe the effects of soil on tank structures.A mechanical model for the soil-foundation-tank-liquid-baffle system with small amount of calculation and high accuracy is proposed using the substructure technique.The analytical solutions are in comparison with data from reported literature and numerical codes to validate the effectiveness and correctness of the model.Detailed dynamic properties and seismic responses of the soil-tank system are given for the baffle number,size and location as well as soil parameter.
基金financial support from National Key R&D Program of China(2022YFE0113000)the National Natural Science Foundation of China(22074138,22374083)+1 种基金the National Science Fund for Distinguished Young Scholars(22025406)Youth Innovation Promotion Association of CAs(Grant No.2020233).
文摘The aggregation ofα-synuclein(α-syn)is strongly influenced by membrane interfaces,but the mechanism of transition from monomers to oligomers at early aggregation stage is not clear.Here,we investigate the adsorption and structure changes ofα-syn on oppositely charged aromatic interfaces through in-situ surface-enhanced infrared absorption(SEIRA)spectroscopy and nano-IR technique.The results show that the synergy of electrostatic and hydrophobic interactions leads to a“fast-slow”two-step aggregation pathway on negatively charged interface.Surface adsorption induces the formation of an extended helix structure and subsequently partial helix unwinding in NAC region,which enables the hydrophobic stacking between nearby NAC regions.Stable antiparallel β-sheet rich aggregates are gradually emerging as further interactions of monomers with the fast formed“first layer”.Monomers electrostatically adsorb on positively charged interface by C-terminus with NAC region and N-terminus stretched in solvent,which serve as an aggregation core and induce further adsorption and gradual formation of aggregates with C-terminus exposure.Our results demonstrate the modulation of surface charge and synergy of electrostatic and hydrophobic interactions on the interaction modes and aggregation pathways,which provide insights into dynamic conformation changes ofα-syn at early aggregation stage and imply the important role of spatial-temporal heterogeneity of membranes inα-synucleinopathies.
