This paper discusses the main impact factors of the local settlement and differential settlement of high- speed railway lines. The analysis results show that groundwater exploitation is the direct cause of differ- ent...This paper discusses the main impact factors of the local settlement and differential settlement of high- speed railway lines. The analysis results show that groundwater exploitation is the direct cause of differ- ential settlement. Based on the study of ballastless track additional load and of vehicle, track, and bridge dynamic responses under different differential settlements, a control standard of differential settlement during operation is proposed preliminarily.展开更多
Boron-based solid fuel is considered advantageous for ducted rocket applications due to its high energy density and dual-stage combustion process.Nonetheless,its performance is constrained by the formation of a protec...Boron-based solid fuel is considered advantageous for ducted rocket applications due to its high energy density and dual-stage combustion process.Nonetheless,its performance is constrained by the formation of a protective boron oxide layer.In the current study,iron nanoparticles are incorporated into boron-based solid fuel to enhance boron's burning.Paraffin wax serves as the primary fuel and binder,while gaseous oxygen is used as an oxidizer.Four different solid fuel combinations were investigated in the experiment:pure paraffin wax,paraffin wax mixed with boron particles,and paraffin wax mixed with boron alongside 10%and 20%iron particles.The main effort of the research is to assess their combustion characteristics,focusing on regression rate and combustion efficiency.While the inclusion of 10%iron particles resulted in a decrease in the regression rate,it led to an improvement in combustion efficiency by reducing the residual active boron content in the condensed combustion product by~60%.Furthermore,it was observed that increasing the proportion of iron particles to 20%further enhanced combustion efficiency to approximately 4%.The entire assessment has been carried out using a lab-scale hybrid propellant ducted rocket motor configuration having an inlet duct on regenerative concept with the secondary combustor.In the present investigation oxygen is injected both in the primary and the secondary combustor,whereas in the existing actual/lab-scale ducted rockets,an energized air is introduced in the secondary combustor.It serves as an economical system for the preliminary investigation of solid fuel impregnated with boron particles.It is expected that the present study could prove valuable strategies for future applications of boron-based hybrid propellants in ducted rocket systems.展开更多
This paper covers predicting high-resolution electricity peak demand features given lower-resolution data.This is a relevant setup as it answers whether limited higher-resolution monitoring helps to estimate future hi...This paper covers predicting high-resolution electricity peak demand features given lower-resolution data.This is a relevant setup as it answers whether limited higher-resolution monitoring helps to estimate future high-resolution peak loads when the high-resolution data is no longer available.That question is particularly interesting for network operators considering replacing high-resolution monitoring by predictive models due to economic considerations.We propose models to predict half-hourly minima and maxima of high-resolution(every minute)electricity load data while model inputs are of a lower resolution(30 min).We combine predictions of generalized additive models(GAM)and deep artificial neural networks(DNN),which are popular in load forecasting.We extensively analyze the prediction models,including the input parameters’importance,focusing on load,weather,and seasonal effects.The proposed method won a data competition organized by Western Power Distribution,a British distribution network operator.In addition,we provide a rigorous evaluation study that goes beyond the competition frame to analyze the models’robustness.The results show that the proposed methods are superior to the competition benchmark concerning the out-of-sample root mean squared error(RMSE).This holds regarding the competition month and the supplementary evaluation study,which covers an additional eleven months.Overall,our proposed model combination reduces the out-of-sample RMSE by 57.4%compared to the benchmark.展开更多
基金supported by the National Nature Science Foundation of China (U1234206 and 61503311)+4 种基金support under the Railways Technology Development Plan of China Railway Corporation (2016X008-J)the Fundamental Research Funds for the Central Universities (2682015CX039)supported by the National United Engineering Laboratory of Integrated and Intelligent Transportation
文摘This paper discusses the main impact factors of the local settlement and differential settlement of high- speed railway lines. The analysis results show that groundwater exploitation is the direct cause of differ- ential settlement. Based on the study of ballastless track additional load and of vehicle, track, and bridge dynamic responses under different differential settlements, a control standard of differential settlement during operation is proposed preliminarily.
基金the Centre of Excellence in Propulsion Systems,Alliance University,Bangalore,for providing funds(Grant No.-AU/DeanR/RC/2022)。
文摘Boron-based solid fuel is considered advantageous for ducted rocket applications due to its high energy density and dual-stage combustion process.Nonetheless,its performance is constrained by the formation of a protective boron oxide layer.In the current study,iron nanoparticles are incorporated into boron-based solid fuel to enhance boron's burning.Paraffin wax serves as the primary fuel and binder,while gaseous oxygen is used as an oxidizer.Four different solid fuel combinations were investigated in the experiment:pure paraffin wax,paraffin wax mixed with boron particles,and paraffin wax mixed with boron alongside 10%and 20%iron particles.The main effort of the research is to assess their combustion characteristics,focusing on regression rate and combustion efficiency.While the inclusion of 10%iron particles resulted in a decrease in the regression rate,it led to an improvement in combustion efficiency by reducing the residual active boron content in the condensed combustion product by~60%.Furthermore,it was observed that increasing the proportion of iron particles to 20%further enhanced combustion efficiency to approximately 4%.The entire assessment has been carried out using a lab-scale hybrid propellant ducted rocket motor configuration having an inlet duct on regenerative concept with the secondary combustor.In the present investigation oxygen is injected both in the primary and the secondary combustor,whereas in the existing actual/lab-scale ducted rockets,an energized air is introduced in the secondary combustor.It serves as an economical system for the preliminary investigation of solid fuel impregnated with boron particles.It is expected that the present study could prove valuable strategies for future applications of boron-based hybrid propellants in ducted rocket systems.
文摘This paper covers predicting high-resolution electricity peak demand features given lower-resolution data.This is a relevant setup as it answers whether limited higher-resolution monitoring helps to estimate future high-resolution peak loads when the high-resolution data is no longer available.That question is particularly interesting for network operators considering replacing high-resolution monitoring by predictive models due to economic considerations.We propose models to predict half-hourly minima and maxima of high-resolution(every minute)electricity load data while model inputs are of a lower resolution(30 min).We combine predictions of generalized additive models(GAM)and deep artificial neural networks(DNN),which are popular in load forecasting.We extensively analyze the prediction models,including the input parameters’importance,focusing on load,weather,and seasonal effects.The proposed method won a data competition organized by Western Power Distribution,a British distribution network operator.In addition,we provide a rigorous evaluation study that goes beyond the competition frame to analyze the models’robustness.The results show that the proposed methods are superior to the competition benchmark concerning the out-of-sample root mean squared error(RMSE).This holds regarding the competition month and the supplementary evaluation study,which covers an additional eleven months.Overall,our proposed model combination reduces the out-of-sample RMSE by 57.4%compared to the benchmark.
