The aviation industry is a sector that is developing, changing and growing every day in terms of technological and legal framework. There are generally three factors that enable airlines to hold on to the market. Thes...The aviation industry is a sector that is developing, changing and growing every day in terms of technological and legal framework. There are generally three factors that enable airlines to hold on to the market. These factors are safety, service quality and price. Airline companies can analyze the customers in the market with a focus on price and quality and develop a business model according to their expectations. For example, business class and economy class passenger expectations are different from each other, so the service and price to be offered to them will be different. However, all customers have one common expectation and that is safety. No matter how high quality the service is or how cheap the price is, no one wants to fly with an airline or plane that is not safe. From an airline company’s point of view, an accident or breakdown of one of the company’s aircraft can cause irreparable image loss and financial damage. If we look at past examples, we see that there are many airline companies or maintenance organizations that could not recover after an accident and went bankrupt. Safety is an indispensable factor. Therefore, there is a unit in the sector called the safety management system (SMS), which collects data by taking a proactive and reactive approach. The way and purpose of the safety management system is to take a proactive approach to recognize and prevent unsafe situations before they cause accidents or breakdowns, or to take a reactive approach to find the causes of accidents and breakdowns that have occurred as a result of certain factors and to take the necessary measures to prevent the same situations from happening again in the sector. The field of data mining, which is necessary to predict the future behavior of customers in the field of marketing, is an area that marketing also values. In this study, data mining studies to ensure safety in the aviation industry and the security of customer information in marketing will be emphasized, firstly, the concept and importance of data mining will be mentioned.展开更多
The paper proposes a three-scale binary medium-based constitutive model on the basis of the meso structures and micro components to describe the elasto-plastic mechanical behavior of mudstone samples.Based on the brea...The paper proposes a three-scale binary medium-based constitutive model on the basis of the meso structures and micro components to describe the elasto-plastic mechanical behavior of mudstone samples.Based on the breakage mechanism of geomaterials,mudstone samples are considered as two different materials(bonded and frictional elements)at mesoscales.From micro to meso scales,given the similar but different mineralogy composition and porosity of the bonded and frictional elements at microscale,as well as their separate mechanical characteristics,different homogenization methods are adopted to obtain their respective meso mechanical properties.At the mesoscale,in view of the unique meso structures and the continuous material transformation,the extended self-consistent scheme(SCS)is improved to be adaptable to elasto-plastic composites with varying meso components.With the consideration of the evolution form of the breakage ratio under the external loading being given based on the assumed strength distribution of the meso bonded elements,the mechanical relations between meso and macro scales are established.Finally,on the basis of the mean-field method and combined with the critical mechanical connections between different scales,the micro-meso-macro constitutive model for mudstone samples are proposed.The model validation shows that,with a few model parameters,the proposed model can well reflect the stress and deformation features of mudstone samples with complex micro-components.展开更多
With the advancements in the era of artificial intelligence,blockchain,cloud computing,and big data,there is a need for secure,decentralized medical record storage and retrieval systems.While cloud storage solves stor...With the advancements in the era of artificial intelligence,blockchain,cloud computing,and big data,there is a need for secure,decentralized medical record storage and retrieval systems.While cloud storage solves storage issues,it is challenging to realize secure sharing of records over the network.Medi-block record in the healthcare system has brought a new digitalization method for patients’medical records.This centralized technology provides a symmetrical process between the hospital and doctors when patients urgently need to go to a different or nearby hospital.It enables electronic medical records to be available with the correct authentication and restricts access to medical data retrieval.Medi-block record is the consumer-centered healthcare data system that brings reliable and transparent datasets for the medical record.This study presents an extensive review of proposed solutions aiming to protect the privacy and integrity of medical data by securing data sharing for Medi-block records.It also aims to propose a comprehensive investigation of the recent advances in different methods of securing data sharing,such as using Blockchain technology,Access Control,Privacy-Preserving,Proxy Re-Encryption,and Service-On-Chain approach.Finally,we highlight the open issues and identify the challenges regarding secure data sharing for Medi-block records in the healthcare systems.展开更多
Purpose–With the yearly increase of mileage and passenger volume in China’s high-speed railway,the problems of traditional paper railway tickets have become increasingly prominent,including complexity of business ha...Purpose–With the yearly increase of mileage and passenger volume in China’s high-speed railway,the problems of traditional paper railway tickets have become increasingly prominent,including complexity of business handling process,low efficiency of ticket inspection and high cost of usage and management.This paper aims to make extensive references to successful experiences of electronic ticket applications both domestically and internationally.The research on key technologies and system implementation of railway electronic ticket with Chinese characteristics has been carried out.Design/methodology/approach–Research in key technologies is conducted including synchronization technique in distributed heterogeneous database system,the grid-oriented passenger service record(PSR)data storage model,efficient access to massive PSR data under high concurrency condition,the linkage between face recognition service platforms and various terminals in large scenarios,and two-factor authentication of the e-ticket identification code based on the key and the user identity information.Focusing on the key technologies and architecture the of existing ticketing system,multiple service resources are expanded and developed such as electronic ticket clusters,PSR clusters,face recognition clusters and electronic ticket identification code clusters.Findings–The proportion of paper ticket printed has dropped to 20%,saving more than 2 billion tickets annually since the launch of the application of E-ticketing nationwide.The average time for passengers to pass through the automatic ticket gates has decreased from 3 seconds to 1.3 seconds,significantly improving the efficiency of passenger transport organization.Meanwhile,problems of paper ticket counterfeiting,reselling and loss have been generally eliminated.Originality/value–E-ticketing has laid a technical foundation for the further development of railway passenger transport services in the direction of digitalization and intelligence.展开更多
In the last decade, Brazil was the scene of two of the world’s biggest disasters related to mining tailings dams. The collapse of the Mariana and Brumadinho dams was catastrophic event that brought to light major env...In the last decade, Brazil was the scene of two of the world’s biggest disasters related to mining tailings dams. The collapse of the Mariana and Brumadinho dams was catastrophic event that brought to light major environmental and humanitarian crises. Facts like this incite debate on the safety of dam construction methods and highlight the need for a broad discussion of dam safety legislation in the country. From the above, this paper promotes a review of various forms of construction of tailings dams and their associated problems, as well as discusses the techniques for soil reinforcement and their construction methods. The work also brings an overview of the Brazilian dams from April to July 2019, tracing the context of the Brazilian tailings dams months after the tragedy of Brumadinho. The methodology includes a robust literature review and discourse analysis. In Brazil, the number of ruptured dams is alarming, especially in the state of Minas Gerais, in which more than 7 have broken in the last two decades. Among the damages, the deaths impact society abruptly and were cataloged 455 deaths, of which 216 correspond to the rupture of the dam of the Córrego do Feijão mine in Brumadinho. To evaluate and diagnose a dam, one should consider ordinance N ° 70,389, 2017 revoked by Resolution ANM n ° 95, of February 7, 2022. In this context, in March 2019, we experienced several disturbing situations regarding dam instability in the state of Minas Gerais, being categorized as risky structures. To exemplify, one can cite dams classified as level 2 risk that became level 3. Due to the above facts, several studies are being conducted to improve soil aspects. For example, we highlight the increase in soil resistance that can be done using commercial and alternative materials available in the environment.展开更多
Abutment piles in soft ground may be subjected to both vertical and horizontal soil movements resulting from approach embankment loads. To constrain the soil movements, the soft soil ground beneath the approach embank...Abutment piles in soft ground may be subjected to both vertical and horizontal soil movements resulting from approach embankment loads. To constrain the soil movements, the soft soil ground beneath the approach embankment is often improved using composite pile foundations, which aim at mitigating the bump induced by high-speed trains passing through the bridge. So far, there is limited literature on exploring the influence of the degree of ground improvement on abutment piles installed in soft soil grounds. In this paper, a series of three-dimensional (3D) centrifuge model tests was performed on an approach embankment over a silty clay deposit improved by cement-fly ash-gravel (CFG) piles combined with geogrid. Emphasis is placed on the effects of ground replacement ratio (m) on the responses of the abutment piles induced by embankment loads. Meanwhile, a numerical study was conducted with varying ground replacement ratio of the pile-reinforced grounds. Results show that the performance of the abutment piles is significantly improved when reinforcing the ground with CFG piles beneath the approach embankment. Interestingly, there is a threshold value of the replacement ratio of around 4.9% above which the effect of CFG pile foundations is limited. This implies that it is essential to optimize the ground improvement for having a cost-effective design while minimizing the risk of the bump at the end of bridge.展开更多
This paper describes a study on the combined impacts of antecedent earthquakes and droughts on disastrous debris flows.This is a novel attempt in quantifying such impacts using the effective peak acceleration(EPA)(to ...This paper describes a study on the combined impacts of antecedent earthquakes and droughts on disastrous debris flows.This is a novel attempt in quantifying such impacts using the effective peak acceleration(EPA)(to represent earthquakes) and standardized precipitation index(SPI)(to represent droughts).The study is based on the analysis of 116 disastrous debris flow events occurred in China's Mainland in the last 100 years covering a wide spectrum of climate types and landforms.It has been found that the combined impacts from earthquakes and droughts on disastrous debris flows do exist and vary from low to very high according to different climate conditions and terrains.The impacts from earthquakes increase with the increased terrain relief,and the impacts from droughts are strongest in semi-humid climate condition(with reduced impacts in humid and semi-arid /arid climate conditions).Hypothetical explanations on the study discoveries have been proposed.This study reveals the possible reasons for the disastrous debris flow distributions around the world and has significant implications in paleo-climate-seismicanalysis and disastrous debris flow risk management.展开更多
Machine learning method has been widely used in various geotechnical engineering risk analysis in recent years. However, the overfitting problem often occurs due to the small number of samples obtained in history. Thi...Machine learning method has been widely used in various geotechnical engineering risk analysis in recent years. However, the overfitting problem often occurs due to the small number of samples obtained in history. This paper proposes the FuzzySVM(support vector machine) geotechnical engineering risk analysis method based on the Bayesian network. The proposed method utilizes the fuzzy set theory to build a Bayesian network to reflect prior knowledge, and utilizes the SVM to build a Bayesian network to reflect historical samples. Then a Bayesian network for evaluation is built in Bayesian estimation method by combining prior knowledge with historical samples. Taking seismic damage evaluation of slopes as an example, the steps of the method are stated in detail. The proposed method is used to evaluate the seismic damage of 96 slopes along roads in the area affected by the Wenchuan earthquake. The evaluation results show that the method can solve the overfitting problem, which often occurs if the machine learning methods are used to evaluate risk of geotechnical engineering, and the performance of the method is much better than that of the previous machine learning methods. Moreover,the proposed method can also effectively evaluate various geotechnical engineering risks in the absence of some influencing factors.展开更多
Observation and measurement were conducted to investigate contact angle andits hysteresis on rough surface. The experimental results indicate that the increase in solidsurface roughness enlarges advancing contact angl...Observation and measurement were conducted to investigate contact angle andits hysteresis on rough surface. The experimental results indicate that the increase in solidsurface roughness enlarges advancing contact angle and decreases receding contact angle, resultingin enhanced hysteresis. It was observed that when Young''s contact angle θ_Y 【 90°, as theroughness of solid surface increased the extent of the decrease in receding contact angle exceededthat of the increase in advancing contact angle. Based on the experimental observations, the conceptof hysteresis tension was introduced to describe the contact angle hysteresis behavior on roughsolid surface. The model provides a thoughtful understanding of the physical nature of contact anglehysteresis, in particular an instructive description of the influence of surface roughness on thehysteresis. The prediction of the model is found in quite good agreement with the experimentalobservation and measurement.展开更多
Environmental impact evaluation system boundary of high-speed railway was defined based on the total life cycle theory,and the index system to evaluate the environmental impact of high-speed railway was established wi...Environmental impact evaluation system boundary of high-speed railway was defined based on the total life cycle theory,and the index system to evaluate the environmental impact of high-speed railway was established with the fuzzy analytic hierarchy method,and the matter-element evaluation model was established on the basis of the extension theory.By calculating its comprehensive interrelatedness,the evaluation rank of environment impacts of high-speed railway was determined.The numerical example shows that the model has vast prospect,which can not only expand the application areas of extension theory,but also change the traditional evaluation methods and provide new ideas and means for environmental impact evaluation of high-speed railway.展开更多
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
In order to find the effect of different viscosity modifier dosages on asphalt binder's performance in bus rapid transit lanes in the city of Chengdu, three different viscosity modifiers were analyzed: TAFPACK-super...In order to find the effect of different viscosity modifier dosages on asphalt binder's performance in bus rapid transit lanes in the city of Chengdu, three different viscosity modifiers were analyzed: TAFPACK-super (TPS), high-viscosity additive (HVA) and road-science- technology (RST), and four different asphalt binders were investigated through laboratory experiments. The percent- ages of the viscosity modifiers used were: TPS (0%, 8%, 10%, 12%, 14% and 16%) and RST and HVA (8% and 12%) depending on the type of asphalt binder. Technical indicators of modifier asphalt were tested through con- ventional and unconventional binder tests. It has been found out that only a percentage greater than or equal to 14% TPS is reasonable to achieve the requirement set by 20,000 Pa. s for the 60℃ dynamic viscosity on local #70 grade asphalt. The results indicate that conventional bin- ders did not meet the requirements of the 60℃ dynamic viscosity when 12% of TPS or HVA modifiers were used. In addition, the B-type styrene-butadienne-styrene (SBS) modified asphalt binder has better viscosity balance than the A-type SBS modified when 8% of each of the three different kinds of viscosity modifiers is used. Therefore, the B-type modified SBS thus appears to be a suitable choice in asphalt mixtures for bus rapid transit lane with the 60℃ dynamic viscosity.展开更多
Finite element method was performed to investigate the influences of beam stiffness, foundation width and cushion thickness on the beating capacity of beam foundation on underlying weak laminated clay. The comparison ...Finite element method was performed to investigate the influences of beam stiffness, foundation width and cushion thickness on the beating capacity of beam foundation on underlying weak laminated clay. The comparison between numerical results and results from field test including plate-bearing test and foundation settlement observation shows reasonable agreement. According to the numerical results, the beam width, length, cross section and cushion thickness were optimized. The results show that the stresses in subgrade soil decrease greatly with increasing the cushion thickness and width of foundation. However, the foundation settlement and influencing depth of displacement also increase correspondingly under conditions of relatively thinner cushion thickness. For the foundations on underlying weak layer, increasing foundation width merely might be inadequate for improving the bearing capacity, and the appropriate width and cushion thickness depend on the response of subgrade. A comparison between rigid and flexible beams was also discussed. The influence of a flexible beam foundation on subgrade is relatively smaller under the same loading conditions, and the flexible beam foundation appears more adaptable to various subgrades. The proposed flexible beam foundation was adopted in engineering. According to the calculation results, beam width of 2.4 m and cushion thickness of 0.8 m are proposed, and a flexible beam foundation is applied in the optimized design, which is confirmed reasonable by the actual engineering.展开更多
Snow avalanches are a common natural hazard in many countries with seasonally snow-covered mountains.The avalanche hazard varies with snow avalanche type in different snow climate regions and at different times.The ab...Snow avalanches are a common natural hazard in many countries with seasonally snow-covered mountains.The avalanche hazard varies with snow avalanche type in different snow climate regions and at different times.The ability to understand the characteristics of avalanche activity and hazards of different snow avalanche types is a prerequisite for improving avalanche disaster management in the mid-altitude region of the Central Tianshan Mountains.In this study,we collected data related to avalanche,snowpack,and meteorology during four snow seasons(from 2015 to 2019),and analysed the characteristics and hazards of different types of avalanches.The snow climate of the mid-altitude region of the Central Tianshan Mountains was examined using a snow climate classification scheme,and the results showed that the mountain range has a continental snow climate.To quantify the hazards of different types of avalanches and describe their situation over time in the continental snow climate region,this study used the avalanche hazard degree to assess the hazards of four types of avalanches,i.e.,full-depth dry snow avalanches,full-depth wet snow avalanches,surface-layer dry snow avalanches,and surface-layer wet snow avalanches.The results indicated that surface-layer dry snow avalanches were characterized by large sizes and high release frequencies,which made them having the highest avalanche hazard degree in the Central Tianshan Mountains with a continental snow climate.The overall avalanche hazard showed a single peak pattern over time during the snow season,and the greatest hazard occurred in the second half of February when the snowpack was deep and the temperature increased.This study can help the disaster and emergency management departments rationally arrange avalanche relief resources and develop avalanche prevention strategies.展开更多
The Heifangtai platform in Northwest China is famous for irrigation-induced loess landslides.This study conducted a centrifuge model test with reference to an irrigation-induced loess landslide that occurred in Heifan...The Heifangtai platform in Northwest China is famous for irrigation-induced loess landslides.This study conducted a centrifuge model test with reference to an irrigation-induced loess landslide that occurred in Heifangtai in 2011.The loess slope model was constructed by whittling a cubic loess block obtaining from the landslide site.The irrigation water was simulated by applying continuous infiltration from back of the slope.The deformation,earth pressure,and pore pressure were investigated during test by a series of transducers.For this particular study,the results showed that the failure processes were characterized by retrogressive landslides and cracks.The time dependent reductions of cohesion and internal friction angle at basal layer with increasing pore-water pressure were responsible for these failures.The foot part of slope is very important for slope instability and hazard prevention in the study area,where concentration of earth pressure and generation of high pore-water pressures would form before failures.The measurements of earth pressure and pore-water pressure might be effective for early warning in the study area.展开更多
Facial paralytic sequelae refer to the old peripheral facial paralysis. No definite duration is defined, but the paralysis lasting more than 3-6 months is generally considered as the sequelae. The authors of this repo...Facial paralytic sequelae refer to the old peripheral facial paralysis. No definite duration is defined, but the paralysis lasting more than 3-6 months is generally considered as the sequelae. The authors of this report think that the causes of the sequelae are various: the treatment may be not in time or not appropriate, or due to the disease situation itself展开更多
Torpedo cars,for the hot metal transportation by rail,play an indispensable role in China Steel Corporation (CSC)'s production.In order to meet the requirements of continual progress in hot metal production and sa...Torpedo cars,for the hot metal transportation by rail,play an indispensable role in China Steel Corporation (CSC)'s production.In order to meet the requirements of continual progress in hot metal production and safety management,the torpedo car tracking system suitable for our identification has been built up.This system not only combines the applications of of radio frequency identification(RFID) for accurately locating and radio modems to transmit the torpedo car position data,but also integrates the monitoring of railway switch machines and level crossings as well as the torpedo cars management system.Accordingly all torpedo car positions and operation data of railway equipments can be displayed in the control center for the reference of the effectively monitoring of torpedo cars and the dispatching of missions.展开更多
Most of Brazilian railways were built more than 100 years ago. Some of them were submitted to rebuilding processes while others were just overloaded by additional layers of ballast. Nowadays, Brazil is going through a...Most of Brazilian railways were built more than 100 years ago. Some of them were submitted to rebuilding processes while others were just overloaded by additional layers of ballast. Nowadays, Brazil is going through a new railway transport impulse in relation to the increase of load, despite of the necessary supply capacity. For this reason, there were developed evaluations from some Brazilian railways in order to determine their operational conditions. This work shows a comparative analysis of results from two parts of studied old railway, aiming to determine minimum features to enable them to accept higher load axis. One of these studied old railway parts did not have a sub-ballast layer in contrast to the other one. The strains and stresses of these old railway track parts were generated by the same locomotive.展开更多
The permanent deformation (rutting) of pavement is a major distress in flexible pavement. It is related to vehicles properties and/or pavement materials and conditions. This article presents an extensive experimental ...The permanent deformation (rutting) of pavement is a major distress in flexible pavement. It is related to vehicles properties and/or pavement materials and conditions. This article presents an extensive experimental investigation in order to compare between the aggregate gradation according to Superpave and Marshall methods of asphalt concrete mix design on pavement rutting and to examine the sensitivity of rutting resistance to aggregate gradation. A wheel truck machine has been used for measurement of pavement rutting (permanent deformation). The tests were carried out at two controlled different air temperature 55℃ and 25℃. The results obtained showed that the adopting of aggregate gradation procedure of Superpave method of pavement mix design for Marshall method of asphalt concrete mix design can reduce the pavement rutting by about 50%. This achievement may be related to missing of three sieves in aggregate gradation procedure of Marshall method which controls rounded and finer aggregate particles. These sieves provide more continuity for aggregate gradation to ensure filling unnecessary gaps and produce more contact points between the aggregates in Hot Mix Asphalt (HMA). The outputs of the research support modifying Marshall method of asphalt concrete mix design by adopting aggregate gradation proposed in Superpave method. The results of study also showed that the coarser aggregate provided more resistance to pavement rutting.展开更多
文摘The aviation industry is a sector that is developing, changing and growing every day in terms of technological and legal framework. There are generally three factors that enable airlines to hold on to the market. These factors are safety, service quality and price. Airline companies can analyze the customers in the market with a focus on price and quality and develop a business model according to their expectations. For example, business class and economy class passenger expectations are different from each other, so the service and price to be offered to them will be different. However, all customers have one common expectation and that is safety. No matter how high quality the service is or how cheap the price is, no one wants to fly with an airline or plane that is not safe. From an airline company’s point of view, an accident or breakdown of one of the company’s aircraft can cause irreparable image loss and financial damage. If we look at past examples, we see that there are many airline companies or maintenance organizations that could not recover after an accident and went bankrupt. Safety is an indispensable factor. Therefore, there is a unit in the sector called the safety management system (SMS), which collects data by taking a proactive and reactive approach. The way and purpose of the safety management system is to take a proactive approach to recognize and prevent unsafe situations before they cause accidents or breakdowns, or to take a reactive approach to find the causes of accidents and breakdowns that have occurred as a result of certain factors and to take the necessary measures to prevent the same situations from happening again in the sector. The field of data mining, which is necessary to predict the future behavior of customers in the field of marketing, is an area that marketing also values. In this study, data mining studies to ensure safety in the aviation industry and the security of customer information in marketing will be emphasized, firstly, the concept and importance of data mining will be mentioned.
基金the funding of Highway Planning,Survey and Design Research Institute,Sichuan Provincial Transport Department(No.2020-WX-15)the National Natural Science Foundation of China(NSFC)(No.U22A20596).
文摘The paper proposes a three-scale binary medium-based constitutive model on the basis of the meso structures and micro components to describe the elasto-plastic mechanical behavior of mudstone samples.Based on the breakage mechanism of geomaterials,mudstone samples are considered as two different materials(bonded and frictional elements)at mesoscales.From micro to meso scales,given the similar but different mineralogy composition and porosity of the bonded and frictional elements at microscale,as well as their separate mechanical characteristics,different homogenization methods are adopted to obtain their respective meso mechanical properties.At the mesoscale,in view of the unique meso structures and the continuous material transformation,the extended self-consistent scheme(SCS)is improved to be adaptable to elasto-plastic composites with varying meso components.With the consideration of the evolution form of the breakage ratio under the external loading being given based on the assumed strength distribution of the meso bonded elements,the mechanical relations between meso and macro scales are established.Finally,on the basis of the mean-field method and combined with the critical mechanical connections between different scales,the micro-meso-macro constitutive model for mudstone samples are proposed.The model validation shows that,with a few model parameters,the proposed model can well reflect the stress and deformation features of mudstone samples with complex micro-components.
文摘With the advancements in the era of artificial intelligence,blockchain,cloud computing,and big data,there is a need for secure,decentralized medical record storage and retrieval systems.While cloud storage solves storage issues,it is challenging to realize secure sharing of records over the network.Medi-block record in the healthcare system has brought a new digitalization method for patients’medical records.This centralized technology provides a symmetrical process between the hospital and doctors when patients urgently need to go to a different or nearby hospital.It enables electronic medical records to be available with the correct authentication and restricts access to medical data retrieval.Medi-block record is the consumer-centered healthcare data system that brings reliable and transparent datasets for the medical record.This study presents an extensive review of proposed solutions aiming to protect the privacy and integrity of medical data by securing data sharing for Medi-block records.It also aims to propose a comprehensive investigation of the recent advances in different methods of securing data sharing,such as using Blockchain technology,Access Control,Privacy-Preserving,Proxy Re-Encryption,and Service-On-Chain approach.Finally,we highlight the open issues and identify the challenges regarding secure data sharing for Medi-block records in the healthcare systems.
基金supported by the National Key R&D Program of China(No.2020YFF0304101).
文摘Purpose–With the yearly increase of mileage and passenger volume in China’s high-speed railway,the problems of traditional paper railway tickets have become increasingly prominent,including complexity of business handling process,low efficiency of ticket inspection and high cost of usage and management.This paper aims to make extensive references to successful experiences of electronic ticket applications both domestically and internationally.The research on key technologies and system implementation of railway electronic ticket with Chinese characteristics has been carried out.Design/methodology/approach–Research in key technologies is conducted including synchronization technique in distributed heterogeneous database system,the grid-oriented passenger service record(PSR)data storage model,efficient access to massive PSR data under high concurrency condition,the linkage between face recognition service platforms and various terminals in large scenarios,and two-factor authentication of the e-ticket identification code based on the key and the user identity information.Focusing on the key technologies and architecture the of existing ticketing system,multiple service resources are expanded and developed such as electronic ticket clusters,PSR clusters,face recognition clusters and electronic ticket identification code clusters.Findings–The proportion of paper ticket printed has dropped to 20%,saving more than 2 billion tickets annually since the launch of the application of E-ticketing nationwide.The average time for passengers to pass through the automatic ticket gates has decreased from 3 seconds to 1.3 seconds,significantly improving the efficiency of passenger transport organization.Meanwhile,problems of paper ticket counterfeiting,reselling and loss have been generally eliminated.Originality/value–E-ticketing has laid a technical foundation for the further development of railway passenger transport services in the direction of digitalization and intelligence.
文摘In the last decade, Brazil was the scene of two of the world’s biggest disasters related to mining tailings dams. The collapse of the Mariana and Brumadinho dams was catastrophic event that brought to light major environmental and humanitarian crises. Facts like this incite debate on the safety of dam construction methods and highlight the need for a broad discussion of dam safety legislation in the country. From the above, this paper promotes a review of various forms of construction of tailings dams and their associated problems, as well as discusses the techniques for soil reinforcement and their construction methods. The work also brings an overview of the Brazilian dams from April to July 2019, tracing the context of the Brazilian tailings dams months after the tragedy of Brumadinho. The methodology includes a robust literature review and discourse analysis. In Brazil, the number of ruptured dams is alarming, especially in the state of Minas Gerais, in which more than 7 have broken in the last two decades. Among the damages, the deaths impact society abruptly and were cataloged 455 deaths, of which 216 correspond to the rupture of the dam of the Córrego do Feijão mine in Brumadinho. To evaluate and diagnose a dam, one should consider ordinance N ° 70,389, 2017 revoked by Resolution ANM n ° 95, of February 7, 2022. In this context, in March 2019, we experienced several disturbing situations regarding dam instability in the state of Minas Gerais, being categorized as risky structures. To exemplify, one can cite dams classified as level 2 risk that became level 3. Due to the above facts, several studies are being conducted to improve soil aspects. For example, we highlight the increase in soil resistance that can be done using commercial and alternative materials available in the environment.
基金funded by the Science and Technology Department of Railway Ministry (Grant No. Z2012061)
文摘Abutment piles in soft ground may be subjected to both vertical and horizontal soil movements resulting from approach embankment loads. To constrain the soil movements, the soft soil ground beneath the approach embankment is often improved using composite pile foundations, which aim at mitigating the bump induced by high-speed trains passing through the bridge. So far, there is limited literature on exploring the influence of the degree of ground improvement on abutment piles installed in soft soil grounds. In this paper, a series of three-dimensional (3D) centrifuge model tests was performed on an approach embankment over a silty clay deposit improved by cement-fly ash-gravel (CFG) piles combined with geogrid. Emphasis is placed on the effects of ground replacement ratio (m) on the responses of the abutment piles induced by embankment loads. Meanwhile, a numerical study was conducted with varying ground replacement ratio of the pile-reinforced grounds. Results show that the performance of the abutment piles is significantly improved when reinforcing the ground with CFG piles beneath the approach embankment. Interestingly, there is a threshold value of the replacement ratio of around 4.9% above which the effect of CFG pile foundations is limited. This implies that it is essential to optimize the ground improvement for having a cost-effective design while minimizing the risk of the bump at the end of bridge.
基金funded by the Ministry of Science and Technology of China (Grant No. 2011BAK12B02)the National Natural Science Foundation of China (Grant No. 41190084)+2 种基金the National Key Technology R&D Program (Grant No 2012 BAK10B04)the Non-Profit Industry Financial Program of MWR (Grant No. 201301058)the Changjiang River Scientific Research Institute of Sciences Innovation Team Project (Grant No. CKSF2012052/TB)
文摘This paper describes a study on the combined impacts of antecedent earthquakes and droughts on disastrous debris flows.This is a novel attempt in quantifying such impacts using the effective peak acceleration(EPA)(to represent earthquakes) and standardized precipitation index(SPI)(to represent droughts).The study is based on the analysis of 116 disastrous debris flow events occurred in China's Mainland in the last 100 years covering a wide spectrum of climate types and landforms.It has been found that the combined impacts from earthquakes and droughts on disastrous debris flows do exist and vary from low to very high according to different climate conditions and terrains.The impacts from earthquakes increase with the increased terrain relief,and the impacts from droughts are strongest in semi-humid climate condition(with reduced impacts in humid and semi-arid /arid climate conditions).Hypothetical explanations on the study discoveries have been proposed.This study reveals the possible reasons for the disastrous debris flow distributions around the world and has significant implications in paleo-climate-seismicanalysis and disastrous debris flow risk management.
基金supported by the National Key Research and Development Program (Grant No. 2017YFC0504901)Sichuan Traffic Construction Science and Technology Project(Grant No. 2016B2–2)Doctoral Innovation Fund Program of Southwest Jiaotong University(Grant No. D-CX201804)
文摘Machine learning method has been widely used in various geotechnical engineering risk analysis in recent years. However, the overfitting problem often occurs due to the small number of samples obtained in history. This paper proposes the FuzzySVM(support vector machine) geotechnical engineering risk analysis method based on the Bayesian network. The proposed method utilizes the fuzzy set theory to build a Bayesian network to reflect prior knowledge, and utilizes the SVM to build a Bayesian network to reflect historical samples. Then a Bayesian network for evaluation is built in Bayesian estimation method by combining prior knowledge with historical samples. Taking seismic damage evaluation of slopes as an example, the steps of the method are stated in detail. The proposed method is used to evaluate the seismic damage of 96 slopes along roads in the area affected by the Wenchuan earthquake. The evaluation results show that the method can solve the overfitting problem, which often occurs if the machine learning methods are used to evaluate risk of geotechnical engineering, and the performance of the method is much better than that of the previous machine learning methods. Moreover,the proposed method can also effectively evaluate various geotechnical engineering risks in the absence of some influencing factors.
文摘Observation and measurement were conducted to investigate contact angle andits hysteresis on rough surface. The experimental results indicate that the increase in solidsurface roughness enlarges advancing contact angle and decreases receding contact angle, resultingin enhanced hysteresis. It was observed that when Young''s contact angle θ_Y 【 90°, as theroughness of solid surface increased the extent of the decrease in receding contact angle exceededthat of the increase in advancing contact angle. Based on the experimental observations, the conceptof hysteresis tension was introduced to describe the contact angle hysteresis behavior on roughsolid surface. The model provides a thoughtful understanding of the physical nature of contact anglehysteresis, in particular an instructive description of the influence of surface roughness on thehysteresis. The prediction of the model is found in quite good agreement with the experimentalobservation and measurement.
基金Project(2011QNZT062)supported by the Fundamental Research Funds for Central Universities of China
文摘Environmental impact evaluation system boundary of high-speed railway was defined based on the total life cycle theory,and the index system to evaluate the environmental impact of high-speed railway was established with the fuzzy analytic hierarchy method,and the matter-element evaluation model was established on the basis of the extension theory.By calculating its comprehensive interrelatedness,the evaluation rank of environment impacts of high-speed railway was determined.The numerical example shows that the model has vast prospect,which can not only expand the application areas of extension theory,but also change the traditional evaluation methods and provide new ideas and means for environmental impact evaluation of high-speed railway.
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.
文摘In order to find the effect of different viscosity modifier dosages on asphalt binder's performance in bus rapid transit lanes in the city of Chengdu, three different viscosity modifiers were analyzed: TAFPACK-super (TPS), high-viscosity additive (HVA) and road-science- technology (RST), and four different asphalt binders were investigated through laboratory experiments. The percent- ages of the viscosity modifiers used were: TPS (0%, 8%, 10%, 12%, 14% and 16%) and RST and HVA (8% and 12%) depending on the type of asphalt binder. Technical indicators of modifier asphalt were tested through con- ventional and unconventional binder tests. It has been found out that only a percentage greater than or equal to 14% TPS is reasonable to achieve the requirement set by 20,000 Pa. s for the 60℃ dynamic viscosity on local #70 grade asphalt. The results indicate that conventional bin- ders did not meet the requirements of the 60℃ dynamic viscosity when 12% of TPS or HVA modifiers were used. In addition, the B-type styrene-butadienne-styrene (SBS) modified asphalt binder has better viscosity balance than the A-type SBS modified when 8% of each of the three different kinds of viscosity modifiers is used. Therefore, the B-type modified SBS thus appears to be a suitable choice in asphalt mixtures for bus rapid transit lane with the 60℃ dynamic viscosity.
基金Projects(50778181, 51178472) supported by the National Natural Science Foundation of China Project(2007045) supported by the Transportation Department of Hunan Province,China
文摘Finite element method was performed to investigate the influences of beam stiffness, foundation width and cushion thickness on the beating capacity of beam foundation on underlying weak laminated clay. The comparison between numerical results and results from field test including plate-bearing test and foundation settlement observation shows reasonable agreement. According to the numerical results, the beam width, length, cross section and cushion thickness were optimized. The results show that the stresses in subgrade soil decrease greatly with increasing the cushion thickness and width of foundation. However, the foundation settlement and influencing depth of displacement also increase correspondingly under conditions of relatively thinner cushion thickness. For the foundations on underlying weak layer, increasing foundation width merely might be inadequate for improving the bearing capacity, and the appropriate width and cushion thickness depend on the response of subgrade. A comparison between rigid and flexible beams was also discussed. The influence of a flexible beam foundation on subgrade is relatively smaller under the same loading conditions, and the flexible beam foundation appears more adaptable to various subgrades. The proposed flexible beam foundation was adopted in engineering. According to the calculation results, beam width of 2.4 m and cushion thickness of 0.8 m are proposed, and a flexible beam foundation is applied in the optimized design, which is confirmed reasonable by the actual engineering.
基金Supported by National High Technology Research and Development Program of China (863 Program) (2007AA11Z221), International Cooperation Project of Shanghai (08210707500), and Natural Science Foundation of Shanghai.(08ZR1420600) . _
基金supported by the Open Project of the Xinjiang Uygur Autonomous Region Key Laboratory(2017D04010).
文摘Snow avalanches are a common natural hazard in many countries with seasonally snow-covered mountains.The avalanche hazard varies with snow avalanche type in different snow climate regions and at different times.The ability to understand the characteristics of avalanche activity and hazards of different snow avalanche types is a prerequisite for improving avalanche disaster management in the mid-altitude region of the Central Tianshan Mountains.In this study,we collected data related to avalanche,snowpack,and meteorology during four snow seasons(from 2015 to 2019),and analysed the characteristics and hazards of different types of avalanches.The snow climate of the mid-altitude region of the Central Tianshan Mountains was examined using a snow climate classification scheme,and the results showed that the mountain range has a continental snow climate.To quantify the hazards of different types of avalanches and describe their situation over time in the continental snow climate region,this study used the avalanche hazard degree to assess the hazards of four types of avalanches,i.e.,full-depth dry snow avalanches,full-depth wet snow avalanches,surface-layer dry snow avalanches,and surface-layer wet snow avalanches.The results indicated that surface-layer dry snow avalanches were characterized by large sizes and high release frequencies,which made them having the highest avalanche hazard degree in the Central Tianshan Mountains with a continental snow climate.The overall avalanche hazard showed a single peak pattern over time during the snow season,and the greatest hazard occurred in the second half of February when the snowpack was deep and the temperature increased.This study can help the disaster and emergency management departments rationally arrange avalanche relief resources and develop avalanche prevention strategies.
基金partially supported by the National Science Foundation of China (Grant No. 41572302)the Funds for Creative Research Groups of China (Grant No. 41521002)
文摘The Heifangtai platform in Northwest China is famous for irrigation-induced loess landslides.This study conducted a centrifuge model test with reference to an irrigation-induced loess landslide that occurred in Heifangtai in 2011.The loess slope model was constructed by whittling a cubic loess block obtaining from the landslide site.The irrigation water was simulated by applying continuous infiltration from back of the slope.The deformation,earth pressure,and pore pressure were investigated during test by a series of transducers.For this particular study,the results showed that the failure processes were characterized by retrogressive landslides and cracks.The time dependent reductions of cohesion and internal friction angle at basal layer with increasing pore-water pressure were responsible for these failures.The foot part of slope is very important for slope instability and hazard prevention in the study area,where concentration of earth pressure and generation of high pore-water pressures would form before failures.The measurements of earth pressure and pore-water pressure might be effective for early warning in the study area.
文摘Facial paralytic sequelae refer to the old peripheral facial paralysis. No definite duration is defined, but the paralysis lasting more than 3-6 months is generally considered as the sequelae. The authors of this report think that the causes of the sequelae are various: the treatment may be not in time or not appropriate, or due to the disease situation itself
文摘Torpedo cars,for the hot metal transportation by rail,play an indispensable role in China Steel Corporation (CSC)'s production.In order to meet the requirements of continual progress in hot metal production and safety management,the torpedo car tracking system suitable for our identification has been built up.This system not only combines the applications of of radio frequency identification(RFID) for accurately locating and radio modems to transmit the torpedo car position data,but also integrates the monitoring of railway switch machines and level crossings as well as the torpedo cars management system.Accordingly all torpedo car positions and operation data of railway equipments can be displayed in the control center for the reference of the effectively monitoring of torpedo cars and the dispatching of missions.
文摘Most of Brazilian railways were built more than 100 years ago. Some of them were submitted to rebuilding processes while others were just overloaded by additional layers of ballast. Nowadays, Brazil is going through a new railway transport impulse in relation to the increase of load, despite of the necessary supply capacity. For this reason, there were developed evaluations from some Brazilian railways in order to determine their operational conditions. This work shows a comparative analysis of results from two parts of studied old railway, aiming to determine minimum features to enable them to accept higher load axis. One of these studied old railway parts did not have a sub-ballast layer in contrast to the other one. The strains and stresses of these old railway track parts were generated by the same locomotive.
文摘The permanent deformation (rutting) of pavement is a major distress in flexible pavement. It is related to vehicles properties and/or pavement materials and conditions. This article presents an extensive experimental investigation in order to compare between the aggregate gradation according to Superpave and Marshall methods of asphalt concrete mix design on pavement rutting and to examine the sensitivity of rutting resistance to aggregate gradation. A wheel truck machine has been used for measurement of pavement rutting (permanent deformation). The tests were carried out at two controlled different air temperature 55℃ and 25℃. The results obtained showed that the adopting of aggregate gradation procedure of Superpave method of pavement mix design for Marshall method of asphalt concrete mix design can reduce the pavement rutting by about 50%. This achievement may be related to missing of three sieves in aggregate gradation procedure of Marshall method which controls rounded and finer aggregate particles. These sieves provide more continuity for aggregate gradation to ensure filling unnecessary gaps and produce more contact points between the aggregates in Hot Mix Asphalt (HMA). The outputs of the research support modifying Marshall method of asphalt concrete mix design by adopting aggregate gradation proposed in Superpave method. The results of study also showed that the coarser aggregate provided more resistance to pavement rutting.