Intelligent manufacturing is a general concept that is under continuous development. It can be categorized into three basic paradigms： digital manufacturing, digital-networked manufacturing, and newgeneration intelli...Intelligent manufacturing is a general concept that is under continuous development. It can be categorized into three basic paradigms： digital manufacturing, digital-networked manufacturing, and newgeneration intelligent manufacturing. New-generation intelligent manufacturing represents an indepth integration of new-generation artificial intelligence （AI） technology and advanced manufacturing technology. It runs through every link in the full life-cycle of design, production, product, and service. The concept also relates to the optimization and integration of corresponding systems; the continuous improvement of enterprises＇ product quality, performance, and service levels; and reduction in resources consumption. New-generation intelligent manufacturing acts as the core driving force of the new indus- trial revolution and will continue to he the main pathway for the transformation and upgrading of the manufacturing industry in the decades to come. Human-cyher-physical systems （HCPSs） reveal the tech- nological mechanisms of new-generation intelligent manufacturing and can effectively guide related the- oretical research and engineering practice. Given the sequential development, cross interaction, and iterative upgrading characteristics of the three basic paradigms of intelligent manufacturing, a technol- ogy roadmap for ＂parallel promotion and integrated development＂ should he developed in order to drive forward the intelligent transformation of the manufacturing industry in China.展开更多
An intelligent manufacturing system is a composite intelligent system comprising humans,cyber systems,and physical systems with the aim of achieving specific manufacturing goals at an optimized level.This kind of inte...An intelligent manufacturing system is a composite intelligent system comprising humans,cyber systems,and physical systems with the aim of achieving specific manufacturing goals at an optimized level.This kind of intelligent system is called a human-cyber-physical system(HCPS).In terms of technology,HCPSs can both reveal technological principles and form the technological architecture for intelligent manufacturing.It can be concluded that the essence of intelligent manufacturing is to design,construct,and apply HCPSs in various cases and at different levels.With advances in information technology,intelligent manufacturing has passed through the stages of digital manufacturing and digital-networked manufacturing,and is evolving toward new-generation intelligent manufacturing(NGIM).NGIM is characterized by the in-depth integration of new-generation artificial intelligence(AI)technology(i.e.,enabling technology)with advanced manufacturing technology(i.e.,root technology);it is the core driving force of the new industrial revolution.In this study,the evolutionary footprint of intelligent manufacturing is reviewed from the perspective of HCPSs,and the implications,characteristics,technical frame,and key technologies of HCPSs for NGIM are then discussed in depth.Finally,an outlook of the major challenges of HCPSs for NGIM is proposed.展开更多
Intelligent technologies are leading to the next wave of industrial revolution in manufacturing.In developed economies,firms are embracing these advanced technologies following a sequential upgrading strategy-from dig...Intelligent technologies are leading to the next wave of industrial revolution in manufacturing.In developed economies,firms are embracing these advanced technologies following a sequential upgrading strategy-from digital manufacturing to smart manufacturing(digital-networked),and then to newgeneration intelligent manufacturing paradigms.However,Chinese firms face a different scenario.On the one hand,they have diverse technological bases that vary from low-end electrified machinery to leading-edge digital-network technologies;thus,they may not follow an identical upgrading pathway.On the other hand,Chinese firms aim to rapidly catch up and transition from technology followers to probable frontrunners;thus,the turbulences in the transitioning phase may trigger a precious opportunity for leapfrogging,if Chinese manufacturers can swiftly acquire domain expertise through the adoption of intelligent manufacturing technologies.This study addresses the following question by conducting multiple case studies:Can Chinese firms upgrade intelligent manufacturing through different pathways than the sequential one followed in developed economies?The data sources include semistructured interviews and archival data.This study finds that Chinese manufacturing firms have a variety of pathways to transition across the three technological paradigms of intelligent manufacturing in nonconsecutive ways.This finding implies that Chinese firms may strategize their own upgrading pathways toward intelligent manufacturing according to their capabilities and industrial specifics;furthermore,this finding can be extended to other catching-up economies.This paper provides a strategic roadmap as an explanatory guide to manufacturing firms,policymakers,and investors.展开更多
Background： Currently, drug-eluting balloon （DEB） appears to be an attractive alternative option for the treatment of in-stent restenosis （ISR）. Nevertheless, the clinical outcomes of DEB have seldom been compare...Background： Currently, drug-eluting balloon （DEB） appears to be an attractive alternative option for the treatment of in-stent restenosis （ISR）. Nevertheless, the clinical outcomes of DEB have seldom been compared to those of new-generation drug-eluting stent （DES）. Thus, this meta-analysis aimed to evaluate the safety and efficacy of DEB compared to those of new-generation DES in the treatment of ISR. Methods： A comprehensive search of electronic databases including PubMed, EMBASE, and Cochrane Library up to November 2, 2017 was performed to identify pertinent articles comparing DEB to new-generation DES for the treatment of ISR. In addition, conference proceedings for the scientific sessions of the American College of Cardiology, American Heart Association, European Society of Cardiology, Transcatheter Cardiovascular Therapeutics, and EuroPCR were also searched. The primary endpoint was target lesion revascularization （TLR） at the longest follow-up. Dichotomous variables were presented as risk ratios （RRs） with 95% confidence intervals （C/s）, while the overall RRs were estimated using the Mantel-Haenszel random-effects model. Results： Five randomized controlled trials （RCTs） and eight observational studies involving 2743 patients were included in the present meta-analysis. Overall, DEB was comparable to new-generation DES in terms ofTLR （RR = 1.24, 95% CI： 0.89-1.72, P = 0.21 ）, cardiac death （RR = 1.55, 95% CI： 0.89-2.71, P= 0.12）, major adverse cardiovascular event （RR = 1.21,95% CI： 0.98-1.48, P = 0.07）, myocardial infarction （RR = 1.12, 95% CI： 0.72-1.76, P = 0.62）, and stent thrombosis （RR = 0.95, 95% CI： 0.38-2.42, P associated with higher risk of all-cause mortality than new-generation DES （RR = 1.65, 95% CI： 1.09-2.50, P = true in the real-world observational studies （RR = 1.79, 95% CI： 1.12-2.88, P = 0.02）. In RCTs, however, no found between the two treatment strategies in the risk of all-cause mortality. 0.92）. However, DEB was 展开更多
With the development of modern information technology-and particularly of the new generation of artificial intelligence(AI)technology-new opportunities are available for the development of the intelligent machine tool...With the development of modern information technology-and particularly of the new generation of artificial intelligence(AI)technology-new opportunities are available for the development of the intelligent machine tool(IMT).Based on the three classical paradigms of intelligent manufacturing as defined by the Chinese Academy of Engineering,the concept,characteristics,and systemic structure of the IMT are presented in this paper.Three stages of machine tool evolution-from the manually operated machine tool(MOMT)to the IMT-are discussed,including the numerical control machine tool(NCMT),the smart machine tool(SMT),and the IMT.Furthermore,the four intelligent control principles of the IMT-namely,autonomous sensing and connection,autonomous learning and modeling,autonomous optimization and decision-making,and autonomous control and execution-are presented in detail.This paper then points out that the essential characteristic of the IMT is to acquire and accumulate knowledge through learning,and presents original key enabling technologies,including the instruction-domain-based analytical approach,theoretical and big-data-based hybrid modeling technology,and the double-code control method.Based on this research,an intelligent numerical control(INC)system and industrial prototypes of IMTs are developed.Three intelligent practices are conducted,demonstrating that the integration of the new generation of AI technology with advanced manufacturing technology is a feasible and convenient way to advance machine tools toward the IMT.展开更多
Internet has become the most important information infrastructure supporting modern socio-economic development, social progress and technological Innovation. Invented 30 years ago, today Internet is facing increasingl...Internet has become the most important information infrastructure supporting modern socio-economic development, social progress and technological Innovation. Invented 30 years ago, today Internet is facing increasingly severe technical challenges. This paper introduces the progress of the major international newgeneration Internet research plans; analyzes its basic characteristics and the principal contradictions during the development; detsiledly introduces the research carried out by 973 Project ＂Research of Future Internet Architecture＂ on the key scientific issues of new-generation Internet architecture and its latest research results; and looks to the future of the research-focus faced with the new situations of the basic research of new-generation Internet architecture as well as the new demands of innovative applications on Internet architecture.展开更多
For the two newly launched satellites(PRN number 27 and 28) of the future global BeiDou navigation satellite system(BDS-3), there is no available broadcast ephemeris data and other initial orbit information, but the i...For the two newly launched satellites(PRN number 27 and 28) of the future global BeiDou navigation satellite system(BDS-3), there is no available broadcast ephemeris data and other initial orbit information, but the initial orbit is the fundamental of the comprehensive analysis of the satellites and their signals. Precise orbit determination(POD) also requires determination of a priori initial value with a certain precision in order to avoid problems such as filter divergence during POD. Compared with the Newton iteration method, which relies on the initial value, this study utilizes the Bancroft algorithm to directly solve the nonlinear equations with the advantage of numerical stability. The initial orbits of these two satellites are calculated based on new code signals, and their results are analyzed and discussed. The experimental results show that, with the exception of very few epochs, when the new code signal is utilized, the median and robust variance factor of the observed residuals computed using pseudo-range observations and the solved initial orbits are less than 4 and 2 m, respectively. It also shows that this solution can be used for rapid initial orbit recovery after maneuvers of the new BeiDou satellites.展开更多
By using the mesh resolution control method based on the nozzle scale,a paralleled super numerical simulation and high-quality mesh model of the launch jet dynamics for new-generation launch vehicles was developed.Bas...By using the mesh resolution control method based on the nozzle scale,a paralleled super numerical simulation and high-quality mesh model of the launch jet dynamics for new-generation launch vehicles was developed.Based upon this,a transient numerical simulation method,combining the pressure and velocity,tightly coupled algorithm and SST turbulence model,was used to complete the unsteady numerical simulation of the launch jet dynamics of the new-generation launch vehicles.The numerical simulation results of the launch jet dynamics,for the new-generation launch vehicles,demonstrated that despite the complex structure of the launch platform,the jet flows of the core stage and booster engines were generally smoothly channeled into the double deflecting trench through the launch platform’s diversion hole at the initial stage of ignition.After the lift off,the jet flows of the core stage and the booster engines began to affect and ablate the grillage-shaped beam and the adjoined surface of the launch platform adjacent to the booster engines.At a higher altitude after lift off,it could be seen for the new-generation launch vehicles the ablation range of high temperature and high-speed jet flows on the launch platform further expanded,which would have a severe ablation effect on the fuel filling tower near the booster engines and even all the support arms.The numerical simulation of launch jet dynamics also established that the jet flows embers at the bottom of the core stage rocket body continued to be affected for an extended period of time due to the large number of nozzles in the new-generation launch vehicles engine and the weak suction effect of the jet flows in the core-stage engines.展开更多
Patients with bone metastatic castration-resistant prostate cancer (mCRPC) might benefit from radium-223 (^(223)Ra) combined withnew-generation hormonal agents (NHAs) in terms of survival and quality of life (QoL). Ho...Patients with bone metastatic castration-resistant prostate cancer (mCRPC) might benefit from radium-223 (^(223)Ra) combined withnew-generation hormonal agents (NHAs) in terms of survival and quality of life (QoL). However, the safety of combination therapiesremains unclear. Therefore, we aimed to perform a network meta-analysis by reviewing the literature about the combination of^(223)Ra with abiraterone acetate plus prednisone (AAP) or enzalutamide and to evaluate the safety of combination therapy in bonemCRPC patients. Ultimately, ten studies (2835 patients) were selected, including four randomized controlled trials (RCTs), fiveretrospective cohort studies, and one single-arm study. Overall, there was no difference in the incidence of fracture between the^(223)Ra+NHA combination group and the ^(223)Ra monotherapy group (odds ratio [OR]: 1.46, 95% confidence interval [CI]: 0.91–2.34,P = 0.66), but the incidences in both the ^(223)Ra+NHA combination group (OR: 3.22, 95% CI: 2.24–4.63, P < 0.01) and the ^(223)Ramonotherapy group (OR: 2.24, 95% CI: 1.23–4.08, P < 0.01) were higher than that in the NHA monotherapy group. However, inthe meta-analysis involving only RCTs, there was no difference between the ^(223)Ra monotherapy group and the NHA monotherapygroup (OR: 1.14, 95% CI: 0.22–5.95, P = 0.88), while the difference between the ^(223)Ra+NHA combination group and the NHAmonotherapy group remained significant (OR: 3.22, 95% CI: 2.24–4.63, P < 0.01). Symptomatic skeletal events (SSEs), SSE-freesurvival (SSE-FS), all grades of common adverse events (AEs), and ≥grade 3 AEs among all groups did not show any significantdifference. Our results indicate that the combination of ^(223)Ra with NHAs was well tolerated in bone mCRPC patients compared to ^(223)Ra monotherapy, even though the incidence of fracture was higher in patients who received ^(223)Ra than that among those whoreceived NHA monotherapy. More evidence is needed to explore the safety and efficiency of ^(223)Ra combination therapies.展开更多
Based on China's special conditions and characteristics of specific group of new-generation migrant workers,this article researches connotation of employment ability of new-generation migrant workers in China,that...Based on China's special conditions and characteristics of specific group of new-generation migrant workers,this article researches connotation of employment ability of new-generation migrant workers in China,that is,the connotation of employment ability of new-generation migrant workers in China should include four aspects:professional knowledge and skills,learning capacity,adaptability and environmental force.On this basis,through the analysis of indicators concerning connotation of employment ability,we get the overall characteristics of employment ability of new-generation migrant workers in China and reason responsible for its serious weakness.Finally we put forward corresponding countermeasures as follows:impart professional knowledge and skills;promote learning capacity;foster adaptive capacity;improve employment environment.展开更多
Based on a theoretical framework,this paper uses a multilevel model to examine the factors that correlate with the settlement intentions of China’s new-generation migrants.The level of regional economic development e...Based on a theoretical framework,this paper uses a multilevel model to examine the factors that correlate with the settlement intentions of China’s new-generation migrants.The level of regional economic development exerts not only random effects,but also an interaction effect with social integration on urban settlement intentions.Economic factors,including household income and home ownership,have a significant positive correlation with settlement intentions,while social char-acteristics such as social integration and social identification also have a positive correlation with the settlement intentions of new-generation migrants.Moreover,family migration strategies,parental migration experiences,short migration dis-tances,and long migration durations enhance urban settlement intentions.The set-tlement intentions exhibit significant inter-group differences between the migrants born in the 1980s and in the 1990s.Differences in the effects of the determinants are observed between these group samples and the total sample.展开更多
Based on China urban labor survey data of 2016, this paper investigates the differences in consumption level and structure between the new and previous generation rural migrant workers in China and identifies the dete...Based on China urban labor survey data of 2016, this paper investigates the differences in consumption level and structure between the new and previous generation rural migrant workers in China and identifies the determinants of migrant workers' consumption. According to descriptive analysis, the new-generation migrant workers' households spend 26% more on an annual per capita basis compared with their previous generation. More specifically, the new-generation migrant workers' households spend 33% more on clothing, food, housing and travel, and 10% more on healthcare on an annual per capita basis compared with their previous generation, while their per capita spending on education is only 73% that of their previous generation. Result of regression analysis shows that with other factors under control, the new-generation migrant workers' households spend 14.9% more on clothing, food, housing and travel compared with their previous generation, and their per capita gross consumption is 10.9% higher than that of their previous generation. Consumption elasticity for clothing, food, housing and travel among the new-generation migrant workers' households and their overall consumption elasticity are both significantly higher than those of the previous generation migrant workers' households. Compared with their previous generation, the spending of the new-generation migrant workers' households on clothing, food, housing and travel represents a higher share of their overall consumption, and the share of their educational consumption is even lower.展开更多
New-generation migrant workers are the " elite" among migrant workers,and whether they can really adapt to the city is one of the real problems to be urgently solved during China's new urbanization,relat...New-generation migrant workers are the " elite" among migrant workers,and whether they can really adapt to the city is one of the real problems to be urgently solved during China's new urbanization,related to the success of new urbanization construction. From the perspective of livelihood capital,this paper uses the measuring indicators in line with the new-generation migrant workers' livelihood characteristics,to analyze the typical characteristics and causes of new-generation migrant workers' urban adaptation in Jianggan District of Hangzhou City based on field survey data. In the study,it is found that the new-generation migrant workers' urban adaptation characteristics are focused on life adaptation,work adaptation and cultural adaptation,but the adaptation in the three areas is not good and there is a big room for improvement.展开更多
The original infrastructure of the Internet can no longer meet personalized and diversified demands of current increasing network subscribers. It has exposed many defects and shortcomings. For examples, the mechanism ...The original infrastructure of the Internet can no longer meet personalized and diversified demands of current increasing network subscribers. It has exposed many defects and shortcomings. For examples, the mechanism of using ports to distinguish services is inflexible and dangerous with the emergence of various services; the current Internet architecture does not make use of the close relationship between network resources and services, but simultaneously maintains two processing systems for the resources and services respectively, wasting both subscribers’ time and network resources; the Internet class of services granularity is not fine enough, failing to meet personalized and diversified user demands. In order to solve these problems, this paper discusses the mechanisms and key technologies for pervasive services in the new-generation Internet. The paper focuses on the definition, classification and identifier design of personalized and diversified user services. The service identifier design fulfills the unified identifier and processing of various network services, discovers the close relationship between services and resources, and can offer personalized and diversified services according to users’ demands.展开更多
Successful global cities present a spectrum of development strategies but share the benefit of the reciprocal dynamics between tailored education systems and matching labour markets.This paper examines burgeoning citi...Successful global cities present a spectrum of development strategies but share the benefit of the reciprocal dynamics between tailored education systems and matching labour markets.This paper examines burgeoning cities in China and investigates the effects of the heterogeneous educational trajectories of young migrant workers in urban China on their labour market performance.Drawing on the National Migrant Dynamics Monitoring Survey,this paper finds striking wage variations among the young migrant population.Migrant workers who attended high schools in current receiving cities earned less than their counterparts who received senior-secondary education elsewhere.Students following the academic track were better off than students following the vocational track.To further explore what has prevented the urban labour market from rewarding migrants who studied in a receiving city,where the education system is expected to better cater to the city’s specific industrial needs,we tested and found evidence of the mediating effects of job industry and occupation.In addition to engaging with empirical debates in the field,this paper develops a theoretical framework to model how the qualitative attributes of an education system affect wage variations among migrant workers.展开更多
文摘Intelligent manufacturing is a general concept that is under continuous development. It can be categorized into three basic paradigms： digital manufacturing, digital-networked manufacturing, and newgeneration intelligent manufacturing. New-generation intelligent manufacturing represents an indepth integration of new-generation artificial intelligence （AI） technology and advanced manufacturing technology. It runs through every link in the full life-cycle of design, production, product, and service. The concept also relates to the optimization and integration of corresponding systems; the continuous improvement of enterprises＇ product quality, performance, and service levels; and reduction in resources consumption. New-generation intelligent manufacturing acts as the core driving force of the new indus- trial revolution and will continue to he the main pathway for the transformation and upgrading of the manufacturing industry in the decades to come. Human-cyher-physical systems （HCPSs） reveal the tech- nological mechanisms of new-generation intelligent manufacturing and can effectively guide related the- oretical research and engineering practice. Given the sequential development, cross interaction, and iterative upgrading characteristics of the three basic paradigms of intelligent manufacturing, a technol- ogy roadmap for ＂parallel promotion and integrated development＂ should he developed in order to drive forward the intelligent transformation of the manufacturing industry in China.
文摘An intelligent manufacturing system is a composite intelligent system comprising humans,cyber systems,and physical systems with the aim of achieving specific manufacturing goals at an optimized level.This kind of intelligent system is called a human-cyber-physical system(HCPS).In terms of technology,HCPSs can both reveal technological principles and form the technological architecture for intelligent manufacturing.It can be concluded that the essence of intelligent manufacturing is to design,construct,and apply HCPSs in various cases and at different levels.With advances in information technology,intelligent manufacturing has passed through the stages of digital manufacturing and digital-networked manufacturing,and is evolving toward new-generation intelligent manufacturing(NGIM).NGIM is characterized by the in-depth integration of new-generation artificial intelligence(AI)technology(i.e.,enabling technology)with advanced manufacturing technology(i.e.,root technology);it is the core driving force of the new industrial revolution.In this study,the evolutionary footprint of intelligent manufacturing is reviewed from the perspective of HCPSs,and the implications,characteristics,technical frame,and key technologies of HCPSs for NGIM are then discussed in depth.Finally,an outlook of the major challenges of HCPSs for NGIM is proposed.
基金This research is supported by the National Natural Science Foundation of China(91646102,L1824039,L1724034,L1624045,and L1524015)the project of China’s Ministry of Education(16JDGC011)+6 种基金the Chinese Academy of Engineering’s consultancy project(2019-ZD-9)the National Science and Technology Major Project(2016ZX04005002)Beijing Natural Science Foundation Project(9182013)the technology projects of the Chinese Academy of Engineering’s China Knowledge Center for Engineering Sciences(CKCEST-2019-2-13,CKCEST-2018-1-13,CKCEST-2017-1-10,and CKCEST-2015-4-2)the UK–China Industry Academia Partnership Programme(UK-CIAPP\260)the Volvo-supported Green Economy and Sustainable Development Projects in the Tsinghua University(20153000181)Tsinghua Initiative Research(2016THZW).
文摘Intelligent technologies are leading to the next wave of industrial revolution in manufacturing.In developed economies,firms are embracing these advanced technologies following a sequential upgrading strategy-from digital manufacturing to smart manufacturing(digital-networked),and then to newgeneration intelligent manufacturing paradigms.However,Chinese firms face a different scenario.On the one hand,they have diverse technological bases that vary from low-end electrified machinery to leading-edge digital-network technologies;thus,they may not follow an identical upgrading pathway.On the other hand,Chinese firms aim to rapidly catch up and transition from technology followers to probable frontrunners;thus,the turbulences in the transitioning phase may trigger a precious opportunity for leapfrogging,if Chinese manufacturers can swiftly acquire domain expertise through the adoption of intelligent manufacturing technologies.This study addresses the following question by conducting multiple case studies:Can Chinese firms upgrade intelligent manufacturing through different pathways than the sequential one followed in developed economies?The data sources include semistructured interviews and archival data.This study finds that Chinese manufacturing firms have a variety of pathways to transition across the three technological paradigms of intelligent manufacturing in nonconsecutive ways.This finding implies that Chinese firms may strategize their own upgrading pathways toward intelligent manufacturing according to their capabilities and industrial specifics;furthermore,this finding can be extended to other catching-up economies.This paper provides a strategic roadmap as an explanatory guide to manufacturing firms,policymakers,and investors.
文摘Background： Currently, drug-eluting balloon （DEB） appears to be an attractive alternative option for the treatment of in-stent restenosis （ISR）. Nevertheless, the clinical outcomes of DEB have seldom been compared to those of new-generation drug-eluting stent （DES）. Thus, this meta-analysis aimed to evaluate the safety and efficacy of DEB compared to those of new-generation DES in the treatment of ISR. Methods： A comprehensive search of electronic databases including PubMed, EMBASE, and Cochrane Library up to November 2, 2017 was performed to identify pertinent articles comparing DEB to new-generation DES for the treatment of ISR. In addition, conference proceedings for the scientific sessions of the American College of Cardiology, American Heart Association, European Society of Cardiology, Transcatheter Cardiovascular Therapeutics, and EuroPCR were also searched. The primary endpoint was target lesion revascularization （TLR） at the longest follow-up. Dichotomous variables were presented as risk ratios （RRs） with 95% confidence intervals （C/s）, while the overall RRs were estimated using the Mantel-Haenszel random-effects model. Results： Five randomized controlled trials （RCTs） and eight observational studies involving 2743 patients were included in the present meta-analysis. Overall, DEB was comparable to new-generation DES in terms ofTLR （RR = 1.24, 95% CI： 0.89-1.72, P = 0.21 ）, cardiac death （RR = 1.55, 95% CI： 0.89-2.71, P= 0.12）, major adverse cardiovascular event （RR = 1.21,95% CI： 0.98-1.48, P = 0.07）, myocardial infarction （RR = 1.12, 95% CI： 0.72-1.76, P = 0.62）, and stent thrombosis （RR = 0.95, 95% CI： 0.38-2.42, P associated with higher risk of all-cause mortality than new-generation DES （RR = 1.65, 95% CI： 1.09-2.50, P = true in the real-world observational studies （RR = 1.79, 95% CI： 1.12-2.88, P = 0.02）. In RCTs, however, no found between the two treatment strategies in the risk of all-cause mortality. 0.92）. However, DEB was
基金The authors would like to express special thanks to Prof.Ji Zhou from the Chinese Academy of Engineering.This paper is supported by the National Natural Science Foundation of China(51675204 and 51575210)the National Science and Technology Major Project of the Ministry of Science and Technology of China(2018ZX04035002-002).
文摘With the development of modern information technology-and particularly of the new generation of artificial intelligence(AI)technology-new opportunities are available for the development of the intelligent machine tool(IMT).Based on the three classical paradigms of intelligent manufacturing as defined by the Chinese Academy of Engineering,the concept,characteristics,and systemic structure of the IMT are presented in this paper.Three stages of machine tool evolution-from the manually operated machine tool(MOMT)to the IMT-are discussed,including the numerical control machine tool(NCMT),the smart machine tool(SMT),and the IMT.Furthermore,the four intelligent control principles of the IMT-namely,autonomous sensing and connection,autonomous learning and modeling,autonomous optimization and decision-making,and autonomous control and execution-are presented in detail.This paper then points out that the essential characteristic of the IMT is to acquire and accumulate knowledge through learning,and presents original key enabling technologies,including the instruction-domain-based analytical approach,theoretical and big-data-based hybrid modeling technology,and the double-code control method.Based on this research,an intelligent numerical control(INC)system and industrial prototypes of IMTs are developed.Three intelligent practices are conducted,demonstrating that the integration of the new generation of AI technology with advanced manufacturing technology is a feasible and convenient way to advance machine tools toward the IMT.
基金the National Basic Research Program of China (Grant No. 2003CB314800)the National Natural Science Foundation of China (Grant No. 90704001)
文摘Internet has become the most important information infrastructure supporting modern socio-economic development, social progress and technological Innovation. Invented 30 years ago, today Internet is facing increasingly severe technical challenges. This paper introduces the progress of the major international newgeneration Internet research plans; analyzes its basic characteristics and the principal contradictions during the development; detsiledly introduces the research carried out by 973 Project ＂Research of Future Internet Architecture＂ on the key scientific issues of new-generation Internet architecture and its latest research results; and looks to the future of the research-focus faced with the new situations of the basic research of new-generation Internet architecture as well as the new demands of innovative applications on Internet architecture.
基金supported by the Collaborative Precision Positioning Project funded by the Ministry of Science and Technology of China (No.2016YFB0501900)China Natural Science Funds (No.41231064,41674022,41574015)
文摘For the two newly launched satellites(PRN number 27 and 28) of the future global BeiDou navigation satellite system(BDS-3), there is no available broadcast ephemeris data and other initial orbit information, but the initial orbit is the fundamental of the comprehensive analysis of the satellites and their signals. Precise orbit determination(POD) also requires determination of a priori initial value with a certain precision in order to avoid problems such as filter divergence during POD. Compared with the Newton iteration method, which relies on the initial value, this study utilizes the Bancroft algorithm to directly solve the nonlinear equations with the advantage of numerical stability. The initial orbits of these two satellites are calculated based on new code signals, and their results are analyzed and discussed. The experimental results show that, with the exception of very few epochs, when the new code signal is utilized, the median and robust variance factor of the observed residuals computed using pseudo-range observations and the solved initial orbits are less than 4 and 2 m, respectively. It also shows that this solution can be used for rapid initial orbit recovery after maneuvers of the new BeiDou satellites.
文摘By using the mesh resolution control method based on the nozzle scale,a paralleled super numerical simulation and high-quality mesh model of the launch jet dynamics for new-generation launch vehicles was developed.Based upon this,a transient numerical simulation method,combining the pressure and velocity,tightly coupled algorithm and SST turbulence model,was used to complete the unsteady numerical simulation of the launch jet dynamics of the new-generation launch vehicles.The numerical simulation results of the launch jet dynamics,for the new-generation launch vehicles,demonstrated that despite the complex structure of the launch platform,the jet flows of the core stage and booster engines were generally smoothly channeled into the double deflecting trench through the launch platform’s diversion hole at the initial stage of ignition.After the lift off,the jet flows of the core stage and the booster engines began to affect and ablate the grillage-shaped beam and the adjoined surface of the launch platform adjacent to the booster engines.At a higher altitude after lift off,it could be seen for the new-generation launch vehicles the ablation range of high temperature and high-speed jet flows on the launch platform further expanded,which would have a severe ablation effect on the fuel filling tower near the booster engines and even all the support arms.The numerical simulation of launch jet dynamics also established that the jet flows embers at the bottom of the core stage rocket body continued to be affected for an extended period of time due to the large number of nozzles in the new-generation launch vehicles engine and the weak suction effect of the jet flows in the core-stage engines.
基金supported by the Science and Technology Support Program of Sichuan Province(2021YFS0119)the Natural Science Foundation of China(No.82172785,81902577,81974398,and 81872107)+1 种基金Research Foundation for the Postdoctoral Program of Sichuan University(2021SCU12014)1.3.5 project for disciplines of excellence,West China Hospital,Sichuan University(ZYJC21020).
文摘Patients with bone metastatic castration-resistant prostate cancer (mCRPC) might benefit from radium-223 (^(223)Ra) combined withnew-generation hormonal agents (NHAs) in terms of survival and quality of life (QoL). However, the safety of combination therapiesremains unclear. Therefore, we aimed to perform a network meta-analysis by reviewing the literature about the combination of^(223)Ra with abiraterone acetate plus prednisone (AAP) or enzalutamide and to evaluate the safety of combination therapy in bonemCRPC patients. Ultimately, ten studies (2835 patients) were selected, including four randomized controlled trials (RCTs), fiveretrospective cohort studies, and one single-arm study. Overall, there was no difference in the incidence of fracture between the^(223)Ra+NHA combination group and the ^(223)Ra monotherapy group (odds ratio [OR]: 1.46, 95% confidence interval [CI]: 0.91–2.34,P = 0.66), but the incidences in both the ^(223)Ra+NHA combination group (OR: 3.22, 95% CI: 2.24–4.63, P < 0.01) and the ^(223)Ramonotherapy group (OR: 2.24, 95% CI: 1.23–4.08, P < 0.01) were higher than that in the NHA monotherapy group. However, inthe meta-analysis involving only RCTs, there was no difference between the ^(223)Ra monotherapy group and the NHA monotherapygroup (OR: 1.14, 95% CI: 0.22–5.95, P = 0.88), while the difference between the ^(223)Ra+NHA combination group and the NHAmonotherapy group remained significant (OR: 3.22, 95% CI: 2.24–4.63, P < 0.01). Symptomatic skeletal events (SSEs), SSE-freesurvival (SSE-FS), all grades of common adverse events (AEs), and ≥grade 3 AEs among all groups did not show any significantdifference. Our results indicate that the combination of ^(223)Ra with NHAs was well tolerated in bone mCRPC patients compared to ^(223)Ra monotherapy, even though the incidence of fracture was higher in patients who received ^(223)Ra than that among those whoreceived NHA monotherapy. More evidence is needed to explore the safety and efficiency of ^(223)Ra combination therapies.
文摘Based on China's special conditions and characteristics of specific group of new-generation migrant workers,this article researches connotation of employment ability of new-generation migrant workers in China,that is,the connotation of employment ability of new-generation migrant workers in China should include four aspects:professional knowledge and skills,learning capacity,adaptability and environmental force.On this basis,through the analysis of indicators concerning connotation of employment ability,we get the overall characteristics of employment ability of new-generation migrant workers in China and reason responsible for its serious weakness.Finally we put forward corresponding countermeasures as follows:impart professional knowledge and skills;promote learning capacity;foster adaptive capacity;improve employment environment.
基金This work was funded by the National Social Science Foundation of China Grant number 19CRK020.
文摘Based on a theoretical framework,this paper uses a multilevel model to examine the factors that correlate with the settlement intentions of China’s new-generation migrants.The level of regional economic development exerts not only random effects,but also an interaction effect with social integration on urban settlement intentions.Economic factors,including household income and home ownership,have a significant positive correlation with settlement intentions,while social char-acteristics such as social integration and social identification also have a positive correlation with the settlement intentions of new-generation migrants.Moreover,family migration strategies,parental migration experiences,short migration dis-tances,and long migration durations enhance urban settlement intentions.The set-tlement intentions exhibit significant inter-group differences between the migrants born in the 1980s and in the 1990s.Differences in the effects of the determinants are observed between these group samples and the total sample.
基金supported by the National Natural Science Foundation of China(NSFC) Project "Industrial Relations Governance during the Lewis Turning Point Period"(Grant No.:71473267)the National Natural Science Foundation of China(NSFC) Project "Human Capital Accumulation in the Supply-side Structural Reform"(Grant No.:71642003)
文摘Based on China urban labor survey data of 2016, this paper investigates the differences in consumption level and structure between the new and previous generation rural migrant workers in China and identifies the determinants of migrant workers' consumption. According to descriptive analysis, the new-generation migrant workers' households spend 26% more on an annual per capita basis compared with their previous generation. More specifically, the new-generation migrant workers' households spend 33% more on clothing, food, housing and travel, and 10% more on healthcare on an annual per capita basis compared with their previous generation, while their per capita spending on education is only 73% that of their previous generation. Result of regression analysis shows that with other factors under control, the new-generation migrant workers' households spend 14.9% more on clothing, food, housing and travel compared with their previous generation, and their per capita gross consumption is 10.9% higher than that of their previous generation. Consumption elasticity for clothing, food, housing and travel among the new-generation migrant workers' households and their overall consumption elasticity are both significantly higher than those of the previous generation migrant workers' households. Compared with their previous generation, the spending of the new-generation migrant workers' households on clothing, food, housing and travel represents a higher share of their overall consumption, and the share of their educational consumption is even lower.
基金Supported by Youth Fund Project of National Natural Science Foundation of China(4140117641201114+5 种基金41501182)Research Project of Zhejiang Provincial Department of Education(Y201432214)Key Humanities and Social Science Research Project of Zhejiang Gongshang University(JYTyyjj20130105)New Starting Point Project of Beijing Union University(ZK10201406)Hangzhou Philosophy and Social Sciences Planning Project(A12YJ04)Research Project of Zhejiang Association of Social Sciences(2013N077)
文摘New-generation migrant workers are the " elite" among migrant workers,and whether they can really adapt to the city is one of the real problems to be urgently solved during China's new urbanization,related to the success of new urbanization construction. From the perspective of livelihood capital,this paper uses the measuring indicators in line with the new-generation migrant workers' livelihood characteristics,to analyze the typical characteristics and causes of new-generation migrant workers' urban adaptation in Jianggan District of Hangzhou City based on field survey data. In the study,it is found that the new-generation migrant workers' urban adaptation characteristics are focused on life adaptation,work adaptation and cultural adaptation,but the adaptation in the three areas is not good and there is a big room for improvement.
基金the National BasicResearch Program of China ("973" Program)under Grants 2007CB307100 and 2007CB307106the Cultivation Finances of Ministry ofEducation for Higher Education Institutes’MajorPrograms in Science and Technology InnovationEngineering under Gant 706005.
文摘The original infrastructure of the Internet can no longer meet personalized and diversified demands of current increasing network subscribers. It has exposed many defects and shortcomings. For examples, the mechanism of using ports to distinguish services is inflexible and dangerous with the emergence of various services; the current Internet architecture does not make use of the close relationship between network resources and services, but simultaneously maintains two processing systems for the resources and services respectively, wasting both subscribers’ time and network resources; the Internet class of services granularity is not fine enough, failing to meet personalized and diversified user demands. In order to solve these problems, this paper discusses the mechanisms and key technologies for pervasive services in the new-generation Internet. The paper focuses on the definition, classification and identifier design of personalized and diversified user services. The service identifier design fulfills the unified identifier and processing of various network services, discovers the close relationship between services and resources, and can offer personalized and diversified services according to users’ demands.
文摘Successful global cities present a spectrum of development strategies but share the benefit of the reciprocal dynamics between tailored education systems and matching labour markets.This paper examines burgeoning cities in China and investigates the effects of the heterogeneous educational trajectories of young migrant workers in urban China on their labour market performance.Drawing on the National Migrant Dynamics Monitoring Survey,this paper finds striking wage variations among the young migrant population.Migrant workers who attended high schools in current receiving cities earned less than their counterparts who received senior-secondary education elsewhere.Students following the academic track were better off than students following the vocational track.To further explore what has prevented the urban labour market from rewarding migrants who studied in a receiving city,where the education system is expected to better cater to the city’s specific industrial needs,we tested and found evidence of the mediating effects of job industry and occupation.In addition to engaging with empirical debates in the field,this paper develops a theoretical framework to model how the qualitative attributes of an education system affect wage variations among migrant workers.
