In scenarios of real-time data collection of long-term deployed Wireless Sensor Networks (WSNs), low-latency data collection with long net- work lifetime becomes a key issue. In this paper, we present a data aggrega...In scenarios of real-time data collection of long-term deployed Wireless Sensor Networks (WSNs), low-latency data collection with long net- work lifetime becomes a key issue. In this paper, we present a data aggregation scheduling with guaran- teed lifetime and efficient latency in WSNs. We first Construct a Guaranteed Lifetime Mininmm Ra- dius Data Aggregation Tree (GLMRDAT) which is conducive to reduce scheduling latency while pro- viding a guaranteed network lifetime, and then de-sign a Greedy Scheduling algorithM (GSM) based on finding the nmzximum independent set in conflict graph to schedule he transmission of nodes in the aggregation tree. Finally, simulations show that our proposed approach not only outperfonm the state-of-the-art solutions in terms of schedule latency, but also provides longer and guaranteed network lifetilre.展开更多
Energy-efficient data gathering in multi-hop wireless sensor networks was studied,considering that different node produces different amounts of data in realistic environments.A novel dominating set based clustering pr...Energy-efficient data gathering in multi-hop wireless sensor networks was studied,considering that different node produces different amounts of data in realistic environments.A novel dominating set based clustering protocol (DSCP) was proposed to solve the data gathering problem in this scenario.In DSCP,a node evaluates the potential lifetime of the network (from its local point of view) assuming that it acts as the cluster head,and claims to be a tentative cluster head if it maximizes the potential lifetime.When evaluating the potential lifetime of the network,a node considers not only its remaining energy,but also other factors including its traffic load,the number of its neighbors,and the traffic loads of its neighbors.A tentative cluster head becomes a final cluster head with a probability inversely proportional to the number of tentative cluster heads that cover its neighbors.The protocol can terminate in O(n/lg n) steps,and its total message complexity is O(n2/lg n).Simulation results show that DSCP can effectively prolong the lifetime of the network in multi-hop networks with unbalanced traffic load.Compared with EECT,the network lifetime is prolonged by 56.6% in average.展开更多
Many researchers have concluded that longer life expectancies prompt increased investment in education,as a prolonged labor supply raises the rate of return on education.Besides explaining the empirical evidence behin...Many researchers have concluded that longer life expectancies prompt increased investment in education,as a prolonged labor supply raises the rate of return on education.Besides explaining the empirical evidence behind this conclusion(at an absolute level),there is another issue to be discussed:does time spent studying and working increase proportionally with higher longevity? Building on an extended life-cycle model,this paper shows that prolonged life expectancy will cause individuals to increase their time in education but may not warrant rises in labor input.Later we show that higher improvement rate of longevity rather than initial life expectancy will promote economic growth,even we exclude the mechanism of human capital formation,and only consider growth effects of higher improvement rate of life expectancy from physical capital investment.展开更多
One of the main contemporary problems requiring urgent attention since its present and future repercussions on particular countries is the decrease of population and related problems of population ageing. The populati...One of the main contemporary problems requiring urgent attention since its present and future repercussions on particular countries is the decrease of population and related problems of population ageing. The population ageing is not a worldwide problem yet, it concerns mostly world developed countries. On the other hand, it is a known fact that the population ageing in developing countries will culminate in few decades and will be more dramatic as the current population ageing in the developed world. In the developed countries, the population ageing is cause by the prolonged human life and the decrease of natality. This trend is resulting from many factors that are related to the modernization of the society which caused the decrease in fertility and natality. The health care improvement resulted in the prolonged life expectancy and a better health condition of the population. The science advance prolonged the average life expectancy which is the main reason for the population ageing.展开更多
The purpose of using life extending control for Black Hawk UH-60 helicopter is to make a trade-off between the handling qualities and the service life of critical components. An increase in service life span results i...The purpose of using life extending control for Black Hawk UH-60 helicopter is to make a trade-off between the handling qualities and the service life of critical components. An increase in service life span results in enhanced safety and the reduction in maintenance costs. This paper presents a design methodology of life extending control for structural durability and high performance of mechanical system, which is based on an explicit dynamic inversion control scheme. A real-time nonlinear fatigue crack growth model is built to predict fatigue damage resulting from the impact of cyclic bending stress on rotor shaft, which serves as an indicator of service life. The 4-axis gainscheduled flight controller, whose gains are adjusted as a function of damage and flight velocity, is designed to regulate roll attitude, pitch attitude, vertical velocity and yaw rate. The nonlinear system simulation results show that the responses can meet the requirements on ADS-33 Level 1 handling qualities and that the 4-axis decoupling control is realized. As the damage increases, the tracking performance is slightly degraded, which results in smaller transients in bending moment response.展开更多
This paper focuses on how aging can affect performance of safety-related structures in nuclear power plant (NPP). Knowledge and assessment of impacts of aging on structures are essential to plant life extension analys...This paper focuses on how aging can affect performance of safety-related structures in nuclear power plant (NPP). Knowledge and assessment of impacts of aging on structures are essential to plant life extension analysis,especially performance to severe loadings such as loss-of-coolant-accidents or major seismic events. Plant life extension issues are of keen interest in countries (like the United States) which have a large,aging fleet of NPPs. This paper addresses the overlap and relationship of structure aging to severe loading performance,with particular emphasis on containment structures.展开更多
In recent years,our country entered the stage of population aging, and this trend continues to increase. Young population declining dependency ratios and the elderly support ratio is growing.Many phenomena are heralds...In recent years,our country entered the stage of population aging, and this trend continues to increase. Young population declining dependency ratios and the elderly support ratio is growing.Many phenomena are heralds the retirement policy must introduce.At the same time, the adjustment of the legal retirement age for women, is also a concern hot spot and a topic of heated academia discussion in politics. As the extension of life expectancy, especially women to longer life expectancy and the education of the extension of women's status, ability to work has been greatly improved. Based on the change of various factors, delay retirement age for women in China's reform is imperative. This paper studies from the perspective of social justice, to the reform of the current situation of the development in our country and foreign experience to research the method of combining the draw delay retirement outstanding aspects of influence on female workers. From a personal health, family factors, career, personal value Suggestions such as, in order to Perfect delay enterprise female worker retirement age policy scheme and implement supporting measures.展开更多
Since China's reform and opening up, the life expectancy of the population has prolonged. As a result, the trend of population aging is becoming increasingly serious. The time was pushed back when young workers enter...Since China's reform and opening up, the life expectancy of the population has prolonged. As a result, the trend of population aging is becoming increasingly serious. The time was pushed back when young workers entered the labor market, while the phenomenon was common that the elderly who should have retired were still engaged in working. Therefore, the retirement age shall be subjected to an imperative delay. In the third Plenary Session of the 18th CPC Central Committee, the central government proposed the "formulation of gradual delay retirement scheme ", which triggered a widespread concern among all sectors in the society. Support and opposition to delay of retirement focus on the impact made by extension of retirement age on the employment. The youth employment, however, is still the issue of social concemThis paper makes a systematic study on the controversy of the relevant scholars, and makes a detailed investigation of the reasons behind the various viewpoints, which is beneficial to the judgment of the rationality between the two parties of the dispute, and then seeks the solution to the problem.展开更多
Overall purpose of a power uprate and lifetime extension project (PLEX) is to modernize the power station cost-efficiently resulting in fulfilling the following overall requirements. The primary target is to meet th...Overall purpose of a power uprate and lifetime extension project (PLEX) is to modernize the power station cost-efficiently resulting in fulfilling the following overall requirements. The primary target is to meet the requirements provided by the local regulations from the regulatory offices. The controlling, monitoring and power supply of safety functions have to comply with these regulations. Any deviations from the existing safety analysis report (SAR) have to be corrected. On top of the safety measures the general technical status should be raised to extend the lifetime to 60 years. A high availability during the modernization has to be assured.展开更多
Pluripotent or multipotent stem cells are involved in development and tissue homeostasis;they have the ability to self-renew and differentiate into various types of functional cells.To maintain these properties,stem c...Pluripotent or multipotent stem cells are involved in development and tissue homeostasis;they have the ability to self-renew and differentiate into various types of functional cells.To maintain these properties,stem cells must undergo sustained or unlimited proliferation that requires the stabilization of telomeres,which are essential for chromosome end protection.Telomerase,an RNA-dependent DNA polymerase,synthesizes telomeric DNA.Through the lengthening of telomeres the lifespans of cells are extended,or indefinite proliferation is conferred;this is intimately associated with stem cell phenotype.This review highlights our current understanding of telomerase as a"stemness"enzyme and discusses the underlying implications.展开更多
We fabricated organic light-emitting diodes (OLEDs) with the thermally activated delayed fluorescence (TADF) mate- rial of 4CzlPN, Which show better stability compared with the 4,4'-Bis(carbazol-9-yl)biphenyl ...We fabricated organic light-emitting diodes (OLEDs) with the thermally activated delayed fluorescence (TADF) mate- rial of 4CzlPN, Which show better stability compared with the 4,4'-Bis(carbazol-9-yl)biphenyl (CBP) based devices. The half lifetime of the device using 4CzlPN as host material has doubled, and a slower voltage rise compared with that of CBP-based devices has been achieved, which indicates the improvement of stability. We attribute the better sta- bility to the good film morphology and difficult crystallization property of 4CzlPN. Our results suggest that employing the 4CzlPN as host material can be a promising way of fabricating OLEDs with longer operation lifetime.展开更多
基金This paper was supported by the National Basic Research Pro- gram of China (973 Program) under Crant No. 2011CB302903 the National Natural Science Foundation of China under Crants No. 60873231, No.61272084+3 种基金 the Natural Science Foundation of Jiangsu Province under Ca-ant No. BK2009426 the Innovation Project for Postgraduate Cultivation of Jiangsu Province under Crants No. CXZZ11_0402, No. CX10B195Z, No. CXLX11_0415, No. CXLXll 0416 the Natural Science Research Project of Jiangsu Education Department under Grant No. 09KJD510008 the Natural Science Foundation of the Jiangsu Higher Educa-tion Institutions of China under Grant No. 11KJA520002.
文摘In scenarios of real-time data collection of long-term deployed Wireless Sensor Networks (WSNs), low-latency data collection with long net- work lifetime becomes a key issue. In this paper, we present a data aggregation scheduling with guaran- teed lifetime and efficient latency in WSNs. We first Construct a Guaranteed Lifetime Mininmm Ra- dius Data Aggregation Tree (GLMRDAT) which is conducive to reduce scheduling latency while pro- viding a guaranteed network lifetime, and then de-sign a Greedy Scheduling algorithM (GSM) based on finding the nmzximum independent set in conflict graph to schedule he transmission of nodes in the aggregation tree. Finally, simulations show that our proposed approach not only outperfonm the state-of-the-art solutions in terms of schedule latency, but also provides longer and guaranteed network lifetilre.
基金Projects(61173169,61103203)supported by the National Natural Science Foundation of ChinaProject(NCET-10-0798)supported by the Program for New Century Excellent Talents in University of ChinaProject supported by the Post-doctoral Program and the Freedom Explore Program of Central South University,China
文摘Energy-efficient data gathering in multi-hop wireless sensor networks was studied,considering that different node produces different amounts of data in realistic environments.A novel dominating set based clustering protocol (DSCP) was proposed to solve the data gathering problem in this scenario.In DSCP,a node evaluates the potential lifetime of the network (from its local point of view) assuming that it acts as the cluster head,and claims to be a tentative cluster head if it maximizes the potential lifetime.When evaluating the potential lifetime of the network,a node considers not only its remaining energy,but also other factors including its traffic load,the number of its neighbors,and the traffic loads of its neighbors.A tentative cluster head becomes a final cluster head with a probability inversely proportional to the number of tentative cluster heads that cover its neighbors.The protocol can terminate in O(n/lg n) steps,and its total message complexity is O(n2/lg n).Simulation results show that DSCP can effectively prolong the lifetime of the network in multi-hop networks with unbalanced traffic load.Compared with EECT,the network lifetime is prolonged by 56.6% in average.
基金the POS DOC Research Fund(Grant No. 05646997) which is sponsored by the Shorenstein AsiaPacific Research Center at Stanford University
文摘Many researchers have concluded that longer life expectancies prompt increased investment in education,as a prolonged labor supply raises the rate of return on education.Besides explaining the empirical evidence behind this conclusion(at an absolute level),there is another issue to be discussed:does time spent studying and working increase proportionally with higher longevity? Building on an extended life-cycle model,this paper shows that prolonged life expectancy will cause individuals to increase their time in education but may not warrant rises in labor input.Later we show that higher improvement rate of longevity rather than initial life expectancy will promote economic growth,even we exclude the mechanism of human capital formation,and only consider growth effects of higher improvement rate of life expectancy from physical capital investment.
文摘One of the main contemporary problems requiring urgent attention since its present and future repercussions on particular countries is the decrease of population and related problems of population ageing. The population ageing is not a worldwide problem yet, it concerns mostly world developed countries. On the other hand, it is a known fact that the population ageing in developing countries will culminate in few decades and will be more dramatic as the current population ageing in the developed world. In the developed countries, the population ageing is cause by the prolonged human life and the decrease of natality. This trend is resulting from many factors that are related to the modernization of the society which caused the decrease in fertility and natality. The health care improvement resulted in the prolonged life expectancy and a better health condition of the population. The science advance prolonged the average life expectancy which is the main reason for the population ageing.
基金Supported by the National Natural Science Foundation of China(No.61170328)
文摘The purpose of using life extending control for Black Hawk UH-60 helicopter is to make a trade-off between the handling qualities and the service life of critical components. An increase in service life span results in enhanced safety and the reduction in maintenance costs. This paper presents a design methodology of life extending control for structural durability and high performance of mechanical system, which is based on an explicit dynamic inversion control scheme. A real-time nonlinear fatigue crack growth model is built to predict fatigue damage resulting from the impact of cyclic bending stress on rotor shaft, which serves as an indicator of service life. The 4-axis gainscheduled flight controller, whose gains are adjusted as a function of damage and flight velocity, is designed to regulate roll attitude, pitch attitude, vertical velocity and yaw rate. The nonlinear system simulation results show that the responses can meet the requirements on ADS-33 Level 1 handling qualities and that the 4-axis decoupling control is realized. As the damage increases, the tracking performance is slightly degraded, which results in smaller transients in bending moment response.
文摘This paper focuses on how aging can affect performance of safety-related structures in nuclear power plant (NPP). Knowledge and assessment of impacts of aging on structures are essential to plant life extension analysis,especially performance to severe loadings such as loss-of-coolant-accidents or major seismic events. Plant life extension issues are of keen interest in countries (like the United States) which have a large,aging fleet of NPPs. This paper addresses the overlap and relationship of structure aging to severe loading performance,with particular emphasis on containment structures.
文摘In recent years,our country entered the stage of population aging, and this trend continues to increase. Young population declining dependency ratios and the elderly support ratio is growing.Many phenomena are heralds the retirement policy must introduce.At the same time, the adjustment of the legal retirement age for women, is also a concern hot spot and a topic of heated academia discussion in politics. As the extension of life expectancy, especially women to longer life expectancy and the education of the extension of women's status, ability to work has been greatly improved. Based on the change of various factors, delay retirement age for women in China's reform is imperative. This paper studies from the perspective of social justice, to the reform of the current situation of the development in our country and foreign experience to research the method of combining the draw delay retirement outstanding aspects of influence on female workers. From a personal health, family factors, career, personal value Suggestions such as, in order to Perfect delay enterprise female worker retirement age policy scheme and implement supporting measures.
文摘Since China's reform and opening up, the life expectancy of the population has prolonged. As a result, the trend of population aging is becoming increasingly serious. The time was pushed back when young workers entered the labor market, while the phenomenon was common that the elderly who should have retired were still engaged in working. Therefore, the retirement age shall be subjected to an imperative delay. In the third Plenary Session of the 18th CPC Central Committee, the central government proposed the "formulation of gradual delay retirement scheme ", which triggered a widespread concern among all sectors in the society. Support and opposition to delay of retirement focus on the impact made by extension of retirement age on the employment. The youth employment, however, is still the issue of social concemThis paper makes a systematic study on the controversy of the relevant scholars, and makes a detailed investigation of the reasons behind the various viewpoints, which is beneficial to the judgment of the rationality between the two parties of the dispute, and then seeks the solution to the problem.
文摘Overall purpose of a power uprate and lifetime extension project (PLEX) is to modernize the power station cost-efficiently resulting in fulfilling the following overall requirements. The primary target is to meet the requirements provided by the local regulations from the regulatory offices. The controlling, monitoring and power supply of safety functions have to comply with these regulations. Any deviations from the existing safety analysis report (SAR) have to be corrected. On top of the safety measures the general technical status should be raised to extend the lifetime to 60 years. A high availability during the modernization has to be assured.
基金supported by the National Basic Research Program of China(2012CB911202)National Natural Science Foundation of China(81071721)+4 种基金the Swedish Cancer Societythe Swedish Research Councilthe Cancer Society in Stockholmthe Stockholm County CouncilKarolinska Institutet
文摘Pluripotent or multipotent stem cells are involved in development and tissue homeostasis;they have the ability to self-renew and differentiate into various types of functional cells.To maintain these properties,stem cells must undergo sustained or unlimited proliferation that requires the stabilization of telomeres,which are essential for chromosome end protection.Telomerase,an RNA-dependent DNA polymerase,synthesizes telomeric DNA.Through the lengthening of telomeres the lifespans of cells are extended,or indefinite proliferation is conferred;this is intimately associated with stem cell phenotype.This review highlights our current understanding of telomerase as a"stemness"enzyme and discusses the underlying implications.
基金supported by the National High Technology Research and Development Program of China(No.2012AA011901)the National Basic Research Program of China(No.2012CB723406)+2 种基金the National Natural Science Foundation of China(No.51573036)the Fundamental Research Funds for the Central Universities of China(No.JD2016JGPY0007)the Industry-University-Research Cooperation Project of Aviation Industry Corporation of China(No.CXY2013HFGD20)
文摘We fabricated organic light-emitting diodes (OLEDs) with the thermally activated delayed fluorescence (TADF) mate- rial of 4CzlPN, Which show better stability compared with the 4,4'-Bis(carbazol-9-yl)biphenyl (CBP) based devices. The half lifetime of the device using 4CzlPN as host material has doubled, and a slower voltage rise compared with that of CBP-based devices has been achieved, which indicates the improvement of stability. We attribute the better sta- bility to the good film morphology and difficult crystallization property of 4CzlPN. Our results suggest that employing the 4CzlPN as host material can be a promising way of fabricating OLEDs with longer operation lifetime.