Based on the computer integrated and flexible laser p rocessing system, we developed an intelligent measuring sub-system. A novel mod el has been built to compensate the deviations of the main frame-structure, and a l...Based on the computer integrated and flexible laser p rocessing system, we developed an intelligent measuring sub-system. A novel mod el has been built to compensate the deviations of the main frame-structure, and a laser tracker system is applied to calibrate the accuracy of the system. Anal yzing the characteristics of all kind surfaces of automobile outer penal moulds and dies, the surface and border to be measured and processed are classified int o four types. A 2-D adaptive measuring method based on Bzier curve and a 3 -D adaptive measuring method based on Spline curve are developed for different types of surface. During the data processing, a 3-D probe compensation method i s described in details. The control software of the sub-measuring system is des cribed. Some measuring experiments are carried out to testify the methods.展开更多
To overcome the obstacles of poor feature extraction and little prior information on the appearance of infrared dim small targets,we propose a multi-domain attention-guided pyramid network(MAGPNet).Specifically,we des...To overcome the obstacles of poor feature extraction and little prior information on the appearance of infrared dim small targets,we propose a multi-domain attention-guided pyramid network(MAGPNet).Specifically,we design three modules to ensure that salient features of small targets can be acquired and retained in the multi-scale feature maps.To improve the adaptability of the network for targets of different sizes,we design a kernel aggregation attention block with a receptive field attention branch and weight the feature maps under different perceptual fields with attention mechanism.Based on the research on human vision system,we further propose an adaptive local contrast measure module to enhance the local features of infrared small targets.With this parameterized component,we can implement the information aggregation of multi-scale contrast saliency maps.Finally,to fully utilize the information within spatial and channel domains in feature maps of different scales,we propose the mixed spatial-channel attention-guided fusion module to achieve high-quality fusion effects while ensuring that the small target features can be preserved at deep layers.Experiments on public datasets demonstrate that our MAGPNet can achieve a better performance over other state-of-the-art methods in terms of the intersection of union,Precision,Recall,and F-measure.In addition,we conduct detailed ablation studies to verify the effectiveness of each component in our network.展开更多
An Adaptive Measurement Scheme (AMS) is investigated with Compressed Sensing (CS) theory in Cognitive Wireless Sensor Network (C-WSN). Local sensing information is collected via energy detection with Analog-to-Informa...An Adaptive Measurement Scheme (AMS) is investigated with Compressed Sensing (CS) theory in Cognitive Wireless Sensor Network (C-WSN). Local sensing information is collected via energy detection with Analog-to-Information Converter (AIC) at massive cognitive sensors, and sparse representation is considered with the exploration of spatial temporal correlation structure of detected signals. Adaptive measurement matrix is designed in AMS, which is based on maximum energy subset selection. Energy subset is calculated with sparse transformation of sensing information, and maximum energy subset is selected as the row vector of adaptive measurement matrix. In addition, the measurement matrix is constructed by orthogonalization of those selected row vectors, which also satisfies the Restricted Isometry Property (RIP) in CS theory. Orthogonal Matching Pursuit (OMP) reconstruction algorithm is implemented at sink node to recover original information. Simulation results are performed with the comparison of Random Measurement Scheme (RMS). It is revealed that, signal reconstruction effect based on AMS is superior to conventional RMS Gaussian measurement. Moreover, AMS has better detection performance than RMS at lower compression rate region, and it is suitable for large-scale C-WSN wideband spectrum sensing.展开更多
Adaptation measures were proposed using“Sunny Rain”to solve Tel Aviv’s environmental problems to cool the air in the city and save humanity from climate catastrophe and fight air pollution;the Yarkon,“Tel Aviv’s ...Adaptation measures were proposed using“Sunny Rain”to solve Tel Aviv’s environmental problems to cool the air in the city and save humanity from climate catastrophe and fight air pollution;the Yarkon,“Tel Aviv’s main river”will no longer be a dirty ditch;the fog from Ben-Gurion Airport was cleaned;neighborhoods,parks,around Tel Aviv were greened and all green spaces were irrigated with“Sunny Rain”.展开更多
Under climate change, rising frequency and serious extreme weather events have challenged agricultural production. Designing appropriate adaptation measures to the extreme weather events require rigorous and empirical...Under climate change, rising frequency and serious extreme weather events have challenged agricultural production. Designing appropriate adaptation measures to the extreme weather events require rigorous and empirical analysis. The overall goals of this study are to understand physical adaptation measures taken by farmers and the impacts of household and community assets on farmers＇ adaptation when they face drought. The analyses are based on a unique data set collected from a household survey in three provinces in China. The survey results show that though not common on annual basis, some farmers did use physical adaptation measures to fight drought. Regression analysis reveals that both household and community assets significantly affect farmers＇ adaptation behaviors. Improving households＇ social capital and wealth, communities＇ network and access to government＇s anti-drought service can facilitate farmers＇ adaptation to drought. Results indicate that community＇s irrigation infrastructure and physical adaptation taken by farmers can substitute each other. Further analysis shows that the households taking adaptation measures have higher crop yields than those without taking these measures. The paper concludes with several policy implications.展开更多
Climate change is having a considerable impact on the availability of water resources for agricultural production on the North China Plain （NCP）, where the shortage of water is currently disturbing the stability and...Climate change is having a considerable impact on the availability of water resources for agricultural production on the North China Plain （NCP）, where the shortage of water is currently disturbing the stability and sustainability of agricultural production with respect to the drying tendency since the 1950s. However, although potential evapotranspiration （ET） has shown a decreasing trend under climate change, actual ET has slightly increased with an acceleration in hydrological cycling. Global climate model （GCM） ensemble projections predict that by the 2050s, the increased crop water demand and intensified ET resulting from global warming will reduce water resources surplus （Precipitation-ET） about 4%-24% and increase significantly the irrigation water demand in crop growth periods. This study assesses possible mitigation and adaptation measures for enabling agricultural sustainability. It is revealed that reducing the sowing area of winter wheat （3.0%-15.9%） in water-limited basins, together with improvement in crop water-use efficiency would effectively mitigate water shortages and intensify the resilience of agricultural systems to climate change.展开更多
The cone is widely used in mechanical design for rotation, centering and fixing. Whether the conicity error can be measured and evaluated accurately will directly influence its assembly accuracy and working performanc...The cone is widely used in mechanical design for rotation, centering and fixing. Whether the conicity error can be measured and evaluated accurately will directly influence its assembly accuracy and working performance. According to the new generation geometrical product specification（GPS）, the error and its measurement uncertainty should be evaluated together. The mathematical model of the minimum zone conicity error is established and an improved immune evolutionary algorithm（IlEA） is proposed to search for the conicity error. In the IIEA, initial antibodies are firstly generated by using quasi-random sequences and two kinds of affinities are calculated. Then, each antibody clone is generated and they are self-adaptively mutated so as to maintain diversity. Similar antibody is suppressed and new random antibody is generated. Because the mathematical model of conicity error is strongly nonlinear and the input quantities are not independent, it is difficult to use Guide to the expression of uncertainty in the measurement（GUM） method to evaluate measurement uncertainty. Adaptive Monte Carlo method（AMCM） is proposed to estimate measurement uncertainty in which the number of Monte Carlo trials is selected adaptively and the quality of the numerical results is directly controlled. The cone parts was machined on lathe CK6140 and measured on Miracle NC 454 Coordinate Measuring Machine（CMM）. The experiment results confirm that the proposed method not only can search for the approximate solution of the minimum zone conicity error（MZCE） rapidly and precisely, but also can evaluate measurement uncertainty and give control variables with an expected numerical tolerance. The conicity errors computed by the proposed method are 20%-40% less than those computed by NC454 CMM software and the evaluation accuracy improves significantly.展开更多
This article provides an assessment of the changes in marine climate drivers(hazards),associated impacts,risks,and adaptation to the coastal China zones and seas since the mid 20th century.The results show that:①Mari...This article provides an assessment of the changes in marine climate drivers(hazards),associated impacts,risks,and adaptation to the coastal China zones and seas since the mid 20th century.The results show that:①Marine climate drivers,such as ocean warming,sea level rise,typhoon,storm surges and marine heat waves(MHWs),have increased significantly in strength,frequency and range over the past decades.②Ocean warming has caused substantial changes in marine phenology,species composition,geographical distribution,and frequent occurrences of ecological disasters such as red tides,green tides,and macro-jellyfish outbreaks,while MHWs have induced degradation in tropical coral reefs and major losses in the marine aquaculture industry in the coastal China seas.③Sea level rise threatens the typical habitats of coastal wetlands such as mangrove and estuaries,and exacerbates coastal erosion,seawater intrusion and the impacts of typhoon,storm surges on the coastal flood disasters.④Human activities,such as large-scale reclamation,pollutant discharge,and overfishing,have increased the exposure and vulnerability of China's marine and coastal ecosystems,leading to the low-aging and miniaturization of fishery types,decline of offshore fishery resources,reduction of coastal wetland areas,and degradation of biodiversity and ecosystem stability.⑤Under different climate scenarios such as low and high greenhouse gases emission scenario(RCP 2.6 and 8.5),as the warming and sea level rise in the coastal China seas continue,extreme sea level(ESL)events will occur more frequently,e.g.,by the end of this century,the current once per century ESL events will become annually or even annually less(RCP 8.5)in many coastal areas,such as at Lvsi and Xiamen tidal gauge stations;and the ESL events could pose serious risks on the coastal areas.Finally,the article further discusses the adaptation measures and related uncertain issues to address climate change in the coastal China zones and seas,and puts forward relevant countermeasures and suggestions in order to reduce its negative impacts on the sustainable development of human community.展开更多
This study focuses on the characters of public perceptions on climate and cryosphere change,which are based on a questionnaire survey in the(U|¨)r(u|¨)mqi River Basin.In comparison with scientific observatio...This study focuses on the characters of public perceptions on climate and cryosphere change,which are based on a questionnaire survey in the(U|¨)r(u|¨)mqi River Basin.In comparison with scientific observation results of climate and cryosphere change,this paper analyzes the possible impact of the change on water resources and agriculture production in the area.Perceptions of most respondents on climate and cryosphere changes confirm the main objective facts.For the selection of adaptation measures addressing the shortage of water resource,the results are as follows:most people preferred to choose the measures like "policy change" and "basic facility construction" which are mostly implemented by the government and the policy-making department;some people showed more preference to the measures of avoiding unfavorable natural environment,such as finding job in or migrating to other places.The urgency of personal participation in the adaptation measures is still inadequate.Some adaptation measures should be implemented in line with local conditions and require the organic combination of "resource-development" with "water-saving".展开更多
Climate change has major impacts on the livelihoods of forest-dependent communities.The unpredictable weather conditions in rural Nepal have been attributed to a changing climate.This study explored the climate change...Climate change has major impacts on the livelihoods of forest-dependent communities.The unpredictable weather conditions in rural Nepal have been attributed to a changing climate.This study explored the climate change adaptation and coping strategies that rural communities adopt for the conservation of natural resources and livelihoods in the mid-hills of Nepal.This paper explored major climatic hazards,assessed different coping and adaptation measures,and barrier faced to climate change adaptation based on perceptions by forest-dependent communities.We conducted focus group discussions,questionnaire surveys,and semistructured interviews with local communities and stakeholders.The results showed that rural communities had experienced significant impacts of climate change and variability.In response,they are practicing diverse coping and adaptation strategies,including the construction of bioengineering structures and planting different species that grow quickly and establish promptly.展开更多
<p align="justify"> <span style="font-family:Verdana;"></span><span style="font-family:Verdana;">Climate change and variability are a reality and have had marked e...<p align="justify"> <span style="font-family:Verdana;"></span><span style="font-family:Verdana;">Climate change and variability are a reality and have had marked effects on both human and ecological systems. Adaptation to such effects either directly or indirectly is viewed as a novel way of reducing the spread of the associated risks. The study was conducted in Rubanda District with a general aim of evaluating the effectiveness of adaptation measures to climate variability used </span><span style="font-family:Verdana;">by smallholder Irish potatoes farmers. Specifically, we sought to appraise</span><span style="font-family:Verdana;"> small</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">holder Irish potato farmers’ perceptions about the effectiveness of climate variability adaptation measures and implications on Irish potato productivity. We undertook a cross-sectional study to collect data from total of 197 farmers using a structured questionnaire. Other participatory methods such as focus group discussions and key informant interview were also used to complement the household survey. Data w</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ere</span></span></span><span><span><span style="font-family:'Minion Pro Capt','serif';"><span style="font-family:Verdana;"> analyzed using SPSS Version 23 to generate descriptive statistics as well as relationships between the adaptation measures and the productivity of the Irish potatoes using a Cobb-Douglas production function. The Cobb-Douglas model revealed that the use of fertilizers was significantly and positively associated with productivity of Irish potato (</span><i><span style="font-family:Verdana;">P </span></i><span style="font-family:Verdana;">< 0.001). Furthermore, Smallholder Irish potato farmers perceived the use of technology, terracing, early planting and application of fertilizers as the most effective climate variability adaptation measures. The study recommends that measures that are cost-effective, efficient and coherent should be promoted to offset the impacts of climate variability which would include the adoption of improved potato varieties and use of fertilizers with proper management of erosion. Off-season planting of Irish potatoes in the wetlands should be discouraged by the local administration and the National Environment Management Authority. This calls for a collective action involving the agricultural practitioners and inline civil society organizations to ensure that farmers have access to such inputs.</span></span></span></span> </p>展开更多
In Central China, the obvious climate change has happened along with global warming. Based on the observational analysis, the climate change has significant effects, both positive and negative, in every field within t...In Central China, the obvious climate change has happened along with global warming. Based on the observational analysis, the climate change has significant effects, both positive and negative, in every field within the study area, and with the harmful effects far more prevalent. Under the A1B scenario, it is reported that temperature, precipitation, days of heat waves, and extreme precipitation intensity will increase at respective rates of 0.38℃ per decade, 12.6 mm per decade, 6.4 d and 47 mm per decade in the 21st century. It is widely believed that these climate changes in the future will result in some apparent impacts on agro-ecosystems, water resources, wetland ecosystem, forest ecosystem, human health, energy sectors and other sensitive fields in Central China. Due to the limited scientific knowledge and researches, there are still some shortages in the climate change assessment methodologies and many uncertainties in the climate prediction results. Therefore, it is urgent and essential to increase the studies of the regional climate change adaptation, extend the research fields, and enhance the studies in the extreme weather and climate events to reduce the uncertainties of the climate change assessments.展开更多
Hydropower is critical to South and Southeast Asia’s energy security,yet climate change threatens its sustainability through altered hydrological cycles.This study assesses the impacts of climate change on hydropower...Hydropower is critical to South and Southeast Asia’s energy security,yet climate change threatens its sustainability through altered hydrological cycles.This study assesses the impacts of climate change on hydropower capacity factors across 12 countries(86% of regional installed capacity)from 2020 to 2100.Using an ensemble of 60 climate-hydrological models(5 GCMs,4 GHMs,3 RCPs),we evaluate shifts in precipitation,glacier melt,and extreme events on seasonal and annual hydropower performance.The objectives are to 1)quantify regional and sub-regional capacity factor trends,2)identify drivers of variability,and 3)propose adaptive strategies for resilient energy systems.Results indicate a regional mean decline in hydropower capacity factors by 4.8%(2020-2059)and up to 5.4%(2060-2099)under high-emission scenarios.The Indian Subcontinent faces severe reductions(6.9% by 2100)due to drier winters and monsoon shifts,while Mainland Southeast Asia declines by 5.9%.Conversely,Himalayan regions(Nepal,Bhutan)show transient declines(-2.4% by 2059)followed by recovery post-2060 as glacial melt temporarily offsets precipitation deficits.Maritime Southeast Asia exhibits mixed trends,with capacity factors rebounding under high warming.To mitigate risks,we recommend integrating hydropower with floating solar photovoltaics,optimizing reservoir operations via AI-driven forecasting,and strengthening transboundary water-energy governance.These strategies can enhance grid resilience,offset seasonal variability,and support decarbonization goals.Policymakers must prioritize regionspecific adaptations,particularly in climate-vulnerable zones like the Indian Subcontinent,to ensure energy security amid escalating hydrological uncertainties.展开更多
Understanding the driving mechanisms of crop suitability is critical for ensuring global food security,particularly in promoting the sustainable development of alpine agriculture and alpine civilizations.In contrast t...Understanding the driving mechanisms of crop suitability is critical for ensuring global food security,particularly in promoting the sustainable development of alpine agriculture and alpine civilizations.In contrast to climate factors,how anthropogenic adaptation measures affect crop suitability remains largely unknown.This overlooked mechanism may explain why climate-driven model simulations underestimate the upper altitude limit for highland barley compared with observed records.Here,we used two decades of site-based phenological observations on the Tibetan Plateau and biophysical modeling,finding that anthropogenic adaptation measures can expand suitable cropping limits.These measures mainly involve breeding genotypes with lower thermal units,which enhance the adaptability of highland barley phenology to cold climates.Such adaptation mechanisms clarify the conflict between thermal niche model predictions and the observed distribution of highland barley up to an altitude of 5000 m.Considering these mechanisms,we developed an explainable framework to predict the potential habitat of highland barley under current climates.Results showed that anthropogenic adaptation measures expanded the suitable cropping area for highland barley by 27×104 km^(2)and the upper altitude limit for highland barley could reliably increase by approximately 50 m.This observation-based evidence underscores the crucial roles of anthropogenic adaptation measures in expanding suitable cropping limits of crops and highlights its importance for supporting food security and simulating accurate crop suitability.展开更多
An objective visual performance evaluation with visual evoked potential （VEP） measurements was first inte- grated into an adaptive optics （AO） system. The optical and neural limits to vision can be bypassed throug...An objective visual performance evaluation with visual evoked potential （VEP） measurements was first inte- grated into an adaptive optics （AO） system. The optical and neural limits to vision can be bypassed through this system. Visual performance can be measured electrophysiologically with VEP, which reflects the objective func- tion from the retina to the primary visual cortex. The VEP ts without and with AO correction were preliminarily carried out using this system, demonstrating the great potential of this system in the objective visual performance evaluation. The new system will provide the necessary technique and equipment support for the further study of human visual function.展开更多
A real-time method for measuring atmospheric parameters based on co-processor field-programmable gate array （FPGA） and main processor digital signal processing （DSP） is proposed for ground-based telescopes with ad...A real-time method for measuring atmospheric parameters based on co-processor field-programmable gate array （FPGA） and main processor digital signal processing （DSP） is proposed for ground-based telescopes with adaptive optics （AO） systems. Coherence length, outer scale, average wind speed, and coherence time are estimated according to closed-loop data on the residual slopes and the corrected voltages of AO systems. This letter introduces the principle and architecture design of the proposed method, which is successfully applied in the 127-element AO system of the 1.8-m telescope of Yunnan Astronomical Observatory. The method enables real-time atmospheric observations with the same object and path of the AO system. This method is also applicable to extended objects.展开更多
Flexible bending sensors have emerged as a technology with significant potential for a wide range of applications,including human-machine interaction,healthcare monitoring,and soft robotics.This paper provides a compr...Flexible bending sensors have emerged as a technology with significant potential for a wide range of applications,including human-machine interaction,healthcare monitoring,and soft robotics.This paper provides a comprehensive review of the working principles,performance evaluation,application areas,and future trends of flexible bending sensors.The challenges faced by these sensors,such as anti-interference,adaptive detection,and multidirectional sensing,are discussed,along with potential solutions and future developmental directions.The paper highlights the importance of materials development,structural design,and manufacturing processes in advancing flexible bending sensor technology.Overall,this review aims to provide valuable insights and guidance for further research and development in the field of flexible bending sensors.展开更多
Climate change can adversely impact the thermal comfort and energy efficiency of the buildings stock. The South Asian countries are particularly vulnerable to the adverse impacts of climate change specially in the for...Climate change can adversely impact the thermal comfort and energy efficiency of the buildings stock. The South Asian countries are particularly vulnerable to the adverse impacts of climate change specially in the form of rising temperatures and increasing frequency of heat waves. The passive building design measures can be useful in mitigating and adapting to the climate change by increasing energy efficiency and reducing greenhouse gas (GHG) emissions. In this study various passive climate change adaptation measures (PCAMs) have been used individually and in form of combinations in order to analyze their impact on the energy efficacy of residential buildings in Pakistan. It has been found that the natural ventilation and front green wall are the most efficient options for reducing the overall energy consumption. By implementation of these PCAMs, cooling demand can be decreased by 27.75% while heating demand can be reduced by 35%. Secondly, the prospect of net zero-energy building and reduced CO2 emissions are also studied. It has been shown that building can achieve net-zero energy on an annual basis at every orientation and it can attain the status of nearly zero-energy building on a monthly basis. Moreover, emitted CO2 can be reduced by 31% by using the renewable energy.展开更多
Human-wildlife conflict has been one of the most trouble-causing issues in many areas of Nepal including Eastern Nepal. This study assessed the human-wildlife conflict status in Paschim Kusaha Village of Koshi Tappu W...Human-wildlife conflict has been one of the most trouble-causing issues in many areas of Nepal including Eastern Nepal. This study assessed the human-wildlife conflict status in Paschim Kusaha Village of Koshi Tappu Wildlife Reserve(KTWR), Sunsari District, Nepal. Data were collected from 47 respondents of different households through questionnaire surveys and formal and informal interviews. Results revealed that the most destructive wild animals were wild elephants, wild boar,and wild water buffalo and the most raided crops were paddy(63.83 %), maize(19.15%), and potato(17.02%). Most of the encounters between humans and wildlife were recorded at night(after dusk and before dawn)(78.72%). Local people were suffering from damage of physical properties, human harassment or nuisance, and depredation of cropland due to wild animals.A total of 70% of respondents had a positive attitude towards conservation despite disturbing human mortality records(22deaths in the last five years) from the reserve area and surrounding. Awareness of wildlife behavior together with conservation and easy access to compensation schemes were suggested to minimize conflicts in the area.展开更多
文摘Based on the computer integrated and flexible laser p rocessing system, we developed an intelligent measuring sub-system. A novel mod el has been built to compensate the deviations of the main frame-structure, and a laser tracker system is applied to calibrate the accuracy of the system. Anal yzing the characteristics of all kind surfaces of automobile outer penal moulds and dies, the surface and border to be measured and processed are classified int o four types. A 2-D adaptive measuring method based on Bzier curve and a 3 -D adaptive measuring method based on Spline curve are developed for different types of surface. During the data processing, a 3-D probe compensation method i s described in details. The control software of the sub-measuring system is des cribed. Some measuring experiments are carried out to testify the methods.
基金the Industry-University-Research Cooperation Fund Project of the Eighth Research Institute of China Aerospace Science and Technology Corporation(No.USCAST2021-5)。
文摘To overcome the obstacles of poor feature extraction and little prior information on the appearance of infrared dim small targets,we propose a multi-domain attention-guided pyramid network(MAGPNet).Specifically,we design three modules to ensure that salient features of small targets can be acquired and retained in the multi-scale feature maps.To improve the adaptability of the network for targets of different sizes,we design a kernel aggregation attention block with a receptive field attention branch and weight the feature maps under different perceptual fields with attention mechanism.Based on the research on human vision system,we further propose an adaptive local contrast measure module to enhance the local features of infrared small targets.With this parameterized component,we can implement the information aggregation of multi-scale contrast saliency maps.Finally,to fully utilize the information within spatial and channel domains in feature maps of different scales,we propose the mixed spatial-channel attention-guided fusion module to achieve high-quality fusion effects while ensuring that the small target features can be preserved at deep layers.Experiments on public datasets demonstrate that our MAGPNet can achieve a better performance over other state-of-the-art methods in terms of the intersection of union,Precision,Recall,and F-measure.In addition,we conduct detailed ablation studies to verify the effectiveness of each component in our network.
基金Supported by the National Natural Science Foundation of China (No. 61102066, 60972058)the China Postdoctoral Science Foundation (No. 2012M511365)the Scientific Research Project of Zhejiang Provincial Education Department (No. Y201119890)
文摘An Adaptive Measurement Scheme (AMS) is investigated with Compressed Sensing (CS) theory in Cognitive Wireless Sensor Network (C-WSN). Local sensing information is collected via energy detection with Analog-to-Information Converter (AIC) at massive cognitive sensors, and sparse representation is considered with the exploration of spatial temporal correlation structure of detected signals. Adaptive measurement matrix is designed in AMS, which is based on maximum energy subset selection. Energy subset is calculated with sparse transformation of sensing information, and maximum energy subset is selected as the row vector of adaptive measurement matrix. In addition, the measurement matrix is constructed by orthogonalization of those selected row vectors, which also satisfies the Restricted Isometry Property (RIP) in CS theory. Orthogonal Matching Pursuit (OMP) reconstruction algorithm is implemented at sink node to recover original information. Simulation results are performed with the comparison of Random Measurement Scheme (RMS). It is revealed that, signal reconstruction effect based on AMS is superior to conventional RMS Gaussian measurement. Moreover, AMS has better detection performance than RMS at lower compression rate region, and it is suitable for large-scale C-WSN wideband spectrum sensing.
文摘Adaptation measures were proposed using“Sunny Rain”to solve Tel Aviv’s environmental problems to cool the air in the city and save humanity from climate catastrophe and fight air pollution;the Yarkon,“Tel Aviv’s main river”will no longer be a dirty ditch;the fog from Ben-Gurion Airport was cleaned;neighborhoods,parks,around Tel Aviv were greened and all green spaces were irrigated with“Sunny Rain”.
基金the National Basic Research Program of China(973 Program,2012CB955700)the National Natural Sciences Foundation of China(70925001,71161140351)+1 种基金the International Development Research Center(107093-001)the Australian Centre for International Agricultural Research(ADP/2010/070)
文摘Under climate change, rising frequency and serious extreme weather events have challenged agricultural production. Designing appropriate adaptation measures to the extreme weather events require rigorous and empirical analysis. The overall goals of this study are to understand physical adaptation measures taken by farmers and the impacts of household and community assets on farmers＇ adaptation when they face drought. The analyses are based on a unique data set collected from a household survey in three provinces in China. The survey results show that though not common on annual basis, some farmers did use physical adaptation measures to fight drought. Regression analysis reveals that both household and community assets significantly affect farmers＇ adaptation behaviors. Improving households＇ social capital and wealth, communities＇ network and access to government＇s anti-drought service can facilitate farmers＇ adaptation to drought. Results indicate that community＇s irrigation infrastructure and physical adaptation taken by farmers can substitute each other. Further analysis shows that the households taking adaptation measures have higher crop yields than those without taking these measures. The paper concludes with several policy implications.
基金Acknowledgment This work was supported by the State＇s Key Project of Research and Development Plan （2010CB428404） and the Natural Science Foundation of China （41471026）.
文摘Climate change is having a considerable impact on the availability of water resources for agricultural production on the North China Plain （NCP）, where the shortage of water is currently disturbing the stability and sustainability of agricultural production with respect to the drying tendency since the 1950s. However, although potential evapotranspiration （ET） has shown a decreasing trend under climate change, actual ET has slightly increased with an acceleration in hydrological cycling. Global climate model （GCM） ensemble projections predict that by the 2050s, the increased crop water demand and intensified ET resulting from global warming will reduce water resources surplus （Precipitation-ET） about 4%-24% and increase significantly the irrigation water demand in crop growth periods. This study assesses possible mitigation and adaptation measures for enabling agricultural sustainability. It is revealed that reducing the sowing area of winter wheat （3.0%-15.9%） in water-limited basins, together with improvement in crop water-use efficiency would effectively mitigate water shortages and intensify the resilience of agricultural systems to climate change.
基金Supported by National Natural Science Foundation of China(Grant No.51075198)Jiangsu Provincial Natural Science Foundation of China(Grant No.BK2010479)+1 种基金Jiangsu Provincial Project of Six Talented Peaks of ChinaJiangsu Provincial Project of 333 Talents Engineering of China(Grant No.3-45)
文摘The cone is widely used in mechanical design for rotation, centering and fixing. Whether the conicity error can be measured and evaluated accurately will directly influence its assembly accuracy and working performance. According to the new generation geometrical product specification（GPS）, the error and its measurement uncertainty should be evaluated together. The mathematical model of the minimum zone conicity error is established and an improved immune evolutionary algorithm（IlEA） is proposed to search for the conicity error. In the IIEA, initial antibodies are firstly generated by using quasi-random sequences and two kinds of affinities are calculated. Then, each antibody clone is generated and they are self-adaptively mutated so as to maintain diversity. Similar antibody is suppressed and new random antibody is generated. Because the mathematical model of conicity error is strongly nonlinear and the input quantities are not independent, it is difficult to use Guide to the expression of uncertainty in the measurement（GUM） method to evaluate measurement uncertainty. Adaptive Monte Carlo method（AMCM） is proposed to estimate measurement uncertainty in which the number of Monte Carlo trials is selected adaptively and the quality of the numerical results is directly controlled. The cone parts was machined on lathe CK6140 and measured on Miracle NC 454 Coordinate Measuring Machine（CMM）. The experiment results confirm that the proposed method not only can search for the approximate solution of the minimum zone conicity error（MZCE） rapidly and precisely, but also can evaluate measurement uncertainty and give control variables with an expected numerical tolerance. The conicity errors computed by the proposed method are 20%-40% less than those computed by NC454 CMM software and the evaluation accuracy improves significantly.
基金The research was supported by the National Key R&D Program[Grant number.2017YFA0604902,2017YFA0604903].
文摘This article provides an assessment of the changes in marine climate drivers(hazards),associated impacts,risks,and adaptation to the coastal China zones and seas since the mid 20th century.The results show that:①Marine climate drivers,such as ocean warming,sea level rise,typhoon,storm surges and marine heat waves(MHWs),have increased significantly in strength,frequency and range over the past decades.②Ocean warming has caused substantial changes in marine phenology,species composition,geographical distribution,and frequent occurrences of ecological disasters such as red tides,green tides,and macro-jellyfish outbreaks,while MHWs have induced degradation in tropical coral reefs and major losses in the marine aquaculture industry in the coastal China seas.③Sea level rise threatens the typical habitats of coastal wetlands such as mangrove and estuaries,and exacerbates coastal erosion,seawater intrusion and the impacts of typhoon,storm surges on the coastal flood disasters.④Human activities,such as large-scale reclamation,pollutant discharge,and overfishing,have increased the exposure and vulnerability of China's marine and coastal ecosystems,leading to the low-aging and miniaturization of fishery types,decline of offshore fishery resources,reduction of coastal wetland areas,and degradation of biodiversity and ecosystem stability.⑤Under different climate scenarios such as low and high greenhouse gases emission scenario(RCP 2.6 and 8.5),as the warming and sea level rise in the coastal China seas continue,extreme sea level(ESL)events will occur more frequently,e.g.,by the end of this century,the current once per century ESL events will become annually or even annually less(RCP 8.5)in many coastal areas,such as at Lvsi and Xiamen tidal gauge stations;and the ESL events could pose serious risks on the coastal areas.Finally,the article further discusses the adaptation measures and related uncertain issues to address climate change in the coastal China zones and seas,and puts forward relevant countermeasures and suggestions in order to reduce its negative impacts on the sustainable development of human community.
基金funded by the "973" National Social Development Research Program "Dynamic process of cryosphere,the mechanism of cryospheric impacts on climate, hydrology and ecologyadaptation measures" (Grant No.2007CB411507)Science of state key laboratory open fund of "The research of typical basin of cryosphere change and its threshold level,adaptation and strategy"(SKLCS08-04)
文摘This study focuses on the characters of public perceptions on climate and cryosphere change,which are based on a questionnaire survey in the(U|¨)r(u|¨)mqi River Basin.In comparison with scientific observation results of climate and cryosphere change,this paper analyzes the possible impact of the change on water resources and agriculture production in the area.Perceptions of most respondents on climate and cryosphere changes confirm the main objective facts.For the selection of adaptation measures addressing the shortage of water resource,the results are as follows:most people preferred to choose the measures like "policy change" and "basic facility construction" which are mostly implemented by the government and the policy-making department;some people showed more preference to the measures of avoiding unfavorable natural environment,such as finding job in or migrating to other places.The urgency of personal participation in the adaptation measures is still inadequate.Some adaptation measures should be implemented in line with local conditions and require the organic combination of "resource-development" with "water-saving".
文摘Climate change has major impacts on the livelihoods of forest-dependent communities.The unpredictable weather conditions in rural Nepal have been attributed to a changing climate.This study explored the climate change adaptation and coping strategies that rural communities adopt for the conservation of natural resources and livelihoods in the mid-hills of Nepal.This paper explored major climatic hazards,assessed different coping and adaptation measures,and barrier faced to climate change adaptation based on perceptions by forest-dependent communities.We conducted focus group discussions,questionnaire surveys,and semistructured interviews with local communities and stakeholders.The results showed that rural communities had experienced significant impacts of climate change and variability.In response,they are practicing diverse coping and adaptation strategies,including the construction of bioengineering structures and planting different species that grow quickly and establish promptly.
文摘<p align="justify"> <span style="font-family:Verdana;"></span><span style="font-family:Verdana;">Climate change and variability are a reality and have had marked effects on both human and ecological systems. Adaptation to such effects either directly or indirectly is viewed as a novel way of reducing the spread of the associated risks. The study was conducted in Rubanda District with a general aim of evaluating the effectiveness of adaptation measures to climate variability used </span><span style="font-family:Verdana;">by smallholder Irish potatoes farmers. Specifically, we sought to appraise</span><span style="font-family:Verdana;"> small</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">holder Irish potato farmers’ perceptions about the effectiveness of climate variability adaptation measures and implications on Irish potato productivity. We undertook a cross-sectional study to collect data from total of 197 farmers using a structured questionnaire. Other participatory methods such as focus group discussions and key informant interview were also used to complement the household survey. Data w</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ere</span></span></span><span><span><span style="font-family:'Minion Pro Capt','serif';"><span style="font-family:Verdana;"> analyzed using SPSS Version 23 to generate descriptive statistics as well as relationships between the adaptation measures and the productivity of the Irish potatoes using a Cobb-Douglas production function. The Cobb-Douglas model revealed that the use of fertilizers was significantly and positively associated with productivity of Irish potato (</span><i><span style="font-family:Verdana;">P </span></i><span style="font-family:Verdana;">< 0.001). Furthermore, Smallholder Irish potato farmers perceived the use of technology, terracing, early planting and application of fertilizers as the most effective climate variability adaptation measures. The study recommends that measures that are cost-effective, efficient and coherent should be promoted to offset the impacts of climate variability which would include the adoption of improved potato varieties and use of fertilizers with proper management of erosion. Off-season planting of Irish potatoes in the wetlands should be discouraged by the local administration and the National Environment Management Authority. This calls for a collective action involving the agricultural practitioners and inline civil society organizations to ensure that farmers have access to such inputs.</span></span></span></span> </p>
基金supported by the Special Climate Change Research Program of China Meteorological Administration(No.CCSF-2010-04)
文摘In Central China, the obvious climate change has happened along with global warming. Based on the observational analysis, the climate change has significant effects, both positive and negative, in every field within the study area, and with the harmful effects far more prevalent. Under the A1B scenario, it is reported that temperature, precipitation, days of heat waves, and extreme precipitation intensity will increase at respective rates of 0.38℃ per decade, 12.6 mm per decade, 6.4 d and 47 mm per decade in the 21st century. It is widely believed that these climate changes in the future will result in some apparent impacts on agro-ecosystems, water resources, wetland ecosystem, forest ecosystem, human health, energy sectors and other sensitive fields in Central China. Due to the limited scientific knowledge and researches, there are still some shortages in the climate change assessment methodologies and many uncertainties in the climate prediction results. Therefore, it is urgent and essential to increase the studies of the regional climate change adaptation, extend the research fields, and enhance the studies in the extreme weather and climate events to reduce the uncertainties of the climate change assessments.
文摘Hydropower is critical to South and Southeast Asia’s energy security,yet climate change threatens its sustainability through altered hydrological cycles.This study assesses the impacts of climate change on hydropower capacity factors across 12 countries(86% of regional installed capacity)from 2020 to 2100.Using an ensemble of 60 climate-hydrological models(5 GCMs,4 GHMs,3 RCPs),we evaluate shifts in precipitation,glacier melt,and extreme events on seasonal and annual hydropower performance.The objectives are to 1)quantify regional and sub-regional capacity factor trends,2)identify drivers of variability,and 3)propose adaptive strategies for resilient energy systems.Results indicate a regional mean decline in hydropower capacity factors by 4.8%(2020-2059)and up to 5.4%(2060-2099)under high-emission scenarios.The Indian Subcontinent faces severe reductions(6.9% by 2100)due to drier winters and monsoon shifts,while Mainland Southeast Asia declines by 5.9%.Conversely,Himalayan regions(Nepal,Bhutan)show transient declines(-2.4% by 2059)followed by recovery post-2060 as glacial melt temporarily offsets precipitation deficits.Maritime Southeast Asia exhibits mixed trends,with capacity factors rebounding under high warming.To mitigate risks,we recommend integrating hydropower with floating solar photovoltaics,optimizing reservoir operations via AI-driven forecasting,and strengthening transboundary water-energy governance.These strategies can enhance grid resilience,offset seasonal variability,and support decarbonization goals.Policymakers must prioritize regionspecific adaptations,particularly in climate-vulnerable zones like the Indian Subcontinent,to ensure energy security amid escalating hydrological uncertainties.
基金supported by the National Natural Science Fundation of China for Excellent Young Scholars(42122003)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA28060200)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(72221002)。
文摘Understanding the driving mechanisms of crop suitability is critical for ensuring global food security,particularly in promoting the sustainable development of alpine agriculture and alpine civilizations.In contrast to climate factors,how anthropogenic adaptation measures affect crop suitability remains largely unknown.This overlooked mechanism may explain why climate-driven model simulations underestimate the upper altitude limit for highland barley compared with observed records.Here,we used two decades of site-based phenological observations on the Tibetan Plateau and biophysical modeling,finding that anthropogenic adaptation measures can expand suitable cropping limits.These measures mainly involve breeding genotypes with lower thermal units,which enhance the adaptability of highland barley phenology to cold climates.Such adaptation mechanisms clarify the conflict between thermal niche model predictions and the observed distribution of highland barley up to an altitude of 5000 m.Considering these mechanisms,we developed an explainable framework to predict the potential habitat of highland barley under current climates.Results showed that anthropogenic adaptation measures expanded the suitable cropping area for highland barley by 27×104 km^(2)and the upper altitude limit for highland barley could reliably increase by approximately 50 m.This observation-based evidence underscores the crucial roles of anthropogenic adaptation measures in expanding suitable cropping limits of crops and highlights its importance for supporting food security and simulating accurate crop suitability.
基金supported by the National Natural Science Foundation of China (No. 61378064)the National High Technology Research and Development Program of China (No. 2015AA020510)
文摘An objective visual performance evaluation with visual evoked potential （VEP） measurements was first inte- grated into an adaptive optics （AO） system. The optical and neural limits to vision can be bypassed through this system. Visual performance can be measured electrophysiologically with VEP, which reflects the objective func- tion from the retina to the primary visual cortex. The VEP ts without and with AO correction were preliminarily carried out using this system, demonstrating the great potential of this system in the objective visual performance evaluation. The new system will provide the necessary technique and equipment support for the further study of human visual function.
基金supported by the National Natural Science Foundation of China under Grant No. 11178004
文摘A real-time method for measuring atmospheric parameters based on co-processor field-programmable gate array （FPGA） and main processor digital signal processing （DSP） is proposed for ground-based telescopes with adaptive optics （AO） systems. Coherence length, outer scale, average wind speed, and coherence time are estimated according to closed-loop data on the residual slopes and the corrected voltages of AO systems. This letter introduces the principle and architecture design of the proposed method, which is successfully applied in the 127-element AO system of the 1.8-m telescope of Yunnan Astronomical Observatory. The method enables real-time atmospheric observations with the same object and path of the AO system. This method is also applicable to extended objects.
基金supported by the National Natural Science Foundation of China[52105563,52475573]Natural Science Foundation of Zhejiang Province[LTGY23E050002]+3 种基金National Key Research and Development Program of China[2023YFC2811500]Zhijiang Youth Project of Zhejiang Provincial Philosophy and Social Science Planning[22ZJQN14YB]Key Research and Development Programme of Zhejiang[2024C03259,2023C03196,2022C03103]Fundamental Research Funds for the Central Universities.
文摘Flexible bending sensors have emerged as a technology with significant potential for a wide range of applications,including human-machine interaction,healthcare monitoring,and soft robotics.This paper provides a comprehensive review of the working principles,performance evaluation,application areas,and future trends of flexible bending sensors.The challenges faced by these sensors,such as anti-interference,adaptive detection,and multidirectional sensing,are discussed,along with potential solutions and future developmental directions.The paper highlights the importance of materials development,structural design,and manufacturing processes in advancing flexible bending sensor technology.Overall,this review aims to provide valuable insights and guidance for further research and development in the field of flexible bending sensors.
文摘Climate change can adversely impact the thermal comfort and energy efficiency of the buildings stock. The South Asian countries are particularly vulnerable to the adverse impacts of climate change specially in the form of rising temperatures and increasing frequency of heat waves. The passive building design measures can be useful in mitigating and adapting to the climate change by increasing energy efficiency and reducing greenhouse gas (GHG) emissions. In this study various passive climate change adaptation measures (PCAMs) have been used individually and in form of combinations in order to analyze their impact on the energy efficacy of residential buildings in Pakistan. It has been found that the natural ventilation and front green wall are the most efficient options for reducing the overall energy consumption. By implementation of these PCAMs, cooling demand can be decreased by 27.75% while heating demand can be reduced by 35%. Secondly, the prospect of net zero-energy building and reduced CO2 emissions are also studied. It has been shown that building can achieve net-zero energy on an annual basis at every orientation and it can attain the status of nearly zero-energy building on a monthly basis. Moreover, emitted CO2 can be reduced by 31% by using the renewable energy.
文摘Human-wildlife conflict has been one of the most trouble-causing issues in many areas of Nepal including Eastern Nepal. This study assessed the human-wildlife conflict status in Paschim Kusaha Village of Koshi Tappu Wildlife Reserve(KTWR), Sunsari District, Nepal. Data were collected from 47 respondents of different households through questionnaire surveys and formal and informal interviews. Results revealed that the most destructive wild animals were wild elephants, wild boar,and wild water buffalo and the most raided crops were paddy(63.83 %), maize(19.15%), and potato(17.02%). Most of the encounters between humans and wildlife were recorded at night(after dusk and before dawn)(78.72%). Local people were suffering from damage of physical properties, human harassment or nuisance, and depredation of cropland due to wild animals.A total of 70% of respondents had a positive attitude towards conservation despite disturbing human mortality records(22deaths in the last five years) from the reserve area and surrounding. Awareness of wildlife behavior together with conservation and easy access to compensation schemes were suggested to minimize conflicts in the area.
