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Modeling Study of the Evolution of the Climate Crisis over Time
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作者 Victor Rogelio Tirado Picado 《Open Journal of Applied Sciences》 2024年第2期330-342,共13页
The research proposal has the following scope. In relation to the general objective, the aim is to model the evolution of the climate crisis over time taking as variables global warming, greenhouse gases, atmospheric ... The research proposal has the following scope. In relation to the general objective, the aim is to model the evolution of the climate crisis over time taking as variables global warming, greenhouse gases, atmospheric temperature and ocean temperature, as well as the continuity of the natural phenomena in terms of their measurement, temporality and projection. To achieve the above, the description of the following specific objectives is proposed: - Identify the variables corresponding to the climate crisis, their relationship and correlation between them;- Develop projection models with mathematical and statistical arrangements to project them in a given time and, in this way, - Propose mitigation measures for different unfavorable scenarios. The main variables that are currently directly linked to Climate Change are: CO<sub>2</sub>, the atmospheric index, precipitation, temperature and wind speed. The correlation that exists between climatic elements is very high, both in historical behavior and projected behavior for 2035, their correlation is estimated at 0.90, 0.95, 0.93 and 91 respectively. The mathematical models used to manipulate the historical and projected analysis of the variables studied: are the normal arrangements, this ensures that the values can be used on a common scale;Then there is the analysis of the historical variables using the linear trend, and finally there is the analysis of the variables projected to the year 2035 using the polynomial trend. In both situations, the direct relationship of greenhouse gases, mainly CO<sub>2</sub>, is directly related to the variations of the variables over time, which is a very worrying result because we can no longer talk about climate change, but rather about CLIMATE CRISIS. To a large extent, a change in the paradigm of exploitation of the resources of our mother earth is required. Alert in an SOS manner to the great powers, which make reasonable use of technology, for this attenuation measures are proposed. 展开更多
关键词 climate Crisis MODEL Climatic Factors evolution TEMPERATURE
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Quantitative distinction of the relative actions of climate change and human activities on vegetation evolution in the Yellow River Basin of China during 1981-2019 被引量:5
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作者 LIU Yifeng GUO Bing +3 位作者 LU Miao ZANG Wenqian YU Tao CHEN Donghua 《Journal of Arid Land》 SCIE CSCD 2023年第1期91-108,共18页
Under the combined influence of climate change and human activities,vegetation ecosystem has undergone profound changes.It can be seen that there are obvious differences in the evolution patterns and driving mechanism... Under the combined influence of climate change and human activities,vegetation ecosystem has undergone profound changes.It can be seen that there are obvious differences in the evolution patterns and driving mechanisms of vegetation ecosystem in different historical periods.Therefore,it is urgent to identify and reveal the dominant factors and their contribution rates in the vegetation change cycle.Based on the data of climate elements(sunshine hours,precipitation and temperature),human activities(population intensity and GDP intensity)and other natural factors(altitude,slope and aspect),this study explored the spatial and temporal evolution patterns of vegetation NDVI in the Yellow River Basin of China from 1989 to 2019 through a residual method,a trend analysis,and a gravity center model,and quantitatively distinguished the relative actions of climate change and human activities on vegetation evolution based on Geodetector model.The results showed that the spatial distribution of vegetation NDVI in the Yellow River Basin showed a decreasing trend from southeast to northwest.During 1981-2019,the temporal variation of vegetation NDVI showed an overall increasing trend.The gravity centers of average vegetation NDVI during the study period was distributed in Zhenyuan County,Gansu Province,and the center moved northeastwards from 1981 to 2019.During 1981-2000 and 2001-2019,the proportion of vegetation restoration areas promoted by the combined action of climate change and human activities was the largest.During the study period(1981-2019),the dominant factors influencing vegetation NDVI shifted from natural factors to human activities.These results could provide decision support for the protection and restoration of vegetation ecosystem in the Yellow River Basin. 展开更多
关键词 vegetation evolution driving mechanisms climate change human activities relative actions Geodetector Yellow River Basin
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A process-oriented approach for identifying potential landslides considering time-dependent behaviors beyond geomorphological features
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作者 Xiang Sun Guoqing Chen +4 位作者 Xing Yang Zhengxuan Xu Jingxi Yang Zhiheng Lin Yunpeng Liu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期961-978,共18页
Geomorphological features are commonly used to identify potential landslides.Nevertheless,overemphasis on these features could lead to misjudgment.This research proposes a process-oriented approach for potential lands... Geomorphological features are commonly used to identify potential landslides.Nevertheless,overemphasis on these features could lead to misjudgment.This research proposes a process-oriented approach for potential landslide identification that considers time-dependent behaviors.The method integrates comprehensive remote sensing and geological analysis to qualitatively assess slope stability,and employs numerical analysis to quantitatively calculate aging stability.Specifically,a time-dependent stability calculation method for anticlinal slopes is developed and implemented in discrete element software,incorporating time-dependent mechanical and strength reduction calculations.By considering the time-dependent evolution of slopes,this method highlights the importance of both geomorphological features and time-dependent behaviors in landslide identification.This method has been applied to the Jiarishan slope(JRS)on the Qinghai-Tibet Plateau as a case study.The results show that the JRS,despite having landslide geomorphology,is a stable slope,highlighting the risk of misjudgment when relying solely on geomorphological features.This work provides insights into the geomorphological characterization and evolution history of the JRS and offers valuable guidance for studying slopes with similar landslide geomorphology.Furthermore,the process-oriented method incorporating timedependent evolution provides a means to evaluate potential landslides,reducing misjudgment due to excessive reliance on geomorphological features. 展开更多
关键词 Geomorphological features evolution history Time-dependent stability calculation Landslides identification Qinghai-Tibet Plateau
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Relationships between tree-ring cell features of Pinus koraiensis and climate factors in the Changbai Mountains,Northeastern China 被引量:4
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作者 Hui Wang Xuemei Shao +3 位作者 Xiuqi Fang Yuan Jiang Chunlan Liu Qing Qiao 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第1期105-114,共10页
Anatomical characteristics have been proven useful for extracting climatic signals. To examine the climatic signals recorded by tree-ring cell features in the Changbai Mountains, we measured cell number and cell lumen... Anatomical characteristics have been proven useful for extracting climatic signals. To examine the climatic signals recorded by tree-ring cell features in the Changbai Mountains, we measured cell number and cell lumen diameter, in addition to ring widths, of Korean pine (Pinus koraiensis) tree rings at sites of varied elevation, and we developed chronologies of cell number (CN), mean lumen diameter (MLD), maximum lumen diameter (MAXLD) and tree-ring width (TRW). The chronologies were correlated with climatic factors monthly mean tem- perature and the sum of precipitation. As shown by our analysis, the cell parameter chronologies were suitable for dendroclimatology studies. CN and TRW shared relatively similar climatic signals which differed from MLD and MAXLD, and growth-climate relationships were elevation- dependent, as shown by the following findings: (1) at each elevation, MLD and MAXLD recorded different monthly climatic signals from those recorded by TRW for the same climatic factors; and (2) MLD and MAXLD recorded cli- matic factors that were absent middle elevations. Cell lumen effective archive for improving for this study area. from TRW at lower and diameter proved to be an the climate reconstruction 展开更多
关键词 climate variability Cell features Pinuskoraiensis DENDROCLIMATOLOGY Growth-climaterelationships
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Millennial-scale evolution of Hunshandake Desert and climate change during the Holocene in Inner Mongolia,northern China 被引量:11
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作者 HeLing Jin Liang Ying Sun Zhong Sun 《Research in Cold and Arid Regions》 2010年第6期505-513,共9页
The Hunshandake Desert is located at the northern edge of the East Asian monsoon region,and its natural environment is sensitive to monsoonal changes.Geologic records suggest that desert evolution corresponding to cli... The Hunshandake Desert is located at the northern edge of the East Asian monsoon region,and its natural environment is sensitive to monsoonal changes.Geologic records suggest that desert evolution corresponding to climate change had experienced several cycles in the Holocene,and the evolutionary process can be distinguished by four dominant stages according to changing trends of the environment and climate.(1) Holocene Ameliorative Period(11.0-8.7 cal ka B.P.),when the desert area gradually shrank following an approaching warm-wet climate and strengthening summer monsoon.(2) Holocene Optimum(8.7-6.0 cal ka B.P.),when the majority of moving sand dunes were stabilized and vegetation coverage quickly expanded in a suitable warm-wet climate and a strong summer monsoon.(3) Holocene Multivariate Period(6.0-3.5 cal ka B.P.),during a low-amplitude desert transformed between moving and stabilized types under alternating functions of cold-dry with warm-wet climate,and winter monsoon with summer monsoon.(4) Holocene Decay Period(since 3.5 cal ka B.P.),when the desert area tended to expand along with a weakened summer monsoon and a dry climate. 展开更多
关键词 Hunshandake Desert desert evolution global climate change HOLOCENE
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Subseasonal features of the Asian summer monsoon in the NCEP climate forecast system 被引量:3
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作者 Song YANG WEN Min R Wayne HIGGINS 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2008年第3期88-103,共16页
The operational climate forecast system (CFS) of the US National Centers for Environmental Prediction provides climate predictions over the world, and CFS products are becoming an important source of information for... The operational climate forecast system (CFS) of the US National Centers for Environmental Prediction provides climate predictions over the world, and CFS products are becoming an important source of information for regional climate predictions in many Asian countries where monsoon climate dominates. Recent studies have shown that, on monthly-to-seasonal time-scales, the CFS is highly skillful in simulating and predicting the variability of the Asian monsoon. The higher-frequency variability of the Asian summer monsoon in the CFS is analyzed, using output from a version with a spectral triangular truncation of 126 waves in horizontal and 64 sigma layers in vertical, focusing on synoptic, quasi-biweekly, and intraseasonal time-scales. The onset processes of different regional monsoon components were investigated within Asia. Although the CFS generally overestimates variability of monsoon on these time-scales, it successfully captures many major features of the variance patterns, especially for the synoptic timescale. The CFS also captures the timing of summer monsoon onsets over India and the Indo-China Peninsula. However, it encounters difficulties in simulating the onset of the South China Sea monsoon. The success and failure of the CFS in simulating the onset of monsoon precipitation can also be seen from the associated features of simulated atmospheric circulation processes. Overall, the CFS is capable of simulating the synoptic-to-intraseasonal variability of the Asian summer monsoon with skills. As for seasonal-tointerannual time-scales shown previously, the model is expected to possess a potential for skillful predictions of the high-frequency variability of the Asian monsoon. 展开更多
关键词 Asian summer monsoon ONSET evolution synoptic-to-intraseasonal variability NCEP climate prediction system
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Climate Features of Regional Fog in Liaoxi Area and Forecast Analysis 被引量:3
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作者 罗春田 郭玲 米孝尉 《Meteorological and Environmental Research》 CAS 2010年第12期18-21,共4页
By using the fog data from 1995 to 2004 of four selected observation stations,the weather features of foggy days in Liaoxi area have been studied in this paper.The favorable surface and upper circulation for fog and i... By using the fog data from 1995 to 2004 of four selected observation stations,the weather features of foggy days in Liaoxi area have been studied in this paper.The favorable surface and upper circulation for fog and its frequency have also been concluded from the statistic.In this paper,the forecasting index of fog,proposed on the basis of the condition and mechanism of the fog occurrence,has been tested by the 10-year analysis.Another test conducted by using the data of 1st July-31st December,2004 also gives a good result which has a vacancy rate of 22.2% and a miss rate of 5.1%. 展开更多
关键词 FOG Advection-radiation fog Atmospheric stability climate features Forecast index China
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Evolution Rules and Spatial Features of Traditional Settlements in Fukou Xing Region 被引量:2
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作者 YUAN Lin LIU Gongxue XUE Binglin 《Journal of Landscape Research》 2018年第5期12-21,共10页
As one of the eight Taihang passes,Fukou Xing is located in the south of the Taihang Mountains and has been an important passage for Shanxi and Hebei in history.Taking traditional settlements in Fukou Xing Region as r... As one of the eight Taihang passes,Fukou Xing is located in the south of the Taihang Mountains and has been an important passage for Shanxi and Hebei in history.Taking traditional settlements in Fukou Xing Region as research object,using the Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER) Global Digital Elevation Model(GDEM)(remote sensing measurement of elevation data) and GIS platform,this paper made a quantitative study on traditional settlement space in mountain environment of this region,and studied space parameters including elevation,terrain,aspect,and boundary,observed and summarized the spatial features.In addition,based on the local chronicles of Ming and Qing dynasties,it mutually verified the quantitative conclusions and qualitative cognition,analyzed the evolution rules of traditional settlements in Fukou Xing region,and finally obtained new understandings of spatial features of traditional settlements in Fukou Xing region. 展开更多
关键词 Fukou Xing REGION TRADITIONAL SETTLEMENT evolution RULES SPATIAL featureS GIS
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Regional Evolution Features and Coordinated Development Strategies for Northeast China 被引量:2
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作者 MEI Lin XU Xiaopo CHEN Mingxiu 《Chinese Geographical Science》 SCIE CSCD 2006年第4期378-382,共5页
Northeast China, as the most important production base of agriculture, forestry, and livestock-breeding as well as the old industrial base in the whole country, has been playin a key role in the construction and deve... Northeast China, as the most important production base of agriculture, forestry, and livestock-breeding as well as the old industrial base in the whole country, has been playin a key role in the construction and development of China's economy. However, after the policy of reform and open-up was taken in China. the economic development speed and efficiency ofthis area have turned to be evidently lower than those of coastal area and the national average level as well, which is so-called 'Northeast Phenomenon' and 'Neo-Northeast Phenomenon'. In terms of those phenomena, this paper firstly reviews the spatial and temporal features of the regional evolution of this area so as to unveil the profound forming causes of 'Northeast Phenomena' and 'Neo-Northeast Phenomena'. And then the paper makes a further exploration into the status quo of this region and its forming causes by analyzing its economy gross, industrial structure, product structure, regional eco-categories, etc. At the end of the paper, the authors put forward the basic coordinated development strategies for Northeast China. namely we can revitalize this area by means of adjustment of economic structure, regional coordination, planning urban and rural areas as a whole, institutional innovation, etc. 展开更多
关键词 regional evolution spatial-temporal feature coordinated development strategy Northeast China
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The Environmental Landscape Evolution of the Loess under the Background of Global Climate Change 被引量:1
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作者 ZHAO Kun-kun1,ZHOU Bao-tong1,WANG Xiao-zhe2,LIU Jing-cai1,FENG Xiao-hong1,CHEN Chun-bo1 1.Department of Geographical Sciences,Southwest University,Chongqing 400715,China 2.Travelling and Environment College,Shaanxi Normal University,Xi’an 710043,China 《Meteorological and Environmental Research》 CAS 2011年第5期28-30,共3页
[Objective] The aim was to study the environment evolution of Shanbei Loess landscape under the background of global climate changes.[Method] The annual and monthly temperature and precipitation in Yulin area in north... [Objective] The aim was to study the environment evolution of Shanbei Loess landscape under the background of global climate changes.[Method] The annual and monthly temperature and precipitation in Yulin area in north Shaanxi from 1952 to 2009 were selected,and by dint of linear regression and M-K mutation,the Loess land form evolution under the global climate change was studied.[Result] The temperature in Yulin area showed increasing tendency from 1952 to 2009 at a speed of 0.287℃/10 a.The year 1994 was a year of mutation of temperature;precipitation decreased at speed of 8.262 mm/10 a and the precipitation fluctuated largely in 1960s,and stably in 1970s,1980s and 1990s.It showed drying tendency.The climate in north Shanxi was becoming warmer.The extreme dry and flood incident,especially the rising drought occurrence frequency had more serious endangerment to the fragile ecological environment.The ' warmer drought' of climate worsened the environment in north Shaanxi,with temperature rising and worsening drought;reduction of precipitation made the wind and sand more active;the frequency of sandstorm increased;desertification of land furthered;the water and soil losses in Loess was serious and might led to degradation of land in north Shaanxi.[Conclusion] The study provided theoretical basis for the ecological and environmental construction in the region. 展开更多
关键词 climate changes Loess landscape Environment evolution North Shaanxi China
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Initiatives to clarify mechanisms of hydrological evolution in human-influenced Yellow River Basin 被引量:2
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作者 Li-liang Ren Shan-shui Yuan +6 位作者 Xiao-li Yang Shan-hu Jiang Gui-bao Li Qiu-an Zhu Xiu-qin Fang Yi Liu Yi-qi Yan 《Water Science and Engineering》 EI CAS CSCD 2023年第2期117-121,共5页
Significant changes in water cycle elements/processes have created serious challenges to regional sustainability and high-quality development in the Yellow River Basin in China.It is necessary to investigate the impac... Significant changes in water cycle elements/processes have created serious challenges to regional sustainability and high-quality development in the Yellow River Basin in China.It is necessary to investigate the impacts of climate change and human activities on hydrological evolution and disaster risk from a holistic perspective of the basin.This study developed initiatives to clarify the mechanisms of hydrological evolution in the human-influenced Yellow River Basin.The proposed research method includes:(1)a tool to simulate multiple factors and a multi-scale water cycle using a grid-based spatiotemporal coupling approach,and(2)a new algorithm to separate the responses of the water cycle to climate change and human impacts,and de-couple the eco-environmental effects using artificial intelligence techniques.With this research framework,key breakthroughs are expected to be made in the understanding of the impacts of land cover change on the water cycle and blue/green water redirection.The outcomes of this research project are expected to provide theoretical support for ecological protection and water governance in the basin. 展开更多
关键词 climate change Human activities Hydrological evolution Runoff change Yellow River Basin
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Late Mesozoic Depositional Features and Basin Evolution of the Western Segment of Bailongjiang Uplift Zone in the Songpan Area
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作者 Meng He,Chengshan Wang,Yuxiu Zhang,Chao Ma,Meng Wang 1.Liaoning Non-ferrous Geological Exploration Institute,Shenyang 110013,China. 2.Research Center for Tibetan Plateau Geology,China University of Geosciences(Beijing),Beijing 100083,China 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期271-271,共1页
On the basis of history study and the depositional study the systematic investigation of late Mesozoic sedimentary features and basin evolution are conducted.The architectural elements analysis of sedimentary environm... On the basis of history study and the depositional study the systematic investigation of late Mesozoic sedimentary features and basin evolution are conducted.The architectural elements analysis of sedimentary environment shows that the depositional environment of the early Jurassic in late Mesozoic basin(Gahai basin) in the study area is lacustrine environment,and is further 展开更多
关键词 Bailongjiang UPLIFT DEPOSITIONAL feature BASIN evolution STRIKE-SLIP RIFTING BASIN late MESOZOIC
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Semi Advised SVM with Adaptive Differential Evolution Based Feature Selection for Skin Cancer Diagnosis
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作者 Ammara Masood Adel Al-Jumaily 《Journal of Computer and Communications》 2015年第11期184-190,共7页
Automated diagnosis of skin cancer is an important area of research that had different automated learning methods proposed so far. However, models based on insufficient labeled training data can badly influence the di... Automated diagnosis of skin cancer is an important area of research that had different automated learning methods proposed so far. However, models based on insufficient labeled training data can badly influence the diagnosis results if there is no advising and semi supervising capability in the model to add unlabeled data in the training set to get sufficient information. This paper proposes a semi-advised support vector machine based classification algorithm that can be trained using labeled data together with abundant unlabeled data. Adaptive differential evolution based algorithm is used for feature selection. For experimental analysis two type of skin cancer datasets are used, one is based on digital dermoscopic images and other is based on histopathological images. The proposed model provided quite convincing results on both the datasets, when compared with respective state-of-the art methods used for feature selection and classification phase. 展开更多
关键词 Classification feature Selection SKIN Cancer Support VECTOR Machine DIFFERENTIAL evolution
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Effect of geomorphologic features and climate change on vegetation distribution in the arid hot valleys of Jinsha River,Southwest China
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作者 ZHOU Yang YI Yu-jun +3 位作者 LIU Hong-xi TANG Cai-hong ZHU Yu-long ZHANG Shang-hong 《Journal of Mountain Science》 SCIE CSCD 2022年第10期2874-2885,共12页
Rapid change of climate in vertical and considerable geomorphologic features form a typical diversity and distribution of biota in mountain ecosystems,i.e.,the subalpine forest zone(SFZ),the valley savanna zone(VSZ),a... Rapid change of climate in vertical and considerable geomorphologic features form a typical diversity and distribution of biota in mountain ecosystems,i.e.,the subalpine forest zone(SFZ),the valley savanna zone(VSZ),and the transition zone between them.The arid hot valley in the middle and lower reaches of Jinsha River,China represents a well target area to study distribution and the driving factors in these typical mountain ecosystems.Therefore,this study selects four sub-sample areas in the arid-hot valley to explore the distinctive changes of vegetation during 1990 to 2020,and their driving factors in the three different vegetation zones on spatiotemporal scales.On the spatial scale,the Moran’s index was applied to identify the transition zone between the SFZ and the VSZ.Results show that the VSZ at low altitudes(less than 600-1000 m from the valley bottom)is mainly affected by geomorphologic features,especially the slope aspect.With increase in altitude,the climate factors(e.g.,humidity,temperature,etc.)play a more significant role in the development of the SFZ,while the effect of geomorphologic features gradually weakens.On the time scale,The SFZ at higher altitudes experienced more rapid changes in temperature(temperature increase of 1.41°C over the last 60 years)than the VSZ at lower altitudes(temperature increase of 0.172°C over the past 60 years).It caused the forest cover increase faster than that of savanna grassland.Humidity and heat conditions are altered by topography and climate conditions,which shapes the development and physiology of plants as they adapt to the different climatic zones.Furthermore,according to the driving factors(geomorphologic and climate factors)of vegetation distribution found in this study,it suggests that suitable tree species should be planted in the transition zone to evolve into the forest zone and making the forest zone to recover from high to low altitudes gradually. 展开更多
关键词 Mountain vegetation distribution Subalpine forest zone Valley savanna zone Geomorphologic features climate change
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Hybrid Global Optimization Algorithm for Feature Selection 被引量:1
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作者 Ahmad Taher Azar Zafar Iqbal Khan +1 位作者 Syed Umar Amin Khaled M.Fouad 《Computers, Materials & Continua》 SCIE EI 2023年第1期2021-2037,共17页
This paper proposes Parallelized Linear Time-Variant Acceleration Coefficients and Inertial Weight of Particle Swarm Optimization algorithm(PLTVACIW-PSO).Its designed has introduced the benefits of Parallel computing ... This paper proposes Parallelized Linear Time-Variant Acceleration Coefficients and Inertial Weight of Particle Swarm Optimization algorithm(PLTVACIW-PSO).Its designed has introduced the benefits of Parallel computing into the combined power of TVAC(Time-Variant Acceleration Coefficients)and IW(Inertial Weight).Proposed algorithm has been tested against linear,non-linear,traditional,andmultiswarmbased optimization algorithms.An experimental study is performed in two stages to assess the proposed PLTVACIW-PSO.Phase I uses 12 recognized Standard Benchmarks methods to evaluate the comparative performance of the proposed PLTVACIWPSO vs.IW based Particle Swarm Optimization(PSO)algorithms,TVAC based PSO algorithms,traditional PSO,Genetic algorithms(GA),Differential evolution(DE),and,finally,Flower Pollination(FP)algorithms.In phase II,the proposed PLTVACIW-PSO uses the same 12 known Benchmark functions to test its performance against the BAT(BA)and Multi-Swarm BAT algorithms.In phase III,the proposed PLTVACIW-PSO is employed to augment the feature selection problem formedical datasets.This experimental study shows that the planned PLTVACIW-PSO outpaces the performances of other comparable algorithms.Outcomes from the experiments shows that the PLTVACIW-PSO is capable of outlining a feature subset that is capable of enhancing the classification efficiency and gives the minimal subset of the core features. 展开更多
关键词 Particle swarm optimization(PSO) time-variant acceleration coefficients(TVAC) genetic algorithms differential evolution feature selection medical data
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A Numerical Study of the Mechanism for the Effect of Northern Winter Arctic Ice Cover on the Global Short-Range Climate Evolution
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作者 倪允琪 张勤 李跃东 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1991年第4期489-498,共10页
By using a nine-layer global spectral model involving fuller parameterization of physical processes, with a rhomboidal truncation at wavenumber 15, experiments are performed in terms of two numerical schemes, one with... By using a nine-layer global spectral model involving fuller parameterization of physical processes, with a rhomboidal truncation at wavenumber 15, experiments are performed in terms of two numerical schemes, one with long-term mean coverage of Arctic ice (Exp.1), the other without the ice (Exp.2). Results indicate that the Arctic region is a heat source in Exp.2 relative to the case in Exp.1. Under the influence of the polar heat source simulated, there still exist stationary wavetrains that produce WA-EUP and weak PNA patterns in Northern winter. That either the Arctic or the tropical heat source can cause identical climatic effects is due to the fact that the anomaly of the Arctic ice cover will directly induce a south-propagating wavetrain, and bring about the redistribution of the tropical heat source / sink. The redistribution is responsible for new wavetrains that will exert impact on the global climate. The simulation results bear out further that the polar region in Exp.2 as a heat source, can produce, by local forcing, a pair of positive and negative difference centers, which circle the Arctic moving eastwards. Observed in the Northern Hemisphere extratropics is a 40-50 day oscillation in relation to the moving pair, both having the same period. 展开更多
关键词 over A Numerical Study of the Mechanism for the Effect of Northern Winter Arctic Ice Cover on the Global Short-Range climate evolution
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Sedimentary elements,evolutions and controlling factors of the Miocene channel system:a case study of the deep-water Taranaki Basin in New Zealand
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作者 Guangxu Wang Wei Wu +5 位作者 Changsong Lin Quan Li Xiaoming Zhao Yongsheng Zhou Weiqing Liu Shiqin Liang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第11期44-58,共15页
Deep-water channel systems are important petroleum reservoirs,and many have been discovered worldwide.Understanding deep-water channel sedimentary elements and evolution is helpful for deep-sea petroleum exploration a... Deep-water channel systems are important petroleum reservoirs,and many have been discovered worldwide.Understanding deep-water channel sedimentary elements and evolution is helpful for deep-sea petroleum exploration and development.Based on high-resolution 3D seismic data,the Miocene channel system in the deep-water Taranaki Basin,New Zealand,was analyzed by using seismic interpretation techniques such as interlayer attribute extraction and strata slicing.The channel system was divided into five composite channels(CC-I to CC-V)according to four secondary level channel boundaries,and sedimentary elements such as channels,slump deposits,inner levees,mass transport deposits,and hemipelagic drape deposits were identified in the channel system.The morphological characteristics of several composite channels exhibited stark variances,and the overall morphology of the composite channels changed from relatively straight to highly sinuous to relatively straight.The evolution of the composite channels involved a gradual and repeated process of erosion and filling,and the composite channels could be divided into three evolutionary stages:initial erosion-filling,later erosion-filling(multistage),and channel abandonment.The middle Miocene channel system may have formed as a consequence of combined regional tectonic activity and global climatic change,and its intricate morphological alterations may have been influenced by the channel's ability to self-regulate and gravity flow properties.When studying the sedimentary evolution of a large-scale deep-water channel system in the Taranaki Basin during the Oligocene-Miocene,which transitioned from a passive margin to plate convergence,it can be understood how tectonic activity affected the channel and can also provide a theoretical reference for the evolution of the deepwater channels in areas with similar tectonic conversion environments around the world. 展开更多
关键词 deep-water channel system channel geomorphology sedimentary evolution climate and region tectonic activities deep-water Taranaki Basin
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Agro-Climatic Risks Analysis in Climate Variability Context in Ségou Region
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作者 Diop Amadou Barro Diakarya 《Open Journal of Statistics》 2023年第1期170-193,共24页
In the Sahel region, the population depends largely on rain-fed agriculture. In West Africa in particular, climate models turn out to be unable to capture some basic features of present-day climate variability. This s... In the Sahel region, the population depends largely on rain-fed agriculture. In West Africa in particular, climate models turn out to be unable to capture some basic features of present-day climate variability. This study proposes a contribution to the analysis of the evolution of agro-climatic risks in the context of climate variability. Some statistical tests are used on the main variables of the rainy season to determine the trends and the variabilities described by the data series. Thus, the paper provides a statistical modeling of the different agro-climatic risks while the seasonal variability of agro-climatic parameters was analyzed as well as their inter annual variability. The study identifies the probability distributions of agroclimatic risks and the characterization of the rainy season was clarified. 展开更多
关键词 climate Variability Agro-Climatic Risks Seasonal evolution Variability Parameters Tests
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我国主要河川径流演变规律与归因及其区域特征 被引量:3
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作者 徐宗学 班春广 张瑞 《水利水电科技进展》 CSCD 北大核心 2024年第1期1-8,共8页
从径流演变规律主要分析方法和主要河川径流演变规律、径流主要归因方法和主要河川径流归因分析、案例分析、我国主要河川径流演变规律与径流归因分析区域分布特征4个方面系统总结和梳理了我国近年来在主要河川径流演变规律与归因及其... 从径流演变规律主要分析方法和主要河川径流演变规律、径流主要归因方法和主要河川径流归因分析、案例分析、我国主要河川径流演变规律与径流归因分析区域分布特征4个方面系统总结和梳理了我国近年来在主要河川径流演变规律与归因及其区域特征研究方面取得的主要研究成果。结果表明:Mann-Kendall非参数趋势检验方法是较为常用的径流演变规律分析方法,水文模型法、统计分析方法和Budyko假设的流域水热耦合平衡方法是进行径流变化归因分析的常用方法,其中Budyko假设的流域水热耦合平衡方法应用较为广泛;我国主要河川径流量除西北诸河和西南河流源区部分河流呈增加趋势外,其他区域河川径流大多呈减少趋势;人类活动是引起我国主要河川径流变化的主要原因。 展开更多
关键词 河川径流 气候变化 人类活动 演变规律 归因分析
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我国国际消费中心城市发展水平测度及动态演进 被引量:1
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作者 曾庆均 易露 唐菁 《中国流通经济》 北大核心 2024年第1期80-94,共15页
国际消费中心城市是消费的高级形态载体。从国际知名度、消费繁荣度、商业活跃度、到达便利度和消费满意度五个维度构建我国国际消费中心城市发展评价指标体系,借助熵权TOPSIS法对其发展水平进行测度,运用核密度估计、收敛性分析、修正... 国际消费中心城市是消费的高级形态载体。从国际知名度、消费繁荣度、商业活跃度、到达便利度和消费满意度五个维度构建我国国际消费中心城市发展评价指标体系,借助熵权TOPSIS法对其发展水平进行测度,运用核密度估计、收敛性分析、修正的引力模型以及社会网络分析方法,以北京、天津、上海、重庆、广州等25个具有竞争力的城市为样本,剖析我国国际消费中心城市发展的动态演进特征。研究发现,2017—2022年我国国际消费中心城市发展水平逐年上升但处于低水平发展阶段,城市间发展差距大且呈现出梯队层级分布态势;从各维度看,国际知名度、消费繁荣度、商业活跃度和消费满意度四个维度发展水平表现为上升趋势,消费繁荣度涨幅最大,到达便利度发展水平较低;国际消费中心城市间发展的绝对差距较大,但城市的追赶效应使得相对差距缩小;从空间格局看,城市初步形成了北部“北京+天津”集聚圈、南部“广州+深圳”集聚圈以及以上海为首的长江联系带的“两圈一带”总体空间网络格局,表现出“高者全局集聚、低者局部扩散”的集散效应特征,城市间有着“核心城市占据主导,边缘城市结构优化”的非均衡空间联系。因此,应立足城市比较优势、深入挖掘并梯次培育特色消费增长点,完善城市交通基础设施建设、突出重点打造现代综合立体交通网络,积极把握我国国际消费中心城市发展的动态变化过程、多层级优化城市消费资源空间配置,重视我国国际消费中心城市发展的空间网络结构特征,逐步形成以点带面、以圈扩容、结构优化的消费空间发展格局。 展开更多
关键词 国际消费中心城市 综合发展水平测度 动态演进特征
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