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全国铁路列车运行图系统数据量分析及其内存管理研究 被引量:3
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作者 吕红霞 杨明伦 《铁道运输与经济》 北大核心 2002年第5期43-44,共2页
在对计算机编制全路列车运行图系统的数据量进行分析、计算的基础上 ,对Win3 2内存管理方法和特点进行了探讨。根据分析与计算的结果 ,确定采用虚拟内存技术管理编图系统数据 ,通过应用虚拟内存的实现技术 ,说明在微机上实现全路列车运... 在对计算机编制全路列车运行图系统的数据量进行分析、计算的基础上 ,对Win3 2内存管理方法和特点进行了探讨。根据分析与计算的结果 ,确定采用虚拟内存技术管理编图系统数据 ,通过应用虚拟内存的实现技术 ,说明在微机上实现全路列车运行图的编制和数据管理是可行的。 展开更多
关键词 铁路 列车运行图 数据量分析 计算机 虚拟内存 中国 内存管理
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A Quantized Kernel Least Mean Square Scheme with Entropy-Guided Learning for Intelligent Data Analysis 被引量:5
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作者 Xiong Luo Jing Deng +3 位作者 Ji Liu Weiping Wang Xiaojuan Ban Jenq-Haur Wang 《China Communications》 SCIE CSCD 2017年第7期127-136,共10页
Quantized kernel least mean square(QKLMS) algorithm is an effective nonlinear adaptive online learning algorithm with good performance in constraining the growth of network size through the use of quantization for inp... Quantized kernel least mean square(QKLMS) algorithm is an effective nonlinear adaptive online learning algorithm with good performance in constraining the growth of network size through the use of quantization for input space. It can serve as a powerful tool to perform complex computing for network service and application. With the purpose of compressing the input to further improve learning performance, this article proposes a novel QKLMS with entropy-guided learning, called EQ-KLMS. Under the consecutive square entropy learning framework, the basic idea of entropy-guided learning technique is to measure the uncertainty of the input vectors used for QKLMS, and delete those data with larger uncertainty, which are insignificant or easy to cause learning errors. Then, the dataset is compressed. Consequently, by using square entropy, the learning performance of proposed EQ-KLMS is improved with high precision and low computational cost. The proposed EQ-KLMS is validated using a weather-related dataset, and the results demonstrate the desirable performance of our scheme. 展开更多
关键词 quantized kernel least mean square (QKLMS) consecutive square entropy data analysis
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Spatial Variability of Soil Properties and Rice Yield Along Two Catenas in Southeast China 被引量:8
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作者 B. RTH B. LENNARTZ 《Pedosphere》 SCIE CAS CSCD 2008年第4期409-420,共12页
In the light of an increasing demand for staple food, especially rice, in southeast China, investigations on the specific site potential expressed as the relationship between soil and crop yield parameters gain increa... In the light of an increasing demand for staple food, especially rice, in southeast China, investigations on the specific site potential expressed as the relationship between soil and crop yield parameters gain increasing importance. Soil texture and several soil chemical parameters as well as plant properties such as crop height, biomass and grain yield were investigated along two terraced catenas with contrasting soil textures cropped with wet rice. We were aiming at identifying correlative relationships between soil and crop properties. Data were analyzed both statistically and geostatistically on the basis of semivariograms. Statistical analysis indicated a significant influence of the relief position on the spatial distribution of soil texture, total carbon and total nitrogen contents. Significant correlations were found for the catena located in a sandstone area (Catena A) between rice yield and silt as well as total nitrogen content. Corresponding relationships were not detectable for paddy fields that developed from Quaternary clays (Catena B). As suggested by the nugget to sill ratio, spatial variability of soil texture, total carbon and nitrogen was mainly controlled by intrinsic factors, which might be attributed to the erosional transport of fine soil constituents, indicating the importance of the relief position and slope in soil development even in landscapes that are terraced. The crop parameters exhibited short ranges of influence and about one third of their variability was unexplained. Comparable ranges of selected crop and soil parameters, found only for Catena A, are indicative of close spatial interactions between rice yield and soil features. Our findings show that especially in sandstone-dominated areas, a site-specific management can contribute to an environmentally safe rice production increase. 展开更多
关键词 rice productivity semivariogram analysis soil properties spatial data
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Food Additives-Ascorbic Acid Quality Assay Test Intelligent Management 被引量:1
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作者 Hairui Zhang Li Zhang +1 位作者 Helin Ye Guofu Zhang 《Journal of Chemistry and Chemical Engineering》 2018年第1期20-25,共6页
In this paper, based on the analysis and test methods of national standards (GB 14754-2010) and chemical analysis and test items carried out by chemical enterprises, a set of automatic processing of quality analysis... In this paper, based on the analysis and test methods of national standards (GB 14754-2010) and chemical analysis and test items carried out by chemical enterprises, a set of automatic processing of quality analysis test data of ascorbic acid products was developed by using access database technology and Visual Basic programming language system, and its stability was investigated. The results show that the software can manage intelligently all aspects of the quality analysis and test of ascorbic acid products, uploading timely the data and results of the analysis and inspection to the network and saving it for users, enterprises and quality management, which set up a network of information sharing platform to ensure the authenticity and reliability of measurement results, improving greatly the speed of data processing, saving valuable time, reducing production costs with good economic efficiency and social benefit. It has practical value for ascorbic acid quality analysis test data processing automatically the results of the implementation of intelligent management. 展开更多
关键词 Food additive ascorbic acid quality analysis test intelligent management software development.
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Understanding the YouTube Partners and Their Data: Measurement and Analysis 被引量:2
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作者 CHENG Xu Fatourechi Mehrdad +2 位作者 MA Xiaoqiang ZHANG Cong LIU Jiangchuan 《China Communications》 SCIE CSCD 2014年第12期26-34,共9页
User generated content,e.g.,from YouTube,the most popular online video sharing site,is one of the major sources of today's big data and it is crucial to understand their inherent characteristics.Recently,YouTube h... User generated content,e.g.,from YouTube,the most popular online video sharing site,is one of the major sources of today's big data and it is crucial to understand their inherent characteristics.Recently,YouTube has started working with content providers(known as YouTube partners) to promote the users' watching and sharing activities.The substantial benefit is to further augment its service and monetize more videos,which is crucial to both YouTube and its partners,as well as to other providers of relevant services.In this paper,our main contribution is to analyze the massive amounts of video data from a YouTube partner's view.We make effective use of Insight,a new analytics service of YouTube that offers simple data analysis for partners.To provide the practical guidance from the raw Insight data,we enable more complex investigations for the inherent features that affect the popularity of the videos.Our findings facilitate YouTube partners to re-design current video publishing strategies,having more opportunities to attract more views. 展开更多
关键词 YouTube partners video popularity viewing behaviour user engagement
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In-line spectroscopy combined with multivariate analysis methods for endpoint determination in column chromatographic adsorption processes for herbal medicine 被引量:3
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作者 Cheng Jiang Haibin Qu 《Acupuncture and Herbal Medicine》 2022年第4期253-260,共8页
Objective: In a chromatographic cycle, the adsorption process is a critical unit operation that has a significant impact on downstream processes and, ultimately, the quality of the final products. The development of a... Objective: In a chromatographic cycle, the adsorption process is a critical unit operation that has a significant impact on downstream processes and, ultimately, the quality of the final products. The development of a rapid method to determine the endpoints of adsorption processes in a large-scale manufacturing is of substantial importance for herbal medicine(HM) manufacturers.Methods: In this study, the adsorption of saponins on a macroporous resin column chromatograph, a critical unit operation in Panax notoginseng(Burkill) F.H.Chen injection manufacturing, was considered as an example. The evaluation results of in-line ultraviolet and visible spectra combined with various multivariate analysis methods, including the moving block standard deviation(MBSD), difference between the moving block average and the target spectrum(DMBA-TS), soft-independent modeling of class analogy(SIMCA), and partial least-squares discriminant analysis(PLS-DA), were compared.Results: MBSD was unsuitable for adsorption processes. The relative standard errors of prediction between the predicted and experimental endpoints were 13.2%, 4.67%, and 5.71% using DMBA-TS, SIMCA, and PLS-DA, respectively.Conclusions: Among the considered analysis methods, SIMCA and PLS-DA were more effective for endpoint determination. The results of this study provide a more comprehensive overview of the effectiveness of various multivariate analysis methods to facilitate the selection of the most suitable method. This study was also conducive to address the issues of the in-line detection of adsorption endpoints to guide practical HM manufacturing. 展开更多
关键词 Adsorption ENDPOINT Herbal medicine Multivariate analysis Ultraviolet and visible
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Weekend and nighttime effect on the prognosis of peptic ulcer bleeding 被引量:6
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作者 Young Hoon Youn Yong Jin Park +3 位作者 Jae Hak Kim Tae Joo Jeon Jae Hee Cho Hyojin Park 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第27期3578-3584,共7页
AIM:To evaluate whether weekend or nighttime admission affects prognosis of peptic ulcer bleeding despite early endoscopy.METHODS:Retrospective data collection from four referral centers,all of which had a formal out-... AIM:To evaluate whether weekend or nighttime admission affects prognosis of peptic ulcer bleeding despite early endoscopy.METHODS:Retrospective data collection from four referral centers,all of which had a formal out-of-hours emergency endoscopy service,even at weekends.A total of 388 patients with bleeding peptic ulcers who were admitted via the emergency room between January 2007 and December 2009 were enrolled.Analyzed parameters included time from patients' arrival until endoscopy,mortality,rebleeding,need for surgery and length of hospital stay.RESULTS:The weekday and weekend admission groups comprised 326 and 62 patients,respectively.There were no significant differences in baseline characteristics between the two groups,except for younger age in the weekend group.Most patients (97%) had undergone early endoscopy,which resulted in a low mortality rate regardless of point of presentation (1.8% overall vs 1.6% on the weekend).The only outcome that was worse in the weekend group was a higher rate of rebleeding (12% vs 21%,P = 0.030).However,multivariate analysis revealed nighttime admission and a high Rockall score (≥ 6) as significant independent risk factors for rebleeding,rather than weekend admission.CONCLUSION:Early endoscopy for peptic ulcer bleeding can prevent the weekend effect,and nighttime admission was identified as a novel risk factor for rebleeding,namely the nighttime effect. 展开更多
关键词 Early endoscopy Nighttime effect Pepticulcer bleeding REBLEEDING Weekend effect
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Sediment records of environmental changes in the south end of the Zhejiang-Fujian coastal mud area during the past 100 years 被引量:5
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作者 王琳淼 李广雪 +3 位作者 高飞 刘玲 刘勇 DADA Olusegun A 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第4期899-908,共10页
Previous studies carried out in the East China Sea (ECS) mud area focused on long-term environmental changes in sedimentary records during the Holoeene, especially during the mid-Holocene high-stand water levels per... Previous studies carried out in the East China Sea (ECS) mud area focused on long-term environmental changes in sedimentary records during the Holoeene, especially during the mid-Holocene high-stand water levels period. These results indicate that sensitive grain size groups can be used as a sedimentary proxy to reconstruct the evolution of the East Asian Winter Monsoon (EAWM). The studies have been carried out mainly in the northern and middle portions of the Zhejiang-Fujian coastal mud, however, similar research in the southern portion and the comparison between sedimentary proxy and modern measured data of EAWM are lacking. In this paper, we focused on a sedimentary record of the past 100 years with an enhanced resolution of 1.8 years. Investigations of the southern end of the Zhejiang-Fujian coastal mud area were conducted on the basis of 21~Pb chronology, grain-size analysis and chemical element analysis. The correspondence between the mean grain size (Mz) of sediment sensitive grain size and the measured EAWM was confirmed for the first time. We found that during the recent 100 years, the variation of the mean grain size of the sensitive population in the southern portion of the Zhejiang-Fujian mud was mainly controlled by the EAWM intensity changes; and not directly related to changes in the sediment discharge from Datong station of the Changjiang River (DTSD). Finally, recent changes in the content of heavy metals in study area reflect the impact of human activities on the environment. 展开更多
关键词 Zhejiang-Fujian coast sedimentary record environmental changes East Asian Winter Monsoon(EAWM)
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Using multispectral landsat and sentinel-2 satellite data to investigate vegetation change at Mount St. Helens since the great volcanic eruption in 1980 被引量:2
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作者 Katharina TELTSCHER Fabian Ewald FASSNACHT 《Journal of Mountain Science》 SCIE CSCD 2018年第9期1851-1867,共17页
Long-term analyses of vegetation succession after catastrophic events are of high interest for an improved understanding of succession dynamics. However, in many studies such analyses were restricted to plot-based mea... Long-term analyses of vegetation succession after catastrophic events are of high interest for an improved understanding of succession dynamics. However, in many studies such analyses were restricted to plot-based measurements. Contrarily, spatially continuous observations of succession dynamics over extended areas and timeperiods are sparse. Here, we applied a change vector analysis(CVA) to investigate vegetation succession dynamics at Mount St. Helens after the great volcanic eruption in 1980 using Landsat. We additionally applied a supervised random forest classification using Sentinel-2 data to map the currently prevailing vegetation types. Change vector analysis was performed with the normalized difference vegetation index(NDVI) and the urban index(UI) for three subsequent decades after the eruption as well as for the whole observation time between 1984 and 2016. The influence of topography on the current vegetation distribution was examined by comparing altitude, slope angles and aspect values of vegetation classes derived by the random forest classification. WilcoxRank-Sum test was applied to test for significant differences between topographic properties of the vegetation classes inside and outside of the areas affected by the eruption. For the full time period, a total area of 516 km2 was identified as re-vegetated, whereas the area and magnitude of re-growing vegetation decreased during the three decades and migrated closer to the volcanic crater. Vegetation losses were mainly observed in regions unaffected by the eruption and related mostly to timber harvesting. The vegetation type classification reached a high overall accuracy of approximately 90%. 36 years after the eruption, coniferous and deciduous trees have established at formerly devastated areas dominating with a proportion of 66%, whereas shrubs are more abundant in riparian zones. Sparse vegetation dominates at regions very close to the crater. Elevation was found to have a great influence on the reestablishment and distribution of the vegetation classes within the devastated areas showing in almost all cases significant differences in altitude distribution. Slope was less important for the different classes-only representing significantly higher values for meadows, whereas aspect seems to have no notable influence on the reestablishment of vegetation at Mount St. Helens. We conclude that major vegetation succession dynamics after catastrophic events can be assessed and characterized over large areas from freely available remote sensing data and hence contribute to an improved understanding of succession dynamics. 展开更多
关键词 Mount St. Helens Vegetation change Remote sensing Change vector analysis (CVA) Supervised classification Topography Density-plots
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Oil–water two-phase flow pattern analysis with ERT based measurement and multivariate maximum Lyapunov exponent 被引量:8
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作者 谭超 王娜娜 董峰 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第1期240-248,共9页
Oil–water two-phase flow patterns in a horizontal pipe are analyzed with a 16-electrode electrical resistance tomography(ERT) system. The measurement data of the ERT are treated as a multivariate time-series, thus th... Oil–water two-phase flow patterns in a horizontal pipe are analyzed with a 16-electrode electrical resistance tomography(ERT) system. The measurement data of the ERT are treated as a multivariate time-series, thus the information extracted from each electrode represents the local phase distribution and fraction change at that location. The multivariate maximum Lyapunov exponent(MMLE) is extracted from the 16-dimension time-series to demonstrate the change of flow pattern versus the superficial velocity ratio of oil to water. The correlation dimension of the multivariate time-series is further introduced to jointly characterize and finally separate the flow patterns with MMLE. The change of flow patterns with superficial oil velocity at different water superficial velocities is studied with MMLE and correlation dimension, respectively, and the flow pattern transition can also be characterized with these two features. The proposed MMLE and correlation dimension map could effectively separate the flow patterns, thus is an effective tool for flow pattern identification and transition analysis. 展开更多
关键词 oil-water two-phase flow flow patterns electrical resistance tomography (ERT) multivariate time-series multivariate maximum Lyapunov exponent correlation dimension
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An Integrated Approach to Oscillation Propagation Identification and Source Locating in Process Multi-loop Systems 被引量:1
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作者 曹稼斌 张亮 +1 位作者 郑建荣 夏春明 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第6期999-1008,共10页
An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the c... An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the component-related ratio index and a mixing matrix, both of which are obtained in data preprocessing by spectral independent component analysis. The complex causality among oscillatory process variables is then revealed by Granger causality test and is visualized in the form of causality diagram. The simplification of causal connectivity in the diagram is performed according to the understanding of process knowledge and the final simplest causality diagram, which represents the main oscillation propagation paths, is achieved by the automated cutting-off thresh-old search, with which less significant causality pathways are filtered out. The source of the oscillation disturbance can be identified intuitively through the final causality diagram. Both simulated and real plant data tests are presented to demonstrate the effectiveness and feasibility of the proposed method. 展开更多
关键词 multi-loop system process oscillation spectral independent component analysis Granger causality test causality diagram propagation path simplification source locating
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Evaluation of wind vectors observed by HY-2A scatterometer using ocean buoy observations,ASCAT measurements,and numerical model data 被引量:5
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作者 李大伟 申辉 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第5期1191-1200,共10页
The first Chinese microwave ocean environment satellite HY-2A was launched successfully in August, 201 I. This study presents a quality assessment of HY-2A scatterometer (HYSCAT) data based on comparison with ocean ... The first Chinese microwave ocean environment satellite HY-2A was launched successfully in August, 201 I. This study presents a quality assessment of HY-2A scatterometer (HYSCAT) data based on comparison with ocean buoy data, the Advanced Scatterometer (ASCAT) data, and numerical model data from the National Centers for Environmental Prediction (NCEP). The in-situ observations include those from buoy arrays operated by the National Data Buoy Center (NDBC) and Tropical Atmosphere Ocean (TAO) project. Only buoys located offshore and in deep water were analyzed. The temporal and spatial collocation windows between HYSCAT data and buoy observations were 30 min and 25 km, respectively. The comparisons showed that the wind speeds and directions observed by HYSCAT agree well with the buoy data. The root-mean-squared errors (RMSEs) of wind speed and direction for the HYSCAT standard wind products are 1.90 m/s and 22.80°, respectively. For the HYSCAT-ASCAT comparison, the temporal and spatial differences were limited to 1 h and 25 km, respectively. This comparison yielded RMSEs of 1.68 m/s for wind speed and 19.1° for wind direction. We also compared HYSCAT winds with reanalysis data from NCEP. The results show that the RMSEs of wind speed and direction are 2.6 m/s and 26°, respectively. The global distribution of wind speed residuals (HYSCAT-NCEP) is also presented here for evaluation of the HYSCAT-retrieved wind field globally. Considering the large temporal and spatial differences of the collocated data, it is concluded that the HYSCAT-retrieved wind speed and direction met the mission requirements, which were 2 rn/s and 20° for wind speeds in the range 2-24 m/s. These encouraging assessment results show that the wind data obtained from HYSCAT will be useful for the scientific community. 展开更多
关键词 HY-2A SCATTEROMETER wind fields EVALUATION
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Nurse-staffing level and quality of acute care services:Evidence from cross-national panel data analysis in OECD countries 被引量:3
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作者 Arshia Amiri Tytti Solankallio-Vahteri 《International Journal of Nursing Sciences》 CSCD 2019年第1期6-16,共11页
Background:Most of previous studies aimed to estimate the effect of nurse staffing on quality of acute hospital care have used stochastic methods and their results are mixed.Objective:To measure the magnitude of effec... Background:Most of previous studies aimed to estimate the effect of nurse staffing on quality of acute hospital care have used stochastic methods and their results are mixed.Objective:To measure the magnitude of effect of nurse-staffing level on increasing quality of acute care services in long-run.Data:The number of practicing nurses'density per 1000 population as the proxy of nurse-staffing level and three Health Care Quality Indicators(HCQI)included 30-day mortality per 100 patients based on acute myocardial infarction(MORTAMIO),hemorrhagic stroke(MORTHSTO)and ischemic stroke(MORTISTO)were collected as a part of ongoing project by OECD.org in panels of 26 OECD countries over 2005-2015 period.Method:Panel data analysis.Results:There were committed relationships from nurse-staffing level to the enhancement of HCQI i.e.1%increase in nurse-staffing level would reduce the rates of patient mortality based on MORTAMIO,MORTHSTO and MORTISTO by 0.65%,0.60%and 0.80%,respectively.Furthermore,the role of nursestaffing level in increasing overall HCQI were simulated at the highest level in Sweden(-3.53),Denmark(-3.31),Canada(-2.59),Netherlands(-2.33),Finland(-2.09),Switzerland(-1.72),Australia(-1.64)and United States(-1.53).Conclusion:A higher proportion of nurses-staffing level is associated with higher quality of acute care services in OECD countries.Also,the nursing characteristics of Sweden,Denmark,Canada,Netherlands,Finland,Switzerland,Australia and United States would be good patterns for other countries to maximize nursing outcomes in the care of patients with acute and life-threatening conditions by reducing the risk of complication,mortality and adverse clinical outcomes. 展开更多
关键词 Quality of acute care Nurse-staffing level OECD countries Panel data analysis
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Intercomparison of Surface Radiative Fluxes in the Arctic Ocean
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作者 SHI Xiao-Xu LIU Ji-Ping 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第6期434-439,共6页
Recent satellite data analysis has provided improved data sets relevant to the surface energy budget in the Arctic Ocean. In this paper, surface radiation properties in the Arctic Ocean obtained from the Surface Radia... Recent satellite data analysis has provided improved data sets relevant to the surface energy budget in the Arctic Ocean. In this paper, surface radiation properties in the Arctic Ocean obtained from the Surface Radiation Budget(SRB3.0) and the International Satellite Cloud Climatology Project(ISCCP-FD) during 1984– 2007 are analyzed and compared. Our analysis suggests that these datasets show encouraging agreement in basin-wide averaged seasonal cycle and spatial distribution of surface albedo; net surface shortwave and all-wave radiative fluxes; and shortwave, longwave, and all-wave cloud radiative forcings. However, a systematic large discrepancy is detected for the net surface longwave radiative flux between the two data sets at a magnitude of ~ 23 W m–2, which is primarily attributed to significant differences in surface temperature, particularly from April to June. Moreover, the largest difference in surface shortwave and all-wave cloud radiative forcings between the two data sets is apparent in early June at a magnitude of 30 W m–2. 展开更多
关键词 Arctic Ocean surface albedo surface radiative flux cloud forcing
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Determinants of Female Employment Rate in the European Union 被引量:1
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作者 Irena Spasenoska Merale Fetahu-Vehapi 《Chinese Business Review》 2011年第11期1076-1090,共15页
The aim of this paper is to provide a clear insight about the determinants of female employment rate in the European Union where we have used panel data analyses of 27 countries members of the European Union from 1995... The aim of this paper is to provide a clear insight about the determinants of female employment rate in the European Union where we have used panel data analyses of 27 countries members of the European Union from 1995 till 2009. Applying dynamic modeling, i.e, generalized method of moments (GMM) econometrics findings have driven us to system estimated model where the following institutional variables have been tested: maternity leave, child care facilities, college education, fertility rate, GDP growth, female unemployment rate and part-time employment. We expect these variables to have a positive impact on the female employment rate except for the female unemployment rate and maternity leave 展开更多
关键词 female employment rate European Union dynamic panel data analysis
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Reconstructing Quintom from WMAP 5-year Observations:Generalized Ghost Condensate
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作者 张敬飞 桂元星 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第8期380-388,共9页
In the 5-year WMAP data analysis, a new parametrization form for dark energy equation-of-state was used, and it has been shown that the equation-of-state, w(z), crosses the cosmological-constant boundary w = -1. Bas... In the 5-year WMAP data analysis, a new parametrization form for dark energy equation-of-state was used, and it has been shown that the equation-of-state, w(z), crosses the cosmological-constant boundary w = -1. Based on this observation, in this paper, we investigate the reconstruction of quintom dark energy model. As a single-real-sealarfield model of dark energy, the generalized ghost condensate model provides us with a successful mechanism for realizing the quintom-like behavior. Therefore, we reconstruct this scalar-field quintom dark energy model from the WMAP 5-year observational results. As a comparison, we also discuss the quintom reconstruction based on other specific dark energy ansatzs, such as the CPL parametrization and the holographic dark energy scenarios. 展开更多
关键词 dark energy quintom ghost condensate
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Three-dimensional conjugate gradient inversion of magnetotelluric full information data 被引量:9
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作者 Lin Chang-Hong Tan Han-Dong Tong Tuo 《Applied Geophysics》 SCIE CSCD 2011年第1期1-10,94,共11页
Based on the analysis of impedance tensor data, tipper data, and the conjugate gradient algorithm, we develop a three-dimensional (3D) conjugate gradient algorithm for inverting magnetotelluric full information data... Based on the analysis of impedance tensor data, tipper data, and the conjugate gradient algorithm, we develop a three-dimensional (3D) conjugate gradient algorithm for inverting magnetotelluric full information data determined from five electric and magnetic field components and discuss the method to use the full information data for quantitative interpretation of 3D inversion results. Results from the 3D inversion of synthetic data indicate that the results from inverting full information data which combine the impedance tensor and tipper data are better than results from inverting only the impedance tensor data (or tipper data) in improving resolution and reliability. The synthetic examples also demonstrate the validity and stability of this 3D inversion algorithm. 展开更多
关键词 MAGNETOTELLURIC full information data 3D inversion conjugate gradient
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Analyzing the Impacts of Minimum Wage Standards on Reducing the Working Poor in China
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作者 Yongjian Hu 《Sociology Study》 2014年第7期573-580,共8页
During the past decades, the transformation of the labor market has significantly impacted on workers' wage structures and their employment in China. Along with the widening wage gaps and the growing income inequalit... During the past decades, the transformation of the labor market has significantly impacted on workers' wage structures and their employment in China. Along with the widening wage gaps and the growing income inequalities, the size of non-standard jobs expanded rapidly in China's urban labor market. As a result of this, the concept of working poor has become increasingly applicable to social and labor market realities in China, Based on the household survey data and by using quantitative analysis, this paper attempts to examine the interaction between the compulsory minimum wage standards and the working poor in the period of China's economic transition. The results show that for those whose monthly wages higher than the compulsory minimum wage standards were less likely to work poor and that workers with wages lower than the minimum wage floor were vulnerable to working poor, which supported the expectation that the implementation of compulsory minimum wages would help to reduce the risk of being a member among the working poor in China's urban labor market. 展开更多
关键词 Working poor minimum wage standards wage gaps logit model
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Unprecedented Retreat in a 50-Year Observational Record for Petermann Glacier, North Greenland 被引量:1
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作者 Ola M. JOHANNESSEN Mohamed BABIKER Martin W. MILES 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第5期259-265,共7页
Petermann Glacier is a marine-terminating outlet glacier that had a 70 km-long floating ice tongue prior to a ~ 270 km2 calving event that was observed from satellite sensors in August 2010,shortening the ice tongue ... Petermann Glacier is a marine-terminating outlet glacier that had a 70 km-long floating ice tongue prior to a ~ 270 km2 calving event that was observed from satellite sensors in August 2010,shortening the ice tongue by ~ 27 km.Further,in July 2012,another 10 km was lost through calving.In order to understand these events in perspective,here the authors perform a long-term data analysis of Petermann Glacier calving-front variability and ice velocity for each year in the 1990s-2000s,supplemented by available observations from the previous three decades.Five major (on the order of 100 krm2) calving events are identified,with ~ 153 km2 calved from 1959 to 1961,~ 168 km2 in 1991,~ 71 km2 in 2001,~ 270 km2 in 2010,and ~ 130 km2 in 2012-as well as ~ 31 k m2 calved in 2008.The increased frequency of major calving events in recent years has left the front terminus position retreated nearly 25 km beyond the range of observed in previous decades.In contrast,stable ice-dynamics are suggested from ice-velocity measurements made each year between 1993-2012,which are on average 1063 m yr-1,with limited interannual variability and no significant trend; moreover,there is no apparent relationship between ice-velocity variability and calving events.The degree to which the massive calving events in 2010 and 2012 represent natural episodic variability or a response to atmospheric and/or oceanic changes remains speculative; however,melt-induced weakening of the floating ice tongue in recent years is strongly suggested. 展开更多
关键词 GREENLAND outlet glaciers iceberg calving satellite remote sensing
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Application of Two-Order Difference to Gap Statistic
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作者 岳士弘 王秀秀 魏苗苗 《Transactions of Tianjin University》 EI CAS 2008年第3期217-221,共5页
Gap statistic is a well-known index of clustering validity, but its realization is difficult to be comprehended and accurately determined. A direct method is presented to improve the performance of the Gap statistic, ... Gap statistic is a well-known index of clustering validity, but its realization is difficult to be comprehended and accurately determined. A direct method is presented to improve the performance of the Gap statistic, which applies the two-order difference of within-cluster dispersion to replace the constructed null reference distribution in the Gap statistic. Hence, the realization of the Gap statistic becomes easy and is reformulated, and its uncertainty in applications is reduced. Also, the limitation of the Gap statistic is analyzed by two typical examples, that is, the Gap statistic is difficult to be applied to the dataset that contains strong-overlap or uneven-density clusters. Experiments verify the usefulness of the proposed method. 展开更多
关键词 clustering validity Gap statistic data structure
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