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Time trends in myopia and high myopia prevalence in young university adults in China 被引量:3
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作者 Hong-Mei Zhang Bing-Qin Li +2 位作者 Yun Zhu Sheng-Xin Liu Rui-Hua Wei 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第10期1676-1681,共6页
AIM:To investigate time trends in myopia and high myopia prevalence over 6y among young university adults in China.METHODS:This is a 6-year series cross-sectional study from 2016 to 2021.Totally 4910 freshmen were enr... AIM:To investigate time trends in myopia and high myopia prevalence over 6y among young university adults in China.METHODS:This is a 6-year series cross-sectional study from 2016 to 2021.Totally 4910 freshmen were enrolled and completed a questionnaire concerning age,gender,and disease history.Students with eye diseases were excluded after a detailed eye examination.The refractive status was measured by non-cycloplegic objective refraction and ocular parameters were measured by Lenstar 900.The examination followed the same protocol each year.Trends over time in myopia and high myopia prevalence,as well as ocular biometry parameters,were analyzed.RESULTS:From 2016 to 2021,the axial length(AL)and corneal radius(CR)increased significantly(P=0.002 for AL;P=0.04 for CR).However,the spherical equivalent(SE)and the ratio of axial length to the corneal radius(AL/CR)did not change significantly(P=0.59 for SE;P=0.24 for AL/CR).The frequency of AL≥26.0 mm increased from 26.6%in 2016 to 29.3%in 2021(P=0.05 for trend).The prevalence of myopia and high myopia did not change significantly in our study(P≥0.18).Compared to a similar cross-sectional study conducted 10 years ago,the prevalence of myopia decreased significantly(94.9%vs 91.8%,P<0.001).Whereas the prevalence of high myopia increased largely(18.12%vs 27.6%,P<0.001).CONCLUSION:The prevalence of high myopia increases in young university adults during 10y period.Myopia control should begin earlier in childhood.However,these interventions are still needed for high myopia even in young adulthood. 展开更多
关键词 MYOPIA high myopia PREVALENCE axial length time trend
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Increasing pancreatic cancer is not paralleled by pancreaticoduodenectomy volumes in Brazil:A time trend analysis
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作者 Lucila M Perrotta de Souza Jessica PL Moreira +3 位作者 Homero S Fogaca José Marcus Raso Eulálio Ronir R Luiz Heitor SP de Souza 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2019年第1期79-86,共8页
Background: Currently, surgical resection represents the only curative treatment for pancreatic cancer(PC), however, the majority of tumors are no longer resectable by the time of diagnosis. The aim of this study was ... Background: Currently, surgical resection represents the only curative treatment for pancreatic cancer(PC), however, the majority of tumors are no longer resectable by the time of diagnosis. The aim of this study was to describe time trends and distribution of pancreaticoduodenectomies(PDs) performed for treating PC in Brazil in recent years. Methods: Data were retrospectively obtained from Brazilian Health Public System(namely DATASUS) regarding hospitalizations for PC and PD in Brazil from January 2008 to December 2015. PC and PD rates and their mortalities were estimated from DATASUS hospitalizations and analyzed for age, gender and demographic characteristics. Results: A total of 2364 PDs were retrieved. Albeit PC incidence more than doubled, the number of PDs increased only 37%. Most PDs were performed in men(52.2%) and patients between 50 and 69 years old(59.5%). Patients not surgically treated and those 70 years or older had the highest in-hospital mortality rates. The most developed regions(Southeast and South) as well as large metropolitan integrated municipalities registered 76.2% and 54.8% of the procedures, respectively. LMIM PD mortality fluctuated, ranging from 13.6% in 2008 to 11.8% in 2015. Conclusions: This study suggests a trend towards regionalization and volume-outcome relationships for PD due to PC, as large metropolitan integrated municipalities registered most of the PDs and more stable mortality rates. The substantial differences between PD and PC increasing rates reveals a limiting step on the health system resoluteness. Reduction in the number of hospital beds and late access to hospitalization, despite improvement in diagnostic methods, could at least in part explain these findings. 展开更多
关键词 Pancreatic cancer PANCREATICODUODENECTOMY time trend analysis Ecological study Hospitalization rates Mortality rates
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Trend and Periodicity of Temperature Time Series in Ontario 被引量:1
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作者 Syed Imran Ahmed Ramesh Rudra +1 位作者 Trevor Dickinson Motahir Ahmed 《American Journal of Climate Change》 2014年第3期272-288,共17页
The trends and periodicities in the annual and seasonal temperature time series at fifteen weather stations within Ontario Great Lakes Basins have been analyzed, for the period 1941-2005, using the statistical analyse... The trends and periodicities in the annual and seasonal temperature time series at fifteen weather stations within Ontario Great Lakes Basins have been analyzed, for the period 1941-2005, using the statistical analyses (Fourier series analysis, t-test, and Mann-Kendall test). The stations were spatially divided into three regions: northwest (NW), southwest (SW), and southeast (SE) to evaluate spatial variability in temperature. The results of the study reveal that the annual maximum mean temperature showed increasing trend for NW, and mixed trends for SW and SE regions. The variability was found to be more for northern stations as compared to southern stations for annual extreme minimum temperature. In addition, the trend slope per 100 years for the average annual extreme minimum temperature increased within the range of -0.8°C (Stratford) to 15°C (Porcupine). The seasonal analysis demonstrated that extreme maximum temperature has an increasing trend and maximum mean temperature has a decreasing trend during summer and winter. The extreme minimum temperature for winter illustrated an increasing trend (90%) with 22% statistically significant for NW region. For the SW region, the trend is also increasing (80%) for most of the temperature variables and 25% of temperature data were significantly increased in the SW region. The SE region stations showed overall very clear increasing trends (95%) for all the temperature variables. The data also showed that 47% of data were statistically significant in the SE region. The analysis of variance accounted for by trend, significant periodicities, and random component show that the pattern is similar for the percent of variance accounted for periodicities, and random component contribute dominantly for the four temperature variables and frost free days (FFD) for all three regions. Overall, the study reveals that the extreme minimum temperature is increasing annually and seasonally, with statistically significant at many stations. 展开更多
关键词 time Series trend PERIODICITY MANN-KENDALL Test T-TEST FROST Free Days
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Conforming to the Trend at An Appropriate Time——My Thoughts on the Building of the Silk Road Economic Belt 被引量:2
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作者 Zhang Zhiming Pu Zhuangyi 《International Understanding》 2013年第4期6-8,共3页
During his state visit to Kazakhstan this September,President Xi Jinping made a concrete proposal to build a Silk Road Economic Belt(SREB for short in the following paragraphs)from the aspects of policy communication,... During his state visit to Kazakhstan this September,President Xi Jinping made a concrete proposal to build a Silk Road Economic Belt(SREB for short in the following paragraphs)from the aspects of policy communication,road connectivity, 展开更多
关键词 My Thoughts on the Building of the Silk Road Economic Belt Conforming to the trend at An Appropriate time
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Analysis of the Main Factors Influencing Food Production in China Based on Time Series Trend Chart
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作者 Shuangjin WANG Jianying LI 《Asian Agricultural Research》 2014年第6期37-42,共6页
Based on the annual sample data on food production in China since the reform and opening up,we select 8 main factors influencing the total food production( growing area,application rate of chemical fertilizer,effectiv... Based on the annual sample data on food production in China since the reform and opening up,we select 8 main factors influencing the total food production( growing area,application rate of chemical fertilizer,effective irrigation area,the affected area,total machinery power,food production cost index,food production price index,financial funds for supporting agriculture,farmers and countryside),and put them into categories of material input,resources and environment,and policy factors. Using the factor analysis,we carry out the multi-angle analysis of these typical influencing factors one by one through the time series trend chart. It is found that application rate of chemical fertilizer,the growing area of food crops and drought-affected area become the key factors affecting food production. On this basis,we set forth the corresponding recommendations for improving the comprehensive food production capacity. 展开更多
关键词 FOOD PRODUCTION Influencing FACTORS time SERIES TR
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Piecewise linear representation of time series based on mean trend in sliding window
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作者 袁同雨 吴绍春 +3 位作者 张建 谷蓉蓉 陈高照 徐勇泉 《Journal of Shanghai University(English Edition)》 CAS 2011年第5期473-478,共6页
Seismic data show some important characteristics, such as big volume and strong timeliness. Specific to the time series data of earthquake precursory observations, a piecewise linear representation based on the slidin... Seismic data show some important characteristics, such as big volume and strong timeliness. Specific to the time series data of earthquake precursory observations, a piecewise linear representation based on the sliding window mean value (PLR_MTSW) algorithm is proposed. With this algorithm, the mutation points can be identified accurately according to the rate Of mean value change, while the main features of time series are maintained well. This algorithm can also smooth the noise and improve the compression accuracy with sliding window. Meanwhile the local extreme points can be identified effectively according to the change of mean value trend within window. 展开更多
关键词 earthquake precursor time series changing rate trend
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Strengthening Exchanges and Cooperation in the Northeast Asia Region Follows the Trend of the Times——Sidelights of the 10^(th) Northeast Asia Youth Forum
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作者 Wen Desheng Bai Ruijun 《International Understanding》 2013年第4期33-35,共3页
The 10thNortheast Asia Youth Forum,with the theme of China-ROK-Japan Youth Employment Guidance,sponsored by Moral Re-Armament/Initiatives of Change(MRA/IC)-Korea was held in Seoul and Cheonan from August 12 to 17.Seve... The 10thNortheast Asia Youth Forum,with the theme of China-ROK-Japan Youth Employment Guidance,sponsored by Moral Re-Armament/Initiatives of Change(MRA/IC)-Korea was held in Seoul and Cheonan from August 12 to 17.Seventy five college students from 37 universities sent by China International Youth Exchange Center,Moral Re-Armament/Initiatives of Change(MRA/IC)-Korea and Japan Society attended the Forum.Lee Boksil,Vice-Minister of Ministry of 展开更多
关键词 Re Sidelights of the 10 Strengthening Exchanges and Cooperation in the Northeast Asia Region Follows the trend of the times TH Northeast Asia Youth Forum Asia
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Statistical Analysis for Assessing Randomness, Shift and Trend in Rainfall Time Series under Climate Variability and Change: Case of Senegal
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作者 Didier Maria Ndione Soussou Sambou +4 位作者 Moussé Landing Sane Seydou Kane Issa Leye Seni Tamba Mouhamed Talla Cisse 《Journal of Geoscience and Environment Protection》 2017年第13期31-53,共23页
The main purpose of this study is to assess the climate variability and change through statistical processing tools that able to highlight annual and monthly rainfall behavior between 1970 and 2010 in six strategical ... The main purpose of this study is to assess the climate variability and change through statistical processing tools that able to highlight annual and monthly rainfall behavior between 1970 and 2010 in six strategical raingauges located in northern (Saint-Louis, Bakel), central (Dakar, Kaolack), and southern (Ziguinchor, Tambacounda) part of Senegal. Further, differences in sensitivity of statistical tests are also exhibited by applying several tests rather than a single one to check for one behavior. Dependency of results from statistical tests on studied sequence in time series is also shown comparing results of tests applied on two different periods (1970-2010 and 1960-2010). Therefore, between 1970 and 2010, exploratory data analysis is made to give in a visible manner a first idea on rainfall behavior. Then, Statistical characteristics such as the mean, variance, standard deviation, coefficient of variation, skewness and kurtosis are calculated. Subsequently, statistical tests are applied to all retained time series. Kendall and Spearman rank correlation tests allow verifying whether or not annual rainfall observations are independent. Hubert’s procedures of segmentation, Pettitt, Lee Heghinian and Buishand tests allow checking rainfall homogeneity. Trend is undertaken by first employing the annual and seasonal Mann-Kendall trend test, and in case of significance, magnitude of trend is calculated by Sen’s slope estimator tests. All statistical tests are applied in the period of 1960-2010. Explanatory analysis data indicates upwards trends for records in northern and central and trend free for southern records. Application of multiple tests shows that the Kendall and spearman ranks correlation tests lead to same conclusion. The difference in tests sensitivity was shown by outcomes of homogeneity tests giving different results either in dates of the shift occurrence or in the significance of an eventual shift. A synthesis analysis of results of tests was carried out to conclude about rainfall behaviors. Tests for homogeneity show that southern rainfall is homogeneous, while northern and central ones are not. According to trend test, upwards trends in Northern and central rainfall trend free in southern assumption in exploratory data analysis have been confirmed. The Sen’s slop estimator shows that all retained trend can be assumed to linear type. The same test over the period 1960-2010 shows independence of observations in all raingauges and exhibits neither trends nor breaks. This seems to show a return to a wet period. 展开更多
关键词 Senegal RAINFALL time Series Test INDEPENDENCE HOMOGENEITY SHIFT trend
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Comparative Analysis of Climatic Change Trend and Change-Point Analysis for Long-Term Daily Rainfall Annual Maximum Time Series Data in Four Gauging Stations in Niger Delta
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作者 Masi G. Sam Ify L. Nwaogazie +4 位作者 Chiedozie Ikebude Jonathan O. Irokwe Diaa W. El Hourani Ubong J. Inyang Bright Worlu 《Open Journal of Modern Hydrology》 2023年第4期229-245,共17页
The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta re... The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta region of Nigeria. Using daily or 24-hourly annual maximum series (AMS) data with the Indian Meteorological Department (IMD) and the modified Chowdury Indian Meteorological Department (MCIMD) models were adopted to downscale the time series data. Mann-Kendall (MK) trend and Sen’s Slope Estimator (SSE) test showed a statistically significant trend for Uyo and Benin, while Port Harcourt and Warri showed mild trends. The Sen’s Slope magnitude and variation rate were 21.6, 10.8, 6.00 and 4.4 mm/decade, respectively. The trend change-point analysis showed the initial rainfall change-point dates as 2002, 2005, 1988, and 2000 for Uyo, Benin, Port Harcourt, and Warri, respectively. These prove positive changing climatic conditions for rainfall in the study area. Erosion and flood control facilities analysis and design in the Niger Delta will require the application of Non-stationary IDF modelling. 展开更多
关键词 Rainfall time Series Data Climate Change trend Analysis Variation Rate Change Point Dates Non-Parametric Statistical Test
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基于时间序列的服装时尚趋势预测研究
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作者 彭涛 田蜜 +3 位作者 刘军平 张自力 胡新荣 何儒汉 《计算机应用与软件》 北大核心 2025年第1期35-40,共6页
针对传统时尚趋势预测方法效率低,高度依赖专家和用户的主观意志,训练数据难以反映真正的时尚趋势等问题,提出一种基于LSTM和时装周图像信息的时尚趋势预测模型。该方法首先通过爬取时尚网站vogue中2013到2021年的四大时装周的秀场图片... 针对传统时尚趋势预测方法效率低,高度依赖专家和用户的主观意志,训练数据难以反映真正的时尚趋势等问题,提出一种基于LSTM和时装周图像信息的时尚趋势预测模型。该方法首先通过爬取时尚网站vogue中2013到2021年的四大时装周的秀场图片,然后分析图片信息,将秀场图片信息与时尚内部知识相结合,最后利用基于注意机制的LSTM模型从时间序列中寻找时尚关系,从而进行时尚趋势预测。实验结果表明,该方法在多个数据集上表现最佳。 展开更多
关键词 时尚趋势预测 时尚分析 时装周 时间序列
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Cancer burden in China:trends,risk factors and prevention 被引量:101
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作者 Dianqin Sun He Li +4 位作者 Maomao Cao Siyi He Lin Lei Ji Peng Wanqing Chen 《Cancer Biology & Medicine》 SCIE CAS CSCD 2020年第4期879-895,共17页
As the most populous country in the world,China has made strides in health promotion in the past few decades.With the aging population,the burden of cancer in China continues to grow.Changes in risk factors for cancer... As the most populous country in the world,China has made strides in health promotion in the past few decades.With the aging population,the burden of cancer in China continues to grow.Changes in risk factors for cancer,especially diet,obesity,diabetes,and air pollution,continue to fuel the shift of cancer transition in China.The burden of upper gastrointestinal cancer in China is decreasing,but still heavy.The rising burden of colorectal,prostate,and breast cancers is also significant.Lung cancer became the top cause of cancer-related deaths,together with smoking as the most important contributor to cancer deaths.The Chinese government has taken several approaches to control cancer and cancer-related risk factors.Many achievements have been made,but some challenges remain.Health China 2030 is ambitious and depicts a bright vision of the future for cancer control in China.The decrease in the cancer burden in China will require cross-sector collaboration and coordinated efforts on primary and secondary preventions by governments,public health organizations,and individuals.In this review,we describe the trends of cancer burden and discuss cancer-related risk factors in China,identifying strategies to reduce the burden of cancer in China. 展开更多
关键词 Cancer burden time trends risk factor PREVENTION China
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黄河源实际蒸发和径流变化多时间尺度归因分析
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作者 曹振江 姬广兴 +5 位作者 杨瑞婷 王雨欣 李凡 张亚丽 陈伟强 黄珺嫦 《水土保持研究》 北大核心 2025年第1期209-217,共9页
[目的]全面分析黄河源区变化环境下水文要素(实际蒸发和径流)变化的主要影响因素,为黄河源区水文循环机理研究和生态环境保护提供参考依据。[方法]基于黄河源区1967-2020年的水文气象数据,使用Mann-Kendall趋势检验法在年、季和月时间... [目的]全面分析黄河源区变化环境下水文要素(实际蒸发和径流)变化的主要影响因素,为黄河源区水文循环机理研究和生态环境保护提供参考依据。[方法]基于黄河源区1967-2020年的水文气象数据,使用Mann-Kendall趋势检验法在年、季和月时间尺度上分析黄河源区实际蒸发和径流的变化特征,采用ABCD水文模型和月尺度Budyko模型在多时间尺度上定量分离出人类活动和气候变化对黄河源区实际蒸发和径流变化的贡献率。[结果](1)1967-2020年黄河源区实际蒸发量在年、季和月时间尺度上都表现为显著增加的趋势;径流在年尺度、旱季、8月、9月表现为不显著减少趋势,在雨季和7月表现为不显著增加趋势。(2)在年尺度、旱季、8月和9月,气候变化对流域实际蒸发的影响较大,其对实际蒸发量变化的贡献率分别为59.61%,108.43%,50.71%,58.17%;在雨季和7月,人类活动对流域实际蒸发的影响较大,其贡献率为62.38%和53.34%。(3)无论是在年尺度、季尺度还是7月、8月、9月,都表现为气候变化对流域径流变化的贡献率较大,贡献率分别为55.58%,56.23%,59.92%,68.70%,51.51%和87.03%。[结论]黄河源区不同时间尺度实际蒸发和径流变化多受气候变化影响较大,但是气候因素和人类活动对它们的贡献率相差较小,未来仍应注重人类活动影响的加剧。 展开更多
关键词 黄河源区 实际蒸发 径流 多时间尺度 趋势分析 ABCD水文模型 月尺度Budyko模型
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Changing trends of clinicopathologic features and survival duration after surgery for gastric cancer in Northeast China 被引量:2
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作者 Zhao Zhai Zi-Yu Zhu +11 位作者 Xi-Liang Cong Bang-Ling Han Jia-Liang Gao Xin Yin Yu Zhang Sheng-Han Lou Tian-Yi Fang Yi-Min Wang Chun-Feng Li Xue-Feng Yu Yan Ma Ying-Wei Xue 《World Journal of Gastrointestinal Oncology》 SCIE CAS 2020年第10期1119-1132,共14页
BACKGROUND Through analyzing the data from a single institution in Northeast China,this study revealed the possible clinicopathologic characteristics that influence the prognosis of patients with gastric cancer(GC).AI... BACKGROUND Through analyzing the data from a single institution in Northeast China,this study revealed the possible clinicopathologic characteristics that influence the prognosis of patients with gastric cancer(GC).AIM To evaluate the changing trends of clinicopathologic features and survival duration after surgery in patients with GC in Northeast China,which is a highprevalence area of GC.METHODS The study analyzed the difference in clinicopathologic features and survival duration after surgery of 5887 patients who were histologically diagnosed with GC at the Harbin Medical University Cancer Hospital.The study mainly analyzed the data in three periods,2000 to 2004(Phase 1),2005 to 2009(Phase 2),and 2010 to 2014(Phase 3).RESULTS Over time,the postoperative survival rate significantly increased from 2000 to 2014.In the past 15 years,compared with Phases 1 and 2,the tumor size was smaller in Phase 3(P<0.001),but the proportion of high-medium differentiated tumors increased(P<0.001).The proportion of early GC gradually increased from 3.9%to 14.4%(P<0.001).A surprising improvement was observed in the mean number of retrieved lymph nodes,ranging from 11.4 to 27.5(P<0.001).The overall 5-year survival rate increased from 24%in Phase 1 to 43.8%in Phase 3.Through multivariate analysis,it was found that age,tumor size,histologic type,tumor-node-metastasis stage,depth of invasion,lymph node metastasis,surgical approach,local infiltration,radical extent,number of retrieved lymph nodes,and age group were independent risk factors that influenced the prognosis of patients with GC.CONCLUSION The clinical features of GC in Northeast China changed during the observation period.The increasing detection of early GC and more standardized surgical treatment effectively prolonged lifetimes. 展开更多
关键词 Gastric cancer Clinicopathologic features SURVIVAL time trends EPIDEMIOLOGY GASTRECTOMY
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2010年-2019年北京市朝阳区学龄前儿童肥胖流行情况研究
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作者 唐友池 于亚滨 +2 位作者 李宏田 王思喆 周玉博 《中国生育健康杂志》 2025年第2期115-120,138,共7页
目的了解北京市朝阳区学龄前儿童肥胖状况的时间变化趋势及分布情况,为儿童发育健康管理提供科学依据。方法研究资料为2010年-2019年北京市朝阳区托幼机构管理的3~6岁学龄前儿童体检记录。采用标准差记分法将身高别体重大于或等于中位数... 目的了解北京市朝阳区学龄前儿童肥胖状况的时间变化趋势及分布情况,为儿童发育健康管理提供科学依据。方法研究资料为2010年-2019年北京市朝阳区托幼机构管理的3~6岁学龄前儿童体检记录。采用标准差记分法将身高别体重大于或等于中位数加2个标准差判断为肥胖;采用Cochran-Armitage检验方法分析学龄前儿童肥胖率时间变化趋势,采用χ2检验比较不同特征儿童和托幼机构特征肥胖率的差异。结果2010年-2019年北京市朝阳区学龄前儿童肥胖发生率分别为4.5%、4.2%、4.3%、4.7%、4.6%、4.3%、4.1%、3.8%、3.4%、3.4%,呈逐年下降趋势(P<0.001);学龄前儿童肥胖率随年龄呈上升趋势(P<0.001),3≤~<4岁、4≤~<5岁、5≤~<6岁、6≤~<7岁儿童肥胖发生率分别为3.0%、3.5%、4.7%、5.9%;本市户籍学龄前儿童肥胖发生率(4.3%)高于外地户籍儿童(3.7%,P<0.001)。按照托幼机构所处地区、类别、卫生保健评价评估情况、举办主体性质分层分析显示,城镇托幼机构学龄前儿童肥胖发生率(4.3%)高于乡镇托幼机构(3.8%,P<0.05);评价定级类别的托幼机构(三类为3.9%、二类为4.7%、一类为4.4%)的学龄前儿童肥胖发生率高于评价定级没有类别的托幼机构(3.5%,P<0.05);具有定期合格的卫生保健评价评估的托幼机构学龄前儿童肥胖发生率(4.3%)高于没有定期开展卫生保健评价评估的托幼机构(2.8%,P<0.05);公办托幼机构学龄前儿童肥胖发生率(4.8%)高于民办托幼机构(3.5%,P<0.05)。结论2010年-2019年北京朝阳区学龄前儿童肥胖率呈逐年下降趋势。分层分析结果提示,宜加强本市户籍和高年龄的学龄前儿童健康教育以控制其肥胖发生风险;宜加强对农村乡镇地区、类别低、未定期进行卫生保健评估、或民办托幼机构的规范化培训以提高其儿童健康管理水平。 展开更多
关键词 学龄前儿童 肥胖 时间变化趋势 分层分析
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新型冠状病毒肺炎疫情前后我国4种肝炎发病趋势的时间序列分析
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作者 陈静 瞿怀荣 +2 位作者 赵巍 冯永华 丁勇 《南京医科大学学报(自然科学版)》 北大核心 2025年第3期334-345,共12页
目的:探讨2019—2023年新型冠状病毒肺炎(coronavirus disease-2019,COVID-19)疫情前后我国4种肝炎(甲肝、乙肝、丙肝和戊肝)发病趋势的变化规律性,为疫情后肝炎防治提供参考依据。方法:通过我国2012—2023年4种肝炎时间序列的描述统计... 目的:探讨2019—2023年新型冠状病毒肺炎(coronavirus disease-2019,COVID-19)疫情前后我国4种肝炎(甲肝、乙肝、丙肝和戊肝)发病趋势的变化规律性,为疫情后肝炎防治提供参考依据。方法:通过我国2012—2023年4种肝炎时间序列的描述统计和季节性分解,对2019—2023年COVID-19疫情前后肝炎月发病数以及时间序列的长期趋势、季节因子和方差贡献率的动态变化进行比较和分析。结果:COVID-19疫情期间的2020—2022年,4种肝炎的平均月发病数低于疫情前的2019年,每种肝炎都出现2012年以来的历史最低值,疫情后的2023年月发病数都出现上升趋势。时间序列的分解表明,甲肝、乙肝、丙肝和戊肝,2012—2019年与2012—2023年的季节因子高度相关,相关系数分别为0.964、0.964、0.947和0.977(P均<0.001)。2012—2019年、2012—2020年、2012—2021年、2012—2022年及2012—2023年4种肝炎的时间序列的方差呈上升趋势,长期趋势的方差贡献率呈上升趋势,与方差的相关系数分别为0.979、0.981、0.890和0.938(P均<0.05),季节因子的方差贡献率呈下降趋势,与方差的相关系数分别为-0.978、-0.986、-0.954和-0.936(P均<0.05)。结论:时间序列分解有助于研究肝炎长期趋势变化和周期性波动的规律性。甲肝和乙肝时间序列图的长期趋势变化特征明显,丙肝、戊肝时间序列图的周期性波动特征明显。疫情防控减少了4种肝炎的月发病数,对月发病数的长期趋势有较大影响,未改变发病低谷期和高峰期的周期性特征。面临疫情后肝炎发病数上升的挑战,要加强疫情后肝炎的监测工作,研究肝炎发病规律性,做好防控和治疗工作。 展开更多
关键词 肝炎 时间序列 长期趋势 季节因子 新型冠状病毒肺炎
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基于seasonal-trend-loess方法的符号化时间序列网络 被引量:3
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作者 汪丽娜 成媛媛 臧臣瑞 《物理学报》 SCIE EI CAS CSCD 北大核心 2019年第23期314-322,共9页
为了有效控制海量数据时间序列网络的规模并使得网络更贴近实际,符号化时间序列网络成为研究热点.结合周期性时间序列的seasonal-trend-loess方法和符号化转化方法,本文提出一种新的符号化时间序列建网方法.该方法考虑了单个数据值的状... 为了有效控制海量数据时间序列网络的规模并使得网络更贴近实际,符号化时间序列网络成为研究热点.结合周期性时间序列的seasonal-trend-loess方法和符号化转化方法,本文提出一种新的符号化时间序列建网方法.该方法考虑了单个数据值的状态又结合了序列的长远变化趋势.以符号模式为节点;依时间顺序推移,以节点间的邻接转换关系定义连边;根据转换方向和转换频次确定连边的方向和权重,建立有向加权网络.分别以航空旅客吞吐量时间序列和因特网流量时间序列为实验数据构建的两个时间序列网络,有明显差异的拓扑特征;进一步对移动通信语音时间序列做了实证分析,挖掘时间序列数据的本质规律. 展开更多
关键词 周期时间序列 seasonal-trend-loess方法 复杂网络 拓扑特征
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基于STOA-VMD和改进TCN模型的水泵机组振动趋势预测
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作者 王伟生 张宁 +5 位作者 邢磊 周保林 郭新帅 安东 高源 张孝远 《人民黄河》 北大核心 2025年第4期141-144,151,共5页
水泵机组振动趋势预测是保障机组正常运行的重要措施,而振动信号的复杂性和非线性使预测变得困难。为此,提出一种基于STOA-VMD和改进时间卷积网络(TCN)的水泵机组振动趋势预测模型。首先采用乌燕鸥算法(STOA)进行变分模态分解(VMD)参数... 水泵机组振动趋势预测是保障机组正常运行的重要措施,而振动信号的复杂性和非线性使预测变得困难。为此,提出一种基于STOA-VMD和改进时间卷积网络(TCN)的水泵机组振动趋势预测模型。首先采用乌燕鸥算法(STOA)进行变分模态分解(VMD)参数优化,实现振动信号的最优自适应分解,然后利用改进TCN对每个分解模态进行预测,最后叠加所有结果得到最终预测结果。以国内某雨水泵站水泵机组为例,基于水导轴承水平向摆度数据进行模型验证。结果表明:上述组合模型的预测值与监测值的变化趋势基本一致,其具有良好的预测能力。与STOA-VMD-TCN、VMD-EnTCN、VMD-TCN、TCN模型相比,所提出模型的E_(MA)、E_(RMS)、E_(MAP)最小,预测精度最高。 展开更多
关键词 时间卷积网络 乌燕鸥算法 变分模态分解 振动信号 趋势预测 水泵机组
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肺结核发病的时空分布特征和气象因素分析
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作者 谢小义 《山东理工大学学报(自然科学版)》 CAS 2025年第1期41-45,共5页
通过对2015—2019年全国肺结核发病率数据(不含香港地区、澳门地区和台湾地区)可视化,探究全国肺结核发病的时空分布特征;通过空间自相关分析和拉格朗日乘数(LM)检验,选取面板数据空间杜宾模型探究有关气象因素对肺结核发病的影响。研... 通过对2015—2019年全国肺结核发病率数据(不含香港地区、澳门地区和台湾地区)可视化,探究全国肺结核发病的时空分布特征;通过空间自相关分析和拉格朗日乘数(LM)检验,选取面板数据空间杜宾模型探究有关气象因素对肺结核发病的影响。研究结果表明,每年的1月和3月是全国肺结核的高发期,且全国肺结核发病率存在空间聚集性,高发区域是新疆、西藏和青海等西北部地区;气温和湿度与当地肺结核发病是负相关关系,与周边地区的肺结核发病是正相关关系。 展开更多
关键词 肺结核 时间流行趋势 空间分布特征 空间杜宾模型
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湖南省带量采购和分级管理政策对碳青霉烯类抗生素利用的影响
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作者 吴泽华 陈君宇 +7 位作者 许林勇 明煜鑫 周宇松 黄勋 付陈超 王朝晖 刘世坤 李佐军 《中国感染控制杂志》 北大核心 2025年第1期105-112,共8页
目的探索抗菌药物带量采购和分级管理政策对碳青霉烯类抗生素利用的影响。方法采用Mann-Kendall趋势检验分析各级医疗机构碳青霉烯类抗生素用药频度(DDDs)、采购金额(Cost)、药品日均费用(DDDc)、每天每1000居民用药频度(DID)的变化趋势... 目的探索抗菌药物带量采购和分级管理政策对碳青霉烯类抗生素利用的影响。方法采用Mann-Kendall趋势检验分析各级医疗机构碳青霉烯类抗生素用药频度(DDDs)、采购金额(Cost)、药品日均费用(DDDc)、每天每1000居民用药频度(DID)的变化趋势,以2020年5月1日为带量采购政策的干预分界点,以2021年9月作为分级管理目录的干预分界点,采用间断时间序列分析法研究带量采购和分级管理政策对碳青霉烯类抗生素临床用药的影响。结果在带量采购政策执行后,碳青霉烯类抗生素DDDs、DID明显上升,但长期趋势变化不显著;与政策执行前相比,碳青霉烯类抗生素的Cost和DDDc瞬时下降,DDDc长期趋势变化显著,但Cost长期趋势变化不显著。分级管理目录更新后,碳青霉烯类抗生素DDDs、Cost瞬时下降,但长期下降趋势不显著,并且DDDc呈长期上升趋势。结论带量采购政策降低了碳青霉烯类抗生素DDDc,短期内降低了Cost;但对DDDs、Cost、DID的长期影响有限;分级管理对医疗机构碳青霉烯类抗生素的利用影响有限。 展开更多
关键词 碳青霉烯类抗生素 抗菌药物带量采购 抗菌药物分级管理 药物利用评价 Mann-Kendall趋势检验 间断时间序列分析
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“国潮风”插画在老字号品牌包装设计中的创新——以“谢馥春”为例
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作者 周晗 《鞋类工艺与设计》 2025年第3期101-103,共3页
随着我国综合实力的提升,国民文化自信也大幅提升,“国潮风”的盛行是在此背景下的必然产物,“国潮风”的包装设计成为消费新趋势。本研究课题通过插画设计对“谢馥春”的包装设计进行创新,将谢馥春一脉相承的古典传统设计理念与现代国... 随着我国综合实力的提升,国民文化自信也大幅提升,“国潮风”的盛行是在此背景下的必然产物,“国潮风”的包装设计成为消费新趋势。本研究课题通过插画设计对“谢馥春”的包装设计进行创新,将谢馥春一脉相承的古典传统设计理念与现代国潮插画的方式结合运用。笔者从插画设计角度出发,通过设计色彩、视觉元素与字体设计3个方面进行创新,将中华传统文化与现代潮流相结合,赋予谢馥春老字号品牌新的生命力。 展开更多
关键词 包装设计 插画设计 老字号品牌 国潮
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