资源类型

期刊论文 58

会议视频 1

年份

2023 8

2022 4

2021 7

2020 3

2019 1

2018 5

2017 5

2016 6

2015 7

2014 2

2013 1

2012 2

2011 3

2008 2

2007 2

2006 1

展开 ︾

关键词

Tetrasphaera 1

CMAQ模型 1

PM2.5 1

严重急性呼吸综合征冠状病毒2 1

中国 1

先天免疫 1

免疫算法 1

免疫进化机制 1

冲突预测 1

决策优化 1

列车运行图 1

动态挖掘进程 1

动态数据挖掘 1

化学吸收 1

协同效应 1

原代肝细胞 1

去分化 1

去隔行 1

发育 1

展开 ︾

检索范围：

排序： 展示方式：

Realtime prediction of hard rock TBM advance rate using temporal convolutional network (TCN) with tunnel

Zaobao LIU; Yongchen WANG; Long LI; Xingli FANG; Junze WANG

《结构与土木工程前沿（英文）》 2022年 第16卷 第4期   页码 401-413 doi: 10.1007/s11709-022-0823-3

摘要： Real-time dynamic adjustment of the tunnel bore machine (TBM) advance rate according to the rock-machine interaction parameters is of great significance to the adaptability of TBM and its efficiency in construction. This paper proposes a real-time predictive model of TBM advance rate using the temporal convolutional network (TCN), based on TBM construction big data. The prediction model was built using an experimental database, containing 235 data sets, established from the construction data from the Jilin Water-Diversion Tunnel Project in China. The TBM operating parameters, including total thrust, cutterhead rotation, cutterhead torque and penetration rate, are selected as the input parameters of the model. The TCN model is found outperforming the recurrent neural network (RNN) and long short-term memory (LSTM) model in predicting the TBM advance rate with much smaller values of mean absolute percentage error than the latter two. The penetration rate and cutterhead torque of the current moment have significant influence on the TBM advance rate of the next moment. On the contrary, the influence of the cutterhead rotation and total thrust is moderate. The work provides a new concept of real-time prediction of the TBM performance for highly efficient tunnel construction.

关键词： hard rock tunnel     tunnel bore machine advance rate prediction     temporal convolutional networks     soft computing     construction big data    

HTML PDF 收藏

Temporal trend of mortality from major cancers in Xuanwei, China

null

《医学前沿（英文）》 2015年 第9卷 第4期   页码 487-495 doi: 10.1007/s11684-015-0413-z

摘要：

Although a number of studies have examined the etiology of lung cancer in Xuanwei County, China, other types of cancer in this county have not been reported systematically. This study aimed to investigate the temporal trend of eight major cancers in Xuanwei County using data from three mortality surveys (1973–1975, 1990–1992, and 2004–2005). The Chinese population in 1990 was used as a standard population to calculate age-standardized mortality rates. Cancers of lung, liver, breast, brain, esophagus, leukemia, rectum, and stomach were identified as the leading cancers in this county in terms of mortality rate. During the three time periods, lung cancer remained as the most common type of cancer. The mortality rates for all other types of cancer were lower than those of the national average, but an increasing trend was observed for all the cancers, particularly from 1990–1992 to 2004–2005. The temporal trend could be partly explained by changes in risk factors, but it also may be due to the improvement in cancer diagnosis and screening. Further epidemiological studies are warranted to systematically examine the underlying reasons for the temporal trend of the major cancers in Xuanwei County.

关键词： cancer     mortality     Xuanwei     temporal trend    

HTML PDF 收藏

The temporal changes of the concentration level of typical toxic organics in the river sediments around

Qiang Li, Xiong Xu, Yaoyao Fang, Ruiyang Xiao, Donghong Wang, Wenjue Zhong

《环境科学与工程前沿（英文）》 2018年 第12卷 第6期 doi: 10.1007/s11783-018-1054-7

摘要：

The current situation of typical organics in the sediments around Beijing was unclear.

56 kinds of typical toxic organics were detected in this article.

Historical data was compared with the data in this study.

The change of different organics in the sediments around Beijing was concluded.

关键词： Organic compounds     Endocrine disrupters     Sediments     Concentration     Temporal changes    

HTML PDF 收藏

Spatio-temporal variations of water quality in Yuqiao Reservoir Basin, North China

Yuan XU,Ruqin XIE,Yuqiu WANG,Jian SHA

《环境科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 649-664 doi: 10.1007/s11783-014-0702-9

摘要： Fuzzy comprehensive assessment and multivariate statistical techniques including cluster analysis, discriminant analysis, principal component analysis, and factor analysis were applied to analyze the water quality status of Yuqiao Reservoir Basin, North China, for assessing its spatio-temporal variations and identifying potential pollution sources. In this paper, we considered data for 14 water quality parameters collected during 1990–2004 at 7 water quality monitoring sites. The results of fuzzy comprehensive assessment revealed that water quality in Yuqiao Reservoir Basin showed a downtrend from 1990 to 2001 with fluctuation, and a slowly upward trend after 2001. The major water quality belonged to Class III and IV. Besides, hierarchical cluster analysis divided 7 monitoring sites into two groups (Group A and B), and 12 months into three periods (low-flow (LF), normal-flow (NF), and high-flow (HF) period). Temp, pH, SS, T-har, DO, NO -N and TP were identified as significant variables affecting spatial variations, and Temp, pH and NO -N were identified as significant variables affecting temporal variations by discriminant analysis. Factor analysis identified four latent pollution sources for water quality variations: nutrient pollution, organic pollution, inorganic pollution, and natural pollution. Moreover, for Group A regions, pollution inputs mainly came from domestic wastewater and industrial sewage. For Group B regions, it is more likely that water pollution resulted from the combined effects of domestic wastewater, hospital wastewater, agriculture runoff, and fishpond discharge, as well as the incoming water from upstream.

关键词： Fuzzy comprehensive assessment     multivariate statistical analysis     water quality    

HTML PDF 收藏

The effect of texture and irrigation on the soil moisture vertical-temporal variability in an urban artificial

Xiaofeng ZHANG,Xu ZHANG,Guanghe LI

《环境科学与工程前沿（英文）》 2015年 第9卷 第2期   页码 269-278 doi: 10.1007/s11783-014-0672-y

摘要： Soil moisture variability in natural landscapes has been widely studied; however, less attention has been paid to its variability in the urban landscapes with respect to the possible influence of texture stratification and irrigation management. Therefore, a case study was carried out in the Beijing Olympic Forest Park to continuously monitor the soil in three typical profiles from 26 April to 11 November 2010. The texture stratification significantly affected the vertical distribution of moisture in the non-irrigated profile where moisture was mostly below field capacity. In the profile where irrigation was sufficient to maintain moisture above field capacity, gravity flow led to increased moisture with depth and thus eliminated the influence of texture. In the non-irrigated sites, the upper layer (above 80 cm) exhibited long-term moisture persistence with the time scale approximating the average rainfall interval. However, a coarse-textured layer weakened the influence of rainfall, and a fine-textured layer weakened the influence of evapotranspiration, both of which resulted in random noise-like moisture series in the deeper layers. At the irrigated site, frequent irrigation neutralized the influence of evapotranspiration in the upper layer (above 60 cm) and overshadowed the influence of rainfall in the deeper layer. As a result, the moisture level in the upper layer also behaved as a random noise-like series; whereas due to deep transpiration, the moisture of the deep layer had a persistence time-scale longer than a month, consistent with characteristic time-scales found for deep transpiration.

关键词： moisture vertical distribution     moisture temporal variation     texture stratification     irrigation     meteorological forcing     urban landscape    

HTML PDF 收藏

Spatial and Temporal Distribution of PM

Xiao-hong Chen,Xiang-bo Tang

《工程管理前沿（英文）》 2016年 第3卷 第2期   页码 171-181 doi: 10.15302/J-FEM-2016017

摘要： Utilizing the initial hourly monitoring data of PM concentrations at 23 monitoring sites across the Chang-Zhu-Tan city cluster between January 2013 and February 2014 that released in Real-time Air Quality Reporting System in Hunan Province, this paper draws diagrams and analyzes the change rule of the pollutants concentration over time. In addition, this paper studies the regional distribution of PM seasonal pollution in the vicinity of the monitoring sites using ArcGIS geographic information system with the Kriging interpolation method. On this basis, this paper puts forward some effective control strategies to cope with regional PM pollution combined with the information of industry distribution and development status in the Chang-Zhu-Tan city cluster.

关键词： PM2.5     spatial and temporal distribution     ArcGIS     the chang-Zhu-Tan city cluster    

HTML PDF 收藏

CLIMATE-CHANGE-INDUCED TEMPORAL VARIATION IN PRECIPITATION INCREASES NITROGEN LOSSES FROM INTENSIVE CROPPING

《农业科学与工程前沿（英文）》 2022年 第9卷 第3期   页码 457-464 doi: 10.15302/J-FASE-2022452

摘要：

● A simple model was used to evaluate how increasing temporal variability in precipitation influences crop yields and nitrogen losses.

关键词： crop yield     fertilizer timing     nitrogen loss     precipitation variability     toy model    

HTML PDF 收藏

Machine learning for detecting mesial temporal lobe epilepsy by structural and functional neuroimaging

Baiwan Zhou, Dongmei An, Fenglai Xiao, Running Niu, Wenbin Li, Wei Li, Xin Tong, Graham J Kemp, Dong Zhou, Qiyong Gong, Du Lei

《医学前沿（英文）》 2020年 第14卷 第5期   页码 630-641 doi: 10.1007/s11684-019-0718-4

摘要： Mesial temporal lobe epilepsy (mTLE), the most common type of focal epilepsy, is associated with functional and structural brain alterations. Machine learning (ML) techniques have been successfully used in discriminating mTLE from healthy controls. However, either functional or structural neuroimaging data are mostly used separately as input, and the opportunity to combine both has not been exploited yet. We conducted a multimodal ML study based on functional and structural neuroimaging measures. We enrolled 37 patients with left mTLE, 37 patients with right mTLE, and 74 healthy controls and trained a support vector ML model to distinguish them by using each measure and the combinations of the measures. For each single measure, we obtained a mean accuracy of 74% and 69% for discriminating left mTLE and right mTLE from controls, respectively, and 64% when all patients were combined. We achieved an accuracy of 78% by integrating functional data and 79% by integrating structural data for left mTLE, and the highest accuracy of 84% was obtained when all functional and structural measures were combined. These findings suggest that combining multimodal measures within a single model is a promising direction for improving the classification of individual patients with mTLE.

关键词： mesial temporal lobe epilepsy     functional magnetic resonance imaging     structural magnetic resonance imaging     machine learning     support vector machine    

HTML PDF 收藏

Assessment of temporal and spatial variations in water quality using multivariate statistical methods

Xue LI,Pengjing LI,Dong WANG,Yuqiu WANG

《环境科学与工程前沿（英文）》 2014年 第8卷 第6期   页码 895-904 doi: 10.1007/s11783-014-0736-z

摘要： This study evaluated the temporal and spatial variations of water quality data sets for the Xin'anjiang River through the use of multivariate statistical techniques, including cluster analysis (CA), discriminant analysis (DA), correlation analysis, and principal component analysis (PCA). The water samples, measured by ten parameters, were collected every month for three years (2008–2010) from eight sampling stations located along the river. The hierarchical CA classified the 12 months into three periods (First, Second and Third Period) and the eight sampling sites into three groups (Groups 1, 2 and 3) based on seasonal differences and various pollution levels caused by physicochemical properties and anthropogenic activities. DA identified three significant parameters (temperature, pH and ) to distinguish temporal groups with close to 76% correct assignment. The DA also discovered five parameters (temperature, electricity conductivity, total nitrogen, chemical oxygen demand and total phosphorus) for spatial variation analysis, with 80.56% correct assignment. The non–parametric correlation coefficient (Spearman R) explained the relationship between the water quality parameters and the basin characteristics, and the GIS made the results visual and direct. The PCA identified four PCs for Groups 1 and 2, and three PCs for Group 3. These PCs captured 68.94%, 67.48% and 70.35% of the total variance of Groups 1, 2 and 3, respectively. Although natural pollution affects the Xin'anjiang River, the main sources of pollution included agricultural activities, industrial waste, and domestic wastewater.

关键词： Xin'anjiang River     multivariable statistical analysis     temporal variation     spatial variation     water quality    

HTML PDF 收藏

Distribution and temporal variability of the solar resource at a site in south-east Norway

Muyiwa S. ADARAMOLA

《能源前沿（英文）》 2016年 第10卷 第4期   页码 375-381 doi: 10.1007/s11708-016-0426-6

摘要： Globally, solar energy is expected to play a significant role in the changing face of energy economies in the near future. However, the variability of this resource has been the main barrier for solar energy development in most locations around the world. This paper investigated the distribution and variability of solar radiation using the a 10-year (2006 to 2015) data collected at Sørås meteorological station located at latitude 59° 39′ N and longitude 10° 47′E, about 93.3 m above sea level (about 30 km from Oslo), in south-eastern part of Norway. It is found that on annual basis, the total number of days with a global solar radiation of less than 1 kWh/(m ·d) is 120 days while the total number of days with an expected global solar radiation greater than 3 kWh/(m ·d) is 156 days (42.74%) per year. The potential energy output from a horizontally placed solar collector in these 156 days is approximately 75% of the estimated annual energy output. In addition, it is found that the inter-annual coefficient of variation of the global solar radiation is 4.28%, while that of diffuse radiation is 4.96%.

关键词： coefficient of variation     global solar radiation     diffuse ratio     albedo     PV energy systems    

HTML PDF 收藏

空中交通延误传播动力学的时空网络视角 Article

Qing Cai, Sameer Alam, Vu N. Duong

《工程（英文）》 2021年 第7卷 第4期   页码 452-464 doi: 10.1016/j.eng.2020.05.027

摘要：

由于日益增长的空中交通需求与有限的空域容量之间的不平衡，空中交通出现了难以解决的延误。由于空中交通与复杂的航空运输系统有关，延误可以在这些系统中被放大和传播，从而导致所谓的延迟传播的紧急行为。对延误传播动力学的理解与现代空中交通管理有着密切的关系。本文提出了一种复杂的网络延迟传播动力学观点。具体来说，我们利用以机场为节点的时空网络对空中交通场景进行建模。为了建立节点间的动态边缘，我们提出了一种时延传播方法，并将其应用于给定的空中交通调度集合。基于所构建的时空网络，提出了三个指标（幅度、严重性和速度）来衡量延迟传播动态。为了验证该方法的有效性，我们对东南亚地区（SAR）和美国的国内航班进行了案例研究。实验表明，美国交通延误传播影响的航班数和传播延迟量的传播幅度分别是SAR的5倍和10倍。实验进一步表明，美国交通的传播速度比SAR快8倍。延迟传播动态显示，SAR约6个枢纽机场存在明显的传播延误，而美国的情况则更为严重，相应数量在16个左右。本工作为跟踪空中交通延误的演变提供了有力的工具。

关键词： 空中交通     运输系统     时延传播动力学     时空网络    

HTML PDF 收藏

Mass concentrations and temporal profiles of PM

Liu YANG,Ye WU,Jiaqi LI,Shaojie SONG,Xuan ZHENG,Jiming HAO

《环境科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 675-684 doi: 10.1007/s11783-014-0731-4

摘要： Mass concentrations of PM , PM and PM were measured near major roads in Beijing during six periods: summer and winter of 2001, winter of 2007, and periods before, during and after the 2008 Beijing Olympic Games. Since the control efforts for motor vehicles helped offset the increase of emissions from the rapid growth of vehicles, the averaged PM concentrations at roadsides during the sampling period between 2001 and 2008 fluctuated over a relatively small range. With the implementation of temporary traffic control measures during the Olympics, a clear “V” shaped curve showing the concentrations of particulate matter and other gaseous air pollutants at roadsides over time was identified. The average concentrations of PM , PM , CO and NO decreased by 31.2%, 46.3%, 32.3% and 35.4%, respectively, from June to August; this was followed by a rebound of all air pollutants in December 2008. Daily PM concentrations near major roads exceeded the National Ambient Air Quality Standard (Grade II) for 61.2% of the days in the non-Olympic periods, while only for 12.5% during the Olympics. The mean ratio of PM /PM near major roads remained relatively stable at 0.55 (±0.108) on non-Olympic days. The ratio decreased to 0.48 (±0.099) during the Olympics due to a greater decline in fine particles than in coarse-mode PM. The ratios PM /PM fluctuated over a wide range and were statistically different from each other during the sampling periods. The average ratios of PM /PM on non-Olympic days were 0.71.

关键词： particulate matter     traffic     control measure     Beijing Olympic Games    

HTML PDF 收藏

Allocation of grassland, livestock and arable based on the spatial and temporal analysis for food demand

Huilong LIN, Ruichao LI, Yifan LIU, Jingrong ZHANG, Jizhou REN

《农业科学与工程前沿（英文）》 2017年 第4卷 第1期   页码 69-80 doi: 10.15302/J-FASE-2017140

摘要： To explore the distribution of food demand and the projected trend in future food demand in China, this paper analyzed the change in current (1998–2012) per-capita demand for grain, grain-consuming and herbivorous livestock products, and predicted the food demand in 2020. The results indicated that in 1998–2012, the national per-capita consumption of grain ration declined by about 36.66%, and the per-capita consumption of grain-consu-ming and herbivorous livestock products increased by about 48% and 34.09%, respectively. The grain-consu-ming livestock products have become the primary source of both calories and protein for consumers. The proportion of herbivorous livestock products in consumer diets has increased steadily and there has been huge potential in substituting beef and mutton for pork in this dynamic market. The demand for food in different provinces of China is highly variable, which is important for planning grassland agriculture development and ensuring food safety. The demand for grain, and grain-consuming and herbivorous livestock products will increase by about 3.3%, 20% and 14% respectively by 2020. Based on the food demand and trend in the development of grassland agriculture, the 31 provinces in China are divided into three priority groups for grassland agriculture development.

关键词： arable land equivalent unit (ALEU)     food equivalent unit (FEU)     food security     grassland agriculture     time trend prediction    

HTML PDF 收藏

基于时空数据的地下空间基础设施智能监测系统 Review

杜博文, 叶俊辰, 朱合华, 孙磊磊, 杜彦良

《工程（英文）》 2023年 第25卷 第6期   页码 194-203 doi: 10.1016/j.eng.2022.07.016

摘要：

基于时空大数据的智能感知、机理认知和劣化预知，不仅促进了基础设施安全的发展，同时也是基础设施建设向智能化转变的基础理论和关键技术。地下空间利用的发展，形成了深、大、聚的三大特征和立体的城市布局。然而，与地上的建筑物和桥梁相比，发生在地下的疾病和退化更为隐蔽，难以识别，在建设和服务期间仍然存在许多挑战。针对这一问题，本文总结了现有的方法，并在现实世界的空间安全管理中评估了它们的长处和短处，并在统一的智能监控系统中，讨论关键科学问题和解决方案。

关键词： 结构健康监测     地下空间结构     机器学习     时空数据    

HTML PDF 收藏

Corrigendum to “High-Speed Railway Train Timetable Conflict Prediction Based on Fuzzy Temporal

null

《工程（英文）》 2017年 第3卷 第1期   页码 150-150 doi: 10.1016/J.ENG.2017.01.002

HTML PDF 收藏

标题 作者 时间 类型 操作

Realtime prediction of hard rock TBM advance rate using temporal convolutional network (TCN) with tunnel

Zaobao LIU; Yongchen WANG; Long LI; Xingli FANG; Junze WANG

期刊论文

Temporal trend of mortality from major cancers in Xuanwei, China

null

期刊论文

The temporal changes of the concentration level of typical toxic organics in the river sediments around

Qiang Li, Xiong Xu, Yaoyao Fang, Ruiyang Xiao, Donghong Wang, Wenjue Zhong

期刊论文

Spatio-temporal variations of water quality in Yuqiao Reservoir Basin, North China

Yuan XU,Ruqin XIE,Yuqiu WANG,Jian SHA

期刊论文

The effect of texture and irrigation on the soil moisture vertical-temporal variability in an urban artificial

Xiaofeng ZHANG,Xu ZHANG,Guanghe LI

期刊论文

Spatial and Temporal Distribution of PM

Xiao-hong Chen,Xiang-bo Tang

期刊论文

CLIMATE-CHANGE-INDUCED TEMPORAL VARIATION IN PRECIPITATION INCREASES NITROGEN LOSSES FROM INTENSIVE CROPPING

期刊论文

Machine learning for detecting mesial temporal lobe epilepsy by structural and functional neuroimaging

Baiwan Zhou, Dongmei An, Fenglai Xiao, Running Niu, Wenbin Li, Wei Li, Xin Tong, Graham J Kemp, Dong Zhou, Qiyong Gong, Du Lei

期刊论文

Assessment of temporal and spatial variations in water quality using multivariate statistical methods

Xue LI,Pengjing LI,Dong WANG,Yuqiu WANG

期刊论文

Distribution and temporal variability of the solar resource at a site in south-east Norway

Muyiwa S. ADARAMOLA

期刊论文

空中交通延误传播动力学的时空网络视角

Qing Cai, Sameer Alam, Vu N. Duong

期刊论文

Mass concentrations and temporal profiles of PM

Liu YANG,Ye WU,Jiaqi LI,Shaojie SONG,Xuan ZHENG,Jiming HAO

期刊论文

Allocation of grassland, livestock and arable based on the spatial and temporal analysis for food demand

Huilong LIN, Ruichao LI, Yifan LIU, Jingrong ZHANG, Jizhou REN

期刊论文

基于时空数据的地下空间基础设施智能监测系统

杜博文, 叶俊辰, 朱合华, 孙磊磊, 杜彦良

期刊论文

Corrigendum to “High-Speed Railway Train Timetable Conflict Prediction Based on Fuzzy Temporal

null

期刊论文