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Global influenza surveillancewith Laplacianmultidimensional scaling

Xi-chuan ZHOU,Fang TANG,Qin LI,Sheng-dong HU,Guo-jun LI,Yun-jian JIA,Xin-ke LI,Yu-jie FENG

《信息与电子工程前沿(英文)》 2016年 第17卷 第5期   页码 413-421 doi: 10.1631/FITEE.1500356

摘要: The Global Influenza Surveillance Network is crucial for monitoring epidemic risk in participating countries. However, at present, the network has notable gaps in the developing world, principally in Africa and Asia where laboratory capabilities are limited. Moreover, for the last few years, various influenza viruses have been continuously emerging in the resource-limited countries, making these surveillance gaps a more imminent challenge. We present a spatial-transmission model to estimate epidemic risks in the countries where only partial or even no surveillance data are available. Motivated by the observation that countries in the same influenza transmission zone divided by the World Health Organization had similar transmission patterns, we propose to estimate the influenza epidemic risk of an unmonitored country by incorporating the surveillance data reported by countries of the same transmission zone. Experiments show that the risk estimates are highly correlated with the actual influenza morbidity trends for African and Asian countries. The proposed method may provide the much-needed capability to detect, assess, and notify potential influenza epidemics to the developing world.

关键词: Surveillance gap     Influenza     Spatial-transmission model    

Interspecies transmission and evolution of the emerging coronaviruses: perspectives from bat physiologyand protein spatial structure

Baicheng HUANG, Kegong TIAN

《农业科学与工程前沿(英文)》 2020年 第7卷 第2期   页码 218-226 doi: 10.15302/J-FASE-2020324

摘要:

Emergent coronaviruses (CoVs) such as SARS-CoV and MERS-CoV have posed great threats to public health worldwide over the past two decades. Currently, the emergence of SARS-CoV-2 as a pandemic causes greater public health concern. CoV diversity is due to the large size and replication mechanisms of the genomes together with having bats as their optimum natural hosts. The ecological behavior and unique immune characteristics of bats are optimal for the homologous recombination of CoVs. The relationship of spatial structural characteristics of the spike protein, a protein that is critical for recognition by host receptors, in different CoVs may provide evidence in explaining the coevolution of CoVs and their hosts. This information may help to enhance our understanding of CoV evolution and thus provide part of the basis of preparations for any future outbreaks.

关键词: bat     coronavirus     evolution     host receptor     spike protein     transmission    

Integrated transmission and generation planning model in a deregulated environment

Enrique B. CEDE?O, Sant ARORA

《能源前沿(英文)》 2013年 第7卷 第2期   页码 182-190 doi: 10.1007/s11708-013-0256-8

摘要: After the deregulation of the Power Sector in the U.S., planning for generation and transmission capacities is decentralized. There is, however, still need for the long term integrated planning of generation and transmission capacities at the macro level, since these two sectors must operate in a coordinated manner. This paper presents a model for integrating generation and transmission expansion planning to identify an indicative expansion plan for the total sector at the macro level. The argument for an integrated model is supported using evidence from integrated planning efforts in real life systems. The application of the proposed model is illustrated using an example that requires expansion of generation and transmission capacities over three regions in a deregulated power system. The example considers that addition of generating capacity should come from renewable sources. The test results show the potential cost saving from integrated planning.

关键词: integrated planning     indicative plans     power generation     transmission     deregulation    

Industrial eco-efficiency and its spatial-temporal differentiation in China

Wei YANG, Fengjun JIN, Chengjin WANG, Chen LV

《环境科学与工程前沿(英文)》 2012年 第6卷 第4期   页码 559-568 doi: 10.1007/s11783-012-0400-4

摘要: The aim of this paper is to study the spatial-temporal differentiation of industrial eco-efficiency in China. Using methods based on the data envelopment analysis (DEA) model and exploratory spatial data analysis (ESDA) and data from 1985, 1995, 2005, and 2008 of 30 provinces in China, the spatial-temporal pattern changes in industrial eco-efficiency are discussed. The results show that: first, the patterns of industrial eco-efficiency are dominated by clustering of relatively low efficiency provinces; second, spatial relationships between the industrial eco-efficiencies of different provinces changed slightly throughout the period and the provinces persistently exhibit spatial concentration of relatively low industrial eco-efficiency; finally, there is an obvious trend in the polarization of industrial eco-efficiency, i.e., the higher level spatial units are concentrated in eastern China, and the lower level spatial units are mainly in western and central China.

关键词: industrial eco-efficiency     data envelopment analysis (DEA) model     exploratory spatial data analysis (ESDA)    

Smart model for accurate estimation of solar radiation

Lazhar ACHOUR, Malek BOUHARKAT, Ouarda ASSAS, Omar BEHAR

《能源前沿(英文)》 2020年 第14卷 第2期   页码 383-399 doi: 10.1007/s11708-017-0505-3

摘要: Prediction of solar radiation has drawn increasing attention in the recent years. This is because of the lack of solar radiation measurement stations. In the present work, 14 solar radiation models have been used to assess monthly global solar radiation on a horizontal surface as function of three parameters: extraterrestrial solar irradiance ( ), duration sunshine ( ) and daylight hours ( ). Since it has been observed that each model is adequate for some months of the year, one model cannot be used for the prediction of the whole year. Therefore, a smart hybrid system is proposed which selects, based on the intelligent rules, the most suitable prediction model of the 14 models listed in this study. For the test and evaluation of the proposed models, Tamanrasset city, which is located in the south of Algeria, is selected for this study. The meteorological data sets of five years (2000–2004) have been collected from the Algerian National Office of Meteorology (NOM), and two spatial databases. The results indicate that the new hybrid model is capable of predicting the monthly global solar radiation, which offers an excellent measuring accuracy of values ranging from 93% to 97% in this location.

关键词: global solar radiation     statistical indicator     hybrid model     spatial database     correlation coefficients    

面条模型中空间关系动态推断方法的研究

李成名

《中国工程科学》 2013年 第15卷 第5期   页码 37-41

摘要:

本文首先提出了面条模型的概念,进而指出基于面条模型的图形处理系统如果不具备动态生成空间关系的能力,就会退化为简单的地理数据库,提出了面条模型中动态推断空间关系的基于Voronoi图的四邻近数学模型(4-adj模型),给出了唯一、完备的推断规则,并指出其优点和不足。

关键词: 面条模型     面条目标     Voronoi图     4-adj模型    

A comprehensive analysis of a 3-P (Pa) S spatial parallel manipulator

Yuzhe LIU,Liping WANG,Jun WU,Jinsong WANG

《机械工程前沿(英文)》 2015年 第10卷 第1期   页码 7-19 doi: 10.1007/s11465-015-0324-3

摘要:

In this paper, a novel 3-degree of freedom (3-DOF) spatial parallel kinematic machine (PKM) is analyzed. The manipulator owns three main motions (two rotations and one translation) and three concomitant motions (one rotation and two translations). At first, the structure of this spatial PKM is simplified according to the characteristic of each limb. Secondly, the kinematics model of this spatial PKM is set up. In addition, the relationship between the main motions and concomitant motions is studied. The workspaces respectively based on the outputs and inputs are derived and analyzed. Furthermore, the velocity model is put forward. Two indexes based on the velocity model are employed to investigate the performance of this spatial PKM. At last, the output error model can be obtained and simulated. The comprehensive kinematics analysis in this paper is greatly useful for the future applications of this spatial PKM.

关键词: parallel mechanism     concomitant motions     kinematics     workspaces     error model    

Choosing configurations of transmission line tower grounding by back flashover probability value

Dmitry KUKLIN

《能源前沿(英文)》 2016年 第10卷 第2期   页码 213-226 doi: 10.1007/s11708-016-0398-6

摘要: There is a considerable number of works devoted to electrical characteristics of grounding. These characteristics are important in general. However, in application to grounding of transmission line towers they are not enough to determine what grounding construction is preferable in some particular case, because these characteristics are calculated or measured apart from the grounded object, and only limited number of current (or voltage) source waveforms is used. This paper indicates reasons in favor of the fact that to choose the optimum design of grounding, the calculation model should include the tower as it is. The probability of back flashover, which provides both qualitative and quantitative estimate of the grounding structure efficiency, can be taken as the criterion for the grounding design. The insulation flashover probability is calculated on the basis of engineering method, which evaluates breakdown strength of insulation for nonstandard waveshapes, and probability data on lightning currents. Different approaches are examined for identifying the back flashover probability, as not only amplitudes but also other parameters can be taken into account. Finite-difference time-domain method is used for calculations of transients. It is found that lightning current waveform can greatly influence calculated back flashover probability value.

关键词: grounding     transmission line tower     back flashover probability     FDTD method    

Availability growth models and verification of power equipment

Jinyuan SHI, Jiamin XU

《能源前沿(英文)》 2021年 第15卷 第2期   页码 529-538 doi: 10.1007/s11708-019-0624-0

摘要: The general availability growth models for large scale complicated repairable system such as electric generating units, power station auxiliaries, and transmission and distribution installations are presented. The calculation formulas for the maintenance coefficient, mathematical expressions for general availability growth models, ways for estimating, and fitting on checking the parameters of the model are introduced. Availability growth models for electric generating units, power station auxiliaries, and transmission and distribution installations are given together with verification examples for availability growth models of 320–1000 MW nuclear power units and 1000 MW thermal power units, 200–1000 MW power station auxiliaries, and 220–500 kV transmission and distribution installations. The verification results for operation availability data show that the maintenance coefficients for electric generating units, power station auxiliaries, transmission and distribution installations conform to the power function, and general availability growth models conform to rules of availability growth tendency of power equipment.

关键词: repairable system     power equipment     electric generating unit     power station auxiliary     transmission and distribution installation     reliability     availability     availability growth model    

Recent transmission of Mycobacterium tuberculosis in China: the implication of molecular epidemiology

null

《医学前沿(英文)》 2018年 第12卷 第1期   页码 76-83 doi: 10.1007/s11684-017-0609-5

摘要:

Tuberculosis (TB) has remained an ongoing concern in China. The national scale-up of the Directly Observed Treatment, Short Course (DOTS) program has accelerated the fight against TB in China. Nevertheless, many challenges still remain, including the spread of drug-resistant strains, high disease burden in rural areas, and enormous rural-to-urban migrations. Whether incident active TB represents recent transmission or endogenous reactivation has helped to prioritize the strategies for TB control. Evidence from molecular epidemiology studies has delineated the recent transmission of ( ) strains in many settings. However, the transmission patterns of TB in most areas of China are still not clear. Studies carried out to date could not capture the real burden of recent transmission of the disease in China because of the retrospective study design, incomplete sampling, and use of low-resolution genotyping methods. We reviewed the implementations of molecular epidemiology of TB in China, the estimated disease burden due to recent transmission of strains, the primary transmission of drug-resistant TB, and the evaluation of a feasible genotyping method of strains in circulation.

关键词: tuberculosis     recent transmission     molecular epidemiology     China    

液力传动箱上箱体强度分析与优化

刘传峰,田爱琴

《中国工程科学》 2008年 第10卷 第5期   页码 70-74

摘要:

计算机模拟模型分析法是机械设计开发的革命,运用有限元分析法可有效地规避设计风险和失误。对液力传动箱上箱体进行三维建模,提出了力学分析模型,将两个方案进行了有限元分析对比,指导设计方案的改进,提出最终解决方案,解决了设计难题。

关键词: 液力传动箱     力学模型     有限元分析     应力图     静强度     疲劳强度    

多径环境下脉冲超宽带系统的传输性能分析

林迪,沙学军,吴宣利,张乃通

《中国工程科学》 2009年 第11卷 第2期   页码 75-81

摘要:

为分析多径环境下脉冲超宽带跳时多址系统的传输性能,通过研究IEEE802.4.53a工作组给出的多 径信道参考模型,提出了一个同时存在符号间干扰、符号内多径干扰和多用户干扰的跳时超宽带系统相干解 调的性能分析模型,分别得到了符号内多径干扰、符号间干扰和多用户干扰的方差,且推导得到了系统的误 比特率计算公式,并用计算机仿真验证了公式的有效性。通过计算相邻多径的平均间隔,论证了符号内脉冲 自身多径的干扰是不可忽略的。在不同的信道环境下,以一定误码率要求作为衡量标准,比较了单用户系统 中仅考虑符号间干扰和同时考虑符号内多径干扰及符号间干扰的用户最高传输速率,并分析了多用户系统 中接入不同用户数时对应的平均传输速率的上限。

关键词: 超宽带     符号内多径干扰     符号间干扰     多用户干扰     传输性能分析模型    

Antibiotic resistome mostly relates to bacterial taxonomy along a suburban transmission chain

《环境科学与工程前沿(英文)》 2022年 第16卷 第3期 doi: 10.1007/s11783-021-1466-7

摘要:

• The α-diversities of resistome were lower in manure and compost than in soils.

关键词: Antibiotic resistance genes     Resistome     Bacterial taxonomy     Transmission chain    

Soil spatial variability impact on the behavior of a reinforced earth wall

Adam HAMROUNI, Daniel DIAS, Badreddine SBARTAI

《结构与土木工程前沿(英文)》 2020年 第14卷 第2期   页码 518-531 doi: 10.1007/s11709-020-0611-x

摘要: This article presents the soil spatial variability effect on the performance of a reinforced earth wall. The serviceability limit state is considered in the analysis. Both cases of isotropic and anisotropic non-normal random fields are implemented for the soil properties. The Karhunen-Loève expansion method is used for the discretization of the random field. Numerical finite difference models are considered as deterministic models. The Monte Carlo simulation technique is used to obtain the deformation response variability of the reinforced soil retaining wall. The influences of the spatial variability response of the geotechnical system in terms of horizontal facing displacement is presented and discussed. The results obtained show that the spatial variability has an important influence on the facing horizontal displacement as well as on the failure probability.

关键词: reinforced earth wall     geosynthetic     random field     spatial variability     Monte Carlo simulation    

Border-search and jump reduction method for size optimization of spatial truss structures

Babak DIZANGIAN, Mohammad Reza GHASEMI

《结构与土木工程前沿(英文)》 2019年 第13卷 第1期   页码 123-134 doi: 10.1007/s11709-018-0478-2

摘要: This paper proposes a sensitivity-based border-search and jump reduction method for optimum design of spatial trusses. It is considered as a two-phase optimization approach, where at the first phase, the first local optimum is found by few analyses, after the whole searching space is limited employing an efficient random strategy, and the second phase involves finding a sequence of local optimum points using the variables sensitivity with respect to corresponding values of constraints violation. To reach the global solution at phase two, a sequence of two sensitivity-based operators of border-search operator and jump operator are introduced until convergence is occurred. Sensitivity analysis is performed using numerical finite difference method. To do structural analysis, a link between open source software of OpenSees and MATLAB was developed. Spatial truss problems were attempted for optimization in order to show the fastness and efficiency of proposed technique. Results were compared with those reported in the literature. It shows that the proposed method is competitive with the other optimization methods with a significant reduction in number of analyses carried.

关键词: optimum design     sensitivity analysis     reduction method     spatial trusses     OpenSees    

标题 作者 时间 类型 操作

Global influenza surveillancewith Laplacianmultidimensional scaling

Xi-chuan ZHOU,Fang TANG,Qin LI,Sheng-dong HU,Guo-jun LI,Yun-jian JIA,Xin-ke LI,Yu-jie FENG

期刊论文

Interspecies transmission and evolution of the emerging coronaviruses: perspectives from bat physiologyand protein spatial structure

Baicheng HUANG, Kegong TIAN

期刊论文

Integrated transmission and generation planning model in a deregulated environment

Enrique B. CEDE?O, Sant ARORA

期刊论文

Industrial eco-efficiency and its spatial-temporal differentiation in China

Wei YANG, Fengjun JIN, Chengjin WANG, Chen LV

期刊论文

Smart model for accurate estimation of solar radiation

Lazhar ACHOUR, Malek BOUHARKAT, Ouarda ASSAS, Omar BEHAR

期刊论文

面条模型中空间关系动态推断方法的研究

李成名

期刊论文

A comprehensive analysis of a 3-P (Pa) S spatial parallel manipulator

Yuzhe LIU,Liping WANG,Jun WU,Jinsong WANG

期刊论文

Choosing configurations of transmission line tower grounding by back flashover probability value

Dmitry KUKLIN

期刊论文

Availability growth models and verification of power equipment

Jinyuan SHI, Jiamin XU

期刊论文

Recent transmission of Mycobacterium tuberculosis in China: the implication of molecular epidemiology

null

期刊论文

液力传动箱上箱体强度分析与优化

刘传峰,田爱琴

期刊论文

多径环境下脉冲超宽带系统的传输性能分析

林迪,沙学军,吴宣利,张乃通

期刊论文

Antibiotic resistome mostly relates to bacterial taxonomy along a suburban transmission chain

期刊论文

Soil spatial variability impact on the behavior of a reinforced earth wall

Adam HAMROUNI, Daniel DIAS, Badreddine SBARTAI

期刊论文

Border-search and jump reduction method for size optimization of spatial truss structures

Babak DIZANGIAN, Mohammad Reza GHASEMI

期刊论文