In order to remotely monitor and maintain large-scale complex equipment in real time, China Telecom plans to create a total solution that integrates remote data collection, transmission, storage, analysis and predicti...In order to remotely monitor and maintain large-scale complex equipment in real time, China Telecom plans to create a total solution that integrates remote data collection, transmission, storage, analysis and prediction. This solution can provide manufacturers with proactive, systematic, integrated operation and maintenance service, and the data analysis and health forecasting are the most important part. This paper conducts health management for the turbine blades. Elman neural network, and improved Elman neural network, i.e., outputhidden feedback(OHF) Elman neural network are studied as the main research methods. The results verify the applicability of OHF Elman neural network.展开更多
Background:Neglected tropical diseases(NTDs)are an important cause of death and disability in Africa.This study estimates the monetary value of human lives lost due to NTDs in the continent in 2015.Methods:The lost ou...Background:Neglected tropical diseases(NTDs)are an important cause of death and disability in Africa.This study estimates the monetary value of human lives lost due to NTDs in the continent in 2015.Methods:The lost output or human capital approach was used to evaluate the years of life lost due to premature deaths from NTDs among 10 high/upper-middle-income(Group 1),17 middle-income(Group 2)and 27 low-income(Group 3)countries in Africa.The future losses were discounted to their present values at a 3%discount rate.The model was re-analysed using 5%and 10%discount rates to assess the impact on the estimated total value of human lives lost.Results:The estimated value of 67860 human lives lost in 2015 due to NTDs was Int$5112472607.Out of that,14.6%was borne by Group 1,57.7%by Group 2 and 27.7%by Group 3 countries.The mean value of human life lost per NTD death was Int$231278,Int$109771 and Int$37489 for Group 1,Group 2 and Group 3 countries,respectively.The estimated value of human lives lost in 2015 due to NTDs was equivalent to 0.1%of the cumulative gross domestic product of the 53 continental African countries.Conclusions:Even though NTDs are not a major cause of death,they impact negatively on the productivity of those affected throughout their life-course.Thus,the case for investing in NTDs control should also be influenced by the value of NTD morbidity,availability of effective donated medicines,human rights arguments,and need to achieve the NTD-related target 3.3 of the United Nations Sustainable Development Goal 3(on health)by 2030.展开更多
The primary objective of this paper is to develop output only modal identification and structural damage detection. Identification of multi-degree of freedom （MDOF） linear time invariant （LTI） and linear time vari...The primary objective of this paper is to develop output only modal identification and structural damage detection. Identification of multi-degree of freedom （MDOF） linear time invariant （LTI） and linear time variant （LTV--due to damage） systems based on Time-frequency （TF） techniques--such as short-time Fourier transform （STFT）, empirical mode decomposition （EMD）, and wavelets--is proposed. STFT, EMD, and wavelet methods developed to date are reviewed in detail. In addition a Hilbert transform （HT） approach to determine frequency and damping is also presented. In this paper, STFT, EMD, HT and wavelet techniques are developed for decomposition of free vibration response of MDOF systems into their modal components. Once the modal components are obtained, each one is processed using Hilbert transform to obtain the modal frequency and damping ratios. In addition, the ratio of modal components at different degrees of freedom facilitate determination of mode shape. In cases with output only modal identification using ambient/random response, the random decrement technique is used to obtain free vibration response. The advantage of TF techniques is that they arc signal based; hence, can be used for output only modal identification. A three degree of freedom 1：10 scale model test structure is used to validate the proposed output only modal identification techniques based on STFT, EMD, HT, wavelets. Both measured free vibration and forced vibration （white noise） response are considered. The secondary objective of this paper is to show the relative ease with which the TF techniques can be used for modal identification and their potential for real world applications where output only identification is essential. Recorded ambient vibration data processed using techniques such as the random decrement technique can be used to obtain the free vibration response, so that further processing using TF based modal identification can be performed.展开更多
基金the National Natural Science Foundation of China(Nos.51505288 and 51875359)the TBT Project of Shanghai(No.18TBT003)the Project of Shanghai Telecom(No.17C1ZA0069SH301)
文摘In order to remotely monitor and maintain large-scale complex equipment in real time, China Telecom plans to create a total solution that integrates remote data collection, transmission, storage, analysis and prediction. This solution can provide manufacturers with proactive, systematic, integrated operation and maintenance service, and the data analysis and health forecasting are the most important part. This paper conducts health management for the turbine blades. Elman neural network, and improved Elman neural network, i.e., outputhidden feedback(OHF) Elman neural network are studied as the main research methods. The results verify the applicability of OHF Elman neural network.
基金This research received no specific grant from any funding agency in the public,commercial or not-for-profit sectors。
文摘Background:Neglected tropical diseases(NTDs)are an important cause of death and disability in Africa.This study estimates the monetary value of human lives lost due to NTDs in the continent in 2015.Methods:The lost output or human capital approach was used to evaluate the years of life lost due to premature deaths from NTDs among 10 high/upper-middle-income(Group 1),17 middle-income(Group 2)and 27 low-income(Group 3)countries in Africa.The future losses were discounted to their present values at a 3%discount rate.The model was re-analysed using 5%and 10%discount rates to assess the impact on the estimated total value of human lives lost.Results:The estimated value of 67860 human lives lost in 2015 due to NTDs was Int$5112472607.Out of that,14.6%was borne by Group 1,57.7%by Group 2 and 27.7%by Group 3 countries.The mean value of human life lost per NTD death was Int$231278,Int$109771 and Int$37489 for Group 1,Group 2 and Group 3 countries,respectively.The estimated value of human lives lost in 2015 due to NTDs was equivalent to 0.1%of the cumulative gross domestic product of the 53 continental African countries.Conclusions:Even though NTDs are not a major cause of death,they impact negatively on the productivity of those affected throughout their life-course.Thus,the case for investing in NTDs control should also be influenced by the value of NTD morbidity,availability of effective donated medicines,human rights arguments,and need to achieve the NTD-related target 3.3 of the United Nations Sustainable Development Goal 3(on health)by 2030.
基金National Science Foundation Grant NSF CMS CAREER Under Grant No.9996290NSF CMMI Under Grant No.0830391
文摘The primary objective of this paper is to develop output only modal identification and structural damage detection. Identification of multi-degree of freedom （MDOF） linear time invariant （LTI） and linear time variant （LTV--due to damage） systems based on Time-frequency （TF） techniques--such as short-time Fourier transform （STFT）, empirical mode decomposition （EMD）, and wavelets--is proposed. STFT, EMD, and wavelet methods developed to date are reviewed in detail. In addition a Hilbert transform （HT） approach to determine frequency and damping is also presented. In this paper, STFT, EMD, HT and wavelet techniques are developed for decomposition of free vibration response of MDOF systems into their modal components. Once the modal components are obtained, each one is processed using Hilbert transform to obtain the modal frequency and damping ratios. In addition, the ratio of modal components at different degrees of freedom facilitate determination of mode shape. In cases with output only modal identification using ambient/random response, the random decrement technique is used to obtain free vibration response. The advantage of TF techniques is that they arc signal based; hence, can be used for output only modal identification. A three degree of freedom 1：10 scale model test structure is used to validate the proposed output only modal identification techniques based on STFT, EMD, HT, wavelets. Both measured free vibration and forced vibration （white noise） response are considered. The secondary objective of this paper is to show the relative ease with which the TF techniques can be used for modal identification and their potential for real world applications where output only identification is essential. Recorded ambient vibration data processed using techniques such as the random decrement technique can be used to obtain the free vibration response, so that further processing using TF based modal identification can be performed.
