1,720,952 research outputs found
Deep Bayesian survival analysis of rail useful lifetime
No full textReliable estimation of rail useful lifetime can provide valuable information for predictive maintenance in railway systems. However, in most cases, lifetime data is incomplete because not all pieces of rail experience failure by the end of the study horizon, a problem known as censoring. Ignoring or otherwise mistreating the censored cases might lead to false conclusions. Survival approach is particularly designed to handle censored data for analysing the expected duration of time until one event occurs, which is rail failure in this paper. This paper proposes a deep Bayesian survival approach named BNN-Surv to properly handle censored data for rail useful lifetime modelling. The proposed BNN-Surv model applies the deep neural network in the survival approach to capture the non-linear relationship between covariates and rail useful lifetime. To consider and quantify uncertainty in the model, Monte Carlo dropout, regarded as the approximate Bayesian inference, is incorporated into the deep neural network to provide the confidence interval of the estimated lifetime. The proposed approach is implemented on a four-year dataset including track geometry monitoring data, track characteristics data, various types of defect data, and maintenance and replacement (M&R) data collected from a section of railway tracks in Australia. Through extensive evaluation, including Concordance index (C-index) and root mean square error (RMSE) for evaluating model performance, as well as a proposed CW-index for evaluating uncertainty estimations, the effectiveness of the proposed approach is confirmed. The results show that, compared with other commonly used models, the proposed approach can achieve the best concordance index (C-index) of 0.80, and the estimated rail useful lifetimes are closer to real lifetimes. In addition, the proposed approach can provide the confidence interval of the estimated lifetime, with a correct coverage of 81% of the actual lifetime when the confidence interval is 1.38, which is more useful than point estimates in decision-making and maintenance planning of railroad systems.Railway Engineerin
Correction to: International Alliance of Urolithiasis (IAU) consensus on miniaturized percutaneous nephrolithotomy (Military Medical Research, (2024), 11, 1, (70), 10.1186/s40779-024-00562-3)
No full textAfter publication of the article, it was brought to our attention that the author name Otas Durutovic was duplicated in the author list and the second one should be replaced by the author Chu Ann Chai, and the affiliations of Ji-Wen Cheng and Chu Ann Chai are incorrect, the correct author list with correct affiliations is shown below: Guo-Hua Zeng, Wen Zhong, Giorgio Mazzon, Wei Zhu, Sven Lahme, Sanjay Khadgi, Janak Desai, Madhu Agrawal, David Schulsinger, Mantu Gupta, Emanuele Montanari, Juan Manuel Lopez Martinez, Shabir Almousawi, Vincent Emanuel F. Malonzo, Seshadri Sriprasad, Otas Durutovic, Vimoshan Arumuham, Stefania Ferretti, Wissam Kamal, Ke-Wei Xu, Fan Cheng, Xiao-Feng Gao, Ji-Wen Cheng, Bhaskar Somani, Mordechai Duvdevani, Kah Ann Git, Christian Seitz, Norberto Bernardo, Tarek Ahmed Amin Ibrahim, Albert Aquino, Takahiro Yasui, Cristian Fiori, Thomas Knoll, Athanasios Papatsoris, Nariman Gadzhiev, Ulanbek Zhanbyrbekuly, Oriol Angerri, Hugo Lopez Ramos, Iliya Saltirov, Mohamad Moussa, Guido Giusti, Fabio Vicentini, Edgar Beltran Suarez, Margaret Pearle, Glenn M. Preminger, Qing-Hui Wu, Chu Ann Chai, Khurshid Ghani, Marcus Maroccolo, Marianne Brehmer, Palle J. Osther, Marek Zawadzki, Azimdjon Tursunkulov, Monolov Nurbek Kytaibekovich, Abdusamad Abdukakhorovich Abuvohidov, Cesar Antonio Recalde Lara, Zamari Noori, Stefano Paolo Zanetti, Sunil Shrestha, Jean de la Rosette, John Denstedt, Zhang-Qun Ye, Kemal Sarica & Simon Choong. The original publication has been updated. © The Author(s) 2024
Rail break prediction and cause analysis using imbalanced in-service train data
No full textTimely detection and identification of rail breaks are crucial for safety and reliability of railway networks. This paper proposes a new deep learning-based approach using the daily monitoring data from in-service trains. A time-series generative adversarial network (TimeGAN) is employed to mitigate the problem of data imbalance and preserve the temporal dynamics for generating synthetic rail breaks. A feature-level attention-based bidirectional recurrent neural networks (AM-BRNN) is proposed to enhance feature extraction and capture two-direction dependencies in sequential data for accurate prediction. The proposed approach is implemented on a three-year dataset collected from a section of railroads (up to 350 km) in Australia. A real-life validation is carried out to evaluate the prediction performance of the proposed model, where historical data is used to train the model and future ’unseen’ rail breaks along the whole track section are used for testing. The results show that the model can successfully predict 9 out of 11 rail breaks three months ahead of time with a false prediction of non-break of 8.2%. Predicting rail breaks three months ahead of time will provide railroads enough time for maintenance planning. Given the prediction results, SHAP method is employed to perform cause analysis for individual rail break. The results of cause analysis can assist railroads to plan appropriate maintenance to prevent rail breaks.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Railway Engineerin
Correction: International Alliance of Urolithiasis (IAU) consensus on miniaturized percutaneous nephrolithotomy
Full text linkAfter publication of the article, it was brought to our attention that the author name Otas Durutovic was duplicated in the author list and the second one should be replaced by the author Chu Ann Chai, and the affiliations of Ji-Wen Cheng and Chu Ann Chai are incorrect, the correct author list with correct affiliations is shown below: Guo-Hua Zeng, Wen Zhong, Giorgio Mazzon, Wei Zhu, Sven Lahme, Sanjay Khadgi, Janak Desai, Madhu Agrawal, David Schulsinger, Mantu Gupta, Emanuele Montanari, Juan Manuel Lopez Martinez, Shabir Almousawi, Vincent Emanuel F. Malonzo, Seshadri Sriprasad, Otas Durutovic, Vimoshan Arumuham, Stefania Ferretti, Wissam Kamal, Ke-Wei Xu, Fan Cheng, Xiao-Feng Gao, Ji-Wen Cheng, Bhaskar Somani, Mordechai Duvdevani, Kah Ann Git, Christian Seitz, Norberto Bernardo, Tarek Ahmed Amin Ibrahim, Albert Aquino, Takahiro Yasui, Cristian Fiori, Thomas Knoll, Athanasios Papatsoris, Nariman Gadzhiev, Ulanbek Zhanbyrbekuly, Oriol Angerri, Hugo Lopez Ramos, Iliya Saltirov, Mohamad Moussa, Guido Giusti, Fabio Vicentini, Edgar Beltran Suarez, Margaret Pearle, Glenn M. Preminger, Qing-Hui Wu, Chu Ann Chai, Khurshid Ghani, Marcus Maroccolo, Marianne Brehmer, Palle J. Osther, Marek Zawadzki, Azimdjon Tursunkulov, Monolov Nurbek Kytaibekovich, Abdusamad Abdukakhorovich Abuvohidov, Cesar Antonio Recalde Lara, Zamari Noori, Stefano Paolo Zanetti, Sunil Shrestha, Jean de la Rosette, John Denstedt, Zhang-Qun Ye, Kemal Sarica & Simon Choong. The original publication has been updated.</p
Yu zhou zhong wei zi dui da chi du jie gou xing cheng de ying xiang
No full textM.Phil.Unlike cold dark matter (CDM), light but massive cosmological neutrinos do not significantly cluster on small scales, due to their high thermal velocities. With finite masses, cosmological neutrinos become part of the total matter field and contribute to its smoothing. The cosmic structure formation in the presence of massive neutrinos is therefore impeded compared to that in the standard ΛCDM cosmology with massless neutrinos. Neutrinos’ masses also distort the anisotropy power spectrum of cosmic microwave background (CMB). Furthermore, a finite chemical potential µ for cosmological neutrinos, still allowed by current data, would have a non-negligible impact on CMB and structure formation. We consistently evaluate effects of neutrino masses and chemical potentials on the matter power spectrum by use of a neutrinoinvolved N-body simulation, with cosmological parameters obtained from a Markov-Chain Monte-Carlo (MCMC) refitting of the CMB data. Our results show that while a finite averaged neutrino mass mν tends to suppress the matter power spectrum in a range of wave numbers, the neutrino degeneracy parameters ξi ≡µi/T comparably enhance the latter, leading to a large parameter degeneracy between them. We provide an empirical formula for the dependencies of the matter power spectrum in a selected range of wave numbers induced by [includes formula] Observing a strong correlation between mν and η, we propose a single redshift-independent vector [includes formula] to parametrize the neutrino effects on the matter power spectrum.Properties of dark matter haloes in massive neutrino cosmology has also been studied using our neutrino-involved simulation code. Our preliminary results suggest that the abundance of very massive haloes (> 10¹⁴M⊙/h) can serve as another sensitive probe for neutrino mass. The clustering effect of these massive haloes is also studied and compared to a previously reported tension between the galaxy cluster abundance and clustering behaviour [1].不同於冷暗物質, 有較⼩質量的中微⼦因其所具有的⾼速度, 在較⼩的宇宙 學尺度上沒有明顯的成團效應 。這導致了對總的物質場的平滑, 從⽽使得 加⼊有質量中微⼦的宇宙結構形成滯後於標準的 ΛCDM 宇宙學模型 。另 ⼀⽅⾯, 中微⼦的質量還改變了宇宙微波背景輻射 (CMB) 的各向異性功率 譜, 故⽽擬合得到的宇宙學參數會受到影響 。除了質量之外, 中微⼦的化學勢 (µ) 也對宇宙結構的形成存在影響 。通過將對 CMB 數據的多鏈蒙特卡洛 擬合 (MCMC) ⽽得到的新的宇宙學參數和加⼊中微⼦的 N 體模擬 (N-body simulation) 系統地結合起來, 我們全⾯地研究了兩個變量, 即中微⼦質量和 化學勢對物質功率譜的影響。結果表明, 中微⼦的簡并參數 [附方程式] 有⼤約和其質量相當的影響, 不過兩者⽅向恰好相反 。這說明在這兩個參數間有很強的簡併, 難以單獨確定 。通過對這兩個變量的反復取樣, 我們提供了⼀條經驗公式來描述質量 mν 和簡併參數 [附方程式] 對物質功率譜的影響 。同時由於這兩個變量本⾝存在的強關聯性, 我們通過對⾓化參數來提供⼀個新的變量 [附方程式] ⽤以表征中微⼦參數對物質功率譜的影響 。除了物質功率譜之外, 我們還⽤我們的 N 體模擬研究了含有質量中微⼦的宇宙學模型中暗物質暈的相關特性 。初步結果顯⽰, ⼤質量暗暈 (> 10¹⁴M⊙/h) 的豐度對中微⼦質量很敏感, 從⽽可以作為⼀個估計中微⼦質量的觀測量 。這項研究也包含了暗暈的成團效應, 并和實際觀測中發現的星系團豐度與成團兩個現象的數據不吻合進⾏了對⽐ 。Zeng, Zhichao = 宇宙中微子對大尺度結構形成的影響 / 曾志超.Thesis M.Phil. Chinese University of Hong Kong 2018.Includes bibliographical references (leaves 73-78).Abstracts also in Chinese.Title from PDF title page (viewed on August 18, 2020).Zeng, Zhichao = Yu zhou zhong wei zi dui da chi du jie gou xing cheng de ying xiang / Zeng Zhichao
Financial Security of Elders in China
Full text linkChina is one of the largest countries in the world in terms of both geography and population size, with lower economic levels compared to the developed countries, and great regional differences. This paper introduces the rapid demographic changes of the Chinese population and the current financial security of elders in China. The World Bank’s multi-pillar model is used to explain the financial security of elders in China, which includes the current pension and health care systems in urban and rural areas in China respectively. The important issues of financial security of elders which the Chinese government should address in the near future are also discussed. The paper concludes with a consideration of the results of social welfare system reforms by the Chinese government and future research interests from a geographer’s perspective.Financial security, elders, social welfare system, China
A Self-Bias-Flip with Charge Recycle Interface Circuit with No External Energy Reservoir for Piezoelectric Energy Harvesting Array
No full textThis article presents a piezoelectric energy harvesting (PEH) interface circuit using a new self-bias-flip with the charge recycle (SBFR) technique without employing any additional energy reservoir. Traditional designs, including synchronous-switch harvesting on inductor (SSHI), synchronous-switch harvesting on capacitor (SSHC), synchronous electric charge extraction (SECE), etc., require additional capacitors or inductors to reverse the voltage on the PEH at the zero-crossing point. This design innovatively uses the inherent capacitors of the piezoelectric harvesters as the flipping capacitors. In order to improve the extract efficiency of the interface, the zero-crossing state is split into a charge recycle stage and a voltage-flip stage. For a piezoelectric array with 2^n PEHs, a configuration with (n-1) phases in the charge recycle stage is adopted to reduce the loss caused by direct charge neutralization. The charge redistribution loss is reduced by employing (2n+1) phases in the voltage-flip stage. The proposed principle has been implemented with discrete components and is verified by three different prototypes. The measurement results show that a flipping efficiency of 67% is achieved by utilizing SBFR with four PEHs. And the proposed interface can provide up to 5.2x improvement when compared with the full-bridge rectifier (FBR).Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Instrumentatio
Tao Xingzhi ge qu. I
No full textSide A. 1. 捧著一顆心來不帶半根草去(一)(二) ; 2. 在我的世界里小孩青年最大 ; 3. 一群小好漢(一)(二) ; 4. 追悼慈母歌 ; 5. 梅香苦 ; 6. 三代 ; 7. 朝陽歌 ; 8. 小庄晓 ; 9. 问江 ; 10. 诗的学校 ; 11. 紀念牛頓与伽利略 ; 12. 拉車 ; 13. 马克思颂 ; 14. 跟青年學 ; 15. 歌唱现代 ; 16. 寂寞 ; 17. 爱国歌 ; 18. 科学的春天 ; 19. 小小徽机真灵巧 ; 20. 玩科学把戏真有趣 ; 21. 水姑娘午曲 -- Side B. 1. 大哉陶子 ; 2. 哭陶先生 ; 3. 我是中国人 ; 4. 國民與我 ; 5. 人民教师我爱你 ; 6. 我们的青春常在 ; 7. 千教万教教人求真, 千学万学学做真人 ; 8. 我要看看世界 ; 9. 今天 ; 10. 少年 ; 11. 我的小怀抱 ; 12. 看荷花舞 ; 13. 人的体操 ; 14. 问到底 ; 15. 立大志, 求大智, 做大事 ; 16. 团结御侮文体 ; 17. 民之所好三首 ; 18. 诗人节祝词 ; 19. 只道早还乡 ; 20. 好了歌 ; 21. 中国小孩子过新年 ; 22. 教师歌 ; 23. 忠心之歌 ; 24. 我爱有趣的谈天会 (未录完).陶城曲 ; 陶城演唱 ; 杜鳴心, 陳貽鑫, 巫漪丽鋼琴演奏.Possibly reproduced from other commercial recording or radio broadcast (Pending for review)"如蘭, 學鐄教授惠存: 陶城, 陳樹新贈, 1988.8.26"--Side A.Electronic reproduction from Rulan Chao Pian Audio Cassette Collection.Composer : 陶城.Singer : 陶城 ; Piano : 杜鳴心, 陳貽鑫, 巫漪丽.Sung in Chinese.Tao Cheng qu ; Tao Cheng yan chang ; Du Mingxin, Chen Yixin, Wu Yili gang qin yan zou."Rulan, Xuehuang jiao shou hui cun: Tao Cheng, Chen Shuxin zeng, 1988.8.26"--Side A.Composer, Tao Cheng.Singer: Tao Cheng ; Piano: Du Mingxin, Chen Yixin, Wu Yili.Detailed contents in vernacular field only
Assessment of climate change impacts on energy capacity planning in Ontario, Canada using high-resolution regional climate model
No full textClimate change may alter energy demand as well as energy supply, thus posing a threat to energy security. This study investigates the long-term energy security responses to climate change for Ontario from a planning perspective. A regional climate model (RCM) is employed to assess the climate-driven changes in energy sectors at a 25 km × 25 km resolution. Reliable projections of changes in climatic variables are provided to assess their impacts on cooling degree days, heating degree days, and energy availability. Quantified sensitivities of residential and commercial energy consumptions to degree days are incorporated with future projections to estimate energy demand changes. We then estimate the impact of climate change on the primary power sources, including nuclear power, hydropower, gas, wind energy, and solar energy from a capacity planning perspective. Results indicate that winter warms more rapidly than summer in Ontario. This leads to heating degree days decreasing 2 times faster than cooling degree days increasing. Changes in degree days result in an increase in summer electricity demand and a reduction in winter gas consumption. We also find that efficiencies of hydropower and wind energy could be reduced in different scales because of decreased resource availability. The efficiency of nuclear power is sensitive to the temperature rise, but relatively less reduced compared to other energy sources. Solar energy production can benefit from climate change for the perspective of a decrease in rainy and cloudy days. With the increased electricity demand and decreased availability of water and wind resources, more green energy capacities are expected to build to ensure the long-term energy security for Ontario
A Discussion on the Operational Mechanism of Private Equity in China
No full textThis article analyses and makes a research on the financing, investment, management and exit mechanism in the operational process of private equity(PE). In the end, the author puts forward four suggestions including updating financing structure, widening financing channels, establishing financing investment risk and technology evaluation systems, establishing the OTC market and consummating the incentive pay contract mechanism, improving the structure of the capital market, and rolling out supporting policies about PE by the government simultaneously.Computer Science, Artificial IntelligenceComputer Science, Interdisciplinary ApplicationsEICPCI-S(ISTP)
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