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Integrated Equipment Health Prognosis Considering Crack Initiation Time Uncertainty and Random Shock 被引量:2
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作者 Fu-Qiong Zhao Ming-Jiang Xie +1 位作者 Zhi-Gang Tian Yong Zeng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第6期1383-1395,共13页
With integrated equipment health prognosis, both physical models and condition monitoring data are utilized to achieve more accurate prediction of equipment remaining useful life (RUL). In this paper, an integrated ... With integrated equipment health prognosis, both physical models and condition monitoring data are utilized to achieve more accurate prediction of equipment remaining useful life (RUL). In this paper, an integrated prognostics method is proposed to account for two important factors which were not considered before, the uncertainty in crack initiation time (CIT) and the shock in the degradation. Prognostics tools are used for RUL pre- diction starting from the CIT. However, there is uncertainty in CIT due to the limited capability of existing fault detection tools, and such uncertainty has not been explic- itly considered in the literature for integrated prognosis. A shock causes a sudden damage increase and creates a jump in the degradation path, which shortens the total lifetime, and it has not been considered before in the integrated prognostics framework either. In the proposed integrated prognostics method, CIT is considered as an uncertain parameter, which is updated using condition monitoring data. To deal with the sudden damage increase and reduction of total lifetime, a virtual gradual degradation path with an earlier CIT is introduced in the proposed method. In this way, the effect of shock is captured through identifying an appropriate CIT. Examples of gear prog- nostics are given to demonstrate the effectiveness of the proposed method. 展开更多
关键词 Crack initiation time Shock Uncertaintyquantification Integrated prognostics Failure timeprediction Bayesian inference GEARS Fatigue crack
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Influence of Initial Value of Transient Time Step on Numerical Simulation of Blow Molding Balloon 被引量:3
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作者 Jinyao Bian Guobao Jin +1 位作者 Peng Qin Guanghui Dai 《American Journal of Computational Mathematics》 2020年第2期266-274,共9页
The correlation between the initial time value of transient iterative parameters and the blowing pressure in the numerical simulation process of blowing balloon is investigated by POLYFLOW. The results show that: 1) A... The correlation between the initial time value of transient iterative parameters and the blowing pressure in the numerical simulation process of blowing balloon is investigated by POLYFLOW. The results show that: 1) As the blow molding pressure increases, the boundary value of the iterative time step decreases rapidly at first and then slowly. At the end of the first step of iterative calculation for each boundary value, the balloon parison is in the mold core cavity. 2) If the initial time value of transient iterative parameters is smaller than the boundary value of the iterative time step, the balloon parison is still in the mold core cavity at the end of the first iteration. However, if the iterative calculation continues, the calculation process may be interrupted when the time step is smaller than the initial time value of the transient iterative parameters, which makes the blow molding simulation of balloon unable to continue. 3) It is suggested that the initial time value of transient iterative parameters is one order of magnitude smaller than the boundary value of the iterative time step to complete smoothly the simulation of blow molding balloon. 展开更多
关键词 Transient Iteration time-Step Initial time Value Balloon Forming Blow Molding Pressure
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Zircon and Apatite U-Pb Geochronology and Geochemistry of the Mafic Dykes in the Shuangxiwu Area, Northwestern Zhejiang Province: Constraints on the Initial Time of Neoproterozoic Rifting in South China
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作者 ZHANG Fengfeng WANG Xiaolei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期135-,共1页
Previous studies have shown that there are some ca.770–750 Ma mafic dykes at the western segment of the Neoproterozoic Jiangnan orogen(JO),and they represent post-orogenic magmatism due to orogenic collapse(Wang
关键词 Pb Northwestern Zhejiang Province Zircon and Apatite U-Pb Geochronology and Geochemistry of the Mafic Dykes in the Shuangxiwu Area Constraints on the Initial time of Neoproterozoic Rifting in South China
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How Kieffer Density Matrix Formalism Aids Different Initial Time Steps, Leading to Lorentz Violations, and Breakup of Primordial Black Holes for GW Generation
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作者 Andrew Beckwith 《Journal of High Energy Physics, Gravitation and Cosmology》 2021年第4期1315-1327,共13页
A result from Kieffer, as outlined at the beginning of the article identifies two different candidates for initial time steps, delta t. We assert that this difference in time steps may be related to a specific early u... A result from Kieffer, as outlined at the beginning of the article identifies two different candidates for initial time steps, delta t. We assert that this difference in time steps may be related to a specific early universe Lorentz Violation. The author asserts that the existence of early universe Lorentz violation in turn is assisting in a breakup of primordial black holes. And that also has a tie into Kieffer different time steps as outlined. And the wrap up is given in the final part of this document. 展开更多
关键词 Kieffer Density Matrix Initial time Lorentz Violations Black Holes
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Non Linear Electrodynamics Contributing to a Minimum Vacuum Energy (“Cosmological Constant”) Allowed in Early Universe Cosmology 被引量:3
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作者 Andrew Walcott Beckwith 《Journal of High Energy Physics, Gravitation and Cosmology》 2016年第1期25-32,共8页
This article poses the question of a minimum cosmological constant, i.e. vacuum energy at the start of the cosmological evolution from a near singularity. We pose this comparing formalism as given by Berry (1976) as t... This article poses the question of a minimum cosmological constant, i.e. vacuum energy at the start of the cosmological evolution from a near singularity. We pose this comparing formalism as given by Berry (1976) as to a small time length, and compare that in its entirety to compare this value given by Berry (1976) with a minimum time length at the start of cosmological space-time evolution. Using the methodology of Zeldovich (1972) as to a problem with electron-positron pair production we also propose another upper bound to the problem of minimum time length which may be accessible to experimental inquiry. This then makes the problem of minimum time length a way of specifying a magnetic field dependence of the cosmological constant, which has major implications to answering if quintessence, i.e. a changing cosmological vacuum energy, or a constant for the “cosmological constant” problem. Our answer is an initial value for the cosmological vacuum energy 10<sup>10</sup> - 10<sup>20</sup> times greater than today which suggests either Quintessence, or if still a constant, a much better value for this parameter than what is suggested by traditional field theory methods. In closing we review how our construct supports work done by Corda, as to early universe models and what the implications are, as to the choices we have made. 展开更多
关键词 Cosmological Vacuum Energy Energy Density Initial time Step
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Preparation for Retarding and High Early Strength Concrete
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作者 胡志坚 FENG Hao WANG Xuefei 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第4期787-789,共3页
The primary objective of this research was to determine optimum dosage of mixing concrete containing plasticizers and fly ash, consistent with desirable structural grade concrete properties. Factorial tests were also ... The primary objective of this research was to determine optimum dosage of mixing concrete containing plasticizers and fly ash, consistent with desirable structural grade concrete properties. Factorial tests were also conducted to investigate the four main factors: water-cementing materials ratio, water content, content of superplasticizers (SP) and fly ash content. It was found that the requirement for setting time played the dominant role in shrinkage and anti-cracking, and fly ash played a critical role in workability and reducing heat of hydration but showed insignificant effects on slump, early strength and initial setting time of concrete. 展开更多
关键词 high slump maintaining performance fly ash retarding and high early strength concrete initial setting time heat of hydration
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The Calculation of Collision Risk on Air-Routes Based on Variable Nominal Separation
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作者 曲玉玲 韩松臣 《Journal of Southwest Jiaotong University(English Edition)》 2010年第4期271-277,共7页
In this paper,a new method to calculate collision risk of air-routes,based on variable nominal separation,is proposed. The collision risk model of air-routes,based on the time variable and initial time interval variab... In this paper,a new method to calculate collision risk of air-routes,based on variable nominal separation,is proposed. The collision risk model of air-routes,based on the time variable and initial time interval variable,is given. Because the distance and the collision probability vary with time when the nominal relative speed between aircraft is not zero for a fixed initial time interval,the distance,the variable nominal separation,and the collision probability at any time can be expressed as functions of time and initial time interval. By the probabilistic theory,a model for calculating collision risk is acquired based on initial time interval distribution,flow rates,and the proportion of aircraft type. From the results of calculations,the collision risk can be characterized by the model when the nominal separation changes with time. As well the roles of parameters can be shown more readily. 展开更多
关键词 Collision risk model Initial time interval Variable nominal separation
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A Theory for the Initial Allocating of Real Time Tasks in Distributed Systems
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作者 鄢勇 金灿明 《Journal of Computer Science & Technology》 SCIE EI CSCD 1992年第2期185-188,共4页
Referring to a set of real time tasks with arriving time,executing time and deadline,this paperdiscusses the problem of polynomial time initial-allocating approximation algorithms in a distributedsystem and five new r... Referring to a set of real time tasks with arriving time,executing time and deadline,this paperdiscusses the problem of polynomial time initial-allocating approximation algorithms in a distributedsystem and five new results are gained which provide a theory for the designing of initial-allocating algorithmsof real time tasks. 展开更多
关键词 REAL time A Theory for the Initial Allocating of Real time Tasks in Distributed Systems OP
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Pre-treatment of pyridine wastewater by new cathodic–anodic-electrolysis packing 被引量:6
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作者 Yang Jin Qinyan Yue +4 位作者 Kunlun Yang Suqing Wu Shengjie Li Baoyu Gao Yuan Gao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第1期43-49,共7页
A novel cathodic–anodic-electrolysis packing(CAEP) used in the treatment of pyridine wastewater was researched, which mainly consisted of 4,4′-diamino-2,2′-disulfonic acid(DSD acid) industrial iron sludge. The ... A novel cathodic–anodic-electrolysis packing(CAEP) used in the treatment of pyridine wastewater was researched, which mainly consisted of 4,4′-diamino-2,2′-disulfonic acid(DSD acid) industrial iron sludge. The physical properties and morphology of the packing were studied. The CAEP was used in a column reactor during the pretreatment of pyridine wastewater. The influence of p H, hydraulic retention time(HRT), the air–liquid ratio(A/L)and the initial concentration of pyridine were investigated by measuring the removal of total organic carbon(TOC) and pyridine. The characterization results showed that the bulk density, grain density, water absorption percentage and specific surface area were 921 kg/m3,1086 kg/m3, 25% and 29.89 m^2/g, respectively; the removal of TOC and pyridine could reach50% and 58% at the optimal experimental conditions(p H = 3, HRT = 8 hr, A/L = 2). Notably,the surface of the packing was renewed constantly during the running of the filter, and the handling capacity was stable after running for three months. 展开更多
关键词 Cathodic-anodic-electrolysis packing Pyridine wastewater pH Hydraulic retention time Air-liquid ratio Initial concentration
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Examination of care processes and treatment optimization for head and neck cancer patients in a community setting"hub and hub"model
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作者 Harleen K.Sethi Elijah Walker +2 位作者 Travis Weinsheim Matthew J.Brennan Christopher E.Fundakowski 《World Journal of Otorhinolaryngology-Head and Neck Surgery》 2022年第2期152-157,共6页
Objective:To examine referral pattern,the timing of diagnostic/staging processes,and treatment initiation for new head and neck cancer patients in a community setting.Methods:Patients with a newly diagnosed previously... Objective:To examine referral pattern,the timing of diagnostic/staging processes,and treatment initiation for new head and neck cancer patients in a community setting.Methods:Patients with a newly diagnosed previously untreated diagnosis of head neck cancer managed at Asplundh Cancer Pavilion/Abington Memorial Hospital from October 2018 to March 2020.Source of referral and preceding workup were examined as well as intervals between initial head and neck consult and various timepoints of treatment initiation.Results:One hundred and five patients were included in the study.The primary referral sources were external general otolaryngology(56.3%).Oral surgery and dermatology obtained tissue biopsy approximately 80%of the time before referral.The average time from the ordering of initial staging positron emission tomography/computed tomography to finalized results was 14 days(range:10-25 days).Patients referred from dermatology and oral surgery were more likely to require single modality care,namely definitive surgical management.Time to treatment initiation average was 37 days(range:29-41 days).Patients with longer treatment times noted significantly higher times to both radiation and medical oncology consults(48.42 vs.18.13 days;P<0.001).Conclusions:No notable differences in treatment initiation times were identified based on referral source or extent of workup performed before head/neck surgery consult.It appears the largest opportunities for improvement in terms of reducing overall treatment length exist in the optimization of radiation initiation time. 展开更多
关键词 head and neck cancer package time referral source time to treatment initiation total treatment length
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