检索结果-南通市图书馆

Remaining useful life prognostics for aeroengine based on superstatistics and information fusion

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2014年第5期27卷 1086-1096页

作者： liu junqiang Zhang Malan Zuo Hongfu Xie Jiwei College of Civil Aviation Nanjing University of Aeronautics and Astronautics

Remaining useful life（RUL） prognostics is a fundamental premise to perform conditionbased maintenance（CBM） for a system subject to performance degradation. Over the past decades,research has been conducted in RUL prognostics for aeroengine. However, most of the prognostics technologies and methods simply base on single parameter, making it hard to demonstrate the specific characteristics of its degradation. To solve such problems, this paper proposes a novel approach to predict RUL by means of superstatistics and information fusion. The performance degradation evolution of the engine is modeled by fusing multiple monitoring parameters, which manifest non-stationary characteristics while degrading. With the obtained degradation curve,prognostics model can be established by state-space method, and then RUL can be estimated when the time-varying parameters of the model are predicted and updated through Kalman filtering algorithm. By this method, the non-stationary degradation of each parameter is represented, and multiple monitoring parameters are incorporated, both contributing to the final prognostics. A case study shows that this approach enables satisfactory prediction evolution and achieves a markedly better prognosis of RUL.

关键词： Degradation Information fusion Kalman filtering Performance Prognostics Remaining useful life Superstatistics

Evaluation of aileron actuator reliability with censored data

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2015年第4期28卷 1087-1103页

作者： Li Huaiyuan Zuo Hongfu liu Ruochen liu junqiang Jing Cai College of Civil Aviation Nanjing University of Aeronautics and Astronautics

For the purpose of enhancing reliability of aileron of Airbus new-generation A350 XWB,an evaluation of aileron reliability on the basis of maintenance data is presented in this *** maintenance data contains large number of censoring samples, information uncertainty of which makes it hard to evaluate reliability of aileron *** that true lifetime of censoring sample has identical distribution with complete sample, if censoring sample is transformed into complete sample, conversion frequency of censoring sample can be estimated according to frequency of complete *** the one hand, standard life table estimation and product limit method are improved on the basis of such conversion frequency, enabling accurate estimation of various censoring *** the other hand, by taking such frequency as one of the weight factors and integrating variance of order statistics under standard distribution, weighted least square estimation is formed for accurately estimating various censoring *** amounts of experiments and simulations show that reliabilities of improved life table and improved product limit method are closer to the true value and more conservative; moreover, weighted least square estimate（WLSE）, with conversion frequency of censoring sample and variances of order statistics as the weights, can still estimate accurately with high proportion of censored data in *** in this paper has good effect and can accurately estimate the reliability of aileron actuator even with small sample and high censoring *** research has certain significance in theory and engineering practice.

关键词： Ailerons Civil aimraft Non-parametric data distri-butions Order statistics Parameter estimation Reliability estimation Weight

Optimizing combination of aircraft maintenance tasks by adaptive genetic algorithm based on cluster search

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2016年第1期27卷 140-156页

作者： Huaiyuan Li Hongfu Zuo Kun Liang Juan Xu Jing Cai junqiang liu College of Civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 211106China Huaiyin Institute of Technology Huai'an 223003China

It is significant to combine multiple tasks into an optimal work package in decision-making of aircraft maintenance to reduce cost,so a cost rate model of combinatorial maintenance is an urgent ***,the optimal combination under various constraints not only involves numerical calculations but also is an NP-hard combinatorial *** solve the problem,an adaptive genetic algorithm based on cluster search,which is divided into two phases,is put *** the first phase,according to the density,all individuals can be homogeneously scattered over the whole solution space through crossover and mutation and better individuals are collected as candidate cluster *** the second phase,the search is confined to the neighbourhood of some selected possible solutions to accurately solve with cluster radius decreasing slowly,meanwhile all clusters continuously move to better regions until all the peaks in the question space is *** algorithm can efficiently solve the combination *** the optimization on decision-making of aircraft maintenance by the algorithm for an example,maintenance which combines multiple parts or tasks can significantly enhance economic benefit when the halt cost is rather high.

关键词： cluster search genetic algorithm combinatorial optimization multi-part maintenance grouping maintenance.

National Happiness at a Time of Economic Growth: A Tracking Study Based on CGSS Data

在线全文

学校读者我要写书评

暂无评论

Social Sciences in China 2013年第4期34卷 20-37页

作者： liu junqiang Xiong Moulin Su Yanga School of Insurance Southwestern University of Finance and Economics Law School Southwestern University of Finance and Economics School of Social Sciences University of California Irvine

In order to respond to the ongoing debate over the Chinese people＇s sense of happiness and to assess the effects of macro-economic and policy changes on the life of ordinary people over the past decade, this study employs data from the Chinese General Social Survey （CGSS） to analyze the development and trends in the happiness （or subjective well-being） of the Chinese people over this period. Based on 5 time points and 44,166 samples, the study finds that the Chinese people＇s sense of happiness has risen steadily over the past decade, and that groups with different political affiliations, household registration, age, income, marital status and ethnicity have all witnessed, to varying degrees, a growing sense of happiness. Economic growth may be the crucial driving force here; if the economy contracts, people＇s sense of happiness may also fall. To maintain the coordinated development of the economy and society, more numerous and more detailed follow-up research on happiness needs to be conducted.

关键词： sense of happiness inequity economic growth

肾血管平滑肌脂肪瘤误诊为肾细胞癌12例临床分析

在线全文

学校读者我要写书评

暂无评论

临床误诊误治 2024年第15期37卷 5-9页

作者：刘俊强王秋莲曹娟丁俊中国人民解放军联勤保障部队第九〇四医院泌尿外科江苏无锡214000

目的探讨肾血管平滑肌脂肪瘤(RAML)和肾细胞癌的临床特点、误诊原因及防范措施。方法回顾性分析2018年7月至2023年5月收治的术前诊断为RCC而术后病理证实为RAML 12例的临床资料。结果12例病变均位于单侧肾,左侧5例,右侧7例。2例因外伤... 详细信息

目的探讨肾血管平滑肌脂肪瘤(RAML)和肾细胞癌的临床特点、误诊原因及防范措施。方法回顾性分析2018年7月至2023年5月收治的术前诊断为RCC而术后病理证实为RAML 12例的临床资料。结果12例病变均位于单侧肾,左侧5例,右侧7例。2例因外伤后住院检查发现,10例因体检发现。术前均误诊为肾癌。误诊时间为5~8 d。入院后均行外科手术治疗,其中开放手术1例,腹腔镜手术11例;行肾部分切除术9例,肾根治性切除术3例。术后病理均为RAML。术后随访1年,均无复发。结论RAML极易误诊为肾细胞癌,特别是肿瘤较小且乏脂型RAML更容易误诊。对于术前性质难以确定的肾肿瘤,尤其是当肿瘤最大径<4 cm时,可以考虑采用肾部分切除术,以避免过度治疗。

关键词：肾血管平滑肌脂肪瘤误诊肾肿瘤腹腔镜检查诊断鉴别肾部分切除术病理学

难治与非难治特发性全面性癫痫患者磁共振脑灰质体积差异研究

在线全文

学校读者我要写书评

暂无评论

生命科学仪器 2024年第2期22卷 14-16页

作者：杨建新刘军强黎义何嘉昱上海市第一人民医院酒泉医院(酒泉市人民医院) 甘肃酒泉735000

目的探讨分析难治与非难治性特发性全面性癫痫患者磁共振检查中脑灰质体积的差异。方法选择2021年1月至2023年12月医院收治的105例癫痫患者,均接受常规的序列检查及高分辨率3D-T1WI结构像,对比两种检查方式显示脑灰质体积的差异情况。... 详细信息

目的探讨分析难治与非难治性特发性全面性癫痫患者磁共振检查中脑灰质体积的差异。方法选择2021年1月至2023年12月医院收治的105例癫痫患者,均接受常规的序列检查及高分辨率3D-T1WI结构像,对比两种检查方式显示脑灰质体积的差异情况。结果在左颞上回和右侧额下回,难治性癫痫患者显示出较小的脑灰质体积;在双侧小脑后叶,脑灰质体积则相对较大。难治性与非难治性癫痫患者的脑灰质体积对比,差异有统计学意义(P<0.05)。结论难治与非难治性特发性全面性癫痫患者的脑结构存在一定的差异,脑灰质损伤显著,这可能是难治性特发性全面性癫痫的关键病理特征,应给予关注及进一步的研究。

关键词：难治性特发性全面性癫痫脑灰质体积

A Personalized Microbe Biodiversity Dataspace Information System

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2007年第5期12卷 932-936页

作者： liu junqiang PENG Zhiyong LI Xuhui ZHENG Congyi FANG Chengxiang State Key Laboratory of Software Engineering Wuhan University Wuhan 430072 Hubei China School of Life Sciences Wuhan University Wuhan 430072 Hubei China

It can not provide dynamic view mechanism in previous dataspace information system. In this paper, the dynamic extendable view mechanism provided by object deputy model is proposed for personalized dataspace information system which can provide rich semantics and enough flexibility. The flexible inheritance avoids a lot of data redundancy. The cross class query mechanism allows users to find more related data based on complex relationships. The personalized dataspace service provides less storage space consumption and shorter query response time. The experiment result shows that our approach is more feasible and efficient than the traditional one.

关键词： object deputy model biodiversity cross class query personalized dataspace

The Construction of Practice of Logistics Management Based on School-Enterprise Cooperation

在线全文

学校读者我要写书评

暂无评论

International English Education Research 2015年第12期 15-16页

作者： liu junqiang The Engineering Technical College of Chengdu University ofTeelmology Leshan Sichuan 614007

Logistics management is a very practical professional. How to cultivate applied Talents for the logistics industry needs to is a question to logistics management *** paper talk about the practice in terms of personnel training mode, curriculum system, practice and practice base construction and faculty building according to the actual situation of their own practice of logistics experience.

关键词： School-Enterprise Cooperation Logistics Management Major Construction

Comprehensive analyses of the proteome and ubiquitome revealed mechanism of high temperature accelerating petal abscission in tree peony

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Horticultural Plant Journal 2024年第1期10卷 205-222页

作者： Chunying liu Ziqi liu Yanchao Yuan Yuxi Zhang Yifu Fang junqiang Chen Shupeng Gai Key Laboratory of Plant Biotechnology in Shandong Province College of Life SciencesQingdao Agricultural UniversityQingdaoShandong 266109China Shandong Academy of Forestry JinanShandong 250014China

Tree peony(Paeonia suffruticosa Andrews)is a well-known ornamental plant with high economic value,but the short fluorescence is a key obstacle to its ornamental value and industry *** temperature accelerates flower senescence and abscission,but the associated mechanisms are poorly *** this study,the tandem mass tag(TMT)proteome and label-free quantitative ubiquitome from tree peony cut flowers treated with 20℃for 0 h(RT0),20℃or 28℃for 60 h(RT60 or HT60)were examined based on morphological observation,***,6970 proteins and 1545 lysine ubiquitinated(Kub)sites in 844 proteins were *** residues(such as glutamate and aspartate)neighboring the Kub sites were in preference,and 36.01%of the Kub sites were located on the protein *** differentially expressed proteins(DEPs)and Kub-DEPs in HT60 vs RT60 were mainly enriched in ribosomal protein,protein biosynthesis,secondary metabolites biosynthesis,flavonoid metabolism,carbohydrate catabolism,and auxin biosynthesis and signaling revealed by GO and KEGG analysis,accompanying the increase of endogenous abscisic acid(ABA)accumulation and decrease of endogenous indoleacetic acid(IAA)***,the expression patterns of six enzymes(SAMS,ACO,YUC,CHS,ANS and PFK)putatively with Kub modifications were analyzed by proteome and real-time quantitative *** cell-free degradation assays showed PsSAMS and PsACO proteins could be degraded via the 26 S proteasome system in tree peony ***,a working model was proposed for the acceleration of flower senescence and abscission by high *** summary,all results contributed to understanding the mechanism of flower senescence induced by high temperature and prolonging fluorescence in tree peony.

关键词： Tree peony Proteome Ubiquitome High temperature Flower senescence