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Energy-Efficient Cluster in Wireless Sensor Network Using Life Time Delay Clustering Algorithms
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作者 V.Kumar N.Jayapandian P.Balasubramanie 《Computer Systems Science & Engineering》 SCIE EI 2022年第10期77-86,共10页
Through Wireless Sensor Networks(WSN)formation,industrial and academic communities have seen remarkable development in recent decades.One of the most common techniques to derive the best out of wireless sensor network... Through Wireless Sensor Networks(WSN)formation,industrial and academic communities have seen remarkable development in recent decades.One of the most common techniques to derive the best out of wireless sensor networks is to upgrade the operating group.The most important problem is the arrangement of optimal number of sensor nodes as clusters to discuss clustering method.In this method,new client nodes and dynamic methods are used to determine the optimal number of clusters and cluster heads which are to be better organized and proposed to classify each round.Parameters of effective energy use and the ability to decide the best method of attachments are included.The Problem coverage find change ability network route due to which traffic and delays keep the performance to be very high.A newer version of Gravity Analysis Algorithm(GAA)is used to solve this problem.This proposed new approach GAA is introduced to improve network lifetime,increase system energy efficiency and end delay performance.Simulation results show that modified GAA performance is better than other networks and it has more advanced Life Time Delay Clustering Algorithms-LTDCA protocols.The proposed method provides a set of data collection and increased throughput in wireless sensor networks. 展开更多
关键词 WSNS Gravity analysis algorithm-GAA life time delay clustering algorithms-LTDCA end to end delay energy efficient
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Phase Wise Supply Chain Model of EOQ with Normal Life Time for Queued Customers: A Computational Approach
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作者 Sant Sharan Mishra Prem Prakash Mishra 《American Journal of Operations Research》 2012年第3期296-307,共12页
In this paper, we mainly aim to compute the optimal inventory in the phase wise supply chain for queued customers in the interval of lower and upper bounds with particular life of the items. Important performance meas... In this paper, we mainly aim to compute the optimal inventory in the phase wise supply chain for queued customers in the interval of lower and upper bounds with particular life of the items. Important performance measures such as total optimal cost of the system and total expected delivery have also been computed by applying the dynamic programming and Drichlet theorem. Finally, numerical demonstration and sensitivity analysis have also been presented to gain the better perspective of the model. 展开更多
关键词 Supply Chain Correlation NORMAL life time Dynamic PROGRAMMING
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Preliminary assessment of excess life time cancer risk due to radon exposure in small scale Tanzanite mines in Tanzania
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作者 Shovi Furaeli Sawe 《Radiation Medicine and Protection》 2025年第5期297-300,共4页
Objective To assess the excess life time cancer risk(ELCR)due to radon exposure in small scale Tanzanite mines in Northern Tanzania.Methods Radon concentrations were measured using the solid state nuclear track detect... Objective To assess the excess life time cancer risk(ELCR)due to radon exposure in small scale Tanzanite mines in Northern Tanzania.Methods Radon concentrations were measured using the solid state nuclear track detectors(SSNTD)type CR-39.Three to six CR-39 detectors were placed in the underground working environment of each mine for a period of four months then removed and sent to Niton laboratory in Italy for processing and determination of radon concentrations.The obtained radon concentrations were used to estimate exposure to radon progenies,excess relative risk(ERR)of developing lung cancer,total lung cancer risk(TCR)and excess lifetime cancer risk(ELCR)using standard equations.Results The radon levels in 58%of the assessed mines were below the action level of 300 Bq/m^(3) recommended by the International Commission on Radiological Protection(ICRP)while 42%were above this limit.The estimated mean exposure to radon and its progenies ranged from 0.08 to 1.18 WLM corresponding to annual effective doses of 0.8 and 11.8 mSv/year,for the minimum and maximum values respectively.These values are below the annual limit of 20mSv for occupational exposure recommended by the ICRP.The ELCR estimated using simplified linear model from BEIR IV report ranged from 0 to 0.03%which is below the U.S.EPA action level of 1.3%due to radon exposure of 148 Bq/m^(3).Conclusion The ELCR due to exposure to radon in the assessed mines is negligible.However,follow up studies are recommended as the depths of the mines increase especially in the mines were radon concentrations exceeded the action level. 展开更多
关键词 RADON Excess life time cancer risk Tanzanite miners Tanzania
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A Method in Mixed Frequency-time domain for Fatigue Life Estimation of Steel Girders of Cable-stayed Bridges Due to Buffeting 被引量:1
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作者 顾明 陈礼忠 项海帆 《应用基础与工程科学学报》 EI CSCD 1998年第4期70-79,共10页
发展了斜拉桥钢主梁抖振疲劳寿命的混合时-频域方法.在本方法中,首先建立了桥面处的风速风向概率密度函数,导出的应力谱因其包括背景分量而不再是窄带谱.据应力谱模拟出了疲劳应力的时间历程,并用雨流计数法统计了其幅值特性.基... 发展了斜拉桥钢主梁抖振疲劳寿命的混合时-频域方法.在本方法中,首先建立了桥面处的风速风向概率密度函数,导出的应力谱因其包括背景分量而不再是窄带谱.据应力谱模拟出了疲劳应力的时间历程,并用雨流计数法统计了其幅值特性.基于修正的Miner定理导出了考虑风速风向作用的桥梁主梁抖振疲劳寿命的估算公式,并用此分析了杨浦大桥钢主梁的抖振疲劳寿命.结果表明,风向对抖振疲劳寿命有很大影响;杨浦大桥主梁的疲劳寿命远大于设计寿命. 展开更多
关键词 斜拉桥 钢主梁 抖振 疲劳寿命 混合时-频域
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A Multi-Hop Dynamic Path-Selection (MHDP) Algorithm for the Augmented Lifetime of Wireless Sensor Networks
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作者 Perumal Kalyanasundaram Thangavel Gnanasekaran 《Circuits and Systems》 2016年第10期3343-3353,共12页
In Wireless Sensor Networks (WSN), the lifetime of sensors is the crucial issue. Numerous schemes are proposed to augment the life time of sensors based on the wide range of parameters. In majority of the cases, the c... In Wireless Sensor Networks (WSN), the lifetime of sensors is the crucial issue. Numerous schemes are proposed to augment the life time of sensors based on the wide range of parameters. In majority of the cases, the center of attraction will be the nodes’ lifetime enhancement and routing. In the scenario of cluster based WSN, multi-hop mode of communication reduces the communication cast by increasing average delay and also increases the routing overhead. In this proposed scheme, two ideas are introduced to overcome the delay and routing overhead. To achieve the higher degree in the lifetime of the nodes, the residual energy (remaining energy) of the nodes for multi-hop node choice is taken into consideration first. Then the modification in the routing protocol is evolved (Multi-Hop Dynamic Path-Selection Algorithm—MHDP). A dynamic path updating is initiated in frequent interval based on nodes residual energy to avoid the data loss due to path extrication and also to avoid the early dying of nodes due to elevation of data forwarding. The proposed method improves network’s lifetime significantly. The diminution in the average delay and increment in the lifetime of network are also accomplished. The MHDP offers 50% delay lesser than clustering. The average residual energy is 20% higher than clustering and 10% higher than multi-hop clustering. The proposed method improves network lifetime by 40% than clustering and 30% than multi-hop clustering which is considerably much better than the preceding methods. 展开更多
关键词 Wireless Sensor Networks (WSN) Cluster Based WSN Multi-Hop Mode Residual Energy Average Delay Multi-Hop Dynamic Path-Selection Algorithm life time
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Sensitivity of the half-life time of water exchange in coastal waters 被引量:1
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作者 Zhenhua CHEN Fangli QIAO +1 位作者 Gang WANG Changshui XIA 《Science China Earth Sciences》 SCIE EI CAS CSCD 2019年第4期643-656,共14页
A three-dimensional model was established to investigate water exchange in coastal waters, and applied to Qinzhou Bay(QZB) in the South China Sea. Given the strong tidal current in QZB, a half-life time was calculated... A three-dimensional model was established to investigate water exchange in coastal waters, and applied to Qinzhou Bay(QZB) in the South China Sea. Given the strong tidal current in QZB, a half-life time was calculated for water exchange by filtering the tidal signal from the concentrations of a conservative substance. In a control run driven by the tide, without external inputs and an open boundary concentration of zero, it was estimated that the average half-life time in QZB was 54.8 d. Numerical experiments showed that wind accounted for an 11.9% reduction in the half-life time to 48.3 d. When rivers were included in the model, the half-life time decreased by 74.6% to 13.9 d. Sensitivity experiments showed that the half-life time for water exchange was greatly affected by the concentration of the conservative substance which was used at the open boundary. In response to 10,20, 30, and 40% increases in the boundary concentration, the half-life time increased to 91.5, 168.3, 186.2, and 229.1 d,respectively. Results also suggested that for coastal bays with large intertidal areas such as QZB, consideration of the wet and dry processes produced more accurate simulations of the hydrodynamics and the half-life times. Simulations, which did not incorporate wet and dry processes, were more than likely to have overestimated or underestimated the half-life times for water exchange. 展开更多
关键词 Sensitivity CONVECTION-DIFFUSION model Water exchange HALF-life time Qinzhou BAY SOUTH China SEA
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A Novel Multiple Dependent State Sampling Plan Based on Time Truncated Life Tests Using Mean Lifetime 被引量:1
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作者 Pramote Charongrattanasakul Wimonmas Bamrungsetthapong Poom Kumam 《Computers, Materials & Continua》 SCIE EI 2022年第12期4611-4626,共16页
The design of a new adaptive version of the multiple dependent state(AMDS)sampling plan is presented based on the time truncated life test under the Weibull distribution.We achieved the proposed sampling plan by apply... The design of a new adaptive version of the multiple dependent state(AMDS)sampling plan is presented based on the time truncated life test under the Weibull distribution.We achieved the proposed sampling plan by applying the concept of the double sampling plan and existing multiple dependent state sampling plans.A warning sign for acceptance number was proposed to increase the probability of current lot acceptance.The optimal plan parameters were determined simultaneously with nonlinear optimization problems under the producer’s risk and consumer’s risk.A simulation study was presented to support the proposed sampling plan.A comparison between the proposed and existing sampling plans,namely multiple dependent state(MDS)sampling plans and a modified multiple dependent state(MMDS)sampling plan,was considered under the average sampling number and operating characteristic curve values.In addition,the use of two real datasets demonstrated the practicality and usefulness of the proposed sampling plan.The results indicated that the proposed plan is more flexible and efficient in terms of the average sample number compared to the existing MDS and MMDS sampling plans. 展开更多
关键词 Adaptive version of multiple dependent state sampling plan time truncated life test quality level weibull distribution mean lifetime
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Physical activity, screen time and pediatric health-related quality of life in the Mississippi Delta 被引量:3
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作者 Tamara T. Perry Page C. Moore +2 位作者 Karen M. Redwine James M. Robbins Judith L. Weber 《Open Journal of Preventive Medicine》 2012年第1期105-111,共7页
Background: The association of physical activity (PA) and screen time (ST) on health-related quality of life (HRQOL) among predominantly low-income children in the Mississippi Delta region has not been previously desc... Background: The association of physical activity (PA) and screen time (ST) on health-related quality of life (HRQOL) among predominantly low-income children in the Mississippi Delta region has not been previously described. Methods: We performed a cross-sectional survey to assess health risks from a representative sample of the population ≥3 years old in the Delta Region of Arkansas, Louisiana, and Mississippi. Linear models were utilized to examine Pediatric Quality of Life Inventory (PedsQL) scores based on reported PA and ST. Results: Median age of the 371 participants was 9.8 years, 57% were African American, and 26% had annual household income ≤$14,999. Overall, 262 (75%) were categorized as physically active and 48% reported >2 hours ST per day. Children reporting exercising 5 - 7 days per week had significantly better PedsQL total score (84.3 vs 80.8;p 2 hours per day) did not significantly impact HRQOL. Conclusions: Findings suggest that PA among children living in the Mississippi Delta was related to higher HRQOL;however, the positive effects of PA on HRQOL may be less for minority and low-income children. 展开更多
关键词 PHYSICAL ACTIVITY SCREEN time Quality of life PEDIATRICS
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Modified DS np Chart Using Generalized Multiple Dependent State Sampling under Time Truncated Life Test
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作者 Wimonmas Bamrungsetthapong Pramote Charongrattanasakul 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2471-2495,共25页
This study presents the design of a modified attributed control chart based on a double sampling(DS)np chart applied in combination with generalized multiple dependent state(GMDS)sampling to monitor the mean life of t... This study presents the design of a modified attributed control chart based on a double sampling(DS)np chart applied in combination with generalized multiple dependent state(GMDS)sampling to monitor the mean life of the product based on the time truncated life test employing theWeibull distribution.The control chart developed supports the examination of the mean lifespan variation for a particular product in the process of manufacturing.Three control limit levels are used:the warning control limit,inner control limit,and outer control limit.Together,they enhance the capability for variation detection.A genetic algorithm can be used for optimization during the in-control process,whereby the optimal parameters can be established for the proposed control chart.The control chart performance is assessed using the average run length,while the influence of the model parameters upon the control chart solution is assessed via sensitivity analysis based on an orthogonal experimental design withmultiple linear regression.A comparative study was conducted based on the out-of-control average run length,in which the developed control chart offered greater sensitivity in the detection of process shifts while making use of smaller samples on average than is the case for existing control charts.Finally,to exhibit the utility of the developed control chart,this paper presents its application using simulated data with parameters drawn from the real set of data. 展开更多
关键词 Modified DS np chart generalizedmultiple dependent state sampling time truncated life test Weibull distribution average run length average sample size
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Extending the Network Lifetime Using Optimized Energy Efficient Cross Layer Module (OEEXLM) in Wireless Sensor Networks
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作者 T. V. PADMAVATHY 《Wireless Sensor Network》 2009年第1期27-35,共9页
In wireless sensor network, the primary design is to save the energy consumption as much as possible while achieving the given task. Most of recent researches works have only focused on the individual layer issues and... In wireless sensor network, the primary design is to save the energy consumption as much as possible while achieving the given task. Most of recent researches works have only focused on the individual layer issues and ignore the importance of inter working between different layers in a sensor network. In this paper, we use a cross-layer approach to propose an energy-efficient and extending the life time of the sensor network. This protocol which uses routing in the network layer, and the data scheduling in MAC layer. The main ob-jective of this paper is to provide a possible and flexible approach to solve the conflicts between the require-ments of large scale, long life-time, and multi-purpose wireless sensor networks. This OEEXLM module gives better performance compared to all other existing protocols. The performance of OEEXLM module compared with S-MAC and directed diffusion protocol. 展开更多
关键词 ROUTING MEDIUM Access Control life time of the Network Energy Efficiency OEEXLM MODULE WIRELESS Sensor Networks
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基于Time-series与Arrhenius模型的夹心曲奇保质期预测及对比分析
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作者 袁辉 张昌龙 +4 位作者 殷志聪 曾焰珺 陈旭 朱杰 刘宇佳 《安徽农业科学》 2025年第22期163-166,170,共5页
对比分析了Time-series模型与Arrhenius模型在夹心曲奇保质期预测中的应用效果。通过加速破坏性试验测定夹心曲奇的主要理化性质,包括水分含量、丙二醛含量以及硬度,构建并验证了2种预测模型。结果表明:Time-series模型在预测精度上更... 对比分析了Time-series模型与Arrhenius模型在夹心曲奇保质期预测中的应用效果。通过加速破坏性试验测定夹心曲奇的主要理化性质,包括水分含量、丙二醛含量以及硬度,构建并验证了2种预测模型。结果表明:Time-series模型在预测精度上更接近实际情况,适用于捕捉品质变化的动态趋势;而Arrhenius模型基于化学反应速率,适用于温度敏感型品质衰变过程。2种模型对于产品货架期预测各有优缺点,可根据具体需求灵活选择或结合使用。 展开更多
关键词 夹心曲奇 理化性质 货架期 time-series模型 Arrhenius模型
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A Time Dependent Inventory Model for Exponential Demand Rate with Constant Production Where Shelf-Life of the Product Is Finite
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作者 Mohammad Ekramol Islam Shirajul Islam Ukil Md. Sharif Uddin 《Open Journal of Applied Sciences》 2016年第1期38-48,共11页
In this paper a time dependent inventory model is developed on the basis of constant production rate and market demands which are exponentially decreasing. It advances in quest of total average optimum cost considerin... In this paper a time dependent inventory model is developed on the basis of constant production rate and market demands which are exponentially decreasing. It advances in quest of total average optimum cost considering those products which have finite shelf-life. The model also considers the small amount of decay. Without having any sort of backlogs, production starts. Reaching at the desired level of inventories, it stops production. After that due to demands along with the deterioration of the items it initiates its depletion and after certain periods the inventory gets zero. The decay of the products is level dependent. The objective of this paper is to find out the optimum inventory cost and optimum time cycle. The model has also been justified with proving the convex property and by giving a numerical example. 展开更多
关键词 Production Inventory Shelf-life time Dependent Demand Class Production Rate
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Remaining useful life estimation for deteriorating systems with time-varying operational conditions and condition-specific failure zones 被引量:6
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作者 Li Qi Gao Zhanbao +1 位作者 Tang Diyin Li Baoan 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2016年第3期662-674,共13页
Dynamic time-varying operational conditions pose great challenge to the estimation of system remaining useful life (RUL) for the deteriorating systems. This paper presents a method based on probabilistic and stochas... Dynamic time-varying operational conditions pose great challenge to the estimation of system remaining useful life (RUL) for the deteriorating systems. This paper presents a method based on probabilistic and stochastic approaches to estimate system RUL for periodically moni- tored degradation processes with dynamic time-varying operational conditions and condition- specific failure zones. The method assumes that the degradation rate is influenced by specific oper- ational condition and moreover, the transition between different operational conditions plays the most important role in affecting the degradation process. These operational conditioqs are assumed to evolve as a discrete-time Markov chain (DTMC). The failure thresholds are also determined by specific operational conditions and described as different failure zones. The 2008 PHM Conference Challenge Data is utilized to illustrate our method, which contains mass sensory signals related to the degradation process of a commercial turbofan engine. The RUE estimation method using the sensor measurements of a single sensor was first developed, and then multiple vital sensors were selected through a particular optimization procedure in order to increase the prediction accuracy. The effectiveness and advantages of the proposed method are presented in a comparison with exist- ing methods for the same dataset. 展开更多
关键词 Degradation Discrete-time Markov chainOperational conditions Remaining useful life esti-mation Sensor selection
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基于数值模拟的丁字湾水交换能力研究
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作者 曹雪峰 邢传玺 +2 位作者 于洁雯 马玉贤 史文奇 《海洋环境科学》 北大核心 2026年第1期116-124,共9页
本文利用FVCOM海洋模式建立了丁字湾海域的三维高分辨率水动力数值模型,通过DYERELEASE模块释放保守溶解态示踪物的方式,以半交换时间为指标研究了丁字湾的水交换过程。结果表明,涨潮时涨潮流通过湾口航道进入湾内部,向岸边辐散;落潮时... 本文利用FVCOM海洋模式建立了丁字湾海域的三维高分辨率水动力数值模型,通过DYERELEASE模块释放保守溶解态示踪物的方式,以半交换时间为指标研究了丁字湾的水交换过程。结果表明,涨潮时涨潮流通过湾口航道进入湾内部,向岸边辐散;落潮时湾内部海水流向航道辐聚,通过航道流出湾口。航道处流速大,两侧岸边流速小。涨潮时流向指向西北,落潮时流向指向东南。涨急时,最大垂线平均流速大于1.2 m/s,落急时,最大垂线平均流速大于1.0 m/s,最大涨潮流速大于最大落潮流速。丁字湾的平均半交换时间为9.6~11.2d。大潮期相比小潮期的海湾水交换能力更强。距离湾口越近,半交换时间越短。半交换时间的空间分布:湾口区域在10 d以内,中部区域为10~35 d,湾底区域基本在35 d以上。 展开更多
关键词 丁字湾 数值模拟 DYE-RELEASE模块 半交换时间 水交换能力
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生命时间结构:教师发展理论研究的一种新视野
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作者 曹永国 《教师发展研究》 2026年第1期83-89,共7页
教师发展理论研究主要有三种路向:一是教师发展的阶段化研究路向,它将教师发展看成普遍存在的阶段性进程,是一种对教师发展的程式化设想;二是教师发展的生命历程研究路向,它将教师发展理解为其生命中的重大事件、社会变迁、文化结构等... 教师发展理论研究主要有三种路向:一是教师发展的阶段化研究路向,它将教师发展看成普遍存在的阶段性进程,是一种对教师发展的程式化设想;二是教师发展的生命历程研究路向,它将教师发展理解为其生命中的重大事件、社会变迁、文化结构等对其形塑过程;三是教师发展的本体论研究路向,它将教师发展视为教师自身的精神成长及其对教育意义的寻求过程。这三种研究路向或失之于静态化描绘,或失之于单一视角勾画。生命时间结构则提供了一个更为完整的研究路向,其连接了社会规划与个体能动,能够剖析时间结构变化中社会结构的运转与教师行为安排、生命意义筹划之关系,揭示现代时间结构中教师的生命处境和时间应对,是教师发展理论研究的一种新视野。 展开更多
关键词 生命时间结构 教师发展理论 互动论 生命历程 加速社会
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基于轴承退化状态估计与1DCNN-BiGRU-SA的轴承寿命预测方法
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作者 吴胜利 刘依航 邢文婷 《制造技术与机床》 北大核心 2026年第3期208-219,共12页
针对滚动轴承运行工况恶劣、有效特征难以提取,且轴承寿命预测存在初始预测时间(first prediction time,FPT)难确定、单一模型精度低的问题,提出一种联合轴承退化状态估计与一维卷积神经网络-双向门控循环单元-自注意力机制(1DCNN-BiGRU... 针对滚动轴承运行工况恶劣、有效特征难以提取,且轴承寿命预测存在初始预测时间(first prediction time,FPT)难确定、单一模型精度低的问题,提出一种联合轴承退化状态估计与一维卷积神经网络-双向门控循环单元-自注意力机制(1DCNN-BiGRU-SA)的轴承寿命预测方法。首先,利用经过三角拓扑聚合优化算法(triangulation topology aggregation optimizer,TTAO)优化的变分模态分解(variational mode decomposition,VMD)并结合皮尔逊相关系数对信号进行降噪重构;其次,对重构信号的时域退化特征进行提取,通过构建退化特征融合机制实现轴承FPT的高精度确定,进而更精准地表征轴承全生命周期内的退化状态演化规律;最后,构建嵌入自注意力机制(self-attention,SA)的1DCNN-BiGRU模型,将多时域特征构成的时间序列作为输入,进行轴承寿命预测。利用XJTU-SY滚动轴承加速寿命试验数据集验证文章所提方法的有效性。研究结果表明,所提出的寿命预测方法具有更高的预测精度。 展开更多
关键词 轴承寿命预测 初始预测时间 三角拓扑聚合优化 特征融合 1DCNN-BiGRU-SA
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Acceptance sampling plan of accelerated life testing for lognormal distribution under time-censoring
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作者 Li Xiaoyang Gao Pengfei Sun Fuqiang 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2015年第3期814-821,共8页
Abstract Lognormal distribution is commonly used in engineering. It is also a life distribution of important research values. For long-life products follow this distribution, it is necessary to apply accelerated testi... Abstract Lognormal distribution is commonly used in engineering. It is also a life distribution of important research values. For long-life products follow this distribution, it is necessary to apply accelerated testing techniques to product demonstration. This paper describes the development of accelerated life testing sampling plans (ALSPs) for lognormal distribution under time-censoring conditions. ALSPs take both producer and consumer risks into account, and they can be designed to work whether acceleration factor (AF) is known or unknown. When AF is known, lift testing is assumed to be conducted under accelerated conditions with time-censoring. The producer and con- sumer risks are satisfied, and the size of test sample and the size of acceptance number arc opti- mized. Then sensitivity analyses are conducted. When AF is unknown, two or more predetermined levels of accelerated stress are used. The sample sizes and sample proportion allo- cated to each stress level are optimized. The acceptance constant that satisfies producer and consumer risk is obtdned by minimizing the generalized asymptotic variance of the test statistics. Finally, the properties of the two ALSPs (one for known-AF conditions and one for unknown AF conditions) are investigated to show that the proposed method is corrcct and usablc through numerical examples. 展开更多
关键词 Accelerated life testing Acceleration factor Acceptance sampling Lognormal distribution Producer and consumerrisks time-censoring
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路面水泥混凝土碳汇环境效益的时滞分析与动态核算
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作者 杨兆宁 张端 +4 位作者 孙博学 高峰 李小青 聂祚仁 崔素萍 《硅酸盐通报》 北大核心 2026年第1期30-39,共10页
水泥材料生命周期内具有显著的碳汇潜力,但目前仍缺乏具体的碳汇环境效益核算方法。本文构建了基于动态指标的路面水泥混凝土碳汇时滞分析模型,系统评估了路面水泥混凝土全生命周期内的碳汇时间分布及其环境效益,并提出了用于修正静态... 水泥材料生命周期内具有显著的碳汇潜力,但目前仍缺乏具体的碳汇环境效益核算方法。本文构建了基于动态指标的路面水泥混凝土碳汇时滞分析模型,系统评估了路面水泥混凝土全生命周期内的碳汇时间分布及其环境效益,并提出了用于修正静态碳核算结果的时间因子α与减排偏移量β。结果表明,100年内水泥材料碳汇总量占水泥生产排放量的22.18%。相比动态方法,采用传统方法高估了53.8%的碳汇效益。此外,时滞分析得到,100年时限内α为0.65,β为38 614.79 kgCO_(2)e,水泥碳汇的环境收益可通过α、β进行快速修正。研究结果可为水泥材料碳汇精准计量提供方法依据,对长寿命基础设施系统的碳管理策略制定具有重要意义。 展开更多
关键词 路面水泥混凝土 碳汇 时滞效应 动态生命周期评价 时间因子 长寿命系统
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基于TimeGAN-GRU的镍镉蓄电池RUL预测 被引量:3
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作者 于天剑 杨雨萌 +3 位作者 刘海涛 伍珣 代毅 向超群 《铁道科学与工程学报》 EI CAS CSCD 北大核心 2024年第12期4899-4909,共11页
镍镉蓄电池广泛用作我国高速列车的辅助电源,其性能可靠性直接关系到高速列车行车安全。蓄电池剩余使用寿命是指其性能从当前状态退化至失效的时长或可充放电次数,是表征电池性能的重要指标。目前,高速列车镉镍蓄电池寿命模型受限于小... 镍镉蓄电池广泛用作我国高速列车的辅助电源,其性能可靠性直接关系到高速列车行车安全。蓄电池剩余使用寿命是指其性能从当前状态退化至失效的时长或可充放电次数,是表征电池性能的重要指标。目前,高速列车镉镍蓄电池寿命模型受限于小样本数据而存在精确性和泛化性差的问题。因此,从全新镍镉蓄电池寿命实验数据中提取电池退化特征,采取时序对抗生成网络对其进行增强从而提高数据规模和质量,并依据分类分数、预测分数、主成分分析、t-分布随机邻域嵌入分析方法对增强效果进行评价。其次,使用增强数据建立门控循环单元方法的高速列车镍镉蓄电池剩余使用寿命预测模型。最终,通过四级修镉镍蓄电池循环寿命实验数据进行不同预测起点验证,并对比时序对抗生成网络-门控循环单元融合模型、门控循环单元模型、长短期记忆模型的预测效果。研究结果表明:对于时序对抗生成网络数据增强效果,真实数据与模拟数据分布相近,平均绝对误差小,模拟数据质量较高;经四级修镍镉蓄电池数据验证的时序对抗生成网络-门控循环单元融合模型相比门控循环单元模型、长短期记忆模型,具有更高的泛化性能和预测精度。针对高速列车镍镉蓄电池在小样本数据限制下建立了具有较好精确性和泛化性的剩余寿命预测模型,为保障高速列车行车安全和优化制定检修方案提供了参考。 展开更多
关键词 蓄电池 镍镉蓄电池 剩余寿命预测 时序对抗生成网络 门控循环单元网络
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三维集成电路盲孔金属化镀液寿命关键影响因素研究
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作者 王澳轩 才旺扎西 王为 《电镀与精饰》 北大核心 2026年第3期12-21,共10页
针对三维集成电路封孔镀铜技术中添加剂寿命有限的问题,为满足提高镀液寿命与镀层质量的工艺优化需求,采用循环喷射实验系统,研究了阴阳极间距、阴极电流密度、阳极材料、电镀温度及放置时间等因素对镀液寿命与镀层性能的影响。结果表明... 针对三维集成电路封孔镀铜技术中添加剂寿命有限的问题,为满足提高镀液寿命与镀层质量的工艺优化需求,采用循环喷射实验系统,研究了阴阳极间距、阴极电流密度、阳极材料、电镀温度及放置时间等因素对镀液寿命与镀层性能的影响。结果表明:在循环喷射条件下,采用极间距30 cm、阴极电流密度70 mA·cm^(-2)、选用惰性Pt阳极及较低温度工艺,可显著提高镀液寿命与镀层质量,其中Pt阳极镀液寿命最高达1.24 Ah/L,且添加剂间的相互作用会加速镀液失效,需严格控制放置时间与配置条件。 展开更多
关键词 三维集成电路 镀液寿命 封孔率 放置时间
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