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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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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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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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基于TimeGAN-GRU的镍镉蓄电池RUL预测
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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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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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Sensitivity of the half-life time of water exchange in coastal waters
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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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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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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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前瞻性护理在预防机械通气患者ICU获得性衰弱中的应用
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作者 张金萍 陶钰 《空军航空医学》 2025年第1期84-87,共4页
目的 探究前瞻性护理在预防机械通气患者发生ICU获得性衰弱(intensive care unit-acquired weakness,ICU-AW)中的作用。方法 选取2022年8月—2023年12月于南京医科大学附属南京医院呼吸与危重症医学科收治的67例机械通气患者。按照随机... 目的 探究前瞻性护理在预防机械通气患者发生ICU获得性衰弱(intensive care unit-acquired weakness,ICU-AW)中的作用。方法 选取2022年8月—2023年12月于南京医科大学附属南京医院呼吸与危重症医学科收治的67例机械通气患者。按照随机数字表法分为对照组(n=33)和研究组(n=34),对照组接受常规护理,研究组在常规护理的基础上接受前瞻性护理。采用医学研究委员会肌力评分(Medical Research Council Muscle Strength,MRC)比较2组肌力,采用日常生活活动量表(Activity of Daily Living,ADL)及巴氏指数(Barthel Index,BI)量表评估2组日常生活能力。采用焦虑自评量表(Self-Rating Anxiety Scale,SAS)及抑郁自评量表(Self-Rating Depression Scale,SDS)评估患者的焦虑、抑郁状态,统计2组患者的机械通气时间及住院时间。结果 护理前2组患者的MRC评分差异无统计学意义(P>0.05),研究组患者护理前后的MRC得分差值高于对照组,差异具有统计学意义(t=4.082,P<0.001);护理前2组患者的ADL得分差异无统计学意义(P>0.05),研究组患者护理前后ADL评分差值高于对照组,差异具有统计学意义(t=8.906,P<0.001);护理前2组患者的BI评分无统计学意义(P>0.05),研究组患者护理前后BI评分差值高于对照组,差异具有统计学意义(t=2.386,P=0.036);护理前2组患者SAS评分及SDS评分差异均无统计学意义(P>0.05),研究组患者护理前后SAS评分及SDS评分差值均高于对照组,差异具有统计学意义(t=5.064、5.238,P均<0.001);研究组患者机械通气时间低于对照组(t=11.063,P<0.001),研究组患者平均住院时间低于对照组(t=10.169,P<0.001)。结论 前瞻性护理可以有效预防ICU-AW,提高患者自理能力,同时缓解患者焦虑、抑郁心理状态,减少其机械通气时间及住院时间,值得在临床中进一步研究与推广。 展开更多
关键词 ICU获得性衰弱 前瞻性护理 生活质量 机械通气时间
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考虑退化相关性的电解电容实时剩余寿命预测
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作者 李小波 汪翔 王睿轶 《燕山大学学报》 北大核心 2025年第2期146-154,共9页
目前对于电解电容的退化特性研究多是基于单个退化特征,难以精确预测电容的剩余寿命。针对这一现状,本文提出考虑退化特征相关性的二元线性Wiener过程退化模型进行电容剩余寿命实时预测。首先利用Box-Cox变换对电容退化数据进行线性化处... 目前对于电解电容的退化特性研究多是基于单个退化特征,难以精确预测电容的剩余寿命。针对这一现状,本文提出考虑退化特征相关性的二元线性Wiener过程退化模型进行电容剩余寿命实时预测。首先利用Box-Cox变换对电容退化数据进行线性化处理,然后将极大似然估计结合自助抽样法得到的模型参数经Bayesian理论进行实时更新,并利用蒙特卡洛算法求解电容的剩余寿命分布,最后通过NASA试验数据进行了验证,并与基于Copula函数处理相关性的算法进行了对比。结果表明,本文算法的预测精度较只考虑电容容值、只考虑等效串联电阻的一维Wiener过程模型分别提高约0.7298%,0.0913%,比基于Copula理论的算法预测精度提高了约0.0832%,可为制订电解电容的视情维修策略提供依据。 展开更多
关键词 电解电容 实时剩余寿命预测 二元维纳过程 Box-Cox变换 Bayesian理论
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航空管路无扩口管接头寿命预测方法研究
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作者 唐杰 孙茹 《重庆理工大学学报(自然科学)》 北大核心 2025年第2期154-162,共9页
为提升对航空管路无扩口接头退化预测的精度和效率,提出一种基于时间卷积网络TCN(temporal convolutional network)和Transformer的特征融合模型(TT模型)。通过TCN模块提取增强后的特征信息,利用融合卷积Transformer模块进一步处理,在... 为提升对航空管路无扩口接头退化预测的精度和效率,提出一种基于时间卷积网络TCN(temporal convolutional network)和Transformer的特征融合模型(TT模型)。通过TCN模块提取增强后的特征信息,利用融合卷积Transformer模块进一步处理,在编码器末尾添加池化层以降低过拟合风险,最终通过全连接层得到预测结果。为验证TT模型的有效性,针对航空管路无扩口接头密封性能使用单向流固耦合方法完成泄漏率模型的建立并获取数据,利用数据集进行试验。结果表明,TT模型与CNN、RNN、LSTM和Transformer模型相比,预测误差分别减少3.53%、6.08%、1.63%和1.75%,有效提高了航空管路无扩口接头退化预测的准确性。 展开更多
关键词 时间序列预测 密封特性 TCN TRANSFORMER 寿命预测
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环氧胶粘剂的低温贮存性能研究
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作者 安东澜 李永亮 +3 位作者 邸安乐 马丽 贺华 黄涛 《中国胶粘剂》 2025年第3期46-50,共5页
环氧树脂与固化剂混合后普遍开始固化反应,因此存在适用期短、贮存困难等问题。有必要建立一种快速可靠的低温贮存性能评估方法,以便对所有环氧固化体系进行快速验证,使之能在结果可靠的前提下降低试验成本。本研究以两种不同的环氧固... 环氧树脂与固化剂混合后普遍开始固化反应,因此存在适用期短、贮存困难等问题。有必要建立一种快速可靠的低温贮存性能评估方法,以便对所有环氧固化体系进行快速验证,使之能在结果可靠的前提下降低试验成本。本研究以两种不同的环氧固化体系为研究对象,在不同温度下对黏度进行表征,按Arrhenius方程拟合,推导出凝胶时间和贮存温度之间的关系,最后根据贮存要求设计了合理贮存温度。研究结果表明:(1)黏度和凝胶时间测试结果表明:在−80℃的贮存温度下,间苯二甲胺固化体系和咪唑固化体系到达贮存期时性能和新配胶相比差异不大,均优于原−20℃贮存胶到达贮存期时的性能。(2)剪切强度测试结果表明:两种固化体系下−80℃贮存胶在到达贮存期时剪切强度满足要求,高于−20℃贮存胶,且和新配胶性能基本一致。(3)在间苯二甲胺固化体系下,−20℃贮存胶的剪切强度略低于指标要求,存在使用风险;在咪唑固化体系下,−20℃贮存胶的剪切强度满足指标要求。 展开更多
关键词 环氧胶粘剂 低温 贮存期 凝胶时间
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基于生产时滞CIR模型的寿险公司利差风险管理
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作者 黄甫喆 李秀芳 陈孝伟 《中央财经大学学报》 北大核心 2025年第1期40-58,共19页
寿险公司使用的经典利率模型主要依赖当前横截面数据,难以充分反映债券风险溢价的预测信息,可能引发资产负债错配和利差损等运营风险。为了提高利率预测准确性及更准确地评估和管理利差风险,本文采用基于生产时滞的CIR模型对利率风险进... 寿险公司使用的经典利率模型主要依赖当前横截面数据,难以充分反映债券风险溢价的预测信息,可能引发资产负债错配和利差损等运营风险。为了提高利率预测准确性及更准确地评估和管理利差风险,本文采用基于生产时滞的CIR模型对利率风险进行建模,深入研究其对寿险公司资产负债评估的影响,同时提出利差风险防范与化解策略。本文首先利用中国国债市场数据,实证检验了远期利率的历史路径在预测零息债券超额收益方面的增益效果,从而证明了引入基于生产时滞的非马尔可夫CIR模型的必要性。进一步地,本文构建了考虑时滞的寿险公司资产负债评估模型,提高了预测的准确度。数值分析结果显示,通过加强资产负债的联动管理、有效降低负债成本、合理安排管理期限等策略,均能有效降低寿险公司的利差风险。最后,本文建议在风险建模、资产负债管理等方面要充分考虑时滞信息,提升寿险公司利差风险管理水平。 展开更多
关键词 资产负债管理 利差风险 寿险公司 时滞 非马尔可夫
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教育的时间感:对教育生活的另一种审视
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作者 车越彤 陈振中 《教育理论与实践》 北大核心 2025年第1期3-10,共8页
社会运行和变化的加速化引发了教育理念和教育行动的演变,教育开始走向一种外在尺度的“时间驱动”。当下教育生活的时间悖论引发了现代教育的速度崇拜、技术理性的价值遮蔽和教育关系的疏离及异化。时间是一条跨越宏观、中观、微观的... 社会运行和变化的加速化引发了教育理念和教育行动的演变,教育开始走向一种外在尺度的“时间驱动”。当下教育生活的时间悖论引发了现代教育的速度崇拜、技术理性的价值遮蔽和教育关系的疏离及异化。时间是一条跨越宏观、中观、微观的“可视化”线索,教育的时间感是指教育行动者在教育活动中能够遵循人发展的生命时间,让自己的教育活动突破时间的工具性框架,并通过真诚有效的对话让自己的视域与学生的视域不断进行交流融合。重塑教育的时间感,需要以生命时间作为教育生活的基本准则,尊重自由时间与闲暇时间;走出“知识竞赛”的线性时间立场,围绕核心素养设计课程教学;联结个人时间体验与集体记忆,以教育机智塑造共同体凝聚力;洞悉教育现象,感悟教育生活。 展开更多
关键词 时间感 教育时间 生命时间 自由时间 闲睱时间 线性时间 个人时间
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高校青年教师学术生活的时间病理与竞速文化——一项网络民族志研究
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作者 张黎 周霖 《大学教育科学》 北大核心 2025年第1期76-86,共11页
以豆瓣小组“高校青椒的自留地”为研究田野,对高校青年教师学术生活的时间病理及其牵涉的文化现象进行网络民族志考察。研究发现,高校青年教师学术生活的时间病理表现为加速化的时间消费、功绩主体的时间异化、时间碎片的弥散游弋,这... 以豆瓣小组“高校青椒的自留地”为研究田野,对高校青年教师学术生活的时间病理及其牵涉的文化现象进行网络民族志考察。研究发现,高校青年教师学术生活的时间病理表现为加速化的时间消费、功绩主体的时间异化、时间碎片的弥散游弋,这形塑了高校青年教师学术生活的“漂浮式”图景:高校青年教师的过度繁忙阻滞学术身份的意义建构,其学术生活被时间的道德化规范操控,原子化时间引发高校青年教师学术生活的时间性断裂。进而言之,高校青年教师学术生活的加速主要原因在于基于行政逻辑的评价体系以及基于绩效权威的时间嵌入机制。在外部驱动力、离心力、自我内驱力的综合作用下,栖居于“竞速轨道”的高校青年教师群体建构出一种“竞速文化”,这不仅仅是行政逻辑的影响结果,同时也是青年教师个体的时间能动性的影响结果。理性审视与正确运用这一时间辩证法,是高校青年教师抵及理想的学术生活节奏的关键所在。 展开更多
关键词 高校青年教师 学术生活 时间病理 竞速文化 网络民族志
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不同运输时间对冬枣货架期品质及微观结构的影响
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作者 景赛 候德华 +5 位作者 粘姝炜 王可翰 史昱雯 姬世春 袁亮 寇莉萍 《中国果菜》 2025年第2期1-8,共8页
冬枣皮薄肉脆,在运输中易受到损伤,影响其品质与商品价值。为探究运输距离对冬枣货架期的影响,实验模拟了不同公路运输距离,利用振动试验台处理冬枣,研究其在常温下的品质变化。结果表明,振动会加速冬枣腐烂、失重和软化,使果皮转红并... 冬枣皮薄肉脆,在运输中易受到损伤,影响其品质与商品价值。为探究运输距离对冬枣货架期的影响,实验模拟了不同公路运输距离,利用振动试验台处理冬枣,研究其在常温下的品质变化。结果表明,振动会加速冬枣腐烂、失重和软化,使果皮转红并失去光泽;还能促使果实生理活动加速,导致可溶性固形物和可滴定酸分解,抗坏血酸含量下降,可溶性蛋白积累受到抑制;能加快原果胶降解,使果肉细胞结构受损。振动20 min对冬枣品质的影响最小,随着振动时间的增加,品质劣变加速。因此冬枣后期应采取减振包装等措施,避免长距离运输。 展开更多
关键词 冬枣 模拟公路运输 振动时间 货架期品质
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基于VMD与TCN-SENet-BiLSTM网络的轴承寿命预测
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作者 张发振 张清华 +3 位作者 秦宾宾 朱冠华 邓兴超 刘迪洋 《机床与液压》 北大核心 2025年第1期15-23,共9页
传统的滚动轴承剩余寿命预测方法存在缺乏明确学习机制和模型预测精度较低等问题,无法有效提取不同时序特征之间的差异所包含的重要退化信息特征。为了进一步提高预测模型精度,提出一种融合SENet注意力机制的时间卷积网络(TCN)和双向长... 传统的滚动轴承剩余寿命预测方法存在缺乏明确学习机制和模型预测精度较低等问题,无法有效提取不同时序特征之间的差异所包含的重要退化信息特征。为了进一步提高预测模型精度,提出一种融合SENet注意力机制的时间卷积网络(TCN)和双向长短时网络(BiLSTM)的剩余使用寿命预测模型。利用变分模态分解将原始信号分解为多个特征分量,使用皮尔逊相关系数对特征进行优化,得到重构后的信号作为模型输入。通过TCN-SENet-BiLSTM模型有效学习重构特征信号与轴承退化之间的复杂关系。最后,运用后处理技术输出平滑后的预测结果,并在IEEE PHM 2012数据集上进行验证。实验结果表明:相较于TCN、TCN-SENet及TCN-BiLSTM 3种模型,基于VMD与TCN-SENet-BiLSTM方法的预测结果最优,平均绝对误差(MAE)和均方根误差(RMSE)均最低。其中,工况1的3号轴承RUL预测的MAE值相比其他3种网络分别下降了36.49%、50.00%和48.35%;工况2的6号轴承RUL预测的RMSE分别下降了24.11%、33.07%和61.54%,且预测的Score值最高为0.866。实验结果验证了基于VMD与TCN-SENet-BiLSTM模型在轴承剩余使用寿命预测中的有效性。 展开更多
关键词 剩余使用寿命 轴承 时间卷积网络 双向长短时记忆网络 变分模态分解
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