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Synergetic optimization operation method for distribution network based on SOP and PV 被引量:1
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作者 Lei Chen Ning Zhang +4 位作者 Xingfang Yang Wei Pei Zhenxing Zhao Yinan Zhu Hao Xiao 《Global Energy Interconnection》 EI CSCD 2024年第2期130-141,共12页
The integration of distributed generation brings in new challenges for the operation of distribution networks,including out-of-limit voltage and power flow control.Soft open points(SOP)are new power electronic devices... The integration of distributed generation brings in new challenges for the operation of distribution networks,including out-of-limit voltage and power flow control.Soft open points(SOP)are new power electronic devices that can flexibly control active and reactive power flows.With the exception of active power output,photovoltaic(PV)devices can provide reactive power compensation through an inverter.Thus,a synergetic optimization operation method for SOP and PV in a distribution network is proposed.A synergetic optimization model was developed.The voltage deviation,network loss,and ratio of photovoltaic abandonment were selected as the objective functions.The PV model was improved by considering the three reactive power output modes of the PV inverter.Both the load fluctuation and loss of the SOP were considered.Three multi-objective optimization algorithms were used,and a compromise optimal solution was calculated.Case studies were conducted using an IEEE 33-node system.The simulation results indicated that the SOP and PVs complemented each other in terms of active power transmission and reactive power compensation.Synergetic optimization improves power control capability and flexibility,providing better power quality and PV consumption rate. 展开更多
关键词 Synergetic optimization Soft open point(sop) Photovoltaic(PV) Distribution network
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Vehicle-oriented ridesharing package delivery in blockchain system
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作者 Xuefei Zhang Junjie Liu +4 位作者 Yijing Li Qimei Cui Xiaofeng Tao Ren Ping Liu Wenzheng Li 《Digital Communications and Networks》 SCIE CSCD 2024年第4期1014-1023,共10页
Package delivery via ridesharing provides appealing benefits of lower delivery cost and efficient vehicle usage.Most existing ridesharing systems operate the matching of ridesharing in a centralized manner,which may r... Package delivery via ridesharing provides appealing benefits of lower delivery cost and efficient vehicle usage.Most existing ridesharing systems operate the matching of ridesharing in a centralized manner,which may result in the single point of failure once the controller breaks down or is under attack.To tackle such problems,our goal in this paper is to develop a blockchain-based package delivery ridesharing system,where decentralization is adopted to remove intermediaries and direct transactions between the providers and the requestors are allowed.To complete the matching process under decentralized structure,an Event-Triggered Distributed Deep Reinforcement Learning(ETDDRL)algorithm is proposed to generate/update the real-time ridesharing orders for the new coming ridesharing requests from a local view.Simulation results reveal the vast potential of the ETDDRL matching algorithm under the blockchain framework for the promotion of the ridesharing profits.Finally,we develop an application for Android-based terminals to verify the ETDDRL matching algorithm. 展开更多
关键词 Blockchain Dynamic matching Ridesharing package delivery
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Multi-Component Resource Recycling from Waste Light-Emitting Diode Under Hydrothermal Condition:Plastic Package Degradation,Speciation of Nano-TiO_(2),and Environmental Impact Assessment
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作者 Yongliang Zhang Lu Zhan Zhenming Xu 《Engineering》 SCIE EI CAS CSCD 2024年第8期253-261,共9页
Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to reduce.As a new type of e-waste,LED is a double-edged sword,as it contains not only precious an... Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to reduce.As a new type of e-waste,LED is a double-edged sword,as it contains not only precious and rare metals but also organic packaging materials.In previous studies,LED recycling focused on recovering precious and strategic metals while ignoring harmful substances such as organic packaging materials.Unlike crushing and other traditional methods,hydrothermal treatment can provide an environment-friendly process for decomposing packaging materials.This work developed a closed reaction vessel,where the degradation rate of plastic polyphthalamide(PPA)was close to 100%,with nano-TiO_(2)encapsulated in plastic PPA being efficiently recovered,while metals contained in LED were also recycled efficiently.Besides,the role of water in plastic PPA degradation that has been overlooked in current studies was explored and speculated in detail in this work.Environmental impact assessment revealed that the proposed recycling route for waste LED could significantly reduce the overall environmental impact compared to the currently published processes.Especially the developed method could reduce more than half the impact of global warming.Furthermore,this research provides a theoretical basis and a promising method for recycling other plastic-packaged e-waste devices,such as integrated circuits. 展开更多
关键词 Waste LED Hydrothermal treatment RECYCLING Plastic PPA degradation Packaging materials
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DSN-BR-Based Online Inspection Method and Application for Surface Defects of Pharmaceutical Products in Aluminum-Plastic Blister Packages
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作者 Mingzhou Liu Yu Gong +2 位作者 Xiaoqiao Wang Conghu Liu Jing Hu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第4期194-214,共21页
Ensuring high product quality is of paramount importance in pharmaceutical drug manufacturing,as it is subject to rigorous regulatory practices.This study presents a research focused on the development of an on-line d... Ensuring high product quality is of paramount importance in pharmaceutical drug manufacturing,as it is subject to rigorous regulatory practices.This study presents a research focused on the development of an on-line detection method and system for identifying surface defects in pharmaceutical products packaged in aluminum-plastic blisters.Firstly,the aluminum-plastic blister packages exhibit multi-scale features and inter-class indistinction.To address this,the deep semantic network with boundary refinement(DSN-BR)model is proposed,which leverages semantic segmentation domain knowledge,to accurately segment the defects in pixel level.Additionally,a specialized image acquisition module that minimizes the impact of ambient light is established,ensuring high-quality image capture.Finally,the image acquisition module,image detection module,and data management module are designed to construct a comprehensive online surface defect detection system.To validate the effectiveness of our approach,we employ a real dataset for instance verification on the implemented system.The experimental results substantiate the outstanding performance of the DSN-BR,achieving the mean intersection over union(MIoU)of 90.5%.Furthermore,the proposed system achieves an inference speed of up to 14.12 f/s,while attaining an F1-Score of 98.25%.These results demonstrate that the system meets the actual needs of the enterprise and provides theoretical and methodological support for intelligent inspection of product surface quality.By standardizing the control process of pharmaceutical manufacturing and improving the management capability of the manufacturing process,our approach holds significant market application prospects. 展开更多
关键词 Surface defect detection system Deep learning Semantic segmentation Aluminum-plastic blister packages identification
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Intervention package on stress management: Improving comprehensive well-being among nurses
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作者 Manda Jaywant PHUKE Tukaram ZAGADE +3 位作者 Vaishali Rajsinh MOHITE Jyoti SALUNKHE Swati INGALE Samir Kasam CHOUDHARI 《Journal of Integrative Nursing》 2024年第4期201-208,共8页
Objective:The main objective of this study is to investigate the effectiveness of the stress management intervention package in improving stress-related burnout.Materials and Methods:An experimental study was done on ... Objective:The main objective of this study is to investigate the effectiveness of the stress management intervention package in improving stress-related burnout.Materials and Methods:An experimental study was done on 300 nurses selected by a nonprobability convenience sampling technique and a quasi-experimental one-group pre-and posttest research design was utilized.Modified expanded nurses stress scale and self-structured three-point Likert scale on the challenges that nurses may face following stressful life events utilized to collect information.The nurses signed up for six interactive sessions on various stress-coping methods by utilizing a variety of teaching strategies such as lecture cum discussion,video slides,group work,and direct interaction with the experts to explore stress-related issues.Results:Continuous stress affects both the body and the mind,causing psychosomatic symptoms.Data found that 2%to 10%of nurses frequently suffered with physical symptoms such as exhaustion,backache,acidity,headache,shoulder stiffness,and insomnia.Following the intervention,the number of nurses who had these symptoms frequently and sometimes decreased.Previously,10%of nurses experienced emotional symptoms frequently;however,after intervention,this figure was reduced to<2%.The greatest proportion of nurses(18%)reported frequently worrying,while 1.3%expressed frequent worrying after intervention.Maximum(5%)of nurses had a tendency to eat too little or too much;this has been reduced to 0.3%after the intervention.The intervention package on stress management significantly improved nurses’Conclusion:An intervention package for stress management was helpful in lowering physical,emotional,psychological,and behavioral stress-related symptoms among nurses. 展开更多
关键词 COMPREHENSIVE intervention package nurses STRESS WELL-BEING
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Signal and Power Integrity Challenges for High Density System-on-Package
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作者 Nathan Totorica Feng Li 《Semiconductor Science and Information Devices》 2022年第2期1-9,共9页
As the increasing desire for more compact,portable devices outpaces Moore’s law,innovation in packaging and system design has played a significant role in the continued miniaturization of electronic systems.Integrati... As the increasing desire for more compact,portable devices outpaces Moore’s law,innovation in packaging and system design has played a significant role in the continued miniaturization of electronic systems.Integrating more active and passive components into the package itself,as the case for system-on-package(SoP),has shown very promising results in overall size reduction and increased performance of electronic systems.With this ability to shrink electrical systems comes the many challenges of sustaining,let alone improving,reliability and performance.The fundamental signal,power,and thermal integrity issues are discussed in detail,along with published techniques from around the industry to mitigate these issues in SoP applications. 展开更多
关键词 system on package(sop) system in package(SiP) system on chip(SoC) Through silicon via(TSV) Signal integrity Power integrity Thermal integrity
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34 GHz Bandpass Filter for Low-temperature Co-fired Ceramic System-in-Package Application
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作者 XU Ziqiang SHI Yu +2 位作者 ZENG Zhiyi LIAO Jiaxuan LI Tian 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第2期309-315,共7页
Modern electronic circuit requires compact,multifunctional technology in communication systems.However,it is very difficult due to the limitations in passive component miniaturization and the complication of fabricati... Modern electronic circuit requires compact,multifunctional technology in communication systems.However,it is very difficult due to the limitations in passive component miniaturization and the complication of fabrication process.The bandpass filter is one of the most important passive components in millimeter(mm)-wave communication system,attracting significant interest in three-dimension(3D) miniaturized design,which is few reported.In this paper,a bandpass filter structure using low-temperature co-fired ceramic(LTCC) technology,which is fully integrated in a system-in package(SIP) communication module,is presented for miniaturized and high reliable mm-wave application.The bandpass filter with 3D end-coupled microstrip resonators is implemented in order to achieve a high performance bandwidth characteristic.Specifically,all of the resonators are embedded into different ceramic layers to decrease the insertion loss and enhance the out-of-band rejection performance by optimizing the coupling coefficient and the coupling strength.A fence structure,which is formed by metal-filled via array with the gap less than quarter wavelength,is placed around the embedded bandpass filter to avoid electromagnetic(EM) interference problem in multilayer structure.This structural model is validated through actual LTCC process.The bandpass filter is successfully manufactured by modifying the co-fireablity characteristics,adjusting the sintering profile,releasing the interfacial stress,and reducing the shrinkage mismatch with different materials.Measured results show good performance and agree well with the high frequency EM full wave simulation.The influence of layer thickness and dielectric constant on the frequency response in fabricated process is analyzed,where thicker ceramic sheets let the filter response shift to higher frequency.Moreover,measured S-parameters denote the center frequency is also strongly influenced by the variation of ceramic material's dielectric constants.By analyzing the relationship between the characteristics of the ceramic tape and the center frequency of the filter,both theoretical and experimental data are accumulated for broadening application filed.With the coupling resonators embedded into the ceramic layers,the bandpass filter exhibits advantages of small size and high reliability compared to conventional planar filter structure,which makes the bandpass filter suitable for SIP communicational application. 展开更多
关键词 three-dimensional(3D) structure bandpass filter low-temperature co-fired ceramic(LTCC) system in package(SIP)
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LTCC SoP RF Transceiver Module for 60 GHz Wireless Gigabit Ethernet Communication System
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作者 Azzemi Ariffin Suhandi Bujang +3 位作者 Mohd Fadzil Amiruddin Salizul Jaafarl Noor Aisyah Mohd. Akib Young Chul Lee 《通讯和计算机(中英文版)》 2010年第6期63-70,共8页
关键词 低温共烧陶瓷 射频收发模块 千兆以太网技术 无线通信系统 GHZ 高清晰度电视 无线电频率 无线网络系统
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Integrated 3D Fan-out Package of RF Microsystem and Antenna for 5G Communications
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作者 XIA Chenhui WANG Gang +1 位作者 WANG Bo MING Xuefei 《ZTE Communications》 2020年第3期33-41,共9页
A 3D fan-out packaging method for the integration of 5G communication RF microsystem and antenna is studied.First of all,through the double-sided wiring technology on the glass wafer,the fabrication of 5G antenna arra... A 3D fan-out packaging method for the integration of 5G communication RF microsystem and antenna is studied.First of all,through the double-sided wiring technology on the glass wafer,the fabrication of 5G antenna array is realized.Then the low power devices such as through silicon via(TSV)transfer chips,filters and antenna tuners are flip-welded on the glass wafer,and the glass wafer is reformed into a wafer permanently bonded with glass and resin by the injection molding process with resin material.Finally,the thinning resin surface leaks out of the TSV transfer chip,the rewiring is carried out on the resin surface,and then the power amplifier,low-noise amplifier,power management and other devices are flip-welded on the resin wafer surface.A ball grid array(BGA)is implanted to form the final package.The loss of the RF transmission line is measured by using the RF millimeter wave probe table.The results show that the RF transmission loss from the chip end to the antenna end in the fan-out package is very small,and it is only 0.26 dB/mm when working in 60 GHz.A slot coupling antenna is designed on the glass wafer.The antenna can operate at 60 GHz and the maximum gain can reach 6 dB within the working bandwidth.This demonstration successfully provides a feasible solution for the 3D fan-out integration of RF microsystem and antenna in 5G communications. 展开更多
关键词 AIP fan‐out package RF microsystem 3D integration 5G communications
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Effect of Freshness Protection Package on Storage and Preservation of Chinese Cabbage 被引量:1
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作者 王希卓 孙洁 +2 位作者 张凯 杨琴 孙海亭 《Agricultural Science & Technology》 CAS 2016年第12期2742-2745,2808,共5页
The effect of freshness protection package on Chinese cabbage placed in the self-made shelf in ventilated storage was investigated, and the physiological-qual-ity indexes change were determined during the storage peri... The effect of freshness protection package on Chinese cabbage placed in the self-made shelf in ventilated storage was investigated, and the physiological-qual-ity indexes change were determined during the storage period. The results showed that the losses of weight and vitamin C were significantly reduced. The accumula-tion of crude fiber was effectively inhibited. But protein content was maintained at a low level and the rotting more serious of Chinese cabbage at the end of the stor-age packaged with the fresh keeping bags. 展开更多
关键词 Freshness protection package Chinese cabbage PRESERVATIon Ventilat-ed storage
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Application of wavelet package filtering in the de-noising of fiber optic gyroscopes 被引量:2
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作者 王其 徐晓苏 《Journal of Southeast University(English Edition)》 EI CAS 2008年第1期46-49,共4页
To reduce the drift error existing in the output signal of fiber optic gyroscopes (FOG), a mathematical model of the FOG output signal is set up; the error characteristics of the FOG output signal are analyzed, and ... To reduce the drift error existing in the output signal of fiber optic gyroscopes (FOG), a mathematical model of the FOG output signal is set up; the error characteristics of the FOG output signal are analyzed, and semi-soft threshold filtering is chosen based on the comparison of hard threshold and soft threshold filtering. The semi-soft threshold wavelet package filtering method is applied in the filtering of the FOG output signal. Experiments of the stationary and dynamic FOG output signals filtered with the wavelet package analysis are carried out in a lab environment, respectively. Experiments done with the real-time measured FOG signal show that the method of semi-soft threshold wavelet package filtering reduces the mean square error from 5 (°)/h to 1 (°)/h, so it is effective in eliminating the white noises and the fractal noises existing in the FOG. The novel method proposed here is proved valid in reducing the FOG drift error, satisfying the technical demands of high precision and realtime processing. 展开更多
关键词 wavelet package analysis signal processing fiber optic gyro threshold filtering
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Integrated power electronics module based on chip scale packaged power devices 被引量:2
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作者 王建冈 阮新波 《Journal of Southeast University(English Edition)》 EI CAS 2009年第3期367-371,共5页
High performance can be obtained for the integrated power electronics module(IPEM) by using a three-dimensional packaging structure instead of a planar structure. A three- dimensional packaged half bridge-IPEM (HB-... High performance can be obtained for the integrated power electronics module(IPEM) by using a three-dimensional packaging structure instead of a planar structure. A three- dimensional packaged half bridge-IPEM (HB-IPEM), consisting of two chip scale packaged MOSFETs and the corresponding gate driver and protection circuits, is fabricated at the laboratory. The reliability of the IPEM is controlled from the shape design of solder joints and the control of assembly process parameters. The parasitic parameters are extracted using Agilent 4395A impedance analyzer for building the parasitic parameter model of the HB- IPEM. A 12 V/3 A output synchronous rectifier Buck converter using the HB-IPEM is built to test the electrical performance of the HB-IPEM. Low voltage spikes on two MOSFETs illustrate that the three-dimensional package of the HB-IPEM can decrease parasitic inductance. Temperature distribution simulation results of the HB-IPEM using FLOTHERM are given. Heat dissipation of the solder joints makes the peak junction temperature of the chip drop obviously. The package realizes three-dimensional heat dissipation and has better thermal management. 展开更多
关键词 integrated power electronics module chip scale package RELIABILITY parasitic parameter thermal management
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Model of gas exchange dynamics for modified-atmosphere packages containing fresh produce
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作者 刘颖 李云飞 +1 位作者 王如竹 田平海 《Journal of Southeast University(English Edition)》 EI CAS 2005年第3期314-318,共5页
A model for modified-atmosphere packaging (MAP) systems containing fruits and vegetables was developed.The computer simulation was performed to predict the gas mass concentrations inside the packages and was success... A model for modified-atmosphere packaging (MAP) systems containing fruits and vegetables was developed.The computer simulation was performed to predict the gas mass concentrations inside the packages and was successfully verified by experiments with yellow peaches at 5,15 and 25 ℃ using two types of packaging films.A Michaelis-Menten type respiration model with noncompetitive inhibition mechanism due to CO2 was adopted while the respiration rates were measured with an improved permeable system method suitable for either steady or unsteady state.The applicability of the model in the design of MAP systems was demonstrated with a calculation to evaluate film specification and equilibrium concentrations of O2 and CO2 in the package containing yellow peaches. 展开更多
关键词 gas exchange dynamics modified-atmosphere package respiration rate yellow peach
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基于电热耦合模型的宽温域锂离子电池SOC/SOP联合估计
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作者 刘莹 孙丙香 +1 位作者 赵鑫泽 张珺玮 《储能科学与技术》 CAS CSCD 北大核心 2024年第9期3030-3041,共12页
准确的状态估计对于锂离子电池安全可靠运行具有重要意义,但由于非线性强,多参数耦合,实现宽温域多参数联合在线估计难度较大。考虑到温度影响,建立电热耦合模型,采用扩展卡尔曼滤波算法(EKF)在线辨识电池参数,通过电压及温度仿真验证... 准确的状态估计对于锂离子电池安全可靠运行具有重要意义,但由于非线性强,多参数耦合,实现宽温域多参数联合在线估计难度较大。考虑到温度影响,建立电热耦合模型,采用扩展卡尔曼滤波算法(EKF)在线辨识电池参数,通过电压及温度仿真验证了模型的准确性;然后针对无迹卡尔曼滤波算法(UKF)历史数据利用率低的问题,引入多新息理论(MI)改进UKF,改进后的算法在非电压平台区荷电状态(SOC)估计均方根误差不超过1.2%,相较于改进前误差降低了30%以上,并结合安时积分法设计切换算法,解决了MIUKF算法在磷酸铁锂电池电压平台区无法通过电压反馈修正SOC估计误差的问题,实现了宽温域复杂工况下全区间SOC的准确估计,在不同SOC初始值条件下验证了结合算法的准确性,均方根误差不超过3%,为峰值功率(SOP)估计提供了可靠的SOC值;最后将温度约束引入到SOP估计中,提出多约束条件下的SOP估计方法,结果表明在高温条件下,温度起到关键限制作用,可以防止电池温升过大,减少安全隐患。 展开更多
关键词 磷酸铁锂电池 宽温域 SOC/sop联合估计 电热耦合模型 改进UKF 多约束条件
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含SOP的交直流混合配电网日前优化调度 被引量:2
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作者 初壮 孙旭 +1 位作者 赵蕾 孙健浩 《电力系统及其自动化学报》 CSCD 北大核心 2024年第1期10-16,36,共8页
为实现交直流混合配电网的高效运行,提出一种含智能软开关的交直流配电网优化调度方法。在对应用于交直流配电网的智能软开关工作原理进行阐述的基础上,建立含智能软开关的交直流配电网优化调度模型。通过线性化和凸松弛技术,将所建立... 为实现交直流混合配电网的高效运行,提出一种含智能软开关的交直流配电网优化调度方法。在对应用于交直流配电网的智能软开关工作原理进行阐述的基础上,建立含智能软开关的交直流配电网优化调度模型。通过线性化和凸松弛技术,将所建立的非线性优化模型转化为二阶锥规划模型,并且采用改进的50节点算例分析验证模型的有效性。算例结果表明,基于所建模型得到的智能软开关运行策略能够降低配电网运行损耗及改善电压越限的情况,显著提高混合配电网的经济性。 展开更多
关键词 交直流混合配电网 智能软开关 二阶锥规划 优化调度
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一种SOP端口不平衡时直流侧电压脉动抑制策略
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作者 张国荣 汤彬 +3 位作者 沈聪 王泰文 徐晨林 夏子鹏 《电测与仪表》 北大核心 2024年第3期95-101,共7页
当柔性多状态开关(SOP)端口电压不平衡时,会引起直流侧电压的波动,给整个系统的稳定性带来很大的影响。根据SOP的数学模型,对波动的原因进行了分析,提出一种基于二阶滑模控制的直流侧电压波动抑制策略;通过引入基于非线性干扰观测器的... 当柔性多状态开关(SOP)端口电压不平衡时,会引起直流侧电压的波动,给整个系统的稳定性带来很大的影响。根据SOP的数学模型,对波动的原因进行了分析,提出一种基于二阶滑模控制的直流侧电压波动抑制策略;通过引入基于非线性干扰观测器的电容补偿器装置,对参考电压电流进行精确地跟踪。考虑多种端口电压不平衡的条件,在MATLAB/Simulink中搭建SOP仿真模型,仿真结果表明,该方法对直流侧电压波动抑制有明显的效果。 展开更多
关键词 柔性多状态开关 端口不平衡 滑模控制 电容器补偿装置
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MUTI-FUNCTIONAL PACKAGE多功能DESIGN包装设计的研究
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作者 张琴 《今日印刷》 2012年第1期65-66,共2页
随着经济的发展,商品的包装越来越受到大家的重视,包装产业亦是迅猛发展,且取得了瞩目的成就。但是随着包装材料使用量的逐渐增大,包装废弃物污染环境的问题也越来越严重。包装绿色设计已日益显现出对环保的积极作用,其作用可以总结为... 随着经济的发展,商品的包装越来越受到大家的重视,包装产业亦是迅猛发展,且取得了瞩目的成就。但是随着包装材料使用量的逐渐增大,包装废弃物污染环境的问题也越来越严重。包装绿色设计已日益显现出对环保的积极作用,其作用可以总结为:有利于保护自然资源,以及在包装的整个设计、制造、使用和回收利用的过程中对生态环境损失最小。 展开更多
关键词 包装设计 package 多功能 生态环境损失 包装废弃物 包装产业 包装材料 污染环境
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RUN TO RUN CONTROL OF TIME-PRESSURE DISPENSING SYSTEM 被引量:6
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作者 ZhaoYixiang LiHanxiong +1 位作者 DingHan XiongYoulun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第2期173-176,共4页
In electronics packaging the time-pressure dispensing system is widely usedto squeeze the adhesive fluid in a syringe onto boards or substrates with the pressurized air.However, complexity of the process, which includ... In electronics packaging the time-pressure dispensing system is widely usedto squeeze the adhesive fluid in a syringe onto boards or substrates with the pressurized air.However, complexity of the process, which includes the air-fluid coupling and the nonlinearuncertainties, makes it difficult to have a consistent process performance. An integrated dispensingprocess model is first introduced and then its input-output regression relationship is used todesign a run to run control methodology for this process. The controller takes EWMA scheme and itsstability region is given. Experimental results verify the effectiveness of the proposed run to runcontrol method for dispensing process. 展开更多
关键词 Electronics packaging Run to run control Dispensing system Process control
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Ultrasonic C-scan Detection for Stainless Steel Spot Welding Based on Wavelet Package Analysis 被引量:5
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作者 刘静 XU Guocheng +2 位作者 徐德生 ZHOU Guanghao FAN Qiuyue 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第3期580-585,共6页
An ultrasonic test of spot welding for stainless steel is conducted. Based on wavelet packet decomposition, the ultrasonic echo signal has been analyzed deeply in time - frequency domain, which can easily distinguish ... An ultrasonic test of spot welding for stainless steel is conducted. Based on wavelet packet decomposition, the ultrasonic echo signal has been analyzed deeply in time - frequency domain, which can easily distinguish the nugget from the corona bond. The 2D C-scan images produced by ultrasonic C scan which contribute to quantitatively calculate the nugget diameter for the computer are further analyzed. The spot welding nugget diameter can be automatically obtained by image enhancement, edge detection and equivalent diameter algorithm procedure. The ultrasonic detection values in this paper show good agreement with the metallographic measured values. The mean value of normal distribution curve is 0.006 67, and the standard deviation is 0.087 11. Ultrasonic C-scan test based on wavelet packet signal analysis is of high accuracy and stability. 展开更多
关键词 stainless steel spot welding ultrasonic test wavelet package analysis nugget diameter
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EFFECTS OF LEAD WIDTHS AND PITCHES ON RELIABILITY OF QUAD FLAT PACKAGE(QFP)SOLDERED JOINTS 被引量:7
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作者 XUE Songbai WU Yuxiu HAN Zongjie WANG Jianxin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第4期40-43,共4页
The finite element method(FEM) is used to analyze the effects of lead widths and pitches on reliability of soldered joints. The optimum simulation for QFP devices is also researched. The results indicate that when t... The finite element method(FEM) is used to analyze the effects of lead widths and pitches on reliability of soldered joints. The optimum simulation for QFP devices is also researched. The results indicate that when the lead pitches are the same, the maximum equivalent stress of the soldered joints increases with the increasing of lead widths, while the reliability of the soldered joints reduces. When the lead widths are the same, the maximum equivalent stress of the soldered joints doesn't decrease completely with the increasing of lead pitches, a minimum value of the maximum equivalent stress values exists in all the curves. Under this condition the maximum equivalent stress of the soldewed joints is relatively the least, the reliability of soldered joints is high and the assembly is excellent. The simulating results indicate the best parameter: The lead width is 0.2 mm and lead pitch is 0.3 mm (the distance between two leads is 0.1 mm), which are benefited for the micromation of QFP devices now. The minimum value of the maximum equivalent stress of soldered joints exists while lead width is 0.25 mm and lead pitch is 0.35 mm (the distance between two leads is 0.1 mm), the devices can serve for a long time and the reliability is the highest, the assembly is excellent. The simulating results also indicate the fact that the lead width is 0.15 mm and lead pitch is 0.2 mm maybe the limit of QFP, which is significant for the high lead count and micromation of assembly. 展开更多
关键词 Quad flat package (QFP) Maximum equivalent stress Soldered joints Assembly optimization Finite element method
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