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Monte-Carlo sampling method in reliability evaluation has defects of great sampling number and low efficiency. This paper proposed control variable method in power system integrated with wind power unit, considering its feather of small unit capacity and large unit number. The proposed method is carried out on the IEEE RTS79 test system, compares with the conventional Monte-Carlo method and the average...
This paper presents the design, development, and evaluation of a high power, i.e., 1200-V/600-A, double-sided multichip phase-leg IGBT module with the purpose of increasing power density compared with conventional wire-bonded IGBT modules. Nanosilver paste is chosen as the die-attach material so as to increase the maximum application temperature by avoiding the creep failure at high temperatures compared...
Degradation prediction is important for safety related products to avoid failures. When the degradations of multiple parameters of a product is taken into account, traditional univariate degradation prediction method is not applicable, especially when the parameters are correlated. To cope with this problem, Mahalanobis distance is proposed, to combine multiple parameters into one unified index. Then...
SF6 Gas-Insulated Metal-Enclosed Transmission Line (GIL) has the advantages of large transmitting capacity, low loss, small electromagnetic pollution for surroundings, strong capability to resist geological disasters, easy operation and maintenance, etc. In-depth research on the key technology of UHV GIL insulating part design, flexible line design, line manufacturing and detection, GIL installing...
Polar coding is a low-complexity method for communication over noisy classical channels, which is capable of providing highly reliable data transmission. This paper proposes an enhanced polar codec scheme for mission critical applications in train-to-ground wireless communications. Firstly, we develop an enhanced polar coding scheme to support reliable data transmission under time-varying channel...
Recently, fault indicators with communication function have been increasingly used in fault diagnosis of distribution networks. In this paper, an objective function which considers the reliability index of the distribution network and economic factors synthetically has been proposed for optimal placement of fault indicators in distribution networks, and binary particle swarm optimization algorithm...
Internet connection is essential for daily life, however not all areas are covered by Internet access due to historical reasons. For example, with 3.7 million daily passengers, London underground system has no WiFi or cellular signal provided during travelling due to legacy reasons. Deploy new access infrastructure need to consider the integrating problem with the current environment, also bring a...
With strong wind predicting and warning system setup, train dispatch system structure will change, and will bring change of work process and reliability of the whole system. In order to build a high reliable railway dispatch system, the paper analyzes three railway dispatch system structures and their fuzzy reliability. The first dispatch system with no wind warning system, the second and the third...
With the building of the energy Internet of Things (IoT), the establishment of a private network dedicated to the control and management of the grid to provide reliable and secure power services is attracting more and more attention. Meanwhile, owing to the rapid development of wireless wideband communication technologies, today's wireless communications are increasingly considered by power communication...
For the miniaturization and multifunction of electronic devices, the vertical interconnection technology has been developed to replace the traditional planar packaging technology. The interposer connection using double-side solder bump is used as the vertical interconnection technology in this study. Three kinds of solder bumps with different diameters of 0.76mm, 1.2 mm and 2mm were prepared and mounted...
Thick film hybrid integrated circuit is a product of thick film technology and semiconductor technology. Because of some outstanding advantages, such as high reliability and high integration, hybrid integrated circuit has been gradually applied to aerospace electronic equipment. The situation of unstable electrical performance caused by individual parameters exceed standard in the hybrid integrated...
The vibrational characteristics of the mid-infrared solid-state laser is an important factor which affects the laser output characteristic and the system integrated performance. Starting with the dynamic equilibrium equation, The simulation models of the vibrating effect of the solid-state laser and the key components are established, and the natural characteristics and dynamic response of the solid-state...
Three-dimensional (3D) package technology is currently considered as one of the best solution to beyond Moore's Law and achieve miniaturization, high density and multi-functional of the device. Copper filled in through silicon via (Cu-TSV) technology with good electrical performance and high reliability, is a new type of 3D packaging technology. Cu-TSV has been widely used in integrated circuit technology...
The samples were soldered using copper pillars and Sn-3.0Ag-0.5Cu solder paste with a typical reflow profile about peak time of 245°C. In order to observe the microstructure and crystal orientations, the sample is grinded and polished to be characterized by scanning electron microscope (SEM) and electron backscattered diffraction (EBSD). By analyzing the microstructure and crystal orientation, the...
Three-dimensional structure has been achieved using interlayer connecting technology with double-side solder bump and the lifetime of the solder joints under thermal shock test has been forecasted by finite element method. The simulation result presents that the stress at the interface between 0.76mm solder bump and PCB is evidently higher than that in other places. The interface between 0.76mm solder...
The SnSbNi solder pastes were reflowed at 270°C and 280°C between the MvpLED chip and the AlN ceramic substrate, and then the SnSbNi solder joints were aged respectively at 200°C for 1h and at 250°C for 3h. The interfacial microstructure and constituents were investigated by SEM and EDS. After the reflow reactions, a thin layer of IMCs was formed at the chip/solder and solder/substrate interfaces,...
Synchrotron radiation x-ray real-time imaging technology was used to study the interface reactions of Sn/Cu and Sn0.7Cu/Cu joints during reflow with soldering time of 1h under temperature of 300/350 °C. This experiment allows us in-situ observe the interfacial IMCs growth and completely avoids Cu6Sn5 precipitation from the solder in cooling stage to affect the morphology and thickness of interfacial...
The purpose of this study was to explore the important factors that influence users’ continuance usage behavior toward mobile online group-buying. Based on the characteristics of the mobile Internet, an extension of the UTAUT model is introduced to verify the proposed hypotheses. The structural equation modeling method is used to analyze the empirical data which come from universities in China. The...
With the development of cloud computing, disk arrays tolerating triple disk failures (3DFTs) are receiving more attention nowadays because they can provide high data reliability with low monetary cost. However, a challenging issue in these arrays is how to efficiently reconstruct the lost data, especially for partial stripe errors (e.g., sector and chunk errors). It is one of the most significant...
In this paper, a new and simple method named Weibull criterion is proposed to identify whether metastable states occur in single random telegraph noise (RTN), which has been verified by both simulation and experiment results. It is helpful for comprehensive understanding of trap properties and providing a direct evidence of oxide traps with multiple states.
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