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In this paper a kind of SSPC was designed and fabricated using thick film hybrid circuit technology. More than 1000 SSPC products went through the screening test according to GJB2438A. The screening procedure including thermal shock, high temperature power burn-in test, constant acceleration, hermetic sealing test and particle impact noise detection (PIND). Also 1000h life test was applied to samples...
Based on the special analysis of the special requirements of electronic products, the creep damage of typical tin-lead solder is more complicated in the harsh environment, and the life and reliability of aerospace products are more important. In addition, based on the typical creep damage cases of aerospace electronic products, this paper elaborates the creep rupture mechanism of solder joint in aerospace...
The performance of Monte-Carlo Simulation(MCS) is highly related to the number of simulation. This paper introduces a hypothesis testing technique and incorporated into a Particle Swarm Optimization(PSO) based Monte-Carlo Simulation(MCS) algorithm to solve the complex network reliability problem. The function of hypothesis testing technique is to reduce the dispensable simulation in network system...
In air-based information network of the Space-Air-Ground Integrated Network, it is critical to select an efficient communication link for each communication. However, some communication may not have fixed rules. In this article, we build a model of the air-based information network, and use the dynamic programming to select the most efficient communication link by minimizing the energy consumption...
Weighting the stream outputs according to their reliability levels is one of the most common stream fusion methods in the multi-stream automatic speech recognition (MS ASR). However, when a MS ASR system works in noisy environments, there are distortion level differences among not only the data streams, but also the feature components inside a stream. In this paper, we first propose a feature component...
A device for fault diagnosis of photovoltaic (PV) panels is presented. By sampling the terminal voltage and current of the panel when the connected PV system is tracking the maximum power point, the device simultaneously utilizes the sampled information to estimate and observe the drift of the intrinsic parameters of the panel. Compared with prior-art approaches of using static current-voltage characteristics...
The objective is to analyze some of the issues in the transforming landscape of distribution networks, especially micro grids, and some power quality implications - the harmonic distortion levels and reduction methods with increased penetration levels of the Photovoltaic Generators (PVGs) in the distribution network. This paper has shown that the worst voltage distortion may be found to be outside...
Power network is important part of national comprehensive energy resources transmission system in the way of energy security promise and the economy society running. Meanwhile, because of many industries involved, the development of grid can push national innovation ability. Nowadays, it makes the inner of smart grid flourish that material science, computer technique and information and communication...
In this paper, a novel parameter named cross-tier interference to signal ratio (CISR) is defined to characterize cross-tier interference in the co-channel deployed two-tier macro and femto networks. Cross-tier interference to signal budget (CISB) is derived to characterize the tolerance of cross-tier interference for given per-tier downlink signal to interference ratio (SIR) targets and outage probability...
A reliability model was presented when test data were used to assess the reliability of system. Considering the property of ballistic discrimination fuze, not only the experimental data of shooting range, but also the data of simulated test should be used. The pattern building method of the ballistic discrimination fuze reliability was investigated, which is used to evaluate reliability of system...
Cloud computing has emerged as a powerful computing paradigm that enables users to access computing services anywhere on demand. It provides a flexible way to implement computation-intensive workflow applications on a pay-per-use basis. Since users are more concerned on the satisfaction of Quality of Service (QoS) in cloud systems, the cloud workflow scheduling problem that addresses different QoS...
In the application of wireless sensor networks (WSNs), energy efficiency is always an important topic for extending the network lifetime. Scheduling the operation modes of sensors can reduce the energy wasted by redundant sensors, but frequent alterations of sensors' modes and different data transmission routes influence the reliability of the WSN. In this paper, a novel algorithm for maximizing the...
in high-voltage substations, poor contacts at the junctions of contacts can generate heat leading to high temperature, arc and fire disaster in serious condition. In this paper, we present a remote temperature monitor system to monitor and alarm when temperature of the contacts increases. The system measures temperature by sensor node based on low power consuming temperature sensor and Zigbee communication...
The future introduction of new satellite constellations such as the European satellite navigation system Galileo, modernized Global Positioning System (GPS) or Compass developed by China will imply great improvements in the number as well as the quality of available measurements which provide chance to support better performance. Due to the navigation resources are kind of time-varying series and...
A design and simulation analysis method with genetic algorithm for the group delay of the ADC system balanced circuits is introduced in this paper. With the discussion of characteristics of linear phase of the system, genetic algorithm technology was introduced into the analysis and calculation of group delay equalization circuit of an anti-aliasing filter with given structure and parameters, genetic...
The minimal cut sets and structure importance of bottom event are achieved by top-down method on diesel engine system downtime failures. The method of combining grey relational analysis with fuzzy membership function is presented to solve the probability of failure modes. Fuzzy grey fault tree model is proposed. The fuzzy relational degree is calculated and diesel engine weak links are found. The...
Effect of Cu substrates and solder alloy on the formation of kirkendall voids in the solder joints during thermal aging was investigated. Solder joints with three types of Cu bonding pads (electroplated Cu, polycrystalline Cu and single-crystal Cu) and Sn-based solders (Sn-3Ag-0.5Cu and Sn-37Pb) were prepared, and subsequently the samples were aged at 150°C and 175°C, Under the same aging conditions,...
Support from the Chinese Academy of Sciences and the General Armament Department, certain technology improvement and enhancement of atomic hydrogen clock was effectively carried out by Shanghai Astronomical Observatory under the promotion of BD, lunar exploration, deep space tracking projects. The atomic hydrogen clock's reliability and performance have been greatly improved. The developed atomic...
With the potential of Global Navigation Satellite system (GNSS) to be the sole-means in civil aviation and other navigation fields, integrity and related techniques become more important among which many researches focus on receiver autonomous integrity monitoring (RAIM) referring to independent integrity monitoring of GNSS without any external assistant navigation facilities. Therefore, the performances...
The three-dimensional elastic frictional finite element model of the wheel/rail interaction is put forward to investigate effect of the curve radius and superelevation on the contact stress and contact force of the rail. The interaction between left and right wheels is considered. The rail model includes 60 kg/m standard rail, sleeper, rail fastening, rubber tie plate and ballast bed. The elastic...
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