Reliability analysis of the inspected and repaired structure requires dealing with a large number of complex random events. Considering many kinds of random factors, a probability of these random events existing possi...Reliability analysis of the inspected and repaired structure requires dealing with a large number of complex random events. Considering many kinds of random factors, a probability of these random events existing possibly in the inspection and repair process and reliability analysis methodologies are proposed. A systematic dynamic reliability model is given for structures in service under the scheduled inspection and repair.展开更多
In order to study whether the random events set can be used in Rudongbank of Nantong or not, we use ADCIRC model to stimulate the storm surge affectingRudong bank based on random events set. Then we use p-III curve to...In order to study whether the random events set can be used in Rudongbank of Nantong or not, we use ADCIRC model to stimulate the storm surge affectingRudong bank based on random events set. Then we use p-III curve to fit peak-value ofsurge of all the years to get the surge of typical return periods. The result shows that theresults of fitting by ADCIRC and by historical data coincide well in lower return periods,but to higher return periods, the results of fitting by ADCIRC are significantly higher thanthat of fitting by historical data. Due to the short time, it’s not enough for the extremestorm surge events to occur, the results of higher return periods are not reliable, so wecan’t rule out the reasonability of results based on random events set. The results offitting based on random events set are accurate in lower return periods and we can alsofully estimate the surge of higher return periods based on random events set. In thesituation of lacking historical data of hundreds of years, random events set can beaccepted as a tool to compute the return period of storm surge. Consideration of globalwarming, the possibility of super typhoons’ appearance will rise, which will result inhigher surge of return periods. In order to prevent the disaster of storm surge, thegovernment needs to deepen and reinforce the coastal engineering like seawalls and embankments.展开更多
The impact of ionizing radiation effect on single event upset（SEU） sensitivity of ferroelectric random access memory（FRAM） is studied in this work. The test specimens were firstly subjected to ^60Co γ-ray and the...The impact of ionizing radiation effect on single event upset（SEU） sensitivity of ferroelectric random access memory（FRAM） is studied in this work. The test specimens were firstly subjected to ^60Co γ-ray and then the SEU evaluation was conducted using ^209Bi ions. As a result of TID-induced fatigue-like and imprint-like phenomena of the ferroelectric material, the SEU cross sections of the post-irradiated devices shift substantially. Different trends of SEU cross section with elevated dose were also found, depending on whether the same or complementary test pattern was employed during the TID exposure and the SEU measurement.展开更多
Using computer-aided design three-dimensional （3D） simulation technology, the recovery mechanism of single event upset and the effects of spacing and hit angle on the recovery are studied. It is found that the multi...Using computer-aided design three-dimensional （3D） simulation technology, the recovery mechanism of single event upset and the effects of spacing and hit angle on the recovery are studied. It is found that the multi-node charge collection plays a key role in recovery and shielding the charge sharing by adding guard rings. It cannot exhibit the recovery effect. It is also indicated that the upset linear energy transfer （LET） threshold is kept constant while the recovery LET threshold increases as the spacing increases. Additionally, the effect of incident angle on recovery is analysed and it is shown that a larger angle can bring about a stronger charge sharing effect, thus strengthening the recovery ability.展开更多
Synergistic effects of the total ionizing dose （TID） on the single event upset （SEU） sensitivity in static random access memories （SRAMs） were studied by using protons. The total dose was cumulated with high flu...Synergistic effects of the total ionizing dose （TID） on the single event upset （SEU） sensitivity in static random access memories （SRAMs） were studied by using protons. The total dose was cumulated with high flux protons during the TID exposure, and the SEU cross section was tested with low flux protons at several cumulated dose steps. Because of the radiation-induced off-state leakage current increase of the CMOS transistors, the noise margin became asymmetric and the memory imprint effect was observed.展开更多
The pattern dependence in synergistic effects was studied in a 0.18 μm static random access memory（SRAM） circuit.Experiments were performed under two SEU test environments：3 Me V protons and heavy ions.Measured re...The pattern dependence in synergistic effects was studied in a 0.18 μm static random access memory（SRAM） circuit.Experiments were performed under two SEU test environments：3 Me V protons and heavy ions.Measured results show different trends.In heavy ion SEU test,the degradation in the peripheral circuitry also existed because the measured SEU cross section decreased regardless of the patterns written to the SRAM array.TCAD simulation was performed.TIDinduced degradation in n MOSFETs mainly induced the imprint effect in the SRAM cell,which is consistent with the measured results under the proton environment,but cannot explain the phenomena observed under heavy ion environment.A possible explanation could be the contribution from the radiation-induced GIDL in pMOSFETs.展开更多
The high flux of energetic electron on geostationary orbit can induce many kinds of malfunction of the satellite there, within which the bulk-charging is the most significant that several broadcast satellite failures ...The high flux of energetic electron on geostationary orbit can induce many kinds of malfunction of the satellite there, within which the bulk-charging is the most significant that several broadcast satellite failures were confirmed to be due to this effect. The electron flux on geostationary orbit varies in a large range even up to three orders accompanied the passage of interplanetary magnetic cloud and the following geomagnetic disturbances. Upon the investigation of electron flux enhancement events, two types of events were partitioned as recurrent events and random ones. Both of the two kinds of events relate to the interplanetary conditions such as solar wind parameters, IMF etc and their evolution characters as well. As for the recurrent events, we found that, (1) all of the events exhibits periodic recurrence about 27 days, (2) significant increase of electron flux relates to interplanetary index and characters of their distribution, (3) the electron flux also has relation to solar activity index. An artificial neural network was constructed to estimate the flux I day ahead. The random electron flux enhancement events are rare and present different distribution figures to the recurrent ones. The figure of the random events and the conditions of their occurrence is also discussed in this paper.展开更多
This paper develops a new simulation technique to characterize single event effects on semiconductor devices. The technique used to calculate the single event effects is developed according to the physical interaction...This paper develops a new simulation technique to characterize single event effects on semiconductor devices. The technique used to calculate the single event effects is developed according to the physical interaction mechanism of a single event effect. An application of the first principles simulation technique is performed to predict the ground-test single event upset effect on field-programmable gate arrays based on 0.25μm advanced complementary metal-oxidesemiconductor technology. The agreement between the single event upset cross section accessed from a broad-beam heavy ion experiment and simulation shows that the simulation technique could be used to characterize the single event effects induced by heavy ions on a semiconductor device.展开更多
Updating or conditioning a body of evidence modeled within the DS framework plays an important role in most of Artificial Intelligence (AI) applications. Rule is one of the most important methods to represent knowledg...Updating or conditioning a body of evidence modeled within the DS framework plays an important role in most of Artificial Intelligence (AI) applications. Rule is one of the most important methods to represent knowledge in AI. The appearance of uncertain reasoning urges us to measure the belief of rule. Now,most of uncertain reasoning models represent the belief of rule by conditional probability. However,it has many limitations when standard conditional probability is used to measure the belief of expert system rule. In this paper,AI rule is modelled by conditional event and the belief of rule is measured by conditional event probability,then we use random conditional event to construct a new evidence updating method. It can overcome the drawback of the existed methods that the forms of focal sets influence updating result. Some examples are given to illustrate the effectiveness of the proposed method.展开更多
A generalized continuous time random walk model which is dependent on environmental damping is proposed in which the two key parameters of the usual random walk theory： the jumping distance and the waiting time, are ...A generalized continuous time random walk model which is dependent on environmental damping is proposed in which the two key parameters of the usual random walk theory： the jumping distance and the waiting time, are replaced by two new ones： the pulse velocity and the flight time. The anomalous diffusion of a free particle which is characterized by the asymptotical mean square displacement （x^2（t）） - t^a is realized numerically and analysed theoretically, where the value of the power index a is in a region of 0 〈 a 〈 2. Particularly, the damping leads to a sub-diffusion when the impact velocities are drawn from a Gaussian density function and the super-diffusive effect is related to statistical extremes, which are called rare-though-dominant events.展开更多
文摘Reliability analysis of the inspected and repaired structure requires dealing with a large number of complex random events. Considering many kinds of random factors, a probability of these random events existing possibly in the inspection and repair process and reliability analysis methodologies are proposed. A systematic dynamic reliability model is given for structures in service under the scheduled inspection and repair.
文摘In order to study whether the random events set can be used in Rudongbank of Nantong or not, we use ADCIRC model to stimulate the storm surge affectingRudong bank based on random events set. Then we use p-III curve to fit peak-value ofsurge of all the years to get the surge of typical return periods. The result shows that theresults of fitting by ADCIRC and by historical data coincide well in lower return periods,but to higher return periods, the results of fitting by ADCIRC are significantly higher thanthat of fitting by historical data. Due to the short time, it’s not enough for the extremestorm surge events to occur, the results of higher return periods are not reliable, so wecan’t rule out the reasonability of results based on random events set. The results offitting based on random events set are accurate in lower return periods and we can alsofully estimate the surge of higher return periods based on random events set. In thesituation of lacking historical data of hundreds of years, random events set can beaccepted as a tool to compute the return period of storm surge. Consideration of globalwarming, the possibility of super typhoons’ appearance will rise, which will result inhigher surge of return periods. In order to prevent the disaster of storm surge, thegovernment needs to deepen and reinforce the coastal engineering like seawalls and embankments.
文摘The impact of ionizing radiation effect on single event upset（SEU） sensitivity of ferroelectric random access memory（FRAM） is studied in this work. The test specimens were firstly subjected to ^60Co γ-ray and then the SEU evaluation was conducted using ^209Bi ions. As a result of TID-induced fatigue-like and imprint-like phenomena of the ferroelectric material, the SEU cross sections of the post-irradiated devices shift substantially. Different trends of SEU cross section with elevated dose were also found, depending on whether the same or complementary test pattern was employed during the TID exposure and the SEU measurement.
基金supported by the State Key Program of the National Natural Science Foundation of China (Grant No.60836004)the National Natural Science Foundation of China (Grant Nos.61076025 and 61006070)
文摘Using computer-aided design three-dimensional （3D） simulation technology, the recovery mechanism of single event upset and the effects of spacing and hit angle on the recovery are studied. It is found that the multi-node charge collection plays a key role in recovery and shielding the charge sharing by adding guard rings. It cannot exhibit the recovery effect. It is also indicated that the upset linear energy transfer （LET） threshold is kept constant while the recovery LET threshold increases as the spacing increases. Additionally, the effect of incident angle on recovery is analysed and it is shown that a larger angle can bring about a stronger charge sharing effect, thus strengthening the recovery ability.
基金supported by the Open Foundation of State Key Laboratory of Electronic Thin Films and Integrated Devices,China(Grant No.KFJJ201306)
文摘Synergistic effects of the total ionizing dose （TID） on the single event upset （SEU） sensitivity in static random access memories （SRAMs） were studied by using protons. The total dose was cumulated with high flux protons during the TID exposure, and the SEU cross section was tested with low flux protons at several cumulated dose steps. Because of the radiation-induced off-state leakage current increase of the CMOS transistors, the noise margin became asymmetric and the memory imprint effect was observed.
文摘针对动态武器目标分配(dynamic weapon target assignment,DWTA)问题,提出一种基于进化算法和局部搜索算法的文化基因算法(memetic algorithm,MA)。以最大化目标毁伤为目标,建立考虑能力约束、策略约束、资源约束、拦截可行性约束条件下的DWTA模型;引入虚拟排列进行编码以满足拦截可行性要求,设计将排列转化为实际分配方案的构造方法,给出算法运行过程中对随机事件的处理方法。通过与遗传算法(genetic algorithm,GA)、MA-GLS(memetic algorithm global local search)求解不同测试实例的对比仿真,结果表明,MA算法具有寻优速度快、优化能力强、稳定性好的优点。
基金Project supported by the National Natural Science Foundation of China(Grant No.U1532261)
文摘The pattern dependence in synergistic effects was studied in a 0.18 μm static random access memory（SRAM） circuit.Experiments were performed under two SEU test environments：3 Me V protons and heavy ions.Measured results show different trends.In heavy ion SEU test,the degradation in the peripheral circuitry also existed because the measured SEU cross section decreased regardless of the patterns written to the SRAM array.TCAD simulation was performed.TIDinduced degradation in n MOSFETs mainly induced the imprint effect in the SRAM cell,which is consistent with the measured results under the proton environment,but cannot explain the phenomena observed under heavy ion environment.A possible explanation could be the contribution from the radiation-induced GIDL in pMOSFETs.
基金Supported by the China-Russia Joint Research Center on Space Weather,Chinese Academy of Sciences
文摘The high flux of energetic electron on geostationary orbit can induce many kinds of malfunction of the satellite there, within which the bulk-charging is the most significant that several broadcast satellite failures were confirmed to be due to this effect. The electron flux on geostationary orbit varies in a large range even up to three orders accompanied the passage of interplanetary magnetic cloud and the following geomagnetic disturbances. Upon the investigation of electron flux enhancement events, two types of events were partitioned as recurrent events and random ones. Both of the two kinds of events relate to the interplanetary conditions such as solar wind parameters, IMF etc and their evolution characters as well. As for the recurrent events, we found that, (1) all of the events exhibits periodic recurrence about 27 days, (2) significant increase of electron flux relates to interplanetary index and characters of their distribution, (3) the electron flux also has relation to solar activity index. An artificial neural network was constructed to estimate the flux I day ahead. The random electron flux enhancement events are rare and present different distribution figures to the recurrent ones. The figure of the random events and the conditions of their occurrence is also discussed in this paper.
文摘This paper develops a new simulation technique to characterize single event effects on semiconductor devices. The technique used to calculate the single event effects is developed according to the physical interaction mechanism of a single event effect. An application of the first principles simulation technique is performed to predict the ground-test single event upset effect on field-programmable gate arrays based on 0.25μm advanced complementary metal-oxidesemiconductor technology. The agreement between the single event upset cross section accessed from a broad-beam heavy ion experiment and simulation shows that the simulation technique could be used to characterize the single event effects induced by heavy ions on a semiconductor device.
基金Supported by the NSFC (No. 60772006, 60874105)the ZJNSF (Y1080422, R106745)Aviation Science Foundation (20070511001)
文摘Updating or conditioning a body of evidence modeled within the DS framework plays an important role in most of Artificial Intelligence (AI) applications. Rule is one of the most important methods to represent knowledge in AI. The appearance of uncertain reasoning urges us to measure the belief of rule. Now,most of uncertain reasoning models represent the belief of rule by conditional probability. However,it has many limitations when standard conditional probability is used to measure the belief of expert system rule. In this paper,AI rule is modelled by conditional event and the belief of rule is measured by conditional event probability,then we use random conditional event to construct a new evidence updating method. It can overcome the drawback of the existed methods that the forms of focal sets influence updating result. Some examples are given to illustrate the effectiveness of the proposed method.
基金supported by the Scientific Research Foundation of Sichuan University for Young Teachers,China (GrantNo. 2009SCU11120)
文摘A generalized continuous time random walk model which is dependent on environmental damping is proposed in which the two key parameters of the usual random walk theory： the jumping distance and the waiting time, are replaced by two new ones： the pulse velocity and the flight time. The anomalous diffusion of a free particle which is characterized by the asymptotical mean square displacement （x^2（t）） - t^a is realized numerically and analysed theoretically, where the value of the power index a is in a region of 0 〈 a 〈 2. Particularly, the damping leads to a sub-diffusion when the impact velocities are drawn from a Gaussian density function and the super-diffusive effect is related to statistical extremes, which are called rare-though-dominant events.
