GNSS信号丢失会导致GNSS/I NS组合导航系统定位失准甚至失效,而现有辅助模型仍存在不足。针对这一问题,本文提出了一种基于遗传算法(GA)优化E l man神经网络的车辆辅助组合导航算法。首先,使用小波阈值去噪算法降低惯导系统测量数据的噪...GNSS信号丢失会导致GNSS/I NS组合导航系统定位失准甚至失效,而现有辅助模型仍存在不足。针对这一问题,本文提出了一种基于遗传算法(GA)优化E l man神经网络的车辆辅助组合导航算法。首先,使用小波阈值去噪算法降低惯导系统测量数据的噪声,然后再使用GA优化E l man神经网络的权重和结构参数,以提高模型的预测精度和泛化能力。其次,构建基于GA-E l man神经网络的车辆辅助导航模型。该模型将系统分为两种模式,在GNSS信号正常时进入训练模式进行在线训练;当GNSS信号丢失后系统变为纯惯导模式,此时启用训练好的模型接收惯导系统的数据进行实时解算和预测。最后,跑车实验结果表明,与PSO-BPNN辅助模型和E l man辅助模型相比,本文所提出算法的定位精度得到有效提升。展开更多
The Kangdian axis basement can be divided into two tectonic layers. The lower tectonic layer is the crystalline basement which is made up of the Archaean Dibadu Formation and early Proterozoic Dahongshan Group. The fo...The Kangdian axis basement can be divided into two tectonic layers. The lower tectonic layer is the crystalline basement which is made up of the Archaean Dibadu Formation and early Proterozoic Dahongshan Group. The former is a kata-metamorphic basic volcano-sedimentary formation of the old geosyncline (old continental nucleus), and the latter is a medium-grade metamorphosed alkali-rich basic volcanic (emanation)-sedimentary formation of the Yuanjiang-Dahongshan marginal rift. They are in disconformable contact. The upper tectonic layer is the folded basement, and made up of the middle-late Proterozoic Kunyang Group. It is the result of Dongchuan-Yuanjiang intercontinental rifting with discordant contract with the underlying and overlying strata. Along with the evolution of Proterozoic from early to late, four types of emanation-sedimentary deposits in the Kangdian axis rift were formed in turn: emanation-sedimentary iron-copper-gold deposits related to basic volcanic rocks in the Yuanmou-Dahongshan marginal rift; emanation-sedimentary iron-copper deposits related to intermediate-basic volcanic rocks in the early stage of the Dongnchuan-Yuanjiang intercontinental rift; emanation-sedimentary copper deposits related to sedimentary rocks in the middle stage; copper deposits related to the late tectonic reworking. From early to late Proterozoic, with the evolution of the Kangdian axis rift and lowering volcanic basicity, the ore-forming elements also evolved from Fe, Cu and (Au) through Cu and Fe to Cu.展开更多
As semiconductor technologies have been shrinking,the speed of circuits,integration density,and the number of I/O interfaces have been significantly increasing.As a consequence,electromagnetic emanation(EME)becomes a ...As semiconductor technologies have been shrinking,the speed of circuits,integration density,and the number of I/O interfaces have been significantly increasing.As a consequence,electromagnetic emanation(EME)becomes a critical issue in digital system designs.Electronic devices must meet electromagnetic compatibility(EMC)requirements to ensure that they operate properly,and safely without interference.I/O buffers consume high currents when they operate.The bonding wires,and lead frames are long enough to play as efficient antennas to radiate electromagnetic interference(EMI).Therefore,I/O switching activities significantly contribute to the EMI.In this paper,we evaluate and analyze the impact of I/O switching activities on the EME.We will change the circuit configurations such as the supply voltage for I/O banks,their switching frequency,driving current,and slew rate.Additionally,a trade-off between the switching frequencies and the number of simultaneous switching outputs(SSOs)is also considered in terms of EME.Moreover,we evaluate the electromagnetic emissions that are associated with the different I/O switching patterns.The results show that the electromagnetic emissions associated I/O switching activities depend strongly on their operating parameters and configurations.All the circuit implementations and measurements are carried out on a Xilinx Spartan-3 FPGA.展开更多
In this paper, Muskhelishvili complex function theory and boundary collocation method are used to calculate the stress intensity factors (SIF) of a plate with two cracks emanating from an arbitrary hole. The calculate...In this paper, Muskhelishvili complex function theory and boundary collocation method are used to calculate the stress intensity factors (SIF) of a plate with two cracks emanating from an arbitrary hole. The calculated examples include a circular, elliptical, rectangular, or rhombic hole in a plate. The principle and procedure by the method is not only rather simple, but also has good accuracy. The SIF values calculated compare very favorably with the existing solutions. A t the same time,the method can be used far different finite plate with two cracks emanating from a hole with more complex geometrical and loading conditions. It is an effective unified approach for this kind of fracture problems.展开更多
In this paper a group of stress functions has been proposed for the calculation of a crack emanating from a hole with different shape (including circular, elliptical, rectangular, or rhombic hole) by boundary collocat...In this paper a group of stress functions has been proposed for the calculation of a crack emanating from a hole with different shape (including circular, elliptical, rectangular, or rhombic hole) by boundary collocation method. The calculation results show that they coincide very well with the existing solutions by other methods for a circular or elliptical hole with a crack in an infinite plate. At the smae time, a series of results for different holes in a finite plate has also been obtained in this paper. The proposed functions and calculation procedure can be used for a plate of a crack emanating from an arbitrary hole.展开更多
The warming of Earth owing to human activities is resulting in an episode of mass extinction. If global warming is not abated quickly, up to one-fourth of the species on our planet will face extinction in only 35 year...The warming of Earth owing to human activities is resulting in an episode of mass extinction. If global warming is not abated quickly, up to one-fourth of the species on our planet will face extinction in only 35 years. The loss of biodiversity is more than just many species disappearing. It could signal the beginning of the collapse of our ecosystems because the loss of one species can trigger a domino effect. Among vertebrates, the so-called cold bloodied species--fishes, amphibians and reptiles--are the most threatened groups.展开更多
Objective:To determine the radium-226 activity concentration,the massic radon exhalation rate and emanation factor of 55 soil samples from the Central Transdanubian Mountains in Hungary as well as possible radon exhal...Objective:To determine the radium-226 activity concentration,the massic radon exhalation rate and emanation factor of 55 soil samples from the Central Transdanubian Mountains in Hungary as well as possible radon exhalation hotspots in the sampling area were determined.Further indoor measurements are planned to investigate the possible exposure to radon of the inhabitants.Methods:The radium-226 activity concentration measurements were carried out with a semiconductor HPGe gamma-ray spectrometer.The massic radon exhalation rate and emanation factor were determined by measuring the radon activity concentrations using the accumulation method with a system developed by our department based on an AlphaGUARD DF2000 portable radon monitor.Results:The activity concentrations of radium-226 were between(11.42.5)and(118.23.0)Bq/kg,while their average was 39.51 Bq/kg.The massic radon exhalation rates were between(1.023.64)mBq⋅kg1⋅h1 and(275.634.05)mBq⋅kg1⋅h1,while their average was 39.51 mBq⋅kg1⋅h1.Finally,the emanation factors were between(0.010.04)and(0.800.03)with an average of 0.30.Conclusions:In our study,the results recorded from the bedrock at the sampling sites were analyzed.9 samples were taken from sites comprised of limestone bedrock,moreover,the average radium-226 activity concentrations and massic radon exhalation rates at these sampling sites were higher than average.It was also concluded that although no regional correlation can be seen from the results,a possible smaller radon hotspot was identified from our measurements where further sampling will be carried out.展开更多
文摘GNSS信号丢失会导致GNSS/I NS组合导航系统定位失准甚至失效,而现有辅助模型仍存在不足。针对这一问题,本文提出了一种基于遗传算法(GA)优化E l man神经网络的车辆辅助组合导航算法。首先,使用小波阈值去噪算法降低惯导系统测量数据的噪声,然后再使用GA优化E l man神经网络的权重和结构参数,以提高模型的预测精度和泛化能力。其次,构建基于GA-E l man神经网络的车辆辅助导航模型。该模型将系统分为两种模式,在GNSS信号正常时进入训练模式进行在线训练;当GNSS信号丢失后系统变为纯惯导模式,此时启用训练好的模型接收惯导系统的数据进行实时解算和预测。最后,跑车实验结果表明,与PSO-BPNN辅助模型和E l man辅助模型相比,本文所提出算法的定位精度得到有效提升。
文摘The Kangdian axis basement can be divided into two tectonic layers. The lower tectonic layer is the crystalline basement which is made up of the Archaean Dibadu Formation and early Proterozoic Dahongshan Group. The former is a kata-metamorphic basic volcano-sedimentary formation of the old geosyncline (old continental nucleus), and the latter is a medium-grade metamorphosed alkali-rich basic volcanic (emanation)-sedimentary formation of the Yuanjiang-Dahongshan marginal rift. They are in disconformable contact. The upper tectonic layer is the folded basement, and made up of the middle-late Proterozoic Kunyang Group. It is the result of Dongchuan-Yuanjiang intercontinental rifting with discordant contract with the underlying and overlying strata. Along with the evolution of Proterozoic from early to late, four types of emanation-sedimentary deposits in the Kangdian axis rift were formed in turn: emanation-sedimentary iron-copper-gold deposits related to basic volcanic rocks in the Yuanmou-Dahongshan marginal rift; emanation-sedimentary iron-copper deposits related to intermediate-basic volcanic rocks in the early stage of the Dongnchuan-Yuanjiang intercontinental rift; emanation-sedimentary copper deposits related to sedimentary rocks in the middle stage; copper deposits related to the late tectonic reworking. From early to late Proterozoic, with the evolution of the Kangdian axis rift and lowering volcanic basicity, the ore-forming elements also evolved from Fe, Cu and (Au) through Cu and Fe to Cu.
基金Project(2018R1D1A1B07043399)supported by Basic Science Research Program through the National Research Foundation,Korea
文摘As semiconductor technologies have been shrinking,the speed of circuits,integration density,and the number of I/O interfaces have been significantly increasing.As a consequence,electromagnetic emanation(EME)becomes a critical issue in digital system designs.Electronic devices must meet electromagnetic compatibility(EMC)requirements to ensure that they operate properly,and safely without interference.I/O buffers consume high currents when they operate.The bonding wires,and lead frames are long enough to play as efficient antennas to radiate electromagnetic interference(EMI).Therefore,I/O switching activities significantly contribute to the EMI.In this paper,we evaluate and analyze the impact of I/O switching activities on the EME.We will change the circuit configurations such as the supply voltage for I/O banks,their switching frequency,driving current,and slew rate.Additionally,a trade-off between the switching frequencies and the number of simultaneous switching outputs(SSOs)is also considered in terms of EME.Moreover,we evaluate the electromagnetic emissions that are associated with the different I/O switching patterns.The results show that the electromagnetic emissions associated I/O switching activities depend strongly on their operating parameters and configurations.All the circuit implementations and measurements are carried out on a Xilinx Spartan-3 FPGA.
文摘In this paper, Muskhelishvili complex function theory and boundary collocation method are used to calculate the stress intensity factors (SIF) of a plate with two cracks emanating from an arbitrary hole. The calculated examples include a circular, elliptical, rectangular, or rhombic hole in a plate. The principle and procedure by the method is not only rather simple, but also has good accuracy. The SIF values calculated compare very favorably with the existing solutions. A t the same time,the method can be used far different finite plate with two cracks emanating from a hole with more complex geometrical and loading conditions. It is an effective unified approach for this kind of fracture problems.
文摘In this paper a group of stress functions has been proposed for the calculation of a crack emanating from a hole with different shape (including circular, elliptical, rectangular, or rhombic hole) by boundary collocation method. The calculation results show that they coincide very well with the existing solutions by other methods for a circular or elliptical hole with a crack in an infinite plate. At the smae time, a series of results for different holes in a finite plate has also been obtained in this paper. The proposed functions and calculation procedure can be used for a plate of a crack emanating from an arbitrary hole.
文摘The warming of Earth owing to human activities is resulting in an episode of mass extinction. If global warming is not abated quickly, up to one-fourth of the species on our planet will face extinction in only 35 years. The loss of biodiversity is more than just many species disappearing. It could signal the beginning of the collapse of our ecosystems because the loss of one species can trigger a domino effect. Among vertebrates, the so-called cold bloodied species--fishes, amphibians and reptiles--are the most threatened groups.
基金Project nos.K146322&K146315 were implemented with financial support provided by the Hungarian Ministry of Culture and Innovation from the National Research,Development and Innovation Fund financed under the OTKA K_23 funding scheme,Hungary.
文摘Objective:To determine the radium-226 activity concentration,the massic radon exhalation rate and emanation factor of 55 soil samples from the Central Transdanubian Mountains in Hungary as well as possible radon exhalation hotspots in the sampling area were determined.Further indoor measurements are planned to investigate the possible exposure to radon of the inhabitants.Methods:The radium-226 activity concentration measurements were carried out with a semiconductor HPGe gamma-ray spectrometer.The massic radon exhalation rate and emanation factor were determined by measuring the radon activity concentrations using the accumulation method with a system developed by our department based on an AlphaGUARD DF2000 portable radon monitor.Results:The activity concentrations of radium-226 were between(11.42.5)and(118.23.0)Bq/kg,while their average was 39.51 Bq/kg.The massic radon exhalation rates were between(1.023.64)mBq⋅kg1⋅h1 and(275.634.05)mBq⋅kg1⋅h1,while their average was 39.51 mBq⋅kg1⋅h1.Finally,the emanation factors were between(0.010.04)and(0.800.03)with an average of 0.30.Conclusions:In our study,the results recorded from the bedrock at the sampling sites were analyzed.9 samples were taken from sites comprised of limestone bedrock,moreover,the average radium-226 activity concentrations and massic radon exhalation rates at these sampling sites were higher than average.It was also concluded that although no regional correlation can be seen from the results,a possible smaller radon hotspot was identified from our measurements where further sampling will be carried out.
