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Soft Fault Diagnosis for Analog Circuits Based on slope Fault Feature and BP Neural Networks

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Tsinghua Science and Technology 2007年第S1期12卷 26-31页

作者：胡梅王红胡庚杨士元 Department of Automation Tsinghua University

Fault diagnosis is very important for development and maintenance of safe and reliable electronic circuits and systems. This paper describes an approach of soft fault diagnosis for analog circuits based on slope fault feature and back propagation neural networks (BPNN). The reported approach uses the voltage relation function between two nodes as fault features; and for linear analog circuits, the voltage relation function is a linear function, thus the slope is invariant as fault feature. Therefore, a unified fault feature for both hard fault (open or short fault) and soft fault (parametric fault) is extracted. Unlike other NN-based diagnosis methods which utilize node voltages or frequency response as fault features, the reported BPNN is trained by the extracted feature vectors, the slope features are calculated by just simulating once for each component, and the trained BPNN can achieve all the soft faults diagnosis of the component. Experiments show that our approach is promising.

关键词： soft fault diagnosis analog circuit back propagation neural network (BPNN) voltage relation function slope

Permian sequence stratigraphy of slope facies in southern Guizhou and chronostratigraphic correlation

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Science China Earth Sciences 2000年第1期43卷 63-76页

作者：史晓颖梅仕龙孙岩 China University of Geosciences Beijing 100083 China

The Permian in slope facies area of southern Guizhou consists of 16 third order sequences, which can be grouped as four sequence sets and further into two mesosequences. Most of them are delineated by conformable or submarine erosion surfaces, and well controlled by conodont and fusulinid zones. Four important sea-level falls are recognized in the area, which occur respectively at the basal Sweetognathodus white! zone, lower S.aff. hanzhongensis zone, middle Jinogondolella xuanhanensis zone and the basal Clarkina y/n/zone. Among the recognized transgression events, three are regarded as the most significant. They occur respectively at the basal Neogondolella exculptus zone, basal Jinogondolella nankingensis zone and the lower Clarkina postbitteri zone, and are all accompanied by faunal turnovers. The key surfaces in sequences can be used to fine-tune the boundaries of bio-chronozones, stages and series.

关键词： Permian sequence stratigraphy slope facies southern Guizhou correlation.

Effects of freeze-thaw cycle and dry-wet alternation on slope stability

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Research in Cold and Arid Regions 2019年第2期11卷 159-172页

作者： YaLing Chou LiYuan Sun BaoAn Li XiaoLi Wang School of Civil Engineering Lanzhou University of Technology Jiangsu JiaoTong Traffic Design Research Institute Co. Ltd.

The typical loess on high slopes along the BaoLan High-speed Rail, China, was selected as the research object. The influence of the freeze-thaw cycle and dry-wet alternation on the shear-strength parameters of the unsaturated loess was investigated by laboratory experimental methods. Moreover, the temperature field, seepage field, and stability of slopes with different gradients were simulated under the effect of the freeze-thaw cycle and dry-wet alternation by using the geotechnical analysis software Geo-Studio. The research results showed(1) when the freeze-thaw cycle was repeated on the slope, with the frozen depth increasing, the melted depth did the same; besides, the closed loop of isotherms formed on the slope;(2) under the action of dry-wet circulation, the negative pore-water pressure and volumetric water content showed an upward tendency. However, owing to the different slope gradients, rainfall infiltration was not the same. As time went by, the differences of the negative pore-water pressure and volumetric water content between the slopes of different gradients continued to increase;(3) with the freeze-thaw cycle and dry-wet alternation increasing, the slope-safety factor decreased. Especially in the early period, the slope-safety factor changed remarkably. For slopes undergoing freeze-thaw action, the slope-safety factor was negatively correlated with the gradient. However, with regard to slopes undergoing dry-wet alternation, the result became more complex because the slope-safety factor was related to both seepage strength and slope grade. Accordingly, further research is needed to study the effect of seepage strength and slope grade on the stability of loess slopes.

关键词： freeze-thaw action dry-wet alternation temperature field seepage field slope stability

Monitoring result analyses of high slope of five-step ship lock in the Three Gorges Project

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Journal of Rock Mechanics and Geotechnical Engineering 2015年第2期7卷 199-206页

作者： Qixiang Fan Hongbing Zhu Jun Gen China Three Gorges Corporation

The construction of the double-lane five-step ship lock of the Three Gorges Project （TGP） wascommenced in 1994, the excavation of the ship lock was completed by the end of 1999, and the ship lockwas put in operation in June 2003. The side slopes of the ship lock are characterized by great height（170 m）, steepness （70 m in height of upright slope）, and great length （over 7000 m in total length）. Inassociation with the ship lock, the surrounding rocks in slope have a high potential to deform, withwhich the magnitude of deformation is restricted. Monitoring results show that the deformation of thefive-step ship lock high slopes of the TGP primarily occurred in excavation period, and deformationtended to be stable and convergent during operation period, suggesting the allowable ranges of deformation.At present, the slopes and lock chambers are stable, and the ship lock works well under normaloperation condition, enabling the social and economic benefits of the TGP. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

关键词： Three Gorges Project(TGP) Five-step ship lock slope Monitoring analysis

Spatiotemporal Distribution of Asian Horseshoe Crab Eggs Are Highly Intermingled with Anthropogenic Structures in Northern Beibu Gulf,China

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Journal of Ocean University of China 2022年第3期21卷 531-540页

作者： KWAN Kit Yue FU Yijian ZHONG Mufeng KUANG Yang BAI Haiwei ZHANG Ce ZHEN Wenquan XU Peng WANG Chun-Chieh ZHU Junhua College of Marine Sciences Beibu Gulf Ocean Development Research CenterBeibu Gulf UniversityQinzhou535011China Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation Qinzhou535011China Guangxi Key Laboratory of Marine Disaster in the Beibu Gulf Qinzhou535011China Guangxi Beibu Gulf Marine Research Center Guangxi Academy of SciencesNanning530007China

Identification,protection and restoration of spawning habitats are vital for protecting the depleted species.Asian horseshoe crabs are ecologically important macroinvertebrates in coastal and estuarine ecosystems.However,their spawning habitat studies were limited to several reports in tropical regions,possibly due to the lack of modified survey methods,particularly in habitats with a lower density of spawning adults,and/or intermingled with anthropogenic structures.In this study,the year-round egg distribution and spawning habitat baselines of Carcinoscorpius rotundicauda and Tachypleus tridentatus were determined in the northern Beibu Gulf,China.Our findings demonstrated that the peak spawning occurred in June–July and ceased in November–January when the average water temperature dropped below 20℃.Egg aggregations were found<10 cm beneath the sediment surface with regular tidal inundation,regardless of seasonal changes,in the vicinity of natural and artificial structures with elevated,mildly sloping substratum within the high tide zones.The nests were characterized by medium-sized sediment grains(0.5–0.9 mm),high temperatures(31–34℃),low water contents(0.8%–0.9%),and total organic carbon contents(0.5%–0.7%),which might maximize the hatching success.The identified nesting beaches were close to nursery habitats for juveniles,and tidal creeks were present as the possible corridor connecting these two important habitats through the dominant mangrove forests.The findings provide valuable insights in the scope of spawning behavior and nest-site selection of Asian horseshoe crabs under a mixture of natural and artificial structures,which could benefit future management efforts for the exploited spawning populations.

关键词： Carcinoscorpius rotundicauda Tachypleus tridentatus mangrove tidal creek sediment texture slope elevated substratum

Self-organized criticality and its application in the slope disasters under gravity

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Science China(Technological Sciences) 2003年第Z1期46卷 20-30页

作者： YAO Lingkan, HUANG Yuan & LU Yang School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China Southwestern Institute of Physics, Chengdu 610031, China SW Jiaotong Univ Sch Civil Engn Chengdu 610031 Peoples R China SW Inst Phys Chengdu 610031 Peoples R China

Firstly, three kinds of sand pile experiments which reflect the universal process of energy dissipation within the slope accumulation under the self-organized action are reviewed. They all show that self-organized criticality (SOC) is related to granular non-uniform. The experiment of Tokamak plasma system is introduced, which shows some of SOC properties of Tokamak plasmas in Ohmic region or L-mode. Secondly, material tests in geotechnical engineering and numerical simulations of micro-structure of sand piles indicate that SOC is determined by the structural characteristics. Finally, according to the principle of SOC, the behavior of slope disasters under gravity and its forecast as well as the design of protection engineering are discussed.

关键词： SOC, sand pile experiment, experiment of Tokamak plasma system, slope disasters under gravitation force.

Impactless biped walking on a slope

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Theoretical & Applied Mechanics Letters 2013年第1期3卷 25-31页

作者： Lulu Gong Werner Schiehlen School of Life Sciences and Technology Tongji University Institute of Eng. Comput. Mechanics University of Stuttgart

Walking without impacts has been considered in dynamics as a motion/force control problem. In order to avoid impacts, an approach for both the specified motion of the biped and its ground reaction forces was presented yielding a combined motion and force control problem. As an application, a walker on a horizontal plane has been considered. In this paper, it is shown how the control of the ground reaction forces and the energy consumption depend on the gradient of a slope. The biped dynamics and the constraints within the biped system and on the ground are discussed. A motion control synthesis is developed using the inverse dynamics principle proven to be most efficient for human walking research, too. The impactless walking with controlled legs is illustrated by a seven-link biped. The ＂flying＂ biped has nine degrees of freedom, with six control inputs. During locomotion, the standing leg has three scleronomic constraints, and the trunk has three rheonomic constraints. However, there are three rheonomic constraints for the prescribed leg motion or three scleronomic constraints for reaction forces of the trailing leg, respectively. The nominal control action for impactless walking can be precomputed and stored. The model proposed allows the investigation of several problems： uphill and downhill walking, optimization of step length,stiction of the feet on the slope and many more. All these findings are also of interest in biomechanics. C 2013 The Chinese Society of Theoretical and Applied Mechanics. [doi：10.1063/2.1301302]

关键词： biped impactless walking motion/force control slope

Research on evolution and prevention of the No.1 large-scale dangerous slope of Erlang Mountain on the Sichuan-Tibet Highway

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Science China(Technological Sciences) 2003年第Z1期46卷 42-51页

作者： ZHANG Xiaoyan The Transportation Department of Sichuan Province, Chengdu 610041, China Transportat Dept Sichuan Prov Chengdu 610041 Peoples R China

Sichuan-Tibet Highway traverses the two principal geomorphic units and their transition belt in western China; it has some hazardous slopes characterized by high altitude and chilliness, high elevation, large scale and complexity. Various hazards usually concur in groups. The integrated hazards of these slopes cannot be reflected by any single hazard; they act on one another and develop at the same time, like many other things experiencing a recurrent evolving course from growth to demise. Based on the mechanisms of the typical dangerous No.1 slope of Erlang Mountain on the Sichuan-Tibet Highway, various simulations through geotechnical test, numerical calculation, and in-situ monitoring have been carried out to control and regularize the last phase of evolution of the slope. The text shows that such slopes have developed under geological and engineering conditions that might have enforced the potentiality of hazards; interactions between different hazards are of more menace than any single factor; structures in cooperation with the hazardous bodies may be effective for preventing such calamities.

关键词： hazards of large slope evolution, hazards concurring in group, structure control.

Experimental study on the progressive failure and its anchoring effect of weak-broken rock vertical slope

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Frontiers of Structural and Civil Engineering 2011年第2期5卷 208-224页

作者： Hehua ZHU Qianwei XU Wenqi DING Feng HUANG Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai 200092China Urban Rail Transit and Railway Engineering Department Tongji UniversityShanghai 200092China

To improve the understanding on the failure behavior and its anchoring effect of weak-broken rock slope,the rock of grade IV according to China is taken as reference prototype,and a series of model tests were carried out in laboratory.These tests can be divided into two categories,that is,with bolt reinforcement and without bolt reinforcement.In which,the stability of slope reinforced with different bolt diameter,different anchor length and different space are studied.The test results show that the collapse of slope is the combination of tension failure at the top and the compression-shearing failure at the bottom of the slope,and its failure process presents progressive characteristics.The contributions of bolt reinforcement are mainly reflected by the aspects of shear resistance,crack resistance and anti-extension.The reinforcement of blot not only can improve the vertical bearing capacity before failure,but also can reduce the vertical settlement and allow greater lateral rock wall deformation;what is more,the stress concentration degree in rock mass can be dispersed,which do help to improve the stability of slope rock mass.

关键词： progressive failure weak-broken rock slope model test bolt