The capabilities of GIS in modeling fault patterns are explored for Irkutsk city in East Siberia with implications for ground stability. The neotectonic structure of the area is visualized in three dimension （3D） ta...The capabilities of GIS in modeling fault patterns are explored for Irkutsk city in East Siberia with implications for ground stability. The neotectonic structure of the area is visualized in three dimension （3D） taking into account fault dips, using the ArcGIS, GlobalMapper and Paradigm Geophysical packages. The study area is divided into blocks of different size classes according to the length-based ranks of the bounding faults, which are of five classes distinguished with the equal interval method. The blocks show different deformation patterns, with different densities and strikes of crossing and bounding faults. The data are statistically processed using GIS to estimate the deformation degrees of blocks in arbitrary units per square kilometer using the attributes of rank and crossing/bounding position of faults and the size of blocks. The deformation degrees are then compared with available estimates of ground stability measured as a score of points corresponding to destabilizing factors. Although the comparison generally confirms some linkage between the deformation degree of blocks and their ground stability, the correlation is intricate and ambiguous. In order to enhance the advantages of GIS in building and analyzing 3D models of fault patterns for estimating ground stability and mitigating geological hazards, it is expected in the future to proceed from the reported initial step of visualization to more advanced analysis.展开更多
Because performance parameters of gear have degradation,a method is proposed to recognize and analyze its faults using the hidden Markov model( HMM). In this method,firstly,the delayed correlation-envelope method is u...Because performance parameters of gear have degradation,a method is proposed to recognize and analyze its faults using the hidden Markov model( HMM). In this method,firstly,the delayed correlation-envelope method is used to extract features from vibration signals. Then,HMMs are trained respectively using data under normal condition,gear root crack condition and gear root breaking condition. Further,the trained HMMs are used in pattern recognition and model assessment. Finally,the results from standard HMM and the proposed method are compared, which shows that the proposed methodology is feasible and effective.展开更多
With the expansion and increasing complexity of data center networks(DCNs),network fault-tolerance has become increasingly important.RRect is a server-centered DCN with a good interconnection structure.In this paper,w...With the expansion and increasing complexity of data center networks(DCNs),network fault-tolerance has become increasingly important.RRect is a server-centered DCN with a good interconnection structure.In this paper,we propose a fault-tolerant routing algorithm RRFP under a conditional fault pattern of RRect,which can find a fault-free path between any two fault-free vertices.Firstly,we study a fault pattern of RRect in the case of restricted faulty vertex sets,{1,2}-restricted connectivity.It is about{2,3}times RRect’s traditional connectivity,indicating that{1,2}-restricted connectivity better evaluates the fault-tolerant capability.Secondly,we design an effective fault-tolerant routing algorithm RRFP under the conditional fault pattern of RRect,and RRFP can accommodate more faulty vertices.Finally,we conduct experiments on RRFP to evaluate its performance.The experimental results show that in terms of the running time,as parameters n and k change,RRFP outperforms Dijkstra’s algorithm by 64%–84%and Breadth-First-Search(BFS)by 56%–71%.The running time of all the three algorithms is very short as parameter m changes.In terms of the constructing path length,as parameters change,RRFP outperforms BFS by 12%–19%.Moreover,the path constructed by RRFP approaches the shortest path of Dijkstra’s algorithm.Moreover,RRFP still maintains a low transmission failure rate(TFR)and high reliability even with an increase in the number of fault elements.展开更多
This paper examines major active faults and the present-day tectonic stress field in the East Tibetan Plateau by integrating available data from published literature and proposes a block kinematics model of the region...This paper examines major active faults and the present-day tectonic stress field in the East Tibetan Plateau by integrating available data from published literature and proposes a block kinematics model of the region. It shows that the East Tibetan Plateau is dominated by strike-slip and reverse faulting stress regimes and that the maximum horizontal stress is roughly consistent with the contemporary velocity field, except for the west Qinling range where it parallels the striking of the major strike-slip faults. Active tectonics in the East Tibetan Plateau is characterized by three faulting systems. The left-slip Kunlun-Qinling faulting system combines the east Kunlun fault zone, sinistral oblique reverse faults along the Minshan range and two major NEE-striking faults cutting the west Qinling range, which accommodates eastward motion, at 10--14 mm/a, of the Chuan-Qing block. The left-slip Xianshuihe faulting system accommodated clockwise rotation of the Chuan-Dian block. The Longmenshan thrust faulting system forms the eastern margin of the East Tibetan Plateau and has been propagated to the SW of the Sichuan basin. Crustal shortening across the Longmenshan range seems low （2-4 mm/a） and absorbed only a small part of the eastward motion of the Chuan-Qing block. Most of this eastward motion has been transmitted to South China, which is moving SEE-ward at 7-9 mm/a. It is suggested from geophysical data interpretation that the crust and lithosphere of the East Tibetan Plateau is considerably thickened and theologically layered. The upper crust seems to be decoupled from the lower crust through a decollement zone at a depth of 15-20 kin, which involved the Longmenshan fault belt and propagated eastward to the SW of the Sichuan basin. The Wenchuan earthquake was just formed at the bifurcated point of this decollement system. A rheological boundary should exist beneath the Longmenshan fault belt where the lower crust of the East Tibetan Plateau and the lithospheric mantle of the Yangze block are juxtaposed.展开更多
Three series of sandbox modeling experiments were performed to study the fault-increment pattern in extensional basins. Experimental results showed that the tectonic action mode of boundaries and the shape of major bo...Three series of sandbox modeling experiments were performed to study the fault-increment pattern in extensional basins. Experimental results showed that the tectonic action mode of boundaries and the shape of major boundary faults control the formation and evolution of faults in extensional basins. In the process of extensional deformation, the increase in the number and length of faults was episodic, and every ＇episode＇ experienced three periods, strain-accumulation period, quick fault-increment period and strain-adjustment period. The more complex the shape of the boundary fault, the higher the strain increment each ＇episode＇ experienced. Different extensional modes resulted in different fault-increment patterns. The horizontal detachment extensional mode has the ＇linear＇ style of fault-increment pattern, while the extensional mode controlled by a listric fault has the ＇stepwise＇ style of fault-increment pattern, and the extensional mode controlled by a ramp-flat boundary fault has the ＇stepwise-linear＇ style of fault-increment pattern. These fault-increment patterns given above could provide a theoretical method of fault interpretation and fracture prediction in extensional basins.展开更多
This article proposes an enhanced differential fault analysis（DFA） method named as fault-propagation pattern-based DFA（FPP-DFA）.The main idea of FPP-DFA is using the FPP of the ciphertext difference to predict the...This article proposes an enhanced differential fault analysis（DFA） method named as fault-propagation pattern-based DFA（FPP-DFA）.The main idea of FPP-DFA is using the FPP of the ciphertext difference to predict the fault location and the fault-propagation path.It shows that FPP-DFA is very effective on SPN structure block ciphers using bitwise permutation,which is applied to two block ciphers.The first is PRESENT with the substitution permutation sequence.With the fault model of injecting one nibble fault into the r-2nd round,on average 8 and 16 faults can reduce the key search space of PRESENT-80/128 to 214.7 and 221.1,respectively.The second is PRINTcipher with the permutation substitution sequence.For the first time,it shows that although the permutation of PRINTcipher is secret key dependent,FPP-DFA still works well on it.With the fault model of injecting one nibble fault into the r-2nd round,12 and 24 effective faults can reduce the key search space of PRINTcipher-48/96 to 213.7 and 222.8,respectively.展开更多
Based on the outcrop survey,3D seismic data interpretation,drilling data analysis,the structural patterns and distribution of fault damage zones in carbonate strata of Tazhong Paleo-uplift were established to reveal t...Based on the outcrop survey,3D seismic data interpretation,drilling data analysis,the structural patterns and distribution of fault damage zones in carbonate strata of Tazhong Paleo-uplift were established to reveal the oil and gas enrichment law in the fault damage zones.The following findings were reached:(1)Through the filed survey,the fault damage zone system consists of fault core,damage zone with branch fault and fracture network.Affected by the active nature of the major faults,the fault damage zones differ in planar pattern and scale along the major faults.(2)3D seismic profiles reveal that there are three types of fault damage zones in carbonate strata in Tazhong paleo-uplift,strike-slip fault damage zones,thrust fault damage zones and superimposed fault damage zones.Featuring3 flowers and 3 root belts in vertical,the strike-slip fault damage zone can be subdivided into linear type,oblique type,feather type and horsetail type in plane.Thrust fault damage zones can be further divided into fault anticline type,anticline type and slope type.As the superimposition result of the above two kinds of fault damage zones,superimposed fault damage zones appear in three patterns,intersect type,encompassment type and penetrating type.(3)Cores from wells and geochemical data show oil and gas may migrate along the major fault and laterally.The feather type in strike-slip fault system,fault anticline type in thrust fault damage zone and intersect type in superimposed fault damage zone are possible sites for high production and efficiency wells.展开更多
This paper introduces concepts of symptom vector and fuzzy symptom vector forspacecraft condition recognition and fault diagnosis,defines an operator and suggests a fuzzy pat-tern recognition method of fault diagnosis...This paper introduces concepts of symptom vector and fuzzy symptom vector forspacecraft condition recognition and fault diagnosis,defines an operator and suggests a fuzzy pat-tern recognition method of fault diagnosis for spacecraft.This method is verified by examples andresults are checked from an expert system.展开更多
Fieldwork along several segments of the Altyn Tagh Fault,between 85 and 95°E,confirms that it ranks as one of the most active faults of Asia.In the East,near Aksay,the active fault trace offsets numerous stream c...Fieldwork along several segments of the Altyn Tagh Fault,between 85 and 95°E,confirms that it ranks as one of the most active faults of Asia.In the East,near Aksay,the active fault trace offsets numerous stream channels,terrace risers and fans tens to hundreds of meters. 14 C dating of organic remains and charcoal within terrace gravels indicates that most of the terraces were emplaced after the beginning of the Holocene,implying a left\|slip rate of about 2cm/a.Large mole tracks attest to the occurrence of great earthquakes.Even larger mole tracks are found north of Lenghu,within the Altun Shan push\|up,a 6000 m high range in a restraining bend of the fault,now sliced by its most active strand.North of Huatougou,at the transition between another push\|up mountain and a recent pull\|apart basin,a spectacular sequence of five flat\|floored,hanging channels,beheaded by the fault from a unique source in the mountain,have been horizontally displaced by up to 1250m.Cosmogenic dating of the abandonment of these channels and of nearby offset terrace risers confirms the slip\|rate at Aksay.Several km to the west,pressure ridges exceeding 10m in height across a large young fan,imply the repeat of several great earthquakes in a relatively short time span.展开更多
Monitoring of potential bearing faults in operation is of critical importance to safe operation of high speed trains.One of the major challenges is how to differentiate relevant signals to operational conditions of be...Monitoring of potential bearing faults in operation is of critical importance to safe operation of high speed trains.One of the major challenges is how to differentiate relevant signals to operational conditions of bearings from noises emitted from the surrounding environment.In this work,we report a procedure for analyzing acoustic emission signals collected from rolling bearings for diagnosis of bearing health conditions by examining their morphological pattern spectrum（MPS） through a multi-scale morphology analysis procedure.The results show that acoustic emission signals resulted from a given type of bearing faults share rather similar MPS curves.Further examinations in terms of sample entropy and Lempel-Ziv complexity of MPS curves suggest that these two parameters can be utilized to determine damage modes.展开更多
Comprehensively utilizing the seismic,logging,drilling and outcrop data,this research studies the characteristics of the Cambrian faults and their control on the sedimentation and reservoirs in the Ordos Basin.The res...Comprehensively utilizing the seismic,logging,drilling and outcrop data,this research studies the characteristics of the Cambrian faults and their control on the sedimentation and reservoirs in the Ordos Basin.The results show that:(1)Three groups of faults striking North-East(NE),near East-West(EW),and North-West(NW)were developed in the Cambrian.The NE and near EW faults,dominated by the normal faults,are the synsedimentary faults and the main faults of the Cambrian.(2)According to the roles of faults in tectonic units and the development scale of the faults,the Cambrian faults can be divided into three grades.The second-grade faults,large in scale,controlled the boundary of the Cambrian sags of the Ordos Basin.The third-grade faults,smaller in scale than the second-grade fault,controlled the high and low fluctuations of local structures.The fourth-grade faults,very small in scale,were adjusting faults developed inside the local tectonic units.(3)The Cambrian faults had strong control on the sedimentation and reservoir of the Cambrian.Controlled by the second-grade and the third-grade faults,the paleogeographical framework of the Cambrian presents combination characteristics of the bulge-sag macro-structures and the high-low differentiation micro-geomorphology.This paleogeographical pattern not only controlled the development of the oolitic beach facies in the Cambrian but also the distribution of high-quality reservoirs.(4)Under the control of the faults,the micro-paleogeomorphological high parts closely adjacent to the margin of the Cambrian sags are the favorable exploration areas.展开更多
On August 8,2017,an M_(W)6.5 earthquake occurred in Jiuzhaigou County,Sichuan Province,China,on the eastern margin of the Qinghai-Tibet Plateau.This study investigates the coseismic deformation field and fault model w...On August 8,2017,an M_(W)6.5 earthquake occurred in Jiuzhaigou County,Sichuan Province,China,on the eastern margin of the Qinghai-Tibet Plateau.This study investigates the coseismic deformation field and fault model with ascending and descending Sentinel-1 synthetic aperture radar(SAR)images,aftershock distribution,and elastic half-space dislocation model.The regional fault slip pattern is then quantita-tively examined using the boundary element method.The results show that the ascending and descending interferometric synthetic aperture radar(InSAR)coseismic deformation fields display an overall NNW-SSE trend,with more significant deformation on the southwest side of the fault.The coseismic fault geometry is divided into NW and SE sub-faults with strikes of 162.1°and 149.3°,respectively.The coseismic fault slip is dominated by a left-lateral strike-slip movement with an average rake of-2.31°,mainly occurring at a depth of 0-13.04 km with a shape of an approximately inverted triangle.The fault slip features two peak slip zones,with a maximum of 1.39 m.The total seismic moment is 6.34×10^(18)N·m(M_(W)6.47).The boundary element calculation quantitatively indicates that the regional fault slip pattern may be mainly attributable to the changing strike and dip.The strike changes from NNWeSSE to nearly NS direction,and the dip gradually decreases from the Jiuzhaigou earthquake fault in the north to the Huya fault in the south.With these characteristics,the Huya and the Jiuzhaigou earthquake faults form the eastern boundary of the Minshan uplift zone and accommodate the accumulated deformation.展开更多
It is easy to apply lines in design drawings to create different styles, however, there is no guarantee that all the style lines drawn are able to be manufactured. In this paper, we focus on one undeliverable style to...It is easy to apply lines in design drawings to create different styles, however, there is no guarantee that all the style lines drawn are able to be manufactured. In this paper, we focus on one undeliverable style to enhance our understanding of the relationship between the design sketch and the pattern design process. In order to evidence that such style is unworkable, a systematic display of pattern development, and to be reinforced by mathematical evaluation, will be introduced and addressed. When one can easily detect design fault, waste of product development time can be minimized.展开更多
In this paper, the analysis of faults with different scales and orientations reveals that the distribution of fractures always develops toward a higher degree of similarity with faults, and a method for calculating th...In this paper, the analysis of faults with different scales and orientations reveals that the distribution of fractures always develops toward a higher degree of similarity with faults, and a method for calculating the multiscale areal fracture density is proposed using fault-fracture self-similarity theory. Based on the fracture parameters observed in cores and thin sections, the initial apertures of multiscale fractures are determined using the constraint method with a skewed distribution. Through calculations and statistical analyses of in situ stresses in combination with physical experiments on rocks, a numerical geomechanical model of the in situ stress field is established. The fracture opening ability under the in situ stress field is subsequently analyzed. Combining the fracture aperture data and areal fracture density at different scales, a calculation model is proposed for the prediction of multiscale and multiperiod fracture parameters, including the fracture porosity, the magnitude and direction of maximum permeability and the flow conductivity. Finally, based on the relationships among fracture aperture,density, and the relative values of fracture porosity and permeability, a fracture development pattern is determined.展开更多
Based on the integrated design and airworthiness verification of civil aircraft system,this paper completes the simulation modeling and fault modeling of aircraft electrical system. The aircraft electrical system is c...Based on the integrated design and airworthiness verification of civil aircraft system,this paper completes the simulation modeling and fault modeling of aircraft electrical system. The aircraft electrical system is constructed in the form of dual generators and dual-channel power supply. The main power supply adopts the three-stage power generation system,the auxiliary power supply system uses the permanent magnet synchronous power generation system and a battery. The transmission and distribution system is responsible for the electrical power conversion and the logic control in the system fault-pattern. The simulation results show that the system is reasonable and effective,which provides a reference for the optimal design and control of the actual aircraft electrical system.展开更多
This paper presents modeling tools based on Boolean satisfiability (SAT) to solve problems of test generation for combinational circuits. It exploits an added layer to maintain circuit-related information and value ju...This paper presents modeling tools based on Boolean satisfiability (SAT) to solve problems of test generation for combinational circuits. It exploits an added layer to maintain circuit-related information and value justification relations to a generic SAT algorithm. It dovetails binary decision graphs (BDD) and SAT techniques to improve the efficiency of automatic test pattern generation (ATPG). More specifically, it first exploits inexpensive reconvergent fanout analysis of circuit to gather information on the local signal correlation by using BDD learning, then uses the above learned information to restrict and focus the overall search space of SAT-based ATPG. Its learning technique is effective and lightweight. The experimental results demonstrate the effectiveness of the approach.展开更多
Based on data of fault movement surveying, we simulate the evolution process of three dimensional stress field in North China by three dimensional finite element method. Evolutional patterns in one-year time scale fro...Based on data of fault movement surveying, we simulate the evolution process of three dimensional stress field in North China by three dimensional finite element method. Evolutional patterns in one-year time scale from 1986 to 1997 have been illustrated and the evolution characteristics of stress field have been analyzed. In comparison with the seismic activity among that time interval in North China, we have primarily discussed the relationship between the evolution of stress field and seismic activity.展开更多
文摘The capabilities of GIS in modeling fault patterns are explored for Irkutsk city in East Siberia with implications for ground stability. The neotectonic structure of the area is visualized in three dimension （3D） taking into account fault dips, using the ArcGIS, GlobalMapper and Paradigm Geophysical packages. The study area is divided into blocks of different size classes according to the length-based ranks of the bounding faults, which are of five classes distinguished with the equal interval method. The blocks show different deformation patterns, with different densities and strikes of crossing and bounding faults. The data are statistically processed using GIS to estimate the deformation degrees of blocks in arbitrary units per square kilometer using the attributes of rank and crossing/bounding position of faults and the size of blocks. The deformation degrees are then compared with available estimates of ground stability measured as a score of points corresponding to destabilizing factors. Although the comparison generally confirms some linkage between the deformation degree of blocks and their ground stability, the correlation is intricate and ambiguous. In order to enhance the advantages of GIS in building and analyzing 3D models of fault patterns for estimating ground stability and mitigating geological hazards, it is expected in the future to proceed from the reported initial step of visualization to more advanced analysis.
文摘Because performance parameters of gear have degradation,a method is proposed to recognize and analyze its faults using the hidden Markov model( HMM). In this method,firstly,the delayed correlation-envelope method is used to extract features from vibration signals. Then,HMMs are trained respectively using data under normal condition,gear root crack condition and gear root breaking condition. Further,the trained HMMs are used in pattern recognition and model assessment. Finally,the results from standard HMM and the proposed method are compared, which shows that the proposed methodology is feasible and effective.
基金supported by the National Natural Science Fund for Distinguished Young Scholars of China under Grant No.62125203the National Natural Science Foundation of China under Grant Nos.61932013,62102196,62372248,and 62302235+1 种基金the Natural Science Fund for Colleges and Universities in Jiangsu Province of China under Grant No.24KJA520006the Postgraduate Research and Practice Innovation Program of Jiangsu Province of China under Grant No.SJCX23_0275.
文摘With the expansion and increasing complexity of data center networks(DCNs),network fault-tolerance has become increasingly important.RRect is a server-centered DCN with a good interconnection structure.In this paper,we propose a fault-tolerant routing algorithm RRFP under a conditional fault pattern of RRect,which can find a fault-free path between any two fault-free vertices.Firstly,we study a fault pattern of RRect in the case of restricted faulty vertex sets,{1,2}-restricted connectivity.It is about{2,3}times RRect’s traditional connectivity,indicating that{1,2}-restricted connectivity better evaluates the fault-tolerant capability.Secondly,we design an effective fault-tolerant routing algorithm RRFP under the conditional fault pattern of RRect,and RRFP can accommodate more faulty vertices.Finally,we conduct experiments on RRFP to evaluate its performance.The experimental results show that in terms of the running time,as parameters n and k change,RRFP outperforms Dijkstra’s algorithm by 64%–84%and Breadth-First-Search(BFS)by 56%–71%.The running time of all the three algorithms is very short as parameter m changes.In terms of the constructing path length,as parameters change,RRFP outperforms BFS by 12%–19%.Moreover,the path constructed by RRFP approaches the shortest path of Dijkstra’s algorithm.Moreover,RRFP still maintains a low transmission failure rate(TFR)and high reliability even with an increase in the number of fault elements.
基金the auspice of National Key Basic Project(973)(granted number 2008CB425702)National Science and Technology Project(granted Number SinoProbe-08)China Geological Survey project(granted number1212010670104)
文摘This paper examines major active faults and the present-day tectonic stress field in the East Tibetan Plateau by integrating available data from published literature and proposes a block kinematics model of the region. It shows that the East Tibetan Plateau is dominated by strike-slip and reverse faulting stress regimes and that the maximum horizontal stress is roughly consistent with the contemporary velocity field, except for the west Qinling range where it parallels the striking of the major strike-slip faults. Active tectonics in the East Tibetan Plateau is characterized by three faulting systems. The left-slip Kunlun-Qinling faulting system combines the east Kunlun fault zone, sinistral oblique reverse faults along the Minshan range and two major NEE-striking faults cutting the west Qinling range, which accommodates eastward motion, at 10--14 mm/a, of the Chuan-Qing block. The left-slip Xianshuihe faulting system accommodated clockwise rotation of the Chuan-Dian block. The Longmenshan thrust faulting system forms the eastern margin of the East Tibetan Plateau and has been propagated to the SW of the Sichuan basin. Crustal shortening across the Longmenshan range seems low （2-4 mm/a） and absorbed only a small part of the eastward motion of the Chuan-Qing block. Most of this eastward motion has been transmitted to South China, which is moving SEE-ward at 7-9 mm/a. It is suggested from geophysical data interpretation that the crust and lithosphere of the East Tibetan Plateau is considerably thickened and theologically layered. The upper crust seems to be decoupled from the lower crust through a decollement zone at a depth of 15-20 kin, which involved the Longmenshan fault belt and propagated eastward to the SW of the Sichuan basin. The Wenchuan earthquake was just formed at the bifurcated point of this decollement system. A rheological boundary should exist beneath the Longmenshan fault belt where the lower crust of the East Tibetan Plateau and the lithospheric mantle of the Yangze block are juxtaposed.
文摘Three series of sandbox modeling experiments were performed to study the fault-increment pattern in extensional basins. Experimental results showed that the tectonic action mode of boundaries and the shape of major boundary faults control the formation and evolution of faults in extensional basins. In the process of extensional deformation, the increase in the number and length of faults was episodic, and every ＇episode＇ experienced three periods, strain-accumulation period, quick fault-increment period and strain-adjustment period. The more complex the shape of the boundary fault, the higher the strain increment each ＇episode＇ experienced. Different extensional modes resulted in different fault-increment patterns. The horizontal detachment extensional mode has the ＇linear＇ style of fault-increment pattern, while the extensional mode controlled by a listric fault has the ＇stepwise＇ style of fault-increment pattern, and the extensional mode controlled by a ramp-flat boundary fault has the ＇stepwise-linear＇ style of fault-increment pattern. These fault-increment patterns given above could provide a theoretical method of fault interpretation and fracture prediction in extensional basins.
基金Supported by the National Natural Science Foundation ofChina (60772082,61173191,and 61272491)
文摘This article proposes an enhanced differential fault analysis（DFA） method named as fault-propagation pattern-based DFA（FPP-DFA）.The main idea of FPP-DFA is using the FPP of the ciphertext difference to predict the fault location and the fault-propagation path.It shows that FPP-DFA is very effective on SPN structure block ciphers using bitwise permutation,which is applied to two block ciphers.The first is PRESENT with the substitution permutation sequence.With the fault model of injecting one nibble fault into the r-2nd round,on average 8 and 16 faults can reduce the key search space of PRESENT-80/128 to 214.7 and 221.1,respectively.The second is PRINTcipher with the permutation substitution sequence.For the first time,it shows that although the permutation of PRINTcipher is secret key dependent,FPP-DFA still works well on it.With the fault model of injecting one nibble fault into the r-2nd round,12 and 24 effective faults can reduce the key search space of PRINTcipher-48/96 to 213.7 and 222.8,respectively.
基金Supported by the China National Science and Technology Major Project(2016ZX05004-004)
文摘Based on the outcrop survey,3D seismic data interpretation,drilling data analysis,the structural patterns and distribution of fault damage zones in carbonate strata of Tazhong Paleo-uplift were established to reveal the oil and gas enrichment law in the fault damage zones.The following findings were reached:(1)Through the filed survey,the fault damage zone system consists of fault core,damage zone with branch fault and fracture network.Affected by the active nature of the major faults,the fault damage zones differ in planar pattern and scale along the major faults.(2)3D seismic profiles reveal that there are three types of fault damage zones in carbonate strata in Tazhong paleo-uplift,strike-slip fault damage zones,thrust fault damage zones and superimposed fault damage zones.Featuring3 flowers and 3 root belts in vertical,the strike-slip fault damage zone can be subdivided into linear type,oblique type,feather type and horsetail type in plane.Thrust fault damage zones can be further divided into fault anticline type,anticline type and slope type.As the superimposition result of the above two kinds of fault damage zones,superimposed fault damage zones appear in three patterns,intersect type,encompassment type and penetrating type.(3)Cores from wells and geochemical data show oil and gas may migrate along the major fault and laterally.The feather type in strike-slip fault system,fault anticline type in thrust fault damage zone and intersect type in superimposed fault damage zone are possible sites for high production and efficiency wells.
基金Supported by the National Natural Science Foundation of China and National Project No.863
文摘This paper introduces concepts of symptom vector and fuzzy symptom vector forspacecraft condition recognition and fault diagnosis,defines an operator and suggests a fuzzy pat-tern recognition method of fault diagnosis for spacecraft.This method is verified by examples andresults are checked from an expert system.
文摘Fieldwork along several segments of the Altyn Tagh Fault,between 85 and 95°E,confirms that it ranks as one of the most active faults of Asia.In the East,near Aksay,the active fault trace offsets numerous stream channels,terrace risers and fans tens to hundreds of meters. 14 C dating of organic remains and charcoal within terrace gravels indicates that most of the terraces were emplaced after the beginning of the Holocene,implying a left\|slip rate of about 2cm/a.Large mole tracks attest to the occurrence of great earthquakes.Even larger mole tracks are found north of Lenghu,within the Altun Shan push\|up,a 6000 m high range in a restraining bend of the fault,now sliced by its most active strand.North of Huatougou,at the transition between another push\|up mountain and a recent pull\|apart basin,a spectacular sequence of five flat\|floored,hanging channels,beheaded by the fault from a unique source in the mountain,have been horizontally displaced by up to 1250m.Cosmogenic dating of the abandonment of these channels and of nearby offset terrace risers confirms the slip\|rate at Aksay.Several km to the west,pressure ridges exceeding 10m in height across a large young fan,imply the repeat of several great earthquakes in a relatively short time span.
基金supported by the National Natural Science Foundation of China (Grant 51205017)the National Science and Technology Support Program (Grant 2015BAG12B01)the National Basic Research Program of China (Grant 2015CB654805)
文摘Monitoring of potential bearing faults in operation is of critical importance to safe operation of high speed trains.One of the major challenges is how to differentiate relevant signals to operational conditions of bearings from noises emitted from the surrounding environment.In this work,we report a procedure for analyzing acoustic emission signals collected from rolling bearings for diagnosis of bearing health conditions by examining their morphological pattern spectrum（MPS） through a multi-scale morphology analysis procedure.The results show that acoustic emission signals resulted from a given type of bearing faults share rather similar MPS curves.Further examinations in terms of sample entropy and Lempel-Ziv complexity of MPS curves suggest that these two parameters can be utilized to determine damage modes.
基金Supported by the China National Science and Technology Major Project(2016ZX05007-002).
文摘Comprehensively utilizing the seismic,logging,drilling and outcrop data,this research studies the characteristics of the Cambrian faults and their control on the sedimentation and reservoirs in the Ordos Basin.The results show that:(1)Three groups of faults striking North-East(NE),near East-West(EW),and North-West(NW)were developed in the Cambrian.The NE and near EW faults,dominated by the normal faults,are the synsedimentary faults and the main faults of the Cambrian.(2)According to the roles of faults in tectonic units and the development scale of the faults,the Cambrian faults can be divided into three grades.The second-grade faults,large in scale,controlled the boundary of the Cambrian sags of the Ordos Basin.The third-grade faults,smaller in scale than the second-grade fault,controlled the high and low fluctuations of local structures.The fourth-grade faults,very small in scale,were adjusting faults developed inside the local tectonic units.(3)The Cambrian faults had strong control on the sedimentation and reservoir of the Cambrian.Controlled by the second-grade and the third-grade faults,the paleogeographical framework of the Cambrian presents combination characteristics of the bulge-sag macro-structures and the high-low differentiation micro-geomorphology.This paleogeographical pattern not only controlled the development of the oolitic beach facies in the Cambrian but also the distribution of high-quality reservoirs.(4)Under the control of the faults,the micro-paleogeomorphological high parts closely adjacent to the margin of the Cambrian sags are the favorable exploration areas.
基金supported by the National Key Research and Development Program of China(2018YFC1503603,2016YFB0501405)the National Natural Science Foundation of China(41874011,41774011)。
文摘On August 8,2017,an M_(W)6.5 earthquake occurred in Jiuzhaigou County,Sichuan Province,China,on the eastern margin of the Qinghai-Tibet Plateau.This study investigates the coseismic deformation field and fault model with ascending and descending Sentinel-1 synthetic aperture radar(SAR)images,aftershock distribution,and elastic half-space dislocation model.The regional fault slip pattern is then quantita-tively examined using the boundary element method.The results show that the ascending and descending interferometric synthetic aperture radar(InSAR)coseismic deformation fields display an overall NNW-SSE trend,with more significant deformation on the southwest side of the fault.The coseismic fault geometry is divided into NW and SE sub-faults with strikes of 162.1°and 149.3°,respectively.The coseismic fault slip is dominated by a left-lateral strike-slip movement with an average rake of-2.31°,mainly occurring at a depth of 0-13.04 km with a shape of an approximately inverted triangle.The fault slip features two peak slip zones,with a maximum of 1.39 m.The total seismic moment is 6.34×10^(18)N·m(M_(W)6.47).The boundary element calculation quantitatively indicates that the regional fault slip pattern may be mainly attributable to the changing strike and dip.The strike changes from NNWeSSE to nearly NS direction,and the dip gradually decreases from the Jiuzhaigou earthquake fault in the north to the Huya fault in the south.With these characteristics,the Huya and the Jiuzhaigou earthquake faults form the eastern boundary of the Minshan uplift zone and accommodate the accumulated deformation.
文摘It is easy to apply lines in design drawings to create different styles, however, there is no guarantee that all the style lines drawn are able to be manufactured. In this paper, we focus on one undeliverable style to enhance our understanding of the relationship between the design sketch and the pattern design process. In order to evidence that such style is unworkable, a systematic display of pattern development, and to be reinforced by mathematical evaluation, will be introduced and addressed. When one can easily detect design fault, waste of product development time can be minimized.
基金supported by the Fundamental Research Funds for the Central Universities (2652017308)the National Natural Science Foundation of China (Grant Nos. 41372139 and 41072098)the National Science and Technology Major Project of China (2016ZX05046-003-001 and 2016ZX05034-004003)
文摘In this paper, the analysis of faults with different scales and orientations reveals that the distribution of fractures always develops toward a higher degree of similarity with faults, and a method for calculating the multiscale areal fracture density is proposed using fault-fracture self-similarity theory. Based on the fracture parameters observed in cores and thin sections, the initial apertures of multiscale fractures are determined using the constraint method with a skewed distribution. Through calculations and statistical analyses of in situ stresses in combination with physical experiments on rocks, a numerical geomechanical model of the in situ stress field is established. The fracture opening ability under the in situ stress field is subsequently analyzed. Combining the fracture aperture data and areal fracture density at different scales, a calculation model is proposed for the prediction of multiscale and multiperiod fracture parameters, including the fracture porosity, the magnitude and direction of maximum permeability and the flow conductivity. Finally, based on the relationships among fracture aperture,density, and the relative values of fracture porosity and permeability, a fracture development pattern is determined.
基金supported by the Key Research and Development Program of Shaanxi Province(2018GY-185)
文摘Based on the integrated design and airworthiness verification of civil aircraft system,this paper completes the simulation modeling and fault modeling of aircraft electrical system. The aircraft electrical system is constructed in the form of dual generators and dual-channel power supply. The main power supply adopts the three-stage power generation system,the auxiliary power supply system uses the permanent magnet synchronous power generation system and a battery. The transmission and distribution system is responsible for the electrical power conversion and the logic control in the system fault-pattern. The simulation results show that the system is reasonable and effective,which provides a reference for the optimal design and control of the actual aircraft electrical system.
基金Supported by Joint Research Fund for Overseas Chinese Young Scholars (No. 50128503) and National Natural Science Foundation of China (No. 50390060)
文摘This paper presents modeling tools based on Boolean satisfiability (SAT) to solve problems of test generation for combinational circuits. It exploits an added layer to maintain circuit-related information and value justification relations to a generic SAT algorithm. It dovetails binary decision graphs (BDD) and SAT techniques to improve the efficiency of automatic test pattern generation (ATPG). More specifically, it first exploits inexpensive reconvergent fanout analysis of circuit to gather information on the local signal correlation by using BDD learning, then uses the above learned information to restrict and focus the overall search space of SAT-based ATPG. Its learning technique is effective and lightweight. The experimental results demonstrate the effectiveness of the approach.
基金State Natural Science Foundation of China (49574223)Key Project (95-04-04-03-01) from China Seismological Bureau under (Nint
文摘Based on data of fault movement surveying, we simulate the evolution process of three dimensional stress field in North China by three dimensional finite element method. Evolutional patterns in one-year time scale from 1986 to 1997 have been illustrated and the evolution characteristics of stress field have been analyzed. In comparison with the seismic activity among that time interval in North China, we have primarily discussed the relationship between the evolution of stress field and seismic activity.
