Brittleness and ductility of shale are closely related to shale gas exploration and production. How to predict brittleness and ductility of shale is one of the key issues in the study of shale gas preservation and hyd...Brittleness and ductility of shale are closely related to shale gas exploration and production. How to predict brittleness and ductility of shale is one of the key issues in the study of shale gas preservation and hydraulic fracturing treatments. The magnitude of shale brittleness was often determined by brittle mineral content(for example, quartz and feldspars) in shale gas exploration.However, the shale brittleness is also controlled by burial depth. Shale brittle/ductile properties such as brittle, semibrittle and ductile can mutually transform with burial depth variation. We established a work flow of determining the burial depth interval of brittle–ductile transition zone for a given shale. Two boundaries were employed to divide the burial depth interval of shale brittle/ductile properties. One is the bottom boundary of the brittle zone(BZ), and the other is the top boundary of the ductile zone(DZ). The brittle–ductile transition zone(BDTZ) is between them.The bottom boundary of BZ was determined by the overconsolidation ratio(OCR) threshold value combined with pre-consolidation stress which the shale experienced over geological time. The top boundary of DZ was determined based on the critical confining pressure of brittle–ductile transition. The OCR threshold value and the critical confining pressure were obtained from uniaxial strain andtriaxial compression tests. The BZ, DZ and BDTZ of the Lower Silurian Longmaxi shale in some representative shale gas exploration wells in eastern Sichuan and western Hubei areas were determined according to the above work flow. The results show that the BZ varies with the maximum burial depth and the DZ varies with the density of the overlying rocks except for the critical confining pressure.Moreover, the BDTZ determined by the above work flow is probably the best burial depth interval for marine shale gas exploration and production in Southern China. Shale located in the BDTZ is semi-brittle and is not prone to be severely naturally fractured but likely to respond well to hydraulic fracturing. The depth interval of BDTZ determined by our work flow could be a valuable parameter of shale gas estimation in geology and engineering.展开更多
One of the main concerns in cyclic behavior of soft clay is gradual degradation with the progression of loading cycle.A series of cyclic constant-volume direct simple shear(CDSS) loading tests was performed on Malaysi...One of the main concerns in cyclic behavior of soft clay is gradual degradation with the progression of loading cycle.A series of cyclic constant-volume direct simple shear(CDSS) loading tests was performed on Malaysia offshore clay to study its undrained degradation.The testing program consists of stresscontrolled tests with cyclic shear ratio ranging from 0.34 to 0.83 at different overconsolidation ratios(OCRs).For a given cyclic stress ratio in stress-controlled tests,the accumulated cyclic strain and pore water pressure increase with elevated number of cycles.In heavily overconsolidated clay specimens,the negative cyclic pore water pressure is generated followed by positive cyclic pore water pressure as cyclic tests progress.The post-cyclic strength of offshore clay specimens is reduced by undrained cyclic stresscontrolled loading.展开更多
The liquefaction of loess under dynamic loading is studied experimentally with a dynamic triaxial test system. The effects of over-consolidation ratio (OCR), saturation degree and the frequency of dynamic loading upon...The liquefaction of loess under dynamic loading is studied experimentally with a dynamic triaxial test system. The effects of over-consolidation ratio (OCR), saturation degree and the frequency of dynamic loading upon loess liquefaction are investigated. The development of pore pressure within loess samples is also discussed. Based on the experimental results, the empirical relationship between pore pressure ratio and loading cycle number ratio is established for normal consolidated saturated loess.展开更多
Ridgetail white prawn(E xopalaemon carinicauda) are of significant economic importance in China where they are widely cultured. However,there is little information on the basic biology of this species. We evaluated th...Ridgetail white prawn(E xopalaemon carinicauda) are of significant economic importance in China where they are widely cultured. However,there is little information on the basic biology of this species. We evaluated the effect of temperature(16,19,22,25,28,31,and 34°C) on the standard metabolic rates(SMRs) of juvenile and adult E. carinicauda in the laboratory under static conditions. The oxygen consumption rate(OCR),ammonia-Nexcretion rate(AER),and atomic ratio of oxygen consumed to nitrogen consumed(O:N ratio) of juvenile and adult E. carinicauda were significantly influenced by temperature( P< 0.05). Both the OCR and AER of juveniles increased significantly with increasing temperature from 16 to 34°C,but the maximum OCR for adults was at 31°C. Juvenile shrimp exhibited a higher OCR than the adults from 19 to 34°C. There was no significant difference between the AERs of the two life-stages from 16 to 31°C( P >0.05). The O:N ratio in juveniles was significantly higher than that in the adults over the entire temperature range(P <0.05). The temperature coefficient(Q 10) of OCR and AER ranged from 5.03 to 0.86 and 6.30 to 0.85 for the adults,respectively,and from 6.09–1.03 and 3.66–1.80 for the juveniles,respectively. The optimal temperature range for growth of the juvenile and adult shrimp was from 28 to 31°C,based on Q 10 and SMR values. Results from the present study may be used to guide pond culture production of E. carinicauda.展开更多
In today’s digital era,the text may be in form of images.This research aims to deal with the problem by recognizing such text and utilizing the support vector machine(SVM).A lot of work has been done on the English l...In today’s digital era,the text may be in form of images.This research aims to deal with the problem by recognizing such text and utilizing the support vector machine(SVM).A lot of work has been done on the English language for handwritten character recognition but very less work on the under-resourced Hindi language.A method is developed for identifying Hindi language characters that use morphology,edge detection,histograms of oriented gradients(HOG),and SVM classes for summary creation.SVM rank employs the summary to extract essential phrases based on paragraph position,phrase position,numerical data,inverted comma,sentence length,and keywords features.The primary goal of the SVM optimization function is to reduce the number of features by eliminating unnecessary and redundant features.The second goal is to maintain or improve the classification system’s performance.The experiment included news articles from various genres,such as Bollywood,politics,and sports.The proposed method’s accuracy for Hindi character recognition is 96.97%,which is good compared with baseline approaches,and system-generated summaries are compared to human summaries.The evaluated results show a precision of 72%at a compression ratio of 50%and a precision of 60%at a compression ratio of 25%,in comparison to state-of-the-art methods,this is a decent result.展开更多
Invoice document digitization is crucial for efficient management in industries.The scanned invoice image is often noisy due to various reasons.This affects the OCR(optical character recognition)detection accuracy.In ...Invoice document digitization is crucial for efficient management in industries.The scanned invoice image is often noisy due to various reasons.This affects the OCR(optical character recognition)detection accuracy.In this paper,letter data obtained from images of invoices are denoised using a modified autoencoder based deep learning method.A stacked denoising autoencoder(SDAE)is implemented with two hidden layers each in encoder network and decoder network.In order to capture the most salient features of training samples,a undercomplete autoencoder is designed with non-linear encoder and decoder function.This autoencoder is regularized for denoising application using a combined loss function which considers both mean square error and binary cross entropy.A dataset consisting of 59,119 letter images,which contains both English alphabets(upper and lower case)and numbers(0 to 9)is prepared from many scanned invoices images and windows true type(.ttf)files,are used for training the neural network.Performance is analyzed in terms of Signal to Noise Ratio(SNR),Peak Signal to Noise Ratio(PSNR),Structural Similarity Index(SSIM)and Universal Image Quality Index(UQI)and compared with other filtering techniques like Nonlocal Means filter,Anisotropic diffusion filter,Gaussian filters and Mean filters.Denoising performance of proposed SDAE is compared with existing SDAE with single loss function in terms of SNR and PSNR values.Results show the superior performance of proposed SDAE method.展开更多
基金financially supported by the National Science&Technology Special Project(Grant No.2016ZX05061001)
文摘Brittleness and ductility of shale are closely related to shale gas exploration and production. How to predict brittleness and ductility of shale is one of the key issues in the study of shale gas preservation and hydraulic fracturing treatments. The magnitude of shale brittleness was often determined by brittle mineral content(for example, quartz and feldspars) in shale gas exploration.However, the shale brittleness is also controlled by burial depth. Shale brittle/ductile properties such as brittle, semibrittle and ductile can mutually transform with burial depth variation. We established a work flow of determining the burial depth interval of brittle–ductile transition zone for a given shale. Two boundaries were employed to divide the burial depth interval of shale brittle/ductile properties. One is the bottom boundary of the brittle zone(BZ), and the other is the top boundary of the ductile zone(DZ). The brittle–ductile transition zone(BDTZ) is between them.The bottom boundary of BZ was determined by the overconsolidation ratio(OCR) threshold value combined with pre-consolidation stress which the shale experienced over geological time. The top boundary of DZ was determined based on the critical confining pressure of brittle–ductile transition. The OCR threshold value and the critical confining pressure were obtained from uniaxial strain andtriaxial compression tests. The BZ, DZ and BDTZ of the Lower Silurian Longmaxi shale in some representative shale gas exploration wells in eastern Sichuan and western Hubei areas were determined according to the above work flow. The results show that the BZ varies with the maximum burial depth and the DZ varies with the density of the overlying rocks except for the critical confining pressure.Moreover, the BDTZ determined by the above work flow is probably the best burial depth interval for marine shale gas exploration and production in Southern China. Shale located in the BDTZ is semi-brittle and is not prone to be severely naturally fractured but likely to respond well to hydraulic fracturing. The depth interval of BDTZ determined by our work flow could be a valuable parameter of shale gas estimation in geology and engineering.
基金support from Ministry of Education (MOE)FRGS grantCSL Sdn Bhd,Malaysia
文摘One of the main concerns in cyclic behavior of soft clay is gradual degradation with the progression of loading cycle.A series of cyclic constant-volume direct simple shear(CDSS) loading tests was performed on Malaysia offshore clay to study its undrained degradation.The testing program consists of stresscontrolled tests with cyclic shear ratio ranging from 0.34 to 0.83 at different overconsolidation ratios(OCRs).For a given cyclic stress ratio in stress-controlled tests,the accumulated cyclic strain and pore water pressure increase with elevated number of cycles.In heavily overconsolidated clay specimens,the negative cyclic pore water pressure is generated followed by positive cyclic pore water pressure as cyclic tests progress.The post-cyclic strength of offshore clay specimens is reduced by undrained cyclic stresscontrolled loading.
基金The project supported by the National Natural Science Foundation of China(50178005)
文摘The liquefaction of loess under dynamic loading is studied experimentally with a dynamic triaxial test system. The effects of over-consolidation ratio (OCR), saturation degree and the frequency of dynamic loading upon loess liquefaction are investigated. The development of pore pressure within loess samples is also discussed. Based on the experimental results, the empirical relationship between pore pressure ratio and loading cycle number ratio is established for normal consolidated saturated loess.
基金Supported by the National Key Technology Research and Development Program of China(No.2011BAD13B01)the National Natural Science Foundation of China(General Program)(No.41376165)the China Agriculture Research System CARS-47
文摘Ridgetail white prawn(E xopalaemon carinicauda) are of significant economic importance in China where they are widely cultured. However,there is little information on the basic biology of this species. We evaluated the effect of temperature(16,19,22,25,28,31,and 34°C) on the standard metabolic rates(SMRs) of juvenile and adult E. carinicauda in the laboratory under static conditions. The oxygen consumption rate(OCR),ammonia-Nexcretion rate(AER),and atomic ratio of oxygen consumed to nitrogen consumed(O:N ratio) of juvenile and adult E. carinicauda were significantly influenced by temperature( P< 0.05). Both the OCR and AER of juveniles increased significantly with increasing temperature from 16 to 34°C,but the maximum OCR for adults was at 31°C. Juvenile shrimp exhibited a higher OCR than the adults from 19 to 34°C. There was no significant difference between the AERs of the two life-stages from 16 to 31°C( P >0.05). The O:N ratio in juveniles was significantly higher than that in the adults over the entire temperature range(P <0.05). The temperature coefficient(Q 10) of OCR and AER ranged from 5.03 to 0.86 and 6.30 to 0.85 for the adults,respectively,and from 6.09–1.03 and 3.66–1.80 for the juveniles,respectively. The optimal temperature range for growth of the juvenile and adult shrimp was from 28 to 31°C,based on Q 10 and SMR values. Results from the present study may be used to guide pond culture production of E. carinicauda.
文摘In today’s digital era,the text may be in form of images.This research aims to deal with the problem by recognizing such text and utilizing the support vector machine(SVM).A lot of work has been done on the English language for handwritten character recognition but very less work on the under-resourced Hindi language.A method is developed for identifying Hindi language characters that use morphology,edge detection,histograms of oriented gradients(HOG),and SVM classes for summary creation.SVM rank employs the summary to extract essential phrases based on paragraph position,phrase position,numerical data,inverted comma,sentence length,and keywords features.The primary goal of the SVM optimization function is to reduce the number of features by eliminating unnecessary and redundant features.The second goal is to maintain or improve the classification system’s performance.The experiment included news articles from various genres,such as Bollywood,politics,and sports.The proposed method’s accuracy for Hindi character recognition is 96.97%,which is good compared with baseline approaches,and system-generated summaries are compared to human summaries.The evaluated results show a precision of 72%at a compression ratio of 50%and a precision of 60%at a compression ratio of 25%,in comparison to state-of-the-art methods,this is a decent result.
文摘Invoice document digitization is crucial for efficient management in industries.The scanned invoice image is often noisy due to various reasons.This affects the OCR(optical character recognition)detection accuracy.In this paper,letter data obtained from images of invoices are denoised using a modified autoencoder based deep learning method.A stacked denoising autoencoder(SDAE)is implemented with two hidden layers each in encoder network and decoder network.In order to capture the most salient features of training samples,a undercomplete autoencoder is designed with non-linear encoder and decoder function.This autoencoder is regularized for denoising application using a combined loss function which considers both mean square error and binary cross entropy.A dataset consisting of 59,119 letter images,which contains both English alphabets(upper and lower case)and numbers(0 to 9)is prepared from many scanned invoices images and windows true type(.ttf)files,are used for training the neural network.Performance is analyzed in terms of Signal to Noise Ratio(SNR),Peak Signal to Noise Ratio(PSNR),Structural Similarity Index(SSIM)and Universal Image Quality Index(UQI)and compared with other filtering techniques like Nonlocal Means filter,Anisotropic diffusion filter,Gaussian filters and Mean filters.Denoising performance of proposed SDAE is compared with existing SDAE with single loss function in terms of SNR and PSNR values.Results show the superior performance of proposed SDAE method.
