The Inner Product Masking(IPM)scheme has been shown to provide higher theoretical security guarantees than the BooleanMasking(BM).This scheme aims to increase the algebraic complexity of the coding to achieve a higher...The Inner Product Masking(IPM)scheme has been shown to provide higher theoretical security guarantees than the BooleanMasking(BM).This scheme aims to increase the algebraic complexity of the coding to achieve a higher level of security.Some previous work unfolds when certain(adversarial and implementation)conditions are met,and we seek to complement these investigations by understanding what happens when these conditions deviate from their expected behaviour.In this paper,we investigate the security characteristics of IPM under different conditions.In adversarial condition,the security properties of first-order IPMs obtained through parametric characterization are preserved in the face of univariate and bivariate attacks.In implementation condition,we construct two new polynomial leakage functions to observe the nonlinear leakage of the IPM and connect the security order amplification to the nonlinear function.We observe that the security of IPMis affected by the degree and the linear component in the leakage function.In addition,the comparison experiments from the coefficients,signal-to-noise ratio(SNR)and the public parameter show that the security properties of the IPM are highly implementation-dependent.展开更多
Debonding at the cement-casing interface is recognized as a principal failure mechanism leading to CO_(2) leakage in wells.This detachment gives rise to a microannulus,which notably possesses greater permeability than...Debonding at the cement-casing interface is recognized as a principal failure mechanism leading to CO_(2) leakage in wells.This detachment gives rise to a microannulus,which notably possesses greater permeability than undamaged cement,undermining its sealing efficacy.Conventionally,the permeability of the microannulus is regarded as a uniform value throughout the well.However,fundamentally,a microannulus is one type of fracture,and its gap or aperture size is affected by the effective stress.In this work,we developed a unique experimental apparatus.This equipment facilitates the curing of cement inside a steel casing,the formation of a microannulus between the casing and the cement,and the investigation of the fluid flow dynamics along the microannulus under laboratory-replicated in situ conditions.The microannulus was formed by injecting fluid from one end of the setup,and receiving similar amount of fluid on the other end signified the development of the leakage channel.Additionally,strain gauges affixed to the casing’s external surface yielded key information on the microannulus’s opening and closure.We observed a noticeable decline in microannulus hydraulic aperture(or permeability)in relation to effective stress and an exponential equation fits their relationship.Our findings also indicate a distinct behavior when comparing liquid CO_(2) with water.Specifically,it is easier for liquid CO_(2) to create the microannulus.However,the hydraulic aperture range for this microannulus(0.7-6 mm)is considerably smaller than that created by water flow(2-17 mm).Finally,we integrated the stressdependent microannulus aperture size into the combined analysis of well mechanical integrity and well leakage.The outcomes consistently demonstrated that when factoring in the stress-dependent aperture sizes,the leakage rates are 3e5 times compared to a fixed aperture model.The traditional assumption of a constant aperture significantly underestimates fluid leakage risks.展开更多
The adjustment of the gas drainage rate has an immediate impact on air leakage in gob,thus resulting in the change of self-heating of coal.While regulating the gas drainage parameters,the risk of spontaneous combustio...The adjustment of the gas drainage rate has an immediate impact on air leakage in gob,thus resulting in the change of self-heating of coal.While regulating the gas drainage parameters,the risk of spontaneous combustion of coal should be considered.The risk assessment of gas control and spontaneous combustion of coal under gas drainage in a tunnel was investigated at different gas drainage rates.The distributions of the air volume along the working face,the gas management effects and the width of the oxidation zone were subjected to risk analysis.As the simulation results showed,with increasing gas drainage rate,although the safety of gas dilution by ventilation was assured,the intensifying air leakage caused the oxidation zone to move into the deeper gob and led to an increase in the width of the oxidation zone.A risk assessment method was proposed to determine a suitable gas drainage rate for the upper tunnel.The correctness of the risk assessment and the validity of the numerical modelling were confirmed by the field measurements.展开更多
A biloma is a rare disease characterized by an abnormal intra-or extrahepatic bile collection due to a traumatic or spontaneous rupture of the biliary system.Laboratory findings are nonspecific.The diagnosis is usuall...A biloma is a rare disease characterized by an abnormal intra-or extrahepatic bile collection due to a traumatic or spontaneous rupture of the biliary system.Laboratory findings are nonspecific.The diagnosis is usually suspected on the basis of a typical history(right upper quadrant abdominal pain,chills,fever and recent abdominal trauma or surgery) and is confirmed by detection of typical radiologic features.We report the case of a patient with a history of previous cholecystectomy for lithiasis who presented with clinical symptoms and laboratory data suggestive of acute pancreatitis.Imaging studies also revealed the presence of a chronic and asymptomatic biloma,which could be mistaken for a pseudocyst.The atypical location and ultrasound findings suggested an alternative diagnosis.We therefore reviewed the known literature for bilomas,focusing on the role of ultrasonography,which can reveal some typical aspects,such as location and imaging features.Weconclude that ultrasound plays a key role in the assessment of a suspected biloma in patients with appropriate history and clinical features and provides valuable diagnostic clues even in the absence of these.展开更多
China is the third country to develop and utilize shale gas after the United States and Canada. However,shale gas development has significant environmental problems,such as huge consumption of both land and water reso...China is the third country to develop and utilize shale gas after the United States and Canada. However,shale gas development has significant environmental problems,such as huge consumption of both land and water resources,water pollution risk of hydraulic fracturing,leakage risk of shale gas and so on. At present,environmental impact assessment of shale gas development in China has been conducted based on the Technical Guideline for Environmental Impact Assessment——Constructional Project of Petroleum and Natural Gas Development on Land which lacks clear guidance on selection and quantitative analysis of pollution factors. In this paper,based on the experience of shale gas development in America,special environmental problems that need to be noticed for shale gas development were summarized,and the supplement to the technical guideline for environmental impact assessment of shale gas development was discussed to improve the environmental impact assessment system.展开更多
基金the Hunan Provincial Natrual Science Foundation of China(2022JJ30103)“the 14th Five-Year”Key Disciplines and Application Oriented Special Disciplines of Hunan Province(Xiangjiaotong[2022]351)the Science and Technology Innovation Program of Hunan Province(2016TP1020).
文摘The Inner Product Masking(IPM)scheme has been shown to provide higher theoretical security guarantees than the BooleanMasking(BM).This scheme aims to increase the algebraic complexity of the coding to achieve a higher level of security.Some previous work unfolds when certain(adversarial and implementation)conditions are met,and we seek to complement these investigations by understanding what happens when these conditions deviate from their expected behaviour.In this paper,we investigate the security characteristics of IPM under different conditions.In adversarial condition,the security properties of first-order IPMs obtained through parametric characterization are preserved in the face of univariate and bivariate attacks.In implementation condition,we construct two new polynomial leakage functions to observe the nonlinear leakage of the IPM and connect the security order amplification to the nonlinear function.We observe that the security of IPMis affected by the degree and the linear component in the leakage function.In addition,the comparison experiments from the coefficients,signal-to-noise ratio(SNR)and the public parameter show that the security properties of the IPM are highly implementation-dependent.
基金Financial support for this work from the U.S.Department of Energy(DOE)Office of Basic Energy Sciences for“Center for Coupled Chemo-Mechanics of Cementitious Composites for EGS(C4M)”,DOE’s“National Risk Assessment Partnership(NRAP)”programDOE Office of Energy Efficiency&Renewable Energy’s Geothermal Technologies Office for“Advanced Downhole Acoustic Sensing for Wellbore Integrity”is gratefully acknowledged.
文摘Debonding at the cement-casing interface is recognized as a principal failure mechanism leading to CO_(2) leakage in wells.This detachment gives rise to a microannulus,which notably possesses greater permeability than undamaged cement,undermining its sealing efficacy.Conventionally,the permeability of the microannulus is regarded as a uniform value throughout the well.However,fundamentally,a microannulus is one type of fracture,and its gap or aperture size is affected by the effective stress.In this work,we developed a unique experimental apparatus.This equipment facilitates the curing of cement inside a steel casing,the formation of a microannulus between the casing and the cement,and the investigation of the fluid flow dynamics along the microannulus under laboratory-replicated in situ conditions.The microannulus was formed by injecting fluid from one end of the setup,and receiving similar amount of fluid on the other end signified the development of the leakage channel.Additionally,strain gauges affixed to the casing’s external surface yielded key information on the microannulus’s opening and closure.We observed a noticeable decline in microannulus hydraulic aperture(or permeability)in relation to effective stress and an exponential equation fits their relationship.Our findings also indicate a distinct behavior when comparing liquid CO_(2) with water.Specifically,it is easier for liquid CO_(2) to create the microannulus.However,the hydraulic aperture range for this microannulus(0.7-6 mm)is considerably smaller than that created by water flow(2-17 mm).Finally,we integrated the stressdependent microannulus aperture size into the combined analysis of well mechanical integrity and well leakage.The outcomes consistently demonstrated that when factoring in the stress-dependent aperture sizes,the leakage rates are 3e5 times compared to a fixed aperture model.The traditional assumption of a constant aperture significantly underestimates fluid leakage risks.
基金financially sponsored by the National Natural Science Foundation of China (Nos. 51774114 and 51404090)
文摘The adjustment of the gas drainage rate has an immediate impact on air leakage in gob,thus resulting in the change of self-heating of coal.While regulating the gas drainage parameters,the risk of spontaneous combustion of coal should be considered.The risk assessment of gas control and spontaneous combustion of coal under gas drainage in a tunnel was investigated at different gas drainage rates.The distributions of the air volume along the working face,the gas management effects and the width of the oxidation zone were subjected to risk analysis.As the simulation results showed,with increasing gas drainage rate,although the safety of gas dilution by ventilation was assured,the intensifying air leakage caused the oxidation zone to move into the deeper gob and led to an increase in the width of the oxidation zone.A risk assessment method was proposed to determine a suitable gas drainage rate for the upper tunnel.The correctness of the risk assessment and the validity of the numerical modelling were confirmed by the field measurements.
文摘A biloma is a rare disease characterized by an abnormal intra-or extrahepatic bile collection due to a traumatic or spontaneous rupture of the biliary system.Laboratory findings are nonspecific.The diagnosis is usually suspected on the basis of a typical history(right upper quadrant abdominal pain,chills,fever and recent abdominal trauma or surgery) and is confirmed by detection of typical radiologic features.We report the case of a patient with a history of previous cholecystectomy for lithiasis who presented with clinical symptoms and laboratory data suggestive of acute pancreatitis.Imaging studies also revealed the presence of a chronic and asymptomatic biloma,which could be mistaken for a pseudocyst.The atypical location and ultrasound findings suggested an alternative diagnosis.We therefore reviewed the known literature for bilomas,focusing on the role of ultrasonography,which can reveal some typical aspects,such as location and imaging features.Weconclude that ultrasound plays a key role in the assessment of a suspected biloma in patients with appropriate history and clinical features and provides valuable diagnostic clues even in the absence of these.
文摘China is the third country to develop and utilize shale gas after the United States and Canada. However,shale gas development has significant environmental problems,such as huge consumption of both land and water resources,water pollution risk of hydraulic fracturing,leakage risk of shale gas and so on. At present,environmental impact assessment of shale gas development in China has been conducted based on the Technical Guideline for Environmental Impact Assessment——Constructional Project of Petroleum and Natural Gas Development on Land which lacks clear guidance on selection and quantitative analysis of pollution factors. In this paper,based on the experience of shale gas development in America,special environmental problems that need to be noticed for shale gas development were summarized,and the supplement to the technical guideline for environmental impact assessment of shale gas development was discussed to improve the environmental impact assessment system.
