Accurately predicting the production rate and estimated ultimate recovery(EUR)of shale oil wells is vital for efficient shale oil development.Although numerical simulations provide accurate predictions,their high time...Accurately predicting the production rate and estimated ultimate recovery(EUR)of shale oil wells is vital for efficient shale oil development.Although numerical simulations provide accurate predictions,their high time,data,and labor demands call for a swifter,yet precise,method.This study introduces the DuongeCNNeLSTM(D-C-L)model,which integrates a convolutional neural network(CNN)with a long short-term memory(LSTM)network and is grounded on the empirical Duong model for physical constraints.Compared to traditional approaches,the D-C-L model demonstrates superior precision,efficiency,and cost-effectiveness in predicting shale oil production.展开更多
The oil-film oscillation in dimensional nonlinear problem. In this a large rotating machinery is a complex high- paper, a high pressure rotor of an aero engine with a pair of liquid-film lubricated bearings is modeled...The oil-film oscillation in dimensional nonlinear problem. In this a large rotating machinery is a complex high- paper, a high pressure rotor of an aero engine with a pair of liquid-film lubricated bearings is modeled as a twenty-two-degree-of-freedom nonlinear system by the Lagrange method. This high-dimensional nonlinear system can be reduced to a two-degree-of-freedom system preserving the oil-film oscillation property by introducing the modified proper orthogonal decomposition （POD） method. The effi- ciency of the method is shown by numerical simulations for both the original and reduced systems. The Chen-Longford （C-L） method is introduced to get the dynamical behaviors of the reduced system that reflect the natural property of the oil-film oscillation.展开更多
The C-L method was generalized from Liapunov-Schmidt reduction method, combined with theory of singularities, for study of non-autonomous dynamical systems to obtain the typical bifurcating response curves in the syst...The C-L method was generalized from Liapunov-Schmidt reduction method, combined with theory of singularities, for study of non-autonomous dynamical systems to obtain the typical bifurcating response curves in the system parameter spaces. This method has been used, ar an example, to analyze the engineering nonlinear dynamical problems by obtaining the bifurcation programs and response curves which are useful in developing techniques of control to subharmonic instability of large rotating machinery.展开更多
Using the data taken from Tibet II High Density （HD） Array （1997 February-1999 September） and Tibet-III array （1999 November--2005 November）, our previous northern sky survey for TeV γ-ray point sources has now...Using the data taken from Tibet II High Density （HD） Array （1997 February-1999 September） and Tibet-III array （1999 November--2005 November）, our previous northern sky survey for TeV γ-ray point sources has now been updated by a factor of 2.8 improved statistics. From 0.0° to 60.0° in declination （Dec） range, no new TeV T-ray point sources with sufficiently high significance were identified while the well-known Crab Nebula and Mrk421 remain to be the brightest TeV γ-ray sources within the field of view of the Tibet air shower array. Based on the currently available data and at the 90% confidence level （C.L.）, the flux upper limits for different power law index assumption are re-derived, which are approximately improved by 1.7 times as compared with our previous reported limits.展开更多
The topological bifurcation diagrams and the coefficients of bifurcation equation were obtained by C_L method.According to obtained bifurcation diagrams and combining control theory,the method of robust control of per...The topological bifurcation diagrams and the coefficients of bifurcation equation were obtained by C_L method.According to obtained bifurcation diagrams and combining control theory,the method of robust control of periodic bifurcation was presented,which differs from generic methods of bifurcation control.It can make the existing motion pattern into the goal motion pattern.Because the method does not make strict requirement about parametric values of the controller,it is convenient to design and make it.Numerical simulations verify validity of the method.展开更多
基金funded by the National Natural Science Foundation of China(No.51974356).
文摘Accurately predicting the production rate and estimated ultimate recovery(EUR)of shale oil wells is vital for efficient shale oil development.Although numerical simulations provide accurate predictions,their high time,data,and labor demands call for a swifter,yet precise,method.This study introduces the DuongeCNNeLSTM(D-C-L)model,which integrates a convolutional neural network(CNN)with a long short-term memory(LSTM)network and is grounded on the empirical Duong model for physical constraints.Compared to traditional approaches,the D-C-L model demonstrates superior precision,efficiency,and cost-effectiveness in predicting shale oil production.
基金Project supported by the National Natural Science Foundation of China (No. 11072065)
文摘The oil-film oscillation in dimensional nonlinear problem. In this a large rotating machinery is a complex high- paper, a high pressure rotor of an aero engine with a pair of liquid-film lubricated bearings is modeled as a twenty-two-degree-of-freedom nonlinear system by the Lagrange method. This high-dimensional nonlinear system can be reduced to a two-degree-of-freedom system preserving the oil-film oscillation property by introducing the modified proper orthogonal decomposition （POD） method. The effi- ciency of the method is shown by numerical simulations for both the original and reduced systems. The Chen-Longford （C-L） method is introduced to get the dynamical behaviors of the reduced system that reflect the natural property of the oil-film oscillation.
文摘The C-L method was generalized from Liapunov-Schmidt reduction method, combined with theory of singularities, for study of non-autonomous dynamical systems to obtain the typical bifurcating response curves in the system parameter spaces. This method has been used, ar an example, to analyze the engineering nonlinear dynamical problems by obtaining the bifurcation programs and response curves which are useful in developing techniques of control to subharmonic instability of large rotating machinery.
基金Supported by Grants-in-Aid for Scientific Research on Priority Areas (712) (MEXT)Japan Society for Promotion of Science(JSPS)+1 种基金National Natural Science Foundation of China (10675134,10533020)Chinese Academy of Sciences
文摘Using the data taken from Tibet II High Density （HD） Array （1997 February-1999 September） and Tibet-III array （1999 November--2005 November）, our previous northern sky survey for TeV γ-ray point sources has now been updated by a factor of 2.8 improved statistics. From 0.0° to 60.0° in declination （Dec） range, no new TeV T-ray point sources with sufficiently high significance were identified while the well-known Crab Nebula and Mrk421 remain to be the brightest TeV γ-ray sources within the field of view of the Tibet air shower array. Based on the currently available data and at the 90% confidence level （C.L.）, the flux upper limits for different power law index assumption are re-derived, which are approximately improved by 1.7 times as compared with our previous reported limits.
文摘The topological bifurcation diagrams and the coefficients of bifurcation equation were obtained by C_L method.According to obtained bifurcation diagrams and combining control theory,the method of robust control of periodic bifurcation was presented,which differs from generic methods of bifurcation control.It can make the existing motion pattern into the goal motion pattern.Because the method does not make strict requirement about parametric values of the controller,it is convenient to design and make it.Numerical simulations verify validity of the method.
