Data mining is the process of extracting implicit but potentially useful information from incomplete, noisy, and fuzzy data. Data mining offers excellent nonlinear modeling and self-organized learning, and it can play...Data mining is the process of extracting implicit but potentially useful information from incomplete, noisy, and fuzzy data. Data mining offers excellent nonlinear modeling and self-organized learning, and it can play a vital role in the interpretation of well logging data of complex reservoirs. We used data mining to identify the lithologies in a complex reservoir. The reservoir lithologies served as the classification task target and were identified using feature extraction, feature selection, and modeling of data streams. We used independent component analysis to extract information from well curves. We then used the branch-and- bound algorithm to look for the optimal feature subsets and eliminate redundant information. Finally, we used the C5.0 decision-tree algorithm to set up disaggregated models of the well logging curves. The modeling and actual logging data were in good agreement, showing the usefulness of data mining methods in complex reservoirs.展开更多
The laminated overburden model(La Model)has been widely used for pillar design and stability analysis.As a boundary element program,the La Model program is sensitive to the boundary condition,which should be considere...The laminated overburden model(La Model)has been widely used for pillar design and stability analysis.As a boundary element program,the La Model program is sensitive to the boundary condition,which should be considered before creating the model.To eliminate the boundary effect in a La Model pillar stability analysis,a suitable boundary buffer zone is needed around the model edge.The radius of influence(R)and the abutment load extent(D)are two major factors that affect the stresses and displacements calculated in LaM odel.To determine the optimum buffer zone extent,a database of case histories was analyzed using the La Model program.Values for R and D were varied until a buffer zone having negligible influence on the pillar stability factor(SF)of the active mining zone(AMZ)was determined.展开更多
The solution of a slope stability problem can be approached by its least upper-bound and maximum lower-bound with high accuracy. The limit equilibrium methods that employ vertical slices imply a lower bound of the fac...The solution of a slope stability problem can be approached by its least upper-bound and maximum lower-bound with high accuracy. The limit equilibrium methods that employ vertical slices imply a lower bound of the factor of safety. It has been successfully extended to the area of active earth pressure analysis that accounts for different input of locations of earth pressure applications. Those methods that employ slices with inclined interfaces give an upper-bound approach to the stability analysis. It enjoys a sound mechanical background and is able to provide accurate solutions of soil plasticity. It has been successfully extended to the area of bearing capacity analysis in which various empirical coefficients are no longer necessary. The 3D upper- and lower-bound methods under this framework have been made possible and show great potential for solving various engineering problems.展开更多
We compute the mass and temperature of third order Lovelock black holes with negative Gauss-Bonnet coefficient a2 〈 0 in anti-de Sitter space and perform the stability analysis of topological black holes. When k = -1...We compute the mass and temperature of third order Lovelock black holes with negative Gauss-Bonnet coefficient a2 〈 0 in anti-de Sitter space and perform the stability analysis of topological black holes. When k = -1, the third order Lovelock black holes are thermodynamically stable for the whole range r＋. When k = 1, we found that the black hole has an intermediate unstable phase for D = 7. In eight dimensional spacetimes, however, a new phase of thermodynamically unstable small black holes appears if the coefficient a is under a critical value. For D ≥ 9, black holes have similar the distributions of thermodynamically stable regions to the case where the coefficient ＆ is under a critical value for D = 8. It is worth to mention that all the thermodynamic and conserved quantities of the black holes with fiat horizon do not depend on the Loveloek coefficients and are the same as those of black holes in general gravity.展开更多
A simple and direct approach to handle summation is presented. With this approach, we analytically investigate Bose–Einstein condensation of ideal Bose gas trapped in an isotropic harmonic oscillator potential. We ge...A simple and direct approach to handle summation is presented. With this approach, we analytically investigate Bose–Einstein condensation of ideal Bose gas trapped in an isotropic harmonic oscillator potential. We get the accurate expression of which is very close to (0.43% larger than) the experimental data. We find the curve of internal energy of the system vs. temperature has a turning point which marks the beginning of a condensation. We also find that there exists specific heat jump at the transition temperature, no matter whether the system is macroscopic or finite. This phenomenon could be a manifestation of a phase transition in finite systems.展开更多
The aim of this research is to analyze the emergence of the concepts of sustainable development （SD） and corporate social responsibility （CSR） in companies in time and space. A spatio-temporal reading will indicat...The aim of this research is to analyze the emergence of the concepts of sustainable development （SD） and corporate social responsibility （CSR） in companies in time and space. A spatio-temporal reading will indicate the most important socio-political and environmental events that have emerged with these two concepts. In order to complete the odyssey, a spatio-temporal analysis has retraced the epistemological evolution of these latter, whilst at the same time remarking the appropriation that has been made by the different institutional and organizational actors. The historical and epistemological reviews tell us that these two concepts, which came into existence almost 80 years, have indefinite outlines; one can be substituted for the other. However, thanks to this odyssey, we have reduced the boundaries even further between sustainable development and social responsibility and shown their theoretic and historical association. The perspective adopted shows that the concept of corporate social responsibility is closely connected to that of sustainable development. This connection means that researchers in management science are faced with more new problem issues reaching further than the simple lack of conceptual consensuses.展开更多
基金sponsored by the National Science and Technology Major Project(No.2011ZX05023-005-006)
文摘Data mining is the process of extracting implicit but potentially useful information from incomplete, noisy, and fuzzy data. Data mining offers excellent nonlinear modeling and self-organized learning, and it can play a vital role in the interpretation of well logging data of complex reservoirs. We used data mining to identify the lithologies in a complex reservoir. The reservoir lithologies served as the classification task target and were identified using feature extraction, feature selection, and modeling of data streams. We used independent component analysis to extract information from well curves. We then used the branch-and- bound algorithm to look for the optimal feature subsets and eliminate redundant information. Finally, we used the C5.0 decision-tree algorithm to set up disaggregated models of the well logging curves. The modeling and actual logging data were in good agreement, showing the usefulness of data mining methods in complex reservoirs.
文摘The laminated overburden model(La Model)has been widely used for pillar design and stability analysis.As a boundary element program,the La Model program is sensitive to the boundary condition,which should be considered before creating the model.To eliminate the boundary effect in a La Model pillar stability analysis,a suitable boundary buffer zone is needed around the model edge.The radius of influence(R)and the abutment load extent(D)are two major factors that affect the stresses and displacements calculated in LaM odel.To determine the optimum buffer zone extent,a database of case histories was analyzed using the La Model program.Values for R and D were varied until a buffer zone having negligible influence on the pillar stability factor(SF)of the active mining zone(AMZ)was determined.
基金Project (Nos. 50539100,50679035 and 50509027) supported by the National Natural ScienceFoundation of China
文摘The solution of a slope stability problem can be approached by its least upper-bound and maximum lower-bound with high accuracy. The limit equilibrium methods that employ vertical slices imply a lower bound of the factor of safety. It has been successfully extended to the area of active earth pressure analysis that accounts for different input of locations of earth pressure applications. Those methods that employ slices with inclined interfaces give an upper-bound approach to the stability analysis. It enjoys a sound mechanical background and is able to provide accurate solutions of soil plasticity. It has been successfully extended to the area of bearing capacity analysis in which various empirical coefficients are no longer necessary. The 3D upper- and lower-bound methods under this framework have been made possible and show great potential for solving various engineering problems.
文摘We compute the mass and temperature of third order Lovelock black holes with negative Gauss-Bonnet coefficient a2 〈 0 in anti-de Sitter space and perform the stability analysis of topological black holes. When k = -1, the third order Lovelock black holes are thermodynamically stable for the whole range r＋. When k = 1, we found that the black hole has an intermediate unstable phase for D = 7. In eight dimensional spacetimes, however, a new phase of thermodynamically unstable small black holes appears if the coefficient a is under a critical value. For D ≥ 9, black holes have similar the distributions of thermodynamically stable regions to the case where the coefficient ＆ is under a critical value for D = 8. It is worth to mention that all the thermodynamic and conserved quantities of the black holes with fiat horizon do not depend on the Loveloek coefficients and are the same as those of black holes in general gravity.
基金国家自然科学基金，the Chinese Foundation of High Education
文摘A simple and direct approach to handle summation is presented. With this approach, we analytically investigate Bose–Einstein condensation of ideal Bose gas trapped in an isotropic harmonic oscillator potential. We get the accurate expression of which is very close to (0.43% larger than) the experimental data. We find the curve of internal energy of the system vs. temperature has a turning point which marks the beginning of a condensation. We also find that there exists specific heat jump at the transition temperature, no matter whether the system is macroscopic or finite. This phenomenon could be a manifestation of a phase transition in finite systems.
文摘The aim of this research is to analyze the emergence of the concepts of sustainable development （SD） and corporate social responsibility （CSR） in companies in time and space. A spatio-temporal reading will indicate the most important socio-political and environmental events that have emerged with these two concepts. In order to complete the odyssey, a spatio-temporal analysis has retraced the epistemological evolution of these latter, whilst at the same time remarking the appropriation that has been made by the different institutional and organizational actors. The historical and epistemological reviews tell us that these two concepts, which came into existence almost 80 years, have indefinite outlines; one can be substituted for the other. However, thanks to this odyssey, we have reduced the boundaries even further between sustainable development and social responsibility and shown their theoretic and historical association. The perspective adopted shows that the concept of corporate social responsibility is closely connected to that of sustainable development. This connection means that researchers in management science are faced with more new problem issues reaching further than the simple lack of conceptual consensuses.
