According to the geological and mining technical conditions of No.18128 sub- level caving face with suspend-shift support,the first working face of the working area,the distribution laws of abutment pressure were stud...According to the geological and mining technical conditions of No.18128 sub- level caving face with suspend-shift support,the first working face of the working area,the distribution laws of abutment pressure were studied by jointly employing FIAC^(3D) numerical simulations and field tests.With the full consideration of these laws and the service time- limit of the mining district,the optimal location of the terminal mining line,should be 60 m away from the W4-B8 track dip,which was 20 m shorter than the 80 m distance deter- mined according to traditional experiences.The retained coal safety pillar for the protect- ing of dips,already proved by the industrial practice,can not only improve the rate of coal recovery and satisfy the subsequent service requirement for the following working faces, but also decrease the maintaining expenditure and thus increase profits.展开更多
A semi-analytical method in time domain is presented for analysis of the transient response of nonuniform transmission lines. In this method, the telegraph equations in time domain is differenced in space domain first...A semi-analytical method in time domain is presented for analysis of the transient response of nonuniform transmission lines. In this method, the telegraph equations in time domain is differenced in space domain first, and is transformed into a set of first-order differential equations of voltage and current with respect to time. By integrating these differential equations with respect to time, and precise computation, the solution of these differential equations can be obtained. This method can solve the transient response of various kinds of transmission lines with arbitrary terminal networks. Particularly, it can analyze the nonuniform lines with initial conditions, for which there is no existing effective method to analyze the time response so far. The results obtained with this method are stable and accurate. Two examples are given to illustrate the application of this method.展开更多
A wireless distributed monitoring terminal was designed with embedded Linux used on the basis of ARM board, and an application program was developed for data collection, processing and transmission. Data were collecte...A wireless distributed monitoring terminal was designed with embedded Linux used on the basis of ARM board, and an application program was developed for data collection, processing and transmission. Data were collected from the surrounding environment and transmitted to a server via WLAN in the form of Extensible Markup Language (XML) stream, so the terminal had good flexibility to be compatible with different sensors, network devices and information systems from multiple manufacturers.展开更多
Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits o...Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits of multi terminal DC (MTDC) tie lines as compared to the traditional HVAC forms the main objective of this paper. Probabilistic load flow (PLF) is applied to determine the system parameters while the uncertainties are modelled using Scenario Based Method (SBM). The simulation results reveal that with the use of MTDC tie lines, the frequency and voltage stability in the MAMODED with renewable energy sources (RES) are enhanced while keeping the MTDC power exchange interface nodes at secure levels.展开更多
This paper investigates the control systems and coordination mechanisms applied in the relationships between cruise line companies and terminal concessionaires in the cruise events management when the ships are stoppi...This paper investigates the control systems and coordination mechanisms applied in the relationships between cruise line companies and terminal concessionaires in the cruise events management when the ships are stopping on the quay. Using a case study methodology and focusing on the Italian context, this exploratory study, through a qualitative approach, interviewed two main cruise terminal concessionaires and indirectly observed events planned by cruise companies in sea ports selected for outlining the role of control systems, coordination, and knowledge sharing between the players in cruise events decision-making processes. The first results show that the cruise event management processes on ship berthing and on terminal are separated. The cruise companies don＇t involve terminal concessionaires in the event organization considering them only service suppliers Also, the concessionaires conceive the events planned in the cruise infrastructures as a business unit to optimize the space use, without any forms of coordination or control with cruise companies. Knowledge sharing, coordination, and control among the two players could support the planning, and management of ＂new cruise events＂ in which the visitors may be led from the infrastructure to the ships stopped on the quay. This study offers a set of key performance indicators to support the management, control, and coordination of each inter-organizational relationship identified. Managerial implications and suggestions for improving cruise events management have been provided.展开更多
In this study, we perform a series of numerical calculations on two vessels in the time domain. One vessel maintains its position using an internal turret and catenary mooring lines, while the other is moored to the f...In this study, we perform a series of numerical calculations on two vessels in the time domain. One vessel maintains its position using an internal turret and catenary mooring lines, while the other is moored to the former vessel via an STS （ship-to-ship） mooring system. We obtain hydrodynamic forces using the HOBEM （higher-order boundary element method）. Then, we determine their coefficients using the convolution function method in the time domain. We model the catenary mooring lines using the finite element method, and the STS mooring lines are treated as linear SPs （springs） with constraints. To optimize the STS system, we conduct parametric studies on STS mooring systems. Finally, we compare the motion and structural responses of the initial and modified configurations.展开更多
An accurate numerical algorithm for three-line fault involving different phases from each of two-parallel lines is presented. It is based on one-terminal voltage and current data. The loop and nodel equations comparin...An accurate numerical algorithm for three-line fault involving different phases from each of two-parallel lines is presented. It is based on one-terminal voltage and current data. The loop and nodel equations comparing faulted phase to non-faulted phase of two-parallel lines are introduced in the fault location estimation modal, in which the faulted impedance of remote end is not involved. The effect of load flow and fault resistance on the accuracy of fault location are effectively eliminated, therefore an accurate algorithm of locating fault is derived. The algorithm is demonstrated by digital computer simulations and the results show that errors in locating fault are less than 1%.展开更多
基金the National Natural Science Foundation of China(50674002)the Educational Department of Anhui Province(KJ2008B109)
文摘According to the geological and mining technical conditions of No.18128 sub- level caving face with suspend-shift support,the first working face of the working area,the distribution laws of abutment pressure were studied by jointly employing FIAC^(3D) numerical simulations and field tests.With the full consideration of these laws and the service time- limit of the mining district,the optimal location of the terminal mining line,should be 60 m away from the W4-B8 track dip,which was 20 m shorter than the 80 m distance deter- mined according to traditional experiences.The retained coal safety pillar for the protect- ing of dips,already proved by the industrial practice,can not only improve the rate of coal recovery and satisfy the subsequent service requirement for the following working faces, but also decrease the maintaining expenditure and thus increase profits.
文摘A semi-analytical method in time domain is presented for analysis of the transient response of nonuniform transmission lines. In this method, the telegraph equations in time domain is differenced in space domain first, and is transformed into a set of first-order differential equations of voltage and current with respect to time. By integrating these differential equations with respect to time, and precise computation, the solution of these differential equations can be obtained. This method can solve the transient response of various kinds of transmission lines with arbitrary terminal networks. Particularly, it can analyze the nonuniform lines with initial conditions, for which there is no existing effective method to analyze the time response so far. The results obtained with this method are stable and accurate. Two examples are given to illustrate the application of this method.
文摘A wireless distributed monitoring terminal was designed with embedded Linux used on the basis of ARM board, and an application program was developed for data collection, processing and transmission. Data were collected from the surrounding environment and transmitted to a server via WLAN in the form of Extensible Markup Language (XML) stream, so the terminal had good flexibility to be compatible with different sensors, network devices and information systems from multiple manufacturers.
文摘Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits of multi terminal DC (MTDC) tie lines as compared to the traditional HVAC forms the main objective of this paper. Probabilistic load flow (PLF) is applied to determine the system parameters while the uncertainties are modelled using Scenario Based Method (SBM). The simulation results reveal that with the use of MTDC tie lines, the frequency and voltage stability in the MAMODED with renewable energy sources (RES) are enhanced while keeping the MTDC power exchange interface nodes at secure levels.
文摘This paper investigates the control systems and coordination mechanisms applied in the relationships between cruise line companies and terminal concessionaires in the cruise events management when the ships are stopping on the quay. Using a case study methodology and focusing on the Italian context, this exploratory study, through a qualitative approach, interviewed two main cruise terminal concessionaires and indirectly observed events planned by cruise companies in sea ports selected for outlining the role of control systems, coordination, and knowledge sharing between the players in cruise events decision-making processes. The first results show that the cruise event management processes on ship berthing and on terminal are separated. The cruise companies don＇t involve terminal concessionaires in the event organization considering them only service suppliers Also, the concessionaires conceive the events planned in the cruise infrastructures as a business unit to optimize the space use, without any forms of coordination or control with cruise companies. Knowledge sharing, coordination, and control among the two players could support the planning, and management of ＂new cruise events＂ in which the visitors may be led from the infrastructure to the ships stopped on the quay. This study offers a set of key performance indicators to support the management, control, and coordination of each inter-organizational relationship identified. Managerial implications and suggestions for improving cruise events management have been provided.
文摘In this study, we perform a series of numerical calculations on two vessels in the time domain. One vessel maintains its position using an internal turret and catenary mooring lines, while the other is moored to the former vessel via an STS （ship-to-ship） mooring system. We obtain hydrodynamic forces using the HOBEM （higher-order boundary element method）. Then, we determine their coefficients using the convolution function method in the time domain. We model the catenary mooring lines using the finite element method, and the STS mooring lines are treated as linear SPs （springs） with constraints. To optimize the STS system, we conduct parametric studies on STS mooring systems. Finally, we compare the motion and structural responses of the initial and modified configurations.
文摘An accurate numerical algorithm for three-line fault involving different phases from each of two-parallel lines is presented. It is based on one-terminal voltage and current data. The loop and nodel equations comparing faulted phase to non-faulted phase of two-parallel lines are introduced in the fault location estimation modal, in which the faulted impedance of remote end is not involved. The effect of load flow and fault resistance on the accuracy of fault location are effectively eliminated, therefore an accurate algorithm of locating fault is derived. The algorithm is demonstrated by digital computer simulations and the results show that errors in locating fault are less than 1%.
