In this paper a new mechanica1 medel indicating the mechanical behaviour of main floor in longwall mining is proposed. In the medel the unfractured rnain floor is considered as an elasto plastic plate, and the combina...In this paper a new mechanica1 medel indicating the mechanical behaviour of main floor in longwall mining is proposed. In the medel the unfractured rnain floor is considered as an elasto plastic plate, and the combination of fractured blocks as a voussoir beam. Using the plastic hmit theory of plates, th limit load acting on rnain floor and the position of its largest deformation are gotten. The stability conditions for the key blocks of the voussoir beam are analysed by "S-R" stability theory. The results of the theoretical analysis are important for the study on the water inrush from seam floor.展开更多
Most rivers in Vietnam flow directly to the sea where the interaction between fresh and salt water occurs. Because of uneven flow distribution through the year with only 20% annual flow in the dry season, while fresh ...Most rivers in Vietnam flow directly to the sea where the interaction between fresh and salt water occurs. Because of uneven flow distribution through the year with only 20% annual flow in the dry season, while fresh water requirement for socio-economic activity in this season is much higher. With this situation, the simulation and finding out the mechanism of saline water intrusion into the estuary in general will help to suggest suitable solutions to control the situation. This paper presents results done at the Huong river estuary. Based on the data collected in current years and using MIKE11 softwave, number scenarios were simulated and found out the intruded process of saline water into the river. They will be very important parameters for which solutions to control negative effects to serve socio-economic development at the downstream of Huong river will be recommended and implemented in the later stage.展开更多
The paper follows possible specification of a control algorithm of a WS （water management system） during floods using the procedures of AI （artificial intelligence）. The issue of minimizing negative impacts of flo...The paper follows possible specification of a control algorithm of a WS （water management system） during floods using the procedures of AI （artificial intelligence）. The issue of minimizing negative impacts of floods represents influencing and controlling a dynamic process of the system where the main regulation elements are water reservoirs. Control of water outflow from reservoirs is implicitly based on the used model （titled BW） based on FR （fuzzy regulation）. Specification of a control algorithm means dealing with the issue of preparing a knowledge base for the process of tuning fuzzy regulators based on an I/O （input/output） matrix obtained by optimization of the target behaviour of WS. Partial results can be compared with the regulation outputs when specialized tuning was used for the fuzzy regulator of the control algorithm. Basic approaches follow from the narrow relation on BW model use to simulate floods, without any connection to real water management system. A generally introduced model allows description of an outflow dynamic system with stochastic inputs using submodels of robust regression in the outflow module. The submodels are constructed on data of historical FS （flood situations）.展开更多
文摘In this paper a new mechanica1 medel indicating the mechanical behaviour of main floor in longwall mining is proposed. In the medel the unfractured rnain floor is considered as an elasto plastic plate, and the combination of fractured blocks as a voussoir beam. Using the plastic hmit theory of plates, th limit load acting on rnain floor and the position of its largest deformation are gotten. The stability conditions for the key blocks of the voussoir beam are analysed by "S-R" stability theory. The results of the theoretical analysis are important for the study on the water inrush from seam floor.
文摘Most rivers in Vietnam flow directly to the sea where the interaction between fresh and salt water occurs. Because of uneven flow distribution through the year with only 20% annual flow in the dry season, while fresh water requirement for socio-economic activity in this season is much higher. With this situation, the simulation and finding out the mechanism of saline water intrusion into the estuary in general will help to suggest suitable solutions to control the situation. This paper presents results done at the Huong river estuary. Based on the data collected in current years and using MIKE11 softwave, number scenarios were simulated and found out the intruded process of saline water into the river. They will be very important parameters for which solutions to control negative effects to serve socio-economic development at the downstream of Huong river will be recommended and implemented in the later stage.
文摘The paper follows possible specification of a control algorithm of a WS （water management system） during floods using the procedures of AI （artificial intelligence）. The issue of minimizing negative impacts of floods represents influencing and controlling a dynamic process of the system where the main regulation elements are water reservoirs. Control of water outflow from reservoirs is implicitly based on the used model （titled BW） based on FR （fuzzy regulation）. Specification of a control algorithm means dealing with the issue of preparing a knowledge base for the process of tuning fuzzy regulators based on an I/O （input/output） matrix obtained by optimization of the target behaviour of WS. Partial results can be compared with the regulation outputs when specialized tuning was used for the fuzzy regulator of the control algorithm. Basic approaches follow from the narrow relation on BW model use to simulate floods, without any connection to real water management system. A generally introduced model allows description of an outflow dynamic system with stochastic inputs using submodels of robust regression in the outflow module. The submodels are constructed on data of historical FS （flood situations）.
