Exploitation of coal seams in the Upper Silesian Coal Basin is conducted in complex and difficult conditions. These difficulties are connected with the occurrence of many natural mining hazards and limitations resulti...Exploitation of coal seams in the Upper Silesian Coal Basin is conducted in complex and difficult conditions. These difficulties are connected with the occurrence of many natural mining hazards and limitations resulting from the existing in this area surface infrastructure. One of the most important problems of Polish mining is the rock burst hazard and reliable evaluation of its condition. During long-years’ mining practice in Poland a comprehensive system of evaluation and control of this hazard was developed. In the paper the main aspects of rock burst hazard state evaluation will be presented, comprising: 1) rock mass inclination for rock bursts, i.e., rock strength properties investigation, comprehensive parametric evaluation of rock mass inclination for rock bursts, prognosis of seismic events induced by mining operations, methods of computer-aided modelling of stress and rock mass deformation parameters distribution, strategic rock mass classification under rock burst degrees; 2) immediate seismic and rock burst hazard state evaluation, i.e., low diameter test drilling method, seismologic and seismoacoustic method, comprehensive method of rock burst hazard state evaluation, non-standard methods of evaluation; 3) legal aspects of rock burst hazard state evaluation. Selected elements of the hazard state evaluation system are illustrated with specific practical examples of their application.展开更多
Background Heart failure is a significant problem leading to repeated hospitalizations. Telemonitoring and hemodynamic monitoring have demonstrated success in reducing hospitalization rates, but not all studies report...Background Heart failure is a significant problem leading to repeated hospitalizations. Telemonitoring and hemodynamic monitoring have demonstrated success in reducing hospitalization rates, but not all studies reported significant effects. The aim of this systematic review and meta-analysis is to examine the effectiveness of telemonitoring and wireless hemodynamic monitoring devices in reducing hospitalizations in heart failure. Methods ＆ Results PubMed and Cochrane Library were searched up to 1st May 2017 for articles that investigated the effects of telemonitoring or hemodynamic monitoring on hospitalization rates in heart failure. In 31,501 patients （mean age： 68 ± 12 years; 61% male; follow-up 11 ± 8 months）, telemonitoring reduced hospitalization rates with a HR of 0.73 （95% CI： 0.65-0.83; P 〈 0.0001） with significant heterogeneity （I2 = 94%）. These effects were observed in the short-term （≤ 6 months： HR = 0.77, 95% CI： 0.65-0.89; P 〈 0.01） and long-term （≥ 12 months： HR = 0.73, 95% CI： 0.62-0.87; P 〈 0.0001）. In 4831 patients （mean age 66 ± 18 years; 66% male; follow-up 13 ± 4 months）, wireless hemodynamic monitoring also reduced hospitalization rates with a HR of 0.60 （95% CI： 0.53-0.69; P 〈 0.001） with significant heterogeneity （I2 = 64%）.This reduction was observed both in the short-term （HR = 0.55, 95% CI： 0.45-0.68; P 〈 0.001; I2 = 72%） and long-term （HR = 0.64, 95% CI： 0.57-0.72; P 〈 0.001; I2 = 55%）. Conclusions Telemonitoring and hemodynamic monitoring reduce hospitalization in both short- and long-term in heart failure patients展开更多
This paper proposes a optimal control problem for a general nonlinear systems with finitely many admissible control settings and with costs assigned to switching of controls. With dynamic programming and viscosity sol...This paper proposes a optimal control problem for a general nonlinear systems with finitely many admissible control settings and with costs assigned to switching of controls. With dynamic programming and viscosity solution theory we show that the switching lower-value function is a viscosity solution of the appropriate systems of quasi-variational inequalities（the appropriate generalization of the Hamilton-Jacobi equation in this context） and that the minimal such switching-storage function is equal to the continuous switching lower-value for the game. With the lower value function a optimal switching control is designed for minimizing the cost of running the systems.展开更多
Using directional antennas in Wireless Ad hoc Networks (WANETs) offers great potential of reducing the radio interference, and improving the communication throughput. Directional antennas, however, introduces new prob...Using directional antennas in Wireless Ad hoc Networks (WANETs) offers great potential of reducing the radio interference, and improving the communication throughput. Directional antennas, however, introduces new problems in the wireless Media Access Control (MAC), that is, the deafness and new hidden terminal problem, which may cause severe performance degradation. To solve the problems, we propose an effective Circular RTR Directional MAC (CRDMAC) protocol for WANETs by using a sub-transmission channel and Ready to Receive (RTR) packets, which modifies the IEEE 802.11 Distributed Coordinated Function (DCF). The sub-channel avoids collisions to other ongoing transmission, and the RTR packets notify the neighbor nodes that the mutual transmission has been finished. We evaluate the CRDMAC protocol through simulations and the results show that the proposed protocol outperforms existing DMAC (directional MAC) protocol and the CRCM (Circular RTS and CTS MAC) protocol in terms of throughput and packet drop rate.展开更多
基金Project R0903003 supported by the Research-Development Project of Poland
文摘Exploitation of coal seams in the Upper Silesian Coal Basin is conducted in complex and difficult conditions. These difficulties are connected with the occurrence of many natural mining hazards and limitations resulting from the existing in this area surface infrastructure. One of the most important problems of Polish mining is the rock burst hazard and reliable evaluation of its condition. During long-years’ mining practice in Poland a comprehensive system of evaluation and control of this hazard was developed. In the paper the main aspects of rock burst hazard state evaluation will be presented, comprising: 1) rock mass inclination for rock bursts, i.e., rock strength properties investigation, comprehensive parametric evaluation of rock mass inclination for rock bursts, prognosis of seismic events induced by mining operations, methods of computer-aided modelling of stress and rock mass deformation parameters distribution, strategic rock mass classification under rock burst degrees; 2) immediate seismic and rock burst hazard state evaluation, i.e., low diameter test drilling method, seismologic and seismoacoustic method, comprehensive method of rock burst hazard state evaluation, non-standard methods of evaluation; 3) legal aspects of rock burst hazard state evaluation. Selected elements of the hazard state evaluation system are illustrated with specific practical examples of their application.
文摘Background Heart failure is a significant problem leading to repeated hospitalizations. Telemonitoring and hemodynamic monitoring have demonstrated success in reducing hospitalization rates, but not all studies reported significant effects. The aim of this systematic review and meta-analysis is to examine the effectiveness of telemonitoring and wireless hemodynamic monitoring devices in reducing hospitalizations in heart failure. Methods ＆ Results PubMed and Cochrane Library were searched up to 1st May 2017 for articles that investigated the effects of telemonitoring or hemodynamic monitoring on hospitalization rates in heart failure. In 31,501 patients （mean age： 68 ± 12 years; 61% male; follow-up 11 ± 8 months）, telemonitoring reduced hospitalization rates with a HR of 0.73 （95% CI： 0.65-0.83; P 〈 0.0001） with significant heterogeneity （I2 = 94%）. These effects were observed in the short-term （≤ 6 months： HR = 0.77, 95% CI： 0.65-0.89; P 〈 0.01） and long-term （≥ 12 months： HR = 0.73, 95% CI： 0.62-0.87; P 〈 0.0001）. In 4831 patients （mean age 66 ± 18 years; 66% male; follow-up 13 ± 4 months）, wireless hemodynamic monitoring also reduced hospitalization rates with a HR of 0.60 （95% CI： 0.53-0.69; P 〈 0.001） with significant heterogeneity （I2 = 64%）.This reduction was observed both in the short-term （HR = 0.55, 95% CI： 0.45-0.68; P 〈 0.001; I2 = 72%） and long-term （HR = 0.64, 95% CI： 0.57-0.72; P 〈 0.001; I2 = 55%）. Conclusions Telemonitoring and hemodynamic monitoring reduce hospitalization in both short- and long-term in heart failure patients
基金Supported by the SRFEB of Henan Province(2003110002)
文摘This paper proposes a optimal control problem for a general nonlinear systems with finitely many admissible control settings and with costs assigned to switching of controls. With dynamic programming and viscosity solution theory we show that the switching lower-value function is a viscosity solution of the appropriate systems of quasi-variational inequalities（the appropriate generalization of the Hamilton-Jacobi equation in this context） and that the minimal such switching-storage function is equal to the continuous switching lower-value for the game. With the lower value function a optimal switching control is designed for minimizing the cost of running the systems.
基金supported by the Grant-in-Aid for Scientific Research of Japan Society for Promotion of Science(JSPS)Collaboration Research Grant of National Institute of Informatics (NII) ,Japan
文摘Using directional antennas in Wireless Ad hoc Networks (WANETs) offers great potential of reducing the radio interference, and improving the communication throughput. Directional antennas, however, introduces new problems in the wireless Media Access Control (MAC), that is, the deafness and new hidden terminal problem, which may cause severe performance degradation. To solve the problems, we propose an effective Circular RTR Directional MAC (CRDMAC) protocol for WANETs by using a sub-transmission channel and Ready to Receive (RTR) packets, which modifies the IEEE 802.11 Distributed Coordinated Function (DCF). The sub-channel avoids collisions to other ongoing transmission, and the RTR packets notify the neighbor nodes that the mutual transmission has been finished. We evaluate the CRDMAC protocol through simulations and the results show that the proposed protocol outperforms existing DMAC (directional MAC) protocol and the CRCM (Circular RTS and CTS MAC) protocol in terms of throughput and packet drop rate.
