Enterprise groups are characterized by multiple levels of enterprises with large scales of assets and complex business models.In the process of administration and management of funds,there are often some problems,such...Enterprise groups are characterized by multiple levels of enterprises with large scales of assets and complex business models.In the process of administration and management of funds,there are often some problems,such as unreasonable internal funds allocation,high financing costs,and flawed funds control.Centralized fund management is a tool for the overall allocation of intra-group fiinds and the coordinated management of group investment and financing.It can optimize the resource allocation of enterprise groups and reduce financing costs as well as capital risks.By selecting centralized fund management,establishing control and early warning system,as well as building information system and other steps,enterprise groups can better implement centralized fund management and improve their capital control.展开更多
With the rapid development of Virtual Private Network (VPN), many companies and organizations use VPN to implement their private communication. Traditionally, VPN uses security protocols to protect the confidentiality...With the rapid development of Virtual Private Network (VPN), many companies and organizations use VPN to implement their private communication. Traditionally, VPN uses security protocols to protect the confidentiality of data, the message integrity and the endpoint authentication. One core technique of VPN is tunneling, by which clients can access the in- ternal servers traversing VPN. However, the tunneling technique also introduces a concealed security hole. It is possible that if one vicious user can establish tunneling by the VPN server, he can compromise the internal servers behind the VPN server. So this paper presents a novel Application-layer based Centralized Information Access Control (ACIAC) for VPN to solve this problem. To implement an efficient, flexible and multi-decision access control model, we present two key techniques to ACIAC—the centralized management mechanism and the stream-based access control. Firstly, we implement the information center and the constraints/events center for ACIAC. By the two centers, we can provide an abstract access control mechanism, and the material access control can be decided dynamically by the ACIAC’s constraint/event mechanism. Then we logically classify the VPN communication traffic into the access stream and the data stream so that we can tightly couple the features of VPN communication with the access control model. We also provide the design of our ACIAC prototype in this paper.展开更多
A microgrid(MG)refers to a set of loads,generation resources and energy storage systems acting as a controllable load or a generator to supply power and heating to a local area.The MG-generated power management is a c...A microgrid(MG)refers to a set of loads,generation resources and energy storage systems acting as a controllable load or a generator to supply power and heating to a local area.The MG-generated power management is a central topic for MG design and operation.The existence of dispersed generation(DG)resources has faced MG management with new issues.Depending on the level of exchanges between an MG and the main grid,the MG operation states can be divided into independent or grid-connected ones.Energy management in MGs aims to supply power at the lowest cost for optimal load response.This study examines MG energy management in two operational modes of islanded and grid-connected,and proposes a structure with two control layers(primary and secondary)for energy management.At the principal level of control,the energy management system is determined individually for all MG by taking into consideration the probability constraints and RES uncertainty by the Weibull the probability density function(PDF),generation resources’power as well as the generation surplus and deficit of each MG.Then,the information of the power surplus and deficit of each MG must be sent to the central energy management system.To confirm the proposed structure,a case system with two MGs and a condensive load is simulated by using a multi-time harmony search algorithm.Several scenarios are applied to evaluate the performance of this algorithm.The findings clearly show the effectiveness of the proposed system in the energy management of several MGs,leading to the optimal performance of the resources per MG.Moreover,the proposed control scheme properly controls the MG and grid’s performance in their interactions and offers a high level of robustness,stable behavior under different conditions and high quality of power supply.展开更多
目的探讨“四体系一平台”护理管理模式预防重症监护病房(intensive care unit,ICU)中心导管相关血流感染(central line associated blood stream infection,CLABSI)的效果,降低CLABSI发生率。方法采用不同病例前-后对照研究,选取2019年...目的探讨“四体系一平台”护理管理模式预防重症监护病房(intensive care unit,ICU)中心导管相关血流感染(central line associated blood stream infection,CLABSI)的效果,降低CLABSI发生率。方法采用不同病例前-后对照研究,选取2019年9月至2021年8月本院4个外科ICU病区收治的5968例患者作为研究对象,其中2019年9月至2020年8月收治的2852例患者设为实施前组,2020年9月至2021年8月收治的3116例患者设为实施后组。实施前组应用常规护理管理方法,实施后组应用“四体系一平台”护理管理模式。比较两组患者CLABSI发生率,实施前后护士输液附加装置更换合格率、手卫生依从性;两组患者置管最大无菌屏障合格率、皮肤消毒合格率。结果应用“四体系一平台”护理管理模式后,患者CLABSI率由1.96‰(29/14765)降至0.97‰(17/17458),两组比较,差异具有统计学意义(χ^(2)=5.504,P=0.019);护士输液附加装置更换合格率(92.86%v 99.73%,χ^(2)=264.498,P<0.001)、手卫生方法正确率(99.02%v 99.73%,χ^(2)=32.342,P<0.001)、手卫生依从性(99.18%v 99.49%,χ^(2)=5.664,P=0.019)、最大无菌屏障合格率(95.93%v 99.69%,χ^(2)=10.399,P=0.002)、皮肤消毒合格率(93.61%v 98.80%,χ^(2)=67.630,P<0.001)均较实施前组提高,两组比较,差异有统计学意义。结论“四体系一平台”护理管理模式有利于促进ICU护士在导管维护时的规范性、有效性和依从性,降低ICU患者CLABSI率。展开更多
文摘Enterprise groups are characterized by multiple levels of enterprises with large scales of assets and complex business models.In the process of administration and management of funds,there are often some problems,such as unreasonable internal funds allocation,high financing costs,and flawed funds control.Centralized fund management is a tool for the overall allocation of intra-group fiinds and the coordinated management of group investment and financing.It can optimize the resource allocation of enterprise groups and reduce financing costs as well as capital risks.By selecting centralized fund management,establishing control and early warning system,as well as building information system and other steps,enterprise groups can better implement centralized fund management and improve their capital control.
基金Project (No. 60373088) supported by the National Natural ScienceFoundation of China
文摘With the rapid development of Virtual Private Network (VPN), many companies and organizations use VPN to implement their private communication. Traditionally, VPN uses security protocols to protect the confidentiality of data, the message integrity and the endpoint authentication. One core technique of VPN is tunneling, by which clients can access the in- ternal servers traversing VPN. However, the tunneling technique also introduces a concealed security hole. It is possible that if one vicious user can establish tunneling by the VPN server, he can compromise the internal servers behind the VPN server. So this paper presents a novel Application-layer based Centralized Information Access Control (ACIAC) for VPN to solve this problem. To implement an efficient, flexible and multi-decision access control model, we present two key techniques to ACIAC—the centralized management mechanism and the stream-based access control. Firstly, we implement the information center and the constraints/events center for ACIAC. By the two centers, we can provide an abstract access control mechanism, and the material access control can be decided dynamically by the ACIAC’s constraint/event mechanism. Then we logically classify the VPN communication traffic into the access stream and the data stream so that we can tightly couple the features of VPN communication with the access control model. We also provide the design of our ACIAC prototype in this paper.
文摘A microgrid(MG)refers to a set of loads,generation resources and energy storage systems acting as a controllable load or a generator to supply power and heating to a local area.The MG-generated power management is a central topic for MG design and operation.The existence of dispersed generation(DG)resources has faced MG management with new issues.Depending on the level of exchanges between an MG and the main grid,the MG operation states can be divided into independent or grid-connected ones.Energy management in MGs aims to supply power at the lowest cost for optimal load response.This study examines MG energy management in two operational modes of islanded and grid-connected,and proposes a structure with two control layers(primary and secondary)for energy management.At the principal level of control,the energy management system is determined individually for all MG by taking into consideration the probability constraints and RES uncertainty by the Weibull the probability density function(PDF),generation resources’power as well as the generation surplus and deficit of each MG.Then,the information of the power surplus and deficit of each MG must be sent to the central energy management system.To confirm the proposed structure,a case system with two MGs and a condensive load is simulated by using a multi-time harmony search algorithm.Several scenarios are applied to evaluate the performance of this algorithm.The findings clearly show the effectiveness of the proposed system in the energy management of several MGs,leading to the optimal performance of the resources per MG.Moreover,the proposed control scheme properly controls the MG and grid’s performance in their interactions and offers a high level of robustness,stable behavior under different conditions and high quality of power supply.
