In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated...In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV constraint.The boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to constrain the body line-of-sight(BLOS)in IEGC system to fit a circular FOV.Then,the nonlinear adaptive controller is designed to estimate the changing aerodynamic parameters.The generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking accuracy.Furthermore,the command filters are used to solve the"differential expansion"problem during the backstepping design.The Lyapunov theory is used to prove the stability of the overall closed-loop IEGC system.Finally,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.展开更多
顶级品质的音响器材,由于其昂贵的价格与稀缺性,对于大多数人而言,平日里能够亲自接触并体验的机会实属难得。就在11月,我们来到了典雅音响花园,试听IsoTek EVO3 Super Titan 20A电源处理器,试听现场刚好搭配了Gryphon贵丰的Commander...顶级品质的音响器材,由于其昂贵的价格与稀缺性,对于大多数人而言,平日里能够亲自接触并体验的机会实属难得。就在11月,我们来到了典雅音响花园,试听IsoTek EVO3 Super Titan 20A电源处理器,试听现场刚好搭配了Gryphon贵丰的Commander指挥官、后级为Gryphon贵丰Apex单声道后级系统。展开更多
僵尸网络(Botnet)是一种从传统恶意代码形态进化而来的新型攻击方式,为攻击者提供了隐匿、灵活且高效的一对多命令与控制信道(Command and Control channel,C&C)机制,可以控制大量僵尸主机实现信息窃取、分布式拒绝服务攻击和垃圾...僵尸网络(Botnet)是一种从传统恶意代码形态进化而来的新型攻击方式,为攻击者提供了隐匿、灵活且高效的一对多命令与控制信道(Command and Control channel,C&C)机制,可以控制大量僵尸主机实现信息窃取、分布式拒绝服务攻击和垃圾邮件发送等攻击目的。该文提出一种与僵尸网络结构和C&C协议无关,不需要分析数据包的特征负载的僵尸网络检测方法。该方法首先使用预过滤规则对捕获的流量进行过滤,去掉与僵尸网络无关的流量;其次对过滤后的流量属性进行统计;接着使用基于X-means聚类的两步聚类算法对C&C信道的流量属性进行分析与聚类,从而达到对僵尸网络检测的目的。实验证明,该方法高效准确地把僵尸网络流量与其他正常网络流量区分,达到从实际网络中检测僵尸网络的要求,并且具有较低的误判率。展开更多
Adaptive optimization is one of the means that agile organization of command and control resource (AOC2R) adapts for the dynamic battlefield environment. A math model of the adaptive optimization of AOC2R is put for...Adaptive optimization is one of the means that agile organization of command and control resource (AOC2R) adapts for the dynamic battlefield environment. A math model of the adaptive optimization of AOC2R is put forward by analyzing the interrelating concept and research. The model takes the adaptive process as a multi-stage decision making problem. The 2-phases method is presented to calculate the model, which obtains the related parameters by running the colored Petri net (CPN) model of AOC2R and then searches for the result by ant colony optimization (ACO) algorithm integrated with genetic optimization techniques. The simulation results demonstrate that the proposed algorithm greatly improves the performance of AOC2R.展开更多
The global economic downturn caused primarily by the US sub-prime mortgage crisis in 2007 engendered revenue loss of the multinational corporations. Existing studies have yet to depict the detrimental impacts on city...The global economic downturn caused primarily by the US sub-prime mortgage crisis in 2007 engendered revenue loss of the multinational corporations. Existing studies have yet to depict the detrimental impacts on city's command and control functions induced by the sub-prime mortgage crisis together with its residual wave of global economic recession on the global spatial economy. Recent and previous studies have produced an 'instant history' of the global spatial economy before the global economic downturn undermines the global economy in late 2008. How- ever, the waxes and wanes of major cities' command and control functions on the global economic arena before and after the outbreak of financial crisis and its associated geo-economic transitions are still poorly understood. This paper attempts to contribute a new set of customized data to update and fill in the gap in the literature with the investigation of the command and control functions of cities arotmd the world from 2005 to 2009. Particular attentions are paid to the time-space relationship of the geo-economic transition that can capture the recent historical images of the com- mand and control situation of different cities in the world.展开更多
In this paper the geographical information system (GIS) is applied to earthquake and tsunami emergency work and an earthquake and tsunami emergency command system (ETECS) for seaside cities is developed which is c...In this paper the geographical information system (GIS) is applied to earthquake and tsunami emergency work and an earthquake and tsunami emergency command system (ETECS) for seaside cities is developed which is composed of a basic database and six subsystems. By employing this system, the responsible municipal departments can make rapid prediction before the occurrence of earthquake or tsunami, make commanding decisions concerning the disaster-fight during the disastrous event, and make rapid estimates of the casualties and economic losses. So that the government could conduct relief work in time and planning for future disaster reduction and prevention.展开更多
GIS assist in specific planning and decision-making processes in irrigation through the input, spatial analysis and output of relevant information. The real strength of GIS is its ability to integrate information. Thi...GIS assist in specific planning and decision-making processes in irrigation through the input, spatial analysis and output of relevant information. The real strength of GIS is its ability to integrate information. This integration power makes the scope of GIS almost infinite. The unique integration capability of GIS allows disparate data sets to be brought together to create a complete picture of a situation. GIS technology illustrates relationships, patterns and connections that are not necessarily obvious in any one data set but are amazingly apparent once the data sets are integrated. GIS also helps us to assess the performance of the irrigation command areas. GIS based system helps a canal to analyze the spatial information about its engineers and farmers to improve planning, management and supply of water resources to its corresponding blocks. In order to manage the water efficiently in the command area, it is needless to say that calculation and evaluation of water demands in detail at block and minor level to be given overriding priority. Blocks and Chak boundaries can be delineated from the Digital Elevation Model using GIS techniques. These boundaries will help to plan and allocate the water resources to improve the water allocation strategies and in turn water use efficiency and can make inter-canal comparisons. The delineated block boundaries can be refined exactly using the drainage, topography and existing canal network in GIS platform.展开更多
This paper investigates the heading tracking problem of surface vehicles with unknown model parameters.Based on finite/fixed-time control theories and in the context of command filtered control,two novel adaptive cont...This paper investigates the heading tracking problem of surface vehicles with unknown model parameters.Based on finite/fixed-time control theories and in the context of command filtered control,two novel adaptive control laws are developed by which the vehicle can track the desired heading within settling time with all signals of the closed-loop system are uniformly bounded.The effectiveness and performance of the schemes are demonstrated by simulations and comparison studies.展开更多
The Trusted Platform Module (TPM) is a dedicated hardware chip designed to provide a higher level of security for computing platform. All TPM functionalities are implemented in TPM corntrends to achieve specific sec...The Trusted Platform Module (TPM) is a dedicated hardware chip designed to provide a higher level of security for computing platform. All TPM functionalities are implemented in TPM corntrends to achieve specific security goals. We attempt to analyze the security properties of these commands, especially the key management API. Our study utilizes applied pi calculus to forrmlize the commands and determine how their security properties affect TPM key rmnagement. The attacker is assumed to call TPM comrmnds without bounds and without knowing the TPM root key, expecting to obtain or replace the user key. The analysis goal in our study is to guarantee the corre- sponding property of API execution and the integrity of API data. We analyze the security properties of TPM commands with a process reduction method, identify the key-handle hijack attack on a TPM newly created key, and propose reasonable solutions to solve the problem. Then, we conduct an experiment involving a key-handle attack, which suc- cessfully replaces a user key with an attacker's key using lmlicious TPM software. This paper discloses the weakness of the relationship between the key handle and the key object. After the TPM software stack is compromised, the attacker can hunch a keyhandle attack to obtain the user key and even break into the whole storage tree of user keys.展开更多
文摘In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV constraint.The boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to constrain the body line-of-sight(BLOS)in IEGC system to fit a circular FOV.Then,the nonlinear adaptive controller is designed to estimate the changing aerodynamic parameters.The generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking accuracy.Furthermore,the command filters are used to solve the"differential expansion"problem during the backstepping design.The Lyapunov theory is used to prove the stability of the overall closed-loop IEGC system.Finally,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.
文摘顶级品质的音响器材,由于其昂贵的价格与稀缺性,对于大多数人而言,平日里能够亲自接触并体验的机会实属难得。就在11月,我们来到了典雅音响花园,试听IsoTek EVO3 Super Titan 20A电源处理器,试听现场刚好搭配了Gryphon贵丰的Commander指挥官、后级为Gryphon贵丰Apex单声道后级系统。
文摘僵尸网络(Botnet)是一种从传统恶意代码形态进化而来的新型攻击方式,为攻击者提供了隐匿、灵活且高效的一对多命令与控制信道(Command and Control channel,C&C)机制,可以控制大量僵尸主机实现信息窃取、分布式拒绝服务攻击和垃圾邮件发送等攻击目的。该文提出一种与僵尸网络结构和C&C协议无关,不需要分析数据包的特征负载的僵尸网络检测方法。该方法首先使用预过滤规则对捕获的流量进行过滤,去掉与僵尸网络无关的流量;其次对过滤后的流量属性进行统计;接着使用基于X-means聚类的两步聚类算法对C&C信道的流量属性进行分析与聚类,从而达到对僵尸网络检测的目的。实验证明,该方法高效准确地把僵尸网络流量与其他正常网络流量区分,达到从实际网络中检测僵尸网络的要求,并且具有较低的误判率。
文摘Adaptive optimization is one of the means that agile organization of command and control resource (AOC2R) adapts for the dynamic battlefield environment. A math model of the adaptive optimization of AOC2R is put forward by analyzing the interrelating concept and research. The model takes the adaptive process as a multi-stage decision making problem. The 2-phases method is presented to calculate the model, which obtains the related parameters by running the colored Petri net (CPN) model of AOC2R and then searches for the result by ant colony optimization (ACO) algorithm integrated with genetic optimization techniques. The simulation results demonstrate that the proposed algorithm greatly improves the performance of AOC2R.
基金Foundation item:Under the auspices of Hui Oi Chow Trust Fund(No.200902172004)Mrs.Li Ka Shing Fund,Strategic Research Theme on Contemporary China,Small Project Funding provided by the University of Hong Kong(No.200807176152)
文摘The global economic downturn caused primarily by the US sub-prime mortgage crisis in 2007 engendered revenue loss of the multinational corporations. Existing studies have yet to depict the detrimental impacts on city's command and control functions induced by the sub-prime mortgage crisis together with its residual wave of global economic recession on the global spatial economy. Recent and previous studies have produced an 'instant history' of the global spatial economy before the global economic downturn undermines the global economy in late 2008. How- ever, the waxes and wanes of major cities' command and control functions on the global economic arena before and after the outbreak of financial crisis and its associated geo-economic transitions are still poorly understood. This paper attempts to contribute a new set of customized data to update and fill in the gap in the literature with the investigation of the command and control functions of cities arotmd the world from 2005 to 2009. Particular attentions are paid to the time-space relationship of the geo-economic transition that can capture the recent historical images of the com- mand and control situation of different cities in the world.
文摘In this paper the geographical information system (GIS) is applied to earthquake and tsunami emergency work and an earthquake and tsunami emergency command system (ETECS) for seaside cities is developed which is composed of a basic database and six subsystems. By employing this system, the responsible municipal departments can make rapid prediction before the occurrence of earthquake or tsunami, make commanding decisions concerning the disaster-fight during the disastrous event, and make rapid estimates of the casualties and economic losses. So that the government could conduct relief work in time and planning for future disaster reduction and prevention.
文摘GIS assist in specific planning and decision-making processes in irrigation through the input, spatial analysis and output of relevant information. The real strength of GIS is its ability to integrate information. This integration power makes the scope of GIS almost infinite. The unique integration capability of GIS allows disparate data sets to be brought together to create a complete picture of a situation. GIS technology illustrates relationships, patterns and connections that are not necessarily obvious in any one data set but are amazingly apparent once the data sets are integrated. GIS also helps us to assess the performance of the irrigation command areas. GIS based system helps a canal to analyze the spatial information about its engineers and farmers to improve planning, management and supply of water resources to its corresponding blocks. In order to manage the water efficiently in the command area, it is needless to say that calculation and evaluation of water demands in detail at block and minor level to be given overriding priority. Blocks and Chak boundaries can be delineated from the Digital Elevation Model using GIS techniques. These boundaries will help to plan and allocate the water resources to improve the water allocation strategies and in turn water use efficiency and can make inter-canal comparisons. The delineated block boundaries can be refined exactly using the drainage, topography and existing canal network in GIS platform.
基金supported by the National Natural Science Foundation of China(U1808205)the Fundamental Research Funds for the Central Universities(N2023011)+1 种基金the Youth Foundation of Hebei Educational Committee(QN2020522)the Natural Science Foundation of Hebei Province(F2020501018)。
文摘This paper investigates the heading tracking problem of surface vehicles with unknown model parameters.Based on finite/fixed-time control theories and in the context of command filtered control,two novel adaptive control laws are developed by which the vehicle can track the desired heading within settling time with all signals of the closed-loop system are uniformly bounded.The effectiveness and performance of the schemes are demonstrated by simulations and comparison studies.
基金This paper was supported by the National Natural Science Foundation of China under Grants No.91118006, No. 61202414 the Knowledge Innovation Project of Chinese Academy of Science under Grant No. ISCAS2009-DR14.
文摘The Trusted Platform Module (TPM) is a dedicated hardware chip designed to provide a higher level of security for computing platform. All TPM functionalities are implemented in TPM corntrends to achieve specific security goals. We attempt to analyze the security properties of these commands, especially the key management API. Our study utilizes applied pi calculus to forrmlize the commands and determine how their security properties affect TPM key rmnagement. The attacker is assumed to call TPM comrmnds without bounds and without knowing the TPM root key, expecting to obtain or replace the user key. The analysis goal in our study is to guarantee the corre- sponding property of API execution and the integrity of API data. We analyze the security properties of TPM commands with a process reduction method, identify the key-handle hijack attack on a TPM newly created key, and propose reasonable solutions to solve the problem. Then, we conduct an experiment involving a key-handle attack, which suc- cessfully replaces a user key with an attacker's key using lmlicious TPM software. This paper discloses the weakness of the relationship between the key handle and the key object. After the TPM software stack is compromised, the attacker can hunch a keyhandle attack to obtain the user key and even break into the whole storage tree of user keys.