In a CPM network, the longest path problem is one of the most important subjects. According to the intrinsic principle of CPM network, the length of the paths between arbitrary two nodes is presented. Furthermore, the...In a CPM network, the longest path problem is one of the most important subjects. According to the intrinsic principle of CPM network, the length of the paths between arbitrary two nodes is presented. Furthermore, the length of the longest path from start node to arbitrary node and from arbitrary node to end node is proposed. In view of a scheduling problem of two activities with float in the CPM scheduling, we put forward Barycenter Theory and prove this theory based on the algorithm of the length of the longest path. By this theory, we know which activity should be done firstly. At last, we show our theory by an example.展开更多
This paper describes the replacement of a controller for a programmable universal machine for assembly (PUMA) 512 robot with a newly designed PC based (open architecture) controller employing a real-time direct contro...This paper describes the replacement of a controller for a programmable universal machine for assembly (PUMA) 512 robot with a newly designed PC based (open architecture) controller employing a real-time direct control of six joints. The original structure of the PUMA robot is retained. The hardware of the new controller includes such in-house designed parts as pulse width modulation (PWM) amplifiers, digital and analog controllers, I/O cards, signal conditioner cards, and 16-bit A/D and D/A boards. An Intel Pentium IV industrial computer is used as the central controller. The control software is implemented using VC++ programming language. The trajectory tracking performance of all six joints is tested at varying velocities. Experimental results show that it is feasible to implement the suggested open architecture platform for PUMA 500 series robots through the software routines running on a PC. By assembling controller from off-the-shell hardware and software components, the benefits of reduced and improved robustness have been realized.展开更多
This paper investigates the routing among autonomous systems (ASs) with quality of service (QoS) requirements. To avoid the intractability of the problem, abstract QoS capability must be informed among ASs, because th...This paper investigates the routing among autonomous systems (ASs) with quality of service (QoS) requirements. To avoid the intractability of the problem, abstract QoS capability must be informed among ASs, because the routhing which constrained QoS has been proved to be nondeterministic polynomial-time (NP) hard even inside an AS. This paper employs the modified Dijkstra algorithm to compute the maximum bottleneck bandwidth inside an AS. This approach lays a basis for the AS-level switching capability on which interdomain advertisement can be performed. Furthermore, the paper models the aggregated traffic in backbone network with fractional Brownian motion (FBM), and by integrating along the time axis in short intervals, a good estimation of the distribution of queue length in the next short intervals can be obtained. The proposed advertisement mechanism can be easily implemented with the current interdomain routing protocols. Numerical study indicates that the presented scheme is effective and feasible.展开更多
Three progressive stages of testing techniques are elaborated,which are en-tirely manual operating,taking separate instruments testing and computer program con-trolling.The testing method and principle are detailed ba...Three progressive stages of testing techniques are elaborated,which are en-tirely manual operating,taking separate instruments testing and computer program con-trolling.The testing method and principle are detailed based on the testing process formeteorological parameters,air pressure,air quality and rotating velocity.And every testingtechnique is analyzed.Finally, the technique outlook is viewed.All this plays a leading rolein development of the testing techniques.展开更多
The rate-based feedback PD-P controller of two freedom-degrees is proposed for the congestion control in computer networks to improve the abilities against disturbance. Moreover, the Dahlin algorithm is used for setti...The rate-based feedback PD-P controller of two freedom-degrees is proposed for the congestion control in computer networks to improve the abilities against disturbance. Moreover, the Dahlin algorithm is used for setting the controller to overcome the adverse effect caused by the propagation delay effectively. The research results show that the proposed scheme not only can make sources respond to the changes of network state more quickly, but also has a good robustness against estimated error of the delay. Then the packet queue level in buffer will be stabilized on the set-point quickly, and the delay and its jitter of the packet queuing will also become smaller. Besides, the flexible bandwidth allotment can be obtained by setting the weight coefficients.展开更多
This paper introduces a solution to the secure requirement for digital rights management （DRM） by the way of geospacial access control named geospacial access control （GeoAC） in geospacial field. The issues of aut...This paper introduces a solution to the secure requirement for digital rights management （DRM） by the way of geospacial access control named geospacial access control （GeoAC） in geospacial field. The issues of authorization for geospacial DRM are concentrated on. To geospacial DRM, one aspect is the declaration and enforcement of access rights, based on geographic aspects. To the approbation of digital geographic content, it is important to adopt online access to geodata through a special data infrastructure （SDI）. This results in the interoperability requirements on three different levels： data model level, service level and access control level. The interaction between the data model and service level can be obtained by criterions of the open geospacial consortium （OGC）, and the interaction of the access control level may be reached by declaring and enforcing access restrictions in GeoAC. Then an archetype enforcement based on GeoAC is elucidated. As one aspect of performing usage rights, the execution of access restrictions as an extension to a regular SDI is illuminated.展开更多
To solve the problem of advanced digital manufacturing technology in the practical application, a knowledge engineering technology was introduced into the computer numerical control(CNC) programming. The knowledge acq...To solve the problem of advanced digital manufacturing technology in the practical application, a knowledge engineering technology was introduced into the computer numerical control(CNC) programming. The knowledge acquisition, knowledge representation and reasoning used in CNC programming were researched. The CNC programming system functional architecture of impeller parts based on knowledge based engineering(KBE) was constructed. The structural model of the general knowledge-based system(KBS) was also constructed. The KBS of CNC programming system was established through synthesizing database technology and knowledge base theory. And in the context of corporate needs, based on the knowledge-driven manufacturing platform(i.e. UG CAD/CAM), VC++6.0 and UG/Open, the KBS and UG CAD/CAM were integrated seamlessly and the intelligent CNC programming KBE system for the impeller parts was developed by integrating KBE and UG CAD/CAM system. A method to establish standard process templates was proposed, so as to develop the intelligent CNC programming system in which CNC machining process and process parameters were standardized by using this KBE system. For the impeller parts processing, the method applied in the development of the prototype system is proven to be viable, feasible and practical.展开更多
Thailand was implementing the policy of HIV/A1DS prevention in risky group, The youth is one of groups with sexual risk behaviors to HIV/AIDS. This research aims to elucidate the process of policy implementation at th...Thailand was implementing the policy of HIV/A1DS prevention in risky group, The youth is one of groups with sexual risk behaviors to HIV/AIDS. This research aims to elucidate the process of policy implementation at the national and regional levels, and to explain the obstacles of policy implementation. The method was qualitative study. The stakeholders were 88 people. The data were collected by in-depth interview and coded by a computer program. The policy was transferred from the national AIDS committee to the Department of Disease Control （DDC） and provincial level. This process was lacking budget support. The provincial AIDS committee was monitored by the provincial health office, cooperating with the central level. The major role was to transfer the policy to the school, Local Administration Organization （LAO） and associated organization. The activity was funded by provincial, global funds, and outside sources. In the community, the core activities were AIDS knowledge, establishing core youth groups, and building the network of AIDS. The obstacle at the national level was changing the policy process from one with a budget to one without budget. In the area of practice, the AIDS problem and the effects of the risk behavior in youth groups were slightly concerned.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.70671040)and Specialized Research Fund for the Doctoral Program of High Education(Grant No.20050079008).
文摘In a CPM network, the longest path problem is one of the most important subjects. According to the intrinsic principle of CPM network, the length of the paths between arbitrary two nodes is presented. Furthermore, the length of the longest path from start node to arbitrary node and from arbitrary node to end node is proposed. In view of a scheduling problem of two activities with float in the CPM scheduling, we put forward Barycenter Theory and prove this theory based on the algorithm of the length of the longest path. By this theory, we know which activity should be done firstly. At last, we show our theory by an example.
文摘This paper describes the replacement of a controller for a programmable universal machine for assembly (PUMA) 512 robot with a newly designed PC based (open architecture) controller employing a real-time direct control of six joints. The original structure of the PUMA robot is retained. The hardware of the new controller includes such in-house designed parts as pulse width modulation (PWM) amplifiers, digital and analog controllers, I/O cards, signal conditioner cards, and 16-bit A/D and D/A boards. An Intel Pentium IV industrial computer is used as the central controller. The control software is implemented using VC++ programming language. The trajectory tracking performance of all six joints is tested at varying velocities. Experimental results show that it is feasible to implement the suggested open architecture platform for PUMA 500 series robots through the software routines running on a PC. By assembling controller from off-the-shell hardware and software components, the benefits of reduced and improved robustness have been realized.
文摘This paper investigates the routing among autonomous systems (ASs) with quality of service (QoS) requirements. To avoid the intractability of the problem, abstract QoS capability must be informed among ASs, because the routhing which constrained QoS has been proved to be nondeterministic polynomial-time (NP) hard even inside an AS. This paper employs the modified Dijkstra algorithm to compute the maximum bottleneck bandwidth inside an AS. This approach lays a basis for the AS-level switching capability on which interdomain advertisement can be performed. Furthermore, the paper models the aggregated traffic in backbone network with fractional Brownian motion (FBM), and by integrating along the time axis in short intervals, a good estimation of the distribution of queue length in the next short intervals can be obtained. The proposed advertisement mechanism can be easily implemented with the current interdomain routing protocols. Numerical study indicates that the presented scheme is effective and feasible.
文摘Three progressive stages of testing techniques are elaborated,which are en-tirely manual operating,taking separate instruments testing and computer program con-trolling.The testing method and principle are detailed based on the testing process formeteorological parameters,air pressure,air quality and rotating velocity.And every testingtechnique is analyzed.Finally, the technique outlook is viewed.All this plays a leading rolein development of the testing techniques.
文摘The rate-based feedback PD-P controller of two freedom-degrees is proposed for the congestion control in computer networks to improve the abilities against disturbance. Moreover, the Dahlin algorithm is used for setting the controller to overcome the adverse effect caused by the propagation delay effectively. The research results show that the proposed scheme not only can make sources respond to the changes of network state more quickly, but also has a good robustness against estimated error of the delay. Then the packet queue level in buffer will be stabilized on the set-point quickly, and the delay and its jitter of the packet queuing will also become smaller. Besides, the flexible bandwidth allotment can be obtained by setting the weight coefficients.
基金Funded by the Large-Scale Security SoC Project of Wuhan Science and Technology Bureau of China (No. 20061005119).
文摘This paper introduces a solution to the secure requirement for digital rights management （DRM） by the way of geospacial access control named geospacial access control （GeoAC） in geospacial field. The issues of authorization for geospacial DRM are concentrated on. To geospacial DRM, one aspect is the declaration and enforcement of access rights, based on geographic aspects. To the approbation of digital geographic content, it is important to adopt online access to geodata through a special data infrastructure （SDI）. This results in the interoperability requirements on three different levels： data model level, service level and access control level. The interaction between the data model and service level can be obtained by criterions of the open geospacial consortium （OGC）, and the interaction of the access control level may be reached by declaring and enforcing access restrictions in GeoAC. Then an archetype enforcement based on GeoAC is elucidated. As one aspect of performing usage rights, the execution of access restrictions as an extension to a regular SDI is illuminated.
基金Project(12ZT14)supported by the Natural Science Foundation of Shanghai Municipal Education Commission,China
文摘To solve the problem of advanced digital manufacturing technology in the practical application, a knowledge engineering technology was introduced into the computer numerical control(CNC) programming. The knowledge acquisition, knowledge representation and reasoning used in CNC programming were researched. The CNC programming system functional architecture of impeller parts based on knowledge based engineering(KBE) was constructed. The structural model of the general knowledge-based system(KBS) was also constructed. The KBS of CNC programming system was established through synthesizing database technology and knowledge base theory. And in the context of corporate needs, based on the knowledge-driven manufacturing platform(i.e. UG CAD/CAM), VC++6.0 and UG/Open, the KBS and UG CAD/CAM were integrated seamlessly and the intelligent CNC programming KBE system for the impeller parts was developed by integrating KBE and UG CAD/CAM system. A method to establish standard process templates was proposed, so as to develop the intelligent CNC programming system in which CNC machining process and process parameters were standardized by using this KBE system. For the impeller parts processing, the method applied in the development of the prototype system is proven to be viable, feasible and practical.
文摘Thailand was implementing the policy of HIV/A1DS prevention in risky group, The youth is one of groups with sexual risk behaviors to HIV/AIDS. This research aims to elucidate the process of policy implementation at the national and regional levels, and to explain the obstacles of policy implementation. The method was qualitative study. The stakeholders were 88 people. The data were collected by in-depth interview and coded by a computer program. The policy was transferred from the national AIDS committee to the Department of Disease Control （DDC） and provincial level. This process was lacking budget support. The provincial AIDS committee was monitored by the provincial health office, cooperating with the central level. The major role was to transfer the policy to the school, Local Administration Organization （LAO） and associated organization. The activity was funded by provincial, global funds, and outside sources. In the community, the core activities were AIDS knowledge, establishing core youth groups, and building the network of AIDS. The obstacle at the national level was changing the policy process from one with a budget to one without budget. In the area of practice, the AIDS problem and the effects of the risk behavior in youth groups were slightly concerned.
