The paper discusses the barriers of integration of management systems （IMS）. A model based on process is explored, It is indicated that integrating management systems should not ignore the characteristics of the man...The paper discusses the barriers of integration of management systems （IMS）. A model based on process is explored, It is indicated that integrating management systems should not ignore the characteristics of the management systems, especially scope issues. IMS needs to take into the continuous improvement.展开更多
The motivation of this work is to obtain single PI/PID tuning formula for different types of processes with enhanced disturbance rejection performance. The proposed tuning formula consistently gives better performance...The motivation of this work is to obtain single PI/PID tuning formula for different types of processes with enhanced disturbance rejection performance. The proposed tuning formula consistently gives better performance in comparison to several well-known methods at the same degree of robustness for stable, integrating and unstable processes. For the selection of the closed-loop time constant(τc), a guideline is provided over a broad range of time-delay/time-constant ratios on the basis of the peak of maximum sensitivity(Ms). An analysis has been performed for the uncertainty margin with the different process parameters for the robust controller design. It gives the guideline of the Ms-value settings for the PI controller designs based on the process parameters uncertainty. Furthermore, a relationship has been developed between Ms-value and uncertainty margin with the different process parameters(k, τ and θ). Simulation study has been conducted for the broad class of processes and the controllers are tuned to have the same degree of robustness by measuring the maximum sensitivity, Ms, in order to obtain a reasonable comparison.展开更多
An IMC-PID controller was proposed for unstable second-order time delay system which shows the characteristics of inverse response(RHP zero). A plot of Ms versus λ was suggested to calculate the suitable tuning param...An IMC-PID controller was proposed for unstable second-order time delay system which shows the characteristics of inverse response(RHP zero). A plot of Ms versus λ was suggested to calculate the suitable tuning parameter λ, which provides a trade-off between performance and robustness. Six different forms of process models were selected from literature to show the applicability of the present method. Performance of controller was calculated by ITAE and total variation TV and compared with recently published tuning rules. Undesirable overshoot was removed by using a set-point weighting parameter. Robustness was tested by introducing a perturbation into the various model parameters and closed-loop results show that the designed controller is robust in the case of model uncertainty. The proposed method shows an overall better closed-loop response as compared to other recently reported methods.展开更多
随着电力配变网络基础设施规模的不断扩大,各类安全二次设备、边缘终端节点和业务系统产生的信息通信流量数据在格式、协议、语义特征层面存在显著差异。主要存在现有缓解框架缺乏多源异构网络异常流量检测数据归一化处理算法,网络攻击...随着电力配变网络基础设施规模的不断扩大,各类安全二次设备、边缘终端节点和业务系统产生的信息通信流量数据在格式、协议、语义特征层面存在显著差异。主要存在现有缓解框架缺乏多源异构网络异常流量检测数据归一化处理算法,网络攻击行为分析依赖人工特征提取的规则引擎,以及难以确定有效的网络攻击缓解措施等痛点。针对以上痛点,提出了一种基于归一化处理和TrafficLLM的网络攻击缓解框架(Network Attack Mitigation Framework Based on Normalized Processing and TrafficLLM,NAMF-NPTLLM)。该框架涵盖数据解析、归一化处理、模型微调和生成攻击缓解方案4个核心阶段。首先,在特征选择阶段,通过构建集成学习模型,融合多类基学习器的特征评估结果,精准提取对分类结果影响较大的关键特征。其次,将选取的关键特征通过归一化处理,生成统一的自然语言token序列形式表达,为该网络攻击缓解框架的流量异常分析TrafficLLM模型提供标准化输入。然后,对TrafficLLM模型进行微调,使该模型能够理解提示词模板指令并学习攻击行为的流量模式。最后,通过微调后的大模型进行推理,生成攻击缓解指令,使得该框架能够根据攻击行为特征动态调整网络攻击缓解策略。通过在CIC-DDoS2019数据集上进行实验验证,与传统方法相比,该框架将网络攻击行为分类的准确率达到99.80%,提高了1.3%。实验结果表明,该框架对于缓解海量多源异构电力网络终端流量攻击,具有更好的准确性和有效性。展开更多
To overcome the deficiencies addressed in the conventional PID control and improve the dynamic performance and robustness of the system, a simple design and parameters tuning approach of internal model control-PID （I...To overcome the deficiencies addressed in the conventional PID control and improve the dynamic performance and robustness of the system, a simple design and parameters tuning approach of internal model control-PID （IMC-PID） controller was proposed for the first order plus time-delay （FOPTD） process and the second order plus time-delay （SOPTD） process. By approximating the time-delay term of the process model with the first-order Taylor series, the expressions for IMC-PID controller parameters were derived, and they had only one adjustable parameter 2 which was directly related to the dynamic performance and robustness of the system. Moreover, an analytical approach of selecting 2 was given based on the maximum sensitivity Ms. Then, the robust tuning of the system could be achieved according to the value of Ms. In addition, the proposed method could be extended to the integrator plus time-delay （IPTD） process and the first order delay integrating （FODI） process. Simulation studies were carried out on various processes with time-delay, and the results show that the proposed method could provide a better dynamic performance of both the set-point tracking and disturbance rejection and robustness against parameters perturbation.展开更多
文摘The paper discusses the barriers of integration of management systems （IMS）. A model based on process is explored, It is indicated that integrating management systems should not ignore the characteristics of the management systems, especially scope issues. IMS needs to take into the continuous improvement.
基金the support provided by King Abdulaziz City for Science and Technology (KACST) through the "KACST Annual Program" at King Fahd University of Petroleum & Minerals (KFUPM) for funding this work through project number AT-32-41
文摘The motivation of this work is to obtain single PI/PID tuning formula for different types of processes with enhanced disturbance rejection performance. The proposed tuning formula consistently gives better performance in comparison to several well-known methods at the same degree of robustness for stable, integrating and unstable processes. For the selection of the closed-loop time constant(τc), a guideline is provided over a broad range of time-delay/time-constant ratios on the basis of the peak of maximum sensitivity(Ms). An analysis has been performed for the uncertainty margin with the different process parameters for the robust controller design. It gives the guideline of the Ms-value settings for the PI controller designs based on the process parameters uncertainty. Furthermore, a relationship has been developed between Ms-value and uncertainty margin with the different process parameters(k, τ and θ). Simulation study has been conducted for the broad class of processes and the controllers are tuned to have the same degree of robustness by measuring the maximum sensitivity, Ms, in order to obtain a reasonable comparison.
基金India (MHRD, India) for providing financial support
文摘An IMC-PID controller was proposed for unstable second-order time delay system which shows the characteristics of inverse response(RHP zero). A plot of Ms versus λ was suggested to calculate the suitable tuning parameter λ, which provides a trade-off between performance and robustness. Six different forms of process models were selected from literature to show the applicability of the present method. Performance of controller was calculated by ITAE and total variation TV and compared with recently published tuning rules. Undesirable overshoot was removed by using a set-point weighting parameter. Robustness was tested by introducing a perturbation into the various model parameters and closed-loop results show that the designed controller is robust in the case of model uncertainty. The proposed method shows an overall better closed-loop response as compared to other recently reported methods.
文摘随着电力配变网络基础设施规模的不断扩大,各类安全二次设备、边缘终端节点和业务系统产生的信息通信流量数据在格式、协议、语义特征层面存在显著差异。主要存在现有缓解框架缺乏多源异构网络异常流量检测数据归一化处理算法,网络攻击行为分析依赖人工特征提取的规则引擎,以及难以确定有效的网络攻击缓解措施等痛点。针对以上痛点,提出了一种基于归一化处理和TrafficLLM的网络攻击缓解框架(Network Attack Mitigation Framework Based on Normalized Processing and TrafficLLM,NAMF-NPTLLM)。该框架涵盖数据解析、归一化处理、模型微调和生成攻击缓解方案4个核心阶段。首先,在特征选择阶段,通过构建集成学习模型,融合多类基学习器的特征评估结果,精准提取对分类结果影响较大的关键特征。其次,将选取的关键特征通过归一化处理,生成统一的自然语言token序列形式表达,为该网络攻击缓解框架的流量异常分析TrafficLLM模型提供标准化输入。然后,对TrafficLLM模型进行微调,使该模型能够理解提示词模板指令并学习攻击行为的流量模式。最后,通过微调后的大模型进行推理,生成攻击缓解指令,使得该框架能够根据攻击行为特征动态调整网络攻击缓解策略。通过在CIC-DDoS2019数据集上进行实验验证,与传统方法相比,该框架将网络攻击行为分类的准确率达到99.80%,提高了1.3%。实验结果表明,该框架对于缓解海量多源异构电力网络终端流量攻击,具有更好的准确性和有效性。
基金Project(2007011049) supported by the Natural Science Foundation of Shanxi Province,China
文摘To overcome the deficiencies addressed in the conventional PID control and improve the dynamic performance and robustness of the system, a simple design and parameters tuning approach of internal model control-PID （IMC-PID） controller was proposed for the first order plus time-delay （FOPTD） process and the second order plus time-delay （SOPTD） process. By approximating the time-delay term of the process model with the first-order Taylor series, the expressions for IMC-PID controller parameters were derived, and they had only one adjustable parameter 2 which was directly related to the dynamic performance and robustness of the system. Moreover, an analytical approach of selecting 2 was given based on the maximum sensitivity Ms. Then, the robust tuning of the system could be achieved according to the value of Ms. In addition, the proposed method could be extended to the integrator plus time-delay （IPTD） process and the first order delay integrating （FODI） process. Simulation studies were carried out on various processes with time-delay, and the results show that the proposed method could provide a better dynamic performance of both the set-point tracking and disturbance rejection and robustness against parameters perturbation.
