This work aimed to construct an epidemic model with fuzzy parameters.Since the classical epidemic model doesnot elaborate on the successful interaction of susceptible and infective people,the constructed fuzzy epidemi...This work aimed to construct an epidemic model with fuzzy parameters.Since the classical epidemic model doesnot elaborate on the successful interaction of susceptible and infective people,the constructed fuzzy epidemicmodel discusses the more detailed versions of the interactions between infective and susceptible people.Thenext-generation matrix approach is employed to find the reproduction number of a deterministic model.Thesensitivity analysis and local stability analysis of the systemare also provided.For solving the fuzzy epidemic model,a numerical scheme is constructed which consists of three time levels.The numerical scheme has an advantage overthe existing forward Euler scheme for determining the conditions of getting the positive solution.The establishedscheme also has an advantage over existing non-standard finite difference methods in terms of order of accuracy.The stability of the scheme for the considered fuzzy model is also provided.From the plotted results,it can beobserved that susceptible people decay by rising interaction parameters.展开更多
Rate control plays a critical role in achieving perceivable video quality under a variable bit rate,limited buffer sizes and low delay applications.Since a rate control system exhibits non-linear and unpredictable cha...Rate control plays a critical role in achieving perceivable video quality under a variable bit rate,limited buffer sizes and low delay applications.Since a rate control system exhibits non-linear and unpredictable characteristics,it is difficult to establish a very accurate rate-distortion(R-D)model and acquire effective rate control performance.Considering the excellent control ability and low computing complexity of the fuzzy logic in non-linear systems,this paper proposes a bitrate control algorithm based on a fuzzy controller,named the Fuzzy Rate Control Algorithm(FRCA),for All-Intra(AI)and low-delay(LD)video source coding.Contributions of the proposed FRCA mainly consist of four aspects.First,fuzzy logic is adopted to minimize the deviation between the actual and the target buffer size in the hypothetical reference decoder(HRD).Second,a fast lookup table is employed in fuzzy rate control,which reduces computing cost of the control process.Third,an input domain determination scheme is proposed to improve the precision of the fuzzy controller.Fourth,a novel scene change detection is introduced and integrated in the FRCA to adaptively adjust the Group-of-Pictures(GOP)length when the source content fluctuates.The FRCA can be transplanted and implemented in various industry coders.Extensive experiments show that the FRCA has accurate variable bit-rate control ability and maintains a steady buffer size during the encoding processes.Compared with the default configuration encoding under AI and LD,the proposed FRCA can achieve the target bit rates more accurately in various classical encoders.展开更多
Purpose–The purpose of this paper is to deal with the stabilization of the continuous Takagi Sugeno(TS)fuzzy models using their discretized forms based on the decay rate performance approach.Design/methodology/appro...Purpose–The purpose of this paper is to deal with the stabilization of the continuous Takagi Sugeno(TS)fuzzy models using their discretized forms based on the decay rate performance approach.Design/methodology/approach–This approach is structured as follows:first,a discrete model is obtained from the discretization of the continuous TS fuzzy model.The discretized model is obtained from the Euler approximation method which is used for several orders.Second,based on the decay rate stabilization conditions,the gains of a non-PDC control law ensuring the stabilization of the discrete model are determined.Third by keeping the values of the gains,the authors determine the values of the performance criterion and the authors check by simulation the stability of the continuous TS fuzzy models through the zero order hold.Findings–The proposed idea lead to compare the performance continuous stability results with the literature.The comparison is,also,taken between the quadratic and non-quadratic cases.Originality/value–Therefore,the originality of this paper consists in the improvement of the continuous fuzzy models by using their discretized models.In this case,the effect of the discretization step on the performances of the continuous TS fuzzy models is studied.The usefulness of this approach is shown through two examples.展开更多
极端冰灾天气下线路覆冰闪络跳闸是激发大电网脆弱性、导致大面积停电的重要因素。覆冰闪络跳闸等现象的风险评估是建立冰灾防御体系的基础。基于电网层面,进行了冰灾天气下线路覆冰闪络跳闸的风险状态识别与风险建模。根据覆冰闪络跳...极端冰灾天气下线路覆冰闪络跳闸是激发大电网脆弱性、导致大面积停电的重要因素。覆冰闪络跳闸等现象的风险评估是建立冰灾防御体系的基础。基于电网层面,进行了冰灾天气下线路覆冰闪络跳闸的风险状态识别与风险建模。根据覆冰闪络跳闸特性分析,界定了输电网绝缘系统的脆弱点,即覆冰期绝缘系统冰凌桥接、融冰期冰凌断流等临界点。进一步建立了覆冰闪络状态的划分原则与风险等级,并对预测冰况进行了模糊模式识别和风险评级,为运行人员提供了动态风险信息。针对数据的小样本、多输入等特点,采用统计学习理论结构风险最小化方法,构建了最小二乘支持向量机(least squares support vector machine,LSSVM)冰闪跳闸风险评估模型,依据贝叶斯(Bayesian)证据推理优化模型参数。通过与误差反向传播人工神经网络(artificial neural networkwith error back propagation,BP-ANN)算法对比,验证了该模型的有效性。最后通过脆弱性指标分析了网架结构破坏的严重性与电网绝缘系统的脆弱性。展开更多
基金the support of Prince Sultan University for paying the article processing charges(APC)of this publication.
文摘This work aimed to construct an epidemic model with fuzzy parameters.Since the classical epidemic model doesnot elaborate on the successful interaction of susceptible and infective people,the constructed fuzzy epidemicmodel discusses the more detailed versions of the interactions between infective and susceptible people.Thenext-generation matrix approach is employed to find the reproduction number of a deterministic model.Thesensitivity analysis and local stability analysis of the systemare also provided.For solving the fuzzy epidemic model,a numerical scheme is constructed which consists of three time levels.The numerical scheme has an advantage overthe existing forward Euler scheme for determining the conditions of getting the positive solution.The establishedscheme also has an advantage over existing non-standard finite difference methods in terms of order of accuracy.The stability of the scheme for the considered fuzzy model is also provided.From the plotted results,it can beobserved that susceptible people decay by rising interaction parameters.
基金supported by ZTE Industry-Academia-Research Cooperation Funds under Grant No.CON1503180004the Postdoctoral Science Foundation of China under Gant No.2014M552342the Foundation of Science and Technology Department of Sichuan Province,China under Grant No.2014GZ0005
文摘Rate control plays a critical role in achieving perceivable video quality under a variable bit rate,limited buffer sizes and low delay applications.Since a rate control system exhibits non-linear and unpredictable characteristics,it is difficult to establish a very accurate rate-distortion(R-D)model and acquire effective rate control performance.Considering the excellent control ability and low computing complexity of the fuzzy logic in non-linear systems,this paper proposes a bitrate control algorithm based on a fuzzy controller,named the Fuzzy Rate Control Algorithm(FRCA),for All-Intra(AI)and low-delay(LD)video source coding.Contributions of the proposed FRCA mainly consist of four aspects.First,fuzzy logic is adopted to minimize the deviation between the actual and the target buffer size in the hypothetical reference decoder(HRD).Second,a fast lookup table is employed in fuzzy rate control,which reduces computing cost of the control process.Third,an input domain determination scheme is proposed to improve the precision of the fuzzy controller.Fourth,a novel scene change detection is introduced and integrated in the FRCA to adaptively adjust the Group-of-Pictures(GOP)length when the source content fluctuates.The FRCA can be transplanted and implemented in various industry coders.Extensive experiments show that the FRCA has accurate variable bit-rate control ability and maintains a steady buffer size during the encoding processes.Compared with the default configuration encoding under AI and LD,the proposed FRCA can achieve the target bit rates more accurately in various classical encoders.
文摘Purpose–The purpose of this paper is to deal with the stabilization of the continuous Takagi Sugeno(TS)fuzzy models using their discretized forms based on the decay rate performance approach.Design/methodology/approach–This approach is structured as follows:first,a discrete model is obtained from the discretization of the continuous TS fuzzy model.The discretized model is obtained from the Euler approximation method which is used for several orders.Second,based on the decay rate stabilization conditions,the gains of a non-PDC control law ensuring the stabilization of the discrete model are determined.Third by keeping the values of the gains,the authors determine the values of the performance criterion and the authors check by simulation the stability of the continuous TS fuzzy models through the zero order hold.Findings–The proposed idea lead to compare the performance continuous stability results with the literature.The comparison is,also,taken between the quadratic and non-quadratic cases.Originality/value–Therefore,the originality of this paper consists in the improvement of the continuous fuzzy models by using their discretized models.In this case,the effect of the discretization step on the performances of the continuous TS fuzzy models is studied.The usefulness of this approach is shown through two examples.
文摘极端冰灾天气下线路覆冰闪络跳闸是激发大电网脆弱性、导致大面积停电的重要因素。覆冰闪络跳闸等现象的风险评估是建立冰灾防御体系的基础。基于电网层面,进行了冰灾天气下线路覆冰闪络跳闸的风险状态识别与风险建模。根据覆冰闪络跳闸特性分析,界定了输电网绝缘系统的脆弱点,即覆冰期绝缘系统冰凌桥接、融冰期冰凌断流等临界点。进一步建立了覆冰闪络状态的划分原则与风险等级,并对预测冰况进行了模糊模式识别和风险评级,为运行人员提供了动态风险信息。针对数据的小样本、多输入等特点,采用统计学习理论结构风险最小化方法,构建了最小二乘支持向量机(least squares support vector machine,LSSVM)冰闪跳闸风险评估模型,依据贝叶斯(Bayesian)证据推理优化模型参数。通过与误差反向传播人工神经网络(artificial neural networkwith error back propagation,BP-ANN)算法对比,验证了该模型的有效性。最后通过脆弱性指标分析了网架结构破坏的严重性与电网绝缘系统的脆弱性。
