The IMC(Internal Model Control) controller based on robust tuning can improve the robustness and dynamic performance of the system.In this paper,the robustness degree of the control system is investigated based on Max...The IMC(Internal Model Control) controller based on robust tuning can improve the robustness and dynamic performance of the system.In this paper,the robustness degree of the control system is investigated based on Maximum Sensitivity(Ms) in depth.And the analytical relationship is obtained between the robustness specification and controller parameters,which gives a clear design criterion to robust IMC controller.Moreover,a novel and simple IMC-PID(Proportional-Integral-Derivative) tuning method is proposed by converting the IMC controller to PID form in terms of the time domain rather than the frequency domain adopted in some conventional IMC-based methods.Hence,the presented IMC-PID gives a good performance with a specific robustness degree.The new IMC-PID method is compared with other classical IMC-PID rules,showing the flexibility and feasibility for a wide range of plants.展开更多
This paper presents a robust color image hiding method based on YCbCr color system in discrete cosine transform （DOT） domain,which can hide a secret color image behind a public color cover image and is compatible wi...This paper presents a robust color image hiding method based on YCbCr color system in discrete cosine transform （DOT） domain,which can hide a secret color image behind a public color cover image and is compatible with the international image compression standard of JPEG. To overcome the grave distortion problem in the restored secret image,this paper proposes a new embedding scheme consisting of reasonable partition of a pixel value and sign embedding. Moreover, based on human visual system （HVS） and fuzzy theory,this paper also presents a fuzzy classification method for DOT sub-blocks to realize the adaptive selection of embedding strength. The experimental results show that the maximum distortion error in pixel value for the extracted secret image is ±1. And the color cover image can provide good quality after embedding large amount of data.展开更多
Due to the lack of a unified authentication model certain mistakes occurred in the use of the wa-termarking authentication methods. To clarify the confusion, authentication models of robust and fragile wa-termarking a...Due to the lack of a unified authentication model certain mistakes occurred in the use of the wa-termarking authentication methods. To clarify the confusion, authentication models of robust and fragile wa-termarking are developed respectively in the paper. Concrete algorithms are proposed to prove the models that different Discrete Wavelet Transform (DWT) domains are utilized to embed the watermarks and quanti-zation method is presented with Just Notice Differences (JNDs) threshold as the quantization size. After the key technologies about the two methods are discussed, we detail the comparison of the two modes and rec-ommend their respective application scenarios as applicable results.展开更多
基金Supported by the National Natural Science Foundation of China（61273132）Doctoral Fund of Ministry of Education of China（20110010110010）
文摘The IMC(Internal Model Control) controller based on robust tuning can improve the robustness and dynamic performance of the system.In this paper,the robustness degree of the control system is investigated based on Maximum Sensitivity(Ms) in depth.And the analytical relationship is obtained between the robustness specification and controller parameters,which gives a clear design criterion to robust IMC controller.Moreover,a novel and simple IMC-PID(Proportional-Integral-Derivative) tuning method is proposed by converting the IMC controller to PID form in terms of the time domain rather than the frequency domain adopted in some conventional IMC-based methods.Hence,the presented IMC-PID gives a good performance with a specific robustness degree.The new IMC-PID method is compared with other classical IMC-PID rules,showing the flexibility and feasibility for a wide range of plants.
基金This workis partially supported by National Science Foundation(Grant No.A0324676)
文摘This paper presents a robust color image hiding method based on YCbCr color system in discrete cosine transform （DOT） domain,which can hide a secret color image behind a public color cover image and is compatible with the international image compression standard of JPEG. To overcome the grave distortion problem in the restored secret image,this paper proposes a new embedding scheme consisting of reasonable partition of a pixel value and sign embedding. Moreover, based on human visual system （HVS） and fuzzy theory,this paper also presents a fuzzy classification method for DOT sub-blocks to realize the adaptive selection of embedding strength. The experimental results show that the maximum distortion error in pixel value for the extracted secret image is ±1. And the color cover image can provide good quality after embedding large amount of data.
文摘Due to the lack of a unified authentication model certain mistakes occurred in the use of the wa-termarking authentication methods. To clarify the confusion, authentication models of robust and fragile wa-termarking are developed respectively in the paper. Concrete algorithms are proposed to prove the models that different Discrete Wavelet Transform (DWT) domains are utilized to embed the watermarks and quanti-zation method is presented with Just Notice Differences (JNDs) threshold as the quantization size. After the key technologies about the two methods are discussed, we detail the comparison of the two modes and rec-ommend their respective application scenarios as applicable results.
