In this paper, to model check real-time value-passing systems, a formallanguage Timed Symbolic Transition Graph and a logic system named Timed Predicate μ-Calculus areproposed. An algorithm is presented which is loca...In this paper, to model check real-time value-passing systems, a formallanguage Timed Symbolic Transition Graph and a logic system named Timed Predicate μ-Calculus areproposed. An algorithm is presented which is local in that it generates and investigates thereachable state space in top-down fashion and maintains the partition for time evaluations as coarseas possible while on-the-fly instantiating data variables. It can deal with not only data variableswith finite value domain, but also the so called data independent variables with infinite valuedomain. To authors knowledge, this is the first algorithm for model checking timed systemscontaining value-passing features.展开更多
Background Radiation detection has been a main interest for researchers as all kind of produced particles in atomic and subatomic physics based on the measurement systems so-called detector.Detection efficiency is one...Background Radiation detection has been a main interest for researchers as all kind of produced particles in atomic and subatomic physics based on the measurement systems so-called detector.Detection efficiency is one of the main parameters in detection system besides many other different parameters of the detector.The detector in experimental physics is an instrument that converts radiation energy into an electrical signal,and this is achieved basically by either ionization or excitation.The choice for any type of a detector(gas-filled,scintillation or semiconductor)for any application depends upon the X-ray of gamma energy range of interest.A working model is therefore developed which is capable of describing the overall NaI(Tl)detection efficiency as a function of several known parameters.Purpose The attenuation coefficients for the bismuth borate glasses with different concentrations were measured using gamma spectroscopy technique.The numerical absolute efficiency calibration of a detector can be determined by In-Situ Object Calibration Software(ISOCS)and Monte Carlo Neutral Particle version 5(MCNP5)techniques which does not require any calibration standards or reference materials.Methods By using the ISOCS and MCNP5 methodologies,the full energy peak efficiency of a scintillator detector(3“X3”NaI(Tl))exposed to Co-60 and Cs-137 gamma ray sources with average accuracy range 0.126–1.224%for the used samples can be detected.The used materials are ternary and are located between the detector and the source to determine the attenuation coefficients for these samples by using the calculated full energy peak efficiencies of a detector.Results The average accuracy ranged from−1.808 to 1.960%for linear attenuation coefficient(μ),while it ranged from−1.999 to 1.888%and from−1.924 to 1.960%for half value layer(HVL)and mass linear attenuation coefficient(μm),respectively.Conclusion The calculated values of the absolute full energy peak efficiency have been used to determine the attenuation coefficients of展开更多
为了提取机械设备被强背景噪声淹没的故障特征,采用一种具有通用意义的基于奇异值分解(Singular value decomposition,SVD)的子空间降噪算法对信号进行处理,即?-SVD降噪算法。传统的SVD降噪算法是?-SVD降噪算法中拉格朗日乘子??0时的一...为了提取机械设备被强背景噪声淹没的故障特征,采用一种具有通用意义的基于奇异值分解(Singular value decomposition,SVD)的子空间降噪算法对信号进行处理,即?-SVD降噪算法。传统的SVD降噪算法是?-SVD降噪算法中拉格朗日乘子??0时的一种特殊情况。?-SVD降噪算法包含滤值因子,能够抑制以噪声贡献占主导的奇异值对降噪后信号的信息贡献量。?-SVD降噪算法涉及延迟时间、嵌入维数、降噪阶次、噪声功率和拉格朗日乘子等5个参数。讨论了?-SVD降噪算法的参数选择方法,并着重研究降噪阶次和拉格朗日乘子对降噪效果的影响。齿轮故障仿真信号和齿轮早期裂纹故障振动信号的试验结果表明,?-SVD降噪算法在降噪效果方面要优于传统的SVD降噪算法,可以在强背景噪声情况下更好地提取出齿轮的故障特征。展开更多
为了解决奇异值分解(singular value decomposition,SVD)算法提取水印时需要原始载体图像的缺陷,以及量化索引调制(quantization index modulation,QIM)均匀量化不适用于非均匀信号的问题,通过引入μ律压缩技术,提出一种新的基于DWT-SV...为了解决奇异值分解(singular value decomposition,SVD)算法提取水印时需要原始载体图像的缺陷,以及量化索引调制(quantization index modulation,QIM)均匀量化不适用于非均匀信号的问题,通过引入μ律压缩技术,提出一种新的基于DWT-SVD压缩量化的数字图像盲水印算法。该算法对载体图像进行分块,对每一分块实施离散小波变换(discrete wavelet transform,DWT),以及对变换后的近似部分系数进行SVD分解,使用μ律压缩函数压缩分解后的最大奇异值,用QIM的方法嵌入二值水印。算法只用到了最大奇异值,可以盲提取水印,消除因传输原始载体图像产生的不安全性,μ律压缩技术也减小了嵌入水印对原始载体图像的扰乱。仿真实验结果表明,该算法保持了较高的透明性,并对高斯噪声、中值滤波、联合图像专家小组(joint photographic experts group,JPEG)压缩、缩放等常见攻击具有更强的鲁棒性。展开更多
文摘In this paper, to model check real-time value-passing systems, a formallanguage Timed Symbolic Transition Graph and a logic system named Timed Predicate μ-Calculus areproposed. An algorithm is presented which is local in that it generates and investigates thereachable state space in top-down fashion and maintains the partition for time evaluations as coarseas possible while on-the-fly instantiating data variables. It can deal with not only data variableswith finite value domain, but also the so called data independent variables with infinite valuedomain. To authors knowledge, this is the first algorithm for model checking timed systemscontaining value-passing features.
文摘Background Radiation detection has been a main interest for researchers as all kind of produced particles in atomic and subatomic physics based on the measurement systems so-called detector.Detection efficiency is one of the main parameters in detection system besides many other different parameters of the detector.The detector in experimental physics is an instrument that converts radiation energy into an electrical signal,and this is achieved basically by either ionization or excitation.The choice for any type of a detector(gas-filled,scintillation or semiconductor)for any application depends upon the X-ray of gamma energy range of interest.A working model is therefore developed which is capable of describing the overall NaI(Tl)detection efficiency as a function of several known parameters.Purpose The attenuation coefficients for the bismuth borate glasses with different concentrations were measured using gamma spectroscopy technique.The numerical absolute efficiency calibration of a detector can be determined by In-Situ Object Calibration Software(ISOCS)and Monte Carlo Neutral Particle version 5(MCNP5)techniques which does not require any calibration standards or reference materials.Methods By using the ISOCS and MCNP5 methodologies,the full energy peak efficiency of a scintillator detector(3“X3”NaI(Tl))exposed to Co-60 and Cs-137 gamma ray sources with average accuracy range 0.126–1.224%for the used samples can be detected.The used materials are ternary and are located between the detector and the source to determine the attenuation coefficients for these samples by using the calculated full energy peak efficiencies of a detector.Results The average accuracy ranged from−1.808 to 1.960%for linear attenuation coefficient(μ),while it ranged from−1.999 to 1.888%and from−1.924 to 1.960%for half value layer(HVL)and mass linear attenuation coefficient(μm),respectively.Conclusion The calculated values of the absolute full energy peak efficiency have been used to determine the attenuation coefficients of
文摘为了提取机械设备被强背景噪声淹没的故障特征,采用一种具有通用意义的基于奇异值分解(Singular value decomposition,SVD)的子空间降噪算法对信号进行处理,即?-SVD降噪算法。传统的SVD降噪算法是?-SVD降噪算法中拉格朗日乘子??0时的一种特殊情况。?-SVD降噪算法包含滤值因子,能够抑制以噪声贡献占主导的奇异值对降噪后信号的信息贡献量。?-SVD降噪算法涉及延迟时间、嵌入维数、降噪阶次、噪声功率和拉格朗日乘子等5个参数。讨论了?-SVD降噪算法的参数选择方法,并着重研究降噪阶次和拉格朗日乘子对降噪效果的影响。齿轮故障仿真信号和齿轮早期裂纹故障振动信号的试验结果表明,?-SVD降噪算法在降噪效果方面要优于传统的SVD降噪算法,可以在强背景噪声情况下更好地提取出齿轮的故障特征。
文摘为了解决奇异值分解(singular value decomposition,SVD)算法提取水印时需要原始载体图像的缺陷,以及量化索引调制(quantization index modulation,QIM)均匀量化不适用于非均匀信号的问题,通过引入μ律压缩技术,提出一种新的基于DWT-SVD压缩量化的数字图像盲水印算法。该算法对载体图像进行分块,对每一分块实施离散小波变换(discrete wavelet transform,DWT),以及对变换后的近似部分系数进行SVD分解,使用μ律压缩函数压缩分解后的最大奇异值,用QIM的方法嵌入二值水印。算法只用到了最大奇异值,可以盲提取水印,消除因传输原始载体图像产生的不安全性,μ律压缩技术也减小了嵌入水印对原始载体图像的扰乱。仿真实验结果表明,该算法保持了较高的透明性,并对高斯噪声、中值滤波、联合图像专家小组(joint photographic experts group,JPEG)压缩、缩放等常见攻击具有更强的鲁棒性。
