We developed a scheme based on wood surface novel wood recognition spectral features that aimed to solve three problems. First was elimination of noise in some bands of wood spectral reflection curves. Second was imp...We developed a scheme based on wood surface novel wood recognition spectral features that aimed to solve three problems. First was elimination of noise in some bands of wood spectral reflection curves. Second was improvement of wood feature selection based on analysis of wood spectral data. The wood spectral band is 350-2500 nm, a 2150D vector with a spectral sampling interval of 1 nm. We developed a feature selection proce- dure and a filtering procedure by solving the eigenvalues of the dispersion matrix. Third, we optimized the design for the indoor radian＇s mounting height. We used a genetic algorithm to solve the optimal radian＇s height so that the spectral reflection curves had the best classification infor- mation for wood species. Experiments on fivecommon wood species in northeast China showed overall recogni- tion accuracy 〉95 % at optimal recognition velocity.展开更多
Instead of calculating the number π in this article special attention is paid to the method of measuring it. It has been found that there is a direct and indirect measurement of that number. To perform such a measure...Instead of calculating the number π in this article special attention is paid to the method of measuring it. It has been found that there is a direct and indirect measurement of that number. To perform such a measurement, a selection was made of some mathematical and physical quantities which within themselves contain a number π. One such quantity is a straight angle Pi, which may be expressed as Pi = π rad. By measuring the angle, using the direct method, we determine the number π as π = arccos(-1). To implement an indirect measurement of the number π, a system consisting of a container with liquid and equating it with the measuring pot has been conceived. The accuracy of measurement by this method depends on the precision performance of these elements of the system.展开更多
Objective To compare the phase radians in several cerebral regions between patients with Parkinson’s disease （PD） and control subjects, and to evaluate whether iron deposition quantified by susceptibility-weighted ...Objective To compare the phase radians in several cerebral regions between patients with Parkinson’s disease （PD） and control subjects, and to evaluate whether iron deposition quantified by susceptibility-weighted imaging （SWI） is related to the severity of motor symptoms of PD. Methods SWI consisted of both magnitude and phase images from a fully flow-compensated, 3-dimensional and gradient-echo （GRE） sequence. Magnitude and phase data were collected at GE HD 1.5T. The regions evaluated included frontal white matter, grey matter, cerebrospinal fluid, putamen, caudate nucleus （CN）, sub- stantia nigra pars compacta （SNc）, substantia nigra pars reticulata （SNr）, and red nucleus （RN）. A total number of 42 patients （12 patients without cognitive dysfunction, and 30 with cognitive dysfunction from mild to moderate degrees） and 30 control subjects were employed in the present study. Results The phase radians of SNc, CN and RN in PD patients were lower than those in control subjects （P〈0.05）. Conclusion The phase radians can be used to estimate the brain iron deposition in PD patients, which may be helpful in the diagnosis and longitudinal monitoring of PD.展开更多
基金financially supported by the Fund of Forestry 948 Project (No. 2011-4-04)the Fundamental Research Funds for the Central Universities (No. 2572014EB05-01)
文摘We developed a scheme based on wood surface novel wood recognition spectral features that aimed to solve three problems. First was elimination of noise in some bands of wood spectral reflection curves. Second was improvement of wood feature selection based on analysis of wood spectral data. The wood spectral band is 350-2500 nm, a 2150D vector with a spectral sampling interval of 1 nm. We developed a feature selection proce- dure and a filtering procedure by solving the eigenvalues of the dispersion matrix. Third, we optimized the design for the indoor radian＇s mounting height. We used a genetic algorithm to solve the optimal radian＇s height so that the spectral reflection curves had the best classification infor- mation for wood species. Experiments on fivecommon wood species in northeast China showed overall recogni- tion accuracy 〉95 % at optimal recognition velocity.
文摘Instead of calculating the number π in this article special attention is paid to the method of measuring it. It has been found that there is a direct and indirect measurement of that number. To perform such a measurement, a selection was made of some mathematical and physical quantities which within themselves contain a number π. One such quantity is a straight angle Pi, which may be expressed as Pi = π rad. By measuring the angle, using the direct method, we determine the number π as π = arccos(-1). To implement an indirect measurement of the number π, a system consisting of a container with liquid and equating it with the measuring pot has been conceived. The accuracy of measurement by this method depends on the precision performance of these elements of the system.
文摘Objective To compare the phase radians in several cerebral regions between patients with Parkinson’s disease （PD） and control subjects, and to evaluate whether iron deposition quantified by susceptibility-weighted imaging （SWI） is related to the severity of motor symptoms of PD. Methods SWI consisted of both magnitude and phase images from a fully flow-compensated, 3-dimensional and gradient-echo （GRE） sequence. Magnitude and phase data were collected at GE HD 1.5T. The regions evaluated included frontal white matter, grey matter, cerebrospinal fluid, putamen, caudate nucleus （CN）, sub- stantia nigra pars compacta （SNc）, substantia nigra pars reticulata （SNr）, and red nucleus （RN）. A total number of 42 patients （12 patients without cognitive dysfunction, and 30 with cognitive dysfunction from mild to moderate degrees） and 30 control subjects were employed in the present study. Results The phase radians of SNc, CN and RN in PD patients were lower than those in control subjects （P〈0.05）. Conclusion The phase radians can be used to estimate the brain iron deposition in PD patients, which may be helpful in the diagnosis and longitudinal monitoring of PD.
