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101.
Let f: V × V → F be a totally arbitrary bilinear form defined on a finite dimensional vector space V over a field F, and let L(f) be the subalgebra of 𝔤𝔩(V) of all skew-adjoint endomorphisms relative to f. Provided F is algebraically closed of characteristic not 2, we determine all f, up to equivalence, such that L(f) is reductive. As a consequence, we find, over an arbitrary field, necessary and sufficient conditions for L(f) to be simple, semisimple or isomorphic to 𝔰𝔩(n) for some n. 相似文献
102.
103.
A new model for automatic normalization of multitemporal satellite images using Artificial Neural Network and mathematical methods 总被引:1,自引:0,他引:1
Relative Radiometric Normalization is often required in remote sensing image analyses particularly in the land cover change detection process. Normalization process minimizes the radiometric differences between two images caused by inequalities in the acquisition conditions rather than changes in surface reflectance. A wide range of RRN methods have been developed to adjust linear models. This paper proposes an automated Relative Radiometric Normalization (RRN) method to adjust a non-linear model based on an Artificial Neural Network (ANN) and unchanged pixels. The proposed method includes the following stages: (1) automatic detection of unchanged pixels based on a new idea that uses CVA (Change Vector Análysis) method, PCA (Principal Component Analysis) transformation and K-means clustering technique, (2) evaluation of different architectures of perceptron neural networks to find the best architecture for this specific task and (3) use of the aforementioned network for normalizing the subject image. The method has been implemented on two images taken by the TM sensor. Experimental results confirm the effectiveness of the presented technique in the automatic detection of unchanged pixels and minimizing imaging condition effects (i.e., atmosphere and other effective parameters). 相似文献
104.
Ramezanizadeh Mahdi Ahmadi Mohammad Ali Ahmadi Mohammad Hossein Alhuyi Nazari Mohammad 《Journal of Thermal Analysis and Calorimetry》2019,137(1):307-316
Journal of Thermal Analysis and Calorimetry - Due to the enhanced thermophysical specifications of nanofluids, such as thermal conductivity, these types of fluids are appropriate candidates for... 相似文献
105.
Karami Fatemeh Ahmadi Nadooshan Afshin Westerberg Lars G. Tadi Beni Yaghoub 《Journal of Thermal Analysis and Calorimetry》2019,137(1):327-342
Journal of Thermal Analysis and Calorimetry - This study was conducted with the aim of investigating the Newtonian nanofluid flow in a catheterized tapered artery through using a completely... 相似文献
106.
B. Nasr Esfahani M. Ahmadi F. Ahmadi 《International Journal of Theoretical Physics》2008,47(12):3130-3138
Fidelity for two-particle wave packets of spin-
particles moving around the Schwarzschild spacetime is discussed. Both acceleration and gravity cause to produce a Wigner
rotation that transforms the wave packet as it moves along a specified path in the gravitational field. For considered circular
paths, the fidelity between the spin parts of initial and final states of the system, called the spin fidelity, is obtained
as a function of angular velocity, elapsed proper time and radius of circular paths. For fixed elapsed proper time and angular
momentum of the centroid, there always exists one circular orbit with determined radius on which the fidelity of spin parts
is minimum. Using a numerical approach, the behavior of the spin fidelity in terms of the angular velocity, as well as the
radius of paths is described for both the spin singlet and spin triplet states. 相似文献
107.
Molecular Diversity - In this research, QSAR modeling was carried out through SMILES of compounds and on the basis of the Monte Carlo method to predict the antioxidant activity of 79 derivatives of... 相似文献
108.
Acoustic performance of dissipative silencer was evaluated to determine the effectiveness of perforated duct porosity and absorbent material density in reducing occupational noise exposure propagated from centrifugal fan. Design charts were applied to predict noise reduction and length of a dissipative silencer. Dissipative silencers with various punched duct porosity (14%, 30% and 40%) and sound absorbent density (80 Kg/m3, 120 Kg/m3, and 140 Kg/m3) were designed and fabricated. According to ISO9612 and ISO11820, noise level was measured before and after installing all nine test silencers at fixed workstations around the discharge side of a centrifugal fan in a manufacturing plant. On average, the noise level at the discharge side of a fan without silencer was measured to be 93.6 dBA, whereas it was significantly mitigated by 67.4 dBA to 70.1 dBA after installing all silencers. Dynamic insertion loss for a dissipative silencer with 100 cm length was predicted to be 27.9 dB, which was in agreement with experimental ones. Although, there was no significant differences between insertion loss of silencers, the one with 30% porosity and 120 Kg/m3 rock wool density had the highest insertion loss of 26.2 dBA. Dissipative silencers noticeably reduced centrifugal fan noise exposures. Increasing sound absorbent density and duct porosity up to a certain limit could probably be effective in noise reduction of dissipative silencers. 相似文献
109.
Ahmadpour Javad Ahmadi Mahyar Javdani Amirhossein 《Journal of Thermal Analysis and Calorimetry》2019,135(3):1943-1949
Journal of Thermal Analysis and Calorimetry - Nowadays, most of the world’s energy consumption is from fossil fuels. One of these fossil fuels is natural gas condensate which consists of... 相似文献
110.
Methylthiouracil‐modified Carbon Paste Electrode as a New Voltammetric Sensor Based on a 1,4‐Michael Addition Reaction for Detection of Dopamine 下载免费PDF全文
M. Arab Chamjangali A. Ahmadi Reskety N. Goudarzi G. Bagherian 《Electroanalysis》2015,27(12):2708-2717
A sensitive dopamine sensor was constructed based on the modified carbon paste electrode with methylthiouracil as a nucleophile in the 1,4‐Michael addition reaction. An ECE mechanism was suggested for dopamine oxidation at the modified electrode. Design of experiments was used in the optimization of variables. Under the optimum conditions, calibration graph was linear in the range of 0.20–15.0 µM with a detection limit of 73 nM. The relative standard deviations (n=5) for 0.50 µM of dopamine was 3.83 %. The selectivity of the sensor was also studied. The developed sensor was applied for analysis of pharmaceutical and biological samples. 相似文献