Because of the low voltage transfer ratio in a conventional matrix converter and no improvement can be made by employing different control strategies, a new Buck-Boost matrix converter is proposed by employing a doubl...
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Because of the low voltage transfer ratio in a conventional matrix converter and no improvement can be made by employing different control strategies, a new Buck-Boost matrix converter is proposed by employing a doubleloop control strategy. The fundamental principle of this control strategy and its design method are introduced. Various characteristics are then compared among this control strategy, the sliding mode control and the discrete sliding mode control. The validity of this control strategy is also tested by simulation. The results show that the double-loop control strategy makes the system in better dynamic performance and stronger harmonic suppression than the sliding mode control and the discrete sliding mode control, and achieves lower harmonic distortion and higher steady-state precision. These are the most valuable advantages of the proposed converter in engineering applications.
Two new lanthanide complexes,[Eu2(Pht)2(HPht)2(Phen)2(H2O)4](1)and [Gd(3-CNC6H4COO)3(H2O)2]n(2)(where Pht2-=dianion of o-phthalic acid,HPht-=mono-anion of o-phthalic acid,Phen=1,10-phenanthroline,3-CNC6H4COO=3-cyanobe...
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Two new lanthanide complexes,[Eu2(Pht)2(HPht)2(Phen)2(H2O)4](1)and [Gd(3-CNC6H4COO)3(H2O)2]n(2)(where Pht2-=dianion of o-phthalic acid,HPht-=mono-anion of o-phthalic acid,Phen=1,10-phenanthroline,3-CNC6H4COO=3-cyanobenzoate)have been synthesized and their crystal structures were determined by X-ray *** result shows that 1,3-dicyanobenzene was hydrolyzed to give 3-cyanobenzoate under the hydrothermal *** compound 2 forms a one-dimensional coordination polymer,whereas the compound 1 is a *** title complex 1 crystallizes in the triclinic system,space group P1,with lattice parameters a=1.01048(6)nm,b=1.06755(7)nm,c=1.19266(8)rim,a=90.188(3)°,β=99.526(2)°,y=100.981(2)°,V=1.24479(14)nm3,Z=1,Dc=1.861 Mg/*** title complex 2 crystallizes also in the triclinic system,space group P1,with lattice parameters a=0.93749(9)nm,b=1.14943(10)nm,c=1.27024(11)nm,a=90.188(3)°,β=73.788(5)°,y=86.757(5)°,V=1.19389(19)nm3,Z=2,Dc=1.757 Mg/*** photophysical property of 1 has been studied with excitation and emission spectra,which exhibits strong red emission.
The static load tests on one hollow tubular joint and three tubular joints filled concrete have been conducted in this study. The distribution of stress concentration factors along the weld, the locations of hot spot ...
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The static load tests on one hollow tubular joint and three tubular joints filled concrete have been conducted in this study. The distribution of stress concentration factors along the weld, the locations of hot spot stress and the corresponding peak SCF values subjected to axially load were obtained. Simultaneously, the constant amplitude fatigue tests on tubular joints have been carried out. The test results showed that the phenomenon of stress concentration was improved significantly due to presence of concrete;furthermore the fatigue behavior was enhanced;the fatigue S-N curve of hollow tubular joints is not suitable for tubular joints filled concrete.
This paper presented a simple CFD algorithm for the simulation of the impact of outdoor water body on the relative humidity in the buildings with natural ventilation. The simulation results agree well with the measure...
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This paper presented a simple CFD algorithm for the simulation of the impact of outdoor water body on the relative humidity in the buildings with natural ventilation. The simulation results agree well with the measured data. The correlation and regression were performed on the simulation results. The sensitivity analysis shows that the impact of outdoor humidity parameters variation on the indoor relative humidity is mostly significant. The correlation relationship and the regression formula were obtained among water body area, distance from buildings, outdoor temperature, humidity and velocity of inflow and indoor relative humidity.
Locally linear embedding (LLE) is a prevalent manifold learning method in pattern recognition and machine learning. It preserves the intrinsic structure information of data set and has been widely applied to feature e...
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Locally linear embedding (LLE) is a prevalent manifold learning method in pattern recognition and machine learning. It preserves the intrinsic structure information of data set and has been widely applied to feature extraction and dimensionality reduction. This paper introduces LLE to aircraft pose recognition. The representative motion poses of an aircraft in the air are analyzed. Unfolding results of aircraft images in different poses show LLE has a natural connection to clustering. Moreover, we employ back propagation neural networks and nearest neighbor algorithms to classify the input samples after dimensionality reduction. computer simulation testifies the efficiency and accuracy of LLE in aircraft pose recognition.
The anodizing oxidation process on 2024 aluminum alloy was researched in the mixed electrolyte with the composition of 30 g/L boric acid, 2 g/L sulfosalicylic acid and 8 g/L phosphate. The results reveal that the pre-...
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The anodizing oxidation process on 2024 aluminum alloy was researched in the mixed electrolyte with the composition of 30 g/L boric acid, 2 g/L sulfosalicylic acid and 8 g/L phosphate. The results reveal that the pre-treatment and the composition of the mixed electrolyte have influence on the properties of the films and the anodizing oxidation process. Under the condition of controlled potential, the anodizing oxidation current—time response curve displays "saddle" shape. First, the current density reaches a peak value of 8-20 A/dm2 and then decreases rapidly, finally maintains at 1-2 A/dm2. The film prepared in the mixed electrolyte is of porous-type with 20 nm in pore size and 500 μm-2 in porosity. Compared with the conventional anodic film obtained in sulfuric acid, the pore wall of the porous layer prepared in this work is not continuous, which seems to be deposited by small spherical grains. This porous structure of the anodic film may result from the characteristics of the mixed electrolyte and the special anodizing oxidation process. The surface analysis displays that the anodic film is amorphous and composed of O, Al, C, P, S, Si and no copper element is detected.
A logic analysis model for aluminum hydroxide calcinations process was proposed, which includes four kinds of parameters and two units, namely, feeding, operation, structure and index parameters, process control and c...
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A logic analysis model for aluminum hydroxide calcinations process was proposed, which includes four kinds of parameters and two units, namely, feeding, operation, structure and index parameters, process control and combustion unit. Integrated fuzzy algorithm, artificial neural networks and genetic algorithms, a kind of fuzzy neural network was constructed and optimized. A strategy for calcinations adjustment that consists of five fuzzy neural network models and a fuzzy linguistic inference model was schemed, whose primary functions include feeding computing, fuel flux computing, the ratio of air to fuel computing, and flux tracking of air and fuel. The application of optimal control indicates that temperature error is ±5°C. Optimal control is beneficial to practical operation and energy-saving.
The mutation step-size control for monogenic-mutation-based evolution strategies(ES) is investigated. After analyzing the relation between the step-size and the progress rate, we propose a step-size control scheme for...
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The mutation step-size control for monogenic-mutation-based evolution strategies(ES) is investigated. After analyzing the relation between the step-size and the progress rate, we propose a step-size control scheme for the monogenicmutation-based ES. By transversal simulations, the adaptabilities of the hologenetic mutation operator and the monogenic mutation operator to the mutation step-size are analyzed by comparisons. Through simulation, it is shown that the monogenic mutation with a large mutation step-size may have a promising convergence-rate over a large varying range. This shows that the single-gene mutation is robust against the variation of mutation step-size. By analyzing the global convergence, we introduce a uniform mutation operator as an accessory operator to improve the global convergence performance. Thus, a new evolution strategy (μ + λ +k)-ES is established by combining the monogenic mutation Gauss mutation and the uniform mutation. Finally, simulation results are given to demonstrate the effectiveness of the algorithm.
In automated planning under uncertainty, extended goals are often expressed as temporal logic formulas, particularly as CTL (computation tree logic) formulas and EAGLE formulas. Though it is said that the capability o...
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In automated planning under uncertainty, extended goals are often expressed as temporal logic formulas, particularly as CTL (computation tree logic) formulas and EAGLE formulas. Though it is said that the capability of representing the "intentional" aspects of goals and the possibility of dealing with failure are the main new features of EAGLE with respect to CTL, there is not enough work devoted to formal comparison of semantics of these two languages. According to the formal semantics of EAGLE and CTL goals on Kripke structures (i.e., execution structures induced by plans from initial states), it is proven that many EAGLE goals including some having been deemed to be unexpressive in CTL (e.g., some EAGLE goals in which TryReach operator and Fail operator appear) can be expressed in CTL in fact, and an analysis of the characters of these two languages in expressing extended goals and guiding the search for plans that satisfy them is given.
A modal wavefront sensing technique of using binary holography optical element (BHOE), and a detail theoretical analysis on the principle of the modal wavefront sensor of this type are presented. The primary design ap...
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A modal wavefront sensing technique of using binary holography optical element (BHOE), and a detail theoretical analysis on the principle of the modal wavefront sensor of this type are presented. The primary design approach of the BHOE is introduced. The effect on the unknown beam intensity of the aberration of single Zernike mode is also studied. The BHOE is encoded and designed with computer, and simulations are carried out to verify the feasibility and validity of the wavefront sensing approach. With the optical parallel processing ability, the speed of the wavefront sensor is highly improved, eliminating the computational overhead or post-processing in wavefront reconstruction stage. Compared with the conventional wavefront sensors, our technique is suitable for the large bandwidth situation, e.g. the atmosphere transmission in airborne enviroments, the requirements for high update rates, the large scintillation environments and so on.
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