Applied Mechanics and Materials Vols. 55-57

Abstract: This paper introduces the designs on visual attention measurement system based on the visual attention theory. The measurement system simulated the traffic environment and driving conditions, to examine the reaction time and accuracy of judge response of drivers. It applies to research the top-down and bottom-up controls of visual attention in three-dimensional (3D) space. It included the setting of observation location, stimuli location, moving speed, environmental illuminance and the design of software control interface. The paper describe how the stimuli can be presented by the control system and introduce the design of variable periphery environmental illuminance and obversion targets for detect tasks in detail. The results are demonstrated that this measurement system can be used to examine the reaction time and accuracy of judgment response in three environmental illuminance conditions.

Abstract: This paper focuses on the end effect problem of the empirical mode decomposition (EMD) algorithm, which results in a serious distortion in the EMD sifting process. A new method based on fuzzy inductive reasoning (FIR) is proposed to overcome the end effect. Fuzzy inductive reasoning method has simple inferring rules and strong predictive capability. The fuzzy inductive reasoning based method uses the sequence near the end as the input signal of fuzzy inductive reasoning model. This predictive value can be obtained after fuzzification, qualitative modeling ,qualitative simulation and debluring. The simulation results have shown that the fuzzy inductive reasoning based method has equivalent performance to the neural network based method.

Abstract: SiO₂, CaO and MgO was chosen as main raw material and Solid State method was used to prepare the samples. The precursor was directly sintered at 1000°Cfor 3h to obtain new green CaMgSi₂O₆:Eu³⁺,Li⁺Phosphors.The effects of the content of the doping ions Eu³⁺ on the luminescent properties have been studied. The structure, morphology and luminescent properties of the phosphors were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM),UV and PL-PLE spectra respectively.The results showed that the CaMgSi₂O₆:Eu³⁺,Li⁺ was base-centered monoclinic crystals, the phosphor particle distributed uniformly.The phosphor has a strong absorptive capacity excited by 248 nm ultraviolet ray, and could emit the strong red light with the wavelength of 590nm(⁵D₀→⁷F₁)and 615nm(⁵D₀→⁷F₂). The CaMgSi₂O₆:Eu³⁺,Li⁺ is a new type of red fluorescent material.

Abstract: The numerical analysis and calculation of magnetic field is one of the key issues for designing the magnetic drive mechanisms. This paper discusses the method of finite element analysis of the magnetic field based on ANSYS software, analyzes and simulates the magnetic field in the axial magnetic drive mechanism of the latest textile twisting spindles by means of ANSYS, analyzes and calculates the magnetic induction intensity, magnetic field intensity distribution with the different thickness of the air gap between the drive rotor and driven rotor, and the different quantity of magnets. The analysis method and results can provide reference for the design of magnetic drive mechanisms.

Abstract: This paper presents the results of the study undertaken in Rwanda to investigate the spatial integration of cities. It was revealed that the economic subordination degree appears to be very low because the economy of all cities in country depends on Kigali City, the capital of Rwanda that detains more than 70% of national economy.

Abstract: A new kind of lead-free ferromagnetic-ferroelectric (FM/FE) composite was successfully prepared by incorporating the dispersed 0.15Ni_0.98Co_0.02Fe₂O₄ (NCF) ferromagnetic nanoparticles into 0.85(K_0.5Na_0.5)NbO₃-LiSbO₃ (KNN-LS) ferroelectric micromatrix. The relative dielectric constant (ε_r) of the ceramic as a function of frequency (0.1 -200 kHz) under different dc bias electric field strengths was investigated in detail. ε_r increases with increasing dc bias electric field, while tanδ decreases with the increase in frequency. At room temperature, the high dielectric tunability (K_D=11.41%) and high figure of merit (FOM=15.66) under the low dc electric field of 3 kV/cm, clearly imply that these ceramics are promising materials for tunable microwave device applications.

Abstract: Model for predicting wood density of Larch was established using near-infrared spectroscopy (NIR) combined with support vector machine (SVM). A hundred and seventeen Larch samples were used in the study. Wood density of samples was measured according to standard test methods for physical and mechanical properties of wood. Support vector machines for regression (SVR) was used for model building. Radial basis function (RBF) was used as kernel function to establish a model for predicting wood density. For the train set, the coefficient of determination (R²) and the mean square error (MSE) were 0.8504 and 0.6460×10^-3, while the R² and MSE was 0.8520 and 0.4451×10^-3, respectively, for the test set. Results showed that using SVM in near-infrared spectroscopy calibration could significantly improve the model performance in order to rapidly and accurately predict wood density.

Abstract: The main purpose of this design is to raise the drawing power of the vacuum cleaner. All researches were done at the original vacuum model which typed U36. After analyzing the structure and work principle of the vacuum cleaner, a related influence factor of vacuum inhalation efficiency and combine the principle of an experiment method were put forward. Then Improvement design of motor, seal system, filter system and blow vent had been analyzed and tested by experiment method respectively. At last, the total effect of drawing power and noise testing had been tested. The results showed that the improvement design is successful.

Abstract: In this paper, a kind of unsaturated polyester resin (UPR) was prepared by using renewable soybean oil, glycerol, propylene glycol and anhydride as raw materials. In this process, soybean oil firstly reacted with glycerol to yield monoglyceride, then, propylene glycol partly replaced by monoglyceride reacted with anhydride to yield UPR. The effect of weight content of monoglyceride on the mechanical properties of UPR was systematically studied. Results showed that with the increase of weight content of monoglyceride, the curing exothermic peak of UPR was dropped; the curing shrinkage and flexural strength and tensile strength were decreased. But the impact strength and the tensile elongation were increased. When the weight content of monoglyceride was 40%, the impact strength and the tensile elongation could reach 102.074 kJ/m² and 27.69%, respectively. The prepared UPR had some advantages such as low-cost, flexible and high production efficiency.

Abstract: In this article, a kind of SMC artificial marble was prepared. In order to enhance the mechanical properties and prolong the using life of SMC artificial marble, some effects such as fiber content, filler content and molding temperature etc. on the mechanical properties were carefully studied, too. Results showed that the increase of fiber content could improve the impact strength of SMC artificial marble when the fiber length was 10mm and the increase of filler content would decrease the flexural strength of SMC artificial marble. And the molding temperature at the range of 130°C ~ 160°C had little influence on the mechanical properties of SMC artificial marble. Comparing with natural marble and casting marble, SMC artificial marble owed superior overall performance and it was much more suitable for industry production.