Advanced Materials Research Vols. 472-475

Abstract: This paper designs several common methods, which is applied to situation that seam image could keep the same format when it is compressed, then analyses several problems existing in image processing. According a comparison in sundry compress methods’ characteristics and application, this paper eventually chooses a compress method that is suitable to original image, which is based on wavelet transform image compression and coding. Compress experiments shows that, the image compression ratio this paper designs could be exceeded up to 0.74 on the condition of the same format. The quality of seam image is basically intact, which could provide a desirable method in seam image efficient transmit.

Abstract: Real time modeling and rendering of natural Phenomena has been a hotspot and One of the most difficult tasks in Computer Graphics, it has been found wide application in many domains such as computer animation, computer games, special effects of movie, landscaping, battlefield simulation and virtual reality etc.. Realistic simulation is generally consisting of natural elements simulation and man-made elements simulation, natural elements simulation is relatively complicated. However, in natural elements simulation trees simulation is one of the most complex technologies. In this paper, propose a method that is real-time visualization of animated trees in the wind. Compared with other previous studies, our work is to develop a physical model of real movement by the trees swaying animation. We describe the method is consistent with nature scene that branches move in the wind. Then, we describe a simple animation of trees swaying, in the local graphics processor.

Abstract: Abstract. In present study, the effect of irradiation along with applied load and three periods on the ultraviolet (UV) aging of the polycarbonate polymer was investigated by observing the changes in the mechanical properties. Dog bone specimens of polycarbonate were subjected to different test conditions namely in the amount of applied load and the variation in exposure time to the UV lamp. The results showed that, with a constant applied load of 1kN, increase in the exposure time in UV radiation caused the mechanical properties to relatively increase at first and decrease gradually afterwards. However, for constant exposure time, the tensile strength showed much decrease with increase in applied load. For the test conducted at higher applied load of 3kN, the mechanical properties of material relatively improves in a drastic manner for the higher exposure time. It was inferred that the increase in applied load has a crucial role in the UV aging of polycarbonate for the given exposure time. Moreover, the morphology of the fracture area under different test conditions was observed by Scanning Electron Microscope (SEM).

Abstract: This paper studied and framed TIG and A-TIG welding procedure of LY12 aluminum alloy and analyzed the metallurgical structure and hardness of weld zone of TIG and A-TIG under different welding current. The result showed the strengthening phase which separated out from the basal body of TIG weld zone was obviously fewer than A-TIG and the strengthening phase of TIG obviously decreased when welding current increased. Compared with TIG weld zone, surface activating flux changed the metallurgical structure of A-TIG weld zone and the strengthening phase of A-TIG weld zone was more than TIG. The strengthening phase of A-TIG weld zone did not obviously decreased when welding current increased that implied the strengthening phase of A-TIG did not obviously dissolve into the basal body as TIG and only coarsened with the increase of welding current. The hardness experiment of weld zone showed that the hardness of A-TIG weld zone was higher than TIG and the hardness of 60%NaF+40%SiO2 activating flux of A-TIG weld zone was higher than 40%NaF+60%SiO2 activating flux.

Abstract: As the fire-resistance performance of high-strength concrete has emerged as a social issue and Korean Ministry of Land, Transport & Maritime Affairs has announced the standard for the fire-resistance performance of the concrete, studies to improve its fire-resistance have been conducted actively. In this paper, the study to develop high-strength concrete mixed with fiber-cocktail, a hybrid of polypropylene fiber and steel fiber was conducted. The fire-resistance test of 100MPa high-strength concrete and the analysis of steel bar temperatures for finding the optimal cross-sectional condition showed that the larger the section size is, the lower the temperature of steel bars is. It was also shown that the concrete columns with section sizes of 600mm x 600mm and 800mm x 800mm secure fire-resistance performance and the former is the optimal section size in terms of economic efficiency. The analysis of steel bar temperatures of the column having section size of 600mm x 600mm showed that the polypropylene fiber to steel fiber ratio of 1.5 to 40 (㎏/㎥) is the optimal for the fiber cocktail.

Abstract: To efficiently evaluate the tracking index of theodolite ,as well as avoiding influence resulted from higher harmonics when used opto dynamic target and use equivalent sine to evaluate the tracking index, in this paper, we resorted to General Regression Neural Network to do the new research on theodolite tracking accuracy evaluation method. Experimental results indicate that the method realized the equivalent sine to evaluate the tracking index of theodolite and avoided the higher harmonics influence with opto dynamic target. The research in this paper has important value to the engineering practice.

Abstract: The elastic stress and strain fields in an elasto-plastic circular cross-section bar with semicircular groove subjected to uniaxial tension are systematically investigated using the finite element method. It is found that the stress and strain concentrations are different, especially after the partial region near the groove root yielding. The coupled influences of the loading levels and Poisson’s ratios on the stress and strain concentrations are examined. The maximum of strain concentration factor is always at the groove root, but the maximum of stress concentration factor is at the groove root only while the loading levels are lower.

Abstract: YG8 coatings were deposited on AISI H13 steel substrates by means of electrospark deposition (ESD). The coatings were characterized in terms of their microstructure, hardness, friction and wear behavior. Micro-indentation and tribometer testers were employed to measure the mechanical properties of YG8 coatings and AISI H13 steel. The results showed that the hardness of the coatings ranged from 1820 to 1880 HV, with a higher value than that of AISI H13 steel (510HV). The average coefficient of steady-state friction of the coatings under the loads of 10N, 20N and 30N against Si3N4 balls were 0.39, 0.46 and 0.38, with a lower value than that of AISI H13 steel under the load of 10N and 20N(0.65). The wear mechanism in the electrospark deposited YG8 coating could be mainly characterized by micro-abrasive wear, delamination wear and oxidative wear while the dominant wear mechanism for AISI H13 steel was a severe abrasive wear.

Abstract: First-principles supercell calculations, which are based on density functional theory, were performed to study the site preference behavior and elastic properties of 5d (Hf-Au) transition-metal elements in B2 ductility YAg alloy. It is found that all alloying elements Hf, Ta, W, Re, Os, Ir, Pt and Au occupy the Y sub-lattice. Micro-alloying transition metals W, Re, Os, Ir and Pt decrease the lattice parameters of Y8Ag8 except Hf, Ta and Au, among which Y8Ag7Hf shows the largest variance. Furthermore, the calculated elastic constants show that Hf, Ta, W, Re, Os, Pt and Au improve the ductility of YAg alloy, and Y8Ag7Hf presents the most ductility among these alloy, while Ir transforms ductile into brittle for YAg alloy. In addition, Os alloying element increases the hardness of YAg alloy.

Abstract: Online group-buying characterized by Groupon model is developing rapidly in recent years. This study presents three perspectives of price stimulation, demand extendibility, and perceived trust to investigate factors influencing consumer participation intention in Online group-buying. Based on the foundation of existing empirical research results, an empirically validated comprehensive model is proposed and tested.