Advanced Materials Research Vols. 230-232

Abstract: This paper researchs the space vector change and machine vision recognition based on plane target cooperation identification.Then establishes plane target imaging model, space attitude measurement algorithm and software flow, which are utilized in the measurement of automobile four-wheel location. The results indicate that this method is feasible in the automobile four-wheel location technology with the advantages of good anti-interference, fast speed, wide range and high accuracy.

Abstract: The Vibration screener is widely use in metallurgy, building materials, chemical industry, grain, mine, etc. In this paper, we analyze the motion of object on the screener, and then build the mathematical model to maximize the productivity ratio. Take the example of straight Line vibration screeners with mode ZKB. After maximizing with our method, the result shows that our method increases 22% in the productivity ratio, and the chance of object touching the screen holes increases 43%. This paper provides an effective method for the optimal design of screener in future.

Abstract: The microstructure of Cu₇₅Cr₂₅ alloys was investigated by using vacuum non-consumable arc melting, electromagnetic levitation and splat quenching. The microstructure and solidification behavior of the Cr-rich were investigated by scanning electron microscopy (SEM). The results showed that inhomogeneous Cr-rich dendrite distributes on Cu-rich matrix for arc melted alloys. The microstructure consisting of a fine dispersion of Cr-rich dendrite in a Cu-rich matrix for electromagnetic levitated alloys. However, the morphology and size of the Cr-rich phase vary greatly with the cooling rate for splat quenched alloys. The Cr-rich phase show both dendrites and spheroids, this means liquid phase separation occurred during rapid solidification.

Abstract: Joints can reflect and transmit stress waves, thus joints affect rock fracturing, and accordingly they could affect blasting efficiency. In this paper, numerical and experimental investigations have been implemented and the effect of joints on wave propagation and rock fracturing has been discussed. A dynamic numerical model of jointed rock mass has been established by using finite difference method. The simulation results show that as joints are parallel to wave propagation, the corresponding rock damage zones increase. Blasting experiments by using artificial joints have been carried out. Generally the experimental results agree with our numerical results.

Abstract: Wet gelcast body contains the same amount of water as the starting slurry, which has to be eliminated by a subsequent drying step. But in an indirect solid freeform fabrication (ISFF) process, the wet gelcast body is surrounded by an integral sacrificial mold, and drying cracks may be formed due to mold constrains. In the paper, freeze-drying was first introduced to deal with the wet gelcast body for preventing the cracking by minimizing drying shrinkage. First, the contents of non-freezing, freezing bound and free water in polyacrylamide gel (PAG) were evaluated by differential scanning calorimetry(DSC). Secondly, the prefreezing temperature and time were determined by an electrical resistance method. The change rule of the freeze-drying shrinkage with the prefreezing temperature was discovered. Finally, complex-shaped ceramic parts were fabricated to verify the feasibility and effectiveness of the freeze-drying process.

Abstract: In emotion classification of speech signals, the popular features employed are statistics of fundamental frequency, energy contour, duration of silence and voice quality. However, the performance of systems employing these features degrades substantially when more than two categories of emotion are to be classified. In this paper, a text independent method of emotion classification of speech is proposed. The proposed method makes use of short time log frequency power coefficients(LFPC) to represent the speech signals and a discrete Hidden Markov Model (HMM) as the classifier. The category labels used are, the archetypal emotions of anger, joy, sadness and neutral. Results show that the proposed system yields an average accuracy of 82.55%and the best accuracy of 94.4% in the classification of 4 emotions. Results also reveal that LFPC is a better choice as feature parameters for emotion classification than the traditional feature parameters.

Abstract: This paper first introduces the principle of AGC and conventional AGC in Hot Strip Mill (HSM). A linearized and discretized state-space model used for rolling force and thickness control is obtained by using recursive squares method. A data fusion algorithm based on Kalman filter is presented. For hot strip systems with complex multi-variables, an asynchronous fusion estimation algorithm is built and applied to the thickness prediction of the hot strip mill and the plasticity coefficient Q of strip prediction. Finally, real-time prediction on thickness and plasticity coefficient of the coming strip is synthetically utilized in hot strip rolling thickness control system, to improve the quality of final coming strip thickness.

Abstract: The rigid-visco-plastic finite element model for the hot forging process of half axle gear was established, and the enclosed-die forging processes with different process parameters were simulated. As for the present forming process, the main influence factors on precision forming quality were identified and analyzed. The results show that proper die structure and cavity dimensions, suitable web thickness and position can improve material filling effect, which ensures gear tooth dimensions.

Abstract: A surface blasting model of rock with pre-existing randomly distributed defects, including voids, pores and small open joints, under blasting loads are established by using finite difference method. A shock equation of state, obtained from the existing test results, is employed for the granite near the explosive charge, and for the granite far from the charge, a linear EOS is applied. The granite dynamic strengths, which increase with strain rate, are calculated based on the existing test results. The simulation results show that under blasting, most of cracks are initiated at the defect tips independently; the damage range increases as defect density decreases;spalling is easily happening near a free surface as there is a blasting near the surface.

Abstract: To prolong network lifetime, lifetime maximization routing based on genetic algorithm (GALMR) for wireless sensor networks is proposed. Energy consumption model and node transmission probability are used to calculate the total energy consumption of nodes in a data gathering cycle. Then, lifetime maximization routing is formulated as maximization optimization problem. The select, crosss, and mutation operations in genetic algorithm are used to find the optimal network lifetime and node transmission probability. Simulation results show that GALMR algorithm are convergence and can prolong network lifetime. Under certain conditions, GALMR outperforms PEDAP-PA, LET, Sum-w and Ratio-w algorithms.