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In order to reduce the wear of parts caused by long-term friction, and to reduce the frequency of parts replacement, ZA alloy with low hardness and good wear resistance is chosen to replace the traditional copper alloy as the material to manufacture automotive bushing, and the semi-solid die casting is used. On this basis, the software AnyCasting is used to simulate and analyze the filling and solidification process, the filling sequence, the variation of temperature field, and the part region where defects are prone to occur in the semi-solid process. The simulation results show that under the parameters set in the simulation process, when casting filling rate reached 90%, the metal started to solidify; since the gate place is easy for heat dissipation, when the temperature of the alloy liquid reached its liquidus temperature 595°C, the phenomenon of solid-liquid phase separation appeared at the gate; the defects such as gas trapping, residual stress and deformation would appear both in the place of first filling and the parting surface; when the preheat temperature of the mold was 150°C-200°C,the alloy liquid possesses liquidity. The simulation results offer certain theoretical instruction to optimize the semi-solid casting process of ZA Alloy automotive bushing manufacturing, as well as reducing or avoiding a variety of quality defects arose in the actual casting process.

The deformation process of stainless steel particle sputtering on copper substrate to make coat was simulated by ANSYS/LS-DYNA software in the paper. The results showed that: when the steel particles are sputtered on the copper substrate, the contacting place of copper substrate with stainless steel particle top generates maximum stress and strain firstly, and then stainless steel particle shrinks from the bottom to the center, while the top flattens to the both sides. Subsequently, the bottom of the particle gradually spreads along the substrate with the stress increasing gradually, while the strain distribution and top of the particles basically unchanged, then, the particle flattens and its stress gradually spreads to particle interior, at the same time, the bottom of particle gradually shrinks and its top gradually expands to the end. Through analyzing equivalent stress and strain distributions, the kinetic and internal energy distributions of sputtering particle unit and substrate unit contacting together, the variation rules of mechanics and energy parameters in the sputtering process are elaborated further. It laid an important theoretical basis about exploring the basic laws and mechanics parameters variation in magnetron sputtering coating process.

Data mining discovers knowledge and useful information from large amounts of data stored in databases. With the increasing popularity of object-oriented database system in advanced database applications, it is significantly important to study the data mining methods for object-oriented database. This paper proposes that higher-order logic programming languages and techniques is very suitable for object-oriented data mining, and presents a framework for object-oriented data mining based on higher-order logic programming. Such a framework is inductive logic programming which adopts higher-order logic programming language Escher as knowledge representation formalism. In addition, Escher is a generalization of the attribute-value representation, thus many higher-order logic learners under this framework can be upgraded directly from corresponding propositional learners.

Research shows that recommendations comprise a valuable service for users of a digital library. We proposed a hybrid document recommender system based on random walk. It builds correlation network among users based on the conditional probability in order to solve the sparsity of collaborative filtering. On the other hand, it computes the rating of source user for target item not only based on the neighborhoods’ ratings for target item but also based on the neighborhoods’ ratings for item which is most similar to target item. This can solve the cold start problem of recommender systems. We performed an evaluation on the dataset of National Science and Technology Library. Experimental results illustrate the superiority of the proposed method.

This paper proposed an echo canceller to reduce the computational complexity of the long delay echo cancellation. Two adaptive filters were used for constructing this echo canceller. One was designed as a delay estimator, which used down-sampled sub-band signals to estimate the echo delay time. The other was designed as a short-tap filter to subtract the echo from the recorded signal with delay compensation. Experimental results showed that the output signal-to-noise ratio from the proposed canceller with low complexity is similar to that from the conventional canceller based on a long-tap filter.

The authors proposed a trainable formant synthesis method based on the multi-channel Hidden Trajectory Model (HTM). In the method, the phonetic targets, formant trajectories and spectrum states from the oral, nasal, voiceless and background channels were designed to construct hierarchical hidden layers, and then spectrum were generated as observable features. In model training, the phonemic targets were learned from one-hour training speech data and the boundaries of phonemes were also aligned. The experimental results showed that the speech could be reconstructed with the formant trainable model by a source-filter synthesizer.

Phase change energy storage building material has become a widespread attention for the field of building energy conservation because of its excellent storage properties. The phase change material which is able to adjust the indoor temperature, belongs to the low temperature phase change material. There are lots of kinds of it, and then how to find a suitable phase change material has become a key problem. In this paper, the characteristics of the inorganic material, single organic material, and binary organic material were tested, and the phase change temperature and latent heat of composited phase change material were analysed by differential scanning calorimetry(DSC), which could provide a theoretical basis for the search for the appropriate phase change material.