The Precedence Effect in Three Species of Birds (Melopsittacus undulatus, Serinus canaria, and Taeniopygia guttata).

The perceived locations of paired auditory images, simulating direct sounds and their echoes, have been recently studied in budgerigars (Melopsittacus undulatus; M. L. Dent & R. J. Dooling, 2003a, 2003b). In this article, the authors extend those experiments to include measurements of the precedence effect using a discrimination paradigm in two additional bird species: canaries (Serinus canaria) and zebra finches (Taeniopygia guttata). Although time courses of summing localization, localization dominance, and echo thresholds were similar across all species, budgerigars had slightly higher overall levels of discrimination. The results from these experiments add further support that the precedence effect in birds is similar to that found in other animals and that the ability to suppress echoes that might degrade localization and auditory object perception may be a general property of the vertebrate auditory system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of protein and lipid concentration of the test lubricant on the wear of ultra high molecular weight polyethylene

To gain a better understanding of the ultra-high molecular weight polyethylene (UHMWPE) wear mechanism in the physiological environment, the effects of protein and lipid constituents of synovial fluid on the specific wear rate of UHMWPE were examined experimentally. The multidirectional sliding pin-on-plate wear tester was employed to simulate the simplified sliding condition of hip joint prostheses. Bovine serum γ-globulin and synthetic l--DPPC were used as model protein and lipid constituents of synovia, respectively. Results of the wear test indicated that the UHMWPE wear rate primarily depended on the protein concentration of the test lubricant. Lipids acted as a boundary lubricant and reduced polyethylene wear in the low protein lubricants. However, the polyethylene wear rate increased with increasing lipid concentrations if the protein concentration was within the physiological level. Increased interactions between protein and lipid molecules and lipid diffusion to polyethylene surface might be responsible for the increased wear.     

On the Auditory Modality Superiority Effect in Serial Recall: Separating Input and Output Factors.

The modality effect in immediate recall refers to superior recall of the last few items within lists presented in spoken as opposed to printed form. The locus of this well-known effect has been unclear. N. Cowan, J. S. Saults, E. M. Elliott, and M. Moreno (2002) introduced a new method to distinguish between the effects of input serial position, output serial position, and the number of items yet to be recalled and found that large modality effects occurred only in conditions in which delay and interference at output (from items already recalled) was high. The authors replicated that finding, even when the response period included output interference acoustically similar to the spoken stimuli to be recalled. However, the authors found that output delay and interference act only by lowering the level of performance to a more sensitive range. The modality effect thus originates during encoding of the list to be recalled, not during output. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lexical Influences in Audiovisual Speech Perception.

Phoneme identification with audiovisually discrepant stimuli is influenced hy information in the visual signal (the McGurk effect). Additionally, lexical status affects identification of auditorily presented phonemes. The present study tested for lexical influences on the McGurk effect. Participants identified phonemes in audiovisually discrepant stimuli in which lexical status of the auditory component and of a visually influenced percept was independently varied. Visually influenced (McGurk) responses were more frequent when they formed a word and when the auditory signal was a nonword (Experiment 1). Lexical effects were larger for slow than for fast responses (Experiment 2), as with auditory speech, and were replicated with stimuli matched on physical properties (Experiment 3). These results are consistent with models in which lexical processing of speech is modality independent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于GWO-SVM的下肢假肢穿戴者骑行相位识别

针对下肢假肢穿戴者骑行相位识别的问题,提出基于灰狼算法优化的支持向量机(GWO-SVM)分类模型. 建立下肢多源信息系统,采集膝关节、踝关节的加速度信号以及膝关节角度信号. 应用奇异值分解,对采集到的信号进行降噪处理. 在对信号进行降噪处理之后,为了避免单一信号不确定的影响,从数据冗余角度,选取各信号的特征点,开展归一化处理,组成多维特征向量,作为SVM分类模型的输入. 为了能够进一步提高分类精度,加强全局优化能力,利用GWO算法对核参数进行优化. 通过与PSO-SVM分类模型、GA-SVM分类模型对比表明,基于GWO优化的SVM分类模型对骑行相位的识别率为94%,高于其他方法优化的SVM分类模型.     

口腔修复用Y-TZP陶瓷材料制备工艺研究

采用国产3Y-TZP亚微米粉体，通过双向模压结合等静压成形有效克服了条形试样的烧结弯曲，探讨了24h排胶工艺对预烧试样力学性能的影响，通过对预烧试样热膨胀曲线的测定、不同烧结温度试样力学性能和密度的比较及XRD定量分析确定了适宜的烧结工艺。结果表明，牙科支架用陶瓷，将预烧试样升至1550℃保温0．5h，排胶工艺对预烧试样的抗弯强度和断裂韧性并无显著影响，对于即可获得足够的抗弯强度，提高其断裂韧性。     

Preparation for femur prosthesis of ceramic-metal combination artificial hip joint

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基于相位编码的音频信息隐藏方法

针对听觉感知无差异时的局部相位失真条件,在宽带音频信号实验的基础上,提出一种利用局部相位分区实现信息隐藏的新算法。相对于经典的相位调制算法,利用局部相位信息,在保证听觉相似性的同时,能提高信息的嵌入量、改善误码率。理论分析和实验结果表明了该算法的有效性。     

一种高性能人造视网膜微刺激器的设计

微刺激器是人造视网膜系统的核心组成部分,其设计面临诸多挑战.设计了一个驱动4×4微电极阵列的人造视网膜微刺激器,通过采用内部计数和内部RAM策略,将传输数据量减小到1/16.通过采用宽摆幅共源共栅结构使微刺激器的输出阻抗和输出电压摆幅分别达到2～4兆欧姆和90%以上,提高了其生物环境适应性.通过引入电荷平衡机制,减小了失配引起的电荷积累,提高了人造视网膜长期工作的安全性.仿真结果验证了该微刺激器方案的正确性.