Absolute pitch: Frequency-range discriminations in pigeons (Columba livia)--comparisons with zebra finches (Taeniopygia guttata) and humans (Homo sapiens).

Absolute pitch (AP) is the ability to classify individual pitches without an external referent. The authors compared results from pigeons (Columba livia, a nonsongbird species) with results (R. Weisman, M. Njegovan, C. Sturdy, L. Phillmore, J. Coyle, & D. Mewhort, 1998) from zebra finches (Taeniopygia guttata, a songbird species) and humans (Homo sapiens) in AP tests that required classification of contiguous tones into 3 or 8 frequency ranges on the basis of correlations between the tones in each frequency range and reward. Pigeons' 3-range discriminations were similar in accuracy to those of zebra finches and humans. In the more challenging 8-range task, pigeons, like zebra finches, discriminated shifts from reward to nonreward from range to range across all 8 ranges, whereas humans discriminated only the 1st and last ranges. Taken together with previous research, the present experiments suggest that birds may have more accurate AP than mammals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Robust Speaker Verification with Principal Pitch Components

We are presenting a new method that improves the accuracy of text dependent speaker verification systems. The new method exploits a set of novel speech features derived from a principal component analysis of pitch synchronous voiced speech segments. We use the term principal pitch components (PPCs) or optimal pitch bases (OPBs) to denote the new feature set. Utterance distances computed from these new PPC features are only loosely correlated with utterance distances computed from cepstral features. A distance measure that combines both cepstral and PPC features provides a discriminative power that cannot be achieved with cepstral features alone. By augmenting the feature space of a cepstral baseline system with PPC features we achieve a significant reduction of the equal error probability of incorrect customer rejection versus incorrect impostor acceptance. The proposed method delivers robust performance in various noise conditions.     

Development of capillaries for wire bonding of low-k ultra-fine-pitch devices

Although wire bonding has been a well-established technology for many years, the bonding tool design becomes more complex and the process is very sensitive for wire bonding of low-k ultra-fine-pitch microelectronics devices. In this study, two different types of external transition profile were considered in order to use lower ultrasonic-generator power for preventing pad damage. The ultrasonic vibration displacements of the capillaries were measured using a laser interferometer. The measurement results revealed that the amplification factor (the ratio of the vibration displacement at the capillary tip to that at the transducer point) of a capillary with a small radius transition between the bottleneck angle and the main taper angle was 37% higher than that of a capillary with a sharp transition, and this led to satisfactory results in terms of ball size, ball height, ball shear and stitch pull. To solve the ball lift problem for wire bonding of low-k ultra-fine-pitch devices, optimization of the capillary internal profile was attempted to improve bondability. Actual bonding responses were tested. Compared to a standard design, a capillary with a smaller chamfer angle, a larger inner chamfer and a larger chamfer diameter could increase the percentage of the intermetallic compound in the bond interface. Metal pad peeling and ball lift failures were not observed after an aging test.     

煤焦油沥青制备中间相

煤焦油沥青在微型高压釜中、氮气氛下,通过改变反应温度和停留时间,制取了中间相沥青(MP)。采用FTIR、偏光显微镜、XRD和SEM对MP进行了表征,表明煤焦油沥青经脱氢缩合反应转变成MP。其最佳反应条件为400℃、7h。     

EQ153汽车后桥壳钢板碾薄技术

通过对三种轧制工艺方法的分析、比较,阐述了凸轮辊进行钢板碾薄的原理和应用.此项技术的研制填补了国内空白.     

降低沥青熔化系统中重油消耗的措施

针对碳素厂沥青熔化过程中重油消耗较大的现状，提出了沥青原料管理、沥青熔化设备改进和重油燃烧状态调节等改进措施，取到了降低环境污染和重油消耗的良好效果。     

The influence of linguistic experience on the cognitive processing of pitch in speech and nonspeech sounds.

In the present experiment, the authors tested Mandarin and English listeners on a range of auditory tasks to investigate whether long-term linguistic experience influences the cognitive processing of nonspeech sounds. As expected, Mandarin listeners identified Mandarin tones significantly more accurately than English listeners; however, performance did not differ across the listener groups on a pitch discrimination task requiring fine-grained discrimination of simple nonspeech sounds. The crucial finding was that cross-language differences emerged on a nonspeech pitch contour identification task: The Mandarin listeners more often misidentified flat and falling pitch contours than the English listeners in a manner that could be related to specific features of the sound structure of Mandarin, which suggests that the effect of linguistic experience extends to nonspeech processing under certain stimulus and task conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Study of Graphitic Crystallites in Some Carbonized Residues Prepared From Catalytic Cracking of Asphalt

This paper demonstrates the carbonization of asphalt collected from the Morgah Oil Refinery, Rawilpindi, Pakistan. The asphalt (80/90) was carbonized in a micro-autoclave under nitrogen environment at 300°C. To enhance cracking reactions of side chains, and condensation of polycyclic configurations, the sample was also loaded with catalysts such as Zeolite Socony Mobil No. 5 (ZSM-5), phosphotungstic acid, coal ash and Utmanzai clay (UTIMAC). Each carbonized residue was crushed with mortar and pestle and soxhlet extracted with n-pentane for removal of oil, dried and analyzed by X-ray diffractometery (XRD). The appearance of distinct bands correspond to crystallites in some samples particularly those loaded with UTIMAC has established graphitization.     

基于可调桨在线培训系统的研究

本文以船舶学员培训为背景,提出了一套可调桨在线培训系统。综合应用了计算机网络技术、串口通讯技术、网络通讯技术、仿真技术、VC++编程技术、控制工程的最新理论成果实现了可调桨在线培训系统,具有实时监控、学员培训、网络通讯、数据管理及报警等功能,大大提高了学员培训效率.     

Dynamic Force Modelling for a Ball-End Milling Cutter Based on the Merchant Oblique Cutting Theory

A new dynamic force model for a ball-end milling cutter is presented in this paper. Based on the principle of the power remaining constant in cuts, the Merchant oblique cutting theory has been successfully used for the differential cutting edge segment of a ball-end milling cutter. A concise method for characterising the relationship of the complex geometry of a ball-end milling cutter and the milling process variables is determined, so that the force coefficients can be decomposed. The geometric property of a ball-end milling cutter and the dynamics of the milling process are integrated into the general model to eliminate the need for the experimental calibration of each cutter geometry and milling process variable. The milling experiments prove that this model can predict accurately the cutting forces in three Cartesian directions.