Biomimetic pattern recognition theory and its applications

Biomimetic pattern recogntion (BPR), which is based on "cognition" instead of "classification", is much closer to the function of human being. The basis of BPR is the Principle of homology-continuity (PHC), which means the difference between two samples of the same class must be gradually changed. The aim of BPR is to find an optimal covering in the feature space, which emphasizes the "similarity" among homologous group members, rather than "division" in traditional pattern recognition. Some applications of BPR are surveyed, in which the results of BPR are much better than the results of Support Vector Machine. A novel neuron model, Hyper sausage neuron (HSN), is shown as a kind of covering units in BPR. The mathematical description of HSN is given and the 2-dimensional discriminant boundary of HSN is shown. In two special cases, in which samples are distributed in a line segment and a circle, both the HSN networks and RBF networks are used for covering. The results show that HSN networks act better than RBF networks in generalization, especially for small sample set, which are consonant with the results of the applications of BPR. And a brief explanation of the HSN networks' advantages in covering general distributed samples is also given.

Discussion on the basic mathematical models of neurons - Double synaptic weight neuron in general-purpose neurocomputer, theory and application

Based on the introduction of the traditional mathematical models of neurons in general-purpose neurocomputer, a novel all-purpose mathematical model-Double synaptic weight neuron (DSWN) is presented, which can simulate all kinds of neuron architectures, including Radial-Basis-Function (RBF) and Back-propagation (BP) models, etc. At the same time, this new model is realized using hardware and implemented in the new CASSANN-II neurocomputer that can be used to form various types of neural networks with multiple mathematical models of neurons. In this paper, the flexibility of the new model has also been described in constructing neural networks and based on the theory of Biomimetic pattern recognition (BPR) and high-dimensional space covering, a recognition system of omni directionally oriented rigid objects on the horizontal surface and a face recognition system had been implemented on CASSANN-H neurocomputer. The result showed DSWN neural network has great potential in pattern recognition.

InN layers grown by MOCVD on SrTiO3 substrates

Epitaxial wurtzite InN thin films have been grown by metal-organic chemical vapor deposition on (1 1 1) SrTiO3 (STO) substrates. Interestingly, twin domain epitaxy induced by the surface reconstruction of STO is observed with the in-plane orientation relationships of [(1) over bar 1 0 0]InN parallel to [<(1)over bar > 1 0]STO and [2 <(1 1)over bar > 0]InN parallel to[<(1)over bar > 1 0]STO, which is helpful to release the strain. The InN films on STO substrates exhibit a strong photoluminescence emission around 0.78 eV. Particularly, using STO substrates opens up a possibility to integrate InN with the functional oxides. (C) 2009 Elsevier B.V. All rights reserved

基于结构理解的笔迹智能编辑

随着人机界面朝着自然高效的方向发展,手写笔迹的结构分析和智能编辑越来越被人们所关注。给出了一种基于多层次相互作用的结构理解的笔迹智能编辑方法。该方法先自下而上初步提取单字、行、段,然后自上而下利用整体信息对组成信息进行精确分割,提取的信息表示成一个多层次的结构。基于笔迹的结构,用户可以使用笔手势对笔迹进行编辑。实验评估表明,该方法对笔迹的智能编辑具有较好的效果。

不同耕作方式对黄土高原旱地麦田土壤物理性状的影响

通过冬小麦田间试验,研究了免耕、深松、翻耕三种不同耕作措施对土壤物理特性的影响。结果表明:冬小麦收获时,免耕与其它处理相比,增大了土壤容重、土壤硬度,其土壤干筛法>0.25 mm团聚体含量比深松和翻耕每层平均增加3%和5%,但较冬小麦耕作处理前每层平均下降5%;免耕条件下,湿筛法>0.25 mm团聚体含量比深松和翻耕每层平均增加11%和32%,较冬小麦耕作处理前每层平均下降42%;免耕可增加土壤蓄水量,收获期土壤蓄水量为373.1 mm,较深松和翻耕提高17%和8%;随着降水量的增加,冬小麦收获期水分入渗速率逐渐减少;且不同耕作方式水分入渗速率为免耕>深松>翻耕。

施肥对干旱胁迫下夏玉米根系提水的调节作用研究

以耐旱性玉米品种郑单958号为材料,采用两室分根土培装置,通过时域反射计(TDR)对上下土层土壤含水量进行控制和观测,研究施肥对干旱胁迫条件下玉米根系提水作用的影响.结果表明,玉米根系在土层上干下湿条件下(即上下层土壤存在一定水势差时)存在明显提水作用;玉米根系提水量在整个生育期呈单峰变化,并以吐丝期最大;上层土壤施肥可以调节玉米根系提水作用强弱,整个生育期根系总提水量表现为NP配施>单施P>CK>单施N,NP配施处理全生育期单株提水量(1 948.6 g)分别是单施P处理、CK和单施N处理的1.5倍、3.1倍和3.5倍.玉米整个生育期根系总提水量与收获期不同层次根系干重和体积存在极显著正相关关系,也与其地上部分生物量和籽粒产量呈极显著或显著正相关关系.可见,玉米根系的提水作用强弱因生育期和施肥处理而变化,施肥主要通过影响根系生长来调节其提水作用;在一定水分环境条件下,玉米根系提水作用能促进作物生长,提高其籽粒产量.

NEAR-RESONANCE RAMAN-SCATTERING OF LONGITUDINAL OPTICAL PHONON MODES AND INTERFACE MODES IN GAAS/ALAS SUPERLATTICES

The near-resonance Raman scattering of GaAs/AlAs superlattices is investigated at room temperature. Owing to the resonance enhancement of Frohlich interaction, the scattering intensity of even LO confined modes with A1 symmetry becomes much stronger than that of odd modes with B2 symmetry. The even modes were observed in the polarized spectra, while the odd modes appear in the depolarized spectra as in the off-resonance case. The second-order Raman spectra show that the polarized spectra are composed of the overtone and combinations of even modes, while the depolarized spectra are composed of the combinations of one odd mode and one even mode. The results agree well with the selection rules predicted by the microscopic theory of Raman scattering in superlattices, developed recently by Huang and co-workers. In addition, the interface modes and the combinations of interface modes and confined modes are also observed in the two configurations.

1300 nm超辐射发光二极管寿命测试

作为光纤陀螺用光源的超辐射发光二极管(SLD)随着工作时间的延续,其性能会发生退化。采用加速老化的实验方法来估算InGaAsP SLD管芯的工作寿命。分别在环境温度373 K和358 K下对5只SLD管芯进行加速老化,并通过对P-t曲线拟合来推算和估计管芯的老化速率和激活能。计算出了器件的激活能平均值约为0.82 eV,SLD管芯在室温下的工作寿命超过10~6 h,可以满足光纤陀螺用光源的寿命要求。对影响SLD管芯可靠性的因素以及管芯的退化机理进行了分析,为研制高可靠性的超辐射发光二极管提供了理论基础。