醛酮类化合物离子迁移谱QSSR研究

采用按氢分类的分子电性距离矢量(H-MEDV)为结构描述筒,对30个脂肪族醛酮类化合物进行了结构表征。采用逐步回归(SMR)方法对变量进行了筛选,多元线性回归(MLR)方法对化合物的结构与离子迁移常数(K_0)之间的关系进行建模。所得模型的复相关系数(R)为0.984,标准偏差(SD)为0.030。采用"留一法(LOO)"对模型进行了交互检验,得到的复相关系数(R_(cv))为0.973,标准偏差(SD_(cv))为0.039。结果显示该模型具有较强的预测能力及良好的稳定性,对于有机化合物离子迁移谱的QSSR研究具有一定的参考价值。     

氯苯与氯酚类化合物毒性的预测

基于定量结构-活性相关(QSAR)研究氯苯、氯酚类化合物的性质具有重要意义。采用分子电性距离矢量(MEDV)表征氯苯、氯酚类有机毒物的分子结构,运用多元线性回归建立定量结构毒性相关(QSTR)模型,同时采用逐步回归结合统计检测筛选模型变量,建立了22个氯苯、氯酚类有机污染物结构与对戈卑鱼(Guppy)半数致死浓度lg1/(LC_(50))回归方程。另外采用内部及外部双重验证的办法深入分析和检验模型的稳定性。建模的复相关系数(R_(cum))、留一法(LOO)交互校验复相关系数(R_(CV))和外部样本校验复相关系数(Q_(ext))分别为0.976 2、0.944 6和0.973 1。表明用MEDV表征氯苯、氯酚类有机物分子结构信息较好,所建QSTR模型的稳定性和预测能力良好。     

醛酮化合物结构表征与色谱保留指数模拟

通过构建分子顶点原子之间的关系对35个醛酮类化合物进行了结构表征,采用多元线性回归和逐步回归的方法建立了该类化合物结构与色谱保留指数之间的关系模型,模型的复相关系数(R)为0.978,标准偏差(SD)为37.305。采用"留一法"交互检验和外部样本预测的方法对模型的稳定性和预测能力进行了评价,交互检验的复相关系数(R_(cv))为0.970,标准偏差(SD_(cv))为43.477;外部预测的复相关系数(R_(test))为0.996,标准偏差(SD_(test)为17.004。结果表明所采用的分子结构描述符能够恰当表现该类化合物结构特征,所建模型具有良好的稳定性和预测能力。     

新分子电性距离矢量用于苯取代衍生物QSRR的研究

本实验室新近提出按氢分类分子电性距离矢量(H-MEDV),用于对110个烷基苯气相色谱保留指数和54个二取代苯液相色谱容量因子进行结构表征,运用多元线性回归(multiple linear regression,MLR)以建立定量结构色谱保留关系(QSRR)模型,同时利用逐步回归结合统计检测对模型变量作筛选,建模计算值复相关系数(R_(cum))、留一法(leave-one-out,LOO)交互校验(cross-validation,CV)复相关系数(Q_(LOO)),对上述样本分别为0．9950、0．9937和0．9648、0．9530。研究结果表明,H-MEDV能较好表征该类分子结构信息,值得进一步推广。     

卤代苯甲醚结构表征及醇/水分配系数模拟

采用按键分类的分子电性距离矢量对27个卤代苯甲醚化合物进行了结构表征,分别采用多元线性回归和偏最小二乘回归方法构建了该类化合物正辛醇/水分配系数(lgK_(OW))的预测模型。两模型的复相关系数(R)均为0.995,标准偏差(SD)分别为0.070和0.064。分别利用"留一法"对两模型的稳健性及预测能力进行了评价,得到交互检验的复相关系数(R_(CV))分别为0.994和0.993,标准偏差(SD_(CV))分别为0.079和0.080。结果表明所建模型具有良好的稳健性和预测能力,同时也证明了按键分类的分子电性距离矢量在卤代苯甲醚类化合物QSPR研究中的适用性。     

酯类化合物气相色谱定量结构保留关系的研究

采用分子电性距离矢量(MEDV)表征酯类化合物的分子结构,同时运用多元线性回归技术建立了81个酯类化合物,在2种固定相(Carbowax1540和Cqualane)上,气相色谱保留指数(RI)与MEDV的定量结构-色谱保留关系(QSRR)模型。在2种固定相上的QSRR模型的建模计算值复相关系数(Rcum)、留一法(leave-one-out)交互校验复相关系数(QCV)分别为0.9968和0.9958(Carbowax1540);0.9935和0.9908(Cqualane),结果表明MEDV能理想地表征酯类化合物的分子结构,所建模型具有良好稳定性和预测能力。     

有机酸类化合物~(13)C-NMR化学位移预测（英文）

采用原子电性距离矢量(Atomic electronegative distance vector,AEDV),描述了14个有机酸类化合物中不同等价碳原子的化学微环境,以多元线性回归(MLR)和偏最小二乘回归(PLS)方法建立~(13)C核磁共振定量结构波谱关系模型,两模型的复相关系数(R)均为0.984和0.962,标准误差(SD)分别为11.021和16.244。经"留一法"交互检验的复相关系数(R_(CV))分别为0.981和0.939,标准误差(SD_(CV))分别为12.061和17.121。研究结果表明,使用该方法所建模型可以用于预测有机酸类化合物~(13)C NMR化学位移,模型具有良好的稳定性和预测能力。     

四氢咪唑苯二氮卓酮类抗艾滋病药物定量构效关系的研究

采用三维全息原子场作用矢量(3D-HoVAIF)研究89个四氢咪唑苯二氮卓酮(TIBO)类抗艾滋病药物的定量构效关系(QSAR).分别运用偏最小二乘回归、人工神经网络建模,同时采用内部及外部双重验证的办法深入分析和检验模型的稳定性.PLS与ANN建模的复相关系数(R2cum)、留一法(leave-one-out,LOO)交互校验(cross-validation,CV)复相关系数(Q2CV)和外部样本校验复相关系数(Q2ext),分别为0.802、0.710、0.552和0.871、0.864、0.760.表明用3D-HoVAIF表征TIBO类抗艾滋病药物分子结构信息较好,建立QSAR模型的稳定性和预测能力良好,运用ANN建模优于PLS及前人报道的多元线性回归(multiple linear regression,MLR).     

分子表面随机采样分析用于HIV整合酶抑制剂的QSAR研究

采用分子表面随机采样分析对26个香豆素类衍生物抗艾滋病药物进行定量构效关系研究。运用多元线性回归(multiple linear regression,MLR)建模,同时采用内部及外部双重验证的办法对所得模型稳定性能进行深入分析和检验。MLR建模的复相关系数(_(cum)~2)、留一法(1eave-one-out,LOO)交互校验(cross-validation,CV)复相关系数(Q_(CV)~2)和外部样本校验复相关系数r~2(test)分别为0.936、0.894、0.772。结果表明,RASMS能较好表征香豆素类衍生物抗艾滋病药物分子的结构信息,且所建模型具有良好稳定性和预测能力,可用于研发新型HIV整合酶抑制剂。     

圆角桉叶精油成分结构与色谱保留相关性研究

应用按氢分类的分子电性距离矢量(H-MEDV)对圆角桉叶精油的51种组分的气相色谱保留时间(tR)进行了定量结构-色谱保留关系研究.通过多元线性回归,得到模型(M1)的复相关系数(R1)为0.971,标准偏差(SD1)为2.921.用逐步回归的方法挑选了8个变量进行建模,得到的模型(M2)复相关系数(R2)为0.970...     

任务图模型中实时任务设计

仿真技术的进步推动了实时系统（如核反应堆，军事战场和fly-wire系统）的深入研究，用仿真方法解决实时问题，必须首先给出实时系统描述模型，TCM（task graph model)模型是实时系统描述模型之一，其模型最重要的成员是实时任务，使用量化仿真方法定义了实时任务的4种参数，并细分任务为子任务，此方法更易描述实时应用系统，更易构造TGM的执行模型，其层次化的结构更容易进行研究和软件实现，TGM模型及其任务设计已成功地应用于分布式三星实时侦察仿真系统。     

一种基于校正误差的立体相机标定算法

立体相机的标定是一个精确求解各个相机内参数以及相机之间关系参数的过程.它是三维重建的基础,其标定精度的好坏直接影响立体重建的结果.为此提出了一种使用校正误差作为代价函数的立体相机标定算法.该算法首先使用传统的基于重投影误差的方法对单个相机的内参数进行标定,然后利用校正误差完成对相机之间关系参数的标定求解.由于校正误差的计算只与相机内参数以及关系参数有关,可以避免在标定过程中使用难以精确标定的相机外参数.实验结果表明本算法能够有效的提高立体相机标定的精度.     

Physiological and biochemical responses during incremental uphill load carriage

The present study aimed to examine the effect of carrying different magnitudes of load on the changes and relationships of salivary Immunoglobulin A (IgA) and cortisol concentrations and the physiological parameters. Twelve Indian soldiers performed an intense uphill treadmill walking at two speeds viz. 2.5 km h⁻¹ and 4 km h⁻¹ without any load and carrying 10.7 kg, 17 kg and 21.4 kg loads for 36 min. Salivary IgA concentration relative to total protein decreased significantly after each exercise session and cortisol concentration increased concomitantly with physiological variables e.g. heart rate (HR), oxygen consumption (VO₂), minute ventilation (VE) and energy expenditure (EE). An inverse correlation (P < 0.05) was observed between IgA with HR for all the conditions except when the participants walked at 4 km h⁻¹ carrying 17 kg and 21.4 kg load. The degree and type of physiological and biochemical responses may help in designing combat training, operations and developing preventive strategies of military personnel involving intense exercise.Relevance to industry: Walking with load in incremental uphill terrain is highly stressful and fatiguing. Results of the present study will help in designing training schedules for maintaining the optimal fitness of an individual during uphill walking with loads in different speeds.     

A wavelet-based parameterization for speech/music discrimination

This paper addresses the problem of parameterization for speech/music discrimination. The current successful parameterization based on cepstral coefficients uses the Fourier transformation (FT), which is well adapted for stationary signals. In order to take into account the non-stationarity of music/speech signals, this work proposes to study wavelet-based signal decomposition instead of FT. Three wavelet families and several numbers of vanishing moments have been evaluated. Different types of energy, calculated for each frequency band obtained from wavelet decomposition, are studied. Static, dynamic and long-term parameters were evaluated. The proposed parameterization are integrated into two class/non-class classifiers: one for speech/non-speech, one for music/non-music. Different experiments on realistic corpora, including different styles of speech and music (Broadcast News, Entertainment, Scheirer), illustrate the performance of the proposed parameterization, especially for music/non-music discrimination. Our parameterization yielded a significant reduction of the error rate. More than 30% relative improvement was obtained for the envisaged tasks compared to MFCC parameterization.     

外激励参数未知系统的同步控制及其参数识别

考虑外激励的振幅和频率未知的混沌系统.把系统未知参数扩张成系统的新的状态量,构造新的驱动系统.用参数自适应控制方法构造一个响应系统,使之与驱动系统的结构相同.基于级联系统的稳定性理论,通过两个步骤来设计控制器和参数自适应律,使得驱动—响应系统能够达到完全同步.当驱动—响应系统达到完全同步时,就可以识别出系统的未知参数振...     

一种基于PSD的机器人动态轨迹测量系统的研制

本文介绍了一个基于 PSD 的机器人动态位置测量系统,描述了系统的构成,并对该系统中的标定方法,数据处理方法和为提高系统的性能所采取的硬件措施进行探讨,本系统通过长期考机和初步应用,表明了它具有良好的可靠性和有效性.     

Camera calibration for a mobile robot prototype

Stereovision is an effective technique to use a CCD video camera to determine the 3D position of a target object from two or more simultaneous views of the scene. Camera calibration is a central issue in finding the position of objects in a stereovision system. This is usually carried out by calibrating each camera independently, and then applying a geometric transformation of the external parameters to find the geometry of the stereo setting. After calibration, the distance of various target objects in the scene can be calculated with CCD video cameras, and recovering the 3D structure from 2D images becomes simpler. However, the process of camera calibration is complicated. Based on the ideal pinhole model of a camera, we describe formulas to calculate intrinsic parameters that specify the correct camera characteristics, and extrinsic parameters that describe the spatial relationship between the camera and the world coordinate system. A simple camera calibration method for our CCD video cameras and corresponding experiment results are also given. This work was presented in part at the 7th International Symposium on Artificial Life and Robotics, Oita, Japan, January 16–18, 2002     

粒子群优化算法在船型优化设计中的应用仿真

研究船舶外形结构优化设计,由于船舶在航行过程中,不同型号的船舶机动性能力和稳定性存在着较大差异,造成船舶外形的梯度信息突变明显.传统的优化设计方法多是基于梯度信息的优化设计方法,在船舶外形结构梯度发生突变的情况下,很容易陷入梯度差过大,结果不收敛,造成外形设计的缺陷较为明显.为解决上述问题,提出一种基于粒子群优化算法的船舶外形优化设计,利用粒子群的搜索能力,对设计结构中的参数进行最优搜索.针对船舶外形梯度信息差异大,很难小范围收敛的问题,通过遗传算法对其进行优化,使得参数在小范围内也能实现最优化.保证设计结果的稳定,仿真结果表明,改进算法设计的船舶外形参数在升力、阻力和升阻比等参数上有了较为明显的优化,在全航行周期中具有更优的性能.     

基于几何方法的摄像机内外参数求解

根据摄像机透视投影模型的几何意义,从几何角度推导了由投影矩阵求解摄像机内外参数的过程以及任意矩阵能够成为透视投影变换描述的约束条件。     

Influence of dielectric material near tunnel junction on analog/RF and linearity figure of merits in hetero dielectric (HG) TFET: A detailed study

In this work, the effect of dielectric material near the source region on analog/RF and linearity figure of merits in hetero gate TFET (HG-TFET) are investigated through Technology Computer Aided Design device simulator. The various dielectric materials considered in this study are SiO₂, Al₂O₃, and HfO₂. The several RF/analog metrics studied in this work are transconductance (g_m), output conductance (g_d), gain (g_m/g_d), gate capacitance, cut-off frequency, and gain frequency product. Furthermore, the various linearity parameters discussed are higher order derivative of g_m (g_m2 and g_m3), voltage intercept points (VIP2 and VIP3), 3rd-order input intercept power, and 3rd-order intermodulation power for different high-k dielectric near the source region in HG-TFET. Results reveal that RF/analog performance is improved, whereas, the linearity characteristic is suppressed in HG-TFET using HfO₂ as the gate dielectric near the source.