基于NIRS技术的食用醋品牌溯源研究

以四种品牌152组食用醋样品为研究对象,采用漫反射与透射两种近红外光谱采集模式分别进行光谱数据采集,并以此建立了食用醋品牌溯源模型,重点考察光谱采集模式、光谱预处理方法等对溯源模型精度的影响。结果表明,选取114组样品为训练集,原始光谱数据经过多元散射校正、二阶求导预处理后,采用偏最小二乘判别分析法(PLS1-DA)建立的食用醋NIRS品牌溯源模型,对38组测试集样品进行预测,透射光谱模型的决定系数(R2)、校准均方根误差(root-mean-square error of calibration, RMSEC)、预测均方根误差(root-mean-square error of prediction, RMSEP)分别为0.92,0.113,0.127,正确识别率为76.32%;漫反射光谱模型R2,RMSEC,RMSEP分别为0.97,0.102,0.119,正确识别率为86.84%。由此说明,近红外光谱结合PLS1-DA可以用来建立食用醋品牌溯源模型,且漫反射光谱模型预测效果更好。     

Optimal acquisition and production policy in a hybrid manufacturing/remanufacturing system with core acquisition at different quality levels

We study the acquisition and production planning problem for a hybrid manufacturing/remanufacturing system with core acquisition at two (high and low) quality conditions. We model the problem as a stochastic dynamic programming, derive the optimal dynamic acquisition pricing and production policy, and analyze the influences of system parameters on the acquisition prices and production quantities. The production cost differences among remanufacturing high- and low-quality cores and manufacturing new products are found to be critical for the optimal production and acquisition pricing policy: the acquisition price of high-quality cores is increasing in manufacturing and remanufacturing cost differences, while the acquisition price of low-quality cores is decreasing in the remanufacturing cost difference between high- and low-quality cores and increasing in manufacturing and remanufacturing cost differences; the optimal remanufacturing/manufacturing policy follows a base-on-stock pattern, which is characterized by some crucial parameters dependent on these cost differences.     

Acquiring new use of multiplication through classroom teaching: an exploratory study

This article analyzes the process in which pupils acquire new uses of multiplication to measure area. Behaviors of five 4th-grade pupils in a series of lessons on areas were studied in depth by qualitative case-study methodology. Their use of multiplication changed as the lesson evolved, characterized conceptually as “using multiplication as a label,” “using it positively to approach problems which have not been solved before,” and “using it effectively to achieve the goal of measuring areas.” These three phases show the pupils’ understanding of multiplication in the context of measuring areas from a secondary accompaniment to a powerful tool of thinking. The phases observed and the students’ progress between the phases differs noticeably among the pupils. Factors that foster learners’ progress are investigated by comparing their behaviors.     

包含度理论

不确定性是复杂系统的特征。在人工智能与专家系统中，不确定性的研究越来越具有重要意义。Ｚａｄｅｈ［１］于１９６５年提出模糊集，把经典集合扩充到模糊集合，从而解决了“对象”的不确定性。本文引进了包含度的概念，解决了“关系”的不确定性。同时指出，包含度不仅是各种不确定性推理方法的概括，而且解决了知识获取与矛盾规则排除两个重要问题。     

ICP直读光谱仪的光电测量系统

该系统基于微型机ISA总线，由负高压控制电路、负高压发生器、光电倍增管、前置放大器、程控增益放大器、V／F转换器和定时计数器等构成。负高压在294－944V间分100档程控可调，程控增益放大器在1－256间分5档，V／F转换器满童程输出频率为1MHZ，计数长度和测量时间任意设定，适用于各类ICP直读光谱仪。     

Advances in bio-imaging: a survey from WWMR 2010

The paper deals with a survey on major advances in the field of bio-imaging presented at the WWMR2010 Conference, held in Florence (Italy) from 4th to 9th July 2010. The selected contributions have been organized into the following headings: Hyperpolarization, Acquisition Methods and Molecular Imaging applications. Overall, the Conference has witnessed an outstanding progress in either methods and applications that further stresses the key-role of MRI in many fields of biomedicine.     

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介绍了在QNX实时操作系统下分布式采集控制程序的编写。现场机器负责数据采集存储,并按照预设的参数进行控制。控制室机器负责参数设置与波形的显示,同时负责在控制室远程启动现场机器程序并返回运行的状态,以便在现场机器程序出现异常情况下采取相应的措施。经测试,系统的实时性和可靠性很好地满足了EAST装置LHCD系统单管测试的需要。     

An assessment of the sharpness of carotid artery tissue boundaries with acquisition voxel size and field strength

A measure of the sharpness of vessel wall interfaces in carotid artery MRI may be useful for assessing the conspicuity of the wall's features. An edge detection technique was used to measure the signal intensity gradients in 2D time-of-flight (2D-TOF) and double-inversion recovery black-blood (DIR-BB) carotid artery images of normal subjects that were acquired at 1.5 T with 0.55 x 0.55 x 2.0-mm (0.6 mm3) acquisition voxels and zero filled to reduce the in-plane reconstructed voxel size by one half in each dimension as well as with 0.27 x 0.27 x 2.0-mm (0.15 mm3) acquisition voxels and at 3.0 T with 0.27 x 0.27 x 2.0-mm (0.15 mm3) acquisition voxels using surface coils. The gradient intensities of the lumen-to-background interface varied closely with the contrast-to-noise ratio of the 2D-TOF imaging. For the DIR-BB imaging, in which higher spatial frequency artery structures are visible, the gradient intensities at the interfaces were higher than theoretically predicted at both field strengths with smaller acquisition voxels. The use of acquisition voxels smaller than those previously used at 1.5 T can improve the visualization of carotid artery structures at 1.5 and 3.0 T with surface coil reception.     

基于ARINC818机载音视频的测试方案设计

某型飞机在试飞测试任务过程中,需要对多路机载音视频进行抽引、采集、记录与遥测,用于飞机实时动态监控与事后回放分析。该型飞机的显控数据采用ARINC818(又名航空电子视频总线Avionics Digital Video Bus)专用图像传输协议进行光纤视频传输,对ARINC818总线视频的抽引采集在试飞任务中为首次。由于目前机载采集系统的限制,本文设计了一种基于ARINC818的机载测试系统,满足了该型飞机多通道、高分辨率、多视频格式的信号采集记录。