基于两次二维Daubechies小波变换的纸病在线辨识方法研究

针对造纸生产线上纸病在线检测系统光源不均匀性和纸病难以识别的问题,通过建立纸病图像背景模型实现动态补偿光源的不均匀成分,并根据不同纸病图像的灰度分布规律,两次使用二维小波变换增强其灰度轮廓信息和提取灰度特征,以实现纸病的在线辨识。实验结果表明,该方法可以显著提高纸病辨识精度。     

基于几何及灰度特征的纸病检测算法研究

针对当前纸病在线检测系统实时性强和信息量大的特点,提出了一种高效、灵活的基于几何及灰度特征的纸病检测算法.首先采用邻域均值法对纸病图像去噪,然后根据灰度直方图选取合适阈值将图像二值化,并运用边界跟踪法检测出纸病边缘,最后提取出纸病的几何及灰度特征并分析其特征量将纸病分类.按照该算法依次对常见5种纸病进行检测,结果表明,基于几何及灰度特征的纸病检测算法能够准确地检测并分类常见纸病.     

改进Hough变换在纸病检测系统中的应用

通过对褶皱纸病的分析研究,提出一种基于改进Hough变换的检测方法.利用边缘检测对纸病信息进行去噪和简单提取,采取Hough变换的方法将纸张从图像灰度空间转换到参数空间,从变换后的参数空间中提取纸病图像中的褶皱特征并进行识别.实验结果表明,此方法识别率高、计算速度快、检测效果好.     

基于模糊逻辑的纸病检测动态阈值数学方案规则与实现

为验证并提高动态阈值数学算法在纸病检测工作中的通用性,基于模糊逻辑通过实验法获取了不同时段待检测纸张图像灰度数据;对检测纸张图像灰度变化规律进行了总结,使用Visual Studio 2018进行编程并验证。研究结果表明:基于模糊逻辑的纸病检测动态阈值数学方案,能够很好地适应纸病检测流程中的实际光线变化,能够显著提升待检测纸张纸病检测系统的鲁棒性,从而保证该数学算法方案在纸病检测工作中的通用性。     

马尔可夫随机场在纸病检测中的应用研究

纸病检测是造纸生产过程中重要的环节,现有的纸病检测系统一般采用阈值算法或边缘检测算法对图像进行分割。为解决阈值分割和边缘检测分割方式中存在的误分以及过度分割问题,本研究提出了基于马尔可夫（MarKov）随机场的纸病图像分割方法。通过MarKov随机场理论对纸病图像纹理进行分析得到纹理特征参数,利用纹理特征参数以及最大差值对正常背景和纸病区域进行分割。结果表明,相比于其他分割算法,基于MarKov随机场的纸病图像分割方法可有效提取出纸病图像的纹理细节和轮廓特征,提高分割的准确度。     

基于FPGA和CCD相机的纸病检测系统的设计与实现

针对高速纸机纸病检测时,图像数据处理量大和实时性的要求,文中采用FPGA(Field Programmable Gate Array)和线阵CCD(Charge-coupled Device)相机技术,介绍了一种高速纸病检测系统的设计。利用FPGA并行性和高速运算能力的特点,控制线阵CCD实现高速下图像采集和进行纸病图像预处理,抓取出纸病图像并上传到上位机,然后利用灰度阈值分割和二值图像分型盒维数的方法确定纸病类型。结果表明,该设计有效提高了纸病检测速度,降低了成本。     

基于阈值分割及分形特征的纸病图像识别算法研究

针对脏点、孔洞、褶子和裂口等常见的典型纸病识别问题,在分析纸病图像灰度特征及分形特征基础上,提出了一种基于图像双阈值分割盒维数特征的纸病识别算法,该算法采用灰度阈值分割提取纸病区域及二值数字图像分形盒维数计算结果,确定纸病类型.实验结果表明,该算法识别率较高,且简单迅速.     

基于CNN的深层次特征提取纸病辨识方法研究

针对当前纸病检测方法中纸病特征量难分离以及难点纸病特征量难构建的瓶颈问题,提出基于卷积神经网络（CNN）的纸病辨识方法。该方法根据纸病图像的特点设计了纸病检测的CNN结构,在此基础上利用CNN自动提取纸病图像的深层次特征,结合Softmax实现对纸病的辨识。实验结果表明,基于CNN的深层次特征提取纸病辨识方法优于现有的纸病检测方法,能够对包括难点纸病在内的各种纸病进行精确辨识。     

基于机器视觉的低对比度纸病识别算法研究

利用机器视觉识别纸病时,若背景与目标纸病的对比度低,且采用单一的边缘检测算法,将会出现对目标纸病边缘定位不准确、抗噪性能不好等问题。对此,提出了一种解决方法,即首先分别用LOG算子和基于数学形态学的边缘检测方法对低对比度纸病图像进行边缘检测,然后对这两种边缘检测算法得到的图像进行小波融合,融合得到的图像中纸病边缘定位准确且具有一定的抗噪性,最后,对此进行了实验验证。研究结果表明,文中提出的解决方法可行,即可将该方法用于基于机器视觉的低对比度纸病识别。     

基于位平面的纸病检测算法研究

针对当前纸病检测算法存在抗干扰能力差、定位不准确和运算复杂等问题,提出一种基于位平面的纸病检测算法。首先,采用自适应中值滤波算法对纸病图像进行滤波,然后,对滤波后的图像进行位平面分解,并运用格雷码对位平面加以增强,最后,使用数学形态学对其进行边缘检测,得到最终的纸病检测结果。仿真结果表明：该方法运算简单,能够较好地检测出纸病缺陷,并具有较好的抗干扰性和定位准确性。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.