复配表面活性剂与氧化剂强化的氧脱木素

为了改善浆料中木素的反应活性,提高氧脱木素能力,从而改善氧脱木素的选择性,可以在氧脱木素过程中添加适当的强化助剂。本文研究了常见的氧化剂对氧脱木素的强化作用,并筛选出NaNO3作为氧脱木素强化剂与复配表面活性剂X配合使用进行氧脱木素。当复配表面活性剂X用量为0.5%、NaNO3用量为0.2%时,氧脱木素率比常规氧脱木素增加了19.9个百分点,白度提高了15.7%ISO,而黏度下降却较小。     

自适应动态峰值剪切直方图均衡化

传统的直方图均衡化算法在增强图像的同时可能会引入一些视觉退化效应,如一些图像的部分区域出现过度增强。为了克服这个缺点,已有一些灰度均值保持算法,但是这些算法并不能很好地保持图像处理前后灰度均值的稳定性。提出了一种自适应动态峰值剪切直方图均衡化算法：使用滤波器对原图像的直方图进行滤波操作,并且根据图像的信息来确定分割区间及区间数目;对分割的区间进行重新映射;对区间的直方图进行剪切操作,然后分别地进行均衡化处理,并对处理后的图像进行灰度归一化操作。实验结果表明,该算法可以很好地在保持原图像均值的前提下实现图像增强。     

一种基于低亮温目标的毫米波辐射图像分割方法

与红外与可见光探测器相比，毫米波辐射计具有全天时全天候的工作能力。毫米波金属目标辐射图像的分割识别是制导应用中急需解决的重要问题。文中首先根据毫米波辐射特性确定不同亮温目标区域，然后利用形态学复合算法对辐射图像进行预处理，最后采用分水岭算法完成图像分割。3mm波段辐射图像分割结果表明，该算法可对低亮温毫米波辐射图像进行有效分割，分割后的目标轮廓形状与光学场景相符，与特征模板库匹配后可用于不同目标识别。     

Extrinsic parameter's adjustment and potential implications in Plasmodium falciparum malaria diagnosis

Malaria is a major public health concern, affecting over 3.2 billion people in 91 countries. The advent of digital microscopy and Machine learning with the aim of automating Plasmodium falciparum diagnosis extensively depends on the extracted image features. The color of the cells, plasma, and stained artifacts influence the topological, geometrical, and statistical parameters being used to extract image features. During microscopic image acquisition, custom adjustments to the condenser and color temperature controls often have an influence on the extracted statistical features. But, our human visual system sub-consciously adjusts the color and retains the originality in a different lighting environment. Despite the use of appropriate image preprocessing, findings from the literature indicate that statistical feature variations exist, allowing the risk of P. falciparum misinterpretation. In order to eliminate this pervasive variation, the current work focuses on preprocessing the extracted statistical features rather than the prepossessing of the source image. It begins with the augmentation of series images for a microscopic field by inducing illumination variations during the microscopic image acquisition stage. A set of such image series is analyzed using a Nonlinear Regression Model to generalize the relationship between microscopic images acquired with variable ambient brightness and a specific feature. The projection point of the centroid feature onto the brightness parameter is identified in the model and it is denoted as the optimum brightness factor (OBF). Using the model, the feature correction factor (CF) is calculated from the rate of change of feature values over the interval OBF, and the brightness of the test image is processed. The present work has investigated OBF for selected image textural features, namely Contrast, Homogeneity, Entropy, Energy, and Correlation individually from its co-occurrence matrices. For performance analysis, the best state-of-the-art method uses selected texture as a subset feature to evaluate the effectiveness of P. falciparum malaria classification. Then, the impact of proposed feature processing is evaluated on 274 blood smear images with and without Feature Correction (FC). As a result, the “p” value is less than .05, which leads to the result that it is highly significant and the classification accuracy and F-score of P. falciparum malaria are increased.     

城市隧道照明设计探讨

根据近些年的城市隧道工程设计经验,介绍了隧道照明的设计依据、标准及基本要求,分析了城市隧道照明设计的照明标准值、灯具布置、应急照明、照明控制、配线、节能措施等方面内容,并对隧道照明工程设计实例进行了探讨。     

On the bright side: The influence of brightness on overall taste intensity perception

Ambient light luminance (i.e., brightness or dimness) is a frequently used tool by managers to enhance the overall ambience in their restaurants. The current research explores how a change in a restaurant’s ambient brightness influences the overall taste intensity perception of the food that is being served there. We conducted a between-group experiment in a field setting (i.e., a fine-dining restaurant), where we manipulated the illuminance level of the ambient light (dim vs. bright). Guests were served a dish—tailored to our research question—and asked to evaluate its overall taste intensity. The results demonstrate that guests exposed to the bright ambient light perceived the overall taste of the dish as more intense as opposed to guests exposed to the dim ambient light. The results thus show that modifying the ambient illuminance level in a restaurant does not only affect the overall ambience but also changes the overall taste experience of the food being served. This finding is not only theoretically relevant for research on multisensory integration, but it also provides tools for taste modulation, and—as such—for strategies to decrease salt and sugar consumption among diners.     

Perception of brightness when the eyes are closed

To describe the lighting environment during sleep accurately, it is necessary to know the extent to which light is still perceived when the eyelids are closed. In this study, we measured the perception of equivalent brightness under closed-eye and open-eye conditions in binocular photopic vision. The light sources used were monochromatic red (peak wavelength 630 nm), yellow (593 nm), green (515 nm), and blue (460 nm) LEDs, as well as a white LED (T_cp = 4188 K, R_a = 93). A total of 33 subjects (Asian adults aged 22 years on average) with eyelids of approximately the same color were recruited. The average effective transmittances of their closed eyes were 52.4% ± 31.5% for red, 26.2% ± 18.2% for yellow, 21.6% ± 16.7% for green, 4.5% ± 3.9% for blue, and 42.7% ± 24.8% for white light. These values were up to 10 times higher than eyelid transmittances reported previously, so eyelid transmittance cannot by itself explain perceived closed-eye brightness. There were also significant individual differences. As it is unlikely that the physical transmittances of the eyelids differed from subject to subject, psychological factors may be responsible. This phenomenon should be further investigated in the future.     

基于亮度分级和方向密度的无监督文本定位

提出一种基于RGB亮度分级和方向密度的自然场景无监督文本定位方法,该方法基于场景文本通常与局部背景有较大的对比度这一特性,分别在R、G、B三个颜色层进行亮度分级,以降低背景复杂性;然后,利用文字笔画的显著方向性,以方向密度为依据进行文本区域粗定位;再进一步利用SVM多类分类器实现文本区域精确判别。新方法克服了一般无监督方法颜色聚类数目选定困难的问题,限制了候选区域的种类,从而降低了SVM分类器的训练难度,具有较高的准确性和鲁棒性。     

LED光谱特性及其在中间视觉下的应用

为了研究中间视觉下LED的光度特性,运用LED光色电综合分析仪测量了不同电流下五种颜色多个LED的光谱,然后计算了不同中间视觉亮度下的光通量,并分析和研究了中间视觉修正系数Rm随电流和亮度的变化。研究表明:电流在12～24mA范围内,同一颜色LED的相对光谱整体变化小于8%,因此在普通照明要求下,可以用平均光谱来描述LED的相对光谱。在中间视觉下,绿、白这两种颜色LED的中间视觉修正系数Rm的对数与亮度的对数存在线性关系,红、黄、蓝LED的Rm的对数与亮度的对数存在二次曲线关系。其中,蓝、绿、白LED的Rm随亮度增大而减小,红、黄LED的Rm随亮度增大而增大。该研究为中间视觉下LED灯具的设计提供了理论基础。     

原纸对颜料涂布纸性能的影响

原纸是颜料涂布的基材，它对涂布纸的质量和生产有着非常重要的影响。文章就原纸的一些基本性能，如均一性、光学性能及强度指标等对涂布纸的影响进行了探讨。