The Application of Digital Optical 3D Image Analyzer Evaskin in The Evaluation of Wrinkles

To verify the effectiveness of digital optical 3D image analyzer EvaSKIN in the objective and quantitative evaluation of wrinkles.A total of 115 subjects were recruited,the facial images of the subjects were collected by digital optical 3D image analyzer and manual camera,the changes of crow’s feet with age were analyzed.Pictures obtained by manual photography can be directly used for observation and preliminary grading of wrinkles.However,the requirements for evaluators are high,and the results are prone to errors,which will affect the accuracy of the evaluation.Therefore,skilled raters are needed.Compared with the manual photography method,the digital optical 3D image analyzer EvaSKIN can realize three-dimensional extraction of wrinkles,and obtain the change trend of crow’s feet with age.20~30 years old,wrinkles begin to appear slowly;wrinkles will increase rapidly at the age of 30~50;The length of 50~60 year old wrinkles is basically fixed,the wrinkles develop longitudewise,gradually widen and deepen,and the area,depth and volume increase is obvious,and the skin aging condition is intensified.the digital optical 3D image analyzer EvaSKIN realizes the 3D extraction of wrinkles,quantifies the circumference,area,average depth,maximum depth and volume of wrinkles,realizes the objective and quantitative evaluation of wrinkle state,is more accurate in the measurement of wrinkles,and provides a new instrument and method for the evaluation of wrinkles.it is a perfect and supplement to the traditional evaluation methods,and to a certain extent,it helps the research and development and evaluation institutions of cosmetics to obtain more abundant and three-dimensional data support.

Performance Analysis and Evaluation of Geometric Parameters in Stereo Deflectometry

This paper presents a novel geometric parameters analysis to improve the measurement accuracy of stereo deflectometry.Stereo deflectometry can be used to obtain form information for freeform specular surfaces.A measurement system based on stereo deflectometry typically consists of a fringe-displaying screen,a main camera,and a reference camera.The arrangement of the components of a stereo deflectometry system is important for achieving high-accuracy measurements.In this paper,four geometric parameters of a stereo deflectometry system are analyzed and evaluated:the distance between the main camera and the measured object surface,the angle between the main camera ray and the surface normal,the distance between the fringe-displaying screen and the object,and the angle between the main camera and the reference camera.The influence of the geometric parameters on the measurement accuracy is evaluated.Experiments are performed using simulated and experimental data.The experimental results confirm the impact of these parameters on the measurement accuracy.A measurement system based on the proposed analysis has been set up to measure a stock concave mirror.Through a comparison of the given surface parameters of the concave mirror,a global measurement accuracy of 154.2 nm was achieved.

PERFORMANCE EVALUATION OF SEVERAL FUSION APPROACHES FOR CCD/SAR IMAGES

Several image fusion approaches for CCD/SAR images are studied and the performance evaluation of these fusion approaches is completed in this paper. Firstly, the preprocessing of CCD/SAR images before fusion is fulfilled. Then, the image fusion methods including linear superposition, nonlinear operator method and multiresolution methods, of which the multiresolution methods include Laplacian pyramid, ratio pyramid, contrast pyramid, gradient pyramid, morphological pyramid and discrete wavelet transform, are adopted to fuse two types of images. Lastly, the four performance measures, standard deviation, entropy, cross entropy and spatial frequency, are calculated to compare the fusion results by different fusion approaches in this paper. Experimental results show that contrast pyramid, morphology pyramid and discrete wavelet transformation in multiresolution approaches are more suitable for CCD/SAR image fusion than other ones proposed in this paper and the objective performance evaluation of CCD/SAR image fusion approaches are effective.

Flow control performance evaluation of a tri-electrode sliding discharge plasma actuator

Tri-electrode sliding discharge(TED)plasma actuators are formed by adding a direct current(DC)exposed electrode to conventional dielectric barrier discharge(DBD)plasma actuators.There are three TED modes depending on the polarity and amplitude of the DC supply:DBD discharge,extended discharge and sliding discharge.This paper evaluates the electrical,aerodynamic and mechanical characteristics of a TED plasma actuator based on energy analysis,particle image velocimetry experiments and calculations using the Navier-Stokes equation.The flow control performances of different discharge modes are quantitatively analyzed based on characteristic parameters.The results show that flow control performance in both extended discharge and sliding discharge is more significant than that of DBD,mainly because of the significantly higher(up to 141%)body force of TED compared with DBD.However,conductivity loss is the primary power loss caused by the DC polarity for TED discharge.Therefore,power consumption can be reduced by optimizing the dielectric material and thickness,thus improving the flow control performance of plasma actuators.

建筑幕墙玻璃影像变形分析与研究

幕墙玻璃的影像变形是目前建筑行业普遍存在的现象。以幕墙玻璃影像变形为研究对象,总结了其变形类型、产生原因、技术指标和国内外现有检测方法,指出幕墙玻璃的变形种类多、表面形貌复杂多样,其影像变形受生产工艺、设计安装、环境等因素的影响,是一个复杂的动态过程,分析表明根据实际需要选取不同技术指标、综合使用玻璃表面形貌检测与视觉评价检测方法,才能实现玻璃表面形貌与人眼视觉效果的精确对标。

Area and volume ratios for prediction of visual outcome in idiopathic macular hole

AIM： To predict the visual outcome in patients undergoing macular hole surgery by two novel three-dimensional morphological parameters on optical coherence tomography （OCT）： area ratio factor （ARF） and volume ratio factor （VRF）. METHODS： A clinical case series was conducted, including 54 eyes of 54 patients with an idiopathic macular hole （IMH）. Each patient had an OCT examination before and after surgery. Morphological parameters of the macular hole, such as minimum diameter, base diameter, and height were measured. Then, the macular hole index （Mill）, tractional hole index （THI）, and hole form factor （HFF） were calculated. Meanwhile, novel postoperative macular hole （MH） factors, ARF and VRF were calculated by three-dimensional morphology. Bivariate correlations were performed to acquire asymptotic significance values between the steady best corrected visual acuity （BCVA） after surgery and 2D/3D arguments of MH by the Pearson method with two-tailed test. All significant factors were analyzed by the receiver operating characteristic （ROC） curve analysis of SPSS software which were responsible for vision recovery. ROC curves analyses were performed to further discuss the different parameters on the prediction of visual outcome. RESULTS： The mean and standard deviation values of patients＇ age, symptoms duration, and follow-up time were 64.8＋8.9y （range： 28-81）, 18.6＋11.5d （range： 2-60）, and 11.4＋0.4mo （range： 6-24）, respectively. Steady-post-BCVA analyzed with bivariate correlations was found to be significantly correlated with base diameter （r＇0.521, P〈0.001）, minimum diameter （r=0.514, P〈0.001）, MHI （r -0.531, P〈0.001）, THI （r=-0.386, P=-0.004）, HFF （r=-0.508, P〈0.001）, and ARF （r=-0.532, P〈0.001）. Other characteristic parameters such as age, duration of surgery, height, diameter hole index, and VRF were not statistically significant with steady-post-BCVA. According to area under the curve （AUC） values, values of ARF, MHI, HFF, minimum diameter, THI, and base diameter are 0.806, 0.772, 0.750, 0.705, 0.690, and 0.686, respectively. However, Steady-post-BCVA analysis with bivariate correlations for VRF was no statistical significance. Results of ROC curve analysis indicated that the MHI value, HFF, and ARF was greater than 0.427, 1.027 and 1.558 respectively which could correlate with better visual acuity. CONCLUSION： Compared with MHI and HFF, ARF could effectively express three-dimensional characteristics of macular hole and achieve better sensitivity and specificity. Thus, ARF could be the most effective parameter to predict the visual outcome in macular hole surgery.

Performance evaluation of a WDM/OCDM based hybrid optical switch utilizing efficient resource allocation

A hybrid optical switch （HOS） with physical layer of wavelength division multiplexing and optical code division multiplexing （WDM/OCDM） scheme is proposed. An additional feature to the HOS than optical cross connect （OXC） is that the controller can process requests for both circuit establishment and burst scheduling. In our study, the measurement criteria of HOS are the blocking probability, probability of error, and probability of outage. To simplify the analysis, no distinction is made between a circuit in progress and a burst in progress. Moreover, a minimum fit （MinF） resource allocation strategy is applied in order to increase the bandwidth efficiency and control the multiplexing interference of the OCDM. A 2D Markov model for the HOS is presented using the MinF strategy. Numerical results reveal that the code parameters and the resource allocation strategy greatly affect the performance. Certain periority can be achieved by assigning shorter codes to high periority users and longer codes to low periority users. Also, the probability of error and outage are reduced bv aonling the MinF strategy.

Efficiency Analysis of the Autofocusing Algorithm Based on Orthogonal Transforms

Efficiency of the autofocusing algorithm implementations based on various orthogonal transforms is examined. The algorithm uses the variance of an image acquired by a sensor as a focus function. To compute the estimate of the variance we exploit the equivalence between that estimate and the image orthogonal expansion. Energy consumption of three implementations exploiting either of the following fast orthogonal transforms: the discrete cosine, the Walsh-Hadamard, and the Haar wavelet one, is evaluated and compared. Furthermore, it is conjectured that the computation precision can considerably be reduced if the image is heavily corrupted by the noise, and a simple problem of optimal word bit-length selection with respect to the signal variance is analyzed.

全光网在高校数据中心网络中的应用与性能评估

随着高校数据中心网络规模的不断扩大和应用需求的增加,全光网作为一种高带宽、低延迟的网络技术,逐渐在高校数据中心网络中得到应用。文章针对全光网在高校数据中心网络中的应用与性能评估进行了研究。首先介绍了全光网的概念和特点,以及高校数据中心网络的需求和挑战。然后重点探讨了全光网在高校数据中心网络中的应用,包括拓扑结构设计、传输技术应用以及设备选型和部署。接着介绍了全光网在高校数据中心网络中的性能评估,包括评估指标、评估方法和实验设计,并给出了实验结果和分析。最后对研究工作进行了总结,并展望了未来的研究方向。

面料性能对不同款式衣褶造型变化规律的影响

为更好地在服装设计中应用褶皱造型,深入剖析面料性能对衣褶造型效果的影响,基于自由端垂荡褶、阴褶、斜向褶、翻折式垂荡褶、抽褶5款特征明显有代表性的衣褶造型和棉机织物、醋酯纤维机织物、涤纶针织物3种不同性能的面料正交组合制作15件样衣,建立灰度共生矩阵和模糊评价模型,从客观指标和主观评分2方面定量分析不同面料和不同款式之间衣褶造型效果的对应关系。研究结果表明,不同类别的褶皱造型对面料要求存在差异:外力施加类褶皱应避免使用针织面料;垂荡褶类端部固定褶皱可以减少面料易变形产生的负面影响;悬垂性好的面料可以改善随机褶类褶皱分布的不规律性。

基于数字图像的秘密共享实验教学设计

传统密码学课程的秘密共享教学侧重于理论基础,对实际应用的关注却相对较少,导致教学效果并不理想。为解决这一问题,设计了一种激发学生兴趣并提升科研能力的综合性实验。该实验将数字图像处理技术与秘密共享进行研究与结合,采用性能评价指标对该算法进行性能评价。实验结果表明,该实验采用理论与实践结合的方式,激发学生的学习兴趣,有助于学生深入了解秘密共享的原理和技术。

纱线条干均匀度检测技术的研究进展

纱线条干均匀度是评估纱线质量和质地的重要指标,对纺织品质量、性能以及加工工艺有着重要影响,因此准确快速地测定条干均匀度在纺织工业中具有重要意义。通过回顾国内外相关文献,综合讨论了电容式、光电式和图像处理3种条干均匀度检测技术,并对各自的研究进展进行了详细阐述。重点讨论了条干均匀度检测技术的准确度、评价指标和技术要领等,分析了影响条干均匀度检测技术发展的相关因素,并从理论依据、研究方法和应用评价等角度讨论了条干均匀度检测技术目前存在的问题,为纺织工业中的条干均匀度检测提供一定参考,从而促进纺织行业的工业生产和技术进步。

硬式内窥镜检测仪评估硬式内窥镜光学性能的研究

目的:应用硬式内窥镜检测仪检测法和目测检测法检测评估硬式内窥镜的导光性能和成像性能,探讨硬式内窥镜检测仪检测硬式内窥镜光学性能的应用效果。方法:选取2022年5月至2023年5月北京协和医学院肿瘤医院膀胱镜手术使用的174件硬式内窥镜,分别采用目测法和检测仪法对174件硬式内窥镜进行清洗消毒后的检测。根据检测方式不同,将其分为目测组(90件)和检测仪组(84件)。对比分析两种检测硬式内窥镜导光性能和成像性能的方法,比较两种检测方法的检测效果。结果:检测仪组和目测组光通量不合格检出率分别为11.9%(10/84)和0(0/90),两组硬式内窥镜导光性能的光通量检测比较,差异有统计学意义(x^(2)=9.276,P<0.05)。硬式内窥镜成像性能检测中检测仪组和目测组的成像质量不合格检出率分别为9.5%(8/84)和1.11%(1/90),两组比较差异有统计学意义(x^(2)=6.269,P<0.05)。结论:应用硬式内窥镜检测仪可提高消毒供应中心工作人员检测硬式内窥镜光学性能的准确率,完善硬式内窥镜的质控管理,降低硬式内窥镜损耗率,延长硬式内窥镜的使用寿命,为临床提供更加安全有效的医疗器械,保障医疗安全。

基于机器视觉的锂电池缺陷检测研究进展

锂电池作为新能源汽车的核心组件之一,其复杂的制造工艺流程不可避免地引入各种缺陷,严重影响产品的质量,缺陷检测已成为锂电池制造流程中的重要环节,而兼顾了精度与速度优势的机器视觉方法受到高度关注。本文综述了近15年来基于机器视觉的锂电池缺陷检测方法的研究进展。首先简介锂电池表面常见的缺陷类型,阐明视觉缺陷检测的主要流程。然后重点阐述了基于传统图像处理的锂电池缺陷检测方法,对检测流程中的图像预处理、图像分割、特征提取、分类识别4大步骤进行了详细的解释说明,并对比每个步骤中各类方法的优缺点。接着按分类网络、检测网络、分割网络这3类综述了基于深度学习的锂电池缺陷检测方法。随后整理了10个锂电池自建数据集和缺陷检测性能评价指标。最后指出针对锂电池缺陷检测目前面临着诸多方面的技术挑战,并对未来的工作进行了展望。

Objective visual performance evaluation with visual evoked potential measurements based on an adaptive optics system

An objective visual performance evaluation with visual evoked potential （VEP） measurements was first inte- grated into an adaptive optics （AO） system. The optical and neural limits to vision can be bypassed through this system. Visual performance can be measured electrophysiologically with VEP, which reflects the objective func- tion from the retina to the primary visual cortex. The VEP ts without and with AO correction were preliminarily carried out using this system, demonstrating the great potential of this system in the objective visual performance evaluation. The new system will provide the necessary technique and equipment support for the further study of human visual function.

基于多源遥感的高山峡谷区崩滑识别及易发性评价

我国西南高山峡谷区地质环境脆弱、气候条件复杂,是地质灾害的高发区。受传统调查手段和成本的限制,已发现的地质灾害点主要分布在低海拔地区的河流、道路和居民区周边,而高海拔地区的崩滑地质灾害隐患调查存在大量空白。本文以怒江流域贡山段为研究区,采用InSAR技术和光学影像相结合的方式,识别补充崩滑地质灾害隐患936处;将研究区崩滑灾害隐患分为单体滑坡、单体崩塌和高位崩滑3种类型,其中单体滑坡198处,单体崩塌226处,高位崩滑675处。基于补充完善的崩滑地质灾害隐患数据,使用信息量模型和频率比模型对怒江流域贡山段区域开展易发性评价,发现研究区内极高、高易发区主要分布在河流两岸、道路周边和高海拔植被稀疏地区,中、低易发区则分布在山体中下部的植被茂密地区。与未补充完善灾害数据得到的易发性评价结果进行对比可知,完善灾害数据得到的评价结果更符合研究区崩滑灾害现状,说明利用SBAS-InSAR技术结合光学影像识别高山峡谷区崩滑灾害具有较好的可靠性。通过ROC曲线得出两种模型评价结果的AUC值分别为0.752和0.824,表明两种模型的评价结果具有较高的准确性。

基于图像显著性的空中光学伪装效果评估方法

针对传统伪装效果评估在大场景空中图像不适用问题,提出一种基于图像显著性的空中光学伪装效果评估方法。采用频率调谐(frequency-tuned,FT)模型生成全局显著图和显著区域图,使用残余谱(spectrum residual,SR)模型生成局部显著图;根据显著图计算全局显著均值、显著区域占比和局部显著均值3个指标;通过熵权法综合3个指标得到综合显著性评估系数来量化评估,在林地和雪地背景下获取伪装目标空中光学图像进行实验验证。结果表明:该方法能较好地体现不同伪装效果的差异,优于目标背景相似度加权模型,且可根据显著图优化伪装方案。

基于图像识别的灭火防护服液密性能试验研究

为保障危险化学品事故特种消防救援人员安全,本文运用整装喷淋试验平台,选取消防队伍广泛配备的2套不同品牌化学防护服、1套传统灭火防护服、1套新型灭火防护服,开展平行重复试验。分别使用传统网格统计法和图像识别方法计算染色区域面积,运用面料液密性试验平台研究不同喷射压力、不同喷射时间对灭火防护服液密性能的影响。结果表明:图像识别方法与传统网格统计法测得的平均染色面积相对误差率小于10%,验证了该方法在此领域具有准确性、可行性。传统灭火防护服面料随着喷射时间、喷射压力的增加,染色区域面积增大;而新型消防面料在相同条件下染色面积更小。新型灭火防护服面料采用内侧复合双组份PTFE膜、外层涂布硅橡胶涂层的复合芳纶梭织布,相比于传统灭火防护服面料,增加了复合膜材料和硅橡胶涂层,抗液体穿透能力更强。

PVC透明制品的配方研究及光学性能评价

针对PVC透明制品的特殊光学性能要求,通过正交配方设计研究了增塑剂、内润滑剂、外润滑剂、热稳定剂和冲击改性剂对制品雾度、透明度和黄色指数的影响,并得出了PVC透明片材的最优配方:外润滑剂0.2份、冲击改性剂2份、内润滑剂0.3份、增塑剂12份、热稳定剂4份。

空间频域成像在烧伤中的应用现状及研究进展

烧伤是指热力、化学物质、电流、放射线等造成的组织损伤,其预后与烧伤严重程度密切相关,若评估不当不仅影响患者的治疗进程,还可能给患者造成严重的精神创伤,故准确评估烧伤严重程度至关重要。空间频域成像(SFDI)因具有非接触、大视场、无创、快速成像等优点,可通过定量测定组织吸收和散射系数量化血液相关成分,在烧伤严重程度的评估中发挥了一定作用。为更好地指导SFDI在烧伤中的应用,本文对其原理、应用方法以及在烧伤严重程度评估中的应用现状及研究进展进行了综述。