Changes in visual performance after implantation of different intraocular lenses

AIM:To evaluate the trending visual performance of different intraocular lenses(IOLs)over time after implantation.METHODS:Ninety-one patients received cataract surgery with implantations of monofocal(Mon)IOLs,segmental refractive(SegRef)IOLs,diffractive(Dif)IOLs,and extendeddepth-of-focus(EDoF)IOLs were included.The aberrations and optical quality collected with iTrace and OQAS within postoperative 6mo were followed and compared.RESULTS:Most of the visual parameters improved over the postoperative 6mo.The postoperative visual acuity(POVA)of the Mon IOL,SegRef IOL,and EDoF IOL groups achieved relative stability in earlier states compared with the Dif IOL group.Nevertheless,the overall visual performance of the 3 IOLs continued to upturn in small extents within the postoperative 6mo.The optical quality initially improved in the EDoF IOL group,then in the Mon IOL,SegRef IOL,and Dif IOL groups.POVA and objective visual performance of the Mon IOL and EDoF IOL groups,as well as POVA and visual quality of the Dif IOL group,improved in the postoperative 1mo and stabilized.Within the postoperative 6mo,gradual improvements were observed in the visual acuity and objective visual performance of the SegRef IOL group,as well as in the postoperative optical quality of the Dif IOL group.CONCLUSION:The visual performance is different among eyes implanted with different IOLs.The findings of the current study provide a potential reference for ophthalmologists to choose suitable IOLs for cataract patients in a personalized solution.

Comparison of visual performance with iTrace analyzer following femtosecond laser-assisted cataract surgery with bilateral implantation of two different trifocal intraocular lenses

AIM:To compare the postoperative binocular visual performance with an iTrace analyzer following femtosecond laser-assisted cataract surgery(FLACS)combined with bilateral implantation of two different types of diffractive trifocal intraocular lenses(IOL).METHODS:During this retrospective observational study,patients who received bilateral FLACS combined with implantation of two different types of diffractive trifocal IOLs were evaluated.According to the IOLs’different types and design,the patients were divided into AT LISA tri839MP group(tri839 group)and AcrySof PanOptix TFNT00 group(TFNT group).Study parameters included preoperative and postoperative uncorrected distance visual acuity(UDVA)at 5 m,uncorrected near visual acuity(UNVA)at 30 cm and 40 cm,uncorrected intermediate visual acuity(UIVA)at 60 cm and 80 cm,postoperative refractive status,objective visual qualities and total high order aberrations(HOAs)postoperatively.The postoperative complications were also recorded.RESULTS:Totally 56 eyes of 28 patients(tri839 group,n=26;TFNT group,n=30)were included.Preoperative baseline characteristics between groups were not statistically significantly different.UDVA was not significantly different between groups except for 1wk follow-up due to the postoperative corneal edema.TFNT group showed statistically significant better UNIA at 60 cm than tri839 group at the 1wk(0.05±0.19 vs 0.15±0.10 logMAR,P=0.013),1mo(0.05±0.12 vs 0.15±0.09 logMAR,P=0.001)and 3mo(0.04±0.12 vs 0.15±0.11 logMAR,P=0.001)follow-up,while tri839 group showed statistically significant better UNIA at 80 cm than TFNT group at the 1d(0.14±0.15 vs 0.20±0.14 logMAR,P=0.041)and 1mo(0.09±0.07 vs 0.14±0.10 logMAR,P=0.042)follow-up.Postoperative refractive status showed stable at every visit.Modulated transfer function(MTF)values and strehl ratio(SR)values were improved and HOAs were lower significantly after surgery.CONCLUSION:FLACS with bilateral implantations of both tri839 and TFNT00 can achieve satisfactory natural whole-course vision,high postoperative refractive stability and good visual quality but without significantly difference.iTrace aberration instrument can accurately evaluate the visual quality under different status.

Visual performance after conventional LASIK and wavefront-guided LASIK with iris-registration:results at 1 year

AIM:To compare visual performance of wavefrontguided laser in situ keratomileusis(LASIK) with iris-registration(Wg-LASIK group) and conventional LASIK(LASIK group) one year after surgery and analyze the correlation between wavefront aberrations and visual performance.·METHODS:Eight hundred and fifty-two myopic eyes of 430 patients were enrolled in this prospective study and divided into two groups:Wg-LASIK group(436eyes) and LASIK group(416 eyes).A Wavescan Wavefront aberrometer was used to analyze Zernike coefficients and the root-mean-square(RMS) of higher order aberrations,and Optec 6500 visual function instrument was used to measure contrast sensitivity(CS)before and 3,6,12 months after surgery.·RESULTS:The mean spherical equivalent(SE) in WgLASIK group was significantly better than those in LASIK group one year after surgery(P =0.024).Wg-LASIK eyes showed better CS values than LASIK eyes at all spatial frequencies with and without glare after surgery(P all【0.01).Moreover,the increase of higher RMS(RMSh),coma,RMS3,RMS4,RMS5 in Wg-LASIK group were significantly lower than those in LASIK group 1 year after surgery(P all 【0.05).The increase of coma,spherical aberration(SA),RMS3 and RMS4 in Wg-LASIK and coma and RMS3 in LASIK group were negatively correlated with reduction of contrast sensitivity 1 year after surgery.·CONCLUSION:A significant better visual performance is got in Wg-LASIK group compared with LASIK group 1year after surgery,and the Wg-LASIK is particularly suitable for eyes with high-magnitude RMSh.

Visual performance with accommodating and multifocal intraocular lenses

AIM： To compare the visual functional outcomes with accommodating and multifocal intraocular lenses（IOLs）.METHODS： Our retrospective comparative study included 51 patients（60 eyes） received implantation of an accommodating IOL（Tetraflex;16 patients,20 eyes）,a refractive multifocal IOL（Re Zoom;18 patients,20 eyes）,or a diffractive multifocal IOL（ZMA00;17 patients,20 eyes）.Subjective refraction,visual acuity,contrast sensitivity（CS）,intraocular aberration,and subjective photic phenomena were detected at 3mo after surgery.RESULTS： The spherical equivalent in the three groups was-0.38±0.54 D,0.14±0.56 D,and 0.35±0.41 D,respectively.No statistically significant differences were found in uncorrected and corrected distance visual acuity and uncorrected intermediate visual acuity among the groups（P=0.39）.The Re Zoom group had significantly better distance-corrected intermediate visual acuity than the ZMA00 group（P=0.003）.The ZMA00 group had significantly better near visual acuity than the other groups（P〈0.05）.Better contrast sensitivity values were observed in the Tetraflex group under most of the spatial frequencies conditions（P=0.025）.The total aberration was lowest in the ZMA00 group（P=0.000）,and the spherical aberration was highest in the Tetraflex group（P=0.000）.The three groups had similar frequency of ghosting and glare,and the Tetraflex group had a low rate of halos（P=0.01）.CONCLUSION： Both accommodating and multifocal IOLs can successfully restore distance and uncorrected intermediate visual acuities.Tetraflex accommodating IOLs perform better in CS and with less halos of photic phenomena.Re Zoom refractive multifocal IOLs havebetter performance in distance-corrected intermediate visual acuity than ZMA00 diffractive multifocal IOLs,and the latter achieved better near visual acuity and efficiently decreased the optical aberration.

Total plant performance evaluation based on big data: Visualization analysis of TE process

The performance evaluation of the process industry, which has been a popular topic nowadays, can not only find the weakness and verify the resilience and reliability of the process, but also provide some suggestions to improve the process benefits and efficiency. Nevertheless, the performance assessment principally concentrates upon some parts of the entire system at present, for example the controller assessment. Although some researches focus on the whole process, they aim at discovering the relationships between profit, society, policies and so forth, instead of relations between overall performance and some manipulated variables, that is, the total plant performance. According to the big data of different performance statuses, this paper proposes a hierarchical framework to select some structured logic rules from monitored variables to estimate the current state of the process. The variables related to safety and profits are regarded as key factors to performance evaluation. To better monitor the process state and observe the performance variation trend of the process, a classificationvisualization method based on kernel principal component analysis(KPCA) and self-organizing map(SOM) is established. The dimensions of big data produced by the process are first reduced by KPCA and then the processed data will be mapped into a two-dimensional grid chart by SOM to evaluate the performance status. The monitoring method is applied to the Tennessee Eastman process. Monitoring results indicate that off-line and on-line performance status can be well detected in a two-dimensional diagram.

Visualization Analysis for Business Performance of Chinese Listed Companies Based on Gephi

When conducting company performance evaluations,the traditional method cannot reflect the distribution characteristics of the company’s operating conditions in the entire securities market.Gephi is an efficient tool for data analysis and visualization in the era of big data.It can convert the evaluation results of all listed companies into nodes and edges,and directly display them in the form of graphs,thus making up for the defects of traditional methods.This paper will take all the listed companies in the Shanghai and Shenzhen Stock Exchange as the analysis object.First uses tushare and web crawlers to collect the financial statement data of these companies.And then,uses the Economic Value Added model to calculate the EVA of each listed company and build graph data.Next,import the graph data into gephi to generate the distribution graph of all listed companies’performance,and summarize the distribution characteristics of business performance.Finally,select a listed company that you want to analyze in detail,using the traditional DuPont analysis method to conduct micro level visualization analysis of the business performance to find the main factors affecting the company’s operating performance.Incorporating gephi into traditional performance analysis methods will make the results of traditional analytical methods more effective and complete.

Ransomware Classification Framework Using the Behavioral Performance Visualization of Execution Objects

A ransomware attack that interrupted the operation of Colonial Pipeline(a large U.S.oil pipeline company),showed that security threats by malware have become serious enough to affect industries and social infrastructure rather than individuals alone.The agents and characteristics of attacks should be identified,and appropriate strategies should be established accordingly in order to respond to such attacks.For this purpose,the first task that must be performed is malware classification.Malware creators are well aware of this and apply various concealment and avoidance techniques,making it difficult to classify malware.This study focuses on new features and classification techniques to overcome these difficulties.We propose a behavioral performance visualization method using utilization patterns of system resources,such as the central processing unit,memory,and input/output,that are commonly used in performance analysis or tuning of programs.We extracted the usage patterns of the system resources for ransomware to performbehavioral performance visualization.The results of the classification performance evaluation using the visualization results indicate an accuracy of at least 98.94%with a 3.69%loss rate.Furthermore,we designed and implemented a framework to perform the entire process—from data extraction to behavioral performance visualization and classification performance measurement—that is expected to contribute to related studies in the future.

Influence of probucol-assisted retinal photocoagulation therapy on the visual performance and serum biochemical indexes in patients with early proliferative diabetic retinopathy

Objective: To explore the influence of probucol-assisted retinal photocoagulation therapy on the visual performance and serum biochemical indexes in patients with early proliferative diabetic retinopathy. Methods: A total of 170 patients with early proliferative DR who were treated in the hospital between December 2014 and May 2017 were retrospectively analyzed and divided into the control group (n=107) who received retinal photocoagulation therapy alone and the probucol group (n=63) who received probucol-assisted retinal photocoagulation therapy. The differences in the contents of visual performance indexes as well as serum angiogenesis indexes, inflammatory mediators and oxidative stress indexes were compared between the two groups before treatment and after 6 weeks of treatment. Results: Before treatment, the differences in the levels of visual performance indexes as well as serum contents of angiogenesis indexes, inflammatory mediators and oxidative stress indexes were not statistically significant between the two groups of patients. After 6 weeks of treatment, mean vision, 30 visual acuity and 30-60 visual acuity of probucol group were higher than those of control group;serum angiogenesis indexes HIF-1, VEGF and Ang-2 contents were lower than those of control group;serum inflammatory mediators ICAM-1, IL-2, IL-23 and TNF-α contents were lower than those of control group;serum oxidative stress index MDA content was lower than that of control group whereas TAC content was higher than that of control group. Conclusion: Probucol-assisted retinal photocoagulation therapy can effectively optimize the visual performance and promote the homeostasis recovery in patients with early proliferative diabetic retinopathy.

Preliminary evaluation of the VIsion PERformance(VIPER) simulator

Background:This study evaluated the VIsion PERformance(VIPER)simulator’s ability to assess the functional visual performance in warfighters conducting civilian and military tasks.Methods:Thirty service members,aged 25–35 years old with a best corrected distance visual acuity(VA)better than or equal to 20/20 or logarithm of the minimum angle of resolution(logMAR)0.00,were randomized to locate and identify road signs and mock improvised explosive devices(IEDs)under either daytime conditions or with infrared imagery,with(cc)and without(sc)wearing their habitual correction.Participants also underwent binocular uncorrected(UDVA)and corrected(CDVA)visual assessment,refraction,contrast sensitivity testing and wavefront aberrometry.Results:The mean age was 28.47 years.The manifest spherical equivalent was–3.16±1.75 diopters(D),the UDVA in both eyes(OU)was logMAR 0.83±0.47,and the CDVA OU was–0.11±0.06.For VIPER,the mean difference in the detection distance(DD)for road signs ccDD vs.scDD was(76.7±52.8)m(P<0.001).The average difference in identification distance(ID)ccID vs.scID was(13.9±6.3)m(P<0.001).The mean accuracies were 83.5%and 27.9%for cc and sc,respectively(P<0.001).The regression analysis indicated that a 1.6 m change in the distance accounts for a 1%change in the accuracy(P=0.002).Without correction,a 4.1 m change accounts for a 1%change in the accuracy(P<0.001).The average IED ccDD was(29.9±8.2)m,and that for scDD was(13.2±13.6)m(P<0.001).The average IED ccID was(32.2±6.2)m and that for the scID was(7.4±10.3)m(P<0.001).The mean IED identification accuracy was 46.7 and 11.4%for cc and sc,respectively(P<0.001).Conclusions:The preliminary results reflect VIPER’s ability to assess functional visual performance when detecting and identifying signs and IEDs.Furthermore,VIPER is able to detect performance changes with and without correction.

Investigating Iranian Test-takers＇ Performance Over Taking Different Modalities of Listening Comprehension Test

Visual and pictorial materials are extensively used in teaching listening comprehension textbooks. Although the use of still image is currently implemented in some distinguished testing systems, video test is not a popular modality due to the fact that this kind of test may result in test-takers＇ confusion during the test. In the present study, a sample of 80 Iranian EFL （English as a Foreign Language） students was selected to compare their performance on three different modalities of listening test： audio-only test, pictorial （listening with still image test）, and visual （video） listening test. The analysis of one-way repeated measure ANOVA （Analysis of Variance） was used to compare the students＇ scores. The results of Bonferroni Post Hoc Test confirm that there were significant differences in scores among audio-only, pictorial, and visual tests. The results of this study highlight the greater performance of students in pictorial listening test which is statistically significant.

A Performance Analysis Tool for PVM Parallel Programs

In this paper,we introduce the design and implementation of ParaVT,which is a visual performance analysis and parallel debugging tool.In ParaVT,we propose an automated instrumentation mechanism.Based on this mechanism,ParaVT automatically analyzes the performance bottleneck of parallel applications and provides a visual user interface to monitor and analyze the performance of parallel programs.In addition,it also supports certain extensions.

Effect of changing mesopic and photopic light conditions on visual functions

AIM:To determine the effects of change in light conditions on refractive error and visual functions including visual acuity,stereopsis and contrast sensitivity.METHODS:This cross-sectional study was conducted in the optometry clinic of the Shahid Beheshti School of Rehabilitation on 48 students in 2021-2022.All of them had eye health and normal visual function and could have refractive errors or not.Light intensity of 4 lx was considered equivalent to photopic light condition and light intensity of 1 lx was considered to be equivalent to mesopic light condition.The amount of refractive error was checked by auto refractometer and its changes in mesopic light condition were subjectively measured.Also,visual acuity,stereopsis and contrast sensitivity(in five spatial frequencies of 1.5,3,6,12,and 18 cycles per degree),were measured first in photopic light condition and then in mesopic light condition,by Snellen control vision chart,stereo butterfly test and the M&S technology monitor test respectively.RESULTS:In the 48 student subjects with an average age of 22.69±3.56y,mean of refractive error as sphere equivalent,visual acuity and stereopsis were-1.25±1.74 diopters,0 logMAR,44.37±13.03 seconds of arc,respectively in photopic light condition while in mesopic light was equal to-1.56±1.75 diopters,0.12±0.09 logMAR and 50.62±33.35 seconds of arc,respectively.The mean of contrast sensitivity measured at spatial frequencies of 1.5,3,6,12,and 18 cycles per degree in photopic condition was equal to 2.38±0.04,2.37±0.07,2.04±0.21,1.27±0.32,0.82±0.27 logarithm of contrast sensitivity,respectively and in mesopic lighting condition was equal to 2.34±0.12,2.30±0.16,1.84±0.28,1.02±0.28,0.63±0.24 logarithm of contrast sensitivity,respectively.Statistical analysis showed a significant difference between the two lighting conditions in all evaluated variables[refractive error(P<0.001),visual acuity(P<0.001),stereopsis(P=0.008)and contrast sensitivity(P<0.001)].CONCLUSION:The refractive error of the student subjects in mesopic light condition change towards myopia,and its amount is clinically significant.Also,the examination and comparison of the factors of visual acuity,stereopsis and contrast sensitivity in these two lighting conditions show that the decrease in brightness level to the mesopic level causes a decrease in the aforementioned visual functions.

Dynamic Visible Light Positioning Based on Enhanced Visual Target Tracking

In visible light positioning systems,some scholars have proposed target tracking algorithms to balance the relationship among positioning accuracy,real-time performance,and robustness.However,there are still two problems:(1)When the captured LED disappears and the uncertain LED reappears,existing tracking algorithms may recognize the landmark in error;(2)The receiver is not always able to achieve positioning under various moving statuses.In this paper,we propose an enhanced visual target tracking algorithm to solve the above problems.First,we design the lightweight recognition/demodulation mechanism,which combines Kalman filtering with simple image preprocessing to quickly track and accurately demodulate the landmark.Then,we use the Gaussian mixture model and the LED color feature to enable the system to achieve positioning,when the receiver is under various moving statuses.Experimental results show that our system can achieve high-precision dynamic positioning and improve the system’s comprehensive performance.

汉明码信息隐藏实验仿真系统设计

现有信息隐藏仿真实验过程抽象、可视化效果差,难以满足实验教学需求。针对这类问题,采用QT5和Python设计开发汉明码信息隐藏实验仿真系统。系统实现3种汉明码信息隐藏算法,展示汉明码信息隐藏结果,将汉明码信息隐藏算法具体过程可视化,引入性能分析方法对各类汉明码信息隐藏算法进行性能评测。实验教学结果表明,该系统界面设计简单明了、易理解,化抽象为具体,有助于提高学生学习兴趣,辅助教师的课程讲解。

地铁车站照度对乘客主观情绪和视觉绩效认知的影响研究

[目的]合理的照明环境对提高地铁车站服务水平、保证乘客疏散安全、促进公共交通可持续发展起着重要作用。为促进地铁车站照明环境设计的科学化和合理化,需研究地铁车站不同照度环境对乘客主观情绪和视觉绩效认知的影响。[方法]采用眼动追踪技术、视觉绩效认知评估技术、三维情绪评估模型相结合的方法,提出了眼动试验评估、视觉绩效认知评估、主观情绪评估3个评估类别共计8个参数的计算方法。设置了试验流程,将照度作为自变量,选取了5个照度水平进行试验研究。构建了不同照度同乘客主观情绪、视觉绩效认知参数之间的关系模型,并对试验结果分别进行了单因素方差分析、相关度分析及综合分析。[结果及结论]照度对乘客主观PAD(愉悦度、唤醒度、控制度)、视觉绩效认知均有显著影响。提高乘客的愉悦度和唤醒度,能够缩短乘客的视觉认知时间。照度在200~230 lx时,乘客的主观情绪、视觉绩效认知水平均达到最优。

视程障碍现象仪在低温天气条件下的业务性能测试评估

文章利用在锡林浩特国家综合气象观测试验基地安装的3种不同型号的视程障碍现象仪观测的PM 10和PM 2.5数据,在满足资料完整性的基本条件下,分析各仪器在低温天气条件下的可靠性及适应性,并对同一型号两台设备进行数据一致性分析评估,检验视程障碍仪在低温环境下的应用效果。经过试验测试,各型号设备在低温环境下的可靠性较高、运行稳定,适应性较强;通过对3种型号6台设备进行绝对偏差分析,得出设备在低温环境下均通过一致性评估。研究结果为视程障碍现象仪业务化应用提供了重要参考依据。

基于齿廓曲线的外啮合齿轮泵排量计算

渐开线外啮合齿轮泵以结构简单、造价低廉等优点而在矿山、工程等领域应用广泛,但目前关于精准计算其瞬时流量、排量的文献较少。为此,基于齿轮啮合机制、轮齿齿廓性质以及转角和啮合点的关系,建立齿轮泵瞬时输出流量的数学及仿真模型。针对齿轮泵重合度、齿轮变位、卸荷槽、侧隙等影响因素对模型进行论证,进而提出一种精准计算渐开线外啮合齿轮泵排量的方法,并采用Simulink仿真软件对不同类型外啮合齿轮泵的瞬时流量进行仿真模拟。同时利用3种不同型号齿轮泵验证排量公式,其最大误差在5%以内。验证计算模型有效性后,基于MATLAB设计了齿轮泵计算辅助平台,实现了外啮合齿轮泵瞬时流量、排量性能可视化,以简化计算流程,适应工程化应用。

基于光环境影响的皮影戏表演效果评价研究

皮影戏表演画面效果评价对于演出装置的改良及表演效果的提升具有重要意义,至今未有学者进行研究。本研究在16种照明环境下对32名受试者进行心理物理实验,对色彩鲜艳度、细节清晰度、表现力与吸引力三种视觉属性进行主观评价获得相应评分,分析照明指标参数与主观视觉评价之间的相关性。初步研究表明,3500 K为最佳色温,白炽灯光源中100 W功率最佳,LED光源2800~4500 K色温下照度达到200 lx时主观评价最高,5300 K以上的LED光源需要搭配更高的照度,照度与GAI_BB_8的线性组合可以实现对皮影戏表演画面呈现效果的有效评价。研究成果初步确定了不同光环境下皮影戏演出的最佳照明条件,为皮影戏表演画面效果的量化评价及演出装置的改良提供了参考。

一种结合光流追踪的双目视觉里程计算法

针对特征点法视觉里程计频繁计算和匹配描述子导致系统实时性能变差的问题,提出一种结合光流追踪的双目视觉里程计算法;首先进行初始化,生成初始的关键帧和地图点,随后在追踪线程中使用光流追踪特征点获取匹配关系,计算并优化相机位姿;满足生成关键帧的条件后,将当前帧设置为关键帧,提取图像的ORB特征点,并使用描述子匹配获取与上一关键帧特征点的匹配关系,三角化生成新的地图点;最后在优化线程中将新的关键帧和地图点使用滑动窗口算法进行优化,剔除冗余关键帧和地图点;在KITTI数据集上的实验结果表明,所提出的算法轨迹误差与双目模式下的ORB-SLAM3算法处于同一水平,同时实时性能有大幅度提高,追踪每一帧图像的平均时间从52 ms降至16 ms,在保证高精度的情况下运行速度大大提高,具有较高的实用价值。

基于无人系统的智能视觉控制算法研究

无人系统应用范围的急剧扩大,使得视觉感知环境愈加复杂多变,致使传统视觉控制算法难以有效控制视觉传感器获取精准的视觉感知图像,从而影响无人系统的稳定运行,故提出基于无人系统的智能视觉控制算法研究。应用Gamma曲线非线性变换无人系统视觉感知图像灰度值,再应用灰度世界法来增强图像的对比度。以处理后的图像为基础,计算其图像矩,即空间矩、中心矩和归一化中心矩,以描述图像的全局和局部特性。根据得到的无人系统视觉感知信息,搭建智能视觉控制框架。获取期望图像特征矩阵,提取当前时刻图像特征矩阵,通过基于改进萤火虫算法的极限学习机对摄像机转角进行非线性映射,从而获取智能视觉控制定律,以此消除视觉感知图像误差,实现智能视觉的有效控制。实验结果显示:在不同实验组别背景下,应用提出算法获得的视觉控制平均时间最小值达到了1 s,视觉控制平均误差最小值达到了0.12%,充分证实了提出算法的应用性能更佳。