Mathematical modeling of retinal birefringence scanning.

Retinal birefringence scanning (RBS) is a new technique that is used to detect the fixation of the eye remotely and noninvasively. The method is based on analysis of polarization changes induced by the retina. In this study, the principles of RBS were mathematically modeled to facilitate a better understanding of the origins of the signals obtained. Stokes vector analysis and Mueller matrix multiplication were augmented with Poincaré sphere representation. The cornea was modeled as a linear retarder. The foveal area was modeled as a radially symmetric birefringent medium. The model accurately predicted the frequency and phase of RBS signals obtained during central and paracentral fixation. The signal that indicates central fixation during RBS likely results from a combination of the radial birefringence of the Henle fibers and the overlying corneal birefringence.     

Automated detection of foveal fixation by use of retinal birefringence scanning

Foveal fixation was monitored in normal subjects remotely and continuously by use of a noninvasive retinal scan. Polarized infrared light was imaged onto the retina and scanned in a 3 degrees annulus at 44 Hz. Reflections were analyzed by differential polarization detection. In all 32 eyes studied, the detected signal was predominantly 88 Hz during central fixation (within +/-1 degree) and 44 Hz during paracentral fixation. Phase shift at 44 Hz correlated with the direction of eye displacement. Potential applications of this technique include screening for eye disease, eye position monitoring during clinical procedures, and use of eye fixation to operate devices.     

Study of eccentric fixation with secondary visual feedback.

Secondary visual feedback (2VFB) is a visual signal derived from continuous measurement of eye position and provides an extra artificial indication of the point of gaze. 2VFB may be eccentrically displaced and subjects are able to visually superimpose 2VFB onto a visual target signal and thus achieve and maintain eccentric fixation. Initial transient patterns of movement depend upon training but even naive subjects can achieve eccentric fixation within the first 40 s of such a task. Individual strategies and idiosyncratic patterns are exaggerations of normal control and fixational eye movements. The variance of maintained fixation increases with eccentricity and appears to be related to visual acuity as well as to precision of ocular motor control.     

食品包装材质对消费者绿色购买意愿影响的眼动研究

目的 探讨食品包装材质对消费者注意加工流程和绿色购买意愿影响的内在机制。方法 采用包装材质2(环保/普通)×食品类型2(实用品/享乐品)双因素实验设计,在货架购物场景下采用Tobii Glasses 2眼镜式眼动仪,采集被试者浏览货架不同食品时的眼动数据(平均注视时间、注视次数、热点图),并结合行为数据综合分析。结果 在平均注视时间上,包装材质与食品类型的交互作用显著,注视次数交互作用不显著;环保材质包装的食品获得更多关注,被试者偏好于选择环保包装的享乐食品。结论 包装材质与食品类型共同影响消费者的视觉感知效果与加工过程,环保包装对青年消费者的绿色购买意愿有正向促进作用。     

Accurate determination of quantity of material in thin films by Rutherford backscattering spectrometry

Ion beam analysis (IBA) is a cluster of techniques including Rutherford and non-Rutherford backscattering spectrometry and particle-induced X-ray emission (PIXE). Recently, the ability to treat multiple IBA techniques (including PIXE) self-consistently has been demonstrated. The utility of IBA for accurately depth profiling thin films is critically reviewed. As an important example of IBA, three laboratories have independently measured a silicon sample implanted with a fluence of nominally 5 × 10(15) As/cm(2) at an unprecedented absolute accuracy. Using 1.5 MeV (4)He(+) Rutherford backscattering spectrometry (RBS), each lab has demonstrated a combined standard uncertainty around 1% (coverage factor k = 1) traceable to an Sb-implanted certified reference material through the silicon electronic stopping power. The uncertainty budget shows that this accuracy is dominated by the knowledge of the electronic stopping, but that special care must also be taken to accurately determine the electronic gain of the detection system and other parameters. This RBS method is quite general and can be used routinely to accurately validate ion implanter charge collection systems, to certify SIMS standards, and for other applications. The generality of application of such methods in IBA is emphasized: if RBS and PIXE data are analysed self-consistently then the resulting depth profile inherits the accuracy and depth resolution of RBS and the sensitivity and elemental discrimination of PIXE.     

Cycloplegic refraction and non-cycloplegic refraction using contralateral fogging: a comparative study

The purpose of this study is to compare the retinoscopy values obtained from cycloplegic refraction and non-cycloplegic refraction done with contralateral fogging procedure on children. Performing retinoscopy on children is a challenge because of two significant problems encountered during the procedure, which include maintaining fixation and control of accommodation. Although cycloplegic refraction is a gold standard in order to relax the accommodation completely, it has its own limitations. Whereas when assessing refractive error using static retinoscopy, it is conventional to fog the contralateral eye with a high amount of plus lens, to prevent a blur-driven accommodative response from stimulating consensual accommodation in the examined eye. The study was performed on 31 healthy, non-strabismic subjects of 7 to 16 years of age. Initially the refractive status of the eye was assessed objectively by non-cycloplegic refraction, done by fogging the contralateral eye with +6.00?D, in a dimly illuminated room. Then 2 drops of cyclopentolate 1% were instilled separated by 5?min, in the tested eye. Retinoscopy was performed 25 to 30?min after the first drop was instilled. A statistically significant mean difference exists between the findings obtained (p?<?0.05) in the spherical equivalent retinoscopy values (mean of 0.2944?D higher) with cycloplegic refraction when compared to non-cycloplegic refraction done with contralateral fogging. Non-cycloplegic refraction done with contralateral fogging technique as effective as the gold standard cycloplegic refraction technique for the measurement of refractive error in healthy, non-strabismic children.     

An Adaptive Algorithm for Eye-Gaze-Tracking-Device Calibration

Eye-gaze tracking has been an important and interesting area of research for quite some time now. In laboratory experiments for psychological research, eye-gaze tracking constitutes a helpful tool to probe the perceptual or the cognitive processes of the subjects. In day-to-day applications, eye-gaze tracking can be used as a computer interface for both industrial and nonindustrial applications, which require hands-free installations. It can also be used to help disabled people to use computers for communication and for environmental control. This paper aims to develop a computer system to facilitate the study of visual scanning and eye fixation during image exploration. The system uses an infrared device to detect horizontal and vertical eye movements. This paper mainly focuses its attention on the calibration procedure that can be effectively utilized for correction of the nonlinearities in the oculomotor for the eyes of each individual subject. An adaptive calibration algorithm has been developed by employing a polynomial model. Several experiments have been carried out to demonstrate that the proposed approach is a rapid one and is accurate for the study of visual perception and recognition processes.     

游艇关键造型特征的眼动追踪研究

目的 为建立眼动数据和感性意象评价之间的数学关系,提出一种基于眼动参数的造型评价方法。方法 以游艇为研究对象,通过SMIRED500型眼动仪设备的应用,结合语义差分法进行主观评价,通过眼动追踪记录受试者在观看不同造型风格游艇时的眼动数据,对采集的眼动数据进行单因素方差分析,保留瞳孔直径大小、总注视时间、眼跳到该区域次数及首视点持续时间四项有效眼动数据,并结合主观问卷探讨不同游艇的视觉认知规律,采用多元线性回归方程进行数据建模,明确各项眼动数据对感性评价的影响权重,研究了被视者的眼动追踪数据与主观评价之间的关联关系。结论 建立眼动数据与感性评价之间的数学关系模型,并验证了模型的有效性,对产品造型方案评选及产品设计方案改进提供了有力的支持。     

老龄服务机器人色彩设计的视觉认知绩效研究

目的 在智能养老广泛应用的背景下,探索服务机器人设计色彩对老年人视觉认知绩效的影响。方法 选取24名老年被试者进行眼动实验,获取被试者观察8组实验图片时的眼动指标。首先,对总注视次数和第一次注视时间这两项眼动数据进行客观分析,采用单因素方差分析方法来验证数据的显著性;其次,对老年被试者与青年被试者数据进行t检验分析,研究不同年龄段用户对服务机器人色彩设计的视觉认知绩效是否存在差异;最后,利用相关性分析方法验证色弱是否会影响老年人的视觉认知绩效。结论 老年人对黑色比较敏感,对白色极容易忽略,冷暖色之间不存在显著差异;不同年龄段用户对颜色关注度存在差异;色弱会略微影响老年人的视觉认知绩效,但不会影响老年人对色彩的选择。     

基于眼动模式的木质民居个性化定制构件配置方法研究

木质民居是苗侗族传统建筑文化,个性化定制乃是当今木质民居建筑设计的潮流。为快速配置木质民居个性化定制构件,使得其造型意象真正满足消费者隐性需求,提出一种基于眼动模式的个性化定制构件配置方法。首先,研究了木质民居的组成和人们对构件配置的认知。其次,依据蚁群优化算法思想,建立木质民居个性化定制构件配置过程图解模型;将木质民居个性化定制构件库系统中的构件区域划分为兴趣区域（area of interest,AOI）和注视区域（area of fixation,AOF）;以眼动模式中热点图数据为基础,建立眼动数据可视化模型,并以围栏为例,提取注视区域（AOF）的灰度直方图、注视点数目、注视时间及平均注视时间等。再次,计算木质民居个性化定制构件系统中兴趣区域内设计特征的选择概率,以此构建定制构件的适应度函数,寻求配置方案的最优解。最后,以木质民居个性化定制项目为例,论述该方法的配置过程;结合七等级Likert量表实验对眼动实验结果进行对比验证。T检验结果验证了该个性化定制构件配置方法的可行性,能在符合用户隐性需求的基础上进行高效配置,为产品个性化定制模块配置提供一种新的技术方法。     

Influence of ion energy on damage induced by Au-ion implantation in silicon carbide single crystals

This article reports on the influence of the ion energy on the damage induced by Au-ion implantation in silicon carbide single crystals. 6H-SiC samples were implanted with Au ions at room temperature at two different energies: 4 and 20 MeV. Both Rutherford Backscattering spectrometry in channelling geometry (RBS/C) and Raman spectroscopy were used to probe the ion implantation-induced damage. Results show that the accumulated damage increases with the fluence up to the amorphization state. RBS/C data indicate that 4-MeV implantation induces more damage than 20-MeV implantation at a given fluence. This effect is attributed to nuclear collisions since the amount of damage is identical at 4 or 20 MeV when the fluence is rescaled in dpa. Surprisingly, Raman data detect more damage for 20-MeV implantation than for 4-MeV implantation at low fluence (below 10¹³ cm⁻²) where point defects are likely formed.     

Reliability-guided Rayleigh backscattering spectrum correlation method for distributed strain measurements in optical fibres

We present a method of reliability-guided Rayleigh backscattering correlation for distributed strain measurements in optical fibres. In this method, a reference Rayleigh-backscattering-spectrum (RBS) range that is larger than the measurement RBS range is defined to extend the matching range. To obtain the best match between reference and measurement spectra, the zero-mean normalized cross correlation (ZNCC) is employed to evaluate the degree of similarity. The path for searching the maximum similarity matching pattern is guided using Newton’s iteration method. The reliability of the computed RBS shift is identified by the ZNCC coefficient distribution. The experiments show that the proposed method has high reliability in computing the RBS shift. Even at a relatively large strain (e.g. 5000?µ?), the proposed method can stably demodulate the strain within a relative error of ?1% and a spatial resolution of 1.6?cm over a 22-meter-long single-mode fibre. This shows that the proposed method has an advantage in regard to relatively large strain measurements.     

On the validity of the reduced bending stiffness method for laminated composite plate analysis

The ‘reduced bending stiffness’ (RBS) method has been used on occasions in the past as a means of simplifying the analysis of the flexural behavior of unsymmetrically laminated composite plates. However, the validity of the method has never been established. This paper makes direct comparisons between relatively simple, exact solutions for the static deflections, buckling loads and vibration frequencies of simply-supported plates and those arising from the RBS method. Extensive calculations are made for wide ranges of the physical parameters involved (aspect ratio, moduli ratio, lamination orientation angle, numbers of plies). The RBS method is found to yield sufficient accuracy for cross-ply plates, but errors up to 29% are obtained for angle-ply plates constructed with materials currently under development.     

基于眼动仪的智能冰箱人机界面评估方法研究

目的通过眼动测试实验对智能冰箱人机界面进行无意识认知评估和可用性评估,提出优化解决方案。方法采用眼动跟踪技术测试,以3款智能冰箱人机界面为例,对智能冰箱人机界面进行无意识认知评估指标(首次注视时间)和可用性评估指标(进入次数、注视点、注视时间)分析,并结合用户体验(问卷调查、用户访谈)所得出的调查实验结果,对智能冰箱人机界面进行再设计改良。结论将无意识认知评估、可用性评估以及用户体验相结合的评估方法适用于智能冰箱人机界面,设计出优良的智能冰箱人机界面,能够完善产品用户体验,同时为其他人机界面设计提供新的思路。     

Effects on driving performance of visual field defects: a driving simulator study

To elucidate the possible traffic safety risks induced by visual field defects, a method was developed based on a driving simulator. The capacity to detect stimuli of different sizes appearing in 24 different positions on the screen in front of the driver was measured. Two groups of normal subjects and a number of subjects with different visual field defects were studied. In the groups of normals, the median reaction times were fairly homogenous. There was a slight difference between central and peripheral stimuli, which was somewhat larger for the older subjects. Among the subjects with field defects, the individual variations were very dominant. Very few of these showed a capacity to compensate for their deficiency. In order to gain insight into possible compensatory mechanisms of these persons, eye movement recordings were made. The results indicate that the visual search pattern may be of importance in this respect. Some comparisons with respect to detection capacity were also made with one-eyed subjects and with optically generated field restrictions (spectacles and spectacle frames).     

基于眼动追踪的汽车造型特征线设计方法研究

目的 在汽车造型设计开发之前,有效预测汽车造型特征线产生的意象是否真正符合用户隐性意图,便于提高汽车行业情感意象设计水平。方法 首先,获取用户群体需求信息,引导设计方向;其次,建立汽车造型意象认知模型,通过案例分析,构建“标杆车”造型特征线目标意象集;再次,依据眼动实验,提出基于眼动指标（注视点数目、注视时间、平均注视时间）的汽车造型特征线提取模型,进行汽车造型特征线显著性分析与特征线提取;最后,采用形状文法坐标变换规则,结合贝赛尔曲线描述,通过类比形式进行规则映射分析,使用矢量工具Adobe Illustrator 改变特征曲线各锚点与控制点坐标值,实现汽车造型特征的继承与变异。结果 以阿尔特SUV概念研发项目为例,论述该设计方法,通过奔跑的狮子形态进行意象类比,得出最终设计方案。结论 对最终设计方案进行用户喜好度意象评估,用户喜好度为87.65%,证实了该汽车造型意象设计方法的可行性,为汽车行业满足用户群体偏好特征意象,提供了一种新的设计方法。     

Characterization of surface profiles of LPCVD silicon nitride films by RBS profile

Abstract

A Rutherford backscattering spectrometry (RBS)‐profile was applied to the characterization of the surface profile of silicon nitride films prepared by low pressure chemical vapor deposition (LPCVD). This method detected inhomogeneity in the silicon nitride films and demonstrated Si‐richness near the interface. This method was also used to study the silicon nitride profiles associated with bird's beak formation in VLSI devices. This paper presents a scheme for an auto‐search routine for an RBS‐profile program. The potential of the RBS‐profile method for the characterization of LPCVD silicon nitride films are demonstrated.     

钢框架梁翼缘削弱型节点力学性能的试验研究

梁翼缘削弱的梁柱刚性连接是将塑性铰外移的一种典型节点形式。为研究这种连接形式在循环荷载作用下的滞回性能,共进行了6个模型的拟静力加载试验,其中5个模型用于研究梁翼缘的削弱深度、削弱长度、削弱起始位置对节点连接的破坏形态、极限荷载、最大塑性转角、延性性能的影响。作为比较,还进行了一个传统型梁柱全焊接刚性模型连接的试验。试验结果表明:梁翼缘削弱节点比传统梁柱刚性连接具有良好的塑性变形能力和耗能性能,试验中5个节点的塑性转角都大于0.04rad,延性系数大于4.0,达到了抗弯钢框架连接塑性转角不小于0.03rad,延性系数不小于4.0的要求。而普通梁柱全焊接刚性连接的塑性转角仅达到0.026rad,延性系数仅为2.4。5个试件的破坏主要以翼缘削弱处平面外刚度较弱而导致梁发生扭转失稳或梁下翼缘与柱连接的对接焊缝的脆性断裂为主。研究结果表明:将梁翼缘进行适当的削弱后形成的骨型节点可以增加梁柱节点的耗能性能,是一种较为理想的延性节点。     

Monochromatic aberrations of human eyes in the horizontal visual field

We measured the monochromatic aberrations of five subjects' right eyes both temporally and nasally out to 40 degrees from fixation. We used a Hartmann-Shack sensor with modifications to equipment and software to enable off-axis measurements. Results were standardized for 6-mm pupils. There was considerable variation among subjects in the pattern of aberrations. Aberrations were generally greater in the nasal visual field than in the temporal visual field; in the case of third-order aberrations, this was true for all subjects. The contribution of third-order Zernike aberrations to the root-mean-square aberration increased up to four times from the center to the edge of the field, but the contribution of fourth- to sixth-order Zernike aberrations varied little across the visual field. Results were similar to those of a previous investigation using laser ray tracing and were of the order of those predicted by Navarro's finite schematic eye.     

The Effect of Modifying Structure to Display Product Versus Graphical Representation on Packaging

Research is presented that investigates whether the amount of physical product visible from the primary display panel of a package has an effect on consumer attention and purchase decision in the category of grill ware. It is hypothesized that a package providing the most physical product exposure will be preferred by consumers over alternative structural designs. To test this, three similar products were placed in four distinct package structures varying the amount of visible product exposure (0%, 40%, 90% and 100%). The packages were positioned on the shelves of the fully immersive simulated shopping environment CUshop?. A total of 127 participants were fitted with eye‐tracking glasses and presented a shopping list that included one of the three grill ware products (fork, spatula and tongs). Participants were asked to shop as they normally would, and data concerning their visual attention in the store and final purchase selection was collected. Purchase patterns showed that the packaging that revealed the most physical product possible was chosen more than the other three configurations tested. Analysis of eye‐tracking data supports expected behaviour, suggesting that consumers prefer to see at least some of the product, with the 0% visible product receiving significantly fewer fixations, a slower time to first fixation and lower total fixation durations. Copyright © 2012 John Wiley & Sons, Ltd.