基于可供性的文化意象交互式智能音箱设计研究

目的 探索将文化民俗有效融入现代产品中的技术思路，保留并延续中华传统文化的生命力，有助于提升用户体验。方法 分析可供性与文化意象之间的主客观互通性;挖掘交互式智能音箱中的可供性触点;构建形态、感官、认知及情境四类可供性的设计框架;以楚文化意象为例进行设计实践，对智能音箱的产品造型与交互操作方式进行设计，并进行设计评价。结果 在可供性理论指导下的楚文化意象交互式智能音箱产品外观及交互体验设计较好地满足了设计目标和用户需求。结论 可供性有助于文化意象的正确提取与转化，可将意象抽象为具有实际意义的设计要素，帮助用户在生理与认知两个层面理解产品的使用方法，同时进一步回味、体验文化内涵和文化精髓。     

优化特征提取的互动式人脸活体检测研究

针对人脸识别系统中出现的通过照片或视频“欺诈”解锁问题，提出一种活体检测方法，通过随机指令判断被检测对象是否为真人。利用HOG特征和随机森林算法对摄像头采集的图像进行人脸检测，预测脸部68个特征点位置，把68个特征点位置和脸部位置的相对位置归一化后作为姿态的特征，提取的姿态特征与SVM分类器相结合，训练出分类效果较好的头部姿态估计分类器。通过多次实验，对特征提取方法进行优化，进一步提高检测准确率。最后，使用随机互动式命令序列对被检测人发出指令，实现活体检测。该方法对头部姿态估计具有较高的鲁棒性，并且可以有效地防范照片和视频认证攻击。     

Expert system for problem solving in distance university education: The successful case of the subject “operations management”

Acquiring the skills needed to solve certain types of problems is one of the main challenges of distance university education, demanding extra motivation from students to tackle it. New technology should be one of our great allies in addressing these problems. This article proposes an expert system with a web‐based problem‐solving simulator for a multidevice environment in order to allow students to access an unlimited number of problems with their corresponding solutions, immediately, anytime and anywhere. The types of problems that can be used are those based on quantitative methods with a fixed methodology to be followed. A successful case study was carried out for the subject Operations Management at the Distance University of Madrid (UDIMA), with three different problem simulators having been developed. The results were very satisfactory compared with previous academic years in terms of motivation. A decrease in students that did not sit the final examination was observed, as was an increase in the number of visits to the Moodle classroom. Students also responded positively in their assessments of the initiative.     

Surface energy and separation mechanics of droplet interface phospholipid bilayers

Droplet interface bilayers are a convenient model system to study the physio-chemical properties of phospholipid bilayers, the major component of the cell membrane. The mechanical response of these bilayers to various external mechanical stimuli is an active area of research because of its implications for cellular viability and the development of artificial cells. In this article, we characterize the separation mechanics of droplet interface bilayers under step strain using a combination of experiments and numerical modelling. Initially, we show that the bilayer surface energy can be obtained using principles of energy conservation. Subsequently, we subject the system to a step strain by separating the drops in a step-wise manner, and track the evolution of the bilayer contact angle and radius. The relaxation time of the bilayer contact angle and radius along with the decay magnitude of the bilayer radius were observed to increase with each separation step. By analysing the forces acting on the bilayer and the rate of separation, we show that the bilayer separates primarily through the peeling process with the dominant resistance to separation coming from viscous dissipation associated with corner flows. Finally, we explain the intrinsic features of the observed bilayer separation by means of a mathematical model comprising the Young–Laplace equation and an evolution equation. We believe that the reported experimental and numerical results extend the scientific understanding of lipid bilayer mechanics, and that the developed experimental and numerical tools offer a convenient platform to study the mechanics of other types of bilayers.     

基于内隐测量的APP交互流程可用性评估方法

目的 研究内隐测量用于交互流程评估的普遍方法，选取适合的参考指标建立评估标准，旨在提出一套完整且通用的评估策略。方法 以带有拍摄功能的宠物社交类APP为载体，提出两种不同的交互流程，建立交互原型，并提取两套原型中差异较大的流程进行对比实验，采用眼动仪收集被测的无意识行为，依据首次注视时间、兴趣区域注视率，注视点图等指标分析实验数据，并与外显测量结果相结合，衡量用户操作情况以及APP的交互性能。结果 根据实验和数据分析，得出以拍摄界面为主页是更适合宠物社交APP的交互方式。结论 内隐测量评估作为一种新兴的产品可用性评估方式，不仅在交互界面设计评估上得到了广泛的应用，还可作为产品交互流程的评估方法，并具有深度挖掘的意义。     

Morphological and optical properties of PdxAg1-x alloy nanoparticles

Alloy nanoparticles (NPs) can offer a wide range of opportunities for various applications due to their composition and structure dependent properties such as multifunctionality, electronic heterogeneity, site-specific response, and multiple plasmon resonance bands. In this work, the fabrication of self-assembled Pd_xAg_1-x NPs alloy nanostructures with distinct size, density, shape, and composition is demonstrated via the solid-state dewetting of sputtered Pd/Ag thin films on c-plane sapphire. The initial stage of bilayer dewetting exhibits the nucleation of voids, followed by the expansion of voids and cluster breakdown and finally shape transformation along with the temperature control. Bilayer composition shows a substantial influence on the dewetting such that the overall dewetting is enhanced along with the increased Ag composition, i.e. Pd_0.25Ag_0.75 > Pd_0.5Ag_0.5 > Pd_0.75Ag_0.25. On the other hand, the size and density of NPs can be efficiently controlled by varying the initial thickness of bilayers. Reflectance peaks in UV and near-infrared (NIR) regions and a wide absorption band in the visible region arisen from the surface plasmon resonance are observed in reflectance spectra. The peak intensity depends on the composition of Pd_xAg_1-x NPs and the NIR peaks gradually blue-shift with the size decrement.     

数字花卉植物的全息可视化与交互实现

花卉植物形态、结构与生长过程的数字化和可视化是现代林业科研的重要研究内 容，数字花卉植物在科普、教育、展示等方面都有着广泛的应用与需求。全息影像技术是一种 新兴的前沿技术，其原理源自佩珀尔幻象，通常用于生成立体感强的影像，实现数字幻象与真 实世界的融合，拥有良好的观赏性，用户接受度较高。将全息影像技术与数字花卉植物相关研 究进行结合，可以加强数字花卉植物的可视化效果，从而实现更好的科普、教育、展示效果。 因此在现有的研究基础之上，考虑实现数字花卉植物的全息可视化，并在可视基础上增加了用 户交互实现，设计出一套兼具展示性和交互性的流程，力求总结出一种具有完整可行性的方案， 从而对数字花卉植物的新型表现形式进行深入研究，以期对数字植物研究与应用的进一步发展 提供参考。     

丝素基双层敷料的制备及其性能

针对丝素蛋白(SF)吸水性差、力学性能不足等问题,以丝素蛋白为基材,亲水性葡萄糖(Glu)和塑化剂甘油(Gly)为辅料,通过冷冻干燥法制备得到SF/Glu海绵,然后通过蒸发溶剂法制备聚氨酯(PU)薄膜。通过医用热熔胶黏合SF/Glu海绵与PU薄膜获得丝素基双层敷料,并对双层敷料的结构和性能进行分析。结果表明:在Gly质量分数为0.5%,PU质量分数为8%,Glu质量分数为10%条件下制备的双层敷料,其吸水率高达自身质量的12.5倍,溶失率低于2%,保水时间延长至11 h;Glu和SF的相容性较好,Glu可使SF维持较稳定的β-折叠结构;制备的双层敷料无细胞毒性,且具有阻菌功能。     

Influence of the weight ratio of polydimethylsiloxane modified gelatin to silicone rubber on the potential performance of asymmetric bilayer membranes as wound dressings

Asymmetric bilayer membranes have been regarded as ideal wound dressings for skin regeneration. Our previous work reported the potential advantages of polydimethylsiloxane modified gelatin/silicone rubber (PGE/SR) asymmetric bilayer membrane as a wound dressing. However, it is still unknown whether the proportion of the two components of the bilayer membrane has a prominent influence on its relevant performance. Herein, various PGE/SR membranes with different PGE:SR weight ratios (100:25, 100:50 and 100:100) were fabricated through a self‐stratification method driven by surface tension gradients. Subsequently, the effects of the PGE:SR ratios on the relevant performance (i.e. porous structure, mechanical properties, degradability and biocompatibility) of PGE/SR membranes were systematically investigated. The current results demonstrate that the separating force between the PGE and SR components was reduced significantly on increasing the content of SR, and in particular the PGE/SR1 membrane (100:25) exhibited a well‐defined asymmetric bilayer structure with high porosity, appropriate toughness, water uptake, swelling ratio and water permeability. Concomitantly, the maximum weight loss for the PGE/SR1 membrane was ca 70.65% after 9 days of enzymatic degradation, which met the typical healing period of a normal skin wound. In addition, both the original and degraded PGE/SR1 membrane possessed favorable cytocompatibility in vitro, suggesting its potential application as a wound dressing. © 2019 Society of Chemical Industry