Users' psychological perception and perceived readability of wearable devices for elderly people

As the population of elderly people in society rises, the importance of technology to assist health management is growing with the demographic shift. Wearable personal computing has been the common solution proposed by related projects to fulfil the needs of elderly people. These add-on devices are attached to the users, and result in uneasiness or discomfort while wearing them in public areas. In this study, three common wearing positions – wrist, upper arm, and neck – were investigated in terms of psychological perception and perceived readability. Twenty-four Taiwanese participants in Miaoli area were asked to wear the designed prototypes for a certain time. The participants completed questionnaires and participated in an open-ended interview. Data of psychological perceptions, visibility, and readability about wearable devices were collected. The results evidenced that the personal attributes of gender, smart device user, and requirement for medical care affect the psychological perception and user attitudes. The statistical results indicated significant differences in elderly people's attitudes towards wearable devices attached to different parts of the body. The wrist was the most favourable location to attach a wearable device.     

基于K均值聚类和粒子群优化的多核SVM图像分割

图像分割是图像理解和计算机视觉的重要内容.针对单核SVM在进行图像分割过程中不能兼顾分割精度高和泛化性能好的问题,提出一种基于K均值聚类和优化多核SVM的图像分割算法.该算法首先运用K均值聚类算法自动选取训练样本,然后提取其颜色特征和纹理特征作为训练样本的特征属性,并使用其对构造的多核SVM分割模型进行训练,最后用粒子群优化算法对多核核参数、惩罚因子以及核权重系数联合寻优,使生成的多核SVM具有更好的分割性能.实验结果表明,本文方法在有效提取图像目标细节的同时,获得了更高的分割精度,与基于单核的SVM分割模型相比,具有更强的泛化能力.     

自底向上构建高效BVH的研究

光线追踪中,加速结构对于减少光线与几何体求交的计算量起到了不可或缺的作用,找到一种高效的加速结构仍然是本领域的研究热点之一.传统的加速结构如BVH,都是自顶向下的构建方式,由于其本身的限制,构造出的加速结构往往不是最优的.为了改进自顶向下的缺陷,提出了一种自底向上BVH的构建方式,它使用了BVH和空间划分的混合结构,并引入了一种改进的表面积启发代价函数和多个构建参数来优化最后的构建结果.最后实验表明,此文中提出的方式比传统的BVH与KD-Trees有更好的加速效果,可以实现对前两者5%-10%的提速.最后,文中还给出了一些加速方案来减少构建时间.     

RBC-CC: RBC-Based Cascade Caching Scheme for Content-Centric Networking

With the increasing demand of content dissemination, Content-Centric Networking (CCN) has been proposed as a promising architecture for future Internet. In response to the challenges in CCN caching, we develop an online caching scheme (named RBC-CC) exploiting the concept of Routing Betweenness Centrality (RBC) and “prefetching”, aiming at significantly reducing costly inter-ISP traffic and largely reducing content access hops. Simulation results demonstrate that the proposed caching scheme can significantly outperform the popular caching approaches in terms of the saving rate of inter-ISP traffic. Besides, RBC-CC performs well in reducing the average access hops and incurs the least cache evictions. Further, we present a thorough analysis regarding the impact of access pattern, cache size, content popularity and population on the caching performance. We then come to the conclusion that our scheme is featured with good stability and scalability as well as its effectiveness.     

Visual topic discovering,tracking and summarization from social media streams

Multimedia Tools and Applications - Nowadays, microblogging has become popular, with hundreds of millions of short messages being posted and shared every minute on a variety of topics in social...     

<Emphasis Type="Italic">υ</Emphasis>-Support vector machine based on discriminant sparse neighborhood preserving embedding

In this paper, we mainly focus on two issues (1) SVM is very sensitive to noise. (2) The solution of SVM does not take into consideration of the intrinsic structure and the discriminant information of the data. To address these two problems, we first propose an integration model to integrate both the local manifold structure and the local discriminant information into ?₁ graph embedding. Then we add the integration model into the objection function of υ-support vector machine. Therefore, a discriminant sparse neighborhood preserving embedding υ-support vector machine (υ-DSNPESVM) method is proposed. The theoretical analysis demonstrates that υ-DSNPESVM is a reasonable maximum margin classifier and can obtain a very lower generalization error upper bound by minimizing the integration model and the upper bound of margin error. Moreover, in the nonlinear case, we construct the kernel sparse representation-based ?₁ graph for υ-DSNPESVM, which is more conducive to improve the classification accuracy than ?₁ graph constructed in the original space. Experimental results on real datasets show the effectiveness of the proposed υ-DSNPESVM method.     

Effects of a radial electric field on the thinning of a slightly viscoelastic liquid jet

In this work, we study numerically the thinning of a perfectly conducting, slightly viscoelastic liquid jet under a radial electric field by using a one-dimensional model. In the presence of the electric field, the viscoelastic jet develops into a stable beads-on-a-string structure with a uniform thickness filament as in the non-electrified case, but the \( 1/3De \) (De: the Deborah number) exponential law of filament thinning and polymer stress growth holds no more. The electric field decelerates the thinning of the jet and induces periodic oscillations of the flow properties. The balance between the surface tension, viscoelastic stress and electrostatic force is absent in the filament, and as a result, the extensional flow there becomes unsteady.     

Optimized design of sandwich panels for integral thermal protection systems

This paper proposes a new ITPS panel with special corrugated-core webs which are designed with cutouts for weight saving. The structural design problem was formulated with mass per unit area of the ITPS as the objective function and some functional requirements as constraints. We developed the optimizer fulfilling both thermal and structural functions for minimal areal density. The optimization problem was solved by interpolating the residual error of response surface approximation (RSA) with Radial Basis Function (RBF) to establish the improved RSA (IRSA). The 400 preliminary design points were obtained using Latin Hypercube Sampling method. The quadratic polynomial RSA of the ITPS sandwich panel performance was generated by the least squares method (LSM) based on finite element results and IRSA was used to optimize the constraints. Transient heat transfer, stress and buckling analyses were conducted using finite element method (FEM). Finally, a new ITPS panel with optimal dimensions was obtained. The optimization results show that the areal density of the new ITPS panel decreases by 26.27 % compared with the previous research, which proves the potential of this new design optimization method for the future spacecraft vehicles.     

On design optimization for structural crashworthiness and its state of the art

Optimization for structural crashworthiness and energy absorption has become an important topic of research attributable to its proven benefits to public safety and social economy. This paper provides a comprehensive review of the important studies on design optimization for structural crashworthiness and energy absorption. First, the design criteria used in crashworthiness and energy absorption are reviewed and the surrogate modeling to evaluate these criteria is discussed. Second, multiobjective optimization, optimization under uncertainties and topology optimization are reviewed from concepts, algorithms to applications in relation to crashworthiness. Third, the crashworthy structures are summarized, from generically novel structural configurations to industrial applications. Finally, some conclusions and recommendations are provided to enable academia and industry to become more aware of the available capabilities and recent developments in design optimization for structural crashworthiness and energy absorption.

     

Multi-objective and multi-case reliability-based design optimization for tailor rolled blank (TRB) structures

Structural and Multidisciplinary Optimization - Light weight and crashworthiness signify two main challenges facing in vehicle industry, which often conflict with each other. In order to achieve...