浅谈数字产品软件界面中的语义符号

指出产品语义定义的内涵在数字技术时代面临的新挑战,并提出数字产品软件界面中包含视觉界面、菜单和图标3个层次,然后分析设计符号在这3个层次中使用时的一些规律和分别代表的含义.     

Neurobiology suggests the design of modular architectures for neural control

The existence of modular structures in the biological world strongly suggests that the training of this kind of structure is actually feasible. It is a key indication for the development of neural network applications, especially in the field of robotics. Indeed, a single network can only efficiently treat problems with few independent variables; the combination of several networks is necessary to address more complex tasks. We investigate learning techniques and show that using a particular form of architecture can ease the training of a modular structure: a bi-directional structure that allows combining several neural networks. The approach is illustrated with Kohonen's self-organizing maps for a robotic visual servoing task.     

A review of visual inertial odometry from filtering and optimisation perspectives

Visual inertial odometry (VIO) is a technique to estimate the change of a mobile platform in position and orientation overtime using the measurements from on-board cameras and IMU sensor. Recently, VIO attracts significant attentions from large number of researchers and is gaining the popularity in various potential applications due to the miniaturisation in size and low cost in price of two sensing modularities. However, it is very challenging in both of technical development and engineering implementation when accuracy, real-time performance, robustness and operation scale are taken into consideration. This survey is to report the state of the art VIO techniques from the perspectives of filtering and optimisation-based approaches, which are two dominated approaches adopted in the research area. To do so, various representations of 3D rigid motion body are illustrated. Then filtering-based approaches are reviewed, and followed by optimisation-based approaches. The links between these two approaches will be clarified via a framework of the Bayesian Maximum A Posterior. Other features, such as observability and self calibration, will be discussed.     

Development of a leg part of a humanoid robot-design of a biped walking robot having antagonistic driven joints using a nonlinear spring mechanism

The authors are engaged in studies of biped walking robots from the following two viewpoints. One is a viewpoint as a human science. The other is a viewpoint towards the development of humanoid robots. In the current research concerning a biped walking robot, there is no developed example of a life-size biped walking robot with antagonistically driven joints by which the human musculo-skeletal system is imitated in the lower limbs. Humans are considered to exhibit walking behavior which is both efficient and capable of flexibly coping with contact with the outside environment. However, developed biped walking robots cannot realize human walking. The human joint is driven by two or more antagonistic muscle groups. Humans can vary the joint stiffness, using nonlinear spring characteristics possessed by the muscles themselves. The function is an indispensable function for a humanoid. Therefore, the authors designed and built an anthropomorphic biped walking robot having antagonistic driven joints. In this paper, the authors introduce the design method of the robot. The authors performed walking experiments with the robot. As a result, a quasi-dynamic biped walking using antagonist driven joint was realized. The walking speed was 7.68 s per step with a 0.1 m step length.     

Tracking vision system for real-time motion analysis

This paper describes a high-speed motion tracking system based on full-search correlation matching. Incorporating the Advanced Correlation Processor, which computes more than 500 motion vectors per frame, the system enables the detection and tracking of moving objects at a video rate. The system is implemented on a single board and can be mounted inside a PC. Thus, it is compact and economical, and is well suited for a wide variety of applications such as automatic surveillance, traffic monitoring and sports play analysis.     

Enhancing density-based clustering: Parameter reduction and outlier detection

Clustering is a widely used unsupervised data mining technique. It allows to identify structures in collections of objects by grouping them into classes, named clusters, in such a way that similarity of objects within any cluster is maximized and similarity of objects belonging to different clusters is minimized. In density-based clustering, a cluster is defined as a connected dense component and grows in the direction driven by the density. The basic structure of density-based clustering presents some common drawbacks: (i) parameters have to be set; (ii) the behavior of the algorithm is sensitive to the density of the starting object; and (iii) adjacent clusters of different densities could not be properly identified. In this paper, we address all the above problems. Our method, based on the concept of space stratification, efficiently identifies the different densities in the dataset and, accordingly, ranks the objects of the original space. Next, it exploits such a knowledge by projecting the original data into a space with one more dimension. It performs a density based clustering taking into account the reverse-nearest-neighbor of the objects. Our method also reduces the number of input parameters by giving a guideline to set them in a suitable way. Experimental results indicate that our algorithm is able to deal with clusters of different densities and outperforms the most popular algorithms DBSCAN and OPTICS in all the standard benchmark datasets.     

Robust image-based visual servoing using invariant visual information

This paper deals with the use of invariant visual features for visual servoing. New features are proposed to control the 6 degrees of freedom of a robotic system with better linearizing properties and robustness to noise than the state of the art in image-based visual servoing. We show in this paper that by using these features the behavior of image-based visual servoing in task space can be significantly improved. Several experimental results are provided and validate our proposal.     

用于并行共焦测量的DMD控制方法研究

激光共焦测量采用并行的方式可以有效提高测量效率,但用于并行共焦测量的光分束器件普遍存在制作困难、价格偏高的不足.从数字微镜器件的空间光调制机理入手,主要研究数字微镜器的控制方法,通过构建任意所需的点光源阵列,实现了并行共焦测量.结果表明,测量装置可根据不同的被测物便捷地更换点光源参数;测量装置具有很好的柔性,且测量误差小.     

高分辨率静止轨道遥感卫星可见光及近红外波段邻近效应建模及分析

结合高分辨率静止轨道遥感卫星的特点,通过对已有研究方法的适当改进,给出了基于大气辐射传输机理的高分辨率静止轨道遥感卫星可见光及近红外波段的点扩散函数(Point-spread Function,PSF)模型,并进行邻近效应分析预研究.文中对邻近像元到目标像元距离、邻近像元范围(区域)、观测天顶角、气溶胶光学厚度及其散射相函数的非对称因子等因素对邻近效应的影响进行了系统地实验,并对各因素的影响机制进行了一定分析.结果显示,邻近像元对目标像元入瞳处辐亮度的贡献最高可达2.3％左右.故在对该类型遥感卫星进行大气影响分析、成像模拟、大气校正时考虑邻近效应是必要的.     

What controls distribution of larval and juvenile yellow perch? The role of habitat characteristics and spatial processes in a large,shallow lake

The goal of this study was to determine the relative contribution of environmental and spatial processes governing the distribution of larval and juvenile yellow perch (Perca flavescens) in two shallow embayments of a large fluvial lake on the St. Lawrence River system. We tested the hypotheses that: i) larval distribution is not related to habitat characteristics, presumably due to their relatively low swimming capacity, whereas ii) these environmental variables drive juvenile distribution, reflecting a more active habitat selection. This study is one of the first attempts to partition the relative roles of environmental and spatial factors in shaping the distribution of a freshwater fish through its early ontogeny. We show that larvae were not spatially aggregated within the embayments and that habitat characteristics, mainly related to aquatic vegetation, played an important role in explaining their distribution. In contrast, juvenile abundances were not significantly related to habitat characteristics, despite being spatially structured over multiple scales. Contrary to our predictions, habitat association was stronger for larvae than for juveniles which were aggregated independent of habitat characteristics. Increased swimming capacities may thus facilitate the aggregation of juveniles rather than strengthening their association with habitat, at least at the scales considered here (ca 3 km²). These results shed a new light on the factors governing larval and juvenile yellow perch distribution, suggesting that active habitat choice might begin earlier than previously thought.