A new wearable input device: SCURRY

A new wearable input device named SCURRY, developed by the Samsung Advanced Institute of Technology, is introduced in this paper. Based on inertial sensors, this device allows a human operator to select a specified character, an event, or an operation as the input he/she wants spatially through both hand motion and finger clicking. It is a glovelike device, which can be worn on the human hand, composed of a base module, including one controller and two angular-velocity sensors (gyroscopes) on the back of the hand, and four ring-type modules (rings), including two-axis acceleration sensors (accelerometers) on four fingers. The base and the ring modules are integrated modules containing sensors, a transceiver or receiver for communication, and a microcontroller, which makes the device compact and light. The two gyroscopes embedded in the base module have a role in detecting the direction (up, down, right, and left) of the hand motion, and the accelerometers have a role in detecting finger motion generated by finger clicking. An algorithm for the exact finger-click recognition composed of three parts (feature extraction, valid-click discrimination, and crosstalk avoidance) is proposed to improve the recognition performance of finger clicking on SCURRY. The experimental results and discussions are presented. SCURRY can be used as a wearable mouse spatially, by allowing any three fingers to be operated as the left, middle, and right mouse buttons, and in a similar manner, as a wearable keyboard, as it allows a human operator to point and select any character, event, or operation by his hand motion and finger clicking.     

Using role-based control to produce locomotion in chain-type self-reconfigurable robots

This paper presents a role-based approach to the problem of controlling locomotion of chain-type self-reconfigurable robots. In role-based control, all modules are controlled by identical controllers. Each controller consists of several playable roles and a role-selection mechanism. A role represents the motion of a module and how it synchronizes with connected modules. A controller selects which role to play depending on the local configuration of the module and the roles being played by connected modules. We use role-based control to implement a sidewinder and a caterpillar gait in the CONRO self-reconfigurable robot. The robot is made from up to nine modules connected in a chain. We show that the locomotion speed of the caterpillar gait is constant even with loss of 75% of the communication signals. Furthermore, we show that the speed of the caterpillar gait decreases gracefully with a decreased number of modules. We also implement a quadruped gait and show that without changing the controller the robot can be extended with an extra pair of legs and produce a hexapod gait. Based on these experiments, we conclude that role-based control is robust to signal loss, scales with an increased number of modules, and is a simple approach to the control of locomotion of chain-type self-reconfigurable robots.     

Characteristic analysis of a novel in-pipe driving robot

Gas and liquid pipelines are all around us in today’s society. The frequent inspection and maintenance of such pipeline grids is very important, especially for urban areas where there are dense populations. Many driving mechanisms for in-pipe crawling have been reported in previous studies. In this paper, a novel in-pipe drive design is presented. The proposed design uses modular helical drives. In between helical drives is a conic coil spring that allows extension and retraction. Since conic springs can be designed with telescopic feature, the proposed design can be made very compact. Furthermore, the proposed design also has much better mobility when turning a bend due to its flexible body (conic springs make the inchworm robot a compliant mechanism). The proposed design can be controlled with three modes of motion: synchronized motion (for small load), inchworm motion (for medium load), and rigid motion (for heavy load). Analysis on gripping force, locomotion force, together with experimental results will be presented as well.     

A real-time motion estimation and compensation LSI with wide searchrange for MPEG2 video encoding

This paper presents a motion estimation and compensation large scale integration (LSI) for the MPEG2 standard. An embedded RISC processor and special hardware modules enable the LSI to achieve a sufficient ability to perform real-time operation and provide the availability to realize many kinds of block matching algorithms. Using a three-step hierarchical telescopic search algorithm, a single chip accomplishes real-time motion estimation with search ranges of ±32.5×±32.5 pixels for motion vectors. The chip was fabricated using 0.5-μm CMOS technology and has an area of 16.5×16.5 mm² and 2.0 M transistors     

Improving the climbing/descent performance of stair-climbing mobility systems confronting architectural barriers with geometric disturbances

This paper presents a new study on the obstacle-climbing ability of Stair-Climbing Mobility Systems (SCMSs), taking into account the effects related to the presence of geometric disturbances on the obstacles. In this research, we use an SCMS that combines two different locomotion mechanisms to climb up and down stairs: one based on wheels and the other based on Sliding Supports. The combination of these mechanisms allows stairs of different sizes, and even stairs with geometric disturbances such as stairs with irregular or uneven treads, to be surpassed. However, the difficulty of the obstacle-climbing problem increases if the stair height is either large or its geometry is altered, in which case the obstacle climbing ability, and consequently the user’s safety may be highly compromised. In order to increase its adaptability to large-sized stairs and to reduce the effect of geometric disturbances, two important improvements have been made to the previous SCMS. One of these has been achieved by incorporating appropriate drive systems and redesigning the mechanisms that control the wheels. Thanks to this, the proposed SCMS is more lightweight and easy to control, and is above all more robust to geometric disturbances on the obstacles. The other concerns the trajectory planning, which has been improved by using a strategy that allows the size and shape of the stair to be estimated and accordingly allows a smooth and accurate reference trajectory to be tracked. This strategy is based on information obtained from laser distance sensors. This second improvement simplifies the control problem, reduces the time needed to surpass stairs and improves the user’s safety and comfort. Experimental results demonstrate the effectiveness of the proposed improvements when the SCMS climbs/descends staircases when both considering and not considering the effects of geometric disturbances on the steps.     

一种用于MPEG2 MP@ML视频编码器单片集成的低功耗运动估值器

本文给出了一种用于MPEG2 MP@ML视频编码器单片集成的低功耗运动估值器实现,它基于一种低复杂性的改进的多分辨率望远镜搜索算法,在粗分辨率运动矢量搜索过程中,采用以运动跟踪搜索和自适应望远镜搜索组成的两阶段可提前中断搜索来替换单一的传统望远镜搜索.模拟结果表明新算法的计算负载仅为传统算法的30％左右,却可以保持与之相同的视频解码图质量.本文采用心动阵列和改进的树结构阵列来分别加速运动矢量的粗分辨率搜索和优化搜索,并通过门控时钟和屏蔽操作数等方法来实现低功耗.     

一种适合于低代价、低功耗VLSI实现的块匹配运动估值算法

本文给出了一种用于块匹配运动估值的改进的多分辨率望远镜搜索(MRTlcS)算法.它以望远镜的逆向搜索取代了传统的望远镜搜索,这一改进有效地降低了VLSI实现时对片上存储器容量和带宽的要求.此外本文还采用运动跟踪和自适应搜索窗技术来减小运动估值的计算复杂性.适合于低代价、低功耗VLSI实现是新算法的显著特点.模拟结果表明新算法要求的平均运算量仅为MRTlcS算法的30%左右,而仍然可以得到相似的视频解码图质量.本文也给出了新算法和MRTlcS算法用于VLSI实现时的硬件代价和功耗比较.     

基于望远镜搜索的块匹配运动估值的低功耗VLSI结构

在一种基于望远镜搜索的块匹配运动估值的VLSI实现中,对用于加速搜索的传统心动阵列引擎进行了结构上的改进,从而能够显著地降低功耗.方法是使用一种新的块匹配误差计算的提早跳出技术,并通过在阵列处理单元中屏蔽操作数来避免不必要的计算操作.基于算法模拟结果的简单估计表明：使用新结构搜索引擎的运动估值,功耗可降低到原来的40％左右,而仍然保持着相同的处理速度和相似的视频解码图质量.     

基于望远镜搜索的块匹配运动估值的低功耗VLSI结构

在一种基于望远镜搜索的块匹配运动估值的 VL SI实现中 ,对用于加速搜索的传统心动阵列引擎进行了结构上的改进 ,从而能够显著地降低功耗 .方法是使用一种新的块匹配误差计算的提早跳出技术 ,并通过在阵列处理单元中屏蔽操作数来避免不必要的计算操作 .基于算法模拟结果的简单估计表明 :使用新结构搜索引擎的运动估值 ,功耗可降低到原来的 40 %左右 ,而仍然保持着相同的处理速度和相似的视频解码图质量 .     

一种基于超宽带雷达的日常活动分类方法

近年来,随着智能物联网应用的快速发展,雷达传感器由于具有保护隐私、全天候全天时工作、不受光线和遮挡影响等优点,在人体目标日常行为活动识别方面受到了学术界和产业界的极大重视。针对一种超低辐射的超宽带雷达（Impulse Radio Ultra-Wideband,IR-UWB）,提出了一种室内人员日常活动（包含静止、坐下、走路、起立）分类方法。该方法首先利用目标检测方法检测出目标有效距离单元;其次,提出了基于平均多普勒频率、信息量和多普勒能量的3种微多普勒特征进行动静目标粗分类;最后,采用长短期记忆神经网络（Long Short-Term Memory,LSTM）对人体活动进行细分类。实验结果表明,人体活动细分类的平均准确率能达到92.52%。     

Long‐term performance degradation of various kinds of photovoltaic modules under moderate climatic conditions

Various kinds of photovoltaic (PV) modules have been developed and practically operated as PV systems up to present. Investigation of the long‐term reliability of PV modules is indispensable for the use of PV systems as reliable energy sources. In this study, we show the results of outdoor exposure test in which the performance of 14 PV modules composed of five different kinds made by six different PV manufacturers have been measured since July 2004. The average performance is calculated in each year from 2005 to 2008, and the performance degradation is quantitatively evaluated. The results are that the magnitude of the performance degradation can be clearly classified by the kinds of the PV modules. The performance difference of the single‐crystalline silicon (sc‐Si) modules between 2005 and 2008 is from 1.9% to 2.8%. Polycrystalline silicon (pc‐Si) modules show performance degradation from 0.7% to 1.4%. The performance of an amorphous silicon/crystalline silicon (a‐Si:H/c‐Si) decreased by 0.7%. Although a pair of a‐Si modules had been already exposed to sunlight for about 6 months, the pair of modules show 4.4% of performance degradation. More than half of the performance degradation happened during the initial period from 2005 to 2006. This indicates that it takes about 2 years until the performance of a‐Si modules is stable. The performance is quite stable after 2006. Interestingly, the performance of the cupper indium gallium diselenide modules in 2008 is about 0.8% higher than that in 2005. Copyright © 2010 John Wiley & Sons, Ltd.     

Router plugins: a software architecture for next-generation routers

Present-day Internet protocol routers typically employ monolithic operating systems that are not easily upgradable and extensible. With the rapid rate of protocol development it is becoming increasingly important to dynamically upgrade router software in an incremental fashion. We have designed and implemented a high-performance, modular, extended services router software architecture in the Net BSD operating system kernel. This architecture allows code modules, called plugins, to be dynamically added and configured at run time. One of the novel features of our design is the ability to bind different plugins to individual flows; this allows for distinct plugin implementations to seamlessly coexist in the same runtime environment. We achieve high performance through a carefully designed modular architecture, an innovative packet classification algorithm that is highly efficient, and by caching that exploits the flow-like characteristics of Internet traffic. Compared to a monolithic best effort kernel, our implementation requires an average increase in packet processing overhead of only 8%, or 600 cycles per packet when running on an Intel Pentium Pro at 233 MHz. By shortcutting the forward loop based on the per-flow state we establish, we can forward packets up to three times faster than the best effort kernel     

一种基于L_∞范式的求解已知旋转相机重建算法

基于多幅图像序列的三维重建过程中,相机模型的坐标统一是非常重要的基础。在已知两两相机之间的相对关系的情况下,将相机模型统一至同一世界坐标系,并恢复特征点的三维坐标。本文给出了一种基于L∞范式的求解已知旋转相机重建方法。给出了一种基于L∞范式的几何结构和运动问题的新框架,并用实验证明了算法能够达到很好的性能。     

Designing asynchronous standby circuits for a low-power pager

We have designed asynchronous standby circuits for a pager decoder which dissipate four times less power and are 40% larger in size than synchronous designs. For the total pager unit this means a 37% reduction in power dissipation for nearly no additional area. The decoded chip, which apart from the standby circuits is completely synchronous, has been fabricated and was first-time-right. Two problems had to be solved to incorporate asynchronous subcircuits in a synchronous environment: synchronization and testing. A synchronization scheme is described that allows a free intermixing of asynchronous and synchronous modules and a test strategy is proposed in which the scan test facilities in the synchronous environment are used to test the asynchronous modules. One function is prevalent in the standby circuits, namely counting. In an appendix we present the asynchronous design of a so-called loadable counter whose power consumption does not depend on its size     

单相驱动旋转型驻波超声电机的运动机理

尽管单相驱动的旋转型驻波超声电机的原型样机早已研制成功,但对这类电机的运动机理的研究却一直局限在定性研究上。对于单相驱动的旋转型驻波超声电机来说,定子上的齿是运动传递的关键部分。因此对齿的运动特性的研究对进一步研究定、转子的摩擦接触过程有很重要的意义。以单相驱动的旋转型驻波超声电机为研究对象,通过假设定子的振动模态法对单相驱动的旋转型驻波超声电机的定子上的齿的运动特性进行了理论推导,并作了计算机仿真研究,得出了齿的运动轨迹以及速度曲线。     

Control of functional neuromuscular stimulation systems forstanding and locomotion in paraplegics

The authors adopt a control-systems perspective in reviewing past applications of functional neuromuscular stimulation for providing lower extremity motor function in paralyzed individuals. Specifically, their approach emphasizes direct computer-controlled electrical stimulation of paralyzed muscle rather than triggering reflexes. In experimental settings it provides paralyzed individuals with the ability to do functional tasks while standing, to walk short distances on varying surfaces, to negotiate obstacles, and to climb and descend stairs     

Human activity recognition based on transformed accelerometer data from a mobile phone

Mobile phones are equipped with a rich set of sensors, such as accelerometers, magnetometers, gyroscopes, photometers, orientation sensors, and gravity sensors. These sensors can be used for human activity recognition in the ubiquitous computing domain. Most of reported studies consider acceleration signals that are collected from a known fixed device location and orientation. This paper describes how more accurate results of basic activity recognition can be achieved with transformed accelerometer data. Based on the rotation matrix (Euler Angle Conversion) derived from the orientation angles of gyroscopes and orientation sensors, we transform input signals into a reference coordinate system. The advantage of the transformation is that it allows activity classification and recognition to be carried out independent of the orientation of sensors. We consider five user activities: staying, walking, running, ascending stairs, and descending stairs, with a phone being placed in the subject's hand, or in pants pocket, or in a handbag. The results show that an overall orientation independent accuracy of 84.77% is achieved, which is a improvement of 17.26% over those classifications without input transformation. Copyright © 2014 John Wiley & Sons, Ltd.     

Permanent magnet-based guided-wave magnetooptic Bragg cell modules

Compact magnetostatic forward volume wave-based guided-wave magnetooptic (MO) Bragg cell modules have been realized by utilizing a pair of small samarium-cobalt permanent magnets together with a pair of current-carrying coils. A highly uniform DC magnetic field, has been obtained in the air gap where yttrium iron garnet-gadolinium gallium garnet (YIG-GdGG) waveguide samples are inserted. A tunable DC magnetic field as large as 2446 Oe corresponding to a tunable carrier frequency band of 6.85 GHz has been achieved. The resulting MO Bragg cell modules, at the optical wavelength of 1.303 μm, with carrier frequencies ranging from 2.0 to 12.0 GHz have provided performance characteristics comparable to those obtained by using a bulk electromagnet. Compact MO Bragg cell modules have potential applications, such as scanning, switching of light beams, and real-time processing of wide-band microwave signals without requiring frequency down-conversion     

一种新的使用两种比特分辨率图象的块匹配运动估计算法及其低功耗VLSI结构

本文给出了一种新的块匹配运动估计算法,它根据视频图像内容的复杂程度自适应地选择常规的或者低比特分辨率的图像来进行块匹配,并且采用了一种混合使用两种比特分辨率图像的新望远镜搜索算法.模拟结果表明,新算法具有较低的计算复杂性,并且能够保证较好的视频质量.基于该算法,我们设计了一种新的脉动阵列结构的搜索引擎.该引擎具有可分割的数据通道,从而在使用低比特分辨率图像进行块匹配时能够通过加强处理的并行性来提高吞吐率.新的运动估计器可工作在较低的时钟频率和电源电压之下,具有低的功耗消耗.     

Multicamera Tracking of Articulated Human Motion Using Shape and Motion Cues

We present a completely automatic algorithm for initializing and tracking the articulated motion of humans using image sequences obtained from multiple cameras. A detailed articulated human body model composed of sixteen rigid segments that allows both translation and rotation at joints is used. Voxel data of the subject obtained from the images is segmented into the different articulated chains using Laplacian Eigenmaps. The segmented chains are registered in a subset of the frames using a single-frame registration technique and subsequently used to initialize the pose in the sequence. A temporal registration method is proposed to identify the partially segmented or unregistered articulated chains in the remaining frames in the sequence. The proposed tracker uses motion cues such as pixel displacement as well as 2-D and 3-D shape cues such as silhouettes, motion residue, and skeleton curves. The tracking algorithm consists of a predictor that uses motion cues and a corrector that uses shape cues. The use of complementary cues in the tracking alleviates the twin problems of drift and convergence to local minima. The use of multiple cameras also allows us to deal with the problems due to self-occlusion and kinematic singularity. We present tracking results on sequences with different kinds of motion to illustrate the effectiveness of our approach. The pose of the subject is correctly tracked for the duration of the sequence as can be verified by inspection.