Semantic role labeling for Arabic language using case-based reasoning approach

Many natural language processing areas use semantic roles in order to improve the applications of the extracted information, the question answering and the machine translation, etc. In Arabic, the work of constructing the semantic role labeling system or the annotated corpus is extremely limited compared to their speaker’s number and to English language as well. In this paper, we present a supervised method for the semantic role labeling of Arabic sentences. Hence, we use the feedback capacity of the case-based reasoning to annotate new sentences from already annotated ones besides the use of the Arabic PropBank as a reference to the semantic labels. We test our method under a wide range corpus that contains 2332 attributes and 5291 arguments. Accordingly, an Arabic semantic role labeling system is tested, for the first time, in that corpus. As a result, our method shows the ability to annotate new sentences from the labeled sentences or the construction of the annotated corpus.     

Human motion recognition using a wireless sensor-based wearable system

The future of human computer interaction systems lies in how intelligently these systems can take into account the user’s context. Research on recognizing the daily activities of people has progressed steadily, but little focus has been devoted to recognizing jointly activities as well as movements in a specific activity. For many applications such as rehabilitation, sports medicine, geriatric care, and health/fitness monitoring the importance of combined recognition of activity and movements can drive health care outcomes. A novel algorithm is proposed that can be tuned to recognize on-the-fly range of activities and fine movements within a specific activity. Performance of the algorithm and a case study on obtaining optimal features from sensor and parameter values for the algorithm to detect fine motor movements are presented.     

依存关系语义角色标注研究

描述了一个基于依存关系的语义角色标注系统,该系统把依存关系作为语义角色标注的基本单元。通过手工或自动标注出来的依存关系,构造出依存关系树,并从树上抽取特征。用最大熵模型对句中谓词的语义角色进行识别和分类。为了消除不必要的结构化信息,在预处理阶段,依存关系树经过了Xue的剪枝算法处理。通过特征工程,丰富的特征及其组合被应用于系统。最终使用 CoNLL 2008 shared task提供的数据作为训练、开发和测试集,使用手工标注的依存关系,F1值达到了86.25%;使用MSTParser自动产生的依存关系,F1值达到了81.66%。     

穿戴系统中的天线设计

采用U型缝加载技术,设计了一种用于穿戴系统的双频平面倒F天线(PIFA),分别工作于GSM(全球通)的900 MHz和WLAN(无线局域网)的2.45 GHz频段,两个频段的相对阻抗带宽分别为10%和5%;在两个谐振频点处,天线的增益分别为0.4 dBi和1.7 dBi.天线具有低剖面结构、重量轻、结构简单等优点,完全满足穿戴系统中长、短距离无线通信要求.     

Distributed multi-camera visual mapping using topological maps of planar regions

This paper presents a multi-agent solution for cooperative visual mapping using planar regions. Each agent is assumed to be equipped with a conventional camera and has limited communication capabilities. Our approach starts building topological maps from independent image sequences where natural landmarks extracted from conventional images are grouped to create a graph of planes. With this approach the features observed in several images belonging to the same planar region are stored only once, reducing the size of the individual maps. In a distributed scenario this is very important because smaller maps can be transmitted faster, which makes our approach better suited for cooperative mapping. The later fusion of the individual maps is obtained via distributed consensus without any initial information about the relations between the different maps. Experiments with real images in complex scenarios show the good performance of our proposal.     

Spatial conferencing using a wearable computer

Wearable computers provide constant access to computing and communications resources; however, there are many unanswered questions as to how this computing power can be used to enhance communication. We describe a wearable augmented reality communication space that uses spatialised 3D graphics and audio cues to aid communication. The user is surrounded by virtual avatars of the remote collaborators that they can interact with using natural head and body motions. The use of spatial cues means that the conferencing space can potentially support dozens of simultaneous users. We report on two experiments that show users can understand speakers better with spatial rather than non-spatial audio, and that minimal visual cues may be sufficient to distinguish between speakers. Additional informal user studies with real conference participants suggest that wearable communication spaces may offer significant advantages over traditional communication devices.     

可穿戴智能戒指在多媒体投影系统中的应用

以可穿戴智能戒指为核心,利用激光变频、图像处理、视频跟踪定位、无线通信传输、无线调频收发等技术设计了一种多媒体投影系统。系统包括可穿戴智能戒指、无线收发模块、图像传感器、计算机等部分,其中可穿戴智能戒指集无线鼠标、无线激光教鞭、无线语音麦克功能于一体,实现合三为一。与其他多媒体投影系统相比,本戒指具有小巧实用,便携省电等特点,能够为课堂教学与协作会议带来生动便捷的交互式体验。     

面向室内退化环境的多传感器建图方法

在室内同时定位与建图(SLAM)的实际应用中,对称单一结构环境易造成激光SLAM错误建图,低质量光照或低纹理环境易造成视觉SLAM失效.针对上述室内退化环境,提出一种将激光、视觉、惯性测量单元(IMU)进行紧耦合的LVI-SLAM方法.在该方法前端,设计视觉评价环节对视觉信息置信度进行自适应调整;在该方法后端,进行位姿图优化以及多传感器回环抑制累积误差.视觉评价实验、单走廊实验以及大场景建图实验的结果证明了该方法的鲁棒性和精确性.在面积为1050 m2的复杂室内环境下,采用该方法建图误差为0.9％.     

Evaluation of physiological workload assessment methods using heart rate and accelerometry for a smart wearable system

Work metabolism (WM) can be accurately estimated by oxygen consumption (VO₂), which is commonly assessed by heart rate (HR) in field studies. However, the VO₂–HR relationship is influenced by individual capacity and activity characteristics. The purpose of this study was to evaluate three models for estimating WM compared with indirect calorimetry, during simulated work activities. The techniques were: the HR-Flex model; HR branched model, combining HR with hip-worn accelerometers (ACC); and HR?+?arm-leg ACC model, combining HR with wrist- and thigh-worn ACC. Twelve participants performed five simulated work activities and three submaximal tests. The HR?+?arm-leg ACC model had the overall best performance with limits of agreement (LoA) of ?3.94 and 2.00?mL/min/kg, while the HR-Flex model had ?5.01 and 5.36?mL/min/kg and the branched model, ?6.71 and 1.52?mL/min/kg. In conclusion, the HR?+?arm-leg ACC model should, when feasible, be preferred in wearable systems for WM estimation.

Practitioner Summary: Work with high energy demand can impair employees’ health and life quality. Three models were evaluated for estimating work metabolism during simulated tasks. The model combining heart rate, wrist- and thigh-worn accelerometers showed the best accuracy. This is, when feasible, suggested for wearable systems to assess work metabolism.     

激光—相机系统语义栅格建图和路径规划

目的 SLAM（simultaneous localization and mapping）是移动机器人在未知环境进行探索、感知和导航的关键技术。激光SLAM测量精确，便于机器人导航和路径规划，但缺乏语义信息。而视觉SLAM的图像能提供丰富的语义信息，特征区分度更高，但其构建的地图不能直接用于路径规划和导航。为了实现移动机器人构建语义地图并在地图上进行路径规划，本文提出一种语义栅格建图方法。方法 建立可同步获取激光和语义数据的激光-相机系统，将采集的激光分割数据与目标检测算法获得的物体包围盒进行匹配，得到各物体对应的语义激光分割数据。将连续多帧语义激光分割数据同步融入占据栅格地图。对具有不同语义类别的栅格进行聚类，得到标注物体类别和轮廓的语义栅格地图。此外，针对语义栅格地图发布导航任务，利用路径搜索算法进行路径规划，并对其进行改进。结果 在实验室走廊和办公室分别进行了语义栅格建图的实验，并与原始栅格地图进行了比较。在语义栅格地图的基础上进行了路径规划，并采用了语义赋权算法对易移动物体的路径进行对比。结论 多种环境下的实验表明本文方法能获得与真实环境一致性较高、标注环境中物体类别和轮廓的语义栅格地图，且实验硬件结构简单、成本低、性能良好，适用于智能化机器人的导航和路径规划。     

Airwriting: a wearable handwriting recognition system

We present a wearable input system which enables interaction through 3D handwriting recognition. Users can write text in the air as if they were using an imaginary blackboard. The handwriting gestures are captured wirelessly by motion sensors applying accelerometers and gyroscopes which are attached to the back of the hand. We propose a two-stage approach for spotting and recognition of handwriting gestures. The spotting stage uses a support vector machine to identify those data segments which contain handwriting. The recognition stage uses hidden Markov models (HMMs) to generate a text representation from the motion sensor data. Individual characters are modeled by HMMs and concatenated to word models. Our system can continuously recognize arbitrary sentences, based on a freely definable vocabulary. A statistical language model is used to enhance recognition performance and to restrict the search space. We show that continuous gesture recognition with inertial sensors is feasible for gesture vocabularies that are several orders of magnitude larger than traditional vocabularies for known systems. In a first experiment, we evaluate the spotting algorithm on a realistic data set including everyday activities. In a second experiment, we report the results from a nine-user experiment on handwritten sentence recognition. Finally, we evaluate the end-to-end system on a small but realistic data set.     

一种穿戴式系统电源控制器设计与实现

设计了一种穿戴系统电源控制器,是基于单片机控制的电源控制器,为穿戴式系统提供电源管理功能。具有双电池的充电/供电管理,内置单片机,电源开关软控制,并可遥控关机,可实时监控并指示控制器各工作状态,可指示电池电量信息,与上位机通信上传工作状态及电池电量等信息。具有充满保护、过流保护、短路保护、输入反接保护、双电池并接工作等保护功能。具有效率高、体积小、操作简单、功能全、双电池配置灵活、金属外壳电磁兼容性好、可靠性高等优点。可以用太阳能电源或手摇发电机通过控制器给电池充电,提高其野外使用适应性。     

Change propagation analysis for system modeling using Semantic Web technology

Change propagation potentially affects many aspects of a SysML-based system model during the iterative process of Model-Based Systems Engineering (MBSE). However, few authors have addressed the implication of engineering change and its impact. To address having a successful change process, this article analyzes and explicitly represents different scenarios of how a system model is changed from a formal perspective, i.e., how a system model should be changed, and how model elements should be added, deleted or modified in response to design changes. A workflow is introduced to guide the change process taking change propagation into account. Second, change impact relationships among requirements, behaviors, and structures of the system model are formalized by an ontology to make the semantics both human-understandable and machine-readable. Reasoning rules are defined as well in order to improve automation of the change process. Finally, an experiment using a water distiller system showed that the identification of change impact information could help designers complete the change in less time and with higher quality.     

Evaluation of a wearable computer system for telemonitoring in a critical environment

This paper reports on the evaluation of a wearable computer system designed for use in a critical environment, namely the intensive care unit of a hospital. The nature of the application raised ethical issues for testing in a clinical environment and standard evaluation techniques could not easily be applied. The system was therefore evaluated by clinicians in a multi-tasking environment with a simulated set of patient scenarios. Measures of suitability and wearability were applied. The results were encouraging and the system was deemed suitable for further evaluation in the clinical setting, subject to ethical approval.     

An adaptive control strategy for postural stability using a wearable robot

Wearable robots are expected to expand the use of robotics in rehabilitation since they can widen the assistance application context. An important aspect of a rehabilitation therapy, in terms of lower extremity assistance, is balance control. In this article, we propose and evaluate an adaptive control strategy for robotic rehabilitation therapies to guarantee static stability using a wearable robot. Postural balance control can be implemented either acting on the hip, on the ankle joint or on both, depending on the kind of perturbation acting on the subject: internal or external. Internal perturbations can be produced by any voluntary movement of the body, such as bending the trunk. External perturbations, in the form of an impact force, are applied by the exoskeleton without any prior notice to observe the proactive response of the subject. We have used a 6 degree of freedom planar lower limb exoskeleton, H1, to perform this analysis. The developed control strategy has been designed to provide the necessary assistance, related to balance recovery and postural stability, under the “Assist-as-needed” paradigm. The interaction forces between orthosis and subject are monitored, as they play a relevant role in the definition of assistive and resistive movements to be applied to the joints. The proposed method has been tested with 5 healthy subjects in presence of internal and external disturbances. The results demonstrate that knowing the stability limit of each subject, in combination with a therapeutically selected scaling factor, the proposed adaptive control helps in providing an effective assistance in therapy. This method is efficient in handling the individual and combined effect of external perturbations acting on any joint movements.     

MeditAid: a wearable adaptive neurofeedback-based system for training mindfulness state

A recent interest in interaction design is towards the development of novel technologies emphasizing the value of mindfulness, monitoring, awareness, and self-regulation for both health and well-being. Whereas existing systems have focused mostly on relaxation and awareness of feelings, there has been little exploration on tools supporting the self-regulation of attention during mindfulness sitting meditation. This paper describes the design and initial evaluation of MeditAid, a wearable system integrating electroencephalography technology with an adaptive aural entrainment for real-time training of mindfulness state. The system identifies different meditative states and provides feedback to support users in deepening their meditation. We report on a study with 16 meditators about the perceived strengths and limitations of the MeditAid system. We demonstrate the benefits of binaural feedback in deepening meditative states, particularly for novice meditators.     

一种可穿戴自适应环境监测系统设计

为了能够清楚地了解周围环境信息,设计了一种能够实时测量温度、湿度、PM2. 5浓度和甲醛浓度4种环境信息的无监督自适应移动环境监测系统。系统主要由可穿戴的移动硬件设备和手机端应用(APP)软件2部分组成。可穿戴设备将采集到的环境信息处理后,通过蓝牙发送到手机端APP软件。提出了一种无监督自适应的室内外场景识别算法,通过采集的环境信息对室内外的场景进行自动识别和区分。设计的系统体积小、识别精度高,适用于便携系统的应用场景,具有较好的实用性。