关键词： informal science   communities of practice   acts of authentication   student talk   disciplinary engagement   robotics   scientific practice  

摘要： While the science classroom primarily remains a site for knowledge acquisition through teacher directed experiences, other sites exist outside of the classroom that allow for student generation of scientific knowledge. These sites provide opportunities for linguistic and social interactions to play a powerful role in situating students' science learning experiences. Augmenting students' formal school science experiences with informal experiences outside of the classroom enables them to intersect their personal knowledge with canonical disciplinary knowledge. This allows for conditions of practice that are more relevant to the students. In this study we introduce the notion of acts of authentication to examine the nature of students' linguistic and social activities in an informal settinga regional robotics competition. These acts of authentication are a) participating in talk (including everyday);b) participating in productive disciplinary engagement (by co-constructing and critiquing knowledge);and c) being a member of a community of practice. We used Critical Discourse Analysis to examine students' and mentor's dialogic language to gain insights into the nature of their robotics experiences. Our findings indicate that the robotics experience offered rich opportunities for students to engage in acts of authentication. Our study offers conceptual insights into how the culture of the robotics activities both constructs and is constructed by the linguistic and social experiences of the students and their mentors. (c) 2015 Wiley Periodicals, Inc. J Res Sci Teach 52: 268-295, 2015

关键词： EEG signal processing   Wavelet transforms and authentication   Autonomous system security  

摘要： The world is seeing the emergence of brainwave computing and its application in our daily communication and security is on the horizon. One of the interesting areas of interaction modality is robotic environment where involvement of illegitimate users may cause severe threat to environment thereby, a continuous monitoring is mandatory. In this paper, we have presented a study of potential of brainwaves and their computing for providing higher security. This work utilizes EEG signal generated by visual stimuli for keying in the password. In order to construct a model for user authentication, we have selected the time-frequency analysis method called wavelet analysis to decompose original signal corresponding to EEG sub-band frequency, thereby extracting statistical measures and energy calculation of each decomposed waves. Furthermore, we have selected and employed the neural network based on learning vector quantization for correct classification. Classification rate has been calculated over the different combination of channels. (C) 2014 Elsevier B.V. All rights reserved.

关键词： ROBOTICS   AWARDS   PLAQUES, plaquettes -- Design & construction  

摘要： A personal narrative is presented which explores the author's experience of coaching his students to design and build a robotics trophy using a light-emitting diode (LED) electronics for the post-season robotics tournament at the Dalton School in New York City.

关键词： borderline ovarian tumour   prognostic factors   staging procedures   omentectomy   peritoneal biopsies   cytology  

摘要： Background: Incomplete surgical staging is a negative prognostic factor for patients with borderline ovarian tumours (BOT). However, little is known about the prognostic impact of each individual staging procedure. Methods: Clinical parameters of 950 patients with BOT (confirmed by central reference pathology) treated between 1998 and 2008 at 24 German AGO centres were analysed. In 559 patients with serous BOT and adequate ovarian surgery, further recommended staging procedures (omentectomy, peritoneal biopsies, cytology) were evaluated applying Cox regression models with respect to progression-free survival (PFS). Results: For patients with one missing staging procedure, the hazard ratio (HR) for recurrence was 1.25 (95%-CI 0.66-2.39;P = 0.497). This risk increased with each additional procedure skipped reaching statistical significance in case of two (HR 1.95;95%-CI 1.06-3.58;P = 0.031) and three missing steps (HR 2.37;95%-CI 1.22-4.64;P = 0.011). The most crucial procedure was omentectomy which retained a statistically significant impact on PFS in multiple analysis (HR 1.91;95%-CI 1.15-3.19;P = 0.013) adjusting for previously established prognostic factors as FIGO stage, tumour residuals, and fertility preservation. Conclusion: Individual surgical staging procedures contribute to the prognosis for patients with serous BOT. In this analysis, recurrence risk increased with each skipped surgical step. This should be considered when re-staging procedures following incomplete primary surgery are discussed.

关键词： Arduino   Automation   Mass spectrometry   Open-source electronics   Robotics   Sample handling  

摘要： Mass spectrometry (MS) is an important analytical technique with numerous applications in clinical analysis, biochemistry, environmental analysis, geology and physics. Its success builds on the ability of MS to determine molecular weights of analytes, and elucidate their structures. However, sample handling prior to MS requires a lot of attention and labor. In this work we were aiming to automate processing samples for MS so that analyses could be conducted without much supervision of experienced analysts. The goal of this study was to develop a robotics and information technology-oriented platform that could control the whole analysis process including sample delivery, reaction-based assay, data acquisition, and interaction with the analyst. The proposed platform incorporates a robotic arm for handling sample vials delivered to the laboratory, and several auxiliary devices which facilitate and secure the analysis process. They include: multi-relay board, infrared sensors, photo-interrupters, gyroscopes, force sensors, fingerprint scanner, barcode scanner, touch screen panel, and internet interface. The control of all the building blocks is achieved through implementation of open-source electronics (Arduino), and enabled by custom-written programs in C language. The advantages of the proposed system include: low cost, simplicity, small size, as well as facile automation of sample delivery and processing without the intervention of the analyst. It is envisaged that this simple robotic system may be the forerunner of automated laboratories dedicated to mass spectrometric analysis of biological samples. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Space Tether-Net System   Approaching maneuver   Dynamics   Configuration control  

摘要： In order to eliminate the limitation of the Space Tether-Net System in the field of maneuver and control, we propose the Maneuvering-Net Space Robot System (MNSRS) in this paper, which can capture and remove the space debris dexterously. We focus on the approaching phase towards the space debris, which is a challenging problem for the MNSRS, especially the coupled dynamics modeling and configuration control problems. Firstly the system and mission overview of the MNSRS is described in detail. After that, a coupled dynamics modeling, which divides the MNSRS into finite mass points connected with massless springs, is established to describe dynamic characteristics of the MNSRS in approaching phase. Then the configuration variation of the MNSRS in approaching phase is analyzed. Finally the configuration control of the MNSRS in approaching phase is investigated. (C) 2014 COSPAR. Published by Elsevier Ltd. All rights reserved.

关键词： 机器人教学   区域发展   教育实践   比赛开始   信息技术   应用领域   保俶塔   机器人竞赛   教学实践探索   中所  

摘要： 从机器人的发明来说,最初它仅仅是作为科学研究和社会生产的工具。然而,因为机器人技术综合了物理、工程学以及信息技术等多学科知识,其设计及实践过程中所需知识和技术具有综合性、广泛性的特点,所以它具备很好的教育价值。机器人教育的兴起也正是对其应用领域的再扩大和再发展。

关键词： 机器人动力学   柔性并联平台   动力刚化   屈曲行为  

摘要： 在考虑轴向力影响下,对刚柔耦合3-PRR平面柔性并联平台进行了动力学建模,分析了柔性并联平台的动力刚化问题和屈曲行为。柔性并联平台由动平台、静平台和三根对称的柔性梁组成,运用拉格朗日法和假设模态法对系统进行了刚柔耦合动力学建模,并建立了柔性梁振动频率和轴向力之间的函数关系。Matlab仿真结果表明:柔性梁受到的轴向力和动平台的速度及位形相关,当柔性梁受轴向拉力时,出现动力刚化现象,固有频率增加;当柔性梁受轴向压力时,出现动力柔化现象,固有频率减小;当轴向压力增加达到极限值时,柔性梁会发生屈曲行为。模态试验和不同速度下的轨迹控制实验验证了所建动力学模型和理论分析的正确性。

关键词： 外骨骼机器人   步态分析   动力学仿真  

摘要： 阐述了正常人体的行走步态及稳定性.构建了人体七杆模型,对其进行了动力学分析.介绍了人体特性参数.利用Solidworks软件建立了下肢外骨骼机器人的三维装配体模型,并导入ADAMS软件中进行仿真研究.通过仿真结果,不仅验证了理论分析的正确性,也得到了各个关节的力矩变化规律及大小.同时,为其控制系统设计和电机选型提供了重要的理论依据.

关键词： 管道机器人   变径机构   动力学分析   仿真  

摘要： 介绍了4种支承轮式管道机器人变径方案的工作原理,比较分析得出丝杠螺母副变径机构具有更高的驱动效率。在此基础上,基于虚功原理分析了丝杠螺母—支承杆变径机构的驱动特性,并应用多体动力学仿真软件ADAMS对其进行了动力学仿真验证,结果显示丝杠螺母—支承杆变径机构具有更高的驱动效率和更强的管径适应能力,并给出了其驱动电动机随管径变化的一般动力学特性,为支承轮式管道机器人推广应用奠定了基础。