Effects of auditory,haptic and visual feedback on performing gestures by gaze or by hand

Modern interaction techniques like non-intrusive gestures provide means for interacting with distant displays and smart objects without touching them. We were interested in the effects of feedback modality (auditory, haptic or visual) and its combined effect with input modality on user performance and experience in such interactions. Therefore, we conducted two exploratory experiments where numbers were entered, either by gaze or hand, using gestures composed of four stroke elements (up, down, left and right). In Experiment 1, a simple feedback was given on each stroke during the motor action of gesturing: an audible click, a haptic tap or a visual flash. In Experiment 2, a semantic feedback was given on the final gesture: the executed number was spoken, coded by haptic taps or shown as text. With simultaneous simple feedback in Experiment 1, performance with hand input was slower but more accurate than with gaze input. With semantic feedback in Experiment 2, however, hand input was only slower. Effects of feedback modality were of minor importance; nevertheless, semantic haptic feedback in Experiment 2 showed to be useless at least without extensive training. Error patterns differed between both input modes, but again not dependent on feedback modality. Taken together, the results show that in designing gestural systems, choosing a feedback modality can be given a low priority; it can be chosen according to the task, context and user preferences.     

Development of broadband forward‐wave directional couplers loaded by periodic patterned ground structure

In this paper two wideband Forward‐Wave Directional Couplers (FWDCs) with 0 dB and 3 dB coupling level are proposed. Using periodic patterned ground structure in a microstrip coupled lines by a new unit cell; even‐ and odd‐mode characteristic impedances of the couplers are equal over a wide frequency range. Moreover, it provides a constant phase difference between even and odd‐modes. The proposed cell is modeled using the equivalent circuit model and a design procedure is introduced for designing FWDCs for an arbitrary value of coupling level. The introduced couplers are numerically investigated and a prototype of both couplers is made. It is shown that for 0 dB coupling level, the measured coupling is 0.85 dB with 1 dB flatness over fractional bandwidth of 96% bandwidth. In case of 3 dB coupling, the measured coupling level is 3.5 dB at 7.42 GHz with 1 dB flatness over fractional bandwidth of 67.1%.     

一种德州扑克的牌力评估方法

德州扑克是机器博弈领域中一种很好的研究对象,与国际象棋、西洋棋等不同,其涉及了诸如不完整信息抽象与处理、多智能体竞争、风险评估与管理、对手建模等多方面的问题研究。其中,不完备信息抽象与处理是其他问题研究的基础,抽象与处理信息就是要对当前牌局进行评估以供后续工作使用。针对牌局信息不完整的情况,讨论了一些评估牌力方法,分析了这些方法的利弊,并提出了一种新的牌力评估方法,以提升计算速度,减少资源占用。实验结果表明,新的方法摒弃了查找表,达到了节省空间的目的,同时也具备较快的计算速度。     

机器人动态抓取的变比例导引路径规划方法

研究机器人手眼协调系统接近和抓取运动目标的路径规划方法,提出了一种脱胎于比例导引方法的变比例导引（ＶＧＰ）路径规划方法,这 方法设定手扑的视角在接近目标过程中以镁速不断变化,因而可以使手扑从目标运动前方拦截到目标,另外,机器人手扑在接近目标时,可以同时调整手主的接近姿态,以包抄的方式以目标。这种路径规划方法能够容许更大的目标位置估计误差,并能处理目标的机动运动,因而优于传统的目标跟踪路径规划方法,     

手握工具的美学研究

手握工具的美学研究是近年来现代设计技术研究的一个热点问题,手握工具中的优秀的美学设计产品在市场上也越来越多的涌现出来。但是,人们对于手握工具美学的真正含义并不是非常清晰。本文就手握工具的美学的含义和内容做了具体的分析,并把产品设计中的手握工具的美学思维同秩序设计思维、精致设计思维、细节设计思维、人性化设计思维相结合,对手握工具美学的含义进行了新的探索,通过对人机交互发展过程的简要总结,结合几个典型产品设计案例的深入研究和分析,揭示出了人机交互中手握工具的设计美学与产品的内在关系。     

线上线下结合的实时手势跟踪系统

手势识别跟踪一般采用线下训练分类器,不能有效检测跟踪形变的手势,针对手势形变及在窗口的暂时性消失等问题,提出了一种通过线下训练结合线上提取样本对分类器进行训练的检测方法,同时采用跟踪一检测一学习(TLD)的方法不断对跟踪器的结果进行纠正.试验结果表明,本算法对手势形变、短暂消失具有很好的适应性,与TLD算法相比较具有更好的稳定性.     

男性·女性·牵手——格罗丽亚·内勒小说《戴妈妈》的生态女性主义解读

从生态女性主义的角度解读当代美国非裔女作家格罗丽亚·内勒小说《戴妈妈》,通过分析小说中反复出现的"手"意象揭示"牵手"的寓意:牵手意味着相互依存与和谐;生态的和谐需要人与自然的牵手,种族间的和谐需要白人与黑人牵手,不同性别之间的和谐需要男性与女性的牵手。     

The transmission of vibration through gloves: effects of push force,vibration magnitude and inter-subject variability

The extent to which a glove modifies the risks from hand-transmitted vibration is quantified in ISO 10819:1996 by a measure of glove transmissibility determined with one vibration magnitude, one contact force with a handle and only three subjects. This study was designed to investigate systematically the vibration transmissibility of four ‘anti-vibration’ gloves over the frequency range 16–1600 Hz with 12 subjects, at six magnitudes of vibration (0.25–8.0 ms^?2 r.m.s.) and with six push forces (5 N to 80 N). The four gloves showed different transmissibility characteristics that were not greatly affected by vibration magnitude but highly dependent on push force. In all conditions, the variability in transmissibility between subjects was as great as the variability between gloves. It is concluded that a standardised test of glove dynamic performance should include a wide range of hands and a range of forces representative of those occurring in work with vibratory tools.

Statement of Relevance: The transmission of vibration through anti-vibration gloves is highly dependent on the push force between the hand and a handle and also highly dependent on the hand that is inside the glove. The influence of neither factor is well reflected in ISO 10819:1996, the current standard for anti-vibration gloves.     

Hand-hold location and trunk kinematics during box handling

Trunk kinematics variables have been shown to be related to low back injury risk during lifting tasks and it was hypothesised that changes in hand-hold positions could influence trunk kinematics and thereby risk. Fourteen subjects lifted a 5 or 10 kg box using four different hand placement locations (two symmetric and two asymmetric) while their trunk kinematics (position, velocity and acceleration in the sagittal, coronal and transverse planes) were captured using the lumbar motion monitor (LMM). These kinematics data were then used to calculate the probability of high risk group membership (PHRGM) as defined in the LMM risk assessment model. The results showed significant effects of hand placement on trunk kinematics, resulting in significant changes in the PHRGM variable ranging from a low of 20% in a the symmetric low load condition to a high of 38% under the asymmetric, 10 kg condition.

Statement of Relevance: Manual materials handlers use a variety of hand-hold positions on boxes during lifting. Where a lifter grabs the box can influence the trunk kinematics during the lifting task and these kinematics have been shown to provide some insight into risk of low back injury. This study documents the trunk postures and kinematics as a function of hand-hold position.     

Low mean level sustained and intermittent grip exertions: Influence of age on fatigue and recovery

The goal of this study was to quantify localised muscle fatigue resulting from low mean levels of exertion in younger (< 40 years) and older (>50 years) adults. Fatigue, elicited in the finger flexor muscles by intermittent (10% mean maximum voluntary contraction (MVC)) and sustained (8% MVC) handgrip exercises, was quantified by a muscle twitch force response before, immediately after and during 3 h following exercise. Despite greater mean loads, recovery time was shorter following intermittent than sustained contractions, which suggests that recovery from fatigue is more sensitive to rest within the work cycle than mean work. The more pronounced effects for younger than older individuals following the sustained exertion indicate that changes in muscle fibre type composition might predispose older individuals to be more resistant to fatigue resulting from sustained contractions of low level. Performing hand exertion tasks requiring low mean force levels contributes to similar long-lasting fatigue effects regardless of gender and age. Intermittent periods of complete rest reduce muscle fatigue. Since fatigue was not perceived during recovery from the tested sustained and intermittent contractions, subjective evaluations may not be a reliable indicator of localised muscle fatigue.