Effects of etiquette strategy on human–robot interaction in a simulated medicine delivery task

The objective of this study was to examine the extent to which a model of linguistic etiquette in human–human interaction could be applied to human–robot interaction (HRI) domain, and how different etiquette strategies proposed through the model might influence performance of humans and robots as mediated by manipulations of robot physical features, in a simulated medicine delivery task. A “wizard of Oz” experiment was conducted in which either a humanoid robot or a mechanical-looking robot was used to present medicine reminding utterances (following different etiquette strategies) to participants, who were engaged in a primary cognitive task (a Sudoku puzzle). Results revealed the etiquette model to partially extend to the HRI domain. Participants were not sensitive to positive language from robots (e.g., appreciation of human values/wants) and such a strategy did not succeed in supporting or enhancing the “positive face” of human users. Both “bald” (no linguistic courtesy) and mixed strategies (positive and “negative face” (minimizing user imposition) saving) resulted in moderate user perceived etiquette scores (PE). However, individual differences suggested such robot linguistic strategies should be applied with caution. Opposite to this, a negative face saving strategy (supporting user freedom of choice) promoted user task and robot performance (in terms of user response time to robot requests), and resulted in the highest PE score. There was also evidence that humanoid robot features provide additional social cues that may be used by patients and support human and robot performance, but not PE. These results provide a basis for determining appropriate etiquette strategies and robot appearance to promote better collaborative task performances for future health care delivery applications of service robots.     

Effects of particle–fluid coupling on particle transport and capture in a magnetophoretic microsystem

A numerical analysis is presented of the effects of particle–fluid coupling on the transport and capture of magnetic particles in a microfluidic system under the influence of an applied magnetic field. Particle motion is predicted using a computational fluid dynamic CFD-based Lagrangian–Eulerian approach that takes into account dominant particle forces as well as two-way particle–fluid coupling. Two dimensionless groups are introduced that characterize particle capture, one that scales the magnetic and hydrodynamic forces on the particle and another that scales the distance to the magnetic field source. An analysis is preformed to parameterize capture efficiency with respect to the dimensionless numbers for both one-way and two-way particle–fluid coupling. For one-way coupling, in which the flow field is uncoupled from particle motion, correlations are developed that provide insight into system performance towards optimization. The difference in capture efficiency for one-way versus two-way coupling is analyzed and quantified. The analysis demonstrates that one-way coupling, in the dilute limit, provides a conservative estimate of capture efficiency in that it overpredicts the magnetic force needed to ensure particle capture as compared with a more rigorous fully coupled analysis. In two-way coupling there is a cooperative effect between the magnetic force and a particle-induced fluidic force that enhances capture efficiency. Thus, while one-way coupling is useful for rapid parametric screening of particle capture performance, more accurate predictions require two-way particle–fluid coupling. This is especially true when considering higher capture efficiencies and/or higher particle concentrations.     

Effects of identical example–problem and problem–example pairs on learning

Examples are often an integral part of online learning environments directed at the acquisition of problem-solving skills. An unresolved issue, however, is when examples should be provided to learners. Prior research has suggested that example–problem pairs are more effective than problem–example pairs for novice learners. However, in those studies, the problem–example pairs condition may have been hindered by the fact that the examples and problems were not identical within and across pairs. The present experiment therefore employed a between-subjects design with two conditions to compare the effects of learning to solve one particular problem from studying/practicing either in an example–problem–example–problem sequence (EP condition; n = 16) or in a problem–example–problem–example sequence (PE condition; n = 16). Results show that participants in the EP condition outperformed their counterparts in the PE condition during the learning phase, but that this difference had disappeared on the test tasks after participants in the PE group had also studied the example a second time.     

The Effects of Social Networking Sites on Consumer–Brand Relationships

In the era of a vastly changing marketing communications environment, social media and social networking sites (SNS) have become an attractive outlet for brand promotions and advertising. As traditional media such as television, radio, and newspapers prove ineffective in establishing a valuable rapport with consumers, it is social networks which are expected to build bonds and engage online users into an amusing dialog, play, and intercourse with brands. This study applies an experimental design to assess the effects of SNS on the relationship between brands and consumers. Customer-based brand equity is adopted in this study as a reflective measure of consumer–brand connection. In order to evaluate hypothesized interactions, the linear mixed effects models are used. The results show very little (if any) impact of SNS on brand equity. Relevant explanations are discussed and further research directions are indicated.     

An adaptive Stochastic Finite Elements approach based on Newton–Cotes quadrature in simplex elements

In this paper an adaptive Stochastic Finite Elements approach with Newton–Cotes quadrature and simplex elements is developed for resolving the effect of random parameters in flow problems. The stochastic response is represented by a piecewise polynomial approximation by subdividing probability space into simplex elements. The quadrature approximation in the elements leads to solving uncoupled deterministic problems for varying parameter values. The elements are refined adaptively using a refinement measure based on the curvature of the approximation of the response weighted by the probability represented by the elements. Due to the Newton–Cotes quadrature the required number of deterministic solves is relatively low, since (i) the deterministic samples are reused in successive refinement steps due to the location of the quadrature points, and (ii) the samples are used in approximating the response in multiple elements, because most quadrature points are located on the boundaries of the elements. Monotonicity and extrema of the samples are preserved in the piecewise polynomial approximation of the response by subdividing elements where necessary in subelements with a linear approximation of the response. Applications to flows in a piston problem, a stall flutter model and transonic flow over a NACA0012 airfoil with uniformly and lognormally distributed random parameters demonstrate that the method is capable of resolving complex problems with singularities in probability space effectively. Resolving singularities is important since they can result in high sensitivities, and oscillatory or unphysical predictions.     

The influence of lumbar extensor muscle fatigue on lumbar–pelvic coordination during weightlifting

Lumbar muscle fatigue is a potential risk factor for the development of low back pain. In this study, we investigated the influence of lumbar extensor muscle fatigue on lumbar–pelvic coordination patterns during weightlifting. Each of the 15 male subjects performed five repetitions of weightlifting tasks both before and after a lumbar extensor muscle fatiguing protocol. Lumbar muscle electromyography was collected to assess fatigue. Trunk kinematics was recorded to calculate lumbar–pelvic continuous relative phase (CRP) and CRP variability. Results showed that fatigue significantly reduced the average lumbar–pelvic CRP value (from 0.33 to 0.29 rad) during weightlifting. The average CRP variability reduced from 0.17 to 0.15 rad, yet this change ws statistically not significant. Further analyses also discovered elevated spinal loading during weightlifting after the development of lumbar extensor muscle fatigue. Our results suggest that frequently experienced lumbar extensor muscle fatigue should be avoided in an occupational environment.

Practitioner Summary: Lumbar extensor muscle fatigue generates more in-phase lumbar–pelvic coordination patterns and elevated spinal loading during lifting. Such increase in spinal loading may indicate higher risk of back injury. Our results suggest that frequently experienced lumbar muscle fatigue should be avoided to reduce the risk of LBP.     

Agency Effects in Human–Computer Interaction

The studies presented in this article explore a human-centered conceptualization of agents and agency based on the observation that people attribute agency to sufficiently complex interactive systems. Although agency attribution appears to be an unconscious human response, findings from social psychology, affective computing, and perceptual-motor studies suggest agency attribution influences human–computer interaction (HCI). Three studies are presented that examine whether recent findings on agency attribution in physical environments also apply in the virtual environments characteristic of HCI. Results of the studies indicate that agency effects operate in desktop computing environments. Agency effects, however, appear to be influenced by learning effects that preserve a previously observed relationship between perception and action but alter how this effect is expressed. Results suggest that there are both bottom-up and top-down contributions to agency effects in HCI.     

Computation in finite-strain viscoelasticity: finite elements based on the interpretation as differential–algebraic equations

In this article the interpretation of current non-linear finite element calculations applied to constitutive equations of evolutionary type as a system of differential–algebraic equations is continued [P. Ellsiepen, S. Hartmann, Int. J. Numer. Methods Engrg. 51 (2001) 679]. This procedure is applied to a model of finite-strain viscoelasticity which incorporates a particular model of non-linear rate dependence. Three specific topics are studied: firstly, we investigate a possible treatment of the interpretation in view of mixed finite elements. Secondly, the application of stiffly accurate diagonally implicit Runge–Kutta methods, which yield on element level the same structure as a Backward-Euler-based integration step, is analysed. It is shown that the resulting stress algorithm is reducible to the solution of only three non-linear equations at each Gauss point (one Maxwell element). Lastly, the effect with respect to expense and achievable accuracy of a time-adaptive procedure is focused, which is necessary in the case of different time scales such as relaxation or creep dominated processes.     

Quadratic divergence-free finite elements on Powell–Sabin tetrahedral grids

Given a tetrahedral grid in 3D, a Powell–Sabin grid can be constructed by refining each original tetrahedron into 12 subtetrahedra. A new divergence-free finite element on 3D Powell–Sabin grids is constructed for Stokes equations, where the velocity is approximated by continuous piecewise quadratic polynomials while the pressure is approximated by discontinuous piecewise linear polynomials on the same grid. To be precise, the finite element space for the pressure is exactly the divergence of the corresponding space for the velocity. Therefore, the resulting finite element solution for the velocity is pointwise divergence-free, including the inter-element boundary. By establishing the inf-sup condition, the finite element is stable and of the optimal order. Numerical tests are provided.     

Design characteristics of a workload manager to aid drivers in safety–critical situations

Cognition, Technology & Work - The objective of this study was to evaluate a workload manager designed to supervise the presentation of in-vehicle information for two age groups of drivers...     

Effects of speed–accuracy instructions on oculomotor scanning and target recognition in a simulated baggage X-ray screening task

Visual search tasks are often carried out under high levels of time stress. Transportation security screeners, for example, face demands to achieve high levels of accuracy while maintaining rapid passenger throughput. An experiment examined the strategies by which operators regulate visual search performance under such conditions. Observers performed a simulated baggage-screening task under instructions to emphasise either response speed or accuracy. Behavioural measures and eye movements were recorded. Observers made fewer and briefer fixations under emphasise-speed than under emphasise-accuracy instructions. Losses in accuracy were produced by more frequent failures to fixate on targets and a decrease in the detection rate of non-fixated targets. The likelihood with which observers detected a fixated target was similar across speed–accuracy instructions. Results will inform efforts to model visual search in naturalistic tasks, allowing more accurate prediction of response times and error rate and may aid the design of training programmes and other interventions to improve search performance under stress.     

Modelling and experimental verification of the effect of parasitic elements on the performance of an active-clamped current-fed DC–DC converter

Current-fed DC–DC converter has received a lot of attention recently for the fuel cell power source applications. This is due to its attractive features, such as low input current ripple, high voltage conversion ratio and high efficiency. Unfortunately, a high voltage stress across the switches and hard switching is the main drawback of the current-fed topologies. Therefore, an active clamp circuit is often implemented to suppress any voltage overshoot across the switches and achieving zero-voltage switching. In this paper, based on detailed analysis on the converter performance it was found that parasitic elements of the converter can have a large impact on promising features of current-fed converters with an active clamp. This has not been reported in the literature. It has been shown through an in-depth analysis on the converter that particularly during the switch overlap period the parasitic elements create undesirable oscillations leading to additional circulating energy that adds to the conduction losses of the converter. It also results in voltage ringing across the clamp switch, oscillations in the current through the clamp circuit and high voltages across the bridge switches, even when the switches are conducting. Based on this finding a number of modifications have been proposed and these have been verified by thorough simulation and experiment.     

Application of the Box–Behnken design to the optimization of process parameters in foam cup molding

Currently, foam molding technologies are widely adopted for most bra styles, which demonstrate the incomparable advantages in the contemporary intimate apparel industry. The determination of proper molding conditions, such as molding temperatures and length of time on the basis of cup sizes and styles, is crucial in achieving the required cup shape with high stability, which is regarded as the most challenging part of the molded bra making process. To determine the optimal process parameter settings, numerous process trials are generally required to evaluate the molding variables and their interactions. This study proposes a novel systematic methodology to identify the optimal molding process parameters based on design of experiment (DOE) and a parameterization-based remesh method to evaluate the 3D shape conformity of molded cups. By solving the regression equation obtained from a Box–Behnken design (BBD) and analyzing the response surface plots, the results prove that molding temperature has greater influence than the length of the dwell time on the 3D shape conformity of molded cups. The optimal molding conditions can be determined for the cup depths of different sized mold heads, which are validated by the experimental results.     

The energy cost of women walking and running in shoes and boots∗

The purpose of this study was to determine the difference in energy cost for women walking and running in shoes versus heavier boots. Seven subjects wore athletic shoes (mean weight = 514 ± 50g) and leather military boots (mean weight = 1371 ± 104g) at three walking speeds (4·0, 5·6 and 7·3km/hour) and two running speeds (8middot;9 and 10·5 km/hour). During each walking and running trial oxygen uptake ([Vdot]O₂ ml kg^?1 min^?1) was measured. The [Vdot]O₂ for women wearing boots were significantly higher (P < 0·05) than for shoes for both walking and running, with the exception of the slowest walking speed. The average increment in energy cost was 1·0% per 100-g increase in weight per pair of footwear. These results are similar to those reported for men from other studies which found increments in energy cost of 0·7 to 0·9% per 100-g increase in weight of footwear.     

A hybrid genetic algorithm–adaptive network-based fuzzy inference system in prediction of wave parameters

An important issue in application of fuzzy inference systems (FISs) to a class of system identification problems such as prediction of wave parameters is to extract the structure and type of fuzzy if–then rules from an available input–output data set. In this paper, a hybrid genetic algorithm–adaptive network-based FIS (GA–ANFIS) model has been developed in which both clustering and rule base parameters are simultaneously optimized using GAs and artificial neural nets (ANNs). The parameters of a subtractive clustering method, by which the number and structure of fuzzy rules are controlled, are optimized by GAs within which ANFIS is called for tuning the parameters of rule base generated by GAs. The model has been applied in the prediction of wave parameters, i.e. wave significant height and peak spectral period, in a duration-limited condition in Lake Michigan. The data set of year 2001 has been used as training set and that of year 2004 as testing data. The results obtained by the proposed model are presented and analyzed. Results indicate that GA–ANFIS model is superior to ANFIS and Shore Protection Manual (SPM) methods in terms of their prediction accuracy.     

User experience in safety–critical domains: a survey on motivational orientations and psychological need satisfaction in acute care

Cognition, Technology & Work - The relevance of user experience in safety–critical domains has been questioned and lacks empirical investigation. Based on previous studies examining user...     

Effects of El Niño on spring phenology of the highest mountain in north-east Asia

Normalized difference vegetation index (NDVI) data on the highest mountain in north-east Asia were analysed to understand their temporal variability and response to large-scale El Niño–Southern Oscillation (ENSO) events. We demonstrated that El Niño events played an important role in determining the phenology conditions in the Mt Baekdu area in north-east Asia. The analysis confirmed that the onset of phenological spring was earlier during ENSO years. This was evident from a negative trend of about??16 days for each increase of 1 in the ENSO index in year-to-year variations in spring timing and those in ENSO magnitudes. Over two decades, the phenological phases were negatively correlated with air temperature variations under atmospheric warming at the mountain. However, such changes in NDVI are not likely to be affected by changes in local precipitation, as inferred from the analysis of forest types in this area. On the basis of NDVI changes during ENSO years, the results of this study emphasized the importance of the elevation effect and forest types on the ecological response. Moreover, we addressed a significant remote connection between local phenology at the highest mountain in north-east Asia and large-scale atmospheric and oceanic phenomena.     

Effects of training on truck drivers’ interaction with cyclists in a right turn

Cognition, Technology & Work - With encounters between trucks and cyclists still being a major safety issue and physical as well as technological improvements far from ubiquitous...