Dimitra Dodou
Delft University of Technology, BioMechanical Engineering, Faculty Member
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This study is the third iteration in a series of studies aimed to develop a system that allows driving blindfolded. We used a sonification approach, where the predicted angular error of the car 2 seconds into the future was translated... more
This study is the third iteration in a series of studies aimed to develop a system that allows driving blindfolded. We used a sonification approach, where the predicted angular error of the car 2 seconds into the future was translated into spatialized beeping sounds. In a driving simulator experiment, we tested with 20 participants whether a surround-sound feedback system that uses four speakers yields better lane-keeping performance than binary directional feedback produced by two speakers. We also examined whether adding a corner support system to the binary system improves lane-keeping performance. Compared to the two previous iterations, this study presents a more realistic experimental setting, as participants were unfamiliar with the feedback system and received the feedback without headphones. The results show that participants had poor lane-keeping performance. Furthermore, the driving task was perceived as demanding, especially in the case of the additional corner support. ...
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The aging of paintings is inevitable and over the years degradation occurs due to exposure to a variety of environmental influences. One of these degradations is craquelure, fracture patterns in the paint. 3D imaging techniques offer... more
The aging of paintings is inevitable and over the years degradation occurs due to exposure to a variety of environmental influences. One of these degradations is craquelure, fracture patterns in the paint. 3D imaging techniques offer opportunities to capture the surface of a painting and these patterns at high resolution. In this paper we present a 3D scanner that is able to capture surface topography and color of oil paintings at high resolution utilizing fringe-encoded stereo imaging scanning system. The scanner is capable of automated capture of an area of 1x1m2, capturing a painting at a spatial resolution of 7 micron and a depth accuracy of 34 microns. Scanning at this resolution creates potential research opportunities for documentation and monitoring oil paintings under its environmental influences. A scan was made of 'Girl with a Pearl Earring' (c.1665), painted by Johannes Vermeer, which exhibits fine craquelure patterns. The scanner is able to capture the painting ...
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Likert questionnaires are widely used in survey research, but it is unclear whether the item data should be investigated by means of parametric or nonparametric procedures. This study compared the Type I and II error rates of the t test... more
Likert questionnaires are widely used in survey research, but it is unclear whether the item data should be investigated by means of parametric or nonparametric procedures. This study compared the Type I and II error rates of the t test versus the Mann-Whitney-Wilcoxon (MWW) for five-point Likert items. Fourteen population distributions were defined and pairs of samples were drawn from the populations and submitted to the t test and the t test on ranks, which yields the same results as MWW. The results showed that the two tests had equivalent power for most of the pairs. MWW had a power advantage when one of the samples was drawn from a skewed or peaked distribution. Strong power differences between the t test and MWW occurred when one of the samples was drawn from a multimodal distribution. Notably, the Type I error rate of both methods was never more than 3% above the nominal rate of 5%, even not when sample sizes were highly unequal. In conclusion, for five-point Likert items, th...
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Flexible steerable needles have the potential to allow surgeons to reach deep targets inside the human body with higher accuracy than rigid needles do. Furthermore, by maneuvering around critical anatomical structures, steerable needles... more
Flexible steerable needles have the potential to allow surgeons to reach deep targets inside the human body with higher accuracy than rigid needles do. Furthermore, by maneuvering around critical anatomical structures, steerable needles could limit the risk of tissue damage. However, the design of a thin needle (e.g., diameter under 2 mm) with a multi-direction steering mechanism is challenging. The goal of this paper is to outline the design and experimental evaluation of a biologically inspired needle with a diameter under 2 mm that advances through straight and curved trajectories in a soft substrate without being pushed, without buckling, and without the need of axial rotation. The needle design, inspired by the ovipositor of parasitoid wasps, consisted of seven Nickel Titanium wires and had a total diameter of 1.2 mm. The motion of the needle was tested in gelatin phantoms. Forward motion of the needle was evaluated based on the lag between the actual and the desired insertion ...
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This article synthesizes the latest information on the relationship between the Driver Behaviour Questionnaire (DBQ) and accidents. We show by means of computer simulation that correlations with accidents are necessarily small, because... more
This article synthesizes the latest information on the relationship between the Driver Behaviour Questionnaire (DBQ) and accidents. We show by means of computer simulation that correlations with accidents are necessarily small, because accidents are rare events. An updated meta-analysis on the zero-order correlations between the DBQ and self-reported accidents yielded an overall r of .13 (fixed-effect and random-effects models) for violations (57,480 participants; 67 samples) and .09 (fixed-effect and random-effects models) for errors (66,028 participants; 56 samples). An analysis of a previously published DBQ dataset (975 participants) showed that by aggregating across four measurement occasions, the correlation coefficient with self-reported accidents increased from .14 to .24 for violations and from .11 to .19 for errors. Our meta-analysis also showed that DBQ violations (r = .24; 6,353 participants; 20 samples) but not DBQ errors (r = - .08; 1,086 participants; 16 samples) corre...
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The main challenge in designing diagnostic devices able to move along the colon is their locomotion method. Manipulating friction with the colonic surface is a key requirement for their safe and atraumatic propagation. One possible... more
The main challenge in designing diagnostic devices able to move along the colon is their locomotion method. Manipulating friction with the colonic surface is a key requirement for their safe and atraumatic propagation. One possible solution is to generate friction by means of adhesive forces. For this purpose, a diagnostic device can be covered with mucoadhesive films that stick to the mucus layer of the colonic surface and generate high static friction. This paper investigates whether micropatterning the mucoadhesive films is able to enhance the grip with the colonic surface even more than flat mucoadhesive films. This idea is inspired by the sponge-form adhesive secretion of sea stars which is released by numerous tubular feet. Experiments in vitro showed that the frictional performance of mucoadhesive micropatterns exceed that of non-patterned mucoadhesive films. Moreover, the grip achieved by mucoadhesive micropatterns is far higher than the grip generated by non-mucoadhesive micropatterns made of an elastomeric material. Mucoadhesive micropatterned films also avoid the risk of damaging the colonic surface, since they interact only with the mucus layer and leave the colonic epithelium unaffected.
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Where we agree Before we respond to the commentators’ criticism, it would be useful to elucidate where we agree and disagree. The commentators appear to agree with the meta-analysis in itself. That is, their dispute does not concern the... more
Where we agree Before we respond to the commentators’ criticism, it would be useful to elucidate where we agree and disagree. The commentators appear to agree with the meta-analysis in itself. That is, their dispute does not concern the meta-analytic procedures or numeric outcomes per se. The commentators also agree that the correlation between the DBQ and self-reported accidents is susceptible to bias having a random and systematic component (but they disagree about the possible direction and magnitude of the bias, see below). Furthermore, they agree that the DBQ has no proven predictive power of recorded accidents, as our meta-analysis showed by a 95% confidence interval of −.03 to .13.
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ABSTRACT
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Research Interests: Engineering, Psychology, Forecasting, Injury Prevention, Risk Taking, and 15 moreMedicine, Safety, Humans, Female, Male, Occupational Safety and Health, Driver Behaviour Questionnaire, Meta Analysis, Aged, Middle Aged, Questionnaires, Human Factors and Ergonomics, Adult, Poison Control, and Accidents Traffic
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The most effective screening method for colonic cancer is colonoscopy. However, colonoscopy cannot be easily embraced by the population because of the related pain intensity. Robotic devices that pull themselves forward through the colon... more
The most effective screening method for colonic cancer is colonoscopy. However, colonoscopy cannot be easily embraced by the population because of the related pain intensity. Robotic devices that pull themselves forward through the colon are a possible alternative. The main challenge for such devices is their locomotion method along the slippery colon. This study focuses on devices which regularly switch between high friction to grip and low friction to slide and introduces a new method to manipulate friction by means of mucoadhesives. Mucoadhesives are polymers adhering to the mucus that covers the intestinal surface. We showed experimentally that mucoadhesive films can generate high static friction with the colon. In contrast with Coulomb friction, the static friction increases with the film area. The film geometry is of influence as well. Strikingly, when reducing the area by opening holes within the film structure, static friction can be considerably increased. A theoretical model was developed to express the frictional behaviour of mucoadhesive films. The role of geometry in the static friction offers new outlets to friction manipulation and provides new options for the design of the device. It seems also feasible to expand and apply the idea of increasing and manipulating friction by means of adhesive forces when gripping or handling soft, sensitive, or vulnerable objects. The artifice is to increase the adhesive forces up to a level that friction starts being controlled by adhesion, but without exceeding a ceiling of forces beyond which the adhesive falls into the area of permanent joints.
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It is known that statistically significant (positive) results are more likely to be published than non-significant (negative) results. However, it has been unclear whether any increasing prevalence of positive results is stronger in the... more
It is known that statistically significant (positive) results are more likely to be published than non-significant (negative) results. However, it has been unclear whether any increasing prevalence of positive results is stronger in the "softer" disciplines (social sciences) than in the "harder" disciplines (physical sciences), and whether the prevalence of negative results is decreasing over time. Using Scopus, we searched the abstracts of papers published between 1990 and 2013, and measured longitudinal trends of multiple expressions of positive versus negative results, including p-values between 0.041 and 0.049 versus p-values between 0.051 and 0.059, textual reporting of "significant difference" versus "no significant difference," and the reporting of p < 0.05 versus p > 0.05. We found no support for a "hierarchy of sciences" with physical sciences at the top and social sciences at the bottom. However, we found large differ...
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A common limitation in human factors research is that vehicle simulators often lack perceptual fidelity. Video games, on the other hand, are becoming increasingly realistic and may be a promising tool for simulator-based human factors... more
A common limitation in human factors research is that vehicle simulators often lack perceptual fidelity. Video games, on the other hand, are becoming increasingly realistic and may be a promising tool for simulator-based human factors research. In this work, we explored whether an off-the-shelf video game is suitable for research purposes. We used Grand Theft Auto (GTA) V combined with a Smart Eye DR120 eye tracker to measure eye movements of participants cycling in hazardous traffic situations. Twenty-seven participants encountered various situations that are representative of urban cycling, such as intersection crossings, a car leaving a parking spot in front of the cyclist, and the opening of a car door in front of the cyclist. Data of participants' gaze on the computer monitor as recorded by the eye tracker were translated into 3D coordinates in the virtual world, as well as into semantic information regarding the objects that the participant was focusing on. We conclude that GTA V allows for the collection of useful data for human factors research.
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An important research question in the domain of highly automated driving is how to aid drivers in transitions between manual and automated control. Until highly automated cars are available, knowledge on this topic has to be obtained via... more
An important research question in the domain of highly automated driving is how to aid drivers in transitions between manual and automated control. Until highly automated cars are available, knowledge on this topic has to be obtained via simulators and self-report questionnaires. Using crowdsourcing, we surveyed 1692 people on auditory, visual, and vibrotactile takeover requests (TORs) in highly automated driving. The survey presented recordings of auditory messages and illustrations of visual and vibrational messages in traffic scenarios of various urgency levels. Multimodal TORs were the most preferred option in high-urgency scenarios. Auditory TORs were the most preferred option in low-urgency scenarios and as a confirmation message that the system is ready to switch from manual to automated mode. For low-urgency scenarios, visual-only TORs were more preferred than vibration-only TORs. Beeps with shorter interpulse intervals were perceived as more urgent, with Stevens' power law yielding an accurate fit to the data. Spoken messages were more accepted than abstract sounds, and the female voice was more preferred than the male voice. Preferences and perceived urgency ratings were similar in middle-and high-income countries. In summary, this international survey showed that people's preferences for TOR types in highly automated driving depend on the urgency of the situation.
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We present a meta-analysis of 24 effect sizes from transfer of training experiments using whole body simulator motion as an independent variable. Three moderator variables were investigated: experiment design, task type, and subjects'... more
We present a meta-analysis of 24 effect sizes from transfer of training experiments using whole body simulator motion as an independent variable. Three moderator variables were investigated: experiment design, task type, and subjects' experience. Due to the large heterogeneity of the included experiments, we used a random-effects model. Correction for measurement error was applied. The results revealed an overall transfer effect in favor of motion (d = 0.51). Effects were weaker in true transfer (d = 0.10) than in quasi-transfer with different (d = 0.73) and identical (d = 1.19) motion, stronger for helicopter (d = 0.86) and disturbance tasks (d = 0.84) than for maneuvering fixed-wing aircraft (d = 0.07), and stronger for subjects without flight experience (d = 1.57) than for pilots with intermediate (d = 0.53) and expert (d = −0.01) experience. In conclusion, motion seems important for flight-naive individuals learning tasks with external disturbances or control of vehicles with low dynamic stability, but not for experts learning fixed-wing aircraft maneuvering tasks. Effects are attenuated in true transfer as compared to quasi-transfer. Flight simulators are valuable tools for pilot training. Training in a simulator is inherently safe and can be cost-effective. Research has shown that the use of flight simulators combined with aircraft training produces more performance Correspondence should be sent to Joost C.
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When fully automated cars will be widespread is a question that has attracted considerable attention from futurists, car manufacturers, and academics. This paper aims to poll the public’s expectations regarding the deployment of fully... more
When fully automated cars will be widespread is a question that has attracted considerable attention from futurists, car manufacturers, and academics. This paper aims to poll the public’s expectations regarding the deployment of fully automated cars. In 15 crowdsourcing surveys conducted between June 2014 and January 2019, we obtained answers from 18,970 people in 128 countries regarding when they think that most cars will be able to drive fully automatically in their country of residence. The median reported year was 2030. The later the survey date, the smaller the percentage of respondents who reported that most cars would be able to drive fully automatically by 2020, with 15–22% of the respondents providing this estimate in the surveys conducted between 2014 and 2016 versus 3–5% in the 2018 surveys. Respondents who completed multiple surveys were more likely to revise their estimate upward (39.4%) than downward (35.3%). Correlational analyses showed that people from more affluent countries and people who have heard of the Google Driverless Car (Waymo) or the Tesla Autopilot reported a significantly earlier year. Finally, we made a comparison between the crowdsourced respondents and respondents from a technical university who answered the same question; the median year reported by the latter group was 2040. We conclude that over the course of 4.5 years the public has moderated its expectations regarding the penetration of fully automated cars but remains optimistic compared to what experts currently believe.
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Less developed countries are overrepresented in traffic accidents, but knowledge on national differences in aberrant driving behaviours is scarce. This study investigated relationships between traffic violations measured with a 7-item... more
Less developed countries are overrepresented in traffic accidents, but knowledge on national differences in aberrant driving behaviours is scarce. This study investigated relationships between traffic violations measured with a 7-item Driver Behaviour Questionnaire and traffic accident involvement for an international crowdsourced sample. At the level of respondents (N = 6006), self-reported violations correlated moderately with self-reported accidents (Spearman ρ = .26). At the national level (N = 41), self-reported non-speeding violations (a composite consisting of three types of aggressive violations, tailgating, and using a mobile phone without a hands-free kit) correlated strongly with road traffic death rate per population (ρ = .77) and with developmental status (ρ = − .79), whereas self-reported speeding violations (a composite of speeding on a motorway and on a residential road) did not (ρ = − .08 and .22, respectively). Moreover, self-reported non-speeding violations correlated strongly with mean annual temperature (ρ = .58), while self-reported speeding violations did not (ρ = − .16). These cross-national correlates of traffic violations can be explained by developmental factors that lead to violation-provoking traffic situations or by the effect of temperature on aggression.
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Common factor analysis (CFA) and principal component analysis (PCA) are widely used multivariate techniques. Using simulations, we compared CFA with PCA loadings for distortions of a perfect cluster configuration. Results showed that... more
Common factor analysis (CFA) and principal component analysis (PCA) are widely used multivariate techniques. Using simulations, we compared CFA with PCA loadings for distortions of a perfect cluster configuration. Results showed that nonzero PCA loadings were higher and more stable than nonzero CFA loadings. Compared to CFA loadings, PCA loadings correlated weakly with the true factor loadings for underextraction, overextraction, and heterogeneous loadings within factors. The pattern of differences between CFA and PCA was consistent across sample sizes, levels of loadings, principal axis factoring versus maximum likelihood factor analysis, and blind versus target rotation.