64 research outputs found

    Eye Pointing in Stereoscopic Displays

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    This study investigated eye pointing in stereoscopic displays. Ten participants performed 18 tapping tasks in stereoscopic displays with three different levels of parallax (at the screen, 20 cm and 50 cm in front of the screen). The results showed that parallax had significant effects on hand movement time, eye movement time, index of performance in hand click and eye gaze. The movement time was shorter and the performance was better when the target was at the screen, compared to the conditions when the targets were seen at 20 cm and 50 cm in front of the screen. Furthermore, the findings of this study supports that the eye movement in stereoscopic displays follows the Fitts’ law. The proposed algorithm was effective on the eye gaze selection to improve the good fit of eye movement in stereoscopic displays

    The Investigation of Laparoscopic Instrument Movement Control and Learning Effect

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    Laparoscopic surgery avoids large incisions for intra-abdominal operations as required in conventional open surgery. Whereas the patient benefits from laparoscopic techniques, the surgeon encounters new difficulties that were not present during open surgery procedures. However, limited literature has been published in the essential movement characteristics such as magnification, amplitude, and angle. For this reason, the present study aims to investigate the essential movement characteristics of instrument manipulation via Fitts' task and to develop an instrument movement time predicting model. Ten right-handed subjects made discrete Fitts' pointing tasks using a laparoscopic trainer. The experimental results showed that there were significant differences between the three factors in movement time and in throughput. However, no significant differences were observed in the improvement rate for movement time and throughput between these three factors. As expected, the movement time was rather variable and affected markedly by direction to target. The conventional Fitts' law model was extended by incorporating a directional parameter into the model. The extended model was shown to better fit the data than the conventional model. These findings pointed to a design direction for the laparoscopic surgery training program, and the predictive model can be used to establish standards in the training procedure

    Evaluating Direct Pointing and Indirect Cursor Interactions with Fitts' Law in Stereoscopic Environments

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    The development of virtual environment research has reached the stage of human interaction with three-dimensional (3D) objects. In this study, Fitts' method was used to such interaction techniques in virtual environment, and the Fitts' law applicability in 3D virtual environment was also considered. The experiment included two modes of interaction: direct interaction and indirect interaction that utilize different techniques depending on how users interact with 3D objects. Both interaction techniques were conducted in three indexes of difficulties and three egocentric target distances (a distance from participant to target). Movement time and throughput were measured for each interaction technique. The results show that the direct pointing technique is more efficient for interaction with the targets close to the participant, while the indirect cursor technique may be a viable option for targets further away from participant. Throughputs were found to be significantly higher for the direct pointing technique compared to the indirect cursor technique. The results of the mean movement time were highly correlated with the targets' index of difficulty for all interaction techniques, supporting evidence that Fitts' law can be applied to the interactions in 3D virtual environment. Based on the results, developers of VE application may relate to these findings in designing proper users' interactions

    Evaluating Direct Pointing and Indirect Cursor Interactions with Fitts' Law in Stereoscopic Environments

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    The development of virtual environment research has reached the stage of human interaction with three-dimensional (3D) objects. In this study, Fitts' method was used to such interaction techniques in virtual environment, and the Fitts' law applicability in 3D virtual environment was also considered. The experiment included two modes of interaction: direct interaction and indirect interaction that utilize different techniques depending on how users interact with 3D objects. Both interaction techniques were conducted in three indexes of difficulties and three egocentric target distances (a distance from participant to target). Movement time and throughput were measured for each interaction technique. The results show that the direct pointing technique is more efficient for interaction with the targets close to the participant, while the indirect cursor technique may be a viable option for targets further away from participant. Throughputs were found to be significantly higher for the direct pointing technique compared to the indirect cursor technique. The results of the mean movement time were highly correlated with the targets' index of difficulty for all interaction techniques, supporting evidence that Fitts' law can be applied to the interactions in 3D virtual environment. Based on the results, developers of VE application may relate to these findings in designing proper users' interactions

    Eye movement parameters for performance evaluation in projection-based stereoscopic display

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    The current study applied Structural Equation Modeling (SEM) to analyze the relationship among index of difficulty (ID) and parallax on eye movement time (EMT), fixation duration (FD), time to first fixation (TFF), number of fixation (NF), and eye gaze accuracy (AC) simultaneously. EMT, FD, TFF, NF, and AC were measured in the projection-based stereoscopic display by utilizing Tobii eye tracker system. SEM proved that ID had significant direct effects on EMT, NF, and FD also a significant indirect effect on NF. However, ID was found not a strong predictor for AC. SEM also proved that parallax had significant direct effects on EMT, NF, FD, TFF, and AC. Apart from the direct effect, parallax also had significant indirect effects on NF and AC. Regarding the interrelationship among dependent variables, there were significant indirect effects of FD and TFF on AC. Our results concluded that higher AC was achieved by lowering parallax (at the screen), longer EMT, higher NF, longer FD, and longer TF

    Identification of Workplace Social Sustainability Indicators Related to Employee Ergonomics Perception in Indonesian Industry

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    Sustainability indicators have provided a breakthrough for companies to assess their performance in supporting corporate sustainability. There is no standard framework for these support-defining indicators to conduct a social sustainability performance assessment. There is a limitation of quantitative social sustainability indicators appropriate for performing ergonomic concept assessments. Ergonomics, as a field concerning people and their interactions with the environment, in particular, the workplace, can play a role in social sustainability, besides its conventional approach of workplace re-engineering. Three major areas of ergonomics were analyzed. The indicators were established based on a review of the literature and confirmed using a factor analysis that covered all major aspects of workplace ergonomics. The factor analysis aimed to reduce the complexity of workplace social sustainability indicators related to ergonomics. The final result integrated 73 indicators into 17 indicators based on three major areas of ergonomics. The findings showed that the best workplace social sustainability indicators were divided into five factors: employee well-being, safety concerns, workplace comfort, musculoskeletal health, and environmental concerns. It would be very beneficial for the industry and the government to support corporate social sustainability and the global sustainability index

    Time Pressure Affects the Risk Preference and Outcome Evaluation

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    It is ubiquitous that food delivery riders do not have unlimited periods of time for deliberation to make decisions. Time pressure plays a significant role in decision-making processes. This study investigated how time pressure affected risk preference and outcome evaluation through behavioral and electrophysiological responses during decision-making. Participants finished a simple gambling task under three different time constraint conditions (high/medium/low). Behavioral and event-related potentials (ERPs) data were recorded during the experiment. The results showed that the decision time of people was shorter under high time pressure than under medium and low time pressures. People tend to make more risky choices when under high time pressure. The feedback-related negativity (FRN) amplitude was smaller in the high time pressure than in medium and low time pressure conditions. These findings provided evidence that time pressure has an impact on the risk decision-making process

    Time Pressure Affects the Risk Preference and Outcome Evaluation

    No full text
    It is ubiquitous that food delivery riders do not have unlimited periods of time for deliberation to make decisions. Time pressure plays a significant role in decision-making processes. This study investigated how time pressure affected risk preference and outcome evaluation through behavioral and electrophysiological responses during decision-making. Participants finished a simple gambling task under three different time constraint conditions (high/medium/low). Behavioral and event-related potentials (ERPs) data were recorded during the experiment. The results showed that the decision time of people was shorter under high time pressure than under medium and low time pressures. People tend to make more risky choices when under high time pressure. The feedback-related negativity (FRN) amplitude was smaller in the high time pressure than in medium and low time pressure conditions. These findings provided evidence that time pressure has an impact on the risk decision-making process

    Lifting speed preferences and their effects on the maximal lifting capacity

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    Modeling the Effect of Target Shape on Movement Performance in a 1D2D Fitts Task

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    Fitts’ law is used as a performance measurement metric in human–computer interactions. The original formulation implied that movement time was identical for movements with the same value of the index of difficulty under varied movement amplitude and target width. An experiment was designed to test this implication. The result indicates that movement time is related to the index of difficulty when the amplitude is constant. Nowadays, most of the icons in applications are represented as two-dimensional targets. An object of equal width and height is a particular case of a two-dimensional target. This target area could be a factor in a Fitts task and impact the movement time, number of errors, and perceived difficulty. Therefore, the area could replace the target width in the formulation of the index of difficulty. The modified index of difficulty is easy to implement without the complexity of post-calculation. Researchers can design the index of difficulty before the empirical test. This research proposes a modified index of difficulty by varying the target’s area and applying the square-root movement time model simultaneously, which results in an excellent performance with a higher R-square and satisfies the residual normality robustly than the traditional formulation of Fitts’ law
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