Task Duration Research Articles

Enhancing methods engineering education with a digital platform: usability and educational impact on industrial engineering students

IntroductionWork study aims to comprehend the potential of human work by assessing the duration of tasks and identifying methods for reducing them to enhance productivity and efficiency. On the other hand, methods engineering analyzes job processes to determine the most efficient and cost-effective techniques, resulting in improved operations. These areas are essential in the field of industrial engineering. Traditionally, they are taught using printed manuals and classroom-based instruction. Nevertheless, these conventional strategies frequently encounter difficulties engaging students and generating solid comprehension of the topics.MethodsThis study involved the development of a digital platform to improve methods engineering education. The platform adapts the curriculum of the methods engineering course offered at Universidad Panamericana. Each laboratory's practice includes detailed instructions and tasks for students to complete. Upon finishing, students submit their reports, which the professor then assesses. If the report meets the required standards, it is approved; otherwise, students must repeat the activities. An experience system serves as a tracker for course completion and keeps track of the student's progress.ResultsAn experimental group of 26 students who responded to Doll and Torkzadeh's end-user computer satisfaction survey tested the platform. Participants responded positively, particularly regarding the platform's accuracy (73.08% high satisfaction), ease of use (majority rated 5 for user-friendliness), and timeliness (majority satisfied with up-to-date information). However, the format dimension received mixed ratings, indicating areas for improvement. Additionally, participants appreciated the platform's ability to track progress and motivate the completion of laboratories, with 61.54% finding the content relevant and valuable for learning methods engineering concepts.DiscussionThe results suggest that integrating digital platforms into educational settings could significantly enhance educational settings, particularly in engineering courses where conventional approaches struggle to maintain student interest and engagement. Participants' positive responses support digital platforms' potential to complement and improve teaching methods. Future research will focus on integrating adaptive learning and generating micro-credentials to certify student expertise.

Curriculum Design and Sim2Real Transfer for Reinforcement Learning in Robotic Dual-Arm Assembly

Robotic systems are crucial in modern manufacturing. Complex assembly tasks require the collaboration of multiple robots. Their orchestration is challenging due to tight tolerances and precision requirements. In this work, we set up two Franka Panda robots performing a peg-in-hole insertion task of 1 mm clearance. We structure the control system hierarchically, planning the robots’ feedback-based trajectories with a central policy trained with reinforcement learning. These trajectories are executed by a low-level impedance controller on each robot. To enhance training convergence, we use reverse curriculum learning, novel for such a two-armed control task, iteratively structured with a minimum requirements and fine-tuning phase. We incorporate domain randomization, varying initial joint configurations of the task for generalization of the applicability. After training, we test the system in a simulation, discovering the impact of curriculum parameters on the emerging process time and its variance. Finally, we transfer the trained model to the real-world, resulting in a small decrease in task duration. Comparing our approach to classical path planning and control shows a decrease in process time, but higher robustness towards calibration errors.

Digital eye strain symptoms worsen during prolonged digital tasks, associated with a reduction in productivity

PurposeIt is often stated that digital eye strain can impact productivity and/or work accuracy, but the relationship between symptoms, productivity, and work accuracy has been unclear. Hence this study tracked the development of visuo-ocular symptoms during prolonged digital tasks and to explore the impact of higher and lower cognitive load levels on visuo-ocular symptoms, productivity, and work accuracy. MethodsThirty-five participants (23.2 ± 4.0 years) who had digital eye strain (diagnosed with the Computer Vision Syndrome Questionnaire) undertook an uninterrupted laptop adapted Eriksen Flanker task for 60 min on two separate days, once with a high cognitive load in randomised sequence. Symptoms were assessed at baseline and every 10 min throughout the task. ResultsAll visuo-ocular symptom scores significantly worsened (F = 87.783, p < 0.001) with time, with the symptom severity increasing faster with the higher cognitive load (F = 7.110, p < 0.001). The mean total number of tasks completed was greater for the lower (1060.8 ± 296.5) than the higher (532.2 ± 123.4) cognitive load tasks (F = 138.830, p < 0.001), reducing with time (F = 7.339, p < 0.001), but in a similar way for both cognitive loads (F = 1.795, p = 0.154). Task accuracy was not affected by the cognitive load of the task (F = 1.729, p = 0.197) and was consistent over time (F = 1.885, p = 0.135). ConclusionsSymptoms increased with task duration in individuals with digital eye strain, with a faster rate for more demanding tasks. This was associated with a decrease in the task completion rate (productivity), but not the work accuracy.

Influence of brick laying height on biomechanical load in masons: Cross-sectional field study with technical measurements.

Work-related musculoskeletal disorders (WMSDs) located in the low back and neck/shoulder regions are major concerns for both workers, workplaces, and society. Masons are prone to WMSD, because their work is characterized by repetitive work and high physical workload. However, the knowledge on the physical workload during bricklaying is primarily based on subjective measurements. This cross-sectional field study with technical measurements aimed to quantify physical workload in terms of muscular activity and degree of forward bending during bricklaying at different working heights among masons, i.e., knee, hip, shoulder, and above shoulder height. Twelve male (36.1±16.1 years) experienced masons participated in a cross-sectional field study with technical measurements. Surface electromyography from erector spinae longissimus and upper trapezius muscles and an inertial measurement unit-sensor placed on the upper back were used to assess the physical workload (level of muscle activation and degree of forward bending) different bricklaying heights. Manual video analysis was used to determine duration of work tasks, frequency, type, and working height. The working heights were categorized as 'knee', 'hip', 'shoulder', and 'above shoulder'. The 95 percentiles of the normalized Root Mean Square (RMSn) values were extracted assess from erector spinae and trapezius recordings to assess strenuous level muscle of muscle activation. The RMSn of dominant erector spinae muscle increased from hip- to shoulder height (from 26.6 to 29.6, P < 0.0001), but not from hip to above shoulder height and decreased from hip to knee height (from 26.6 to 18.9, P < 0.0001). For the dominant trapezius muscle, the RMSn increased from hip- to shoulder- and above shoulder height (from 13.9 to 19.7 and 24.0, respectively, P < 0.0001) but decreased from hip- to knee height (from 13.9 to 11.5, P < 0.0001). Compared to hip height (27.9°), an increased forward bending was detected during bricklaying at knee height (34.5°, P < 0.0001) and a decreased degree of forward bending at shoulder- and above shoulder height (17.6° and 12.5°, P < 0.0001, respectively). Based on technical measurements, bricklaying at hip height showed the best compromise between muscular load and degree of forward bending. This study contributes to the development of the work environment for masons and can help guide preventive initiatives to reduce physical workload.

Temporal localization of upper extremity bilateral synergistic coordination using wearable accelerometers.

The human upper extremity is characterized by inherent motor abundance, allowing a diverse array of tasks with agility and adaptability. Upper extremity functional limitations are a common sequela to Stroke, resulting in pronounced motor and sensory impairments in the contralesional arm. While many therapeutic interventions focus on rehabilitating the weaker arm, it is increasingly evident that it is necessary to consider bimanual coordination and motor control. Participants were recruited to two groups differing in age (Group 1 (n=10): 23.4 ±2.9 years, Group 2 (n=10): 55.9 ±10.6 years) for an exploratory study on the use of accelerometry to quantify bilateral coordination. Three tasks featuring coordinated reaching were selected to investigate the acceleration of the upper arm, forearm, and hand during activities of daily living (ADLs). Subjects were equipped with acceleration and inclination sensors on each upper arm, each forearm, and each hand. Data was segmented in MATLAB to assess inter-limb and intra-limb coordination. Inter-limb coordination was indicated through dissimilarity indices and temporal locations of congruous movement between upper arm, forearm, or hand segments of the right and left limbs. Intra-limb coordination was likewise assessed between upper arm-forearm, upper arm-hand, and forearm-hand segment pairs of the dominant limb. Acceleration data revealed task-specific movement features during the three distinct tasks. Groups demonstrated diminished similarity as task complexity increased. Groups differed significantly in the hand segments during the buttoning task, with Group 1 showing no coordination in the hand segments during buttoning, and strong coordination in reaching each button with the upper arm and forearm guiding extension. Group 2's dissimilarity scores and percentages of similarity indicated longer periods of inter-limb coordination, particularly towards movement completion. Group 1's dissimilarity scores and percentages of similarity indicated longer periods of intra-limb coordination, particularly in the coordination of the upper arm and forearm segments. The Expanding Procrustes methodology can be applied to compute objective coordination scores using accessible and highly accurate wearable acceleration sensors. The findings of task duration, angular velocity, and peak roll angle are supported by previous studies finding older individuals to present with slower movements, reduced movement stability, and a reduction of laterality between the limbs. The theory of a shift towards ambidexterity with age is supported by the finding of greater inter-limb coordination in the group of subjects above the age of thirty-five. The group below the age of thirty was found to demonstrate longer periods of intra-limb coordination, with upper arm and forearm coordination emerging as a possible explanation for the demonstrated greater stability.

Virtual Reality (VR) Technology in Laparoscopy Surgery: The Effect of Large Viewing Angle from the Head-Mounted Display (HMD) and Laparoscopic Performance

Background: A vital component of laparoscopic surgery is its display monitor. The viewing angle of the laparoscopic monitor impacts on the performance of the surgeon. Given that head-mounted display (HMD), an integral part of Virtual Reality (VR) technology, offers a large viewing angle, this project aimed to determine the potential benefits of using HMD in performing laparoscopic tasks. Methods: 54 laparoscopic/endoscopic clinicians performed a simulated laparoscopic task with three different monitors (HMD, 21-inch and 15-inch monitor) in a random order. Duration of task, distance travelled by graspers and manipulation errors were recorded and analyzed. Simulation Sickness Questionnaires (SSQs) were also given to participants. Results: There were statistically significant differences in all performance metrics recorded across all groups when compared to each other (P&lt;0.05). HMD had the longest task completion duration followed by 15-inch and 21-inch monitors. However, the distance travelled by the graspers and error rate was lowest in the HMD group followed by 21-inch and 15-inch monitors. The SSQ questionnaire showed that eye strain and headache are the two most common transient side effects recorded by users of HMD. Conclusion: The study shows that HMD users perform fewer mistakes and are more precise with the movement of graspers compared to other groups. As such, HMD has the potential to enhance laparoscopic performance. HMD is cost effective and has the added benefit of improving surgical ergonomics. Further research should focus on ensuring that HMD is a viable and safe alternative to conventional laparoscopic monitor as well as in identifying barriers to adoption.

Determining a Fuzzy Model of Time Buffer Size in Critical Chain Project Management

Abstract Elaborating and applying a new model for estimating the time buffer size of a project programme, which shall guarantee a 90 % probability of timely project execution. The research included source text analysis to provide information on a research gap and the identification of the research problem. The research problem was identified: the time buffer size in a critical path programme does not guarantee a 90 % probability of timely project execution. A new model was then elaborated to estimate the buffer size; it was applied in a technical production preparation project. An additional comparative analysis was performed using the following methods to verify the model more accurately: half of the time total of a path, the sum of squares (SSQ), and the root square error method (RSEM). The application of the fuzzy model to estimate the buffer size in a critical chain programme offers can shorten the total planned project duration. It has a higher probability of timely project execution than other methods for estimating the buffer size. It guarantees a 90 % probability of timely project execution, keeping aggressive task times, which eliminates unwanted situations such as student syndrome, Parkinson’s law, overestimating task duration, and multitasking. Project programming is an inherent part of the project planning stage in project management. Recently, project management has been increasingly developing, which has been confirmed by the article’s source literature analysis. The analysis revealed a research gap in models estimating project buffer size, which might guarantee a 90 % probability of timely project execution. Thus, a fuzzy model for estimating time buffer size in a critical chain was developed, constituting added value to the science of management and quality of production engineering (currently, mechanical engineering). The fuzzy model for estimating time buffer size was applied in one Polish enterprise in a project for a new product’s technical production preparation. The fuzzy model for estimating time buffer size permits the shortening of the duration of tasks to aggressive times, guaranteeing a 90 % probability of project timely execution. The elaborated model for estimating time buffer size may be applied further in practice in projects programmed using the critical chain method.

Smartphone-Based Sit-to-Stand Analysis for Mobility Assessment in Middle Age.

Mobility can decline in middle age and growing evidence highlights the importance of assessing mobility at this stage of life. Smartphone-based accelerometry during sit-to-stand has been shown to identify mobility impairments, but its utility in detecting subtle mobility deterioration in middle age has not been tested. This study aimed to examine whether smartphone-based accelerometry data measured during sit-to-stand tests performed on a regular chair and a cushioned sofa could be useful for detecting subtle changes in mobility in middle age. Twenty-three young (25.0±2.5 years), 25 middle-aged (52.0±5.2 years), and 17 older adults (70.0±4.1 years) performed the 5-times sit-to-stand test on both a standard chair and a sofa. A smartphone attached to the participants' lower back was used to measure lower-limb muscle power, maximal vertical velocity (MVV) during rising, the duration of the total task and the subphase of transition from sitting to standing (SiToSt), and repetition variability using the dynamic time warping method. Middle-aged adults had reduced lower-limb muscle power compared to young adults (5.25 ± 1.08 vs 6.19 ± 1.38 W/kg, p = .034), being more pronounced on the sofa (6.23 ± 1.61 vs 8.08 ± 2.17 W/kg, p = .004). Differences between middle-aged and young adults in terms of MVV (p = .011) and SiToSt duration (p = .038) were only detected on the sofa, and the middle-aged adults showed less variability compared to the older adults on the chair (p = .018). There was no difference in total task duration between the middle-aged group and the young or older adults in either condition. Most common tests are limited in their ability to detect early mobility deterioration in midlife due to a ceiling effect. Our results, which show the potential of smartphone-based sit-to-stand assessment in detecting subtle mobility decline in midlife, could serve as a screening tool for this purpose.

Performance During a Task That Simulates Passive Sonar Operator Duties Under Conditions of Varying Workloads.

It is critical to develop and implement lab-based computer experiments that simulate real-world tasks in order to characterize operational requirements and challenges or identify potential solutions. Achieving a high degree of laboratory control, operational generalizability, and ease-of-use for a task is challenging, often leading to the development of tasks that can satisfy some facets but not all. This can result in insufficient solutions that leave real-world stakeholders with unsolved problems. This issue is addressed using a customized passive sonar simulator application that provides extensive researcher control over the design and manipulation of a sonar task; a visual appearance and cognitive demand similar to a true submarine-based sonar task; and a convenient and short training routine for sonar novices. The task requires participants to watch for multiple signal sources of varying appearance and salience and subsequently classify these signals into their respective categories. The current study investigated the effects of stimulus signal strength and signal density on sonar task performance-including metrics of classification accuracy, classification confidence, and response times-finding an interaction between signal density and signal strength that resulted in greater performance errors with high signal density at the weakest signal strength. The lab-based sonar application provides new possibilities for research, not limited to signal intensity and signal density but also through the manipulation of parameters such as the number of unique targets, target appearance, and task duration. This application may illuminate the operational demands that each of these factors may have on operator behavior within the dynamic tasks.

WCET Analysis Based on Micro-Architecture Modeling for Embedded System Security

To ensure the timely execution of hard real-time applications, scheduling analysis techniques must consider safe upper bounds on the possible execution durations of tasks or runnables, which are referred to as Worst-Case Execution Times (WCET). Bounding WCET requires not only program path analysis but also modeling the impact of micro-architectural features present in modern processors. In this paper, we model the ARMv8 ISA and micro-architecture including instruction cache, branch predictor, instruction prefetching strategies, out-of-order pipeline. We also consider the complex interactions between these features (e.g., cache misses caused by branch predictions and branch misses caused by instruction pipelines) and estimate the WCET of the program using the Implicit Path Enumeration Technique (IPET) static WCET analysis method. We compare the estimated WCET of benchmarks with the observed WCET on two ARMv8 boards. The ratio of estimated to observed WCET values for all benchmarks is greater than 1, demonstrating the security of the analysis.

Pacing Behavior Development: The Role of Task Experience and the Presence of Competitors.

Self-regulation of effort during exercise (i.e. pacing) is a determinant of exercise performance, which develops during childhood and adolescence. Yet, the various aspects of pacing under development, such as the capability to use task experience and retain the task goal in the presence of other competitors, have remained relatively unexplored. 9 adolescents (14.9 ± 2.1 years old) and 14 adults (24.2 ± 3.2 years old) completed four 4-km cycling trials in a well-controlled laboratory setting. After one familiarization visit, trials were performed in random order: alone, with the goal to finish the trial as fast as possible (AloneTime), with a competitor and the same goal (CompTime), or with a competitor and the goal to finish first (CompFirst). Within each age group, repeated measurement ANOVAs (p < 0.05) examined the differences in the estimated task duration, pacing behavior (distribution of mean power output per 500 m) and performance (finish time) between visits (4) or conditions (3). In contrast to adults (p < 0.05, η2p > 0.20), adolescents did not exhibit a change in estimation of task duration, pacing behavior or performance over repeated visits (p > 0.05, η2p < 0.10). Adolescents altered their pacing behavior in the presence of a competitor independent of the task goal (CompTime & CompFirst), whereas adults only demonstrated this alteration when instructed to finish first (CompFirst). Adolescents are still developing the capability to 1) use experience from previous tasks to adjust their pacing behavior, and 2) inhibit the intuitive action of engaging with the competitor to retain the more abstract task goal of finishing the trial as fast as possible. These findings establish novel experimental evidence for the underpinnings of pacing behavior development.

Improvement of Motor Task Performance: Effects of Verbal Encouragement and Music-Key Results from a Randomized Crossover Study with Electromyographic Data.

External motivational stimuli have been shown to improve athletic performance. However, the neurophysiological mechanisms underlying this improvement remain poorly understood. This randomized crossover study investigated the effects of music and verbal encouragement on measures of muscle excitation and myoelectric manifestations of fatigue in the biceps brachii and brachioradialis muscles during an endurance task. Fifteen untrained (mean age 29.57 ± 2.77 years) and 13 trained individuals (mean age 32.92 ± 2.90 years) were included. The endurance task, performed to exhaustion, consisted of keeping the dominant arm flexed to 90 degrees while holding a dumbbell loaded to 80% of 1RM with a supine grip in three randomized conditions: standard, with self-selected music, and with verbal encouragement. The untrained subjects showed an increase in task duration of 15.26% (p < 0.003) with music and 15.85% (p < 0.002) with verbal encouragement compared to the condition without external stimuli. There were no significant differences in the myoelectric manifestations of fatigue between the different conditions. Regarding the muscle excitation metrics, although the mean amplitude, peak value, and area under the curve remained unchanged across conditions, a significant reduction in the trend coefficient, indicating motor unit recruitment over time, was observed with both music (biceps brachii: -10.39%, p < 0.001; brachioradialis: -9.40%, p < 0.001) and verbal encouragement (biceps brachii: -7.61%, p < 0.001; brachioradialis: -6.51%, p < 0.001) compared to the standard condition. For the trained participants, no significant differences were observed between conditions in terms of task duration and outcome measures related to muscle excitation and myoelectric manifestations of fatigue, suggesting the possible presence of a ceiling effect on motivation. These results highlight the important role of external motivational stimuli, such as music and verbal encouragement, in improving task performance in untrained subjects, probably through more effective and efficient recruitment of motor units.

CAN SIMPLE REACTION TIME TO A VISUAL STIMULUS BE USED AS A MEASURE OF THE BALANCE TASK INTENSITY?

Correctly determining the frequency, intensity and duration of balance tasks (BT) is crucial for effective balance training. While the frequency and BT duration are well defined, understanding BT intensity remains limited. Higher BT intensity demands greater attentional capacity for postural control. To assess the role of attention in postural control the dual-task paradigm including BT with reaction time (RT) is often used, suggesting RT as a potential measure of BT relative intensity. The study aimed to determine whether simple RT can be a surrogate for the relative BT intensity. Twenty randomly selected participants performed six repetitions of two-legged and one-legged stances on firm and compliant surfaces on a force plate. During the execution of the BT, the participants had to react on illumination of the light by pressing a switch held in their dominant hand. The center of pressure (COP) velocity and the RT were investigated. The BT were categorized into low, moderate and high intensities. The results showed a significant increase in COP velocity from low to high intensity BT (p=0.001; η2=0.79). Moderate intensity BT resulted in a 123.6% increase in COP velocity compared to the low intensity BT. During high-intensity BT COP velocity increased by 244.2 % (p &lt; 0.001). There were no differences in RT between different BT intensities (p=0.596; η2=0.03). The results suggest that RT may not accurately reflect the BT intensity. Therefore, it can be concluded that simple visual RT could not be used as a measure of relative intensity of BT.

Probing sustained attention and fatigue across the lifespan.

Trait fatigues reflects tiredness that persists throughout a prolonged period, whereas state fatigue is a short-term reaction to intense or prolonged effort. We investigated the impact of sustained attention (using the SART) on both trait and state fatigue levels in the general population. An online version of the SART was undertaken by 115 participants, stratified across the whole adult lifespan. While pre-task trait fatigue was a strong indicator of the initial state fatigue levels, undergoing the task itself induced an increase in reported subjective state fatigue, and an accompanying reduction in subjective energy rating. Consistent with this finding, greater subjective state fatigue levels were associated with reduced accuracy. In addition, age was the best predictor of inter-participant accuracy (the older the participants, the greater the accuracy), and learning (i.e., task duration reducing reaction times). Moreover, a ceiling effect occurred where participants with higher trait fatigue did not experience greater state fatigue changes relative to those with low trait scores. In summary, we found improved accuracy in older adults, as well as a tight coupling between state fatigue and SART performance decline (in an online environment). The findings warrant further investigation into fatigue as a dynamic, task-dependent state and into SART performance as an objective measure and inducer of fatigue.

Mixed Graph Colouring as Scheduling a Partially Ordered Set of Interruptible Multi-Processor Tasks with Integer Due Dates

We investigate relationships between scheduling problems with the bottleneck objective functions (minimising makespan or maximal lateness) and problems of optimal colourings of the mixed graphs. The investigated scheduling problems have integer durations of the multi-processor tasks (operations), integer release dates and integer due dates of the given jobs. In the studied scheduling problems, it is required to find an optimal schedule for processing the partially ordered operations, given that operation interruptions are allowed and indicated subsets of the unit-time operations must be processed simultaneously. First, we show that the input data for any considered scheduling problem can be completely determined by the corresponding mixed graph. Second, we prove that solvable scheduling problems can be reduced to problems of finding optimal colourings of corresponding mixed graphs. Third, finding an optimal colouring of the mixed graph is equivalent to the considered scheduling problem determined by the same mixed graph. Finally, due to the proven equivalence of the considered optimisation problems, most of the results that were proven for the optimal colourings of mixed graphs generate similar results for considered scheduling problems, and vice versa.

Comparison of Depth-Related Visuomotor Task Performance in Uniocular Individuals and in Binocular Controls With and Without Temporary Monocular Occlusion.

Do one-eyed (uniocular) humans use monocular depth cues differently from those with intact binocularity to perform depth-related visuomotor tasks that emulate complex activities of daily living? If so, does performance depend on the participant's age, duration of uniocularity and head movements? Forty-five uniocular cases (age range 6-37years; 2.4months-31.0years of uniocularity) and 46 age-similar binocular controls performed a task that required them to pass a hoop around an electrified wire convoluted in depth multiple times, while avoiding contact as indicated by auditory feedback. The task was performed with and without head restraint, in random order. The error rate and speed were calculated from the frequency of contact between the hoop and wire and the total task duration (adjusting for error time), respectively, all determined from video recordings of the task. Head movements were analyzed from the videos using face-tracking software. Error rate decreased with age (P < 0.001) until the late teen years while speed revealed no such trend. Across all ages, the error rate increased and speed decreased in the absence of binocularity (P < 0.001). There was no additional error reduction with duration of uniocularity (P = 0.16). Head movements provided no advantage to task performance, despite generating parallax disparities comparable to binocular viewing. Performance in a dynamic, depth-related visuomotor task is reduced in the absence of binocular viewing, independent of age-related performance level. This study finds no evidence for a prolonged experience with monocular depth cues being advantageous for such tasks over transient loss of binocularity.

Two-list genetic algorithm for optimizing work package schemes to minimize project costs

Optimizing work package schemes is challenging under uncertain task duration. This paper develops a two-list genetic algorithm (TLGA) to optimize work package schemes with minimal project costs under deterministic and stochastic task durations. First, this paper defines the deterministic and stochastic work package scheme problem. Second, the TLGA, comprising a task and a work packaging list, is developed to generate the deterministic work package scheme and issue work package policies through stochastic distribution simulations. Moreover, a graphical user interface with TLGA is developed to enhance its practical application. Finally, experiments show that the TLGA can reduce the total cost by up to 19.57% in the deterministic problem, and the minimum gap between the TLGA and the state-of-the-art heuristics is only 3.91%. However, the TLGA can reduce the running time by about 66%. In the stochastic problem, this paper analyzes the impact of stochastic distributions on work package policies.

Perception of task duration affects metabolic cost during split-belt adaptation.

Individuals can markedly reduce the metabolic cost of a walking adaptation task if they believe they must sustain the task for a prolonged time. The variables typically used to track adaptation do not track the reductions in metabolic cost observed in our study. Metabolic cost reduction can occur without clear changes in biomechanical factors.

Exploring the utility of process scores in elucidating the role of cognitive and affective factors that influence verbal fluency performance in Parkinson’s disease

Objectives Cognitive and affective factors have been implicated in verbal fluency (VF) performance in Parkinson’s disease (PD). This exploratory study aimed to investigate the relationships between cognitive and affective variables on traditional (“core”) and "process” (error and interval) scores of VF and elucidate unique information these scores may provide regarding mechanisms underlying VF. Methods Sixty-two PD patients without dementia completed clinical neuropsychological examinations consisting of attention, processing speed, language, executive functioning, visuospatial, memory, and mood measures. Hierarchical regression and negative binomial regression analyses were used to evaluate relationships between outcome and predictor variables. Results Generativity results revealed that processing speed and working memory explained up to 34% of the variance of total letter fluency responses (p = <.001) and processing speed explained 24% of the variance for total semantic fluency (p = .003). For category switching generativity, only age predicted 20% of the variance (p = .01). Two executive functioning measures were negatively associated with error production over the duration (b = −.055, p = .028; b = −.062, p = .004) and final 45-second interval (b = −.072, p = .003; b = −.044, p = .033) of the category switching task. In the initial 15-second task interval, a positive predictive relationship between error production and indifference apathy (b = .616, p = .044) was demonstrated. Conclusions Findings demonstrate the potential utility of "process” scores in detecting subtle cognitive impairment in Parkinson’s disease patients without dementia and tentatively evidence the role of indifference apathy in task initiation.

A Short Summary of Multi-Agent Combinatorial Path Finding with Heterogeneous Task Duration (Extended Abstract)

A Short Summary of Multi-Agent Combinatorial Path Finding with Heterogeneous Task Duration (Extended Abstract)