scholarly journals Control Modification of Grasp Force Covaries Agency and Performance on Rigid and Compliant Surfaces

2021 ◽  
Vol 8 ◽  
Author(s):  
Raviraj Nataraj ◽  
Sean Sanford
Keyword(s):  
Brain Injuries ◽  
Tracking Error ◽  
Interval Estimation ◽  
Time Interval ◽  
Surface Type ◽  
User Control ◽  
Force Magnitude ◽  
Compliant Surfaces ◽  
Continuous User ◽  
And Performance

This study investigated how modifications in the display of a computer trace under user control of grasp forces can co-modulate agency (perception of control) and performance of grasp on rigid and compliant surfaces. We observed positive correlation (p < 0.01) between implicit agency, measured from time-interval estimation for intentional binding, and grasp performance, measured by force-tracking error, across varying control modes for each surface type. The implications of this work are design directives for cognition-centered device interfaces for rehabilitation of grasp after neurotraumas such as spinal cord and brain injuries while considering if grasp interaction is rigid or compliant. These device interfaces should increase user integration to virtual reality training and powered assistive devices such as exoskeletons and prostheses. The modifications in control modes for this study included changes in force magnitude, addition of mild noise, and a measure of automation. Significant differences (p < 0.001) were observed for each surface type across control modes with metrics for implicit agency, performance, and grasp control efficiency. Explicit agency, measured from user survey responses, did not exhibit significant variations in this study, suggesting implicit measures of agency are needed for identifying co-modulation with grasp performance. Grasp on the compliant surface resulted in greater dependence of performance on agency and increases in agency and performance with the addition of mild noise. Noise in conjunction with perceived freedom at a flexible surface may have amplified visual feedback responses. Introducing automation in control decreased agency and performance for both surfaces, suggesting the value in continuous user control of grasp. In conclusion, agency and performance of grasp can be co-modulated across varying modes of control, especially for compliant grasp actions. Future studies should consider reliable measures of implicit agency, including physiological recordings, to automatically adapt rehabilitation interfaces for better cognitive engagement and to accelerate functional outcomes.

Time Estimation Performance Before, during and after Physical Activity

1988 ◽  
Vol 32 (15) ◽  
pp. 985-989 ◽  
Author(s):  
T. Mihaly ◽  
P.A. Hancock ◽  
M. Vercruyssen ◽  
M. Rahimi
Keyword(s):  
Interval Estimation ◽  
Time Estimation ◽  
Cycle Ergometer ◽  
Estimation Accuracy ◽  
Physical Work ◽  
Time Interval ◽  
Individual Subject ◽  
Knowledge Of Results ◽  
The Individual ◽  
Experimental Findings

An experiment is reported which evaluated performance on a 10-sec time interval estimation task before, during and after physical work on cycle ergometer at intensities of 30 and 60% VO2max, as scaled to the individual subject. Results from the eleven subjects tested indicate a significant increase in variability of estimates during exercise compared to non-exercise phases. Such a trend was also seen in the mean of estimates, where subjects significantly underestimated the target interval (10 seconds) during exercise. Subjects also performed more accurately with information feedback than without knowledge of results, but they were still not able to overcome the effects of exercise. As suggested by the experimental findings, decreased estimation accuracy and increased variability can be expected during physical work and is part of a body of evidence which indicates that exercise and its severity has a substantive impact on perceptual and cognitive performance.

scholarly journals Time-Interval Estimation Training Modulate Motor Behavior and Cerebral Cortex Activity in Parkinson Disease Patients: Preliminary Study

2019 ◽  
Vol 09 (01) ◽  
Author(s):  
Francisco Magalhaes ◽  
Victor Marinho ◽  
Carla Ayre ◽  
Kaline Rocha ◽  
Silmar Teixeira ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Parkinson Disease ◽  
Motor Behavior ◽  
Interval Estimation ◽  
Time Interval ◽  
Preliminary Study

Exploring time interval estimation for familiar and unfamiliar musical pieces

2021 ◽  
Author(s):  
Anastasiya Paltarzhitskaya ◽  
Daria Kleeva ◽  
Maria Osadchaya ◽  
Mikhail Lebedev ◽  
Andriy Myachykov ◽  
...  
Keyword(s):  
Interval Estimation ◽  
Time Interval

Do ETFs outperform CEFs in fixed income investing?

2015 ◽  
Vol 30 (4) ◽  
pp. 231-246 ◽  
Author(s):  
C. Edward Chang ◽  
Thomas M. Krueger ◽  
H. Doug Witte
Keyword(s):  
Performance Measures ◽  
Tracking Error ◽  
Exchange Traded Funds ◽  
Fixed Income ◽  
Turnover Rates ◽  
Operating Characteristics ◽  
Content Type ◽  
Market Values ◽  
Significant Difference ◽  
And Performance

Purpose – For a number of reasons ranging from their more recent introduction to their perceived lesser excitement relative to stock-based peers, there have been few studies of fixed income (mainly bond) exchange-traded funds (ETFs). The purpose of this paper is to fill the void by comparing performance measures of fixed income ETFs to fixed income closed-end funds (CEFs). Design/methodology/approach – This paper examines operating characteristics as well as risk and performance measures of all available fixed income ETFs and CEFs in the USA over the last five and ten years ending on December 31, 2014. Operating characteristics include expense ratios, annual turnover rates, tax cost ratios, and tracking error ratios. Performance measures include average annual returns, risks (measured by standard deviations), and risk-adjusted returns (measured by Sharpe ratios and Sortino ratios). Findings – This study finds material and significant difference in a variety of expenses, return measures, and risk measures. Sharpe and Sortino ratio significance is highly dependent on whether net asset values or market values serve as the dependent variable. ETFs would be the preferred choice of fixed income investors who are presumed to be focussing on market-based return measures. Originality/value – This paper empirically compares operating characteristics as well as risk and performance measures of US fixed income ETFs and fixed income CEFs in the same Morningstar categories over the last five and ten years.

scholarly journals Korean Business Groups and Performance of Group-Affiliated Professional Sport Teams: Focusing on the Asian Financial Crisis

2020 ◽  
Vol 12 (17) ◽  
pp. 6888
Author(s):  
Youngshin Woo ◽  
Wooseok Choi ◽  
Insik Min ◽  
Mugoan Jeong
Keyword(s):  
Financial Crisis ◽  
Business Groups ◽  
Professional Sports ◽  
Asian Financial Crisis ◽  
Time Interval ◽  
Sports Teams ◽  
Sport Teams ◽  
Athletic Success ◽  
And Performance ◽  
The Impact

This study examines the impact of Korean business groups, chaebols, on the sporting performance of their affiliated professional sports teams using game data from 1983 to 2013. We investigated whether or not chaebol ownership of professional sports teams is more efficient than non-chaebol ownership in achieving athletic success on the field of play. Our empirical evidence found that the chaebol-affiliated teams are more likely to be the league winners or finalists than non-chaebol teams are. We also tested the relationship between the financial crisis in the wider economy that deflates firm resources and athletic outcomes in the affiliated teams. In the tests, which divide the sample period into three 10-year periods, the results of two sub-samples (1983–1993 and 2004–2013) were in line with previous results. We, however, identified an exception when chaebol teams did not play in more final matches of a league between 1994 and 2003, the time interval that includes the period of drastic restructuring of business groups during the 1997 Asian financial crisis.

One-minute time interval estimation as a novel potent indicator of emotional concerns in cancer patients prior to starting chemotherapy

2019 ◽  
Author(s):  
Ivan Shterev Donev ◽  
Dragomir Svetozarov Stoyanov ◽  
Teodorika Vitalinova Panayotova ◽  
Martina Stoyanova Ivanova ◽  
Yavor Kostadinov Kashlov ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Interval Estimation ◽  
Time Interval

scholarly journals Time and Temperature Dependent Changes of Platelet Aggregation

1977 ◽  
Author(s):  
K. Breddin ◽  
H.J. Krzywanek
Keyword(s):  
Platelet Aggregation ◽  
Incubation Temperature ◽  
Inhibitory Effect ◽  
Blood Sampling ◽  
Time Interval ◽  
Temperature Dependent ◽  
Aggregation Pattern ◽  
And Performance ◽  
Incubation Temperatures ◽  
Induced Aggregation

ADP-, collagen and epinephrine-induced aggregation change markedly if citrate blood or PRP are kept at different incubation temperatures or/and if the time interval between blood sampling and testing varies. With a growing time interval the response of PRP to ADP, collagen or epinephrine increases. Desaggregation after ADP-aggregation decreases with time. If PRP is incubated at 4°C or 10°C aggregation is increased in comparison with room temperature. At 37°C aggregation is markedly inhibited. This inhibitory effect is almost fully reversible several hours after blood sampling. Corresponding results were obtained with PAT III, measuring spontaneous aggregation tendency. Morphologic platelet changes show some correlation with the time and temperature dependent changes of the aggregation pattern. In clinical studies the time interval between blood sampling and testing and the incubation temperature of PRP should be strictly controlled. If enhanced platelet aggregation is to be studied the time interval between venepuncture and performance of the test should be 30 - 60 min for ADP-or collagen-induced aggregation and between 90 and 360 min for PAT III. PRP should always be kept at 20 - 25°C.

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