• The Journal of Korea Robotics Society
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• v.17 no.3
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• pp.347-352
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• 2022

The paper presents how to update impedance control parameters for dual-arm manipulators using EMG signals and motions of the operator. Since the hand motions of the dual-arm are modeled to be the mass-spring-damper system in this paper, the impedance parameter update method is an important issue to reflect the operator's force. However, task space inertia to be used as the mass parameter goes to infinity if the manipulator approaches a kinematic singularity. To alleviate this issue, the impedance (stiffness and damping) parameters are divided with a diagonal element of the task space inertia. Also, the stiffness and damping matrices are updated using the normalized EMG signals captured from the operator's forearm. Through this process, the motion of the dual-arm manipulator is more stabilized even though it approaches the kinematic singularity.

• Therapeutic Science for Rehabilitation
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• v.10 no.2
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• pp.95-108
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• 2021

Objective : This study aimed to develop prototypes of "smart stacking cones" by combining ICT to evaluate and train the upper extremity function and dual task performance in patients with central nervous system impairment, and to identify the complementary point to the completion of the device through a usability test. Methods : This prototype comprised of a hardware and software system that enabled the evaluation and training of patients and the management of data obtained from patients' performance. Specific measurement variables were established so that patient performance could be measured correctly. Based on the measurement variables, a the prototype included a 'single task evaluation modes', 'dual task evaluation mode', 'single task training mode', and 'dual task training modes'. Additionally, a usability test was conducted to assess clinical applicability and overall satisfaction for the prototype. Results : The results of the usability test were generally found to be appropriate. The 'content adequacy' in the usability test was the area with the highest level of adequacy and the lowest level of inadequacy. Additionally, overall 'satisfaction' in the usability test was the area with the highest appropriate and inappropriate levels. Hence, the overall satisfaction results were unstable. Conclusion : Future studies should be conducted to identify the clinical effectiveness of the device by applying an upgraded smart stacking cone to an actual patient group.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.176-181
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• 2000

Collision free task planning for dual-arm robot which perform many subtasks in a common work space can be achieved in two steps : path planning and trajectory planning. path planning finds the order of tasks for each robot to minimize path lengths as well as to avoid collision with static obstacles. A trajectory planning strategy is to let each robot move along its path as fast as possible and delay one robot at its initial position or reduce speed at the middle of its path to avoid collision with the other robot.

• The Journal of Korean Physical Therapy
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• v.14 no.3
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• pp.418-432
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• 2002

본 연구의 목적은 다음과 같이 네 가지이다. 첫째, dual-strategy hypothesis 모델의 이론적인 배경을 서술한다. 둘째, 보행시작 시 (Gait Initiation)와 장애물 보행시작 (Stepping over obstacles)시의 motor task를 dual-strategy hypothesis 모델의 관정에서 서술한다. 셋째, 파킨슨씨 환자군과 뇌졸증 환자군을 이 모델의 관점에서 서술한다. 마지막으로, dual strategy hypothesis모델의 임상적용 가능성에 대해서 간단히 서술하는 것이다.

• Korean Journal of Child Studies
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• v.34 no.6
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• pp.1-11
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• 2013

The purpose of this study was to investigate the process of counterfactual reasoning which children undergo, based on mental model theory and dual process theory. The subjects were 120 four-year-olds and 120 five-year-olds from Ulsan. Counterfactual reasoning task conditions were created, including task type and content, which were type 1-specific, type 1-general, type 2-specific, type 2-general. There were two stories used for each task condition. Children's counterfactual reasoning score range was 0 to 8. Data were analyzed using SPSS by mean, standard deviation, one sample t-test, repeated measures of Anova. The results of this study were as follows. First, children's counterfactual reasoning was above chance level regardless of the task condition. Second, children's counterfactual reasoning was lowest when type 1-specific or type 2-specific tasks were given, slightly higher when type1-general tasks were given, and the highest when type 2-general tasks were given. There was no significant difference between 4-year-old and 5-year-old children's counterfactual reasoning.

• Therapeutic Science for Rehabilitation
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• v.9 no.2
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• pp.7-25
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• 2020

Objective : The purpose of this study was to analyze the effects of dual-task training on stroke patients. Methods : We searched the databases such as NDSL, RISS, PubMed, CoChrane and EMBASE for publications in the past decade. Finally, 10 papers were selected. Qualitative assessment was performed according to the traditional single-layer evidence model, and meta-analysis was performed using the Comprehensive Meta Analysis 3.0 program. Results : The quality level of each of the 10 selected papers all correspond to I and II in the traditional single-layer evidence model. The motor tasks that constitute dual-task training comprised walking or balancing tasks in 7 articles and the motor tasks related to upper extremity were selected in 3 studies. The effect sizes for ADL function and Cognitive function were 0.65 and 0.64 (medium size effect) respectively. Moreover, the effect sizes of Lower extremity and Upper extremity motor function were 0.34 and 0.22 (small size effect) respectively. The effect size of ADL function and Cognitive function were statistically significant p<0.05). Conclusion : This study confirmed that dual-ask training can be a useful intervention technique for recovering a stroke patient's ability to perform daily activities and cognitive functions. This could be used as a helpful data when selecting appropriate intervention for stroke patients in the clinical setting.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.1
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• pp.93-108
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• 2022

PURPOSE: This review sought to confirm the correlation between dual-task gait and cognitive function in cognitively impaired and healthy older adults. METHOD: We used four databases (DBs), Pubmed, Cochrane library, Kmbase, and Koreamed. Searches were carried out according to the PICOS method, P (participants) were the elderly (above 65 years) with cognitive decline, I (intervention) was walking with dual tasks, C (control group) comprised the elderly without cognitive decline, O (outcome) was the correlation between gait and cognitive function and S (study) was the cross-sectional study. For the methodological quality assessment of each study, we used the Quality Assessment Tool for Observation Cohort and Cross-Sectional Studies provided by the National Institutes of Health (NIH). RESULTS: A total of 10 articles were included in this systematic review. For the components of gait, we used pace, rhythm, and variability and we observed that mild cognitive impairment mostly causes low gait performance while performing dual tasks. Among the 10 articles, 9 articles studied pace, of which 7 showed significant results. However, 2 were not significant. Also, 1 article that studied rhythm and 3 articles that studied variability showed significant results. The methodological quality of the 10 studies was fair. CONCLUSION: Gait pace was found to have a high correlation between memory, which is a cognitive ability, and overall cognitive function. It was observed that older adults with mild cognitive impairment have reduced gait pace in single-task walking, and further decrease in dual-task gait pace shows the correlation between memory and gait pace during walking.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.2
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• pp.23-33
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• 2021

Purpose : This study aimed to investigate the effects of dual-task training according to the variability of the walking environment on balance, gait, and function in patients with stroke. Methods : Twenty-five patients with stroke were randomly assigned to experimental group I (n=12) and experimental group II (n=13). Experimental group I and II performed obstacle and non-obstacle walking training, respectively, along with cognitive tasks for 21 minutes per session, 3 times a week for 6 weeks. Both groups received additional general physical therapy for 30 minutes per session. The functional reach test (FRT), gait analyzer (G-Walk), and functional independence measure (FIM) were used to evaluate balance, gait and function of pre- and post-interventions, respectively, while gait cadence, gait velocity, and stride length were evaluated using a gait analyzer. Results : In the within-group comparison of FRT, all the two groups showed significant post-intervention improvements (p<.05). In within-group comparison of gait cadence, all the two groups showed significant post-intervention improvements (p<.05). In within-group comparison of gait velocity, all the two groups showed significant post-intervention improvements (p<.05). In within-group comparison of stride length, experimental group I showed significant post-intervention improvements (p<.05), while experimental group II did not show significant post-intervention improvements (p>.05). In within-group comparison of FIM scores, experimental group I showed significant post-intervention improvements (p<.05), while experimental group II did not show significant post-intervention improvements (p>.05). There was a significant difference in the change of FIM scores pre- and post-intervention (p<.05) in the between-group comparison. Conclusion : The results of this study show that dual-task training with cognitive tasks and walking training can improve the balance, gait and function of patients with stroke, and obstacle walking training is effective for improving functions including activities of daily living compared to non-obstacle walking training.

• PNF and Movement
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• v.10 no.1
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• pp.25-33
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• 2012

Purpose : The purpose of this study was to compare the effect of treadmill training and cognitive task with in the course of treadmill training at the same time with chronic stroke patients. Methods : Fourteen chronic stroke patients participated. Participants were randomly assigned to the control and experimental group(7 experimental, 7 control). All of participants were in-patients at local hospital and had been receiving a traditional rehabilitation program, five days a week. The both groups have undergone 4weeks. The experimental group trained in treadmill and cognitive task at the same time, but control group trained only treadmill. 10m walking test, Timed Up & Go (TUG) test and 6 Minutes walking(6M walking) test to measure the walking speed, dynamic balance and waling endurance ability were carried out before and after the training. Results : The result of the study were as follow:10m walking test were significantly increased both groups(p<.01), but not significant between groups(p>.05). TUG test were significantly increased both groups(p<.001) and between groups(p<.01). 6M walking test were significantly increased both groups(p<.001), but not significant between groups(p>.05). Conclusion : Ahead of return to the community to patients with stroke, cognitive task with in the course of treadmill training at the same time was effective in improving the dynamic balance ability.

• Journal of the Ergonomics Society of Korea
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• v.32 no.6
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• pp.517-528
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• 2013

Objective: The objective of this study was to suggest a multi-modal controller type for Smart TV Control. Background: Recently, many issues regarding the Smart TV are arising due to the rising complexity of features in a Smart TV. One of the specific issues involves what type of controller must be utilized in order to perform regulated tasks. This study examines the ongoing trend of the controller. Method: The selected participants had experiences with the Smart TV and were 20 to 30 years of age. A pre-survey determined the first independent variable of five tasks(Live TV, Record, Share, Web, App Store). The second independent variable was the type of controllers(Conventional, Mouse, Voice-Based Remote Controllers). The dependent variables were preference, task completion time, and error rate. The experiment consist a series of three experiments. The first experiment utilized a uni-modal Controller for tasks; the second experiment utilized a dual-modal Controller, while the third experiment utilized a triple-modal Controller. Results: The first experiment revealed that the uni-modal Controller (Conventional, Voice Controller) showed the best results for the Live TV task. The second experiment revealed that the dual-modal Controller(Conventional-Voice, Conventional-Mouse combinations) showed the best results for the Share, Web, App Store tasks. The third experiment revealed that the triple-modal Controller among all the level had not effective compared with dual-modal Controller. Conclusion: In order to control simple tasks in a smart TV, our results showed that a uni-modal Controller was more effective than a dual-modal controller. However, the control of complex tasks was better suited to the dual-modal Controller. User preference for a controller differs according the Smart TV functions. For instance, there was a high user preference for the uni-Controller for simple functions while high user preference appeared for Dual-Controllers when the task was complex. Additionally, in accordance with task characteristics, there was a high user preference for the Voice Controller for channel and volume adjustment. Furthermore, there was a high user preference for the Conventional Controller for menu selection. In situations where the user had to input text, the Voice Controller had the highest preference among users while the Mouse Type, Voice Controller had the highest user preference for performing a search or selecting items on the menu. Application: The results of this study may be utilized in the design of a controller which can effectively carry out the various tasks of the Smart TV.