• Journal of the Korean Society of Physical Medicine
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• v.18 no.2
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• pp.41-48
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• 2023

PURPOSE: Falls are caused by a decline in physical and cognitive function. A quantitative evaluation tool that can comprehensively evaluate motor and cognitive functions for elderly people with an impaired physical function. This study assessed the clinical application potential by confirming the correlation between the physical function tests, cognitive and the stepping trail-making test (S-TMT). METHODS: Fourteen community-dwelling older patients (65-75 years) were recruited. The study conducted cognitive function tests with the trail-making test (TMT-A, B), and physical function tests (6-minute walking test (6MWT), short physical performance battery (SPPB), and timed up and go (TUG)). The results of were analyzed using SPSS version 21.0. Descriptive statistics were used for the general characteristics of the study subjects, and the correlations between S-TMT, other functional tests were examined through Pearson's correlation analysis. The statistical significance was set to .05. RESULTS: S-TMT had a significant positive correlation with the TUG (r = .588^*) and trail-making test-B (TMT-B) (r = .689^*, p < .05). Furthermore, S-TMT showed a negative correlation between SPPB (r = -.397) and 6MWT (r = -.422), but it was not statistically significant. CONCLUSION: S-TMT is a cognitive-gait dual-task performance evaluation tool that can be performed safely. A significant correlation was confirmed between the TUG test and the TMT-B. S-TMT is a dual-task screening tool that can evaluate both physical and cognitive functions simultaneously.

• Communications for Statistical Applications and Methods
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• v.22 no.2
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• pp.137-146
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• 2015

Singh (2013) considered the dual problem to the calibration of design weights to obtain a new generalized linear regression estimator (GREG) for the finite population total. In this work, we have made an attempt to suggest a way to use the dual calibration of the design weights in case of multi-auxiliary variables; in other words, we have made an attempt to give an answer to the concern in Remark 2 of Singh (2013) work. The same idea is also used to generalize the GREG estimator proposed by Deville and S$\ddot{a}$rndal (1992). It is not an easy task to find the optimum values of the parameters appear in our approach; therefore, few suggestions are mentioned to select values for such parameters based on a random sample. Based on real data set and under simple random sampling without replacement design, our approach is compared with other approaches mentioned in this paper and for different sample sizes. Simulation results show that all estimators have negligible relative bias, and the multivariate case of Singh (2013) estimator is more efficient than other estimators.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.7
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• pp.40-50
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• 1996

An unified compliant control algorithm to regulate the force by dual arms is proposed, where tow arms are treated as one arm in a kinematic viewpoint. The force error calculated form the information of two force/torque sensors attached to the end of each arm is transferred to minimum actuator coordinates, and then is distributed to total system actuator coordinates. The position adjustment at the total actuator coordinates is computed based on the effective computed based on the effective compliance matrix with respect to total actuator coordinates, which is obtained by coordinate transformation between the task coordinates and the total actuator coordinates. An experiment is carried out for dual arms with asymmetric kinematic structure to control an interaction force between manipulators and the environment. The performances of the proposed control algorithm are experimentally compared to those of dual arms employing master/slave scheme. The proposed compliant control algorithm not only ouperforms other algorithms, but also can be treated as an unified approach n the sense that it can be applied to arbitrary dual arm systems with general kinematic structures.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.279-280
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• 2012

In this paper, as a part of studying the fast battery charger, designed the charging system by applying dual converter. This dual converter was applied to the charging system for reducing time by dividing high current which prevents the damage of parts from heating of components. In this paper continued the task by switching the topology of the dual converter for fast charging battery into SISO, PISO, and PIPO. The study to derive the optimized system topology by analyzing the efficiency of charging system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5B
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• pp.287-294
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• 2005

It is impossible to replace overnight the present Internet Protocol Version 4(IPv4)-based Internet with Internet Protocol Version 6(IPv6). These two protocols are expected to coexist for a number of years during the transition period. A number of transition mechanisms are proposed by Internet Engineering Task Force(IETF) Next Generation Transition Working Group(Ngtrans WG). However, most of them provide only the mechanism to initiate sessions from hosts within the IPv6 network to those within the IPv4 network, but do not support the initiation from IPv4 hosts to IPv6 ones. In this paper, we propose the IPv4-to-IPv6 Dual Stack Transition Mechanism(4to6 DSTM) which can operate even in the case that IPv4 clients in the IPv4 network initiate connections with dual stack servers in the IPv6 network.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.1
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• pp.51-59
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• 2017

PURPOSE: This study compared cognitive task-directed functional motor control ability for reaching and kicking movements in younger and older adults. METHODS: Subjects were divided into two groups of younger and older adults, with 13 subjects in each group. Subjects were required to perform a dual task combining a functional movement and cognitive component. The task consisted of reaching and kicking movements. Participants performed indicated movements when a target appeared on a monitor. The target randomly appeared on the monitor every 10 seconds. The total performance time (TPT), joint angular velocity (JAV), and muscle activation time were used to evaluate motor control ability. RESULTS: There were significant differences in all evaluation factors in a comparison of younger and older adults (p<.05). TPT was significantly shorter in older adults, and JAV and muscle activation time were significantly slower than that in the younger adult group. Although the results for older adults were within the normal range for functional assessment, their motor control abilities were significantly worse for cognitive tasks compared with those of younger adults. CONCLUSION: The results of this study indicated that a motor control assessment tool using a cognitive task would be helpful in assessment of motor control ability in healthy older adults.

• Physical Therapy Rehabilitation Science
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• v.3 no.2
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• pp.134-141
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• 2014

Objective: The purpose of this study was to compare with different distance across three conditions in stroke survivors with the grading of cognitive state. Design: Cross-sectional study. Methods: Twelve stroke patients who agreed to active participation were included. Participants were allotted to normal cognitive (CN) group (n=7) and cognitive impairment (CI) group (n=5) and then walked on a self-paced walkway at three conditions on the Time Up and Go (TUG) test and the 6 minute walk test (6MWT): 1) walking with your comfortable speed, 2) walking while carrying a tray with glasses, 3) walking with a verbal cognitive task. The TUG test was repeated three successful times on each condition. For the 6MWT, participants were tested one time. Results: The CI group walked slower than the CN group at the three conditions on the TUG test. However, there was no significant difference between two groups to each condition. A significant effect of dual tasking was found only in error of verbal cognitive task condition for the TUG test (p<0.05). On the 6MWT, the participants in the CI group walked short distance rather than the CN group (p<0.05). There were significant differences between two groups not only at all conditions but also at error of verbal cognitive task condition as well (p<0.05). Conclusions: To consider the results of different distances such as the TUG test and the 6MWT, we think that exercises in long distance would be more effective to patients with CI. Those would be improved patient's endurance in cognitive problem.

• Korean Journal of Cognitive Science
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• v.7 no.3
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• pp.115-134
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• 1996

The study was designed to investigate implicit and explicit memory for words with processing theory.From experiment 1 to experiment 3,in a study phase,subjects first viewed stimulus words and were required to rate likeness of words of semantic processing task and to count lines of words of perceptual processing task.In a test phase,subjects were tested by implicit word completion task and explicit cued recall task.In experiment 1,levels of processing (LOP)effects were examined.Lop effects were obtained on the explicit memory tasks but not on the implicit memory tasks.In experiment 2,repertition of perceptual processing task influenced onlu implicit memory task.In experiment 3,bepertiotion of semantic processing task affected both implicit memory task and explicit memory task.These findings suggest that repetition effect of stimulus words are explanied better in dual process theory than transfer-appropriate processing theory.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.3
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• pp.99-108
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• 2020

PURPOSE: This study examined the effects of the confusion level in performing dual tasks using smartphones while walking in subjects with chronic ankle instability (CAI). METHODS: Twenty subjects with CAI and 20 healthy subjects participated in the study. The spatial, temporal, spatial-temporal, and variability gait parameters were measured using GAITRite under four different conditions: general gait, web surfing during gait, texting during gait, and gaming during gait. Two-way repeated-measures analysis of variance was used to analyze the interaction according to the group (2) and confusion level in dual-tasks (4). One-way repeated-measures analysis of variance was used to compare the changes within the group according to the confusion level in dual-tasks. The changes between groups were compared using an independent t-test. The statistical significance level was set to p = .05. RESULTS: Significant interactions in the temporal and spatial-temporal gait parameters were found between the dual-task conditions and the other groups (p < .05). Significant within-group differences in the spatial, temporal, and spatial-temporal gait parameters were found according to the confusion level in dual tasks (p < .05). Significant between-group differences were observed in the temporal and spatial-temporal gait parameters according to the confusion level in dual tasks (p < .05). CONCLUSION: The effect of the confusion level in dual tasks was greater in subjects with CAI than in healthy individuals. This study suggests that to prevent reinjury to the ankle, subjects with CAI should avoid dual tasks such as using smartphones while walking.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.817-821
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• 1991

Coordinated motion control of two arms of a dual-arm robot has been studied by many researchers, because of it's potential application in assembly as well as the handling of large and heavy objects beyond the capacity of single arm. This paper derives dynamic equation of a dual-arm robot, and describes some constrains to pick up a simply shaped object at prespecified position on it. This paper concludes with describing both PD and self-tunning control algorithm for the above task.