• Dementia and Neurocognitive Disorders
• /
• v.22 no.4
• /
• pp.139-147
• /
• 2023

Background and Purpose: Dual walking task such as crossing over an obstacle may serve as an excellent tool for predicting early cognitive decline. Thus, this study aimed to investigate correlation between walking while crossing over an obstacle and executive functions under different gait phases to validate the use of walking with an obstacle for predicting early cognitive decline. Methods: A cross-sectional study was conducted on 48 elderly individuals from 2 day-care centers and 3 welfare-centers in Seoul and Gyeonggi, Korea. Executive function tests (Trail Making Test, Stroop test) and dual walking tests (gait speed, cadence, stance time, gait cycle time) were performed and compared using partial correlation analysis. Results: There were significant correlations between executive function and most of the gait variables (stance time, cadence, and gait cycle time) (p<0.05) when crossing over an obstacle while walking. Especially, stance time exhibited significant correlations with most executive functions (p<0.05). Conclusions: When evaluating executive function during walking with an obstacle, post-obstacle-crossing phase and stance time need to be observed.

• PNF and Movement
• /
• v.21 no.1
• /
• pp.11-18
• /
• 2023

Purpose: This study aims to compare the effects of obstacle walking training combined with cognitive tasks on balance, gait, and activities of daily living in patients with stroke. Methods: A single-subject design was used, where one stroke patient participated. Obstacle walking training combined with cognitive tasks was performed for 1 hour per day for a total of 10 times during the intervention phase. The subjects were measured five times in the baseline phase, 10 times in the intervention phase, and five times in the follow-up phase. The outcome measurements included the Berg balance scale (BBS), the 10-meter walk test (10 MWT), and the Korean modified Barthel index (K-MBI). Results: In this study, the results showed that the 10 MWT scores during the intervention period improved and that this improvement remained, even during the post-period. In addition, BBS and K-MBI values for stroke patients increased significantly after training. Conclusion: The results of this study revealed that obstacle walking training combined with cognitive task training may be helpful to improve balance, gait, and activities of daily living in stroke patients. Therefore, obstacle walking training combined with cognitive tasks is recommended for stroke patients.

• Journal of the Korean Society of Physical Medicine
• /
• v.17 no.3
• /
• pp.51-58
• /
• 2022

PURPOSE: This study aimed to evaluate the correlation between executive function and gait evaluations for the elderly, and validate the obstacle gait evaluation as a cognitive impairment test tool. METHODS: This study was a cross-sectional design. 79 people aged 65 years or older were selected as subjects. The Korean version of the Mini-Mental State Examination (MMSE-KC) to evaluate overall cognitive function and the Trail Making Test (TMT) A, B to measure executive function were performed. The 4-meter walking speed test and the walking speed test while crossing over an obstacle were carried out to evaluate gait. The Spearman's correlation was used to measure the correlation between cognition and gait speed. RESULTS: There was no significant correlation between the 4 m gait speed and executive function( TMT-A (p = .056), TMT-B (p = .115)). However, there was a significant correlation between the 4 m gait speed and MMSE-KC (r = .277, p < .05). There was also a significant correlation between walking speed while crossing over an obstacle and all tests (MMSE-KC (r = .382, p < .01). TMT-A (r = -.327, p < .01), TMT-B (r = -.283, p < .05)). CONCLUSION: It was found that the gait speed while crossing over an obstacle was correlated with all cognitive function tests. Therefore, we suggest the use of the gait speed test while crossing over an obstacle rather than the simple gait test to diagnose cognitive decline.

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

• Journal of Electrical Engineering and Technology
• /
• v.9 no.3
• /
• pp.1034-1042
• /
• 2014

For the remote operation of the mobile robot, the human operator depends fully on the sensory information which is the partial information of the workspace of the mobile robot. It is usually very hard to fully manually operate the mobile robot in this situation. We propose the efficient guidance navigation method for improving the efficiency of the remote operation with the expanded guide circle using the sensory information. The guidance command is generated from the proposed algorithm using the expanded guide circle. We evaluated the performance of the proposed algorithm using the experiments.

• Journal of the Korean Society of Safety
• /
• v.21 no.5 s.77
• /
• pp.103-111
• /
• 2006

The purpose of this study was to analyse the relationships between cognitive abilities and driving characteristics of elderly drivers. Driving characteristics of elderly and younger drivers who were driving a fixed base driving simulator vehicle were examined. Participants consisted of 12 drivers over age 65 (the 'older' group) and 12 drivers between the ages of 25 and 55 (the "younger" group). As indices of cognitive ability, critical flicker fusion frequency (CFF) tests and cognitive reaction tests were given before the driving task. CFF was also tested after the simulated driving task for both groups. Cognitive reaction tests, which were composed of speed estimation tests, multiple choice reaction tests and obstacle avoidance tests, were developed by the Korean Road Traffic Safety Authority in 2003. CFF values between the two groups exhibited significant differences both before and after the task, with a p-value less than 0.01 and a t-value of -3.01 before the test and a p-value less than 0.031 and a t-value of -2.35 after the test. Older drivers' CFF values were lower than those of the younger. However, there was no difference in older or younger driver CFF values before and after the task within the same group. Except for the multiple choice reaction test, there was no difference in cognitive reaction test results between the two groups. The elderly drivers made more errors though they did not differ from the younger drivers in reaction times. At the simulated driving task the reaction time of the elderly driver was longer than that of the younger; however, the driving speed of the elderly was lower and the number of collisions greater. There was a positive correlation (r=.496) between the number of errors in the multiple choice reaction test and the number of collisions in the driving task. Therefore, it was identified that critical attributes contributing to automobile crashes involving elderly drivers included cognitive difficulty in judging and responding to complex situations.

• Proceedings of the Korean Information Science Society Conference
• /
• 2011.06a
• /
• pp.352-354
• /
• 2011

The performance of multihop cognitive radio networks (CRN) can be improved significantly by using multiple channels in spectrum underlay fashion. However, interference due to the sharing of common radio channel and congestion due to the contention among those flows that share the same links become an obstacle to meet this challenge. How to control efficiently congestion and allocate power optimally to obtain a high end-to-end throughput is a key objective in this work. We reexamined the Network Utility Maximum (NUM) problem with a new primary outage constraint and proposed a novel resource allocation strategy to solve it effectively and efficiently.

• Journal of Internet Computing and Services
• /
• v.12 no.1
• /
• pp.1-10
• /
• 2011

The spectrum sensing is one of the fundamental functions to realize the cognitive radios. One of problems in the spectrum sensing is that the performance of spectrum sensing can be degraded due to fading and shadowing. In order to overcome the problem, cooperative spectrum sensing method is proposed, which uses a distributed detection model and can increase sensing performance. However, the performance of cooperative spectrum sensing can be still affected by the interference factors such as obstacle and malicious user. Especially, most of cooperative spectrum sensing methods only considered the stationary primary user. In the ubiquitous environment, however the mobile primary users should be considered. In order to overcome the aforementioned problem, in this paper we propose a robust spectrum detection method based on localization where we estimate the location of the mobile primary user, and then based on the location and transmission range of primary user we detect interference users if there are, and then the local sensing reporting from detected interference users are excluded in the decision fusion process. Through simulation, it is shown that the sensing performance of the proposed scheme is more accurate than that of conventional other schemes

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.1
• /
• pp.83-89
• /
• 1999

For the object-oriented development methods authorized by OMG a number of official methodologies such as Booch, Coad/Yourdon methods are used in the development of the object-oriented soft ware and each methodology represents its process of analysis and design using different symbols. Between those notation methodologies there exist some differences as a matter of development, information for transfer, accordingly they act on the transfer of the information in the object-oriented development as obstacle and give rise to they natural outcome of error. The aim of this study is in the presentation of ideas that decrease the probability of errors by means of verify8ing the transferring ability of information which the existing diagrammatic notation methodologies have had on the basis of cognitive science, minimizing the cognitive load from the object-oriented development through enhancing symbols in each obstacles to transferring information and removing them.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.7
• /
• pp.4005-4013
• /
• 2013

Background: Although breast cancer is a major public health worry among Asian women, adherence to screening for the disease remains an obstacle to its prevention. A variety of psycho-social and cultural factors predispose women to delay or avoidance of screening for breast cancer symptoms at the early stages when cure is most likely to be successful. Yet few interventions implemented to date to address this condition in this region have drawn on health behavior theory. Materials and Methods: This paper reviews the existing literature on several cognitive theories and models associated with breast cancer screening, with an emphasis on the work that has been done in relation to Asian women. To conduct this review, a number of electronic databases were searched with context-appropriate inclusion criteria. Results: Little empirical work was found that specifically addressed the applicability of health theories in promoting adherence to the current breast cancer prevention programs Among Asian women. However, a few studies were found that addressed individual cognitive factors that are likely to encourage women's motivation to protect themselves against breast cancer in this region of the world. The findings suggest that multi-level, socio-cultural interventions that focus on cognitive factors have much promise with this issue. Conclusions: Interventions are needed that effectively and efficiently target the personal motivation of at-risk Asian women to seek out and engage in breast cancer prevention. Concerning implications, personal motivation to seek out and engage in individual preventive actions for breast cancer prevention among Asian women is a timely, high priority target with practical implications for community development and health promotion. Further studies using qualitative, anthropologic approaches shaped for implementation in multi-ethnic Asian settings are needed to inform and guide these interventions.