• Journal of the Korea Society for Simulation
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• v.28 no.2
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• pp.119-129
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• 2019

Although line production systems with finite buffers have been studied over several decades, except for some special cases there are no explicit expressions for system performances such as waiting times(or response time) and blocking probability. Recently, a max-plus algebraic approach for buffer-sharing systems with constant processing times was introduced and it can lead to analytic expressions for (higher) moment and tail probability of stationary waiting. Theoretically this approach can be applied to general processing times, but it cannot give a proper way for computing performance measures. To this end, in this study we developed simulation models using @RISK software and the expressions derived from max-plus algebra, and computed and compared blocking probability, waiting time (or response time) with respect to two blocking policies: communication(BBS: Blocking Before Service) and production(BAS: Blocking After Service). Moreover, an optimization problem which determines the minimum shared-buffer capacity satisfying a predetermined QoS(quality of service) is also considered.

• Journal of Gynecologic Oncology
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• v.29 no.6
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• pp.82.1-82.13
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• 2018

Objective: The impact of beta blockers (BBs) on survival outcomes in ovarian cancer was investigated. Methods: By using Korean National Health Insurance Service Data, Cox proportional hazards regression was performed to analyze hazard ratios (HRs) with 95% confidence intervals (CIs) adjusting for confounding factors. Results: Among 866 eligible patients, 206 (23.8%) were BB users and 660 (76.2%) were non-users. Among the 206 BB users, 151 (73.3%) were non-selective beta blocker (NSBB) users and 105 (51.0%) were selective beta blocker (SBB) users. BB use in patients aged ${\geq}60$ years, longer duration use (${\geq}1$ year), in patients with Charlson Comorbidity Index (CCI) ${\geq}3$, and in cardiovascular disease including hypertension was associated with better survival outcome. These findings were observed in both NSBB and SBB. When duration of medication was analyzed based on number of days, NSBB (${\geq}180$ days) was associated with improved overall survival (OS) with a relatively shorter period of use compared to SBB (${\geq}720$ days). In multivariate Cox proportional hazards model, longer duration of BB medication (${\geq}1$ year) was an independent favorable prognostic factor for both OS and disease-specific survival in ovarian cancer patients. Conclusion: In our nationwide population-based cohort study, BB use was associated with better survival outcomes in ovarian cancer in cases of long term duration of use, in older patients, and in cardiovascular and/or other underlying disease (CCI ${\geq}3$).

• Journal of Korean Physical Therapy Science
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• v.27 no.3
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• pp.35-44
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• 2020

Background: This study was to confirm the effect and feasibility of knee extension assist orthosis (KEAO) on balance and gait in subacute stroke patients. Design: Case study. Methods: The subjects of the study were 4 subacute stroke patients, who had an onset period of less than 6 months. The limit of stability (LOS) and berg balance scale (BBS), timed up and go test (TUG) were used to verify the dynamic balance ability, static balance ability, and gait ability pre and post and after wearing the knee extension assist orthosis (KEAO). In addition, the satisfaction survey was to confirm the feasibility of the knee extension assist orthosis (KEAO) through the to Korean quebec user evaluation of satisfaction assistive technology 2.0 (K-QUEST 2.0). Results: After the wearing on KEAO, the distance for the limit of stability decreased by mean 541.25±240.46 mm2, and the score on the berg balance scale improved by mean 5±2.71 point, and the time for the timed up and go test deceased by mean 3.75±1.71 second. The stability and durability were found to be full score, and the control, ease, effectiveness were some high score, and the size, weight, comfort were some low score in the satisfaction and feasibility. Conclusion: The knee extension assist orthosis (KEAO) produce in this study was improved the static balance ability, dynamic balance ability and gait ability of subacute stroke patients, and the satisfaction and feasibility were high in the stability, durability and effectiveness of the user.

• Archives of Orthopedic and Sports Physical Therapy
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• v.14 no.2
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• pp.117-126
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• 2018

Purpose: The purpose of this study was to evaluate the effect of task-oriented exercise and abdominal muscle contraction using functional electrical stimulation (FES) on abdominal muscle thickness and balance of stroke patients. Methods: Ten stroke patients who met the selection criteria were assigned randomly into two groups of five. One group received FES therapy before task-oriented training (experimental group), while the other group received a FES placebo before task-oriented training (control group). The Mann-Whitney U test was used to compare the groups, and the Wilcoxon Signed-ranks test was used to compare differences between the groups before and after intervention. The Mann-Whitney U test was used to compare the rate changes of each item before and after intervention, between the two groups. Results: In the rectus abdominalis and external oblique muscle thickness tests that used ultrasound, there was a statistically significant difference in the experimental group (p<.05),but no significant difference in the control group (p>.05). There was also a significant difference between the groups (p<.05). In the Balance test that used the Berg Balance Scale (BBS) and timed up and go test (TUG), there was a statistically significant difference in the experimental and control groups (p<.05), but there was no significant difference between the groups (p>.05). Conclusions: FES therapy before task-oriented training increases the thickness of abdominal muscles and improves balance abilities.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.1
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• pp.21-29
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• 2023

Purpose : Using a smartphone while walking districts attention and increases the risk of losing balance or falling. Ankle instability is caused by decreased muscle strength and decreased neuromuscular ability leading to postural control problems. Dual tasks increases the risk of falls by reducing postural control in adults with ankle instability. This study aimed to investigate the effect of performing a dual task on balance and muscle activity in adults with ankle instability using a smartphone. Methods : Forty-nine individuals with ankle instability participated in this study. A game of finding the wrong picture was performed using a smartphone in the dual task, and only looking at the blank screen of a smartphone was evaluated in the single task. The participants randomly performed single and dual task to evalutate balance and muscle atcitivy. Balance was evaluated using the Biodex balance system (BBS), and muscle activity was evaluated using surface EMG. Muscle activity of the gastrocnemius and tibialis anterior was measured at the same time as balance. Results : The results of this study showed that overall, anteior/posterior, and medial/lateral balance indices all showed significant differences when performing the dual task compared with those during the single task (p<.05). The muscle activity results showed a significant difference compared with that of the gastronemius muscle on the nondominant side during the dual task (p>.05). Conclusion : The results of this study showed that maintaining balance is more difficult when performing the dual task than during the single task, and only the muscle activity of the nondominant gastrocnemius muscle decreased. The dual task causes a decrease in concentration for postural control, which negatively affects postural stability. Individuals with ankle ankle instability should refrain from performing dual tasks, such as using smartphones, to prevent ankle damage.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.807-812
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• 2023

This study examines the training effectiveness of airsoft guns that look and operate like real guns. Airsoft guns were developed in Japan in the late 1970s and are now popular for leisure sports and training, especially in countries where gun ownership is permitted. In particular, Taiwan has been promoting airsoft gun games to train citizen soldiers, and military leaders such as the United States have also utilized airsoft guns for live fire combat training and combat troops' live fire training. However, due to strict usage regulations and the perception that it is a toy, it is underutilized in Korea despite being a good training tool. Therefore, this study will prove the effectiveness of airsoft guns and improve the military's combat capabilities through practical training using airsoft guns. In addition, it will improve the negative perception of airsoft guns and foster a new sports industry.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.3
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• pp.179-188
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• 2024

Purpose : The home-visiting exercise guidance service is a component of the community-based integrated care policy in District J of Busan Metropolitan City. This study aims to investigate the effects of the service provided by physical therapists on depression, pain, and balance among the elderly. Methods : Three elderly individuals were selected as study participants. Depression was assessed using the beck depression inventory (BDI) and the short geriatric depression scale-Korea (SGDS-K). Pain was evaluated using the visual analog scale (VAS). Balance was assessed using the berg balance scale (BBS), functional reach test (FRT), and timed up and go test (TUGT). The evaluation data were compared by averaging the values from the first and eighth sessions. Additionally, the overall satisfaction with the home-visiting exercise guidance service was surveyed. Results : In the depression assessment, the beck depression inventory score decreased (by 16.67±5.69 points), and the short geriatric depression scale score decreased (by 4.67±2.52 points). The visual analog scale score for pain decreased (by 2.67±0.58 points). In the balance assessment, the berg balance scale score increased (by 7.67±2.52 points), the functional reach test distance extended (by 4.67±0.58 cm), and the timed up and go test time decreased (by 5.33±0.58 s). Overall satisfaction with the home-visiting exercise guidance service was high (4.26±0.14 points). Conclusion : The home-visiting exercise guidance service received high satisfaction ratings from the participants. It was effective in reducing depression and pain while improving balance, potentially reducing fall risk factors among the elderly. These findings suggest that the home-visiting exercise guidance service, delivered by physical therapists, could significantly enhance the quality of life for elderly individuals by addressing issues related to depression, pain, and fall prevention within the community. Consequently, it is recommended that this service be continued and expanded as part of government policy.

• Therapeutic Science for Rehabilitation
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• v.8 no.3
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• pp.57-68
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• 2019

Purpose: This study aimed to investigate the effects of a short-term group multimodal intervention program that mixes physical activity, cognitive motion, and social interaction, on the cognitive function and depression level of healthy over 75-year-old individuals. Method: This study used a one group pre-test-post-test design, and intervention was made for 70 minutes per session, once a week, for four sessions in total. To compare changes in cognitive function, depression level and physical function before and after intervention, this study used the Mini-Mental State Examination-Dementia Screening (MMSE-DS), Geriatric Depression Scale-Short Form (GDS-SF), and Berg Balance Scale (BBS). Result: After applying group multimodal interventions to healthy over 75-year-old individuals, there was a statistically significant improvement in their cognitive function (p < 0.01), and there was a statistically significant decrease in their depression level (p < 0.05). Also, there was an increase in the rating score of the degree of balance from $46.83{\pm}9.11$ points before the intervention, to $48.08{\pm}7.00$ points after the intervention; however, it was not statistically significant (p > 0.05). Conclusion: Short-term group multimodal intervention that mixes physical activity, cognitive motion, and social interaction had a significant effect on slowing down the deterioration of cognitive function in healthy over 75 year-old individuals, and decreased their depression level. This study is significant in that it presents a foundation for providing more systematic intervention for the prevention of dementia and depression in the healthy older individuals. Follow-up studies should verify the result through research on the effects of an occupational therapist's professional treatment, and experimental group-control research.

• The Journal of Korean society of community based occupational therapy
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• v.6 no.2
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• pp.1-10
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• 2016

Objective : The purpose of this study was to examine the effect of multi-sensory stimulation training on cognitive function and balance skill of the community resident elderly. Methods : 10 participants who is over aged 65 years carry out multisensory stimulation training program for 12weeks, once a week for 60minutes. The multisensory stimulation training program is consisted of total 12 topic based on body schema, gross muscle and tactile stimulation. The result was measured using Mini-Mental State Examination-Korean and Berg Balance Scale to evaluate before and after of cognitive function and balance skill. And after intervention, the satisfaction of the program was investigated. Wilcoxon matched-pair signed rank test was used to compare pre- post difference of cognitive function and balance skill. Results : There was significant difference in cognitive function and balance skill(p<.05) and the satisfaction is positive at the end of the program. Conclusion : The multisensory stimulation training program has positive effects on cognitive function and balance skill for elderly. And the satisfaction is positive at the end of the program. The multisensory stimulation training program can enhance the satisfaction to elderly in the aging society. So, additional studies is needed for efficient use.

• The Journal of the Korea Contents Association
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• v.14 no.1
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• pp.30-39
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• 2014

The purpose of this study is to suggest the feasible strategies to vitalize e-learning through investigating the characteristics of e-learning and the evaluations of distance learners on online courses in the domestic universities in Korea. First, in order to accomplish this, 10 Universities and 17 Cyber Universities were selected to explore their characteristics and main projects of e-learning for the administration level investigation. Secondly, content analysis of the bulletin board systems(BBS) and in-depth interviews on distance learners in Cyber Universities were conducted for the user level investigation. The results revealed that Universities in Korea were focused on establishing mobile or smart campuses, diversifying online educational contents, enhancing online interactive systems, and educating e-learning system and smart device utilization. However, distance learners reported that mobile e-learning lacked stability when taking online courses despite its convenience for purpose of academic administration. In addition, distance learners requested the social application workshops to improve on their learning experience as well as the interactions among peers. Therefore, it is important to focus more on how to establish the education-oriented e-learning environment rather than how to implement the administrative projects to animate e-learning in the domestic universities in Korea.