• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.311-331
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• 2021

Climate change with extreme hydrological events has become a significant concern for agricultural water systems. Climate change affects not only irrigation availability but also agricultural water requirement. In response, adaptation strategies with soft and hard options have been considered to mitigate the impacts from climate change. However, their implementation has become progressively challenging and complex due to the interconnected impacts of climate change with socio-economic change in agricultural circumstances, and this can generate more uncertainty and complexity in the adaptive management of the agricultural water systems. This study was carried out for the agricultural water supply system in Seongju dam watershed in Seonju-gun, Gyeongbuk in South Korea. The first step is to identify system disturbances. Climate variation and socio-economic components with historical and forecast data were investigated Then, as the second step, problematic trends of the critical performance were identified for the historical and future climate scenarios. As the third step, a system structure was built with a dynamic hypothesis (causal loop diagram) to understand Seongju water system features and interactions with multiple feedbacks across system components in water, agriculture, and socio-economic sectors related to the case study water system. Then, as the fourth step, a mathematical SD (system dynamics) model was developed based on the dynamic hypothesis, including sub-models related to dam reservoir, irrigation channel, irrigation demand, farming income, and labor force, and the fidelity of the SD model to the Seongju water system was checked.

• The Journal of Korean Physical Therapy
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• v.24 no.2
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• pp.73-81
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• 2012

Purpose: The aim of the present study was to measure the standing balance symmetry of stroke patients using a force-plate with computer system, and to investigate the correlation between the standing balance symmetry and that of the walking function in stroke patients. Methods: 48 patients with stroke (34 men, 14 women, $56.8{\pm}11.72$ years old) participated in this study. Static standing balance was evaluated by the weight distribution on the affected and the nonaffected lower limbs, sway path, sway velocity, and sway frequency, which reflected the characteristic of body sway in quiet standing. Dynamic standing balance was evaluated by anteroposterior and mediolateral sway angle, which revealed the limit of stability during voluntary weight displacement. Symmetry index of static standing balance, (SI-SSB) calculated by the ratio of the affected weight distribution for the nonaffected weight distribution, and symmetric index of dynamic standing balance (SI-SDB) by the ratio of the affected sway angle for the nonaffected sway angle. Functional balance assessed by a Berg balance scale (BBS), and the functional walking by 10m walking velocity, as well as the modified motor assessment scale (mMAS). Results: Static balance scales and SI-SSB was the only correlation with BBS (p<0.05). Dynamic balance scales and SI-DSB, not only was correlated with BBS, but also with 10m walking velocity and mMAS (p<0.01). Additionally, there was a significant difference between SI-SSB and that of SI-DSB (p<0.01). Conclusion: The balance and the walking function relate to real life in the stroke showed strong relationships with the dynamic standing balance symmetry in the frontal plane and the ability of anterior voluntary weight displacement in sagittal plane.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.4
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• pp.149-162
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• 2018

PURPOSE: The aim of this study was to investigate the effect of scapular dynamic taping on pain, disability, upper body posture, and range of motion (ROM) in the postoperative shoulder. METHODS: Twenty-two patients who underwent acromioplasty and rotator cuff repair surgery volunteered for this study. The subjects were randomly divided into an experimental group (EG, n=11) and a control group (CG, n=11). For the EG, exercise therapy, manual therapy, and scapular dynamic taping were applied for 6 weeks; for the CG, only exercise therapy and manual therapy were applied for 6 weeks. Shoulder pain, disability, upper body posture, and ROM were evaluated at baseline, after 3 weeks of intervention, and after 6 weeks of intervention. Assessment tools included quadruple visual analog scale (QVAS) for level of pain; shoulder pain and disability index (SPADI) for functional disability level; forward head angle (FHA), forward shoulder angle (FSA), and pectoralis minor index (PMI) for upper body posture; and ROM testing. RESULTS: Significant differences were observed between the EG and CG in SPADI total scores; internal rotation and external rotation ROM of the glenohumeral joint ; FSA ; and PMI. All groups showed statistically significant improvement in QVAS; SPADI; flexion; abduction; external rotation and internal rotation ROM of the glenohumeral joint; FSA; and PMI. CONCLUSION: These results suggest that, for patients who have undergone acromioplasty and rotator cuff repair surgery, the addition of scapular dynamic taping during therapy is effective for improvement of shoulder disability level, ROM, and upper body posture.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.33-34
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• 2012

As the distributed power system with PV and ESS is highlighted to be one of the most prominent structure to replace the traditional electric power system, power flow scheduling is expected to bring better system efficiency. Optimal energy management system (EMS) where the power from PV and the grid is managed in time-domain using ESS needs an optimization process. In this paper, main optimization method is implemented using dynamic programming (DP). To overcome the drawback of DP in which ideal future information is required, prediction stage precedes every EMS execution. A simple auto-regressive moving-average (ARMA) forecasting followed by a PI-controller updates the prediction data. Assessment of the on-line optimal EMS scheme has been evaluated on several cases.

• Journal of Electrical Engineering and Technology
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• v.8 no.2
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• pp.197-205
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• 2013

Real time transient stability assessment mainly depends on real-time prediction. Unfortunately, conventional techniques based on offline analysis are too slow and unreliable in complex power systems. Hence, fast and reliable stability prediction methods and simple stability criterions must be developed for real time purposes. In this paper, two new methods for real time determining critical clearing time based on clustering identification are proposed. This article is covering three main sections: (i) clustering generators and recognizing critical group; (ii) replacing the multi-machine system by a two-machine dynamic equivalent and eventually, to a one-machine-infinite-bus system; (iii) presenting a new method to predict post-fault trajectory and two simple algorithms for calculating critical clearing time, respectively established upon two different transient stability criterions. The performance is expected to figure out critical clearing time within 100ms-150ms and with an acceptable accuracy.

• Corrosion Science and Technology
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• v.9 no.2
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• pp.87-91
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• 2010

It is pointed out that non-wetting behavior of liquid Zn alloy occurs on high-tensile strength steels, which usually contain Si and Mn. There have been a lot of investigations to improve the above wettability of liquid Zn alloy with steels containing Si and Mn. Although those studies evaluated the wettability qualitatively by observation of the surface of steels galvanized by Zn or exfoliation test of Zn with substrate steels and so on, it is required to evaluate the wettability of liquid Zn with steels by measuring contact angle, work of adhesion, spreading velocity etc. which are usually used to assessment of general wetting behavior. In the present work, we evaluated the wettability of liquid Zn with steels containing Si and Mn by applying a sessile drop method to measure the change in contact angle and diameter of liquid Zn droplet wetted on steels.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.437-446
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• 2023

As the interest in sustainable and environmentally friendly agriculture continues to grow, there is a corresponding increase in organic fertilizers utilization. However, studies on ammonia (NH₃) emissions, which are primarily generated in the agricultural sector, by organic fertilizers are lacking. Additionally, the reliance on imported ingredients in the production of organic fertilizers hinders the widespread adoption of organic fertilizers. This study aims to evaluate NH₃ volatilization by incorporating rice husk biochar into organic fertilizers. The study also aims to assess whether domestically produced rice husk biochar can serve as a viable substitute for imported ingredients. Here, the dynamic chamber method was used under controlled conditions. Results show that inorganic fertilizers readily undergo hydrolysis, thereby rapidly generating significant amounts of NH₃, particularly in the initial stages. In contrast, organic fertilizers decompose gradually, leading to relatively long-term NH₃ emissions. The incorporation of rice husk biochar into organic fertilizers demonstrated diminished daily NH₃ emissions compared to those from commercial organic fertilizers, resulting in decreased total NH₃ volatilization. These findings show that the combination of rice husk biochar can reduce NH₃ volatilization and serve as an alternative to imported ingredients for organic fertilizers. The results of this study can be utilized as fundamental information for the assessment of biochar as a potential ingredient for organic fertilizers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1894-1903
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• 2015

The purpose of this study was to examine the effects of group task-oriented circuit training (TOCT) based on motor learning applied in conjunction with physical and occupational therapy on functional activity, activities of daily living (ADLs), and quality of life in individuals with chronic stroke. Six chronic stroke patients participated for a duration of 31 weeks. Treatment outcomes were assessed via Chedoke-McMaster Stroke Assessment, the Berg Balance Scale, the Assessment of Motor and Process Skill (AMPS), and the Stroke Impact Scale pre- and post-intervention. The participants exhibited significant improvements in impairment, static and dynamic balance, and mood and emotion after group TOCT. The results of AMPS indicated an improvement in the motor area in 3 of the subjects. In the process area, 4 of the subjects exhibited improvement. The results of this study suggest that TOCT is beneficial to physical functions for chronic hemiparetic stroke patients in community-dwelling.

• PNF and Movement
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• v.9 no.2
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• pp.45-53
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• 2011

Purpose : Many researchers have attempted to identity the reliability used in clinical examination of balance and gait performance for individuals of hemiparetic stroke. The study aims to evaluate whether the reliabilities of three popular clinical measures of balance and gait performance was consistency regardless of applicate experience of those clinical measures compared with previous studies for persons with hemiparetic stroke. Methods : A total of three hemiparetic stroke populations and twenty-six physical therapists were recruited from Glory hospital, Inchen, Korea in this study. The three clinical measures, involving Berg balance test (BBT), dynamic gait index (DGI), and Tinetti performance-oriented mobility assessment (POMA), were assessed in two sessions that were seven days apart. Results : The POMA was showed a good intrarater and interrater reliabilities in people with hemiparetic stroke regardless of measure's experience in clinical field. However BBT and DGI were showed below moderate intrarater and interrater reliabilities. Conclusion : The POMA could be a reliable measure to evaluate functional postural stability and gait performance in hemiparetic stroke patients compared with other two clinical measures regardless of measure's experience of physical therapists.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.2
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• pp.35-59
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• 2003

Generally high-tech ventures have few resources with which to withstand unpredictable environmental jolts. Therefore environmental changes may have severe effects on the performance of high-tech ventures. Unfortunately previous empirical studies for predicting the performance of ventures hardly deal with such dynamic changes of performance. We try to examine the performance changes of ventures through a longitudinal study before and after severe environmental changes, namely IMF Bailout Memorandum. For the empirical study, we classified venture firms into four types based on entrepreneur's assessment of their performance changes and investigated how these four types differ in characteristics of entrepreneurs, environment, strategy, and organizational features. We found that differentiation strategies, fit between strategy and environmental changes, entrepreneur's trust and activities such as networking and knowledge accumulation about customers, and decentralized organizational structure were important to the performance changes of high-tech ventures.