• Korean Journal of Materials Research
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• v.15 no.11
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• pp.697-704
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• 2005

The deformation behavior of a bulk amorphous and crystallized amorphous $Zr_{22.5}Ti_{14}Cu_{12.5}Ni_{10}Be_{22.5}$ alloy extracted from a commercial golf club head was characterized at room temperature ana $300^{\circ}C$. At room temperature, amorphous specimens revealed higher yield stress and ductility than partially crystallized alloy specimens. Amorphous alloy displayed some plasticity before fracture, which resulted from strain hardening and repeated crack initiation and propagation. The fracture is mainly localized on one major shear band, and the compressive fracture angle of the amorphous specimen between the stress axis and the fracture plane was about $40^{\circ}$ Scanning electron microscope observations revealed mainly a vein-like structure in the amorphous alloy But the fracture surface of partially crystallized amorphous alloy consisted of vein-like and featureless fracture structure. The partially crystallized alloy extracted from the thick part of the club fractured in the elastic region, at a much lower stress level than the amorphous, suggesting that relatively coarse crystal particles formed during cooling cause the brittle fracture.

• Journal of muscle and joint health
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• v.15 no.1
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• pp.88-95
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• 2008

Purpose: This study was to evaluate and compare the effectiveness of the Resistance Exercise Program on pain, stiffness, ADL and bone mineral density in Arthritis Patients at home. Methods: Forty-two patients participated in this study and they were divided randomly into two groups (exercise and control group). Two subjects dropped during the study period. The exercise group had a structured training which was 50 minutes in duration, five times per week for a period of 16 weeks and the control group without any scheduled treatment. Data were gathered for 16 weeks (May 21, 2007- September 10, 2007) and were analyzed by using SPSS Win 12.0. Results: The pain, stiffness, ADL, balance and bone mineral density in the exercise group were improved significantly after the Resistance Exercise Program. However, a significant improvement on the above mentioned variables was not observed in the control group.

• Proceedings of the Korea Contents Association Conference
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• 2019.05a
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• pp.385-386
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• 2019

본 연구의 목적은 균형에 이상이 있는 20대 정상 성인에게 혈류제한성 탄력밴드 훈련 적용 시 균형능력 회복에 미치는 효과를 알아보고자 하였다. 12명의 남성을 대상으로 대조군(n=6), 실험군(n=6)으로 무작위할당하였다. 두 군은 고강도 축구경기를 통한 균형능력 손상 유발 후 실험군은 1주일 3회 1시간씩 4주 동안 혈류제한성 탄력밴드 훈련을 실시하였고, 대조군은 아무런 훈련을 실시하지 않았다. 모든 대상자는 경기 전, 경기 후, 경기 4주 후에 정적 및 동적 균형을 측정하였다. 연구 결과, 정적균형에서 대조군은 경기 전으로 유의한 회복을 나타내지 않았으나, 실험군은 유의한 회복을 나타냈다. 동적균형에서는 대조군과 실험군 모두에서 유의한 회복을 나타냈다. 혈류제한성 탄력밴드 운동은 단기간에 효율적으로 근력을 향상시킴으로써 균형능력 회복에 긍정적 영향을 줄 수 있다고 판단된다.

• Journal of Fashion Business
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• v.26 no.2
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• pp.83-94
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• 2022

The purpose of this study was to analyze the reality of clothes-wearing among physically disabled women and propose trouser designs. As a research method, an in-depth interview method was adopted for 10 women in their 30s and 50s with lower limb disabilities who could wear trousers and use wheelchairs. The study results identified the following factors that should be considered in the design of trousers. First, a semi-casual design that could hide physical deficiencies, was not different from ready-made clothes and enabled various looks was desirable. Second, the proper material would have little transformation in the form, have remarkable durability and laundry fastness, two-directional stretch, and hide deficiencies with a sense of thickness and density. Third, an "L-frame" pattern in a sitting position, and a straight fit were desirable. Finally, pockets can impose pressure according to their form, size, position, and sewing method, highlighted the need for a sewing approach to minimize seams in the fabric. For adjustment, an elastic band would be a good choice in terms of type, length, position, and material as it could satisfy both the convenience of putting on and taking off and comfort in wearing at the same time. Decorative design details can also impose pressure according to a sense of thickness, which means that they should be avoided in parts that are close to the body or can impose pressure according to posture.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.853-859
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• 2022

In this study, we analyzed the instantaneous trajectory generation capability and target arrival rate of a mobile robot by changing the parameter of the TEB (Timed Elastic Band) Local Planner among local planners that affect the instantaneous obstacle avoidance ability of the mobile robot using ROS (Robot Operating System) simulation and real experience. As a result, we can expect a decrease in the target arrival time of the mobile robot through a decrease in the parameter values of the TEB Local Planner's min_obstacle_dist, inflation_dist, and penalty_epsilon. However, if this parameter is reduced too much, the risk of obstacle collision of the moving robot is increases, so it is important to combine the appropriate values to construct the parameter.

• International journal of advanced smart convergence
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• v.11 no.3
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• pp.197-205
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• 2022

In order to investigate the effect of an 8-week elastic band exercise program according to age on the isokinetic strength and dynamic equilibrium of the knee, 10 women under 49 years old and 10 women over 50 years old were selected. Dynamic equilibrium was measured through Y-Balance test one week before the exercise program, and power and endurance were confirmed by measuring isokinetic muscle strength of the knee. After measurement, small tool exercise was performed for 8 weeks. After 8 weeks of exercise, isokinetic muscle strength and dynamic equilibrium were measured. As a result, isokinetic muscle strength, which checks muscle strength and muscular endurance, increased after measurement than before measurement regardless of age, and dynamic equilibrium increased after measurement rather than before measurement, and the group under 49 years of age was higher than the group over 50 years old. We think that small tool exercise improves isokinetic muscle strength and is effective in neuromuscular development, improving dynamic stability ability, which is an important factor in preventing falls.

• Korean Journal of Exercise Nutrition
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• v.23 no.3
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• pp.50-55
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• 2019

[Purpose] The purpose of this study was to identify the relationships between muscle mass, muscle strength, and physical and cognitive functions and to examine the effects of resistive Theraband® exercise on sarcopenia-associated variables in the older population. [Methods] A total of 28 elderly women (age: 69.90 ± 0.8 years) participated in this study, 15 of whom underwent elastic band exercise for 1 hour per day, twice per week for 8 weeks. The correlation analysis was conducted to identify the associations between body composition, skeletal muscle mass indices, grip strength, and physical and cognitive functions. All variables were assessed at baseline and post-exercise. [Results] Skeletal muscle mass was significantly associated with grip strength and physical function. Gait speed was positively correlated with grip strength and physical function, but not with cognitive function. Theraband® exercise significantly improved gait speed and physical function. [Conclusion] The present data suggest that skeletal muscle mass is highly correlated with grip strength and physical function. Eight weeks of resistive Theraband® exercise favorably affects sarcopenia by improving gait speed and mobility of elderly women.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.10
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• pp.1057-1068
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• 2014

This paper proposes elastic-plastic constitutive relations for a composite material with two phases-inclusion and matrix phases-using a homogenization scheme. A thermodynamic framework is employed to develop non-local plasticity constitutive relations, which are specifically represented in terms of the second-order gradient terms of the internal state variables. A combined two back-stress evolution equation is also established and the degradation of the state and internal variables is expressed by continuum damage mechanics in terms of the damage factor. Then, deformation localization is analyzed; the analysis results show that the proposed model yields a wide range of shear band formation behaviors depending on the evolution of the specific internal state variables. The analysis results also show good agreement with the results of simplified Rice instability analyses.

• PNF and Movement
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• v.13 no.4
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• pp.181-188
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• 2015

Purpose: This study aimed to examine the effects of proprioceptive neuromuscular facilitation (PNF) lower extremity patterns combined with elastic bands applied to stroke patients diagnosed with hemiplegia through self-training using the non-paralyzed side approach and the paralyzed side approach, and to investigate the differences in the effects. Methods: Nine chronic stroke patients who were being treated not more than twice a week at H, K, R, and C hospitals located in Gangwon-do, performed self-training for 16 minutes, two times per day for four weeks between August and October 2015. The subjects' balance ability was measured using the Tetrax stability index, the weight distribution index, the Berg Balance Scale (BBS), and the Timed Up and Go (TUG) test before the experiment and four weeks later. Among the statistical methods, paired t-tests were conducted for intra-group comparison of the measurements taken before and after the experiment, and independent t-tests were conducted for inter-group comparison of the ex post facto values. The statistical significance level was set to 0.05. Results: When the lower extremity patterns were applied to the non-paralyzed side group and the paralyzed side group, significant intra-group differences were observed for the Tetrax stability index, the weight distribution index, the Berg Balance Scale (BBS), and Timed Up and Go (TUG) tests (p<0.05); however, the inter-group comparisons showed no significant differences. Conclusion: The non-paralyzed side approach was found to be easy for patients to participate in and it also affected the patients' paralyzed side. Although the paralyzed side approach produced good exercise effects in a short period of time, it could result in adverse effects, such as a decrease in motivation and self-confidence. Therefore, these approaches are considered to be more effective when they are selectively applied depending on the purpose of the intervention and the degree of a patients' participation.

• Korea-Australia Rheology Journal
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• v.17 no.1
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• pp.1-7
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• 2005

Acrylonitrile-Butadiene-Styrene (ABS), polycarbonate (PC) and their alloys are an important class of engineering thermoplastics that are widely used for automotive industry, computer and equipment housings. For the process of recycling mixtures of ABS and PC, it is desirable to know how sensitive the blend properties are to changes in compositions. It was for this reason that blends of virgin ABS and virgin PC at five different compositions, namely, $15\%,\;30\%,\;50\%,\;70%$ and $85\%$ by weight of ABS were prepared and characterised by rheological and mechanical measurements. Rheological properties of these blends in steady, oscillatory and transient step shear and mechanical properties, namely, tensile strength, elongation-at-break and Izod impact strength are reported. The results show that PC behaves in a relatively Newtonian manner, but ABS exhibits significant shear thinning. The ABS-rich blends show a trend that is similar to that of ABS, while PC-rich blends, namely $0\%$ and $15\%$, exhibit a nearly Newtonian behaviour. However, at a fixed shear rate or frequency, the steady shear or the dynamic viscosity varied respectively in a non-mono-tonic manner with composition. Except for $15\%$ blend, the viscosities of other blends fall into a narrow band indicating a wide-operation window of varying blend ratio. The blends exhibited a lower viscosity than either of the two pure components. The other noticeable feature was that the blends at $70\%$ and $85\%$ ABS content had a higher G' than pure ABS, indicating an enhancement of elastic effect. The tensile yield strength of the blends followed the 'rule of mixtures' showing a decreasing value with the increase of ABS content in PC. However, the elongation-at-break and the impact strength did not appear to obey this 'rule of mixtures,' which suggests that morphology of the blends also plays a significant role in determining the properties. Indeed, scanning electron micrographs of the fracture surfaces of the different blends validate this hypothesis, and the $15\%$ blend is seen to have the most distinct morphology and correspondingly different behaviour and properties.