• Journal of The Korean Society of Integrative Medicine
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• v.3 no.1
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• pp.71-80
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• 2015

Purpose: The purpose of this study was to compared the muscle activities of vastus medialis, vastus lateralis, rectus femoris in open kinetic chain and closed kinetic chain. Methods: Subjects of the study were 30 adults students. They were divided into 2 group, one for open kinetic chain and other for closed kinetic chain of extension, flexion, the maximum extension for vastus medialis, vastus latarealis, rectus femoris muscle activation. Results: Rectus femoris increased open kinetic chain group about all posture and vastus medialis increased open kinetic chain group about the maximum extension and flexion. and vastus lateralis increased open kinetic chain group about the maximum extension and flexion. Conclusion: Muscle activation are at the highest with the open kinetic chain in vastus medialis, vastus lateralis, rectus femoris. probably steady exercise thinked for open kinetic chain and closed kinetic chain.

• Korean Institute of Interior Design Journal
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• v.15 no.2 s.55
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• pp.21-28
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• 2006

The purpose of this study was to analyze the characteristics of Kinetic Architecture focused on case studies, categorize them and to research the possible applications of Kinetic Architecture. The results are as follow: first, the background of Kinetic Architecture is from the art, machine, nature and ancient architectures. Second, characteristics of Kinetic Architecture are deployability, modularity, lightweight, simplexity and interchangeability of parts. Third, the types of Kinetic Architecture are dynamically self-erecting structures, kinetic components, incremental architecture, mobile and disposable architecture. Finally, today the application cases of Kinetic Architecture are divided into the spital and skin part. The spital part is a temporary space, the multi-purpose spaces, housing, commercial spaces, and the educational spaces. The skin part offers functional(controling environments), artistic images through variation of materials and structural objects in the elevation.

• 한국연소학회:학술대회논문집
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• 2013.06a
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• pp.91-94
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• 2013

Commercial computational fluid dynamics (CFD) codes traditionally rely on the computational efficiency of the simplified single-film apparent char kinetic model to predict char particle temperatures and char conversion rates in pulverized coal boilers. The aim of this study is to evaluate the reliability of the single-film apparent kinetic model and to suggest the importance of proper use of this model. For this, a parametric study was conducted with a consideration of main parameters such as Stefan flow, product species, particle evolution, and kinetic parameters.

• The Journal of Korean Physical Therapy
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• v.17 no.3
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• pp.297-310
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• 2005

Open kinetic chain exercise has lost favour in rehabilitation after cruciate ligament reconstruction due to concerns that this exercise is harmful to the graft and will be less effective in improving function. Therefore rehabilitation has focused over the past decade on closed kinetic chain exercise. Open kinetic chain and closed kinetic chain exercises were compared for their effects on proprioception, muscle strength and knee instability in the early period of cruciate ligament reconstruction rehabilitation. The study subjects were 14 patients in 28weeks from cruciate reconstruction surgery(11 male, 3 female; mean age = 44.36 years). Closed kinetic chain exercise group used ball, balance pad and air cushion, to perform weightbearing exercises and the open kinetic chain exercise group used elastic rope and N-K table, to perform non-weightbearing exercises. Between tests, subjects trained 5 times per week for 2 weeks. Statistical analysis was by Wilcoxon signed rank test and Mann Whitney U test. In result, this study shows that both open and closed kinetic chain exercise programs lead to an improved muscle strength and Lysholm score. But there was no improvement in proprioception at both exercises. Closed versus open kinetic chain exercise in early period of rehabilitation after cruciate ligament reconstruction surgery do not differ in their effects on knee proprioception, muscle strength and instability. But the effect of closed kinetic chain exercises was showed more improvement than open kinetic chain exercises between pre-post exercises. Therefore further study is required to assess effect of both groups in more long period.

• KIEAE Journal
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• v.14 no.5
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• pp.67-73
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• 2014

This study aims at examining kinetic efficient shading systems and their implementation methods. These days, the importance of the shading devices are getting more significant due to the energy problem. Cordially, suitable shade designs are required as an important element for the exterior envelope of the building. This study employs the optimal shading design as an efficient shading method with the kinetic system that can be converted actively by the altitude of the sun. The proposed kinetic shading system works not only as a lightshelf in case the altitude of the sun is high but also as a vertical louver when the sun is getting lower in order to block the direct sunlight. This study has analyzed the thermal performance and shading coefficient of the kinetic shading system in comparison to existing fixed shading devices using the Ecotect. The results, in sum, conclude that the suggested kinetic shading system could decrease direct sunlights 26.2% more than the existing shading methods.

• Journal of Biosystems Engineering
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• v.1 no.1
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• pp.49-54
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• 1976

No reliable basic data were available on the kinetic friction coefficients between grains and frictional surfaces being used in grain handling equipments in Korea. In order to determine appropriate kinetic friction coefficient between three grains (Tongil, Jinheung, barley) and two surfaces at four levels of moisture content of grain, the laboratory tests using the newly designed experimental apparatus and strain gage measuring system were carried out, and the relationship among factors that affect kinetic friction coefficients of grains were analyzed. The results of this study are summarized as follows ; 1. Kinetic friction coefficient of samples being tested was dependent on surfaces and moisture content of grains . The ranges of them were 0.369-0.512 for Tongil variety , 0.347-0.469 for Jinheung variety, and 0.360-0.502 for barley, respectively. 2. There was a little difference of kinetic friction coefficients between two varieties of rice at the same testing conditions. Because the interaction had been large among treatments , each value of kinetic friction coefficient determined in this study should be used only for the corresponding conditions in this study . 3. Kinetic friction coefficients in creased linearly with increase in moisture content of grains and their regression equations were shown in Table.4. 4. Kinetic friction coefficients on a PVC surfaces was shown a little lower values than on the steel surfaces at various moisture levels, but especially in Jinheung and barley, a big difference was shown.

• The Journal of Korean Physical Therapy
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• v.31 no.1
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• pp.13-17
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• 2019

Purpose: This study examined the effects of flexible flatfeet on the accuracy of knee joint motions in closed and open kinetic chain tasks. Methods: Twenty-four healthy participants were recruited for this study. The subjects were divided into two groups using a navicular drop (ND) test: flexible flatfoot group (n=12, male: 6, aged $22.00{\pm}2.22years$) and age-matched control group (n=12, males: 6, aged $22.17{\pm}1.53years$). The accuracy of knee motion was measured quantitatively by tracing through the flexion and extension motion of the knee joints in the closed kinetic chain and the open kinetic chain. Results: There was a significant difference in the accuracy index between the groups in closed kinetic chain task, but there was no significant difference in the open kinetic chain task. In addition, there was a significant difference in the accuracy index between the closed kinetic chain and the open kinetic chain task in the flexible flatfoot group. In addition, a significant negative correlation was observed between the ND and accuracy index in the closed kinematic chain task, but there was no significant relationship between the ND and accuracy index in the open kinematic chain task. Conclusion: Flexible flatfeet can affect the accuracy of the adjacent joints, such as the knee joint in the closed kinematic chain.

• PNF and Movement
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• v.18 no.3
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• pp.333-341
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• 2020

Purpose: The purpose of this study was to investigate the effect of open and closed kinetic chain exercises with a sling on neck flexor thickness during chin-in movement in office workers with forward head posture. Methods: Thirty-one selected subjects randomly performed chin-in movement in open kinetic chain and closed kinetic chain exercises using a sling. All subjects were measured for their neck flexor thickness using ultrasound measurement equipment during the performance of chin-in movement in open and closed kinetic chain exercised. A paired t-test was used to compare the thickness of the total neck flexor, superficial, and deep neck flexor, respectively, between open and closed kinetic chain exercises with chin-in movement. Results: The thickness of the superficial neck flexor diminished in size more greatly during the chin-in movement with the closed kinetic chain than the open kinetic chain, but this was not a statistically significant difference (p > 0.05). On the other hand, the thickness of the total neck flexor and deep neck flexor had more greatly increased during the chin-in movement with the closed kinetic chain than the open kinetic chain, and this was a statistically significant differences (p < 0.05). Conclusion: This study suggested that chin-in movement with a closed kinetic chain is more effective in activating the deep neck flexor than the open kinetic chain. Thus, we believe that the closed kinetic chain exercise using a sling is an effective intervention to correct the postural alignment of individuals with forward head posture.

• PNF and Movement
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• v.7 no.3
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• pp.17-27
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• 2009

The purpose of this study was to investigate the effect of close kinetic chain(CKC) and open kinetic chain(OKC) posion on proprioceptive neuromuscular facilitation applied to the unilateral upper extremity on the muscle activation of lower extremity. All subjects were randomly assigned to two groups: open kinetic chain group(n=5),closed kinetic chain group(n=5). All participants were PNF patterns applied on the unilateral upper extremity in all subjects were the kinetic chain(CKC) and open kinetic chain(OKC) posion on flexion/abduction/external rotation. The hold and approximation techniques for the irradiation were applied to end range. All measurements for each subject took the following tests: pre-test, post - test in 4weeks, post-testin 8weeks. EMG data was collected from the vastus medialis, tibialis anterior, biceps femoris, and gastrocnemius muscle of both lower extreamity using surface EMG system, Each EMG value in individual muscle was normalized for maximal voluntary contraction. The data were analyzed using Two-way analysis of variance(ANOVA) with repeated measures to determine the statistical significances. The results of this study are summarized as follows. First, during for close kinetic chain(CKC) and open kinetic chain(OKC) posion on PNF pattern application, all of the %MVIC values of close kinetic chain and open kinetic chain posion increased sign ificantly compared(p<0.05). Second, The close kinetic chain(CKC) and open kinetic chain(OKC) posion on PNF pattern application was significantly increased with in the intervention period(p<.05). Third, there was a no significant open kinetic chain posion on PNF pattern application of sing muscle group with in the intervention period.(p<0.05) there was a significant close kinetic chain posion on PNF pattern application of sing muscle group with with in the intervention period(p<0.05). Forth, interaction of the exercise position and muscle was also significant. Post-hoc tests revealed that the activation levels of vastus medialis muscle and tibialis anterior muscle was higher in the closed kinetic chain position(p<.05). that the activation levels of vastus medialis and gastrocnemius muscle was higher in the open kinetic chain position(p<.05). In conclusion, it was found that the application of PNF patterns to the unilateral upper extremity effect on the muscle activation of lower extremity and both open kinetic chain exercise and closed kinetic chain exercise was significantly increased muscle activity. Further studies are needed to analyzed long term effects and subjects resulting from these changed.

• Journal of International Academy of Physical Therapy Research
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• v.1 no.2
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• pp.126-135
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• 2010

The purpose of this study is to investigate the effects of closed and open kinetic chain exercise for increasing knee joint function on the knee position sense in the normal adults. Thirty normal adults(male 15, female 15; mean age: $22.13{\pm}2.58$ years) were participated in this study into two groups, each with 15 people. The group I was trained that closed kinetic chain exercise on the knee joint and the group II was trained that open kinetic chain exercise on the knee joint. Exercise programs performed for 4 weeks, 3 times a week were using Shuttle 2000-1 closed kinetic chain exercise and Knee Extensor open kinetic chain exercise(HUR, Filand). The results of this study were as follows: 1) There were statistically significant decreasing of measuring error degree in $0-20^{\circ}$ were found between before and after training in closed kinetic chain exercise(p<.05). 2) There were statistically significant decreasing of measuring error degree in $21-40^{\circ}$ were found between before and after training in closed kinetic chain exercise(p<.05). 3) There were statistically significant decreasing of measuring error degree in $41-60^{\circ}$ were found between before and after training in closed kinetic chain exercise(p<.05). 4) There were statistically significant decreasing of measuring error degree in $0-20^{\circ}$ were found between before and after training in open kinetic chain exercise(p<.05). 5) There were statistically significant decreasing of measuring error degree in $21-40^{\circ}$ were found between before and after training in open kinetic chain exercise(p<.05). 6) There were statistically significant decreasing of measuring error degree in $41-60^{\circ}$ were found between before and after training in open kinetic chain exercise(p<.05). In conclusion, these results suggest that closed and open kinetic chain exercise has increased in the knee joint proprioception between before and after training. Especially, closed kinetic chain exercise could be more useful intervention than open kinetic chain exercise for increasing proprioceptive sense.