• Physical Therapy Korea
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• v.15 no.1
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• pp.1-11
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• 2008

The purpose of this study was to assess the influence of two shoe size conditions on foot pressure, ground reaction force (GRF), and lower extremity muscle fatigue. Seven healthy men participated. They randomly performed walking and running in two different conditions: proper shoe size and 10 mm greater than proper shoe size. Peak foot pressure, and vertical, anterior and mediolateral force components were recorded with the Parotec system and Kisler force platform. To assess fatigue, the participants performed treadmill running for twenty-five minutes twice, each time wearing a different shoe size. Surface electromyography was used to confirm localized muscle fatigue using power spectral analysis of four muscles (tibialis anterior, gastrocnemius medialis, rectus femoris, and biceps femoris). The results were as follows: 1) In walking conditions, there was a significantly higher peak pressure in the 10 mm greater than proper shoe size insole sensor 1, 2, 14, and 18 (p<.05). 2) In running conditions, there was a significantly higher peak pressure in the 10 mm greater than proper shoe size insole sensor 5, 14, and 15 (p<.05). 3) In walking conditions, there was a significantly higher first maximal vertical GRF in the 10 mm greater than proper shoe size (p<.05). 4) In running conditions, no GRF components were significantly different between each shoe size condition (p>.05). 5) Muscle fatigue indexes of the tibialis anterior and rectus femoris were significantly increased in the 10 mm greater than proper shoe size condition. These results indicate that wearing shoes that are too large could further exacerbate the problems of increased foot pressure, vertical GRF, and muscle fatigue.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.685-692
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• 2020

In this study, the experimental and analytical study were performed on the location of longitudinal cracks in the middle of underground box structures. The location where the longitudinal cracking occurred was investigated that the overlapping joint of the rebar and the section of maximum tensile stress generated. Using the finite element analysis, the strength reduction ratio of the rebar was estimated by lack of overlap joint length. As the result of adequacy investigation for the length of the overlap joint presented in the design criteria, it was analytically proved that the lack of the overlap joint length could be cause the decreasing cross-sectional force and concrete cracking. As the result of this study, the adequacy of the overlapping criterion in the current design criteria was confirmed based on the finite element analysis and actual field case. In the case of overlapping joints installed in inappropriate position, it was considered that a long term crack control would be need to ensure the sufficient safety factor for the designed cross-sectional force.

• Korean Journal of Applied Biomechanics
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• v.23 no.3
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• pp.253-259
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• 2013

The purpose of this study is to evaluate the influence of posture elements on symmetrical weight bearing during STS (sit-to-stand) in patients with chronic stroke. The subjects were patients diagnosed with stroke: a total of 24 patients (16 males and 8 females) participated in this study. All the participants performed STS tasks(3 foot postures and 2 arm postures). Two force plates (AMTI) were used to measure the peak vertical ground reaction force(Peak Fz) and the symmetrical ratio to peak vertical ground reaction force. The data were analyzed using independent t-test and 2-way repeated analysis of variance. The results of this study were as follows: 1) The peak Fz placed more weight on the paretic leg during STS and 2) The symmetrical ratio to the peak Fz showed a significant difference according to the foot and arm posture (p<.05), and had the highest AYM_GA ($0.87{\pm}0.12$). These results indicate that arm and leg postures during STS in patients with chronic stroke had the highest AYM_GA. We believe that the outcome of this study will be a reference for the prognosis of STS in patients with stroke.

• Korean Journal of Heritage: History & Science
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• v.46 no.2
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• pp.136-149
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• 2013

We studied the characteristics and the growth mechanism of surface cracks from the Naksansa seven-storied stone pagoda(Treasure No. 499). The pagoda is composed of both medium-grained, porphyritic biotite granite and hornblende-biotite granite. Alkali feldspar megacrysts are easily found as phenocrysts in the rocks. Surface cracks intensely developed at the lower part of the stone pagoda, and their directions are of vertical, horizontal, and diagonal. The rocks of the pagoda have intrinsic microcracks which can be defined as rift and grain rock cleavages. Both rock cleavages seems likely to have led to the crack growth and consequently to the mechanical deterioration of the pagoda. The vertical cracks developed parallel to the vertical compressive stress, whereas horizontal ones formed by tensile strength normal to the vertical compression. In addition mineral cleavages and twin planes of alkali feldspar phenocrysts seems to have been closely related to the mechanical breakdown of the rocks in the NE part of the pagoda.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.61-69
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• 2019

This study analyzed the process of university mergers that took place in Finland and Norway in order to present policy implications for the Korean government considering university merger as an effective policy instrument for restructuring of the Korean higher education system. Based on reviewing the previous literature and related documents, researchers conducted a comparative case study on the context, strategies, and outcomes of the implementation of university merger policies of the two countries. The results of analyses suggested that combination of government's clear direction-setting and enhanced autonomy of merging institutions was essential for successful mergers. Considerations on upgrading the structure of the whole higher education sector to meet new needs of the future society were also suggested.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.4
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• pp.45-52
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• 2022

PURPOSE: This study examined the center of pressure (COP) and ground reaction force (GRF) characteristics during each task-oriented sit-to-stand in stroke patients. METHODS: Twenty stroke subjects were included in this study. The task consisted of sit-to-stand (SS), sit-to-stand for reaching (SR), and sit-to-stand for walking (SW). The response time, COP, and GRF were measured during each task. The COP and GRF data were obtained using a two-force plate. The force plates were placed on a chair (below the buttock) and floor (below the feet). RESULTS: Significant differences were observed between SS (1.48 ± .48 s) and SR (2.09 ± 0.82 s) and between SS and SW (2.27 ± .72 s) in the preparatory phase time during each sit-to-stand exercise (p = .002) and showed significant differences between SS (13.90 ± 6.44 cm) and SW (34.62 ± 39.38 cm) and between SR (16.14 ± 8.04 cm) and SW in the mediolateral COP range during each sit-to-stand exercise (p = .013). CONCLUSION: These findings suggest that more complex task-oriented sit-to-stand exercise requires a high-level motor programming process than a simple sit-to-stand task. Therefore, a variety of tasks-oriented sit-to-stand exercises will be useful training to achieve better ADL ability for stroke patients.

• PNF and Movement
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• v.20 no.1
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• pp.135-145
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• 2022

Purpose: The purpose of this study was to investigate the association between cognitive and motor inhibition by comparing muscle activity and ground reaction force during unplanned gait termination according to reaction time measured through the stop-signal task. Methods: Sixteen young adults performed a stop-signal task and an unplanned gait termination separately. The subjects were divided into fast and slow groups based on their stop-signal reaction time (SSRT), as measured by the stop-signal task. Electromyography (EMG) and ground reaction force (GRF) were compared between the groups during unplanned gait termination. The data for gait termination were divided into three phases (Phase 1 to 3). The Mann-Whitney U test was used to compare spatiotemporal gait parameters and EMG and GRF data between groups. Results: The slow group had significantly higher activity of the tibialis anterior in Phase 2 and Phase 3 than the fast group (p <0.05). In Phase 1, the fast group had significantly shorter time to peak amplitude (TPA) of the soleus than the slow group (p <0.05). In Phase 2, the TPA of the tibialis anterior was significantly lower in the fast group than the slow group (p <0.05). In Phase 3, there was no significant difference in the GRF between the two groups (p >0.05). There were no significant difference between the two groups in the spatiotemporal gait parameters (p >0.05). Conclusion: Compared to the slow group, the fast group with cognitive inhibition suppressed muscle activity for unplanned gait termination. The association between SSRT and unplanned gait termination shows that a participant's ability to suppress an incipient finger response is relevant to their ability to construct a corrective gait pattern in a choice-demanding environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.982-991
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• 2006

The screen quota system is one of the most controversial issues in the Korean film industry. There are two different points of view regarding the system. Some say it is highly effective to protect and nurture Korean movies. However, others argue that it hurts the duality of the Korean movies. The number of days, for which Korean movies have to play on local screens, has been reduced to 73, starting on July 1st, 2006. Actually, it is 50 percent fewer than the previous year. In facL Korea has implemented the screen quota. system two times. First, it was practiced from 1935 to 1945, during the Japanese colonial period. This was to regulate imported movies, especially American ones, as the Japanese government was to use movies for the political propaganda. In 1935, the number of foreign movies screened had to be less than three fourths of the total. And they gradually reduced the size by two thirds in 1936, and again by half in 1937. After the attack on Pearl Harbor when the Pacific War happened, Japan completely banned importing American movies in Korea. The reason why it regulated the imported foreign films is to increase the number of domestic movies, both Japanese and Korean. It was for making propaganda films fur carrying the war. The second practice of the screen quota is from 1967 to the present year. It was designed to boom the Korean film industry. However, the competitive power of Korean films has not been improved in spite of the practice of the system. Moreover, the film industry has gone through the depression. Korean film agencies have occupied the Korean film market thanks to the protection by government. The founding of the film agencies has been strongly regulated. So has importing foreign movies. Under the special protection like this, Korean film agencies have been enjoying the monopoly In the mean time, they have pursued income not by making quality movies but by importing foreign movies. As a result, cinema audiences turn away form Korean films and prefer foreign movies. Furthermore, the screen quota system hurts the relationship between film producers and distributors, imposing the duties only on theaters. In short, the screen quota system has satisfied neither film producers, theater runners, nor film goers. In other words. the excessive protection has weakened the competitive power of Korean film industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.931-938
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• 2002

The growth of enterobacteria, Bifidobacterium infantis KCTC 3270, was promoted by natural products bearing antioxidative capacity and mixed combinations of two, three and four kinds of them. B. infantis was expressed a good growth by Aurantii nobilis pericarpium majus L., Astragali radix, Epimedii herba, alone, and two mixed combinations of Epimedii herba and Theae folium, Epimedii herba and Crataegi fructus, Epimedii herba and Eucommiae cortex, and three mixed combinations of Theae folium, Epimedii herba and Chelidonium majus L., Theae folium, Epimedii herba and Aurantii nobilis pericarpium, Theae folium, Chelidonium majus L. and Auantii nobilis pericar pium, Theae folium, Chelidonium majus L. and Astragali radix, Theae folium, Aurantii nobilis pericarpium and puerariae radix, Epimedii herba, Chelidonium majus L. and Aurantii nobilis pericarpium, and four mixed com-binations of Theae folium, Chelidonium majus L., Astragali radix and Epimedii herba, and Theae folium, Chelidonium majus L., Astragali radix and Puerariae readix, and Theae folium, Epimedii herba, Aurantii nobilis pericarpium and Puerariae radix, and Theae folium, Chelidonium majus L., Aurantii nobilis pericarpium and Puerariae radix. The best four mixed combination ofr the growth of B. infantis was Theae folium, Chelidonium majus L. Astragali radix and Epimedii herba, which promoted 2.1 times than that of control, and its antioxidative capacity was also 5 times higher, and the ratio of elimination of hydroxyl radical was more than 80% in each dilution rate. As these combinations of natural products might activate some parts of body, they could be applied to pharmaceutical applications, functional foods, antiaging tea, also expected to promote useful bacterial growth for fermentative beverage bearing multifunction.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.347-362
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• 2020

Iron (hydro)oxides in aqueous environments are primarily formed due to mining activities, and they are known to be typical colloidal particles disturbing surrounding environments. Among them, hematites are widespread in surface environments, and their behavior is controlled by diverse factors in aqueous environments. This study was conducted to elucidate the effect of environmental factors, such as ionic composition and strength, pH, and natural organic matter (NOM) on the behavior of colloidal hematite particles. In particular, two analytical methods, such as dynamic light scattering (DLS) and single-particle ICP-MS (spICP-MS), were compared to quantify and characterize the behavior of colloidal hematites. According to the variation of ionic composition and strength, the aggregation/dispersion characteristics of the hematite particles were affected as a result of the change in the thickness of the diffuse double layer as well as the total force of electrostatic repulsion and van der Walls attraction. Besides, the more dispersed the particles were, the farther away the aqueous pH was from their point of zero charge (PZC). The results indicate that the electrostatic and steric (structural) stabilization of the particles was enhanced by the functional groups of the natural organic matter, such as carboxyl and phenolic, as the NOM coated the surface of colloidal hematite particles in aqueous environments. Furthermore, such coating effects seemed to increase with decreasing molar mass of NOM. On the contrary, these stabilization (dispersion) effects of NOM were much more diminished by divalent cations such as Ca²⁺ than monovalent ones (Na⁺), and it could be attributed to the fact that the former acted as bridges much more strongly between the NOM-coated hematite particles than the latter because of the relatively larger ionic potential of the former. Consequently, it was quantitatively confirmed that the behavior of colloidal hematites in aqueous environments was significantly affected by diverse factors, such as ionic composition and strength, pH, and NOM. Among them, the NOM seemed to be the primary and dominant one controlling the behavior of hematite colloids. Meanwhile, the results of the comparative study on DLS and spICPMS suggest that the analyses combining both methods are likely to improve the effectiveness on the quantitative characterization of colloidal behavior in aqueous environments because they showed different strengths: the main advantage of the DLS method is the speed and ease of the operation, while the outstanding merit of the spICP-MS are to consider the shape of particles and the type of aggregation.