• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.3
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• pp.11-17
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• 2012

In this study, an experiment with large-scale model was performed according to raising embankment in order to investigate the cause of collapse by a change in water level of reservoir. Also, the settlement and pore water pressure by high water level and a rapid drawdown were compared and analyzed. After raising embankment for inclined core, there was no infiltration by leakage. For the vertical core, the pore water pressure showed a largely change by faster infiltration of pore water than in the inclined core. In a rapid drawdown, inclined core was remained stable but vertical core showed a largely change in pore water pressure. A settlement after a raising embankment showed a larger measure of settlement than before the raising embankment. The leakage quantity before a raising embankment and an inclined extension showed no leakage. Leakage in vertical extension was measured 160 $l$. From the result, a instrument system that can accurately estimate a change of pore water pressure shall be established for a rational maintenance and stabilization of raising embankment for agricultural reservoir.

• BMB Reports
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• v.43 no.3
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• pp.176-181
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• 2010

The primary sigma factor ($\sigma^{A}$) of Staphylococcus aureus, a potential drug target, was little investigated at the structural level. Using an N-terminal histidine-tagged $\sigma^{A}$ (His-$\sigma^{A}$), here we have demonstrated that it exits as a monomer in solution, possesses multiple domains, harbors primarily $\alpha$-helix and efficiently binds to a S. aureus promoter DNA in the presence of core RNA polymerase. While both N- and C-terminal ends of His-$\sigma^{A}$ are flexible in nature, two Trp residues in its DNA binding region are buried. Upon increasing the incubation temperature from 25$^{\circ}$ to 40$^{\circ}C$, $\sim$60% of the input His-$\sigma^{A}$ was cleaved by thermolysin. Aggregation of His-$\sigma^{A}$ was also initiated rapidly at 45$^{\circ}C$. From the equilibrium unfolding experiment, the Gibbs free energy of stabilization of His-$\sigma^{A}$ was estimated to be +0.70 kcal $mol^{-1}$. The data together suggest that primary sigma factor of S. aureus is an unstable protein. Core RNA polymerase however stabilized $\sigma^{A}$ appreciably.

• Biomedical Science Letters
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• v.10 no.4
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• pp.523-528
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• 2004

The core factor of the study is integrated environment based PC-Cluster system and high speed access rate up to 155 Mbps, continuous collection system for bioinformatics information at home and abroad. The results of the study are establishment and stabilization of information and communication infrastructure, establishment and stabilization of high performance computer network up to 155 Mbps, development of PC-Cluster system with 32 nodes, a parallelized BLAST on Cluster system, which can provides scalable speedup in terms of response time, and development of collection and search system for bioinformatics information.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.4
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• pp.19-27
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• 2021

In this study, a high-pressure subsacle thrust chamber was developed to verify the core technology for KSLV-II performance enhancement. The core technologies are the design of an injector for high-pressure combustion, development of a combustion stabilization device using the additive manufacturing technique, and the design and fabrication of mixing head and regeneratively cooled combustion chamber. The core technologies, which have been verified through the development of high-pressure subscale thrust chamber, will be used to develop large engine liquid rocket engine thrust chamber in the future.

• Journal of the Korean Electrochemical Society
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• v.4 no.3
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• pp.104-108
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• 2001

Naphthalene derived mesophase pitch WP) was spun into short fibers by using melt-blown technology. The pitch fibers oxidative stabilization were carried out heating rates of $2^{\circ}C/min,\;5^{\circ}C/min\;and\; 10^{\circ}/min$. The heating rate was a key factor to maximate the capacity of the Li-ion secondary battery through controlling the morphology of the graphitized fiber. The diameters of the melt-blown fibers prepared were in the range of $4{\mu}m\~16{\mu}m$ with functions of air jet speed, air temperature and the temperature of the nozzle. The graphitized fibers of $10{\mu}m$ diameters showed various morphological structure with heating rate of the stabilization. Radial, radial-random and skin-core cross-sectional structure of the fibers were observed at the respective heating rate of $2^{\circ}C/min\;5^{\circ}C/min\;and\;10^{\circ}C/min$. Most crystalline structure of graphite was obtained from the fiber stabilized at heating rate of $10^{\circ}C/min$ exhibiting the best anode performance with 400 mAh/g of capacitance and $96.8\%$ of charge/discharge efficiency.

• Physical Therapy Rehabilitation Science
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• v.9 no.3
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• pp.184-190
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• 2020

Objective: Patients with low back pain can possibly have impaired core muscle function, which is the common cause of low back pain. Spinal stabilization exercises are recommended for prevention and reinforcement. This study aimed to compare the effects of different types of feedback on abdominal and lumbar multifidus (LM) muscle recruitment during spinal stabilization exercises. Design: Cross-sectional study. Methods: Fifty-seven healthy subjects (sex=male 21/female 36, age=21.28±1.60 years) were divided into three different groups: the control group (n=19), the auditory feedback (AF) group (n=19), and the visual and auditory feedback (VAF) group (n=19). The control group received no feedback, whereas the AF group only received AF during exercises and the VAF group received the AF and visual feedback through the real-time ultrasound images. The main outcome measure was the assessment of the thickness of the abdominal muscles and LM measured by a dual ultrasound. Results: When VAF was applied, the thickness of the transverse abdominis significantly increased rather than when feedback was not applied or with AF only (p<0.05). The VAF group showed significant differences in both the control group and the AF group in the post-hoc test (p<0.05), and there was no significant difference between the control group and the AF group. Conclusions: With spinal stabilization exercises, VAF should be applied in standing posture for healthy adults to further promote the production of effective contractions.

• Journal of The Korean Society of Integrative Medicine
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• v.1 no.4
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• pp.57-66
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• 2013

PURPOSE: The purpose of this study was to investigate the effects using pressure biofeedback and teaching abdominal hollowing exercise on pelvic stabilization during the active straight leg raising test. METHOD: The subjects were divided into 3 groups who were fourty eight healthy participants, aged 20~25 years recruited for this study. First group wad control group. This group didn't any education. Second group was teaching them for a week. And last group was teaching abdominal hollowing exercise. The rotation angles of pelvic were measured by the motion anayalyser on flat surface and on form roll for the active leg raising. RESULT: Using pressure biofeedback and teaching abdominal hollowing exercise groups were significantly effective than control group in rotation angles of pelvis. And using pressure biofeedback group was more effective than teaching core stability muscles contraction group. CONCLUSION: This study suggested that patients with low back pain and pelvic instability can improve pelvic stabilization through pressure biofeedback and teaching abdominal hollowing exercise.

• Physical Therapy Rehabilitation Science
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• v.13 no.1
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• pp.78-85
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• 2024

Objective: This Study aimed to examine the changes in muscle activity of trunk muscles by performing three squat exercises on normal adults. Design: cross-sectional study Methods: Thirty-two adult subjects participated in this study. General squat, overhead squat, and overhead squat combined with abdominal stabilization were randomly performed for 5 seconds, 3 times, to calculate the average muscle activation. Muscle activation was normalized using electrodes on the rectus abdominis, external oblique, internal oblique, and erector spinae muscles to measure maximum voluntary isometric contraction (MVIC) for 5 seconds, repeated 3 times each. Results: There was a significant difference in the mean and maximal muscle activity of the bilateral erector spinae (ES) when comparing the squat to the overhead squat (p<0.05). There was a significant difference (p<0.05) in the mean and maximal muscle activity of the bilateral external oblique (EO) when comparing the overhead squat to the overhead squat combined with the abdominal stabilization technique. When comparing the squat to the overhead squat with abdominal stabilization, there was a significant difference in the mean and maximum muscle activity of the bilateral RA, EO, and left Internal oblique (IO) (p<0.05), and there was a significant difference in the maximum muscle activity of the bilateral erector spinae (ES) (p<0.05). Post hoc tests showed significant differences between squatting methods for the RA, EO, IO, and ES (p<0.017). Conclusion: The results of this study showed that squats combined with abdominal stabilization were more effective at activating core muscles than squats or overhead squats alone.

• Korean Journal of Applied Biomechanics
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• v.28 no.4
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• pp.213-218
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• 2018

Objective: The purpose of this study was to examine the effect of the core muscle strength enhancement of the elderly on 8 weeks training using the core exercise equipment for the elderly on the ability to control the whole-body center of mass in posture stabilization. Method: 16 females (10 exercise group, 6 control group) participated in this study. Exercise group took part in the core strength training program for 8 weeks with total of 16 repetitions (2 repetitions per week) using a training device. External perturbation during standing as pulling force applied at the pelvic level in the anterior direction was provided to the subject. In a UCM model, the controller selects within the space of elemental variables a subspace (a manifold, UCM) corresponding to a value of a performance variable that needs to be stabilized. In the present study, we were interested in how movements of the individual segment center of mass (elemental variables) affect the whole-body center of mass (the performance variable) during balance control. Results: At the variance of task-irrelevant space, there was significant $test^*$ group interactions ($F_{1,16}=7.482$, p<.05). However, there were no significant main effect of the test ($F_{1,16}=.899$, p>.05) and group ($F_{1,16}=1.039$, p>.05). At the variance of task-relevant space, there was significant $test^*$ group interactions ($F_{1,16}=7.382$, p<.05). However, there were no significant main effect of the test ($F_{1,16}=.754$, p>.05) and group ($F_{1,16}=1.106$, p>.05). Conclusion: The results of this study showed that the 8 weeks training through the core training equipment for the elderly showed a significant decrease in the $Vcm_{TIR}$ and $Vcm_{TR}$. This result indicates that the core strength training affects the trunk stiffness control strategy to maintain balance in the standing position by minimizing total variability of individual segment CMs.

• Rapid Communication in Photoscience
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• v.3 no.4
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• pp.85-87
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• 2014

We studied the characteristics of emissive state of the first (p-G1) and second (p-G2) generation of phenylacetylene dendrimers bearing stilbene as a core by using time-resolved fluorescence spectroscopy in cyclohexane (c-Hex) and N, N-dimethylformide (DMF), which are nonpolar and polar solvents, respectively. Time-dependent red-shift of emission spectra p-G2 both in c-Hex and DMF was observed in comparison with p-G1. Besides, the time constant of red-shift of spectra was found to be larger in DMF than in c-Hex. This indicates that the emissive state of p-G2 has a polar character in DMF as a result of charge delocalization from core to peripheral dendrons followed by stabilization of emissive state.