• Journal of the Korean Society of Physical Medicine
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• v.6 no.2
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• pp.109-118
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• 2011

Purpose: The purpose of this study was to investigate the effect of core stabilization exercise on foot pressure in the hemiplegic patients. Methods: A total of 28 subjects(n=28) who were diagnosed with hemiplegic caused by a stroke were randomly divided into bridge exercise(BX, n=14) and crunch exercise(CX, n=13) groups and each group executed the exercises 20 minutes a day, 4 times per week over an 8 week period. Foot pressure was measured on the fore, mid, and hind foot for peak pressure, and distance of center of pressure(COP). Results: The peak pressure on the mid foot for BX and CX were significantly different according to the exercise period(p<.05). Peak pressure on the hind foot of BX was significantly different according to exercise period(p<.05), however there was not in CX. The effects of each exercises period were significantly different according to pre-after 8weeks(p<.05). According to exercise period(p<.05), COP distances of BX and CX were significantly different. Conclusion: The results show that both BX and CX verified an improvement in gait ability. Especially, since we confirmed BX was attributed more to gait ability than CX. This is considered to be effective on those hemiplegic patients who need core-stabilization and gait stability.

• Journal of the Korea Fashion and Costume Design Association
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• v.10 no.2
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• pp.117-124
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• 2008

People have used the manner of expression "clothing" to find out and to symbolize the styles that suits one's roles, behaviors or altitudes. Moreover, the symbolic meaning of clothing is important as it reflects the culture of a time period as well at the life style of each classes of society. In the aspect in which clothing is critical data to re-examine a time period as to trace history, clothing is significant for understanding the characteristics of each time periods, and by focusing on women's wedding dress, a costume worn for one of the most essential ceremonies in one's life, this article studies how trends of each period have been symbolized through clothing. Thus, this study aims to set a foundation to understand the cultural features of a time period through the wedding ceremony. The article inquires about the hwalot to also understand its meaning during the period of its existence, and develops designs for modern wedding dresses for women. I. The wedding dress of women expressed the following meanings by using shapes, colors and patterns of the hwalot. 1) The formative art of hwalot is the ultimate beauty. 2) The wedding dress of women emphasized aesthetics. 3) The symbols praying for harmony between red and indigo, or the union of yin and yang indicates that marriage had been considered as a precious ceremony-an important matter of life. 4) The meaning of good auspice such as health, longevity, immortality, good luck and stability had been frequently used since people sought for new and eternal life. 5) The symbols of wealth and fame have been frequently used by those pursuing a wealthy life. 6) Marriage was considered as a union of families, and not a union of two individuals. II. This article presents two types of modern wedding dresses.

• The Journal of Information Systems
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• v.32 no.1
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• pp.179-199
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• 2023

Purpose This study builds a prediction model to find stocks that can reach intrinsic value among KOSPI and KOSDAQ-listed companies to improve the stability and profitability of the stock investment. And investment simulations are conducted to verify whether stock investment performance is improved by comparing the prediction model, random stock selection, and the market indexes. Design/methodology/approach Value investment theory and machine learning techniques are applied to build the model. Various experiments find conditions such as the algorithm with the best predictive performance, learning period, and intrinsic value-reaching period. This study selects stocks through the prediction model learned with inventive variables, does not limit the holding period after buying to reach the intrinsic value of the stocks, and targets all KOSPI and KOSDAQ companies. The stock and financial data are collected for 21 years (2001-2021). Findings As a result of the experiment, using the random forest technique, the prediction model's performance was the best with one year of learning period and within one year of the intrinsic value reaching period. As a result of the investment simulation, the cumulative return of the prediction model was up to 1.68 times higher than the random stock selection and 17 times higher than the KOSPI index. The usefulness of the prediction model was confirmed in that the number of intrinsic values reaching the predicted stock was up to 70% higher than the random selection.

• Journal of The Korean Astronomical Society
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• v.56 no.2
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• pp.277-286
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• 2023

It is difficult to distinguish the pure signal produced by an orbiting planetary companion around giant stars from other possible sources, such as stellar spots, pulsations, or certain activities. Since 2003, we have obtained radial (RV) data from evolved stars using the high-resolution, fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) at the Bohyunsan Optical Astronomy Observatory (BOAO). Here, we report the results of RV variations in the binary star HD 135438. We found two significant periods: 494.98 d with eccentricity of 0.23 and 8494.1 d with eccentricity of 0.83. Considering orbital stability, it is impossible to have two companions in such close orbits with high eccentricity. To determine the nature of the changes in the RV variability, we analyzed indicators of stellar spot and stellar chromospheric activity to find that there are no signals related to the significant period of 494.98 d. However, we calculated the upper limits of rotation period of the rotational velocity and found this to be 478-536 d. One possible interpretation is that this may be closely related to the rotational modulation of an orbital inclination at 67-90 degrees. The other signal corresponding to the period of 8494.1 d is probably associated with a stellar companion orbiting the giant star. A Markov Chain Monte Carlo (MCMC) simulation considering a single companion indicates that HD 135438 system hosts a stellar companion with 0.57^+0.017 _-0.017 M_⊙ with an orbital period of 8498 d.

• Journal of The Korean Astronomical Society
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• v.56 no.2
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• pp.195-199
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• 2023

This paper is written as a follow-up observations to reinterpret the radial velocity (RV) of HD 36384, where the existence of planetary systems is known to be ambiguous. In giants, it is, in general, difficult to distinguish the signals of planetary companions from those of stellar activities. Thus, known exoplanetary giant hosts are relatively rare. We, for many years, have obtained RV data in evolved stars using the high-resolution, fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) at the Bohyunsan Optical Astronomy Observatory (BOAO). Here, we report the results of RV variations in the M giant HD 36384. We have found two significant periods of 586 d and 490 d. Considering the orbital stability, it is impossible to have two planets at so close orbits. To determine the nature of the RV variability variations, we analyze the HIPPARCOS photometric data, some indicators of stellar activities, and line profiles. A significant period of 580 d was revealed in the HIPPARCOS photometry. H_α EW variations also show a meaningful period of 582 d. Thus, the period of 586 d may be closely related to the rotational modulations and/or stellar pulsations. On the other hand, the other significant period of 490 d is interpreted as the result of the orbiting companion. Our orbital fit suggests that the companion was a planetary mass of 6.6 M_J and is located at 1.3 AU from the host.

• Journal of the Korean Society of Food Culture
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• v.36 no.3
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• pp.325-332
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• 2021

This study sought to investigate the effects of heat-moisture treatment (HMT) and ethanol treatment (EOH) for improving the quality and storage stability of Tteokbokki Tteok. The quality characteristics were evaluated by moisture, pH, color, texture profile analysis, and observing the microbial properties after the heat-moisture treatment or ethanol treatment. As the storage period increased, the moisture content of Tteokbokki Tteok tended to decrease except for the HMT group (p<0.05) while the pH did not show significant variation except for the EOH group (p<0.05). While measuring the color, the L-value tended to increase in all groups during the storage period. The a-value and the b-value showed the highest values in the HMT group and the control (CON) group, respectively. In the texture profile analysis, all groups showed a significant tendency to increase levels of hardness and chewiness as the storage period increased (p<0.05). The HMT group showed an increase in hardness and adhesiveness, which are characteristics of the HMT treatment. The results of examining the microbial properties of Tteokbokki Tteok showed that the total microbial count in the HMT group was 4.52 on the 8^th day of storage, which was lower than the level in the CON group and the EOH group on the 4^th day of storage. Yeast and mold were not measured during the storage period. Thus the results of this study showed that when manufacturing Tteokbokki Tteok, the heat-moisture treatment of rice powder increased the storage stability by delaying microbial growth and also had positive effects on quality.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.285-296
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• 1999

Preloading method is used to prevent the settling of a foundation and to increase the strength of ground by consolidation settlement in advance. But, the embankment used in preloading method brings large deformation and sliding failure in the soft ground. Recently, reinforcement method is often used in embankment in order to prevent sliding failure. But, until now, the research on the stability analysis considering both the rate of strength increase of clay by embankment load and increase of resistance force by the geosynthetics in the embankment body is not found. In this study, the stability analysis program(REAP) for embankment including these two points is developed. By this program(REAP), the stability analysis can be done about during the gradual increase of embankment and the stability counterplan can be established when the safety factor is lower than allowable safety factor of design. After calculating the position of sliding failure surface, the force of geosynthetics which is selected by either the effective tensile strength or tensile force caused by the displacement of soil mass in this position is applied to stability analysis. And the increase of resisting moment can be calculated by this force. Also, the construction period can be estimated and the time for the appropriate counterplan can be decided in order to maintain the stability of embankment. And then, safe and economical embankment design can be performed.

• Journal of Korean Dental Science
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• v.8 no.2
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• pp.49-56
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• 2015

Purpose: The effect of accelerated aging on color stability of various dual-cured self-adhesive resin cements were evaluated in this study. Materials and Methods: Color stability was examined using three different brands of dual-cured self-adhesive resin cements: G-CEM LinkAce (GC America), MaxCem Elite (Kerr), and PermaCem 2.0 (DMG) with the equivalent color shade. Each resin cement was filled with Teflon mold which has 6 mm diameter and 2 mm thickness. Each specimen was light cured for 20 seconds using light emitting diode (LED) light curing unit. In order to evaluate the effect of accelerated aging on color stability, color parameters (Commission Internationale de l'Eclairage, CIE $L^*$, $a^*$, $b^*$) and color differences (${\Delta}E^*$) were measured at three times: immediately, after 24 hours, and after thermocycling. The $L^*$, $a^*$, $b^*$ values were analyzed using Friedman test and ${\Delta}E^*$ values on the effect of 24 hours and accelerated aging were analyzed using t-test. These values were compared with the limit value of color difference (${\Delta}E^*=3.7$) for dental restoration. One-way ANOVA and Scheff's test (P<0.05) were performed to analyze each ${\Delta}E^*$ values between cements at each test period. Result: There was statistically significant difference in comparison of color specification ($L^*$, $a^*$, $b^*$) values after accelerated aging except $L^*$ value of G-CEM LinkAce (P<0.05). After 24 hours, color difference (${\Delta}E^*$) values were ranged from 2.47 to 3.48 and $L^*$ values decreased and $b^*$ values increased in all types of cement and MaxCem Elite had high color stability (P<0.05). After thermocycling, color change's tendency of cement was varied and color difference (${\Delta}E^*$) values were ranged from 0.82 to 2.87 and G-CEM LinkAce had high color stability (P<0.05). Conclusion: Color stability of dual-cured self-adhesive resin cements after accelerated aging was evaluated and statistically significant color changes occurred within clinically acceptable range.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.4
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• pp.114-123
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• 2012

This study is aimed to assess the stability of cable bridge by determining the geometric shape of the suspension bridge among the domestic coastal structures in public use after their completion of construction and the displacement of the target suspension bridge after public use. For this purpose, this study calculated the length between pylon piers for each period, sag, sag ratio and the displacement of pylon. Compared to the management standards for each step across different pylon behaviors of the target suspension bridge, this study found that the target suspension bridge behaves stably within the maintenance standards. To identify the behaviors of a suspension bridge accurately, the priority is put on the determination of geometric shape. Therefore, it is required to determine the surveyed shape model on a regular basis across public use period and increased traffics, which is expected to contribute considerably to ensuring the stability of the suspension bridge in its maintenance.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.18.1-18.1
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• 2011

Some applications of carbon nanotubes (CNTs) as field emitters, such as x-ray tubes and microwave amplifiers, require high current emission from a small emitter area. To emit the high current density, CNT emitters should be optimally fabricated in terms of material properties and morphological aspects including high crystallinity, aspect ratio, distribution density, height uniformity, adhesion on a substrate, low outgassing rate during electron emission in vacuum, etc. In particular, adhesion of emitters on the substrate is one of the most important parameters to be secured for high current field emission from CNTs. So, we attempted a novel approach to improve the adhesion of CNT emitters by incorporating metal oxide layers between CNT emitters. In our previous study, CNT emitters were fabricated on a metal mesh by filtrating the aqueous suspensions containing both highly crystalline thin multiwalled CNTs and thick entangled multiwalled CNTs. However, the adhesion of CNT film was not enough to produce a high emission current for an extended period of time even after adopting the metal mesh as a fixing substrate of the CNT film. While a high current was emitted, some part of the film was shown to delaminate. In order to strengthen the CNT networks, cobalt-nickel oxides were incorporated into the film. After coating the oxide layer, the CNT tips seemed to be more strongly adhered on the CNT bush. Without the oxide layer, the field emission voltage-current curve moved fast to a high voltage side as increasing the number of voltage sweeps. With the cobalt-nickel oxide incorporated, however, the curve does not move after the second voltage sweep. Such improvement of emission properties seemed to be attributed to stronger adhesion of the CNT film which was imparted by the cobalt-nickel oxide layer between CNT networks. Observed after field emission for an extended period of time, the CNT film with the oxide layer showed less damage on the surface caused by high current emission.