• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.78.2-78.2
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• 2010

We report the detection of a low-amplitude 380.8-day radial velocity (RV) variations in oscillating K2 III star ${\alpha}$ Ari (HD 12929). We do not found the correlation between RV variations and equivalent widths of chromospheric activity indicators ($H{\alpha}$ and CaII 8662 ${\AA}line$). The bisector analysis shows that bisector velocity span (BVS) and RV variations are not strongly correlated with each other. These result suggest that the RV variations could have been produced either by planetary companion or by the surface spots. If this RV variation is indeed caused by a planetary companion, an orbital solution with a period of P = 381 days, a semi-amplitude of K = 41 m/s, and an eccentricity of e = 0.25 fits the data best. Assuming a possible stellar mass of $M_{\bigstar} = 1.4-5.6 M\odot$, we estimate the minimum mass for the companion of m sini = 1.8-4.5 $M_{Jup}$ with an orbital semi-major axis of 1.2-1.9 AU. If confirmed, our finding gives a support to search for exoplanets around giant stars with multi-periodic oscillations.

• Journal of Veterinary Clinics
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• v.34 no.3
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• pp.185-188
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• 2017

This study assessed the seroprevalence of Babesia gibsoni in companion dogs in Korea by enzyme linked immunosorbent assay using recombinant BgTRAP antigen. Dogs were randomly selected from those admitted for various reasons to local private veterinary hospitals and the Animal Medical Center of Chonbuk National University. With the owners' permission, extra blood was drawn from each dog for serological assays. Of the 188 selected dogs, seven (3.72%) were positive for B. gibsoni, including six of 167 (3.59%) indoor and one of 12 (8.33%) outdoor dogs. Of the seven dogs positive for B. gibsoni, four were aged > 10 years, two were < 1 year, and one was between 1 and 10 years; and two were Yorkshires and one each was Shih-tzu, Maltese, Pekinese, beagle and mixed. Concurrent diseases or chief complaints were anemia in two dogs, both of which had a history of confirmed babesiosis by polymerase chain reaction, and non-anemic diseases in five. Geographically, four dogs were from Jeonbuk/Jeonju, and one each from Seoul, Gyounggi-do, and Jeonnam/Gwangju. To our knowledge, this is the first report of companion dogs in Korea being seropositive for B. gibsoni. Serologic screening of subclinical or carrier dogs can detect this potentially dangerous disease and assess its epidemiology.

• Journal of The Korean Astronomical Society
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• v.47 no.2
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• pp.69-76
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• 2014

We report the detection of an exoplanet candidate in orbit around ${\sigma}$ Persei from a radial velocity (RV) survey. The system exhibits periodic RV variations of $579.8{\pm}2.4$ days. The purpose of the survey is to search for low-amplitude and long-period RV variations in giants and examine the origin of the variations using the fiber-fed Bohyunsan Observatory Echelle Spectrograph installed at the 1.8-m telescope of Bohyunsan Optical Astronomy Observatory in Korea. We present high-accuracy RV measurements of ${\sigma}$ Per made from December 2003 to January 2014. We argue that the RV variations are not related to the surface inhomogeneities but instead a Keplerian motion of the planetary companion is the most likely explanation. Assuming a stellar mass of $2.25{\pm}0.5$ $M_{\odot}$, we obtain a minimum planetary companion mass of $6.5{\pm}1.0$ $M_{Jup}$, with an orbital semi-major axis of $1.8{\pm}0.1$ AU, and an eccentricity of $0.3{\pm}0.1$ around ${\sigma}$ Per.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.109.2-109.2
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• 2012

Current microlensing follow-up observations focus on high-magnification events because of the high efficiency of planet detection. However, central perturbations of high-magnification events caused by a planet can also be produced by a very close or a very wide binary companion, and the two kinds of central perturbations are not generally distinguished without time consuming detailed modeling (a planet-binary degeneracy). Hence, it is important to resolve the planet-binary degeneracy that occurs in high-magnification events. In this paper, we investigate caustic-crossing high-magnification events caused by a planet and a wide binary companion. From this study, we find that because of the different magnification excess patterns inside the central caustics induced by the planet and the binary companion, the light curves of the caustic-crossing planetary-lensing events exhibit a feature that is discriminated from those of the caustic-crossing binary-lensing events, and the feature can be used to immediately distinguish between the planetary and binary companions.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.107.2-107.2
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• 2012

The purpose of the present study is to search for and study the origin of planetary companion by a precise radial velocity (RV) survey for K dwarfs. The high-resolution spectroscopy of the fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) at Bohyunsan Optical Astronomy Observatory (BOAO) is used from September 2008 to June 2012. We report the detection of two new exoplanets in orbit around HD 208527, and HD 220074 with exhibiting a periodic variation of 875.5 and 672.1 days. The examinations of surface inhomogeneous are no related to the RV variations and Keplerian motion is the most likely explanation, which suggests that the RV variations arise from an orbital motion under the influence of planetary companion. We obtain the minimum masses for the exoplanets of 11.5 and 11.1 MJup with an orbital semi-major axis of 2.3 and 1.6 AU and an eccentricity of 0.08 and 0.14, respectively. From the literatures and our estimations of stellar parameters, the luminosity class of HD 208527 is changed K dwarf to K giant and the spectral type of HD 220074 is confirmed M giant rather than K dwarf. HD 220074 is the first M giant star harboring a planetary companion.

• Journal of The Korean Astronomical Society
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• v.54 no.2
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• pp.71-88
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• 2021

We use N-body/hydrodynamic simulations to study the evolution of the spin of a Milky Way-like galaxy through interactions. We perform a controlled experiment of co-planar galaxy-galaxy encounters and study the evolution of disk spins of interacting galaxies. Specifically, we consider cases where the late-type target galaxy encounters an equally massive companion galaxy, which has either a late or an early-type morphology, with a closest approach distance of about 50 kpc, in prograde or retrograde sense. By examining the time change of the circular velocity of the disk material of the target galaxy from each case, we find that the target galaxy tends to lose the spin through prograde collisions but hardly through retrograde collisions, regardless of the companion galaxy type. The decrease of the spin results mainly from the deflection of the orbit of the disk material by tidal disruption. Although there is some disk material which gains the circular velocity through hydrodynamic as well as gravitational interactions or by transferring material from the companion galaxy, it turns out that the amount of the material is generally insufficient to increase the overall galactic spin under the conditions we set. We find that the spin angular momentum of the target galaxy disk decreases by 15-20% after a prograde collision. We conclude that the accumulated effects of galaxy-galaxy interactions will play an important role in determining the total angular momentum of late-type galaxies.

• Journal of the Korean Society of Clothing and Textiles
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• v.42 no.6
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• pp.962-976
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• 2018

This study examined: 1) the influence of 3 social presence types including shopping companions, other consumers, and sales associates on the consumer's purchase decision at a retail store; 2) the difference in the influence by shopping situation involving shopping together or shopping alone; and 3) the differences by consumer susceptibility to social influence and self-confidence. The study conducted three experiments with the retail shopping scenario manipulating consumer's positive self-evaluation, but lack of confidence after trying on a clothing product. Experiment 1 and Experiment 2 examined the positive influence of social presence while Experiment 3 examined the negative influence. The results showed that the positive comment of a shopping companion had the highest influence on the purchase decision. Such impact was more observable under the low susceptibility to normative influence. The negative comments of sales associate and shopping companion lowered the purchase decision. There was no difference by shopping situation. The results imply that influences of social presence on the consumer's purchase decision are different by positive or negative comments and such influences are not different by shopping situation.

• Journal of Environmental Science International
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• v.30 no.2
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• pp.191-194
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• 2021

This study aimed to provide information and data for the management of insect breeding farms by identifying the appropriate density when rearing Protaetia brevitarsis larvae. The breeding box of the insects was filled with 2 L of fermented sawdust on a 50 × 35 × 15 cm sheet of plastic, and the density of the treatments was 200, 300 and 400 P. brevitarsis in the first, second, and third larval stages. Each treatment was repeated five times, and the sawdust medium was replaced three times (10 intervals). The experiments were conducted for a total of 30 days from March 1, 2020. Overall, 200 P.brevitarsis in the first, second, and third larval stages reared in the breeding box had a higher average survival rate and lower average mortality rate, thereby contributing to efficient production. In conclusion, this result suggests a way to increase production efficiency through the environmental management of insect breeding farms.

• Journal of Veterinary Science
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• v.21 no.3
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• pp.42.1-42.22
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• 2020

Regenerative medicine using stem cells from various sources are emerging treatment modality in several refractory diseases in veterinary medicine. It is well-known that stem cells can differentiate into specific cell types, self-renew, and regenerate. In addition, the unique immunomodulatory effects of stem cells have made stem cell transplantation a promising option for treating a wide range of disease and injuries. Recently, the medical demands for companion animals have been rapidly increasing, and certain disease conditions require alternative treatment options. In this review, we focused on stem cell application research in companion animals including experimental models, case reports and clinical trials in dogs and cats. The clinical studies and therapeutic protocols were categorized, evaluated and summarized according to the organ systems involved. The results indicate that evidence for the effectiveness of cell-based treatment in specific diseases or organ systems is not yet conclusive. Nonetheless, stem cell therapy may be a realistic treatment option in the near future, therefore, considerable efforts are needed to find optimized cell sources, cell numbers and delivery methods in order to standardize treatment methods and evaluation processes.

• Journal of The Korean Astronomical Society
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• v.56 no.1
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• pp.35-40
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• 2023

We have been conducting a exoplanet search survey using Bohyunsan Observatory Echelle Spectrograph (BOES) for the last 18 years. We present the detection of exoplanet candidate in orbit around HD 18438 from high-precision radial velocity (RV) mesurements. The target was already reported in 2018 (Bang et al. 2018). They conclude that the RV variations with a period of 719 days are likely to be caused by the pulsations because the Lomb-Scargle periodogram of HIPPARCOS photometric and H_α EW variations for HD 18438 show peaks with periods close to that of RV variations and there were no correlations between bisectors and RV measurements. However, the data were not sufficient to reach a firm conclusion. We obtained more RV data for four years. The longer time baseline yields a more accurate determination with a revised period of 803 ± 5 days and the planetary origin of RV variations with a minimum planetary companion mass of 21 ± 1 M_Jup. Our current estimate of the stellar parameters for HD 18438 makes it currently the largest star with a planetary companion.