• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.152.1-152.1
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• 2011

We report preliminary results of long-slit near-infrared (NIR) spectroscopy of Luminous Blue Variables (LBVs) with moderate resolution of R ~ 2400. We obtained Jshort (1.04-1.26 micron) and Ks (2.02-2.31 micron) band spectra of 4 LBVs and 3 LBV candidates in Southern hemisphere using IRIS2, infrared imager and spectrograph, mounted on the 4-m Anglo-Australian Telescope. All targets are fairly bright in NIR so that we can obtain high signal-to-noise ratio for clear line detection and modeling. They are also widely distributed in the HR diagram so that we can compare the spectral properties of LBVs in different temperature and luminosity ranges. Among them, we present the results of two well-known LBVs AG Car and HR Car. Their spectra show similar properties with hydrogen, He I, and metallic lines such as Fe II and Mg II, most of them in emission. We discuss, in particular, the He I 1.083 micron lines formed in stellar wind because these two LBVs show large variation in their He I line intensities, compared to previous studies. Since the He I 1.083 line is known to be anticorrelated with the photometric variation of LBVs, strong line intensities with P-Cygni profiles in both stars indicate that they are now near the visual minimum phase. We model the obtained spectra using non-LTE atmosphere code CMFGEN of Hillier (1998) to derive stellar parameters such as wind velocity and mass loss rate, and discuss the long-term variability of stellar parameters of these LBVs. deduced from our otometric solution.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.559-563
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• 2015

Monitor of All-sky X-ray Image (MAXI) is a Japanese X-ray all-sky surveyer mounted on the International Space Station (ISS). It has been scanning the whole sky since 2009 during every 92-minute ISS rotation. X-ray transients are quickly found by the real-time nova-search program. As a result, MAXI has issued 133 Astronomer's Telegrams and 44 Gamma-ray burst Coordinated Networks so far. MAXI has discovered six new black holes (BH) in 4.5 years. Long-term behaviors of the MAXI BHs can be classified into two types by their outbursts; a fast-rise exponential-decay type and a fast-rise flat-top one. The slit camera is suitable for accumulating data over a long time. MAXI issued a 37-month catalog containing 500 sources above a ~0.6 mCrab detection limit at 4-10 keV in the region ${\mid}{b}{\mid}$ > $10^{\circ}$. The SSC instrument utilizing an X-ray CCD has detected diffuse soft X-rays extending over a large solid angle, such as the Cygnus super bubble. MAXI/SSC has also detcted a Ne emission line from the rapid soft X-ray nova MAXI J0158-744. The overall shapes of outbursts in Be X-ray binaries (BeXRB) are precisely observed with MAXI/GSC. BeXRB have two kinds of outbursts, a normal outburst and a giant one. The peak dates of the subsequent giant outbursts of A0535+26 repeated with a different period than the orbital one. The Be stellar disk is considered to either have a precession motion or a distorted shape. The long-term behaviors of low-mass X-ray binaries (LMXB) containing weakly magnetized neutron stars are investigated. Transient LMXBs (Aql X-1 and 4U 1608-52) repeated outbursts every 200-1000 days, which is understood by the limit-cycle of hydrogen ionization states in the outer accretion disk. A third state (very dim state) in Aql X-1 and 4U 1608-52 was interpreted as the propeller effect in the unified picture of LMXB. Cir X-1 is a peculiar source in the sense that its long-term behavior is not like typical LMXBs. The luminosity sometimes decreases suddenly at periastron. It might be explained by the stripping of the outer accretion disk by a clumpy stellar wind. MAXI observed 64 large flares from 22 active stars (RS CVns, dMe stars, Argol types, young stellar objects) over 4 years. The total energies are $10^{34}-10^{36}$ erg $s^{-1}$. Since MAXI can measure the spectrum (temperature and emission measure), we can estimate the size of the plasma and the magnetic fields. The size sometimes exceeds the size of the star. The magnetic field is in the range of 10-100 gauss, which is a typical value for solar flares.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.613-618
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• 2010

Purpose: The coronal approach for repair of frontal sinus fractures is associated with significant adverse sequelae including a long scar, alopecia, paresthesias, and, uncommonly, facial nerve injury. To minimize these complications, an endoscopic approach for repair of frontal sinus fractures was developed. The authors now present the results of an endoscopy-assisted approach for the treatment of frontal sinus fractures. Methods: From 2002 to 2009, five patients with frontal sinus fracture underwent endoscopic repair. Two slit incisions were placed in the scalp, and one or two stab incisions directly over the fractures were placed in the forehead. After subperiosteal dissection, fracture segments were reduced under direct vision and fixed with microplates or fibrin glue. Results: All patients had good cosmetic results and remained free of sinus complaints. There were no perioperative complications reported. Conclusion: Endoscopic repair of frontal sinus fractures is an efficacious technique that significantly reduces patient morbidity. A relatively wide range of anterior table fractures can be reduced using an endoscope. In cases of complicated comminuted fractures, fibrin glue helps to achieve satisfactory endoscopic reduction. Endoscopic repair is an alternative treatment for various anterior table fractures of the frontal sinus.

• Membrane Journal
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• v.12 no.4
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• pp.207-215
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• 2002

The hindered diffusion in confined spaces is an important phenomenon to understand in a micro-scale the filtration mechanism determined by the particle motion in membrane pores. Compared to the case of spherical colloids, both the theoretical investigations and the experiments on the hindered diffusion of polyelectrolytes is actually more difficult, due to lots of relevant parameters resulting from the complicated conformational properties of the polyelectrolyte chain. We have successfully performed the Brownian dynamics simulations upon a single polyeiectrolyte confined in a slit-like pore, where a coarse-grained bead-spring model incorporated with Debye-Huckel interaction is properly adopted. For the given sizes of both the polyelectrolyte and the pore width, the hindered diffusion coefficient decreases as the solution ionic concentration decreases. It is evident that a charge effect of the pore wall enhances the hindered diffusion of polyelectrolyte. Simulation results allow us to make sense of the diffusive transport through the micro-pore, which is restricted by the influences of the steric hindrance of polyelectrolytes as well as the electrostatic repulsion between the polyelectrolytes and pore wall.

• Journal of the Korean Society of Costume
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• v.18
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• pp.247-268
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• 1992

The Clothing expresses people's desire of beauty most directly of all cultural inheritances, and it teach us how the human culture has changed and developed. In this study researched the history of buttonholes which make the clothes more functional and beautiful. Buttons and Buttonholes is one of detailed elements they used as a fastener or as a decoration on clothing. Button have been used since ancient times, in early times long before buttons were used as fasteners they had significant decorative and symbolic value. In ancient times, clothes fastened with pins, brooches, fibular and ties. In medieval Europe, it was not until the 13th century that they used the button in functional use, and then Chong Ryung-Lk was introduced from orient, and they became popular as fasteners on clothing during the 13th century when fitted clothes replaced loose garments. Garments were laced together or fastened with buttons, until buttonholes were invented in the 13th century. But as early as the 14th century it appears that someone discovered that a loop slipped over a button, or button pushed through a slit in the cloth, would make a good clothes fastener. Many buttons made during the modern ages were convex medallions set in metal rims and decorated with partraits of famous men and women. During the modern ages, buttons, with ligh-ographed pictures, covered with celluloid of glass were popular. In the 19th century, the mass production by machine made people use the button easily, and many different material of button easily and many different material of button was made. With the begining of the 20th century. the development of plastics led to various and functional buttons. The type of buttonholes also became various, as bound buttonhole, Tailred buttonhole, Worked buttonhole, Loop buttonhole and so on. The button has many forms which were imitated by nature, or made geometrically and the appearance of the button from behind is classified by what has holes and what has holes and what has a shank, and I also classified the kinds of button by the quality of the material design and use. Like this, with the passing of the time buttons and buttonholes have changed in appearance with the change of clothes, and they have standed for something meaningful as well as fixed the opening and made clothes more beautiful.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.159-165
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• 2018

In this paper, a low-loss wideband waveguide transducer is proposed for millimeter-wave communication and radar applications. A conventional E-plane probe transducer is generally designed using thin and flexible substrate at millimeter-wave frequencies, considering the very small waveguide size. However, it results in serious performance degradation caused by the bending of the substrate. In order to alleviate this problem and provide a reliable performance, we propose an extended E-plane probe transducer where the probe substrate is extended to and fix ed in the slit area formed in the waveguide wall. It is fabricated using $127{\mu}m$-thick substrate with dielectric constant of 2.2. The measurement in the back-to-hack configuration shows the excellent insertion loss of 1.35 dB (${\pm}0.35dB$) including the loss of 3 cm-long thru waveguide and return loss better than 13.8 dB over entire W-band (75-110 GHz). Therefore, it can be effectively applied for millimeter-wave high-speed communications and high-sensitivity radars.

• Journal of The Korean Astronomical Society
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• v.53 no.5
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• pp.103-115
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• 2020

We analyze the spatially resolved kinematics of gas and stars for a sample of ten hidden type 1 AGNs in order to investigate the nature of their central sources and the scaling relation with host galaxy stellar velocity dispersion. We select our sample from a large number of hidden type 1 AGNs, which are identified based on the presence of a broad (full width at half maximum ≳1000 km s^-1) component in the Hα line profile and which are frequently mis-classified as type 2 AGNs because AGN continuum and broad emission lines are weak or obscured in the optical spectral range. We used the Blue Channel Spectrograph at the 6.5-m Multiple Mirror Telescope to obtain long-slit data with a spatial scale of 0.3 arcsec pixel^-1. We detected broad Hβ lines for only two targets; however, the presence of strong broad Hα lines indicates that the AGNs we selected are all low-luminosity type 1 AGNs. We measured the velocity, velocity dispersion, and flux of stellar continuum and gas emission lines (i.e., Hβ and [O III]) as a function of distance from the center. The spatially resolved gas kinematics traced by Hβ or [O III] are generally similar to the stellar kinematics except for the inner center, where signatures of gas outflows are detected. We compare the luminosity-weighted effective stellar velocity dispersions with the black hole masses and find that our hidden type 1 AGNs, which have relatively low back hole masses, follow the same scaling relation as reverberation-mapped type 1 AGN and more massive inactive galaxies.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.5
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• pp.442-449
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• 1984

Turbulent jet flow has been studied in many ways; a plane jet, a rectangular jet, an annular jet, a round jet, a wall jet, a parallel jet, a valve jet, a cross jet, a slit jet and etc. In this report, a 45.deg. cross jet flow was tried by using two same dimensioned nozzels(dia..phi.20)which were set up at the exit of the subsonic wind tunnel. Each jet flows to the direction of 22.5.deg. to the axis of downstream of the mixed flow. The centerline of each jet meets at the distance of 217.3mm and their mixing flow could be imagined to develop beyond that distance, so the measurement was effectuated at X/X$_{0}$=1.2-1.5. The section of the mixed flow a elliptic circle which is formed by the 22.5.deg. inclined flows to the X direction. This experimental study aimed at the investigation of the turbulent mixing process of two jets; the mean velocities, the turbulent shear stresses, the correlation coefficients, and the momentum were respectively measured. The mean velocity distribution profiles of the down-stream component measured in the Y direction coincide well with the empirical equation of Gortler and those measured in the Z direction agree with the equation of H. Schlichting. Other mean velocities V over bar and W over bar components were randomly distributed. The higher values with same order of the intensity of turbulence were largely distributed at the central part of the flow. The momentum was decreased up to 70% by the shock losses and the development of intense turbulences, but it kept its value constantly beyond X/d=14. Two-channel hot-wire anemometer systems (model 1050 series), X-type hot-wire made of tungsten (dia. .phi.e.mu.m, long 3mm, model 0252 T5), a computer(model HP 9845B0, and a plotter (model HP 9872C) were used for the experiments and the analyses.s.

• The Research Journal of the Costume Culture
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• v.16 no.2
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• pp.263-277
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• 2008

In picture bible, the picture is helpful for showing story more vividly and specifically and it is helpful for finding the meaning of bible hidden behind familiarity. It plays the role of the most powerful testimony and expression, with which human provides himself. The purpose of study was to grasp the relation among historical background of the middle age, human's characteristic and symbolic color by considering the fact that the costume expressed in Maciejowski Bible, which is a picture bible of the middle age and observing type, color and decoration of costume. Among 46 folios organizing Maciejowski Bible, 129 pictures explaining the Book of Genesis, the Book of Exodus, the Book of Leviticus, the Book of Numbers, the Book of Deuteronomy, the Book of Joshua and the Book of Judges, which belong to the former 400 years of the old Testament, were analyzed for people's costumes. The pictures shown in Maciejowski Bible portrays object, costume and behavior on the background of France of the 13th century so we can find out the precious natures of middle age's costume, weapon and armor. Especially, the portrait about finger armor of chain mail attached in hauberk becomes the outstanding evidence that can encroach the discussion over whether it was used in the end of 1300s. Regarding costumes of main characters, they wore chemise and braies as underwear, wore tunic or cotte having various lengths from the length reaching knee to the length reaching 8round as basic costume and wore mantle with different-colored lining and hose with various colors. In the war picture, we can see hauberk made with chain mail and cyclas with long slit, which was worn over hauberk, barrel helmet, norman helmet and steel school cap. Regarding cap. man usually wore coif, beret, shade-shaped cap, straw hat and woman wore the decoration using veil and hairlace and used the method to wrap whole hair with net. As the colors used in the costume of the picture bible, scarlet, blue, green and brown were usually used in order. They usually wore costumes decorated splendidly with the colors haying hish brightness and chroma.

• Korean Journal of Ophthalmology
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• v.32 no.6
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• pp.438-444
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• 2018

Purpose: To compare the success rates of performing only silicone tube intubation versus carrying out both conjunctival resection and silicone tube intubation. Methods: The subjects of this study involved 62 patients (96 eyes) between October 2015 and May 2017 who were diagnosed as having punctal stricture or nasolacrimal duct stenosis. Out of 96 eyes, 47 underwent only silicone tube intubation, and 49 underwent both silicone tube intubation and conjunctival resection. Three parameters were measured at 1, 3, and 6 months after the surgery: the area of the tear meniscus using RTVue-100 anterior segment optical coherence tomography, the height of the tear meniscus using a slit lamp microscope, and the subjective satisfaction of patients as a result of improved sympotms like epiphora. The surgery was considered successful when the patients' experienced the resolution of symptoms and reduction of the area and height of the tear meniscus. Results: The area of the tear meniscus, height of the tear meniscus, and subjective satisfaction of patients was superior in the group that underwent both silicone tube intubation and conjunctival resection compared silicone tube intubation only. Based on these results, the success rate of the surgery was 68.9% in the group that underwent only silicone tube intubation and 78.7% in the group that underwent both silicone tube intubation and conjunctival resection. Conclusions: The resection of relaxed plica semilunares seems to increase the success rate of silicone tube intubation through the reduction of the area and height of the tear meniscus. Therefore, after determining the degree of conjunctivochalasis, if it was found to be severe, a combination with conjunctival resection was expected to increase the success rate of the surgery.