• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.61.1-61.1
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• 2011

We have performed simultaneous observations at 22GHz and 43GHz on AGNs hosted by elliptical galaxies using KVN radio telescope. We have constructed the sample, based on two major surveys in radio and optical band, i.e. Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) and Sloan Digital Sky Survey (SDSS) DR7, respectively. We restricted the redshift range 0.01 < z < 0.06 and the absolute magnitude Mr < -19.4 in order to satisfy volume limited sample. We also checked clear detection of four distinctive emission lines ([NII], [OIII], $H{\alpha}$, $H{\beta}$) so as to utilize on BPT diagram, distinguishing AGNs from star-forming galaxies. Elliptical galaxies have been selected by visual inspection making use of SDSS optical images. Then, we cross-matched the elliptical galaxies with FIRST detections. About 35% of the galaxies have been detected throughout KVN observations. We derive spectral index, applying the flux of different radio frequencies from FIRST (1.4GHz) and KVN (22GHz) and classify into steep, flat or inverted spectrum. We have found that most of the detected galaxies have flat spectrum while the rest of them have steep spectrum. This implies that a number of detected galaxies might have compact structure associated with the central region of the galaxies. The relation between black hole mass and radio luminosity has shown relatively tighter correlation in high frequency than in low frequency, which confirms that high frequency in radio band is appropriate to study the center of the galaxies.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.10 no.1
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• pp.284-305
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• 1997

A Literatural study on the etiological factors, classification, prescription of hemorrhoids and hemorrhoids complicated by anal fistula following results were obtained. 1. The cause of hemorrhoids are long time sit, long time gate, overfatigue, overeating, imbalance of stool( constipation or diarrhea), pregnant fertility(overfatigue after childbirth, insufficiency of middle warmer energy), uncontrol sexual excess, pathgenic factors of wetness, heat, wind, dry, genetic cause, excess of anxiety, pile up of heat poison, weakness of entrails and viscera. The cause of hemorrhoid complicated by anal fistula are attack of external wind, heatness, dry, fire, wetness(pathgenic factors), inapporiate treatment and chronic disease, greasy diet, excess of anxiety, constipation, uncontrol sexual excess, obstacle of circulation of vital energy and blood on anal site. 2. Classification of hemorrhoids are female hemorrhoids, male hemorrhoids, pulse hemorrhoids, intestines hemorrhoids, vital energy hemorrhoids, wine hemorrhoids, blood hemonhoids, flowing hemorrhoids. Classification with other method are external hemorrhoids, internal hemorrhoids, mixed hemorrhoids, excrescence hemorrhoids, nipple homorrhoids. External hemorrhoids is classified of varicosis of hemorrhoidal vein, connective tissue form, thrombus form. Classification of hemorrhoid complicated by anal fistula are simple lower hemorrhoid, lower mixed hemorrhoid, deep hemorrhoid, outer of one hole hemorrhoid, a horseshoe hemorrhoids. Once more classificated of four are space of sphincter muscle form, penetration sphincter muscle form, upper of sphincter muscle form, outer of sphincter muscle form. 3. Therapy method of hermorrhoid and hemorrhoid complicated by anal fistula are internal method, fumigation method method, ointment, method of close with medicine, necrotizing method, hot medicated compress( gxternal method), injection, insertion, bind, (operation) and acupuncture therapy (the others method) 4. Herb medicine for many used of internal method are Scutellaria baikalensis George(黃芩), Coptis japonia Makino(黃連), Rehmania giutinosa Liboschitz ex Fischer & Meyer(生地黃), Poncirus trifoliata Refinesque(枳殼), Sanguisorba officinalis Linne(地楡), Sophora japonica L.(槐花), Cnidium officinale Makino (川芎), Astragalus membranaceus Bunge(황기), Angelica gigas Nakai (當歸). 5. Herb medicine for many used of fumigation are Schlechtendalia Chinesis J. Bell (五倍子), Artemisia Vulgaris L. var indica Maxim(艾葉), Poncirus trifoliata Refinesque (枳殼), Nepeta japonica Maximowicy(荊芥), And herb medicine for many used of ointment are Calomelas(輕粉), Alum(白礬), Boswellia carterii Birdwood(乳香), Os Draconis Fossilia Ossis Mastodi(龍骨).

• Korean Journal of Medicinal Crop Science
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• v.23 no.1
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• pp.27-36
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• 2015

Shading and soil environment are the main factors of growth and yield in ginseng (Panax ginseng C. A. Meyer). Ginseng yield is directly related to survival rate because of increased missing plant for their growing period. Under field conditions, diseases and pests significantly affect plant survival rate. We evaluated the seedling establishment, growth and ginsenoside of the ginseng plants, under controlled management conditions in a plastic greenhouse, when their treated with different types of organic matter. Ginseng seeds were sown at a rate of three seeds per hole, and the seeding space measured $10cm{\times}15cm$. Compared to the control, treatment of cattle manure vermicompost (CMV) was shown to increase seedling establishment and decrease ginsenoside content. Root weights of plants treated with CMV were higher than those of plants treated with other types of organic matter. In addition, seedling establishment of 2-year-old ginseng plants was decreased when it was compared to that of 1-year-old ginseng plants. Our results indicated that organic matter type and rate were associated with seedling establishment, growth characteristic and ginsenoside content in greenhouse of ginseng direct-sowing culture.

• Journal of the Korea Convergence Society
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• v.8 no.7
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• pp.123-129
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• 2017

Morphological and ultrastructural characteristics of human hair medulla was investigated with scanning electron microscopy and transmission electron microscopy. The medulla is located in the central position of hair shaft and appear greatly variable forms which discontinuous shape arranged from hair root to apical portion according to longitudinal axis. The thickness of medulla from a single hair presented as very variable in size. The diameter of cross section of human hair medulla measured as $21{\mu}m$ and longitudinal section showed $27{\mu}m$. It grows up to 1/3 from 1/4 in diameter of human hair shaft. It appears emptied hole during separating of macrofibrils in the keratinocyte. The empty space measured $6.5{\mu}m$ in diameter as maximum size and it was filled with air.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.68.2-68.2
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• 2016

We present the variability and time lag measurements of PG 0934+013 based on the photometric and spectroscopic monitoring campaign over two years. We obtained 46 epochs of data from the spectroscopic campaign, which was carried out using the South African Large Telescope with 1 week cadence over two sets of 4 month-long observing period, while we obtained 80 epochs of B band data from the campaign. Due to the six month gap between two campaigns, we separately measured the time lag of the $H{\beta}$ emission line by comparing the emission line light curve with the B band continuum light curve using the cross-correlation function techniques. We determined the time lags and black hole mass.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.133-137
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• 2015

The Galactic center uniquely provides opportunities to resolve how star clusters form in neutral gas overdensities engulfed in a large-scale accretion flow. We have performed sensitive Green Bank 100m Telescope (GBT), Karl G. Jansky Very Large Array (JVLA), and Submillimeter Array (SMA) mapping observations of molecular gas and thermal dust emission surrounding the Galaxy's supermassive black hole (SMBH) Sgr $A^{\ast}$. We resolved several molecular gas streams orbiting the center on ${\gtrsim}10$ pc scales. Some of these gas streams appear connected to the well-known 2-4 pc scale molecular circumnuclear disk (CND). The CND may be the tidally trapped inner part of the large-scale accretion flow, which incorporates inflow via exterior gas filaments/arms, and ultimately feeds gas toward Sgr $A^{\ast}$. Our high resolution GBT+JVLA $NH_3$ images and SMA+JCMT 0.86 mm dust continuum image consistently reveal abundant dense molecular clumps in this region. These gas clumps are characterized by ${\gtrsim}100$ times higher virial masses than the derived molecular gas masses based on 0.86 mm dust continuum emission. In addition, Class I $CH_3OH$ masers and some $H_2O$ masers are observed to be well associated with the dense clumps. We propose that the resolved gas clumps may be pressurized gas reservoirs for feeding the formation of 1-10 solar-mass stars. These sources may be the most promising candidates for ALMA to probe the process of high-mass star-formation in the Galactic center.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.99-107
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• 2014

In this paper, a landmark based localization system using a Kinect sensor is proposed and evaluated with the implemented system for precise and autonomous navigation of low cost robots. The proposed localization method finds the positions of landmark on the image plane and the depth value using color and depth images. The coordinates transforms are defined using the depth value. Using coordinate transformation, the position in the image plane is transformed to the position in the body frame. The ranges between the landmarks and the Kinect sensor are the norm of the landmark positions in body frame. The Kinect sensor position is computed using the tri-lateral whose inputs are the ranges and the known landmark positions. In addition, a new matching method using the pin hole model is proposed to reduce the mismatch between depth and color images. Furthermore, a height error compensation method using the relationship between the body frame and real world coordinates is proposed to reduce the effect of wrong leveling. The error analysis are also given to find out the effect of focal length, principal point and depth value to the range. The experiments using 2D bar code with the implemented system show that the position with less than 3cm error is obtained in enclosed space($3,500mm{\times}3,000mm{\times}2,500mm$).

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.69-69
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• 2000

(Ba, Sr)TiO3 (BST)[1-3] 박막은 유전상수가 크고 고주파에서도 유전특성 저하가 적기 때문에 ULSI DRAM(Dynamic Random Access Memory)에 응용 가능한 물질로 최근 각광을 받고 있다. 하지만, 아직 BST 박막을 DRSM에 바로 적용하기 위해선 몇 가지 문제점이 있다. 그 중 누설전류 문제는 디바이스 응용시 매우 중요한 요소이다. 특히, DRAM에서 refresh time와 직접적인 관련이 있어 디바이스 내의 신뢰도 및 전력소모를 결정하는 주된 인자가 된다. 지금까지, BST 박막의 인가전업, 온도, 그리고 전극물질에 따른 누설전류 현상들이 고찰되었고, 이에 관한 많은 전도기구 모델들이 제시되었다. Schottky emission, Poole-Frenkel emission, space charge limited conduction 등이 그 대표적인 예이다. 하지만 아쉽게도 BST 박막의 정확한 누설 전류 전도 기구를 완전히 설명하는데는 아직 한계가 있다. 따라서 본 연구에서는 제작된 BST 커패시터 내의 기본적인 전기적 성질을 조사하고, 정확한 누설전류 기구 규명에 초점을 두고자 한다. 이를 위해 기존의 여러 기구들과 비교 분석할 것이다. 하부전극으로 사용하기 위해 스퍼터링 방법으로 p-Si(100) 기판위에 RuO2 박막을 약 120nm 증착하였다. 증착전의 chamberso의 초기압력은 5$\times$10-6 Torr이하의 압력으로 유지시켰다. Ar/O2의 비는 이전 실험에서 최적화된 9/1로 하였다. BST 박막 증착 시 5분간 pre-sputtering을 실시한 후 하부전극 기판위에 BST 박막을 증착하였다. 증착이 끝난 후 시편을 상온까지 냉각시킨 후 꺼내었다. 전기적 특성을 측정하기 상부전극으로 RuO2와 Al 박막을 각각 상온에서 100nm 증착하였다. 이때 hole mask를 이용하여 반경이 140um인 원형의 상부전극을 증착하였다. BST 박막의 증착온도가 증가하고 Ar/O2 비가 감소할수록 제작된 BST-커패시터의 전기적 성질이 우수하였다. 증착온도 $600^{\circ}C$, ASr/O2=5/5에서 증착된 막의 누설전류는 4.56$\times$10-8 A/cm2, 유전상수는 600 정도의 값을 나타내었다. 인가전압에 따른 BST 커패시터의 transition-current는 Curie-von Schweider 모델을 따랐다. BST 박막의 누설전류 전도기구는 기존의 Schottky 모델이 아니라 modified-Schottky 무델로 잘 설명되었다. Modified-Schottky 모델을 통해 BST 박막의 광학적 유전율 $\varepsilon$$\infty$=4.9, 이동도 $\mu$=0.019 cm2/V-s, 장벽 높이 $\psi$b=0.79 eV를 구하였다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.10
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• pp.983-990
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• 2010

Reduction of acoustic loads of space launch vehicles can be achieved by acoustic absorbers satisfying strict cleanness requirements. This limited the use of general porous materials and requires non-porous sound absorbers. Micro-perforated panel absorbers(MPPA) is one of promising sound absorbers satisfying the cleanness requirement for launch vehicles. However, its applicability was limited to low sound pressure levels according to the acoustic impedance model of micro-perforated panels. In this paper the applicability of micro-perforated panel absorbers at high incident sound pressure was investigated in experimental ways. The absorption characteristics of a micro-perforated panel absorber was simulated according to its design variables, e.g., minute hole diameters and aperture ratios. It was shown that optimal design can be readily done by using proposed design charts. Experiments were conducted to measure acoustic properties of the designed micro-perforated panel absorbers. The results showed that acoustic resistance increases rapidly as incident sound pressure level does but change of acoustic reactance can be neglected in a practical point of view. This caused the decrease of peak value of absorption coefficient at high incident sound pressure level, but the amount of reduction can be accepted in practice. The major advantage of the micro-perforated panel absorber(wide absorption bandwidth) was still kept at high sound pressure level.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.508-519
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• 2021

In this study, a model was developed to predict the peak particle velocity (PPV) that affects people and the surrounding environment during blasting. Four machine learning models using the k-nearest neighbors (kNN), classification and regression tree (CART), support vector regression (SVR), and particle swarm optimization (PSO)-SVR algorithms were developed and compared with each other to predict the PPV. Mt. Yogmang located in Changwon-si, Gyeongsangnam-do was selected as a study area, and 1048 blasting data were acquired to train the machine learning models. The blasting data consisted of hole length, burden, spacing, maximum charge per delay, powder factor, number of holes, ratio of emulsion, monitoring distance and PPV. To evaluate the performance of the trained models, the mean absolute error (MAE), mean square error (MSE), and root mean square error (RMSE) were used. The PSO-SVR model showed superior performance with MAE, MSE and RMSE of 0.0348, 0.0021 and 0.0458, respectively. Finally, a method was proposed to predict the degree of influence on the surrounding environment using the developed machine learning models.