• 원예과학기술지
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• 제35권3호
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• pp.373-380
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• 2017

Amaryllis ($Hippeastrum{\times}johnsonii$) is commonly propagated by three methods: seeds, offset bulblets, and twin scaling. Since the number and size of bulblets produced by these methods are low, we conducted an experiment to evaluate different bulb cutting methods for propagation. For this purpose, bulbs (circumference of 30 - 35 cm) were sectioned or notched into 8, 12, or 16 segments or twin-scaled into 48, 72, or 96 segments for bulblet formation. Our results show that the largest number of bulblets was produced by the twin scaling method, but they take longer to grow to a final, commercial size. Sectioning and notching resulted in larger, but fewer bulblets than twin-scaling. Compared to notching, sectioning provided more space for the bulblets to grow, and is therefore the recommended method. While increasing the number of sections cut from a single bulb resulted in a larger number of bulblets, the diameter of the bulblets decreased. Therefore, sectioning the bulb into 8 segments was the best method for producing an acceptable number of vigorous bulblets.

• 한국대기환경학회지
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• 제10권2호
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• pp.137-145
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• 1994

A visibility analysis model based on the Mie theory is applied to the measurements during the fall, 1993 in Seoul. Model estimations of the total extinction coefficient $b_{ext}$, and the particle scattering coefficient, $b_{sp}$ are in good agreement with the measured values by a transmissometer and a nephelometer, respectively. These values show strong dependency on the mass loading of fine particles( $D_{p}$ ＜3.0${\mu}{\textrm}{m}$) but show no apparent relation with that of coarse particles(3.0${\mu}{\textrm}{m}$＜ $D^{p}$ ＜10${\mu}{\textrm}{m}$). Relative humidity plays an important role in determining the size of particles which in turn, affects the optical efficiency of aerosol. Based on the composition analysis with cut size nitrate concentration is higher than the sulfate concentration in PM3-10 but they are comparable to each other in PM3. Considering in 1985, it demonstrates a drastic increase of nitrate concentration between 1985 and 1993. It is found that measured and estimated light extinction budget were in good agreement within 10% and that scattering by particles is responsible for about 50-55% and 70-80 % of total extinction during clear and smoggy periods respectively.y.

• 반도체디스플레이기술학회지
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• 제10권1호
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• pp.91-94
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• 2011

This paper presents light transmission efficiency by optical adhesive thickness between MLA and aperture layer and by aperture hole size. The gap between MLA and Aperture layer is adjusted by the shim. The more optical adhesive thickness increases, the better light transmission efficiency increases up to a point. After that, the light transmission efficiency decreases because stray lights cannot transmit through the aperture layer owing to cut-off by aperture layer. And as a result of light transmission efficiency with changing aperture hole size, the light transmission efficiency is proportional to area of aperture hole. The more specified process is made, the better data and sample will be got.

• Spatial Information Research
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• 제10권4호
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• pp.501-513
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• 2002

Eurasian otter (Lutra lutra) is one of endangered wildlife species whose population size is declining in Korea. To manage and conserve habitat for Eurasian otter, it is crucial to understand which habitat components affect otter habitat qualities. The objectives of this study were to develop a habitat suitability model of Eurasian otter in Soraksan National Park, to validate the model in Odaesan National Park. The research methods of this study were as follows. First, trace data and characters of Eurasian otter habitat were collected with Geographic Information System (GIS) data and Global Positioning System (GPS) receivers between 2000 and 2002. Second, the habitat use factors were identified as habitat characteristics of Eurasian otter and classified with habitat use and availability analyses. Third, significant factors of habitat model were extracted by Chi-square test. The last, Eurasian Otter Habitat Suitability Model (EOHSM) was employed by logistic regression method. Otter habitat use was positively associated with the reeds and shrubs areas adjacent to streams, the size of boulders, and low human disturbance in Soraksan National Park by EOHSM. This model had a classification accuracy of 74.4% at cutoff value of 0.5. Model validation showed a classification accuracy of 86.6 % at cut off value of 0.5 for otter habitat in Odaesan National Park.

• 한국전기전자재료학회논문지
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• 제21권11호
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• pp.1029-1035
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• 2008

$LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ cathode materials prepared from different precursors in lithium rechargeable batteries were characterized by various analytical methods. $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ powders were synthesized by using solid-state reaction method and their physical and chemical properties were analyzed by XRD, SEM, particle size analyzer and TCP-AES. These materials showed different crystallinity, particle size, surface morphology and chemical composition. Also, the charge/discharge cycling of $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ electrodes was carried out under various cut-off voltages and it showed different behaviors. It was found that the electrochemical cyclability of $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ was strongly related to its crystallinity.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2004년도 춘계학술대회
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• pp.303-306
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• 2004

참멍게의 체액세포로부터 산추출 후, 조 추출물에서 천연항균소재를 개발하기 위해 먼저 멍게 조 추출액을 직접 Tricine-SDS PAGE를 통하여 주요 펩타이드들의 분자량의 범위를 살펴본 결과 6kDa 이하의 분자량의 펩타이드들이 다량 존재함을 알수 있었다. 펩타이드들의 size별 항균활성을 알아보기 위해 여러 사이즈의(100, 50, 30, 10 kDa)의 한외여과만으로 여과하여 그 여과액들의 specific 활성을 알아본 결과 여과막의 cut-off size에 상관없이 거의 인정한 specific activity를 가짐을 알 수 있었다. 멍게 조 추출액의 여러 미생물에 대한 항균 스펙트럼을 알아보기 위해 E.coli, P. aeruginosa, S. typhi, V. parahaemolyticus, L. monocytogenes, B. sutillus, S. aureus, S. mutans 균주들을 $10^5 CFU/ml$로 부터 4log 감소시키는 농도를 측정한 결과 각각 200, 50, 60, 10, 25, 30, 100, 100ppm 농도였으며, 대표적 상용화 항균 펩타이드인 Nisin과의 항균활성 비교 결과 비슷하거나 월등히 뛰어난 결과를 보여주었다. 또한 추출액의 열안정성을 측정하기 위해 $100^{\circ}C$에서 10분간 가열한 후 원액과의 항균력의 차이를 Radial diffusion assay로 알아본 결과 항균력의 차이가 거의 없음을 알 수 있었다.

• 한국산업융합학회 논문집
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• 제5권4호
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• pp.367-372
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• 2002

Experimental study was conducted for lapping process after WEDMed specimen. In order to decide the lapping depth of the specimen, the number of the grain size was increased from 400, 600 to 800 to obtain the better surface. Observation of scanning electron microscope, hardness test, surface roughness test and energy dispersive spectrum(EDS) analysis were used for this experimental study. From the comparison and analyses of the results of between the wire-cut electrical discharge machining and the lapping, the following results were obtained. The surface roughness after lapping was found to be improved as increasing the number of lapping process like 1st, 2nd, 3rd lapping and the number of grain size such as 400, 600, 800. The surface hardness after increasing the lapping depth of the specimen was slowly increased. It was found that after 3rd lapping process the hardness was reached the hardness of original base material. It was found that the small amount of coating components within 3% was remained after the 1st lapping process, compared to that approximately 16% after WEDM process.

• Nuclear Engineering and Technology
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• 제53권5호
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• pp.1619-1625
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• 2021

This paper demonstrates the possible nondestructive analysis of iron artifacts' metallurgical characteristics using neutron imaging. Ancient kingdoms of the Korean Peninsula used a direct smelting process for ore smelting and iron bloom production; however, the use of iron blooms was difficult because of their low strength and purity. For reinforcement, iron ingots were produced through refining and forge welding, which then underwent various processes to create different iron goods. To demonstrate the potential analysis using neutron imaging, while ensuring artifacts' safety, a sand iron ingot (SI-I) produced using ancient traditional iron making techniques and a sand iron knife (SI-K) made of SI-I were selected. SI-I was cut into 9 cm², whereas the entirety of SI-K was preserved for analysis. SI-I was found to have an average grain size of 3 ㎛, with observed α-Fe (ferrite) and pearlite with a body-centered cubic (BCC) lattice structure. SI-K had a grain size of 1-3 ㎛, α-Ferrite on its backside, and martensite with a body-centered tetragonal (BCT) structure on its blade. Results show that the sample's metallurgical characteristics can be identified through neutron imaging only, without losing any part of the valuable artifacts, indicating applicability to cultural artifacts requiring complete preservation.

• 대한안전경영과학회지
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• 제21권3호
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• pp.23-27
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• 2019

The first aim of the study is to improve the productivity by uniformizing the thickness of coating and reducing quality-inspection time. The second aim is to cut down on the raw materials for coating by prevent the waste of spraying in the air during a painting process through a real-time coating-size-recognition monitering to fit the target components. To achieve the two aims, a simplified version of automatic coating control system for recognition of coating for vessels and Spray. With the sytem, following effects are expected: First, quality improvement will be achieved by uniformizing the film-thickness. Second, it will reduce the waste of coating paint by constructing the speed of the coating, the spray gun robot transfer time, and the number of DBs according to the size of the vessel. Third, as a 3D industry, it will be able to solve the difficulty of supply of labors and save up the labor costs. Therefore, in the future, further research will be needed to be applied to various products with DB design that designates the variable value, which is added for each type of pieces by comparing the difference between various types of workpieces and linear ones.

• Journal of information and communication convergence engineering
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• 제16권4호
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• pp.252-257
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• 2018

A wideband double radiator circular disc annular monopole antenna is proposed is this work. The radiators are etched on the surfaces of two Taconic TLY-5 substrates with a circular hole cut out of each of the radiators initially at the centers of the radiators with subsequent downward displacement of the holes. The antenna is designed with a two-step feeding transformer system for impedance matching between the input power source supplied by a $50-{\Omega}$ SMA connector and the monopole radiators. The transformer system improves the bandwidth performance at higher frequencies. The proposed antenna achieves a wideband having the capability of working between 0.645 and 18.775 GHz, corresponding to a -10 dB bandwidth of 186.7% with gain ranging from 0.95 to 8.26 dBi. In comparison to other metal disc planar monopole antennas, the proposed antenna has a small total size width due to the size of the ground plane, which has a diameter 100 mm. The frequency range of the antenna provides applications in global positioning systems, mobile communications, ultra-wideband short distance communications, and wireless computer networks.