• Title/Summary/Keyword: Growth Distance

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Effect of MgO on Microstructural Evolution of Alumina Prepared from Hydrosol-Gel Process of Boehmite in Plaster Mold (석고몰드속에서 Boehmite의 Hydrosol-Gel로부터 제조된 알루미나의 미세구조에 미치는 M\ulcorner의 영향)

  • 오경영;정창주
    • Journal of the Korean Ceramic Society
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    • v.30 no.12
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    • pp.1029-1038
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    • 1993
  • The microstructures of aluminas, included of dissolved CaO as $\alpha$-alumina seeded pseudo-boehmite hydrosol was gelled in plaster mold and doped of MgO as dipping of calcines(120$0^{\circ}C$-2h) into Mg-nitrate solution, were compared to the one of which additives are excluded during the gellation. It was formed the boundary layer of 300~350${\mu}{\textrm}{m}$ distance from surface to the inside, containing of approximately 500ppm CaO by dissolved Ca from plaster mold. As the MgO addition to the boundary layer with dissolved CaO, the microstructure of the layer was uniformed and inhibited the grian growth, compared to one of that additives be excluded specimen and of MgO doped-inside region. This result was considered as abnormal grain growth and effect of flat boundary formation be appeared by effects of dissolved CaO, were decreased by MgO co-doping.

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A Multimedia Contents Recommendation for Mobile Web Users

  • Kang, Mee;Cho, Yoon-Ho;Kim, Jae-Kyeong
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2004.11a
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    • pp.323-330
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    • 2004
  • As mobile market grows more and more fast, the mobile contents market, especially music contents for mobile phones have recorded remarkable growth. In spite of this rapid growth, mobile web users experience high levels of frustration to search the desired music. New musics are very profitable to the content providers, but the existing collaborative filtering (CF) system can't recommend them. To solve these problems, we propose an extended CF system to reflect the user's real preference by representing the characteristics of users and musics in the feature space. We represent the musics using the music contents based acoustic features in multi-dimensional feature space, and then select a neighborhood with the distance based function. Furthermore, this paper suggests a recommendation for procedure for new music by matching new music with other users' preference. The suggested procedure is explained step by step with an illustration example.

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Development and Evaluation of LED Lamp with Rectangular Light Distribution for Growth of Plant (식물성장용 사각배광 LED 조명 개발 및 평가)

  • Yun, Jung-Hyun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.2
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    • pp.126-131
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    • 2014
  • In this paper, plant crops used in the region to grow crops for the LED lighting area of a rectangle to fit the light distribution to maximize the efficiency of a rectangular distribution was made of LED lights. After the fabrication of LED lamps, light distribution, and in the area of $1.2m{\times}3m$ was the analysis of Illuminance chart. As a result of examining the performance light distribution for total Emin/Eav is 56%, and the target area of the light distribution compared to normal lamps Emin/Eav is improved by about 17%. In addition, plants grown in the area to minimize the outgoing light distribution can be focused on the cultivation area, according to the distance of the plants and be able to have the best luminous efficacy is judged.

An Analysis of the Growth Factors of Local Food (로컬푸드의 성장요인 분석: 완주 로컬푸드의 신뢰성향상을 중심으로)

  • Yoon, Jangwon;Song, Jaehoon
    • Journal of Applied Reliability
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    • v.16 no.1
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    • pp.15-25
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    • 2016
  • Purpose: The purpose of this study is to identify the success factor of local food markets compared to other types of markets such as large discount stores. Methods: SWOT analysis was conducted. In addition to the analysis, we also have interviewed the local farmers and retailers to elaborate the analysis results. Results: The study shows the success factors to the local markets are minimizing the stages of distribution channels, shortening the travel distance from producers to consumers, providing fresh foods, maintaining small amount of production system, and supporting customers. Conclusion: Customer satisfaction is one of the key factors for the successful growth of local food markets. It is strongly recommend to find strategic ways of meeting customer needs since the local food markets are facing tough competition form the large retail stores armed with huge amount of capitals and infrastructures.

Study on the Phase Interface Tracking Numerical Schemes by Level Set Method (Level Set 방법에 의한 상경계 추적 수치기법 연구)

  • Kim, Won-Kap;Chung, Jae-Dong
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.116-121
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    • 2006
  • Numerical simulations for dendritic growth of crystals are conducted in this study by the level set method. The effect of order of difference is tested for reinitialization error in simple problems and authors founded in case of 1st order of difference that very fine grids have to be used to minimize the error and higher order of difference is desirable to minimize the reinitialization error The 2nd and 4th order Runge-Kutta scheme in time and 3rd and 5th order of WENO schemes with Godunov scheme are applied for space discretization. Numerical results are compared with the analytical theory, phase-field method and other researcher's level set method.

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Four New Species of Dictyoceratid Sponges (Demospongiae) from Korea

  • Lee, Kyung-Jin;Sim, Chung-Ja
    • Animal cells and systems
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    • v.11 no.1
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    • pp.55-60
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    • 2007
  • Four new species, Semitaspongia jejuensis, Scalarispongia regularis, S. nigra and Dysidea violata are described from Jejudo, Korea. They were collected from 15 m depth by SCUBA diving and from intertidal area by hand. Semitaspongia jejuensis n. sp. is easily distinguished from other Semitaspongia species in growth form, conules, colour, skeletal structure, diameter of fibre and habitat. Scalarispongia regularis n. sp. is very close to S. scalaris (Schmidt, 1862) in skeletal structure, but S. scalaris has longer conules, larger meshes, longer distance between primary fibres, and highly developed subdermal canal system. Scalarispongia nigra n. sp. is very close to S. regularis in skeletal structure but can be easily distinguished by its black colour of external surface and growth form. Dysidea violata n. sp. is similar with D. ethria (Laubenfels, 1936) in sponge appearance, but D. etheria is clearly defined by its blue colour and thickness of fibre.

Transitional Dark Energy - A solution to the H0 tension

  • Keeley, Ryan
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.59.2-59.2
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    • 2019
  • In this talk, I will explain the implications of a rapid appearance of dark energy between the redshifts ($z$) of one and two on the expansion rate and growth of perturbations. Using both Gaussian process regression and a parametric model, I show that this is the preferred solution to the current set of low-redshift ($z<3$) distance measurements if $H_0=73~\rm km\,s^{-1}\,Mpc^{-1}$ to within 1\% and the high-redshift expansion history is unchanged from the $\Lambda$CDM inference by the Planck satellite. Dark energy was effectively non-existent around $z=2$, but its density is close to the $\Lambda$CDM model value today, with an equation of state greater than $-1$ at $z<0.5$. If sources of clustering other than matter are negligible, we show that this expansion history leads to slower growth of perturbations at $z<1$, compared to $\Lambda$CDM, that is measurable by upcoming surveys and can alleviate the $\sigma_8$ tension between the Planck CMB temperature and low-redshift probes of the large-scale structure.

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A Study on the Analysis of the Physiological Growth Condition and Improvement of Street Trees in Seoul (서울시 가로수 생육환경분석 및 개선에 관한 연구)

  • 한봉호;이경재
    • Korean Journal of Environment and Ecology
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    • v.10 no.1
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    • pp.39-48
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    • 1996
  • The planting pattern of Seoul street tree could be divided into six patterns, that was, one row, double row, median strip type and bicycle road type. The protection facilities of installed street tree was inadequate, because it was so small and weak. Recently, the growth rate of street tree in Seoul was decreasing because of air pollution. Strong alkali soil proved to be inappropriate for the growth of street tree. Soil hardness of treepit equipped with treegrill was lower than unequipped one. From the analysis of correlation between the growth environments of street tree, we could conclude that the vitality of street tree are proportioned to the distance from the center of Seoul. The way of improvement for physiological growth and increase of street tree were as follows; establishment reform of street facilities, the installation of protection equipment, continuous and systematic management.

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Analysis of Health Status of Street Trees and Major Affecting Factors on Deogyeong-daero in Suwon (수원시 덕영대로의 가로수 건강성 평가 및 주요 영향요인 분석)

  • Kim, Eun-Young;Jung, Kyung-Min
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.22 no.2
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    • pp.49-57
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    • 2019
  • The street trees increase the liveability of cities by reducing stormwater runoff, improving air quality, storing carbon, providing shade, and ameliorating the urban heat-island effect. In this study, the health status of street trees in Suwon was evaluated, and the factors affecting the growth of the trees were also derived. In order to evaluate the growth and health of street trees, field survey was carried out on a total of 125 trees in 25 sections of the Deogyeong-daero where is through the city. During the field survey, the following items were examined: Street trees health status (i.e. species, height, DBH (diameter at breast height), planting types, vigor, etc.), soil factors (i.e. soil temperature, humidity, pH, hardness, etc.), and environmental factors (i.e. landuse, road width, etc.). As the results of field survey, the main species of the street trees was Zelkova serrata, which was healthy in most of the sections. The factors such as planting types, soil temperatures, tree root cover, road extension, distance from the road were derived to affect the growth and health of street trees, and the differences were significant. The results of this study were derived the following conclusions for vigorous street trees: First, it is important to install and maintain the protection facilities like tree root cover for the growth of trees. Second, it is necessary to discuss how to plant multiple trees in narrow spaces like a street green space. Third, it is important to provide appropriate soil conditions continuously for growth of threes. Finally, it should be utilized as a mitigation measure of urban heat island effects.

Distribution and Habitat Condition of Crypsinus hastatus in Buyeogun (부여군 고란초의 생육지 환경조건과 분포)

  • Song, Hong Seon;Kim, Seong Min
    • Korean Journal of Medicinal Crop Science
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    • v.24 no.1
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    • pp.27-30
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    • 2016
  • Background : This text was conducted to evaluate the distribution, shape characteristics and habitat condition of Crypsinus hastatus in Buyeo Korea. Methods and Results : In Buyeo, Crypsinus hastatus was distributed at an altitude of 31.2 m, a slope of 82.5% and a distance from river water of 27.2 m. The leaf blade was oblong, 2.7 cm long, 1.2 cm wide with a petiole length of 2.3 cm. The total population comprised 2,100 individuals, with the highest proportion being individuals with a leaf blade of length 0.5 - 1 cm. The temperature and light intensity of the growth point were lower, but the humidity higher, than that of growth around. The chemical properties of the soil were as follows: pH 4.42, organic matter 77.99 g/kg, electrical conductivity 0.50 dS/m, nitrate nitrogen 20.50 mg/kg and available phosphate 165.7 mg/kg. Exchangeable cation content of potassium, magnesium, sodium and calcium was 0.35, 0.70, 0.09 and $2.04cmol^+/kg$, respectively. Conclusions : In Buyeo, Crypsinus hastatus was distributed in $5.3m^2$ area of Nakhwaam, Naeseongri and Jeongamri. However, the population of the medicinal resources seemed to decrease owing to the poor environmental conditions of the habitat.