• Title/Summary/Keyword: growth characteristic

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Characteristic Analysis of $Al_2$O$_3$Thin Films Grown by Atomic Layer Deposition (ALD법으로 성장시킨 $Al_2$O$_3$ 박막의 특성분석)

  • 성석재;김동진;배영호;이정희
    • Proceedings of the IEEK Conference
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    • 2001.06b
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    • pp.185-188
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    • 2001
  • In this study, $Al_2$O$_3$films have been deposited with Atomic Layer Deposition(ALD) for gate insulator for MPTMA and $H_2O$ at low temperature below 40$0^{\circ}C$ . Conventional methods of $Al_2$O$_3$thin film deposition have suffered from the poor step coverage due to reduction of device dimension and increasing contact/via hole aspect ratio. ALD is a self-limiting growth process with controlled surface reaction where the growth rate is only dependent on the number of growth cycle and the lattice parameter of materials. ALD growth process has many advantages including accurate thickness control, large area and large batch capability, good uniformity, and pinholes freeness.

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Approximate Yield Criterion for Voided Anisotropic Ductile Materials

  • Kim, Youngsuk;Sungyeun Won;Kim, Dogsoo;Hyunsung Son
    • Journal of Mechanical Science and Technology
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    • v.15 no.10
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    • pp.1349-1355
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    • 2001
  • As most fractures of ductile materials in metal forming processes occurred due to the results of evolution of internal damage - void nucleation, growth and coalescence. In this paper, an approximate yield criterion for voided (porous) anisotropic ductile materials is developed. The proposed approximate yield function is based on Gurson's yield function in conjunction with the Hosford's non-quadratic anisotropic yield criterion in order to consider the characteristic of anisotropic properties of matrix material. The associated flow rules are presented and the laws governing void growth with strain are derided. Using the proposed model void growth of an anisotropic sheet under biaxial tensile loading and its effect on sheet metal formability are investigated. The yield surface of voided anisotropic sheet and void growth with strain are predicted and compared with the experimental results.

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The behaviour of the internal bubbles in $CaF_{2}$ crystals during the annealing process ($CaF_{2}$ 결정의 annealing시 내부 bubbles의 거동)

  • Shim, Kwang-Bo;Park, Dai-Chul;Joo, Kyoung;Auh, Keun-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.6 no.4
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    • pp.595-599
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    • 1996
  • The behaviour of the internal bubbles present in $CaF_{2}$ crystals was characterized crystallographically using a variety of the mircroscopical technique. The bubble defects were found to be aligned on the characteristic planes and directions depending on the crystals structure of the $CaF_{2}$. The AFM analysis revealed that these behaviors are related to the S-surface formation by the negative grain growth mechanism.

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Dry Matter Accumulation and Leaf Mineral Contents as Affected by Excessive Soil Water in Soybean

  • Seong, Rak-Chun;Kim, Jeong-Gyu;Nelson, C. Jeny
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.44 no.2
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    • pp.129-133
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    • 1999
  • Excessive soil water at vegetative growth stages during the rainy season induces yield losses in soybeans. Our objectives were to obtain basic information about the cultivar differences and to understand the stress-tolerance process for due to excessive soil water. Previous experiments revealed soybean genotypic differences in tolerance to excessive soil water. A field experiment was conducted at the Research Farm of Korea University near Seoul on 21 May 1998. Soybean[Glycine max (L.) Merrill] cultivars, 'Hannamkong' (sensitive) and 'Taekwan-gkong'(tolerant) were planted in vinyl-lined plots(1.2 x 4.2 x 0.3 m deep) and control plots. Drip irrigation began at VI growth stage to submerge the soil surface. Three weeks of excessive soil water treatment reduced all growth parameters measured to soybean plants. Excessive soil water stress resulted in decreases of N, P, K, Ca, Mg and Cu, and increases of Fe and Mn contents in soybean leaves. The stress index of tolerant cultivars under excessive soil water showed no large difference in soybean growth characteristics measured at three growth stages. However, K, Ca, Mg, Fe and Mn contents in soybean leaves appeared to differ between sensitive and tolerant cultivars. From the above results, stress and tolerance indices are proposed for a method to test cultivar differences in plant responses within a species under adverse growth environments.

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Observations on Some of the Mycelial Growth and Pigmentation Characteristics of Cordyceps militaris Isolates

  • Shrestha, Bhushan;Lee, Won-Ho;Han, Sang-Kuk;Sung, Jae-Mo
    • Mycobiology
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    • v.34 no.2
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    • pp.83-91
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    • 2006
  • Characteristic growth patterns of Cordyceps militaris isolates on various media, under varying light conditions and at varying incubation periods were examined. Light was found to be the most critical single factor in determining the density, texture, and pigmentation of the mycelial culture of the fungus. However, under the light condition, the degree of pigmentation and mycelial density were found to be affected by the incubation period and type of medium. Irrespective of the variations in medium type or incubation period, there was no pigmentation of the mycelium under dark condition. Radial growth of the mycelium was faster under dark incubation rather than under light incubation. Abundant mycelial density and darkest pigmentation of C. militaris isolates were produced in nutritionally rich media like SDAY, SMAY and CZYA, suggesting that these media may fulfill all the requirements for vegetative growth of the fungus. Growth characteristics of C. militaris isolates could be easily observed by the simple agar culture method, which would be useful to characterize the phenotypic characteristics of large number of pure cultures of the fungus under given conditions of growth factors such as medium, light and temperature.

Growth of Salix gracilistyla Miq. Originated from Provenance in Gangwon-do, Korea for Bioenergy Resource

  • Hyunseok Lee
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2020.12a
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    • pp.59-59
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    • 2020
  • Salix gracilistyla has a characteristic of fast growth especially in the river side or infertile soil, showing a lot of lateral branches and a strong root system among the Salix. spp. On the basis of results observed, we provide several growth characteristics of S. gracilistyla among some selected provenances. In two-year results, root collar diameter ranged from 33.5 mm to 56.7 mm. Taeback showed the lowest value, and Jeongseon and Hoengseong were higher than the other areas in the traits above. Height growth was the lowest in Samcheok and the highest in Wonju. To examine growth and development of lateral branches is important because S. gracilistyla has a lot of lateral branches which account for high biomass production. Length of lateral branch showed high variation, in which the highest number was observed in Yeongwol and the lowest in Samcheok. Many lateral branches were shown in Wonju. Preliminary study on biomass resources evaluation, we analyzed correlation between volume and length, and volume and root diameter. High correlation was observed between root diameter and plant volume. And we compared the observed volume with the caculated volume by regression formula. To evaluate Salix species as biomass resources, it is needed to survey growth characteristics continuously and adopt selection of individuals or families of high biomass and caloric values by reliable data. In addition, Salix spp. can be also applicable to selection breeding regime because of feasible propagation and fast growth.

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The Study of Steering Effect in Multilayer Growth (두꺼운 박막 성장시 Steering 효과 연구)

  • Seo J.;Kim J.S.
    • Journal of the Korean Vacuum Society
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    • v.15 no.4
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    • pp.410-420
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    • 2006
  • The dynamic effects, such as the steering and the screening effects during deposition on an epitaxial growth is studied by kinetic Monte Carlo simulation. In the simulation, we incorporates molecular dynamic simulation to rigorously take the interaction of the deposited atom with the substrate atoms into account, We find three characteristic features of the surface morphology developed by grazing angle deposition: (1) enhanced surface roughness, (2) asymmetric mound, and (3) asymmetric slopes of mound sides, Regarding their dependence on both deposition angle and substrate temperature, a reasonable agreement of the simulated results with the previous experimental ones is found. The characteristic growth features by grazing angle deposition are mainly caused by the inhomogeneous deposition flux due to the steering and screening effects, where the steering effects play the major role rather than the screening effects. Newly observed in the present simulation is that the side of mound in each direction is composed of various facets instead of all being in one selected mound angle even if the slope selection is attained, and that the slope selection does not necessarily mean the facet selection.

A Study on Success Factors for Entrepreneurs in IT Ventures (IT 창업 기업의 창업 성공 요인에 대한 연구)

  • Shin, Yu-Sub;Choi, Myeong-Gil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.7
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    • pp.2371-2385
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    • 2010
  • What are the success factors of IT venture entrepreneur that through initial phase and enter to the growth phase ? Both the duration of jobless growth and the economic recession are worsening employment market. Entrepreneurship is be proposed to a method for creating jobs and reducing the economic gap. Research on Entrepreneurship and the support of government policy has already been operated for a long time ago. Research on growth and duration of the entrepreneur in initial phase, compared with growth phase are insignificant in quantity or quality. Therefore, this study researches essential factors about growth and duration of the entrepreneur in the initial phase through cases related them. entrepreneur of this subject are classified the hardware development group and the software development group associated with manufacturing characteristic funded existence. There is a research on evaluation factors about selection and result evaluation of selecting Entrepreneur. And this can be investigated by studying to Entrepreneur's growth and duration in initial phase. There are affecting factors about growth and duration of first step. And they are divided by internal, external, synthetic, and characteristic factors of growth phase. The result of this study is be used to develop pre-established educational program, consulting guidelines and establish support policy.

The Growth Characteristic of the Main Afforestation Species Using the Change of the Annual Ring in Uiseong Area (연륜 변화를 이용한 의성지역 주요 조림수종의 생장특성)

  • Lee Dong-Sup;Kim Dong-Geun;Bea Kwan-Ho;Suh Hyoung-Min
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.7 no.4
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    • pp.274-281
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    • 2005
  • The climate of the Uisong Area is wet in the heat of summer and cold and dry in winter, The climate is highly consistent. The typical forest soil of the Uisong Area has an acidity of pH 4.5-5.6. The thickness of soil A layers is thin to an average of 10-20 cm and is a typical brown forest soil type. The growth characteristic of this climate and soil environment is as follows. In the case of Larix leptolepis, it takes 5-9 years to reach 6 cm diameter, The annual growth rate falls off greatly at an age of 17-19 years. The change of annual rings is more apparent on the north slopes compared with the east and northeast slopes. Pinus rigida takes 7-9 years to reach a 6 cm diameter. Annual growth rates of Pinus rigida fall greatly when age reaches 19 years. The change of annual ring growth of Pinus rigida was most apparent in the west and northeast slopes compared with the south and east slopes. In the case of Pinus koraiensis, the change of the annual ring width according to the characteristics of the slope is not important. Pinus koraiensis takes 6 yearsto reach the 6cm diameter, and annual growth rate fell off at age 19 years. In the case of Quercus acutissima, the growth of the valley trees is more stable than for trees grown at the mountain base. Annual growth rate of Quercus autissima fell off 19 years after planting. Ring growth of Robinia pseudo-acasia on northeast slopes appears much like that on northwest slopes. In conclusion, the main silviculture species reaches a 6 cm diameter in 5-9 years of growth, and the annual growth rate begins to fall between years 13 and 19 in the Uisong Area.