• Title/Summary/Keyword: early growth stage

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The effect of dry matter allocation at the early seedling stare on the growth of two grass species (두 초본 종의 생장에 있어서 실생 초기의 물질분해 효과)

  • Park, Young-Mok
    • The Korean Journal of Ecology
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    • v.15 no.3
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    • pp.297-309
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    • 1992
  • The growth of digitaria adscendens and eleusine indica, annual weeds common in japan, was experimentally analyzed under varying untrient conditions. compared with e. indica, d. adscendensshowed a higher the two under high nitrogen availability. Higher net assimilation rate(nar) in d. adscendens than e. india was responsible for high RGR in D. adscendens under the low nitrogen availability. The different of NAR in the two species was induced not by leaf nitrogen content but by nitrogen use efficiency. Under unfertilized conditions nitrogen uptake rate(nur) was greater in d. adscendens than e. indica. Specific absorption rate in two species was similar, but root mass was greater in d. adscendens than e. indica.d. adscendens allocated more dry matter to roots than e. india earlier stage of seedlings. The contributed to higher rot mass and in turn resulted in higher nur in d. adscendens than that in e. india. It is concluuded that the larger allocation of dry matter to roots at early seedling stage in d. adscendens plays an important role in obtaining nitrogen for the continuation of growth under low nitrogen availability.

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DISCRIMINATION OF EARLY MATURING PADDY RICE CROPS USING MULTI-TEMPORAL SAR IMAGES

  • Hong, Suk-Young;Jang, Min-Won;Kim, Yi-Hyun;Park, No-Wook
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.243-245
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    • 2007
  • This study was begun to classify the paddy fields by the rice varieties and to monitor the temporal change in rice growth using SAR backscatter coefficients $({\sigma}^{circ})$. For nine fine-beam mode images of Radarsat-1 SAR, a growing period time-series of backscatter coefficients was set up from April to October in 2005, and was compared with the field-measured rice growth parameters such as LAI (leaf area index), plant height, fresh and dry biomass, and water content in grain and plant for 45 parcels in Dangjin-gun, Chungcheongnam Province, South Korea. The average backscatter coefficients for early-maturing rice varieties (13 parcels) were ranged from -18.17dB to -6.06dB and were lower than for medium-late maturing rice varieties during most of the growing season. At around the heading stage (July 30) for early-maturing rice, both rice crops showed the highest backscatter coefficient values and the difference was the greatest before harvesting early-maturing rice. The temporal difference in backscatter coefficients between rice varieties was expected to play a key role to identify early-maturing rice fields. On the other hand, comparison with field-measured rice growth parameters showed that the backscatter coefficients decreased or stayed on the plateau after heading stage even though the growth of rice canopy advanced.

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A Study of Stress ratio on the Fatigue Crack Growth Characteristics of Pressure Vessel SA516 Street at Low Temperature (저온 압력용기용 SA516강의 응력비에 따른 피로크랙 전파특성에 관한 연구)

  • 박경동;하경준
    • Proceedings of the KWS Conference
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    • 2001.05a
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    • pp.220-223
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    • 2001
  • In this study, CT specimens were prepared hem ASTM SA516 which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at $25^{\circ}C$, -3$0^{\circ}C$, -6$0^{\circ}C$, -8$0^{\circ}C$, -l$0^{\circ}C$ and -l2$0^{\circ}C$ and in the range of stress ratio of 0.1, 0.3 by means of opening mode displacement. At the constant stress ratio, the threshold stress intensity factor range ΔK$_{th}$ in the early stage of fatigue crack growth ( Region I ) and stress intensity factor range ΔK in the stable of fatigue crack growth ( Region II) was increased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm da/dN - ΔK in Region II, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It assumed that the fatigue crack growth rate da/dN is rapid in proportion to descend temperature in Region H and the cryogenic-brittleness greatly affect a material with decreasing temperature.e.greatly affect a material with decreasing temperature.

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Case Study on the Growth Factors of Young Technology Startups in the Cosmetics Industry: Focusing on the Six-month Challenge Platform project of Chungbuk Creation Economic Innovation Center (화장품산업 초기 기술창업기업의 성장요인에 관한 사례연구: 충북창조경제혁신센터 6개월챌린지플랫폼사업의 지원기업 중심으로)

  • Jeong, Do Youn;Om, Kiyong
    • Knowledge Management Research
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    • v.20 no.2
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    • pp.197-216
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    • 2019
  • The Korean government has been focusing on supporting technology startups to solve social and economic problems such as low growth, declining economic growth rate, rising youth unemployment rate and lack of new growth engine. Although the failure rate of young technology startups is very high, relevant researches are still scant. On the basis of previous researches, this study has identified four growth factors of technology startups: characteristics of entrepreneurs, technical superiority and originality of business items, focused marketing strategy, and follow-up government support projects. Five young technology startup cases were selected and analyzed in the cosmetics industry which were supported by the Six-month Challenge Platform project of Chungbuk Creation Economic Innovation Center. The main findings of the case study were as follows: First, product development through inhouse R&D rather than external contracted R&D was beneficial to acquiring follow-up government support projects and external investment. Second, choosing a small niche market and concentrating marketing efforts on the target market had a positive effect on firm performance. And, third, relevance of entrepreneurs' college major and technological originality of business items were confirmed to influence firm performance positively in the early stage. The results are expected to help young technology startups survive successfully and establish a foothold for growth in their early stage.

Dry Matter Production and Growth Analysis of Nicotiana tabacum L. (Local Leaf Tobacco) I. Varietal Difference on Individual Population in Factors of Dry Matter Production. (재래종 잎담배의 물질생산 및 생육해석 I. 물질생산요인의 개채군별 품종간차이)

  • 안대진;신승구;민영근;유익상
    • Journal of the Korean Society of Tobacco Science
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    • v.5 no.2
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    • pp.17-24
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    • 1983
  • Varietal difference of crop stand, growth of each organs and the factors of dry matter Production at different growth stage of three local tobacco varieties (Hyangcho, Youngwolyub and Yonginyub) were investigated in 1979 and 1980. Varietal variation of total standing crops was clear from 45th day after transplanting to end maximum value of photosyntheticinon-photosynthetic organs was Hyangcho: 1.9, Youngwolyub; 1.6, Yonginyub; 2.3. Maximum value of L/S and T/R ratio was clear from 35th day after transplanting to 45th day. RGR, NAR and CGR were in decreasing order of Yonginyub) Youngwolyub)Hyangcho through out growth stage, LAR and SLA were in decreasing from early growth stage to last growth stage, LAI was obtained to maximum value in the large growth state and LAI was increasing order of during the total growth period that it was Hyangcho is 7.6. Youngwolyub is 9.1 and Yonginyub is 8.7, SLA was Hyangcho;$2.088\textrm{cm}^2$/g/leaf, Youngwclyub;$2.173\textrm{cm}^2$/g/leaf and Yonginyub;$2.020\textrm{cm}^2$/g/leaf, respectively.

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Effect of Shading Rate and Duration on Growth and Flowering of Lilium spp. in Forcing (나리속(屬) 식물의 촉성재배(促成栽培)에 있어 차광정도(遮光程度)와 기간(期間)이 생육(生育)에 미치는 영향)

  • Jung, Woo-Yoon;Choi, Sang-Tai
    • Current Research on Agriculture and Life Sciences
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    • v.17
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    • pp.71-77
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    • 1999
  • The study aimed to identify effect of shading rate and duration on the growth and flowering of Lilium species in faring culture. Plant height of 'Gelria' and 'Casablanca' increased by higher shading at early growth stage, whereas that of 'Jolanda' and 'Dream Land' decreased. Also, plant height of 3 cultivars except 'Gelria' were longer by higher shading at whole growth stage, that of 'Gelria' was shorter as compared to in untreated plants. In cultivar 'Gelria', blasting increased and days to flowering shorted in higher shading only except 100% shading treatment at early growth stage. In 100% shading treatment, Blasting of 'Jolanda' was occurred 15.7% and the number of flower buds of 'Dream Land' and 'Casablanca' were reduced. Flower buds of 'Gelria' were not induceded in continued shading condition regardless of shading degree, the number of flower buds and flower size of 'Jolanda' and 'Dream Land' was reduced by 75% and 50% shading, respectively and in 'Casablanca', days to flowering was longer by shading at whole growth stage. Growth of daughter bulbs in 'Gelria', 'Jolanda' and 'Dream Land' was not influenced by shading at early growth stage but those of 'Casablanca' was inactive. Whereas that of 4 cultivars were inactive in continused shading condition.

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Treatment outcome in patients with triple negative early stage breast cancers compared with other molecular subtypes

  • Kim, Ja Young;Chang, Sei-Kyung;Park, Heily;Lee, Bo-Mi;Shin, Hyun Soo
    • Radiation Oncology Journal
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    • v.30 no.3
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    • pp.124-131
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    • 2012
  • Purpose: To determine whether triple negative (TN) early stage breast cancers have poorer survival rates compared with other molecular types. Materials and Methods: Between August 2000 and July 2006, patients diagnosed with stage I, II early stage breast cancers, in whom all three markers (estrogen receptor, progesterone receptor, and human epidermal growth factor receptor [HER]-2) were available and treated with modified radical mastectomy or breast conserving surgery followed by radiotherapy, were retrospectively reviewed. Results: Of 446 patients, 94 (21.1%) were classified as TN, 57 (12.8%) as HER-2 type, and 295 (66.1%) as luminal. TN was more frequently associated with young patients younger than 35 years old (p = 0.002), higher histologic grade (p < 0.0001), and nuclear (p < 0.0001). The median follow-up period was 78 months (range, 4 to 130 months). There were 9 local relapses (2.0%), 15 nodal (3.4%), 40 distant metastases (9.0%), and 33 deaths (7.4%) for all patients. The rates of 5-year OS, DFS, LFS, and DMFS for all patients were 95.5%, 89.9%, 95.4%, and 91.7%, respectively. There were no significant differences in OS, DFS, LFS, and DMFS between triple negative and other subtypes (p > 0.05). Conclusion: We found that patients with TN early stage breast cancers had no difference in survival rates compared with other molecular subtypes. Prospective study in homogeneous treatment group will need for a prognosis of TN early stage breast cancer.

A Study on the Stress ratio affect on the Fatigue Crack Characteristics of Pressure Vessel SA516 Steel at Low Temperature (저온 압력용기용 SA516강의 응력비에 따른 피로크랙 전파특성에 관한 연구)

  • 박경동;하경준;박형동
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.6
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    • pp.1228-1236
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    • 2001
  • In this study, CT specimens were prepared from ASTH A5l6 steel which was used for pressure vessel plates for moderate and lower temperature service. And we got the fellowing characteristics from fatigue crack growth test carried out in the environment of room and low temperature at $25^{\circ}C$ , $-30^{\circ}C$, $-60^{\circ}C$, $-80^{\circ}C$, $-100^{\circ}C$ and $-120^{\circ}C$ and in the range of stress ratio of 0.1, 0.3 by means of opening mode displacement. At the constant stress ratio, the Threshold stress intensity factor range ΔAKth in the early stage of fatigue crack growth (Region I) and stress intensity factor range $\DeltaK$ in the stable of fatigue crack growth (Region II) was increased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm da/dN-$\Delta$K in Region II that is, the fatigue clack growth exponent m increased with descending temperature at the constant stress ratio. It assumed that the fatigue crack growth rate da/dN is rapid in proportion to descend temperature in Region II and the cryogenic-brittleness greatly affect a material with decreasing temperature.

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A Study of Fatigue Crack Threshold Characteristics in Pressure Vessel Steel at Low Temperature (압력용기용 강의 저온 피로크랙 하한계 특성에 관한 연구(II))

  • 박경동;김정호;정찬기;하경준
    • Journal of Ocean Engineering and Technology
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    • v.14 no.3
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    • pp.78-83
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    • 2000
  • In this study, CT specimens were prepared from AST SA516 Gr. 70 which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at 25$^{\circ}C $, -60$^{\circ}C $, -80$^{\circ}C $ and -100$^{\circ}C $ and in the range of stress ratio of 0.05, 0.3 by means of opening mode displacement. At the constant stress ratio, the threshold stress intensity factor range ${\delta} K_{th}$ in the early stage of fatigue crack growth (Region I) and stress intensity factor range $\delta $K in the stable of fatigue crack growth (Region II) were increased in proportion to descending temperature. It was assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm da/dN -$\delta $K in Region II, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It was assumed that the fatigue crack growth rate da/dN is rapid in proportion to descending temperature in Region II and the cryogenic-brittleness greatly affect a material with decreasing temperature.

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A Study on the Fatigue Crack Propagation Threshold Characteristic in Steel of Pressure Vessel at Low Temperature (압력용기용 강의 저온 피로크랙전파 하한계 특성에 관한 연구)

  • 박경동;박상오
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2001.05a
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    • pp.326-331
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    • 2001
  • In this study. CT specimens were prepared from ASME SA5l6 which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at $25^{\circ}C$, -3$0^{\circ}C$, -6$0^{\circ}C$, -8$0^{\circ}C$, -10$0^{\circ}C$ and -12$0^{\circ}C$ in the range of stress ratio of 0.1 by means of opening mode displacement. At the constant stress ratio, the threshold stress intensity factor range ΔKsub/th/ in the early stage of fatigue crack growth ( Region I) and stress intensity factor range ΔK in the stable of fatigue crack growth ( Region II) was increased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm da.dN -ΔK in RegionII, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It assumed that the fatigue crack growth rate da/dN is rapid in proportion to descend temperature in Region II and the cryogenic-brittleness greatly affect a material with decreasing temperature.

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