• Title, Summary, Keyword: Growth characteristics

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Characteristics of Fatigue Crack Growth in SM570, POSTEN60, 80 Steel (SM570, POSTEN60 및 80 강재의 피로균열성장특성)

  • Jeong, Young-Wha;Kim, lk-Gyeom;Kang, Sung-Lib;Nam, Wang-Hyone;Kim, Eun-Sung
    • Journal of Industrial Technology
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    • v.21 no.A
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    • pp.329-336
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    • 2001
  • In this study, a series of fatigue tests are carried out in order to estimate quantitatively the characteristics of fatigue crack growth rate for high strength steels of SM570, POSTEN60, and POSTEN80 steel, that is, the influence on fatigue crack growth rate according to the welding line, the characteristics of fatigue crack growth according to the welding method and the kinds of steel, and the characteristics of fatigue crack growth for base metal, heat affected zone and weld metal. From the test results, in case that the notch if parallel to welding line, it knows that the retardations of fatigue crack growth rate in crack tip at early stage increase remarkably than in case that the notch is perpendicular to welding line due to compressive residual stress. And the characteristics of fatigue crack growth rate according to welding method are that the dispersion of fatigue crack growth rate in case of FCAW method is smaller than that of SAW method. Also, it knows that the fatigue crack growth rate converges in high stress intensity factor range.

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Changes of Growth Characteristics and Ginsenoside Content by Growth Stages and Different Planting Position in Panax ginseng C.A. Meyer (인삼의 재식위치와 생육시기에 따른 생육특성 및 진세노사이드 함량 변화)

  • Kwon, Soon-Goo;Lee, Chung-Yeol;Oh, Dong-Joo;Li, Guan-Ying;Cha, Sun-Woo;Lee, Seong-Woo
    • Korean Journal of Medicinal Crop Science
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    • v.18 no.1
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    • pp.51-55
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    • 2010
  • This study was conducted to investigate the effect of planting position on the growth characteristics, yield and ginsenoside content in Panax ginseng C.A. Meyer at different growth stages. Referring to shoot growth characteristics, stem length, stem diameter and leave area were higher at front than rear, increasing as the proceeding of growth stages. But a lower chlorophyll contents was caused at front compared to rear and decreased as the proceeding of growth stages contrarily. According to root characteristics, root length and main body length were higher at front, with a positive correlation to growth stages, which was also shown on fresh root weight and dry root weight with the maximum in August. Meanwhile, the effect of planting position on ginsenoside content could also be definite by the highest content at front showing high light intensity, increasing as the proceeding of growth stages as well.

Variation in Tree Growth Characteristics, Pilodyn Penetration, and Stress-wave Velocity in 65 Families of Acacia mangium Trees Planted in Indonesia

  • HIDAYATI, Fanny;LUKMANDARU, Ganis;INDRIOKO, Sapto;SUNARTI, Sri;NIRSATMANTO, Arif
    • Journal of the Korean Wood Science and Technology
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    • v.47 no.5
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    • pp.633-643
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    • 2019
  • Growth characteristics [stem diameter (D), tree height (H)] and wood properties [Pilodyn penetration (P) and stress-wave velocity (SWV)] were measured for 65 families of 6-year-old Acacia mangium trees planted in Indonesia, in order to characterize their variation in D, H, P, and SWV. Therefore, the correlations between the measured characteristics were also determined, and their significant differences observed. Furthermore, their low to moderate values of narrow-sense heritability was obtained, and the results indicated the characteristics to be genetically controlled in A. mangium. In addition, highly significant positive correlations were observed among the growth characteristics, suggesting a close relationship, while there was no significant association between the growth characteristics and P, as well as SWV, indicating their independent. Therefore, these results demonstrate a potential for the improvement of both growth and wood properties of A. mangium trees, using the appropriate breeding programs. In addition, 18 families showed good performance in D and SWV, signifying their positive prospect of being considered as plus trees for the next generation breeding cycles.

A Study on the Analysis Procedures of Nonlinear Growth Curve Models (비선형 성장곡선 모형의 분석 절차에 대한 연구)

  • 황정연
    • Journal of the Korean Society for Quality Management
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    • v.25 no.1
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    • pp.44-55
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    • 1997
  • In order to determine procedures for a, pp.opriate model selection of technological growth curves, numerous time series that were representative of growth behavior were collected according to data characteristics. Three different growth curve models were fitted onto data sets in an attempt to determine which growth curve models achieved the best forecasts for types of growth data. The analysis of the results gives rise to an a, pp.oach for selecting a, pp.opriate growth curve models for a given set of data, prior to fitting the models, based on the characteristics of the goodness of fit test.

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Growth of nickel-catalyzed carbon nanofibers using MPCVD method and their electrical properties

  • Kim, Sung-Hoon
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.14 no.1
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    • pp.1-5
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    • 2004
  • Carbon nanofilaments were formed on silicon substrate via microwave plasma-enhanced chemical vapor deposition method. The structure of carbon nanofilaments was identified as the carbon nanofibers. The extent of carbon nanofibers growth and the diameters of carbon nanofibers increased with increasing the total pressure. The growth direction of carbon nanofibers was horizontal to the substrate. Laterally grown carbon nanofibers showed the semiconductor electrical characteristics.

Evaluation of Plant Growth according to the Wavelength Characteristics of the LED Light Source (LED광원의 광파장 특성에 따른 식물의 성장도 평가)

  • Hwang, Jong-Dae;Ko, Dong-Su
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.13 no.5
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    • pp.98-106
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    • 2014
  • This study was carried out to evaluate the plant growth rate according to the wavelength characteristics of LED light sources. In order to achieve this, red, green, blue and white LEDs were arrayed in a rectangle array consisting of LED modules which can be combined with each other.. This can facilitate the selection of the optimal characteristics of the light from monochromatic red, green, blue and white LEDs or mixed LEDs for plant growth. Experiments to evaluate the growth rate according to the wavelength characteristics of the LEDs with several plants, in this case ice plants, lettuce, barley, broccoli and chives, were performed.

Forest Management Using Growth and Ecological Characteristics by Site Types in the Natural Deciduous Forest (천연(天然) 활엽수림(闊葉樹林)의 입지유형별(立地類型別) 생장(生長) 및 생태적(生態的) 특성(特性)을 이용(利用)한 산림관리(山林管理))

  • Shin, Man Yong;Lee, Seung Man;Lee, Don Koo
    • Journal of Korean Society of Forest Science
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    • v.94 no.1
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    • pp.26-33
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    • 2005
  • The study was carried out to provide information about growth and ecological characteristics by site types of natural deciduous forest in Pyeongchang, Gangwon Province. The data were collected from four aspects(the East, the West, the South, and the North) with three elevation(higher than 1.000 m, 700~1,000 m, lower than 700 m) and three topographical conditions(ridge, hill, and valley). Growth parameters by site types were evaluated based on the growth performances of dbh for the last 5 to 10 years; which were also estimated based on both Pressler and Schneider formulae. In addition, ecological characteristics such as Shannon-Wiener's diversity index, evenness index and richness index were analyzed by site types. The management methods by site types were suggested by considering stand density, growth patterns, and ecological characteristics. It was found that the stands on the South and the East are necessary the tending practices to improve growth and ecological characteristics. On the other hand, the West and the North needed the tending practices focusing on stand density management to increase growth rate rather than ecological management. It was also found that the area lower than 700 m in elevation showed Higher growth rate than other areas. As a management standard considered in terms of growth rate, it was suggested that tending practices should be applied to the stands of which growth rate for the last 5 to 10 years were lower than 2%. Considering topographical conditions, valley area showed better ecological characteristics than both ridge and hilly areas. Consequently, it was revealed that the valley areas were suitable for the ecological management.

Growth characteristics by age measurement of Prunus yedoensis on Jeju Island, Korea (제주도 자생 왕벚나무의 연륜생장 특성 분석)

  • Seo, Yeon Ok;Kim, Chan-Soo;Song, Gwan Pil;Jung, Sung Cheol
    • Journal of Environmental Science International
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    • v.27 no.7
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    • pp.555-560
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    • 2018
  • This study conducted to analyze the growth characteristics of old Prunus yedoensis on Jeju island. The diameter growth per year was measured using a DTRS-2000 instrument. The DBH, ground DBH and height of the investigated P. yedoensis were 137 cm, 143 cm, and 15.5 m, respectively. Our analysis showed that the age of the old P. yedoensis was 93 years. An annual diameter growth of $2.85mm{\pm}0.96$ was observed. The result of age estimation, about $265{\pm}64$ years in P. yedoensis on Jeju island. This information could be useful to understand the annual diameter growth characteristics the P. yedoensis distributed on Jeju island.

Growth Characteristics of Rhizophagus clarus Strains and Their Effects on the Growth of Host Plants

  • Lee, Eun-Hwa;Eom, Ahn-Heum
    • Mycobiology
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    • v.43 no.4
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    • pp.444-449
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    • 2015
  • Arbuscular mycorrhizal fungi (AMF) are ubiquitous in the rhizosphere and form symbiotic relationships with most terrestrial plant roots. In this study, four strains of Rhizophagus clarus were cultured and variations in their growth characteristics owing to functional diversity and resultant effects on host plant were investigated. Growth characteristics of the studied R. clarus strains varied significantly, suggesting that AMF retain high genetic variability at the intraspecies level despite asexual lineage. Furthermore, host plant growth response to the R. clarus strains showed that genetic variability in AMF could cause significant differences in the growth of the host plant, which prefers particular genetic types of fungal strains. These results suggest that the intraspecific genetic diversity of AMF could be result of similar selective pressure and may be expressed at a functional level.

An Empirical Study on High-technology Innovative SMEs' Characteristics and their Bottlenecks across the Growth Stages (기술혁신형 중소기업의 특성과 성장단계에 따른 애로요인의 실증적 연구)

  • Chang, Young-Soon;Kim, Ju-Mi
    • IE interfaces
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    • v.20 no.3
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    • pp.418-426
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    • 2007
  • This study is to suggest the government's support direction for the small and medium sized enterprises (SMEs) by examining the relations among technology level, innovation factors, entrepreneur's characteristics, and start-up reasons. The management bottlenecks and the necessary fields of government's support are also investigated across the company's growth stages. Empirical analysis was conducted based on the 318 Korean SMEs' data receiving the Venture and/or Inno-biz certification. Results show that managing difficulties of the company have typical pattern according to the stage of growth. The characteristics of an entrepreneur such as age, education background and past experience affect the early stage of starting business. We also found that the technology level is closely connected with operational innovation activities and circumstances, entrepreneur's characteristics, start-up motives, and technological innovation activities.