• Title/Summary/Keyword: Rate of growth

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A Study on the Growth Characteristics of Riparian Plants on the Artificial Floating Islands (인공섬 수생식물 생육특성에 관한 연구)

  • Kim, Yong-Kyu;Koo, Bon-Hak;Ahn, Tong-Mahn
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.4
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    • pp.25-35
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    • 2001
  • This study aims to find out the growth characteristics of riparian plants on the artificial floating islands (AFI). Three types of experiments were performed. The vegetation growth were compared by the plant-supporting materials; natural cotton mat, coir mat on the AFI or in the water, and natural soil at the waterfront. Major findings are; 1. The survival rate of riparian plants was 100% on both coir-mat and cotton-matislands, which implies that we may substitute cheaper cotton for expensive coir-mat. 2. Both natural cotton mat and coir mat were good for the growth of plants. Especially, the natural cotton mat was good for Sparganium stoloniferum and Miscanthus sacchariflorus, and the coir mat was good for Typha latifolia. 3. The growth rate of stem and root showed difference between the stem-removed plants and stem-remaining plants. As a whole, the growth rate of stem-removed plants was bigger than the one of stem-remaining plants. 4. The growth rate of plants showed difference between those grown on the AFI and those grown in the water. The growth rate of plant on the AFI was bigger than the one in the water. 5. The growth rate of plants on the AFI was bigger than the one on the natural soil at the waterfront.

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Comparing the Performance of 17 Machine Learning Models in Predicting Human Population Growth of Countries

  • Otoom, Mohammad Mahmood
    • International Journal of Computer Science & Network Security
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    • v.21 no.1
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    • pp.220-225
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    • 2021
  • Human population growth rate is an important parameter for real-world planning. Common approaches rely upon fixed parameters like human population, mortality rate, fertility rate, which is collected historically to determine the region's population growth rate. Literature does not provide a solution for areas with no historical knowledge. In such areas, machine learning can solve the problem, but a multitude of machine learning algorithm makes it difficult to determine the best approach. Further, the missing feature is a common real-world problem. Thus, it is essential to compare and select the machine learning techniques which provide the best and most robust in the presence of missing features. This study compares 17 machine learning techniques (base learners and ensemble learners) performance in predicting the human population growth rate of the country. Among the 17 machine learning techniques, random forest outperformed all the other techniques both in predictive performance and robustness towards missing features. Thus, the study successfully demonstrates and compares machine learning techniques to predict the human population growth rate in settings where historical data and feature information is not available. Further, the study provides the best machine learning algorithm for performing population growth rate prediction.

Comparison of Growth Performances in Seedling of Allium microdictyon Prokh. and Allium ochotense Prokh. (산마늘과 울릉산마늘 유묘의 생장특성 비교)

  • Lee,K.C.;Kim,H.S.;Han,S.K.;Lee,K.M.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.19 no.1
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    • pp.129-137
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    • 2017
  • This study was conducted to investigate of growth performances and net assimilation rate(NAR) of Allium microdictyon Prokh. distributed inland and Allium ochotense Prokh. originated Ulleung-do. The Allium microdictyon on the growth of 1-2 years showed the largest relative growth rate, and showed high relative growth from three to four years. Allium ochotense on the growth from one year to three years showed high relative growth rate. The T/R rate of Allium ochotense of 2~5years was in the range of 0.4~0.5. However, The T/R rate of Allium microdictyon was increased as increasing with age. This implies that Allium microdictyon was consumed more energy on growing subterranean part. The LWR of 1~3years old Allium ochotense. was showed more smaller than 4~5years old. It seems that the growth characteristics of Allium ochotense 1-3 years after sowing the leaf growth consume more energy than Allium microdictyon. Net assimilation rate(NAR) of Allium ochotense for 1-3 years after sowing was higher than that of Allium microdictyon. In this time, the material of Allium ochotense has a higher production efficiency can be seen indirectly.

Effect of Nitriding on Fatigue Crack Initiation and Growth Rate in Ni-Cr-Mo Steel (SNCM강의 피로균열의 발생 및 전파속도에 미치는 질화처리의 영향)

  • Kim, Min-Gun;Lim, Bok-Kyu
    • Journal of the Korean Society for Heat Treatment
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    • v.16 no.6
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    • pp.315-319
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    • 2003
  • Effect of nitriding on fatigue crack initiation and growth rate has been studied in Ni-Cr-Mo steel. Specimens were nitrided at $860^{\circ}C$ for 15 hr. The fatigue limit of nitrided specimens were superior to those ofannea1ed($860^{\circ}C$, 15 hr) specimens. Based on detailed observations of slip band and micro crack initiation, it is concluded that the excellent fatigue limit of nitrided specimens is attributed to improved slip initiation resistance by nitriding. The characteristic of fatigue crack growth rate of nitrided specimens was investigated by comparing with those of annealed specimens. It was found that the crack growth rate was markedly decreased and the threshold stress intensity factor range was improved by nitriding. It is concluded that the excellent fatigue limit of nitrided specimens is also attributed to improved fatigue crack growth rate and threshold stress intensity factor range by nitriding.

Effect of Nitriding on Fatigue Crack Initiation and Growth Rate in SNCM (SNCM강의 피로균열의 발생 및 전파속도에 미치는 질화처리의 영향)

  • Kim, Min-Gun;Lee, Sang-Ho
    • Journal of Industrial Technology
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    • v.23 no.A
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    • pp.3-7
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    • 2003
  • Effect of nitriding on fatigue crack initiation and growth rate has been studied on SNCM. Specimens were nitrided for 15 hr at $860^{\circ}C$. The fatigue limit of nitrided specimens was superior to that of annealed($860^{\circ}C$, 15 hr) specimens. Based on detailed observations of slip band and micro crack initiation, it is concluded that the excellent fatigue limit of nitrided specimens is attributed to improved slip initiation resistance by nitriding. The characteristic of fatigue crack growth rate of nitrided specimens was investigated and compared with those of annealed specimens. It was found that by nitriding the crack growth rate was markedly decreased and the threshold stress intensity factor range was improved. It is concluded that the excellent fatigue limit of nitrided specimens is also attributed to improved fatigue crack growth rate and threshold stress intensity factor range by nitriding.

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Regulation of Tylosin Biosynthesis by Cell Growth Rate in Streptomyces fradiae (Streptomyces fradiae에서 균 성장속도에 의한 tylosin 생합성 조절)

  • 강현아;이정현;이계준
    • Korean Journal of Microbiology
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    • v.25 no.4
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    • pp.353-359
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    • 1987
  • The aim of the present study was to investigate the effects of growth rate on the biosynthesis of tylosin in Streptomyces fradiae. In order to elucidate the relation between the growth rate and the tylosin formation rate, the activities of enzymes involved in oxaloacetate metabolism were determined using cells grown at different growth rates in chemostats. As the results, it was found that the specific rate of tylosin formation($q_{p}$) was closely related to the specific cell growth rate and the maximum value of $q_{p}$ was 1.1mg tylosin, $q_{p}$ cell, $0.013h^{-1}$ at the growth rate $0.013h^{-1}$. However further increase in the growth rate over $0.013h^{-1}$ resulted in apparent decrease of $1_{p}$. The synthesis and activities of citrate synthase, aspartate aminotransferase, and PEP carboxylase were very low at lower growth rate. On the other hand, the activity and synthesis of methylmalonyl-CoA carboxyltransferase was closely related to tylosin formation. Therefore it was concluded that tylosin formation was apparently controlled by the growth rate.

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The Short-run and Long-run Dynamics Between Liquidity and Real Output Growth: An Empirical Study in Indonesia

  • JUMONO, Sapto;SOFYAN, Joel Faruk;SUGIYANTO, Sugiyanto;MALA, Chajar Matari Fath
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.5
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    • pp.595-605
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    • 2021
  • The objectives of this research are to see if the phenomena of "demand following" and "supply leading" exist in the business cycle, as well as to look at how liquidity and output react to changes in credit risk, investment-saving gap, inflation, exchange rate, and growth rate of real national output. Employing quarterly data of Maluku and North Maluku (2008-2019), this study utilizes VAR/VECM for inferential analysis. This research found three important findings. First, liquidity and output growth influenced each other in the long run. Second, the determinants of output growth for Maluku are liquidity, investment-saving gap, and inflation, while the determinants of liquidity are output-growth, the gap of investment-saving, and inflation. Third, the determinants of output growth for North Maluku are liquidity, credit risk, investment-saving gap, inflation, exchange rate, and the national output-growth, while the determinants of liquidity are output-growth, credit risk, investment-saving gap, inflation, exchange rate, and national output-growth. The findings of this study supported the hypothesis of demand following and supply leading theory in the Maluku and North Maluku business cycles. This study concludes that economic development would improve if supported by liquidity adequacy through increased deposit growth.

Controlled growth of Carbon Nanotubes using thermal CVD

  • Lee, Tae-Jae;Lyu, Seung-Chul;Choi, Sang-Kyu;Lee, Cheol-Jin;Lee, Jin-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.674-677
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    • 2002
  • Vertically aligned CNTs were grown on Fe-deposited $SiO_2$ substrates using thermal CVD of acetylene gas. The size of Fe particle is controlled by the flow rate of $NH_3$ and pretreatment time, which leads to control the diameter of CNTs. As the diameter of CNTs decreases, the growth rate is enhanced with an inverse dependence of the CNT diameter. The growth rate of CNTs increases linearly as the growth time increases until 30 min but is rapidly decreased over 40 min. We found an inverse relation between the diameter and growth rate of carbon nanotubes. As the diameter of CNTs increases, the compartment layers of bamboo-shaped CNTs appear more frequently. A base-growth model is suitable to explain the dependence of growth rate and structure of CNTs on the diameter size of catalytic particles.

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Influence of Evaluation Methods for Fatigue Crack Growth Process (피로균열 성장과정에 대한 평가방법의 영향)

  • 안철봉
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.1
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    • pp.119-125
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    • 1999
  • The distribution of fatigue crack growth rate is subjected to the measuring interval and calculated method of growth rate. In this paper, in order to establish the method of determining the distribution of fatigue crack growth rate, which ignores those influences, a series of fatigue crack growth experiments and measuring intervals of crack length calculated reasonable are presented. The main conclusions obtained are summarized as follows: 1) As a result of the ΔP constant test and ΔK constant test, it is thought that an approximate measuring interval of 0.3~0.7mm is reasonable, which allows for few errors and is little subjected to the calculated method of crack growth rate. 2) After generally comparing the error estimation by using the experimental data of CCT specimen with the error rating of the CT specimens, it is possible that the fatigue test has few errors within the measuring interval, ξ(Δa/W)=0.0067~0.017, regardless of the dimension of specimen geometry.

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Effect of specific growth rate on the extracellular expression of Baccillus stearothermophillus Ll lipase in recombinant Saccharomyces cerevisiae

  • An, Jeong-O;Jang, Hyeong-Uk;Lee, Hong-Won;An, Ik-Seong;Ham, Seung-Ju;Jeong, Jun-Gi
    • 한국생물공학회:학술대회논문집
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    • 2001.11a
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    • pp.367-369
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    • 2001
  • Recombinant lipase gene (pYEGA ${\alpha}$ -lip) originated from Bacillus stearothermophillus Ll was overexpressed in Saccharomyces cerevisiae. The lipase gene expression level was compared by controlling a constant specifjc growth rates( ${\mu}$ = 0.03, 0.05, 0.07 and $0.1h^{-1}$. Cell g개wth was successfully controlled at the desired rates by feeding rate of glucose and the formation of by-product or accumulation of the glucose was not observed. Above the growth rate of $0.1h^{-1}$. the desired growth rate could not be achieved caused accumulation of by-products(ethanol). The lipase production increased as the specific growth rate decreased. The specific production rate at the lowest specific growth rater(${\mu}$ =0.03) was above 2- folds than the others.

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