• Journal of the korean society of oceanography
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• v.39 no.4
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• pp.222-233
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• 2004

Using nitrogen as the limiting nutrient, the default version of a microplankton-detritus model linked chlorophyll concentration to the autotroph nitrogen. However, phosphorus dynamics were added to simulate the results of a microcosm experiment. Using standard parameter values with a single value of microheterotroph fraction in the microplankton taken from the observed range, the best simulation successfully captured the main features of the time-courses of chlorophyll and particulate organic carbon, nitrogen and phosphorus, with root-mean-square error equivalent to 29% of particulate concentration. A standard version of microbiological model assumes complete internal cycling of nutrient elements; adding a term for ammonium and phosphate excretion by microheterotrophs did not significantly improve predictions. Relaxing the requirement for constant microheterotroph fraction resulted in an autotroph-heterotroph model AH, with dynamics resembling those of a Lotka-Volterra predator-prey system. AH fitted the microcosm data worse than did MP, justifying the suppression of Lotka-Volterra dynamics in MP. The paper concludes with a discussion of possible reasons for the success of the simple bulk dynamics of MP in simulating microplankton behaviour.

• Journal for History of Mathematics
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• v.27 no.6
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• pp.409-419
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• 2014

In school mathematics, the logarithmic function is defined as the inverse function of an exponential function. And the natural logarithm is defined by the integral of the fractional function 1/x. But historically, Napier had already used the concept of logarithm in 1614 before the use of exponential function or integral. The calculation of the logarithm was a hard work. So mathematicians with arithmetic ability made the tables of values of logarithms and people used the tables for the estimation of data. In this paper, we first take a look at the mathematicians and mathematical principles related to the appearance and the developments of the logarithmic tables. And then we deal with the confusions between mathematicians, raised by the estimation data which were known as proportional parts or mean differences in common logarithmic tables.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.2
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• pp.142-146
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• 1989

Anther and/or tissue culture of cross pollinated crops would be very important because it can result in the direct use of haploids or doubled haploids for developing superior hybrids or varieties. The objective of the study was to investigate the response frequencies in anther and/or tissue-cultured hybrids of corn. pearl millet and buckwheat to identify agronomically acceptable germplasm of the crops. 27 crosses of corn inbred lines were evaluated by plating their anthers on N6. MS and Yu-Pei media. Two genotypes of FR1l41/FR16 hybrid cultured on N6 medium and Fla 2BT73/S6013 hybrid cultured on N6 medium responded with one anther producing calli when plated after 5$^{\circ}C$ low temperature treatment for one week. Immature embryos of corn hybrid Suwon 19 responded producing calli that were regenerated to plants at a 8.6 percent success rate. Of the 20 corn hybrids. immature tessels of FR1l41/FR16. B68/A1l6N//KS15. KS16/KS17. GA209/DB578 and SDB126/GA209 crosses responded at a relatively higher success rate producing calli that were regenerated to plants. In tissue culture of elongating culms of pearl millet x Napier grass interspecific hybrid. 2.5-4.0mm long pieces of the culm were good for callus induction resulting in higher success rate. The epicotyl of buckwheat was very good for tissue culture. and the node produced the plants regenerated directly without callus induction on the B5 medium containing I ppm BA and 0.05 ppm IBA. There were great differences in response to anther and/or tissue culture of corn, pearl millet and buckwheat due to genotype x medium and environment interactions.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.6
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• pp.637-642
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• 1996

This experiment was conducted to determine RDP values of locally available feedstuffs that are commonly used in ruminant rations in Bangladesh. Four cattle were fistulated in the rumen for the in situ nylon bag studies. Seventeen different feedstuff sample (9 roughages and 8 concentrates) were evaluated in $4{\times}14cm$ nylon bags and incubated in the rumen for different periods of time (2, 6, 12, 24, 48 and 72 h). The variation in crude protein (CP) contents reflected on the average CP disappearance value throughout the rumen incubation. Soluble fraction (a), insoluble but degradable fraction (b) along with the rate of degradation also varied widely among the various feedstuffs. Under 2% of rumen outflow rate, the percentages of the calculated protein degradabilities of roughages were rice straw, 16.7; maize grass, 70.6; oat grass, 70.8; dhal grass, 71.1; sunhemp, 78.4; napier grass, 62.4; matikalai grass, 72.1; khesarikalai grass, 76.9 and daincha browse, 78.4, respectively. The results in the protein degradabilities (%) in 8% ruminal outflow rate of concentrates were wheat bran, 61.6; rice polish (red), 61.3; rice polish (auto), 30.9; mustard oil cake, 71.8; sesame oil cake, 74.2; coconut oil cake, 57.9; soybean meal, 49.2 and fish meal, 37.9, respectively.

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.19.3-19.3
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• 2011

1631년 정두원이 명나라로부터 가져온 네 권의 과학서와 한 편의 보고서 가운데, 치력연기(治曆緣起)라는 책과 서양공헌신위대경소(西洋貢獻神威大鏡疏)가 강화도의 외규장각에 소장되고 있었다. 이 점에 유의하여 강화도 외규장각에 소장되어 있었던 천문학 및 수학 관련 서적을 조사해 보았다. 외규장각 소장 도서의 목록에 해당하는 외규장각형지안(外奎章閣形止案)을 조사하여, 소장 도서의 내역과 소장 상태의 변천을 알아낼 수 있다. 그 결과 서양공헌신위대경소는 1791년 신해박해 때 천주교 서적으로 오인되어 소각되었고, 치력연기는 1866년 병인양요 때 프랑스 해군에 의해 소각되었음을 알 수 있었다. 외규장각에는, Napier의 대수(logarithm)에 관한 아이디어가 반영되어 있는 쟈크 로우(Rho)의 주산(籌算)이란 책이 소장되어 있었고, 조선조 양대 물시계에 관한 보고서인 흠경각영건의궤(欽敬閣營建儀軌)와 보루각중수의궤(報漏閣重修儀軌)가 있었으며, 조선 국왕들이 천문에 관해 작성한 어제 및 어필이 소장되어 있었으며, 천문류초(天文類抄)와 천기대요(天機大要)와 같은 널리 사용되던 천문 및 음양학관련 서적이 소장되어 있었다. 특히, 1866년 프랑스 해군에 의해 약탈되어 현재 프랑스 파리 국가도서관에 소장되어 있는 천상열차분야지도는 숙종석각의 탁본으로 추정된다. 현재 10여 개의 탁본이 국내외에 남아 있으나, 최근 프랑스로부터 반환되게 된 외규장각 도서 내역에 천상열차분야지도가 포함되지 못하였다. 이와 관련하여 약간 토의하고자 한다.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.9
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• pp.1288-1293
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• 2002

Four adult rams ($22.25{\pm}0.90kg$) were used in a $4{\times}4$ latin square design to evaluate the rations without ($T_1$) or with supplementation of sunflower acid oil at 5 ($T_2$), 10 ($T_3$) or calcium soap at 10% of dietary DM ($T_4$) on nutrient digestibility and balances of nitrogen, calcium and phosphorus. The basal ration contained 60 parts Brazilian napier grass hay and 40 parts concentrate mixture. The DM, CF, NDF and ADF digestibilities and nitrogen retention (g/d) decreased (p<0.01) by inclusion of sunflower acid oil at 5% of dietary DM. In addition, depression (p<0.01) in digestibilities of CP, nitrogen free extract (NFE), cellulose, hemicellulose, retention of calcium and phosphorus (g/d) were also observed with increasing the level of sunflower acid oil to 10% of dietary DM. The EE digestibility, total digestible nutrients (TDN) content and calcium retention (g/d) were significantly higher (p<0.01) for ration supplemented with calcium soap. It is concluded that sunflower acid oil supplementation in free form as low as 5% of dietary DM is deleterious to fibre digestion in sheep while as calcium soap, it can be fed up to 10% of dietary DM as an energy source without any adverse effect.

• Journal for History of Mathematics
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• v.17 no.3
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• pp.33-42
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• 2004

${\varrho}$ is the real constant number that appears not only in calculus but also in a real life. The concept of the number ${\varrho}$ first appeared in an appendix of Napier's work on logarithms in 1618. The early developments on the logarithm became part of an understanding of the number ${\varrho}$. In 1727, the number ${\varrho}$ was studied by Euler explicitly. It ton14 almost 100 years to understand the number ${\varrho}$ which we learn in high school nowadays. By studying the origin of the number ${\varrho}$, we can guess that many mathemetician's research in our time will have significant meaning in the future although it looks like just some calculations of cohomology or K-theory etc.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.670-686
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• 2017

MapReduce (MRV1), a popular programming model, proposed by Google, has been well used to process large datasets in Hadoop, an open source cloud platform. Its new version MapReduce 2.0 (MRV2) developed along with the emerging of Yarn has achieved obvious improvement over MRV1. However, MRV2 suffers from long finishing time on certain types of jobs. Speculative Execution (SE) has been presented as an approach to the problem above by backing up those delayed jobs from low-performance machines to higher ones. In this paper, an adaptive SE strategy (ASE) is presented in Hadoop-2.6.0. Experiment results have depicted that the ASE duplicates tasks according to real-time resources usage among work nodes in a cloud. In addition, the performance of MRV2 is largely improved using the ASE strategy on job execution time and resource consumption, whether in a multi-job environment.

• Computers and Concrete
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• v.30 no.1
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• pp.19-32
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• 2022

This paper presents an investigation into the failure of RC columns under impact loadings. A numerical simulation of 19 identical RC columns subjected to single and repeated impact loadings was performed. A free-falling hammer was dropped at midspan with the same total kinetic energy input but varying mass and momentum. The specimens under the repeated impact test were struck two times at the same location. The colliding index, defined as the impact energy-momentum ratio, was proposed to explain the different impact responses under equal-energy impacts. The increase of colliding index from low to high indicates the transition of the impact response from static to dynamic and failure mode from flexure to shear. This phenomenon was more evident when the column had a greater axial load and was impacted with a high colliding index. The existence of the axial load had an inhibitory effect on the crack development and increased the shear resistance. The second impact changes the failure mode from flexural to brittle shear as found in the specimen with 20% axial load subjected to high a colliding index. Moreover, a deflection prediction equation based on the impact energy and force was limited to the low colliding index impact.

• Journal for History of Mathematics
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• v.35 no.5
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• pp.131-146
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• 2022

This study is to find out how to use the materials of East Asian history in mathematics classroom. Although the use of the history of mathematics in classroom is gradually considered advantageous, the usage is mainly limited to Western mathematics history. As a result, students tend to misunderstand mathematics as a preexisting thing in Western Europe. To fix this trend, it is necessary to deal with more East Asian history of mathematics in mathematics classrooms. These activities will be more effective if they are organized in the context of students' real life or include experiential activities and discussions. Here, the study suggests a way to utilize the mathematical ideas of Bāguà and Liùshísìguà, which are easily encountered in everyday life, and some concepts presented in 『Nine Chapter』 of China and 『GuSuRyak』 of Joseon. Through this activity, it is also important for students to understand mathematics in a more everyday context, and to recognize that the modern mathematics culture has been formed by interacting and influencing each other, not by the east and the west.