• 제목/요약/키워드: method of science

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Hydrazine-Copper 방법을 이용한 연속흐름제어장치를 통한 식물체의 nitrate 분석 (Continuous-Flow Analysis for Determination of Nitrate Using Hydrazine-Copper Method in Plan)

  • 박양호;박소현;이주영;장병춘;이기상
    • 한국토양비료학회지
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    • 제39권4호
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    • pp.204-208
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    • 2006
  • 이연구의 목적은 연속흐름제어장치를 통한 식물체의 nitrate 분석방법 및 RQflex 방법 및 salicylic acid 방법과 비교를 통해 그 정확성을 확인하고자 함에 있다. 분석은 메론, 수박, 오이, 그리고 토마토 잎을 현장에서 채취 후, 분석시까지 초저온 냉동고에 보관후 분석하였다. RQflex로 측정한 결과가 CFA방법이나 salicylic acd 방법보다 약간 높게 나왔으며, CFA방법과 salicylic acid 방법과의 상관관계는 $R^2=0.9671$을 보였으며, RQflex와의 상관관계는 $R^2=0.9739$를 보였다.

Acceleration of the AFEN Method by Two-Node Nonlinear Iteration

  • Moon, Kap-Suk;Cho, Nam-Zin;Noh, Jae-Man;Hong, Ser-Gi
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1998년도 춘계학술발표회논문집(1)
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    • pp.87-92
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    • 1998
  • A nonlinear iterative scheme developed to reduce the computing time of the AFEN method was tested and applied to two benchmark problems. The new nonlinear method for the AFEN method is based on solving two-node problems and use of two nonlinear correction factors at every interface instead of one factor in the conventional scheme. The use of two correction factors provides higher-order accurate interface noes as well as currents which are used as the boundary conditions of the two-node problem. The numerical results show that this new method gives exactly the same solution as that of the original AEFEN method and the computing time is significantly reduced in comparison with the original AFEN method.

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Efficient Exponentiation in Extensions of Finite Fields without Fast Frobenius Mappings

  • Nogami, Yasuyuki;Kato, Hidehiro;Nekado, Kenta;Morikawa, Yoshitaka
    • ETRI Journal
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    • 제30권6호
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    • pp.818-825
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    • 2008
  • This paper proposes an exponentiation method with Frobenius mappings. The main target is an exponentiation in an extension field. This idea can be applied for scalar multiplication of a rational point of an elliptic curve defined over an extension field. The proposed method is closely related to so-called interleaving exponentiation. Unlike interleaving exponentiation methods, it can carry out several exponentiations of the same base at once. This happens in some pairing-based applications. The efficiency of using Frobenius mappings for exponentiation in an extension field was well demonstrated by Avanzi and Mihailescu. Their exponentiation method efficiently decreases the number of multiplications by inversely using many Frobenius mappings. Compared to their method, although the number of multiplications needed for the proposed method increases about 20%, the number of Frobenius mappings becomes small. The proposed method is efficient for cases in which Frobenius mapping cannot be carried out quickly.

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Enhanced Second-order Implicit Constraint Enforcement for Dynamic Simulations

  • Hong, Min;Welch, Samuel W.J.;Jung, Sun-Hwa;Choi, Min-Hyung;Park, Doo-Soon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제2권1호
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    • pp.51-62
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    • 2008
  • This paper proposes a second-order implicit constraint enforcement method which yields enhanced controllability compared to a first-order implicit constraints enforcement method. Although the proposed method requires solving a linear system twice, it yields superior accuracy from the constraints error perspective and guarantees the precise and natural movement of objects, in contrast to the first-order method. Thus, the proposed method is the most suitable for exact prediction simulations. This paper describes the numerical formulation of second-order implicit constraints enforcement. To prove its superiority, the proposed method is compared with the firstorder method using a simple two-link simulation. In this paper, there is a reasonable discussion about the comparison of constraints error and the analysis of dynamic behavior using kinetic energy and potential energy.

Student Perceptions of Peer Assessment in an Action Research Context

  • Shin, Myeong-Kyeong;Yager, Robert-E.;Oh, Phil-Seok
    • 한국지구과학회지
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    • 제25권3호
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    • pp.129-141
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    • 2004
  • A peer assessment method was implemented as part of an action research project where the primary goal was to create constructivist science classrooms. Student reflective writings, which had been created in the process of action research, were analyzed to examine the perceptions of the students concerning the peer assessment method employed in their earth science classrooms. Five perception categories and thirteen statements were developed from the student writings. These indicated that the students appreciated the positive nature of peer assessment and the effects of it as an alternative method for promoting learning. It was also revealed, however, that some students displayed inappropriate behaviors toward peer assessment which led to negative perceptions of the new assessment method. Implications for future use of peer assessment in science classrooms are discussed. Limitations founded in the present study as well as possible solutions are provided.

Back Projection Histogram Method in Homogeneous Field for Microwave Subsurface Radar

  • Tanaka, Masayuki;Ohyama, Shinji;Kobayashi, Akira
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.456-456
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    • 2000
  • The back projection histogram method has been proposed as the method to construct an image from waves reflected from a buried object for subsurface radar. This method is compose of two phases, i.e., a back projection image construction process and a back projection image superposition process. A simulation analysis of this method has been studied. In this paper, an experimental study is demonstrated in air as the homogeneous Held using three cylinders as buried objects.

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Characteristics of Volatile Components from Magnolia ovobata Thunb. by Different Analysis Methods

  • Chung, Hae-Gon;Bang, Jin-Ki;Kim, Geum-Soog;Seong, Nak-Sul;Cho, Joon-Hyeong;Kim, Seong-Min
    • 한국약용작물학회지
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    • 제12권2호
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    • pp.102-107
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    • 2004
  • This study was carried out to establish an optimum method for identifying the volatile components of Magnolia ovobata Thunb. using the dynamic headspace (Purge & Trap) and simultaneous distillation and extraction (SDE) method. Between the two different identification analysis, the volatile components were more easily detected in the SDE than the Purge & Trap method. Among the identified volatile components, the 12 compounds were detected to have similar retention times and match quality within the 45 minutes in both identification methods. The maximum values of the major volatile components were detected differently by SDE and (Purge & Trap) method such as ${\alpha}-pinene$ (3.4, 18.2%), ${\beta}-pinene$ (3.5, 10.3%), l-limonene (5.2, 15.4%). These results indicated that the Dynamic Headspace (Purge & Trap) was much more reliable method for identifying the volatile components of Magnolia ovobata Thunb. as compared to the SDE method.

초마디 멀티프런탈 방법의 효율적인 구현 (An Efficient Implementation of the Supernodal Multifrontal Method)

  • 박찬규;박순달
    • 경영과학
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    • 제19권2호
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    • pp.155-168
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    • 2002
  • In this paper, some efficient implementation techniques for the multifrontal method, which can be used to compute the Cholesky factor of a symmetric positive definite matrix, are presented. In order to use the cache effect in the cache-based computer architecture, a hybrid method for factorizing a frontal matrix is considered. This hybrid method uses the column Cholesky method and the submatrix Cholesky method alternatively. Experiments show that the hybrid method speeds up the performance of the supernodal multifrontal method by 5%~10%, and it is superior to the Cholesky method in some problems with dense columns or large frontal matrices.

STS 교수-학습이 초등학교 과학적 태도 교육에 미치는 효과 (The Effect of STS Teaching-learning Method on the Scientific Attitude of the Elementary School Students)

  • 남철우;최춘호;김정길;김석중;송판섭;한광래;최도성
    • 한국초등과학교육학회지:초등과학교육
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    • 제21권2호
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    • pp.159-170
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    • 2002
  • This study examined the effect on the education of scientific attitude in the process of primary school education by application of STS teaching-learning method with an unit of 6th grade in primary school "environmental pollution and nature conservation". The attitude relating science education, on the other side, is classified into 4 parts; attitude for science, social meaning of science, attitude for science subject and scientific attitude. The study of sexual difference on the above points was examined too. The results was taken as follows. 1. STS Teaching-learning method gives positive effect on the education of scientific attitude more than traditional teaching method, especially on the point of the attitude of science lesson and scientific attitude. 2. STS education has an great influence on the social meaning of the scientific attitude relating science education , investment in science, relation with society, solving social problem, contribution to development of society and technology 3. STS teaching-teaming is thought to be the learning that is more effective for boy than girl. In conclusion The STS Teaching-loaming method is preferable in order to increase the scientific attitude of the Elementary school students. students.

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배암차즈기 추출물의 기능성원료 표준화를 위한 지표성분으로서 Hispidulin의 분석법 평가 (Analytical Method for the Validation of Hispidulin as a Marker Compound for the Standardization of Salvia plebeia R. Br. Extracts as a Functional Ingredient)

  • 전윤정;곽호영;최종길;이제혁;최수임
    • 한국약용작물학회지
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    • 제24권4호
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    • pp.271-276
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    • 2016
  • Background: In the present study, we established an HPLC (high performance liquid chromatography)-analysis method for the determination of marker compounds as a part of the material standardization for the development of health-functional foods from Salvia plebeia R. Br. extract. Methods and Results: The quantitative determination method of hispidulin as a marker compound was optimized by HPLC analysis using a YMC hydrosphere C18 column with a gradient elution system. This method was validated using specificity, linearity, accuracy, and precision tests. It showed a high linearity in the calibration curve with a coefficient of correlation ($r^2$) of 0.999995. The method was fully validated, and was sensitive, with the limit of detection (LOD) at $0.09{\mu}g{\cdot}m{\ell}^{-1}$ and limit of quantification (LOQ) at $0.27{\mu}g{\cdot}m{\ell}^{-1}$. The relative standard deviation (RSD) values of the data from intra- and inter-day precision were 0.05 - 0.22% and 0.32 - 0.42%, respectively, and the intra- and inter-day accuracy of hispidulin were 99.5 - 102.3% and 98.8 - 101.5%, respectively. The average content of hispidulin in Salvia plebeia R. Br. extract was $3.945mg{\cdot}g^{-1}$ (0.39%). Conclusions: These results suggest that the developed HPLC method is very efficient, and that it could contribute to the quality control of Salvia plebeia R. Br. extracts as a functional ingredient in health functional foods.