• East Asian mathematical journal
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• 제34권2호
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• pp.203-217
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• 2018

This study examined preservice elementary teachers' patterns and tendencies in thinking of drawn models of multiplication with fractions. In particular, it investigated preservice elementary teachers' work in a context where they were asked to select among drawn models for symbolic expressions illustrating multiplication with non-whole number fractions including a mixed number. Preservice teachers' interpretations of fraction multiplication used in interpreting different types of drawn models were analysed-both quantitatively and qualitatively. Findings and implications are discussed and further research is suggested.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제31권2호
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• pp.153-166
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• 2017

본 연구에서는 예비교사가 문제 만들기 과제를 위해 분수곱셈지식을 사용하는 과정에서 드러나는 이해의 정도와 유형을 미국사례를 중심으로 조사하였다. 이를 위하여, 미국 대학 교사교육과정의 입문단계와 종료단계에 있는 총 164명의 예비초등교사를 대상으로 분수곱셈에 대한 문장제 문제를 작성하게 하고, 이를 수학적 정교성과 작성한 문제에 사용한 분수곱셈의 의미의 유형으로 분석하였다. 분석결과는 교육과정 입문단계와 종료단계의 예비교사 그룹 간의 차이점, 각 그룹, 그리고 전체적인 경향에 대해 기술하였고, 분수곱셈 지도와 교사교육에 대한 시사점을 제공하였다.

• 한국식품조리과학회지
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• 제20권4호
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• pp.352-357
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• 2004

This study was performed to predict the multiplication growth patterns of Salmonella typhimurium according to the holding methods and times in cooked foods served at foodservice institutions. When simmered pork in soy sauce and ham and cucumber salad were inoculated with S. typhimurium (7.00 logCFU/g) and tested according to holding methods and times, room temperature holding showed a continuous increase in S. typhimurium count as time passed, whereas 80$^{\circ}C$ heating table sharply reduced the count to 4.00 (logCFU/g) after 2hrs of holding and to zero after 6hrs, which suggested that all S. typhimurium were destroyed. However, 5$^{\circ}C$ refrigerator holding showed a count increase, although it wasis still lower than that at room temperature and at 10$^{\circ}C$ cold table holding, which suggested that S. typhimurium is comparatively resistive to low temperature.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제22권4호
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• pp.281-294
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• 2019

본 연구의 목적은 초등학교 3학년 2학기의 곱셈 학습에서 반성적 활동을 적용함으로써 학업성취도의 수학 학습과정 중에 나타나는 오류 및 처치 행동을 분석하는 데 있다. 연구참여하는 학생들에게 곱셈단원에 대하여 반성적 활동을 적용하여 수업을 재구성하여 진행하였다. 이들의 수학 학업성취도의 변화를 알아보기 위하여 사전 사후 검사를 실시하였고, 반성적 활동에서의 학습자의 오류 처치양상을 분석하기 위해 포커스 그룹의 수학적인 의사소통을 녹음하여 분석하였다. 그리고 오류 유형 및 오류 처치를 위하여 학생들의 활동지와 녹음된 대화를 분석하였다. 연구 결과, 반성적 활동을 적용한 경우 학습자의 수학학업성취도가 상승하였다. 두 자리 수의 곱셈을 학습할 때 오류 유형은 다양하게 나타났다. 그리고 반성적 활동은 학습자가 곱셈 알고리즘에 대해 반성하고 오류가 있는 계산을 분석하여 자신의 오류를 반성적으로 되돌아보고 처치하도록 돕게 됨을 확인하였다.

• 전자공학회논문지A
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• 제29A권9호
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• pp.8-14
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• 1992

The radiation pattern of a rectangular-grid array antenna consisted of rectangular waveguides is represented by multiplication of its element and array factors. Calculated radiation patterns for excitation of TES110T mode inside the waveguides suffer from the blindness at a particular direction on E-plane. Numerical simulations show that the blindness can be removed by inserting dielectric plug inside the waveguides or covering dielectric sheath in front of the waveguides.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제5권2호
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• pp.111-119
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• 2001

Over the years, the benefits of instructional manipulatives in mathematics education have been verified by classroom practice and educational research. The purpose of this paper is to introduce how the instructional material, specifically, geoboard could be used and integrated in elementary mathematics classroom in order to develop student's mathematical concepts and process in terms of the following areas: (1) Number '||'&'||' Operation : counting, fraction '||'&'||' additio $n_traction/multiplication (2) Geometry : geometric concepts (3) Geometry : symmetry '||'&'||' motion (4) Measurement : area '||'&'||' perimeter (5) Probability '||'&'||' Statistics : table '||'&'||' graph (6) Pattern : finding patterns Further, future study will continue to foster how manipulatives will enhance children's mathematics knowledge and influence on their mathematics performance.

• 대한기계학회논문집
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• 제18권10호
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• pp.2577-2584
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• 1994

A method of digital image processing thechnique, which can multiply and sharpen isochromatic fringes in photoelasticity on both occasions, is developed. To test the method, photoelastic fringe patterns of a disk compressed by two diametrically opposite cocentrated loads are simulated and these patterns are processed to yield sharpened lines. The method is then aplied to measurement of residual stresses in glass bar. The procedure is proved to be capable of extraction sharpened lines accurately from photoelastic multiplied fringes, and yields good experimental results consistently and precisely.

• 한국식품과학회지
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• 제35권3호
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• pp.429-435
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• 2003

가정배달급식의 저장기간 중 식중독 발생에 대비하여 식중독균의 증식 양상을 사전에 예측하기 위한 기본자료를 얻고자 표고고기전, 갈치조림, 더덕구이에 주요 식중독 원인균을 접종하여 wrap 포장, 상압 및 진공포장 처리한 후, -18, 4, $25^{\circ}C$에서 5일간 포장방법 및 저장조건에 따른 변화를 살펴보았다. 가정배달급식을 위한 음식에 주요 식중독균을 접종한 결과, 식중독균의 성장 및 증식은 적용된 음식을 진공포장 처리하여 냉장 및 냉동저장시에 억제되는 것으로 입증되었고, 접종된 주요 식중독균의 포장방법 및 저장조건에 따른 성장 및 증식은 저장온도에 유의적인 영향을 받는 것으로 나타났으며, 특히, L. monocytogenes는 저장기간에 대해서도 유의적인 영향을 받는 것으로 나타났다. 따라서 표고고기전과 갈치조림의 냉장저장 시에는 L. monocytogenes가 저장 5일에 증가하므로 음식품질을 유지하고 식중독균 발생을 방지하기 위해서는 3일까지 저장하는 것이 바람직한 것으로 판단되었다.

• Nuclear Engineering and Technology
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• 제48권1호
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• pp.55-63
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• 2016

Calculation of the core neutronic parameters is one of the key components in all nuclear reactors. In this research, the energy spectrum and spatial distribution of the neutron flux in a uranium target have been calculated. In addition, sensitivity of the core neutronic parameters in accelerator-driven subcritical advanced liquid metal reactors, such as electron beam energy ($E_e$) and source multiplication coefficient ($k_s$), has been investigated. A Monte Carlo code (MCNPX_2.6) has been used to calculate neutronic parameters such as effective multiplication coefficient ($k_{eff}$), net neutron multiplication (M), neutron yield ($Y_{n/e}$), energy constant gain ($G_0$), energy gain (G), importance of neutron source (${\varphi}^*$), axial and radial distributions of neutron flux, and power peaking factor ($P_{max}/P_{ave}$) in two axial and radial directions of the reactor core for four fuel loading patterns. According to the results, safety margin and accelerator current ($I_e$) have been decreased in the highest case of $k_s$, but G and ${\varphi}^*$ have increased by 88.9% and 21.6%, respectively. In addition, for LP1 loading pattern, with increasing $E_e$ from 100 MeV up to 1 GeV, $Y_{n/e}$ and G improved by 91.09% and 10.21%, and $I_e$ and $P_{acc}$ decreased by 91.05% and 10.57%, respectively. The results indicate that placement of the Np-Pu assemblies on the periphery allows for a consistent $k_{eff}$ because the Np-Pu assemblies experience less burn-up.

• 한국식물병리학회지
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• 제10권4호
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• pp.305-313
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• 1994

Typically susceptible lesions were developed on pepper (cv. Hanbyul) leaves inoculated with the compatible strains Ds 1 of Xanthomonas campestris pv. vesicatoria. The lesions appeared first water-soaked and then turned yellow with a chlorotic area. In contrast, the leaves inoculated with the incompatible strain 81-23 initially turned yellow and then developed local necrosis. Multiplication of x. c. pv. vesicatoria in pepper leaves also were distinctly different between the two strains. The strain Ds 1 multiplied more greatly than did the strain 81-23 in the infected leaves. X. c. pv. vesicatoria infection of pepper leaves induced the synthesis of soluble proteins, especially more greatly in the compatible than in the incompatible interactions. Some pathogenesis-related (PR) proteins were detected in the intercellular washing fluid (IWF) and extracts of the infected pepper leaves. In particular, the 32 kDa protein on SDS-PAGE gels appeared intensely in the incompatible interaction. In contrast, some proteins with moluecular masses of 65, 71, and 75 kDa disappeared in the infected pepper leaves. Isoelectric focusing could identify the pIs of soluble proteins in infected pepper leaves. The accumulation of the IWF from infected leaves was more conspicuous in the incompatible than the compatible interaction. These results suggest that some extremely acidic and basic proteins were induced and accumulated in the intercellular spaces of infected pepper leaves.