• 한국초등수학교육학회지
• /
• 제17권3호
• /
• pp.395-411
• /
• 2013

나눗셈 맥락에는 크게 포함제 맥락과 등분제 맥락이 있다. 아동들은 학습을 통하여 포함제 맥락과 등분제 맥락에서 자연수 나눗셈 세로 형식 계산법의 원리를 점진적으로 이해해 갈 것으로 기대된다. 수학 교과서와 교사용 지도서는 아동들의 자연수 나눗셈 계산법의 종합적 이해를 지원할 수 있도록 구성되는 것이 바람직하다. 2007 교육과정에 따른 교과서와 교사용 지도서의 자연수 나눗셈 관련 내용을 분석한 결과, 교과서와 교사용 지도서는 편의적으로 포함제 맥락과 등분제 맥락을 사용하고 있었다. 이와 같은 편의적인 사용은 포함제와 등분제 맥락에서 자연수 나눗셈 계산법의 종합적 이해를 어렵게 할 수 있다. 이 논문에서는 교과서와 지도서 분석 결과를 바탕으로 포함제와 등분제 맥락에서 자연수 나눗셈 계산법의 종합적 이해를 도모하는 데 필요한 제언을 제시하였다.

• Toxicological Research
• /
• 제26권3호
• /
• pp.203-208
• /
• 2010

Bronchoalveolar lavage (BAL) is a useful tool in researches and in clinical medicine of lung diseases because the BAL fluid contains biochemical and cytological indicators of the cellular response to infection, drugs, or toxicants. However, the variability among laboratories regarding the technique and the processing of the BAL material limits clinical research. The aim of this study was to determine the suction frequency and lavage fraction number necessary to reduce the variability in lavage using male Sprague-Dawley rats. We compared the total cell number and protein level of each lavage fraction and concluded that more cells and protein can be obtained by repetitive lavage with a suction frequency of 2 or 3 than by lavage with a single suction. On the basis of total cell recovery, approximately 70% of cells were obtained from fractions 1~3. The first lavage fraction should be used for evaluation of protein concentration because fractions 2~5 of lavage fluid were diluted in manifolds. These observations were confirmed in bleomycin-induced inflamed lungs of rats. We further compared the BAL data from the whole lobes with data from the right lobes and concluded that BAL data of the right lobes represented data of the whole lobes. However, this conclusion can only be applied to general lung diseases. At the end, this study provides an insight into the technical or analytical problems of lavage study in vivo.

• 대한수학교육학회지:학교수학
• /
• 제14권2호
• /
• pp.191-212
• /
• 2012

학생들의 산술 활동 (수의 사칙연산) 학습에 관한 연구 중 분수량을 포함한 나눗셈 문제의 해결을 위한 자연수 지식의 활용을 상세히 다룬 연구가 매우 부족한 실정이다. 교수실험이 연구방법으로 사용된 본 정성연구에서는, 일년간 행해진 교수실험 중 일부 자료의 분석을 바탕으로 다양한 포함제 분수나눗셈 상황을 해결하기 위해 어떻게 자연수 나눗셈의 기본이 되는 단위분할 도식을 수정, 구성해 나갈 수 있는지에 대한 가능한 발달 경로(나머지가 있는 단위분할 도식, 분수 단위분할 도식)를 제시하고 있다. 따라서 본 연구는 다른 수 체계(자연수, 분수)에서 같은 종류의 연산(나눗셈)에 대한 조작적 연결성을 고찰함으로써 현재 학생들이 가지고 있는 수 연산에 관한 분절적 이해를 올바르게 지도할 수 있는 방안을 제시한다.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제47권1호
• /
• pp.91-106
• /
• 2008

Interviews with 24 pupils in grade 1-2 were used to investigate awareness of the relation between situation and computation in simple quotitive and partitive division problems as informally experienced. Then it was suggested how to connect children's informal knowledge and formal knowledge of division. Most subjects counted cubes or made drawing, and related these methods to the situation described in the problems. In result, quotitive division was experienced as a dealing situation, where the number of items represented by the divisor was repeatedly taken from the whole number. And estimate-adjust was the most frequently displayed way of experiencing partitive division. Therefore, partitive division with its two measurement variables can be related to a measurement model. And children should be taught column algorithms for division with estimated-adjust which pupils used for partitive division problems.

• 대한예방한의학회지
• /
• 제21권3호
• /
• pp.75-85
• /
• 2017

Objectives : The new health technology assessment (nHTA) involves evaluating the safety and efficacy of the new health technology under the Medical Services Act by the New Health Technology Assessment Project Division from 2007. The purpose of this study is to understand the status of applications and recent trends of the results, and suggest strategies for the development of new health technologies in Korean Medicine. Methods : We investigated and analyzed the results of evaluation of new health technology of whole conventional medical and the list of new health technologies in Korean Medicine provided by the New Health Technology Assessment Project Division from 2007 to 2016. Results : The number of applications for new health technology of Korean medicine was low as 41 items in the whole number of 2,013 items. The evaluation method of new health technologies in both, the whole medical and Korean medicine fields was the same, but the tendency in results was very different. Most of the new health technology items in Korean medicine were classified as existing technology (20 items), early stage technology (7 items), and Only 2 items were evaluated as research stage technology. Conclusions : In order to develop new health technology in the Korean medical field, we have made suggestions about the health technology assessment systems, R&D infrastructures, and corporation with conventional medicines.

• Reproductive and Developmental Biology
• /
• 제36권4호
• /
• pp.255-260
• /
• 2012

The purpose of this study was to assess follicular viability and competence through in vitro culture of preantral follicles isolated from vitrified mouse whole ovaries. Mouse preantral follicles were enzymatically isolated from vitrified- warmed and fresh ovaries and cultured for 10 days followed by in vitro oocyte maturation. In vitro matured oocytes were fertilized and cultured to the blastocyst stage. Five minutes pre-exposure to vitrification solution of whole ovaries had significantly higher (p<0.05) oocyte survival and maturation rates than between 10 min exposure groups. Oocyte diameter was significantly smaller (p<0.05) in the 5 and 10 min exposure groups ($69.4{\pm}2.8$ and $67.8{\pm}3.1$) when compared to that of control group ($71.7{\pm}2.1$). There was no statistical significant difference in blastocyst development rates between vitrification group (8.6%) and the fresh control group (12.0%). The mean number of cells per blastocyst was significantly lower (p<0.05) in the vitrification group ($41.9{\pm}20.2$) than in the fresh control group ($55.1{\pm}22.5$). The results show that mouse oocytes within preantral follicles isolated from the vitrified whole ovaries can achieve full maturation, normal fertilization and embryo development.

• Journal of Veterinary Science
• /
• 제22권2호
• /
• pp.24.1-24.16
• /
• 2021

Background: Bovine tuberculosis (TB) is caused by Mycobacterium bovis, a well-known cause of zoonotic tuberculosis in cattle and deer, and has been investigated in many physiological and molecular studies. However, detailed genome-level studies of M. bovis have not been performed in Korea. Objectives: To survey whole genome-wide single-nucleotide polymorphism (SNP) variants in Korean M. bovis field isolates and to define M. bovis groups in Korea by comparing SNP typing with spoligotyping and variable number tandem repeat typing. Methods: A total of 46 M. bovis field isolates, isolated from laryngopharyngeal lymph nodes and lungs of Korean cattle, wild boar, and Korean water deer, were used to identify SNPs by performing whole-genome sequencing. SNP sites were confirmed via polymerase chain reaction using 87 primer pairs. Results: We identified 34 SNP sites with different frequencies across M. bovis isolates, and performed SNP typing and epidemiological analysis, which divided the 46 field isolates into 16 subtypes. Conclusions: Through SNP analysis, detailed differences in samples with identical spoligotypes could be detected. SNP analysis is, therefore, a useful epidemiological tracing tool that could enable better management of bovine TB, thus preventing further outbreaks and reducing the impact of this disease.

• Tuberculosis and Respiratory Diseases
• /
• 제81권3호
• /
• pp.216-221
• /
• 2018

Background: The number of immigrants with tuberculosis (TB) increases each year in South Korea. Determining the transmission dynamics based on whole genome sequencing (WGS) to cluster the strains has been challenging. Methods: WGS, annotation refinement, and orthology assignment for the GenBank accession number acquisition were performed on two clinical isolates from Chinese immigrants. In addition, the genomes of the two isolates were compared with the genomes of Mycobacterium tuberculosis isolates, from two native Korean and five native Chinese individuals using a phylogenetic topology tree based on the Multiple Alignment of Conserved Genomic Sequence with Rearrangements (Mauve) package. Results: The newly assigned accession numbers for two clinical isolates were CP020381.2 (a Korean-Chinese from Yanbian Province) and CP022014.1 (a Chinese from Shandong Province), respectively. Mauve alignment classified all nine TB isolates into a discriminative collinear set with matched regions. The phylogenetic analysis revealed a rooted phylogenetic tree grouping the nine strains into two lineages: strains from Chinese individuals and strains from Korean individuals. Conclusion: Phylogenetic trees based on the Mauve alignments were supposed to be useful in revealing the dynamics of TB transmission from immigrants in South Korea, which can provide valuable information for scaling up the TB screening policy for immigrants.

• 수산해양기술연구
• /
• 제46권4호
• /
• pp.324-334
• /
• 2010

This investigation was carried out to research on the actual states for bycatch and discards of catches caught by funnel net from December, 2007 to June, 2010. Fishing grounds were Manheung-dong and Ocheon-dong in the coastal waters of Yeosu. The number of the investigation was 21 in Manheung-dong and 7 in Ocheon-dong fishing ground. In Manheung-dong, the species of catches were 26 of fish, 6 of cephalopod and 5 of crustacean. In Ocheon-dong, the species of catches were 25 of fish, 6 of cephalopod and 4 of crustacean. In the two all fishing grounds, the largest amount of species was revealed as gray mullet. Among these catches, the number of non marketable species that were classified and discarded ones, were 9 in Manheung-dong and 7 in Ocheon-dong. Also, among the marketable species which were small entity or too tiny catches to commercialize and not fresh ones were discarded. The proportion that they dominate in the whole catches was 37.1% in the number of catches and 5.4% in the weight of catches in Manheung-dong, and 6.9% in the number of catches and 0.3% in the weight of catches in Ocheon-dong. In case of Manheung-dong, the monthly discarding proportion was the highest with 59.4% in the number of catches in may and 17.6% in the weight of catches in November, and in case of Ocheon-dong, the both of them were the highest in February, with 28.0% in the number of catches and 5.1% in the weight of catches.

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