• Proceedings of the Korean Association for Survey Research Conference
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• 2006.12a
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• pp.67-83
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• 2006

In successive sampling on two occasions the problem of estimating a finite population quantile has been considered. The theory developed aims at providing the optimum estimates by combining (i) three double sampling estimators viz. ratio-type, product-type and regression-type, from the matched portion of the sample and (ii) a simple quantile based on a random sample from the unmatched portion of the sample on the second occasion. The approximate variance formulae of the suggested estimators have been obtained. Optimal matching fraction is discussed. A simulation study is carried out in order to compare the three estimators and direct estimator. It is found that the performance of the regression-type estimator is the best among all the estimators discussed here.

• Journal of the Korean Statistical Society
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• v.36 no.4
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• pp.543-556
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• 2007

In successive sampling on two occasions the problem of estimating a finite population quantile has been considered. The theory developed aims at providing the optimum estimates by combining (i) three double sampling estimators viz. ratio-type, product-type and regression-type, from the matched portion of the sample and (ii) a simple quantile based on a random sample from the unmatched portion of the sample on the second occasion. The approximate variance formulae of the suggested estimators have been obtained. Optimal matching fraction is discussed. A simulation study is carried out in order to compare the three estimators and direct estimator. It is found that the performance of the regression-type estimator is the best among all the estimators discussed here.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.2
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• pp.112-116
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• 2002

Effects of artificial electron donors to deliver reducing power on enzymic denitrification were investigated using nitrate reductase and nitrite reductase obtained from Ochrobactrum antroyi. The activity of nitrite reductase in the soluble portion was almost the same as that in the precipitated portion of the cell extract. Nitrate removal efficiency was higher with benzyl viologen than with methyl viologen or NADH as an artificial electron donor. The turn-over numbers of nitrate and nitrite reductase were 14.1 and 1.9 umol of nitrogen reduced/min$.$mg cell extracts, respectively when benzyl viologen was used as an electron donor.

• The Plant Pathology Journal
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• v.18 no.2
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• pp.74-76
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• 2002

This study unexpectedly detected a deletion in the promoter region of ras gene in two Korean strains of oak mushrooms, Lentinula edodes (Berk.). Sequencing of the promoter regions revealed that one type consisting of two strains had a 113 bp deletion in the region. The pas promoter region of Korean strains differed by 16 bases from that of the Japanese strains. Between the two types of Korean strains, except for the deleted portion, only a single site appeared to be different.

• The Mathematical Education
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• v.47 no.3
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• pp.291-310
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• 2008

This article is based on an international collaborative study that aimed to investigate mathematical preparation of prospective elementary teachers in several selected education systems in East Asia. This article reports the Korean portion of the study. A survey instrument was developed to explore not only prospective teachers' knowledge of elementary mathematics curriculum and their beliefs in their preparation and mathematics instruction but also their subject matter knowledge and pedagogical content knowledge on the topic of fraction division. A total of 291 seniors in 3 universities participated in the survey. The results reveal these prospective teachers' strengths and weaknesses with regard to their knowledge of fraction division, and suggest that content-specific pedagogical knowledge needs to be emphasized in the teacher preparation program.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.311-312
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• 2005

The precipitation of U(VI) in the presence of phosphate and carbonate was investigated in the pH range of 4 to 13 and the following was obtained as a result of this experimental condition. U(VI) precipitates as a $NaUO_{2}PO_{4}$ at pH<9 but as mixtures of phosphate, hydroxides and/or carbonate at pH>9. The portion of the phosphate in the precipitate decreases almost linearly to near zero with an increasing pH in the range of 9 to 13. The U(VI) phosphate is dissolved by the carbonate complex formation at pH<10.5. The ternary complex of a carbonate and phosphate is not found.

• Nutrition Research and Practice
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• v.14 no.6
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• pp.667-678
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• 2020

BACKGROUND/OBJECTIVES: This study aimed to improve portion size estimation aids (PSEAs) used in the nutrition survey of the Korea National Health and Nutrition Examination Survey (KNHANES) and validate the accuracy and precision of the newly developed aids. SUBJECTS/METHODS: We conducted intensive interviews with survey experts in KNHANES and consulted with experts to collect opinions about improvement of PSEAs. Based on the results of the interviews, 5 types of PSEAs (rice bowl, earthen pots, mounds, measuring spoons, and thickness sticks) were newly developed using 3-dimensional (3D) modeling or modification of color or shape. Validation tests were conducted with 96 adults 20 years old or older. For the rice bowl and earthen pots, the participants were asked to select the more similar PSEA in size after being shown the real dishes. For the mounds, measuring spoons, and thickness sticks, the participants were presented with actual plates of food and asked to estimate the given portion sizes using the given PSEAs. RESULTS: The improved 2-dimensional (2D) picture aid for the rice bowl reflecting the size distortion by angle of view using 3D modeling was perceived more closely to the actual size than the current 2D picture (P < 0.001). The change of the color of 2D pictures and 3D models, the change of shape of the measuring spoons, and the 3-dimensionalization of the 2D mounds had no significant improvement in the subjects' perception. CONCLUSIONS: The currently used 2D PSEAs need to be fully redesigned using 3D modeling to improve subjects' perception. However, change of color or shape will not be necessary. For amorphous foods, it is suggested that more evaluation be performed before reaching a final conclusion in the use of PSEAs, or alternative ways to improve accuracy of estimation need to be explored.

• Tuberculosis and Respiratory Diseases
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• v.61 no.3
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• pp.273-278
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• 2006

Endobronchial leiomyoma is a rare tumor that accounts for less than 2% of pulmonary benign tumors. A 32 year-old woman was admitted with fever, cough and sputum for a month. She had suffered from intermittent cough over three years. The chest X-ray and chest CT(computed tomography) showed a nodular lesion obstructing the proximal portion of the left lower lobar bronchus and atelectasis of the left lower lobe. Flexible Bronchoscopy detected a mass obstructing the distal portion of the left main bronchus and endobronchial biopsy showed benign smooth muscle cells. There was no abnormal finding in the uterine examination. Therefore this case was diagnosed as primary endobronchial leiomyoma. The lobectomy was performed due to intractable pneumonia and secondary parenchymal destruction. Postoperative course was uneventful and she was discharged in good health.

• Journal of Animal Science and Technology
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• v.58 no.9
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• pp.34.1-34.9
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• 2016

Background: By-products of pickled radish (BPR) are considered food waste. Approximately 300 g/kg of the total mass of raw materials becomes BPR. Production of pickled radish has grown continuously and is presently about 40,000 metric tons annually in Korea. The objective of the present study was thus to explore the possibility of using BPR as a ruminant feed ingredient. Results: BPR contained a large amount of moisture (more than 800 g/kg) and ash, and comprised mostly sodium (103 g/kg DM) and chloride (142 g/kg DM). On a dry matter basis, the crude protein (CP) and ether extract (EE) levels in BPR were 75 g/kg and 7 g/kg, respectively. The total digestible nutrient (TDN) level was 527 g/kg and the major portion of digestible nutrients was carbohydrate; 88 % organic matter (OM) was carbohydrate and 65 % of total carbohydrate was soluble or degradable fiber. The coefficient of variation (CV) of nutrient contents among production batches ranged from 4.65 to 33.83 %. The smallest CV was observed in OM, and the largest, in EE. The variation in CP content was relatively small (10.11 %). The storage stability test revealed that storage of BPR at $20^{\circ}C$ (room temperature) might not cause spoilage for 4 d, and possibly longer. If BPR is refrigerated, spoilage can be deferred for 21 d and longer. The in vitro ruminal fermentation study showed that substitution of annual ryegrass straw with BPR improved ruminal fermentation, as evidenced by an increase in VFA concentration, DM degradability, and total gas production. Conclusion: The major portion of nutrients in BPR is soluble or degradable fiber that can be easily fermented in the rumen without adverse effects, to provide energy to ruminant animals. Although its high sodium chloride content needs to be considered when formulating a ration, BPR can be successfully used as a feed ingredient in a ruminant diet, particularly if it is one component of a total mixed ration.

• Journal of Educational Research in Mathematics
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• v.22 no.1
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• pp.53-68
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• 2012

This paper investigated the conceptual schemes four children constructed as they related division number sentences to various types of fraction: Proper fractions, improper fractions, and mixed numbers in both contextual and abstract symbolic forms. Methods followed those of the constructivist teaching experiment. Four fifth-grade students from an inner city school in the southwest United States were interviewed eight times: Pre-test clinical interview, six teaching / semi-structured interviews, and a final post-test clinical interview. Results showed that for equal sharing situations, children conceptualized division in two ways: For mixed numbers, division generated a whole number portion of quotient and a fractional portion of quotient. This provided the conceptual basis to see improper fractions as quotients. For proper fractions, they tended to see the quotient as an instance of the multiplicative structure: $a{\times}b=c$ ; $a{\div}c=\frac{1}{b}$ ; $b{\div}c=\frac{1}{a}$. Results suggest that first, facility in recall of multiplication and division fact families and understanding the multiplicative structure must be emphasized before learning fraction division. Second, to facilitate understanding of the multiplicative structure children must be fluent in representing division in the form of number sentences for equal sharing word problems. If not, their reliance on long division hampers their use of syntax and their understanding of divisor and dividend and their relation to the concepts of numerator and denominator.