• Research in Mathematical Education
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• v.18 no.4
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• pp.237-256
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• 2014

This paper reports findings from a written assessment which was designed to investigate Chinese primary school students' understanding of the equal sign and equation structure. The investigation included a sample of 110 Grade 3, 112 Grade 4, and 110 Grade 5 students from four schools in China. Significant differences were identified among the three grades and no gender differences were found. The majority of Grades 3 and 4 students were found to view the equal sign as a place indicator meaning "write the answer here" or "do something like computation", that is, holding an operational view of the equal sign. A part of Grade 5 students were found to be able to interpret the equal sign as meaning "the same as", that is, holding a relational view of the equal sign. In addition, even though it was difficult for Grade 3 students to recognize the underlying structure in arithmetic equation, quite a number of Grades 4 and 5 students were able to recognize the underlying structure on some tasks. Findings in this study suggest that Chinese primary school students demonstrate a relational understanding of the equal sign and a strong structural sense of equations in an earlier grade. Moreover, what found in the study support the argument that students' understanding of the equal sign is influenced by the context in which the equal sign is presented.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.2
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• pp.105-113
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• 2019

The objective of this study was to investigate Alaska pollock Theragra chalcogramma roe grade distribution among blocks and its nutritional components by grade. M grade roe was predominantly distributed in blocks labeled as L and M (52.1 and 82.8%, respectively), and S grade roe was mainly found in blocks labeled as S (98.6%). Products labeled as containing KB and KC grade roe contained 77.1 and 65.5% normal roe, respectively. Among the five roe grades (L, M, S, G, and Off), total amino acid content was higher in normal roe than in abnormal roe. The major amino acids found in normal roe were leucine, aspartic acid, and glutamic acid, whereas G and Off grade roe contained leucine and glutamic acid, but not aspartic acid. The calcium, phosphorus, potassium, and iron contents of the five roe grades were within the ranges 13.0-20.0, 314.4-392.0, 124.1-157.7, and 1.7-2.2 mg/100 g, respectively. The five roe grades contained total fatty acid contents of 765-1,252 mg/100 g, with no significant differences among grades. The major fatty acids were 16:0, 18:1n-9, 20:5n-3, and 22:6n-3.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.4 no.4
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• pp.141-145
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• 2023

This study surveyed the changes in the proportion of Ecological and Natural Map (ENM) grades in Korea, the distribution ratio of ENM 1st-grade areas by region, and the current status of regional public appeals for the five-year period from 2017 to 2021. The nationwide changes in ENM grades revealed an increase in 1st-grade, 3rd-grade, and separately managed areas but a decrease in the ratio of 2nd-grade areas. Nationwide, Gangwon had the highest distribution ratio of 1st-grade areas, at 46.77%, while Gwangju had the lowest, at 0.05%. In the five-year study period, 383 appeals concerning ENM grades were received and processed. Gangwon had the greatest number of appeals, with 96, while Sejong had the fewest, with 1. A significant correlation was observed between the distribution ratio of 1st-grade areas and public appeals.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.20 no.4
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• pp.252-258
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• 2017

Purpose: Blunt trauma of pancreas in children is uncommon and its management varies from observational to early operative intervention. We analysed the feasibility and outcome of non-operative management in all grades of paediatric pancreatic injuries. Methods: A total of 15 patients of pancreatic trauma seen in a Paediatric Surgery Unit were retrospectively analyzed. Results: Age of the patients ranged from 3-11 years (mean, 7.7 years). The mode of injury was local trauma in 9 children. Only 3 patients had associated injuries and all were haemodynamically stable. Serum amylase levels were raised in 12 patients at admission which ranged from 400-1,000 IU. Computed tomography scan made a correct diagnosis in 14 patients. Grades of the injury varied from grade I-V (1, 3, 6, 4, 1 patients respectively). Fourteen patients were managed conservatively. One patient underwent laparotomy for suspected superior mesenteric hematoma. The average duration of enteral feeds was 3.7 days and of hospital stay was 9.4 days. Six patients formed pancreatic pseudocysts; two were managed conservatively while the other four underwent cystogastrostomy. The patients were followed up for a period of 1-12 years. All remained asymptomatic and none had exocrine or endocrine deficiencies. Conclusion: Non-operative treatment for isolated blunt trauma of pancreas in children may be safely followed for all the grades of injury; if associated injuries requiring surgical intervention are ruled out with a good quality imaging and the patients are hemodynamically stable. It did not increase the hospital stay and morbidity and avoided operative intervention on acutely injured pancreas.

• Journal of The Korean Association of Information Education
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• v.19 no.1
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• pp.45-56
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• 2015

This article examines the effects of a long term robot based instruction on the creativity of elementary students. To explain these effects, we conducted similar creativity test twice to 237 students of schools which had been designated as a robot based instruction model from 2011 to 2012. From these test results, the following three conclusions may be drawn: (1) The creativity of students who had participated in long term robot based instruction increased significantly, especially after the first test. (2) The fluency and originality as two of the sub-creativity factors are also accelerated significantly, especially after the first test. (3) The creativity of male and female students are all improved significantly but the test period factor and the interaction factor between male and female are not significant. (4) All elementary students of the lower grades(1st and 2nd grades), middle grades(3rd and 4th grades) and higher grades(5th and 6th grades) increased significantly but the test period factor and the interaction factor between the grades were not significant. On the other hand, the creativity improvement between lower-middle grades and higher grades is significant.

• Journal of Korean Neurosurgical Society
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• v.59 no.6
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• pp.577-583
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• 2016

Objective : The inter-rater reliability of the modified Knosp's classification was measured before the analysis. The clinical validity of the parasellar extension grading system was evaluated by investigating the extents of resection and complication rates among the grades in the endoscopic endonasal transsphenoidal surgery (EETS) for pituitary adenomas. Methods : From November 2008 to August 2015, of the 286 patients who underwent EETS by the senior author, 208 were pituitary adenoma cases (146 non-functioning pituitary adenomas, 10 adrenocorticotropic hormone-secreting adenomas, 31 growth hormone-secreting adenomas, 17 prolactin-secreting adenomas, and 4 thyroid-stimulating hormone-secreting adenomas; 23 microadenomas, 174 macroadenomas, and 11 giant adenomas). Two neurosurgeons and a neuroradiologist independently measured the degree of parasellar extension on the preoperative sellar MRI according to the modified Knosp's classification. Inter-rater reliability was statistically assessed by measuring the intraclass correlation coefficient. The extents of resection were evaluated by comparison of the pre- and post-operative MR images; the neurovascular complications were assessed by reviewing the patients' medical records. The extent of resection was measured in each parasellar extension grade; thereafter, their statistical differences were calculated. Results : The intraclass correlation coefficient value of reliability across the three raters amounted to 0.862. The gross total removal (GTR) rates achieved in each grade were 70.0, 69.8, 62.9, 21.4, 37.5, and 4.3% in Grades 0, 1, 2, 3A, 3B, and 4, respectively. A significant difference in the extent of resection was observed only between Grades 2 and 3A. In addition, significantly higher complication rates were observed in the groups above Grade 3A. Conclusion : Although the modified Knosp's classification system appears to be complex, its inter-rater reliability proves to be excellent. Regarding the clinical validity of the parasellar extension grading system, Grades 3A, 3B, and 4 have a negative predictive value for the GTR rate, with higher complication rates.

• Korean Journal of Applied Biomechanics
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• v.17 no.1
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• pp.69-79
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• 2007

The purpose of this study was to examine the characteristics of throwing motion in the elementary school students from the developmental point of view. For the purpose of this, total of nine subjects(each of three students in five, third, and first grades) were participated. They were asked to throw the ball as far as they can and the motions were videotaped with the 30frames/sec and 1/500 shutter speed. The successful motions for each subject were selected for three dimensional analysis. The collected data were analyzed using DV express 1.0 and Kwon3D 3.0 softwares. The results obtained from this study were as follows; 1. Total time for the throwing motion of the first grade was longer than that of the fifth and third grades. 2. The resultant displacement and velocity of COM for the fifth and third grades were greater than that of the frist grade. 3. The first grade tended to flex the trunk forward excessively during the throwing motion. 4. The fifth grade tended to place the upper arm close to the sagital plane and move the forearm and hand freely. 5. Looking at the greater variability of the angular velocity of the hand segment, the fifth grade seemed to have faster and more flexible movement of the wrist. 6. There were somewhat differences in the patterns and magnitudes of ground reaction forces among the different grades.

• Journal of Nutrition and Health
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• v.32 no.7
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• pp.802-811
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• 1999

The purposes of this study were to 1) examine the dietary patterns of fatty acids and the fatty acid composition in serum, 2) determine selenium (Se) concentrations, and 3) investigate how serum fatty acid compositon affects serum levels of Se in Korean elementary school children. The subjects consisted of 168 school children(82 boys & 86 girls) belonging to 1st through 6th grades, and their dietary assessment was evaluated. The serum fatty acid composition was analyzed by GLC, and the ICP/MS method was employed to measure serum Se concentration. Total average intake of PUFA, MUFA and SFA were 10.5g, 12.7g, 11.2g respectively. Total average dietary P/M/S ratio was 1.10/1.18/1.0. The average intake of $\omega$3 fatty acids and $\omega$6 fatty acids were 1.33g, 9.19g, respectively. The $\omega$6/$\omega$3ratio was 14.2 which is higher than the recommended range. In serum fatty acid composition, PUFA, MUFA, SFA were 40.6%, 28.1% and 31.6% respectively. The average $\omega$3 fatty acid composition was 3.80%, and the mean value of $\omega$6 series was 36.8%. The M/S ratio of girls was significantly higher than boy's in fatty acids intake and in serum composition. Mean Se concentration of total subjects was 416.7ug/l and it was significantly higher in the lower grades(1st-3rd)than in the upper grades(4th~6th, p<0.05). Although the mean serum Se concentration was negatively correlated with PUFA composition in total boys and girls, it was not significant. Serum Se concentration was negatively correlated with P/S ratio and C24:1 concentration(p<0.05). In addition, serum composition of $\omega$6 PUFA and C24:1 showed negative correlations with serum Se in only lower grades girl(1st~3rd), and further studies are needed to clarify in these phenomena. In conclusion, the mean serum Se concentration was significantly lower in upper grades (4th~6th)than in lower grades(1st~3rd) of elementary school children and was negatively correlated with P/S ratio of serum fatty acids. More detailed studies on relationship between Se and fatty acids are required.

• Journal of Korean Elementary Science Education
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• v.27 no.4
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• pp.399-419
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• 2008

The purpose of this study was to develop performance assessment materials of scientific inquiry skills on 62 scientific activities in elementary science textbook for third and fourth grades. For this study, a total of 318 elementary teachers were sampled and surveys were carried out to examine the status of performance assessment of scientific inquiry skills in school. The classification system of assessment methods by Hart(1994) was also analyzed to create assessment strategy of scientific inquiry skills for elementary school students. Based on the quantitative data analysis, literature study and existing performance assessment materials analysis, performance assessment materials were developed and applied to science classes for third and fourth grades. Teachers and students were interviewed after the classes for asking about merits and improvements and the performance assessment materials were revised.

• Journal of Powder Materials
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• v.3 no.1
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• pp.13-24
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• 1996

Two grades of Permalloy strips, Fe-45Ni(PB) and Fe-78Ni-4Mo-5Cu(PC) were fabricated by powder rolling process from elemental powder mixtures. The roll compacted green strips were sintered, homogenized, cold rolled with or without an intermediate annealing and finally heat treated to measure magnetic properties. For a given thickness reduction, rolling with an intermediate annealing was found more effective to achieve a full densification with no visible micropores and also to obtain better magnetic properties. Increasing the final rolling reduction also produced a marked improvement of the magnetic properties whereas the cooling rate during the final heat treatment has little effect in both grades. Addition of a small amount, 0.4% Mn slightly degraded the properties. As an overall, The PM strips produced via powder rolling yielded the similar soft magnetic properties to the corresponding commercial grades produced via wrought processing.