• Research in Mathematical Education
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• v.18 no.3
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• pp.187-208
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• 2014

This study engages in the features of interaction in elementary school mathematics lessons as reflected in the class discourse. 28 pre-service teachers documented the discourse during observation of their tutor-teachers' lessons. Mapping the interaction patterns was performed by a unique graphic model developed for that purpose and enabled providing a spatial picture of the discourse conducted in the lesson. The research findings present the known discourse pattern "initiation-response-evaluation / feedback" (IRE/F) which is recurrent in all the lessons and the teacher's exclusive control over the class discourse patterns. Hence, the remaining time of the lesson for the pupils' discourse is short and meaningless.

• Korean Journal of Remote Sensing
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• v.16 no.4
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• pp.315-325
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• 2000

Observations were made to validate ocean color algorithms in the Ulleung Basin, East Sea in May 2000. Small scale and meso-scale surveys were conducted for the validation of ocean color products (nLw: normalized water-leaving radiance and chlorophyll concentration). There were discrepancies between SeaWiFS and in situ nLw showing the current aerosol models of standard SeaWiFS processing software are less than adequate (Gordon and Wang, 1994). Applying the standard SeaWiFS in-water algorithm resulted in an overestimation of chlorophyll concentration. This is because that CDOM absorption was higher than the estimated chlorophyll absorption. TSS concentration was also high. Therefore, the study region deviated from Case 1 waters. The source of these materials seems to be the entrainment of coastal water by the Tsushima Warm Current. Study of the bio-optical properties in other season is desirable.

• Cross-Cultural Studies
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• v.20
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• pp.347-370
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• 2010

In the latter part of the $20^{th}$ century, the road in American culture has been identified with independence, mobility, and speed, but in his seminal poem, "Song of the Open Road," Walt Whitman characterized road journeys as simultaneously physical, intellectual, and spiritual, a view embraced by Vincent Van Gogh whose Terrace of a Caf? at Night illustrates in paint what Whitman said in words. Others such as Jack Kerouac in On the Road followed in Whitman's tradition, one taken up even more recently by David Lynch, whose films are best known for a condemnation of American suburban life, but whose Straight Story evokes a profound spirituality as part of the road. This essay explores spirituality in these various texts.

• New Physics: Sae Mulli
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• v.68 no.11
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• pp.1225-1230
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• 2018

Schwinger pair production of electrons and positrons in a strong electric field is a prediction of nonperturbative quantum field theory, in which the out-vacuum is superposed of multi-particle states of the in-vacuum. Solving the Dirac or Klein-Gordon equation in the background field, though a linear wave equation, and finding the pair-production rate is a difficult or nontrivial job. The phase-integral method has recently been introduced to compute the pair production in space-dependent electric fields, and a complex analysis method has been employed to calculate the pair production in time-dependent electric fields. In this paper, we apply the complex analysis method to a Sauter-type electric field and other hyperbolic-type electric fields that vanish in the past and future and show that the Stokes phenomena in pair production occur when the time-dependent frequency for a given momentum has finite simple poles (polons) with pure imaginary residues.

• YAKHAK HOEJI
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• v.7 no.4
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• pp.75-85
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• 1963

Radioactivation analysis is based upon irradiation of nuclei with elementary particles. In many cases the interaction gives rise to radioactive nuclei, which can be detected and identified by the emitted radiation. If we irradiate under identical conditions an unknown quantity of a certain atomic species and a known quantity of the same species, the following relatio will exist between the induced radioactivities and the irradiated masses: $\frac{Activity standard}{activity unknown}$=$\frac{Mass standard}{Mass unknown}$ From this equation the mass of the unknown can be easily calculated. This relatively siple technique (abstract made from the irradiating facility) allows quantitative determination of about 60 elements with a sensibility that most of the time considerably exceeds the sensibility of conventional analysis techniques. General review articles from Gordon and Meinke should be consulted for further detail.

• Journal of Plant Biology
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• v.30 no.1
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• pp.11-20
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• 1987

Phenolic compounds, p-coumaric and p-hydroxybenzoic acids, known as inhibitors for development and growth of many pioneer species on early stage of succession were used for the test fo susceptibility in various herbs collected from abandoned agricultural fields in the vicinity of Amherst(U. S. A.). The percent inhibition was generally greater for p-coumaric acid than for p-hydroxybenzoic acid. Concentrations of 5$\times$10-5 and 5$\times$10-4M generally had no significant effects, but at 5$\times$10-3M was inhibitory to germination and growth of tested species. And the percent inhibition caused by the two phenolics was correlated (r=.843, p<.01). Also the indices of resistance for germination and elongation were significant (r=.695, p<.01) in this study. While Cirsium and Lepidium invading species of early stage of succession were sharply susceptible for toxic activity by phenolic acids.

• Korean Journal of Radiology
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• v.22 no.6
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• pp.970-982
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• 2021

Dual-energy CT (DECT) provides insights into the material properties of tissues and can differentiate between tissues with similar attenuation on conventional single-energy imaging. In the conventional CT scanner, differences in the X-ray attenuation between adjacent structures are dependent on the atomic number of the materials involved, whereas in DECT, the difference in the attenuation is dependent on both the atomic number and electron density. The basic principle of DECT is to obtain two datasets with different X-ray energy levels from the same anatomic region and material decomposition based on attenuation differences at different energy levels. In this article, we discuss the clinical applications of DECT and its potential robust improvements in performance and postprocessing capabilities.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.2
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• pp.62-67
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• 2014

A glomerular filtration rate (GFR) study is a test that uses radioactive materials or tracers (radiopharmaceuticals) and a computer to see how well the kidneys are working. Asan Medical Center analyzed and compared data between kidney depth, acquired from kidney donors' CT image and acquired from Gates method's GFR value that are calculated by Tonnesen equation. This study was able to confirm that kidney depth measured from CT image was higher than the Gates Method's GFR value, which was calculated by Tonnessen equation; the direct relationship among pathologic results is confirmed. Particularly, kidney donor whose kidney was at the pelvic area had direct relationship with other clinical results. During the GFR test, it is necessary to confirm the location of kidney has no change with reference of CT image. If kidney depth is manually corrected using CT image when we measures GFR of deformed or horse-shoe kidney, it would be possible to acquire the compatible value which is equivalent to clinical result. There would be a possible issue of appropriateness that whether the applied GFR using CT image's kidney depth has clinical validity. In case of a pediatric patient, the GFR derived from Tonnesen was quiet underestimated while manual method and Gordon stay in normal range. Which results may be correct among them? There have been many reports about kidney depth, to be an accurate index of GFR in children. As one of the study performers, we should contemplate what the best option for pediatric patients would be.

• Journal of the Korean Wood Science and Technology
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• v.4 no.1
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• pp.15-20
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• 1976

This is the abstract of the study on the check by static driving nail in Pinus koraiensis Sieb. et Zucc., Abies holophylla Maximowicz, and Larix leptolepis Gordon Pinet. which are commercial woods and main forestation species in Korea. The static driving resistance of nail is decresed straightly and the surface and back check's length and width were increased in proportion to increase of the moisture content, but the surface check length and width were over twice as large as the back check, also the check were happened in order of Pinus koraiensis Sieb. et Zucc., Abies holophylla Maximowicz., and Larix leptolepis Gordon Pinet. As the driving nail speed was increased, surface check length and width were increased and the back check was over twice as large as the surface check.

• The Korean Nurse
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• v.30 no.5
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• pp.61-74
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• 1991

The purpose of this study was to determine the values of freshman nursing students and to determine changes each year over the four years of the study and to provide base data for curriculum and student guidance. The sample consisted of the freshman students who entered college of nursing from 1988 through 1991. The total sample was 358 students and data were collected during March of each of the four years. The data were analyzed using t-test, ANOVA and Pearson Correlation to examine the relationship between the subcategories of values and Duncan multiple range test to examine the relationship between the scores for each year and the demographic data. The instrument used in this study was the Survey of Personal Values and Interpersonal Values modified by UngYun Hwang and KyungHae Lee in accordance with L.V. Gordon's instrument. This tool provides scores on practical mindedness, achievement, variety, decisiveness, orderliness, goal orientation, support, conformity, recognition, independence, benevolence and leadership. The results of the study were as follows: 1. The nursing freshman students surveyed had the highest score for goal orientation (21.44) and the lowest for variety (17.13) on the SPY (Survey of Personal Values) and the highest score for benevolence (21.19) and lowest for leadership (17.00) on the SIV (Survey of Interpersonal Values]. In accordance with the standarized scores for Gordon's Spy for other' woman college students, the students in the study were between the 78% ile - 97 % ile and were in the 72 % ile 97%ile for the SlV. 2. When t-test scores were compared, no significant variation was found between the years for each of the values (P< .05). 3. A significant variation was found on variety, between 1989 and 1991 (P< .05), and between 1988 and 1991. The highest score was in 1991 in both comparisons. Supporting was also higher for 1991 than for 1988 (P< .05). 4. Religion and occupation of father did not show any significant differences (P< .05). There was no significant difference in values according to the student's religion or the occupation of their father. Students born in the metropolitan area had a higher score on variety than those from the rural area and vice versa on regulartiy (P< .05). The results of this study show that there is a higher score on values for'! University freshman than shown for freshmen in other universities reported from other research, To keep or promote values, it is very important that there be a systematic strategy of education and special educational programs.