• Journal of The Korean Association For Science Education
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• 제30권4호
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• pp.452-471
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• 2010

As the Korean College scholastic Ability Test (CSAT) has been implemented for 17 years since 1994, it is becoming more and more difficult to make new items that haven't been previously used to measure students' thinking ability. Therefore, it is necessary to keep conducting research on making new test items that can measure students' scholastic ability reliably. For this reason, multiple choice items on the Japanese university entrance exam, which is a Japanese National Center Test for University Admissions (NCTUA) equivalent of CSAT, were analyzed in order to draw implications for CSAT item development. In this study, we analyzed the Japanese NCTUA administered in January 2009 to investigate the structure of its science test. We also analyzed the NCTUA items by the domains of contents and behaviors, and tried to predict item difficulty from the perspective of Korean applicants. Major findings are as follows: Most NCTUA items measure understanding knowledge or low level thinking ability. Also the alloted time for each item is longer than CSAT. The number of test items, and the number of choice and alloted points for each item are diverse, unlike CSAT. The number of items using real-life materials are much more, but the items are not rigorous in sentence expression compared to CSAT. And the difference of difficulty level among science tests were larger with reference to CSAT. Also science score is required for most applicants regardless whether they are taking liberal arts or going onto the science track.

• Economic and Environmental Geology
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• 제44권2호
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• pp.109-122
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• 2011

The major Mo deposits in South Korea were formed during the Jurassic Daebo orogeny, the Late Cretaceous and the Tertiary post-orogenic igneous activities, and are characterized by a variety of genetic types such as pegmatite, greisen, skarn, porphyry and vein types. The Jangsu mine is a pegmatite-style deposit which is genetically related to the Jurassic ilmenite-series two-mica granite with the Mo mineralization age of $159.6{\pm}4.5$ Ma. The Geumseong mine occurs as a skarn/porphyry-style deposit associated with highly fractionated granite. Its age of Mo mineralization within aplitic cupola is about 96.5~l07.5 Ma. The Yeonil mine is a porphyry-style deposit, and the Geumeum mine is a veinlet-style deposit along the fracture zone with their mineralization ages of $58.4{\pm}1.6$ and $54.4{\pm}1.2$ Ma, respectively. The contrasts in the style of Mo mineralization in Korea reflect the different environment of the related magmatism. The Jurassic mineralization, being related to deep-seated granitoids, occurs as a pegmatite-style deposit, whereas the Cretaceous one, being related to subvolcanic granitoids, occurs as skarn/porphyry/vein-type ore deposits. The Tertiary Mo mineralization has a close relationship with the igneous activities associated with the Tertiary basin formation along the east coast, Korean peninsular.

• Korean Journal of Remote Sensing
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• 제36권3호
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• pp.487-501
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• 2020

As a viable option for retrieval of LST (Land Surface Temperature), this paper presents a DNN (Deep Neural Network) based approach using 148 Landsat 8 images for South Korea. Because the brightness temperature and emissivity for the band 10 (approx. 11-㎛ wavelength) of Landsat 8 are derived by combining physics-based equations and empirical coefficients, they include uncertainties according to regional conditions such as meteorology, climate, topography, and vegetation. To overcome this, we used several land surface variables such as NDVI (Normalized Difference Vegetation Index), land cover types, topographic factors (elevation, slope, aspect, and ruggedness) as well as the T₀ calculated from the brightness temperature and emissivity. We optimized four seasonal DNN models using the input variables and in-situ observations from ASOS (Automated Synoptic Observing System) to retrieve the LST, which is an advanced approach when compared with the existing method of the bias correction using a linear equation. The validation statistics from the 1,728 matchups during 2013-2019 showed a good performance of the CC=0.910~0.917 and RMSE=3.245~3.365℃, especially for spring and fall. Also, our DNN models produced a stable LST for all types of land cover. A future work using big data from Landsat 5/7/8 with additional land surface variables will be necessary for a more reliable retrieval of LST for high-resolution satellite images.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제15권12호
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• pp.7134-7147
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• 2014

This study examined one of the contemporary issues that may be interesting to academics and practitioners regarding the driving force of the growth rate for the firms belonging to the chaebols in the Korean capital markets. With respect to the empirical results obtained from two hypothesis tests, the first hypothesis was to identify any financial determinants on the growth rate by applying both dynamic panel data and static panel data models. The debt ratios relevant to the book- and market-value showed their positive relationships with the DV of GROWTH1, along with other significant IDVs such as one-period lagged DV of GROWTH_1, SIZE1 and FOS with statistical significance. Second, by employing conditional quantile regression (CQR) analysis, the control variables, such as ROA, SMARKET, time dummy variable of F2010 and F2011, and the industry dummies of IND3 and IND10, provided evidence of their significant influences on DV of GROWTH1.

• Journal of the Korean earth science society
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• 제28권1호
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• pp.87-104
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• 2007

As part of the SPVS (Short-Period Variability Survey) which is a wide-field $(90'{\times}60')$ photometric monitering program at Bohyunsan Optical Astronomy (BOAO), we performed V band time-series CCD photometric observations ofthe young open cluster NGC 129 for 11 nights between October 12, 2004 and November 3, 2005 using the 155mm refractor equipped with $3K{\times}2K$ CCD camera. From the observation we obtained 2400 V band CCD frames and color-magnitude diagram of the cluster. To transform instrumental magnitude to standard magnitude, we applied ensemble normalization technique to all observed time-series data. After the photometric reduction process, we examined variations of 9537 stars. As a result, sixty six of the new variable stars were discovered. To determine the periods of the sevariables, we used DFT(Discrete Fourier Transform) and phase-matching technique. According to light curve shape, period, amplitude and the position on a C-M diagram, we classified these variables as 9 SPB type, 9 ${\delta}$ Scuti type, 29 eclipsing, 17 long term variables. However, two of them were not classified. From this study, we learned that small telescopes could be a very useful tool to observe variable stars in the open cluster in survey program.

• Journal of Global Scholars of Marketing Science
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• 제16권1호
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• pp.73-91
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• 2006

This study was conducted for market segmentation of cruise tourist according to launching the "T" in Busan. Benefit segmentation was used to identify attributes of cruise services; importance of ship's physical appearance and importance of service and activities. 24 attributes were distilled to 5 factors: 'Facility & Service', 'Atmospherics of cruise ship', 'Escape', 'Choice', 'Safety'. A K-means cluster analysis identified three clustered segments for five importance factors in which high loyalty customers were found to be the most important segment. Based on the findings, three distinct groups were formed: 'Moderators', 'High Loyalty', 'Spurious'. The most important factors by high loyalty groups were identified 'Safety', 'Facility & Service', 'Atmospherics of cruise ship', 'Choice', 'Escape' in order. The results of the study showed statistically significant differences among the three groups in terms of demographic and behavioral variables. Especially, the target market should be considered by 'High Loyalty' group and 'Moderators' group in order. Positioning strategies and marketing mix strategies for effectively targeting the segments were discussed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• 제26권3호
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• pp.254-264
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• 1990

Using the meteorological data, surface weather map, and oceanographic data for 5 years(1984-1988). I investigated the characteristics of the fog occurrence and the role of the inshore in Pusan about the fog occurrence. And the meteorological data and sea surface temperature(SST), which were observed in July, 1989 in Suyoung Bay, were compared with those in Pusan. The fogs in Pusan concentrate in May, June and July. And at fog occurrence time the principal wind directions are Southwest(SW) winds, which easily supply with water vapor, and a series of Northeast(NE) wind. At the fog days pressure patterns are pattern 7 in spring time (March, April, and May) and pattern 10 and pattern 13 in summer time (June, July, and August). Also the advection fog(sea fog) is closely related with the relationship between warm and cold advection in 850~700mb and cold and warm SST rather than the increase of the instability of atmosphere in 850~500mb. The fogs in Taegu, which is the inland region, mainly occur at dawn in fall time due to the strong night radiation fog. On the other hand in Pusan the coastal region, the fogs occur from late spring time to summer time (May, June, and July). Because there is the abundant supply of the water vapor from the ocean owing to a series of South(S) wind at this time. Then the atmosphere, which has high relative humidity, reaches easily the supersaturation by the radiation cooling. In Suyoung Bay and Pusan the meteorological observation data, SST and fog days are almost similar. And I think that the mechanism of the fog occurrence nearly accords with both regions.

• Journal of Wetlands Research
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• 제22권2호
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• pp.130-138
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• 2020

As of 2017, the sewerage penetration rate of Seoul and metropolitan cities is more than 90%, and the number of domestic sewage treatment plants increased by 25% from 3,064 in 2010 to 4,072 in 2017. Among them, sewage treatment plant operated by SBR system is 585, which is 17% higher than 2010. In order to improve the water quality of the water source and improve the operation of the small sewage facilities, the improvement of the process was studied by applying the modelling to 49 facilities of the sewage treatment plant in Andong Imha dam area with more than 500㎥/day 3 places and 46 places less than 500㎥/day. As an improvement plan for modelling, candidate data were derived by reviewing operation data for 5 years. 49 facilities are operated by 12 types of operating processes. Among them, 1 place mort than 500㎥/day with SBR method and 9 facilities with less than 500㎥/day were selected by dividing 46 sites into 3 types. As a result of applying modelling to more than 500㎥/day, it was possible to improve the quality of discharged water through SRT control and it was found that applying model to sites of small scale treatment plants can improve the removal efficiency of TP by up to 14.4%. As a result, the data of this study could be used to improve and improve the operation of sewage treatment plants and RCSTP(Rural Community Sewage Tratment Plant).

• Communications of Mathematical Education
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• 제29권4호
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• pp.745-762
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• 2015

In order to examine the change in mathematical inclinationn of middle level engineering college freshmen, we analyse the change of mathematical inclination between 2011 year and 2015 year freshmen who took college scholastic ability test which are based on the national mathematics curriculum 7th and 7th revision, respectively. In medium-sized D university, 2011 year and 2015 year engineering freshmen were taken the test for mathematical inclination, the survey for mathematical background and the recognition of college mathematics and basic mathematical ability test. The outcomes of this survey are followings: Firstly, between 2011 year and 2015 year freshmen, the mean of confidence and flexibility are same, but the 2015's mean of willpower, curiosity, value and esthetics are greater than 2011's. Secondly, in the mean of flexibility, willpower and curiosity, natural science's mean is greater than humanity's. Thirdly, the mean of mathematical inclination's factors is depend on college mathematics goal. Fourthly, there is little correlation between mathematical basic ability and mathematical inclination. Moreover for 2011 year and 2015 year freshmen, the mean of mathematical inclination's factors except value is proportional to mathematical basic ability. For the success of college mathematics in engineering college, this study suggests that high school mathematics curriculum and college scholastic ability test must contain calculus. We also suggest that college mathematics class must be focused on mathematical inclination improvement.

• Journal of the Korean Chemical Society
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• 제43권4호
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• pp.461-468
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• 1999

Acetolactate synthase (ALS) catalyzes the first common reaction in the biosynthesis of branched-chain amino acids, valine, leucine, and isoleucine. ALS is the common target of several classes of structurally diverse herbicides, the triazolopyrimidines, the imidazolinones, the sulfonylureas, and pyrimidyl-oxy-benzoates. We examined ihibitory activities of newly synthesized triazolopyrimidine sulfonamide derivatives using partially purified ALS from barley. $IC_{50}$ values for the active derivatives are 0.5nM∼8$\mu$M. Among them TP1 and TP2 are the most potent ALS inhibitors with $IC_{50}$ values of 0.5nM and 1.6nM, respectively. These inhibitors are more potent in the inhibition of barley ALS than commercial herbicides, Metosulam ($IC_{50}$;3.6 nM), Flumetsulam ($IC_{50}$;126 nM), and Cadre ($IC_{50};4 {\mu}M$). The progress curves for inhibition of ALS by TP2 showed that the amount of inhibition increases with time. The inhibition of ALS by TP2 was mixed-type inhibition with respect to pyruvate. Dual inhibition analyses of TP2 versus an imidazolinone, Cadre, and Leu showed parallel and intercepting kinetic pattern, respectively. The results suggest that TP2 binds to ALS competively with Cadre but not with Leu. Chemical modification of cysteinly residues in ALS decreased the sensitivity of ALS to Leu, while the modification did not affect the sensitivity of ALS to TP2 and Cadre.