• Journal of the Korean earth science society
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• v.33 no.4
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• pp.360-375
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• 2012

The purpose of this study was to compare 10th grade students' understanding of concepts about the plates' motions depending on the different spatial ability. Based on previous studies and literature reviews, two instruments were selected and used in this study. The Spatial Perception Test developed in Korean Testing Center was applied to measure students' spatial ability. Another instrument for testing students' understandings of plates' motions consists of a total of 10 items. The instruments were distributed to 118 students who were 10th graders in metropolitan city. The results are as follows: First, a correlation coefficient between conceptual understanding of plates' motions and spatial ability was r=0.439 (p<.01). It indicates that conceptual plates' motions and spatial ability have a moderate relationship. The students were divided into two groups (high and low) by spatial ability. The independent t-test was performed and reveals that the statistically significant difference between high and low groups. On the other hand, the 6 students (3 higher spatial ability students and 3 lowers) were selected and interviewed individually to find the differences in their understanding of the concept of plates' motions. The findings from interviews indicate that most students recognized about concepts of trench and ocean ridge, a rise and drop of the mantle, and divergent and convergent boundaries. However, students had misconceptions about section of trench and ocean ridge. In addition, the students who had higher spatial ability knew the more proper concepts about the creation and extinction of plate, crustal movements, and bottom of the ocean extension, whereas the students who had the lower spatial ability had misconceptions.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.19-30
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• 2000

LaF, KzFS1, LBO glass were manufactured successfully by using platinum crucible in LaF and using clay crucible in the KzFS1 and LBO. There was optically transparent and the refractive indexes were measured by minum deviation method of prism. LaF, KzFS1, LBO show that the refrective indexes are $n_d$ = 1.770 in LaF, $n_d$ = 1.603 in KzFS1, $n_d$ = 1.560 in LBO. The transmittance were obtained that LaF has 85%, and KzFS1 has 83% and LBO has 89% in visible range. These glasses have no any absorption spectrum under visible range. Therefore it has no any color.

• Journal of the Korean Vacuum Society
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• v.20 no.5
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• pp.356-360
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• 2011

Indium oxide ($In_2O_3$) single layer and $In_2O_3$/copper (Cu) bi-layer films were prepared on glass substrates by RF and DC magnetron sputtering without intentional substrate heating. In order to determine the effect of the Cu bottom layer on the optical, electrical and structural properties of $In_2O_3$ films, 3-nm-thick Cu film was deposited on the glass substrate prior to deposition of the $In_2O_3$ films. As-deposited $In_2O_3$ films had an optical transmittance of 79% in the visible wavelength region and a sheet resistance of 2,300 ${\Omega}/{\square}$, while the $In_2O_3$/Cu film had optical and electrical properties that were influenced by the Cu bottom layer. $In_2O_3$/Cu films had a lower sheet resistance of 110 ${\Omega}/{\square}$ and an optical transmittance of 71%. Based on the figure of merit, it can be concluded that the Cu bottom layer effectively increases the performance of $In_2O_3$ films for use as transparent conducting oxides in flexible display applications.

• Journal of KIISE:Software and Applications
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• v.36 no.5
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• pp.353-360
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• 2009

Software, once developed, has a long life and evolves through numerous additions and modifications because of the faults, the changes in user requirements, the changes in environments, and so forth. With the evolution of the software, assuring the quality of the software is getting more difficult because of numerous versions of the software. Meanwhile, regression testing has been used to support the software testing activities and assure acquiring appropriate quality through several versions of software. Regression testing, however, is too expensive because it requires lots of test cases executions and the number of test cases increases sharply as the software evolves. For this reason, several techniques are suggested to help conducting regression testing then test case prioritization technique is understood the most effective and efficient technique to support regression testing. In this paper, we propose an approach, Historical Value-Based Approach, which is based on the use of historical information to estimate the current cost and fault severity for cost-cognizant test case prioritization. As a result of the proposed approach, software testers who perform regression testing prioritize their test cases more effectively so that the test effectiveness of them can be improved in terms of APFDc.

• Progress in Medical Physics
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• v.26 no.1
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• pp.18-27
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• 2015

Since a Compton camera has high detection sensitivity due to electronic collimation and a good energy resolution, it is a potential imaging system for nuclear medicine. In this study, we investigated the feasibility of a Compton camera for multi-tracer imaging and proposed a rotating Compton camera to satisfy Orlov's condition for 3D imaging. Two software phantoms of 140 and 511 keV radiation sources were used for Monte-Carlo simulation and then the simulation data were reconstructed by listmode ordered subset expectation maximization to evaluate the capability of multi-tracer imaging in a Compton camera. And the Compton camera rotating around the object was proposed and tested with different rotation angle steps for improving the limited coverage of the fixed conventional Compton camera over the field-of-view in terms of histogram of angles in spherical coordinates. The simulation data showed the separate 140 and 511 keV images from simultaneous multi-tracer detection in both 2D and 3D imaging and the number of valid projection lines on the conical surfaces was inversely proportional to the decrease of rotation angle. Considering computation load and proper number of projection lines on the conical surface, the rotation angle of 30 degree was sufficient for 3D imaging of the Compton camera in terms of 26 min of computation time and 5 million of detected event number and the increased detection time can be solved with multiple Compton camera system. The Compton camera proposed in this study can be effective system for multi-tracer imaging and is a potential system for development of various disease diagnosis and therapy approaches.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.16 no.1
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• pp.27-35
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• 1980

The purpose of the present study is to find the light intensity which induces maximum gathering rate and to observe the variation of the gathering rate both in' daytime and at night by using two species of commercial fishes: rock bream, Oplegnathus fasciatus(Temminet et Schlegel) and glass-puffer,\ulcorner Fugu.niphobles (Jordan \ulcorneret. Snyder). An experimental tank($360L{\times}50W{\times}55H cm$) was set up in a dark room. An illumination system was attached to one end of the tank to control horizontal light intensity. Six artificial light sources were prepared by combination of two light bulbs (5W, 150W) and seven filters. During the. experiment water depth was maintained 50 em level in the tank. The tank was marked into six longitudinal sections each, being 60 cm long to observe the distribution of fish. The fish were acclimatized in dark condition for 40 minutes prior to the main experiment. Upon turning on the light, the number of fish in each section was counted40 times every 30 seconds, and the gathering rates were obtain from th~ average number of. fish' in each section. The light intensity inducing maximum gathering rate is as follows: rock bream: 162.0 lux (104,3--238, 1 lux) (day), 162.0 lux (104.3--238.1 lux) (night). grass puffer: 16.6 lux (10.6--24.5 lux) (day), 1. 9 lux (1. 2-2. 9 lUX) (night). Trend .of the gathering rate in illumination time revealed different results in two fish species. Gathering rate of rock bream showed the increasing trend fluctuately with the lapse of ' illumination time. However, that of grass puffer showed the increasing trend gradually at the early period of the illumination time and the uniform trend at the latter period with little distictive fluctuation.

• Food Science and Preservation
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• v.19 no.2
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• pp.257-262
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• 2012

pasting characteristics. Their water contents, water holding capacities, solubilities, swelling power, amylose contents, damaged starches, particle sizes and pasting characteristics were measured. The water content and water holding capacities of various types of rice flours collected in the market were 7.64-14.97% and 95.22-232.94%, respectively. Their solubilities and swelling power were 1.97-37.40% and 1.33-5.76, respectively. Various types of rice flour had 32.11-305.67 ${\mu}m$ particle sizes. Among the various types of rice flour collected in the market, the lowest starch damaged content was 3.17%. The peak viscosities of the samples were 17.74-295.95 RVA. Among the rice flours that were collected in the market, the lowest pasting temperature was $69.72^{\circ}C$. As a result, it was shown that rice flour types with high starch damage contents tend to have higher expressed water holding capacities. Moreover, the samples with lower particle sizes tended to have final viscosities, and pasting temperatures.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.3
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• pp.353-360
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• 2008

This study evaluated the quality characteristics of dried noodles made of wheat flour supplemented with different concentrations of skate powder. Cooking quality, mechanical texture properties, gelatinization temperature and viscosity were measured, after which sensory evaluation was performed with prepared noodles. Water binding capacity, solubility and swelling power of the composite skate powder and wheat flours were higher than those of pure wheat flour. Gelatinization temperature of the composite skate powder and wheat flours increased, while initial, interim, and maximum-viscosity at $95^{\circ}C$, decreased, with increasing skate powder content. In relation to color values, increasing skate flour content led to decrease in L and b values and increase in a value. For the textural characteristics, the addition of skate powder increased hardness, springiness, chewiness and adhesiveness. Overall, noodles made with 3% skate powder were preferred compared to other samples.

• Journal of the Korea Computer Graphics Society
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• v.21 no.1
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• pp.1-11
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• 2015

Researchers have developed virtual reality environments to provide audience with more visually immersive experiences than previously possible. One of the most popular solutions to build the immersive VR space is a multi-projection technique. However, utilization of multiple projectors requires large spaces, expensive cost, and accurate geometry calibration among projectors. This paper presents a novel omnidirectional projection system with a single projector and a single spherical mirror.We newly designed the simple and intuitive calibration system to define the shape of environment and the relative position of mirror/projector. For successful image projection, our optimized omnidirectional image generation step solves image distortion produced by the spherical mirror and a calibration problem produced by unknown parameters such as the shape of environment and the relative position between the mirror and the projector. Additionally, the focus correction is performed to improve the quality of the projection. The experiment results show that our method can generate the optimized image given a normal panoramic image for omnidirectional projection in a rectangular space.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.5
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• pp.356-360
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• 2000

This study was carried out to assess the neutralization ability of $NH_4{^+}$ and $Ca^{2+}$ on the acidity of rainwater in Korea. The rainwater was collected in Ansung area for six months from May to October in 1993, 1994, 1995, 1997, and 1998, respectively. Rainwater were analyzed for chemical composition and their theoretical pH values were calculated. As for the results, the distribution rates of rain at the pH 5.0~5.6 range were high. The equivalent ratio of $SO_4{^2-}/NO_3{^-}$ was decreased since 1994. Theoretical acidity which was calculated by-$log([H^+]+[NH_4{^+}]+[Ca^{2+}])$ was 5.0~12.6 times higher than measured acidity in Ansung area each monitoring year. The monthly difference between measured pH and theoretical pH was lower in July and August than any other month. $NH_4{^+}$ contributed more to the neutralization of rainwater acidity than $Ca^{2+}$. And the neutralization ratio of rainwater acidity by these two ions decreased during the years from 91.8% in 1993 to 88.7% in 1998.