• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.97-99
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• 1998

This paper presents a numerical study of the behavior of the transformer winding, when stressed by the standard impulse voltage. The mathematical model of the transformer takes several points into the account. Capacitance of not adjacent winding as well as adjacent winding, eddy current loss caused by self and mutual inductance given as the functions of frequency. Not like the previous approach where calculation of capacitance is performed, in average sense. In this paper, capacitance of both adjacent and not adjacent winding is calculated using the numerical approach(B.E.M.), so they can get the more accurate value of capacitance. Because of frequency dependency of inductance, numerical-laplace-transform technique is required. Finally, to validate this approach, a simple test winding is simulated.

• Korean Journal of Food Science and Technology
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• v.10 no.3
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• pp.344-349
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• 1978

Rheological properties of Yangeng were studied by compression test with rheometer. The viscoel-asticity changed at strain 0.22 at the tested rate of strain. The optimum temperature and solid content for structure formation were $40^{\circ}C$ and Brix 70 respectively. The time-temperature dependency of rheological properties were empirically formulated.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.5
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• pp.61-68
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• 2021

Movable weirs with multi-stage control are necessary in many Korean rivers to actively control the water storage level. A mesh dependency test was performed to determine the appropriate number of meshes for structural analysis of movable weirs. The standing angles of movable weirs were set to 60°, 45°, 30°, and 15° for stress analysis. The standing angle of 0° was excluded from the analysis because it was unloaded. Changes in the standing angle led to changes in the water depth, maximum pressure, maximum strain, and maximum stress. The maximum average stress and the structural safety of the multi-stage control movable weir were computed and tested using the Ansys FEA software package.

• Ocean and Polar Research
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• v.44 no.2
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• pp.179-190
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• 2022

Data missing in optical satellite images caused by natural variations have been a crucial barrier in observing the status of marine surfaces. Although there have been many attempts to fill the gaps of non-observation, there is little research to analyze the ratio of missing grids to overall sea grids and their seasonal patterns. This report introduces the method of quantifying the distribution of missing points and then shows how the missing points have spatial correlation and seasonal trends. Both temporal and spatial integration methods are compared to assess the effectiveness of reducing missing data. The temporal integration shows more outstanding performance than the spatial integration. Moran's I and K-function with statistical hypothesis testing show that missing grids are clustered and there is a non-random distribution from daily integration. The result of the seasonality test for Moran's I through a periodogram shows dependency on full-year, half-year, and quarter-year periods respectively. These analysis results can be used to deduce appropriate integration periods with permissible estimation errors.

• English Language & Literature Teaching
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• v.15 no.2
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• pp.261-280
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• 2009

This study focuses on providing the pedagogical implications of stress in English pronunciation teaching since stress is one the most important characteristic factors in English pronunciation (Bolinger, 1976; Brown, 1994; Celce-Murcia, Brinton & Goodwin, 1996; Kreidler, 1989). The author investigated stress production regarding in terms of duration, pitch, and intensity by a group of native speakers of English and a group of low-proficiency South Kyungsang Korean college students for their pre-test. For both of the pre- and post-test, the same stimuli, which consisted of a one-syllable word, two two-syllable words, three three-syllable words, and three four-syllable words, were used along with the various sentence positions: isolation, initial, medial, and final. Soft ware programs, ALVIN and Praat, were used to record and analyze the data. Since Celce-Murcia et al. (1996), Klatt (1975), and Ladefoged (2001) treat duration of the stressed syllable more significantly than other factors, pitch and intensity, with respect to the listener's point of view, the author developed a special method of teaching English stress using a traditional Korean drum to emphasize duration. In addition, the results from the native speakers' production showed that their main strategy to realize stress was through lengthening stressed syllables. After six weeks of stress instruction using the drum, the production of the native speakers and the SK Korean participants from the pre- and post-test were compared. The results from the post-test indicated that the participants showed great improvement not only in duration but also in pitch after the stress instruction. Pitch improvement was unexpected but well-explained by the statement that long vowels receive accent in loan word adaptation in North Kyungsang Korean. The results also showed that the Korean participants' pitch values became more even in their duration values for each syllable as the structure of the word or the sentence became more complex, due to their dependency upon their L1.

• Journal of the Korea Society of Computer and Information
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• v.15 no.12
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• pp.189-196
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• 2010

Domestic software test maturity level is the most Level 2 below based on TMMi. The first condition of enhancement of test maturity is that know exactly what the current maturity. There is no Level 1 definition in TMMi, but even the same level of maturity level of an organization, there are clear differences. In this study, grasp a maturity level of Level 1 organization, while less effort to improve in Level organization, the ways to achieve Level 2 is presented. Sub practices with dependencies in Level 2 is grouped with the corresponding process areas and define a Level 1 newly at 3 phases. If sub practices with dependencies are tied and improve a process, it will produce the effect which attains the practices all at once. Verify the adequacy of three phases, as a result, an organization clearly identify Test Maturity Level 1, we know that the organization can set specific improvement goals and direction.

• Journal of the Korea Concrete Institute
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• v.24 no.6
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• pp.715-726
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• 2012

Since strength and diffusion coefficient of concrete, representative concrete properties that in change with age, the time effect must be considered in the analysis of chloride penetration. In this study, an evaluation of correlation between accelerated diffusion coefficient, apparent diffusion coefficient, and compressive strength in high performance concrete with various mineral admixtures such as ground granulated blast furnace slag, fly ash, and silica fume was performed. For this work, thirty mix proportions were prepared. Accelerated diffusion coefficients at the age of 28, 91, 180, and 270 days were evaluated. For apparent diffusion coefficient, submerging test for 6 months was performed. For evaluation of compressive strength with ages, the compressive strength test was carried out at an age of 7, 28, 91, 180 days. The results of accelerated diffusion coefficient, apparent diffusion coefficient, and strength were compared, and the correlation was analyzed considering time dependency. From this study, linear relationship between accelerated diffusion and apparent diffusion coefficient were obtained regardless of concrete age. The linear relations were also observed in strength-accelerated diffusion coefficient and strength-apparent diffusion coefficient regardless of concrete age.

• 한국노년학
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• v.36 no.4
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• pp.1177-1189
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• 2016

The dependency is a problem in the aged. The purpose of this study was to investigate depression, urinary incontinence, sleep patterns, and dependence, and to identify affecting factors of dependence on elderly patients in medical and care hospital. The subjects consisted of 209 elderly inpatients in the J city. The variables of dependency, depression, urinary incontinence, sleep were measured using questionnaires. Data analysis was performed using the SPSS 23.0 program, using descriptive statistic, t-test, ANOVA, Pearson correlation coefficient, and multiple regression analysis. Major findings of this study are as follows. The mean score of depression is $6.83{\pm}4.14$(out of 15), urinary incontinence is $6.44{\pm}9.63$(out of 60), sleep hour is $8.09{\pm}1.55$, quality of sleep is $39.37{\pm}6.55$(out of 60), and dependence is $42.68{\pm}8.78$(out of 85). The economic dependence among the subdomain of dependence is the highest dependence score. Dependence was positively correlated with depression(r=.26, p<.001), urinary incontinence(r=.35, p<.001). Factors Influencing dependence were depression (${\beta}.227$, p=.001), urinary incontinence (${\beta}=.259$, p<.001), and explanation of dependence is 11.5%. These results suggest that it is necessary for multidisciplinary approach and nursing intervention for decreasing dependence.

• Journal of the Korea Concrete Institute
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• v.29 no.4
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• pp.371-378
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• 2017

In this study, the flexural behavior of the RC Arch Deck under static loading was evaluated. Flexural test was carried out using an actual size RC Arch Deck with a length of 2.5 m, a center thickness of 100 mm and an end thickness of 160 mm. The test results showed that it's ultimate load was 1.74 times higher than the ultimate design load. On the other hand, it showed that the flexural behavior has different behaviors (i.e. different stiffness). This type of structural behavior indicates that it has inter-dependency between the deck and the supporting girder. Therefore, it is necessary to confirm the precise behavior by the static loading test of the RC Arch Deck, excluding the girder effect in the future study. The overall results showed that RC Arch Deck has excellent structural performance due to the structural advantages of the arch shape. In the future, the RC Arch Deck can be applied as a long span slab.

• Tunnel and Underground Space
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• v.9 no.4
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• pp.328-336
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• 1999

To characterize the hydro-mechanical behavior of a rock joint, a rotary shear testing apparatus was devised in this study. Shear stress was driven by twisting the end of a sample in the rotary shear testing apparatus. The test results show that the rotary shear test underestimates the peak shear strength of a rock joint. The torque is known as a function of the radial distance from the axis of rotation, resulting in the radial variation of the shear stress. Fluid flow through rock joints is mainly dependent on the Joint roughness, contact area, initial aperture. To examine the dependency, the relationship between the hydraulic and the mechanical apertures for shear-flow was established by measuring the initial aperture. It shows that the mechanical aperture and the hydraulic aperture increase linearly with the dilatancy. The difference between the hydraulic and mechanical apertures describes the deviation from the behavior predicted by the parallel plate model.