• Magazine of the Korean Society of Agricultural Engineers
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• v.23 no.2
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• pp.61-69
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• 1981

The paddies in the hillsides in Gonggeun-myeon, Hoingseong-gun, Kangweon-do keep a steep slope and run in and out. A land consolidation in such an area, therefore, will require high ratio of land loss and a large amount of earth moving if it follows the existing design criteria to separate drainage and irrigation ditches in a scheme. Due to the consequent decrease in construction cost, the project has not been envisaged. in order to secure the introduction of small-medium size farm machineries into the paddies, farm plots were planned to be straight and drainage with taking care of topography. Findings from the comparison of methodologies are as follows. 1. In places with a solpe of more than 1/30, a reduction in earth moving can be expected with parallel plots to the contours. 2, For the sake of effective using of farm machineries, it is thought that a plot should be running straight parallel to the contours and the ratio of length and width of a plot be more than six. 3. In places with a slop of more than 1/10, a reduction in earth moving and a effective introduction of farm-machineries can he expected with straight parllel plots to the contours. But it is undesirable to introduce a scheme in this places because of the difficulties in acreage computation and farmers' hesitation. 4. The system with a canal for both irrigation and drainage is highly effective to decrease the ratio of land loss as well as construction cost. 5. Parallel plots to the contours and a canal for both irrigation and drainage are highly effective in the decrease in construct cost. 6. To avoid the subdivision of a cooperation in farming is desirable of a plots, has more than two owners.

• The Korean Journal of Applied Statistics
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• v.29 no.4
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• pp.657-678
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• 2016

This study deals with the effect of online word-of-mouth (OWOM) variables on the box office. From the result of statistical analysis on 276 films with audiences of more than five hundred thousand released in the Korea from 2012 to 2015, it can be seen that the variables showing the size of OWOM (such as the number of the portal movie rater, blog, and news after release) are associated more with the box office than the portal movie rating showing the direction of OWOM as well as variables showing the inherent properties of the film such as grade, nationality, release month, release season, directors, actors, and distributors.

• Korean Journal of Plant Resources
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• v.22 no.2
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• pp.123-127
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• 2009

This study was carried out to investigate the classification and the growing characteristics of biennial weed species in a newly formed transplanting lawn grass land. Measuring size in the experimental plot was $1{\times}1m$ in the 9 different locations, and experimental design was randomized complete plot with 3 replications. The results obtained are summarized as follows. 1) Weed species in a newly formed lawn field are consisted of 29.4% of Cruciferae, 29.4% of Compositae, 23.5% of Caryophyllaceae, 11.8% of Gramineae, and 5.9% of Labiatae family 2) Emerging percentage of weed species are consisted of 47.1% on October, 41.2% on November, 5.9% on both September and December, respectively. 3) Distribution rate about flowering time of weed species was in order of 58.5% on May, 23.5% on April, 11.8% on March, and 5.9% on June. 4) Weed species were grouped according to the plant height. It was observed that below 20cm, 20-40cm, 40-60cm and above 60cm of plant height were 23.5%, 47.1%, 17.6% and 11.8%, respectively.

• The Korean Journal of Applied Statistics
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• v.34 no.4
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• pp.589-597
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• 2021

In simple and multiple regression, there is a difference in the meaning of regression coefficients, and not only are the estimates of regression coefficients different, but they also have different signs. Understanding the relative contribution of explanatory variables in a regression model is an important part of regression analysis. In a standardized regression model, the regression coefficient can be interpreted as the change in the response variable with respect to the standard deviation when the explanatory variable increases by the standard deviation in a situation where the values of the explanatory variables other than the corresponding explanatory variable are fixed. However, the size of the standardized regression coefficient is not a proper measure of the relative importance of each explanatory variable. In this paper, the estimator of the regression coefficient in multiple regression is expressed as a function of the correlation coefficient and the coefficient of determination. Furthermore, it is considered in terms of the effect of an additional explanatory variable and additional increase in the coefficient of determination. We also explore the relationship between estimates of regression coefficients and correlation coefficients in various plots. These results are specifically applied when there are two explanatory variables.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.9
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• pp.801-811
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• 2021

Lightning can deliver large amounts of energy to the aircraft in a short period of time, resulting in catastrophic consequence. In particular, lightning strikes accompanied by high temperature heat and current can damage aircraft surface and internal electronic equipment, seriously affecting flight safety. Lightning experiments to analyze this effect use a Component A waveform with a maximum current of 200 kA as specified in SAE ARP 5412B. However, the actual lightning occurs mostly below 35kA and lightning indirect tests are conducted by reducing waveforms to prevent damage to internal electronic equipment. In this study, we examine previous methods to plot the Component A reduced waveform and identify their limitations. We then propose a new method to plot the reduced waveform based on adjusting the correction factor of the aircraft lightning Component A waveform. Finally, the electromagnetic analysis software EMA3D was used to compare the internal induced current size reduction ratio of the internal cable harness of the EC-155B helicopter.

• Korea Science and Art Forum
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• v.24
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• pp.1-13
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• 2016

The aim of this study is to find the reasons of success and failure of digital animations in terms of 'immersion.' For the purpose, the causes of immersion were analyzed through complex comparison about concepts and stories of two animation films with similar size of budget: 'Shrek 2' which ranked number 1 in the box-office of animation and 'Mars Needs Moms' which ranked number 172 in the same category. The complex results showed that immersion becomes bigger with creativity and popularity of the characters' outer concept, diversity and organic of the characters' inner concept, and diversity and consistency of the background. Moreover, gradual arrangement of characters' appearance in the story and increasing number of the characters, and visual changes around the plot heightening with a well-organized passage increase immersion. After all, immersion of digital animation requires developing creative, diverse, and popular concept and arranging and strengthening strategic well-organized plot of parts and the whole. This is the key to convergence it.

• Journal of the Korean Ceramic Society
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• v.25 no.4
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• pp.415-423
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• 1988

Mixtures of carbon and silica (about 0.46${\mu}{\textrm}{m}$) which was synthesized by the hydrolysis of ethyl silicate, the molar ratio of silica/carbon was fixed as 1/10(weight ratio : 1/2), were nitrided in the temperature range 135$0^{\circ}C$~150$0^{\circ}C$. The phse of the product Si3N4 was $\alpha$ phase and the morphology was hexagnoal prism and the nitridation reaction was completed in 5 hrs at 150$0^{\circ}C$ or 7hrs at 145$0^{\circ}C$. The reaction rate above 150$0^{\circ}C$ was diffusion-controlled, following Jander equation. Activation energy Q was derived from the Arrhenius plot and the value was about 101kcal/mol. Axis ratio of Lattice constants(c/a) was 0.726 and unit volume was $\AA$3, the larger the molar ratio of carbon/Alkoxide was, the smaller the particle size of $\alpha$Si3N4 was.

• Journal of the Korean housing association
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• v.10 no.2
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• pp.155-163
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• 1999

The purpose of this study was to investigate the residents' actual usage at three rest areas and three playgrounds in an apartment complex. This study was conducted with field study in J apartment complex in Incheon from August 14 to August 30, 1998. According to the results of the study, there were more users in playgrounds than in the rest areas. The rest area near the place for the elderly in the complex was used mainly by the elderly females. The playground located near the main entrance of the complex was frequently used because it is the biggest one in size and has an enough space for playing. Furthermore, the condition of shading areas by trees and buildings influenced the rate of use of the residents. Therefore, to increase the usage rate of rest areas and playgrounds, they should be located near to the places which have community amenities and should have accessible entrance for residents. Landscape design of the apartment complex should be done with the plot plan of the complex simultaneously. Moreover, the number and the kinds of trees to be planted in the apartment complex should be considered carefully.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.380-382
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• 1995

Yellow spot or blotch symptoms on the upper surface of leaf, without the production of velvet-like fungi on the lower surface of leaf as in the gray mold of tomato caused by Cladosporium fulvum, were observed in tomato (cv. Seokwang) plants in May, 1995, in a vinyl-house of the experimental plot of Gyeongnam Provincial Rural Development Administration, Chinju, Gyeongnam, Korea. We identified this disease as powdery mildew of tomato caused by Oidiopsis taurica (L v.) Arnaud (=Leveillula taurica), which was new to Korea. Conidia of the fungus were borne on uni- or bi-septated conidiophores which were developed through the stomata of the tomato leaf. The conidia were slender, clavate and variable in size (31~111.6$\times$13.1 ${\mu}{\textrm}{m}$). The fungal conidia isolated from tomato leaves were inoculated to tomato plants, and the occurrence of the same disease was confirmed based on the symptomatology and the morphology of the pathogen reisolated.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.15-18
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• 1996

Shewhart control chart is a basic technique to monitor the state of a process. We observe observations of a group of size four or five in a rational way and plot some statistics (e.g., means and ranges) on the chart. When setting up the control chart, the control limits are calculated based on preliminary 20-40 samples, which were supposedly obtained from stable operating conditions. But it may be hard to believe, especially at the beginning of constructing the chart for the first time, whether the process is stable and hence all samples were generated under the homogeneous operating conditions. In this report we suggest a mechanism to obtain robust control limits under self-criticism. When outliers are present in the sample, we obtain tighter control limits and hence increase the sensitivity of the chart. Examples will be given via simulation study.