• Journal of Institute of Control, Robotics and Systems
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• v.18 no.3
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• pp.230-236
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• 2012

Shielding the air-gap magnetic field of the electrodynamic wheel below a conductive plate and opening the shielding plate partially, a thrust force and a normal force generate on the conductive plate at the open area. But, as only the variable controlling both forces is a rotating speed of the electrodynamic wheel, it is very difficult to control the forces independently by the speed. So, we discuss a novel method controlling the forces effectively through manipulating a size of the open area. The independent control is made possible by virtue of the feature that the relative ratio between both forces is irrelevant to an air-gap length and determined uniquely for a specific rotating speed of the wheel. Therefore, the rotating speed and the size of open area become new control variables. The feasibility of the method is verified experimentally. Specially, the controllable magnetic forces are used in a noncontact conveyance of the conductive plate.

• Journal of Powder Materials
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• v.11 no.6 s.47
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• pp.493-502
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• 2004

In this study, nano-sized indium oxide powder with the average particle size below 100 nm is fab-ricated from the indium chloride solution by the spray pyrolysis process. The effects of the reaction temperature, the concentration of raw material solution and the inlet speed of solution on the properties of powder were studied. As the reaction temperature increased from 850 to $1000^{\circ}C$, the average particle size of produced powder increased from 30 to 100 nm, and microstructure became more solid, the particle size distribution was more irregular, the intensity of a XRD peak increased and specific surface area decreased. As the indium concentration of the raw material solution increased from 40 to 350 g/l, the average particle size of the powder gradually increased from 20 to 60 nm, yet the particle size distribution appeared more irregular, the intensity of a XRD peak increased and spe-cific surface area decreased. As the inlet speed of solution increased from 2 to 5 cc/min., the average particle size of the powder decreased and the particle size distribution became more homogeneous. In case of the inlet speed of 10 cc/min, the average particle size was larger and the particle size distribution was much irregular compared with the inlet speed of 5 cc/min. As the inlet speed of solution was 50 cc/min, the average particle size was smaller and microstructure of the powder was less solid compared with the inlet speed of 10 cc/min. The intensity of a XRD peak and the variation of specific area of the powder had the same tendency with the variation of the average par-ticle size.

• Korean Institute of Interior Design Journal
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• v.26 no.2
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• pp.92-100
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• 2017

In order to improve the functions of libraries in each region, it is necessary to establish the guideline of area of space size according to size and region. Therefore, this study aims to present the guideline of area of space size of public libraries for the revision of the manual of 2013. The study findings are as follows. First, the theoretical and preceding studies have raised a need to present the guidelines on the areas of public libraries nationwide since the guidelines of areas presented in Gyeonggi Province have been derived from the provincial libraries of Gyeonggi only. It is also necessary to analyze and verify the guidelines of areas of public libraries nationwide in Korea based on the guidelines of areas for Gyeonggi Province. Second, I have analyzed the areas of public libraries nationwide. I have conducted comparative analysis and verification in comparison with the areas in Gyeonggi Province through the ${\pm}5%$ error range presented in the existing manual, which has led to the conclusion that the guidelines of areas in Gyeonggi Province are within the error range and thus are applicable to public libraries nationwide. Third, I have presented the five different types of guidelines of areas. This study is expected to facilitate accelerating the decision-making and policy establishment as part of the construction and remodeling plans. In the future, however, more detailed studies on libraries bigger than $5,000m^2$ is needed.

• Journal of Biosystems Engineering
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• v.34 no.1
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• pp.8-14
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• 2009

When a farmer buys a tractor, the power size of a tractor is determined by various factors such as farm size, farmer's age, farming type, topographical area of farm. Relationships between tractor selection and these factors were found. Three regression models were developed to analyze the relationship. Those models were an OLS-1 model (based on 567 samples having tractors), an OLS-2 model, and a Tobit model (both based on the 1,941 samples). Regression analysis results showed that farm size and farmer's age affected selection of power size for all models at an 1% significance level. It was also shown that some farming types also had significant relationships with the tractor power size. Upland cultivating farmers and livestock farmers had larger tractors than rice cultivating farmers, while orchard farmers had smaller tractors. As for the topographical area, only middle area had significant difference with plain area. Farmers who had a rice-transplanter or a combine had larger tractors than those who didn't.

• Journal of Engineering Education Research
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• v.19 no.4
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• pp.14-23
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• 2016

This study is to analyze the team interaction in accordance with the team size. Thereby, it is to reveal the team size for the attainment of the effective team interaction and the specific goals to achieve the purpose of this study are as follows. Firstly, the frequency and percentage of team interaction in accordance with the team size are presented. Secondly, the statistical verification of the team interaction in the social emotional area is conducted. Thirdly, the statistical verification of the team interaction in the task area is conducted. In order to do this study, we explain the purpose of study, confidentiality, and withdrawal right were described and then 32 persons who agreed to participate were selected as the subjects for the study. After that, the autonomous organization of team was induced and a total of 8 teams were organized - 3 teams comprised of 3 members, 3 teams of 4 members, 1 team of 5 members, and 1 team of 6 members. Further, Bales' (1950) Interaction Process Analysis (IPA) was used in order to analyze the team interaction, and Mangold INTERACT was used as a coding program. The results of study are as follows. Firstly, the highest frequency of the team interaction showed up in the case of five or six members and the lowest in the case of 3 members. Secondly, a statistically significant difference in the social emotional (positive) area showed up in accordance with the team size and the team organizations of three or four members were effective. Thirdly, a statistically significant value in the answer area showed up in accordance with the team size and the team organizations of five or six members were effective.

• Journal of Korea Multimedia Society
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• v.17 no.8
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• pp.915-922
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• 2014

We propose an adaptive zoom motion estimation method where a picture is divided into two areas based on the distance information with a depth camera : the one is object area and the other is background area. In the proposed method, the zoom motion is only applied to the object area except the background area. Further, the block size of motion estimation for the object area is set to smaller than that of background area. This adaptive zoom motion estimation method can be reduced at the complexity of motion estimation and can be improved at the motion estimation performance by reducing the block size of the object area in comparison with the conventional zoom motion estimation method. Based on the simulation results, the proposed method is compared with the conventional methods in terms of motion estimation accuracy and computational complexity.

• Journal of Digital Convergence
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• v.13 no.6
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• pp.297-305
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• 2015

Forest area was applied as health promotion place for resident. Korea Forest Service set the term of "forest healing" based on the application of forest area as health promotion, which multidisciplinary approach in forest policy, and construct the "healing forest" for the healing space. Handicapped was excluded from the forest healing service as healing forest was located in the point away from urban area. The standard of healing forest size was difficult to set as urban forest area was fragmented. This study conducted on adequate standard of healing forest size in urban region. This study surveyed the laws related to the outdoor recreation place, and the walking range of the handicapped (elders, disabilities). The results were deduced with interrelationship between two factors(forest policy, human walking range). Healing forest size was not departmentalized for urban area compared with the standard of similar outdoor space (tourism complex, urban parks). Healing forest size was changed from 50ha to 25ha in national forest, from 30ha to 15ha in private forest considered with walking range of handicapped. This study contributes the evidence as the standard of healing forest size for health promotion in urban resident.

• Textile Coloration and Finishing
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• v.11 no.6
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• pp.1-6
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• 1999

The porosities of PET fibers were investigated using a nitrogen porosimeter according to oxygen plasma treatment and dyeing with a disperse dye, and they were discussed in terms of the change of internal micro-structure of the PET fiber. The total pore volume, surface area and average pore size of the plasma treated PET fibers increased expectably compared with the untreated sample. The PET fibers treated with oxygen plasma and then dyed with a disperse dye were increased significantly in the surface area and the total pore volume comparing with those of plasma treated only, but decreased in the average pore size. The increase of the surface area, after dyeing, of the plasma treated PET fibers was due to addition of the surface area of the dye itself to that of the PET fiber. The increase of the total pore volume of the plasma treated PET fibers by dyeing, which is the opposite result to the general idea that the pore volume of fibers would be reduced by occupation of dye molecules in the pores, could be explained by the free-volume model. This is that the amorphous region in the fiber expanded by occupation of dye molecules, and the marginal space surrounding dyes was generated as many smaller pores, and the decrease of the average pore size of the dyed sample also could be explained The decrease of the average pore size was caused by the splitting of a larger pore into smaller pores.

• Journal of Soil and Groundwater Environment
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• v.25 no.1
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• pp.84-94
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• 2020

Jeju Island is seeking reliable ways to secure alternative water resources using rainwater in order to conserve and manage its groundwater as sustainable water resources. The purpose of this study is to investigate the rainwater storage capability of small-size storage facilities installed at farmhouses in Uigwi and Wimi of Namwon-eup region. The rainwater outflows from the storage facilities in rain events were analyzed. The appropriate size of rainwater utilizing facilities are suggested to be about 5,800 ㎥ in Uigwi area and 4,900 ㎥ in Wimi area based on the calculation from the rainfall frequency and runoff amounts. If those facilities are put into operation in Uigwi and Wimi area, it is estimated approximately 32.3 and 11.5% of total agricultural water can be supplied by the facilities. Wimi area showed low rainwater usage because of less number of facilities relative to the size of farm areas and less intensive underground water usage. It is analyzed that more than 55% of agricultural water can be supplied by rainwater if 70 facilities without the rainwater facilities are connected to the rainwater utilizing facilities.

• Journal of Mechanical Science and Technology
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• v.16 no.5
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• pp.732-742
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• 2002

This paper presents twin spray characteristics of two impinging F-O-O-F type injectors in which fuel and oxidizer impinge on each other to atomize under the various conditions. The droplet size and velocity in the impinging spray flow field were measured using PDPA. The droplet size and velocity were investigated at the mixture ratios of 1.5, 2.0, 2.47 and 3.0 for four injectors in which two single F-O-O-F injectors were arranged at the intervals of 20.8, 31.2, 41.6 and 62.4mm respectively. In general, the arithmetic mean diameter, SMD and standard deviation of droplet size in the interaction area (X=0 and Y=0mm) were smaller, while the axial velocity in the interaction area was slightly higher. An empirical correlation is obtained for the (D$\_$10/)$\_$D//(D$\_$10/)$\_$c/ value under the assumptions of two identical droplets and these with different size and velocity. The droplets with low Weber numbers below 40 have possibility to coalesce, while those over 40 tend to disintegrate after impingement in the interaction area.