• Transactions of the Korean hydrogen and new energy society
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• v.29 no.5
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• pp.434-441
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• 2018

The pore size of nickel (Ni) bottom electrode layer (BEL) for low-temperature solid oxide fuel cells embedded with ultrathin-film electrolyte was controlled by changing the substrate surface morphology and deposition process parameters. For ~150-nm-thick Ni BEL, the upper side of an anodic aluminum oxide (AAO) substrate with ~65-nm-sized pores provided ~1.7 times smaller pore size than the lower side of the AAO substrate. For ~100-nm-thick Ni BEL, the AAO substrate with ~45-nm-sized pores provided ~2.6 times smaller pore size than the AAO substrate with ~95-nm-sized pores, and the deposition pressure of ~4 mTorr provided ~1.3 times smaller pore size than that of ~48 mTorr. On the AAO substrate with ~65-nm-sized pores, the Ni BEL deposited for 400 seconds had ~2 times smaller pore size than the Ni BEL deposited for 100 seconds.

• Journal of Navigation and Port Research
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• v.35 no.2
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• pp.159-165
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• 2011

The aim of paper is to calculate the optimized size of Mobile Harbor(MH) which would be operated in South Korea coast area. MH is the combined entity which has the function of both ship and container port. In estimating the optimized size, the total cost concept is applied to the different size of MH. Trade-off factors for calculating total cost are MH cost and the over-capacity lost cost. The factors for MH cost estimation are the cargo demand, distance from origin to destination, voyage route and MH's fixed and variable cost in both sailing and port. The other cost is the over-capacity lost cost which is occurred from dead space in case of oversize compared with a voyage demand. The alternatives for the least cost are 250TEU, 500TEU, 750TEU and 1,000TEU sized vessel. The result of research is that 250TEU sized vessel is optimized in a South Korea costal service. If the coastal area be separated in terms of voyage distance or the specific area in considering trade, the optimized size is changed depending upon distance.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.11
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• pp.63-68
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• 2019

The dimensional quality of flexible foams is often difficult to be evaluated through general machine vision inspection methods due to the free deformation of the outer shape. For the evaluation of the dimensions of flexible foams, methods of estimating the size of the product through the expansion rate of the product surface are evaluated. Specimens with various dimensions and surface gratings are prepared, and the degree of surface expansion is measured through machine vision. The correlation, between the measured surface grid size and the actual size of test specimens, is analyzed. We further analyze the correlation between the size of test specimens and the position of the surface grid. This study provides a basis for estimating the actual dimensions of specimens by measuring the surface expansion of flexible foams.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.3
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• pp.428-435
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• 2024

The important factors in the design of the gun propellant are impetus, flame temperature and pressure. In this paper, we considered a nitrocellulose based propellant composition that replaced sensitive NG(Nitroglycerin) with RDX(Cyclotrimethylenetrinitramine) and DEGDN(Diethylene glycol dinitrate) which high energy and low sensitivity. Particle size and content of RDX are the two main factors that affect the burning stability of RDX-based propellants. Among them, the characteristics of the propellant according to the particle size of RDX were confirmed. The relative combustion rate(R.Q., Relative Quickness) of the propellant changed according to the RDX particle size, and internal ballistics of properties of propellant were also varied. The particle size of RDX can be confirmed as a major factor in the combustion and internal ballistics characteristics of the propellant.

• Animal Systematics, Evolution and Diversity
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• v.12 no.3
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• pp.203-210
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• 1996

Four external and 27 cranial characters of Korean field mice (Apodemus peninsulae) from nine regions in China and Korea, representing three subspecies, were analyzed by multivariate methods. Four size-forms were recognized a largest-size form Mt. Weolak and Yeoncheon in Korea (= subspecies peninsulae) and Kirin and Heilung in China (= subspecies praetor), a large-size form from Inner Mongolia in China (= subspecies praetor) and Sanxi and Sandong in China (= subspecies sowerbyi), a middle-size form from Beijing in China (= subspecies sowerbyi), and a small-size form from Xinjiang in China (= subspecies sowerbyi). Although Corbet (1978) recognized only two subspecies in A. peninsulae, subspecies peninsulae and sowerbyi, within its distributional range in the continent of Asia, it was revealed in this study with morphometric characters that A. peninsulae could not be classified simply into two subspecies, because subspecies praetor and subspecies sowerbyi formed the large-size form and because subspecies sowerbyi was so diverse in its morphology as to be composed of three size-forms. Further analyses with the samples from other regions of China and Russia seem to be necessary to clarify the taxonomy of A. peninsulae.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.1
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• pp.41-48
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• 2011

A mobile laser-induced breakdown detection (LIBD) system was developed for the field measurement of the size and concentration of aquatic colloidal nanoparticles sampled from Korea Atomic Energy Research Institute Underground Research Tunnel (KURT). The established LIBD apparatus is based on the optical detection of a laser-induced plasma by means of a two-dimensional optical imaging method for determining the size of nanoparticle. Calibration curve for determining the size of nanoparticle was obtained from the polystyrene reference particles of a well-defined size. The first direct application was made at KURT for investigating the particle sizes in groundwater. By comparing the size of particles in groundwater with the sizes of reference particles, the mean particle size of approximately $108{\pm}26$ nm with the concentration lower than 50 ppb was determined.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.388-395
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• 2018

Significant efforts have been applied toward fabricating three-dimensional (3D) scaffolds using 3D-bioprinting tissue engineering techniques. Gelatin has been used in 3D-bioprinting to produce designed 3D scaffolds; however, gelatin has a poor printability and is not useful for fabricating desired 3D scaffolds using 3D-bioprinting. In this study, we fabricated pore size controlled 3D gelatin scaffolds with two step 3D-bioprinting approach: a low-temperature ($-10^{\circ}C$) freezing step and a crosslinking process. The scaffold was crosslinked with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The pore sizes of the produced 3D gelatin scaffolds were approximately 30% smaller than the sizes of the designed pore sizes. The surface morphologies and pore sizes of the 3D gelatin scaffolds were confirmed and measured using scanning electron microscopy (SEM). Human dermal fibroblasts (HDFs) were cultured on a 3D gelatin scaffold to evaluate the effect of the 3D gelatin scaffold pore size on the cell proliferation. After 14 days of culture, HDFs proliferation throughout the 3D gelatin scaffolds prepared with more than $580{\mu}m$ pore size was approximately 14% higher than proliferation throughout the 3D gelatin scaffold prepared with a $435{\mu}m$ pore size. These results suggested that control over the 3D gelatin scaffold pore size is important for tissue engineering scaffolds.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.331-346
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• 2021

The purpose of this study was to comprehensively examine the effect of capstone design education on learning outcomes and propose directions for effective design and implementation of capstone design classes. For achieving this, a 21 studies meeting the standards among the academic journals and thesis published in Korea by September 2020 were selected, and based on 83 effect sizes, the meta analyses were carried out. The results of this study were as follows: First, the total effect size of capstone design education was 0.96, which is a large effect size. Second, the effect size was large in order of affective, cognitive, and social areas. Third, the effect size of vocational basic ability showed a large effect size while creativity showed a medium-sized one. Fourth, the effect size showed highest for design subject, the grade in the third or fourth, there was help from industrial corporation, theory and practice. Based on these results, this study proposed instructional design implications in order to increase the learning effects of capstone design in Korea.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.247-254
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• 2012

Objective: The objective of the study is to analyze adult men's somatotype characteristics, age range from 20s to 50s comparing the direct anthropometric measurement values and to provide the basis information for developing clothing patterns. Background: The comparative study among the age groups is very fundamental to understand the body characteristics of each subjects group. Therefore, comparison of body measurements in age groups was applied in this study. Method: The anthropometric data from the $5^{th}$ Anthropometry of Size Korea(2004) and $6^{th}$ Anthropometry of Size Korea(2010) were applied for the data analysis. Results: As a result, the chest depth/chest width index(the value of chest depth divided by chest width) was increased and the waist depth/waist width index was decreased in all age groups. In addition, the hip depth/hip width index was decreased in age of 20's and 50's. This means that the chest width and hip width were decreased and the waist width were increased. From the data of the 5th Size Korea, the obese men(BMI: 25~30) in the 50s showed the highest percentage of 47.1%, and 44.8% of obese men(BMI: 25~30) in the 40s recorded the highest rate base on the data of the 6th Size Korea. Conclusion: It is concluded that the some differences were showed between the 5th anthropometric data and the 6th data. In particular, obesity tendencies of men in their 20's and 30's were observed significantly compared to other age groups. Application: These findings from the study can be utilized men's wear design and construction that reflect body characteristics.

• Journal of Korea Foundry Society
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• v.3 no.3
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• pp.167-173
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• 1983

The effect of sand grain size on the various properties of mold is not only basic but important interest which we have to deal with.And the relation among the various properties of mold (strength, permeability, flowability, compactability, hardness, deformation, toughness etc.) is very complicated and inaccurate, so we can delineate the behavior of mixture (sand+water+bentonite) with experience only. Within recent years a so-called rigid-water theory has been accepted as a means of advancing logical explanations for the research aimed at delineating sand-clay-water relationships. By changing grain size or mesh no. of grain, specimens have been subjected to green compressive strength, permeability, deformation, flowability, compactablity, toughness at room temperature. Under constant mulling energy and ratio of water/bentonite, the results obtained were as follows: 1. With decreasing grain size green compressive strength of the specimen increased. 2. With decreasing grain size permeability decreased. 3. With decreasing grain size flowability and bulk density decreased but compactability increased. 4. With decreasing grain size deformation decreased but toughness increased. 5. At 60 mesh no., the properties of specimen are conspicuously changed. The reason is that the total surface area of sand grain which affects the type of bonding between sand grains is more changed at 60 mesh number.