• KEPCO Journal on Electric Power and Energy
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• v.7 no.1
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• pp.167-169
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• 2021

In this study, monodispersive silica nanoparticles with double mesoporous shells were synthesized, and the pore size of synthetic mesoporous silica nanoparticles was controlled. Cetyltrimethylammonium chloride (CTAC), N, N-dimethylbenzene, and decane were used as soft template and induced to form outer mesoporous shell. The resultant double mesoporous silica nanoparticles were consisted of two layers of shells having different pore sizes, and it has been confirmed that outer shells with larger pores (Mean pore size > 2.5 nm) are formed directly on the surface of the smaller pore sized shell (Mean pore size < 2.5 nm). It was confirmed that the regulation of the molar ratio of pore expansion agents plays a key role in determining the pore size of double mesoporous shells.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.6
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• pp.923-934
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• 2021

Most apparel products have national standards for sizing; however, for gloves, national sizing standards have not yet been established. This study aims to analyze children's hand dimensions and propose a size specification for children's gloves that shows children's hand-related size information. Among the 3D measurements of sixth Size Korea Project, the measurement data of 19 dimensions related to the hands of 1,057 boys and girls aged 7-13 years old were analyzed. The distribution and growth trend of hand measurements for boys and girls demonstrated considerable mean differences and distribution trends by gender and age as per hand dimensions, which leads to the conclusion that it is necessary to show these results in the children's glove design. Based on these results, the cross-distribution maps of children's hand length and hand circumference were drafted; furthermore, the distribution relationship with an adult hand size was identified. Based on the distribution of hand sizes, the distribution of adult hand sizes overlapped with children's hand sizes was verified, and children's glove size specifications were presented. The results can be used as useful data such as measures for setting the size range and sizing system for children's gloves.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.521-530
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• 2021

Objectives: This was to examine and explore the elements of Size Korea 6th 3D head anthropometric database and to provide basic information for the selection of respirators in Korea. Methods: This was a pilot study for the first year of work in a two-year-project initiated at KOSHA in 2021. 3D head dimensions data were obtained from the Size Korea Center managing the Size Korea 6th 3D national anthropometry survey databases. The 3D head dimensions data, including 45 dimensions, were used in line with ISO standards (e.g., ISO/TS 16976-2) for examinations, comparisons, statistical analyses, etc. Results: A total of 3,088 subjects were finally determined in this study. The main features were: Male subjects were 52.5%; the highest age group was 15-29 at 36.7%; unhealthy weight group based on BMI was 31.7%; and survey area was the capital region. For the 6th 3D head dimensions data with 45 items, the means and standard deviations for 'Face length' were 115.9±7.5 cm for males and 107.3±6.9 cm for females respectively while those for 'Face width' item were not available since there was no such item in the data. Numerous findings were discussed accordingly. Conclusions: This study showed that there were likely requirements for improvements in the 6th 3D head anthropometric data as follows: Standardization of Korean and English terms; addition of head dimensions items missed in the Size Korea survey; and reliability of generalizability for subjects, suggesting that the study results can be used for further studies or improvement of respirator selection in Korea.

• International Journal of Advanced Culture Technology
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• v.9 no.1
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• pp.1-6
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• 2021

This study aims to test the relationship between the change in population size and population composition and crime changes. The analytical model includes variables representing changes in population size and population composition, three dependent variables for crime changes, and three control variables. Changes in popuvpdllation size and population composition are measured by indicators such as population size, gender, age groups, and immigrants and foreign workers, and crime changes by felonious, burglary, and violent crime volumes. The sample includes 154 cities and counties in South Korea, and the sample period is from 2010 to 2017. As a result of the analysis, I examine that the decrease in the number of young and men are likely to lead to a decline in felonious and violent crimes, but a high rate of the elderly and the increasing racial heterogeneity are likely to accelerate the fear and worries about crimes.

• International Journal of Advanced Culture Technology
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• v.9 no.2
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• pp.91-99
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• 2021

In Korea, some pharmaceutical companies and agricultural machine manufacturers associate the length of the credit period with the retailer's order size. This kind of commercial practice is based on the principle of economy of scale from the supplier's point of view and tends to make retailer's order size large enough to qualify a certain credit period break. Also, the credit period allowed by the supplier makes it possible to reduce the retail price expecting that the retailer can earn more profits by the stimulating the customer's demand. Since the retailer's order size is affected by the end customer's demand, it is reasonable to determine the retail price and the order size simultaneously. In this regard, this paper analyzes the retailer's problem who has to decide his sales price and order quantity from a supplier who offers different credit periods depending on his order size. And we show that the retailer's order size large enough to qualify a certain credit period break. Also, it is assumed that the end customer's demand rate is represented by a linear decreasing function of the retail price.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.80-89
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• 2021

In Korea, marine fish landed at ports are randomly sampled on a periodic basis (e.g., daily or weekly), and body sizes (e.g., lengths and weights) of those sampled fish are measured. The motivation for our study is whether or not such measurements reflect the size distribution, especially the length distribution of fish landed (= a population), because such length measurements are key data for a length-based assessment model. The current sampling method is to sample fish landed at ports by body size group (e.g., very small, small, medium, large, very large), using the sampling weights as the number of boxes by body size group. In this study, we showed that length composition data about fish sampled by the current method did not represent the length frequency distribution of the fish landed, and suggested that an alternative sampling method should be applied of using the sampling weights as the number of fish landed by body size group. We also introduced a method for determining an appropriate sample size.

• Elastomers and Composites
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• v.56 no.1
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• pp.12-19
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• 2021

The abrasion behaviors of NR/BR blend vulcanizates were investigated using NR/BR = 100/0, 80/20, and 60/40 compounds. The abrasion test was performed using a laboratory abrasion tester (LAT) at slip angles of 1° and 7°. The size distributions of the wear particles and the abrasion rates were examined according to the rubber compositions and slip angles. The most abundant wear particles at the slip angle of 1° were sizes above 1,000 ㎛, irrespective of the rubber composition. The most abundant wear particles at 7° slip angle had sizes in the range of 212-500 ㎛, except for the NR = 100 sample. The wear particle size distribution shifted to a smaller size as the slip angle and BR content increased. The abrasion rate at 7° was much larger than that at 1° slip angle. Furthermore, the abrasion rate was notably increased by adding BR to NR.

• Journal of the Korea Fashion and Costume Design Association
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• v.25 no.3
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• pp.157-164
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• 2023

The purpose of this study is to compare and analyze bust point information presented in literature and the 8th Korean Anthropometric Survey (Size Korea 2021) as a basis for pattern making for Korean adult women. Therefore, the the bust point position was analyzed through the length from the side neckline to the bust point and the horizontal length from the bust point to the chest. The results are as follows. First, Size Korea's population shows an increase in bust circumference and Side Neck Point to Bust Point with age, with the largest Bust-Point Breadth in the 30s, followed by the 20s, 40s, 60s, and 50s. Second, the Bust-Point Breadth in the female Basic Bodice pattern of Kang Soon-hee, and Oh Sun-hee, which were created from the bust circumference measurements of Size Korea's population, was wider than the measurements, and the difference was verified as a highly significant. Third, in the female Basic Bodice pattern of Kang Soon-hee, and Oh Sun-hee created with the bust circumference dimensions of Size Korea's population, the length of Neck Point to Bust Point was shorter than the measured value, and the difference was highly significant. Fourth, the Bust-Point Breadth and Neck Point to Bust Point in the female Basic Bodice pattern of Kang Soon-hee, and Oh Sun-hee, which were created with the bust circumference of the population of Size Korea by age, were analyzed in different age groups and showed significant differences from the measurements of Size Korea.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.1
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• pp.1-16
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• 2021

This study classified short adult male body types and identified characteristics by body type according to Size Korea's 7th human system measurement data for men in their 20s to 60s. There were four body types for short adult males. Type 1 was a 'short bird legs-normal body shape' with an average body size, low body height, short torso length, thin legs, and no sagging shoulders. Type 2 was a 'short torso thin body' with a small body size, a slim body, a high body height, a short torso length and no sagging shoulders. Type 3 was a 'thick leg-overweight body shape' with a large body size, thick legs, low body height, small shoulder length and obesity. Type 4 was a 'long bird legs-normal body' with a normal body size, high body height, thin legs, long torso and sagging shoulders. The development of clothing design and pattern reflecting the body shape characteristics of short adult males should be improved to fit clothing and suitability. It is necessary to increase the satisfaction of ready-to-wear for consumers with various body types by adding the size for shorter men through a subdivision of the ready-made size system.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2277-2288
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• 2021

To regulate the safety protocols in nuclear facilities, radioactive aerosols have been extensively researched to understand their health impacts. However, most measured particle-size distributions remain at low resolutions, with the particle sizes ranging from nanometer to micrometer. This study combines the high-resolution detection of 500 size classes, ranging from 6 nm to 10 ㎛, for aerodynamic diameter distributions, with a regional lung deposition calculation. We applied the new approach to characterize particle-size distributions of aerosols generated during the plasma arc cutting of simulated non-radioactive steel alloy wastes. The high-resolution measured data were used to calculate the deposition ratios of the aerosols in different lung regions. The deposition ratios in the alveolar sacs contained the dominant particle sizes ranging from 0.01 to 0.1 ㎛. We determined the distribution of various metals using different vapor pressures of the alloying components and analyzed the uncertainties of lung deposition calculations using the low-resolution aerodynamic diameter data simultaneously. In high-resolution data, the changes in aerosols that can penetrate the blood system were better captured, correcting their potential risks by a maximum of 42%. The combined calculations can aid the enhancement of high-resolution measuring equipment to effectively manage radiation safety in nuclear facilities.