• Journal of the Ergonomics Society of Korea
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• v.24 no.2
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• pp.51-56
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• 2005

Human perceptional speed is different from its real speed. There is lack of research that the perceptional speed is different from real speed in 2-dimension, because most research of speed perception has concentrated on points and lines. This research investigates the effects of object size on speed perception. In this research, we used 2-D circular objects of the different size, 0.9, 1.8 and $3.6^{\circ}$. The objects moved 9.0, 13.5 and $18.0^{\circ}$ with three different speeds, 6.0, 9.0 and $18.0^{\circ}$/s. Six participants were exposed to the environment with standard scene(size: $1.8^{\circ}$, speed: $9.0^{\circ}$/s and travel distance: $13.5^{\circ}$). After the first scene, another scene in which the object had changed to different sizes, speeds and distances, was shown to the participants. A magnitude estimation method was used to construct a scale of the perceived speed level. The relationship between the perceived and the actual speed level was explained by Stevens's power law that the value was 0.978 with the exponent of 0.992. The size of object had an effect on the speed perception but travel distance was not. The perceptional speed of bigger object was lower than of smaller object. It showed that the degrees of perceptional speed decreased as size of object increased.

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.363-370
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• 2012

Objective: The objective of this study is to analyze standards of ISO 9001, ISO 14001, KOSHA 18001, GAP and ISO 22000 to make an integrated system and check whether an integrated system can be used at small size companies. Background: There are many certification criteria for quality, safety and health such as ISO 9001, ISO 14001, KOSHA 18001, GAP and ISO 22000. However, these criteria are difficult and complicated to be used at a small size company. Thus. it is not easy for small size companies to obtain certifications using these criteria. But customers and workers of small size companies want the key points of these systems to be implemented. Method: ISO 9001, ISO 14001, KOSHA 18001, GAP and ISO 22000 were analyzed to find the commonality and duplications as well as the importance of the items in these standards. And a survey was conducted to check whether certain aspects of the anticipated integrated system can be implemented at small size companies. Results: Items were classified into categories based upon the importance to food safety, quality, safety, environment, and health. Items which are common among standards were also identified and thus give ideas to make the new standards simpler than the currently available standards. Items which were important but may not be easily implemented at the small size companies were also identified. Conclusion: By considering the fact that the currently used accreditation standards have many similar aspects, these systems can be integrated into one new system which small size companies can use relatively easily.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.7 s.155
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• pp.1146-1159
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• 2006

The purpose of this study was to offer body suit sizing system for young women aged 18-24. Many anthropometric measurements and other related data form 418 subjects were analyzed by various statistical methods. As a result of cluster analysis, we categorized somatotypes into 3 types: H-type, A-type, N-type as the most common. Subjects was covered 86.5% by KS body suit sizing system and 33.2% by body suit company. So we considered to produce AAA, AA cup size and small size body suit for raising the coverage. As size distribution by cluster analysis, H-type was mainly distributed ${70{\sim}85(AAA{\sim}D)}$ and M, L's hip size. A-type was mostly was ranged ${70{\sim}85(A{\sim}C)}$ and S, M size. N-type was widely showed ${65{\sim}85(AAA{\sim}I)}$ and S, M, L's hip size. Accordingly, it is reasonable to consider size distribution and physical characteristics by these figure types when suggesting sizing system as well as design and production.

• Journal of Korea Foundry Society
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• v.10 no.6
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• pp.528-537
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• 1990

7XXX aluminum alloy powders produced by the self-manufactured rotating disc atomizer were investigated to determine the influence of the atomization parameters on the particle size distributions in air atmosphere. The particle size distributions are almost always bimodal with the dominant mode on the large particle size. Average powder size of 7XXX aluminum alloy is $74/{\mu}m~125/{\mu}m$ when melt is poured with the rate of 9g /sec at 730$^{\circ}C$ on a rotating disc of 30㎜ diameter at 6300rad/sec. The mass of finer particle increased when disc diameter, angular velocity, pouring temperature increased and pouring rate decreased. The powder shapes of bimodal change from acicular to tear-drop and from tear-drop to ligament with increasing powder size. Powder shape was determined by the atomization mechanism and oxidation in liquid state. Microstructure of powders appeared to be cell and cellular dendrite. The SDAS of Al-7.9wt%Zn-2.4wt%Mg-1.5wt%Cu-0.9wt%Ni Powders is $0.8{\mu}m~1.0{\mu}m$ for the powders of $size＋44{\mu}m~53{\mu}m$ and $1.6{\mu}m∼1.8{\mu}m$ for the powders of $size＋105{\mu}m~125{\mu}m$, repectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.129-132
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• 2006

This paper is to investigate passing performance of high performance concrete between reinforcing bar depending on maximum size of coarse aggregates. Increase in maximum size of coarse results in decrease in water demand and sand to aggregate to secure target slump flow. The larger the maximum size of coarse aggregates is, the denser the space between reinforcing bar is, the amount of concrete passed through the reinforcing bar cage shows to decrease. HPC has favorable passing performance, regardless of aggregate size, when only vertical reinforcing bar is arranged. Whereas, when vertical and horizontal reinforcing bar is arranged at the same time, proper space between reinforcing bar is considered larger than 32mm in case of using 20mm coarse aggregate, 38mm in case of using 25mm aggregate. The increase in maximum size of coarse aggregate leads to increase compressive strength slightly. Length change shows to be decreased with the increase in maximum size of coarse aggregate.

• Particle and aerosol research
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• v.5 no.2
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• pp.63-70
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• 2009

The size distribution and number concentration of atmospheric aerosol were measured and compared using APS 3321 and Dust Monitor 1.108. The particle size distribution and number concentration measured by two devices were also compared at a particle generation system of standard PSL and fly ash. The number concentration of atmospheric aerosol measured by APS was higher than that by Dust Monitor in particle size range of less than $3.0{\mu}m$, but there was good accordance between them in particle size range of over $3.0{\mu}m$. In the particle generation system of PSL and fly ash, different measurement results were shown because the particle concentration was higher than that of atmospheric aerosol. The number concentration measured by Dust Monitor was higher than that by APS in most particle size ranges. However, the peak concentration of PSL particles measured by Dust Monitor was lower than that by APS. The difference of the collection efficiency in a scrubber by APS and Dust Monitor measurement was less than 10%, but in the particle size of $1.5{\mu}m$, it was over 20%.

• KIEAE Journal
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• v.13 no.1
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• pp.101-108
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• 2013

The purpose of this research was to analyze the correlation of residential satisfaction and the size of housing unit in apartment housing through the case study of 1,619 samples of 36 housing estates. The contents of this research consisted of two main parts. The first part was to identify the differences of residential satisfaction of dwellers, based on the size of housing unit, in apartment housing. The second part was to analyze the characteristics of residential environment, which might have an influence on the differences of residential satisfaction. the findings of this study were that the residential satisfaction of dwellers was proportional to the size of housing unit except $39m^2$ under housing unit, and the size of housing unit was not proportional to the residential satisfaction of outdoor openness exactly, but the size of housing unit was proportional to increase of the distance between building and building, and decrease of the building surface coverage ratio to outdoor area. This research will contribute to the establishment of the site planning methods which increase residential satisfaction in apartment housing, while promoting the quality of residential environment in Korea.

• Journal of Biosystems Engineering
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• v.12 no.1
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• pp.31-38
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• 1987

In order to improve the traditional post harvest system in Korea, a model for mechanized rice drying and storage system was developed and introduced as the first part of the study(Park, 1986). As the second part of the study, capital requirement and cost of the model system was analyzed. Also, optimum size of the model system was estimated by comparing with the traditional harvest system. From the study, the following results can be concluded: 1. The capital requirement of the model system decreases as the model size increases. For example, a model system having 500 ton storage capacity requires 439,000 Won/ton. However it requires 313,200 Won/ton only, if the model size increases to 1000 ton. 2. Also, total cost of the model system decreases as the model size increases. For example, total costs of the model system having 500 ton and 1000 ton storage capacity are 101,208 Won/ton and 69,320 Won/ton, respectively. 3. The breakeven point (optimum size) of the model can be estimated around 630 ton storage capacity if the operation rate is assumed as 100%. However, the optimum size of the model is 710 ton, if the operation rate it assumed 80%.

• Textile Coloration and Finishing
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• v.27 no.4
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• pp.229-244
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• 2015

The effects of synthesis conditions on characteristics of the calcium-azo complex pigment, C.I. Pigment Red 57:1, were studied. It was mainly considered that the industrially required synthesis conditions for lowering electrical conductivity of the pigment solution keeping pigment quality such as particle size and color characteristics. Three parameters were chosen as control factors during the synthesis. The first was the amount of hydrochloric acid added to transform sodium nitrite into nitrous acid. The second was the amount of calcium chloride added to insolubilize the synthesized azo dye. The final factor was pH control during the coupling reaction. The electrical conductivity and pigment aggregate particle size were dependent on the amount of hydrochloric acid and calcium chloride. Higher HCl concentration gave brighter yellowish-red color because of smaller particle aggregate size and narrower size distribution. Amount of charged ions in the synthesis process might affect the "lake" formation resulting different particle aggregate size and color shade.

• International Journal of Contents
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• v.5 no.1
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• pp.37-45
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• 2009

This paper empirically tests pecking order theory. Korean listed firms are used as the samples. On the whole we find supportive results for pecking order theory. The fixed effect model on the whole period shows that as pecking order theory suggests that debt ratio decreases as cash flow. ROA, physical assets, and firm size increase. Again, it is shown that corporate debt ratio significantly decreases as cash flow or ROA increases in every sub-sample, which coincides with the prediction of pecking order theory. Corporate debt ratio significantly decreases as physical assets or jinn size increases in case of the whole sample, pre-financial crisis period, and the sub-samples by q-ratio, which also supports the prediction of pecking order theory. Statistical significance of the coefficients of physical assets or firm size completely disappears after Korean financial crisis. Perhaps it is because the role of physical assets or firm size as a mitigator of information asymmetry significantly weakens after the financial crisis as Korean financial market becomes more transparent. For small firms only size variable is negatively and significantly related with debt to assets. It seems that size is an important factor for smaller firms in making financing decision.