• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.1
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• pp.31-36
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• 2020

An investigation was conducted to determine whether the ratio of the fluid to the charged particles affects the panel reflexibility rate and the drifting current flowing in the panel, in electrophoretic-based electronic paper. In this regard, three panels were produced in this study with the ratio of the charged particles to the fluid set as 1:5, 1:1, and 5:1. Each sample was driven using an identical input pulse, for which the current flowing in the panel and the output voltage of the photodiode were measured for the panel reflexibility rate. Consequently, the drifting current initially exhibited a peak value and a saturated value at a later point. This value was proportional to the ratio of the charged particles, and it was similar to this ratio when it is higher than 1:1. The output voltage of the photodiode due to the panel reflexibility rate was proportional to the ratio of the charged particles. However, the response speed decreased if the ratio was higher than 1:1. It is expected that the results of this study will contribute to the analysis of the charging of charged particles in electrophoretic-based electronic paper, and the selection of an appropriate concentration.

• Journal of the Korean Society of Clothing and Textiles
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• v.39 no.5
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• pp.778-788
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• 2015

This study evaluated the characteristics and sensibility of work clothes materials developed that took into account the work environment of major industrial settings, for which a selection was made according to spring/autumn use and winter use. The physical properties of the existing and test weaving of the work clothes materials were compared after the test weaving of work clothes materials through material design, which altered the yarn count, composition, weave and density of material. To evaluate sensibility of work clothes materials subjectively, seven ranks' semantic differential scale questions were developed with polar adjective pairs. The test weaving of work clothes materials showed improved performance (such as tensile strength, dimensional change, water vapor permeability, and color fastness) compared to the existing materials. The common factor analysis indicated that the explanatory power of the cumulative variance for the spring/autumn use and winter use was 71.19% and 69.53%, respectively.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.3105-3105
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• 2001

Ingests and fecal contamination on a poultry carcass is a food safety hazard due to potential microbiological contamination. A visible/near-infrared (NIR) spectrometer was used to discriminate among pure ingesta and fecal material, breast skin contaminated with ingesta or fecal material and uncontaminated breast skin. Birds were fed isocaloric diets formulated with either maize, mile, or wheat and soybean meal for protein requirements. Following completion of the feeding period (14 days), the birds were humanely processed and eviscerated to obtain ingests from the crop or proventriculus and feces from the duodenum, ceca, and colon portion of the digestive tract. Pure feces and ingesta, breast skin, and contaminated breast skin were scanned from 400 to 2500 nm and analyzed from 400 to 900 nm. Principal component analysis (PCA) of reflectance spectra was used to discriminate between contaminates and uncontaminated breast skin. Results indicate that visible (400 to 760 nm) and NIR 760-900 nm spectra can detect contaminates. From PCA analysis, key wavelengths were identified for discrimination of uncontaminated skin from contaminates based the evaluation of loadings weights.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.264-267
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• 2006

The purpose of this study is to examine the advertisements of eco-friendly interior products and finishing materials in 3 interior design magazines which have been published for 4 years since 2002: to identify specific types of the products and materials that consumers can choose and to analyze their special ingredients which have functions and effectiveness related to health. Literature review and content analysis on the advertisements were employed. The results are as follows: The amount of advertisements has been continuously increasing due to the public concerns on well-being and finishing material types absolutely took the greatest proportion (92.8%) among them. Floor coverings, wall papers, and paints are the big 3 materials in the finishing material advertisements. The frequently mentioned health-related ingredients in them were charcoal, natural jade, nanosilver, yellow soil and quartz porphyry, And their main functions were emission of negative ions and ultra infrared. However, it's not easy to find their scientific test results on health. Objective guidelines are needed for the right selection of interior products and materials to maintain healthy interior environment.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.156-163
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• 2003

In order to investigate the possibility of punching process of brittle material by ball impact, the effects of sealing materials about impact damage of soda-lime glass by small spheres were evaluated experimentally. The using of sealing materials in the development of perfect cone crack was more effective than no using of sealing materials. At the sealing materials condition, in the case of 5mm-thick specimen, Copper and PMMA sealing were more effective in producing a perfect cone formation than the other sealing materials. And in the case of 8mm-thick specimen, Aluminum sealing was most effective in producing a perfect cone formation. The impact velocity range over which perfect cones were formed was influenced by both the thickness of specimen and sealing materials. By a proper selection of sealing materials, the application fur industrial technology for hole (or nozzle) punching process of brittle materials is expected.

• Transactions of Materials Processing
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• v.22 no.2
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• pp.86-92
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• 2013

When stamping ultra-high-strength steel (UHSS), the phenomenon of galling, which corresponds to a transfer of material from the sheet to the tool surface, occurs because of the high contact pressure between tool and workpiece. Galling leads to increased friction, unstable interface conditions, scratches on the sheet and the tool surfaces and, eventually, premature tool surface failures. Therefore, a simple and accurate evaluation method for tool scratching is necessary for the selection of tool material and coating, as well as for a better optimization of process conditions such as blank holder force and die radius. In this study, the pin-on-disc (PODT) and pin-on-flat surface (POFST) tests are conducted to quantitatively evaluate scratch-related tool life for stamping of UHSS. The variation of the friction coefficient is used as an indicator of scratch resulted from galling. The U-channel ironing test (UCIT) is performed in order to validate the results of the friction tests. This study shows that the POFST test provides a good quantitative estimation of tool life based on the occurrence of scratch.

• Current Industrial and Technological Trends in Aerospace
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• v.6 no.2
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• pp.60-68
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• 2008

The characteristic and properties of materials are rapidly degraded when subjected to the synergistic effects of the space environment such as atomic oxygen, radiation, vacuum and thermal cycling. In order to understand the mechanism of material property variation in space environment and to develop new space materials applicable to the future space program, advanced space organizations such as NASA, ESA and JAXA have been continuing many researches on material test specimens used on ISSE(International Space Station Experiment) or LDEF(Long Duration Exposure Facility). In this paper, the selection requirements and verification trend of materials in space applications

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.427-432
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• 2004

As it is keen competition of a construction market and the recognition that increases construction productivity for maintaining competitiveness, it is increased importance of an interest about productivity and efficiency in the construction industry. This study measures productivity through the instance of investigation that the existing productivity measurement method was utilized and presented a work improvement matter based on the measured contents. The proposed improvement matter is verified through a simulation technique. The purpose of this paper is for a field supervisor to have presented the way that a selection does the most suitable work method to be suitable for a situation, and can forecast production, though a simulation technique is not the most alternative that considered field condition in analyzing productivity measurement.

• Journal of the Korean Institute of Educational Facilities
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• v.14 no.1
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• pp.58-65
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• 2007

For the moderns who spend more than 80% of the time inside a building, interior environment became important since it directly affects their health. Recently as noxiousness of the air contaminants of the interior space stood out as well as the above trend, the Ministry of Environment enacted a lawto maintain the interior air quality at certain level of standard in the multi use facility and newly constructed apartment. To make the indoor air clean, removal technology of various contaminants should be developed and interior materials with chemical treatment should be restrained. In other words, selection of interior finish affects indoor air quality from the initial design stage to the construction stage. However, only limited contaminants emission data of building materials are supplied by related companies. There is no average contaminants emission data for overall materials. Moreover, high cost and equipments for one time measurement of VOCs emission of interior finish are the obstacles of active research and data measurement. Therefore, this paper searched the current condition of average VOCs & HCHO emission of various interior finish based on the study requested to research center from the building material company through Stands Test Method for Indoor Air Quality.

• Journal of computational fluids engineering
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• v.9 no.4
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• pp.55-63
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• 2004

The three-dimensional Stokes flow within a staggered screw channel is obtained by using a finite volume method. The geometry is intended to mimic the single screw extruder having staggered arrangement of flights. The flow solution is then subjected to the analysis of the stirring performance. In the analysis of the stirring performance, the stretching-mapping method developed by the author is employed for calculating the materials' stretching exponents, which are to be used in quantification of the mixing effect. The numerical results Indicate that the staggered geometry gives indeed far much better stirring-performance than the standard (nonstaggered) flight geometry. It was also shown that care must be given to the selection of the basis planes for evaluating the local stretching rate, and it turns out that the best method (H-method) has its basis plane just on the half way between the past and future evolution of fluid particles subjected to the defromation. In evaluating the stretching exponent, the expansion ratio must be considered which is one of the characteristic differences of the actual three-dimensional flows from the two-dimensionmal counterparts. The larger axial pressure-difference causes in general the smaller stirring performance while the flow rate is increased. The smaller channel length also increases the stirring performance.