• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.359-365
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• 2015

Floor mortar experiences dry shrinkage by temperature and humidity difference of internal matrix with material type. Also, since floor mortar is influenced by environmental conditions during placing and curing period, cracks are likely to be occurred. In this study, it was evaluated the hardening and dry shrinkage properties of non-sintered binder based floor mortar utilizing alpha-hemihydrate gypsum which has expansibility in order to prevent crack of the floor mortar. It was applied to the construction site, and examined the effects of external environmental conditions on shrinkage deformation and cracking. Different types of slag accelerated initial and final setting in comparison with cement mortar and its compressive strength was satisfied standard compressive strength for floor mortar. Also shrinkage deformation behavior after the initial expansion exhibited a similar tendency with the cement mortar. From the field application result, no crack was found from slag mortar, and it is determined that the slag mortar has better dimensional stability than cement mortar caused by external environment conditions.

• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.427-434
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• 2021

Modern people express their beauty through hair coloring, but hair can be damaged by repeated chemical treatments. In order to increase the durability of dyeing and minimize the hair damage, in this study, the acidic amino acids including aspartic acid (Asp) and glutamic acid (Glu) were used to post-treat hair during hair coloring. The post-treatment with 0.75% Asp and Glu solution was carried out at room temperature for 20 minutes after dyeing bleached hair with cherry red and blue silver colors. After repeated shampooing of 1, 5, 10, 15, 20, and 25 times, L^*a^*b^* value of dyed hair was measured to confirm the dyeing durability, and the changes in tensile strength, porosity, and surface properties of the hair were also analyzed to determine the condition of the hair. In the case of cherry red and blue silver staining, the Asp and Glu experimental group showed higher color persistence than the control group, and the Asp and Glu experimental group showed higher tensile strength, lower porosity and smooth surface properties than the control group. In particular, the Asp test group showed superior color persistence and lower hair damage than the Glu test group. This study, therefore, if damaged in dyeing and bleaching in the field of hair after treatment with asp glu a combination of hair cosmetics in the development of basic data look forward to be.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.30-38
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• 2023

As the number of old buildings subject to safety inspection increases, the burden on designated institutions and management entities that are responsible for safety management is increasing. Accordingly, when selecting buildings subject to safety inspection, appropriate safety inspection standards and appropriate technology are essential. The current safety inspection standards for old buildings give low scores when it is difficult to confirm damage such as cracks in structural members due to finishing materials. This causes the evaluation results to be underestimated regardless of the actual safety status of the structure, resulting in an increase in the number of aging buildings subject to safety inspection. Accordingly, this study proposed a thermal imaging technique, a non-destructive and non-contact inspection, to detect cracks inside finishing materials. A concrete specimen was produced to observe cracks inside the finishing material using a thermal imaging camera, and thermal image data was measured by exciting a heat source on the concrete surface and cracked area. As a result of the measurement, it was confirmed that it was possible to observe cracks inside the finishing material with a width of 0.3mm, 0.5mm, and 0.7mm, but it was difficult to determine the cracks due to uneven temperature distribution due to surface peeling and peeling of the wallpaper. Accordingly, as a result of performing data analysis by deriving the amplitude and phase difference of the thermal image data, clear crack measurement was possible for 0.5mm and 0.7mm cracks. Based on this study, we hope to increase the efficiency of field application and analysis through the development of technology using big data-based deep learning in the diagnosis of internal crack damage in finishing materials.

• Science of Emotion and Sensibility
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• v.14 no.4
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• pp.525-530
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• 2011

Emotion is composed of various feelings such as pleasure, sorrow, comfortability, and so on. The complicated process of the measurement has long been recognized as a major hindrance for the studies of emotion. Previously, individuals' emotion has mainly been measured by means of self-report, interview, EEG (electroencephalogram), ECG (electrocardiogram), EOG (electroculography), and body temperature. With thanks to nano/micro technologies, the possibility in the development of emotion-on-a-chip (EOC) has begun to be proposed. EOC will make it possible to analyze one's psychological status by taking a drop of blood. Discovery of emotional biomarkers in body fluids, understanding of the correlation between those biomarkers and the results from brain science are prerequisites to validate the EOC technology. In this paper, paper microfluidics are introduced as a good candidate for the EOC. As paper microfluidics is cost-effective and easy to use it is expected to be a useful device for the emotion measurement. We present the design and fabrication process for the simple paper-based microfluidic device and discuss the possible application in the field of measuring the human emotion.

• Korean Journal of Weed Science
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• v.15 no.3
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• pp.175-182
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• 1995

The experiment was conducted to obtain basic information on weed ecology and effective weed control in direct-seeded rice Gelds at National Yeongnam Agricultural Experiment Station in 1994. Double cropping system of rice-barley reduced weed occurrence about 30% as compared with rice single cropping due to allelopathic effect of barley residue or stubble. Occurrences of red rice (weedy rice), barnyard grass and water foxtail were closely related with tillage method; the greatest occurred in no tillage plot followed by rotavation only and plow plus rotavation. Period of seed germination of barnyard grass and carbgrass varied with temperature and soil depth. In the same environmental condition, the germination period of barnyard grass shortened 3 to 5 days as compared with that of carbgrass. Two systematic applications of herbicides, that is, the first application at 10 to 15 days after seeding and the second at just after flooding, were the most recommendable system in dry-seeded rice field in terms of weed suppression and yield capacity.

• Korean journal of applied entomology
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• v.35 no.2
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• pp.140-145
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• 1996

This study was conducted to investigate the winter ecology of the green leafhopper(GLH), Nephotettix cincticeps Uhler, in Milyang, south-eastern part of Korea from early December to early April during 1990 to 1992. The instar distribution in the overwinteing GLH population collected in December 5th was most of 4th instar 77% to 79% followed by 3rd instar 15% to 17% and 5th instar 3%. These instar distribution rate in the overwintering GLH was changed with collecting dates during overwintering periods of the GLH. Among the GLH population collected, as a result, the distribution rate of the 5th instar was significantly increased in February 20th and was most of 5th instar 70% to 71% in March 19th and was adult 47% to 50% in April 8th. During two overwintering periods of the GLH, the averaged instars converted the instar distribution of the overwintering GLH into the numerical values were 3.91 and 3.86 instar in December 5th, 4.11 and 4.07 instar in February 20th, 4.75 and 4.79 instar in March 19th and 5.42 and 5.45 instar in April 8th respectively. In addition to, the developmental index between pre-collected date and post-collected date of the overwintering GLH was roughly more than 1.0 value. It means that the overwintering GLH was developed without cease though the development was very slow and deponded upon air temperature. The overwintering GLH population were significantly more collected at the levee than at the barley field.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.3
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• pp.116-126
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• 2021

Diesel particulate filter (DPF) is a typical application field of cordierite (Mg₂Al₄Si₅O₁₈) honeycomb. Green body for DPF honeycomb was extruded using slurry paste and sintered at the temperature range of 980~1450℃. Quantitative crystal phase analysis was carried out by using Rietveld refinement method for powder XRD data. In conjunction with the quantitative Rietveld analysis, SEM-EDS analysis was carried for the crystal phases (indialite, cordierite, cristobalite, alumina, spinel, mullite, pro-enstatite). After removing amorphous phase on the sintered surfaces by chemical etching method, the shape and composition of the crystal phases can be clearly identified by SEM-EDS method. By combining the Rietveld refinement method and SEM-EDS analysis, crystal phase evolution process in DPF cordierite ceramics could be clarified. In addition, the coefficient of thermal expansion (CTE) of the DPF honeycombs were measured and compared with the calculated CTEs based on the quantitative crystal phase analysis results.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.265-271
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• 2021

Intertidal mud crab (Macrophthalmus japonicus) is an organism with a hard chitinous exoskeleton and has function for an osmotic control in response to the salinity gradient of seawater. Crustacean exoskeletons change in their natural state in response to environmental factors, such as changes in the pH and water temperature, and the presence of pollutant substances and pathogen infection. In this study, the ecotoxicological effects of irgarol exposure and heavy metal distribution were presented by analyzing the surface roughness of the crab exoskeleton. The exoskeleton surface roughness and variation reduced in M. japonicus exposed to irgarol. In addition, it was confirmed that the surface roughness and variation were changed in the field M. japonicus crab according to the distribution of toxic heavy metals(Cd, Pb, Hg) in marine sediments. This change in the surface roughness of the exoskeleton represents a new end-point of the biological response of the crab according to external environmental stressors. This suggests that it may affect the functional aspects of exoskeleton protection, support, and transport. This approach can be utilized as a useful method for monitoring the aquatic environment as an integrated technology of mechanical engineering and biology.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.485-492
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• 2018

This study would analyze visual components in the best seller cover design in 2017. The visual components were classified through a preliminary review with editorial design experts, and the top 20 best sellers at the Kyobo Book Centre, which recorded the top rank in sales in 2017 were selected as the subjects of the study. The subjects of the survey were 50 graduates from the design-related departments, who could judge the components, and the following results were drawn as an analysis. First, most layouts were a comparison type, and The Temperature of Language took the highest position at 45.5%. Second, in the typography, having a correlation with the section, most were composed of a Serif, and 'Sapiens' took the highest position at 92.5%. Third, the image is concerned with the illustration, in which The Miracles of the Namiya General Store took the highest position at 93.2%. These visual components of the cover design act as an important factor in choosing books for readers who first encounter the books. Thus, it would be necessary to continue to conduct studies of visual components in best sellers, and hopefully, this study would be helpful for the development of the publication market as it is utilized in the marketing field based on these studies.

• Journal of Astronomy and Space Sciences
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• v.14 no.2
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• pp.312-319
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• 1997

The magnetometer is one of the most important payloads for scientific satellite to monitor the near-earth space environment. The electromagnetic variations of the space environment can be observed with the electric and magnetic field measurements. In practice, it is well known that the measurement of magnetic fields needs less technical complexities than that of electric fields in space. Therefore the magnetometer has long been recognized as one of the basic payloads for the scientific satellites. In this paper, we discuss the scientific fluxgate magnetometer which will be on board the KITSAT-3. The main circuit design of the present magnetometer is based on that of KITSAT-1 and -2 but its facilities have been re-designed to improve the resolution to about 5nT for scientific purpose. The calibration and noise level test of this circuit have been performed at the laboratory of the Tierra Tecnica company in Japan.