• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.10a
• /
• pp.791-794
• /
• 1999

Exact estimation of cement content in a hardened concrete can provide useful data to evaluate the quality and strength of the concrete and might be used to inspect the quality of precast concrete secondary products. Observation obtained in this research included : (1) the volume of coarse aggregate in the hardened concrete measured by the area comparison method has a high accuracy ; (2) the cement content in the mortar and the X-ray intensity of Ca-K$\alpha$ have a correlation factor of 0.96 ; (3) the cement content in the ready mixed concrete was estimated with high accuracy such as correlation factor of 0.99 and standard deviation of 0.64.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1997.04a
• /
• pp.229-232
• /
• 1997

A free space transmission method using standard gain horn antennas in the frequency range from 9.0 to 10.5GHz is applied to determine the dielectric properties of grain such as rough rice, brown rife and barley. The dielectric constant and loss factor, which depend on the moisture content of the wetted grain are obtained from the measured attenuation and phase shift by vector network analyzer. The effect of density fluctuation, which is an important parameter governing the dielectric properties of grain, on the dielectric constant and loss factor is presented. A new density-independent model in terms of measured attenuation and moisture density is proposed for reducing the effects of density fluctuation on the moisture content measurement.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.1151-1156
• /
• 2003

The dynamic properties of short-fiber reinforced Chloroprene rubber for vibration isolators have been studied as functions of interphase conditions and fiber content. The loss factor showed the maximum at strain amplitude 2%, and increased 0.09 for matrix, 0.05 for reinforced rubber with increasing frequency respectively. The dynamic ratio rapidly decreased with increasing strain amplitude, and some increased with increasing frequency. The better interphase condition showed the lower dynamic ratio. Therefore, the short-fiber reinforced rubber could have the better isolation in frequency ratio(${\sqrt{2}}min$.) compared to frequency ratio(${\sqrt{2}}max$.). And we have investigate the possibility of applying short-fiber reinforced rubber to automotive engine mount.

• International Journal of Contents
• /
• v.16 no.3
• /
• pp.87-100
• /
• 2020

This research explored the impact the thoughts and opinions of lecturers teaching university general English courses have on their virtual classes and discussed the differences and similarities in their perspectives. As a research methodology, the Q-method was used, which usually consists of five steps: Q-population, Q-statements, Q-participants, Q-sorting, and factor analysis using PQMethod, a computer software program. A total of 30 statements were finally selected and 26 people directly involved in teaching online university general English courses were selected as participants in this study. Based on the results of the factor analysis, this research discovered three different factors, which were interaction & content-oriented, online teaching favored, and content-oriented. The results of this study can contribute to developing the future directions of virtual university general English classes to help learners improve their English skills and prepare lecturers for the future.

• Journal of the Korea Furniture Society
• /
• v.21 no.3
• /
• pp.229-236
• /
• 2010

Wood material is positive with the concept of eco-friendly materials. Wood toy preference of foreign brands is also a real problem. Therefore, in this domestic situation on Toys Brand Development, there are many problems yet to be solved. At First, a wood material for toys requires the development of more sophisticated and precision materials. Second, new content, product development and training program development of the toys are needed. Characters and content development time and effort should be invested. In present, Korean brand development of wood toy with educational effects is very important issues as the use of wood to match the low carbon & green growth.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.745-748
• /
• 2008

On investigation about quick measurement technology of unit water at range of W/B=35% in high strength, the average error of the Di-electric constant moisture tester A has measured more than $23.0kg/m^3$ unit water content of design and the average error of the method of unit volume weigh was less than $-9.6kg/m^3$. The average error with mixing factor has influenced with a kind of sand, but had not influenced with unit water content of design. Therefore, it will be for introduce business decide require more than a study about cement, sand, superplasticizer, etc.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.03a
• /
• pp.148-154
• /
• 2004

As a rocket propellent of hydrocarbon fuels, the characteristics of liquefied natural gas was evaluated with the viewpoint of the constituents and content, the cooling performance as a coolant, and characteristic velocity and specific impulse as parameters of the engine performance. Content of methane was a principal factor to determine the characteristics as a rocket propellant and more than 90 % of it was needed as a fuel and coolant in the regenerative cooled liquid rocket engine. Some constituents of the liquefied natural gas can be frozen by the pre-cooling of the pipe lines, therefore they can be a factor disturbing the normal working of engine. In case the content of methane is around 90% in the liquefied natural gas, a normalized stoichiometric O/F mixture ratio of 0.75 is suggested for a nominal operation condition to get the maximum specific impulse and characteristic velocity.

• Spatial Information Research
• /
• v.10 no.4
• /
• pp.533-550
• /
• 2002

Soil organic matter (SOM) content and other physical soil properties were extracted from a digital soil database, the Soil Survey Geographic (SSURGO) database, to map the amount of SOM and determine its relationship with topographic positions in floodplain areas along a river basin in Douglas County, Kansas. In the floodplains, results showed that slope and SOM content had a significant negative relationship. Soils near river channels were deep and nearly level, and they had the greatest SOM content in the floodplain areas. For the whole county, SOM content was influenced primarily by soil depth and percent SOM by weight. Among different slope areas, soils on mid-range slopes (10-15%) and ridgetops had the highest SOM content because they had relatively high percent SOM content by weight and very deep soils, respectively. SOM content was also significantly variable among different land cover types. Forest/woodland had significantly higher SOM content than others, followed by cropland, grassland, and urban areas.

• Korean Journal of Materials Research
• /
• v.13 no.6
• /
• pp.360-364
• /
• 2003

$Sr_{l}$ $\pm$x/$Bi_{2}$ $\pm$y/$Ta_2$ $O_{9}$ and $Sr_{l}$ $\pm$$Bi_{x}$ $2\pm$y$Nb_2$$O_{9}$ ceramics were prepared by a solid state reaction method. X-ray diffraction analysis indicated that single-phase of Bi-layered perovskite was obtained. According to Sr/Bi content ratio, Curie temperature( $T_{c}$), electromechanical factor($K_{p}$ ) and mechanical quality factor($Q_{m}$ ) were measured. The Curie temperature of SBN(SBT) rose from $414^{\circ}C$(314$^{\circ}C$) to $494^{\circ}C$(426$^{\circ}C$) when Sr/Bi content ratio was increased. In the case of Sr/Bi content ratio = 0.55/2.3, the maximum value of the mechanical quality factor $Q_{m}$ of SBT and SBN were obtained 3320 and 1010, respectively.

• Journal of Korean Academy of Nursing
• /
• v.52 no.6
• /
• pp.582-597
• /
• 2022

Purpose: This study aimed to translate the Infertility Stigma Scale (ISS) into Korean and to evaluate its reliability and validity in the Korean context. Methods: Data were collected from 350 women who underwent in vitro fertilization (IVF). Data were analyzed using SPSS WIN 25.0 and AMOS 22.0. Content validity was analyzed using the item-level content validity index (I-CVI) and scale-level content validity index/averaging (S-CVI/Ave). The preliminary survey was conducted on 20 women who had experienced IVF at least once to check the level of understanding of the tool and the time required to fill out the questionnaire. Exploratory and confirmatory factor analyses were used to test construct validity. Additionally, hypothesis-testing construct validity were tested. Cronbach's α was used to assess the reliability. Results: The Korean-ISS (K-ISS) consists of 25 items, excluding two items from the original ISS questionnaire. Exploratory factor analysis identified four factors, which explained 75.6% of the total variance. The four distinct factors were infertility stigma with self-devaluation (56.8%), public stigma (8.1%), social withdrawal (6.5%), and family stigma (4.2%). In the confirmatory factor analysis, the 25 items in the four-factor structure were validated (χ² /df ≤ 3, RMSEA ≤ 10). The hypothesis-testing construct validity of K-ISS against FPI (r = .58~.71, p < .001) and FQI (r = - .49~- .65, p < .001) was tested and found to be significant. The internal consistency reliability of the K-ISS, assessed using Cronbach's α, was .97. Conclusion: The K-ISS has satisfactory construct validity and reliability; therefore, it can help minimize the negative impact of stigma by measuring the stigma associated with women experiencing infertility.