• Journal of the Korean School Mathematics Society
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• v.16 no.3
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• pp.479-498
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• 2013

As education is one of key factors to improve national competitiveness, quality education becomes a top priority in all countries around the world. In South Korea, The Basic Skills Competency Test is administered annually to select below-basic third graders and provide intervention programs. The Basic Skills Competency Test was designed to diagnose the minimal competency of third graders according to a national-level standards. The purpose of this study was to analyze standard-setting procedures and set cut-off scores. This study offered the empirical evidence that standard-setting is generally applicable in schools by the modified Ebel method. More future researches addressing appropriate and efficient standard-setting methods in real school situations are needed to be taken in.

• Toxicological Research
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• v.35 no.2
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• pp.103-117
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• 2019

The mixture of 5-chloro-2-methylisothiazol-3(2H)-one (CMIT) and 2-methylisothiazol-3(2H)-one (MIT), CMIT/MIT, is a preservative in cosmetics. CMIT/MIT is a highly effective preservative; however, it is also a commonly known skin sensitizer. Therefore, in the present study, a risk assessment for safety management of CMIT/MIT was conducted on products containing 0.0015% of CMIT/MIT, which is the maximum MIT level allowed in current products. The no observed adverse effect level (NOAEL) for CMIT/MIT was 2.8 mg/kg bw/day obtained from a two-generation reproductive toxicity test, and the skin sensitization toxicity standard value for CMIT/MIT, or the no expected sensitization induction level (NESIL), was $1.25{\mu}g/cm^2/day$ in humans. According to a calculation of body exposure to cosmetics use, the systemic exposure dosage (SED) was calculated as 0.00423 mg/kg bw/day when leave-on and rinse-off products were considered. Additionally, the consumer exposure level (CEL) amounted to $0.77512{\mu}g/cm^2/day$ for all representative cosmetics and $0.00584{\mu}g/cm^2/day$ for rinse-off products only. As a result, the non-cancer margin of safety (MOS) was calculated as 633, and CMIT/MIT was determined to be safe when all representative cosmetics were evaluated. In addition, the skin sensitization acceptable exposure level (AEL)/CEL was calculated as 0.00538 for all representative cosmetics and 2.14225 for rinse-off products; thus, CMIT/MIT was considered a skin sensitizer when all representative cosmetics were evaluated. Current regulations indicate that CMIT/MIT can only be used at concentrations 0.0015% or less and is prohibited from use in other cosmetics products. According to the results of this risk assessment, the CMIT/MIT regulatory values currently used in cosmetics are evaluated as appropriate.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.4
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• pp.255-265
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• 2015

Shelter system is applying to weapon systems as usage of performing specific mission with arranging several electronic equipments and operators. Recently the electronic equipments is changing from development products to COTS(commecial off-the-shelf) for demonstrating high performance at low cost. As internal operators of shelter system conduct several missions for specific or long time in this present situation, one of the most important element considering the best combat power is internal noise level. Therefore, I desire to analyze the features and foresee multiple noise level with test for conforming whether requirements of design is met or not in this research paper.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.11
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• pp.1144-1150
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• 2009

Appropriate vibration model is required to predict in advance the vibration level of a large vehicle which carries sensitive electronic/mechanical equipments and drives often on the unpaved and/or off-road conditions. Central tire inflation system(CTIS) is recently adopted to improve the mobile operation of military and bulletproof vehicles. In this paper, full vehicle model(FVM) having 11 degrees of freedom and equipped with CTIS has been developed for a large vehicle which has $8\times8$ wheels$\times$driving wheels. Usability of the developed model is validated via road tests for three different modes (i.e. highway, country, and mud/sand/snow modes) and for various velocity conditions. The developed FVM can be used to predict the vibration level of the large vehicle as well as to determine the driving velocity criterion for different road conditions.

• Journal of Audiology & Otology
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• v.25 no.2
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• pp.65-71
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• 2021

Background and Objectives: In masking level difference (MLD), the masked detection threshold for a signal is determined as a function of the relative interaural differences between the signal and the masker. Study 1 analyzed the results of school-aged children with good school performance in the MLD test, and study 2 compared their results with those of a group of children with poor academic performance. Subjects and Methods: Study 1 was conducted with 47 school-aged children with good academic performance (GI) and study 2 was carried out with 32 school-aged children with poor academic performance (GII). The inclusion criteria adopted for both studies were hearing thresholds within normal limits in basic audiological evaluation. Study 1 also considered normal performance in the central auditory processing test battery and absence of auditory complaints and/or of attention, language or speech issues. The MLD test was administered with a pure pulsatile tone of 500 Hz, in a binaural mode and intensity of 50 dBSL, using a CD player and audiometer. Results: In study 1, no significant correlation was observed, considering the influence of the variables age and sex in relation to the results obtained in homophase (SoNo), antiphase (SπNo) and MLD threshold conditions. The final mean MLD threshold was 13.66 dB. In study 2, the variables did not influence the test performance either. There was a significant difference between test results in SπNo conditions of the two groups, while no differences were found both in SoNo conditions and the final result of MLD. Conclusions: In study 1, the cut-off criterion of school-aged children in the MLD test was 9.3 dB. The variables (sex and age) did not interfere with the MLD results. In study 2, school performance did not differ in the MLD results. GII group showed inferior results than GI group, only in SπNo condition.

• Korean Journal of Audiology
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• v.25 no.2
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• pp.65-71
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• 2021

Background and Objectives: In masking level difference (MLD), the masked detection threshold for a signal is determined as a function of the relative interaural differences between the signal and the masker. Study 1 analyzed the results of school-aged children with good school performance in the MLD test, and study 2 compared their results with those of a group of children with poor academic performance. Subjects and Methods: Study 1 was conducted with 47 school-aged children with good academic performance (GI) and study 2 was carried out with 32 school-aged children with poor academic performance (GII). The inclusion criteria adopted for both studies were hearing thresholds within normal limits in basic audiological evaluation. Study 1 also considered normal performance in the central auditory processing test battery and absence of auditory complaints and/or of attention, language or speech issues. The MLD test was administered with a pure pulsatile tone of 500 Hz, in a binaural mode and intensity of 50 dBSL, using a CD player and audiometer. Results: In study 1, no significant correlation was observed, considering the influence of the variables age and sex in relation to the results obtained in homophase (SoNo), antiphase (SπNo) and MLD threshold conditions. The final mean MLD threshold was 13.66 dB. In study 2, the variables did not influence the test performance either. There was a significant difference between test results in SπNo conditions of the two groups, while no differences were found both in SoNo conditions and the final result of MLD. Conclusions: In study 1, the cut-off criterion of school-aged children in the MLD test was 9.3 dB. The variables (sex and age) did not interfere with the MLD results. In study 2, school performance did not differ in the MLD results. GII group showed inferior results than GI group, only in SπNo condition.

• Geotechnical Engineering
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• v.12 no.5
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• pp.5-16
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• 1996

When braced excavation with temporary retaining wall installation, is performed in loose sand with high ground water level boiling may be induced and considerable damage on the excavation works and structures in the vicinity can take place. Recently, for the purpose of reinforcement of ground and cut-off of ground water behind the temporary retaining wall, high pressure jet grouting is widely used. The purpose of this paper is to investigate the effects of jet grouting on ground reinforcement and cut -off of the ground water behind temporary retaining walls for braced excavation. A series of both laboratory and field tests has been performed. The test results show that high pressure jet grouting has sufficient effects on reinforcement of stiffness of ground and retaining wall. The permeability of the improved ground was 10-f_ 10-3cm l s smaller than those of the original ground. Therefore, the effect on cut off of ground water behind temporary retaining walls could be improved by high pressure jet grouting method.

• Journal of Convergence for Information Technology
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• v.9 no.6
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• pp.175-182
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• 2019

This study was conducted to test the assessment validity and examine the cut-off scores for driving risk as a part of the Self-report Assessment Forecasting Elderly Driving Risk (SAFE-DR) development project. The 132 senior drivers were categorized as either risky of 58 or safe of 74 drivers through the Drivers 65 Plus. Based on this initial assessment, we analyzed the risk prediction cut-offs. Furthermore, we tested the construct, content, and predictive validity. The cut-off score for the prediction of driving risk was found to be 74.5 points. The positive predictive value was 88.6%, and the negative predictive value was 86.3% about the cut-off score, signifying an excellent level of discrimination. Convergent validity, nomological validity, and content validity were found to be appropriate. Therefore, this study confirms that SAFE-DR is an appropriate assessment that can be used to screen dangerous elderly drivers.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.2
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• pp.207-213
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• 2008

This study examined the effects of added amounts of skate (Raja kenojei) flour on the physical and sensory properties, and consumer acceptability of Jook. As the level of skate flour increased the L-values and b-values decreased, and a-values increased. The Jook also had higher viscosity and lower spread ability values as the amount of skate flour increased. Sensory characteristics, such as color intensity, viscosity, nutty taste, and off-flavor increased significantly with the addition of skate flour. A consumer acceptability test indicated that the 3% skate flour group had the highest overall acceptability, appearance, flavor, and texture. In conclusion, to enhance the quality of Jook, a 3% addition of skate flour would be the useful.

• Journal of the Korean Home Economics Association
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• v.47 no.3
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• pp.79-85
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• 2009

This study examined the effects of added amounts of Lotus root powder on the physical and sensory properties, and consumer acceptability of Jook. As the level of Lotus root powder increased, L-value decreased and a and b values increased. The Jook also had higher viscosity and lower spreadability values as the amount of Lotus root powder increased. Sensory characteristics, such as color intensity, viscosity, nutty taste, and off-flavor increased significantly with the addition of Lotus root powder. A consumer acceptability test indicated that the 25% Lotus root powder group had the highest overall acceptability, appearance, flavor, and texture. In conclusion, to enhance the quality of Jook, a 25% addition of Lotus root powder would be the most beneficial.