• Journal of the Korean Geosynthetics Society
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• v.10 no.3
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• pp.25-32
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• 2011

The matric suction and volumetric water content of dredging soils obtained from Saemangeum area were measured by the automated Soil-Water Characteristic Curve (SWCC) apparatus under both drying and wetting conditions. Based on the test result, SWCCs of the dredging soils were estimated by the van Genuchten(1980) model. The matric suction of drying process is larger than that of wetting process at a same effective degree of saturation. The suction stresses for various matirc suctions were estimated using Lu and Likos(2006) model and the Suction Stress Characteristic Curves (SSCC) were predicted using the independent parameter of SWCC. The suction stress of drying path was increased and decreased, while the suction stress of wetting path was continuously decreased with increasing the effective degree. Also, the suction stress of drying path is larger than that of wetting path at a same effective degree of saturation. The Hydraulic Conductivity Function(HCF) was also predicted by the van Genuchten(1980) model. The hydraulic conductivity was increased with increasing the volumetric water content. The hydraulic conductivity of drying path is larger than that of wetting path at a same matric suction. According to the results of SWCCs and SSCCs, the hysteresis phenomenon of suction stress or matric suction during both drying and wetting paths was occurred. The main reason of hysteresis phenomenon is a ink bottle effect of water among soil particles.

• Journal of the Korean Geotechnical Society
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• v.36 no.10
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• pp.33-39
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• 2020

A geological repository has been considered as an option for the disposal of high-level radioactive waste (HLW). The HLW is disposed in a host rock at a depth of 500~1,000 meters below the ground surface based on the concept of engineered barrier system (EBS). The EBS is composed of a disposal canister, buffer material, backfill material, and gap-filling material. The compacted bentonite buffer is very important since it can restrain the release of radionuclide and protect the canister from the inflow of ground water. The saturation of the buffer decreases because high temperature in a disposal canister is released into the surrounding buffer material, but saturation of the buffer increases because of the inflow of ground water. The unsaturated properties of the buffer are critical input parameters for the entire safety assessment of the engineered barrier system. In Korea, Gyeongju bentonite can be considered as a candidate buffer material, but there are few test results of the unsaturated properties considering temperature variation. Therefore, this paper conducted experiment of soil-water characteristic curve for the Gyeongju compacted bentonite considering temperature variation under a constant water content condition. The relative error showed approximately 2% between test results and modified van-Genuchten model values.

• Journal of the Korean Home Economics Association
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• v.24 no.2
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• pp.113-122
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• 1986

The purpose of this study was to investigate the relationship between personality and color preference, thereby to suggest a personality profile on the basis of colors selected for children's preference. Materias used to determine the degree of color preference were 24 color papers which were developed and described in a previous research by Lee & Lee. The Instrument used ot determine children's personality was Burks' Behavior Rating Scales-Preschool and Kindergarten Edition. Subjects wee 70 3-, 4- and 5- year old children attending the Y Child Development research institute. Data were analyzed with SPSS using mainly F-test and Duncan's Multiple Range Test. Results showed that among 24 colors used, white, violet, sapphire, sky blue, blue, green yellow, pink, green, red, gold, purple, van dyke brown, blue, green, silver were found to be significantly related to persionality. Judging from this results, white and violet seemed to be most predictive colors to personality. Personality aspects significantly related to specific colors were discussed and a profile of personality based on color preference were developed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.433-439
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• 2018

In this paper, a SDINS(strapdown inertial navigation system) rapid initial alignment technique with adaptive time delay compensation is proposed. The proposed method consists of two steps. In first step, misalignment and data latency are estimated by conducting pre-transfer alignment. Then, hybrid alignment is designed to rapidly find the misalignment changes induced by pyro-shock. To improve the performance of hybrid alignment, adaptive time delay compensation method is suggested. We verify the performance improvement of the proposed alignment scheme comparing with the conventional transfer alignment method by van test. The test result shows that the proposed alignment technique improves alignment performance.

• Journal of Korea Society of Industrial Information Systems
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• v.9 no.2
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• pp.1-8
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• 2004

In this paper, we propose three estimators of Kullback-Leibler Information functions using the data from accelerated life tests. This acceleration model is assumed to be a cumulative exposure model. Some asymptotic properties of proposed estimators are proved. Simulations are performed for comparing the small sample properties of the proposed estimators under use condition of accelerated life test.

• Journal of Information Technology Applications and Management
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• v.25 no.1
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• pp.33-45
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• 2018

This study was initiated to investigate the essential skill factors for system designers in order to build the right information systems. The predicted variables are mathematical modeling skill, verbal modeling skill, general IT knowledge, and general business knowledge. The test was administrated to 43 students majoring in Management Information Systems (MIS) at Hannam University, South Korea. In this study, we used Pearson Correlation Analysis to test the relationships among variables. Overall, our study suggested that there is a strong positive relationship between mathematical and verbal skills and IS modeling ability. A marginal positive relationship between the general IT knowledge and IS modeling ability was also found. Unexpectedly, there was no significant relationship between general business knowledge and IS modeling ability.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.3
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• pp.242-250
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• 2003

We propose the monitoring system scheme for the CPS/INS integrated navigation system. The design requirements of the monitoring system are suggested and the software scheme based on GUI is proposed. The proposed monitoring system consists of an I/O interface part, a navigation data display part, and a post-processing part. The I/O interface part is responsible for data communication between the monitoring system and a navigation computer unit. The navigation data display part provides various display methods to show the navigation data to user in real-time. The post-processing part collects the navigation data to analyze the performance of navigation system. The proposed monitoring system software was developed using the Visual C++ programming language and a van test was carried out to demonstrate the real-time operation of the monitoring system. The test result shows that the proposed monitoring system can be effectively applied to the CPS/INS integrated navigation system.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.94-94
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• 2000

In this paper, the performance of INS/GPS integration is analyzed. Generally the integration method is classified into two method. One is loosely coupled integration, Another is tightly coupled integration. For the simulation, the error model of Kalman fitter is defined and the result of simulation is analyzed. When the number of visible satellites is less than four, the error of tightly coupled integration is smaller than that of loosely coupled integration. To very the result of simulation, van test that use LP-81 IMU and Millen3151R GPS receiver is carried out.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.189-189
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• 2015

In this study, the corrosion resistance and adhesion of electrophoretic paint (E-paint) were studied on AZ31 magnesium alloy pretreated in cerium chemical conversion coating solutions with the addition of various ethanol concentrations. It was found that with increasing ethanol concentration from 0 to 90 percent can decrease the formation of $Mg(OH)_2/MgO$ and increase the formation of nano-crystalline cerium oxides on the coating. Both corrosion resistance and adhesion of E-painted AZ31 increased with increasing ethanol concentration. The best E-paint sample was observed on the sample pretreatment in cerium chemical conversion coating solution with the addition of 80 percent of ethanol. This sample showed an excellent adhesion without paint detached after water immersion test for 500 h at $40^{\circ}C$, and only a few blisters observed at the near scratched sites after 1000 h salt-spray test.

• Mycobiology
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• v.30 no.1
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• pp.47-50
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• 2002

Seed-borne fungi of some maize cultivars/lines grown during the months from May to September of 2001, collected from Dongguk University farm, Go Young City, IL Sang Gu, Korea were detected by blotter method. In all six fungi namely Alternaria alternata(Fr.) Keissler, Aspergillus niger Van Tiegh, Fusarium moniliforme Sheldon, Fusarium sp., Penicillium sp. and Ustilago zeae Unger. were found to associated with maize seeds. Prevalence of seed-borne fungi also varied. The highest percentages of seed-borne fungi were recorded with Fusarium moniliforme and the lowest in Penicillium sp. Transmission of all seed-borne pathogens from seeds to seedlings were also detected by test tube seedling symptom test. Among the seed-borne fungi, Alternaria alternata, Fusarium moniliforme and Fusarium sp. produced distinct seed rot and seedling infection symptoms. All the transmitted seed-borne fungi might be caused primary source of infection to the maize crop.