• Computers and Concrete
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• v.16 no.4
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• pp.643-667
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• 2015

3-dimentional precast recycled aggregate concrete (RAC) finite element models were developed by means of the platform OpenSees to implement sophisticated nonlinear model subjected to seismic loads. Efforts were devoted to the dynamic responses (including dynamic characteristics, acceleration amplifications, displacements, story drifts) and capacity curve. In addition, this study extended the prediction on dynamic response of precast RAC model by parametric study of material properties that represent the replacement percentage of recycled coarse aggregate (RCA). Principles and assumptions that represent characteristics of precast structure and influence of the interface between head of column and cast-in-place (CIP) joint on the stiffness of the joints was put forward and validated by test results. The comparison between simulated and tested results of the precast RAC frame shows a good correlation with most of the relative errors about 25% in general. Therefore, the adopted assumptions and the platform OpenSees are a viable approach to simulate the dynamic response of precast frames made of RAC.

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.266-272
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• 2010

Natural Ginger extract was extracted from Ginger component using ethanol as a solvent, and we tested various pharmaceutical characteristics in this extract. Characteristics experiment to use natural Ginger extract tested antimicrobial experiment using microbe, and analyzed organic and inorganic component with analysis instrument. From the result of characteristics experiment, some conclusions are obtained as follow. In this experiment, natural Ginger extract was obtained about 22.50 g-Ginger extract(extraction ratio : 1.80%) as liquid state of some viscous yellow-brown color. The result of antimicrobial experiment with staphylococcus aureus and aspergillus niger in microbe decreased more and more according to passage of reaction time. This phenomenon could know that Ginger extract has influenced to antimicrobial effect. In the result of instrumental analysis, aromatic organic components of benzimidazole(1.283), propyl isothiocyanate or isothiocyanic acid(1.477) etcs from Ginger extract were detected with GC/MS and inorganic component of Ca(27.6 ppm), K(24.08 ppm), Mg(6.03 ppm), Na(1.02 ppm), Zn(1.02 ppm), Sb(0.711 ppm) and Li(0.079 ppm) etcs from Ginger extract were detected with ICP/OES.

• Journal of Korean Society of Transportation
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• v.14 no.3
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• pp.91-125
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• 1996

The purpose of this paper is comparatively to evaluate the confidence of Vehicle-Detector informations for various detectors in order to test to be possible the application of these to real time traffic signal control. The detectors which are tested for this study are Circle-Shaped Loop, Ultrasonic, Microwave and Image detector. The tested items for each detectors are traffic volume, degree of saturation for through and left turn movement, speed and queue length, etc. These items for each are tested at the field according to several situations, such as dry day, raining day, night and daytime. The result of these tests are performed comparative analysis and statistical examination in order to increase the confidence of the experiments.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.147-152
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• 1999

The purpose of this study is to offer foundmental information of fly ash concrete for field application. Through before study of fly ash concrete, various properties were checked. but when fly ash was added In concrete, entrained air quantity was decreased as fly ash substitution is increased in fresh concrete. so entrained air(below AE) quantity and a kind of AE according to fly ash substitution was tested basic properties. Also water-reducing efficiency was tested. And hydration heat according to fly ash substitution was tested by KR-100. As result of test, according to fly ash substitution increase, entrained air quantity is increase for target entrained air quantity, water-reducing efficiency and hydration heat are positive.

• Journal of The Korean Association For Science Education
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• v.24 no.1
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• pp.1-16
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• 2004

The purpose of this study was to examine the role of cognitive conflict in the conceptual change process. Ninety-seven high school students in Korea participated in this study. Before instruction, we conducted pretests to measure learning motivation and learning strategies. During instruction, we tested the students' preconceptions about Newton's 3rd Law and presented demonstrations. After this, we tested the students' cognitive conflict levels and provided students learning sessions in which we explained the results of the demonstrations. After these learning sessions, we tested the students' state learning motivation and state learning strategy. Posttests and delayed posttests were conducted with individual interviews. The result shows that cognitive conflict has direct/indirect effects on the conceptual change process. However, the effects of cognitive conflict are mediated by other variables in class, such as state learning motivation and state learning strategy. In addition, we found that there was an optimal level of cognitive conflict in the conceptual change process. We discuss the complex role of cognitive conflict in conceptual change, and the educational implications of these findings.

• Journal of the Korean Society for Railway
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• v.4 no.1
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• pp.31-37
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• 2001

There are three examples of noise reduction test by joint improvement. One of them is tested for electric car at joint rail and another is tested at expansion joint and long welded rail and the third is tested at open deck bridge. We can know from the result that the noise reduction effect of rail welding is very different to the type of track and the car. The condition of the test has some differences, but it may be useful reference of noise reduction

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.135-151
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• 1982

In order to investigate the effectiveness of Osmose process for the practical treatment of wood this study has been made using water soluble preservatives such as Malenit and chromated zinc chloride. The results obtained in this investigation are as follows: 1. The penetration of Malenit in sapwood has been observed deeper than that of chromated zinc chloride for all species tested in this investigation. 2. The penetration of preservatives applied in soft wood, ie. Pinus densiflora and Larix leptolepis has been observed better results than that of hard wood, i.e., Quercus accutissima and Carpinus laxiflora. 3. The longer stack covering, despite of preservatives applied and size of wood tested, has given better penetration for all species tested, and the fastest diffusion has been occured in 15 days from they day started. Following after 15 days diffusion had gradualy become slower. 4. The length of time needed for effective penetration has taken 45 days for all species tested, reaching twenty millimeters (20mm) in depth in case of Malnit, that means also more than 50% of penetration into sapwood portion. However it has taken 45 days fer Pinus densiflora and Larix leptolepis, reaching fifteen millimeters (15mm) and 60 days for Quercus accutissima and Carpinus laxiflora, reaching same fifteen millimeters in case of chromated zinc chloride, that means also less than 50% (except 50% for Larix) of penetration into sapwood portion. 5. Deeper penetration of preservatives from the wood surface has been observed in the larger wood than the smaller wood for all species tested, although the penetration ratio between the width of sapwood and the length penetrated has been observed smaller in larger wood than smaller wood. 6. The relation between moisture content of wood and the penetration of preservatives into wood tested has shown the linear regression, that is, the more moisture content brought the deeper penetration. 7. Following the result obtained at this investigation osmose process with Malenit applied has indicated as a useable process for the none pressure treatment of wood.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.95-102
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• 2003

Corestone rock mass has complex characters because it is made up of stronger and stiffer corestone in a weaker and softer matrix. Physical model corestone rock mass made up of stiffer corestone in weaker matrix were tested in uniaxial compression and numercal modelling analysis The result of the uniaxial compression tests showed that increasing the corestone proportion generally increased the modulus of deformation. And the strength decreased in the lower corestone proportion, but it increased in the higher proportion(45%, 65% corestone by volume). The strength and the modulus of deformation were not affected by different size coretone on the same proportion. The result of the numerical modelling analysis showed similar trend compared with the result of the result of the uniaxial compression test. But though the result of th uniaxial compression test is similar to the result of the numerical modelling analysis, it's unreasonalble to apply the results of this paper to in situ corestone rock mass. So mere laboratory tests including triaxial test and the other numerical program analyses are necessary to apply the results to in situ corestone mass

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.4
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• pp.1-21
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• 2001

The purpose of this stuffy is to derive critical success factors for ERP system implementation by integrating managerial, technical. human resource and organizational culture factors welch have been proposed as influencing factors for the performance of ERP system implementation in previous studios. Especially, this stuffy divides ERP system implementation process into preparation stave, implement stage and settle-down and stabilization stave, and then derives critical success factors in each stage. The data for empirical analysis of the research model are collected from 64 companies and the respondents for questionnaire consist of ERP system implementation project managers and user department managers in companies which have already operated it after ERP system installation. The main results of this study are as follows. First, it derives 27 success factors through comprehensive review of various factors which may affect ERP system implementation performance, and categorizes them into one of three stapes preparation stave, implement stage, and settle-down and stabilization stage. Second, the relationship between many success factors at each stave (preparation stave, implement stage, and settle-down and stabilization stave) and performance variables is tested. As a result, the significant correlations between many success factors at each stage and ERP system implementation performance are found, and the difference among success factors in the degree of influencing the system performance is significantly shown. finally, the relationship between process-oriented performance variables and result-oriented performance ones is tested. As a result, it is found that there is significant correlation between process-oriented performance variables except for one variable-project resource management appropriateness - and result-oriented performance ones. The theoretical contribution of this study is to derive a comprehensive model of critical success factors for implementing ERP system project from the system deve1opment life cycle perspective, and empirically test it through field survey with a wide range of data collection. And, the practical implication of this study is to present the desirable guidelines for performing ERP system implementation project successfully.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.4 s.19
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• pp.37-47
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• 2005

The purpose of this study is to estimate the bearing capacity and settlement characteristics of the weathered granite masses, and on the process to achieve the purpose, in the first place, the weathered degree according to the absorption index was examined and reviewed, then plate bearings test in in-situ depth were tested, and finally the result was compared and examined with the result of the existing, estimate method and pressuremeter test. In order to achieve the purpose of this study, a typical area distributed with weathered granite masses, gyeonggi area, was chosen as a sample site for testing, and in the result, it appeared and found out that the more the weathered degree increases when the plate bearing test are tested, the more the bearing capacity decreases a numerical indexes and the more greatly the width of the decrease of bearing capacity increases around the boundary of specific, weathered degrees. Also, In the result from estimating the bearing capacity of weathered granite masses by the existing, suggested formula, it appeared that there is a tendency that the more the weathered degree increases, the more similar the bearing capacity becomes with the result of plate bearing tests.