• Journal of the Korean Geotechnical Society
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• v.15 no.4
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• pp.153-166
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• 1999

Since the reliability of results by the existing analyzing method is low, in the case of for excavation performed in urban area whose stability is of great importance, construction control based on field monitoring is always necessary. But the field monitoring reflects only the behavior of construction process that has already been carried out, and it has limitations in predicting the behavior of the expected construction process, which is practically more important for construction control. In this study, construction control system for excavation which can predict the behavior of the expected processes during construction with high degree of accuracy, is developed by adopting inverse analysis. The inverse analied applied field monitoring results to excavation analysis can improve the reliability of predicted results. The developed system uses an elasto-plastic soil spring model for the excavation analysis and the minimization of least squared errors between measured displacements and calculated displacements for the inverse analysis. All the required processes for construction control can be performed as an integrated work within the system reflecting real time application and user's convenience. Their applicabilitis are confirmed by two case studies.

• Applied Biological Chemistry
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• v.27
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• pp.56-67
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• 1984

As in many other country, the use of organic matter in Korea has long history. Farmers understand the value of organic matter as the source of plant nutrient and soil improving agent in general. Since 50 years ago, the sources of organic matter in paddy soils were compost, rice and barly straw, green manure, animal waste, fish and beancake, etc.. Application of green manures such as vetch and chinese milk vetch showed no significant effect on the yield of brown rice in paddy soil. On the other hand, the effects of compost and rice straw showed more significant on the yield of brown rice in paddy soil. Application of rice straw in rice cultivation is commonly made at different times between harvest, early spring and several weeks before transplanting. Considering the suitable paddy soil for application of rice straw under well to moderately well drained soil, the yield was pronounced more than poorly drained soil. Based on laboratory and field experimants, application of rice straw promoted the decrease of oxidation-reduction potential in well to moderately well drained soil. This results to be enhanced the release of some mineral nutrients,. such as potassium, calcium, silicon, and increase of availability of soil phosphorus. In the field experiments, results obtained from nitrogen fraction on the immobilization-mineralization of the tracer nitrogen applied in paddy soil,the amount and index of organic nitrogen incoporated in soil was more pronounced in rice straw application than control. Rice straw and its transformation products incoporated in the soil, provided the inflow of energy necessary to maintain heterotrophic microbes activities. Rice straw and its transformation products, especially soluble carbohydrate, enhanced the population of free-living heterotrophic $N_2$ - fixing microbes. Moreover, rice straw and its transformation products in paddy soil, enhanced the activities of soil enzymes such as dehydrogenase and urease.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.3
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• pp.182-188
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• 1991

With a purpose of finding out the effects of cattle slurry applicatioin on the dry matter yield, yield component, and botanical composition in the mixed sward, a field experiment was conducted with two times and five levels of cattle slurry application. The experimental field was laid.out in a split-plot design with three replications, and lasted from September. 1986 to October, 1990 at the Livestock Experiment Station in Suweon, The results obtained are summarized as follows: 1. At each harvest time, the plant growth of the plots with cattle slurry application was slightly worse when compared to dressing of mineral fertilizer. 2. Average dry matter yield for 4 years was not significantly different between the slurry application times, just after cutting, and 15 days after cutting, The DM yield in the plot with cattle slurry 30 m!/ha and mineral fertilizer(9,095 kg/ha) and with cattle slurry 60 m1/ha and mineral fertilizer(8, 987 kg/ha) were decreased by 8% and 10% than that of the plot with mineral fertilizer application(9,937 kg/ha), respectively. 3. The DM yield component of the plots with cattle slurry application just after cutting was much better when compared to manuring 15 days after cutting. And it was much better in the plot with cattle slurry 60 m"/ha and mineral fertilizer which was composed of 73.8% grasses(6.636 kg/ha). 24.6% legumes (2,207 kdha) and 1.6% weeds(144 kdha). 4. In general, the botanical composition was relatively good in the plots with slurry application just after cutting. Grassland vegetation of the plots with cattle slurry 60 m"/ha and mineral fertilizer was changed into much better botanical composition with 66.8% grasses, 30.2% legumes and 3. 1% weeds at the end of the experiment.xperiment.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.442-451
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• 2008

The evaluation of field degree of consolidation on soft clays has been an important problem in geotechnical areas. Monitoring either settlements or pore water pressures has been widely applied in the filed, but occasionally they have some problems. This study addresses the suggestion and application of another method for evaluating the degree of consolidation using shear wave velocities. A research site where soft clay layers were consolidated by surcharging loads was chosen. Laboratory tests were performed to determine the relation between shear wave velocity and effective stress. Field seismic tests were conducted several times during the consolidation of the clay layers. The tests results show that the shear wave velocity increased significantly as clays consolidated. The shear wave velocities at each field stress states were derived from the laboratory results and the degree of consolidation was evaluated by comparing the shear wave velocities obtained by laboratory and field seismic methods. In most stress states, the degree of consolidation evaluated using the shear wave velocity matched well with that obtained from field settlement record, showing the potential of applying the method using shear waves in the evaluation of field degree of consolidation on soft clay deposits.

• Current Optics and Photonics
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• v.7 no.2
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• pp.119-126
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• 2023

The vibratory and rotational levels of many biological macromolecules lie in the terahertz (THz) band, which means that THz techniques can be used to identify and detect them. Moreover, since the biological activity of most biomolecules only becomes apparent in aqueous solution, we use microfluidic technology to study the biological properties of these biomolecules. THz time-domain spectroscopy was used to study the THz absorption characteristics of graphene oxide (GO) aqueous solution at different concentrations and different exposure times in fixed electric or magnetic fields. The results show that the spectral characteristics of the GO solution varied with the concentration: as the concentration increased, the THz absorption decreased. The results also show that after placing the solution in an external electric field, the absorption of THz first increased and then decreased. When the solution was placed in a magnetic field, the THz absorption increased with the increase in standing time. In this paper, these results are explained based on considerations of what is occurring at the molecular scale. The results of this study provide technical support for the further study of GO and will assist with its improved application in various fields.

• Computers and Concrete
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• v.30 no.5
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• pp.323-337
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• 2022

This paper proposes a numerical model to simulate the rotational behavior of steel fiber in fresh cement-based materials in the presence of a magnetic field. The results indicate that as the aspect ratio of fiber increases, the required minimum magnetic field intensity to make fiber rotate in viscous fluid increases. The optimal magnetic field intensity is 0.03 T for aligning steel fiber in fresh cement-based materials to ensure that the applying time of the magnetic field can be conducted concurrently with the vibrating process to increase the aligning efficiency. The orientation factor of steel fiber in cement mortar can exceed 0.85 after aligning by 0.03 T of the uniform magnetic field. When the initial angle of the fiber to the magnetic field direction is less than 10°, the magnetic field less than 0.03 T cannot make the fiber overcome the yield stress of fluid to rotate. The coarse aggregate in steel fiber-reinforced concrete is detrimental to the rotation and alignment of the steel fiber. But the orientation factor of ASFRC under the 0.03T of the magnetic field can also exceed 0.8, while the orientation factor of SFRC without magnetic field application is around 0.6.

• The Journal of Information Systems
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• v.20 no.3
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• pp.81-109
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• 2011

The increase in the number of smartphone users has recently been steep, which started to offer companies and individuals more opportunities to enter into a new business field. Furthermore, the smartphone applications have become one of the hottest topics inside and outside the mobile industry. Still the market is in its infancy and intention to pay of charged application of most smartphone users is relatively low. However, rate of charged application in appstore is expected to be increase steadily for some years to come. In this perspective, it is important to consider the smartphone mobile application. Research on smartphone application is still in its early stage. Thus, the purpose of this study is to find what are the effective factors on user satisfaction and intention to pay of mobile application. Based on information system success model, we proposed system quality(stability, usability, security), information quality(timeliness, accuracy, enjoyment) and service quality(reactivity, reliability, empathy) as factors to effect on user satisfaction in mobile application. The results showed that stability, usability, timeliness, accuracy, enjoyment, reactivity and empathy affected significantly user satisfaction. The relationship among satisfaction and intention to pay of mobile application was significantly supported. The implications of the findings is that firms and individual developers of mobile application should focus on customer retention through enhancing satisfaction and quality.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.870-872
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• 2008

It is known that AC electric field to drive IPS mode of liquid crystal display (LCD) causes reduction of the contrast after long period of display operation. Our results are presented in this paper on a base of a model of interaction between surface of PI alignment film and LC molecules. We conclude that the surface viscosity of PI alignment film is one of the most important factors for the contrast reduction phenomenon.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.154-155
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• 2015

This study was to review the basic characteristics in order to evaluate field application of the emergency road repair materials for development of CAC(Calcium Aluminate Composite) usage. The experiment was conducted with two phases of field and laboratory conditions and the laboratory experiment consisted indoor and outdoor tests for compressive and flexural strength. In the result of an experiment, for the compressive strength test, the specimens that cured in the laboratory conditions were not satisfied the requirement of standards, while the specimens that cured in the field conditions were well satisfied with those. For flexural strength test, the result value was satisfied with the requirement on the standards only in outdoor curing condition of laboratory experiment. Based on these results, it is expected that the CAC can be used as an emergency road repair material for field conditions.

• Korean Journal of Mathematics
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• v.12 no.2
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• pp.193-200
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• 2004

We shall introduce the notion of the windowed Fourier transform in $\mathbb{Q}_p$ and show that, for any given function $g{\in}L^2(\mathbb{Q}_p)$ of norm, the windowed Fourier transform of $f$ with respect to $g$ be a function of norms, and moreover be expressible to a summation form. The results obtained in this paper will be usable to the field of research in data compression for signal processing according to the following scheme.