• Bulletin of the Korean Chemical Society
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• v.20 no.6
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• pp.720-726
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• 1999

It has been proved by the semi-classical gauge invariant formulation (GIF) that the correct interaction operator for coupling the field-free material states with the radiation field must be the position form regardless of the gauge chosen for expressing the electromagnetic potentials, in accordance with the well-established principle of gauge invariance. The semi-classical GIF is now extended to the quantized radiation field interacting with matter by defining the energy operator for the quantized radiation field in the presence of matter. It will be shown in this paper that the use of the energy operator guarantees the position form of the interaction operator even in the Coulomb gauge, contrary to the conventional approach in which the dark material Hamiltonian is used to get the interaction operator of the momentum form. The multipolar Hamiltonian is examined in the context of the quantum mechanical gauge transformation.

• Nuclear Engineering and Technology
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• v.1 no.2
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• pp.103-106
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• 1969

A new representation for the Dirac equation, which may be appropriate to describe the interaction of the charged particle with the electric field, is derived by introducing a gauge-independent unitary transformation. It is shown that in this representation the effective Hamiltonian without potentials has a new feature in the non-relativistic limit.

• Communications of the Korean Mathematical Society
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• v.16 no.3
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• pp.405-413
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• 2001

The inverse boundary value problem for the steady state heat equation with convection term is considered in a simply connected bounded domain with smooth boundary. Taking the Dirichlet to Neumann map which maps the temperature on the boundary to the that flux on the boundary as an observation data, the global uniqueness for identifying the convection term from the Dirichlet to Neumann map is proved.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.117-120
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• 2008

The Purpose of this is properties of CFT filled with expansion concrete. CFT(concrete filled steel tube) is the structure that circle shape steel column filled with concrete. 3 kinds of expansive additives and variation of replacement rate. we changed expansive additive from 0%, 10%, 20%, 30% of ratio of addition rate are selected for this experiment. Merits of CFT are concrete internal force rising influenced by steel shape restriction, reinforcing the local buckling, excellent resistance to transformation. Generally, High rise building using CFT utilize the high strength and fluidity concrete for packing the tube inside. As the result a steel tube charged expensive concrete has stiffness 1.5times more than a steel tube not charged concrete. Increase of resisting power about compressive stress by binding expansion of expansive concrete affects strength increase and softness.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.411-415
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• 2002

In this paper, a mechanical probe for CMM (Coordinate Measuring Machine) with a three-axis force-sensing unit is proposed, which is capable of measuring an actual contact position without the lobbing effect and the pre-travel error. The force-sensing unit detects the external force, which is act on the stylus of CMM during the measuring process. Thus, the contact point of the stylus of CMM can be estimated ken the direction of measured force components. Based on the structural analysis of the proposed CMM probe, the transformation matrix is derived and calibrated so that it shows linear relationships between the estimated force components from the output voltages and the real input forces. And, the relationships are verified through the computer simulation. The results show that the proposed mechanical probe is very useful fur detecting the contacting force components on measuring process of CMM.

• Fashion & Textile Research Journal
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• v.1 no.2
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• pp.148-153
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• 1999

The purpose of this study was to manufacturing of personal dress form by replica method for draping. The objects were physical body and personal dress form of their torso somatotype. Comparing the measurements of Martin method and of sliding gauge method to examine the fitness of dress form. Dress form was found bigger than physical body. This was due to the transformation in processing that wrap a Suck-Go bandage and pack a polyurethane foam. On the basis of the result, manufacturing of personal dress form and foundation by draping, it was wearing done test on the physical body, through the procedure that investigate the possibility of usage and the manufacture of personal dress form.

• Journal of Korea Water Resources Association
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• v.41 no.6
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• pp.587-595
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• 2008

In order to aid the derivation of the IDF relationship for a station with insufficient duration-rainfall data, an approach to derive a simple and practical IDF formula is presented. The IDF formula is described simply by the term of the two parameters and a design frequency. The model parameters were estimated from a statistical technique based on the normal distribution of transformed rainfall intensities. In order to give the transformed data, both the Kruskal-Wallis statistic and the Manly transformation of duration-rainfall data were adopted. With the methods, the proposed IDF formula becomes a simpler model that compares well with conventional form. In addition, it allows avoiding an exceptional condition of the higher rainfall intensity for longer duration. The performance of the proposed formula was evaluated by using the limited rainfall data for short duration from two gauge stations. The result showed that the IDF formula developed in this work was an effective tool, providing a reliable relationship between the intensity and duration even though insufficient data are only available.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.29-33
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• 2004

This paper presents ESPI system for the measurement of thermal expansion coefficient of STS430 up to 1,000$^{\circ}C$. Existing methods, strain gauge and moire have the limitation of contact to object and do not supply the coefficient up to 800$^{\circ}C$. There needs to measure the data up to 800$^{\circ}C$, because heat resistant materials have high melting temperature up to 1,000$^{\circ}C$. In previous studies related to thermal strain analysis, the quantitative results are not reported by ESPI at high temperature, yet. In-plane ESPI and vacuum chamber for the reduction of air turbulence and oxidation are designed for the measurement of the coefficient up to 1,000$^{\circ}C$and speckle correlation fringe pattern images are processed by commercial image filtering tool-smoothing, thinning and enhancement- to obtain quantitative results, which is compared with references data. The comparison shows two data are agreed within 4.1％ blow 600$^{\circ}C$ however, there is some difference up to 600$^{\circ}C$. Also, the incremental ratio of the coefficient is changed up to 800$^{\circ}C$. The reason is the phase transformation of STS430 probably begins at 800$^{\circ}C$.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.11
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• pp.69-74
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• 2004

This paper presents ESPI system for the measurement of thermal expansion coefficient of STS430 up to 1,00$0^{\circ}C$ . Existing methods, strain gauge and moire have the limitation of contact to object and do not supply the coefficient up to 80$0^{\circ}C$ . There needs to measure the data up to 80$0^{\circ}C$, because heat resistant materials have high melting temperature up to 1,000'E In previous studies related to thermal strain analysis, the quantitative results have not reported by ESPI at high temperature, yet. In-plane ESPI and vacuum chamber for the reduction of air turbulence and oxidation are designed for the measurement of the coefficient up to 1,00$0^{\circ}C$ and speckle correlation fringe pattern images are processed by commercial image filtering tool-smoothing, thinning and enhancement- to obtain quantitative results, which is compared with references data. The comparison shows two data are agreed within 4.1% blow $600^{\circ}C$ however, there is some difference up to $600^{\circ}C$. Also, the incremental ratio of the coefficient is changed up to 80$0^{\circ}C$ . The reason is the phase transformation of STS430 probably begins at 80$0^{\circ}C$

• Atmosphere
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• v.24 no.3
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• pp.433-444
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• 2014

Although the Radar-AWS Rainrate (RAR) calculation system operated by Korea Meteorological Administration estimated precipitation using 2-dimensional composite components of single polarization radars, this system has several limitations in estimating the precipitation accurately. To to overcome limitations of the RAR system, the Korea Meteorological Administration developed and operated the RMQ (Radar-based Multi-sensor Quantitative Precipitation Estimation) system, the improved version of NMQ (National Mosaic and Multi-sensor Quantitative Precipitation Estimation) system of NSSL (National Severe Storms Laboratory) for the Korean Peninsula. This study introduced the RMQ system domestically for the first time and verified the precipitation estimation performance of the RMQ system. The RMQ system consists of 4 main parts as the process of handling the single radar data, merging 3D reflectivity, QPE, and displaying result images. The first process (handling of the single radar data) has the pre-process of a radar data (transformation of data format and quality control), the production of a vertical profile of reflectivity and the correction of bright-band, and the conduction of hydrid scan reflectivity. The next process (merger of 3D reflectivity) produces the 3D composite reflectivity field after correcting the quality controlled single radar reflectivity. The QPE process classifies the precipitation types using multi-sensor information and estimates quantitative precipitation using several Z-R relationships which are proper for precipitation types. This process also corrects the precipitation using the AWS position with local gauge correction technique. The last process displays the final results transformed into images in the web-site. This study also estimated the accuracy of the RMQ system with five events in 2012 summer season and compared the results of the RAR (Radar-AWS Rainrate) and RMQ systems. The RMQ system ($2.36mm\;hr^{-1}$ in RMSE on average) is superior to the RAR system ($8.33mm\;hr^{-1}$ in RMSE) and improved by 73.25% in RMSE and 25.56% in correlation coefficient on average. The precipitation composite field images produced by the RMQ system are almost identical to the AWS (Automatic Weather Statioin) images. Therefore, the RMQ system has contributed to improve the accuracy of precipitation estimation using weather radars and operation of the RMQ system in the work field in future enables to cope with the extreme weather conditions actively.