• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.170-178
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• 2005

Multi-hole type oxygen combustion burner was developed for industrial gasification and smelting furnace. We investigated characteristics of flame, radiation transfer, and soot emission in the convectional oxygen burner with respect to the feeding condition of fuel and oxygen. Regarding the results of the conventional burner, we designed new burners which have larger fuel consumption rate and radiation heat transfer. We changed the size and hole number and shape of the exit plane of the burner. In addition, the performance of the burner was tested with respect to the feeding condition of the fuel and air: Normal Diffusion flame(NDF) and Inverse Diffusion Flame(IDF). We investigated the flame configuration, radiation heat transfer, and soot formation by using a CCD camera, heat flux meter, and Laser Induced Incadescence(LII), respectively. The stable operating condition was obtained by the flame configuration and the flame of the burner which has dented exit plane was more stable in whole operating conditions. The characteristics of radiative heat transfer were sensitive to the feeding condition of reactants and the flame of 75% primary oxygen and 25% secondary oxygen of the IDF case shows maximum radiation heat transfer. The soot volume fraction of the flame was measured in the axial direction of the flame and the amount of soot volume fraction is proportion to the radiation heat transfer. As a result, we can get the optimal operating condition of the newly designed burner which enhances the characteristics of flame stabilization and radiation heat transfer.

• 한국항공우주학회지
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• 제35권11호
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• pp.999-1005
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• 2007

공력미계수에 대한 실시간 추정은 비정상적인 조종면 작동의 경우, 고장에 대한 정보를 분석하여 비행임무를 계속 수행하거나 본부로 회항비행을 지속할 수 있도록 하는 재형상 제어를 위해 필요하다. 본 논문에서는 고장허용제어시스템에 대한 기반 연구로서 무인비행기 안전성 향상을 위하여 조종면 작동불능과 같은 고장에 대해 검출 방법을 제시하였다. 조종면 고장검출을 위한 실시간 시스템식별 알고리듬은 퓨리에 변환기법을 사용하였으며 프로그램 성능 및 검증을 위해 HILS 시험을 수행하였다. 고장 조종면은 피칭모멘트, 요잉모멘트, 롤링모멘트에 대한 조종면 효과를 나타내는 조종미계수들을 실시간 추정하여 정상상태의 값과 비교하여 검출된다. 비행시험 결과를 통해 고장상태의 조종미계수 값은 정상상태의 값보다 작다는 것을 정량적으로 확인하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제37권1호
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• pp.21-28
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• 2014

배양된 췌장베타세포와 신경세포를 10% FBS (fetal bovine serum), 11.1 mM glucose의 normal 조건과 1% FBS, 30 mM glucose의 hyperglycemia 조건으로 배양하고, 저 LET X-선을 0.5 Gy/hr의 선량률로 총 선량이 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 Gy가 되도록 저 LET 방사선을 조사한 후 MTT assay로 생존율을 측정하고 비교하였다. 분화된 췌장베타세포에 방사선을 조사하지 않았을 때는 normal 조건에 비해 hyperglycemia 조건의 생존율이 경미한 감소를 보였다. 그러나 X선의 총 선량이 점차 누적됨에 따라 normal 조건에서 생존율이 조금씩 감소하는 것에 비해 hyperglycemia 조건에서는 급격히 감소하여 시너지 효과를 나타냈다. 미분화된 신경세포에서는 방사선을 조사하지 않은 때도 normal 조건에 비해 hyperglycemia 조건의 생존율이 뚜렷하게 감소하였다. X선의 총 선량이 점차 누적됨에 따라 normal 과 hyperglycemia 조건 모두에서 비교적 급격한 세포사멸이 나타났지만 그 생존율의 감소비율이 거의 평행하게 진행되어 시너지 효과를 보이지 않았다.

• International Journal of Contents
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• 제7권4호
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• pp.50-55
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• 2011

To achieve efficient field formulations and fast numerical computations, the reciprocal relations and equivalence between tangential and normal boundary conditions for electromagnetic fields are discussed in terms of the Maxwell's differential equations. Using the equivalence of each boundary condition, we propose the six essential boundary conditions, which may be applicable to matching electromagnetic discontinuities to efficiently design RF devices. In order to verify our approach, the reflection characteristics of a rectangular waveguide step are compared with respect to six essential boundary conditions.

• Transactions on Control, Automation and Systems Engineering
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• 제4권3호
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• pp.195-198
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• 2002

In this note, we suggest a new matching condition and extend the stability analysis to the ultimate boundness of state $\chi$(t) for uncertain input-delay systems, using a sliding control with delay compensation.

• Smart Structures and Systems
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• 제19권2호
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• pp.203-211
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• 2017

This paper provides a numerical solution for multiple confocal elliptic dissimilar cylinders. In the problem, the inner elliptic notch is under the traction free condition. The medium is composed of many confocal elliptic dissimilar cylinders. The transfer matrix method is used to study the continuity condition for the stress and displacement along the interfaces. Two cases, or the infinite matrix case and the finite matrix case, are studied in this paper. In the former case, the remote tension is applied in y- direction. In the latter case, the normal loading is applied along the exterior elliptic contour. For two cases, several numerical results are provided.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.131-134
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• 1991

In order to determine an operating pattern of SLIM in an experimental MAGLEV vehicle, operating characteristics of SLIM are obtained using a disk type test facility. The test results are compared with the pre-estimated values. It is found that a closed loop control is required for operating at a constant slip-frequency condition which makes the normal force minimum.

• 대한수학회보
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• 제55권4호
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• pp.1137-1147
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• 2018

In this paper, we discovered a sufficient condition ensuring the weighted composition operators $C_{{\omega}_1,{\varphi}_1},{\cdots},C_{{\omega}_N,{\varphi}_N}$ were disjoint supercyclic on $H({\Omega})$ endowed with the compact open topology. Besides, we provided a condition on inducing symbols to guarantee the disjoint supercyclicity of non-constant adjoint multipliers $M^*_{{\varphi}_1},M^*_{{\varphi}_2},{\cdots},M^*_{{\varphi}_N}$ on a Hilbert space ${\mathcal{H}}$.

• 대한수학회보
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• 제49권6호
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• pp.1193-1198
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• 2012

By constructing suitable Lyapunov functionals and combining with matrix inequality technique, a new simple sufficient condition is presented for the global asymptotic stability of the Cohen-Grossberg neural network models. The condition contains and improves some of the previous results in the earlier references.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.95.5-95
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• 2002

Tool condition monitoring is recognized important in CNC machining processes since the excessive wear or breakage of tool has to be noticed immediately in an automated manufacturing system to keep the quality and productivity. In this research, as an economic way of detecting the status of tool change, the wavelet transform has been applied to the measurement of spindle motor current. The energy of a specific level shows the difference between a normal tool and worn one. By setting a limit on the change of energy, it is possible to notify the time to inspect the tool.