http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
7차 슬기로운 생활 교과의 교육과정 운영실태와 개선방향
남경희,남호엽,조용채 서울교육대학교 2003 한국초등교육 Vol.14 No.2
Overall objectives of 'Life for Wisdom' are to help pupils have an interest in the interaction between oneself, and society around them and nature through concrete activities and personal experiences, think about oneself and one's own life. The purpose of this paper is to find a reform measure of the management of 'Life for Wisdom' in 7th National Curriculum, and the method of it is to inquiry the management through questionnaire. As findings on inquiry, Consideration should be given to the following items: 1. To intensify the principal of integrations and to raise the standard of integrations 2. To raise the quality of activity in the contents of a textbook. 3. To expand experiences and to select the optimal material in the lessons. 4. To value much of the process in the evaluations.
인슐린 비의존형 당뇨병 환자에서 혈장 Endothelin-1농도의 변화
신양수,조희충,김원식,국기용,김용화,정종훈,문철웅,배학연,양성훈 朝鮮大學校 附設 醫學硏究所 1992 The Medical Journal of Chosun University Vol.17 No.2
Endothelin(ET) is a 21-residue peptide originally isolated from the cultured porcine endothelial cells. There are at least three genes for endothelin:endothelin-1(ET-1), endothelin-2(ET-2), and endothelin-3(ET-3). Endothelins are present in various human biological fluids including plasma, urine, breast milk, and saliva and have been found elevated plasma ET concentrations in patients with diabetes mellitus, Patients undergoing maintenance hemodialysis due to chronic renal failure, patients with acute myocardial infarction, and patients with subarachnoid hemorrhage. Endothelial cell damage is suspected to occur in diabetic patients and may be one important cause of angiopathy, a major complication in diabetes mellitus. The elevation of ET in diabetic patients may be a marker of, and further exacerbate, their vascular disease. We measured the levels of ET-1 in plasma of 50 patients with non-insulin dependent diabetes mellitus(NIDDM) and 25 normal subjects by radioimmunoassay. The plasma ET-1 concentration (mean±S.D.) in NIDDM was 6.461 A2.510 f㏖/ ㎖, and was significantly higher than in normal subjects (4.567±1.155f㏖/㎖) (P<0.05). The plasma ET-1 concentration (mean±S.D.) in diabetic retinopathy group( 7.15±2.454 f㏖/ml) was significantly elevated than those in otherwise uncomplicated groups (5.348±2.390 f㏖/㎖)(P<0.01). The correlation between any clinical parameters and plasma ET-1 levels in NIDDM was not significant, In conclusion, this study suggest that the elevated levels of ET-1 in diabetic patients may be play a important role in the pathogenesis of diabetic complications.
Efficient electromagnetic boundary conditions to accelerate optimization of RF devices
Cho, Yong-Heui The Korea Contents Association 2011 International Journal of Contents Vol.7 No.4
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.
Cho, Yong-Heui The Korea Contents Association 2011 International Journal of Contents Vol.7 No.4
The scattering solutions for multiple rectangular metallic gratings in a perfectly conducting plane excited by the TE and TM delta sources are presented using an overlapping T-block method. A reflectarray composed of rectangular metallic gratings shows fanbeam radiation patterns that are useful for an electromagnetic fence. The scattering characteristics of multiple rectangular gratings were computed in terms of total radiated power and antenna directivity. The design method of a fan-beam reflectarray to obtain high directivity was also compared with superdirective radiation and parabolic reflector phase.
High Gain Metal-Only Reflectarray Antenna Composed of Multiple Rectangular Grooves
Yong Heui Cho,Woo Jin Byun,Myung Sun Song IEEE 2011 IEEE transactions on antennas and propagation Vol.59 No.12
<P>Using an overlapping T-block method based on mode-matching technique and virtual current cancellation, the scattering formulations for a metal-only reflectarray antenna composed of multiple rectangular grooves are rigorously presented in fast convergent integrals. By matching the normal boundary conditions at boundaries, we get the simultaneous equations of the TE and TM modal coefficients for plane-wave incidence and Hertzian dipole excitation. A metallic-rectangular-grooves based reflectarray fed by a pyramidal horn antenna was fabricated and measured with near-field scanning, thus resulting in 42.3 [dB] antenna gain at f = 75 [GHz]. Our circular reflectarray has 30 [cm] diameter and 5 961 rectangular grooves on its metal surface. The simultaneous equations for a Hertzian dipole feed are solved to approximately obtain the radiation characteristics of a fabricated reflectarray. The measured results are compared with those of the overlapping T-block method and the FDTD simulation and they show favorable agreements in terms of radiation patterns and antenna gain.</P>
Analytical Dispersion Equations of a Lossy Coaxial Waveguide in the Microwave and Visible Spectra
Yong Heui Cho 한국전자파학회JEES 2021 Journal of Electromagnetic Engineering and Science Vol.21 No.2
Analytical hybrid-mode dispersion relations of a lossy coaxial waveguide were rigorously analyzed using a mode-matching technique. In order to model a practical coaxial line with inevitable losses, we adopted an all-dielectric coaxial waveguide surrounded by the perfect electric conductor (PEC) boundary. The rigorous dispersion characteristics of the TM01, TE01, and EH11 modes were investigated for lossy coaxial waveguides filled with different electrical conductivities. Based on the exact solutions, approximate but accurate dispersion equations were proposed for the TM0p, TE0p , EHmp, and HEmp modes in order to estimate and compare the behaviors of complex propagation constants in the microwave and visible spectra.
A probe compensation equation using symplectic form
Yong Heui Cho 한국콘텐츠학회 2009 ICCC International Digital Design Invitation Exhib Vol.2009 No.12
Using symplectic form, we propose a probe compensation equation for planar, circular cylindrical, and spherical near-field antenna measurement. In the near-field antenna measurement, the probe compensation procedure is essential to increase accuracy of measurement. The symplectic form which is mainly used in mathematics is judiciously utilized to deduce a generalized probe compensation equation.