좌전하행지 관동맥 개구부위의 망사형의 관(Slotted Tube)스텐트와 나선형 코일(Coil)스텐트 삽입후 단기 및 장기 암상 경과의 비교

박훈기,박성욱,이일수,이상곤,김진우,이근,정상식,이철환,홍명기,김재중,박승정 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.6

제주지역에서 무선호출 주파수의 전파 특성

이청민,장재성,강부식 濟州大學校工科大學附屬産業技術硏究所 1993 尖端技術硏究所論文集 Vol.4 No.-

Received field strength in land mobile-radio communication must consider characteristics besides. This paper analysis propagation chracterics to multipath and then compute theoretical value of field strength which vectorial compose and compared with measured value. Seorm base station is to unity south area of Cheju by single propagation area. But Gunwelak base station cause a weak and impossible received field area to increase obstruction. In order to replace it, we necessary technique study of new mobile communication propagation environment. For take a accuracy received field strength, the first thing field strength of a point must measure many times and calculate mean value of it. The second we must suggest and analytical modeling to compose to these measured values.

마이크로 펄스 플라즈마 질화법에 의한 선박엔진용 부품의 표면경화에 관한 연구

이재식,유용주 울산대학교 1996 공학연구논문집 Vol.27 No.2

본 연구는 마이크로 펄스 플라즈마 질화처리한 FCD60, S53C, SCM440강재를 고주파 유도경화 열처리한 동일 강재와의 비교분석을 통해 강 표면에 생성된 경화층의 두께와 경도 및 조직을 조사하고 마모시험을 행하였다. Hv550의 유효경도를 갖는 경화깊이는 마이크로 펄스 플라즈마 질화의 경우 FCD60, S53C, SCM440에서 각각 30㎛,25㎛,25㎛이었고, 고주파 유도경화 열처리는 각각 1.4mm이었다. 경화층의 XRD분석결과 마이크로 펄스 플라즈마 질화의 경우 FCD60과 S53C는 주로 r'- Fe₄N, SCM440은 r' - Fe₄N과 ε- Fe₃N의 혼합상이 생성되었으며, 고주파 유더경화 열처리된 경화층은 α- Fe로 모재와 같았다. 또한, 마모시험결과 상온에서는 고주파 유도경화 열처리에 의해 생성된 경화층이 내마모성이 좋으나, 고온(150℃)과 윤활상태에서는 마이크로 펄스 플라즈마 질화처리하에 의하여 생성된 질화층의 내마모성이 우수하였다. The case hardening of FCD60, S53C and SCM440 by micro-pulse plasma nitriding and high frequency induction heat treatment was invesigated. The effective case depth (of which hardeness is over Hv550) of FCD60, S53C and SCM440 nitrided by micro-;ulse plasma method was 30, 25 and 25㎛, respectively. XRE analysis of nitrided layer, showed that mixture of r' - Fe₄N and ε- Fe₃N phases formed on SCM440, r' -Fe₄N single phase formed on S53C and FCD60. In case of hihh frequency induction heat treatment, hardened layer was α - Fe single phase. The hardened hayer formed by high frequency induction heat treatment was more resistant to wear than nitrided layer at room temperature, however nitrided layer by micro-pulse plasma nitriding was more resistant to wear than induction hardened layer at high temperature and lubricated condition.

제주지역에서 무선호출 주파수의 전파 특성

이청민,강부식,장재성 濟州大學校 工科大學 産業技術硏究所 1993 産業技術硏究報告 Vol.4 No.-

Received field strength in land mobile-radio communication must consider characteristics besides. This paper analysis propagation chracterics to multipath and then compute theoretical value of field strength which vectorial compose and compared with measured value. Seorm base station is to unity south area of Cheju by single propagation area. But Gunwelak base station cause a weak and impossible received field area to increase obstruction. In order to replace it, we necessary technique study of new mobile communication propagation environment. For take a accuracy received field strength, the first thing field strength of a point must measure many times and calculate mean value of it. The second we must suggest an analytical modeling to compose to these measured values.

저작시 개구근 및 폐구근의 활성도에 관한 연구

이재현,천재식 단국대학교 치의학연구소 1990 논문집 Vol.2 No.-

The author obserbed the relationships of the action potential, masticatory force, and the surface area of masticatory Muscles. Fifty dental students who has no problems on occlusion, were participated in this study. E. M. G was taken from the masseter, digastric and anterior valley of temporal muscles, using Nohon Kohden MEM-3102 electromyograph. Masticatory forces were taken by MPM-3000 gnathodynamometer in clenching state. Surface area of Masseter Muscles were calculated from computerized Tomograph. The result were as follow ; 1. The action potential of working side was higher than that of Non-working side. 2. Mean Maximal occlusal force was 42±7Kg. The maximal action petential of Masseter muscle was 720±50μV. The maximal action potential of auterior valley of temporal muscle was 840±70μV. The maximal action potential of digastric Muscle was 150±40μV. 3. The difference of Surface area of Masseter Muscle seemed to be one of the causes of the difference of masticatory forces.

이중면 불연속 구형 도파관의 특성 해석

강부식,장재성,이청민 濟州大學校工科大學附屬産業技術硏究所 1993 尖端技術硏究所論文集 Vol.4 No.-

Double-plane steps discontinuity in rectangular waveguide is investigated with ?? mode analysis. This method accounts for the influence of evanescent fields and power transmission due to higher order modes. For these discontinuites the electromagnetic fields are derived and the scattering matrix is derived by applying the continuous condition in discontinuity. The scattering coefficients of a X-band to Ku-band waveguide transition as well as of resonant iris with finite thickness(t=2.0㎜) are calculated and compared with Patzelt's result. The scattering coefficients of the resonant iris(a=7.112㎜, b=3.556㎜, a₁=4.0㎜, b₁=1.0㎜, t=0.5㎜) are calculated and compared with Bornemann's results.

몰리브덴(V)와 시트릭액시드계 착물합성과 그 성질

최식영,이재덕 安東大學 1989 安東大學 論文集 Vol.11 No.1

A new series of dioxo-di-μ-oxo-dimolybdate(v), ◁화학식 삽입▷(원문을 참조하세요), has been prepared by reaction of pyridinum oxoisothiooyantomolybdate(v) with citric acid derivatives containing amine carboxyl groups. The properties and possible molecular structure of these complexes were discussed by elemental analysis, spectroscopic studies and magnetic susceptibility measurements. The infrared spectra of these complexes all show two strong Mo=O2 stretching bands in the 900~980cm-1, MoO2Mo very prominent strectching bands at around 410~425 and 735~750cm^(-1) to symmetrical and asymmetrical O-bridge stretching, a coordinated coo^(-) asymmetrical band in the 1585~1640cm^(-1). Also, d-d transition of molybdenyl complexes corresponding to ^(2)B_(2)-^(2)B_(1) occured in the 24,800~28,000cm^(-1) region, charge transfer transition corresponding to ligand-to-molybdenum in the 32,500~33,800, 42,000 ~47,500cm^(-1) region. The complexes synthesized were yellow or orange and diamagnetic.

콩의 개화기 전후 공급과 수용부위의 생장반응과 수량에 대한 질소의 효과

박재홍,송범헌,이철원,손석용,김홍식,박상일 忠北大學校 農業科學硏究所 2002 農業科學硏究 Vol.19 No.-

This study was conducted to examine the nitrogen effects on the growth responses, the nodulation, and the distribution of dry weight of plant tissues at major growth stages before and after the flowering stage, and to evaluate the yield components and yields with different nitrogen levels. Hwangkeum cultivar(Glycine max L mereill) was cultivated under five different nitrogen levels, 0, 2, 4, 6, 8, N Kg/10a. Stem length and branching number, which were investigated with different N levels at major growth stages, were rapidly increased for 14days for before and after the flowering stage compared to the other growth stages. They were clearly higher with treatment of 2 and 4 N kg/10a than those of other N treatments. Pod number was slightly increased from the flowering to beginning maturity. It was the highest in the treatment of 2 N Kg/10a. Comparing grain number per pod with different N levels, two grains per pod was much higher in all N treatments except for the treatment of 6 N Kg/10a. Dry weight of shoot(including leaf, stem, and pod) was rapidly increased from the flowering stage to the full seed stage and then gradually increased after the full seed stage, whereas the dry weight of root(including the nodule and root) was rapidly increased until to full pod stage and then linearly decreased from the full pod stage until the beginning maturity stage. Comparing dry weight with different N levels, the dry weight of shoot was the highest in the treatment of 4 N Kg/10a, while it of root was the highest in the treatment of 2N Kg/10a. The dry weight of nodule was the highest, 13.1 Kg/10a, at full pod stage. Comparing the dry weight of nodule with different N levels, it was increased to the application amount of 4 N Kg/10a and then clearly decreased with more application amount of N than 4 Kg/10a. The yield components which were mostly affected to the yield were pod number per plant and grain number per plant. They were 57.5 and 106.1, respectively, with treatment of 4 N Kg/10a, which showed the highest yield, about 266 Kg/10a. Comparing yield index with different N levels to the control, the yields with treatment of 2 and 4 Kg/10a were increased to 21% and 34%, respectively.

콩의 개화기전후 공급과 수용부위의 무기영양성분함량 및 흡수량에 대한 질소의 효과

박재홍,송범헌,이철원,손석용,김홍식,박상일 忠北大學校 農業科學硏究所 2002 農業科學硏究 Vol.19 No.-

This study was conducted to examine the nitrogen effects on the uptaken amounts and utilization of mineral nutrients between source and sink tissues at major growth stages before and after the flowering stage with different nitrogen levels Hwangkeum cultivar(Glycine max L Mereill) was cultivated under five different mtrogen levels, 0, 2, 4, 6, 8 N kg/10a Comparing contents of total-N with different plant tissues at major growth stages before and after the flowering, total-N contents of leaves was gradually decreased from the flowering to the beginning maturity, while it of pod was continuously increased from the full seed to the beginning maturity Total-N content was higher in the treatment of 4 N Kg/10a that those of others The uptaken amount of N determined with different growth stage was rapidly increased maturity Higher proportion of uptaken N were into the leaves at the full seed stage, and they were transported from the leaves into pod at the beginning maturity stage Comparing major mineral elements of the leaves and the pod with different N leaves, in case of the leaves, the content of Fe, Mn, and Zn was decreased throughout the growth stages, whereas the content of Ca and Mg was decreased from the flowering to the full seed and then it was increased after the full seed stage In case of pod, the content of K, Fe, Mn, Zn, and Na was decreased from the flowering to the beginning maturity, while contest of Mg was increased.

이중면 불연속 구형 도파관의 특성 해석

강부식,이청민,장재성 濟州大學校 工科大學 産業技術硏究所 1993 産業技術硏究報告 Vol.4 No.-

Double-plane steps discontinuity in rectangular waveguide is investigated with TE^(x)_(mn) mode analysis. This method accounts for the influence of evanescent fields and power transmission due to higher order modes. For these discontinuites the electromagnetic fields are derived and the scattering matrix is derived by applying the continuous condition in discontinuity. The scattering coefficients of a X-band to Ku-band waveguide transition as well as of resonant iris with finite thickness (t=2.0mm) are calculated and compared with Patzelt's result. The scattering coefficients of the resonant iris (a= 7.112mm, b= 3.556mm, a_(1) = 4.0mm, b_(1) =1.0mm, t=0.5mm) are calculated and compared with Bornemann's results.