• Journal of Magnetics
• /
• 제2권1호
• /
• pp.1-6
• /
• 1997

The magnetic and magnetostrictive properties of melt-spun ribbons of the alloys (R0.33Fe0.67)1-xBx (R=Tb0.3Dy0.7 and 0$\leq$x$\leq$0.06) are ivestigated as a function of wheel speed during melt-quenching. The saturation magnetiation of the alloys with a crystalline phase ranges from 70 to 80 emu/g and does not vary substantially with the B content. The saturation magnetization of an amorphous phase, which is formed at the condition of thigh wheel speed and high B content, is reduced significantly, however. The coercive force is minimum at x= 0.02 and increases monotonously with the further increase of B content when the microstructure mainly consists of a crystalline phase, but again it is reduced significantly by the formation of an amorphous phase. The low field sensitivity of magnetostriction with magnetic field is found to be good for the alloys with x$\leq$0.04 over a wide range of wheel speed. This magnetostrictive behavior is in contrast with that observed previously for Dy-Fe and Tb-Fe based alloys and is thought to be due to low intrinsic magnetocrystalline anisotropy of the compound.

• Journal of Information Display
• /
• 제11권3호
• /
• pp.109-112
• /
• 2010

The solid phase compositions and dielectric properties of silicon nitride ($SiN_x$) films prepared using the plasma enhanced chemical vapor deposition (PECVD) technique at a low temperature ($200^{\circ}C$) were studied. Controlling the source gas mixing ratio, R = $[N_2]/[SiH_4]$, and the plasma power successfully produced both silicon-rich and nitrogen-rich compositions in the final films. The composition parameter, X, varied from 0.83 to 1.62. Depending on the film composition, the dielectric properties of the $SiN_x$ films also varied substantially. Silicon-rich silicon nitride (SRSN) films were obtained at a low plasma power and a low R. The photoluminescence (PL) spectra of these films revealed the existence of nano-sized silicon particles even in the absence of a post-annealing process. Nitrogen-rich silicon nitride (NRSN) films were obtained at a high plasma power and a high R. These films showed a fairly high dielectric constant ($\kappa$ = 7.1) and a suppressed hysteresis window in their capacitance-voltage (C-V) characteristics.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2006년도 춘계학술발표대회
• /
• pp.231-234
• /
• 2006

현재까지는 실시간 임베디드 소프트웨어 개발을 위한 효율적인 소프트웨어 모델링 언어가 부족하다. 그런데 모델 자체가 코드처럼 수행 가능한 통합 모델링언어를 xUML(Executable UML)이라 한다[2,4,7]. 이는 기존의 UML x.x에 실행과 관련된 개념과 시간에 관련된 규칙을 더한 것이다. 다시 말해 xUML의 모델은 실행과 테스트, 디버깅이 가능하다[2,4]. 본 논문에서는 기존의 UML x.x버전들과 xUML이 실시간 임베디드 소프트웨어를 모델링 하는데 적합한지를 비교/분석한 후, 임베디드 소프트웨어 모델링에 xUML을 적용하고자 부족한 면을 보완 및 확장하였다. 확장된 xUML의 노테이션은 병렬과 실시간 처리까지도 표현이 가능하도록 제안하였다. 사례 연구로서 두개의 터치센서로 동작하는 실시간 임베디드 시스템의 모델링을 보여준다.

• 한국지반환경공학회 논문집
• /
• 제12권4호
• /
• pp.25-31
• /
• 2011

본 연구의 목표는 전자빔공정을 통한 1,4-dioxane 처리의 최적화를 이루기 위해 실험계획법을 적용하는 것이다. 주요 인자를 1,4-dioxane removal efficiencies(%), TOC removal efficiencies(%)로 반응표면분석법(RSM) 중 중심합성실험법을 이용하여 수학적으로 표시하였다. 1,4-dioxane의 농도를 "$x_1$", Irradiation intensity를 "$x_2$"로 지정하였다. 1,4-dioxane 농도와 removal efficiencies(%)의 코드화된 회귀방정식은 $y=71.00-10.85x_1+20.67x_2+{1.53x_1}^2-{7.92x_2}^2-1.23x_1x_2$, 1,4-dioxane 농도와 TOC Removal efficiencies(%)의 코드화된 회귀방정식은 $y=44.48-13.25x_1+9.54x_2+{5.43x_1}^2-{1.35x_2}^2+4.45x_1x_2$로 나타났다. 모델 예측식의 $R^2$(Adj.)가 90%이상으로 실험적인 관찰결과 잘 맞는 것으로 나타났다. 마지막으로 조류 Pseudokirchneriella Subcapitata를 이용하여 전자빔에 의한 1,4-dioxane에 대한 독성평가를 실시한 결과 전자빔 조사선량의 증가에 따라 생물학적 방해영향이 저감되었다.

• 한국세라믹학회지
• /
• 제48권4호
• /
• pp.323-327
• /
• 2011

The effects of $Dy_2O_3$ and $Er_2O_3$ co-doping on electrical properties and temperature stability of barium titanate ($BaTiO_3$) ceramics were investigated in terms of microstructure and structural analysis. The dielectric constant and the insulation resistance (IR) of 0.7 mol% $Dy_2O_3$ and 0.3 mol% $Er_2O_3$ co-doped dielectrics had about 60% and 20% higher than the values of undoped one, respectively, and the temperature coefficient of capacitance (TCC) met the X7R specification. The addition of $Dy_2O_3$ contributed to electrical properties caused by increase of tetragonality; however, preferential diffusion of $Dy^{3+}$ ions toward A site in $BaTiO_3$ grain exhibited an adverse effect on temperature stability by grain growth. On the other hand, The $Er_2O_3$ addition in $BaTiO_3$ could affect the TCC behavior and the IR with suppression of grain growth caused by reinforcement of grain boundary and electrical compensation. Therefore, the enhanced electrical properties and temperature stability through the co-doping could be deduced from the increase of tetragonality and the suppression of grain growth.

• Journal of Preventive Medicine and Public Health
• /
• 제10권1호
• /
• pp.44-51
• /
• 1977

In order to determine values for the body weight by height groups for Korean adults men who are fully grown up 4,028 (30-39 age-group ; 2,318, 40-49 age-group 1,340, and 50-59 age group : 370) apparently healthy males subjects were randomly selected for the measurement of body weight by height groups. 1) The avergae body height and weight of Korean adult men were $168.3{\pm}4.6cm$ and $63.4{\pm}7.1kg$ in 30-39 age group, $167.7{\pm}4.7cm$ and $63.4{\pm}7.4kg$ in 40-49 age group, and $167.3{\pm}5.2cm$ and $63.3{\pm}8.0kg$ in 50-59 age group. 2) A correlation coefficient of r=+0.52(P<0.001) between body height and weight was found in 30-39 age group of 2,318 subject, r=+0.48(P<0.001) in 40-49 of 1,340 and r=+0.53(P<0.001) in 50-59 of 370 with the aid of there coefficients of linear regression equation body weight and height were established for male as follow; for 30-39 age group, Y(weight in kg)=0.81X(height in cm)-73.02, 40-49 age group, Y(weight in kg)=0.74X(height in cm)-61.82, 50-59g age-group, Y(weight in kg)=0.82X(height in cm)-73.83. 3) With the aid of above listed various equation standard values for body weight by height group, with over weighing and under weighing values were established. 4) Standard bodyweight of Korean was lower than those of American, Japanese and several other formulas for ideal body weight.

• 한국결정학회지
• /
• 제12권4호
• /
• pp.212-215
• /
• 2001

NaOAC·3H₂O 존재 하에서, manganese nitrate(Mn(NO₃)₂·H₂O )와 imidzole-4,5-dicarboxylic acid(IDCH₂)가 수열반응하여, 실험식 [Mn(IDC)(H₂O)]을 가지는 2차원 배위고분자 합성되었다. 화합물 1의 구조가 분광학적 방법(IR) 및 X-ray 회절법으로 규명되었다. 화합물의 1의 결정학적 자료: 사방정계 공간군 Pbca, a=7.257(5) Å b=13.687(5)Å, c=14.332(6)Å Z=8, R(wR₂)=0.0498(0.0999).

• 한국결정학회지
• /
• 제12권4호
• /
• pp.207-211
• /
• 2001

Cd(SCN)₂{CH/sub 6/H/sub 10/(NH₂)₂}₂(1) 착물을 합성하고 단결성 X-선 회절법으로 구조를 규명하였다. 이 착물은 단사정계, 공간국 P2₁/ space group with a=11.842(2), b=7.926(2), c=11.291(2) Å, β=106.73(3)°V=1014.8(4)Ų, Z=2 로 결정화되었으며, 1775 개의 독립적인 회절반점에 대한 최종 신뢰도 인자 R₁및 ωR₂값은 각각 0.0518 및 0.1315이었다. 착물의 결정 구조는 2개의1,2-Diaminocyclohexane리간드의 질소 원자 xy 평면에서 Cd(II) 금속원자에 chelate 되어 5-membered ring을 형성하며, 2개의 thiocyanate 리간드의 황 원자가 z 축 방향으로 Cd(II) 금속 원자에 트란스 형태로 결합함으로 써 z축 방향으로 약간 늘러진 팔면체 구조의 착물을 형성한다.

• 한국자기학회지
• /
• 제5권5호
• /
• pp.841-845
• /
• 1995

The effect of small addition of Nb on the electrical resistivity and Hall coeffcient of the amorphous $Fe_{83}Zr_{7}B_{10}$ alloy and annealed ones ones below the crystallization temperature were investigated, which has been considered to be suitable for high frequency core material. At room temperature, their resistivities $\rho$ and the spontaneous Hall coeffcients $R_{s}$ are $~1.6\;{\mu}{\Omega}m$ and $~3{\times}10^{-8}m^{3}/As$, respectively. $R_{s}$ and $\rho$ are decreased with increasing temperature from 100 K to room temperature. Side-jump effect was adopted to analyze the effect of the small variation of conentration and annealing. The quantity of $R_{s}/{\rho}^{2}$ at room temperature, which is directly related to the electronic structure of the mother alloy, remained almost a constant except as quenched one as it can be predicted from the side-jump effect. The unexpected temperature dependence of $R_{s}/{\rho}^{2}$ measured at low fields much below Tc is left as a question.

• 한국자기학회지
• /
• 제5권5호
• /
• pp.772-777
• /
• 1995

The effect of small addition of Nb on the electrical resistivity and Hall coefficient of the amorphous $Fe_{83}Zr_{7}B_{10}$ alloy and annealed ones below the crystallization temperature were investigated, which has been considered to be suitable for high frequency core material. At room temperature, their resistivities $\rho$ and the spontaneous Hall coefficients $R_{s}$ are $~1.6\;{\mu}{\Omega}m$ and $~3{\times}10^{-8}m^{3}/As$, respectively. $R_{s}$ and $\rho$ are decreased with increasing temperature from 100 K to room temperature. Side-jump effect was adopted to analyze the effect of the small variation of concentration and annealing. The quantity of $R_{s}/{\rho}^{2}$ at room temperature, which is directly related to the electronic structure of the mother alloy, remained almost a constant except as quenched one as it can be predicted from the side-jump effect. We suggested the temperature dependence of $R_{s}/{\rho}^{2}$ can be compared to Ms{T}.