• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.8 no.1
• /
• pp.23-26
• /
• 2002

This study was carried out to investigate vibration shock and dropping shock of refrigerator during physical distribution. The values of vibration shock were measured to be ${\sim}3G$ for up and down direction, ${\sim}0.8G$ for right and left direction and ${\sim}0.5G$ for back and forth direction on the national road. There was no damage during transport. From the results of dropping test by KS A 1026(General Rules of Performance Testing for Packaged Freights), relative equations were gained as follow : y = 0.12x + 7.63(where y is G-factor and x is Dropping height). The maximum values of dropping shock during materials handling were measured to be 11G. This shock value was corresponding to dropping shocks of dropping height 28.3cm by KS A 1026.

• Journal of the Korean Chemical Society
• /
• v.25 no.1
• /
• pp.21-25
• /
• 1981

A study was made of the influence of butyl alcohol on the distribution coefficients of barium and mercury ions between the ion exchange resin, Dowex 50w-x8, 200~400 mesh and solutions containing hydrochloric acid, butyl alcohol and water. The determination of the distribution coefficients of barium and mercury are made by using the batch method. The distribution coefficients of metal ions decrease generally as the number of branches of carbon in the molecule of butyl alcohol increase. It shows that solubility in water and stereo-isomerism of the butyl alcohol have influence upon the distribution coefficient of barium and mercury.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1995.05b
• /
• pp.827-832
• /
• 1995

한국원자력연구소 실증소각시설의 성능 및 운전성을 입증하기 위하여 방사성동위원소를 포함한 모의폐기물 및 원자력발전소 발생 방사성폐기물에 대한 시험소각을 실시하였다. 비휘발성인 $^{60}$Co 및 $^{54}$Mn의 거동은 비산재의 거동과 거의 유사하였으며 각각의 제염계수는 4.7 x $10^{5}$및 6.2 x $10^{5}$이었다. 반휘발성인 $^{137}$Cs의 경우에는 8$50^{\circ}C$ 및 $700^{\circ}C$의 다른 소각온도에서 각각 2.8 $\times$ $10^4$, 2.6 $\times$ $10^3$으로 소각온도의 의존성을 보여주었다. 원자력발전소에서 운반된 건조 방사성폐기물(DAW)에 대한 시험소각은 성공적으로 수행되었다. 총 베타/감마 방사능에 대한 제염계수가 1.1 $\times$ $10^{5}$이었으며 결과적인 연돌에서의 배출농도는 0.019 Bq/N㎥으로 기체상 배출물에 대한 최대허용농도를 만족시킬 수 있었다.수 있었다.

• Archives of Pharmacal Research
• /
• v.8 no.1
• /
• pp.1-6
• /
• 1985

The crystal structure or $\gamma$-hydroxy-$\betha$-aminobutyric acid was determined by MULTAN system with X-ray intensity data on a diffractometer and refined by the least-squares method to an R-value 0.034 for 711 reflections. The crystals were orthorhombic, space group $P2_{1}2_{1}2_{1}$, Z = 4, with a = 10.220, b = 8.257 and c = 6.556$\AA$. The molecule takes the zwitterionic form and skeletal conformation is trans-transform. The molecules are held together by intra-and intermolecular NH-O and OH--O hydrogen bonds.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.8
• /
• pp.1805-1810
• /
• 2009

The adsorptions of trimethygallium (TMG) and arsine (As$H_3$) on H/Si(100)-2x1 surface were theoretically investigated. In the case of TMG adsorption, methane loss reaction, surface methylation, hydrogen loss reaction and ring closing reaction channels were found. The mechanism of As$H_3$ adsorption on the surface was also identified. Among these, the methane loss reaction depositing –Ga(C$H_3)_2$ was found to be the major channel due to its low barrier height and the large exothermicity. The surface methylation reaction is the second most favorable channel. In contrast, arsine turned out to be less reactive on the surface, implying that Arsine surface reaction would be the rate limiting step in the overall ALD process.

• Journal of Magnetics
• /
• v.8 no.2
• /
• pp.85-88
• /
• 2003

The magnetic and transport properties far single crystals of Ru-doped mono-layered manganites $La_{0.5}Sr_{1.5}-Mn_{1-x}Ru_xO_4$ (0$\leq$$\chi$$\leq$0.1) have been studied using neutron diffraction and magnetization measurements. Temperature dependent magnetization data reveal that with an increase in the Ru concentration the parent charge ordered antiferromagnetic state is gradually destroyed and new ferromagnetic phase evolves. In the low Ru-doped system spin glass behavior is apparent in low temperature region, which is confirmed by ac and do magnetization measurements. The competing magnetic interaction between Mn/Mn and Mn/Ru couples is the most likely cause of the spin glass transition.

• Journal of Institute of Control, Robotics and Systems
• /
• v.9 no.8
• /
• pp.623-631
• /
• 2003

We have fabricated the two-dimensional inverted pendulum system and designed its controller. The two-dimensional inverted pendulum system, which is composed of X-Y table, is actuated through timing belt by each of two geared DC motors. And the control goal is that the rod is always kept to a vertical position to any distrubance and is quickly moved to the desired position. Because this system has generally nonlinear dynamic characteristics and X-axis and Y-axis move together, it is very difficult to find its exact mathematical model and to design its controller. Therefore, we have designed the PID controller with simple structure and excellent performance. Genetic algorithm(GA), which is blown as one of probabilistic searching methods, and human's heuristic control strategy are introduced to design an optimal PID controller. The usefulness of the proposed GA based PID coefficient searching technique is verified through the experiments and computer simulations.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.44 no.6
• /
• pp.799-805
• /
• 1995

An infrared radiator of cordierite system were manufactured byslurry casting anddry pressing method. The characteristics of cordierite (2MgO.2Al$_{2}$O$_{3}$.5SiO$_{2}$)+30wt% clay+Xwt% MnO$_{2}$ of infrared radiator have been investigated as a function of MnO$_{2}$ additives (X=0, 0.1, 0.25, 0.5, 1.0, 1.5, 2.0, 2.5). The thermal expansioncoefficient was decreased with increasing amounts of MnO$_{2}$ additives. Otherwise, the spectral emissivity was increased in the below 4.5.mu.m wavelength. Also, the infrared radiator of cordierite system which spectral emissivity was approximately 1.0 can be attainable at from 4.5.mu.m to 8.mu.m wavelength. The spectral emissivity was decreased from 8.mu.m to 14.mu.m above X=2.5.

• Journal of the Korean Ceramic Society
• /
• v.37 no.1
• /
• pp.77-81
• /
• 2000

Silica glass films to utilize optical waveguides was fabricated by Aerosol Flame Deposition(AFD) method. As the amount of B2O3 increased in the sol solution of (92-x)SiO2-xB2O3-8P2O5, the thermophoretic deposition rate onto Si substrate was markedly lowered due to vaporizing out of B2O3 and P2O5 during the vaporization and reaction of the aerosol in the flame. GeO2 was added to 62SiO2-30B2O3-8P2O5 in order to control easily the refractive index of glass films. As the amount of GeO2 increased from 2 to 12 wt%, its refractive index increased from 1.4633 up to 1.4716.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.26 no.7
• /
• pp.1026-1035
• /
• 2002

The purposes of this study were to classify the front view of trunk of adult males into several kinds of shape and to provide the characteristics and silhouette of each group which has same shape. As the sample, subjects were l290 males of 20 to 54 year-old. The procedure and results were follows; l. The principal component analysis was used to obtain the shape factor of the front of the trunk 8 factors in the front which explained 86.8% of total variance were extracted. 2. As the result of the cluster analysis of factor scores, the font of body was classified in 4 types. 4 types were named X, A, Y and H type in the front considering the characteristics of each type.