• Proceedings of the Korean Fiber Society Conference
• /
• 1998.04a
• /
• pp.14-19
• /
• 1998

Increasing demand for high modulus high strength polymeric materials have drawn considerable interest in industry. Thermotropic liquid crystal polymers (TLCP), differing from lyotropic liquid crystal polymers, have excellent melt processability and mechanical property resulting from the high degree of molecular orientation under a shear flow field in the molten state with relatively low viscosity$\^$1,2/.(omitted)

• Proceedings of the SCSK Conference
• /
• 2003.09a
• /
• pp.225-231
• /
• 2003

To search and development a new material with superior melanogenesis inhibitory activity, the bioactivities (obs. pl$_{50}$) of alkyl-3,4-dihydroxybenzoyl esters and N-alkyl-3,4-dihydroxybenz-oyl amides as substrate molecules were measured in mouse melanoma cells. And also, we have studied that 3-D QSARs (3 dimensional Quantitative Structure-Activity Relationships) between molecular interaction field of substrates and the bioactivities were analyzed using CoMFA (Comparative Molecular Field Analyses) method. When cross-validation value (q$^2$) is 0.68 at 3 components, the Pearson correlation coefficient ($r^2$) is 0.900. From the basis on the findings, the model was appeared by the contour map such as steric field and electrostatic field relationships between quantitative structure and the bioactivity of the various substrate derivatives. Measured bioactivities (obs. pl$_{50}$) of unknown compounds are very similar to predicted activity (pred. pl$_{50}$) according to the CoMFA model. As the results of prediction, we could conclude that the bioactivities were increased by creation of R$_1$ substitution of 5,5-dime-thylhexoxy, 6,6-dimethylheptyl, 1-amino-6,6-dimethylheptyl group etc and R$_2$ substitution of hydroxy, methyl, methoxy group etc.p etc.

• Journal of radiological science and technology
• /
• v.9 no.1
• /
• pp.73-81
• /
• 1986

This paper carried out an experiment on the characteristics of time, temperature, electric field and the dependense of electrode materials and gap length by the conduction current of the insulating oil used for x-ray tube housing. The obtained results can be summarized as following: 1. In the x-ray tube housing insulating oil with vacuum condition, conduction current is declined more than the x-ray tube housing insultaing oil with the air, and is held stable states. 2. At the low electric field the higher temperature of the x-ray tube housing insulating oil is increased, the more conduction current. 3. The dependence of electrode material is appeared at the low electric field and the short gap length than the high and the long with Fe> Cu >Al. 4. At the I-E characteristics, the low electric field than 1000 [V/cm] is appeared Ohm's law region, and the high become saturation region. 5. At the same electric field, the longer gap length become, the more conduction current is increased, and the same applied voltage, the longer, the less conduction current is decreased, the less low than high temperature x-ray tube housing insulating oil.

• Proceedings of the Korea Contents Association Conference
• /
• 2009.05a
• /
• pp.584-586
• /
• 2009

Dualized program for building Public Administration scholarship in Korea has been, in a sense, a result of theoretical tension between the two positions, politics/administration dualism vs. politics/administration monism. The program has maintained its integrity by its dependence on a foundational question, "Is administration a different field of action from politics?" Korean community for the study of public administration has maintained its oneness by internally asking this question even though the two external philosophical positions were relatively indubitable. Strating from the well-known changes in the community, this brief outline for the future full exegesis tries to read carefully one point shown in the second chapter of one of the most seminal proposals for foundation of modern Public Administration, one paragrahp in the second chapter of "The Study of Administration" by Woodrow Wilson. What was the contemporary meaning of Wilson's classic distinction made in 1887? Keeping this research question in our mind, we will attempt to prepare for the full understanding of a kind of internal distinction Wilson explicitly draws between the constitutional and the administrative.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.1442-1447
• /
• 2003

Computer is a very powerful machine which is widely using for data processing, DB construction, peripheral device control, image processing etc. Consequently, many researches and developments have progressed for high performance processing unit, and other devices. Especially, the core units such as semiconductor parts are rapidly growing so that high-integration, high-performance, microminiat turization is possible. The packaging in the semiconductor industry is very important technique to de determine the performance of the system that the semiconductor is used. In this paper, the inspection of the inner defects such as delamination, void, crack, etc. in the semiconductor packages is studied. ESPI which is a non-contact, non-destructive, and full-field inspection method is used for the inner defect inspection and its results are compared with that of C-Scan method.

• Proceedings of the KIEE Conference
• /
• 2002.11d
• /
• pp.183-186
• /
• 2002

The paper is proposed intantaneous torque control of IPMSM for drive of wide speed range. The control scheme is based on the mathematical model of the motor and is applicable to the constant torque and field weakening operations The scheme allows the motor to be driven with maximum torque per ampere (MTPA) characteristic below base speed and it maintains the maximum voltage limit of the motor wide field weakening and the motor current limit under all conditions of operation accurately. For each control mode. a condition that determines the optimal d-axis current $i_d$ for maximum torque operation is derived. The proposed control algorithm is applied to PMSM drive system for drive of wide speed range, the operating characteristics controlled by maximum torque control are examined in detail by simulation.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.7
• /
• pp.1057-1064
• /
• 2005

Photoluminescence (PL) spectra of Eu(III) and Tb(III) complexes with mixed oxydiacetate (ODA) and 1,10-phenanthroline (phen) ligands and with homoleptic ODA reveal characteristic line-splitting at 10 K, depending on the site-symmetry of the lanthanide ion in the complex. The energy-level schemes of the $^7F_J$ states and the emitting levels for Eu(III) and Tb(III) ions have been proposed by simulating the line splitting in the framework of crystal-field Hamiltonian. The sets of refined crystal-field parameters for the experimentally determined sitesymmetry satisfactorily reproduce the experimental energy-level schemes. In addition, the PL quantum yield and the decay time were determined at room temperature. The PL quantum yields of [$Eu(ODA){\cdot}(phen){\cdot}4H_2O]^+$ and [Tb$(ODA){\cdot}(phen){\cdot}4H_2O]^+$ in the crystalline state (Q = 17.7 and Q = 56.6%, respectively) are much greater than those of [Eu($ODA)_3]^{3-}and\;[Tb(ODA)_3]^{3-}$(Q = 1.1 and Q = 1.3, respectively), due to the energy transfer from phen to the lanthanide ion. In the aqueous state, the relaxation of the phen moiety due to the solvent results in the reduction of the quantum yield and the shortening of the lifetime.

• Korean Journal of Agricultural Science
• /
• v.31 no.2
• /
• pp.149-160
• /
• 2004

This study had carried out an analysis of leaf tobacco production cost by cost items, growing stages, and farm sizes per 10a to provide the basic data for determination of the purchasing price of leaf tobacco by KT&G. Considering the survey results of 12 tobacco farm households, the composition rates of production cost by items revealed as 7-10% for land service, 5-22% for depreciation, 13-25% for material costs, 50-65% for labour cost respectively. The production cost of leaf tobacco by growing stages were shown as 15.3% in nursery bed period, 32.3% in main growing period in field, 30.8% in harvesting period and 21.6% in packing period. The magnitude of wage expenditure was appeared as harvesting stage, packing stage, growing stage on main field and nursery bed stage in order. The amount of material costs were revealed as the growing stage in main field, harvesting stage, nursery bed stage and packing stage respectively. The production costs of leaf tobacco per 10a by farm sizes were shown as 1,615,879won for small farm, 1,446,896won for medium farm and 1,454,408won for large farm respectively. The production cost of leaf tobacco had shown decreasing tendency according to increasing farm sizes. To promote the international market competitiveness of leaf tobacco producing farms, labour saving production technologies and cost effective farm size to decrease tobacco production cost should be developed.

• Journal of Korea Game Society
• /
• v.10 no.1
• /
• pp.3-13
• /
• 2010

This research will suggest a Digital Physical Field Game (Digital PFG) as a new ubiquitous paradigm. Based on the evolution of videogame paradigm which is affected by the social paradigm evolves, meanings of "participation" and "communication" as an interaction in the videogames are examined. Additionally, a general concept of ubiquitous games and its limitations are also investigated. Based on that, a new game paradigm which contains a concept of ubiquitous games, Digital PFG's main concepts and examples are newly designed and proposed. As contributions of this research, next are expected, such as, improved immersive contents for the serious games and new approaches to the theme and science parks design as a user participated digital contents.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.6 no.1
• /
• pp.149-158
• /
• 2002

The carbonation process is affected by both the concrete material properties such as W/C ratio, types of cement and aggregates, admixture characteristics and the environmental factors such as $CO_2$ concentration, temperature, humidity. Based on results of preliminary study on carbonation, this study is to develop a carbonation prediction model by taking account of $CO_2$ concentration, temperature, humidity ad W/C ratio among major factor affecting the carbonation process. And to constitute a model formula which correspond to the mix design of the nuclear power plant, test coefficient that correspond to the design of the nuclear power plant is obtained based on the results of accelerated carbonation test. Also a field coefficient which is obtained based on results of the field examination is included to improve the conformity of the actual structures of nuclear power plant.