• Journal of Advanced Marine Engineering and Technology
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• v.19 no.3
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• pp.91-98
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• 1995

To control speed or torque of induction motors, scalar control method that regulates the value of stator current had been used conventionally. But, vector control method which contrls the direction and the value of stator current at the same time has been introduced lately and employed widely. This paper describes comparative analyses of above two methods by computer simulation. As a result of the simulation, both methods showed good responses for high speed, but, vector control method characterized much better performance for low speed and sinusoidal input.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.10a
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• pp.182-185
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• 2005

To survive in rapidly changing business environment, the enterprise should adapt its business process to the changing environment. The system integration is an important issue to tackle this challenge. It is unavoidable direction that SOA (Service Oriented Architecture) is accepted as an upcoming IT standard to support flexible business processes and integration. In this paper, SOA is introduced, and the Web services and ESB (Enterprise Service Bus) ate also introduced as a foundation technology to implement SOA-enabled solutions. The pilot project, which is introduced in this paper, will be a good reference for future SOA implementation.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2414-2418
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• 2007

N-Hydroxy diketopiperazine derivatives from L- and D-forms of Ser and Cys were synthesized for the first time and the ring conformation of both analogues in water was determined to be close to flat via NMR and ab initio calculations. However, the side chain of the Ser analogue was oriented toward a pseudo-equatorial position while that of the Cys analogue was slightly oriented toward a pseudo-axial direction, with a slightly distorted boat-shaped ring conformation. Among them, the D-Cys analogue was found to be a weak inhibitor of α- glucosidase.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.329.1-329.1
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• 2014

In this paper, we report electrical, optical and structural properties of Al-doped zinc oxide (AZO) thin films deposited at different substrate temperatures and pressures. The films were prepared by radio frequency (RF) magnetron sputtering on glass substrates in argon (Ar) ambient. The X-ray diffraction analysis showed that the AZO films deposited at room temperature (RT) and 20 Pa were mostly oriented along a-axis with preferred orientation along (100) direction. There was an improvement in resistivity ($3.7{\times}10^{-3}{\Omega}-cm$) transmittance (95%) at constant substrate temperature (RT) and working pressure (20 Pa) using the Hall-effect measurement system and UV-vis spectroscopy, respectively. Our results have promising applications in low-cost transparent electronics, such as the thin-film solar cells and thin-film transistors due to favourable deposition conditions. Furthermore our film deposition method offers a procedure for preparing highly oriented (100) AZO films.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1542-1545
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• 2002

Experimental works were performed to implement the hetero-epitaxial growth of diamond films on the (100)- and (111)-oriented Si substrates. The deposition process used to prepare diamond films consisted of a bias-enhanced nucleation(BEN) step, accompanied with a growth step using a microwave plasma CVD system. The highly oriented diamond films were deposited under the growth condition of relatively low methane concentrations and high temperatures. Material properties and surface morphologies of deposited diamond films were improved by the addition of carburization step into the deposition process.

• Journal of Educational Research in Mathematics
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• v.9 no.1
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• pp.15-29
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• 1999

The purpose of this study is to investigate various mathematics education improvement or reform movements of Western Europe countries (United Kingdom, Germany, etc.) and the United States of America, to see the effects of those movements on Korean mathematics education circle, and to find a direction of Korean mathematics curriculum design. The third Korean mathematics curriculum was most affected by the new mathematics movement of the United States of America. This movement was emphasizing abstract structure, logical rigorousness and discovery learning of mathematics, which was fired from late fifties. Korean mathematics education circle imported the new mathematics early seventies from USA, but serious problems had been found at that time in USA. This study has pointed out that new math oriented Korean mathematics curriculum was not proper and the new mathematics itself was disastrous for most Korean students' learning. The study also points out that they hurried too much introducing the new mathematics and publishing new mathematics oriented textbooks but they had not sufficient teacher training programs. In our future mathematics curriculum reform, we have to remember such a historical lesson.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2001.11a
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• pp.15-24
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• 2001

Upon entering the 21st Century, One of the new paradigm of Housing industry in Korea is to accomplish the foundation of Sustainable Building & Environment. It is easy to understand that Building environment in Korea is appearing the phenomenon of rapid conversion from supply-oriented market to demand-oriented market. Thus, the purpose of this paper is to suggest the direction of a new housing development with "Open Housing"as New Housing System which takes into account durability of housing based on the changeability among Housing-Components, the flexibility of interior space, the remodeling & repairing of housing and the user′s needs with variable life-style. This paper also shows the example of Infill-Systems for the Open housing in Korea on the basis of housing situation, experiences for the Open Housing including assembly technique of Infill-Systems.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.33-35
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• 2000

Na-K-Nb system showed a number of ferroelectric phases in bulk ceramic. [001]-axis oriented single-phase Na$_{0.5}$K$_{0.5}$NbO$_3$ (NKN) thin film have been grown on LaA1O$_3$ substrates using KrF excimer laser. X-ray diffraction $\theta$-2$\theta$ scan, rocking curves, and $\phi$ scan data evidence highly c-axis oriented along the [001] direction.ion.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.573-578
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• 2008

While going through economic development for several decades, Korea has become an industrialized country, and the development of industrial technology accelerated the advent of the information opportunity era. The recent information oriented society has brought forth the development of new information communication technology that enables anybody to obtain information easily and simply, and recently power line communication technology is being developed that allows the use of the existing power line net-works as they are. Each advanced country that faced up to a riffle effect of power line communication technology that enables us to obtain information easily anywhere at anytime is engaged in fierce competition to be a leader in this technology and to preoccupy the standardization of power line communication technology. At this point, this study is to help Korea take the lead in information communication technology by proposing a direction for the standardization that Korean power line communication technology needs to head for by identifying the trend of the worldwide of power line communication technology.

• Journal of the Korean Magnetics Society
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• v.4 no.1
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• pp.48-51
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• 1994

We have studied the room temperature anisotropy in the high $T_{c}$ superconductor $YBa_{2}Cu_{3}O_{7}$ by means of the $^{63}Cu$ nuclear quadrupole resonance (NQR). For the magnetically oriented powder samples, NQR signals were obtained only when the RF magnetic field is applied perpendicular to the direction of the crystalline c-axis. Significant differences in the spin-lattice relaxation times ($T_{1}$) and the lineshapes were observed between the unoriented powder sample and the magnetically oriented sample.