• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1997.10a
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• pp.135-138
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• 1997

The interaction of oblique monochromatic incident waves with a horizontal flexible membrane is investigated in the context of two-dimensional linear hydro-elastic theory. First, analytic diffraction and radiation solutions for a submerged impermeable horizontal membrane are obtained. Second, the theoretical prediction was compared with a series of experiments conducted in a two-dimensional wave tank at Texas A&M University. The measured reflection and transmission coefficients reasonably follow the trend of predicted values. Using the developed computer program, the performance of surface-mounted or submerged horizontal membrane wave barriers is tested with various system parameters and wave characteristics. It is found that the properly designed horizontal flexible membrane can be an effective wave barrier and its efficiency can be further improved using a porous material.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.133-139
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• 2013

Convex combination of two adaptive filters is an efficient method to improve adaptive filter performances. In this paper, a subband convex combination method of two adaptive filters for fast convergence rate in the transient state and low steady state error is presented. The cost function of mixing parameter for a subband convex combination is defined, and from this, the coefficient update equation is derived. Steady state analysis is used to prove the stability of the subband convex combination. Some simulation examples in system identification scenario show the validity of the subband convex combination schemes.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2006.05a
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• pp.407-410
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• 2006

최근 들어 반도체의 기술적인 성장과 네트워크의 발전으로 유비쿼터스 컴퓨팅 환경이 대두되고 있으며 이에 따라 RFID라는 신기술이 등장과 응용에 관한 연구가 활발히 진행되고 있다. 이에 본 논문에서는 기존 RFID 시스템에서 유선망을 사용한 데이터 전송으로 인하여 발생될 수 있는 공간 및 이동성의 제약을 극복하기위하여 저가의 무선전송모듈을 적용하여 휴대형 상품정보제공 시스템을 개발하였다. 무선전송 모듈은 900MHz 대역의 Texas Instruments 사의 TRF6901 chipset을 이용하였고, 이를 제어하는 MPU는 TI사의 MSP430F149로 설계하였다. 본 논문에서 개발한 시스템은 도서관리, 출입통제 시스템등에 범용적으로 적용될 수 있을 뿐 아니라 핸드 헬드형 RFID 시스템에 혁신적인 기대 효과를 예상할 수 있다.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.67.3-67.3
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• 2015

We present the high-resolution Immersion GRating INfrared Spectrograph (IGRINS) spectra of two Class I sources, IRAS03445+3242 and IRAS04239+2436. Both sources show the evidence of Keplerian disks; the broadened CO overtone (${\Delta}v=2$) transitions in emission and neutral metal lines (Mg I, Fe I, and Al I) in absorption. The thin Keplerian disk with a rotational velocity of ~100 km s-1 and a gas temperature of 5000 K at the innermost annulus can reproduce the CO overtone transitions including the bandhead emission. The outer dusty disk or the envelope needs to fit the narrow absorption features overlaid on the broad emission lines in the CO overtone transitions.

• Journal for History of Mathematics
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• v.21 no.1
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• pp.79-96
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• 2008

In early 21st century, universities in Korea has been asked the new roles according to the changes of educational and social environment. With Korea's NURI and Brain Korea 21 project support, some chosen research oriented universities now should produce "teacher of teachers". We look 100 years back America's mathematics and see many resemblances between the status of US mathematics at that time and the current status of Korean mathematics, and find some answer for that. E. H. Moore had produced many good research mathematicians through his laboratory teaching techniques. R. L. Moore was his third PhD students. He developed his Texas/Moore method. In this article, we analyze what R. L. Moore had done through his American School of Topology and Moore method. We consider the meaning that early University of Texas case gives us in PBL(Problem Based Learning) process.

• Journal of the Korean Society for Heat Treatment
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• v.4 no.3
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• pp.21-30
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• 1991

Microstructural analysis was conducted to observe the effect of aging treatments in a Cr-Mn austenitic stainless steel containing nitrogen, and the amount, size, shape and distribution of precipitates were investigated. It was found that on water quenching from $1000^{\circ}C$ after holding 3 h at that temperature, the steel contained no precipitates observable by optical microscopy. Precipitation of phases begins at places most favorable for the formation of nuclei-in the boundaries of grains and twins. Precipitates were studied in detail by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Chemical compositions of precipitates were examined by the use of scanning transmission electron microscopy (STEM) together with an energy dispersive X-ray (EDX) microanalysis. Also chromium depletion adjacent to grain boundary precipitates was investigated by the use of Auger electron spectroscopy (AES) for a direct examination of the fracture surface chemistry.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.741-746
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• 2004

We propose a new technique to the design and real-time implementation of an adaptive controller for robotic manipulator based on digital signal processors in this paper. The Texas Instruments DSPs(TMS320C80) chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved direct Lyapunov method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for a dual arm robot consisting of two 4-d.o.f. robots at the joint space and cartesian space.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2540-2545
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• 2003

We propose a new technique to the design and real-time implementation of an adaptive controller for robotic manipulator based on digital signal processors in this paper. The Texas Instruments DSPs(TMS320C80) chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved direct Lyapunov method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for a dual arm robot consisting of two 4-d.o.f. robots at the joint space and cartesian space.

• Korean Journal of Hydrosciences
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• v.2
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• pp.61-68
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• 1991

This study assessed the contribution of heavy metals to total toxicity as well as the presence other toxic compounds before and after adding the chemical P to concurrently conducted bioassay tests of Daphnia magna and P. Phosphoreum. The following conclusions were drawn from this study : With excessive EDTA dosage, a toxicity reduction in Microtox would occur due to a metal-comples being formed. Microtox was far less sensitive than D. magna to heavy metal toxicity, but extended exposure time and reagent could increase the sensitivity.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.219-222
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• 1991

It is difficult to adapt modern control theory to power conversion system for the price of real time control H/W and the difficulty of S/W implementation. But recent development of large integrated circuit make it possible that One-Chip microprocessor processes high speed arithmatic calculation used in control theory. Specially this chip is called Digital Signal Processing chip. So, this research developes high performance, high reliable digital control system using TMS320C30 of Texas Instrument for real time control in power conversion system.