• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.04a
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• pp.92-95
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• 2003

초전형 센서의 특성 평가 방법에는 여러 가지 방법들이 존재하며, 이에 대한 표준화된 특성 평가방법의 개발이 필요로 한다. 측정 평가의 방법이나 조건 등에 따라서 평가 결과가 크게 변할 수 있는 사항들이며, 따라서 국내 뿐 아니라 대외적으로 다른 나라의 제품들과 신뢰성을 가지고 경쟁을 하기 위해서는 평가항목이나 평가방법의 표준화가 절실하게 요구된다. 초전형 적외선 센서를 평가하는 항목에는 기본적으로 입력에 대한 출력신호의 크기를 평가하는 감도(responsivity), 잡음과 관련되어 센서가 검출할 수 있는 최소의 신호를 나타내는 NEP(Noise Equivalent Power)와 이것을 센서의 감지 면적으로 정규화 시킨 검출능(detectivity), 응답 속도를 나타내는 시정수(time constant)가 있으며 이러한 항목들이 표준화의 대상이 된다. 본 실험에서는 기존의 상용화된 센서들을 가지고 초전형 적외선 센서의 특성을 측정 하였다. 특성을 측정할 때 다른 요인들 보다 노이즈로 인한 영향이 상당히 크므로 측정시 노이즈 발생 문제를 해결하는 방법으로 본 논문에서는 센서 측정에 사용되는 증폭 회로에서 노이즈를 해결하려고 하였다. 우리는 증폭 회로구성에서 노이즈를 제거하기 위해서 신호입력단과 전압 압력에 잡음제거 필터로 R, C를 사용하였다. 회로설계로 제작된 증폭회로와 측정 장치를 가지고 측정을 한 결과 센서의 감도는 $3.0mV_{p-p}$, 응답시간은 20ms정도의 값으로 가장 일반적인(typical) 값을 보인다.

• Journal of the Korean Wood Science and Technology
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• v.34 no.1
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• pp.68-78
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• 2006

The purpose of this study was to estimate the identification of thermophilic hacterial with fermentation of pig manure. To identify the characters of thermophilic bacteria related to fermentation at a high temperature condition, we selected 28 different kinds of original settling thermophilic bacteria that were sampled at different 23 areas. They were distributed 1$1{\times}10^5{\sim}10^8CFU$ at medium and the enzyme activity at $55^{\circ}C$ incubation condition, especially cellulase and a-amylase, were higher than those of $30^{\circ}C$. Partial sequencing data for 165 rDNA region were obtained from 28 samples representing 15 different genera. Bacillus subcilis, one of those bacteria, has endodermic spores at high fermented condition.

• Research in Plant Disease
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• v.24 no.4
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• pp.342-347
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• 2018

Bacterial canker caused by Clavibacter michiganensis is considered to be one of the most serious diseases, leading to economic damage to tomato worldwide. Diagnosis of the bacterial canker on tomato is known to be difficult because the causal pathogen is slow-growing on artificial media as well as causes latent infection in tomato. In this study, as a less time-consuming method, a specific primer set was newly designed for rapid detection of C. michiganensis. The method presented here is so simple, easy, and fast that it can be useful and practical in direct detection of the bacterial canker pathogen from tomato plants.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.672-675
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• 2009

동해 울릉분지에서 취득된 다중채널 탄성파자료 해석에 의하면 이 지역에는 가스하이드레이트 부존가능성을 지시하는 해저모방반사면, 탄성파침니/칼럼, 음향공백대, 증폭반사면, 가스분출 구조 등을 포함하는 5가지 탄성파 지시자가 존재한다. 가장 대표적인 지시자인 해저모방반사면은 연구지역의 남쪽사면의 경우 연속성이 양호하고 강한 진폭을 갖는 반면, 북쪽 중앙분지에서는 상대적으로 진폭이 약하고 연속성이 불량하다. 반사도 감소 및 속도 풀업 특징을 갖는 탄성파 침니/칼럼구조는 중앙분지와 북동쪽해역에 주로 분포하며 가스하이드레이트 혹은 가스유체의 부존가능성을 시사해준다. 반사강도가 약화되어 나타나는 음향공백대는 저탁류/원양성 퇴적물이 분포하는 중앙분지에 부분적으로 발달하며, 칼럼과 연계된 음향공백대는 북동쪽 사면저부에 주로 분포한다. 해저모방반사면의 하부에 위치하는 증폭반사면은 연구지역의 서쪽 사면에 분포하며 강한 음의 진폭특성으로 보아 자유가스를 함유한 층으로 해석된다. 가스분출구조는 주로 쇄설성 퇴적물이 우세한 조사지역의 남쪽 대륙사면지역에 광범위하게 분포하며 돔구조 혹은 폭마크 등을 수반한다.

• Journal of the Korea Society of Computer and Information
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• v.3 no.2
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• pp.139-146
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• 1998

This paper proposes a regularized iterative image restoration using method of conjugate gradient considering a priori information. Compared with conventional regularized method of conjugate gradient, this method has merits to prevent the artifacts by ringing effects and the partial magnification of the noise in the course of restoring the image degraded by blur and additive noise. Proposed method applies the constraints to accelerate the convergence ratio near the edge portions, and the regularized parameter suppresses the magnification of the noise. As experimental results, I show the superior convergence ratio and the suppression by the artifacts of the proposed method compared with conventional methods.

• Korean Journal of Optics and Photonics
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• v.7 no.1
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• pp.1-8
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• 1996

Charge-coupled device(CCD) array detectors are widely used in real time modulation transfer function(MTF) measurement systems. This paper presents the characteristics of two-dimensional CCDs used in a real time MTF measurement system for copy lenses. The MTF characteristics of a copy lens measured by this equipment show different results according to the direction of shift register, shutter speed and the amplifier gain of CCDs. An object generator is fabricated to reduce the variation of MTF values for the irradiance nonuniformity in on-axis and off-axis image plane and this MTF equipment is calibrated by using a standard lens.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.9
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• pp.1985-1997
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• 1997

This paper proposed a regularized iterative image restoration by using method of conjugate gradient. Compared with conventional iterative methods, method of conjugate gradient has a merit to converte toward a solution as a super-linear convergence speed. But because of those properties, there are several artifacts like ringing effects and the partial magnification of the noise in the course of restoring the images that are degraded by a defocusing blur and additive noise. So, we proposed the regularized method of conjugate gradient applying constraints. By applying the projectiong constraint and regularization parameter into that method, it is possible to suppress the magnification of the additive noise. As a experimental results, we showed the superior convergence ratio of the proposed mehtod compared with conventional iterative regularized methods.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.5
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• pp.459-466
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• 2000

A new control method for precision robust speed control of a PMSM(Permanent Magnet Synchronous Motor) using load torque observer is presented. Using this system, we can more precisely evacuate of vestibular function. Until now a rotating chair system, so called 2D-stimulator, which has vertical rotate axis is used to make dizziness. However, an inclined rotating chair system witch is called 3D-stimulator is needed to obtain the precise dizziness data. This 3D-stimulator include unbalanced load caused by unbalanced center of mass. In this case, new compensation method is considered to obtain robust speed control using load torque observer. To reduce the effect of this disturbance, we can use dead-beat observer that has high gain. The application of the load to torque observer is published in for position control. However, there is a problem of using speed information such as amplifying effect of noise. Therefore, we can reduce a noise effect by moving average process. The experimental results are depicted in this paper to show the effect of this proposed algorithm.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.2
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• pp.92-104
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• 1993

In the present study, the velocity profiles and entrance length of developing transitional pulsating flows are investigated both analytically and experimentally in the entrance region of a square duct. The systems of conservation equations for transitional pulsating flows in a square duct are solved analytically by linearizing the non-linear convective terms. Analytical solutions are obtained in the form of infinite series for velocity pofiles. The experimental study for the air flow in a square duct(40mm*40mm*4000mm) is carried out to measure velocity profiles and other parameters by using a hot-wire anemometer with a data acquisition and processing system. The distribution of velocity profiles( $u_{ps}$ / $u_{m,ta}$) in the decelerating period is higher than in the accelerating period. The distribution of the axial component of the axial component of velocity in the transitional flow is nearly uniform in the central region of the duct, and decrease rapidly near the wall. The entrance length correlation of the transitional pulsating flows in a square duct is obtained to be $L_{e}$/ $D_{h}$=0.83 $A_{1}$R $e_{ta}$ /(.omega. sup+1)$^{2}$TEX>

• The KSFM Journal of Fluid Machinery
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• v.12 no.6
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• pp.41-46
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• 2009

This paper deals with the operating-speed (high-speed) balancing of a refinery gasoline HDS (hydrodesulfurization) process recycle-gas 8-stages compressor rotor. A low-speed balancing condition of the rotor was measured as maintaining the G2.5 level. But an inspection run of operating-speed balancing condition, using tilting-pad journal bearings of actual use, showed that while it could be continuously-operated safely at a rated speed of 10,500 rpm, the rotor would not be able to run over 11,000 rpm as the vibration increased very sharply, approaching 11,000 rpm. In order to cure that a series of operating-speed balancing, which first calculated balance correction-weights by applying the influence coefficient measured and calculated at 10,500 rpm and then implemented correction works, was carried-out. The final operating-speed balancing results showed that the vibrations at the bearing pedestals represented very good levels of 0.2 mm/s by decreasing to as much as the 1/10 of the original vibrations and particularly, even at a targeted maximum continuous operating speed, MCS, of 11,500 rpm the vibrations represented about 1 mm/s, which is the operating-speed balancing vibration specification of API. Therefore, the expansion of MCS was successfully accomplished through the operating-speed balancing.