• 전자공학회논문지D
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• 제35D권7호
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• pp.25-31
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• 1998

Modal transmission-line is utilized to analyze the power coupling of optical directional coupler composed by two parallel guiding slabs. By defining a coupling efficiency .eta. amenable to rigorous supermodes and boundary conditions of modal functions, we evaluate the power transfer for TE mode of gainy coupler. The results reveal that optimized power exchange occurs at a novel wavelength .lambda.$_{op}$ , which is generally different from minimum gap .lambda.$_{min}$ between rigorous modes and phase-matching condition .lambda.$_{ph}$ .

• 전자공학회논문지B
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• 제32B권9호
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• pp.1231-1238
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• 1995

In on-line character recognition, to segment input character is important. This paper proposes an internal character segmentation algorithm. The internal segmentation algorithm produces candidate words by considering possible combinations of Korean alphabets. In this process, we make use of projections of strokes onto the horizontal axis to remove ambiguities among candidate words. As a result of experiments, the internal segmentation algorithm shows better performance than external segmentation algorithm as the gap between sample characters becomes smaller.

• 연구논문집
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• 통권24호
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• pp.49-61
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• 1994

In this paper, the experimental unit of the cross inductive radio line and two linear induction motors driven by IGBT inverter for train control was made. In actual condition, the track has straight line, but so as to be able to achieve in small space, the unit prepared was shaped into two circular plates. Then by detecting inductive signal, the position data could be obtained. Also the equipment representing speed and thrust of LIM and train position by means of the experimantal unit could be composed.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.168-171
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• 2003

Generally RF AGC (Roll Force Automatic Gauge Control) controls the roll gap using the variation of rolling force caused by the roll eccentricity and the entry thickness of material, but RE AGC takes the bad effect of the roll eccentricity. The Feed-forward (FF) AGC method, which controls the next stand roll gap by the estimation of the thickness variation due to skid mark is needed to supplement the shortage of RF AGC. In this paper, an adaptive filtering method which takes account of the kind of material, the final objective thickness and the rolling speed is proposed to predict skid mark thickness variation. In addition, an improved estimation method of control point using a speedometer and looper angle is suggested. Via on line test, the performance improvement of the suggested FF AGC method is verified.

• 한국정보통신학회논문지
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• 제6권6호
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• pp.897-903
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• 2002

본 논문에서는 Inset-fed 안테나의 급전구조를 변형하여 기존의 Inset-fed 안테나 보다 그 성능을 향상시킨 안테나를 설계 및 제작하였다. Patch 안테나에서 gap 결합에 의한 급전 방식을 기초로 하여 변형된 급전 방식을 Inset-fed 안테나에 적용하였다. 설계된 안테나는 FDTD에 의한 simulation을 수행하여 최적치를 얻었으며 제작된 안테나는 공진 주파수에서 511은 -l4dB이고 cross polarization level은 -20dB의 특성을 보였다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 추계학술발표대회 개요집
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• pp.138-140
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• 2005

Plasma arc welding(PAW) technology is a proven process that has already been adopted by other industrial fields and recently has been considered to join the tank structure of LNG carrier. The purpose of this study is to introduce PAW process for the root welding of stainless steel pipes instead of TIG welding. There are distinctive features of the PAW compared to TIG welding; higher energy density that can increase welding speed by more than twofold, and longer arc length that can be controlled to trace seam line easily because of allowable gap between workpiece and torch. However, PAW process is also very sensitive to the root gap and misalignment due to the characteristics of long and narrow arc shape. So, we have done various experiments to establish the allowable fit-up condition by changing welding parameters including arc length, with or without filler metal, groove shape, and obtained satisfactory result.

• 한국농림기상학회지
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• 제14권2호
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• pp.45-52
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• 2012

Enrichment planting은 라오스에서 산림복원 프로그램의 일환으로, 이차림에서 수종의 밀도를 증가시키는데 흔히 쓰인다. 본 연구는 다섯 종의 자생수종을 대상으로 임관층을 다양한 방법으로 소개하고 Enrichment planting을 실시하여 라오스에서 개벌 이후 적용할 수 있는 조림방법과 적합한 수종을 조사하였다. 본 연구결과, 수관층의 높이만 조사수종간 그리고 식재처리간 모두에서 통계적으로 유의한 차이가 나타났다. 묘목의 생존율과 수관층의 직경은 조사수종간에서는 유의한 차이가 나타났으나, 식재처리간에는 차이가 없었다. 반면 묘목의 근원경과 묘고는 식재처리간에서만 유의한 차이가 나타났다. 조사수종 중에는 Hopea odorata 와 Dalbergia cochinchinensis 가 다른 수종들에 비해 생존율과 수고생장 모두 양호한 것으로 나타났는데, 이는 이들 수종들이 향후 라오스 산림복원을 위한 Enrichment planting에 적용하기 적합할 것으로 판단된다. 또한 2m간격의 line planting은 묘목의 근원경 생장을 촉진시킬 수 있을 것으로 제안되지만 gap planting과 같이 넓은 간격의 line planting은 묘고생장을 촉진시킨 것으로 나타났다.

• 한국공작기계학회논문집
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• 제14권1호
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• pp.52-57
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• 2005

In the foe of global competition, the requirements for the continuously increasing productivity, flexibility and quality(dimensional accuracy, mechanical properties and surface properties) have imposed a mai or change on steel manufacturing industries. Indeed, one of the keys to achieve this goal is the automation of the steel-making process using AI(Artificial Intelligence) techniques. The automation of hot rolling process requires the developments of several mathematical models for simulation and quantitative description of the industrial operations involved. In this paper, an on-line training neural network for both long-term teaming and short-term teaming was developed in order to improve the prediction of rolling force in hot rolling mill. This analysis shows that the predicted rolling force is very closed to the actual rolling force, and the thickness error of the strip is considerably reduced.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 E
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• pp.1642-1644
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• 1997

The simulation study of lightning faults reducing effects by the installation of surge arresters on the 154 kV transmission line is stated here. For the purpose of detailed simulation of arcing horn, a flashover model with dynamic characteristics of arcing horn gap was represented as a non-linear inductance which is controlled by EMTP/TACS(Electromagnetic Transient Program/fransient Analysis of Control Systems) switches. The back flashover inducing current was increased from 50 kA to 88 kA by the installation of surge arresters on the transmission line which has one ground wire and 20 ohms of tower footing resistances. The great advantage of surge arrester installation on one circuit of the double circuit transmission line is to prevent the simultaneous back flashover up to 190 kA.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.142-144
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• 2009

We demonstrated narrow and good aspect-ratio inkjet-printed silver lines with multi-time over-printing methods. By using this strategy, narrow silver lines were obtained with 200 nm thickness and their width and gap between printed lines of uniform narrow silver lines were 30 ${\mu}m$ and 17 ${\mu}m$, respectively. It also had good conductivity, sheet resistacne of 0.36 ${\Omega}/{\square}$ and specific resistance of $8{\mu}{\Omega}{\cdot}cm$. In current stress test, narrow silver line with 30 ${\mu}m$ width was able to a current flow up to 50 mA (2.1A/$cm^2$). Using surface treatment on poly-arylate substrate with $UVO_3$, we obtained clean-edge narrow line without any edge waviness.