• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.15-18
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• 2021

최장 공통 부분 서열(Longest Common Subsequence, LCS)은 서열 유사도(Similarity)를 측정하기 위한 주요 지표 중 하나로 특별한 가정이 없는 한 두 문자열의 LCS 를 계산하기 위해서는 두 문자열의 길이의 곱에 비례하는 시간이 필요하다. 최근 최장(longest)이라는 조건을 극대(maximal)로 완화한 극대 공통 부분 서열(Maximal Common Subsequence, MCS)이 제시되었고, 두 문자열의 MCS 를 선형에 가까운 시간에 찾는 알고리즘이 개발되었다. 극대는 최장을 보장하지 않기 때문에 두 문자열의 MCS 길이는 LCS 길이와 달리 유일하지 않을 수 있고, LCS 길이가 매우 길어도 길이가 1인 MCS가 존재할 수도 있다. 본 논문에서는 기존 알고리즘에 의해 계산되는 MCS 의 효용성을 알아보기 위해, DNA 등 여러 종류의 실제 데이터와 랜덤 생성된 데이터에 대해 LCS 와 MCS 의 길이를 비교했다. MCS 길이는 LCS 길이 대비 실제 데이터에서 32.1 ~ 60.2%, 랜덤 데이터에서는 27.5 ~ 62.9%로 나타났다. 이 비율은 문자열을 이루고 있는 알파벳 수가 많을수록, 문자열의 길이가 길어질수록 감소했다.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.2
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• pp.108-113
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• 2009

MFL(magnetic flux leakage) inspection is a general method of non-destructive evaluation(NDE) of underground gas pipelines. Pipelines are magnetized by permanent magnets when MFL PIG(pipeline inspection gauge) gets through them. If defects or corrosions exist in pipelines, effective thickness is changed and thus variation of leakage flux occurs. The leakage flux signals detected by hall-sensors are analyzed to characterize defect's geometries such as length, width, depth, and so on. This paper presents several methods for estimating defect's length using MFL signals and their performances are compared for real defects carved in KOGAS pipeline simulation facility. It is found that 80% and 90% of minimum values for axial and peak values for radial signals respectively show the best performance in the point of length estimation error.

• Journal of the Korea Computer Graphics Society
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• v.13 no.3
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• pp.19-24
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• 2007

In this paper, we describe a method of defining an object's real length in order to compare objects' lengths precisely using all real length units in the real world. The browser in our study represents an object's length by referencing to the physical length property defined at modeling when it displays the object. Since objects' lengths are appropriately scaled according to these units, objects can be precisely and visually compared in sire using real world length units. The concept of defining the real length unit is extended to the X3D specification. The units are ranged from $10^{-24}(yotta)\;to\;10^{24}(yocto)$. In addition, we explain the method for processing LOD (Levels Of Detail) and for applying the property of LOLD (Levels of Length Detail) when objects with different LOLD are read into the browser.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.08a
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• pp.188-191
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• 1998

호주 영어의 단어 중 한국인과 일본인이 구별하기 어려운 'work', 'walk', 'wok' 세 단어에 대해 다룬다. 우선 한국인과 일본인이 이들 세 단어를 어떻게 조음할 것인가를 예측하고, 실제로 한국인과 일본인 화자들이 조음한 자료를 가지고 모듬의 음질과 길이 두가지 측면으로 나누어 예측한 사항과 비교하고 또 이들 단어를 조음할 때 한국인과 일본인 사이에 어떤 음성 음운적 특징이 나타나는지도 비교 분석한다. 결과는 모국어의 음성, 음운적 영향이 목표어의 음소를 습득하고 발음하는데에 영향을 미친다는 사실을 보여주고 있다. 하지만 wok/wo k/의 예는 언어 보편적인 요소가 L2의 음소를 습득하는데 있어 또 하나의 요소로 작용하고 있음도 알려주고 있다.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.2 no.2
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• pp.62-67
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• 2009

Purpose: The purpose of this study is to find out the accuracy and usability of the three dimensional ultrasonography in measuring the size of the rotator cuff tear, especially before and after the injection of normal saline into the glenohumeral joint. Materials and Methods: 14 patients of rotator cuff tear who were diagnosed and operated from August 2007 to September 2008 were included in this study and authors compared the size of rotator cuff tear measured with three dimensional ultrasonography with the real size measured intraoperatively. In preoperative ultrasonographic evaluation, horizontal and longitudinal length of rotator cuff tear before and after injection of normal saline intraarticularly. During the arthroscopic operation the size of tear was measured by passing a Kirschner wire through a spinal needle and direct measure was performed in open surgery. Results: The average difference was 8 mm in horizontal and 1.9 mm in longitudinal length of tear without saline injection between ultrasonographic and intraoperative measure. The average difference was 4.1 mm in horizontal and 1.6 mm in longitudinal length of tear after the normal saline injection. Conclusion: In three dimensional ultrasonographic evaluation in rotator cuff tear, intraarticular normal saline injection would produce more accurate results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1997.11a
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• pp.12-12
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• 1997

여러 가지 형태의 연소 불안정성 중에서 50-500Hz 사이에서 발생되며 길이방향 모드(longitudinal mode)로 특징이 있는 저주파수 불안정성이 램제트 혹은 재연소기(Afterburner)의 연소 불안정성에서 가장 중요한 것이라고 여겨진다. 본 논문에서는 램제트 흑은 재연소기에서 일어날 수 있는 길이 방향의 연소 불안정성을 Modal 해석법을 사용하여 수학적인 모델로 만들었다. 특히 이 모델의 선형형태는 어떤 형태든지 선형 속도에 민감한 Burning rate 모델을 사용할 수가 있어서 보다 포괄적인 형태로 만들어져 있으며, 이 모델을 이용하여 여러 가지 연소 형상과 불완전 연소 응답 등을 연구할 수 있다. 본 논문에서는 실제 연소 형상과 유사한 삼각형 모양의 연소 형상을 사용하여 기존의 다른 모델들과 비교 분석하였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.3
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• pp.39-47
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• 2000

In this paper, we propose a new method of finding the true length of the line and long axis of the ellipse at the $\theta$=$\theta$o＋ 90$^{\circ}$ and short axis of the ellipse at the $\theta$ = $\theta$o from the Hough transform (HT) results. Through the simulations, we showed that the true length of the line and ellipse could be obtained with 98 % accuracy by using the distance from the maximum envelope to the minimum envelope. To compare the simulation results with the experimental results, we performed optical experiments by using a HT CGH filter. Through the experiments, we showed that our results were very similar to those of the simulation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.939-942
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• 2014

고속도로 교통 소음 저감을 위해 상용소음예측프로그램인 SoundPLAN과 소음예측 시 주로 사용하는 도로 교통 소음예측식인 RLS-90을 이용하여 경제적이고 효율적인 방음대책 설계방안에 대한 연구를 하였다. 대상지역에서 측정한 실제 소음도와 예측 소음도의 차이를 비교하여 모델을 검증하고 장래교통량에 대하여 소음을 예측하여 방음대책을 설계하였다. 방음벽의 높이와 길이, 저소음 포장의 길이를 조절하고 저소음 포장과 방음벽을 혼용했을 경우에 대하여 소음규제 기준에 적합하게 설계하였고 각각의 설치 단가를 이용하여 경제성을 비교하여 보다 효율적인 방음대책을 알아보았다.

• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.991-995
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• 1996

Renal size(length, width and height) of rabbits was measured by radiographs and nephrosonograms and compared with actual size. After measuring on the radiographs and nephrograms, both kidneys were removed from the body and actual size was also measured. On radiographs, right kidney was observed at the T13-L2 vertebrae and left kidney was at L2-L4 vertebrae. On nephrosonograms, the renal cortex was visible as small, homogenous echoes that were hypoechoic relative to the surrounding tissues, whereas the renal medulla was anechoic to slightly hypoechoic. The actual length, width and height of the left kidney were $35.84{\pm}3.12(mean{\pm}SD)$, $23.52{\pm}3.21$, $15.11{\pm}2.58cm$, respectively, whereas those of the right kidney were $36.02{\pm}3.42$, $23.69{\pm}3.50$ and $14.13{\pm}3.55cm$, respectively. On radiographs, the length and width of both kidneys were a little magnified(102-104%) when compared to actual size. On nephrosonograms, the length, width and height of bothkidneys were lessened(70-96 %) when compared to actual size. The length and width of kidney were 1.85 and 1.25 times the length of the second lumbar vertebrae on the ventrodorsal view. In correlation and correlation coefficient of body weight with the renal size, the body weight and renal size were significantly correlated with each other other(p<0.01) and the correlation coefficents of body weight with left, right and both Kindneys were 0.748, 0.794 and 0.859, respectively.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.570-573
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• 2012

Performance characteristics of subscale diffuser for high-altitude simulation have been numerically investigated. The length of diffuser entrance with respect to nozzle exit diameter was changed to 0, 50, 100%, respectively. In addition, flow characteristics have been studied for various length to diameter ratio of secondary throat diffuser. As a result, the shape of plume was contracted for insufficient length of diffuser entrance. Also, if the length to diameter ratio of secondary throat diffuser were less than 7 or 8, mach disk has been formed inside the diffuser.