• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.210-213
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• 1999

수동소나체계에서 음원의 위치와 관련된 매개변수를 산출하기 위해 정합장처리(Matched Field Processing)가 이용된다 본 연구에서는 수직선배열센서를 이용한 정합장처리에서 음원 위치추정에 영향을 미치는 다양한 요인 중, 수직음속분포 오정합(mismatch)에 의한 영향을 MV 프로세서 (Minimum Variance Processor)를 이용하여 모의실험함으로써 그 결과를 분석하였다. 천해 모의환경에서 동일한 기울기로 증감하는 수직음속분포 오정합은 음원 위치추정에서 거리성분의 오차를 가지며, 상이한 기울기를 갖는 수직음속분포 오정합은 거리와 수심 성분의 오차가 유발됨을 확인할 수 있었다. 심해 모의 환경에서 수직음속분포 오정합은 거리와 수심 성분의 오차가 유발되고, 거리추정의 전반적인 경향은 천해의 동일한 기울기를 가지는 경우와 유사함을 확인할 수 있었다.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06c
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• pp.458-462
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• 2010

본 논문은 X-선 혈관조영영상에서 기울기 정보 및 최대 빈도수를 이용한 카테터 자동 분할 방법을 제안한다. 제안방법은 세 단계로 이루어진다. 첫째, 분할하고자 하는 카테터 관심영역을 설정하고, 영상의 대조대비를 높이기 위한 밝기값 스트레칭을 수행한다. 둘째, 카테터 후보 경계점을 추출하기 위하여 카테터 방향을 고려한 경계 강조 마스크를 영상에 적용한다. 셋째, 카테터 후보 경계점에서 기울기가 크고 최대 빈도수 직경을 갖는 카테터 경계점을 추출하고 이들을 선형 보간하여 최종 카테터 경계를 분할한다. 제안 방법의 평가를 위하여 육안 평가 및 전문가가 수동 분할한 결과와 본 제안방법을 적용하여 얻은 중복 영역 비율과 평균 거리 차이를 측정한 정확성 평가를 수행하였고, 수행시간을 측정하였다. 실험결과 중복 영역 비율은 93.9%${\pm}$2.7%, 평균 거리 차이는 0.116-픽셀, 수행시간은 평균 0.011초로 측정되었다.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.3
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• pp.331-339
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• 2013

The Interest in disease prevention and rehabilitation is increasing depending on increase of patients with spinal. This is being developed using the spine stabilization device is being studied. So far studies have only evaluated the effect on trunk stabilization exercises but analysis of human movement patterns for active movement and passive movement did not. We assessed the muscle activity of trunk and leg muscle during passive and active tilt mode on eight tilt directions at tilt angle of $30^{\circ}$ using 3-D dynamic postural balance training system. We performed experimental study on the muscular activities of trunk muscle about rectus abdominis, external obliques, latissimus dorsi, erector spinae, and leg muscle about rectus femoris, Biceps femoris, Tibialis Anterior, gastrocnemius. As a result, muscle activation was different depending on the direction of movement and pattern. The results indicate that various patterns of spinal stabilization exercise system could be applied to an effective training of chronic low back pain patients.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.212-213
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• 2013

등록 장애인의 수가 매년 증가함에 따라 휠체어 사용 장애인도 역시 증가하고 있으며, 이들은 일상생활에서 휠체어가 필수적이며 건축물 공간 내에서 수직이동을 위해 경사로도 필요하다. 휠체어 사용 장애인의 접근성 확보를 위한 수직이동시설 중 하나인 경사로의 경우 1/12라는 기울기로 인해 많은 공간을 차지하게 되므로 건축물 내 경사로 설치에 소극적으로 대처하고 있다. 기울기(1:12, 1:10, 1:8, 1:6)를 조절할 수 있는 경사로를 설치하여 20대, 30대, 40대, 50대, 60대 각 연령별로 남녀의 비율을 같게 하여 수동식 휠체어를 사용하여 이동 실험을 하였다. 화재와 같은 긴급피난 시 경사로 설치를 통해 계단으로 이동하지 못 하는 휠체어 사용 장애인들의 자력피난과 화재안전을 확보하고자 연구를 진행하였다.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.9
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• pp.695-699
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• 2009

In this paper, we propose an automatic prostate segmentation technique using image intensity and gradient information. Our method is composed of four steps. First, rays at regular intervals are generated. To minimize the effect of noise, the start and end positions of the ray are calculated. Second, the profiles on each ray are sorted based on the gradient. And priorities are applied to the sorted gradient in the profile. Third, boundary points are extracted by using gradient priority and intensity distribution. Finally, to reduce the error, the extracted boundary points are corrected by using B-spline interpolation. For accuracy evaluation, the average distance differences and overlapping region ratio between results of manual and automatic segmentations are calculated. As the experimental results, the average distance difference error and standard deviation were 1.09mm $\pm0.20mm$. And the overlapping region ratio was 92%.

• The Journal of the Acoustical Society of Korea
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• v.37 no.4
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• pp.196-205
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• 2018

This paper presents an algorithm for passive localization of a ship by applying the ray back-propagation technique to the ship radiation noise data. The previous method [S. H. Abadi, D. Rouseff and D. R. Dowling, J. Acoust. Soc. Am. 131, 2599-2610 (2012)] estimates the position of a sound source in the near-field environment with no array tilt by using the RBD (Ray-based Blind Deconvolution) and ray back-propagation techniques. However, when there exists an array tilt, the above method leads to a large position estimation error. In order to overcome the problem, this study proposes an algorithm that estimates the position of a sound source by correcting the array tilt using the RBD and ray back-propagation techniques. The proposed algorithm was verified by using the ship noise of SAVEX15 (Shallow-water Acoustic Variability EXperiment in 2015) experimental data.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.829-831
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• 2004

다양한 개인 생체 정보 중에서 비교적 높은 인식률과 사용자 편의성을 제공하는 것은 홍채 인식이다. 그러나, 현재의 홍채 인식은 수동 영상 획득 시스템으로 비접촉식이라는 사용자 편의성을 제대로 제공을 못하는 것이 현실이다. 이것은 정밀한 홍채 영상 획득을 위하여 고해상도의 영상 획득 장비의 필요와 정확한 홍채 위치 수적의 어려움으로 인한 문제이다. 본 연구에서는 24bit 칼라 영상을 이용한 사랑의 얼굴 형태의 인식과 인식된 얼굴 형태에서의 눈 영역 추적 확대를 통한 실시간 자동 홍채 인식 시스템을 제안하였다. 제안된 시스템에서 얼굴의 피부색을 이용한 얼굴 인식 방법이외에 윤곽선 검출 정보를 이용한 기울기 보정과 눈 영역 검출을 실행하여, 이를 이용하여 눈 영역 추적과 확대를 실행을 한다. 그 다음 과정으로 눈 영역 영상에서 동공 중심을 획득하여 그 중심을 이은 선분으로 기준선을 잡아 홍채를 획득하는 과정으로 이루어지게 된다.

• Journal of KIISE:Software and Applications
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• v.37 no.4
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• pp.273-281
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• 2010

In this paper, we propose an automatic segmentation method of the endo- and epicardial boundary by using ray-casting profile based on intensity distribution and gradient information in CT images. First, endo-cardial boundary points are detected by using adaptive thresholding and seeded region growing. To include papillary muscles inside the boundary, the endo-cardial boundary points are refined by using ray-casting based profile. Second, epi-cardial boundary points which have both a myocardial intensity value and a maximum gradient are detected by using ray-casting based adaptive gradient profile. Finally, to preserve an elliptical or circular shape, the endo- and epi-cardial boundary points are refined by using elliptical interpolation and B-spline curve fitting. Then, curvature-based contour fitting is performed to overcome problems associated with heterogeneity of the myocardium intensity and lack of clear delineation between myocardium and adjacent anatomic structures. To evaluate our method, we performed visual inspection, accuracy and processing time. For accuracy evaluation, average distance difference and overalpping region ratio between automatic segmentation and manual segmentation are calculated. Experimental results show that the average distnace difference was $0.56{\pm}0.24mm$. The overlapping region ratio was $82{\pm}4.2%$ on average. In all experimental datasets, the whole process of our method was finished within 1 second.

• Korean Journal of Environment and Ecology
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• v.31 no.6
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• pp.537-548
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• 2017

The purpose of this study was to investigate the species composition and the aquatic environment of Jojong Stream and Sudong Stream, which were the original habitats of Zacco koreanus population and restored population re-introduced in Bongseonsa Stream. It also compared and analyzed the states of the growth and reproductive ability of Z. koreanus habiting in each of the three streams. The investigation was conducted in June 2016 which was known as the spawning season of Z. koreanus. The results of the physical aquatic environments showed the slight differences in altitude, width and depth of water among three streams, but the bottom structure was found to be quite different in the composition of the boulder, cobble, and pebble among the streams. The result of the physicochemical aquatic environment analysis showed that there were no significant differences in water temperature, pH, DO, BOD, and EC among the three stream. In the fish fauna investigation, 530 individuals of 11 species of 3 families were collected in Bongseonsa Stream, 293 individuals of 12 species of 4 families were collected in Jojong Stream, and 361 individuals of 11 species of 4 families were collected in Sudong Stream. All three streams were dominated by Z. koreanus and Z. platypus. Six Korean endemic species appeared in each of the three streams, showing the high occurrence rate of indigenous species of 50.0% or more. The aggregation index analysis revealed that the mean dominance index ranged from 0.63 (${\pm}0.05$, BS) to 0.72(${\pm}0.01$, JJ), mean diversity index from 1.55 (${\pm}0.06$, JJ) to 1.78 (${\pm}0.11$, BS), mean evenness index from 0.71 (${\pm}0.03$, JJ) to 0.76 (${\pm}0.02$, BS), and mean richness index from 1.61 (${\pm}0.33$, JJ) to 1.73 (${\pm}0.24$, SD). The result indicated that the observed differences between the stream community indices were statistically nonsignificant. The similarity analysis showed that 75.4% similarity was divided into two groups of A and B and that the fish fauna on each analyzed point was similar. The quantitative habitat evaluation index (QHEI) analysis showed that the average value of QHEI was 151.0 (${\pm}46.0$), which means that it was a suboptimal habitat environment. The result of length-weight analysis of Z. koreanus populations showed that the regression coefficient b of the restoration population and the original habitat population were at 3.0 or higher while the condition factor had a positive slope. Moreover, it was found that the slopes of the regression coefficient b and condition factor of the original habitat population were larger than the restored population. The analysis of the length frequency distribution of the Z. koreanus population revealed that all three streams maintained the stable life cycle although it was found that the growth rate of the original habitat population was faster than the restored population in the one-year-old class. The result of the gonadosomatic index (GSI) analysis showed that the GSI median value of the Z. koreanus population in the restored habitat Bongseonsa Stream was higher than the population in the original habitat Jojong Stream and Sudong Stream for both of males and females.

• Journal of IKEEE
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• v.18 no.3
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• pp.362-367
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• 2014

Music score recognition applications running on a smartphone, which is one of the necessities of modern people, have already been released on the market. These applications have the several limitations, especially the recognition rate of printed music scores is low so that many errors occur when the score is played. The major factor to decrease the recognition rate comes from poor tilt-correction of the captured staff-line. In this paper, we propose a efficient method that can automatically shoot the printed music score through preview analysis, which increases the recognition rate via tilt-correction.