• 제목/요약/키워드: Normal regions

검색결과 703건 처리시간 0.024초

보행로봇의 이동경로 인식을 위한 스테레오카메라 기반의 평면영역 추출방법 (A Stereo Camera Based Method of Plane Detection for Path Finding of Walking Robot)

  • 강동중
    • 제어로봇시스템학회논문지
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    • 제14권3호
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    • pp.236-241
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    • 2008
  • This paper presents a method to recognize the plane regions for movement of walking robots. When the autonomous agencies using stereo camera or laser scanning sensor is under unknown 3D environment, the mobile agency has to detect the plane regions to decide the moving direction and perform the given tasks. In this paper, we propose a very fast method for plane detection using normal vector of a triangle by 3 vertices defined on a small circular region. To reduce the effect of noises and outliers, the triangle rotates with respect to the center position of the circular region and generates a series of triangles with different normal vectors based on different three points on the boundary of the circular region. The vectors for several triangles are normalized and then median direction of the normal vectors is used to test the planarity of the circular region. The method is very fast and we prove the performance of algorithm for real range data obtained from a stereo camera system.

B-모드 심초음파도의 연속 영상 분석에 의한 심근경색증 추출 (Extraction of Myocardial Infarction by Consecutive Image Analysis in B-mode Echocardiogram)

  • 손권;조성목
    • 한국산학기술학회논문지
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    • 제7권6호
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    • pp.1116-1121
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    • 2006
  • 본 논문에서는 B-모드 심초음파도의 연속 영상을 분석함으로써 정상심근과 경색심근 사이의 차이점을 구별할 수 있는 기법에 대하여 연구하였다. 2차원 심초음파도를 분석하기 위해서 사람의 심장운동 한 주기에 걸쳐 프레임 내 분석과 프레임 간 분석법을 제시하였고, HGE와 LT로 명명한 새로운 분석변수를 제안하였다. 제안한 변수를 사용한 분석기법은 정상 영역과 경색 영역 사이에 정량적으로 두드러진 특징을 보여주었다. 경색부분에서는 심장주기 전체에 걸쳐 휠씬 높은 값을 나타내었고, 정상조직은 변동이 훨씬 심하게 나타남을 확인할 수 있었다. 실험결과에 따라 제안한 변수들은 심장의 한 주기에 걸쳐 심근의 상태를 관찰할 수 있는 좋은 측정자임을 증명할 수 있었다.

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F-18 FDG PET/MRI와 PET/CT 전신 영상에서 VOI를 이용한 정상부위의 $SUV_{LBM}$-최대치에 의한 영상평가 (Image Evaluation Via $SUV_{LBM}$ for Normal Regions of VOI by Using Whole Body Images Obtained from PET/MRI and PET/CT)

  • 박정규;김성규;조인호;공은정;박명환
    • 한국의학물리학회지:의학물리
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    • 제24권1호
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    • pp.68-75
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    • 2013
  • 본 연구의 목적은 26명의 건강한 검진자들을 대상으로 PET/CT와 PET/MRI의 전신 영상에서 조기 정밀/ 진단 수준을 향상하고자 관심부피를 이용하여 정상부위의 $SUV_{LBM}$-최대치를 이용하여 PET/CT와 PET/MRI를 조영제 사용 유무와 관계없이 동시 평가할 수 있는 데이터를 구축하고자 하였다. 전신 F-18 FDG PET/CT와 전신 F-18 FDG PET/MRI의 정상부위의 VOI를 이용한 $SUV_{LBM}$-최대치평가는 PET/CT를 기준으로 PET/MRI의 영상은 매우 유의한 차이를 보였다(p<0.0001). 그러나 통계학적으로 높은 상관관계를 가진다(R>0.8). PET/MRI의 $SUV_{LBM}$ 평가 시 26.3% 감소하여 판단할 것과 조영제를 사용할 경우는 29.3% 감소하여 판단할 것으로 생각한다. PET/CT와 PET/MRI의 모든 영상의 판독에서는 $SUV_{LBM}$-최대치를 사용하는 것이 편리성과 효율성을 고려하여 임상의나 연구자들에게 많은 도움이 되리라 판단된다.

Propagation of the ionizing radiations leaked out of bright H II regions into the diffuse interstellar medium

  • Seon, Kwang-Il
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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    • pp.33.2-33.2
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    • 2009
  • Diffuse ionized gas (DIG or warm ionized medium, WIM) outside traditional regions is a major component of the interstellar medium (ISM) not only in our Galaxy, but also in other galaxies. It is generally believed that major fraction of the Halpha emission in the DIG is provided by OB stars. In the "standard" photoionization models, the Lyman continuum photons escaping from bright H II regions is the dominant source responsible for ionizing the DIG. Then, a complex density structure must provide the low-density paths that allow the photons to traverse kiloparsec scales and ionize the gas far from the OB stars not only at large heights above the midplane, but also within a galactic plane. Here, I present Monte-Carlo models to examine the propagation of the ionizing radiation leaked out of traditional H II regions into the diffuse ISM applied to two face-on spirals M 51 and NGC 7424. We find that the "standard" scenario requires absorption too unrealistically small to be believed, but the obtained scale-height of the galactic disk is consistent with those of edge-on galaxies. We also report that the probability density functions of the Halpha intensities of the DIG and H II regions in the galaxies are log-normal, indicating the turbulence property of the ISM.

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Bootstrap Confidence Regions of 2-dimensional Vector-valued Process Capability Indices $C_p\;and\;C_{pk}$

  • Park Byoung-Sun;Nam Kyung-Hyun;Cho Joong-Jae
    • 한국품질경영학회:학술대회논문집
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    • 한국품질경영학회 2004년도 품질경영모델을 통한 가치 창출
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    • pp.70-75
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    • 2004
  • In actual manufacturing industries, process capability indices(PCI) are used to determine whether a production process is capable of producing items within a specified specification limits. We study some vector-valued PCIs $C_p=(C_{px},\;C_{py})$ and $C_{pk}=(C_{pkx},\; C_{pky})$ in this article. We propose some asymptotic confidence regions of PCIs with bootstrapping and examine the performance of those asymptotic confidence regions under the assumption of bivariate normal distribution.

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Magnetoencephalography (MEG)의 임상적 유용성 (Magnetoencephalography and Clinical Application)

  • 박현미;신동진
    • Annals of Clinical Neurophysiology
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    • 제1권2호
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    • pp.154-159
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    • 1999
  • Magnetoencephalography (MEG), the measurement of magnetic fields produced by neuronal current associated with normal and pathologic brain activities, is a totally noninvasive method for localizing functional regions of the brain. During the past several years, many clinical research centers are working to expand various fundamental functional brain regions, which can be easily localized, as well as to characterize magnetic abnormalities which accompany a wide variety of cerebral disease. At present, MEG is used in a number of clinical centers throughout the world for the presurgical functional localization of eloquent cortex, and for the non-invasive localization of epileptiform activity. And also, non-invasiveness means that it can be used for screening and repetitive follow-up measurement without concern for adverse effects. As procedures for activating various functional brain regions are standardized, and as the effects of specific cerebral diseases on the MEG are carefully documented in controlled studies, the number of routine neurological applications for MEG will increase significantly. In this paper, the basic principles of MEG are reviewed briefly with its clinical application to neurologic disease.

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정상견 안압의 일변동과 안압계간 측정치의 비교 (Diurnal Change of Intraocular Pressures and Comparison of $Tono-pen^{XL}$ and Schi$\emptyset$tz Tonometer in Normal Dogs)

  • 김완희;권오경
    • 한국임상수의학회지
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    • 제19권4호
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    • pp.415-417
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    • 2002
  • To investigate the diurnal change of intraocular pressures(IOP) and compare of $Tono-pen^{XL}$ and Schi$\emptyset$tz tonometer, we measured the IOP in clinically normal eyes of dogs. To estimate the diurnal change of IOP, the measurements of IOP were taken with $Tono-pen^{XL}$ in 44 normal canine eyes. Two physicians measured the IOP through the central cornea and limbal cornea. To compare of two tonometers, a physician measured the IOP with both $Tono-pen^{XL}$ and Schi$\emptyset$tz (7.5 g) tonometer in 23 clinically normal eyes of dogs. Mean of lOP was 26.51 $\pm$ 6.91 mmHg and IOP was highest as 30.65 mmHg at a.m. 10, but not significantly different within physicians and corneal regions (p > 0.05). Correlation coefficient within two tonometers was too low.

Isolation of a Variant Strain of Pleurotus eryngii and the Development of Specific DNA Markers to Identify the Variant Strain

  • Lee, Hyun-Jun;Kim, Sang-Woo;Ryu, Jae-San;Lee, Chang-Yun;Ro, Hyeon-Su
    • Mycobiology
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    • 제42권1호
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    • pp.46-51
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    • 2014
  • A degenerated strain of Pleurotus eryngii KNR2312 was isolated from a commercial farm. Random amplified polymorphic DNA analysis performed on the genomic DNA of the normal and degenerated strains of this species revealed differences in the DNA banding pattern. A unique DNA fragment (1.7 kbp), which appeared only in the degenerated strain, was isolated and sequenced. Comparing this sequence with the KNR2312 genomic sequence showed that the sequence of the degenerated strain comprised three DNA regions that originated from nine distinct scaffolds of the genomic sequence, suggesting that chromosome-level changes had occurred in the degenerated strain. Using the unique sequence, three sets of PCR primers were designed that targeted the full length, the 5' half, and the 3' half of the DNA. The primer sets P2-1 and P2-2 yielded 1.76 and 0.97 kbp PCR products, respectively, only in the case of the degenerated strain, whereas P2-3 generated a 0.8 kbp product in both the normal and the degenerated strains because its target region was intact in the normal strain as well. In the case of the P2-1 and P2-2 sets, the priming regions of the forward and reverse primers were located at distinct genomic scaffolds in the normal strain. These two primer sets specifically detected the degenerate strain of KNR2312 isolated from various mushrooms including 10 different strains of P. eryngii, four strains of P. ostreatus, and 11 other wild mushrooms.

긴몰개 Squalidus gracilis majimae의 피부백색증에 대한 조직학적 연구 (Histological Study on Cutaneous Albinism of Korean Slender Gudgeon Squalidus gracilis majimae from Korea)

  • 이용주;박종영;오민기
    • 한국어류학회지
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    • 제21권3호
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    • pp.208-213
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    • 2009
  • 긴몰개 Squalidus gracilis majimae 백색증 개체가 자연에서 발견되어 조직학적 분석을 통해 정상개체와의 차이를 비교하였다. 백색증 개체는 정상 개체에 비해 체색의 발현이 이루어지지 않았다. 등, 체측, 배, 미병부 상부, 미병부 하부, 등 뒷지느러미 및 안구조직에 대한 조직형태에서는 정상과 백색증 개체간 차이가 없었으나 멜라닌 색소의 분포 및 발현량에서 차이를 보였다. 정상 개체의 경우, 멜라닌 색소는 배쪽을 제외한 모든 부위에서 잘 발달한 모습을 볼 수 있었다. 그러나 백색증 개체의 경우, 멜라닌 색소는 눈과 몸통의 위쪽부위에서 매우 희미하게 관찰되었고, 아래쪽 부위(배, 미병부 하부, 뒷지느러미)에서는 전혀 발견되지 않았다. 이러한 멜라닌 색소의 분포는 빛과 연관이 있을 것으로 추측되었다.

Depth Map Coding Using Histogram-Based Segmentation and Depth Range Updating

  • Lin, Chunyu;Zhao, Yao;Xiao, Jimin;Tillo, Tammam
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권3호
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    • pp.1121-1139
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    • 2015
  • In texture-plus-depth format, depth map compression is an important task. Different from normal texture images, depth maps have less texture information, while contain many homogeneous regions separated by sharp edges. This feature will be employed to form an efficient depth map coding scheme in this paper. Firstly, the histogram of the depth map will be analyzed to find an appropriate threshold that segments the depth map into the foreground and background regions, allowing the edge between these two kinds of regions to be obtained. Secondly, the two regions will be encoded through rate distortion optimization with a shape adaptive wavelet transform, while the edges are lossless encoded with JBIG2. Finally, a depth-updating algorithm based on the threshold and the depth range is applied to enhance the quality of the decoded depth maps. Experimental results demonstrate the effective performance on both the depth map quality and the synthesized view quality.