• Journal of Information Display
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• 제11권2호
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• pp.68-75
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• 2010

The relation between light sources and screen cells is considered part of the theoretical model of an autostereoscopic 3D display. The geometry of the image and observer regions is presented, including the cases of single and multiple regions. The characteristic function is introduced. Formulas for the geometric parameters are obtained, including areas and angles. Special attention is drawn to the screen location. The method of transforming the formulas between regions is stated. For multiple regions, geometric dissimilarity was found. This allows the model to be applied in finding the geometric characteristics of multiview and integral-imaging 3D displays.

• 한국통신학회논문지
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• 제22권8호
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• pp.1691-1697
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• 1997

This paper presents a new motion compensated error coding method suitable for region based image coding system. Compared with block based conding, the region based coding improves subjective quality as it estimates and compensates 2D (or 3D) translantional, rotational, and scaling motion for each regions. although the region based coding has this advantage, its merit is reduced as bock-DCT (2D-DCT) is used to encode motion-compensated error. To overcome this problem, a new region adaptive motion compensated error coding technique which improver subjective and objective quality in the region boundary is proposed in this paper. In the proposed method, regions with large error are estimated using contour of the regions and contrast between the regions. The regions estiated as those with large error are coded by arbitrarily shaped image segment coding method. The mask information of the coded regions is not transmitted because it is estimated as the same algorithm in the encoder and the decoder. The proposed region adaptive motion conpensated error coding method improves about 0.5dB when it is compared with conventional block based method.

• 한국방사선학회논문지
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• 제18권2호
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• pp.73-81
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• 2024

본 연구는 기분 장애(mood disorder) 환자들과 정상 대조군간의 대뇌 피질 두께를 측정 하여 구조적 이상을 비교하였다. 2020년 9월부터 2022년 8월까지 경상남도 양산 P 병원 정신건강의학과에서 기분 장애 진단을 받은 44명과 이상 병변이 없는 정상인 59명을 대상으로 후향적 연구를 시행하였다. 자기공명영상(MRI) 검사 후 획득한 3D-T1 MPRAGE 영상을 이용하였고, FreeSurfer 소프트웨어를 사용하여 대뇌 피질 두께를 측정하였다. 통계분석은 독립표본 t-검정을 이용하여 두 그룹간 평균의 차이를 측정하고, cohen's d 검정을 통해 두 그룹간 평균 차이의 크기를 평가하였다. 또한, 측정된 평균 피질 두께와 환자의 양성·음성증상(Positive and Negative Syndrome Scale, PANSS)간의 상관관계를 분석하였다. 기분장애 환자는 정상대조군에 비해 양측 상전두이랑(both superior frontal), 주둥이 중전두이랑(both rostral middle frontal), 꼬리 중전두이랑(both caudal middle frontal), 하전두이랑 주름 세곳(both pars opercularis, pars orbitals, pars triangularis), 상측두이랑(both superior temporal), 하측두이랑(both inferior temporal), 외측안와전두피질(both lateral orbito frontal), 내측안와전두피질(both medial orbito frontal), 방추형이랑(both fusiform), 후대상피질(both posterior cingulate), 대상이랑의 협부(both isthmus cingulate), 상두정수리소엽(both superior parietal), 하두정엽(both inferior parietal), 변연상이랑(both supramarginal), 좌측 후중심이랑(left post central), 우측 상부측두고랑(right bank of the superior temporal sulcus), 중측두이랑(right middle temporal), 전대상피질(right rostral anterior cingulate), 뇌섬엽(right insula)의 두께가 유의미하게 감소하였다(p<0.05). 그 중 평균 차이의 크기(cohen's d)가 큰 영역은 좌측 fusiform (d=0.82), pars opercularis (d=0.94), superior frontal (d=0.88), 우측 lateral orbito frontal (d=0.85), pars orbitalis (d=0.89) 로 나타났다. 또한, PANSS와 양측 대뇌 피질의 평균 두께는 약한 음의 상관관계(left hemisphere r=-0.234, right hemisphere r=-0.230)를 나타내었다. 이러한 연구의 결과는 정상인과 비교하여 기분장애 환자의 피질 두께 감소영역을 확인하였고 질환의 증상 정도와 피질 두께 변화의 관련성을 확인하는 데 도움이 될 것으로 기대된다.

• 대한의생명과학회지
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• 제24권4호
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• pp.430-434
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• 2018

Candida glabrata is the second most prevalent causative agent for candidiasis following C. albicans. The opportunistic yeast, C. glabrata, is able to cause the critical bloodstream infections in hospitalized patients. Conventional identification methods for yeasts are often time consuming and labor intensive. Therefore, recent studies on sequence-based identification have been conducted. Recently, sequencing the D1/D2 domain of the large subunit ribosomal RNA gene and the internal transcribed spacers (ITS) 1 and ITS2 regions of the ribosomal DNA has proven useful for DNA-based identification of most species of fungi. In the present study, therefore, fungal ITS and D1/D2 domain regions were targeted and analyzed by DNA sequencing for the accurate identification of C. glabrata clinical isolates. A total of 102 C. glabrata clinical isolates from various clinical samples including bloodstream, catheterized urine, bile and other body fluids were used in the study. The results of the DNA sequence analysis showed that the mean standard deviation of species identity percent score between ITS and D1/D2 domain regions was $97.8%{\pm}2.9$ and $99.7%{\pm}0.46$, respectively. These results revealed that the D1/D2 domain region might be a better target for identifying C. glabrata clinical isolates based on DNA sequences than the ITS1 and ITS2 regions. However, in order to evaluate the usefulness of D1/D2 domain region for species identification of all Candida species, other Candida species such as C. albicans, C. tropicalis, C. dubliniensis, and C. krusei should be verified in further studies additionally.

• 천문학회보
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• 제36권2호
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• pp.54.2-54.2
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• 2011

We present a study of HII regions in M51 using HST/ACS images taken as part of the Hubble Heritage Program. We found about 19,600 HII regions in M51 with $H_{\alpha}$ luminosity in the range of $L=10^{35.5}-10^{39.0}\;erg\;s^{-1}$. The $H_{\alpha}$ luminosity function of HII regions (HII LF) in M51 is well represented by a double power law with its index ${\alpha}=-2.25{\pm}0.02$ for the bright part and ${\alpha}=-1.42{\pm}0.01$ for the faint part, separated at a break point $L=10^{37.1}\;erg\;s^{-1}$. Comparison with simulated HII LFs suggests that this break is caused by the transition of HII region ionizing sources, from low-mass clusters (including several OB stars) to more massive clusters (including several tens of OB stars). The HII LFs with L < $10^{37.1}\;erg\;s^{-1}$ are found to have different slopes for different parts in M51: the HII LF for the interarm region is steeper than those for the arm and the nuclear regions. This observed difference in HII LFs can be explained by evolutionary effects: HII regions in the interarm region are relatively older than those in the other parts of M51. The size distribution of the HII regions is fitted by a double power law with a break at D = 30 pc. The power law index for the small HII regions with 15 pc < D < 30 pc is ${\alpha}=-1.78{\pm}0.04$, whereas ${\alpha}=-5.04{\pm}0.08$ for the large HII region with 30 pc < D < 110 pc. The power law indices of the size distribution are related with those of HII LF, and the relation between the luminosities and sizes of HII regions is fitted well by $L{\propto}D^{3.04{\pm}}$.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1107-1111
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• 2009

Flat panel multiview 3D displays developed in recent years have pseudoscopic regions that appear unnatural to viewers. We suggest a new method to suppress the pseudoscopic regions based on the visual characteristics of binocular rivalry. We confirm the validity of this method experimentally and show that the unnaturalness caused by pseudoscopic regions can be effectively suppressed.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2018년도 하계학술대회
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• pp.200-201
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• 2018

In the workflow of 360 video coding of JVET (Joint Video Experts Team), firstly the 360 videos are projected onto the 2D plane with diverse projection formats, such as Equi-Rectangular Projection (ERP), Cubemap Projection (CMP), Rotated Sphere Projection (RSP), etc. The projection format of RSP has inactive regions in the converted 2D plane. The inactive regions may cause visual artifact as well as the reduction of the coding efficiency due to discontinuity at boundaries between active and inactive regions. In this paper, to overcome these problems, the inactive regions are padded by using two types of adjacent pixels. Then padded regions of RSP are blended with inactive regions padded by proposed method. The experimental results demonstrate that, in terms of end-to-end WS-PSNR-NN, the proposed method achieves 0.1% BD-rate reduction. In addition, the visual artifacts along the borders between discontinuous faces are noticeably reduced.

• Journal of International Society for Simulation Surgery
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• 제1권1호
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• pp.27-31
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• 2014

In this paper, an overview of segmentation and 3D visualization methods are presented. Commonly, the two kinds of methods are used to visualize organs and vessels into 3D from medical images such as CT(A) and MRI - Direct Volume Rendering (DVR) and Iso-surface Rendering (IR). DVR can be applied directly to a volume. It directly penetrates through the volume while it determines which voxels are visualizedbased on a transfer function. On the other hand, IR requires a series of processes such as segmentation, polygonization and visualization. To extract a region of interest (ROI) from the medical volume image via the segmentation, some regions of an object and a background are required, which are typically obtained from the user. To visualize the extracted regions, the boundary points of the regions should be polygonized. In other words, the boundary surface composed of polygons such as a triangle and a rectangle should be required to visualize the regions into 3D because illumination effects, which makes the object shaded and seen in 3D, cannot be applied directly to the points.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.1317-1320
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• 1993

We are concerned with developing a robust method for comprehensive scene analysis. In particular, we address the problem of representing spatial relations between regions in a segmented 2D image. Spatial relations are modeled as fuzzy sets. The method has two aspects, symbolic and quantitative, consisting of assigning labels for spatial relations and numeric degrees to which a relation holds respectively. The procedure of deriving a spatial relation is hierarchical taking into account geometric/physical characteristics of the regions in question.

• 한국콘텐츠학회논문지
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• 제21권3호
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• pp.184-193
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• 2021

본 연구는 우리나라 16개 지역을 대상으로 기술혁신활동과 그 경제적 성과를 분석하였다. 실증분석은 과학기술정책연구원의 서베이 data를 이용하였고, 분석모형은 R&D지출과 매출액에 대한 단순모형 I과 노동변수를 추가한 Cobb-Douglas 모형 II로 분석하였다. 분석결과 모형 I은 전국을 대상으로 한 분석에서는 R&D 지출에 대한 매출액 탄력성이 0.42로 추정되었으며, 지역별로 보면 울산이 0.66으로 최고치를 보인 반면 부산지역은 0.2로 최저치를 보여주고 있다. 모형 II에서는 R&D 지출의 통계적 유의성이 약하고 상대적으로 노동의 통계적 유의성은 높게 나타나고 있는데, 이는 기술투자가 경제적 성과로 나타나는 데에 불확실성이 보다 강하게 존재하기 때문으로 보인다. 이를 보완하기 위해 분산분석을 통해 동질적인 지역을 대상으로 3개 권역으로 구분하였는데, Group A는 상대적으로 규모가 작고 높은 R&D집약도를 보이고 있으며, Group C는 규모가 큰반면 낮은 R&D집약도를 보이고 있다. 분석 결과는 모형 I에서 매출액에 대한 R&D 탄력성은 Group C가 0.48로서 가장 높게 나타나고 있고, Group B는 0.38, Group A는 0.29로서 권역별 차이가 뚜렷하게 나타났다. 모형 II에서는 매출액에 대한 R&D 탄력성은 Group C가 0.088로서 가장 높고, Group B는 0.086, Group A는 0.031의 순으로 나타났다. 노동 탄력성은 Group A가 1.16으로 가장 높고, Group C가 1.13, Group B는 1.10순으로 나타나고 있는데, 이는 중소기업이 다수인 지역에서 매출액에 대한 R&D 탄력성보다는 노동탄력성이 크게 나타나고 있음을 보여주고 있다.