• 제목/요약/키워드: Depth prediction

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3D-AVC에서 색상 영상 정보를 이용한 깊이 영상의 빠른 화면 내 예측 모드 결정 기법 (Fast Intra Mode Decision Algorithm for Depth Map Coding using Texture Information in 3D-AVC)

  • 강진미;정기동
    • 한국멀티미디어학회논문지
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    • 제18권2호
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    • pp.149-157
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    • 2015
  • The 3D-AVC standard aims at improving coding efficiency by applying new techniques for utilizing intra, inter and view predictions. 3D video scenes are rendered with existing texture video and additional depth map. The depth map comes at the expense of increased computational complexity of the encoding process. For real-time applications, reducing the complexity of 3D-AVC is very important. In this paper, we present a fast intra mode decision algorithm to reduce the complexity burden in the 3D video system. The proposed algorithm uses similarity between texture video and depth map. The best intra prediction mode of the depth map is similar to that of the corresponding texture video. The early decision algorithm can be made on the intra prediction of depth map coding by using the coded intra mode of texture video. Adaptive threshold for early termination is also proposed. Experimental results show that the proposed algorithm saves the encoding time on average 29.7% without any significant loss in terms of the bit rate or PSNR value.

후판 압연의 온라인 온도예측 모델 개발 (Development of On-line Temperature Prediction Model for Plate Rolling)

  • 서인식;이창선;조세돈;주웅용
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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    • pp.283-292
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    • 1999
  • Temperature prediction model was developed for on-line application to plate rolling mills of POSCO. The adequate boundary conditions of heat transfer coefficients were obtained by comparing the predicted temperature with the measured temperatures taken by measuring system in plate rolling mill of POSCO. In obtaining the boundary condition which minimize the mean and standard deviation of the difference between prediction and measurement, orthogonal array for experimental design was used to reduce the calculation time of large data set. To predict the temperature drop at four edge of plate in one dimensional model, the energy change by heat transfer though directions perpendicular to thickness direction was treated like that by deformation. And the heat transfer through four edge directions was inferred from that through thickness direction with two coefficients of depth and severity of temperature drop at the edge. The boundary condition for the depth and severity of temperature drop were also determined using the measured temperature.

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HEVC 화면 내 예측을 위한 FAST 에지 검출 기반의 CU 분할 방법 (CU Depth Decision Based on FAST Corner Detection for HEVC Intra Prediction)

  • 전승수;김남욱;전병우
    • 방송공학회논문지
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    • 제21권4호
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    • pp.484-492
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    • 2016
  • High efficiency video coding (HEVC)은 H.264/AVC와 같은 이전 비디오 압축 표준 보다 더 높은 압축 효율을 갖는 최신 비디오 압축 표준이다. 화면 내 예측에서 최대 압축 단위 (LCU)들은 quadtree 구조를 통해 64x64부터 8x8까지의 크기를 갖는 더 작은 압축 단위 (CU)들로 나누어지고, 이들은 다시 예측 단위 (PU)들로 나누어진다. 가능한 크기까지 CU를 분할하면서 RDO (Rate Distortion Optimization) 과정을 통해 최적의 CU 분할 형태가 선택된다. 이 과정에서 HEVC는 많은 계산량을 필요로 한다. 본 논문에서는 HEVC의 계산량을 줄이기 위해, FAST (Features from Accelerated Segment Test) 코너 검출을 이용하여 화면 내 예측을 위한 고속 CU depth 결정 방법 (FCDD)을 제안한다. 제안하는 방법은 기존의 HEVC와 비교하여 약 0.7%의 BDBR 만큼의 적은 압축 성능 감소와 함께 부호화기에서 약 53.73%의 계산 시간을 감소시켰다.

Efficacy of Endoscopic Ultrasonography for Prediction of Tumor Depth in Gastric Cancer

  • Park, Ji-Min;Ahn, Chang-Wook;Yi, Xian;Hur, Hoon;Lee, Kee-Myung;Cho, Yong-Kwan;Han, Sang-Uk
    • Journal of Gastric Cancer
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    • 제11권2호
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    • pp.109-115
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    • 2011
  • Purpose: As the proportion of early gastric cancer (EGC) has recently been increased, minimally invasive treatment is currently accepted as main therapy for EGC. Accurate preoperative staging is very important in determining treatment options. To know the accuracy of endoscopic ultrasonography (EUS), we compared the depth of invasion of the tumor with preoperative EUS and postoperative pathologic findings. Materials and Methods: We retrospectively analyzed 152 patients who underwent EUS before laparoscopic gastrectomy. The preoperative EUS results were compared with the pathological findings. Results: The overall proportion of coincidence for depth of invasion between EUS and pathologic results was 41.4%. Univariate analysis showed that the rate of corrected prediction of EUS for tumor depth significantly decreased for the lesions more than 3cm in diameter (P=0.033), and those with a depressed morphology (P=0.035). In multivariate analysis, the depressed type (P=0.029, OR=2.873) and upper lesion (P=0.035, OR=2.151) was the significantly independent factors influencing the inaccurate prediction of EUS for tumor depth. Conclusions: When we decide the treatment modality considering the clinical depth of invasion by EUS, the possibility of discordance with pathologic results should be considered for the lesions located in the upper third of the stomach and with a depressed morphology.

탄성파 탐사를 활용한 산지사면 토심 추정 및 예측모델 보정 (Soil Depth Estimation and Prediction Model Correction for Mountain Slopes Using a Seismic Survey)

  • 봉태호;임상준;서정일;김동엽;허준
    • 한국산림과학회지
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    • 제112권3호
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    • pp.340-351
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    • 2023
  • 산사태는 매년 막대한 재산 피해와 인명 피해를 유발하는 주요 자연재해 중 하나이며, 기후변화의 영향으로 산사태 취약성은 더욱 증대되고 있다. 사면안정해석을 위한 다양한 매개변수 중 토심은 산사태 및 토석류 분석 시 주요 매개변수이며, 사면 안정성에 영향을 미치는 유역의 수문학적 과정을 평가하는 데 중요한 역할을 한다. 토심을 추정하는 정확한 방법은 현장에서 직접 지층을 조사하는 것이다. 하지만 이를 위해서는 많은 시간과 비용이 요구되므로 다양한 토심 예측 모델들이 제안되었으나 실용성 및 정확성 측면에서 다양한 한계가 존재한다. 본 연구에서는 산지사면에 대한 토심을 추정 하기 위하여 국내 산지를 대상으로 수행된 71개의 탄성파 탐사 결과를 수집하였으며 탄성파 속도 700 m/s를 기준으로 토심을 추정하였다. 이에 따라 사면의 경사, 고도, 토심 자료를 구축하고 토심에 대한 통계적 특성을 파악하였으며 경사와 토심 및 고도와 토심 간 상관관계를 규명하였다. 또한, 사면경사를 기반으로 한 다양한 토심 예측 모델을 조사하고 이에 대한 비교·분석을 수행하였으며 경사를 활용한 보정된 토심 예측식을 제안하였다.

탄뎀 서브머지드 용접 공법의 용접조건에 따른 용입깊이 및 용착면적 예측 (Prediction of Weld Penetration and Deposited Metal Area in Accordance with Weld Parameters in Tandem Submerged Arc Welding Process)

  • 박세진;남성길;권창길
    • Journal of Welding and Joining
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    • 제29권6호
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    • pp.71-76
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    • 2011
  • Submerged arc welding method from both sides is generally applied to the welding of main panel manufacturing process during ship construction. The tandem SAW method is applied to improve the productivity. The various weld defects that occur during tandem SAW method are melt through, incomplete penetration, undercut and overlap etc. It could be thought that the reasons for these defects are mainly lack of prediction ability for penetration depth and deposited metal area. In this research, total 5 kinds of welding factors for experiment like current of lead pole, voltage of lead pole, current of trail pole, voltage of trail pole and welding speed are adopted. Weld tests are carried out for the analysis of variation effects of these factors on penetration depth and deposited metal area. Based on the test and analysis results, it is possible to obtain the prediction equation for the effect of these factors on the amount of deposited metal and penetration depth. As per the verification of the results by additional tests, it is confirmed that the prediction equation, include a error margin of ${\pm}2mm$ for penetration depth and ${\pm}10mm2$ for deposited metal area.

황색종 담배의 생산성에 관여하는 토양특성 제3보. 토양의 형태적 특성이 황색종 담배의 생산성에 미치는 영향 (Study of Boil Characteristics on Productivity of Flue- cured Tobacco (Nicotiana tabacum L.) III. Influence of Morphological Characteristics of Soils on Productivity of Flue-cured Tobacco)

  • 김용연
    • 한국연초학회지
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    • 제9권2호
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    • pp.49-57
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    • 1987
  • This study had been conducted to determine morphological characteristics of soil in the major districts cultivating flue-cured tobacco plant. Also native soil productivities were measured by means of bioassay planting tobacco plant without fertilizer at 87 selected soils through field experiment. Morphological characteristics of troll affecting the dry weight of tobacco leaves cultivated in the field were investigated Among soil morphological characteristics, topograpy, slope, topsoil depth, soil depth, and soil texture had influenced with high significant on the dry weight of tobacco leaves. For prediction of dry weight (productivity) of tobacco leaves without fertilizer , multiple regression analysis were introduced using soul morphological characteristics. A combination of topography, slope, topsoil depth, and soil texture was very reliable for prediction of productivity. The regression equation was y = -16.88 -14, 34$X_1$ +20.43$X_2$ +50.21$X_3$ -7.54$X_4$ +13.45$X_5$ R = $0.670^{**}$ Where $X_1$ : Topography $X_2$ : Slope $X_3$ : Topsoil Depth $X_4$ : Soil Depth $X_5$ : Soil Texture

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시화지역 실트질 지반에서 강제치환심도 예측식 산정 (Prediction Equation of Compulsory Replacement Depth of Silty Layer in Sihwa Region)

  • 박영;임희대
    • 한국지반공학회논문집
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    • 제27권9호
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    • pp.55-66
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    • 2011
  • 강제치환공법은 다른 연약지반 처리공법에 비하여 시공이 단순하고 경제성이 우수하나 현재까지 정확한 이론적 산정기법이 정립되어 있지 않기 때문에 치환심도의 예측이 제대로 이루어지지 않고 있는 실정이다. 본 연구에서는 대다수의 예측식이 지지력을 기반으로 한 내용에서 관점을 바꾸어 액성한계 및 자연함수비에 근거한 새로운 형태의 예측식을 제안하였다. 예측식은 현장에서 관측된 계측결과와 확인보링에 근거하고, 지역성을 대변하기 위해 시화지역의 실트/점토의 특성을 분석한 자료로부터 관계식을 도출하였으며, 이를 회귀분석기법을 적용하여 최종 예측식을 도출하였다.