• 제목/요약/키워드: multiple contrast

검색결과 563건 처리시간 0.026초

Detection of Multiple Salient Objects by Categorizing Regional Features

  • Oh, Kang-Han;Kim, Soo-Hyung;Kim, Young-Chul;Lee, Yu-Ra
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권1호
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    • pp.272-287
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    • 2016
  • Recently, various and effective contrast based salient object detection models to focus on a single target have been proposed. However, there is a lack of research on detection of multiple objects, and also it is a more challenging task than single target process. In the multiple target problem, we are confronted by new difficulties caused by distinct difference between properties of objects. The characteristic of existing models depending on the global maximum distribution of data point would become a drawback for detection of multiple objects. In this paper, by analyzing limitations of the existing methods, we have devised three main processes to detect multiple salient objects. In the first stage, regional features are extracted from over-segmented regions. In the second stage, the regional features are categorized into homogeneous cluster using the mean-shift algorithm with the kernel function having various sizes. In the final stage, we compute saliency scores of the categorized regions using only spatial features without the contrast features, and then all scores are integrated for the final salient regions. In the experimental results, the scheme achieved superior detection accuracy for the SED2 and MSRA-ASD benchmarks with both a higher precision and better recall than state-of-the-art approaches. Especially, given multiple objects having different properties, our model significantly outperforms all existing models.

Massive barium sulfate aspiration during upper gastrointestinal contrast material study in an elderly patient with dysphagia

  • Yun, Hae Ryong;Kim, Chang-gon;Park, Jihye;Park, Yong eun;lee, Yong-il;Yoo, Byung-Woo;Chung, Kyung Soo;Kim, Young Sam;Song, Joo Han
    • Journal of Yeungnam Medical Science
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    • 제33권2호
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    • pp.162-165
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    • 2016
  • Barium sulfate is an inert material used as a radiographic contrast medium during upper gastrointestinal contrast studies for evaluation of patients with dysphagia. Oral barium aspiration is an uncommon but well-reported complication of this procedure. While barium aspiration of small amounts may not cause any symptoms, massive barium aspiration can be life-threatening, particularly in elderly patients with multiple comorbidities. In this case report, we describe an elderly patient with multiple comorbidities who presented with thyrotoxicosis and dysphagia, and then died after massive barium aspiration. Despite administration of intensive medical care with ventilator support and therapeutic bronchoalveolar lavage to remove the aspirated barium, the patient died of multiple organ failure 9 days after barium aspiration. Clinicians should pay attention to elderly patients with predisposing factors for aspiration in whom upper gastrointestinal barium contrast studies are indicated, and should consider other diagnostic tools for evaluation of dysphagia in this population.

컴퓨터단층촬영의 요오드화 조영제 부작용으로 인한 사망 관련 조영제 비교 분석 (Comparative Analysis of Death-Related Iodide Contrast Media due to Adverse Reactions of Contrast Media in Computed Tomography)

  • 유성민;한동균;홍주완
    • 대한방사선기술학회지:방사선기술과학
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    • 제44권1호
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    • pp.47-52
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    • 2021
  • The incidence of adverse reactions to iodide contrast media was found to have increased owing to their increased use in computed tomography, but the exact reasons were unknown. Based on reported iodide contrast media adverse reactions data, it is recommended to the components of iodide contrast media before use to minimize adverse reactions. It was found that the use of iopromide and iomeprol in iodide contrast media resulted in a higher incidences of death and threat of life resulting from adverse reactions than other ingredients. Patients who are administered iodide contrast media containing iopromide and iomeprol during the computed tomography test should be carefully examined by the relevant medical professional, as the significance of gender and age varies from component to component. As multiple iodide contrast agents are available, the use of an appropriate iodide contrast media will reduce the incidence of iodide contrast media adverse reactions.

다수의 단극 음원들을 이용한 속이 빈 실린더 형상의 응향 위치 에너지 집적공간 형성방법 (A method of Shaped Sound Focusing Using Multiple Monopole Sources: Hollow Cylinder shape)

  • 박진영;김양한
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 추계학술대회논문집
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    • pp.537-540
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    • 2005
  • Shaped Sound Focusing is defined as the generation of acoustically bright zone with a certain shape in space using multiple sources. The acoustically bright zone is a spatially focused region with relatively high acoustic potential energy level. In view of the energy transfer, acoustic focusing using multiple sources is essential because acoustic energy is very small to use other type of energy. It can be done by taking optimization techniques which can be acoustic brigtness control and acoustic contrast control. But it has not been frequently concerned about several cases, so the case of hollow cylinder shaped sound focusing is adapted and there wi11 be arguments about available control variables and spatially controllable region in this case.

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디테일 정보 기반의 다중 레이어 블록 오버랩 히스토그램 평활화 (Multiple Layers Block Overlapped Histogram Equalization based on The Detail Information)

  • 황재민;권오설
    • 방송공학회논문지
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    • 제18권5호
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    • pp.722-729
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    • 2013
  • 영상의 밝기가 집중되어 콘트라스트가 낮은 영상의 경우 히스토그램 평활화를 이용하면 영상내의 정보를 쉽게 분별할 수 있다. 기존의 기법에서는 콘트라스트 향상이 초점이었기 때문에 과한 콘트라스트 향상은 인지적으로 부자연스러운 영상을 생성하는 문제가 있었다. 이를 해결하기 위해서 CLAHE 방법은 일정크기로 콘트라스트 향상을 제한하는 기법으로 부자연스러움을 해결하였으나 이러한 경우 영상 내 디테일 정보가 은닉되는 문제가 발생하게 된다. 본 논문에서는 콘트라스트의 제한으로 인한 디테일 정보의 손실을 피하기 위해서 다중 레이어 블록 오버랩 히스토그램 평활화 기법을 기반으로 원 영상의 디테일에 대한 판별을 통해 각 레이어의 마스크를 이용한 디테일 맵을 구성한다. 각 레이어별로 디테일 맵을 이용한 제한된 콘트라스트 향상으로 생성된 영상들을 병합하여 영상 내 정보의 손실을 최소화하였다.

Comparison of Multilevel with Single Level Injection during Lumbar Sympathetic Ganglion Block: Efficacy of Sympatholysis and Incidence of Psoas Muscle Injection

  • Hong, Ji-Hee;Oh, Min-Ju
    • The Korean Journal of Pain
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    • 제23권2호
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    • pp.131-136
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    • 2010
  • Background: We prospectively evaluated the incidence and possible factors causing intramuscular injection during lumbar sympathetic ganglion block and compared the multiple needle technique to the single technique to obtain a profound and complete block effect. Methods: Among 83 patients, 58 patients (group A, n = 27, multiple needle technique and group B, n = 31, single needle technique) were reevaluated for the changes of skin temperature (Ts) and mean segment of longitudinal contrast spread. After injecting the contrast agent, the incidence of psoas muscle injection and the change of Ts was compared between two groups. Results: The incidence of psoas muscle injection was 21.3% (46/216) and it was associated with the level of injection (L2) significantly (${\chi}_2$ = 14.773, P = 0.001). $DT^{post}$ (postblock temperature difference between ipsilateral and contralateral great toe, $4.6{\pm}2.8^{\circ}C$, $1.8{\pm}1.6^{\circ}C$, P < 0.001 for group A and B) and $DT^{net}$ ($DT^{post}$ - $DT^{pre}$, $3.9{\pm}2.7^{\circ}C$, $1.5{\pm}1.5^{\circ}C$, P < 0.001 for group A and B) was significantly higher in group A. The mean segment of longitudinal contrast spread was $8.1{\pm}0.9$ for group A and $3.2{\pm}1.6$ for group B (P < 0.001). Conclusions: The LSGB at the L2 level showed the lowest incidence of psoas muscle injection of contrast. Multiple needle approach showed more significant increase of $DT^{net}$ and $DT^{post}$.

Enhancement of Speckle Contrast in vivo by Combining Linearly Polarized Laser Light and an Analyzer

  • Qureshi, Muhammad Mohsin;Mac, Khuong Duy;Kim, Andrew Hyunjin;Kim, Young Ro;Chung, Euiheon
    • Current Optics and Photonics
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    • 제5권4호
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    • pp.351-361
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    • 2021
  • Speckle imaging is capable of dynamic data acquisition at high spatiotemporal resolution, and has played a vital role in the functional study of biological specimens. The presence of various optical scatterers within the tissue causes alteration of speckle contrast. Thus structures like blood vessels can be delineated and quantified. Although laser speckle imaging is frequently used, an optimization process to ensure the maximum speckle contrast has not been available. In this respect, we here report an experimental procedure to optimize speckle contrast via applying different combinations of varying polarization of the illuminating laser light and multiple analyzer angles. Specifically, samples were illuminated by the p-polarization, 45°-polarization, and s-polarization of the incident laser, and speckle images were recorded without and with the analyzer rotated from 0° to 180° (Δ = 30°). Following the baseline imaging of a solid diffuser and a fixed brain sample, laser speckle contrast imaging (LSCI) was successfully performed to visualize in vivo mouse-brain blood flow. For oblique laser illumination, the maximum contrast achieved with p-polarized and s-polarized light was perpendicular to the analyzer's axis. This study demonstrates the optimization process for maximizing the speckle contrast, which can improve blood-flow estimation in vivo.

명도 콘트라스트 배색에 따른 스트라이프 의복 착용자의 이미지 연구 (The Image of the Stripe Clothes according to Value Contrast Coloration)

  • 문주영;강경자
    • 복식문화연구
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    • 제16권6호
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    • pp.992-1007
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    • 2008
  • This study was meant to offer the data for predicting the product plan answering the diverse demands for consumers based on the results of analyzing the image and formative property by transforming the stripe patterns. The concrete study way is composed of the collected stimulus centering on the interval of the stripe pattern and value contrast coloration. Consequently 192 stimuli, changed by the pattern direction and pattern interval, clothing style, and contrast coloration, are selected. The experimental materials made for this study are a set of stimuli and response scale. The statistics way used in analysis was factor analysis, ANOVA, dispersion analysis, multiple classification analysis. The results of this study were summed as following. Firstly, In the value contrast, a pair of 27 adjectives were made of attractiveness, activeness, gracefulness, visibility, and tenderness dimension. Secondly, the direction of the pattern, interval, clothing style, and contrast coloration were respectively transformed according to value contrast.

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Oral Administration of Nonionic Water-Soluble Contrast Media to Treat Meconium Obstruction in Premature Infants: A Preliminary Study

  • Hong, Hyun Sook;Kim, Sung Shin;Park, Ga Young
    • Neonatal Medicine
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    • 제28권1호
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    • pp.22-28
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    • 2021
  • Purpose: Meconium obstruction of prematurity (MOP) predisposes premature infants to intestinal perforation and prolonged hospitalization if not diagnosed and treated promptly. A standard contrast enema is less effective to treat infants with distal ileal obstructions because the contrast may not reach the obstructed areas. In an effort to avoid risky surgery, we administered oral contrast media to seven clinically diagnosed patients with MOP whose obstructions were not relieved via conventional sonography-guided contrast enema. We retrospectively evaluated whether oral nonionic water-soluble contrast media relieves MOP. Methods: Seven of 67 premature infants with MOP were administered oral contrast media from June 2015 to January 2019. Patients were followed-up radiographically for bowel distention and evacuation of contrast media after oral administration. We recorded radiographic improvements, meconium evacuation, time to first feeding after oral contrast media administration, maternal history, and neonatal clinical factors. Results: We evaluated five male and two female infants. The median gestational ages and body weights at birth were 27+5 weeks and 890 g, respectively. Radiography in five infants revealed multiple distended intestinal loops without air-fluid interfaces. Two infants had gasless abdomens, in which only stomach gas was visible. Oral contrast media (median, 2.5 mL) were administered at a median age of 7 days; five infants (5/7, 71.4%) responded to this treatment. The remaining two infants, who had ileal stenosis and hypoganglionosis, were surgically managed. Five infants (5/7, 71.4%) had maternal risk factors, and two (28.6%) were small for gestational age. Conclusion: Nonionic oral water-soluble contrast medium can serve as a valuable adjunct treatment in premature infants with meconium obstruction.

Android 플랫폼에서 구현 기술에 따른 화질 개선 연산 성능 비교 (Performance Comparison of Implementation Technologies for Image Quality Enhancement Operations on Android Platforms)

  • 이주호;이구연;정충교
    • 디지털콘텐츠학회 논문지
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    • 제14권1호
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    • pp.7-14
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    • 2013
  • 고사양 디지털 카메라를 내장한 스마트 기기의 보급이 급격하게 증가하면서 고해상도 영상의 품질을 개선하는 기능이 중요해지고 있다. 모바일 기기의 제한된 자원과 영상의 정보량을 감안하면 지나치게 복잡하지 않은 알고리즘을 선택해야 하고 가능한 효율적인 구현 기술을 사용해야 한다. 영상의 질을 향상시키는 기법 중 간단하면서도 널리 사용되는 기술은 명암 값 분포를 조절하는 명암비신장 (contrast stretching) 기법이다. 안드로이드 스마트폰의 경우, 구현 기술로는 가상 머신 위에서 동작하는 자바 라이브러리, JNI (Java Native Interface) 기반 원시 (native) C/C++ 구현 기술, 그리고 SIMD (Single Instruction Multiple Data) 기법이 적용된 NEON 구현 기술 등이 있다. 이 연구에서는 이 세 가지 기술을 선형 명암비신장 연산, 그리고 평활화 명암비신장 연산에 적용하여 그 성능을 실증적으로 비교 분석하였다. 그 결과 원시 C/C++과 NEON 라이브러리의 실행 속도는 자바 라이브러리 실행 속도에 비해 각각 56-78배, 50-76배 빠르다는 점을 확인하였다.