• Title/Summary/Keyword: region contrast

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Parametric Image Generation and Enhancement in Contrast-Enhanced Ultrasonography (조영증강 초음파 진단에서 파라미터 영상 생성 및 개선 기법)

  • Kim, Shin-Hae;Lee, Eun-Lim;Jo, Eun-Bee;Kim, Ho-Joon
    • KIPS Transactions on Software and Data Engineering
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    • v.6 no.4
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    • pp.211-216
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    • 2017
  • This paper proposes image processing techniques that improve usability and performance in a diagnostic system of the contrast-enhanced ultrasonography. For a methodology for visualizing diagnostic parameter data in an ultrasonic medical image, an expression of transition time data with successive pixel values and a method of generating a lesion diagnostic parameter image with four categorized values are presented. We also introduce a MRF-based image enhancement technique to eliminate noises from generated parametric images. Such parametric image generation technique can overcome the difficulty of discriminating dynamic change in patterns in the ultrasonography. The technique clarifies the contour of the region in the original image and facilitates visual determination of the characteristics of the lesion through four colors. With regard to this MRF-based image enhancement, we define the energy function of consecutive pixel values and develop a technique to optimize it, and the usability of the proposed theory is examined through experiments with medical images.

Welding Bead Segmentation Algorithm Using Edge Enhancement and Active Contour (에지 향상과 활성 윤곽선을 이용한 용접 비드 영역화 알고리즘)

  • Mlyahilu, John N.;Kim, Jong-Nam
    • Journal of the Institute of Convergence Signal Processing
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    • v.21 no.4
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    • pp.209-215
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    • 2020
  • In this paper, we propose an algorithm for segmenting weld bead images using edge enhancement and active contours. In the proposed method, high-frequency filtering and contrast improvement are performed for edge enhancement, and then, by applying the active contour method, only the weld bead region can be obtained. The proposed algorithm detects an edge through high-frequency filtering and reinforces the detected edge by using contrast enhancement. After the edge information is improved in this way, the weld bead area can be extracted by applying the active contour method. The proposed algorithm shows better performance than the existing methods for segmenting the weld bead in the image. For the objective reliability of the proposed algorithm, it was compared with the existing high pass filtering methods, and it was confirmed that the welding bead segmentation of the proposed method is excellent. The proposed method can be usefully used in evaluating the quality of the weld bead through an additional procedure for the segmented weld bead.

The Effectiveness of CT and MRI Contrast Agent for SUV in 18F-FDG PET/CT Scanning (18F-FDG PET/CT 검사에서 정량분석에 관한 CT와 MRI 조영제의 효과)

  • Cha, Sangyoung;Cho, Yonggwi;Lee, Yongki;Song, Jongnam;Choi, Namgil
    • Journal of the Korean Society of Radiology
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    • v.10 no.4
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    • pp.255-261
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    • 2016
  • In this study, among various factors having influence on SUV, we intended to compare and analyze the change of SUV using CT(4 type) and MRI(3 type) contrast agents which are commercialized now. We used Discovery 690 PET/CT(GE) and NEMA NU2 - 1994 PET phantom as experimental equipment. We have conducted a study as follows; first, we filled distilled water to phantom about two-thirds and injected radioisotope(18F-FDG 37 MBq), contrast agent. Second, we mixed CT contrast agent with distilled water and MRI contrast agent with that water separately. And then, we stirred the fluid and filled distilled water fully not to make air bubble. In emission scan, we had 15minutes scanning time after 40 minutes mixing contrast agent with distilled water. In transmission scan, we used CT scanning and its measurement conditions were tube voltage 120 kVp, tube current 40 mA, rotation time 0.5 sec, slice thickness 3.27 mm, DFOV 30 cm. Analyzing results, we set up some ROIs in 10th, 15th, 20th, 25th, 30th slice and measured SUVmean, SUVmax. Consequently, all images mixed 3 types of MRI contrast agent with distilled water have high SUVmean as compared with pure FDG image but there was no statistical significance. In SUVmax, they have high score and there was statistical significance. And other 4 images mixed 4 types of CT contrast agent with distilled water have significance in both SUVmean and SUVmax. Attenuation correction in PET/CT has been executed through various methods to make high quality image. But we figured out that using CT and MRI contrast agents before PET/CT scanning could make distortion of image and decrease diagnostic value. In that reason, we have to sort out the priority of examination in hospital not to disturb other examination's results. Through this process, we will be able to give superior medical service to our customers.

The Expression and Localization of ZO-1, Claudin 1, and Claudin 4 in the Pig Epididymis (돼지 정소상체에서 ZO-1, Claudin 1 및 Claudin 4의 발현 양상)

  • Park, Yun-Jae;Kim, Bongki
    • Journal of Animal Reproduction and Biotechnology
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    • v.34 no.3
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    • pp.190-196
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    • 2019
  • Tight junctions are constituents of the blood-epididymis barrier that play roles in regulating the unidirectional transcellular transport of ions, water, and solutes to maintain optimal conditions for sperm maturation and storage. Claudin 1 (Cldn1) and 4 (Cldn4) are known as tight junction proteins and are expressed in the basolateral membranes as well as tight junctions in the epididymis of rodents. Here, we examined the expression and localization of Cldn1 and 4 to determine the function of these proteins in the pig epididymis. Cldn1 was highly expressed in the basolateral membrane of epithelial cells in the caput and corpus regions of the epididymis. In the cauda region, however, Cldn1 labeling was significantly decreased in the basolateral membrane of epithelial cells. In contrast, labeling indicated that Cldn4 was expressed in the basolateral membrane in the cauda region of the epididymis and was present at punctate reactive sites in the caput and corpus regions. However, in no region of the epididymis did we detect colocalization of Cldn1 and 4 with labeled ZO-1, the distribution of which is restricted to the tight junctions. Our results indicate that Cldn1 and 4 were region-specifically expressed in the pig epididymis but not present in the tight junctions of epididymal epithelium. In addition, reciprocal regulation in specific regions of the epididymis between Cldn1 and 4 may play an important role in generating an optimal luminal environment for sperm maturation and storage in the pig epididymis.

Comparison of News Frames between National Newspapers and Local Newspapers about Selecting a Site of National Project (국책사업입지선정 관련 중앙·지역신문 간 기사프레임 비교)

  • Lee, Seong-Neung
    • The Journal of the Korea Contents Association
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    • v.11 no.8
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    • pp.488-498
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    • 2011
  • This study is an analysis of how national newspapers and local newspapers frame news contents over selecting of the site of International science-business belt. The results of analysis are as follows. First, in national newspapers, 'incompetent government frame' to criticize inconsistent policies and 'relapse prevention frame' were most commonly found. Second, newspapers in the region chosen as the site of an International Science-business belt and newspapers in the region not chosen showed a severe contrast in news frames. Most of news frames in the region chosen as the site of an International science-business belt were 'development frame' and 'performance frame'. On the other hand, newspapers in the region not chosen produced 'incompetent government frame' and 'protest frame' more than others. Finally, local newspapers in the area not related with the site of an International Science-business belt did not even deal with such an articles. These results show that to win large-scale national projects such as PIMFI facilities, local governments have been too much competitive and connected to a conflict.

Growth and characterization of periodically polarity-inverted ZnO structures grown on Cr-compound buffer layers

  • Park, J.S.;Goto, T.;Hong, S.K.;Chang, J.H.;Yoon, E.;Yao, T.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.259-259
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    • 2010
  • Periodically polarity inverted (PPI) ZnO structures on (0001) Al2O3 substrates are demonstrated by plasmas assisted molecular beam epitaxy. The patterning and re-growth methods are used to realize the PPI ZnO by employing the polarity controlling method. For the in-situ polarity controlling of ZnO films, Cr-compound buffer layers are used.[1, 2] The region with the CrN intermediate layer and the region with the Cr2O3 and Al2O3 substrate were used to grow the Zn- and O-polar ZnO films, respectively. The growth behaviors with anisotropic properties of PPI ZnO heterostructures are investigated. The periodical polarity inversion is evaluated by contrast images of piezo-response microscopy. Structural and optical interface properties of PPI ZnO are investigated by the transmission electron microcopy (TEM) and micro photoluminescence ($\mu$-PL). The inversion domain boundaries (IDBs) between the Zn and the O-polar ZnO regions were clearly observed by TEM. Moreover, the investigation of spatially resolved local photoluminescence characteristics of PPI ZnO revealed stronger excitonic emission at the interfacial region with the IDBs compared to the Zn-polar or the O-polar ZnO region. The possible mechanisms will be discussed with the consideration of the atomic configuration, carrier life time, and geometrical effects. The successful realization of PPI structures with nanometer scale period indicates the possibility for the application to the photonic band-gap structures or waveguide fabrication. The details of application and results will be discussed.

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Variation of Potato virus Y Isolated from Potato, Tobacco, Pea and Weeds in Korea on the C-terminal Region of Coat Protein Gene and 3'Non-translated Region

  • Yun, W.S.;Jung, H.W.;Oh, M.H.;Hahm, Y.I.;Kim, K.H.
    • The Plant Pathology Journal
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    • v.18 no.3
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    • pp.130-137
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    • 2002
  • Potato virus Y (PVY) is one of the most important viruses in many field crops in Korea. In this study, 31 PVY isolates were isolated from infected potato (Solanum tuberosum), tobacco (Nicotiana tabacum), pea (Pisum sativum), and weeds (Veronica persica, Lamium amplexicause and Capsella bursa-pastoris) showing different mosaic symptoms in Jeonbuk, Chungnam, Gangwon, and Gyeongbuk areas in Korea. The 640 nucleotide region containing the C-terminal portion of coat protein (CP) gene and 3'non-translated region (NTR) was amplified by reverse transcription-polymerase chain reaction (RT-PCR) using PVY-specific oligonucleotide primers. Sequence analyses of the amplified DNA fragments showed that the C-terminal portion of CP gene was not significantly different from that of previously reported PVY strains from potato (PVY-OK and -T) and tobacco (PVY-VN) in Korea. Homologies of the deduced CP amino acid sequences were 93.3-99.0% to corresponding regions of the other PVY strains including PV $Y^{N}$, PV $Y^{o}$ , PV $Y^{OK}$ , PV $Y^{T}$ , and PV $Y^{VN}$ . In contrast the sequences located at the 3'-NTR showed more diverse sequence homologies (76.4-99.7%). These results indicate that the C-terminal portion of the CP gene was relatively conserved while sequences at the 3'NTR were more diverse and variable over the host species and the regions where they were isolated.e isolated.

Micromorphology and development of the epicuticular structure on the epidermal cell of ginseng leaves

  • Lee, Kyounghwan;Nah, Seung-Yeol;Kim, Eun-Soo
    • Journal of Ginseng Research
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    • v.39 no.2
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    • pp.135-140
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    • 2015
  • Background: A leaf cuticle has different structures and functions as a barrier to water loss and as protection from various environmental stressors. Methods: Leaves of Panax ginseng were examined by scanning electron microscopy and transmission electron microscopy to investigate the characteristics and development of the epicuticular structure. Results: Along the epidermal wall surface, the uniformly protuberant fine structure was on the adaxial surface of the cuticle. This epicuticular structure was highly wrinkled and radially extended to the marginal region of epidermal cells. The cuticle at the protuberant positions maintained the same thickness. The density of the wall matrix under the structures was also similar to that of the other wall region. By contrast, none of this structure was distributed on the abaxial surface, except in the region of the stoma. During the early developmental phase of the epicuticular structure, small vesicles appeared on wallecuticle interface in the peripheral wall of epidermal cells. Some electron-opaque vesicles adjacent to the cuticle were fused and formed the cuticle layer, whereas electron-translucent vesicles contacted each other and progressively increased in size within the epidermal wall. Conclusion: The outwardly projected cuticle and epidermal cell wall (i.e., an epicuticular wrinkle) acts as a major barrier to block out sunlight in ginseng leaves. The small vesicles in the peripheral region of epidermal cells may suppress the cuticle and parts of epidermal wall, push it upward, and consequently contribute to the formation of the epicuticular structure.

Effects of Meteorological Conditions on Cloud and Snowfall Simulations in the Yeongdong Region: A Case Study Based on Ideal Experiments (영동지역 기상조건이 구름 및 강설 모의에 미치는 영향: 이상 실험 기반의 사례 연구)

  • Kim, Yoo-Jun;Ahn, Bo-Yeong;Kim, Baek-Jo;Kim, Seungbum
    • Atmosphere
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    • v.31 no.4
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    • pp.445-459
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    • 2021
  • This study uses a cloud-resolving storm simulator (CReSS) to understand the individual effect of determinant meteorological factors on snowfall characteristics in the Yeongdong region based on the rawinsonde soundings for two snowfall cases that occurred on 23 February (Episode 1) and 13 December (Episode 2) 2016; one has a single-layered cloud and the other has two-layered cloud structure. The observed cloud and precipitation (snow crystal) features were well represented by a CReSS model. The first ideal experiment with a decrease in low-level temperature for Episode 1 indicates that total precipitation amount was decreased by 19% (26~27% in graupel and 53~67% in snow) compared with the control experiment. In the ideal experiment that the upper-level wind direction was changed from westerly to easterly, although total precipitation was decreased for Episode 1, precipitation was intensified over the southwestern side (specifically in terrain experiment) of the sounding point (128.855°E, 37.805°N). In contrast, the precipitation for Episode 2 was increased by 2.3 times greater than the control experiment under terrain condition. The experimental results imply that the low-level temperature and upper-level dynamics could change the location and characteristics of precipitation in the Yeongdong region. However, the difference in precipitation between the single-layered experiment and control (two-layered) experiment for Episode 2 was negligible to attribute it to the effect of upper-level cloud. The current results could be used for the development of guidance of snowfall forecast in this region.

Impact of Change in Monsoonal Circulation Due to SST Warming on the North East Asian Monsoon: A Model Analysis Using Satellite Based Sub-Grid Hydrometeors

  • Bhattacharya, Anwesa;Park, Rae Seol;Kwon, Young Cheol
    • Asia-Pacific Journal of Atmospheric Sciences
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    • v.54 no.4
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    • pp.545-561
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    • 2018
  • Over the North East Asia, extreme anomalous precipitation were observed in 2013 and 2014. During 2013 summer the precipitation was found to be higher (two standard deviation) than the climatological mean of the region; whereas during 2014, which was a borderline El Ni?o year, precipitation was found to be lower (one standard deviation). To understand the differences of these two anomalous years the Global/Regional Integrated Model system (GRIMs) has been used. The study found that low landsurface temperature and high sea-surface temperature over ocean caused a smaller land-sea contrast of surface temperature between East Asia and North West Pacific Ocean in 2014, which could have caused an eastward shift of mean monsoon circulation in that year compared to the circulation in 2013. Due to a change in the lower level circulation and wind field over East Asia the evaporation and moisture transport patterns became very different in those two years. In 2013, this study found high latent heat flux over Eastern China, which implies an increased surface evaporation over that region, and the moisture transported to the north by the mean monsoon circulation; whereas, there was no correlated transport of moisture to the North East Asia during 2014. The precipitable water over North East Asia has a stronger correlation with the latent heat flux over southern land region than that from Ocean region in the eastern side in both the years. A new approach is proposed to estimate the sub-grid scale hydrometeors from GRIMs, overestimated in the existing model.