• Title/Summary/Keyword: complex segment

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A Study on Optimal Shape-Size Index Extraction for Classification of High Resolution Satellite Imagery (고해상도 영상의 분류결과 개선을 위한 최적의 Shape-Size Index 추출에 관한 연구)

  • Han, You-Kyung;Kim, Hye-Jin;Choi, Jae-Wan;Kim, Yong-Il
    • Korean Journal of Remote Sensing
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    • v.25 no.2
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    • pp.145-154
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    • 2009
  • High spatial resolution satellite image classification has a limitation when only using the spectral information due to the complex spatial arrangement of features and spectral heterogeneity within each class. Therefore, the extraction of the spatial information is one of the most important steps in high resolution satellite image classification. This study proposes a new spatial feature extraction method, named SSI(Shape-Size Index). SSI uses a simple region-growing based image segmentation and allocates spatial property value in each segment. The extracted feature is integrated with spectral bands to improve overall classification accuracy. The classification is achieved by applying a SVM(Support Vector Machines) classifier. In order to evaluate the proposed feature extraction method, KOMPSAT-2 and QuickBird-2 data are used for experiments. It is demonstrated that proposed SSI algorithm leads to a notable increase in classification accuracy.

Current evidence for prognostic benefit of intravascular imaging-guided percutaneous coronary intervention in chronic total occlusion intervention

  • David Hong;Sung Eun Kim;Seung Hun Lee;Seung-Jae Lee;Jong-Young Lee;Sang Min Kim;Sang Yeub Lee;Woochan Kwon;Ki Hong Choi;Taek Kyu Park;Jeong Hoon Yang;Young Bin Song;Seung-Hyuk Choi;Hyeon-Cheol Gwon;Joo-Yong Hahn;Joo Myung Lee
    • The Korean journal of internal medicine
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    • v.39 no.5
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    • pp.702-716
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    • 2024
  • Although percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has been increasing in recent years, CTO PCI is still one of the most challenging procedures with relatively higher rates of procedural complications and adverse clinical events after PCI. Due to the innate limitations of invasive coronary angiography, intravascular imaging (IVI) has been used as an adjunctive tool to complement PCI, especially in complex coronary artery disease. Considering the complexity of CTO lesions, the role of IVI is particularly important in CTO intervention. IVI has been a useful adjunctive tool in every step of CTO PCI including assisted wire crossing, confirmation of wire location within CTO segment, and stent optimization. The meticulous use of IVI has been one of the greatest contributors to recent progress of CTO PCI. Nevertheless, studies evaluating the role of IVI during CTO PCI are limited. The current review provides a comprehensive overview of the mechanistic advantages of IVI in CTO PCI, summarizes previous studies and trials, and presents future perspective of IVI in CTO PCI.

Total Arterial 011-Pump Coronary Revascularization with Multiple Y Arterial Composite Grafts (다중 복합 Y 동맥 이식편(Multiple Y Composite Craft)을 이용한 완저너 동맥 무인공 심폐바이패스 관상동맥우회술)

  • Kim Do-kyun;Lee Kyo Jgon;Joo Hyun Chul;Li Gyjong;Ahn Jiyoung;shim Yungee;Yoo Kyung Jong
    • Journal of Chest Surgery
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    • v.38 no.8 s.253
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    • pp.551-556
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    • 2005
  • Background: Complete arterial off-pump coronary artery bypass grafting (OPCAB) by sequential anastomoses with one or two arterial grafts provides favorable outcomes. However, problems of insufficient graft length, hypopefusion, kinking of graft, and unfavorable course of graft may be encountered. To solve these problems, we have used different technique with multiple arterial Y composite graft to allow end-to-side rather than sequential anastomoses and evaluated the results of this method. Material and Method: Between February 2003 and October 2004, If patients underwent total arterial OPCAB using multiple arterial V composite grafts with left internal mammary artery (LIMA), radial artery (RA), and right internal mammary artery (RIMA). We divided RA into multiple segments by number of distal target site after measuring of individual proper length and constructed arterial composite graft. One of segments was sutured end-to-side to LIMA and other segment was sutured end-to-side to the previously constructed radial graft. Postoperative graft patency was evaluated in 6f patients by multi-slice computed tomegraphy. Result: An average of $2.5\pm0.6$ arteries and $3.7pm0.7$ distal anastomoses per patient were done. There was no perioperative myocardial infarction, clinical hypoperfusion syndromes, and operative mortality. Postoperative mean CK-MB level was $17.4pm29.7\;IU/L.$Overall graft patency was $99.1\%\;(214/216)(LIMA:\;100\%,\;RA:\;98.4\%,\;RIMA:\;100\%).$ Conclusion: This technique allows total arterial OPCAB without technical problems and provides excellent early clinical results and graft patency. We believe that this technique is more convenient in the obtuse marginal area compared to sequential technique, and helpful in patients who require complex arterial grafting.

Media Habits of Sensation Seekers (감지추구자적매체습관(感知追求者的媒体习惯))

  • Blakeney, Alisha;Findley, Casey;Self, Donald R.;Ingram, Rhea;Garrett, Tony
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.2
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    • pp.179-187
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    • 2010
  • Understanding consumers' preferences and use of media types is imperative for marketing and advertising managers, especially in today's fragmented market. A clear understanding assists managers in making more effective selections of appropriate media outlets, yet individuals' choices of type and use of media are based on a variety of characteristics. This paper examines one personality trait, sensation seeking, which has not appeared in the literature examining "new" media preferences and use. Sensation seeking is a personality trait defined as "the need for varied, novel, and complex sensations and experiences and the willingness to take physical and social risks for the sake of such experiences" (Zuckerman 1979). Six hypotheses were developed from a review of the literature. Particular attention was given to the Uses and Gratification theory (Katz 1959), which explains various reasons why people choose media types and their motivations for using the different types of media. Current theory suggests that High Sensation Seekers (HSS), due to their needs for novelty, arousal and unconventional content and imagery, would exhibit higher frequency of use of new media. Specifically, we hypothesize that HSS will use the internet more than broadcast (H1a) or print media (H1b) and more than low (LSS) (H2a) or medium sensation seekers (MSS) (H2b). In addition, HSS have been found to be more social and have higher numbers of friends therefore are expected to use social networking websites such as Facebook/MySpace (H3) and chat rooms (H4) more than LSS (a) and MSS (b). Sensation seekers can manifest into a range of behaviors including disinhibition,. It is expected that alternative social networks such as Facebook/MySpace (H5) and chat rooms (H6) will be used more often for those who have higher levels of disinhibition than low (a) or medium (b) levels. Data were collected using an online survey of participants in extreme sports. In order to reach this group, an improved version of a snowball sampling technique, chain-referral method, was used to select respondents for this study. This method was chosen as it is regarded as being effective to reach otherwise hidden population groups (Heckathorn, 1997). A final usable sample of 1108 respondents, which was mainly young (56.36% under 34), male (86.1%) and middle class (58.7% with household incomes over USD 50,000) was consistent with previous studies on sensation seeking. Sensation seeking was captured using an existing measure, the Brief Sensation Seeking Scale (Hoyle et al., 2002). Media usage was captured by measuring the self reported usage of various media types. Results did not support H1a and b. HSS did not show higher levels of usage of alternative media such as the internet showing in fact lower mean levels of usage than all the other types of media. The highest media type used by HSS was print media, suggesting that there is a revolt against the mainstream. Results support H2a and b that HSS are more frequent users of the internet than LSS or MSS. Further analysis revealed that there are significant differences in the use of print media between HSS and LSS, suggesting that HSS may seek out more specialized print publications in their respective extreme sport activity. Hypothesis 3a and b showed that HSS use Facebook/MySpace more frequently than either LSS or MSS. There were no significant differences in the use of chat rooms between LSS and HSS, so as a consequence no support for H4a, although significant for MSS H4b. Respondents with varying levels of disinhibition were expected to have different levels of use of Facebook/MySpace and chat-rooms. There was support for the higher levels of use of Facebook/MySpace for those with high levels of disinhibition than low or medium levels, supporting H5a and b. Similarly there was support for H6b, Those with high levels of disinhibition use chat-rooms significantly more than those with medium levels but not for low levels (H6a). The findings are counterintuitive and give some interesting insights for managers. First, although HSS use online media more frequently than LSS or MSS, this groups use of online media is less than either print or broadcast media. The advertising executive should not place too much emphasis on online media for this important market segment. Second, social media, such as facebook/Myspace and chatrooms should be examined by managers as potential ways to reach this group. Finally, there is some implication for public policy by the higher levels of use of social media by those who are disinhibited. These individuals are more inclined to engage in more socially risky behavior which may have some dire implications, e.g. by internet predators or future employers. There is a limitation in the study in that only those who engage in extreme sports are included. This is by nature a HSS activity. A broader population is therefore needed to test if these results hold.