• Title/Summary/Keyword: Snakes

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Analyses of Computation Time on Snakes and Gradient Vector Flow

  • Kwak, Young-Tae
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.2
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    • pp.439-445
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    • 2007
  • GVF can solve two difficulties with Snakes that are on setting initial contour and have a hard time processing into boundary concavities. But GVF takes much longer computation time than the existing Snakes because of their edge map and partial derivatives. Therefore this paper analyzed the computation time between GVF and Snakes. As a simulation result, both algorithms took almost similar computation time in simple image. In real images, GVF took about two times computation than Snakes.

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An Initialization of Active Contour Models(Snakes) using Convex Hull Approximation

  • Kwak, Young-Tae
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.3
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    • pp.753-762
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    • 2006
  • The Snakes and GVF used to find object edges dynamically have assigned their initial contour arbitrarily. If the initial contours are located in the neighboring regions of object edges, Snakes and GVF can be close to the true boundary. If not, these will likely to converge to the wrong result. Therefore, this paper proposes a new initialization of Snakes and GVF using convex hull approximation, which initializes the vertex of Snakes and GVF as a convex polygonal contour near object edges. In simulation result, we show that the proposed algorithm has a faster convergence to object edges than the existing methods. Our algorithm also has the advantage of extracting whole edges in real images.

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Multiplication and Antibody Formation of Japanese Encephalitis Virus in Snakes - 1. Antibody responses to the virus and serum

  • Lee, Ho-Wang;Kee, Ryong-Sook
    • The Journal of the Korean Society for Microbiology
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    • v.3 no.1
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    • pp.43-49
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    • 1968
  • Japanese encephalitis(JE) shows its explosive epidemicity in the temperate zone of Asia but little is known on the overwintering mechanism. One of the hypotheses on the overwintering mechanism is that the virus overwinters in the hibernating animals. There has been no report on the proliferation of JE virus(JEV) or antibody formation in the snakes. The purpose of this experiment is to explore the mutual relationship between JEV and snake and to clarify whether JEV proliferates and induce antibody formation in snakes. Three species of non-poisonous common snakes were employed. Precipitation test was carried out after injecting calf serum and, HI and neutralization tests were done by injecting JEV into the snakes. The gamma globulin fraction of pre- and post-injection serum were compared by paper chromatography. According to the results, precipitating antibody reaction to calf serum could be observed only at $4^{\circ}C$. It was failed to demonstrate HI antibody formation but neutralizing antibody could be detected in one of the 9 snakes. Although antibody could not be detected in test-tube, tile result of paper chromatography shows the remarkable increase of gamma globulin fraction after the injection. Above results are strongly indicating the antibody formation in the snakes.

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A New Snakes Algorithm Combined with Disparity Information in the Stereo Images (스테레오 영상에서 변이 정보를 결합한 새로운 스네이크 알고리즘)

  • 김신형;전병태;장종환
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.11C
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    • pp.1088-1097
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    • 2003
  • In this paper, we propose a method that improves the snakes algorithm well known as previously active contour model. Generally, the previous snakes algorithm applied to the 2-D images doesn't get the good results due to the influences about other objects adjacent to contour of object to be extracted. Users directly set the initial snakes points near to the contour of the object to get better results. In this paper, using the disparity information of the stereo images, a new algorithm of the object segmentation is proposed to reduce the influences adjacent to the contour of object. Users can establish initial snakes points automatically from the setting of the interested regions.

Aerobic bacteria from oral cavities and cloaca of snakes in a petting zoo

  • Jho, Yeon-Sook;Park, Dae-Hun;Lee, Jong-Hwa;Lyoo, Young S.
    • Korean Journal of Veterinary Research
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    • v.51 no.3
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    • pp.243-247
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    • 2011
  • It is important to identify the bacteria in snakes because they can cause disease; importantly, bacteria such as Stenotrophomonas maltophilia, Escherichia coli, Proteus vulgaris etc. could be pathogens especially in hospitalized, debilitated hosts, and immunocompromised patients. To analyze the distribution of snakes' bacteria in petting zoo, samples from 20 snakes were collected from 2002 to 2008. Nine bacteria species were isolated from both oral and cloaca while four and six species were identified only from oral and cloaca, respectively. Except for Actinobacter sp., all of the identified strains are opportunistic pathogens, and most of them can cause nosocomial infections in humans. Present results indicate that prevalence of various zoonotic bacterial strains in snakes could be involved in potential transfer of these bacteria into caretakers and other animals. Therefore, it needs to examine the antibiotic resistance of these pathogens to prevent outbreaks.

Growth Pattern of Red-tongued Viper Snake (Gloydius ussuriensis) Inhabiting Gapado, Jeju Island (가파도에 서식하는 쇠살모사의 성장 패턴)

  • Kim, Byoung Soo;Chang, Min-Ho;Oh, Hong Shik
    • Journal of Environmental Impact Assessment
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    • v.25 no.6
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    • pp.477-486
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    • 2016
  • We investigated the growth pattern of Red-tongued viper snakes (Gloydius ussuriensis), which were captured from the islet of the Jeju Island, Gapado between April, 2006 and November, 2009. The results indicated that there were some snakes that grew relatively fast, but most snakes either almost did not grow or grew around 10mm in snout-vent length during one year period. High growth rates was April and June. Since the growth rate of snakes is highly correlated with their foods, these results implied that the feeding activity of Red-tongued viper snakes is high during this period compared to other months. In female, difference in body condition between good-conditioned and bad-conditioned snakes became large as time elapsed from April to June. The body condition of the male Red-tongued viper snakes improved with the progression of time from April till June. Many of the Red-tongued viper snakes were captured between April and June, while they were rarely captured between July and September. Some of the Red-tongued viper snakes were captured during the autumn season. This tendency was because snakes were rarely active during hibernation and peak summer seasons. Thus, Red-tongued viper snakes are active between April and June and between September and November. They then go into hibernation as the temperature dropped in November. Furthermore, the limitation of the movement period of the Red-tongued viper snakes restricted their feeding activities while foods became scarce, which ultimately restricted their overall growth rate. The growth rate of the snakes decreased with age. The snout-vent length of the Red-tongued viper snakes and growth rate showed a negative correlation (r = -0.591), however, it was not statistically significant due to small sample size. The findings from this study could provide meaningful information in the further study of the life cycle of Red-tongued viper snakes.

Movement and Home Range of the Red-Tongued Viper Snake (Gloydius ussuriensis) Inhabiting Gapado

  • Kim, Byoung-Soo;Oh, Hong-Shik
    • Korean Journal of Environment and Ecology
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    • v.29 no.2
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    • pp.192-199
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    • 2015
  • This study was conducted to investigate the movement and home range of the red-tongued viper snake (Gloydius ussuriensis) from June 2006 to June 2009. This snake species inhabits an islet on Jeju Island, Gapado. A total of 132 individual snakes were marked during the study. Among the marked individuals, the number of snakes recaptured more than once was 22 (16.8 %) and the number of individuals recaptured more than twice was eight (6.1 %), indicating a relatively low recapture rate. The durations from capture to recapture varied from 1 to 710 days. However, the capture points were not much different, indicating that the moved distance of snakes and the interval between capture-recapture were not correlated. The home ranges of the Red-tongued viper snakes calculated from data of the snakes which were captured more than three times using the MCP(minimum convex polygon) method were $8{\sim}167m^2(64.0{\pm}57.0m^2)$, suggesting that this snake is relatively sedentary. Home range size differences between female ($Mean=62.0m^2$) and male ($Mean=66.0m^2$) snakes were not significant. In the red-tongued viper population of Gapado, there was no statistically significant relationship between body size and home range size although it was positively correlated (r=0.675). Our results provide valuable data to understand life patterns of the red-tongued viper snakes and will be useful when conducting further ecological studies on other snake species.

Modification of carbohydrate compositions of 31/36 kDa proteins of plerocercoids (sparganum) of Spirometra mansoni grown in different intermediate hosts

  • Yang, Hyun-Jong
    • Parasites, Hosts and Diseases
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    • v.42 no.2
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    • pp.77-79
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    • 2004
  • We purified specific 31/36 kDa antigenic molecules from sparganum in different intermediate hosts (snakes and mice) and analyzed their monosaccharide compositions. Compositional analysis showed that glucose and man nose concentrations were 2-3 fold higher in the 31/36 kDa molecule purified from snakes than those from mice. This result implies that antigenic glycoproteins of sparganum from snakes might be modified in mammalian sparganosis with respect to their carbohydrate composition.

Effects of Low-Level Visual Attributes on Threat Detection: Testing the Snake Detection Theory (저수준 시각적 특질이 위협 탐지에 미치는 효과: 뱀 탐지 이론의 검증)

  • Kim, Taehoon;Kwon, Dasom;Yi, Do-Joon
    • Science of Emotion and Sensibility
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    • v.23 no.3
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    • pp.47-62
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    • 2020
  • The snake detection theory posits that, due to competition with snakes, the primate visual system has been evolved to detect camouflaged snakes. Specifically, one of its hypotheses states that the subcortical visual pathway mainly consisting of koniocellular cells enables humans to automatically detect the threat of snakes without consuming mental resources. Here we tested the hypothesis by comparing human participants' responses to snakes with those to fearful faces and flowers. Participants viewed either original images or converted ones, which lacked the differences in color, luminance, contrast, and spatial frequency energies between categories. While participants in Experiment 1 produced valence and arousal ratings to each image, those in Experiment 2 detected target images in the breaking continuous flash suppression (bCFS) paradigm. As a result, visual factors influenced the responses to snakes most strongly. After minimizing visual differences, snakes were rated as being less negative and less arousing, and detected more slowly from suppression. In contrast, the images of the other categories were less affected by image conversion. In particular, fearful faces were rated as greater threats and detected more quickly than other categories. In addition, for snakes, changes in arousal ratings and those in bCFS response times were negatively correlated: Those snake images, the arousal ratings of which decreased, produced increased detection latency. These findings suggest that the influence of snakes on human responses to threat is limited relative to fearful faces, and that detection responses in bCFS share common processing mechanisms with conscious ratings. In conclusion, the current study calls into question the assumption that snake detection in humans is a product of unconscious subcortical visual processing.

Tumor boundary extraction from brain MRI images using active contour models (Snakes) (스네이크를 이용한 뇌 자기 공명 영상에서 종양의 경계선 추출)

  • Ryeong-Ju Kim;Young-Chul Kim;Heung-Kook Choi
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.2
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    • pp.1-6
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    • 2003
  • The study is to automatically or semi-automatically detect the accurate contour of tumors or lesions using active contour models (Snakes) in the MRI images of the brain. In the study we have improved the energy-minimization problem of snakes using dynamic programming and have utilized the values of the canny edge detector by the image force to make the snake less sensitive in noises. For the extracted boundary, the inside area, the perimeter and its center coordinates could be calculated. In addition, the multiple 2D slices with the contour of the lesion wore combined to visualized the shape of the lesion in 3D. We expect that the proposed method in this paper will be useful to make a treatment plan as well as to evaluate the treatments.

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