• Journal of KIISE:Software and Applications
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• v.29 no.3
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• pp.202-210
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• 2002

During the last few years, the extraction and reconstruction of the blood vessels in the medical image has been actively researched and the analysis for the retinal vessel structure has provided important information for diagnosis and remedy of the retinopathy patients. In this research, we propose the algorithm that tracks automatically the entire retinal vessel in retinal image acquired by the ICG(IndoCyanine Green) technology. This algorithm extracts contours and centers by estimating the local maxima and processing directions and detects bifurcations and junctions by comparing direction components of the local maxima from the gradient magnitude profile of each blood vessel. We present experimental results that the entire blood vessel is automatically reconstructed and is excellent in accuracy and connectivity after applying our algorithm to the ICG retinal images of patients.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.173-181
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• 2014

In this paper, the algorithm that can automatically segment the lung, the airway and the pulmonary vessels in a chest CT was proposed. The proposed method is progressed in three steps. In the first step, the lung and the airway are segmented by the region growing law through the optimal threshold and three-dimensional labeling. In the second, from the start point to the first carina of the airway is segmented by the deduction operation, and the next airway of the bifurcations are segmented by applying a variable threshold technique. In the third step, the left/right lungs are divided by the restoration process for the lung, and the outside of lungs for abnormal is checked by applying the advanced rolling ball algorithm, and if abnormal is found, that part is removed, and it is restored to the normal lungs by connecting the outside of the lung in the form of second-order polynomial. Finally, pulmonary vessels are segmented by applying the three-dimensional connected component labeling method and three-dimensional region growing method. As the results of simulation, it could be confirmed that the pulmonary vascular is accurately divided without loss of tissue around lung.

• Journal of Korean Medical Ki-Gong Academy
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• v.7 no.2
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• pp.134-145
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• 2004

Qi. in ancient east Asian Philosophy and medicine, was the quintessential concept symbolizing material orgin of the world. It was considered as the original matter of the world, and the genesis, development and extinction of everything in heaven and earth was explained through the movement of Qi. Despite its importance, the interpretation of Qi has brought about various bifurcations in the history of Oriental medicine. It is comprehended either as ideal concept, or as actual entity. Also, there exists synthetic idea of considering both sides of Qi. These ideas results from obscure understanding based on textual interpretation apart from actual experince. When experincing Qi through discipline, however, man can understand Qi concretly and actually and even grasp the explanation of the cosmos and life. One problem of Qi discipline was that it couldn't ascend the stage of subjective experience. Now, with the method of 'Hanalmomjit'. a developed form of zifadonggong(自發動功), I could reach coherent results to offer the foundation of objective understanding of Qi. The testees, disciples of Hanalmomjit, could express the characters of herbs in their Qigong actions, and the expression was meaningful and coherent to be considered as expressing the effects described in the classics of herbalogy. This result comes from the capacity of grasping external Qi-status, not only expressing the internal communication of jingluo(經絡) in Hanalmomjit.

• Archives of Plastic Surgery
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• v.47 no.4
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• pp.333-339
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• 2020

Background The purpose of this study was to compare the anatomical features of the internal mammary vessels (IMVs) at the second and third intercostal spaces (ICSs) with regard to their use as recipient vessels in deep inferior epigastric artery perforator (DIEP) flap breast reconstruction. Methods A total of 38 consecutive DIEP breast reconstructions in 36 patients were performed using IMVs as recipient vessels between March 2017 and August 2018. The intraoperative findings and postoperative complications were analyzed. Anatomical analyses were performed using intraoperative measurements and computed tomography (CT) angiographic images. Results CT angiographic analysis revealed the mean diameter of the deep inferior epigastric artery to be 2.42±0.27 mm, while that of the deep inferior epigastric vein was 2.91±0.30 mm. A larger mean vessel diameter was observed at the second than at the third ICS for both the internal mammary artery (2.26±0.32 mm vs. 1.99±0.33 mm, respectively; P=0.001) and the internal mammary vein (IMv) (2.52±0.46 mm vs. 2.05±0.42 mm, respectively; P<0.001). Similarly, the second ICS was wider than the third (18.08±3.72 mm vs. 12.32±2.96 mm, respectively; P<0.001) and the distance from the medial sternal border to the medial IMv was greater (9.49±2.28 mm vs. 7.18±2.13 mm, respectively; P<0.001). Bifurcations of the IMv were found in 18.4% of cases at the second ICS and in 63.2% of cases at the third ICS. Conclusions The IMVs at the second ICS had more favorable anatomic features for use as recipient vessels in DIEP flap breast reconstruction than those at the third ICS.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.9
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• pp.859-866
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• 2010

Nonlinear dynamics of pulsating instability-diffusional-thermal instability with Lewis numbers sufficiently higher than unity-in counterflow diffusion flames, is numerically investigated by imposing a Damkohler number perturbation. The flame evolution exhibits three types of nonlinear behaviors, namely, decaying pulsating behavior, diverging behavior (which leads to extinction), and stable limit-cycle behavior. The stable limit-cycle behavior is observed in counterflow diffusion flames, but not in diffusion flames with a stagnant mixing layer. The critical value of the perturbed Damkohler number, which indicates the region where the three different flame behaviors can be observed, is obtained. A stable simple limit cycle, in which two supercritical Hopf bifurcations exist, is found in a narrow range of Damkohler numbers. As the flame temperature is increased, the stable simple limit cycle disappears and an unstable limit cycle corresponding to subcritical Hopf bifurcation appears. The period-doubling bifurcation is found to occur in a certain range of Damkohler numbers and temperatures, which leads to extend the lower boundary of supercritical Hopf bifurcation.