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Fluid Dynamic Efficiency of an Anatomically Correct Total Cavopulmonary Connection: Flow Visualizations and Computational Fluid Dynamic Studies

  • Yun, S.H.;Kim, S.Y.;Kim, Y.H.
    • International Journal of Vascular Biomedical Engineering
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    • v.1 no.2
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    • pp.36-41
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    • 2003
  • Both flow visualizations and computational fluid dynamics were performed to determine hemodynamics in a total cavopulmonary connection (TCPC) model for surgically correcting congenital heart defects. From magnetic resonance images, an anatomically correct glass model was fabricated to visualize steady flow. The total flow rates were 4, 6 and 8L/min and flow rates from SVC and IVC were 40:60. The flow split ratio between LPA and RPA was varied by 70:30, 60:40 and 50:50. A pressure-based finite-volume software was used to solve steady flow dynamics in TCPC models. Results showed that superior vena cava(SVC) and inferior vena cava(IVC) flow merged directly to the intra-atrial conduit, creating two large vortices. Significant swirl motions were observed in the intra-atrial conduit and pulmonary arteries. Flow collision or swirling flow resulted in energy loss in TCPC models. In addition, a large intra-atrial channel or a sharp bend in TCPC geometries could influence on energy losses. Energy conservation was efficient when flow rates in pulmonary branches were balanced. In order to increase energy efficiency in Fontan operations, it is necessary to remove a flow collision in the intra-atrial channel and a sharp bend in the pulmonary bifurcation.

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Study on Suk Gock's Fortify Yang Theory (석곡 이규준의 부양이론에 관한 연구)

  • Hwang Won Duek
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.3
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    • pp.713-723
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    • 2004
  • With regard of YinYang and Five Elements Theory, predominance of Yin or Yang is a key point to discuss Nourishin Ying or Reinforcing Yang. There are two major branches about studying predominance of Yin or Yang. Zhu Danxi advocated the theory that Yang was always in excess while Yin was often deficient, and thus belonged to the School for Nourishing the Yin. Zhang Jie-bin advocated that Yang is easily deficient while Yin is easily sufficient. It seems that they studied Wang Bing's 'Ministerial fire rule on all thing instead of Imperial Fire' and right Kidney Mingmen theory in Nan Jing, which are both related to the First Yang in the Book of Changes and say Mingmen fire is the host of the body. Zhu Danxi insisted that Mingmen fire was easily in excess and likely to become pathogenic fire while Water phase was easily in deficiency, so the doctors should nourish Yin and suppress Yang. Zhang Jie-bin said that Mingmen fire is vulnerable so the doctors should fortify yang and reinforce Mingmen fire. Suk Gock Master Lee thought that the Book of Changes and Nei Jing had a viewpoint of Fortify Yang as regards of some distinguished Physicians' articles about predominance of YinYang. The author's going to discribe Suk Gock's Fortify Yang Theory with viewpoints of Nei Jing and the Book of Changes.

Dynamic Brittle Fracture Captured with Peridynamics: Crack Branching Angle & Crack Propagation Speed (페리다이나믹스 해석법을 통한 동적취성 파괴거동해석: 분기 균열각도와 균열 전파속도)

  • Ha, Youn-Doh;Cho, Seon-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.6
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    • pp.637-643
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    • 2011
  • The bond-based peridynamic model is able to capture many of the essential characteristics of dynamic brittle fracture observed in experiments: crack branching, crack-path instability, asymmetries of crack paths, successive branching, secondary cracking at right angles from existing crack surfaces, etc. In this paper we investigate the influence of the stress waves on the crack branching angle and the velocity profile. We observe that crack branching in peridynamics evolves as the phenomenology proposed by the experimental evidence: when a crack reaches a critical stage(macroscopically identified by its stress intensity factor) it splits into two or more branches, each propagating with the same speed as the parent crack, but with a much reduced process zone.

Localisation of embedded water drop in glass composite using THz spectroscopy

  • Mieloszyk, Magdalena;Majewska, Katarzyna;Ostachowicz, Wieslaw
    • Smart Structures and Systems
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    • v.21 no.6
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    • pp.751-759
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    • 2018
  • Glass fibre reinforced polymers (GFRP) are widely exploited in many industrial branches. Due to this Structural Health Monitoring systems containing embedded fibre optics sensors are applied. One of the problems that can influence on composite element durability is water contamination that can be introduced into material structure during manufacturing. Such inclusion can be a damage origin significantly decreasing mechanical properties of an element. A non-destructive method that can be applied for inspection of an internal structure of elements is THz spectroscopy. It can be used for identifications of material discontinuities that results in changes of absorption, refractive index or scattering of propagating THz waves. The limitations of THz propagation through water makes this technique a promising solution for detection of a water inclusion. The paper presents an application of THz spectroscopy for detection and localisation of a water drop inclusion embedded in a GFRP material between two fibre optics with fibre Bragg grating sensors. The proposed filtering method allowed to determine a 3D shape of the water drop.

Association of Diet with Menopausal Symptoms in Korean Middle-aged Women (폐경전후기 여성의 폐경증상과 식이섭취의 관계)

  • 박영주;백희영;김영주;홍성숙;김미진;윤지원;문소현
    • Journal of Korean Academy of Nursing
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    • v.33 no.3
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    • pp.386-394
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    • 2003
  • Purpose: This study was designed to explore the association of diet with menopausal symptoms in Korean women, Method: For this cross-sectional survey, 276 women aged between 45-55 years visiting two branches of K-university hospital located in Seoul and Ansan of Kyunggi province were recruited from April to July, 2002. A menopause-specific quality-of-life questionnaire and a food frequency questionnaire were used to measure menopause-related symptoms and the intake of 28 types of foods. Result: No differences were found in the levels of bothersome total menopausal symptoms, physical symptoms, psychosocial symptoms, and sexual symptoms according to the intake of each food. Only higher intake of fishes, seaweeds, and vegetable oils were inversely associated with bothersome levels of vasomotor symptoms. Women with higher intake of yellow-green vegetables and lower intake of coffee, confectionery, and processed foods reported lower hot flush rate. Conclusion: The results suggest that higher intake of yellow-green vegetables and lower intake of coffee, confectionery and processed foods may relieve hot flushes. Further study needs to be pursued to study the relationship with nutrients of these foods and hot flushes.

A Review of Ocean Circulation of the East/Japan Sea (한국 동해 해수순환의 개략적 고찰)

  • 김종규
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2001.10a
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    • pp.103-107
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    • 2001
  • The major studies of an ocean circulation of the East/Japan Sea related to evaluate the feasibility and utilization of deep ocean water are reviewed. The major feature of surface current system of the East/Japan Sea is an inflow of the Tsushima Warm Current through the Korea/Tsushima Strait and the outflow through the Tsugaru and Soya Straits. The Tsushima Warm Current has been known to split into two or three branches in the southern region of the East/Japan Sea. In the cold water region of the East/Japan Sea, the North Korean Cold Current turns to the east near 39$^{\circ}$N after meeting the East Korean Warm Current, then flows eastward. The degree of penetration depends on the strength of the positive wind stress curl, according to the ventilation theory. Various current meter moorings indicate strong and oscillatory deep currents in various parts of the basin. According to some numerical experiments, these currents may be induced by pressure-topography or eddy-topography interaction. However, more investigations are needed to explain clearly the presence of these strong bottom currents. This study concludes the importance of topographical coupling, isopycnal outcropping, different wind forcing and the branching of the Tsushima Warm Current on the circulation of the East/Japan Sea.

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Computer Simulation of Branching Pattern in Magnolia denudata Desr. (백목련의 분지형에 관한 Computer Simulation)

  • Park, Bong-Kyu
    • The Korean Journal of Ecology
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    • v.6 no.4
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    • pp.1-9
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    • 1983
  • The observation of branching pattern on Magnolia denudata Desr. was performed from July 1982 to September 1983 and then computer simulation was carried out. Tree crown pattern depends on not genetic factors but also environmental factors and the determination of branchin pattern which characterized it appears to properly explain the relationships such as branching pattern and allocation of materials through the analysis of influence branches under several assumptions. Now that computer simulated simulated pattern was considered as the accumulation of two factors which controled the growth, it was represented as the stimulated tree which differs in branching rate that described allocation of material necessary for the growth of each branch. There was a tendency of allocation ratio of nutrients, i.e. subbranch to main branch to decrease by the passage of year. Under assumption that branch was branched when accumulated material reached 1, it was possible to represent the allocation of nutrients are residual $nutrient{\times}\frac{1}{1+F};in main; branch, ; residual; nutrient{\times}\frac{F}{1+F}$ in subbranch, A(iA, iC)+$F^(iA-1)$ in current twig. Like this, the basic minute difference of the allocation of nutrients according to the branch resulted in complicated patterns in the tree crown.

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The Economics of Forest Management for Multiple Uses : The Theory and Applications (다목적(多目的) 산림경영(山林經營)의 경제학적(經濟學的) 고찰(考察) : 그 이론(理論)과 응용(應用))

  • Youn, Yeo Chang
    • Journal of Korean Society of Forest Science
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    • v.76 no.2
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    • pp.169-177
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    • 1987
  • The concept of multiple-use forestry can be considered as a simple application of the economic theory which commands the efficient utilization of resources. This paper reviews two important branches of the economic theory-theory of the firm and the capital theory-and discusses various methodologies of measuring the non-timber benefits from the forest. In addition, an empirical analysis with an example of the Deogyu National Park is presented. For this purpose, the Clawson's Travel Cost Method was employed.

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Morphological Traits of S598A Sweetpotato as an Industrial Starch Crop

  • Kim, Kyung-Moon;Kim, Ji-Yeon;Kim, Jung-Il
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.54 no.4
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    • pp.422-426
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    • 2009
  • Sweetpotato is one of the important starch crops, current more considered as an industrial crop rather than food because it has higher starch content (over 80% of biomass), it is used for bio resources for industrial area. In this study, we generated S598A (a mutant gene of oat phytochrome A) sweetpotato plant using Agrobacterium-transformation method. Morphological characteristics of S598A plant were compared with the wild type sweetpotato, S598A had darker green leaves, increased chlorophyll content higher than to two-fold, delayed leaf senescence, shorter plant height (60% shorter than that of the wild type), more number of leaves and petioles about 1.8-fold, shorter petiole length (30% shorter), 1.2-fold more branches and 1.6-fold thicker stem diameters. From this study, S598A plants with such phenotypic characteristics might be able to use the solar energy efficiently, to have increased tolerance to biotic and abiotic stresses and finally to increase productivity (not only starch yield but also root biomass yield). S598A sweetpotato lines are under field trials.

A Comparative Study on the organic Traits of Korea Traditional Architecture and Occidental Architecture (전통한국건축과 서구건축의 유기성에 관한 비교연구)

  • 권영걸
    • Korean Institute of Interior Design Journal
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    • no.14
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    • pp.130-136
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    • 1998
  • The stepping stone of the study is provided through understanding the transformation of the cultural value with the paradigm shift at the turning point of late 20th century and examining the cultural relationaship between the East and the West. By researching the oriental and occidental culture in terms of the origin formation relation and differences which should be divided into broad branches that is natural ideological formative and spatial aspects and so forth. This paper makes it possible to understand the fundamental differences and relativities between two divergent cultures by way of analyzing the architecture in plastic and cognitive aspects to residential space. this study intends to elucidate common traits of korean traditional architecture and that of the Occident and the discrepancies of their attitudes toward nature and space. In Western civilization they used to consider architecture as a physical organization while the oriental people consider it a object what is so of itself. The former concentrated on the functional rationality of scientific technology with the uncontextual propensity which does not consider natural environment the latter could reach the naturalness more harmonious to environment. What counts in the upcoming age of coexistence of Globalism that emphasizes the worlds universality and Nationalism that sticks to local cultural characteristics is to establish the new value system and identity based upon natural order and organic quality. As a result we could recognize the organic quality as a cosmic order could be a valid means to achieve the globalization of our culture through the compatibility between gap and common ground of both cultural sphere.

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