• 대한수학회지
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• 제33권4호
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• pp.1101-1114
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• 1996

In Riemannian geometry, it is one of the important things to study the topological or geometric invariants of manifolds since they characterize the topology of manifolds.

• Tuberculosis and Respiratory Diseases
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• 제57권5호
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• pp.434-438
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• 2004

배 경 : 기관 내관 풍선(cuff)의 압력은 과도하게 높으면 기관에 손상을 일으키고, 낮으면 압력 누출이 초래되므로 적절한 압력 유지가 필요하다. 적절한 cuff의 압력을 유지하기 위해서 시행하는 최소 밀폐압 (minimal occlusion pressure) 방법에서 cuff의 압력은 최고 흡기압(peak inspiratory pressure)의 영향을 받는다고 알려져 있다. 그러나 최고 흡기압 이외의 다른 요소, 특히 환기 용적과의 관련성은 잘 알려져 있지 않다. 이에 저자들은 인공호흡기 치료를 받는 환자들에서 동일한 최고 흡기압을 유지하면서 상시량을 변화시키는 것이 기관 내관 cuff의 최소 밀폐압에 영향을 주는지 보고자 하였다. 방 법 : 인공 호흡기 치료 중인 환자 10명을 대상으로 cuff 압력 측정계를 이용하여 공기 누출이 일어나지 않는 cuff의 최소 압력(최소 밀폐압)을 구하였다. 최고 흡기압을 일정하게 유지하도록 인공호흡기의 설정을 조절하면서 1회 호흡량을 10% 증가시킨 용적과 10% 감소시킨 용적을 각각 적용하면서 최소 밀폐압을 측정하여 비교하였다. 결 과 : 초기 설정에서 최고 흡기압은 $32.6{\pm}4.72cmH_2O$ 였고, 최소 밀폐압은 $19.0{\pm}2.26$ mmHg 였다. 각 환자의 최고 흡기압과 최소 밀폐압 사이에는 의미 있는 상관관계가 있었다(r=0.77, p<0.01). 상시량을 10% 증가시킨 경우(high volume state)의 최소 밀폐압은 $20.3{\pm}2.41$ mmHg로 증가하였고(p<0.05), 상시량을 감소시킨 경우(low volume state)의 최소 밀폐압은 $16.8{\pm}3.01$ mmHg로 감소하였다(p<0.001). 결 론 : 최고 흡기압 뿐만 아니라 1회 호흡량도 기관 내관 cuff의 최소 밀폐압에 영향을 미칠 수 있다.

• Korean Journal of Mathematics
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• 제14권1호
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• pp.13-33
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• 2006

In this article, we study the relations of horizontally conformal maps and harmonic morphisms with the stability of minimal fibers. Let ${\varphi}:(M^n,g){\rightarrow}(N^m,h)$ be a horizontally conformal submersion. There is a tensor T measuring minimality or totally geodesics of fibers of ${\varphi}$. We prove that if T is parallel and the horizontal distribution is integrable, then any minimal fiber of ${\varphi}$ is volume-stable. As a corollary, we obtain that any fiber of a submersive harmonic morphism whose fibers are totally geodesics and the horizontal distribution is integrable is volume-stable. As a consequence, we obtain if ${\varphi}:(M^n,g){\rightarrow}(N^2,h)$ is a submersive harmonic morphism of minimal fibers from a compact Riemannian manifold M into a surface N, T is parallel and the horizontal distribution is integrable, then ${\varphi}$ is energy-stable.

• 대한수학회보
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• 제51권4호
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• pp.1023-1029
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• 2014

In the paper, we define a class of convex bodies in $\mathbb{R}^n$-parallel sections homothety bodies, and for some special parallel sections homothety bodies, we prove that n-cubes have the minimal Mahler volume.

• Korean Journal of Mathematics
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• 제18권2호
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• pp.195-200
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• 2010

Let C be a closed convex set in ${\mathbb{S}}^m$ or ${\mathbb{H}}^m$. Assume that ${\Sigma}$ is an n-dimensional compact minimal submanifold outside C such that ${\Sigma}$ is orthogonal to ${\partial}C$ along ${\partial}{\Sigma}{\cap}{\partial}C$ and ${\partial}{\Sigma}$ lies on a geodesic sphere centered at a fixed point $p{\in}{\partial}{\Sigma}{\cap}{\partial}C$ and that r is the distance in ${\mathbb{S}}^m$ or ${\mathbb{H}}^m$ from p. We make use of a modified volume $M_p({\Sigma})$ of ${\Sigma}$ and obtain a sharp relative isoperimetric inequality $$\frac{1}{2}n^n{\omega}_nM_p({\Sigma})^{n-1}{\leq}Vol({\partial}{\Sigma}{\sim}{\partial}C)^n$$, where ${\omega}_n$ is the volume of a unit ball in ${\mathbb{R}}^n$ Equality holds if and only if ${\Sigma}$ is a totally geodesic half ball centered at p.

• 대한수학회논문집
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• 제20권4호
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• pp.775-779
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• 2005

On a compact n-dimensional manifold $M^n$, a critical point of the total scalar curvature functional, restricted to the space of metrics with constant scalar curvature of volume 1, satifies the critical point equation (CPE), given by $Z_g\;=\;s_g^{1\ast}(f)$. It has been conjectured that a solution (g, f) of CPE is Einstein. The purpose of the present paper is to prove that every compact stable minimal hypersurface is in a certain hypersurface of $M^n$ under an assumption that Ker($s_g^{1\ast}{\neq}0$).

• 호남수학학술지
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• 제30권4호
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• pp.677-683
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• 2008

On a compact n-dimensional manifold M, it has been conjectured that a critical point metric of the total scalar curvature, restricted to the space of metrics with constant scalar curvature of volume 1, should be Einstein. The purpose of the present paper is to prove that a 3-dimensional manifold (M,g) is isometric to a standard sphere if ker $s^*_g{{\neq}}0$ and there is a lower Ricci curvature bound. We also study the structure of a compact oriented stable minimal surface in M.

• 한국실내디자인학회논문집
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• 제14호
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• pp.121-129
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• 1998

It opposition to visual luxury of Post modern Architecture a new tendency characterized as 'simplicity' emerged in architecture. It seems clear that such a tendency so called Minimal Architecture has risen as a reaction to the surfeit of sign and the mixture of languages generated by postmodernism. This new simplicity is also related to the tradition of Modern Architecture and the Minimal Art Movement is 1960's. They adopted simple is also related to the tradition of Modern Architecture and the Minimal Art Movement is 1960's. They adopted simple primary Volume to avoid the main fluence on the already chaotic urban environment As a result a strong monumentality is achieved. The main interests for 'minimal' architects seem to be the making of simple structure and the repetition of modular elements to achieve an economic and efficient construction method. Transparent and honest expression is preferred instead of attaching another ornament skin on to the skeleton of the architecture.

• 복식
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• 제24권
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• pp.157-176
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• 1995

The purpose of this treatise is to study external form and internal meaning of minimal expression fashion which appeared as a major stream in modern fashion trends to understand one aspect of modernism in fashion and also to gain insight into internal value of human beings through fashion. The results can be summarized as follows : Firstly , minimalism is a trend in art attempting to seek essence of the object by presenting simple and disciplined expressions by minimal formative means and minimal production process. Secondly, minimal expression in fashion means seeking simplicity an dpurity by using minimum design elements and minimal productive process. Thirdly, external from of minimal expression fashion can be created through application of following minimal expression techniques. 1. Minimal expression techniques in terms of line mean smooth curve flowing along body contours, straight lines of diagonal lines into desciplined silhouette or rendering internal contour lines. 2. Minimum expression techniques in terms of forms mean forms of smooth curves flowing along boyd or forms with simple geometric forms from qualitative aspects, In terms of volume it means quest for essence of pure body itself by revealing body as it is by minimizing the size of dress or its area and herein is contained using simple geometric pattern or utilizing textiles without any patterns.3. Minimal expression techniques by colors mean simple colors such as primary colors, colors without clear distinctions or natural colors and in terms of quantity it means quest for one color within one item of dress or combination of each items when getting dressed. 4. Minimal expression techniques in terms of fabrics mean fabrics with simple surfaced. In terms of quantity it means quest for essence of tight fitting thin textiles to human body or using transparent materials to human body thus exposing body contours as it is. 5. Minimal expression techniques in terms of productive process mean minimizing process of tailoring , sewing or ornamenting and seeking for simplicity and purity. 6. Minimal expression techniques in terms of manufacturing process mean selection of technique conveying simple image with disciplined simple image. Fourthly, minimal expression fashion with external expression as mentioned in the above lay body-priority style and its internal meaning can be asummed as quest for essence and purity of human body.

• International journal of advanced smart convergence
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• 제9권2호
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• pp.49-57
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• 2020

We have not identified on what gender difference during gait at a pace of one's preferred velocity effects on the function of bilateral lower limb. This study was undertaken to investigate a difference of gait strategy by gender during gait at a one's preferred velocity of participants of adult male and female (n=20). Cinematographic data for motion analysis, ground reaction force (GRF) variables, and muscle volume of lower limb were analyzed. Significant difference of variables on movement of center of mass whole body, joint angle and moment of lower limb, and ground reaction force were tested by 2-way ANOVA analysis (P<0.05). Male group showed more muscle volume than female, and both showed more volume in dominant leg than non-dominant. Main effect by bilateral leg during gait showed higher difference in right than left leg in change of vertical position of center of mass (maximal, minimal). Main effect by gender in vertical change of position and velocity of center of mass showed higher difference in male than female (maximal, minimal). Hip joint showed more flexed and extended angle in male than female, and also dorsiflexion of ankle and flexion moment of knee and hip joint showed higher in male than female group. Therefore, this result was assumed that dominant showed furthermore more contribution for propulsive function than non-dominant leg. Gender difference showed in strategy controlling of biomechanical characteristics, and perhaps influenced by muscle volume.