• Bulletin of the Korean Mathematical Society
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• v.53 no.4
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• pp.1095-1103
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• 2016

B. Y. Chen introduced a series of curvature invariants, known as Chen invariants, and proved sharp estimates for these intrinsic invariants in terms of the main extrinsic invariant, the squared mean curvature, for submanifolds in Riemannian space forms. Special classes of submanifolds in Sasakian manifolds play an important role in contact geometry. F. Defever, I. Mihai and L. Verstraelen [8] established Chen first inequality for C-totally real submanifolds in Sasakian space forms. Also, the differential geometry of slant submanifolds has shown an increasing development since B. Y. Chen defined slant submanifolds in complex manifolds as a generalization of both holomorphic and totally real submanifolds. The slant submanifolds of an almost contact metric manifolds were defined and studied by A. Lotta, J. L. Cabrerizo et al. A Chen first inequality for slant submanifolds in Sasakian space forms was established by A. Carriazo [4]. In this article, we improve this Chen first inequality for special contact slant submanifolds in Sasakian space forms.

• Journal of the Korea Fashion and Costume Design Association
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• v.21 no.4
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• pp.81-96
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• 2019

The study intends to seek the creative ideas that can satisfy the needs of individual consumers by rediscovering the modern meaning and the artistic value of geometric ornaments engraved on the backside of Danyugyung, which is a traditional Korean pattern. In terms of the study method, the symbolic meaning and formative characteristics of Danyugyung were determined, and the form of its pattern and the geometric characteristics were analyzed. Based on this, Photoshop and illustrations were used to apply the shapes of Danyugyung and internal patterns to the textile designs, and the results are as follows. Firstly, it was found that Danyugyung was associated with the bronze mirror, which was used from the Bronze Age to the Early Iron Age, and was the product of artistic activities and an object and acted as a shamanistic and authoritative symbol of the ruling parties, which were responsible for the acts related to the spiritual world. Secondly, it was discovered that forms of Danyugyung were classified into Jomungyung and Semungyung in accordance with Forms of Danyugyung (造飾), and the formative features of the geometric ornaments that were engraved in great detail on the backside could be found in the images which change according to the form of the inner patterns. Thirdly, with regard to the development of the textile designs utilizing the shape and inner patterns of Danyugyung based on the formative features, it was could discover that the simple shape of Danyugyung presented a value which can be applied as a unique design factor delivering a visual rhythm by attempting to create various harmonies overlapping lines engraved on the inner patterns and the shapes of Danyugyung. Based on the above-mentioned outcomes, the possibility was confirmed that Danyugyung can be used as a novel motif and as a standard unit of patterns for textile design. With future studies, I would like to utilize the unique and diverse images as pattern motif for textile design.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1957-1962
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• 2008

As a field of MEMS, micro-heater fabricated by Au is being introduced and developed in recent years. Previous studies about thermal properties of various forms of micro-heater were not sufficient. In this work, numerical and experimental analysis of the heat generation and the temperature distribution of micro-heater packages for 8 different geometric cases were studied. We fabricated a micro-heater package with silicon wafer, on which Cr/Au layer was laminated before 8 geometric forms of micro-heater were patterned. In each cases, temperature distribution was measured with IR thermal camera. According to the experimental results, which show a good agreement with the results analyzed by CFD, it was found that at 0.5W, the temperature of micro-heater chip which contained $20000{\mu}m$-long, serpentine shaped micro-heater was elevated to a relatively high temperature of $78^{\circ}C$ Consequently, we proposed a geometry of micro-heater which has effective thermal characteristics.

• Korean Journal of Human Ecology
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• v.13 no.5
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• pp.799-809
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• 2004

Our study found that the types and forms of patterns of Japan, although they are similar to those of Korea and China, hold their own distinctive aesthetic awareness. They were made so, because the Japanese had not simply copied the patterns from other countries and also had changed them in various ways for ages. Especially, geometric patterns were widely used on some types of kimono costumes and belts in Edo period. One of the most widely used patterns was called Suk Chup Mun, and Tatewaku pattern was another. The San Gil Mun and Chil Bo Mun pattern was least used. In the patterns combination, that of animal and plant patterns was general. A single geometric pattern was not used, but if any, it was in Sima patterns and latticed patterns. On the other hand, the combination of geometric and plant patterns was more frequently used as composite patterns than any other pattern, such as geometric pattern with home tools, or one with animal patterns or nature patterns. The geometric patterns that had appeared in Edo period were combined in paintings along with animal and home tools patterns, so it could become a representative pattern of the age.

• Architectural research
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• v.15 no.4
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• pp.207-214
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• 2013

A form-finding technique is proposed for three-dimensional spatial structures. Two-step discrete finite element (FE) mesh generator based on computer aided geometric design (CAGD) is introduced and used to control the shape of three-dimensional spatial structures. Mathematical programming technique is adopted to search new forms (or shapes) of spatial structures. For this purpose, the strain energy is introduced as the objective function to be minimized and the initial volume (or the initial weight) is considered as constraint function. Numerical examples are carried out to test the capability of the proposed form-finding techniques and provided as benchmark tests.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.25 no.4
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• pp.196-220
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• 2021

This study formulates a new geometric parameterization scheme to effectively address numerical analysis subject to the variation of the fiber radius of a square unit cell. In particular, the proposed mesh-morphing approach may lead to a parameterized weak form whose bilinear and linear forms are affine in the geometric parameter of interest, i.e. the fiber radius. As a result, we may certify the reduced basis analysis of a square unit cell model for any parameters in a predetermined parameter domain with a rigorous a posteriori error bound. To demonstrate the utility of the proposed geometric parameterization, we consider a two-dimensional, steady-state heat conduction analysis dependent on two parameters: a fiber radius and a thermal conductivity. For rapid yet rigorous a posteriori error evaluation, we estimate a lower bound of a coercivity constant via the min-θ method as well as the successive constraint method. Compared to the corresponding finite element analysis, the constructed reduced basis analysis may yield nearly the same solution at a computational speed about 29 times faster on average. In conclusion, the proposed geometric parameterization scheme is conducive for accurate yet efficient reduced basis analysis.

• Bulletin of the Korean Mathematical Society
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• v.36 no.2
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• pp.315-336
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• 1999

In the paper [12] we have introduced the new kind of pseudo-einstein ruled real hypersurfaces in complex space forms $M_n(c), c\neq0$, which are foliated by pseudo-Einstein leaves. The purpose of this paper is to give a geometric condition for non-proper pseudo-Einstein ruled real hypersurfaces to be totally geodesic in the sense of Kimura [8] for c> and Ahn, Lee and the present author [1] for c<0.

• The Journal of Art Theory & Practice
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• no.9
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• pp.151-170
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• 2010

As an art group, De Stijl (1917-1931) led a total art movement encompassing painting, sculpture, design, and architecture. Among these, architecture, as a model of the total art pursued by the group, was encapsulated by the term 'plastic architecture.' The term reflects architecture's shared features with plastic art, especially its pictorial characteristics. Firstly, De Stijl architecture shares geometric form with painting. Assembled in simple, clear and rational structures, the geometric forms signified universal forms, and extended the pictorial experimentation that Mondrian exercised through Neo-Plasticism to architecture. Constructed with colour fields made of concrete wall, De Stijl architecture is geometric abstract painting embodied in space. Together with such pictorial characteristics, large plate glass windows, narrow window frames, and cantilever structure minimize the building's visual weight. De Stijl architecture, which appears suspended in the air, is an architectural version of the abstract paintings of the era that revealed unknown spaces beyond perspective. De Stijl architecture is also an 'open' architecture, where the units placed as if radiating from the center form relations with each other flexibly and organically. The observer in such a space is encouraged to experience space within time, as his/her physical and visual mobility and extension are maximized. De Stijl architecture is an example of how the time-space continuum, represented within picture frame through Cubism, Futurism, and abstract art, can be realized in space. By transforming the ideal space of painting into real space in this way, 'plastic architecture' turned out to be an architectural manifestation of the utopianism of the era, aimed at building a society in 'perfect harmony.' However, such rationalism and universalism are not free from the violence of totalization that deletes various differences. This is evident in the history that followed as the geometric form of architecture and urban planning proliferated across the globe, engulfing the diverse natural landscapes and local cultures.

• Journal of the Korea Fashion and Costume Design Association
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• v.5 no.2
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• pp.103-113
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• 2003

This paper analyses the geometric aspect of Sonia Delaunay′s works on the basis of design elements and principles. Geometric pattern is one of the distinct features of early 20th century avant-garde works. The significance of its pattern and colour comes from the fact that it has not only influenced the contemporary fine art but also offered the basic principle of modern costume design. In 1925 she was designing clothes which could be worn today without appearing old-fashioned. She foresaw the future trends in fashion and interior decoration. One might claim she belongs to the avant-garde even today and no less astonishing a phenomenon than she was in 1925. Sonia Delaunay′s art was one of the first expressions of abstract painting and her "simultaneous contrasts" are among the earliest example of the aesthetic. In Delaunay′s geometric abstraction it is found that the technique of "simultaneous contrasts" is exploited almost without exception. Colour as well as Collage was the favourite technique Delnaunay used in creating a distinct simultaneity. Many "inobjective" paintings as she herself called unite the rigour of simple geometric forms with an inner life and poetry which emanate from the richness of the colour, the musicality of the rhythm, the vibrant breadth of the execution.

• Journal of the Korean Society of Costume
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• v.50 no.6
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• pp.47-58
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• 2000

This paper analyses the geometric aspect of Soma Delaunay's works on the basis of design elements and principles. Geometric pattern is one of the distinct features of early 20th century avant-garde works. The significance of its pattern and colour comes from the fact that it has not only influenced the contemporary fine art but also offered the basic principle of modern costume design. In 1925 she was designing clothes which could be worn today without appearing old-fashioned. She foresaw the future trends in fashion and interior decoration, One might claim she belongs to the avant-garde even today and no less astonishing a phenomenon than she was in 1925. Soma Delaunay's art was one of the first expressions of abstract painting and her "simultaneous contrasts"are among the earliest example of the aesthete. In Delaunay's geometric abstraction it is found that the technique of"simultaneous contrasts" is exploited almost without exception. colour as well as collage was the favourite technique Delnaunay used in creating a distinct simultaneity, Many "inobjective" paintings as she herself called unite the rigour of simple geometric forms with an inner life and poetry which emanate from the richness of the colour, the musicality of the rhythm, the vibrant breadth of the execution.rant breadth of the execution.