• Journal of Ship and Ocean Technology
• /
• v.7 no.2
• /
• pp.1-19
• /
• 2003

This paper introduces a unified theory for the radiation problem of adjacent multiple floating bodies. The particular case of interest is the multiple slender bodies that their centerlines are parallel. The infinite-and finite-depth unified theories for the single-body problem are extended to solve each sub-problem of multiple bodies. The present method is valid for deep water and moderate water depth, and applicable for individually floating bodies as well as multimaran-type vehicles. For the validation of the present method, the heave and pitch hydrodynamic coefficients for two adjacent ships are compared with the results of a three-dimensional method, and an excellent agreement is shown. The application includes the hydrodynamic coefficients and motion RAOs of four trimarans which have different longitudinal and transverse arrangements for sidehulls.

• Proceedings of the KIEE Conference
• /
• 1998.11a
• /
• pp.326-328
• /
• 1998

This paper presents an optimal fuzzy power system stabilizer to damp out low frequency oscillation. The fuzzy logic controllers has been applied to a power system stabilizing controllers. But the design of a fuzzy logic power system stabilizer relies on empirical and heuristic knowledge of human experts as well as many trial-and-errors in general. This paper presents the optimal design method of the fuzzy logic stabilizer using the genetic algorithm, which is the optimization method based on the mechanics of natural selection and natural genetics. The proposed method tunes the parameters of the fuzzy logic stabilizer in order to minimize the consuming time during the design process. In this paper, the proposed method tunes the shape of membership function of the fuzzy variables. The proposed system is applied to the one-machine infinite-bus model of a power system. Through the case study, the efficiency of the fuzzy stabilizing controller tuned by genetic algorithm is verified.

• Journal of the Korean Mathematical Society
• /
• v.44 no.4
• /
• pp.941-947
• /
• 2007

Let M be a complete Riemannian manifold and let N be a Riemannian manifold of nonpositive scalar curvature. Let ${\mu}0$ be the least eigenvalue of the Laplacian acting on $L^2-functions$ on M. We show that if $Ric^M{\ge}-{\mu}0$ at all $x{\in}M$ and either $Ric^M>-{\mu}0$ at some point x0 or Vol(M) is infinite, then every harmonic morphism ${\phi}:M{\to}N$ of finite energy is constant.

• Bulletin of the Korean Chemical Society
• /
• v.16 no.10
• /
• pp.957-968
• /
• 1995

Generalized Multichannel Quantum Defect theory (MQDT) was implemented to the vibrational predissociation of triatomic van der Waals molecules in the previous paper [Bull. Korean Chem. Soc, 12, 228 (1991)]. Implementation was limited to the calculation of the scattering matrix. It is now extended to the calculation of the predissociation spectra and the final rotational distribution of the photofragment. The comparison of the results with those obtained by other methods, such as Golden-rule type calculation, infinite order sudden approximation (IOS), and close-coupling method, shows that the implementation is successful despite the fact that transition dipole moments show more energy dependence than other quantum defect parameters. Examination of the short-range channel basis functions shows that they resemble angle-like functions and provide the validity of the IOS approximation. Besides the validity of the latter, only a few angles are found to play the major role in photodissociation. In addition to the implementation of MQDT, more progress in MQDT itself is made and reported here.

• Nonlinear Functional Analysis and Applications
• /
• v.27 no.2
• /
• pp.381-403
• /
• 2022

The main goal of this research is to solve variational inequalities involving quasimonotone operators in infinite-dimensional real Hilbert spaces numerically. The main advantage of these iterative schemes is the ease with which step size rules can be designed based on an operator explanation rather than the Lipschitz constant or another line search method. The proposed iterative schemes use a monotone and non-monotone step size strategy based on mapping (operator) knowledge as a replacement for the Lipschitz constant or another line search method. The strong convergences have been demonstrated to correspond well to the proposed methods and to settle certain control specification conditions. Finally, we propose some numerical experiments to assess the effectiveness and influence of iterative methods.

• ETRI Journal
• /
• v.44 no.1
• /
• pp.147-154
• /
• 2022

We demonstrate a new double-layer structure for stretchable interconnects, where the top surface of a serpentine polyimide support is coated with a thin eutectic gallium-indium liquid metal layer. Because the liquid metal layer is constantly fixed on the solid serpentine body in this liquid-on-solid structure, the overall stretching is accomplished by widening the solid frame itself, with little variation in the total length and cross-sectional area of the current path. Therefore, we can achieve both invariant resistance and infinite fatigue life by combining the stretchable configuration of the underlying body with the freely deformable nature of the top liquid conductor. Further, we fabricated various types of double-layer interconnects as narrow as 10 ㎛ using the roll-painting and lift-off patterning technique based on conventional photolithography and quantitatively validated their beneficial properties. The new interconnecting structure is expected to be widely used in applications requiring high-performance and high-density stretchable circuits owing to its superior reliability and capability to be monolithically integrated with thin-film devices.

• Journal of the Korean earth science society
• /
• v.34 no.5
• /
• pp.393-401
• /
• 2013

Spherical harmonics power spectrum of the geopotential field of Gaussian-bell type on the sphere was investigated using integral formula that is associated with Legendre polynomials. The geopotential field of Gaussian-bell type is defined as a function of sine of angular distance from the bell's center in order to guarantee the continuity on the global domain. Since the integral-formula associated with the Legendre polynomials was represented with infinite series of polynomial, an estimation method was developed to make the procedure computationally efficient while preserving the accuracy. The spherical harmonics power spectrum was shown to vary significantly depending on the scale parameter of the Gaussian bell. Due to the accurate procedure of the new method, the power (degree variance) spanning over orders that were far higher than machine roundoff was well explored. When the scale parameter (or width) of the Gaussian bell is large, the spectrum drops sharply with the total wavenumber. On the other hand, in case of small scale parameter the spectrum tends to be flat, showing very slow decaying with the total wavenumber. The accuracy of the new method was compared with theoretical values for various scale parameters. The new method was found advantageous over discrete numerical methods, such as Gaussian quadrature and Fourier method, in that it can produce the power spectrum with accuracy and computational efficiency for all range of total wavenumber. The results of present study help to determine the allowable maximum scale parameter of the geopotential field when a Gaussian-bell type is adopted as a localized function.

• Journal of People, Plants, and Environment
• /
• v.23 no.6
• /
• pp.615-624
• /
• 2020

Background and objective: Urbanization caused a reduction in urban green space and a lack of community spaces. An attempt to solve these problems, urban gardens, have become popular and are currently being implemented in various downtown areas. However, urban gardens have some inadequate aspects from a visual or landscape perspective. The goal of this study was to examine the possibility of an aesthetic and productive garden space by introducing cultivation methods through the planting system design process. Methods: The design process using plants was classified and presented to suggest the importance of the landscape and aesthetic value. An urban garden space was designed according to the perspective of 'production scenery' and 'participation aesthetics'. According to the characteristics of the plant, urban gardens were divided into vertical type (corn, millet, sorghum), climbing type (kidney bean, cucumber, bitter gourd), and runner type (melon, watermelon, peanut). After classifying plants according to the shape of the root, the structure supporting climbing was installed and the crops were cultivated in an upright form with a tunnel. Results: In the designed cultivation, each crop cooperates, without invading each other's space. Compared with the conventional cultivation, there was little difference in production, and management was made more convenient since weed outbreaks were effectively suppressed while runner type crops cover over the land's surface. Since the positions of each crop are clearly distinguished, the aesthetic value is improved by offering a sense of rhythm with a balanced design. Conclusion: The results suggest that the cultivation methods through the plant system design process have aesthetic as well as productive value, and the design using plants, an infinite living resource, could lead to an expansion of the design field. Moreover, it would enable a sustainable symbiosis between industry and environment. There is potential for the design industry to make significant progress through collaboration with agriculture, horticulture, and landscape architecture.

• Journal of the Korean Society of Costume
• /
• v.57 no.8
• /
• pp.75-88
• /
• 2007

Nowadays, geometrical form expressed on costume is recognizing as a part of modeling art, at the same time is working to develop it. Also the geometrical form is affording the coinciding lifestyle and sensitivity of customers keeping their pace. As a result, our study is researching on the geometrical form that is used in the pattern, silhouette, and detail of the costume to show the texture in sense of touch and the effect of optical illusion used in variable designs, in order to present the expansion our capability of infinite development included in the study of costume. Specially, geometrical form included in sports wear is very effective since the geometrical form includes short and simple beauty as well as practical design. Thus, this study is wishing to know if satisfying the practical and psychological urge of present human beings may be applied to the golf wear market, which is a type of sport that geometrical form is sent in the fastest way in domestic market. Also we are urged to know what type of design technique is the geometrical form nowadays used and changed to discriminate the artificial commerce and improve the identity of such unique brand. The source of this thesis is wishing to investigate the specialization and the most effective geometrical shape and preference of each type in domestic golf wear goods that applied geometrical goods in $2002{\sim}2006$ and analyze its way of expression.

• The Research Journal of the Costume Culture
• /
• v.29 no.3
• /
• pp.361-373
• /
• 2021

The purpose of this study is to contribute to the role of lines in creative design development by analyzing the expression types and aesthetic characteristics of modern fashion using geometric formativeness of symmography. A literature study was conducted of works since 2009 to examine the general consideration of lines together with analysis of the concept and characteristics of symmography in the formative arts field, and to analyze the expression types and aesthetic characteristics of modern fashion design using the formativeness of symmography. The infinite sense of formativeness and original expression of symmography are used in formative arts such as space design, installation art, and industrial design. Expression types of modern fashion design using geometric formativeness of symmography can be classified into the following three types: two-dimensional graphic pattern, relief surface, and three-dimensional spatial. First, the two-dimensional graphic pattern type forms an optical pattern, providing individuality and visual interest to the textile design. Second, the relief surface type expresses the plane in various ways, so that the thickness changes according to how lines overlap. Third, the three-dimensional spatial type expands the boundaries of clothing and creates a fantastic spatial beauty. Next, the aesthetic formativeness of fashion design using symmography can be classified into repetitive rhythmicity, geometric self-similarity, and optical spatiality. Symmography enables a myriad of geometric patterns to be developed depending on material, color, and the designer's imagination, and helps inspire a variety of designs in fashion that sculpt a three-dimensional human body.