• 대한수학회지
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• 제44권5호
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• pp.1163-1184
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• 2007

In this presentation dedicated to the tricentennial birth anniversary of the great eighteenth-century Swiss mathematician, Leonhard Euler (1707-1783), we begin by remarking about the so-called Basler problem of evaluating the Zeta function ${\zeta}(s)$ [in the much later notation of Georg Friedrich Bernhard Riemann (1826-1866)] when s=2, which was then of vital importance to Euler and to many other contemporary mathematicians including especially the Bernoulli brothers [Jakob Bernoulli (1654-1705) and Johann Bernoulli (1667-1748)], and for which a fascinatingly large number of seemingly independent solutions have appeared in the mathematical literature ever since Euler first solved this problem in the year 1736. We then investigate various recent developments on the evaluations and representations of ${\zeta}(s)$ when $s{\in}{\mathbb{N}}{\backslash}\;[1],\;{\mathbb{N}}$ being the set of natural numbers. We emphasize upon several interesting classes of rapidly convergent series representations for ${\zeta}(2n+1)(n{\in}{\mathbb{N}})$ which have been developed in recent years. In two of many computationally useful special cases considered here, it is observed that ${\zeta}(3)$ can be represented by means of series which converge much more rapidly than that in Euler's celebrated formula as well as the series used recently by Roger $Ap\'{e}ry$ (1916-1994) in his proof of the irrationality of ${\zeta}(3)$. Symbolic and numerical computations using Mathematica (Version 4.0) for Linux show, among other things, that only 50 terms of one of these series are capable of producing an accuracy of seven decimal places.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제9권3호
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• pp.109-122
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• 2020

최근 실감 미디어 콘텐츠에서 높은 관심을 모으고 있는 프로젝션 맵핑은 사용자의 몰입감을 높이는 기술로 손꼽히고 있다. 최근 관객의 참여를 유도하기 위하여 제스처 인식 기술과 결합된 프로젝션 맵핑 콘텐츠들이 선보이고 있다. 그러나 대부분의 기존 방법들은 정적인 물체를 대상으로 프로젝션 맵핑을 수행하고 있다. 이에 본 논문에서는 사용자의 움직임을 추적하여 사용자의 신체상에 미디어 콘텐츠를 동적으로 프로젝션 맵핑시키는 기술을 개발하였다. 프로젝션 되는 미디어 콘텐츠는 미리 정의된 사용자의 제스처를 인식하여 사용자가 맨손으로 제작할 수 있도록 하였다. 이러한 동적 프로젝션 맵핑 기술과 제스처 기반 드로잉 기술을 통합하여 인터랙티브한 실감미디어 시스템을 구현하였다. 제안된 실감 미디어 시스템에서는 사용자의 양손의 움직임과 개폐 상태를 인식하여 그림을 그리는데 필요한 기능을 선택하고, 임의의 물체 색상을 붓의 색으로 설정하는 등의 기능을 통해 자유롭게 그림을 그릴 수 있게 해준다. 또한 사용자가 그린 그림을 사용자의 몸에 동적으로 투사해 사용자가 실시간으로 자신의 티셔츠를 디자인하고 이를 착용해 보는 효과를 가질 수 있도록 하였다.

• 한국문헌정보학회지
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• 제52권3호
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• pp.273-287
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• 2018

국립세종도서관은 국내외 정책정보 개발 및 제공이라는 핵심기능을 원활하게 수행하기 위하여 정책정보 개발에 있어서의 체계성과 실천적 전략 확보가 필수적이다. 즉 국립세종도서관이 범정부차원의 정책정보 특화도서관이라는 본질적 정체성을 정립하고 서비스 역량을 극대화하기 위해서는 국립세종도서관 중장기 발전계획에 입각한 정책정보개발 전략을 모색하고 이를 토대로 한 장서개발정책을 수립하여 실무에 적용해야 한다. 이에 이 연구에서는 국립세종도서관의 정책정보 개발을 위한 전략을 제안하고 이를 통하여 국립세종도서관이 '정책정보 특화도서관'이라는 정체성을 확립할 수 있는 방안을 제시하였다. 구체적으로 정책정보 특화형 전문 장서의 필요성과 개발 방안, 그리고 정책정보와 일반자료를 대상으로 하는 장서개발정책 기본지침과 정책정보에 특화된 장서개발정책의 실천적 세부지침으로 나누어 수행할 것을 제안하였다.

• 수산해양기술연구
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• 제29권1호
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• pp.39-55
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• 1993

Modal Analysis is the process of characterizing the dynamic properties of an elastic structure by identifying its modes of vibration. A mode of vibration is a global property of an elastic structure. That is, a mode has a specific natural frequency and damping factor which can be identified from response data at practically any point on a structure, and it has a characteristic mode shape which identifies the mode spatially over the entire structure. Modal testing is able to be performed on structural and mechanical structure in an effort to learn more about their elastic behavior. Once the dynamic properties of a structure are known its behavior can be predicted and therefore controlled or corrected. Resonant frequencies, damping factors and mode shape data can be used directly by a mechanical designer to pin point weak spots in a structure design, or this data can also be used to confirm or synthesize equations of motion for the elastic structure. These differential equations can be used to simulate structural response to know input forces and to examine the effects of pertubations in the distributed mass, stiffness and damping properties of the structure in more detail. In this paper the measurement of transfer functions in digital form, and the application of digital parameter identification techniques to identify modal parameters from the measured transfer function data are discussed. It is first shown that the transfer matrix, which is a complete dynamic model of an elastic plate structure can be written in terms of the structural modes of vibration. This special mathematical form allows one to identify the complete dynamics of the structure from a much reduced set of test data, and is the essence of the modal approach to identifying the dynamics of a structure. Finally, the application of transfer function models and identification techniques for obtaining modal parameters from the transfer function data are discussed. Characteristics on vibration response of elastic plate structure obtained from the dynamic analysis by Finite Element Method are compared with results of modal analysis.

• 디지털융복합연구
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• 제13권12호
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• pp.203-208
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• 2015

테마파크, 홍보관, 과학관 등의 다면 영상시스템에서 초기 설치 시 빔 프로젝터들간의 하드웨어적 특성 및 설치 후 시간이 경과함에 따라 발생되는 영상의 열화 현상이 발생한다. 본 연구에서는 영상관의 품질과 유지보수의 어려움을 해결하기 위해 10비트 High-depth 및 고해상도 $360^{\circ}$ 프로젝션 영상 분석 기술을 연구하였다. 그 목적은 경제적 손실을 최소화하고, 영상의 품질을 효율적으로 지원할 수 있는 특수영상관 캘리브레이션 시스템 개발을 목표로 한다. 이를 위해 영상 분석 기술의 방법을 제안하였고, 영상 분석 기술에 대한 세부 기능과 평가방법 등을 설명하였다. 평가방법은 평가 항목별로 제시하였고, 실험 방법과 목표치에 대한 추정 값을 제시하였다.

• 복식
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• 제52권5호
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• pp.155-172
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• 2002

The research has the aim of defining the special characteristics of the functionalist fashion design in the 1900s by understanding the essence of functionalism in the sociocultural contexts. Giving careful consideration to functionalist fashion design in the 1990s makes it possible to foresee the way of fashion design to meet the needs of the modems and men of the future world. To obtain the purposes, documentary study and demonstrative study with fashion photographs have been executed. Main results are as follows. Functionalism in the 1990s has been developed in different ways from the analogies in the beginning of the 20th century. It doesn't belong to an analogy but has the fused characteristics. It can be classified into techno functionalism influenced by new technology Pure functionalism related to minimalism. casual functionalism for those who are crazy about the speed and sports and enjoy the freedom and comfort and symbolic functionalism. Mechanical analogy has been developed into techno functionalism. Pure functionalism has come from the blend of mechanical and moral analogy, casual functionalism from mechanical. organic and moral analogy. and symbolic functionalism from organic and moral analogy. Since fashion design has much closer relation to human body and movements. it has been expressed considering a division of men and women and the places and times for the designs more than other designs. More casual manners of formal wear are distinct elements in functionalist fashion design in the 1990s. The 20th century general cultural phenomena including post modernism can be explained by eclectic functionalism. Functionalism considering Practical and conceptional functions ill continue and techno functionalism and casual functionalism in future fashion design will be expressed more strongly with new technology and casual trends of life style.

• 한국전산응용수학회:학술대회논문집
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• 한국전산응용수학회 2003년도 KSCAM 학술발표회 프로그램 및 초록집
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• pp.1-1
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• 2003

In this talk, a reduced-order modeling methodology based on centroidal Voronoi tessellations (CVT's)is introduced. CVT's are special Voronoi tessellations for which the generators of the Voronoi diagram are also the centers of mass (means) of the corresponding Voronoi cells. The discrete data sets, CVT's are closely related to the h-means clustering techniques. Even with the use of good mesh generators, discretization schemes, and solution algorithms, the computational simulation of complex, turbulent, or chaotic systems still remains a formidable endeavor. For example, typical finite element codes may require many thousands of degrees of freedom for the accurate simulation of fluid flows. The situation is even worse for optimization problems for which multiple solutions of the complex state system are usually required or in feedback control problems for which real-time solutions of the complex state system are needed. There hava been many studies devoted to the development, testing, and use of reduced-order models for complex systems such as unsteady fluid flows. The types of reduced-ordered models that we study are those attempt to determine accurate approximate solutions of a complex system using very few degrees of freedom. To do so, such models have to use basis functions that are in some way intimately connected to the problem being approximated. Once a very low-dimensional reduced basis has been determined, one can employ it to solve the complex system by applying, e.g., a Galerkin method. In general, reduced bases are globally supported so that the discrete systems are dense; however, if the reduced basis is of very low dimension, one does not care about the lack of sparsity in the discrete system. A discussion of reduced-ordering modeling for complex systems such as fluid flows is given to provide a context for the application of reduced-order bases. Then, detailed descriptions of CVT-based reduced-order bases and how they can be constructed of complex systems are given. Subsequently, some concrete incompressible flow examples are used to illustrate the construction and use of CVT-based reduced-order bases. The CVT-based reduced-order modeling methodology is shown to be effective for these examples and is also shown to be inexpensive to apply compared to other reduced-order methods.

• 한국생산제조학회지
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• 제18권3호
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• pp.285-293
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• 2009

Thermal infrared cameras have been conducted actively in various application areas, such as military, medical service, industries and cars. Because of their characteristic of sensing the radiant heat emitted from subjects in the range of long-wavelength($3{\sim}5{\mu}m$ or $8{\sim}12{\mu}m$), and of materializing a vision system, when general optics materials are used, they don't react to the light in the range of long-wavelength, and can't display their optic functions. Therefore, the materials with the feature of higher refractive index, reacting to the range of long-wavelength, are to be used. The kinds of materials with the characteristic of higher refractive index are limited, and their features are close to those of metals. Because of these metallic features, the existing producing method of optical systems were direct manufacturing method using grinding method or CAD/CAM, which put limit on productivity and made it difficult to properly cope with the increasing demand of markets. GASIR, a material, which can be molded easily, was selected among infrared ray optics materials in this study, and the optical system was designed with two Aspheric lenses. Because the lenses are molded in the environment of high temperature and high pressure, they require a special metallic pattern. The metallic pattern was produced with materials with ultra hardness that can stand high temperature and high pressure. As for the lens mold, GMP(Glass Molding Press) of the linear transfer method was used in order to improve the productivity of optical systems for thermal infrared cameras, which was the goal of this paper.

• 조형예술학연구
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• 제3권
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• pp.225-247
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• 2001

The analysis of art work that is objective and theoretical needs the help of the cognitive psychology, for the pictorial semiotics requires psychology. The first step to the analysis of art work is about the visual elements and their relations. But the semiotics is lack of the method of the analysis of art work and the some authors don't have treated or been interested in psychological analysis. The main problem of visual semiotics is the density of pictorial representation. It makes the semantic of art work impossible at the very early process of analysis. But the density is not only a matter of visual representation, verbal language also has this problem. The point is that art work functions more art than denotation, but verbal language does more denotation than art. This difference makes difficult to apply the method of language or semiotics to visual art. The possibility of pictorial syntax or perceptual semantics should begin considering the unification of perception and semantics. In principles these two field can be unified. At atomism and holism these are parallel. Therefore perceptual semantics is possible The cognitive psychology can help to formulation of perceptual semantics. At first, the visual representation is incremental and it can be divided at three steps. In these steps each sensation, perception and cognition level has their own role. Perceptual representation of art work should be specified at these three levels. And each of these levels, the special properties of art work should be drawn and examined in the possibility of semiotics. The investigation of psychological levels and semiotic level should be circulated. It will help to formulate the method of analysis of art work.

• 농촌계획
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• 제16권3호
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• pp.103-115
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• 2010

This study was accompanied to develop the management and application plans as resources for rural tourism through the analysis of distribution characteristics, inhabitants' practical use, need item for management and application, and aesthetic/recreation function of Palustrine wetland in rural area. The 2.3 Palustrine wetland per farm village were located, and 77.5% of total wetland was used by agricultural water, landscape, rural tourism The management and water quality were steadily getting better in used wetland than in unused wetland. Also, 91.8% of respondents answered that there is a practical use plan afterward, and much preferred the mode of ecotourism through restoration of ecological wetland. As the results from the appropriateness evaluation of management and application in used wetland for ecotourism, improvement item was required in observation deck, entrance lane, guidance facilities etc. And, insufficient result was deduced in appropriateness of operation program and special learning course, and in participation of inhabitants and experts. The result of evaluation of the aesthetic and recreation functions generally appeared high, but the need improvement item was required in artificial water wall and plantation base that deteriorate biological diversity. These results will be used to data for conservation, management and practical use of wetland, an important natural resource in farm village, which are confronted in crisis of land reclamation by use reduction of use and false management.