• Journal of the Korean Mathematical Society
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• v.50 no.4
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• pp.847-864
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• 2013

By a change of variables we obtain new $y$-coordinates of elliptic curves. Utilizing these $y$-coordinates as meromorphic modular functions, together with the elliptic modular function, we generate the fields of meromorphic modular functions. Furthermore, by means of the special values of the $y$-coordinates, we construct the ray class fields over imaginary quadratic fields as well as normal bases of these ray class fields.

• Journal of the Korean Geotechnical Society
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• v.28 no.11
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• pp.17-31
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• 2012

No analytical solution exists for evaluating in-situ hydraulic conductivity of vertical cutoff walls by analyzing slug test results with consideration of transient flow. There is an analytical solution proposed to interpret a slug test performed in a partially penetrated well within an aquifer. However, this analytical solution cannot be directly applied to the cutoff wall because the solution has been developed exclusively for an infinite aquifer instead of a narrow cutoff wall. To consider the cutoff wall boundary conditions (i.e, constant head boundary and no flux boundary condition), the analytical solution has been modified in this study to take into account the narrow boundaries by introducing the imaginary well theory. Type curves are constructed from the currently derived analytical solution and compared with those of a partially penetrated well within an aquifer. The constant head boundary condition provides faster hydraulic head recovery curve than the aquifer case. On the other hand, no flux boundary condition leads to slower hydraulic head recovery. The bigger the shape factor and deviation of the well and the smaller the width of the vertical cutoff wall are, the more effect of boundary condition was observed. The type curves obtained from the analytical solution for a cutoff wall are similar to those made by the numerical method in the literature.

• Cross-Cultural Studies
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• v.34
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• pp.71-92
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• 2014

This article presents a study on the concept of "Photogenie", which refers to the duality and mentality of the photographic image, with the viewpoint regarding the photographic image by Edgar Morin. First, we will look at the evolution of the concept of "Photogenie". From the field of photography, the term "Photogenie" means objects that produce light, enough to impress the photographic plate. But theorists of cinema at the beginning of the 20th century have changed the meaning of the term. For Louis Delluc, the "Photogenie" means the effect of union between the reproduction of real and artistic genius. For Jean Epstein, the "Photogenie" means mental quality, nonmaterial or inderterminable, of the photographic and cinematographic image. But Morin synthesized the arguements of Delluc and Epstein. For him, the "Photogenie" indicates both a double character of the photographic image and its mental quality. Then, based on this concept of "Photogenie," Morin said on particular aspects in the photographic image. Considering photography as a double in the anthropological sense, it puts emphasis not only the dual nature of the photographic image but also mental and spiritual quality. Combining the theory of the mage Henri Bergson and Jean-Paul Sartre, he builds his own theory of the mage that concerns both photography and cinema. In short, to Morin, the photographic image is a place where coexist absence and presence, the real and the imaginary, perception and memory, the material and mental, as well that a place of mentality which appear all our memories, hallucinations, dreams, imagination etc.

• Advances in nano research
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• v.16 no.1
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• pp.27-40
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• 2024

This work is the first of its kind to integrate Mindlin's theory with analytical methods in order to produce an exact solution to a specific vibration issue as well as a bending problem involving a nanoplate that is supported by a viscoelastic foundation. The plate is exposed to the simultaneous effects of a compressive load in the plate plane and a force operating perpendicular to the plane of the nanoplate. In addition, the flexoelecity effect is included into the plate. The strain gradient component is taken into consideration while calculating the plate equilibrium equation using the nonlocal theory and Hamilton's principle. The free vibration and static responses of the nanoplate seem to be both real and imaginary components because of the appearance of the viscoelastic drag coefficient of the viscoelastic foundation. This study also shows that when analyzing the mechanical response for nanostructure, taking into account the flexoelectricity effect and the influence of the nonlocal parameter, the results will be completely different from the case in which this parameter is ignored. This indicates that it is vital to take into consideration the effects of nonlocal parameters on the nanosheet structure while also taking into consideration the effect of flexoelectricity.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.4
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• pp.287-295
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• 2012

Hydrodynamic performance of a movable submerged breakwater was analyzed using energy dissipation model. Based on two-dimensional boundary element method the equation of motion including a viscous dissipation term proportional to velocity squared was solved by Newton-Raphson method. Energy dissipation coefficients as well as reflection and transmission coefficients of a submerged flat plate were calculated with various plate lengths and thickness. Both real and imaginary components of body displacement and forces were used to solve the motion of breakwater accurately. The effect of the magnitude of dissipation coefficient on the body displacement was evaluated. The results from the potential theory with no dissipation term were found to be an overestimate in resonance frequency.

• Korean Journal of Materials Research
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• v.31 no.7
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• pp.382-385
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• 2021

Well-crystallized vanadium pentoxide V₂O₅ thin films are fabricated on MgO single crystal substrates by using pulsed-laser deposition technique. The linear optical transmission spectra are measured and found to be in a wavelength range from 300 to 800 nm; the data are used to determine the linear refractive index of the V₂O₅ films. The value of linear refractive index decreases with increasing wavelength, and the relationship can be well explained by Wemple's theory. The third-order nonlinear optical properties of the films are determined by a single beam z-scan method at a wavelength of 532 nm. The results show that the prepared V₂O₅ films exhibit a fast third-order nonlinear optical response with nonlinear absorption coefficient and nonlinear refractive index of 2.13 × 10^-10 m/W and 2.07 × 10^-15 cm²/kW, respectively. The real and imaginary parts of the nonlinear susceptibility are determined to be 3.03 × 10^-11 esu and 1.12 × 10^-11 esu, respectively. The enhancement of the nonlinear optical properties is discussed.

• Journal of the Korean Geotechnical Society
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• v.27 no.10
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• pp.105-116
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• 2011

No analytical solution exists for evaluating in-situ hydraulic conductivity of vertical cutoff walls by analyzing slug test results. Recently, an analytical solution to interpret slug tests has been proposed for a partially penetrated well in an aquifer. However, this analytical solution cannot be directly applied to the cutoff wall because the solution has been developed exclusively for an infinite aquifer instead of a narrow cutoff wall. To consider the cutoff wall boundary conditions, the analytical solution has been modified in this study to take into account the narrow boundaries by introducing the imaginary well theory. Two boundary conditions are considered according to the existence of filter cakes: constant head boundary and no flux boundary. Generalized steady-state shape factors are presented for each geometric condition, which can be used for evaluating the in-situ hydraulic conductivity of cutoff walls. The constant head boundary condition provides higher shape factors and no flux boundary condition provides lower shape factors than the infinite aquifer, which enables to adjust the in-situ hydraulic conductivity of the cutoff wall. The hydraulic conductivities calculated from the analytical solution in this paper give about 1.2~1.7 times higher than those from the Bouwer and Rice method, one of the semi-empirical formulas. Considering the compressibility of the backfill material, the analytical solution developed in this study was proved to correspond to the case of incompressible backfill materials.

• Journal of Science of Art and Design
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• v.4
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• pp.5-25
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• 2002

It is not easy to get more attention as a prominent advertising expression among various types of numerous advertisements. Due to the voluminous expansion of advertising communications and the change of the media, new advertising creatives must be needed for serving to differentiate the message , inviting audiences to participate more positively in advertising communications This thesis aims at reviewing the absence as an advertising creative. And this thesis is about the significations of the absence. Chapter I describes the aim of this thesis about the absence as an advertising creative And Chapter II introduces the general concept, perception of the absence and its possibilities as an advertising creative And also mentions about the absence as one of paradoxical expressions with rhetorical theories as well as semiotics. Chapter III deals with the signification of the absence with introducing semiotic methods such as the theory of R. Barthes Chapter IV discusses the signification of the absence as an advertising creative talking into consideration of semiotic theories. And I categorize the types of the absence in advertising expressions. The absence is categorized into 5 types in this thesis. Type (1) is the absence of product which is supposed to be advertised, type (2) is the absence of product and make product image located out of main image of an advertising expression for introducing features of a product itself. And type (3) is the absence of the imaginary audience to invite an audience to participate more spontaneously. Type (4) is the absence of headlines, and type (5) is the absence of almost all visual images and verbal message but a corporate symbol or brand logo. The signification of S types of the absence can be described on the basic of semiotic theories, especially the theory of R. Barthes. It's my hope that this thesis about the absence as an advertising creative will serve as the basic theory for the empirical research about advertising expressions containing images of the absence.

• Korean Institute of Interior Design Journal
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• v.17 no.6
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• pp.120-127
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• 2008

Korean space design image is a kind of writing as well as one of the sign that dissembles itself as a direct transcript of what it represents. Moreover it is pictorial representation and notions such as mental and perceptual imaginary. Significance of Iconology lies in how we transform image and the imagination that produces it into power of trust and respect. From this point of view, the process of this study is illustrated as follows: At first, this study search out concept of archetype, collective unconsciousness and collective representation that found principles on basic theory for interpretation of korean space icon. Secondly, it mentions theoretical background of iconological contents and structure. And it clarifies Iconology as a method that is applicable logic for Korean space design. Finally, as an analysis of korean space design, this study analyse in three steps that are pre-iconological description, iconological analysis, iconological interpretation each in terms of modernization at regional korean space design. In the step of the pre-iconological description, it describe visual representative style based on era and place. In the step of the iconological analysis, the typical structure is classified in status, vernacular, ethnic, traditional. In the step of the iconological interpretation, connotation is categorized into allegory, multivalence, potential. Through this process, this study suggest that iconology is an appropriate analysis system of Korean space design images that represent symbols combined with our collective emotion.

• Journal of Mechanical Science and Technology
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• v.18 no.1
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• pp.45-54
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• 2004

In order to meet the requirement for higher thickness accuracy in cold rolling processes, it is strongly desired to have high performance in control units. To meet this requirement, we have considered an output regulating control system with a roll-eccentricity estimator for each rolling stand of tandem cold mills. Considering entry thickness variation as well as roll eccentricity as the major disturbances, a synthesis of multivariable control systems is presented based on H$\sub$$\infty$/ control theory, which can reflect the knowledge of input direction and spectrum of disturbance signals on the design. Then, to reject roll eccentricity effectively, a weight function having some poles on the imaginary axis is introduced. This leads to a non-standard H_ control problem, and the design procedures for solving this problem are analytically presented. The effectiveness of the proposed control method is evaluated through computer simulations and compared to that of the conventional LQ control and feedforward control methods for roll eccentricity.