• The Journal of the Acoustical Society of Korea
• /
• v.20 no.4
• /
• pp.62-70
• /
• 2001

Based on the recently developed resonance scattering theory for elastic waves, a relationship between the stress components, which may be measured using ultrasonic transducers, of partial waves scattered from cylindrical fluid scatterer, cavity, and resonance scatterer has been derived. The computed resonance scattered stresses exhibit frequency behaviors similar to the corresponding scattering coefficients: particularly, abrupt changes in phase by 180°near the resonant frequencies. By studying the behavior of pressure in the fluid scatterer, the physics of the theory has been further understood. Using the method studied and developed in this paper, nondestructive characterization of fluid inclusions in elastic media is expected to become more reliable.

• Journal of architectural history
• /
• v.22 no.1
• /
• pp.15-27
• /
• 2013

The purpose of this study is to analyze the changing process in the Ddeulzip of Jinsung Lee clan family. The subject of this study is clan family of Jinsung Lee in Andong Cultural Area. The period of Chosun Dynasty is divided into largely three parts. The establishment process for Jinsung Lee's family is analyzed during early (15~16C) and mid(17~18C) periods, and changing process is analyzed during mid(19~20C) and late periods. The characteristics of early Chosun Ddeulzip is that it made a foundation to construct a Ddeulzip form. Those of mid Chosun period is in their strong will to preserve their ancestral house which is well manifested through the restoration of Taegye's ancestral house. During the late Chosun period, many of the different styles of Ddeulzip were constructed due to the stable environment of both political and economical status. The residential house of Jinsung Lee family that were centered in Yean area include diverse forms for both high and middle class social status. Jinsung Lee family's Ddeulzip is thus considered to bring about the firm foundation as a clan family representing the Andong cultural area through the development of Ddeulzip.

• Journal for History of Mathematics
• /
• v.20 no.4
• /
• pp.61-70
• /
• 2007

Combinatorics, often called the 21 st century mathematics, has turned out a very important subject for the present information era. Modern combinatorics has started from some mathematical works, for example, Pascal's triangle and the binomial coefficients, and Euler's problems on the partitions of integers and Konigsberg's bridge problem, and so on. In this paper, we investigate the origin of combinatorics by looking over some interesting ancient combinatorial problems and some important problems which have started various subfields of combinatorics. We also discuss a little on the role of combinatorics in mathematics and mathematics education.

• Journal of architectural history
• /
• v.24 no.2
• /
• pp.45-54
• /
• 2015

The purpose of this study is to analyze the changing process in the Ddeulzip of Jaeryoung Lee's clan family. The subject of this study is clan family of Jaeryoung Lee in Andong Area. The period of Ddeulzip's changing process is divided into largely three parts. The establishment process and changing process for Jaeryoung Lee's family is analyzed during early (15~16C), mid(17~18C) and late(19~20C) periods. The characteristics of early periods is that it made a main ancestral building of Ddeulzip form. Those of mid Chosun period is in their strong will to preserve their ancestral house. During the late period, many of the different styles of Ddeulzip were constructed due to the stable environment of both political and economical status. The residential house of Jaeryoung Lee family that were centered in Youngduk and Youngyang area include diverse forms for both high and middle class social status. Jaeryoung Lee family's Ddeulzip is thus considered to bring about the firm foundation as a clan family representing the Andong cultural area through the development of Ddeulzip.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.2
• /
• pp.220-223
• /
• 2006

In this paper, we studied about the level controller of optical signal with 40 channels by 4 VOA(Variable Optical Attenuator) with 12 channels. Total 8 microprocessors control 40 chamois for control of optical signal level so that a microprocessor controls 5 channels each. Moreover a microprocessor was added to communicate with outside and transfer instruction to each microprocessor. The output optical signal is measured and VOA is controlled as a result of it. The VOA outputs is inputted into PD(Photo Detector) at once. We could control multi-channel optical signals simply like this.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.3
• /
• pp.38-43
• /
• 2004

This paper describes the construction of a circular polariscope. Generally, a circular polariscope contains four optical elements and a light source. The first element following the light source is called the linear polarizer. It converts the ordinary light into plane-polarized light. The second element is a quarter wave plate which converts the plane-polarized light into circularly polarized light. Following the quarter wave plate, a specimen made of transparent photoelastic material is located in a loading device. The second quarter wave plate is set and the last element is the analyzer. These polarizing elements, two quarter wave plates and two linear polarizing filters, were purchased from the USA. Frames and other structures for holding polarizing filters were machined and assembled to be rotated. Light box, which includes four incandescent lamps and two sodium-vapor lamps, was made. In order to proof the function of the newly built polariscope, Tardy compensation test was applied to a rectangular shaped specimen made of poly-carbonate material (PSM 1). The error of the fringe constant, which was measured by the newly built polariscope, was within 4.4 percent compared to the standard value of this material. It is possible to make a good quality of polariscope if accurate polarizing filters will be used.

• The Journal of the Korea Contents Association
• /
• v.10 no.7
• /
• pp.169-178
• /
• 2010

This paper has conducted a theoretical re-inquiry on Gilles Deleuze' thought about Alfred Hitchcock' film based on the image of thought in relation with the concept and theory about film. So, the purpose of this article is to explore that film can acquire the academic significance as a philosophy including an academic denomination of social science and Arts. According to the findings, Gilles Deleuze appeared that A. Hitchcock used the mental-image which can transform the perception-image, the action-image, and the affection-image in film and make the relation including the way which it is developed between character and event. Also, as the mental-image can change the meaning of film, camera is the essence and mental referent. And the mental-image makes the other images a specific frame, permeates into image and transforms it. This paper sets limits to some problems that Deleuze's thought about film generalizes to filmic theory, but has a importance to inquiry new research as a theoretical introspection for the practical discussion about the relation between film and philosophy.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.14 no.3
• /
• pp.88-96
• /
• 2000

The instantaneous power theory have been considered as efficient theory in recent years, because it is easier to understand numerical representation and more soft to control PWM power converter on $\alpha$-$\beta$ stationary reference frame. From the forgoing theory, with regard to the calculating process of compensating reference current, there are many induced components of current/ power, and these components have consequently influence on physical interpretation of instantaneous power theory. Especially, beginners for studing the instantaneous power theory don't have enough informations for standard waveform of induced $\alpha$-$\beta$ components. Therefore, this paper describes simulation works using MATLAB/SIMULINK for $\alpha$-$\beta$ space trajectories and waveforms of $\alpha$-$\beta$ current and power components, induced from the instantaneous power theory. It is respected that the results in this paper are serviceable as basic information to assist beginner for studing the instantaneous power theory.

• Korea journal of population studies
• /
• v.24 no.2
• /
• pp.47-78
• /
• 2001

The primary purpose of this paper is to critically examine the theoretical and methodological issues in the study of generations. The issues include: 1) the concept of generation: 2) the basis of generational formation: 3) internal differentiation of generations: 4) the boundary problems of generations: 4) the boundary problems of generations: and 5) generational differences and generational conflict. From the investigation of these issues, two conclusions are drawn. Firstly, Mannheim's basic concepts and theoretical frameworks are very useful to understand and explain the social movements and sociocultural changes. Secondly, however, further elaboration and modification of the several concepts and frameworks are needed to deal with the problems of generations in general which are not directly connected to social movements. Several points are suggested to elaborate Mannheim's frameworks, which include the reconceptualization of generation, and introducing the concepts of “generation sects” and “manifest-latent generational conflicts”.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.14 no.2
• /
• pp.171-181
• /
• 2002

Among various numerical methods of wave transformations including wave breaking by structure, models using VOF(Volume Of Fluid) method to trace free surface are getting into the spotlight recently. In order to analyze wave transformations and velocity of the wave fields due to the permeable submerged breakwater(PSB), This study applied VOF method to the two-dimensional wave channel installed line-source to generate waves and added dissipation zone to offer a non-reflective boundary. Hydraulic experiments was performed to obtain the application of two-dimensional numerical wave channel. The results of numerical experiments using the two-dimensional wave channel agree well with the experimental data. It was shown that vortices are formed behind the PSB, and in case of the 2-rowed PSB they also are occurred in between PSBs, strongly non-linear waves are developed on the crown of the PSB, and the direction of velocities in porous media is determined by the shape of free surface.