• 한국가시화정보학회지
• /
• 제1권1호
• /
• pp.28-33
• /
• 2003

This paper presents the visualization method in which 3-dimensional(3D) microchannel flow can be detected using a confocal scanning microscope. By soft-lithography, we fabricated various Bio-MEMS(Micro Electro-Mechanical System) devices such as a disposable microchip for a flow cytometer and a micro-mixer, which have 3D structures. Injecting aqueous fluorescent solution in the microfluidic devices, we measured the flow in a steady state by the confocal scanning microscope. At first, we explain the principle of the confocal scanning microscope. And then we show the results from 3D visualization of microscopic flow structures using the confocal scanning microscope.

• 한국가시화정보학회지
• /
• 제1권2호
• /
• pp.3-12
• /
• 2003

This paper describes the general aspects of various visualization techniques employed for marine engineering research including classical naval architecture, ocean engineering and other related topics. Visualization techniques performed mostly by authors' were introduced here, which range from old fashioned methods such as paint and tuft tests to the newly emerging PIV technique and Sonar in broad sense. Brief explanation of each technique was made for the instruction purposes. It is strongly recommended that the interdisciplinary project with experts in other research areas is necessary in order to develop more advanced and profitable techniques.

• 한국가시화정보학회지
• /
• 제10권3호
• /
• pp.37-41
• /
• 2012

Plate-fin heat exchanger is a kind of compact heat exchangers with a good performance in heat transfer. It is widely used in various engineering fields such as aerospace, chemical and biomedical industries. Quantitative and qualitative flow visualization study were performed using the water model of commercial plate-fin heat exchanger with header angles of $30^{\circ}$. The Reynolds number was 100. Conventional digital particle image velocimetry was used to measure the instantaneous velocity fields of the header region and the flow visualization using dye injection and hydrogen bubble method were applied to capture the qualitative flow characteristics. The results showed the existence of separation flow region at the junction area and the bottom wall of the exit region.

• 한국항행학회논문지
• /
• 제14권6호
• /
• pp.975-983
• /
• 2010

본 논문에서는 하노이의 탑 (Tower of Hanoi; ToH) 문제를 확장한 문제들을 소개하고, ToH 문제의 상태 공간을 그래프로 표현하기 위한 새로운 방안을 제시하고자 한다. 확장한 문제들로는 기둥의 수를 늘린 경우, 디스크 스택의 수를 늘린 경우, 그리고 일반 상태 간의 이동에 대한 세 가지를 소개하고, 다른 변종 문제들을 소개하고자 한다. 우리가 본 논문에서 제시한 새로운 표현 방안은 기존의 하노이 그래프 표현에 대해 확장된 방식의 그래프 표현을 제시하는 것이다. 제안된 표현에서는 각 디스크마다 하나의 직교좌표를 부여해 줌으로써 링크의 표시와 상태의 변화가 디스크가 어느 기둥에 배치되어 있는가와 시각적으로 일치된 시각화를 가능하게 해 준다. 제안된 표현을 기존의 하노이 그래프와 비교해 보면, 제안된 표현에서 디스크를 옮길 수 없는 링크를 제거하면 기존의 하노이 그래프와 isomorphic하다. 따라서, 제안된 표현은 기존의 하노이 그래프를 확장하여 표현력을 고도화한 것임을 알 수 있다. 제안된 표현에 대한 독자들의 이해를 돕기 위해, 우리는 본 논문에서 디스크의 개수가 2와 3인 경우에 대한 제안된 표현의 시각화 예를 제시하였다.

• 정보보호학회논문지
• /
• 제27권1호
• /
• pp.147-162
• /
• 2017

IT 환경의 변화 속에서 다양한 서비스와 기기의 출현으로 인하여, IT 규모의 증가와 더불어 데이터의 복잡도가 높아지면서 많은 조직에서 보안 상황 인지를 위한 대량의 데이터 분석 및 처리에 어려움을 겪고 있다. 이에, 조직의 위험관리에 있어서 보안 상황의 인지와 대응이 늦어지는 문제의 해결을 위해, 시각화를 통한 보안 상황 인지 효과의 향상을 제안한다. 이를 위해, 본 연구에서는 시각화와 관련한 다양한 관점에서의 선행 연구를 통해 사용자 유형, 상황 인지 단계, 정보 시각화의 속성 등을 고려하여 효과적 시각화를 위한 평가 요인과 대안을 선정하고 AHP 계층 모델을 수립하였다. 이를 토대로, 다 기준 의사결정 문제의 해결을 위한 AHP 기법을 활용하여 효과적 시각화를 위한 요인과 요인별 대안의 중요도를 산정함으로써, 시각화의 목적 및 사용자 유형에 따라 보안 상황의 인지 효과를 향상할 수 있는 시각화 방안을 제시하고자 한다.

• 대한기계학회논문집A
• /
• 제32권7호
• /
• pp.576-582
• /
• 2008

This paper describes a synthesized photoelastic method developed for the visualization and evaluation of sound pressure distribution of elastic wave in a solid. The visualization of wave stress field is achieved by synthesizing two photoelastic pictures, in which the direction of the principal axis of linear polariscopes differs by $45^{\circ}$. From the analysis of the wave stress distribution using this method, it is possible to evaluate the characteristics of elastic waves in a solid, such as the intensity of stress, directivity and resolution characteristics of the wave emitted from a commercial probe, and characteristics of scattering from various types of defects.

• 한국군사과학기술학회지
• /
• 제5권3호
• /
• pp.33-44
• /
• 2002

In this study, 3-dimensional virtual visualization was performed for a rapid and accurate analysis of sea bottom topography. The visualization was done through the extracted data using the developed program and the generated data using the gridding method. The data extraction program was developed with AutoLISP programming language and this program was able to extract the needed sample bathymetry data from the electronic sea chart systematically as well as effectively The gridded bathymetry data were generated by the interpolation or extrapolation method from the spatially-irregular sample data. As the result of realization for the 3-dimensional virtual visualization, it was shown a proper feasibility in the analysis of the sea bottom topography to determine the route of submarine cable burial.

• International Journal of Fluid Machinery and Systems
• /
• 제1권1호
• /
• pp.148-154
• /
• 2008

The Wells turbine rotor consists of several symmetric airfoil blades arranged around a central hub, and the stagger angle is 90 degrees. These characteristics simplify the total construction of OWC type wave energy converters. Although the Wells turbine is simple, the turbine produces a complicated flow field due to the peculiar arrangement of blades, which can rotate in the same direction irrespective of the oscillating airflow. In order to understand these flows, flow visualization is carried out with an oil-film method in the water tunnel. This research aims to analyze the mechanism of the 3-D flows around the turbine with the flow visualization. The flow visualization explained the influence of attack angle, the difference between fan-shaped and rectangular wings, and the sweep angle.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2001년도 춘계학술대회논문집
• /
• pp.1197-1202
• /
• 2001

Near-field acoustic holography is a powerful tool to visualize sound sources. This method requires pressure measurement at many points for a good hologram. Thus one has to measure carefully so that errors due to the uncertainty of position, sensor mismatch, and so on are reduced. A method to solve this problem is to use a well-designed measurement system. This paper introduces a sound visualization system at center for noise and vibration control (NOVIC), KAIST, and addresses the advantages in terms of the error reduction. The system consists of array microphones, array jigs, a system to control the position and the velocity of the jigs, a data acquisition system, and a monitoring system. This paper also shows some sound visualization results when the system is applied to a speaker and a computer. The results verifies that the sound visualization system is useful for identifying sound sources.

• 한국가시화정보학회지
• /
• 제5권2호
• /
• pp.48-55
• /
• 2007

Flow structure inside a refrigerating compartment of a scale-down display cooler model was investigated experimentally by using PIV (particle image velocimetry) method, a reliable velocity field measurement technique, in the present study. In addition, we also carried out flow visualization regarding flow structure and particle movement inside a display cooler by using a tracer method. As a result, the mean velocity field measurement shows a large scale vortical flow structure inside a refrigerating compartment due to strong entrainment flow, going through a base plate open gaps.