• 조명전기설비학회논문지
• /
• 제25권1호
• /
• pp.50-58
• /
• 2011

In this paper, potential distribution analysis through the six kinds of case studies examined in the environmental conditions change within a limited space, by the power supply system installed. To interpret the potential distribution using electromagnetic field analysis program and the parameters were state of the ground, the outer wall of the configuration state and the presence of human potential distribution was simulated. Potential distribution analysis, the size of nominal voltage, depending on the impedance of human body to be determined on the impact of surprise decision, but if equipped with appropriate protective equipment can be protected from lightning have been confirmed.

• 한국연소학회지
• /
• 제1권1호
• /
• pp.11-18
• /
• 1996

The stabilization characteristics of diffusion flame formed behind a bluff body with fuel injection slits was experimentally investigated by varying main fuel injection angles and auxiliary fuel injection conditions. The flame stability limits, temperature and length of recirculation zone, direct and schlieren photographs of flames were measured in order to study the stabilization mechanism of the diffusion flame. The results of this investigation are as follows. The stability limits can be improved by the condition of the kind and quanity of the injected auxiliary fuel. The length and temperature decrease with injection of auxiliary fuel, and these phenomena are remarkable when LPG is injected into the recirculation zone. When the LPG is injected into the recirculation zone, flame remains sooty. Fluctuation of fuel and main stream is generated actively by air injection.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
• /
• pp.749-751
• /
• 1998

In this study, the wind-mill type ultrasonic motor was fabricated, and then revolution and temperature characteristics of the ultrasonic motor were measured. Brass metal was pressed with umbrella-type using metal mold, then slot of 4 kind was processed in each of thickness. Among sixteen's ultrasonic motors, heat loss on applied voltage was much at stator of the highest resonant point, but heat loss on applied voltage was almost neglected at the lowest resonant point of stator. The thickener thickness of elastic body, revolution speed was decreased. The more slot of elastic body, revolution speed was increased. Applied voltage was changed from $10V_{max}$ to $100V_{max}$. When applied voltage was under $20V_{max}$, ultrasonic motor was not rotated. When applied voltage was over $90V_{max}$, revolution of ultrasonic motor was saturated. Maximum revolution speed was 510[rpm].

• 대한전기학회논문지
• /
• 제38권12호
• /
• pp.1033-1047
• /
• 1989

A finite element method for the analysis of magnetic fields with hysteresis characteristics is proposed. The method employs Preisach model to describe hysteresis of magnetic material, so that even multi-branch or minor-loop characteristics can be taken into account. The problem can be considered as the analysis of a nonlinear equation where magnetization depends not only on the present value of the magnetic field but also on the past values, and the problem can be solved by the iteration method. Measurements were carried out on soft ferrite EI core for the comparison with computer solution, and good agreements were obtained. is investigated. A theoretical approach to gait study is proposed in which the static stability margins for periodic gaits are expressed in terms of the kinematic gait formula. The effects fo the stride length on static stability are analyzed and the relations between static stability and initial body configurations are examined. It is shown that the moving velocity can be increased to some extent without affecting stability margins for a given initial body configuration. Computer simulations are performed to verify the analysis.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2006년도 추계 학술대회논문집
• /
• pp.20-21
• /
• 2006

Three kinds of jet flows encountered in the practical airframe design phase are discussed in this paper. Firstly, the side jet effect on the cavity flow over the flat plate was investigated. Secondly, the aerodynamic modeling of side jet influence on body-tail configuration was presented. Computational study of the similarity parameters was done to minimize the wind tunnel test. Lastly, supersonic jet impingement on a flat plate surrounded by solid walls was simulated numerically for both axi-symmetric and three-dimensional calculations with moving body method.

• 동력기계공학회지
• /
• 제19권3호
• /
• pp.75-80
• /
• 2015

Typically, robot system configured by articulated robot manipulator with 1 DOF transfer unit is being applied in automotive manufacturing automation process. Especially, 1 DOF transfer unit is necessary to extend workspace of robot manipulator. In this configuration, because transfer unit works only one direction, robot manipulator only works in one side in case of car body painting or sealing automation process. it is necessary three robot manipulator system at least. In this paper, in order to robot manipulator works effectively in car body sealing automation application, we are suggested omni-directional manipulator system and conducted studying on redundancy resolution method to solve manipulability-optimal problem.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 1997년도 추계 학술대회논문집
• /
• pp.81-85
• /
• 1997

The Computer code KAIST-ADD LUFUNS has been developed to solve 3D compressible turbluent flow. This method employs Harten-Yee's modified upwind scheme in the explicit part and Steger-Warming Splitting in the implicit part. Flow past RAE wing-body aircraft has been computed for three different flow conditions. The result have shown good comparision with the experimental data. Baldwin-Lomax turbluence model is used for this computer code.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집A
• /
• pp.144-150
• /
• 2001

Considered is non-symmetric contact traction induced by the tilting of a contact body and/or by a far field bulk tensile load to the other body. The problem is under the regime of plane strain. General profile of the contact end is incorporated and partial slip condition is supposed. As an example contact configuration, an indentation of a punch with rounded corners onto a half plane is studied. The variation of the internal stress field due to the tilting and the bulk tension is investigated. An edge crack problem is analyzed to examine the influence of the non-symmetric traction. It is shown that the tilting of a punch does not influence the behaviour of the crack. Rather, the effect of the bulk tension on the cracking behaviour is found considerable.

• 대한자기공명의과학회:학술대회논문집
• /
• 대한자기공명의과학회 2002년도 제7차 학술대회 초록집
• /
• pp.76-76
• /
• 2002

Purpose： The purpose of this study is to optimize the configuration of body RF coil composed of 4 planar subcoils for low field open MRI. Method： Our low field RE coil is composed of 4 subcoils assumed to be located at both the bottom and top sides of permanent magnet. Each subcoils has 3 main strips. The coil system has mirror inversion symmetry. First, the currents on the strips are obtained by inductance calculation and circuit analysis, Second, all the strips are divided into line strip elements across the strips, the self Inductances of line strip elements and the mutual inductances among the line strip elements are calculated, and current distributions of strip are obtained by circuit analysis, where each strip is considered as parallel combination of line strip elements. Finally all the line strip elements are segmented, magnetic field has been calculated by pseudo electric dipole radiation method, where the current elements are regarded as pseudo electric dipole radiation sources. We have performed above procedures for various configurations of RE coil. The field homogeneity is calculated in the 25 cm DSV.

• 한국음향학회:학술대회논문집
• /
• 한국음향학회 2000년도 학술발표대회 논문집 제19권 2호
• /
• pp.239-242
• /
• 2000

In the present study, the influence of car body structures to the noise and vibration characteristics has been sought. The numerical modal analysis for the body-in-white is employed to predict the vibratory response of structure, and then followed by the experimental modal testing to confirm the validity of the model. Using the results of numerical simulations with the designated modal parameters, the optimal structural configuration has been deduced. Special interests have been paid to the sensitivity of sound quality to the structural integrity. Since the structural integrity has a close relationship to the structure-born noise, the substantially low frequency range, which is far below the frequency range almost barely sensible by human auditory organ but still quite influential to overall impression, is especially examined. The subjective assessment agrees with the objective evaluation by means of traditional sound measures as well as psychoacoustic metrics.