• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.35 no.12
• /
• pp.579-585
• /
• 1986

A Reversed Field Pinch(RFP) Plasma automatically forms the reversed field configuration in a stable state by the self-reversal phenomenon. But this process of formation of the reversed field configuration has a problem that instabilities occur. In order to form a RFP configuration in a stable state by removing instabilities, this experimental study attempts to restrain Toroidal magnetic fields and supplement Toroidal flux by employing high frequency rotating fields. As a result, the reversed magnetic field configuration is stably formed in a short period because high frequency rotating fields can deflect poloidal currents and produce magnetic fields in the Toroidal direction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.288-288
• /
• 2010

In this study radio rotatiing field is used in order to form the stable reversed field configuration. The experimental study removing the flux conserving ring not so as to conserve toroidal flux, it was found that there occurred a rapid formation of a stable reversed field configuration, in which toroidal flux was increased shaping reversed field configuration and F-$\Theta$ locus traced close to BFM because it started below F value.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.12
• /
• pp.1673-1678
• /
• 2015

This paper describes magnetic field on power cable in underground transmission systems. Based on specification which is being used in domestic power utility, magnetic field was analyzed in accordance with line arrangement, line burial depth and phase spacing. Magnetic field magnitude and its trend were understood in each circuit type such as double circuits, triple circuits and quadruple circuits of underground transmission systems. In addition, magnetic field was analyzed according to phase arrangement changing in each circuit. Finally, the proper phase arrangement configuration type was suggested by the evaluation of analysis result. Magnetic field was calculated by using Biot-Savart's law. According to the evaluated magnetic fields based on phase layout configuration in each circuit, it figured out that each of magnetic fields was different. As a result, this paper proposes a proper phase layout configuration for generating minimum magnetic field. It is evaluated that the phase layout configuration in each circuit proposed in this paper can be used at actual underground transmission systems.

• The Bulletin of The Korean Astronomical Society
• /
• v.35 no.2
• /
• pp.49.2-49.2
• /
• 2010

In order to understand the configuration of magnetic field producing a solar penumbral microjet that was recently discovered by Hinode, we performed a magnetohydrodynamic simulation reproducing a dynamic process of how that configuration is formed in a modeled solar penumbral region. A horizontal magnetic flux tube representing a penumbral filament is placed in a stratified atmosphere containing the background magnetic field that is directed in a relatively vertical direction. Between the flux tube and the background field there forms the intermediate region in which the magnetic field has a transitional configuration, and the simulation shows that in the intermediate region magnetic reconnection occurs to produce a clear jet- like structure as suggested by observations. The result that a continuous distribution of magnetic field in three-dimensional space gives birth to the intermediate region producing a jet presents a new view about the mechanism of a penumbral microjet, compared to a simplistic view that two field lines, one of which represents a penumbral filament and the other the background field, interact together to produce a jet. We also discuss the role of the intermediate region in protecting the structure of a penumbral filament subject to microjets.

• Korean Journal of Computational Design and Engineering
• /
• v.13 no.4
• /
• pp.305-313
• /
• 2008

A configuration management system was implemented by applying PLM to the defense field. The PLM system has recently been incorporated in a wide range of industries, and it has allowed for improvements in work productivity and expansion of related services by comprehensively managing and securing connection regarding configuration information in the defense field. Implementations include acquisition of configuration related information and reinforcement of BOM-oriented configuration management function, securing compatibility among 3D drawings of different agencies, improvement of drawing and document management functions, comprehensive systematic configuration management focused on product structure, strengthened configuration control functions, a management system according to the work flow and life cycle functions, an integrated configuration management system of 3D model CAD resources and an enhanced management system. This paper covers a case study reviewing the implementation of a PLM-based configuration management information system and its results, so that the information can be made available to other agencies and companies seeking to apply PLM in their organizations.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.4
• /
• pp.362-367
• /
• 2011

The collision-free path of a manipulator should be regenerated in the real time to achieve collision safety when obstacles or humans come into the workspace of the manipulator. A probabilistic roadmap (PRM) method, one of the popular path planning schemes for a manipulator, can find a collision-free path by connecting the start and goal poses through the roadmap constructed by drawing random nodes in the free configuration space. The path planning method based on the configuration space shows robust performance for static environments which can be converted into the off-line processing. However, since this method spends considerable time on converting dynamic obstacles into the configuration space, it is not appropriate for real-time generation of a collision-free path. On the other hand, the method based on the workspace can provide fast response even for dynamic environments because it does not need the conversion into the configuration space. In this paper, we propose an efficient real-time path planning by combining the PRM and the potential field methods to cope with static and dynamic environments. The PRM can generate a collision-free path and the potential field method can determine the configuration of the manipulator. A series of experiments show that the proposed path planning method can provide robust performance for various obstacles.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.287-287
• /
• 2010

In the study in which magnetic flux was conserved by the flux conserving ring, it was found that the field configuration produced by providing radio field was unstable, and the reserved field configuration was not because the instability could not be controlled not be controlled when MHD instability of plasma become high.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1991.04a
• /
• pp.46-58
• /
• 1991

An upper-bound method is applied to determine the final-stage extrsuion load and the deformed configuration of extruded billet. A simple kinematically admissible velocity field for trhee-dimensional deformation at final-stage is proposed. From the proposed velocity field the upper-bound extrusion load, the velocity distribution and the configuration of extruded billet are determined byminimizing the otoal power consumption. Experiments are carried out with full-annealed commercial aluminum billets at room temperature by using different sizes of elliptic punches. The theroretical predictions both in extrusion load and deformed configuration of extruded billet are ingood agreements with the experimentalresults.

• Journal of the Optical Society of Korea
• /
• v.13 no.2
• /
• pp.184-192
• /
• 2009

There are total eight degrees of freedom in designing a three-mirror system. If we correct four kinds of third order aberrations and the system should have the specified effective focal length, the remaining three degrees of freedom can be used for selecting a suitable configuration for a specific application. We suggest an analytic design procedure for a three-mirror telescope system which has a suitably sized secondary mirror and proper separations between mirrors, and is corrected for four kinds of third order aberrations, spherical aberration, coma, astigmatism, and field curvature. Two design examples are shown. One has a compact configuration with off-axial field, the other has relatively long configuration with annular ring field.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1997.04a
• /
• pp.192-198
• /
• 1997

In the concurrent engineering, the CAD-based design model is necessary for multidisciplinary analysis and for computer-aided manufacturing (CAM). A shape and configuration design velocity field computation of structure has been developed using a computer-aided design (CAD) tool, Pro/ENGINEER. The design Parameterization with CAD tool is to characterize the change in dimensions and movements of geometric control points that govern the shape/orientation of the structural boundary. The boundary velocity is obtained by using a CAD-based finite difference method and the domain velocity field is obtained from finite element analysis (FEA) using the boundary displacement method. In this paper, the continuum configuration DSA for NVH problem, which requires the shape velocity field and the orientation velocity field at the same time, is developed using linear shape functions. For validation of continuum design sensitivity coefficients, design sensitivity coefficients are compared with the coefficients computed using by the finite difference method.