• Journal of the Korean Society of Safety
• /
• v.31 no.4
• /
• pp.143-149
• /
• 2016

In this study, a series of numerical simulation of dam break flow was conducted using EFDC model, and input conditions including cell size, time step, and turbulent eddy viscosity were considered to analyze parameter sensitivity. In case of coarse mesh layout, the propagated length of the shock wave front was ${\Delta}_x$ longer than that of other mesh layouts, and the velocity results showed jagged edge, which can be cured by applying fine grid mesh. Turbulent eddy viscosity influenced magnitude of the maximum velocity passing through gate up to 20% and the cell Peclet number less than 2.0 ensured no numerical oscillations.

• Journal of Multimedia Information System
• /
• v.1 no.1
• /
• pp.87-93
• /
• 2014

The aim of microscopic image restoration is to recover the image by applying the inverse process of degradation, and the results facilitate automated and improved analysis of the image. In this work, we consider the problem of image restoration as a minimization problem of convex cost function, which consists of a least-squares fitting term and regularization terms with non-negative constraints. The finite step method is proposed to solve this constrained convex optimization problem. We demonstrate the convergence of this method. Efficiency and restoration capability of the proposed method were tested and illustrated through numerical experiments.

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.319-322
• /
• 2005

This paper describes practical tuning methods and testing of a digital PSS, which uses both frequency and power, with the 220MVA Chungpyung P/P #1 in the KEPCO system to enhance the damping of local modes. In the first step, the objective phase of PSS is computed through a phase leading function to provide compensation between the exciter reference point and the generator air-gap torque before tuning the PSS's time constants. In addition, eigenvalue analysis was used to determine a range of PSS's gain, whichis the more useful for field testing rather than a single gain value. The Real-Time Digital Simulator was used to verify safe operations of the PSS in the presence of disturbances, such as AVR step and three phase fault.

• Proceedings of the KIEE Conference
• /
• 2005.05a
• /
• pp.269-271
• /
• 2005

EMV was formed in February 1999 by Europay International, MasterCard International and Visa International to manage, maintain and enhance the EMV Integrated Circuit Card Specifications for Payment Systems as technology advances and the implementation of chip card programs become more prevalent. The formation of EMV ensures that single terminal and card approval processes are developed at a level that will allow cross payment system interoperability through compliance with the EMV specifications. A credit card environment of the domestic market adopted the standard Local-EMV to have the compatibility with EMV international standard and the EMV migration have been carried out b,# the step-by-step process. It may be possible to adopt various kinds of cryptographic algorithms, however, RSA public key algorithm is currently used. In this paper, as a public key algorithm for the authentication process, Elliptic Curve Cryptographic algorithm is applied to the EMV process. Implementation results is shown. and the possible changes necessary to accommodate Elliptic Curve Cryrtography is proposed.

• Korean Journal of Medicinal Crop Science
• /
• v.12 no.5
• /
• pp.428-435
• /
• 2004

Alkaloid producing species of plants have long been a major component of the medicinal social and magico-religious aspects of human culture. A diverse array of biological activities has been attributed to different alkaloids including numerous members of benzylisoquinoline family of alkaloids. For biotechnological approaches of alkaloid biosynthesis in poppy family, plant regeneration protocol through somatic embryogenesis or shoot organogenesis is a first step. This paper describes the methods and applications of plant regeneration of poppy family.

• Journal of Institute of Control, Robotics and Systems
• /
• v.18 no.11
• /
• pp.1051-1058
• /
• 2012

The unified lateral control algorithm for automatic valet parking for various types of vehicles is presented and its feasibility is shown experimentally via field tests for the given parking scenario. First, a trajectory generation algorithm for forward driving and backward multi-step parking maneuvers is developed. Then, with consideration of different types of vehicles and operating conditions, a kinematic vehicle model is used and validated using field test data. Using the nonlinear vehicle model, the lateral controller is designed based on dynamic surface control. Finally the proposed lateral control law is validated via hardware-in-the-loop simulations for different types of vehicles and experimentally using a test vehicle through field tests.

• The Journal of Society for e-Business Studies
• /
• v.4 no.2
• /
• pp.161-175
• /
• 1999

CALS is a strategy to share integrated product data through a set of standards to achieve efficiencies in business and operational mission areas. In this paper, we studied current status for CALS standard and then analyzed the case of US DoD. The results can be summarized as implementing for two major standard in defense CALS system. They are STEP and XML. Korea Defense can be used to set direction for CALS standard implementation and standard selection process based on this paper's recommendations.

• Journal of the Korean Geotechnical Society
• /
• v.19 no.5
• /
• pp.243-252
• /
• 2003

Environmental Double Pile method was presented as a device to improve low permeable contaminated soil. EDP is one of the latest technology in a concept of one step process that is applied to low permeable contaminated ground to reutilize the site by enhancing drainage, contaminated remediation, bearing capacity of piles. In order to evaluate on-site applicability of this technology, qualities of EDP's drainage, strength and remediation were assessed through a series of experiments; EDP was verified to achieve remediation and improvement of soft ground.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.36 no.10
• /
• pp.703-712
• /
• 1987

A position detection method for 2 phase bifilar permanent magnet step motors is proposed. The back emfgenerated on 2 phase windings by rotor permanent magnet is calculated using motor terminal voltage and current by analog circuit, and the rotor position output is obtained from tese back emf signals through some logical manipulation circuit. This position detector functionally acts like a 2 channel optical incremental encoder, and it is also shown by experimental results that it works well over wide range of speed or under resonant condition where the rotor rings around the detent position. Its resolution is twice of the number of steps per revolution. Bu software implemented on micro-processor, the reliability of position output is enhanced, detecting and correcting error dut to external and/ or internal noise.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.54 no.1
• /
• pp.47-52
• /
• 2005

This paper presents dimming control system for automotive 35W metal halide discharge(MHD) lamp electronic ballast. HID lamp demands a highly efficient ballast and very complex control circuitry that can control complex transient state in applying to automotive. Therefore, in this paper, a microcontroller-based digital control method for the HID lamp ballast is presented for optimal control that can adapt complex transient state, steady state and various environments. In developed dimming system, the system is designed to control the lamp output voltage step by step(continuous) using microcontroller according to CdS sensor. Therefore the designed dimming control system give good driving condition to diver and realize the power control effectively. The results of the proposed system is verified through various experiment results.