• Proceedings of the KIEE Conference
• /
• 1999.07f
• /
• pp.2467-2469
• /
• 1999

In this paper. the stability control system of constant output DC-DC converter is composed of considering a ripple source input and a transient variable sinusoidal power. Also, we design I-PD controller and add phase shift controller. Therefore, it is proposed controller that is stable about the input voltage and load alteration and tracking desired value.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1995.03a
• /
• pp.19-30
• /
• 1995

The analysis had been already completed to detect forming defects for the forming processes of C/R bearing rings. But some unpredicted problems were found through the experiments. So expert redesigned new forming processes to prevent the problems and new analysis was began according to the new processes to find faults for the processes. The forming processes consist of 1 for the outer ring. 6 inner ring. The thickness of metal sheet used is changed to 1.5mm from 1.6mm. Elasto-plastric finite element method is applied to involve the effect of spring back . The most representative alteration is forming of two predents to assist later forming . Thining and distribution of high residual stress are derived from the results of simulations. It is confirmed that the industry expert agree the possiblilty of defects dervied from the new FEM results.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.12
• /
• pp.2157-2165
• /
• 2007

A novel design technology for a high frequency electronic ballast for metal-halide discharge lamps is proposed. A PFC technique is adopted to get unit power factor and output frequency alteration technique is adopted to avoid acoustic resonance. For characteristics evaluation, the designed electronic ballast is presented using normalized parameter. To reduce losses of the ballast. ZVS control technique is adopted and the maximum flux density of magnetic core for inductor should be kept lower. The electronic ballast for 250[W] metal-halide discharge lamp is implemented and 96[%] efficiency and low conducted EMI level are accomplished.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 1999.11a
• /
• pp.121-126
• /
• 1999

In this paper, to bring under robust and accurate control of auto-equipment systems which disturbance, parameter alteration of system, uncertainty and so forth exist, neural network controller called dynamic neural processor(DNP) is designed. In order to perform a elaborate task like as assembly, manufacturing and so forth of components, tracking control on the trajectory of power coming in contact with a target as well as tracking control on the movement course trajectory of end-effector is indispensable. Also, the learning architecture to compute inverse kinematic coordinates transformations in the manipulator of auto-equipment systems is developed and the example that DNP can be used is explained. The architecture and learning algorithm of the proposed dynamic neural network, the DNP, are described and computer simulations are provided to demonstrate the effectiveness of the proposed learning method using the DNP.

• Journal of the Korean Home Economics Association
• /
• v.42 no.4
• /
• pp.179-186
• /
• 2004

The purpose of this study was to analyzed factors that influenced the degree of satisfaction difference of domestic and imported theatre costumes. One hundred and fifty theatrical artists were surveyed by questionnaires, and response from 128 was statistically analyzed. The data was analyzed using frequency, and paired t-test with SPSSWIN 10.0. The results were as follows. 1. The degree of satisfaction between domestic and imported theatrical costumes was different significantly. 2. The degree of satisfaction of domestic theatrical costumes was tow in the areas of design, color, fabric, and suitability with a historical background, compared with imported costumes. A major cause of the low degree of satisfaction was the lack of funds and professional theatrical costume designers. 3. The degree of satisfaction of imported theatrical costumes was low in the cost, size, and alteration and mending facilities, compared with the domestic costumes. The problems of size was caused by the shape difference between Koreans and a foreigners 4. further research should be conducted into the theatre costumes suitable for the domestic theatrical artists's size, and body shape.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.13 no.2
• /
• pp.187-187
• /
• 1999

in order to perform a elaborate task like as assembly, manufacturing and so forth of components, tracking control on the trajectory of power coming in contact with a target as well as tracking control on the movement course trajectory of end-effector is indispensable. In this paper, to bring under robust and accurate control of auto-equipment systems which disturbance, parameter alteration of system, uncertainty and so forth exist, neural network controller called dynamic neural processor(DNP) is designed. Also, the learning architecture to compute inverse kinematic coordinates transformations in the manipulator of auto-equipment system is developed and the example that DNP can be used is explained. The architecture and learning algorithm of the proposed dynamic neural network, the DNP, are described and computer simulation are provided to demonstrate the effectiveness of the proposed learning method using the DNP.

• Journal of Technologic Dentistry
• /
• v.21 no.1
• /
• pp.115-121
• /
• 1999

This investing was carried out to evaluate the alteration of stress distribution on teeth and esthetic crowns. Analyzing the stress distribution by the two-dimensional finite element methods, a model of lower 1st molar according to the porcelain fused metal crown an the porcelain fused glass ceramic core crown and the all glass ceramic crown. 1. The pattern of stress distribution showed no apparent differences. 2. The greatest von Mises values were concentrated around the central fossa of all esthetic crowns. The greatest Maximum principle value were concentrated around the interface between the base of esthetic crown and the abutment tooth. It was found that the apatite glass ceramic could be applicable for use in dental crown prosthesis.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.8 no.3
• /
• pp.49-55
• /
• 2012

Recently, with the rapid development of android-based smartphones, it is becomes a major security issue that the case of Android platform is an open platform. so it is easy to be a target of mobile virus penetration and hacking. Even there are a variety of security mechanisms to prevent the vulnerable points of the Android platform but the reason of most of the security mechanisms were designed at application-level that highly vulnerable to the attacks directly to the operating system or attacks using the disadvantages of an application's. It is necessary that the complementary of the android platform kernel blocks the kernel vulnerability and the application vulnerability. In this paper, we proposed a secure system using linux-based android kernel applied to LIDS(Linux Intrusion Detection and Defense System) and applied a smart phone with s5pc110 chip. As a result, the unauthorized alteration of the application was prevented with a proposed secure system.

• Proceedings of the Korean Information Science Society Conference
• /
• 2012.06c
• /
• pp.286-288
• /
• 2012

Facing the counterfeiting acts towards various products, many manufacturers implement ePedigree system to secure their supply chain. Using ePedigree, a distribution history including a valid product identifier from the manufacturer until the final retailer is recorded. And this ePedigree is signed by each involved supply chain party using digital signature. With this digital signature, any unauthorized alteration to the ePedigree document would generate a failed verification process. If there is a counterfeit product using a fake ePedigree document, it wouldn't be able to pass the verification process either. Hence, there wouldn't be any counterfeit product that could enter the legal supply chain and bought by the consumer. We are proposing to use ECDSA instead of RSA since it has faster performance and shorter key size. At a certain same security level, ECDSA only needs 163 bits, while RSA needs 1024 bits.

• Journal of the Semiconductor & Display Technology
• /
• v.21 no.1
• /
• pp.33-38
• /
• 2022

This study investigates the outlet temperature of coolant heater based on heat and flow volume conditions. Through computer simulation, the coolant temperature at the outlet was analyzed to investigate the heat and flow volume conditions of the coolant heater, and the optimal conditions were derived. Results show that heat and flow volume conditions, it was confirmed that heat condition is 0.424 W/mm³, and flow volume condition is 500 l/h, demonstrates optimal conditions. The results of this study can be utilized to efficiently control the coolant temperature through various heat and flow volume conditions.