• Journal of Power Electronics
• /
• v.8 no.3
• /
• pp.275-279
• /
• 2008

An LLC series resonant converter has many unique characteristics and improvements over PWM topologies. However, many output capacitors are needed in parallel to satisfy output voltage ripple and the rated ripple current of the capacitors. This paper deals with a novel two phase interleaved LLC resonant converter using a phase of the resonant capacitor. The proposed converter can satisfy output voltage ripple and a rated ripple current of capacitors with few output capacitors, relatively. The operation and features are considered in detail and a prototype with a 12V-100A output is investigated.

• Bulletin of the Korean Mathematical Society
• /
• v.55 no.3
• /
• pp.819-835
• /
• 2018

Let $f=h+{\bar{g}}$ be a normalized harmonic mapping in the unit disk $\mathbb{D}$. In this paper, we obtain the sharp radius of univalence, fully starlikeness and fully convexity of the harmonic linear differential operators $D^{\epsilon}{_f}=zf_z-{\epsilon}{\bar{z}}f_{\bar{z}}({\mid}{\epsilon}{\mid}=1)$ and $F_{\lambda}(z)=(1-{\lambda)f+{\lambda}D^{\epsilon}{_f}(0{\leq}{\lambda}{\leq}1)$ when the coefficients of h and g satisfy harmonic Bieberbach coefficients conjecture conditions. Similar problems are also solved when the coefficients of h and g satisfy the corresponding necessary conditions of the harmonic convex function $f=h+{\bar{g}}$. All results are sharp. Some of the results are motivated by the work of Kalaj et al. [8].

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 1999.03a
• /
• pp.307-313
• /
• 1999

This paper reviews and assesses the analogy between the human immune system and network intrusion detection systems. The promising results from a growing number of proposed computer immune models for intrusion detection motivate this work. The paper begins by briefly introducing existing intrusion detection systems (IDS's). A set of general requirements for network-based IDS's and the design goals to satisfy these requirements are identified by a careful examination of the literature. An overview of the human immune system is presented and its salient features that can contribute to the design of competent network-based IDS's are analysed. The analysis shows that the coordinated actions of several sophisticated mechanisms of the human immune system satisfy all the identified design goals. Consequently, the paper concludes that the design of a network-based IDS based on the human immune system is promising for future network-based IDS's

• Journal of Power System Engineering
• /
• v.15 no.4
• /
• pp.11-18
• /
• 2011

A Shock absorber is one of the most important components in vehicle suspension systems. In general, many repeated analyses are required for the design of a shock absorber to satisfy the suspension characteristics of a specific automobile, like fluid flow analysis and mechanical analysis. The purpose of this study is to develop a fast design tool for shock absorber designers. One of the efficient solutions for this can be an empirical design method considering phenomenological effects from the shock absorber design variables. In order to extract the shock absorber's experimental characteristics, we used Taguchi method. This method showed that which design variables have major effects for the shock absorber's damping characteristics. This empirical design method also showed the direction of the design changes to satisfy the designer's intension.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.5 no.1
• /
• pp.52-59
• /
• 2012

The bone material is a composite material consisted of collagen and mineral crystals. Also it shows transversely isotropic symmetry. So far none has shown that the components of the elasticity tensor satisfy the Voigt and Reuss bounds. To determine the effective elastic constant of bone material, the Voigt and Reuss bounds are employed and we show that the components of the elasticity tensor satisfy the Voigt and Reuss bounds. Mathematically this bounds are satisfied on two conditions only out of four conditions.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.7
• /
• pp.196-202
• /
• 1999

Recent trend changes a criterion for evaluation of burner that environmental problem is raised as global issue. For efficient driving problem, the higher thermal efficiency and the lower oxygen in exhaust gas, burner is evaluated the better. For environmental problem, burner must satisfy $NO_{X}$ limit and CO limit. Consequently, 'good burner' means on whose thermal efficiency is high under the constraint of $NO_{X}$ and CO consistency. To make existing burner satisfy recent criterion, it is highly recommended to develop feedback control scheme whose output is the consistency of $NO_{X}$ and CO. This paper describes development of real time flame diagnosis technique that evaluate and diagnose combustion state such as consistency of components in exhaust gas, stability of flame in quantitative sense. This study focuses on wave length of luminescence from chemical reaction measurement of the luminescence via optical measuring apparatus and derive correlation with consistency of components in exhaust gas by image processing technique.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.34 no.3
• /
• pp.71-84
• /
• 2009

This paper considers a remanufacturing and purchasing planning problem, in which either used products(or wastes) are remanufactured or remanufactured products(or final products) are purchased to satisfy dynamic demands of remanufactured products over a discrete and finite time horizon. Also, as remanufactured products are purchased more than or equal to a special quantity Q, a discount price policy is applied. The problem assumes that the related cost(remanufacturing and inventory holding costs of used products, and the purchasing and inventory holding costs of remanufactured products) functions are concave and backlogging is not allowed. The objective of this paper is to determine the optimal remanufacturing and purchasing policy that minimizes the total cost to satisfy dynamic demands of remanufactured products. This paper characterizes the properties of the optimal policy and then, based on these properties, presents a dynamic programming algorithm to find the optimal policy. Also, a network-based procedure is proposed for the case of a large quantity of low cost used products. A numerical example is then presented to demonstrate the procedure of the proposed algorithm.

• Journal of the Korean Society of Systems Engineering
• /
• v.5 no.1
• /
• pp.67-72
• /
• 2009

User Requirements are analyzed and quantified by decision making models and system engineering methods to select alternative concepts which satisfy the various requirements. In this study, the design concepts for guided missile are derived using Quality Function Deployment(QFD) and Analytic Hierarchy Process(AHP). The design alternatives that satisfy the user requirements are extracted by QFD and Morphological Matrix, then the best design concept are obtained using AHP and Pugh concept Selection.

• Proceedings of the KIEE Conference
• /
• 2007.11c
• /
• pp.70-73
• /
• 2007

Many methods have been developed to overcome the PAPR(peak-to-average power ratio) problem. Selective mapping(SLM) partial transmit sequence(PTS), subblock phase weighting(SPW) and gradient descent(GD) are used widely to reduce the PAPR. In this paper, we present a effective PAPR reduction method, decrease the calculation through Radix-2 DIF IFFT procedure and GD method. and can transmit selecting data sequence that satisfy threshold value as one part of proposed method, in case satisfy fixed threshold value, or transmit selecting data sequence with the lower papr operating remained part for performance improvement.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.526-528
• /
• 2008

LLC series resonant converter has many unique characteristics and improvement over PWM topologies. However, many output capacitors should be needed in parallel to satisfy an output voltage ripple and a rated ripple current of the capacitors. This paper is deal with a novel two phase interleaved LLC resonant converter using a phase of the resonant capacitor. The proposed converter can satisfy output voltage ripple and a rated ripple current of capacitors with few output capacitors, relatively. The operation and features is considered in detail and a prototype with a 12V-100A output is investigated.