• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.6
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• pp.544-552
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• 2004

This paper deals with the hybrid active filter which can reduce the 11th/13th harmonics in AC network by using the single tuned filter. Since the proposed algorithm uses the detuning compensation capability of the filter, the output voltage of the proposed active power filter is changed according to the capacitance of capacitors, magnitude of harmonic current, resonance frequency and control mode. In this paper, the control characteristics and the design of hybrid active filter is investigated. A new hybrid active filter with new algorithm, which is an active filter with single tuned filter instead of double tuned filter, is proposed.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.10
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• pp.69-76
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• 2000

Lots of semi-active control devices have been developed in recent years because they have the best features of passive and active system. Especially, controllable magneto-rheological(MR) fluid devices have received significant attention in these area of research. The MR fluid is the material that reversibly changes from a free-flowing, linear viscous fluid to a semisolid with a controllable yield strength in milliseconds when exposed to a magnetic field. If the magnetic field is induced by moving a permanent magnet instead of applying current to a solenoid, it is possible to design a MR damper consuming low power because the power consumption is reduced at steady state. This paper proposes valve mode MR damper using permanent magnetic circuit that has wide range of operation with low power consumption, a design parameter is adopted. The magnetic circuit, material of choke and choke type are selected experimentally with the design parameter. The behaviors of the damper are examined and torque tracking control using PID feedback controller is performed for step, ramp and sinusoidal trajectiories.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.2
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• pp.1-7
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• 2007

Active magnetic bearing has been adopted to support the rotor by electomagnetic force without mechanical contact and lubrication process. A property of the control system for magnetic bearing is improved in accordance with making higher system gain. If the control system has integral part, an excessive overshoot response is shown by making higher integral gain. Therefore, this paper suggests a PID control system in order to eliminate the overshoot at the first stage and improve response characteristics to an impact disturbance at the status of levitation. The control gain was obtained by LQR design method which has the structure of I-PD control system in the state space. The PID control system containing prefilter has the same structure as the I-PD control system. Therefore, the PID control system adopted is able to be tuned by LQR design method. Finally, this paper shows the effect of the prefilter on the active magnetic bearing system through response experiments for levitation responses.

• The Journal of Society for e-Business Studies
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• v.14 no.1
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• pp.35-56
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• 2009

Many process modeling techniques, such as Petri-net, UML Activity Diagram, and EPC, are used to design process models. In this paper, we analyze ubiquitous process design based on workflow patterns. In particular, we focus on process design using active rules that have the form of Event-Condition-Action, and deal with the WS-ECA language, which was devised for ubiquitous web services coordination. We first check whether workflow patterns can be designed with ECA rules, and we then provide WS-ECA representations for ECA rules of the patterns. The contribution of this paper is that ECA rule-based process models were presented based on workflow patterns and they can be a guideline for ubiquitous process modeling.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.4
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• pp.259-267
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• 2019

An active clamp flyback (ACF) converter applies a clamp circuit and circulates the energy of leakage inductance to the input side, thereby achieving a zero-voltage switching (ZVS) operation and greatly reducing switching losses. The switching losses are further reduced by applying a gallium nitride field effect transistor (GaN-FET) with excellent switching characteristics, and ZVS operation can be accomplished under light load with boundary conduction mode (BCM) operation. Optimal design is performed on the basis of loss analysis by selecting magnetization inductance based on BCM operation and a clamp capacitor for loss reduction. Therefore, the size of the reactive element can be reduced through high-frequency operation, and a high-efficiency and high-power-density converter can be achieved. This study proposes an optimal design for a high-efficiency and high-power-density BCM ACF converter based on GaN-FETs and verifies it through experimental results of a 65 W-rated prototype.

• Journal of the Korean Society of Costume
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• v.53 no.6
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• pp.161-173
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• 2003

The purpose of this paper is to classify fashion and trend, and examine how his fashionable philosophy reflects design. What affects his fashion philosophy is Western culture and Paris Revolution. Taking this opportunity, he outgrew the concept of haute couture and established specific fashion philosophy. His fashion philosophy is classified under consideration for women, respect for free emotions, recognition of tradition, and an active intercourse with many people. The characteristics of design through his philosophy are as following: 1. He wanted to release women from clothing restrained the body and make comfortable clothing which everyone can wear. This implies the consideration for women. It is the characteristics of his design to the harmony of functionality, simplicity, decoration and popularity. 2. He respected the free emotions and induced people to wear each parts of clothing which is dismantled freely within the limits coincided with clothing teleology-'wear', It implies autonomy. He also unfolded experimental design: gives the regular space between the clothing and the body and then distorts the body or maximizes modeling. It implies the beauty of space. 3. He elicited the modern design through recognition of tradition. It implies contemporaneousness. 4, As he thought that all of the concepts is based on human, he derived inspiration firm an active intercourse with many people, He established a new style through an active intercourse with artists because if he works alone, he would rise above the popular trend, It comes to the gest artist serieE and implies popularity, The characteristics of design in his fashion philosophy is classified into experimental design and practical design. But the important factor of his fashion philosophy is popularity so he would like to make popular clothing. He designs clothing which fit the public. It results from his firm fashion philosophy that his clothing is practical and decorative and he establishes his works meeting needs of modern. It is the reason that his clothing has perpetuity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.481-482
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• 2014

• Nuclear Engineering and Technology
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• v.43 no.5
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• pp.437-446
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• 2011

Siting criteria for nuclear power plants require that faults be characterized as to their potential for generating earthquakes, or that the absence of the potential for these occurrences be demonstrated. Because the definition of active faults in Korea has been applied by the deterministic method, which depends on the numerical age of fault movement, the possibility of inherent uncertainties exists in determining the maximum earthquake from the fault sources for seismic design. In an attempt to overcome these problems this study suggests new criteria and a probabilistic quantitative diagnostic procedure that could estimate whether a fault is capable of generating earthquakes in the near future.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.196-201
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• 1999

In active control of structures the stroke of a Hybrid Mass Damper is the one of he main constraints of the system because there is limited installation space available in the structure. To design an optimal controller for a HMD system control objective are defined considering these constraints and effectiveness of H-infinity control method with bilinear transform that satisfies the defined objective is examined for the optimum efficiency. Numerical results show that the proposed H-infinity controller satisfies the constraints and provides optimal performance.

• Bulletin of the Korean Chemical Society
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• v.18 no.10
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• pp.1100-1104
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• 1997

Compounds containing a nitrone moiety were designed, synthesized and evaluated as a new type of active site zinc ligating substrate analog inhibitors for carboxypeptidase A. The kinetic results indicated that they are competitive inhibitors for the enzyme, supporting the design rationale that the oxygen of the nitrone forms a coordinative bond to the active site zinc ion. The present study demonstrates that nitrone is useful as a zinc coordinating ligand in the design of inhibitors for zinc containing proteolytic enzymes.