• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1754-1757
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• 2004

For the anti-sway control of traveling cranes, there are several solutions, i.e., by fuzzy control, by optimal control theory, etc. Each of them is reported to be effective. And, H infinity control and $H_2$ control can be also used. However, the full order observer which estimates all states in the controlled object is used in these methods. Therefore, the orders of these controllers are apt to be higher than that of the optimal controller, etc. Because the conventional H2 controller which minimizes $H_2$ norm consists of two parts, that is: feedback gains which make the controlled object stable and the full order observer which estimate those states. If the minimal order observer is used instead of the full order one, the order of the controller can be reduced. In this paper, we propose a new method based on the minimalization of $H_2$ norm using the minimal order observer. And, we confirm the effect of a new $H_2$ controller in the experiments of the anti-sway control of a traveling crane.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.91-98
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• 2017

Previous works for detecting arrhythmia have mostly used nonlinear method such as artificial neural network, fuzzy theory, support vector machine to increase classification accuracy. Most methods require higher computational cost and larger processing time. Therefore it is necessary to design efficient algorithm that classifies PVC(premature ventricular contraction) and decreases computational cost by accurately detecting minimal feature point based on only R peak through optimal R wave. We propose an optimal R wave detection and PVC classification method through extracting minimal feature point in IoT environment. For this purpose, we detected R wave through optimal threshold value and extracted RR interval and R peak pattern from noise-free ECG signal through the preprocessing method. Also, we classified PVC in realtime through RR interval and R peak pattern. The performance of R wave detection and PVC classification is evaluated by using record of MIT-BIH arrhythmia database. The achieved scores indicate the average of 99.758% in R wave detection and the rate of 93.94% in PVC classification.

• Journal of Power Electronics
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• v.9 no.1
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• pp.74-84
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• 2009

The design and implementation of a high performance PID (Proportional Integral & Differential) style controller with zero-phase error tracking property is considered in this article. Unlike a ball screw driven system, the controller in a direct drive system should provide a high level of tracking performance while avoiding the problems due to the absence of the gear system. The stiff mechanical element in a direct drive system allows high precise positioning capability, but relatively high tracking ability with minimal position error is required. In this work, a feasible position controller named 'Unified PID controller' is presented. It will be shown that the function of the closed position loop can be designed into unity gain system in continuous time domain to provide minimal position error. The focus of this work is in two areas. First, easy gain tunable PID position controller without speed control loop is designed in order to construct feasible high performance drive system. Second, a simple but powerful zero phase error tracking strategy using the pre-designed function of the main control loop is presented for minimal tracking error in all operating conditions. Experimental results with a s-curve based position pattern commonly used in industrial field demonstrate the feasibility and effective performance of the approach.

• Korean Institute of Interior Design Journal
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• v.14 no.5 s.52
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• pp.193-204
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• 2005

Design took a radical turn in the 1980's, deconstructing the rigid ideology of the Modernism, often with great humor. Contemporary representable Avant-garde designers, Philippe Starck and Ron Arad brazenly borrowed from the 'historical elements' of previous styles and created bio-morphic forms with whimsical names of furniture. This study is proposed to understand the diversity of contemporary design, by comparing these two furniture designers. It also covers the common factors in contemporary furniture design, and analyzes their individual differences and similarities in design. It helps to plan the foundation of design methods for 21C, and predict and respond to the future as a reference point. Philippe Starck links Romantic Rationalism within Minimal style and Ron Arad links Deconstructivism within High-tech style but both of them pursue of Organic concept design in their furniture through the concept of humanism. They are able to establish a base of contemporary furniture design by adapting new conceptual form, and design process for the general public.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.32 no.1
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• pp.13-23
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• 1983

This paper deals with the three-level PLA constructed by EXCLUSIVE-OR, AND, and OR. (abbreviated as EXANOR). Most PLA circuits have constraints on minimum chip area and minimal input lines. Thus, the reduction of PLA chip area is an important factor in design of logic circuits. In this paper, newly constructed architecture of PLA is proposed and then, its reduction effect is proved theoretically and some of selected examples are illustrated for designing three-level PLA circuits.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.492-495
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• 1995

A simple method to design observers for linear describtor systems with unmeasureable disturbance is represented by the response of a linear free system. The sufficient conditions for the existence of the observer are given. The design procedures of an identify and a minimal order observers are shown, respectively.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.185-188
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• 2005

This paper suggests a control method for efficient topology/parameter evolution in a bond-graph-based GP design framework that automatically synthesizes designs for multi-domain, lumped parameter dynamic systems, We adopt a hierarchical breeding control mechanism with fitness-level-dependent differences to obtain better balancing of topology/parameter search - biased toward topological changes at low fitness levels, and toward parameter changes at high fitness levels. As a testbed for this approach, an eigenvalue assignment problem, which is to find bond graph models exhibiting minimal distance errors from target sets of eigenvalues, was tested and showed improved performance for various sets of eigenvalues.

• 전기의세계
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• v.30 no.8
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• pp.509-516
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• 1981

The optimal control theory is applied to the design of a digital control system for a nuclear reactor. A linear dynamic model obtained at 85% of rated power and a quadratic performance index are used. A minimal order observer used in cascade with the feedback controller is suggested as a state estimator. The total reactor power control is studied in the range of 80% to 100% of rated power, with the steady state and load-following control. The control algorithm considered is suitable for implementation in direct digital control.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.8
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• pp.46-59
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• 1998

This paper presents shape design, surface construction, and cutting path generation for the surface of marine ship propeller blades. A propeller blade should be designed to satisfy performance constraints that include operational speed which impacts rotations per minutes, stresses related to deliverable horst power, and the major length of the marine ship which impacts the blade size and shape characteristics. Primary decision variables that affect efficiency in the design of a marine ship propeller blade are the blade diameter and the expanded area ratio. The blade design resulting from these performance constraints typically consists of sculptured surfaces requiring four or five axis contoured machining. In this approach a standard blade geometry description consisting of blade sections with offset nominal points recorded in an offset table is used. From this table the composite Bezier surface geometry of the blade is created. The control vertices of the Hazier surface patches are determined using a chord length fitting procedure from tile offset table data. Cutter contact points and path intervals are calculated to minimize travel distance and production time while maintaining a cusp height within tolerance limits. Long path intervals typically generate short tool paths at the expense of increased however cusp height. Likewise, a minimal tool path results in a shorter production time. Cutting errors including gouging and under-cut, which are common errors in machining sculptured surfaces, are also identified for both convex and concave surfaces. Propeller blade geometry is conducive to gouging. The result is a minimal error free cutting path for machining propeller blades for marine ships.

• Journal of the Korea Fashion and Costume Design Association
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• v.6 no.1
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• pp.46-54
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• 2004

In this paper, It is examined the patterns of fashion style in the history of subcultural clothing from 1930s to 1960s, focusing on the way each generation resisted the main stream through its styles. The subcultural styles examined and classified in this study are mainly British and American, with a few European and Western Indian styles included. This study understands subcultural style as a way of deviate or resistant expression within a society. The patterns of subcultural styles presented in this study are based on their form of resistance, and they are classified as follows: The pattern is revision, which tries to revise and change the given form by adding new elements. There are two kinds of revision, one is dressing up, which dresses for success, and the other is minimal dressing. Zoot, caribbean, western, teddy boy, rockabilly style are included here. As minimal dressing, there are hipster, beatnik, modernist, mod, rude boy style. In conclusion, it can be said that subcultural style puts the foremost importance on individual freedom. The new and significant development can be found in the fact that subcultural style emerges as a dominating force in our culture. This implies that the energy of a subculture is essential as a formative force of a fashion world.