• International Journal of Automotive Technology
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• 제8권3호
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• pp.299-308
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• 2007

This study proposes a two-layer hierarchical control system that integrates active front wheel steering and four wheel braking torque control to improve vehicle handling performance and stability. The first layer is a robust model matching controller (R-MMC) based on linear matrix inequalities (LMIs), which optimizes an active front steering angle compensation and a desired yaw moment control, and calculates reference wheel slip for the target wheel according to the desired yaw moment. The second layer is a moving sliding mode controller (MSMC) that can track the reference wheel slip in a predetermined time by commanding proper braking torque on the target wheel to achieve the desired yaw moment. Since vehicle sideslip angle measurement is difficult to achieve in practice, a sliding mode observer (SMO) that requires only vehicle yaw rate as the measured input is also developed in this study. The performance and robustness of the SMO and the integrated control system are demonstrated through comprehensive computer simulations. Simulation results reveal the satisfactory tracking ability of the SMO, and the superior improved vehicle handling performance, stability and robustness of the integrated control vehicle.

• 유통과학연구
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• 제19권12호
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• pp.15-22
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• 2021

Purpose: There is still lack of guidance for merchants toward price discount presentations (absolute/relative), especially for consumers in different purchase contexts. Based on the general evaluability theory, this study investigates consumers' preferences for the presentation of discounts in various contexts through experiments. Research design, data and methodology: The relationship between discount presentation and consumers' preference is investigated in Study 1 using a two-factor between-subject design of 2 (purchase type: material vs. experiential) ×2 (discount type: absolute vs. relative). The Moderating effect of thinking mode has been examined in Study 2 via a multi-factor intergroup design of 2 (purchase type: material vs. experiential) ×2 (discount type: absolute vs. relative) ×2 (cognitive load: high vs. low). One-way ANOVA and planned contrast have been performed for analysis. Results: Experiment 1 reveals that consumers prefer absolute discounts rather than relative discounts when in material purchases. However, when in experiential purchases, they are willing to choose relative discounts. Experiment 2 verifies the boundary conditions of matching effect and illustrates the generation of matching effect is determined by thinking mode. Conclusions: Our study enriches the theories of purchase type and thinking mode. Simultaneously, the results provide practical guidance for merchants to formulate the discount presentation and distribution pricing strategies.

• ETRI Journal
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• 제26권4호
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• pp.292-296
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• 2004

In this paper we present a new current-mode electronically tunable universal filter using only plus-type current controlled conveyors (CCCII+s) and grounded capacitors. The proposed circuit can simultaneously realize lowpass, bandpass, and highpass filter functions - all at high impedance outputs. The realization of a notch response does not require additional active elements. The circuit enjoys an independent current control of parameters $\omega_0$ and $\omega_0/Q$. No element matching conditions are imposed. Both its active and passive sensitivities are low.

• 전기학회논문지
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• 제58권8호
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• pp.1592-1594
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• 2009

This paper presents an LMI-based method to design a reduced order output feedback sliding mode controller for a class of uncertain systems. Using LMIs we derive an existence condition of a reduced order sliding mode control law. And we give explicit formulas of the gain matrices. Finally, we give a numerical design example, together with a design algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.439-445
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• 1990

All models of dynamical systems invariably have some measure of uncertainties associated with some of their dynamics. The recent approaches to establish robustness of stabilizing feedback control against the possible uncertainties have a serious limitation, that is their applicability only to the systems that satisfy the matching conditions. Such conditions are rarely met in general applications. If a particular system satisfies the matching conditions, the addition of an actuator will destroy the satisfaction of such conditions. In this paper, we develop robust control algorithm for uncertain multivariable systems in which the matching conditions are not necessarily met. We empoly Lyapunov's second method to derive robust stabilizing controllers which guarantee asymptotic stability against prescribed uncertainties. The derivation consists of transforming the original uncertain system to controllable canonical form and constructing a constant switching surface by designing the closed-loop characteristics as a function of the uncertainties. Numerical examples are discussed as illustrations.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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• pp.455-457
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• 2006

전자기파에 대한 경계조건들의 상호 관계와 등가성을 도파관 스텝 관점에서 고찰한다. 본 연구방법의 명확성을 확인하기 위해 구형도파관 스텝의 특성을 경계조건 관점에서 비교한다. 구형도파관 스텝의 특성은 모드정합법을 기준으로 계산한다. 계산의 명확성을 보기 위하여 수렴 특성 계산과 전자장의 분포를 살펴본다.

• Journal of electromagnetic engineering and science
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• 제18권4호
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• pp.248-253
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• 2018

An electromagnetic boundary-value problem of a tapered rectangular waveguide is rigorously solved based on eigenfunction expansion and the mode-matching method. Scattering parameters of the tapered rectangular waveguide are represented in a series form and calculated in terms of different rectangular waveguide combinations. Computation is performed to analyze reflection and transmission characteristics. Conductor loss by surface current density is also calculated and discussed.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권6호
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• pp.263-267
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• 2004

A new type of interaction circuitry for a broadband gyro-TWT is presented in this paper. A method for the analysis of dispersion characteristics of a periodic structure, which is composed of conducting posts in a rectangular waveguide, is presented. This method utilizes a mode matching technique and equivalent circuit model. The calculated and measured results demonstrate that this periodic structure could be utilized for the interaction circuit of a wide band Gyro-TWT.

• 산업기술연구
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• 제27권B호
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• pp.129-135
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• 2007

In this paper, an modal analysis based on the distribution of the electromagnetic fields on the UWB elliptical patch-slot antenna is presented. We designed the UWB antenna by iterating the dimensional parameters of the antenna as the traditional design method. Then the antenna was carefully analyzed using 3D E-M simulator. The result of the analysis shows that the slot antenna operates on a series of the multi-pole radiations based on TE modes matched to the system impedance. This result gives us an easier method to design the similar antennas, which is the impedance matching to the system impedance after once constructing a proper structure with a series of multi-mode resonances.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.393-399
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• 2018

An electrostatic boundary-value problem of a dielectric-wedge-backed, double-slotted conducting wedge is investigated to analyze an asymmetric coplanar waveguide with an infinite dielectric thickness using the Mellin transform and a mode-matching method. Our theoretical solution based on eigenfunction expansion and residue calculus is a rigorous and fast-convergent series form. Numerical computations are conducted to evaluate the potential field, capacitance, and characteristic impedance for various structures of the asymmetric coplanar waveguide. The computed results show good agreement with the simulated results.