• Journal of the Institute of Convergence Signal Processing
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• v.10 no.2
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• pp.146-150
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• 2009

An Intelligent active roll angle controller design algorithm is discussed. The detailed mathematical formulation and analysis are discussed, and then modeling and design method for active roll angle controller are presented. This paper proposes a design method based upon intelligent robust controller design algorithm to control actively roll angle for improving cornering performance problems. The intelligent robust controller is designed for steady speed driving vehicle system model with representation of steering angle and yaw angular velocity parameters for cornering stability. And the detailed formulation and analysis for the objective vehicle system are investigated.

• Structural Engineering and Mechanics
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• v.85 no.1
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• pp.55-64
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• 2023

Energy-based seismic design and evaluation methods are promising to be involved in the next generation design codes. Accordingly, determining the distribution of earthquake input energy demand among floor levels is quite imperative in order to develop an energy-based seismic design procedure. In this paper, peak floor input energy demands are achieved from relative input energy response histories of several reinforced concrete (RC) frames. A set of 22 horizontal acceleration histories selected from recorded near-fault earthquakes and scaled in time domain to be compatible with the elastic acceleration design spectra of Turkish Seismic Design Code are used in time history analyses. The distribution of the computed input energy per mass values and the arithmetic means through the height of the considered RC frames are presented as a result. It is found that spatial distribution of input energy per mass is highly affected by the number of stories. Very practical yet consistent formulation of distributing the total input energy to story levels is achieved, as a most important contribution of the study.

• Journal of Communications and Networks
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• v.9 no.4
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• pp.419-427
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• 2007

In wavelength-division-multiplexing(WDM) networks a link failure may cause the failure of several high-bit-rate optical channels, thereby leading to large data loss. Recently, various protection and restoration mechanisms have been proposed to efficiently deal with this problem in mesh networks. Among them, dedicated path protection(DPP) is a promising candidate because of its ultra-fast restoration time and robustness. In this work we investigate the issue of planning and optimization of WDM networks with DPP. Integer linear programming(ILP), in particular, is one of the most common exact method to solve the design optimization problem for protected WDM networks. Traditional ILP formalizations to solve this problem rely on the classical flow or route formulation approaches, but both these approaches suffer from a excessively high computational burden. In this paper, we present a variable-aggregation method that has the ability of significantly reducing the complexity of the traditional flow formulation. We compare also the computational burden of flow formulation with variable aggregation both with the classical flow and route formulations. The comparison is carried out by applying the three alternative methods to the optimization of two case-study networks.

• Composites Research
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• v.36 no.2
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• pp.117-125
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• 2023

This paper proposes a new finite element formulation based on enhanced first-order shear deformation theory including the transverse normal strain effect via the mixed formulation (EFSDTM-TN) for the effective thermo-mechanical analysis of laminated composite structures. The main objective of the EFSDTM-TN is to provide an accurate and efficient solution in describing the thermo-mechanical behavior of laminated composite structures by systematically establishing the relationship between two independent fields (displacement and transverse stress fields) via the mixed formulation. Another key feature is to consider the thermal strain effect without additional unknown variables by introducing a refined transverse displacement field. In the finite element formulation, an eight-node isoparametric plate element is newly developed to implement the advantage of the EFSDTM-TN. Numerical solutions for the thermo-mechanical behavior of laminated composite structures are compared with those available in the open literature to demonstrate the numerical performance of the proposed finite element model.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.284-284
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• 1996

Titrated Extract of Centella asiatica (TECA) is a poorly water-soluble extract from the Centella asiatica. Despite excellent wound preparation causes pain due to a low aqueous solubility and high hypertonicity and therefore, the patient's compliance of this drug is low. The objective of this study is to design a formulation of TECA with an improved therapeutic applicability via an adequate solubilization. A mixture of propylene glycol and ethoxylated hydrogenated caster oil achieved an acceptable solubilization of TECA (i.e. 10%) via a formulation of micelle. A preparation of extemporaneous TECA micelle was achieved by a dilution of the original micellar formulation with either water or saline. An estimated distribution of particle size was between 15.9 and 32.6 ㎜. The osmotic pressure of the formulation was found to be much lower than that found In a commercially available injectable (i.e. Madecassole). The erthrocytic hemolysis of micellar solution was lower than that with the conventional dosage form, consistent with the osmotic pressure data. Pain score after an injection of the micellar solution was assessed by the hind-paw writhing test using ICR mice and compared with that found with the conventional injectable. The data indicated that the injection of the micellar solution was a significantly less painful. These results indicated that a micellar solubilization, followed by an extemporaneous dilution, is a novel formulation of TECA with an improved therapeutic applicability.

• The KIPS Transactions:PartB
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• v.9B no.4
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• pp.437-444
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• 2002

There are some important that development of tools to retrieve information by simple operation in large of nave users in the world wide web. In general, query formulation method and operators are variety, not easy to formulate query in information retrieval system or web based retrieval engine. In this paper, we propose "Concept Wizard" to support query formulation with concept term expansion in natural language query information retrieval system. The Concept Wizard are interactively supporting query formulation using thesaurus and Providing plug-in on the web.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.7
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• pp.1234-1242
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• 2003

In this paper we present a simple and efficient robust optimal design formulation for MEMS structures and its application to a resonant-type micro probe. The basic idea is to use the gradient index (GI) to improve robustness of the objective and constraint functions. In the robust optimal design procedure, a deterministic optimization for performance of MEMS structures is followed by design sensitivity analysis with respect to uncertainties such as fabrication errors and change of operating conditions. During the process of deterministic optimization and sensitivity analysis, dominant performance and uncertain variables are identified to define GI. The GI is incorporated as a term of objective and constraint functions in the robust optimal design formulation to make both performance and robustness improved. While most previous approaches for robust optimal design require statistical information on design variations, the proposed GI based method needs no such information and therefore is cost-effective and easily applicable to early design stages. For the micro probe example, robust optimums are obtained to satisfy the targets for the measurement sensitivity and they are compared in terms of robustness and production yield with the deterministic optimums through the Monte Carlo simulation. This method, although shown for MEMS structures, may as well be easily applied to conventional mechanical structures where information on uncertainties is lacking but robustness is highly important.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1254-1261
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• 2003

In this paper we present a simple and efficient robust optimal design formulation and its application to a resonant-type micro probe. The basic idea is to use the Gradient Index (GI) to improve robustness of the objective and constraint functions. In the robust optimal design procedure, a deterministic optimization for performance of MEMS structures is followed by design sensitivity analysis with respect to uncertainties such as fabrication errors and change of operating conditions. During the process of deterministic optimization and sensitivity analysis, dominant performance and uncertain variables are identified to define GI. The GI is incorporated as a term of objective and constraint functions in the robust optimal design formulation to make both performance and robustness improved. While most previous approaches for robust optimal design require statistical information on design variations, the proposed GI based method needs no such information and therefore is cost-efficient and easily applicable to early design stages. For the micro probe example, robust optimums are obtained to satisfy the targets for the measurement sensitivity and they are compared in terms of robustness and production yield with the deterministic optimums through the Monte Carlo simulation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.9
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• pp.1931-1942
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• 2002

In this paper a formulation of robust optimization is presented and illustrated by a design example of vibratory micro gyroscopes in order to reduce the effect of variations due to uncertainties in MEMS fabrication processes. For the vibratory micro gyroscope considered it is important to match the resonance frequencies of the vertical (sensing) and lateral (driving) modes as close as possible to attain a high sensing sensitivity. A deterministic optimization in which the difference of both the sensing and driving natural frequencies is minimized as an objective function results in highly enhanced performance but apt to be very sensitive to fabrication errors. The formulation proposed is to attain robustness of the performance by including the sensitivity of the response with respect to uncertain variables as a term of objective function to be minimized. This formulation is simple and practically applicable since no detail statistical information on fabrication errors is required. The geometric variables, beam width, length and thickness of vibratory micro gyroscopes are adopted as design variables and at the same time considered as uncertain variables because here occur the fabrication errors. A robustness test in terms of a percentage yield by using the Monte Carlo simulation has shown that the robust optimum produces twice more acceptable designs than the deterministic optimum. Improvement of robustness becomes bigger as the amount of fabrication errors is assumed larger. Considering that the magnitude of fabrication errors and uncertainties in a MEMS structure are comparatively large, the present method is illustrated to be a viable approach for a robust MEMS design.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.3
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• pp.316-322
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• 2009

This paper presents an analytical design method of a passive harmonic filter for a three-phase diode rectifier and uses a new transfer function approach in the analysis and design. The transfer function approach derives an analytical formulation of an utility system including passive filters with a basis of Laplace transform and provides a graphical formulation so that a visualized insight into an interaction between individual filter and system response can be attainted. Harmonic impedance, voltage division and current division transfer function are used as a design tool, which makes a calculated filter parameters to satisfy IEEE-519 distortion limits. A simple five-step design procedure is introduced in the filter design, which consists of system analysis, selection of PCC(Point of Common Coupling), filter specification calculation, appropriate filter design for system and filter implementation. Philosophy governing the design procedure is based on a numerical/graphical iterative solution, trial and error with visualization feed-back based on "algebra on the graph". Finally, performance of the designed passive harmonic filter is verified by experiment and shows that 5th, 7th, 9th, 11th and 13th harmonics are decreased within IEEE-519 distortion limits, respectively.