• 디자인학연구
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• 제20권
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• pp.61-72
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• 1997

본 연구의 목적은 수학적 Model에 대한 이해도 제고와 제품디자인 과정에의 응용방법 및 필요성에 대한 인식 제고, 그리고 입 문자를 위한 가이드라인으로서의 어프로우치 및 응용 방법의 제안에 있다. 연구의 절차 및 방법으로서는, 먼저 제품디자인을 위한 과학적 분석의 방법 및 필요성을 제품디자인의 특성과 디자인 프로세스에 대한 고찰을 통해 강조하였다. 다음은 수학적 Model은 디자인 문제와 어떤가 대응관계에 있는가에 대해 논의하였다. 그리고, 수학적 Model은 제품디자인 과정에 어떻게 응용될 수 있는가에 대하여 검토하였다. 마지막으로는, 앞에서 기술한 내용들을 근거로 하여 초보자를 위한 어프로우치 및 응용의 방법을 제안하였다. 연구의 결과, 다음 몇 가지점이 성과 또는 문제점으로 도출되었다. 첫째, 수학적 Model은 여러 가지 요소가 복잡하게 얽혀 있는 디자인 문제를 정량적, 구조적으로 파악하는데 유용하며, 그 필요성은 특히 디자이너 자신의 결론을 관계자에게 정당화하고 납득시키는 도구로서 이용될 수 있는 점. 둘째, 수학적 Model이 디자인 과정에 능숙하게 응용하기 위해서는 무엇보다 응용 가능한 모든 수학적 Model의 실체를 우선 이해해야 하며, 컴퓨터를 사용하지 않고서는 완전한 방법으로 구사하기가 쉽지 않다는 점. 셋째, 수학적 Model에 사용되는 수학적 Model에는 그 종류가 많고 디자인 문제의 해결에 응용될 수 있는 Model은 디자인 타입과 디자인 프로세스에 따라 각기 다르기 때문에 그 응용의 방법을 한 가지로 표준화하거나 구체적으로 제시할 수 없다는 점. 넷째, 처음으로 수학적 Model에 대해 어프로우치 하는 경우는 약간의 수학적 지식 및 컴퓨터 프로그램에 대한 이해를 바탕으로 하여 디자인 프로세스 단계별 및 디자인 타입에 부합되는 Model을 선택하는 것으로 시작할 수 있다는 점 등.

• Geomechanics and Engineering
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• 제14권1호
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• pp.61-69
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• 2018

The first part shows the optimal contact surface for T-shaped combined footings to obtain the most economical dimensioning on the soil (optimal area). This paper presents the second part of a new model for T-shaped combined footings, this part shows a the mathematical model for design of such foundations subject to axial load and moments in two directions to each column considering the soil real pressure acting on the contact surface of the footing with one or two property lines restricted, the pressure is presented in terms of an axial load, moment around the axis "X" and moment around the axis "Y" to each column, and the methodology is developed using the principle that the derived of the moment is the shear force. The classic model considers an axial load and a moment around the axis "X" (transverse axis) applied to each column, i.e., the resultant force from the applied loads is located on the axis "Y" (longitudinal axis), and its position must match with the geometric center of the footing, and when the axial load and moments in two directions are presented, the maximum pressure and uniform applied throughout the contact surface of the footing is considered the same. To illustrate the validity of the new model, a numerical example is presented to obtain the design for T-shaped combined footings subjected to an axial load and moments in two directions applied to each column. The mathematical approach suggested in this paper produces results that have a tangible accuracy for all problems.

• Journal of Computational Design and Engineering
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• 제2권4호
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• pp.261-267
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• 2015

Free-form blades are widely used in different industries, such as aero-engine and steam turbine. Blades that are damaged during service or have production deficiencies are usually replaced with new ones. This leads to the waste of expensive material and is not sustainable. However, material and costs can be saved by repairing of locally damaged blades or blades with localized production deficiencies. The blade needs to be further machined after welding process to reach the aerodynamic performance requirements. This paper outlines an adaptive location approach of repaired blade for model reconstruction and NC machining. Firstly, a mathematical model is established to describe the localization problem under constraints. Secondly, by solving the mathematical model, localization of repaired blade for NC machining can be obtained. Furthermore, a more flexible method based on the proposed mathematical model and the continuity of the deformation process is developed to realize a better localization. Thirdly, by rebuilding the model of the repaired blade and extracting repair error, optimized tool paths for NC machining is generated adaptively for each individual part. Finally, three examples are given to validate the proposed method.

• 조명전기설비학회논문지
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• 제25권9호
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• pp.8-13
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• 2011

In this paper, a mathematical model of the power LED system including the drive circuit will be presented to control the power LEDs current. Using this mathematical model, the constant current adaptive controller will be designed. A constant current drive circuit for power LEDs will be configured using Buck-type converter. Precise constant current controller design is enabled by presenting the mathematical model of power LEDs including the current driving circuits. Using the mathematical model of power LEDs and its drive circuits, the constant current adaptive controller will be designed to obtain the robustness for the parameter uncertainties. In order to verify the validity of the proposed controller, computer simulations are performed.

• 한국CDE학회논문집
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• 제2권1호
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• pp.11-18
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• 1997

Scientific volume visualization addresses the representation, manipulation, and rendering of volumetric data sets, providing mechanisms for looking closely into structures and understanding their complexity and dynamics. In the past several years, a tremendous amount of research and development has been directed toward algorithms and data modeling methods for a scientific data visualization. But there has been very little work on developing a mathematical volume model that feeds this visualization. Especially, in flow visualization, the volume model has long been required as a guidance to display the very large amounts of data resulting from numerical simulations. In this paper, we focus on the mathematical representation of volumetric data sets and the method of extracting meaningful information from the derived volume model. For this purpose, a B-spline volume is extended to a high dimensional trivariate model which is called as a flow visualization model in this paper. Two three-dimensional examples are presented to demonstrate the capabilities of this model.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.431-431
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• 2000

The modeling of 5-bar linkage robot manipulator dynamics by means of a mathematical and neural architecture is presented. Such a model is applicable to the design of a feedforward controller or adjustment of controller parameters. The inverse model consists of two parts: a mathematical part and a compensation part. In the mathematical part, the subsystems of a 5-bar linkage robot manipulator are constructed by applying Kawato's Feedback-Error-Learning method, and trained by given training data. In the compensation part, MLP backpropagation algorithm is used to compensate the unmodeled dynamics. The forward model is realized from the inverse model using the inverse of inertia matrix and the compensation torque is decoupled in the input torque of the forward model. This scheme can use tile mathematical knowledge of the robot manipulator and analogize the robot characteristics. It is shown that the model is reasonable to be used for design and initial gain tuning of a controller.

• 산업공학
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• 제15권1호
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• pp.40-48
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• 2002

Recently, in the competitive environments, every company recognizes the importance of supply network planning models. However, there are so many problems in correctly applying mathematical model to the real world. Because mathematical modeling packages charge planning managers with understanding the models and responsibility for generating plans, fast and accurate model cannot be generated with ease. In this paper, we design the model management system that helps planning managers flexibly create and modify mathematical models and manage model versions. We implement the system with model base concept.

• 소음진동
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• 제3권3호
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• pp.231-243
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• 1993

The dynamic characteristics of two types of mathematical models for a rigid body suspension system are analyzed and compared in this paper. One is a linearized model which is commonly used in the engine mount system analysis, the other is a nonlinear model which usually applied to the pendulum type system. The typical 3 d.o.f's mathematical model, for convenience, is chosen as a simulation model, because it has fundamental dynamic characteristics of suspension system. Time responses and unbalance responses of the rigid body, transmitted forces and torques are simulated by using the mathematical model. From the results of computer simulation, it is approved that he nonlinear model is valid and the linearized model gives erroneous results in the case of the pendulum type suspension system. In addition, in this study the effects of design change on the dynamic characteristics of the suspension system are investigated. Mount locations, mount angles, lengths, stiffness and damping coefficients of suspension bars are chosen as design parameters.

• 대한조선학회논문집
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• 제45권2호
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• pp.192-201
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• 2008

The design process becomes more difficult due to the increasing complexity of products. Thus, without any proper design experience, designer cannot handle his design problems systematically. Besides, the conventional optimal design method cannot be used effectively at the early design stage, since most design problems must be formulated in terms of objective and constraint functions based on the mathematical concepts of Operation Research. Thus, in this paper, new design concept based on FBS (Function-Behavior-Structure) design model is introduced to help the novice designer formulate the complex design problems systematically into a mathematical form. In this FBS model, function means the designer's new intents designer wants to create for, structure stand for a final product configuration and behaviour is a product's performance. FBS design model is thus rather totally different concept used for formulating design problem, compared with conventional optimal design method. To validate this new FBS model, 330K VLCC design case is performed, and we found, though it is one design example case, that this new design concept could be effectively used for future ship design problems since, during the formulating design problem, the only engineering terminology such as function, structure, and behaviour of design product is used based on the engineering concepts, instead of mathematical terminology such as objective and constraints.

• 유공압시스템학회논문집
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• 제2권4호
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• pp.7-13
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• 2005

This paper presents modeling and ostimator/controller design for the hydraulic system in Vehicle Stability Control(VSC) system. A nonlinear mathematical model of the VSC hydraulic system is proposed and its accuracy is experimentally verified. A brake pressure estimator is then designed based on the derived mathematical model of VSC hydraulic system. And a disturbance observer, which compensates the estimation error between the brake pressure and the computed brake pressure is also designed to enhance the accuracy of the estimator. The proposed controller has the form of a feedback controller and determines explicitly the on/off ratio of valves' driving PWM signals by means of making use of the simplified mathematical model in the VSC hydraulic system. The performance of the designed controller whose feedback signal is generated by the brake pressure estimator is validated through experimental results.