• Steel and Composite Structures
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• 제2권3호
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• pp.209-222
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• 2002

This paper describes the buckling phenomenon of a tubular truss with unsupported length through a full-scale test and presents a practical computational method for the design of the trusses allowing for the contribution of torsional stiffness against buckling, of which the effect has never been considered previously by others. The current practice for the design of a planar truss has largely been based on the linear elastic approach which cannot allow for the contribution of torsional stiffness and tension members in a structural system against buckling. The over-simplified analytical technique is unable to provide a realistic and an economical design to a structure. In this paper the stability theory is applied to the second-order analysis and design of the structural form, with detailed allowance for the instability and second-order effects in compliance with design code requirements. Finally, the paper demonstrates the application of the proposed method to the stability design of a commonly adopted truss system used in support of glass panels in which lateral bracing members are highly undesirable for economical and aesthetic reasons.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.911-917
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• 2017

There are generally three folds when developing neural network classifiers. They are as follows: 1) discriminant function; 2) lots of parameters in the design of classifier; and 3) high dimensional training data. Along with this viewpoint, we propose space search optimized polynomial neural network classifier (PNNC) with the aid of data preprocessing technique and simultaneous tuning strategy, which is a balance optimization strategy used in the design of PNNC when running space search optimization. Unlike the conventional probabilistic neural network classifier, the proposed neural network classifier adopts two type of polynomials for developing discriminant functions. The overall optimization of PNNC is realized with the aid of so-called structure optimization and parameter optimization with the use of simultaneous tuning strategy. Space search optimization algorithm is considered as a optimize vehicle to help the implement both structure and parameter optimization in the construction of PNNC. Furthermore, principal component analysis and linear discriminate analysis are selected as the data preprocessing techniques for PNNC. Experimental results show that the proposed neural network classifier obtains better performance in comparison with some other well-known classifiers in terms of accuracy classification rate.

• 한국정밀공학회지
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• 제23권11호
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• pp.78-84
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• 2006

The objective of this study is to design the optimal die profile that can prevent material fracture in the tube drawing process for automobile steering input shaft. First, the CDV(Critical Damage Value) of material is obtained by the compression test and FE-analysis. The occurrence of fracture is estimated by the FE-analysis considering the CDV. In order to achieve the objective of this study, optimization technique and FE-analysis are applied. FPS(Flexible Polyhedron Search) method, which is one of the non-gradient optimization techniques often used in engineering, is used to search optimal die profile. The drawing die profile is represented by Bezier-curve to generate all the possible die profile. Using FPS method and FE-analysis the optimal drawing die profile is determined. To verify tile effectiveness of the redesigned optimal die, the tube drawing experiment is performed. In the experimental result, it is possible to produce sound product without material fracture using the redesigned optimal die.

• 한국해양공학회지
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• 제28권6호
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• pp.546-551
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• 2014

This paper addresses a feedback linearization control problem for the nonlinear dynamics of an underwater glider system. We consider the buoyancy and moment as control inputs, which come from the mass variation and elevator control, respectively. Moment-to-force coupling increases the nonlinearities, which make the controller design difficult. By using a feedback linearization technique, we convert the nonlinear underwater glider to an equivalent linear model and design a linear controller. The controller for the equivalent converted linear system is designed using sufficient conditions in terms of linear matrix inequalities. Then, the control input of the nonlinear model of an underwater glider is formulated from the linear control input. An experimental examination is implemented to verify the effectiveness of the proposed technique.

• 복식
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• 제55권4호
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• pp.29-37
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• 2005

Beauty Art is an act which makes a face beautiful using various methods such as permanent, manicure and make-up. Recently, Beauty Art is recognized as the personal culture expressing the value of beauty and spirit. Therefore, there are growing interests in the comprehensive study of Beauty Art nor only from the beauty industries but also from academia, because Beauty Art is the high value-added field and Is recognized as a style of the dress. The purpose of this study is to open a new view to understand the Nail Art as a fold of experimental plastic art. The arctic expression is added to Beauty Art to develop it from the routine technique of the make-up and hairstyling to creative art. Assemblage is adopted to provide Beauty Art with fine harmonious expression which develop Nail Art into interesting and unique art area. Assemblage meaning compounding or collection is a technique through which three-dimension is added to two-dimension paintings, and which is an expression of an art work by recollection of miscellaneous articles or waste materials. Assemblage is a term which Jean Dubuffet coioned first in order to differentiate collage used by Picaso or Braque. Here, I present Nail Art Designs which applied Jean Dubuffet's works focusing on Automaticity and Happenstantial phenomena of materials, Materialization, and Directness. These features are characteristics of Assemblage which basic frameworks are fantastic collection, accumulation, constructive collection, and object collection.

• 한국자동차공학회논문집
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• 제24권3호
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• pp.273-278
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• 2016

This study makes a relative comparison of the results of tensile test and quasi-static analysis using AGL(Adjuster Guide Loop) model that plays a role in adjusting the height of shoulder belt, of the components of the vehicle seatbelt system and attempts to propose a method of reducing the error rate of the quasi-static analysis technique effectively. This study selects two major factors affecting the result of an analysis, draws the result of analysis through the method of experimental design, one of the statistical techniques and understands the contribution rate of the major factors affecting the result of the analysis through ANOVA(Analysis of Variance).

• 한국산학기술학회논문지
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• 제8권2호
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• pp.245-249
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• 2007

본 논문은 핵발전소의 초음파 비파괴 평가를 수행하기 위하여 핵발전소 설비의 초음파 비파괴 평가시 발생될 수 있는 스펙클 잡음을 억제하고 디컨벌루션 기법을 이용하여 결함의 정확한 위치 및 크기를 추정할 수 있는 영상 처리 기법을 제안하였다. 제안된 방법은 실제 핵발전소의 증기발생기 파이프라인으로 만들어진 시편을 이용하여 영상의 선명도를 확인 할 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.610-615
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• 2005

Visual servoing is the fusion of results from many elemental areas including high-speed image processing, kinematics, dynamics, control theory, and real-time computing. It has much in common with research into active vision and structure from motion, but is quite different from the often described use of vision in hierarchical task-level robot control systems. We present a new approach to visual feedback control using image-based visual servoing with the stereo vision in this paper. In order to control the position and orientation of a robot with respect to an object, a new technique is proposed using a binocular stereo vision. The stereo vision enables us to calculate an exact image Jacobian not only at around a desired location but also at the other locations. The suggested technique can guide a robot manipulator to the desired location without giving such priori knowledge as the relative distance to the desired location or the model of an object even if the initial positioning error is large. This paper describes a model of stereo vision and how to generate feedback commands. The performance of the proposed visual servoing system is illustrated by the simulation and experimental results and compared with the case of conventional method for dual-arm robot made in Samsung Electronics Co., Ltd.

• 한국실천공학교육학회논문지
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• 제5권1호
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• pp.20-27
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• 2013

카운터 밸런싱은 산업현장에서 중량물을 들어 올리거나 운반하는 경우에 부하의 기하학적 형상에 따라 액추에이터에 작용하는 부하가 저항상태로부터 오버러닝 상태로 변화될 때 부하를 안전하게 제어하는 기술이다. 산업현장에서 매우 빈번히 사용되는 기술임에도 불구하고 국내 외에서 설계의 기준이나 실습장치가 없다. 이에, 본 연구에서는 카운터 밸런싱 실습장치 개발에 필요한 아이디어를 내고, 시스템 모델링과 시뮬레이션을 통하여 설계 파라미터를 도출하고 시제품을 제작하여 이 아이디어를 구현하였으며 실험을 통하여 본 실습장치의 유용성을 확인하였다. 본 연구를 통해 개발된 실습장치를 활용하면 학생들이 산업현장에서 만나게 될 카운터 밸런싱 장치의 이해에 큰 도움을 줄 것이라고 기대된다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권4호
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• pp.179-187
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• 2001

In recent years, the switching source devices have the advantage of small, light and high reliability with the high-frequency. But, high-frequency switching has disclosed disadvantage of result from stress and turn-on and turn-off peak losses at the switching instant. Accordingly, in this paper propose ZVS-HB type high-frequency resonant DC/DC converter using soft switching technique (Zero-Voltage-Switching, Zero-Current-Switching) with safety operating of circuit at diving on inductive zone, through the circuit design example using the capacitor $C_3,\;C_4$ with soft switching function and division characteristic of resonant Capacitor C, $C_1,\;C_2$, and, the characteristic analysis of circuit is generally described using normalized parameters. Also, this paper certified a rightfulness of characteristic analysis in comparison with a theoretical values and a experimental values obtain from experiment using MOSFET.