• 대한조선학회논문집
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• 제30권4호
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• pp.17-22
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• 1993

3차원 자유곡면의 교차문제는 기하학적인 방법과 수치적인 방법으로 해결할 수 있으며, 지금까지는 일반적으로 선체형상의 단면을 얻기 위해서 기하학적인 방법인 곡면분할 기법을 사용하여 왔다. 본 논문에서는 할선법, 선형보간법 및 반분법 등 간단한 수치해석 방법들을 사용하여서, Bi-Cubic B-Spline Surface로 표현된 선체형상과 임의의 평면에 의해 교차된 선체 단면형상을 갖는 방법을 수행하여 비교 검토하고자 한다. 곡면간의 교체문제는 임의의 단면형상 파악, 선도작성 및 offset Table 구성에 직접 응용되어진다.

• 대한조선학회논문집
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• 제32권3호
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• pp.29-36
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• 1995

본 연구는 선정된 기준선을 횡단면적 곡선(Sectional Area Curve:SAC)과 NURBS곡선을 사용하여 변환하는 기법을 내용으로 하고 있다. 즉, 선정된 기준선의 광역(global) 선형변환은 횡단면적 곡선의 기하학적 특성을 변형시켜 체계적으로 수행하고, 국소(local) 선형변환은 가중치의 증감과 조정점 이동 등을 통한 NURBS기법을 사용하였으며, 설계자는 이들 변환된 선형의 최종 횡단면적 곡선과 반폭도에서 기본적인 설계요구조건의 만족여부를 검토하게 된다.

• 한국가구학회지
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• 제25권3호
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• pp.165-172
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• 2014

3D form study is one of basic subjects in industrial design education. There are an array of textbooks of visual art, design and architecture, most of which address basic geometrical form study and abstract forms. With the introduction of computerization, current trends are directed to reduce basic form education and students' participation in classes and their accomplishments. This study was intended to develop works under a theme of furniture design with concrete shapes and functions. This study focused on developing relevant process by fusing 3D form study and furniture design which fall into basic design and design studio subjects, respectively. Among 3D form studies, applied were a concept of 3D configuration that explores the relations between surface forms and 3D forms. Furniture design is a challenge to students at beginner or intermediate level in basic design education from initial devising stage to production in kind. To ease high level of difficulties at designing and producing stages, technical education was systematized in the process of conceptualizing, developing idea and production. This type of challenge was carried out during separate semesters, along with a case study done to develop different types of challenges. This study helped students to be motivated and actively participate in classes and well perform advanced form study and technical training from design to actual production.

• 한국공간구조학회논문집
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• 제3권4호
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• pp.77-84
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• 2003

Tensegrity systems are stable structures which are reticulated spatial structures composed of compressive straight members, struts and cables. But there are some difficulties concerning surface stability, surface formation and construction method. One of the ways to solve this problem reasonably is combination of tesile members and rigid members. This structure is a type of flexible strutural system which is unstable initially because the cable material has little initial rigidity. Therefore tensegrity structure need to be introduced to the Initial stress for the self-equilibrated system having stable state. The rigidification of tensegrity systems is related to selfstress states which can be achieved only when geometrical and mechanical requirements are simultaneously satisfied. In this paper, for the stabilization of tesnsegrity structure it is proposed the modified self-equilibrated equation and the range of the various geometrical parameter about unit system. And we generate the model of double layed single curvature arch using the new squew quadruplex unit system.

• 대한기계학회논문집A
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• 제28권12호
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• pp.1845-1855
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• 2004

This paper presents the forward kinematics of the Casing Oscillator that is a construction machine. The Structure of the Casing Oscillator is similar to those of 4 degree-of-freedom mechanisms with a redundancy. With analytical (geometrical) methods, the solutions of the forward position kinematics problem are significantly found by both solving an 8$^{th}$ -order polynomial equation in one unknown variable and using one over-constraint geometrical equation which can be derived under the condition of a redundancy. The proposed forward kinematics has closed-form solutions and allows Auto-Balancing control of the moving platform in real time. Numerical examples are presented and the results are verified by an inverse kinematics analysis.

• BMB Reports
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• 제36권3호
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• pp.243-250
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• 2003

In this paper we investigate (using AM1 semi-empirical as well as HF methods at the STO-3G, 3-21G, 6-31G, 6-$31G^*$ and 6-31+$G^{**}$ level) the conformations, geometrical parameters, Mulliken charges, and solvation effects of the triphosphate form of AZT (AZTTP), as well as the thymidine nucleotide (dTTP) structure. Our calculated geometrical parameters and Mulliken charges, with and without solvation effects, are correlated with recent experimental results.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 춘계학술대회 논문집
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• pp.51-57
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• 2001

In order to estimate attenuation characteristics, nonparametric model is used. Evaluation of this model requires suites of average spectral amplitude data as a function of distance without adopting any assumed parametric forms. Values of Quality factor, Q were estimated for individual frequencies by matrix inversion of S wave amplitude spectra for 21 records of 8 small and intermediate earthquakes (2.7$(1/r)^{1/2}$. The best models for 1/Q values were found to be 0.000453+0.001851/f and 0.000451+0.009261/f, respectively. This results can be compared to the conventional functional form of Q=$af^{b}$ and be used to estimate source spectra and site response.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 춘계학술대회논문집
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• pp.42-45
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• 1997

Weldline movement of tailored blanks originates from two sources, primary and secondary. Primary movement occurs by geometrical reason, that is, just scratched lines on the no-weld blanks move during drawing to be fitted to geometrical change. Secondary movement is induced by the characteristics of tailored blanks itself. The primary movement was mainly dependent on the weldline location and not affected by the type of material. The secondary movement caused by laser welding and/or small strength difference in this study was not dominant compared with primary movement. The formability of tailored blanks always inferior to those of original blanks. This is due to the existence of hardened weld bead. The closer a weldline is to punch corner where drawing is most active, the worse its formability becomes. This is because the weldline prohibits the drawing process. It was confirmed by measuring diagonal length at the blank corner. The mode of fracture was changed form wall break to draw break when the weldling was close to the punch corner.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.585-591
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• 2003

It has been widely known that geometrical or form errors of ball bearings such as ball size error, ball waviness, inner and outer race waviness due to inherent manufacturing imperfection are one of the major sources of uncontrollable non-repeatable run-out (NRRO) vibration in HDD spindle motor. NRRO in HDD is also known to be the primary cause of limiting the storage capacity of HDD. In this paper, We performed vibration analysis for NRRO a ball bearing being used in 3.5" HDD spindle motor. To theoretically estimate NRRO considering the geometrical errors of ball bearing components, a simple three degrees of freedom model was proposed and then vibration analysis for axial and radial NRRO was conducted utilizing the measured geometric imperfection of a bearing with both the waviness magnitude and phase taken into account. Effects of bearing preload and clearance on NRRO was also investigated as an effort to predict their optimum values minimizing bearing NRRO.

• 한국실내디자인학회논문집
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• 제27호
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• pp.28-34
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• 2001

The aim of this study is to understand the composition of plan and the changing aspect of Louis I. Kahn's residential architecture, Louis I. Kahn's spacial composition is characterized by traditional motives and Ecole des Beaux Art which had influenced him. His constituent factors in geometrical form are classified into the propositional system, the cellular multiplication of a special unit, the Poche Space and others. According to the results of this study obtained from above mentioned subjects, it can be concluded that geometrical factors, which constitute space of plan, are totally expressed as a system of order which unites particular ones into whole one.