ezier Control Points for the Image of a Domain Curve on a Bezier Surface

Algorithms to find the Bezier control points of the image of a Bezier domain curve on a Bezier surface are described. The diagonal image curve is analysed and the general linear case is transformed to the diagonal case. This proposed algorithm gives the closed form solution to find the control points of the image curve of a linear domain curve. If the domain curve is not linear, the image curve can be obtained by solving the system of linear equations

MASKLESS LITHOGRAPHY USING RASTERIZATION OF MASSIVE POLYGONS

본 발명에 따른 마스크리스 노광 방법은 다수의 포인트 광들을 이용하여 기판을 노광시키기 위해, 입력된 패턴에서 반복되는 패턴 인스턴스를 추출하고, 패턴 인스턴스 내의 폴리곤을 스캔 방향에 평행하게 세분하여 슬라브들을 생성하며, 패턴 인스턴스 내에서, 포인트 광이 지나는 매 스캔 라인마다, 포인트 광이 점등되는 구간인 스캔 조각들을 상기 슬라브들로부터 계산하고, 스캔 조각들의 위치 정보를 가지는 스캔 데이터를 생성한다. 마스크리스 노광 방법은 스캔 데이터 중에서 점등 위치 정보를 반올림 처리하여 래스터화된 스캔 데이터를 생성하는 단계를 더 포함하고, 이렇게 래스터화된 스캔 데이터에 따라 다수의 포인트 광들이 이동 및 점멸함으로써 기판을 노광시킨다

An efficient polygonal chain intersection algorithm

Presented in this paper is an algorithm for finding all intersections among polygonal chains with an O((n + k) log m) worst-case time complexity, where n is the number of line segments in the polygonal chains, k is the number of intersections, and m is the number of monotone chains. The proposed algorithm is based on the sweep line algorithm. Unlike the previous polygonal-chain intersection algorithms that are designed to handle special only cases, such as convex polygons or C-oriented polygons, the proposed algorithm can handle arbitrarily shaped polygonal chains having selfinter sections and singularities (tangential contact, multiple intersections). The algorithm has been implemented and applied to 1) testing simplicity of a polygon, 2) finding intersections among polygons and 3) offsetting planar point-sequence curves

단면곡선의 궤적을 고려한 곡선망 보간곡면 형성

Curve-net interpolation surface is one of the most popular method in engineering design. Therefore it is supported with many commercial CAD/CAM system. However, construction algorithm of curve-net interpolation surfaces is rarely opened to the public because of its copy-right. In this paper we establish a construction algorithm of curve-net interpolation surface so called sweeping surface which especially concentrates on trajectory of cross-section curve. We also show the method which can construct sweeping surfaces as NURB or Bezier mathematical models. Surfaces having the form of standard mathematical models are very useful for the application of joining, trimming, blending etc. The proposed surface interpolation scheme consists of four steps; (1) preparation of guide curves and section curves, (2) remeshing guide curves and section curves, (3) blending section curves after deformation, and (4) determination of control points for sweeping surface using gordon method. The proposed method guarantee $G^1$-continuety, and construct the surface salifying given section curves and trajectory of section curves

Activity-oriented Modeling of Mass Production System

Described in this paper is a modelling methodology for mass production system simulation. The mass production system under consideration consists of various types of flow lines, special purpose production facilities, conveyor lines, palletized carts, and storage facilities. This type of production system is typical in home appliance industry, automobile industry, footwear industry, etc. where a variety of product mix are mass-produced. The modelling methodology is based on the "discrete-event formalism", and an "activity-oriented world view" is adopted to formalize the system description. A distinctive feature of the modelling methodology is that only the static structure (ie, system components) is included in the fixed model. The dynamic structure of the system is specified through a "data-driven" mechanism, which is an extension of the "experimental frame" concept. Each type of system components (ie, flow line, conveyors, carts, etc.) is formally modeled by using Activity Cycle Diagrams. The issue of "model structuring" is also addressed. The modeling methodology has been successfully applied in a real simulation study of a mass production system

Machining of 2D Parametric Spline Using Cutter Radius Compensation

Free from curves and surfaces are frequently used in designing engineering products such as car, ship, airplane, and hosing of electronic households. In many aspect, it is very nice to use the cutter radius compensation function of CNC controller when contour machining a 2-dimensional curve. However, if the 2D curve is a parametric spline, it is not easy to apply the cutter radius compensation function of CNC controller to the NC data obtained from many commercial CAM system. This is mainly due to the error magnification effect when offsetting line segments with inevitable round-off error at their vertices. Proposed in this paper is an approach to contour machining a 2D parametric spline while using cutter radius compensation. Some implementation results are included

삼각형 Patch 를 이용한 3차원 point data 의 interpolation 을 위한 visually C1C^1 조건의 개선에 관한 연구

학위논문(석사) - 한국과학기술원 : 산업공학과, 1987.2, [ [vi], 48, [3] p. ]Described in this thesis is a visually C``(VC``) condition between two adjacent triangular patches. The main motivation was to improve the Farin``s 3-dimensional scattered point data fitting(3-D SPF) procedure. Two results were obtained in this thesis. One is the improved VC`` condition which can be used in composite triangular surface construction. This condition requires no restriction on boundary curve determination. So, we can select more natural boundary curves, and hence the overall smoothness of fitting surface can be improved. A modified 3-D SPF procedure using this condition was proposed. The other is a generalised solution for corner filleting problem and surface fairing problem. In corner filleting problem, a method to connect a triangular patch VC continuously to existing non-C" rectangular patches was proposed. And a new VC`` condition which enables the local modification of composite triangular surface while satisfying VC`` continuity was also derived.한국과학기술원 : 산업공학과

Surface modeling for 3D scattered data interpolation

학위논문(박사) - 한국과학기술원 : 산업공학과, 1990, [ ix, 91 p. ]한국과학기술원 : 산업공학과