• Journal of KIISE:Computer Systems and Theory
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• v.34 no.4
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• pp.132-137
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• 2007

A point-wise car-like robot moving in the plane changes its direction with a constraint on turning curvature. In this paper, we consider the problem of computing a shortest path of bounded curvature between a prescribed initial configuration (position and orientation) and a polygonal goal, and propose a new geometric proof showing that the shortest path is either of type CC or CS (or their substring), where C specifies a non-degenerate circular arc and S specifies a non-degenerate straight line segment. Based on the geometric property of the shortest path, the shortest path from a configuration to a polygonal goal can be computed in linear time.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.1
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• pp.44-48
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• 1996

In manufacturing of exact products, the offsetting is required to transfer the design data of shape to manufacturing data. In offsetting the degeneracies are occurred, and these problems are mere difficult in freeform shapr manufacuring. This paper is using the geometric properties of B-spline curves to solve the degeneracy of offsetting and to generating of enhanced offsetting. The offsetting of B-spline control polygon spans generates exact control polygon of original shapes. This method is faster in generating offset curve than the normal offsetting, and the resulted offset curves are exact. The additional property of this method is using to control offset shape as B-spline curves. We believe that this method is as effective solution for modifying of offset curves.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.226-231
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• 1998

This paper describes how a priori road geometry and its estimation may be used to detect road boundaries and lane markings in road scene images. We assume flat road and road boundaries and lane markings are all Bertrand curves which have common principal normal vectors. An active contour is used for the detection of road boundary, and we reconstruct its geometric property and make use of it to detect lane markings. Our approach to detect road boundary is based on minimizing energy function including edge related term and geometric constraint term. Lane position is estimated by pixel intensity statistics along the parallel curve shifted properly from boundary of the road. We will show the validity of our algorithm by processing real road images.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.12
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• pp.38-44
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• 1995

This paper presents a method to measure the position and orientation of a Cylindrical Object(unknown the eiameter and length) lying on a floor, using a camera. The two extreme cross section of the cylinder will be viewed as distorted ellipese or circular are, while its limb edge will be shown as two straight lines. The diameter of the cylinder is determined from the geometric properties of the two straight lines, which in turn provides information regarding the length of the cylinder. From the 3-dimensional measurement, the 3D coordinates of the center points of the two extreme cross sections are determined to give the position and orientation of the cylinder. This method is used for automated pick-and-place operations of cylinder, such as sheet coils, or drums in warehouses.

• Journal of Electrical Engineering and information Science
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• v.1 no.1
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• pp.91-97
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• 1996

This paper proves by straightforward computation an interesting property of a recursive indexing: it preserves the entropy of a geometrically-distributes stationary memoryless source. This result is a pleasant surprise because the recursive indexing though one-to-one, is a symbol-to-string mapping and the entropy is measured in terms of the source symbols. This preservation of the entropy implies that the minimum average number of bits needed to represent a geometric memoryless source by the recursive indexing followed by a good binary encoder of a finite imput alphabet remains the same as that by a good encoder of an infinite input alphabet. Therefore, the recursive indexing theoretically keeps coding optimality intact. For this reason recursive indexing can provide an interface for a binary code with a finite code book that performs reasonably well for a source with an infinite alphabet.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.28 no.2
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• pp.59-70
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• 2024

In this paper we present the approximation method of the circular helix by G² cubic polynomial curves. The approximants are G¹ Hermite interpolation of the circular helix and their approximation order is four. We obtain numerical examples to illustrate the geometric continuity and the approximation order of the approximants. The method presented in this paper can be extended to approximating the elliptical helix. Using the property of affine transformation invariance we show that the approximant has G² continuity and the approximation order four. The numerical examples are also presented to illustrate our assertions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1A
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• pp.42-50
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• 2002

In this paper, for a prime number p, a construction method to genarate p-ary d-from sequences with ideal autocorrelation property is proposed and using the ternary sequences with ideal autocorrelation found by Helleseth, Kumar and Martinsen, ternary d-form sequences with ideal autocorrelation introduced. By combining the methods for generation the p-ary extended sequence (a special case of geometric sequences) and the p-ary d-from sequences, a construction method of p-ary unified (extended d-form) sequences which also have ideal autocorrelation property is proposed, which is very general class of p-ary sequences including the binary and nonbinary extended sequences and d-form seuqences. Form the ternary sequences with ideal autocorrelation by Helleseth, Kumar and Martinesen, ternary unified sequences with ideal autocorrelation property are also generated.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.9_10
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• pp.1475-1486
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• 2007

This study aims to develop knitted ware design to meet desire to express diversity in the modern fashion design so that we designed knitted ware by applying african geometric pattern and color to suggest new knitted ware design. We collect data about african texture pattern through technical books, publications, internet, and preceding research and visit and investigate the African museum. We investigate knitted Jacquard texture through preceding research and collect sample and data which is insufficient in the data source. The conclusions in this study are summarized as follows: First, African textile pattern is formulated with animism based on their religious view of art for a basis and African regards nature like animal and plant as a motive and interprets nature in the so that they can create symbolized geometric features that constitute African texture pattern. Those patterns is composed of extremely geometric figures so that they we fit to apply for color jacquad knit design. Second, color knitted jacquad can be distinguished by knitting method and status of knitting as 7 kinds of techniques such as Nomal, Bird'eye, Floating, Tubular, Ladder's back, Blister, Transfer Jacquard, and as a result of preceding research and knitting texture directly, jacquard technique makes different texture under same condition like consistent spinning rate and same crochet hook. Third, Bird'eye Jacquard used generally to make knitted ware and Ladder's back Jacquard, Tubular Jacquard used to make knitted ware light are fit to apply them to 7GG and 12GG machines. We design a cloak as a outer garment, a coat shaped like one-piece dress and a coat with hood by using Tubular Jacquard which can make thick texture and design a jacket, a skirt and a one-piece dress by using Bird'eye Jacquard. we make a light and flimsy one-piece dress by using Ladder's back Jacquard. Fourth, we apply the contrast of $4{\sim}6$ color and line and the contrast of texture and raw material to jacquard in order to emphasize texture property and visual property.

• Communications of the Korean Mathematical Society
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• v.23 no.4
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• pp.479-485
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• 2008

In this note, we study arithmetic properties for the exponents of modular forms on ${\Gamma}_0(p)$ for primes p. Our aim is to refine the result of [4] by using the geometric property of the modular curve of ${\Gamma}_0(p)$.

• Communications for Statistical Applications and Methods
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• v.17 no.5
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• pp.639-645
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• 2010

We consider a subdiagonal bilinear model and give sufficient conditions for the associated Markov chain defined by Pham (1985) to be uniformly ergodic and then obtain the $\beta$-mixing property for the given process. To derive the desired properties, we employ the results of generalized random coefficient autoregressive models generated by a matrix-valued polynomial function and vector-valued polynomial function.