• 대한수학회지
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• 제42권4호
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• pp.847-856
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• 2005

M. Junger, G. Reinelt, and W. R. Pulleyblank asked the following questions ([2]). (1) Is it true that every simple planar 2-edge connected bipartite graph has a 3-partition in which each component consists of the edge set of a simple path? (2) Does every simple planar 2-edge connected graph have a 3-partition in which every component consists of the edge set of simple paths and triangles? The purpose of this paper is to provide a positive answer to the second question for simple outerplanar 2-vertex connected graphs and a positive answer to the first question for simple planar 2-edge connected bipartite graphs one set of whose bipartition has at most 4 vertices.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제27권1호
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• pp.37-55
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• 2023

In this paper we propose a new algorithm for detecting and counting flowers in a complex background based on digital images. The algorithm mainly includes the following parts: edge contour extraction of flowers, edge contour determination of overlapped flowers and flower counting. We use a contour detection technique in Computer Vision (CV) to extract the edge contours of flowers and propose an improved algorithm with a concave point detection technique to find accurate segmentation for overlapped flowers. In this process, we first use the polygon approximation to smooth edge contours and then adopt the second-order central moments to fit ellipse contours to determine whether edge contours overlap. To obtain accurate segmentation points, we calculate the curvature of each pixel point on the edge contours with an improved Curvature Scale Space (CSS) corner detector. Finally, we successively give three adaptive judgment criteria to detect and count flowers accurately and automatically. Both experimental results and the proposed evaluation indicators reveal that the proposed algorithm is more efficient for flower counting.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.213-217
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• 2004

This paper presents a method of constructing the digital logic systems(DLS) using edge-valued decision diagrams(EVDD). The proposed method is as following. The EVDD is a new data structure type of decision diagram(DD) that is recently used in constructing the digital logic systems based on the graph theory. Next, we apply EVDD to function minimization of digital logic systems. The proposed method has the visible, schematical and regular properties.

• Journal of Biosystems Engineering
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• 제4권1호
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• pp.1-23
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• 1979

The use of barley seeder attached to rotary tiller in the rural area has a significant meaning not only for the solution of labor peak season, but also for the increase of land utilization efficiency. The facts that presently being used barley seeders are all based on the mechanical principles of the reverse rotation, center drive and are all using forward rotating tine, which is used to be easily and heavily worn out when it rotates reversely, raise problem of recommending them to rural area in Korea. Therefore, the main objective of the study was to develop new type of rotary tine attachable to barley seeders. To attain the objective the following approaches were applied. (1) The kinematic analysis of reverse rotating barley seeders. (2) The studies on the soil bin and artificial soil. (3) The comparative experiment on the power requirement of prototype tine. The results obtained from the studies are summarized as follow: 1. The kinematic analysis of barley seeder attached to rotary tiller: The following results were obtained from the kinematic analysis for deriving general formulae of the motion and velocity characterizing the rotary tine of barley seeders presently being used by farmers. a) The position vector (P) of edge point (P) in the rotary tine of reverse rotating, center drive was obtained by the following formula. $$P=(vt+Rcos wt)i+Rsin wt j+ \{ Rcos \theta r sin \alpha cos (wt- \beta +\theta r) +Rsin \theta r sin \alpha sin (wt-\beta + \theta r) \} lk $$ b) The velocity of edge point $(P^')$ of reverse rotating, center drive rotary tine was obtained by the following formula. $$(P^')=(V-wR sin wt)i+(w\cdot Rcoswt)j + \{ -w\cdot Rcos \theta r\cdot sin \alpha \cdot sin (wt-\beta +\theta r) + w\cdot Rsin \theta r\cdot sin \alpha \cdot cos (wt- \beta + \theta r \} k $$ c) In order to reduce the power requirement of rotary tine, the angle between holder and edge point was desired to be reduced. d) In order to reduce the power requirement, the edge point of rotary tine should be moved from the angle at the begining of cutting to center line of machine, and the additional cutting width should be also reduced. 2. The studies on the soil bin and artificial soil: In order to measure the power requirement of various cutting tines under the same physical condition of soil, the indoor experiments Viere conducted by filling soil bin with artificially made soil similar to the common paddy soil and the results were as follows: a) When the rolling frequencies$(x)$ of the artificial soil were increased, the densIty$(Y)$ was also increased as follows: $$y=1.073200 +0.070780x - 0.002263x^2 (g/cm^3)$$ b) The absolute hardness $(Y)$ of soil had following relationship with the rolling frequencies$(x)$ and were increased as the rolling frequencies were increased. $$Y=37.74 - \frac {0.64 + 0.17x-0. 0054x^2} {(3.36-0.17x + 0.0054x^2)^3} (kg/cm^3)$$ c) The density of soil had significant effect on the cohesion and angle of internal friction of soil. For instance, the soil with density of 1.6 to 1.75 had equivalent density of sandy loam soil with 29.5% of natural soil moisture content. d) The coefficient of kinetiic friction of iron plate on artificial soil was 0.31 to 0.41 and was comparable with that of the natural soil. e) When the pulling speed of soil bin was the 2nd forward speed of power tiller, the rpm of driving shaft of rotary was similar to that of power tiller, soil bin apparatus is indicating the good indoor tester. 3. The comparative experiment on the power requirement of prototype tine of reverse rotating rotary: According to the preliminary test of rotary tine developed with various degrees of angle between holder and edge pcint due to the kinematic analysis, comparative test between prototype rotary tine with $30 ^\circ $ and $10 ^\circ$ of it and presently being used rotary tine was carried out 2nd the results were as follows: a) The total cutting torque was low when the angle between holder and edge point was reduced. b) $\theta r$ (angle between holder and edge point) of rotary tine seemed to be one: of the factors maximizing the increase of torque. c) As the angle between holder and edge point ($\theta r$) of rotary tine was $30 ^\circ $ rather than $45 ^\circ $, the angle of rotation during cutting soil was reduced and the total cutting torque was accordingly reduced about 10%, and the reduction efficiency of total cutting torque was low when the angle between holder and edge point ($\theta r$) of rotary tine was $10 ^\circ $, which indicates that the proper angle between holder and edge point of rotary tine should be larger than $10 ^\circ $ and smaller than $30 ^\circ $ . From above results, it could be concluded that the use of the prototype rotary tine which reduced the angle between holder and edge point to $30 ^\circ $, insted of $45 ^\circ $, is disirable not only decreasing the power requirements, but also increasing the durabie hour of it. Also forward researches are needed, WIlich determine the optimum tilted angle of rotary brocket, and rearrangement of the rotary tine on the rotary boss.

• 제어로봇시스템학회논문지
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• 제3권1호
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• pp.61-66
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• 1997

로보트 매니퓰레이터가 일정한 접촉 힘을 유지하며 공작물의 표면을 따라가게 하는 작업은 많은 자동화 생산공정에서 유용하게 이용될 수 있다. 일반적인 위치제어용 산업용 로보트를 이러한 공정에 사용하기 위해서는 접촉힘이 계측되어 로보트의 제어에 이용되어야만 한다. 이 연구는 accommodation force control 방식으로 산업용 로보트를 제어하여 edge-following에 응용하도록하며, 접촉 힘의 계측에는 wrist force sensor를 사용한다. 이 시스템의 궤도추적속도와 force regulation 등이 예견제어에 의해 향상될 수 있다. 예견제어에 의해 설계된 전체 제어 시스템은 feedback 제어기와 feedforward 예견제어기로 구성된다. 여기서, 시스템의 안정성은 feedback 제어기에 의해서 결정되며, 예견제어기는 시스템에 미치는 외란을 통제하는 것을 주 기능으로 한다. 일반적으로 선형제어 방식을 채택한 경우와 예견제어를 이용한 edge-following을 실험을 통해 비교함으로써, 예견제어의 효용성을 확인한다.

• 한국통신학회논문지
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• 제18권11호
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• pp.1635-1644
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• 1993

본 논문은 에지개선 필터들의 통계적인 특성과 에지 검출을 위한 전처리 연산자로서의 효용성을 분석한다. 분석 대상인 에지개선 필터들로는 비교와 선택을 수행하는 CS 필터, Hachimura와 Kuwahara가 개발한 HK 필터, 그리고 선택성 평균을 출력시키는 SA필터이며 이 필터들은 잡음 제거 능력 및 손상된 에지를 계단 모양의 에지로 개선시키는 역할을 수행하기 때문에 에지 검출기 사용전에 잡음화된 영상을 전처리하는데 효과적으로 사용될 수 있다. 수치해석을 통한 통계적 분석이 에지개선 필터들의 잡음 제거능력을 살펴보기 위하여 수행되며 에지 검출에 대한 전처리 필터링의 영향은 수치해석 방법을 통하여 얻어진 오류확률들을 중심으로 분석된다. 또한 백색잡음에 의하여 손상된 영상에 필터들을 사용하여 전처리를 수행한 후 Sobel 연산자와 LoG 연산자를 사용하여서 에지 검출전에 전처리기로서 사용된 에지개선 필터들은 후처리기로 사용된 에지 검출기의 성능을 향상시킬 수 있다.

• Journal of the Korean Wood Science and Technology
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• 제19권4호
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• pp.43-51
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• 1991

This study was carried out to determine the withdrawal strength of various screws according to root diameter of screw and embeded length on the face and edge of domestic particleboard and medium density fiberboard. The obtained results were as follows: 1. The withdrawal strength of screw in domestic particleboard and medium density fiberboard was closely related to embeded length of the screw but less dependent on root diameter of the screw. 2. The withdrawal strength on the face and edge of domestic particleboard could be predicted by means of the following expression: $F_{Pf}=4.60{\times}D^{0.24}{\times}L^{1.14}(R^2=0.87)$ $F_{Pe}=0.54{\times}D^{0.43}{\times}L^{1.73}(R^2=0.84)$ Where: $F_{Pf}$ : withdrawal strength on the face of particleboard(kgf) $F_{Pe}$=withdrawal strength on the edge of particleboard(kgf) D=diameter of the screw(mm) L=embeded length(mm) 3. The withdrawal strength on the face and edge of domestic medium density fiberboard could he predicted by means of the following expression: $FM_f=1.53{\times}D^{0.53}{\times}L^{1.39}(R^2=0.93)$ $F_{Me}=1.14{\times}D^{0.66}{\times}L^{1.36}(R^2=0.87)$ where: $F_{Mf}$ = withdrawal strength on the face of medium density fiberboard(kgf) $F_{Mf}$=withdrawal strength on the edge of medium density fiberboard(kgf).

• 한국정보과학회논문지:시스템및이론
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• 제29권12호
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• pp.640-647
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• 2002

본 논문에서는 에지 가시성에 관련된 문제를 재구성 가능한 메쉬(RMESH)에서 상수 시간에 해결하는 것을 고려한다. 에지 가시성에 관련된 기본적인 문제들로 다음의 세 가지 문제를 살펴볼 수 있다. 첫째, 주어진 다각형이 어떤 에지로부터 가시적인가를 판별하라. 둘째, 주어진 다각형을 볼 수 있는 모든 에지를 구하라. 셋째, 주어진 다각형에서 어떤 에지로부터의 가시적인 영역, 즉, 가시성 다각형을 구하라. 이들 문제를 상수 시간에 해결하기 위하여 본 논문에서는 두 에지 사이의 가시성에 관한 다음의 문제를 고려한다: 단순 다각형 P의 두 에지 e와 f가 주어져 있을 때 e로부터 가시적인 f의 영역을 구하라. 본 논문에서는 이 문제를 N-N RMESH에서 상수 시간에 해결하는 알고리즘을 제시한다. 여기서 N은 P의 정점의 개수이다. 이 알고리즘을 이용하면 에지 가시성에 관련된 기본적인 문제들을 모두 RMESH에서 상수시간에 해결할 수 있다. 특히, 세 번째 문제를 N-$N_2$ RMESH에서 상수 시간에 해결하는 것이 가능하다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 D
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• pp.747-749
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• 2000

In this paper, we proposed color stereo matching algorithm using dynamic programming. The conventional gray stereo matching algorithms show blur at depth discontinuities and non-existence of matching pixel in occlusion lesions. Also it accompanies matching error by lack of matching information in the untextured region. This paper defines new cost function makes up for the problems happening in conventional gray stereo matching algorithm. New cost function contain the following properties. I) Edge points are corresponded to edge points. ii) Non-edge points are corresponded to non-edge points. iii) In case of exiting the amount of edges, the cost function has some weight in proportion to path distance. Proposed algorithm was applied in various images obtained by parallel camera model. As the result, proposed algorithm showed improved performance in the aspect of matching error and processing in the occlusion region compared to conventional gray stereo matching algorithms.

• 한국정보처리학회논문지
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• 제3권3호
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• pp.471-477
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• 1996

본 논문에서는 톨연산에 기초한 화상의 경계선 추출 방법을 제안 한다. 첫째로 3$\times$3 window내 에서 경계라고 고려 할 수 있는 구조를 고려하여 톨 멤버쉽 함수를 계산 한다. 이후를 교집합연산과 합집합 연산을 행하며 계산의 편의를 위해 정규화를 행한다. 최종적으로 ;엔트로피 개념에 기초한 thresholding을 행함으로써 경계를 추출 하고자 한다.