• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 추계학술대회논문집A
• /
• pp.824-828
• /
• 2000

Prior to the downloading of the NC codes to a machining center, the NC tool-path can be verified in a computer. The Z-map is one of the tools for the verification of NC tool-path. The Z-map is a two dimensional array in which the height values of the Z-axis direction vectors are stored. The Z-axis direction vectors are arranged in a rectangular grid pattern on the XY plane. The accuracy of the simulation comes from the grid interval. In the rectangular Z-map, the distances between the grid points are different. The distance in diagonal direction is larger than those in X or Y axis directions. For the rendering of the Z-map, a rectangular grid is divided into two triangular facets. Depending on the selection of a diagonal, there are two different cases. In this paper, triangular Z-map, in which the Z-axis direction vectors are arranged in a triangular grid pattern on XY plane, is proposed. In the triangular Z-map, the distances between grid points are equal. There is no ambiguity to make triangular facets for the rendering.

• International Journal of CAD/CAM
• /
• 제3권1_2호
• /
• pp.77-83
• /
• 2003

We propose two algorithms to generate (1) polygonal meshes and (2) developable surface patches far generalized cylinders defined by contours of discrete curves. To solve the contour blending problem of generalized cylinder, the presented algorithms have adopted the algorithm and related properties of LIDM (linear interpolation by direction map) that interpolate geometric shapes based on direction map merging and group scaling operations. Proposed methods are fast to compute and easy to implement.

• 한국CDE학회논문집
• /
• 제8권4호
• /
• pp.243-253
• /
• 2003

This paper presents a new geometric morphing algorithm for polygons based on a simple geometric structure called direction map, which is mainly composed of a circular list of direction vectors defined by two neighboring vertices of a polygon. To generate a sequence of intermediate morphing shapes, first we merge direction maps of given control shapes based on a certain ordering rule of direction vectors, and scale the length of each direction vectors using Bezier or blossom controls. We show that the proposed algorithm is an improvement of the previous methods based on Minkowski sum (or convolution) in th aspects of computational efficiency and geometric properties.

• Journal of Computational Design and Engineering
• /
• 제1권1호
• /
• pp.48-54
• /
• 2014

In this paper, the authors propose a system for assisting mold designers of plastic parts. With a CAD model of a part, the system automatically determines the optimal ejecting direction of the part with minimum undercuts. Since plastic parts are generally very thin, many rib features are placed on the inner side of the part to give sufficient structural strength. Our system extracts the rib features from the CAD model of the part, and determines the possible ejecting directions based on the geometric properties of the features. The system then selects the optimal direction with minimum undercuts. Possible ejecting directions are represented as discrete points on a Gauss map. Our new point distribution method for the Gauss map is based on the concept of the architectural geodesic dome. A hierarchical structure is also introduced in the point distribution, with a higher level "rough" Gauss map with rather sparse point distribution and another lower level "fine" Gauss map with much denser point distribution. A system is implemented and computational experiments are performed. Our system requires less than 10 seconds to determine the optimal ejecting direction of a CAD model with more than 1 million polygons.

• 한국정보기술학회 영문논문지
• /
• 제10권2호
• /
• pp.61-72
• /
• 2020

Recently, researches that are using deep learning technology in various fields are being conducted. The fields include geographic map processing. In this paper, I propose a method to infer where the map area included in the image is. The proposed method generates and learns images including a map, detects map areas from input images, extracts character strings belonging to those map areas, and converts the extracted character strings into coordinates through geocoding to infer the coordinates of the input image. Faster R-CNN was used for learning and map detection. In the experiment, the difference between the center coordinate of the map on the test image and the center coordinate of the detected map is calculated. The median value of the results of the experiment is 0.00158 for longitude and 0.00090 for latitude. In terms of distance, the difference is 141m in the east-west direction and 100m in the north-south direction.

• Korean Journal of Acupuncture
• /
• 제21권3호
• /
• pp.1-20
• /
• 2004

Objective : Today, a study about the meridian is at a standstill because there is no any fundamental study to verify an essence of meridian or to take advantage of meridain. It searched the direction of new meridain study by making out road-map about meridain study to overcome the standstill. Method : It has had a through grasp of the problem of meridian study through analysis of papers for degrees and academy journals of study in connection with meridian published till now. It has made out road-map of Meridian study under a principle establishing road-map because of these problems. Results : The major problems of former studies about meridain are as follows. One is not to have any cooperation with other medical fields. The other is not to have any practical study. It searched the direction of new meridian study by road-map detailed as well as overall to overcome the difficulties. Conclusions : The new direction of meridian study is to build ideal methodical frame and modern meridian model through studying of among school systems. It will interpret newly and modernize traditional meridian theory with being connected with science technology.

• 한국통신학회논문지
• /
• 제34권4C호
• /
• pp.355-362
• /
• 2009

본 논문에서는 영상 블록내의 에지 맵을 이용한 새로운 인트라 필드 디인터레이싱 알고리듬을 제안한다. 기존의 방향성 기반 라인 평균 방식들은 화소단위 상관도를 이용하기 때문에 화소값의 변화에 민감하다는 단점을 가지고 있다. 또 방향성 에지를 탐색할 때 탐색 영역 내에 에지들이 다수 존재할 경우 부적절한 에지 방향을 찾게 되고 이는 화질의 열화를 가져온다는 단점이 있다. 이러한 단점을 극복하기 위해 본 논문은 에지 맵에 의해 계산되는 에지 방향 벡터와 이 벡터가 이용된 보간방식을 제안한다. 먼저 소벨 마스크를 이용하여 에지 방향 벡터를 구한 후, 구해진 에지방향 벡터를 이용해 다섯 개의 에지 방향 벡터의 가중치 값을 구한다. 구해진 값들은 이후에 여러 에지방향으로부터 구해지는 보간값들과 중해짐으로써 최종 보간값을 예측하게 된다. 본 논문의 핵심 아이디어는 에지 검출기를 통해 구해진 하나의 에지 방향 정보만으로 보간작업을 수행하지 않고 사용 가능한 모든 에지방향의 정보로부터 구해지는 결과값들에 가중치를 곱하여 보간작업을 수행하는 방식이다.

• IEIE Transactions on Smart Processing and Computing
• /
• 제5권1호
• /
• pp.43-48
• /
• 2016

We propose plain fingerprint classification based on a core stochastic algorithm that effectively uses a core stochastic model, acquiring more fingerprint minutiae and direction, in order to increase matching performance. The proposed core stochastic algorithm uses core presence/absence and contains a ridge direction and distribution map. Simulations show that the fingerprint classification accuracy is improved by more than 14%, on average, compared to other algorithms.

• 한국콘텐츠학회논문지
• /
• 제13권11호
• /
• pp.347-355
• /
• 2013

본 연구에서는 이명박 대통령의 연설문과 지식경제부의 IT중소벤처기업 지원정책에 대한 내용을 토대로 심층적인 인지지도 분석을 하였다. 또한 정책수단변수와 정책목표변수간의 관계분석을 통해 정책목표를 도출하고, 종합적인 인지지도를 활용하여 성장역량강화, 투자활성화, 창업활성화, 기술경쟁력 제고, 글로벌화, 고용창출 등 정보통신분야 중소벤처기업 지원정책방향을 제시하였다. 그리고 IT중소벤처기업 지원정책의 인지지도 분석을 통해 피드백 루프가 별로 없다는 점과 IT중소벤처기업 지원정책이 선순환 구조를 가지고 있는 양의 피드백 루프구조라는 것을 발견했다.

• Spatial Information Research
• /
• 제16권3호
• /
• pp.317-330
• /
• 2008

본 연구는 수치사진측량의 기본이론을 토대로 디지털 항공카메라 ADS40에 의한 디지털 영상의 획득과 정사영상 생성실험을 수행하여 정사영상 제작공정을 체계화하였으며, 수치지형도와 수치지적도와의 중첩에 의하여 정확도를 분석 및 평가하는데 목적이 있다. 축척 1/5,000 수치지형도와 중첩하여 비교한 결과는 RMSE가 X에서 ${\pm}0.364m$, Y에서 ${\pm}0.413m$, 수치지적도를 중첩하여 비교한 결과는 RMSE가 X에서 ${\pm}1.283m$ Y에서 ${\pm}1.085m$의 오차가 나타남을 알 수 있었다. 최신의 디지털 항공카메라영상의 활용을 위해서는 앞으로 GPS/IMU 데이터와 영상데이터의 동기화, 영상처리시 면적당 지상기준점 수량과 해상도 기준 등에 대한 연구가 필요하다.