• Education of Primary School Mathematics
• /
• v.6 no.1
• /
• pp.1-10
• /
• 2002

The objectives of the current study are on the practical use of geoboard in an elementary school class. To do this, we first investigate how come geoboard is significant in a practical use. Second, we present an example of practical use of geoboard connecting with the analysis of the 7th curriculum. Third, we investigate the results of geoboard which is applied to elementary school class. The results of this research are as follows: First, the instruction of using geoboard can give an interest and curiosity to all students. Second, right triangle, rectangle, square and so on can be easily constructed because geoboard is linked by dots. Third, by constructing figures on geoboard and comparing figures which is made by themselves, students could better understand the concept of figures rather than the explanation of teacher. fourth, students can be improved the ability of problem solving and spatial sense by providing experience for exploration. Fifth, students need not to have anxiety for error because geoband is used and so can be corrected easily.

• Journal of Korea Multimedia Society
• /
• v.18 no.1
• /
• pp.1-8
• /
• 2015

In recent years, ear has emerged as a new biometric trait, because it has advantage of higher user acceptance than fingerprint and can be captured at remote distance in an indoor or outdoor environment. This paper proposes an individual identification method using ear region based on SIFT(shift invariant feature transform). Unlike most of the previous studies using rectangle shape for extracting a region of interest(ROI), this study sets an ROI as a flexible expanded region including ear. It also presents an effective extraction and matching method for SIFT keypoints. Experiments for evaluating the performance of the proposed method were performed on IITD public database. It showed correct identification rate of 98.89%, and it showed 98.44% with a deformed dataset of 20% occlusion. These results show that the proposed method is effective in ear recognition and robust to occlusion.

• Proceedings of the Korean Information Science Society Conference
• /
• 1999.10a
• /
• pp.225-227
• /
• 1999

공간 데이터를 표현하는 색인 구조에 관하여 여러 연구가 진행되어 왔다. 그 중 R-트리 계열의 트리들은 최소 겹침과 최소 영역 증가를 기준으로 최소한계영역(Minimum Bounding Rectangle)을 생성하여 공간을 할당한다. 그러나 R-트리 기반의 트리들은 데이터 분포가 균등한 경우에서는 공간 할당이 적합하게 이루어지는 데 반하여 데이터 분포가 어느 특정 영역에 밀집되어 있는 도메인의 경우에는 공간영역을 비효율적으로 할당하는 문제점이 있다. 본 논문에서는 불균등하고 비대칭적인 데이터 분포에 적합한 트리 구조를 제안하였다. 제안된 트리 구조는 R*-트리를 기반으로 하였으며, 불균등하고 비대칭적인 데이터의 특징을 반영하여 단말 노드 구조를 설계하고 밀집영역에 대한 클러스터링을 반영하도록 삽입 및 삭제 루틴을 변형하였다.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.28.1-28
• /
• 2001

An automatic face recognition(AFR) of individuals is a significant problem in the development of computer vision. An AFR consists of two major parts which are detection of face region and recognition process, and the overall performance of AFR is determined by each. In this paper, the face region is acquired using chromaticity space, but this face region is a simple rectangle which doesn´t consider the shape information. By applying deformable templates to the face region, we can locate the position of the eyes in images. With the face region and the eye location information, more precise face region can be extract from the image. Because processing time is critical in real-time system, we use simplified eye templates and the modified energy function for the efficiency. We can get a good detection performance in experiments.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.6 no.1
• /
• pp.132-150
• /
• 2014

In this study, the inertial properties of fully filled liquid in a tank were studied based on the potential theory. The analytic solution was obtained for the rectangular tank, and the numerical solutions using Green's 2nd identity were obtained for other shapes. The inertia of liquid behaves like solid in recti-linear acceleration. But under rotational acceleration, the moment of inertia of liquid becomes small compared to that of solid. The shapes of tank investigated in this study were ellipse, rectangle, hexagon, and octagon with various aspect ratios. The numerical solutions were compared with analytic solution, and an ad hoc semi-analytical approximate formula is proposed herein and this formula gives very good predictions for the moment of inertia of the liquid in a tank of several different geometrical shapes. The results of this study will be useful in analyzing of the motion of LNG/LPG tanker, liquid cargo ship, and damaged ship.

• Journal of the Semiconductor & Display Technology
• /
• v.9 no.2
• /
• pp.15-20
• /
• 2010

This paper deals with minimizing layout area of FPGA design. FPGAs are becoming increasingly important in the design of ASICs since they provide both large scale integration and user-programmability. This paper describes a method to obtain tight bound on the worst-case increase in area when drivers are introduced along many long wires in a layout. The area occupied by minimum-area embedding for a circuit can depend on the aspect ratio of the bounding rectangle of the layout. This paper presents a separator-based area-optimal embeddings for FPGA graphs in rectangles of several aspect ratios which solves the longest path problem in the constraint graph.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2004.05a
• /
• pp.101-104
• /
• 2004

R-Tree 색인은 기존의 공간 데이터베이스관리시스템에서 공간 데이터 검색을 위하여 많이 사용되고 있는 공간 색인기법이다. 하지만 R-Tree 색인에서 기존의 잠금(Lock) 기반 동시성 제어는 갱신연산의 잠금으로 인해 검색연산의 블록킹 오버헤드(blocking overhead)가 발생한다. 본 논문에서는 R-Tree 색인에서 검색연산의 블록킹 오버헤드의 주요 원인이 되는 노드 분할 연산과 MBR(Minimum Bounding Rectangle) 갱신연산에 대해 각각 노드단위와 노드엔트리 단위의 버전(Version)을 생성하고 유지하여 동시에 발생하는 검색연산이 갱신연산으로 인한 지연이 없이 자신에 알맞은 버전을 읽음으로써, 검색성능을 높일 수 있는 버전 기반의 동시성 제어 기법을 제안한다.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.22 no.4
• /
• pp.484-491
• /
• 2019

General Hyperspectral Image Sensor acquires an image of line form such as a thin rectangle shape because of using 1D array Push Broom or Whisk Broom scanning method. A special mechanism is required for a Hyperspectral Image Sensor to operate for nadir and slant range. To design the mechanism, the characteristics of the flight motion and the overlap rate between consecutive frames were analyzed. Also, system requirements were proposed through modeling and simulation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.12 no.1
• /
• pp.22-28
• /
• 2019

This paper presents a method for detection of an emergency signal expressed by arm gestures based on motion segmentation and face area detection in the surveillance system. The important indicators of emergency can be arm gestures and voice. We define an emergency signal as the 'Help Me' arm gestures in a rectangle around the face. The 'Help Me' arm gestures are detected by tracking changes in the direction of the horizontal motion vectors of left and right arms. The experimental results show that the proposed method successfully detects 'Help Me' emergency signal for a single person and distinguishes it from other similar arm gestures such as hand waving for 'Bye' and stretching. The proposed method can be used effectively in situations where people can't speak, and there is a language or voice disability.

• Design & Manufacturing
• /
• v.14 no.4
• /
• pp.1-10
• /
• 2020

The seal plays a role in preventing oil leakage when the lip and the rotating shaft come into contact with the fluid and air pressure. Recently, micro dimples or micro pockets are processed and used on the lubrication surfaces of thrust bearings, mechanical bearings, and piston rings. Compared to a smooth surface, micro dimples reduce friction and increase the life of parts. This paper analyzed various kinds of micro dimple shapes on the sealing surface, i.e. circle, rectangle, triangle, and trapezoid. For this purpose, Introduced the design of experiments to work out a micro dimple configuration, unlikely to be damaged from cracks and low in contact stress. As a result, the triangular dimple showed the best results. Optimal factors were dimple size 0.15 mm, dimple depth 0.0383 mm, dimple density 40%, and the maximum equivalent stress was 9.1455 MPa, and the maximum contact pressure was 9.6612 MPa. This paper analyzed the optimal shape of dimples by finite element analysis. As a research project, experiments and comparative analysis of micro dimple shapes are needed.