• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
• /
• pp.479-483
• /
• 2006

Indoor positioning is recently highlighted and various kinds of indoor positioning systems are under developments. Since positioning systems have their own characteristics, proper positioning scheme should be chosen according to the required specifications. Positioning methods are often classified into time-based and angle-based one, and this paper presents the error analysis of these location methods. Because measurement equations of these methods are nonlinear, linearization is usually needed to get the position estimate. In this paper, Gauss-Newton method is used in the linearization. To analyze the position error, we investigate the error ellipse parameters that include eccentricity, rotation angle, and the size of ellipse. Simulation results show that the major axes of error ellipses of TOA and AOA method lie in different quadrants at most region of workspace, especially where the geometry is poor. When the TOA/AOA hybrid scheme is employed, it is found that the error ellipse is reduced to the intersection of ellipses of TOA and AOA method.

• 컴퓨터교육학회논문지
• /
• 제14권2호
• /
• pp.83-94
• /
• 2011

생의학분야에서 문헌에 표기된 개체를 인식하기 위해 길이우선매칭기법을 빈번히 사용한다. 길이우선매칭기법은 사전을 이용한 개체인식기법으로 좋은 사전만 구축되어 있다면 빠르고 정확하게 개체를 찾아낼 수 있다는 장점을 가진다. 그러나 개체가 나열되고 중복된 단어가 생략될 경우에는 길이우선매칭기법을 이용할 경우 성능이 현저히 떨어지게 된다. 우리는 이러한 인식성능문제를 해결하기 위해 부분매칭기법을 제안한다. 제안된 부분매칭기법은 생략이 발생될 수 있다는 것을 가정하여 다수의 후보개체를 만들어 내고 그 후에 최적화 알고리즘을 통해 다수의 개체후보 중에서 가장 타당해 보이는 개체를 선택한다. 우리는 생의학분야의 개체 중에서 나열되는 경우가 빈번한 HLA 유전자, HLA 항원, HLA 대립유전자 개체들을 대상으로 길이우선매칭기법과 제안된 부분매칭기법의 개체인식성능을 분석하였다. 3종의 HLA 개체들을 인식하기 위해서 먼저 확장사전과 태그기반사전을 구축하였으며, 그 후 구축된 사전을 이용해 길이우선매칭과 부분매칭을 수행하였다. 실험결과에 따르면 길이우선매칭기법은 HLA 항원 개체에서 좋은 성능을 보였으며 부분매칭기법은 생략된 표현이 빈번한 HLA 유전자 개체, HLA 대립유전자 개체에서 좋은 성능을 보였다. 부분매칭기법은 HLA 대립유전자 개체를 대상으로 95.59%의 높은 F-score를 얻었다.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
• /
• pp.100.2-100.2
• /
• 2007

• 한국결정성장학회지
• /
• 제12권6호
• /
• pp.323-328
• /
• 2002

The model of the shortest chemical bonds is applied for the classification of acentric simple and binary Mo(VI) and W(VI) oxides. It is shown that on the plane of the shortest chemical bonds the compounds are located into the rosette of three intersected ellipses. The correlation between the optical nonlinearity and combination of the bond lengths is discussed.

• 대한수학교육학회지:수학교육학연구
• /
• 제8권1호
• /
• pp.59-71
• /
• 1998

Recently, most classrooms in Korea are fully equipped with multimedia environments such as a powerful pentium pc, a 43″large sized TV, and so on through the third renovation of classroom environments. However, there is not much software teachers can use directly in their teaching. Even with existing software such as GSP, and Mathematica, it turns out that it doesn####t fit well in a large number of students in classrooms and with all written in English. The study is to analyze the characteristics of problem-solving process and to develop a computer program which integrates the instruction of problem solving into a regular math program in areas of quadratic functions and ellipses. Problem Solving in this study included two sessions: 1) Learning of basic facts, concepts, and principles; 2) problem solving with problem contexts. In the former, the program was constructed based on the definitions of concepts so that students can explore, conjecture, and discover such mathematical ideas as basic facts, concepts, and principles. In the latter, the Polya#s 4 phases of problem-solving process contributed to designing of the program. In understanding of a problem, the program enhanced students#### understanding with multiple, dynamic representations of the problem using visualization. The strategies used in making a plan were collecting data, using pictures, inductive, and deductive reasoning, and creative reasoning to develop abstract thinking. In carrying out the plan, students can solve the problem according to their strategies they planned in the previous phase. In looking back, the program is very useful to provide students an opportunity to reflect problem-solving process, generalize their solution and create a new in-depth problem. This program was well matched with the dynamic and oscillation Polya#s problem-solving process. Moreover, students can facilitate their motivation to solve a problem with dynamic, multiple representations of the problem and become a powerful problem solve with confidence within an interactive computer environment. As a follow-up study, it is recommended to research the effect of the program in classrooms.

• 대한기계학회논문집B
• /
• 제37권3호
• /
• pp.259-266
• /
• 2013

광학 현미경을 통해 일정한 시간 간격으로 얻은 세포 이미지로부터 세포 변화를 자동적으로 추적 및 분석하는 것이 세포 트래킹이라고 한다. 세포 변화 과정에서 이웃에 있는 세포들이 겹쳐져 있는 상태를 클러스터라고 하며 세포트래킹에서 클러스터를 다시 세포로 분리하는 작업은 매우 중요하다. 본 논문에서는 타원 근사법을 기반으로 클러스터를 분리하기 위한 알고리즘을 제안한다. 클러스터의 외곽선을 추출한 후 외곽선의 오목정점을 이용하여 클러스터를 라인 세그먼트들로 분리한 다음 휴리스틱을 이용하여 라인 세그먼트들을 결합해 가며 근사 타원을 생성한다. 실험 결과 두 개의 세포가 겹쳐진 클러스터의 경우 평균적으로 91%, 세 개의 세포가 겹쳐진 경우 평균적으로 84% 그리고 겹쳐진 세포의 개수가 네 개 이상인 경우 약 73%의 정확도로 클러스터를 분리해 주었다.

• Journal of Information Processing Systems
• /
• 제14권2호
• /
• pp.469-486
• /
• 2018

We propose an enhanced version of the local binary pattern (LBP) operator for texture extraction in images in the context of image retrieval. The novelty of our proposal is based on the observation that the LBP exploits only the lowest kind of local information through the global histogram. However, such global Histograms reflect only the statistical distribution of the various LBP codes in the image. The block based LBP, which uses local histograms of the LBP, was one of few tentative to catch higher level textural information. We believe that important local and useful information in between the two levels is just ignored by the two schemas. The newly developed method: gradual locality integration of binary patterns (GLIBP) is a novel attempt to catch as much local information as possible, in a gradual fashion. Indeed, GLIBP aggregates the texture features present in grayscale images extracted by LBP through a complex structure. The used framework is comprised of a multitude of ellipse-shaped regions that are arranged in circular-concentric forms of increasing size. The framework of ellipses is in fact derived from a simple parameterized generator. In addition, the elliptic forms allow targeting texture directionality, which is a very useful property in texture characterization. In addition, the general framework of ellipses allows for taking into account the spatial information (specifically rotation). The effectiveness of GLIBP was investigated on the Corel-1K (Wang) dataset. It was also compared to published works including the very effective DLEP. Results show significant higher or comparable performance of GLIBP with regard to the other methods, which qualifies it as a good tool for scene images retrieval.

• 융합신호처리학회논문지
• /
• 제14권1호
• /
• pp.27-32
• /
• 2013

영상처리로 물체를 검출 하는 경우, 타원 형태를 검출 하는 것은 많은 응용 분야에서 중요한 역할을 한다. 실제 영상에서 타원은 영상에 포함된 노이즈나 다른 물체에 가려 보이지 않거나 교차되어 타원 검출이 용이 하지 않다. 이에 본 논문에서는 영상에서 타원을 검출 하기 위하여 경계(edge)를 추출하고, 이미지 정보량을 줄이기 위하여 그룹화 과정을 수행하여 타원 검출의 속도를 향상시켰다. 또한 타원 검출을 위해 5 개의 타원 변수를 랜덤으로 선택한 후 최적의 타원 파라미터 선택을 위해 선형 최소자승 근사법을 적용하였다. 검출된 타원들을 검증하기 위하여 RANSAC 알고리즘을 적용하였다. 본 연구에서 제안한 알고리듬을 구현하여 실제 영상에 적용한 결과 75%의 정확도를 나타내었고, 타 연구와 비교 결과 타원검출 속도 면에서 탁월함을 확인하였다. 이러한 결과는 본 연구에서 제안한 알고리듬이 영상 내 타원을 검출 하기 위한 유효한 방법임을 확인 할 수 있었다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 하계종합학술대회 논문집(4)
• /
• pp.61-64
• /
• 2001

This paper proposes an automatic method for generating and 3D draping the skirt 3D models. The method constructs a 3D basic model of the skirts using elliptic cylinder and generates the various skirt 3D models by controlling the ellipses of the basic model. B-Spline approximates the wrinkles around the ellipse for the various 3D draping changing according to designs and textiles. We make some real skirts and investigate appearances for their drapes. This paper simulates their appearances and obtains good results. Furthermore, adaptation of the skirt 3D model to a personal character implements realistic coordination of the various skirts.

• 전자공학회논문지S
• /
• 제34S권2호
• /
• pp.21-32
• /
• 1997

This paper proposes an elliptical world-modeling mehtrod in order to secure the safety of the mobile robot from the unreliability of ultrasonic sensors and to estimate the lateral orientation of the detected objects. This method is advnatageous because the total amount of data that the robot utilizes is reduced when historical and new data are clusterd during each sensing period and also because the objects in the environment can be almost exactly recognized. This paper also proposes a new local path planning algorithm which is divided into four different situations and gudies the robot through the safe local path using dat acollected in elliptical form. This algorithm can help the AMR navigate by allowing it to sum up the virtual vector forces made form the ellipses in order to select a safe subgoal. This local path plannin gmehtod using the elliptical world model has been proved by several navigation experiments.