• Title/Summary/Keyword: Change points

Search Result 1,781, Processing Time 0.027 seconds

An Improved Guidance Algorithm for Smooth Transition at Way-Points in 3D Space for Autonomous Underwater Vehicles

  • Subramanian, Saravanakumar;Thondiyath, Asokan
    • International Journal of Ocean System Engineering
    • /
    • v.2 no.3
    • /
    • pp.139-150
    • /
    • 2012
  • This paper presents an improved guidance algorithm for autonomous underwater vehicles (AUV) in 3D space for generating smoother vehicle turn during the course change at the way-points. The way-point guidance by the line-of-sight (LOS) method has been modified for correcting the reference angles to achieve minimal calculation and smoother transition at the way-points. The algorithm has two phases in which the first phase brings the vehicle to converge to a distance threshold point on the line segment connecting the first two way-points and the next phase generates an angular path with smoother transition at the way-points. Then the desired angles are calculated from the reference and correction angles. The path points are regularly parameterized in the spherical coordinates and mapped to the Cartesian coordinates. The proposed algorithm is found to be simple and can be used for real time implementation. The details of the algorithm and simulation results are presented.

Intersections of a Polyhedral Surface with Parallel Planes (다면체 곡면과 평행한 평면들과의 교선)

  • Jeon, Cha-Soo;Kim, Young-Yil
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.21 no.4
    • /
    • pp.493-506
    • /
    • 1995
  • Presented in this paper is an algorithm to obtain the intersections of a polyhedral surface composed of triangle facets with a series of parallel planes for extracting machining information from the surface. The change of the topology of the intersection curves is caused by characteristic points of the surface when sectioning the surface with parallel planes. The characteristic points are internal maximum, internal minimum, internal saddle, boundary maximum, boundary minimum, boundary max-saddle, and boundary min-saddle points. The starting points of the intersects are found efficiently and robustly using the characteristic points. The characteristic points as well as the intersection contours can be used to evaluate the machining information for process planning, and to generate NC tool path in CAD/CAM system.

  • PDF

Axial motion stereo method (로보트 팔에 부착된 카메라를 이용한 3차원 측정방법)

  • 이상용;한민홍
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1991.10a
    • /
    • pp.1192-1197
    • /
    • 1991
  • This paper describes a method of extracting the 3-D coordinates of feature points of an object from two images taken by one camera. The first image is from a CCD camera before approaching the object and the second image is from same camera after approaching the object along the optical axis. In the two images, the feature points appear at different position on the screen due to image enlargement. From the change of positions of feature points their world coordinates are calculated. In this paper, the correspondence problem is solved by image shrinking and correlation.

  • PDF

The Comparison of the SIFT Image Descriptor by Contrast Enhancement Algorithms with Various Types of High-resolution Satellite Imagery

  • Choi, Jaw-Wan;Kim, Dae-Sung;Kim, Yong-Min;Han, Dong-Yeob;Kim, Yong-Il
    • Korean Journal of Remote Sensing
    • /
    • v.26 no.3
    • /
    • pp.325-333
    • /
    • 2010
  • Image registration involves overlapping images of an identical region and assigning the data into one coordinate system. Image registration has proved important in remote sensing, enabling registered satellite imagery to be used in various applications such as image fusion, change detection and the generation of digital maps. The image descriptor, which extracts matching points from each image, is necessary for automatic registration of remotely sensed data. Using contrast enhancement algorithms such as histogram equalization and image stretching, the normalized data are applied to the image descriptor. Drawing on the different spectral characteristics of high resolution satellite imagery based on sensor type and acquisition date, the applied normalization method can be used to change the results of matching interest point descriptors. In this paper, the matching points by scale invariant feature transformation (SIFT) are extracted using various contrast enhancement algorithms and injection of Gaussian noise. The results of the extracted matching points are compared with the number of correct matching points and matching rates for each point.

Discussion on the Relationship between Well Points in the Fingers and EX-UE11 Points (수지부 정혈과 십선혈의 관계에 대한 고찰)

  • Da-Eun Yoon;Yeonhee Ryu;In-Seon Lee;Younbyoung Chae
    • Korean Journal of Acupuncture
    • /
    • v.40 no.1
    • /
    • pp.13-17
    • /
    • 2023
  • Objectives : Our goals were to examine how the well points in the fingers came to be and how their placements have changed, as well as to determine how they relate to the EX-UE11 points. Methods : We reviewed the classic textbooks to understand the origin and the changes of locations of the well points in the fingers. We also compared the location and indications between well points in the fingers and EX-UE11 points. Results : At first, the tips of the fingers, which are now thought to be the locations of EX-UE11 points, were once described as containing well points. Currently, well points are positioned 0.1 F cun distal-medial (or lateral) to the medial (or lateral) corner of the nail. In addition to the locational commonality, we found similarities between the well points in the fingers and the EX-UE11 points in terms of their indications; for example, bloodletting at these places is frequently utilized to treat emergencies, including acute stroke and fever. Conclusions : We suggest that it is highly likely that well points in the fingers and EX-UE11 points were initially the same acupuncture point and later classified into two different acupuncture points, given their identical locations and indications. If the clinical relevance between the change process of the well points' locations in the fingers and the EX-UE11 is studied in the historical literature, it is anticipated that the significance and clinical application of well points can be expanded.

A detection procedure for a variance change points in AR(1) models (AR(1) 모형에서 분산변화점의 탐지절차)

  • 류귀열;조신섭
    • The Korean Journal of Applied Statistics
    • /
    • v.1 no.1
    • /
    • pp.57-67
    • /
    • 1987
  • In time series analysis, we usually require the assumption that time series are stationary. But we may often encounter time series whose parameter values subject to change. Inthis paper w propose a method which can detect the variance change point in anAR(1) model which is subjct to changesat non-predictable time points. Proposed method is compared with other methods using the simulated and real data.

Change of Ward Design in Korean Hospital Architecture since 1945 (1945년 이후 한국병원건축 병동부의 변화)

  • Yu, Youngmin
    • Journal of The Korea Institute of Healthcare Architecture
    • /
    • v.22 no.4
    • /
    • pp.67-77
    • /
    • 2016
  • Purpose: This paper aimis to analyze the characteristics of ward plan of Korean hospital architecture constructed in each periods and identify the change since 1945. Methods: Literature review was conducted while ward plans for analysis were sellected. And then the important points of ward design were analyzed in each periods. Results: The important points of ward design - type of corridor in ward plan, number of beds per nursing unit, location of nurse station, organization of multi-bed rooms, location of patient toilet, number of day room, concentration and separation of elevator halls for patient and general- were analyzed and the characteristics of change were identified in each periods. Implications: This paper could be a basic data for arranging the history of hospital architecture in Korea.

A MODIFIED PREY-PREDATOR MODEL WITH COUPLED RATES OF CHANGE

  • HAN, HYEJI;KIM, GWANGIL;OH, SEOYOUNG
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • v.25 no.4
    • /
    • pp.312-326
    • /
    • 2021
  • The prey-predator model is one of the most influential mathematical models in ecology and evolutionary biology. In this study, we considered a modified prey-predator model, which describes the rate of change for each species. The effects of modifications to the classical prey-predator model are investigated here. The conditions required for the existence of the first integral and the stability of the fixed points are studied. In particular, it is shown that the first integral exists only for a subset of the model parameters, and the phase portraits around the fixed points exhibit physically relevant phenomena over a wide range of the parameter space. The results show that adding coupling terms to the classical model widely expands the dynamics with great potential for applicability in real-world phenomena.

Deep Learning-based Scene Change Detection (딥 러닝을 이용한 화면 전환 검출)

  • Lee, Jae-eun;Seo, Young-Ho;Kim, Dong-wook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2019.05a
    • /
    • pp.549-550
    • /
    • 2019
  • In this paper, we propose a method to detect the scene change using deep learning. To extract feature points, we use a deep neural network and express extracted feature points as 128 dimensional vectors using SIFT descriptor. If it is less than 25%, it is determined that the scene is changed.

  • PDF

A Study on the Change of Body Temperature according to Menstrual Cycle (월경주기에 따른 체온변화 관찰)

  • Park, Dae-Soon;Cho, Jung-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub
    • Journal of Oriental Medical Thermology
    • /
    • v.2 no.1
    • /
    • pp.6-10
    • /
    • 2003
  • Purpose : Man is a homoiothermal animal. But by various causes, body temperature can be changed to $1^{\circ}C$. Basal temperature is a very useful method in many fields of OB&GY area. So we observed the change of body temperature according to menstrual cycle. Materials and Methods : We observed 3 female who have very regular 30 days menstrual cycle. The Observation started before the onset of menstruation and body temperature was checked in the same time (11:00 am) of a day. To evaluate the change of body temperature, we examined three points of body. And to observe the body temperature we used the D.I.T.I(Dorex, Inc., USA). Results : On this study we couldn't find the typical biphasic change of body temperature but most of the materials showed the elevation of body temperature on the 14th day. Between the examined three points, the lowest point was showed more typical biphasic change of body temperature.

  • PDF