• Title/Summary/Keyword: Arnold

Search Result 117, Processing Time 0.024 seconds

Obstacle Avoidance Method in the Chaotic Unmanned Aerial Vehicle (카오스 무인 비행체에서의 장애물 회피 방법)

  • Bae, Young-Chul;Kim, Yi-Gon;Kim, Chun-Suk
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.14 no.7
    • /
    • pp.883-888
    • /
    • 2004
  • In this paper, we propose a method to avoid obstacles that have unstable limit cycles in a chaos trajectory surface. We assume all obstacles in the chaos trajectory surface have a Van der Pol equation with an unstable limit cycle. When a chaos UAVs meet an obstacle in an Arnold equation, Chua's equation and hyper-chaos equation trajectory the obstacle reflects the UAV( Unmanned Aerial Vehicle).

Hidden Truncation Normal Regression

  • Kim, Sungsu
    • Communications for Statistical Applications and Methods
    • /
    • v.19 no.6
    • /
    • pp.793-798
    • /
    • 2012
  • In this paper, we propose regression methods based on the likelihood function. We assume Arnold-Beaver Skew Normal(ABSN) errors in a simple linear regression model. It was shown that the novel method performs better with an asymmetric data set compared to the usual regression model with the Gaussian errors. The utility of a novel method is demonstrated through simulation and real data sets.

A Chaotic Underwater Robot (카오스 수중 로봇)

  • Kim, Chun-Suk;Bae, Young-Chul
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • v.9 no.1
    • /
    • pp.937-941
    • /
    • 2005
  • In this paper, we propose a chaotic underwater robots that have unstable limit cycles in a chaos trajectory surface with Arnold equation, Chua's equation. We assume all obstacles in the chaos trajectory surface have a Van der Pol equation with an unstable limit cycle. We also show computer simulation results of Arnold equation and Chua's equation chaos trajectories with one or more Van der Pol obstacles

  • PDF

한국산 서해낙지(Octopus minor) 정자완성에 관한 미세구조

  • 김상원;장남섭;한종민;황선종
    • Proceedings of the Korean Society of Fisheries Technology Conference
    • /
    • 2001.05a
    • /
    • pp.596-598
    • /
    • 2001
  • 두족강(Cephalopoda)의 정자에 관한 연구는 Chun(1903)의 연구를 필두로 많은 연구가 있었다(Pickford 1940, 1957; Franzen, 1967; Young 1977; Fioroni, 1981; Boss, 1982), 이들 중 Franzen(1967)은 광학 현미경을 통해 Cephalopoda를 대상으로 여러종의 정자 변태 과정을 관찰한 바 있다. 특히 전자현미경을 사용한 연구는 1968년 Galangau와 Tuzet에 의해 시작되었고 정자의 미세구조와 상세한 변태과정이 보고되어져 왔다(Longo & Anderson, 1970; Maxwell, 1974, 1975; Fields & Thompson, 1976; Arnold & Williams-Arnold, 1978; Healy, 1988; Alvarez Perez et al. 1990). (중략)

  • PDF

An inventory of Korean living collections in the Arnold Arboretum of Harvard University, USA

  • Lee, Sang Jun;Kim, Jung-Hyun;Nam, Gi-Heum;Kim, Min-Ha;Lim, Chae Eun
    • Journal of Species Research
    • /
    • v.3 no.2
    • /
    • pp.183-194
    • /
    • 2014
  • As part of a study to understand the current status of Korean plant species propagated in foreign countries, we conducted extensive surveys on Korean living collections in the Arnold Arboretum of Harvard University, the oldest public arboretum in North America. Specifically, we collected and identified the voucher specimens of the living collections and further examined the collection databases to understand the history of how Korean plants were introduced to the Arboretum. We found that a total of 154 Korean taxa (belonging to 49 families and 81 genera) have been planted in the arboretum. Most plants originated from seeds that were directly collected in Korea or obtained via seed exchanges with botanical gardens in Asia, Europe, and U.S.A. Of the 154 taxa, 16 are Korean endemic species, and three are listed as endangered species. In addition, 62 taxa are as floristic regional indicator species of Korea used by the Ministry of Environment.

Digital Watermarking based on Wavelet Transform for Color Images (웨이블릿 변환 기반의 컬러 영상에 대한 디지털 워터마킹)

  • Piao, Yong-Ri;Kim, Seok-Tae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2007.06a
    • /
    • pp.127-130
    • /
    • 2007
  • This paper proposes a new Digital Watermarking based on Wavelet Transform for Color Images. To ensure the security of the watermark, enlarged watermark by applying linear bit expansion is inserted in a given intensity to a low frequency subband of the color image Y band which is Wavelet transformed after the Arnold Transformation. When detecting the presence of watermark, F norm function is applied unlike the existing methods. The experiment results verify that the proposed watermarking technique has outstanding quality in regards to fidelity and robustness.

  • PDF

An Improved Secure Semi-fragile Watermarking Based on LBP and Arnold Transform

  • Zhang, Heng;Wang, Chengyou;Zhou, Xiao
    • Journal of Information Processing Systems
    • /
    • v.13 no.5
    • /
    • pp.1382-1396
    • /
    • 2017
  • In this paper, we analyze a recently proposed semi-fragile watermarking scheme based on local binary pattern (LBP) operators, and note that it has a fundamental flaw in the design. In this work, a binary watermark is embedded into image blocks by modifying the neighborhood pixels according to the LBP pattern. However, different image blocks might have the same LBP pattern, which can lead to false detection in watermark extraction process. In other words, one can modify the host image intentionally without affecting its watermark message. In addition, there is no encryption process before watermark embedding, which brings another potential security problem. To illustrate its weakness, two special copy-paste attacks are proposed in this paper, and several experiments are conducted to prove the effectiveness of these attacks. To solve these problems, an improved semi-fragile watermarking based on LBP operators is presented. In watermark embedding process, the central pixel value of each block is taken into account and Arnold transform is adopted to guarantee the security of watermark. Experimental results show that the improved watermarking scheme can overcome the above defects and locate the tampered region effectively.

Color Images Watermarking Based on Wavelet Transform (웨이블릿 변환 기반의 컬러영상 워터마킹)

  • Piao, Yong-Ri;Kim, Seok-Tae
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.11 no.10
    • /
    • pp.1828-1834
    • /
    • 2007
  • This study proposes a new digital watermarking technique based on wavelet transformation on color image. First the $YC_bC_r$ coordinates obtain from RGB color space. then, the correlation of watermark is decreased by Arnold transformation. Next, watermark which has been enlarged by Linear Bit-expansion is inserted at a given intensity in Color images' low frequency sub-bands. When detecting the presence of watermark, F-norm function is applied. As a result of the various experiments on color images, the proposed watermarking technique has outstanding quality in regards to fidelity and robustness.

A Case of Neurilemmoma Originating From Arnold's Nerve (아놀드 신경에서 발생한 외이도의 신경초종 1예)

  • Lee, Oh Hyeong;Park, Jung Mee;Han, Jung Ju;Park, Shi Nae
    • Journal of Clinical Otolaryngology Head and Neck Surgery
    • /
    • v.29 no.2
    • /
    • pp.245-249
    • /
    • 2018
  • Neurilemmoma is a benign tumor that originates from the Schwann cell. It frequently occurs in head and neck regions, but neurilemmoma of external auditory canal is extremely rare. Here, we report a very rare case of 36-year-old male with a tumor located in the posterior wall of external auditory canal, preoperatively suspected as neurilemmoma originated from Arnold's nerve by temporal bone magnetic resonance imaging. The tumor mass was surgically excised and pathologically confirmed as a neurilemmoma.