• Title/Summary/Keyword: Euler Number

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An Improved Nonparametric Change Detection Algorithm Using Euler Number and Structure Tensor (오일러 수와 구조 텐서를 사용한 개선된 Nonparametric 변화 검출 알고리즘)

  • 이웅희;김태희;정동석
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.10C
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    • pp.958-966
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    • 2003
  • Change detection algorithms based on frame difference are frequently used for finding moving objects in image sequences. These algorithms detect the change of frames using estimated statistical background model. But, if this estimated background model is different from the actual statistical distribution, false detections are generated. In this paper, we propose an improved change detection algorithm using euler number and structure tensor. The proposed mapping method which is based on the euler number can be used for reducing the false detections that generated by nonparametric change detection algorithm. In this paper, the change in the region of moving object also can be detected by the proposed method using structure tensor. Experimental result shows that the proposed method reduces the false detections effectively by 90% on "Weather", by 34% on "Mother & daughter" and by 43% on "Aisle" than an existing method does.

Puzzle Rule Algorithm of Euler Square Game (오일러 방진 게임 퍼즐 규칙 알고리즘)

  • Lee, Sang-Un
    • Journal of Industrial Convergence
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    • v.19 no.4
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    • pp.23-28
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    • 2021
  • This paper finds the regular pattern of n = [3, ∞] for Euler square game related with n = 6(6×6=36) thirty-six officer problem that is still unsolved problem. The solution of this problem is exists for n = [3, 10] without n = 6. Also, previous researchers finds the random assigned solution for specific number using computer programming. Therefore, the solution of n = [11, ∞] Euler squares are unsolved problem because of anything but easy. This paper attempts to find generalized patterns for domains that have been extended to n = [3, ∞], while existing studies have been limited to n = [3, 10]. This paper classify the n = [3, ∞] into n = odd, 4k even, 4k+2 even of three classes. Then we find the simple regular pattern solution for n = odd and 4k even(n/2 = even). But we can't find the regular pattern for 4k+2 even(n/2 = odd).

A Heuristic Algorithm for Minimal Area CMOS Cell Layout (최소 면적의 CMOS 기능셀 설계도면을 찾는 휴리스틱 알고리즘)

  • Kwon, Yong-Joon;Kyung, Chong-Min
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1463-1466
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    • 1987
  • The problem of generating minimal area CMOS functional cell layout can be converted to that of decomposing the transistor connection graph into a minimum number of subgraphs, each having a pair of Euler paths with the same sequence of input labels on the N-graph and P-graph, which are portions of the graph corresponding to NMOS and PMOS parts respectively. This paper proposes a heuristic algorithm which yields a nearly minimal number of Euler paths from the path representation formula which represents the give a logic function. Subpath merging is done through a list processing scheme where the pair of paths which results in the lowest cost is successively merged from all candidate merge pairs until no further path merging and further reduction of number of subgraphs are possible. Two examples were shown where we were able to further reduce the number of interlaces, i.e., the number of non-butting diffusion islands, from 3 to 2, and from 2 to 1, compared to the earlier work [1].

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Prediction of Dynamic Stability Derivatives Using Unsteady Euler Equations (비정상 Euler 방정식을 이용한 동안정 미계수 예측)

  • Park Soo Hyung;Kim Yoonsik;Kwon Jang Hyuk
    • 한국전산유체공학회:학술대회논문집
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    • 2001.05a
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    • pp.78-84
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    • 2001
  • A dual-time stepping algorithm combined with a parallelized multigrid DADI method is presented to predict the dynamic damping coefficients. The Basic Finner model is chosen to validate the prediction capability of the present unsteady Euler method. The linearity of the pitch- and roll-damping coefficients is shown in the low angular rates and the interesting large drop and stiff increment in transonic region for roll-damping coefficients are explained in detail. Through the analysis for the pressure distributions at Mach number 1.0 to 1.2, the sudden drop results from the normal shock and the stiff increment of roll-damping reflects the transition of the normal shock to the oblique shock. The results also show that the Euler equations can give the damping coefficients with a comparable accuracy.

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Temperature Preconditioning for Improving Convergence Characteristics in Calculating Low Mach Number Flows, I: Euler Equations (저속 유동 계산의 수렴성 개선을 위한 온도예조건화 I: 오일러 방정식)

  • Lee, Sang-Hyeon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.12
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    • pp.1067-1074
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    • 2007
  • A temperature preconditioning that modulates the derivative of density with respect to temperature is proposed to improve the convergence characteristics of the preconditioned Euler equations. Flows in a two-dimensional channel with a 10% circular bump in the middle of the channel were calculated at different speeds. The numerical dissipation terms of the Roe’s FDS scheme according to the temperature preconditioning are derived. It is shown that the temperature preconditioning accelerates convergence of the preconditioned Euler equations.

Frequency, bending and buckling loads of nanobeams with different cross sections

  • Civalek, Omer;Uzun, Busra;Yayli, M. Ozgur
    • Advances in nano research
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    • v.9 no.2
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    • pp.91-104
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    • 2020
  • The bending, stability (buckling) and vibration response of nano sized beams is presented in this study based on the Eringen's nonlocal elasticity theory in conjunction with the Euler-Bernoulli beam theory. For this purpose, the bending, buckling and vibration problem of Euler-Bernoulli nanobeams are developed and solved on the basis of nonlocal elasticity theory. The effects of various parameters such as nonlocal parameter e0a, length of beam L, mode number n, distributed load q and cross-section on the bending, buckling and vibration behaviors of carbon nanotubes idealized as Euler-Bernoulli nanobeam is investigated. The transverse deflections, maximum transverse deflections, vibrational frequency and buckling load values of carbon nanotubes are given in tables and graphs.

Analytical analysis for the forced vibration of CNT surrounding elastic medium including thermal effect using nonlocal Euler-Bernoulli theory

  • Bensattalah, Tayeb;Zidour, Mohamed;Daouadji, Tahar Hassaine
    • Advances in materials Research
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    • v.7 no.3
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    • pp.163-174
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    • 2018
  • This article studies the free and forced vibrations of the carbon nanotubes CNTs embedded in an elastic medium including thermal and dynamic load effects based on nonlocal Euler-Bernoulli beam. A Winkler type elastic foundation is employed to model the interaction of carbon nanotube and the surrounding elastic medium. Influence of all parameters such as nonlocal small-scale effects, high temperature change, Winkler modulus parameter, vibration mode and aspect ratio of short carbon nanotubes on the vibration frequency are analyzed and discussed. The non-local Euler-Bernoulli beam model predicts lower resonance frequencies. The research work reveals the significance of the small-scale coefficient, the vibrational mode number, the elastic medium and the temperature change on the non-dimensional natural frequency.

Orthogonal Latin squares of Choi Seok-Jeong (최석정의 직교라틴방진)

  • Kim, Sung-Sook;Khang, Mee-Kyung
    • Journal for History of Mathematics
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    • v.23 no.3
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    • pp.21-31
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    • 2010
  • A latin square of order n is an $n{\times}n$ array with entries from a set of n numbers arrange in such a way that each number occurs exactly once in each row and exactly once in each column. Two latin squares of the same order are orthogonal latin square if the two latin squares are superimposed, then the $n^2$ cells contain each pair consisting of a number from the first square and a number from the second. In Europe, Orthogonal Latin squares are the mathematical concepts attributed to Euler. However, an Euler square of order nine was already in existence prior to Euler in Korea. It appeared in the monograph Koo-Soo-Ryak written by Choi Seok-Jeong(1646-1715). He construct a magic square by using two orthogonal latin squares for the first time in the world. In this paper, we explain Choi' s orthogonal latin squares and the history of the Orthogonal Latin squares.

Analysis of Airship Gust Response Using Low Mach Number Preconditioning (저마하수 예조건화 기법을 이용한 비행선의 돌풍 응답 해석)

  • Kim, Joo-Sung;Nam, Hwa-Jin;Kwon, Oh-Joon;Yeom, Chan-Hong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.5
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    • pp.30-40
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    • 2004
  • In the present study, a numerical method has been developed for the calculation of the gust response of an airship using unstructured meshes. A preconditioning method is incorporated for accurate and efficient computations of the Euler equations at the low Mach number range. A simple sharp-edged gust is used as a gust model. The accuracy of the present method is demonstrated through comparisons with an exact line theory. The numerical results show that the variation of lift is relatively larger than that of moment. It is also shown that the static stability of the airship is enhanced with the use of control fins.

A History and Meaning of the Number ${\varrho}$ (${\varrho}$의 역사적 기원과 의의)

  • 김성숙
    • Journal for History of Mathematics
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    • v.17 no.3
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    • pp.33-42
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    • 2004
  • ${\varrho}$ is the real constant number that appears not only in calculus but also in a real life. The concept of the number ${\varrho}$ first appeared in an appendix of Napier's work on logarithms in 1618. The early developments on the logarithm became part of an understanding of the number ${\varrho}$. In 1727, the number ${\varrho}$ was studied by Euler explicitly. It ton14 almost 100 years to understand the number ${\varrho}$ which we learn in high school nowadays. By studying the origin of the number ${\varrho}$, we can guess that many mathemetician's research in our time will have significant meaning in the future although it looks like just some calculations of cohomology or K-theory etc.

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