• 제목/요약/키워드: exact methods

검색결과 1,939건 처리시간 0.026초

이진영상을 이용한 효율적인 에지 기반의 디인터레이싱 보간 알고리즘 (Overload Measurement and Control of Access Control Channel Based on Hysteresis at Satellite Communication of DAMA)

  • 이청언;김성관;이동호
    • 한국통신학회논문지
    • /
    • 제30권8C호
    • /
    • pp.801-809
    • /
    • 2005
  • 본 논문에서는 디인터레이싱 방법 중에서 가장 중요한 요소인 공간 필터의 성능 개선을 위한 새로운 알고리즘을 제안한다. 기존의 에지 기반 알고리즘들은 보간의 성능을 좌우하는 정확한 에지 방향을 판단함에 있어서 만족스럽지 못하다. 제안하는 알고리즘은 에지 대신에 원 영상의 이진화 된 영상을 근간으로 에지의 방향과 기울기를 판단함으로써 효율성과 정확도를 증가시켰으며 보다 완만한 각에서의 방향판단을 위하여 탐색 윈도우 수평 크기를 IS로 증가시켰다. 기존의 에지를 이용한 방항 판단보다 이진화 된 이미지를 근간으로 에지의 방항과 기울기를 판단하여 보간 했을 때 판단의 오류를 최소화하여 차질을 향상시킬 수 있었다. 다양한 종류의 영상에 대한 컴퓨터 모의 실험 결과를 통하여 기존의 에지 기반의 보간 방법들에 비해 성능이 매우 우수함을 보였다.

Effect of higher order terms of Maclaurin expansion in nonlinear analysis of the Bernoulli beam by single finite element

  • Zahrai, Seyed Mehdi;Mortezagholi, Mohamad Hosein;Mirsalehi, Maryam
    • Structural Engineering and Mechanics
    • /
    • 제58권6호
    • /
    • pp.949-966
    • /
    • 2016
  • The second order analysis taking place due to non-linear behavior of the structures under the mechanical and geometric factors through implementing exact and approximate methods is an indispensible issue in the analysis of such structures. Among the exact methods is the slope-deflection method that due to its simplicity and efficiency of its relationships has always been in consideration. By solving the differential equations of the modified slope-deflection method in which the effect of axial compressive force is considered, the stiffness matrix including trigonometric entries would be obtained. The complexity of computations with trigonometric functions causes replacement with their Maclaurin expansion. In most cases only the first two terms of this expansion are used but to obtain more accurate results, more elements are needed. In this paper, the effect of utilizing higher order terms of Maclaurin expansion on reducing the number of required elements and attaining more rapid convergence with less error is investigated for the Bernoulli beam with various boundary conditions. The results indicate that when using only one element along the beam length, utilizing higher order terms in Maclaurin expansion would reduce the relative error in determining the critical buckling load and kinematic parameters in the second order analysis.

지중 매설 강관의 전자유도 전파상수 계산 방식별 적용성 분석 (Analysis on Several Calculation Methods of Propagation Constant for a Buried Metallic Pipe)

  • 이상무;최문환;조평동
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국정보통신학회 2012년도 추계학술대회
    • /
    • pp.590-593
    • /
    • 2012
  • 매설강관에 대한 전파상수는 대지도전율에 의한 매질 영향을 받기 때문에 대기중에서의 해석과 같지 않고 복잡한 초월식을 풀어야 하는 어려움이 있다. 이러한 매설관에 대한 전파상수 해석에 관하여는 Wait의 논문에서 연구되어 있고 이것을 근간으로 일본과 미국에서 각각 전송선 이론에 의한 초월식을 실용적으로 수립하여 제시하고 있다. 본 논문에서는 매설 강관에 대한 몇 가지 다른 형태의 전파상수 계산식에 대하여 시뮬레이션을 통한 값을 다루어 보고 유도전압에 대하여 적절한 산출 적용이 되는 지 검토하여 본 바 정학한 계의 해석에 의한 것과 Wait 근간의 일본 방식에 의한 계산값이 유사한 것으로 도출되었다.

  • PDF

인셉션 모듈 기반 컨볼루션 신경망을 이용한 얼굴 연령 예측 (Facial Age Estimation Using Convolutional Neural Networks Based on Inception Modules)

  • ;조현종
    • 전기학회논문지
    • /
    • 제67권9호
    • /
    • pp.1224-1231
    • /
    • 2018
  • Automatic age estimation has been used in many social network applications, practical commercial applications, and human-computer interaction visual-surveillance biometrics. However, it has rarely been explored. In this paper, we propose an automatic age estimation system, which includes face detection and convolutional deep learning based on an inception module. The latter is a 22-layer-deep network that serves as the particular category of the inception design. To evaluate the proposed approach, we use 4,000 images of eight different age groups from the Adience age dataset. k-fold cross-validation (k = 5) is applied. A comparison of the performance of the proposed work and recent related methods is presented. The results show that the proposed method significantly outperforms existing methods in terms of the exact accuracy and off-by-one accuracy. The off-by-one accuracy is when the result is off by one adjacent age label to the above or below. For the exact accuracy, the age label of "60+" is classified with the highest accuracy of 76%.

요부(腰部) 독맥경(督脈經)의 혈위(穴位) 결정방법(決定方法)에 관한 연구(硏究)(X-선상(線像)을 중심(中心)으로) (The Research about Checking Method of Governor Vessel's Acupoints at Lumbar Regions : (compared with X-ray measuring))

  • 최익선
    • Journal of Acupuncture Research
    • /
    • 제17권4호
    • /
    • pp.1-4
    • /
    • 2000
  • For checking the exact acupuncture points of Governor Vessel(GV) at lumbar regions, five kinds of method were used to 100 patients who have treated in outpatient in our hospital. They were attached distinguishable stainless steel by the methods. And those were compared with X-ray measuring. As a results, the best method to check Yoyang-gwan(GV3, Ya~oyanggua~n) was the way of using both iliac crests at lateral lying position.

  • PDF

차폐분리에 의한 전력케이블 및 접속함의 부분방전 위치 검출 (PD Localization by Metal Sheath Interruption Methods for Power Cable and Accessories)

  • 이창영;신두성;김충식;김동욱;박완기
    • 대한전기학회논문지:전기물성ㆍ응용부문C
    • /
    • 제49권3호
    • /
    • pp.196-201
    • /
    • 2000
  • It is very important not only to detect PD signal but also to locate PD source in power cable line including its accessories. In this paper, the PID localization technique using interruption of metal sheath of cable or accessory is described. By interruption of metal sheath, the polarity of PD pulse to be measured on each part can be compared. With this technique, the exact location of PD in the accessory which has some defects can be found. Although the 'Soft' interruption method, that is, cable sheath is divided by semi-conductive layer with the resistance of higher than 1 k$\Omega$, was used instead of 'Hard' interruption method, it is also possible to detect exact location of PD. This technique is considered to be very effective for detecting PD localization in the type test of cable and accessories.

  • PDF

퍼스컴에 의한 회로 설계시 몬테칼로 시뮬레이션에 의한 프로그램 개발에 관한 연구 (A study on the development of circuit design by new simulation program)

  • 차균현;이근철
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1986년도 하계학술대회논문집
    • /
    • pp.490-491
    • /
    • 1986
  • Design of electronic circuit should be both economical and reliable. If we put weight on economy, reliability will be lessened vice versa. But in some cases, a Designer should do exact design looking down upon economy. Especially, in integrated circuit, we should design as exactly as possible without much tolerance. In my thesis, I have studied the method for the exact design without much consideration in economy, and I also have developed Monte carlo Simulation program which can be operated by new generation of pseudo random number. Here, in my study, I have found out that new generation of pseudo random number was much more superior to any methods suggested by orthers.

  • PDF

Stability of multi-step flexural-shear plates with varying cross-section

  • Xu, J.Y.;Li, Q.S.
    • Structural Engineering and Mechanics
    • /
    • 제16권5호
    • /
    • pp.597-612
    • /
    • 2003
  • In this paper, multi-story buildings with shear-wall structures and with narrow rectangular plane configuration are modeled as a multi-step flexural-shear plate with varying cross-section for buckling analysis. The governing differential equation of such a plate is established. Using appropriate transformations, the equation is reduced to analytically solvable equations by selecting suitable expressions of the distribution of stiffness. The exact solutions for buckling of such a one-step flexural-shear plate with variable stiffness are derived for several cases. A new exact approach that combines the transfer matrix method and closed from solution of one-step flexural-shear plate with continuously varying stiffness is presented for stability analysis of multi-step non-uniform flexural-shear plate. A numerical example shows that the present methods are easy to implement and efficient.

무릎 관절각을 이용한 무릎 근육 길이와 모멘트 암 추정 (Estimation of Knee Muscle Length and Moment Arm Using Knee Joint Angle)

  • 이재강;남윤수
    • 산업기술연구
    • /
    • 제28권A호
    • /
    • pp.167-176
    • /
    • 2008
  • Recently, lots of studies are performed in developing of active orthosis. Exact and simple muscle force estimation is important in developing orthosis which assists muscle force for disabled people or physical laborers. Hill-type muscle model dynamics is common method for estimation of muscle forces. In Hill-type muscle model, we must know muscle length and moment arm which largely affect muscle force. And several methods are proposed to estimate muscle length and moment arm using joint angle. In this study, we compared estimation results of those method with data from body model of opensim to find which method is exact for estimation of muscle length and moment arm.

  • PDF

Improved methods for measuring early reflections from Five-channel room impulse response using newly introduced Peak-Detecting algorithm

  • Kim Lae-Hoon;Doo Sejin;Oh Yangki;Lee Heewon;Sung Koeng-Mo
    • 한국음향학회:학술대회논문집
    • /
    • 한국음향학회 2000년도 하계학술발표대회 논문집 제19권 1호
    • /
    • pp.439-442
    • /
    • 2000
  • When we measure the acoustical properties of a room using multiple microphone system, it is important to grasp exact time delay of the early reflections from impulse response pair. But it is often very difficult to identify the early reflections in natural shape, because a waveform may be deformed due to the characteristics of a sound source loudspeaker, microphone and reflected wall and overlapping of plural waveform. In this paper to obtain more accurate and enough early reflections, we propose the brand-new five-channel sound receiving system and introduce peak-detecting algorithm. The system has microphones mounted at the origin and four points of a regular tetrahedron. The newly introduced peak-detecting algorithm can show exact peak position in each channel, in spite of deformation due to reflected walls, loudspeaker and microphone.

  • PDF