• 제목/요약/키워드: eigen-analysis

검색결과 318건 처리시간 0.023초

서부태평야지역에서 일본 다랑어선망어업의 어획특성 (Catch Specification of Japanese Tuna Purse Seine in the Western Pacific Ocean)

  • 김형석
    • 수산해양기술연구
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    • 제35권3호
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    • pp.243-249
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    • 1999
  • Specificity of catches has been analyzed to japanese tuna purse seine A principle component analysis was used to improve the efficiency of fishing and increase sustainable production and productivity of Korean tuna purse seine.The result are as follows;From the principal component analysis of the fish catches, the first principal component(Z1) to promote principal component score was skipjack Kastsuwonus Pelamis, LINNAEUS and yellowfin tuna Thunnus Albacares, BONNATERRE (Small : smaller than 10kg) and proportion was 86.8% of total. The second principal component(Z2) to increase principal component score was yellowfin tuna (Large : larger than 10kg) and proportion was 9.5%.On the other hand, fish operating that have caught skipjack and yellowfin tuna (Small and Larger) was not so much. Fish catches for one species raised volume of the catches while catches for multi-species decreased it since principal composition score for one species and both species together has been increased.Fish school could be divided into three groups of schools each of which was associated with drift objects, payaho and ship, school associated with shark, whale and porpoise and school of breezing, feeding and jumping from proportion of principal component analysis for fish catches of school types. However, the biological pattern is different among school associated with ship, payaho and school associated with drift objects for analysis eigen vector. School associated with ship, payaho and school associated with drifting object associated is judged as school which be assembled to vessel and drifted log temporary.

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새로운 부등매개변수 면회변형 곡선보 요소 (A New Anisoparametric Out-of-Plane Deformable Curved Beam Element)

  • 유재형;유승원;민옥기
    • 대한기계학회논문집A
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    • 제25권4호
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    • pp.582-591
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    • 2001
  • It is known that the reduced integration, modified shape function, anisoparametric and non-conforming element can reduce the error induced by stiffness locking phenomenon in the finite element analysis. In this study, we propose new anisoparametric curved beam element. The new element based on reduced minimization theory is composed of different shape functions in each displacement field. By the substitution of this modified shape function, the unmatched coefficient that cause stiffness locking in the constraint energy is eliminated. To confirm the availability of this new model, we performed numerical tests for a simple model. As a result of numerical test, the undulate stress patterns are disappeared in static analysis, and displacements and stresses are close to exact solution. Not only in the static analysis but also in the eigen analysis of free vibrated curved beam model, this element shows successful convergent results.

위상최적설계를 이용한 차체 점용접 배치 최적화 연구 (A Study on Optimal Spot-weld Layout Design of the Car Body Structure Using Topology Optimization)

  • 김성래;이채욱;김문영;김찬묵;임홍재
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2012년도 춘계학술대회 논문집
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    • pp.361-366
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    • 2012
  • In this paper, we propose the efficient technique that reduces the number of spot-welds and increases the structural rigidity by using the topology optimization technique. Eigen value analysis is used to evaluate the rigidity of the optimized model. As a first step, the topology optimization is performed to find optimal spot-weld distributions. In this study, the design objective is to maximize the weighted frequencies. The volume fractions of the weld components are used as design constraints, and also the densities of each element in the individual design space are used as design variables. And then, to consider the possibility of spot-weld failure, the contribution rate analysis was performed by using the orthogonal array method of DOE. The spot-welds in the rear panel part are reinforced according to estimation results of the contribution rate analysis. Finally, we obtained optimized spot-weld layout model which has the reduced number of spot-welds and the improved dynamic stiffness.

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한국어판 감성지능 측정도구의 신뢰도와 타당도 검증 (The Reliability and Validity of Korean Version of Wong and Law Emotional Intelligence Scale (K-WLEIS))

  • 정하림;최희정;박명숙
    • 대한간호학회지
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    • 제50권4호
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    • pp.611-620
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    • 2020
  • Purpose: The aim of this study was to evaluate the reliability and validity of the Korean version of the Wong and Law Emotional Intelligence Scale (K-WLEIS). Methods: Data were collected from 360 nursing students using a self reported questionnaire. Exploratory and confirmatory factor analysis were used to test construct validity. Convergence validity was identified by correlation with communication competency. Item convergent and discriminant validity were also analyzed. Reliability was evaluated internal consistency and test-retest reliability. Results: The results of exploratory factor analysis showed that the eigen values ranged from 1.34 to 5.86 and 73.2% of the total explained variance. Confirmatory factor analysis showed adequate model fit indices (χ2/df 1.89, RMSEA .07, GFI .89, CFI .95, and TLI .93) and standardized factor loadings (.48 to .87). The average extracted variances (.71 to .79) and composite reliability (.80 to .87) validated convergence and discriminant validity of the items. Test-retest reliability of intra-class correlation coefficient was .90 and the Cronbach's alpha coefficient was .88. Conclusion: The K-WLEIS is an appropriate scale for measuring the emotional intelligence of Korean nursing students. Therefore, it is expected that the K-WLEIS will be used for nursing education programs to improve nursing students' emotional intelligence.

Photon-counting linear discriminant analysis for face recognition at a distance

  • Yeom, Seok-Won
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제12권3호
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    • pp.250-255
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    • 2012
  • Face recognition has wide applications in security and surveillance systems as well as in robot vision and machine interfaces. Conventional challenges in face recognition include pose, illumination, and expression, and face recognition at a distance involves additional challenges because long-distance images are often degraded due to poor focusing and motion blurring. This study investigates the effectiveness of applying photon-counting linear discriminant analysis (Pc-LDA) to face recognition in harsh environments. A related technique, Fisher linear discriminant analysis, has been found to be optimal, but it often suffers from the singularity problem because the number of available training images is generally much smaller than the number of pixels. Pc-LDA, on the other hand, realizes the Fisher criterion in high-dimensional space without any dimensionality reduction. Therefore, it provides more invariant solutions to image recognition under distortion and degradation. Two decision rules are employed: one is based on Euclidean distance; the other, on normalized correlation. In the experiments, the asymptotic equivalence of the photon-counting method to the Fisher method is verified with simulated data. Degraded facial images are employed to demonstrate the robustness of the photon-counting classifier in harsh environments. Four types of blurring point spread functions are applied to the test images in order to simulate long-distance acquisition. The results are compared with those of conventional Eigen face and Fisher face methods. The results indicate that Pc-LDA is better than conventional facial recognition techniques.

Applied Koopmanistic interpretation of subcritical prism wake physics using the dynamic mode decomposition

  • Cruz Y. Li;Xisheng Lin;Gang Hu;Lei Zhou;Tim K.T. Tse;Yunfei Fu
    • Wind and Structures
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    • 제37권3호
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    • pp.191-209
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    • 2023
  • This work investigates the subcritical free-shear prism wake at Re=22,000 by the Koopman analysis using the Dynamic Mode Decomposition (DMD) algorithm. The Koopman model linearized nonlinearities in the stochastic, homogeneous anisotropic turbulent wake, generating temporally orthogonal eigen tuples that carry meaningful, coherent structures. Phenomenological analysis of dominant modes revealed their physical interpretations: Mode 1 renders the mean-field dynamics, Modes 2 describes the roll-up of the Strouhal vortex, Mode 3 describes the Bloor-Gerrard vortex resulting from the Kelvin-Helmholtz instability inside shear layers, its superposition onto the Strouhal vortex, and the concurrent flow entrainment, Modes 6 and 10 describe the low-frequency shedding of turbulent separation bubbles (TSBs) and turbulence production, respectively, which contribute to the beating phenomenon in the lift time history and the flapping motion of shear layers, Modes 4, 5, 7, 8, and 9 are the relatively trivial harmonic excitations. This work demonstrates the Koopman analysis' ability to provide insights into free-shear flows. Its success in subcritical turbulence also serves as an excellent reference for applications in other nonlinear, stochastic systems.

Dynamic analysis of a rotating tapered composite Timoshenko shaft

  • Zahi Rachid;Sahli Abderahmane;Moulgada Abdelmadjid;Ziane Noureddine;Refassi Kaddour
    • Steel and Composite Structures
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    • 제48권4호
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    • pp.429-441
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    • 2023
  • This research presents an advanced finite element formulation for analyzing the vibratory behaviour of tapered composite shaft rotors, taking into account the impact of the draft angle on the stiffness of the composite shaft laminate. The vibration response of the shaft rotating around its axis is studied using both the finite element hierarchical method and the classical finite element formulation, based on the theory of transverse shear deformation, rotary inertia, gyroscopic effect, and coupling effect due to the stratification of the composite layers of the shaft. The study also includes the development of a program to calculate the Eigen frequencies and critical speeds of the system, and the obtained results are compared with those available in the literature. This research provides valuable insights into the vibratory behaviour of tapered composite shaft rotors and can be useful for designing and optimizing such structures in various industrial applications.

학제적 분야의 정보서비스를 위한 학술지 인용 분석에 관한 연구: Y대학교 생명공학과를 중심으로 (Journal Citation Analysis for Library Services on Interdisciplinary Domains: A Case Study of Department of Biotechnology, Y University)

  • 유소영;이재윤
    • 정보관리학회지
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    • 제25권4호
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    • pp.283-308
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    • 2008
  • 이 연구에서는 자관의 학술지 상호인용 및 동시인용 분석을 통하여 단순 피인용빈도 이상의 학술지 인용 패턴 분석을 시도 하였다. 이 연구를 통해 학술지의 중요도 파악에 있어서 자관 인용 네트워크의 구조적 분석이 인용빈도 이상의 자관 인용 패턴에 대한 설명을 하고 있는지와, Web of Science에서 제공하는 JIF 이외의 일반적 인용 지수 서비스들을 고려해야 할 필요성이 있는지를 살펴보았다. Y대학교 생명시스템대학 생명공학과 전.현직 교수진이 2006년과 2007년에 발표한 학술논문의 인용 네트워크 분석 및 Web of Science 이외의 일반적 인용 지수들간의 관계를 분석한 결과는 다음과 같다. 첫째, 자관의 상호인용 네트워크를 통해 자관의 연구 분야를 확인할 수 있었다. 둘째, 자관의 동시인용 네트워크 지수들은 자관 인용 네트워크의 구조적 속성을 반영하는 인용 패턴의 설명이 가능하며 이는 피인용빈도와 유사하면서도 추가적인 설명력을 가지는 것을 확인하였다. 셋째, 일반적 인용지수로는 JIF 외에도 합산지향지수, h-index와 같은 다양한 일반적 인용 지수들의 설명력이 다양하므로 이를 이용하여 다각적으로 고려하는 것이 필요한 것으로 파악되었다. 또한 학술지 평가에서 인용 색인 데이터베이스의 수록범위보다는 지수의 유형에 따른 설명력 차이가 크다는 것을 확인하였다. 이와 같은 자관의 인용 네트워크 분석은 정보서비스의 여러 분야에서 유용하게 사용될 수 있을 것으로 기대된다.

부분공간법에 의한 건축구조물의 동특성 식별 (System Identification of Building Structure using Subspace Identification Method)

  • 배기환
    • 한국공간구조학회논문집
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    • 제3권4호
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    • pp.53-58
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    • 2003
  • In order to control seismic responses of building structures effectively and stably, it is very important to estimate the dynamic characteristics of target structure exactly based on input-output signal data. In this paper, it is shown that Subspace Identification Method is able to be applied effectively to system identification of building structures. To verify the efficiency of Subspace Identification Method, the vibration experiments were conducted on a specimen structure which is a 5-storied building structure model consisted of H-shaped steel beam, and the simulated seismic responses of the identified structure model were compared with the observed ones under the same excitation. It was observed that the experimental results coincided with the analyzed ones proposed in this paper.

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단층 래티스 돔의 기하학적 비선형 좌굴하중 추정에 관한 연구 (A Study on the Presumption of Geometrically Nonlinear Buckling Load of the Single Layer Layer Latticed Dome)

  • 이정현;최일섭;이상주;한상을
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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    • pp.12-19
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    • 2005
  • The single layer latticed dome is very sensitive on the slenderness ratio and half open angle of the elements, load condition and the connection type because it is organized by a lot of thin elements, so we have to use the geometrically nonlinear buckling load when the buckling behavior of the structures is analyzed But, it is very difficult to design the single layer latticed domes considered all conditions. Therefore the purpose of this paper is to propose the appropriate design method of the single layer latticed dome considered the geometrically nonlinear buckling load in base on the linear buckling load by the eigen-value analysis.

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