• Title/Summary/Keyword: Global/local analysis

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A motion descriptor design combining the global feature of an image and the local one of an moving object (영상의 전역 특징과 이동객체의 지역 특징을 융합한 움직임 디스크립터 설계)

  • Jung, Byeong-Man;Lee, Kyu-Won
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.10a
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    • pp.898-902
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    • 2012
  • A descriptor which is suitable for motion analysis by using the motion features of moving objects from the real time image sequence is proposed. To segment moving objects from the background, the background learning is performed. We extract motion trajectories of individual objects by using the sequence of the $1^{st}$ order moment of moving objects. The center points of each object are managed by linked list. The descriptor includes the $1^{st}$ order coordinates of moving object belong to neighbor of the per-defined position in grid pattern, the start frame number which a moving object appeared in the scene and the end frame number which it disappeared. A video retrieval by the proposed descriptor combining global and local feature is more effective than conventional methods which adopt a single feature among global and local features.

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Application of the Preconditioned Conjugate Gradient Method to the Generalized Finite Element Method with Global-Local Enrichment Functions (전처리된 켤레구배법의 전체-국부 확장함수를 지닌 일반유한요소해석에의 응용)

  • Choi, Won-Jeong;Kim, Min-Sook;Kim, Dae-Jin;Lee, Young-Hak;Kim, Hee-Cheul
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.4
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    • pp.405-412
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    • 2011
  • This paper introduces the generalized finite element method with global-local enrichment functions using the preconditioned conjugate gradient method. The proposed methodology is able to generate enrichment functions for problems where limited a-priori knowledge on the solution is available and to utilize a preconditioner and initial guess of good quality with only small addition of computational cost. Thus, it is very effective to analyze problems where a complex behavior is locally exhibited. Several numerical experiments are performed to confirm its effectiveness and show that it is computationally more efficient than the analysis utilizing direct solvers such as Gauss elimination method.

Study on the Hand Gesture Recognition System and Algorithm based on Millimeter Wave Radar (밀리미터파 레이더 기반 손동작 인식 시스템 및 알고리즘에 관한 연구)

  • Lee, Youngseok
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.12 no.3
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    • pp.251-256
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    • 2019
  • In this paper we proposed system and algorithm to recognize hand gestures based on the millimeter wave that is in 65GHz bandwidth. The proposed system is composed of millimeter wave radar board, analog to data conversion and data capture board and notebook to perform gesture recognition algorithms. As feature vectors in proposed algorithm. we used global and local zernike moment descriptor which are robust to distort by rotation of scaling of 2D data. As Experimental result, performance of the proposed algorithm is evaluated and compared with those of algorithms using single global or local zernike descriptor as feature vectors. In analysis of confusion matrix of algorithms, the proposed algorithm shows the better performance in comparison of precision, accuracy and sensitivity, subsequently total performance index of our method is 95.6% comparing with another two mehods in 88.4% and 84%.

Development of Finite Element Domain Decomposition Method Using Local and Mixed Lagrange Multipliers (국부 및 혼합 Lagrange 승수법을 이용한 영역분할 기반 유한요소 구조해석 기법 개발)

  • Kwak, Jun Young;Cho, Hae Seong;Shin, Sang Joon;Bauchau, Olivier A.
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.6
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    • pp.469-476
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    • 2012
  • In this paper, a finite element domain decomposition method using local and mixed Lagrange multipliers for a large scal structural analysis is presented. The proposed algorithms use local and mixed Lagrange multipliers to improve computational efficiency. In the original FETI method, classical Lagrange multiplier technique was used. In the dual-primal FETI method, the interface nodes are used at the corner nodes of each sub-domain. On the other hand, the proposed FETI-local analysis adopts localized Lagrange multipliers and the proposed FETI-mixed analysis uses both global and local Lagrange multipliers. The numerical analysis results by the proposed algorithms are compared with those obtained by dual-primal FETI method.

2-D Magnetostatic Field Analysis Using Adaptive Boundary Element Method (적응 경계요소법을 이용한 2형원 정자계 해석)

  • 고창섭;정현교;한송엽
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.40 no.3
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    • pp.243-249
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    • 1991
  • Adaptive mesh refinement scheme is incorporated with the boundary element analysis in order to get accurate solution with relatively fewer unnowns for magnetostatic field analysis. A new andsimple posteriori local error estimate is also presented. The local error is defined as an integraktion over the element of the difference between solutions from quadratic interpolation functions and linear interpolation functions and is used as the criterion for mesh refinement. Case study with a singular point reveals that adaptive meshes are more efficient in accuracy of solutions than uniform meshs generated by dividing al the elements evenly. The adaptive meshes give much better rate of convergence in global errors than the uniform meshes.

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Analysis of Composite Sandwich Plates with a Local Shear Deformations (국부전단변형을 고려한 복합샌드위치 평판의 해석)

  • JI, Hyo Seon;Chang, Suk Yoon
    • Journal of Korean Society of Steel Construction
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    • v.10 no.1 s.34
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    • pp.11-24
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    • 1998
  • The composite sandwich plate is constructed by combining two laminated facings with high strength and a thick core of light weight material. The governing equations for the analysis of bending of simply supported sandwich plates with laminated facings are derived and analysed using the analytical method including the local shear deformations. The accuracy of the approach is ascertained by comparing solutions from the sandwich plate theory with composite facings to the laminate plate theory. Since the present analysis considers the bending stiffness of the core and also the transverse shear deformations of the laminated facings, it is expected that the analysis is capable to analyze the general anisotropic laminated plates with global shear deformations.

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Estimation of the Fatigue Damage for an Ice-going Vessel under Broken Ice Condition Part II - Simplified Approach (유빙 하중을 받는 내빙 선박의 피로손상도 추정 Part II - 간이 해석법)

  • Kim, Jeong-Hwan;Kim, Yooil
    • Journal of the Society of Naval Architects of Korea
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    • v.56 no.3
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    • pp.231-241
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    • 2019
  • In this study, a simplified analysis method was developed to evaluate the fatigue damage of an ice-going ship under broken ice condition. The global ice load, which is essentially calculated at the design stage of the Arctic vessel, and the hull form information were used to estimate the local ice load acting on the outer-shell of the ship. The local ice load was applied to the finite element analysis model, and the Weibull parameters for the target fatigue point were derived. Finally, fatigue damage was evaluated by applying the S-N curve and the Palmgren-Miner rule. For the verification of the proposed method, numerical analyses using direct approach were performed for the same conditions. A numerical model that implements the interaction between ice and structure was introduced to verify the local ice load and the stress calculated from the proposed method. Finally, the fatigue analyses of the Baltic Sea for actual ice conditions were performed, and the results of the proposed method, the method using numerical analysis, and the LR method were compared.

The Determinants of Foreign Subsidiary CEO Selection: Effects of Internal and External Network Embeddedness of Foreign Subsidiaries and Market Characteristics of Host Country

  • Lee, Jae-Eun;Yang, Young-Soo
    • Journal of Korea Trade
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    • v.25 no.2
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    • pp.134-151
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    • 2021
  • Purpose - This study empirically analyzes the impact of the internal and external network embeddedness of foreign subsidiaries and local market characteristics of the host country on the CEO selection whether or not to appoint an expatriate as the CEO of a foreign subsidiary. Design/methodology - To conduct an empirical analysis, we obtained a list of the headquarters of Korean MNCs from the Korea Chamber of Commerce and Industry. Based on the list of HQs, we identified a final list of overseas subsidiaries of Korean MNCs that have entered the world from KOTRA (Trade-Investment Promotion Agency for Korea). Then we conducted an empirical analysis based on the results of 391 questionnaires by employing logistic regression analysis. Findings - The results of empirical analysis are as follows. First, the higher the subsidiary's internal network embeddedness, the higher the tendency appoint an expatriate as the CEO. Second, the higher the volatility of the local market, the higher the tendency to appoint an expatriate as the CEO. Third, the stronger the competition in the local market, the lower the tendency to appoint a PCN. Originality/value - This study has significant theoretical implications in that it examines the link between the internal and external embeddedness of overseas subsidiaries and the appointment of parent country nationals (PCNs) as the CEO that prior research has not examined.

MATHEMATICAL ANALYSIS OF NONLINEAR DIFFERENTIAL EQUATION ARISING IN MEMS

  • Zhang, Ruifeng;Li, Na
    • Bulletin of the Korean Mathematical Society
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    • v.49 no.4
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    • pp.705-714
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    • 2012
  • In this paper, we study nonlinear equation arising in MEMS modeling electrostatic actuation. We will prove the local and global existence of solutions of the generalized parabolic MEMS equation. We present that there exists a constant ${\lambda}^*$ such that the associated stationary problem has a solution for any ${\lambda}$ < ${\lambda}^*$ and no solution for any ${\lambda}$ > ${\lambda}^*$. We show that when ${\lambda}$ < ${\lambda}^*$ the global solution converges to its unique maximal steady-state as $t{\rightarrow}{\infty}$. We also obtain the condition for the existence of a touchdown time $T{\leq}{\infty}$ for the dynamical solution. Furthermore, there exists $p_0$ > 1, as a function of $p$, the pull-in voltage ${\lambda}^*(p)$ is strictly decreasing with respect to 1 < $p$ < $p_0$, and increasing with respect to $p$ > $p_0$.

Plastic behavior of circular discs with temperature-dependent properties containing an elastic inclusion

  • Zarandi, Somayeh Bagherinejad;Wang, Yun-Che;Novozhilova, Olga V.
    • Structural Engineering and Mechanics
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    • v.58 no.4
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    • pp.731-743
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    • 2016
  • Plastic behaviors, based on the von Mises yield criterion, of circular discs containing a purely elastic, circular inclusion under uniform temperature loading are studied with the finite element analysis. Temperature-dependent mechanical properties are considered for the matrix material only. In addition to analyzing the plane stress and plane strain disc, a 3D thin disc and cylinder are also analyzed to compare the plane problems. We determined the elastic irreversible temperature and global plastic collapse temperature by the finite element calculations for the plane and 3D problem. In addition to the global plastic collapse, for the elastically hard case, the plane stress problem and 3D thin disc may exhibit a local plastic collapse, i.e. significant pile up along the thickness direction, near the inclusion-matrix interface. The pileup cannot be correctly modeled by the plane stress analysis. Furthermore, due to numerical difficulties originated from large deformation, only the lower bound of global plastic collapse temperature of the plane stress problem can be identified. Without considerations of temperature-dependent mechanical properties, the von Mises stress in the matrix would be largely overestimated.