• Title/Summary/Keyword: reconstruct

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Reconstruction of Defective Type Congenital Cleft Earlobe with S-shaped Flap (새로운 S자형 피판을 이용한 결손형 선천성 이수열의 재건)

  • Kim, Tae Gon;Lee, Taik Jong
    • Archives of Plastic Surgery
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    • v.36 no.6
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    • pp.811-813
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    • 2009
  • Purpose: Congenital cleft earlobe is relatively rare malformation and defective type congenital cleft earlobes are reconstructed with mainly local flap methods rather than primary closure or z - plasty. Various methods are introduced but many of these remain visible scars or require complex operative techniques. We designed a new and simple method of reconstruction for defective type cleft earlobe. Methods: On the posterior surface of the auricle and mastoid area, S - shaped line was drawn continuously. One arc is for turnover hinge flap to make the anterolateral surface of the earlobe, and the other is for transposition flap to reconstruct the posterolateral surface. The donor site of the transposition flap was closed primarily. Results: Four patients were operated by S - shaped flap design method. They were all female and two were right side and others were left. We obtained aesthetically satisfactory postoperative results with inconspicuous scars at the posterior side of the auricle. In one case, minor revision was performed because of insufficient blood supply of the hinge flap. Conclusion: We can reconstruct defective type cleft earlobe with new, simple S - shaped design for hinge flap and transposition flap.

Microwave Imaging of a Large High Contrast Scatterer by Using the Hybrid Algorithm Combining a Levenberg-Marquardt and a Genetic Algorithm (Levenberg-Marquardt와 유전 알고리듬을 결합한 잡종 알고리듬을 이용한 거대 강산란체의 초고주파 영상)

  • 박천석;양상용
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.8 no.5
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    • pp.534-544
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    • 1997
  • The permittivity distribution of a two-dimensional high-contrast object with large size, which leads to the global minimum of cost function, is reconstructed by iteratively using the hybrid algorithm of Levenberg-magquardt algorithm(LMA) plus Genetic Algorithm(GA). The scattered fields calculated in a cost function are expanded in angular spectral modes, of which only effective propagating modes are used. The definition of cost function based on the effective propagating modes enables us to formulate the minimum number of incident waves for the reconstruction of object. It is numerically shown that LMA has an advantage of fast convergence but can't reconstruct a high-contrast object with large size and GA can reconstruct a high-contrast object with large size but has an disadvantage of slow convergence, whereas an inverse scattering technique using the hybrid algorithm adopts only advantages of LMA and GA.

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Weighted Edge Adaptive POCS Demosaicking Algorithm (Edge 가중치를 이용한 적응적인 POCS Demosaicking 알고리즘)

  • Park, Jong-Soo;Lee, Seong-Won
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.3
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    • pp.46-54
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    • 2008
  • Most commercial CCD/CMOS image sensors have CFA(Color Filter Array) where each pixel gathers light of a selective color to reduce the sensor size and cost. There are many algorithms proposed to reconstruct the original clolr image by adopting pettern recognition of regularization methods to name a few. However the resulting image still suffer from errors such as flase color, zipper effect. In this paper we propose an adaptive edge weight demosaicking algorithm that is based on POCS(Projection Onto Convex Sets) not only to improve the entire image's PSNR but also to reduce the edge region's errors that affect subjective image quality. As a result, the proposed algorithm reconstruct better quality images especially at the edge region.

Method of Deciding Elastic Modulus of Left and Right Ventricle Reconstructed by Echocardiography Using Finite Element Method and Stress Analysis

  • Han, Geun-Jo;Kim, Sang-Hyun
    • Journal of Biomedical Engineering Research
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    • v.15 no.2
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    • pp.217-224
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    • 1994
  • In order to study the shape and dimensions of heart, a procedure to reconstruct a three dimensional left ventricular geometry from two dimensional echocardiographic images was studied including the coordinate transformation, curve fitting and interpolation utilizing three dimensional position registration arm. Nonlinear material property of the left ventricular myocardium was obtained by finite element method performed on the reconstructed geometry and by optimization techniques which compared the computer predicted 3D deformation with the experimentally determined deformation. Elastic modulus ranged from 3.5g/$cm^2$ at early diastole to l53g/$cm^2$ at around end diastole showing slightly nonlinear relationship between the modulus and the pressure. Afterwards using the obtained nonlinear material propertry the stress distribution related with oxyzen consumption rate was analyzed. The maximum and minimum of ${\sigma}_1$ (max. principal stress) occurred at nodes on the second level intersection points of x-axis with endocardium and with epicardium, respectively. And the tendency of the interventricular septum to be flattened was observed from the compressive ${\sigma}_1$ on the anterior, posterior nodes of left ventricle and from the most significant change of dimension in $D_{RL}$ (septal-lateral dimension of right ventricle).

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Contour-Based Partial Object Recognition Of Elliptical Objects Using Symmetry (대칭특성을 이용한 타원형 객체의 외형기반 부분인식에 관한 연구)

  • Cho June-Suh
    • The KIPS Transactions:PartB
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    • v.13B no.2 s.105
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    • pp.115-120
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    • 2006
  • In This Paper, We Propose The Method To Reconstruct And Estimate Partially Occluded Elliptical Objects In Images From Overlapping And Cutting. We Present The Robust Method For Recognizing Partially Occluded Objects Based On Symmetry Properties, Which Is Based On The Contours Of Elliptical Objects. A Proposed Method Provides Simple Techniques To Reconstruct Occluded Regions Via A Region Copy Using The Symmetry Axis Within An Object. Based On The Estimated Parameters For Partially Occluded Objects, We Perform Object Recognition On The Classifier. Since A Proposed Method Relies On Reconstruction Of The Object Based On The Symmetry Properties Rather Than Statistical Estimates, It Has Proven To Be Remarkably Robust In Recognizing Partially Occluded Objects In The Presence Of Scale Changes, Object Pose, And Rotated Objects With Occlusion, Even Though h Proposed Method Has Minor Limitations Of Object Poses.

Hierarchical Height Reconstruction of Object from Shading Using Genetic Algorithm (유전자 알고리즘을 이용한 영상으로부터의 물체높이의 계층적 재구성)

  • Ahn, Eun-Young;Cho, Hyung-Je
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.12
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    • pp.3703-3709
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    • 1999
  • We propose a new approach to reconstruct the surface shape of an object from a shaded image. We use genetic algorithm instead of gradient descent algorithm which is apt to take to local minima and also proposes genetic representation and suitable genetic operators for manipulating 2-D image. And for more effective execution, we suggest hierarchical process to reconstruct minutely the surface of an object after coarse and global reconstruction. A modified Lambertian illumination model including the distance factor was herein adopted to get more reasonable result and an experiment was performed with synthesized and real images to demonstrate the devised method, of which results show the usefulness of our method.

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Acoustic holography for an engine radiation noise using equivalent sources (등가음원을 이용한 엔진 방사 소음의 음향 홀로그래피에 대한 연구)

  • Jeon, In-Youl;Ih, Jeong-Guon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.1101-1106
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    • 2004
  • This study presents the reconstruction of sound field radiated from an automotive engine using equivalent sources. Basic concept of the method presented is to replace the engine noise source with elementary sources of multipoles, e.g., monopoles and dipoles. The so-called Helmholtz equation least-squares (HELS) method can reconstruct the sound radiation fields from spherical geometries in a series expansion of spherical Hankel functions and spherical harmonics. In this paper, multi-Point, multipole equivalent sources are employed to reconstruct the sound field radiated from an automotive engine with a fixed rotation speed. To ensure and improve the accuracy of reconstruction, the spatial filters of multipole coefficients and wave-vectors are adopted for suppressing the adverse effect of high-order multipoles. Optimal filter shapes are designed with regularization parameters minimizing the generalized cross validation (GCV) function between actual and reproduced model. After regeneration of field pressures using the proposed method as many as necessary, the vibro-acoustic field of an engine could be reconstructed by using the BEM-based near-field acoustic holography (NAH) technique in a cost-effective manner.

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Weighted Secret Sharing Scheme (가중치를 갖는 비밀분산법)

  • Park, So-Young;Lee, Sang-Ho;Kwon, Dae-Sung
    • Journal of KIISE:Computer Systems and Theory
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    • v.29 no.4
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    • pp.213-219
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    • 2002
  • A secret sharing scheme is a kind of cryptographic protocol to maintain secret information by splitting it to many small pieces of shares and sharing between shareholders. In case of shareholders having different authorization to reconstruct the original secret, it is required a new secret sharing scheme to reflect any hierarchical structure between shareholders. In this paper, we propose a new weighted secret sharing scheme, that is, each shareholder has a weight according to the authorization of reconstructing the secret and an access set which is a subset of shareholders can reconstruct the secret if the sum of weights is equal or greater than a predefined threshold.

3D reconstruction of two-phase random heterogeneous material from 2D sections: An approach via genetic algorithms

  • Pizzocri, D.;Genoni, R.;Antonello, F.;Barani, T.;Cappia, F.
    • Nuclear Engineering and Technology
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    • v.53 no.9
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    • pp.2968-2976
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    • 2021
  • This paper introduces a method to reconstruct the three-dimensional (3D) microstructure of two-phase materials, e.g., porous materials such as highly irradiated nuclear fuel, from two-dimensional (2D) sections via a multi-objective optimization genetic algorithm. The optimization is based on the comparison between the reference and reconstructed 2D sections on specific target properties, i.e., 2D pore number, and mean value and standard deviation of the pore-size distribution. This represents a multi-objective fitness function subject to weaker hypotheses compared to state-of-the-art methods based on n-points correlations, allowing for a broader range of application. The effectiveness of the proposed method is demonstrated on synthetic data and compared with state-of-the-art methods adopting a fitness based on 2D correlations. The method here developed can be used as a cost-effective tool to reconstruct the pore structure in highly irradiated materials using 2D experimental data.

Impact Force Reconstruction of Composite materials based on Improved Regularization Technology

  • Sun, Yajie;Yin, Tao;Yang, Jian;Cai, Zhiyu;Wu, Shaoen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.8
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    • pp.2718-2731
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    • 2021
  • In the structural health monitoring of composite materials, in order to solve the ill-posed problem of impact force reconstruction, regularization techniques are often used to deal with it. Due to the poor convergence of the traditional Tikhonov regularization method, in order to accurately reconstruct the time history of the impact force, this paper improves Tikhonov regularization method and constructs homotopy function with strong convergence. Since the optimal regularization parameters need to be found in the homotopy function, the Newton downhill method is used to find the optimal parameters and the homotopy function can be calculated, which can accurately reconstruct the time history of the impact force. In order to verify the universality of the method in this paper, impact hammers of different materials were used in the experiment in this paper to study and compare the reconstruction effect of impact time history of different impact hammers.