Laser Stripe Center Extraction Based on Hessian Matrix and Regional Growth

2019 ◽  
Vol 56 (2) ◽  
pp. 021203
Author(s):  
刘剑 Liu Jian ◽  
刘丽华 Liu Lihua
Keyword(s):  
Regional Growth ◽  
Hessian Matrix ◽  
Laser Stripe

scholarly journals Segmentation of Cerebrovascular Anatomy from TOF-MRA Using Length-Strained Enhancement and Random Walker

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Ruoxiu Xiao ◽  
Cheng Chen ◽  
Hanying Zou ◽  
Ying Luo ◽  
Jiayu Wang ◽  
...  
Keyword(s):  
Regional Growth ◽  
Hessian Matrix ◽  
Three Dimensional ◽  
Vascular Anatomy ◽  
Seed Point ◽  
Random Walker ◽  
Tof Mra ◽  
Segmentation Methods ◽  
Connected Area ◽  
Seed Points

Cerebrovascular rupture can cause a severe stroke. Three-dimensional time-of-flight (TOF) magnetic resonance angiography (MRA) is a common method of obtaining vascular information. This work proposes a fully automated segmentation method for extracting the vascular anatomy from TOF-MRA. The steps of the method are as follows. First, the brain is extracted on the basis of regional growth and path planning. Next, the brain’s highlighted connected area is explored to obtain seed point information, and the Hessian matrix is used to enhance the contrast of image. Finally, a random walker combined with seed points and enhanced images is used to complete vascular anatomy segmentation. The method is tested using 12 sets of data and compared with two traditional vascular segmentation methods. Results show that the described method obtains an average Dice coefficient of 90.68%, and better results were obtained in comparison with the traditional methods.

Identifikasi Peran dan Strategi Pelabuhan Bebas Sabang

2020 ◽  
Vol 4 (3) ◽  
pp. 167-178
Author(s):  
Zurayna Sari
Keyword(s):  
Economic Development ◽  
Descriptive Analysis ◽  
Regional Growth ◽  
Maintenance Strategy ◽  
Regional Economic ◽  
Growth Center ◽  
Free Port ◽  
And Function ◽  
Role And Function

ABSTRAKPelabuhan berperan sebagai fasilitas penunjang pusat pertumbuhan regional dalam proses pembangunan ekonomi wilayah. Pelabuhan Bebas Sabang diarahkan sebagai pusat pertumbuhan ekonomi regional dan diharapkan dapat meningkatkan perekonomian Kawasan Sabang. Permasalahan yang dihadapi Pelabuhan Bebas Sabang adalah belum optimalnya peran dan fungsi Pelabuhan Bebas Sabang dalam menunjang perekonomian wilayah. Penelitian ini bertujuan untuk mengetahui peran Pelabuhan Bebas Sabang dalam mendorong perkembangan perekonomian Kawasan Sabang. Lingkup materi yang dibahas mencakup peran-peran Pelabuhan Bebas Sabang, menentukan potensi dan masalah serta upaya-upaya peningkatan peran Pelabuhan Bebas Sabang. Metode analisis yang dilakukan adalah analisis deskriptif dengan pendekatan analisis data kualitatif dan kuantitatif. Alat analisis yang digunakan adalah analisis SWOT IFAS-EFAS. Hasil analisis menunjukkan dalam kurun waktu 4 (empat) tahun terakhir dari tahun 2010-2013, Pelabuhan Bebas Sabang belum optimal dalam menjalankan perannya, sehingga membutuhkan strategi pengembangan dengan pendekatan Agressive Maintenance Strategy (strategi perbaikan agresif), yaitu strategi konsolidasi internal dengan memperbaiki faktor-faktor kelemahan untuk memaksimalkan pemanfaatan peluang.Kata kunci: Pengelolaan, SWOT IFAS-EFAS, WilayahABSTRACTPort was supporting facility of regional growth center in the process of regional economic development. Sabang free port was directed as the center of regional economic growth and expected to raise the economy of sabang. Problems faced by sabang free port was yet optimal role and function in supporting the economy of the region. This study aimed to determine the role of sabang free port in supporting the economic development of sabang. The covered material scope included roles of sabang free port, determining the potentials and problems and efforts of increasing the role of sabang free port. The method of analysis was descriptive analysis with qualitative and quantitative approach. The analytical tool used was the swot ifas-efas analysis. The analysis results showed in the period of 4 (four) years from 2010 until 2013, sabang free port was not optimal in carrying out its role yet, so it requires development strategies with agressive maintenance strategy approach, which is internal consolidation strategy by improving vulnerability factors to maximize the utilization of opportunities.Keywords:, Management, Regional, SWOT IFAS-EFAS

scholarly journals Adjoint-based exact Hessian computation

2021 ◽  
Author(s):  
Shin-ichi Ito ◽  
Takeru Matsuda ◽  
Yuto Miyatake
Keyword(s):  
Krylov Subspace ◽  
Hessian Matrix ◽  
Adjoint System ◽  
Coefficient Matrix ◽  
Scalar Function ◽  
Second Order ◽  
Subspace Method ◽  
Initial Value ◽  
Research Fields ◽  
Memory Efficiency

AbstractWe consider a scalar function depending on a numerical solution of an initial value problem, and its second-derivative (Hessian) matrix for the initial value. The need to extract the information of the Hessian or to solve a linear system having the Hessian as a coefficient matrix arises in many research fields such as optimization, Bayesian estimation, and uncertainty quantification. From the perspective of memory efficiency, these tasks often employ a Krylov subspace method that does not need to hold the Hessian matrix explicitly and only requires computing the multiplication of the Hessian and a given vector. One of the ways to obtain an approximation of such Hessian-vector multiplication is to integrate the so-called second-order adjoint system numerically. However, the error in the approximation could be significant even if the numerical integration to the second-order adjoint system is sufficiently accurate. This paper presents a novel algorithm that computes the intended Hessian-vector multiplication exactly and efficiently. For this aim, we give a new concise derivation of the second-order adjoint system and show that the intended multiplication can be computed exactly by applying a particular numerical method to the second-order adjoint system. In the discussion, symplectic partitioned Runge–Kutta methods play an essential role.

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