• Title/Summary/Keyword: $L_2-norm$

Search Result 218, Processing Time 0.032 seconds

Investigation on Natural Radioactivity of Environmental Samples Near the Phosphate Rock Processing Facility (인광석 사용업체 주변 환경시료의 자연방사능 조사)

  • Lee, Gill-Jae;Koh, Sang-Mo;Chang, Byung-Uck;Kim, Tong-Kwon;Kim, Young-Ug
    • Economic and Environmental Geology
    • /
    • v.44 no.1
    • /
    • pp.37-48
    • /
    • 2011
  • Some industrial minerals used in domestic industries such as monazite, apatite, bauxite, and ilmenite belong to NORM (Naturally Occurring Radioactive Materials) because they show a high radioactivity. Products, semi-products, wastes, and by-products which show higher radioactivity than NORM belong to TENORM (Technologically Enhanced Naturally Occurring Radioactive Materials). Apatite used for manufacturing phosphate fertilizer in Namhae Chemical company belongs to NORM, and its by-product, phospo-gypsum, belongs to TENORM. A geological investigation is needed for the future environmental impact assessment of the Namhae Chemical company's site. According to survey results of the Namhae Chemical company's site, soil mineral composition indicated the mixture of minerals derived from the country rock (quartz, feldspar, mica, $l4{\AA}$ mineral, kaolin and amphibole) and minerals from the gypsum open-air storage yard (gypsum and apatite). Soil samples showed average content of U 4.6 ppm and Th 10 ppm, which are similar to average crustal abundances. They also show average contents of $^{40}K$ 191-1,166 Bq/kg, $^{226}Ra$ 15.6-710 Bq/kg, and $^{232}Th$ 17.4-72.7 Bq/kg, which indicate moderate levels of radio nuclide. But $^{226}Ra$ anomaly in the gypsum open storage yard is clearly confirmed and $^{232}Th$ anomaly is also confirmed in the east road side of the factory and nearby mountain areas. Soil external hazard indices ranged 0.24-2.01 with the average 0.54. Although most external hazard indices were lower than 1, which means radiation hazard index to be negligible, 5 samples out of total 40 samples showed higher values than 1, and further detailed investigation is needed.

An approach for improving the performance of the Content-Based Image Retrieval (CBIR)

  • Jeong, Inseong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.30 no.6_2
    • /
    • pp.665-672
    • /
    • 2012
  • Amid rapidly increasing imagery inputs and their volume in a remote sensing imagery database, Content-Based Image Retrieval (CBIR) is an effective tool to search for an image feature or image content of interest a user wants to retrieve. It seeks to capture salient features from a 'query' image, and then to locate other instances of image region having similar features elsewhere in the image database. For a CBIR approach that uses texture as a primary feature primitive, designing a texture descriptor to better represent image contents is a key to improve CBIR results. For this purpose, an extended feature vector combining the Gabor filter and co-occurrence histogram method is suggested and evaluated for quantitywise and qualitywise retrieval performance criterion. For the better CBIR performance, assessing similarity between high dimensional feature vectors is also a challenging issue. Therefore a number of distance metrics (i.e. L1 and L2 norm) is tried to measure closeness between two feature vectors, and its impact on retrieval result is analyzed. In this paper, experimental results are presented with several CBIR samples. The current results show that 1) the overall retrieval quantity and quality is improved by combining two types of feature vectors, 2) some feature is better retrieved by a specific feature vector, and 3) retrieval result quality (i.e. ranking of retrieved image tiles) is sensitive to an adopted similarity metric when the extended feature vector is employed.

Optimal Rates of Convergence in Tensor Sobolev Space Regression

  • Koo, Ja-Yong
    • Journal of the Korean Statistical Society
    • /
    • v.21 no.2
    • /
    • pp.153-166
    • /
    • 1992
  • Consider an unknown regression function f of the response Y on a d-dimensional measurement variable X. It is assumed that f belongs to a tensor Sobolev space. Let T denote a differential operator. Let $\hat{T}_n$ denote an estimator of T(f) based on a random sample of size n from the distribution of (X, Y), and let $\Vert \hat{T}_n - T(f) \Vert_2$ be the usual $L_2$ norm of the restriction of $\hat{T}_n - T(f)$ to a subset of $R^d$. Under appropriate regularity conditions, the optimal rate of convergence for $\Vert \hat{T}_n - T(f) \Vert_2$ is discussed.

  • PDF

Takagi-Sugeno Fuzzy Model-based Iterative Learning Control Systems: A Two-dimensional System Theory Approach

  • Chu, Jun-Uk;Lee, Yun-Jung
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2001.10a
    • /
    • pp.169.3-169
    • /
    • 2001
  • This paper introduces a new approach to analysis of error convergence for a class of iterative learning control systems. First, a nonlinear plant is represented using a Takagi-Sugeno(T-S) fuzzy model. Then each iterative learning controller is designed for each linear plant in the T-S fuzzy model. From the view point of two-dimensional(2-D) system theory, we transform the proposed learning systems to a 2-D error equation, which is also established in the form of T-S fuzzy model. We analysis the error convergence in the sense of induced 2 L -norm, where the effects of disturbances and initial conditions on 2-D error are considered. The iterative learning controller design problem to guarantee the error convergence can be reduced to linear matrix inequality problems. In comparison with others, our learning algorithm ...

  • PDF

ANALYSIS OF VELOCITY-FLUX FIRST-ORDER SYSTEM LEAST-SQUARES PRINCIPLES FOR THE OPTIMAL CONTROL PROBLEMS FOR THE NAVIER-STOKES EQUATIONS

  • Choi, Young-Mi;Lee, Hyung-Chun
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • v.14 no.2
    • /
    • pp.125-140
    • /
    • 2010
  • This paper develops a least-squares approach to the solution of the optimal control problem for the Navier-Stokes equations. We recast the optimality system as a first-order system by introducing velocity-flux variables and associated curl and trace equations. We show that a least-squares principle based on $L^2$ norms applied to this system yields optimal discretization error estimates in the $H^1$ norm in each variable.

MULTI-DEGREE REDUCTION OF BÉZIER CURVES WITH CONSTRAINTS OF ENDPOINTS USING LAGRANGE MULTIPLIERS

  • Sunwoo, Hasik
    • Journal of the Chungcheong Mathematical Society
    • /
    • v.29 no.2
    • /
    • pp.267-281
    • /
    • 2016
  • In this paper, we consider multi-degree reduction of $B{\acute{e}}zier$ curves with continuity of any (r, s) order with respect to $L_2$ norm. With help of matrix theory about generalized inverses we can use Lagrange multipliers to obtain the degree reduction matrix in a very simple form as well as the degree reduced control points. Also error analysis comparing with the least squares degree reduction without constraints is given. The advantage of our method is that the relationship between the optimal multi-degree reductions with and without constraints of continuity can be derived explicitly.

A Fourth-Order Accurate Numerical Boundary Scheme for the Planar Dielectric Interface: a 2-D TM Case

  • Hwang, Kyu-Pyung
    • Journal of electromagnetic engineering and science
    • /
    • v.11 no.1
    • /
    • pp.11-15
    • /
    • 2011
  • Preserving high-order accuracy in high-order FDTD solutions across dielectric interfaces is very important for practical time-domain electromagnetic simulations. This paper presents a fourth-order accurate numerical boundary scheme for the planar dielectric interface to be used in the fourth-order FDTD method proposed earlier by the author. The interface scheme for the two-dimensional (2-D) transverse magnetic (TM) polarization case is derived and validated by monitoring the $L_2$ norm errors in the numerical solutions of a partially-filled cavity demonstrating its fourth-order convergence and long-time numerical stability in the presence of the planar dielectric interface.

A Study on Correlation between Power of Trunk Flexors, Extensors and Lumbar Lordotic Angle in Normal Adults (정상 성인에서 체간 굴근, 신근의 근력과 요추 전만각의 상관관계에 관한 연구)

  • Choi, Bo-Mi;Yi, Jeong-Min;Kim, Hyun-Soo
    • The Journal of Churna Manual Medicine for Spine and Nerves
    • /
    • v.7 no.2
    • /
    • pp.39-52
    • /
    • 2012
  • Objectives : The purpose of this study was to investigate the correlation between lumbar lordotic angle and the power of trunk flexors, extensors in normal adults Methods : 34 normal participants participated in this study. Their lumbar lordotic angle(L1-S1 Cobb's angle and L1-L5 cobb's angle) was measured by x-ray taken on lateral direction, erect cross-arm position. And muscle power of trunk flexors and extensors of each participant measured using Cybex HUMAC NORM. Results : 1. The average of L1-S1 Cobb's angle was $47.21{\pm}8.88^{\circ}$ and the average of L1-L5 Cobb's angle was $36.32{\pm}9.62^{\circ}$(Table IV). 2. The average ratio of trunk flexors/extensors was $6.44{\pm}19.31%$(Table V). The average power of the trunk flexors was $165.18{\pm}55.05$(Newton-Meter/kg), and the power of trunk extensors was $257.18{\pm}85.53$ (Newton-Meter/kg)(Table VI). 3. Lumbar lordotic angle has no relation to the ratio of trunk flexors/extensors(Table VII, Fig. 4). 4. Lumbar lordotic angle has no relation to both the power of the trunk flexors and extensors(Table VIII, Fig. 5, Fig. 6). Conclusions : These results suggest that the lumbar lordotic angle measured by radiograph could not evaluate the power and ratio of trunk flexors, extensors.

  • PDF

Robust Stabilization of Uncertain Nonlinear Systems via Fuzzy Modeling and Numerical Optimization Programming

  • Lee Jongbae;Park Chang-Woo;Sung Ha-Gyeong;Lim Joonhong
    • International Journal of Control, Automation, and Systems
    • /
    • v.3 no.2
    • /
    • pp.225-235
    • /
    • 2005
  • This paper presents the robust stability analysis and design methodology of the fuzzy feedback linearization control systems. Uncertainty and disturbances with known bounds are assumed to be included in the Takagi-Sugeno (TS) fuzzy models representing the nonlinear plants. $L_2$ robust stability of the closed system is analyzed by casting the systems into the diagonal norm bounded linear differential inclusions (DNLDI) formulation. Based on the linear matrix inequality (LMI) optimization programming, a numerical method for finding the maximum stable ranges of the fuzzy feedback linearization control gains is also proposed. To verify the effectiveness of the proposed scheme, the robust stability analysis and control design examples are given.

L2-NORM ERROR ANALYSIS OF THE HP-VERSION WITH NUMERICAL INTEGRATION

  • Kim, Ik-Sung
    • Bulletin of the Korean Mathematical Society
    • /
    • v.39 no.1
    • /
    • pp.9-22
    • /
    • 2002
  • We consider the hp-version to solve non-constant coefficient elliptic equations with Dirichlet boundary conditions on a bounded, convex polygonal domain $\Omega$ in $R^{2}.$ To compute the integrals in the variational formulation of the discrete problem we need the numerical quadrature rule scheme. In this paler we consider a family $G_{p}= {I_{m}}$ of numerical quadrature rules satisfying certain properties. When the numerical quadrature rules $I_{m}{\in}G_{p}$ are used for calculating the integrals in the stiffness matrix of the variational form we will give its variational fore and derive an error estimate of ${\parallel}u-\tilde{u}^h_p{\parallel}_0,{\Omega}'$.