• Title/Summary/Keyword: Planar curve

Search Result 90, Processing Time 0.027 seconds

Planar Optical Waveguide Temperature Sensor Based on Etched Bragg Gratings Considering Nonlinear Thermo-optic Effect

  • Ahn, Kook-Chan;Lee, Sang-Mae;Jim S. Sirkis
    • Journal of Mechanical Science and Technology
    • /
    • v.15 no.3
    • /
    • pp.309-319
    • /
    • 2001
  • This paper demonstrates the development of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include design and fabrication of the etched planar waveguide Bragg grating optical temperature sensor. The typical bandwidth and reflectivity of the surface etched grating has been ∼0.2nm and ∼9%, respectively, at a wavelength of ∼1552nm. The temperature-induced wavelength change is found to be slightly non-linear over ∼200$^{\circ}C$ temperature range. Typically, the temperature-induced fractional Bragg wavelength shift measured in this experiment is 0.0132nm/$^{\circ}C$ with linear curve fit. Theoretical models with nonlinear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance.

  • PDF

A method Based on Boundary Deformation for Planar Grid Generation

  • Liu, Xinru;Liu, Duanfeng;Han, Xuli
    • International Journal of CAD/CAM
    • /
    • v.8 no.1
    • /
    • pp.63-67
    • /
    • 2009
  • This paper puts forward a method based on the boundary deformation for planar grid generation. Many methods start with the special properties of grid and switch to the solution of a direct optimization or a non-linear minimum cost flow. Though with high theoretical significance, it's hard to realize due to the extremely complicated computing process. This paper brings out the automatic generation of planar grid by studying the boundary deformational properties of planar grid, which leads to uniform grid and enjoys the simplicity of computation and realization.

TENSOR PRODUCT SURFACES WITH POINTWISE 1-TYPE GAUSS MAP

  • Arslan, Kadri;Bulca, Betul;Kilic, Bengu;Kim, Young-Ho;Murathan, Cengizhan;Ozturk, Gunay
    • Bulletin of the Korean Mathematical Society
    • /
    • v.48 no.3
    • /
    • pp.601-609
    • /
    • 2011
  • Tensor product immersions of a given Riemannian manifold was initiated by B.-Y. Chen. In the present article we study the tensor product surfaces of two Euclidean plane curves. We show that a tensor product surface M of a plane circle $c_1$ centered at origin with an Euclidean planar curve $c_2$ has harmonic Gauss map if and only if M is a part of a plane. Further, we give necessary and sufficient conditions for a tensor product surface M of a plane circle $c_1$ centered at origin with an Euclidean planar curve $c_2$ to have pointwise 1-type Gauss map.

A Study on Surface Flattening for 3 Dimensional Shoe Pattern Design (신발패턴의 3차원 설계를 위한 곡면의 평면전개에 관한 연구)

  • Song S. J.;Kim S. H.
    • Korean Journal of Computational Design and Engineering
    • /
    • v.9 no.3
    • /
    • pp.266-275
    • /
    • 2004
  • In this paper, a method for generating the planar developments of three-dimensional shoe upper surfaces is proposed. This method is based on the optimization technique minimizing the geometric error occurred on the developed planar surface. Additionally, a rapid mapping algorithm to transform a curve on flattened plane to original surface (or vice versa) is proposed. These techniques are implemented on the 2D/3D integrated shoe design system. Using this system, a prototype running shoe can be designed more precisely and can be manufactured more quickly.

Segmentation of Arcs and Line Segments in Planar Curve Using CI Method (CI 방법을 이용한 2차원 곡선 내의 호 및 선분 분리)

  • Lyu, Sung-Pil
    • Journal of Internet Computing and Services
    • /
    • v.9 no.1
    • /
    • pp.145-158
    • /
    • 2008
  • The detected arcs by the cone intersection(CI) method exist within a tolerant error from the original curve. But the position of breakpoint by the CI method is sensitive to the tolerant error. The deviation of breakpoint position makes ill effects to the detection of arc center or radius. In this paper a improved CI method for center detection and arc segmentation is proposed. The detected arcs from curves by the proposed method have very stable mean of deviations from the original curves. The experimental results show that the position of breakpoint by the proposed method is closer to real position than the one by other methods.

  • PDF

ANALYSIS AND EXPERIMENT OF DIELECTROPHORETIC FORCE ON A CELL IN A PLANAR ELECTRODE STRUCTURE (초소형 평면 전극 구조에서 세포에 작용하는 DIELECTROPHORETIC FORCE의 해석 및 실험)

  • Choi, Jung-Hoon;Lee, Sang-Wook;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
    • /
    • 1995.11a
    • /
    • pp.597-599
    • /
    • 1995
  • We have analyzed the dielectrophoretic(DEP) force on a cell in a micro planar electrode structure. We fabricate a micro planar electrode structure using micro machining technology and measure the motion of a cell that is accelerated by DEP force. DEP force on a cell is calculated by curve fitting the motion of a cell. Radish and yeast are used for the experiment. In case of radish, DEP force is increased as the voltage and the frequency is increased, and in case of yeast, DEP force is increased only as the voltage is increased DEP force on a yeast does not vary when the frequency varies from 1 MHz to 3 MHz. The result will be helpful to the manipulation of cells using DEP force.

  • PDF

Evaluation of Usefulness of SPECT-CT at the Examination of Digestive System Leakage Patients (소화기계 Leakage 환자 검사 시 SPECT-CT의 유용성 평가)

  • Ham, Jun Cheol;Oh, Shin Hyun;Choi, Yong Hoon;Kang, Chun Koo;Kim, Jae Sam
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.22 no.1
    • /
    • pp.98-102
    • /
    • 2018
  • Purpose When examining patients with digestive system Leakage, it is not easy to distinguish between bile leakage and bleeding only with Planar images. I would like to evaluate the utility of leakage of bile, confirmation of gastrointestinal bleeding and location discrimination using SPECT-CT. Materials and Methods SPECT-CT was performed according to the request of the reading room after acquiring Planar image for a total of 13 patients, including 8 patients suspected of bile leakage and 5 patients suspected of gastrointestinal bleeding, among patients visiting this specification went. We used Symbia T16 from SIEMENS and Discovery 670 from GE. Planar and SPECT-CT images were evaluated with a score of 1 to 10 by 4 experienced nuclear medicine doctors. Using the sensitivity and the specificity, the evaluation of the inspection by the ROC curve was carried out. The final diagnosis was confirmed by follow-up observation as a result of reoperative surgery. Results The sensitivity, specificity and accuracy of SPECT-CT were 91.7%, 100% and 94.2%, respectively. Planar images were 83.3%, 68.8% and 78.8%, respectively. Planar images showed lower diagnostic accuracy compared to SPECT-CT (78.8%, 94.2%, p<0.05). Moreover, the reliability of the diagnosis of SPECT-CT by ROC curve analysis showed a more useful result than the Planar image (p<0.05). Conclusion SPECT-CT had high sensitivity and specificity for diagnosis of biliary leakage and gastrointestinal bleeding and location discrimination. When SPECT-CT is additionally performed together with Planar images, it may be considered to improve bile leakage and diagnosis of gastrointestinal bleeding patients and position discrimination evaluation. There is usefulness depending on the patient's age and position, but consideration of additional CT exposure may be done sufficiently.

An analytical analysis of the pullout behaviour of reinforcements of MSE structures

  • Ren, Feifan;Wang, Guan;Ye, Bin
    • Geomechanics and Engineering
    • /
    • v.14 no.3
    • /
    • pp.233-240
    • /
    • 2018
  • Pullout tests are usually employed to determine the ultimate bearing capacity of reinforced soil, and the load-displacement curve can be obtained easily. This paper presents an analytical solution for predicting the full-range mechanical behavior of a buried planar reinforcement subjected to pullout based on a bi-linear bond-slip model. The full-range behavior consists of three consecutive stages: elastic stage, elastic-plastic stage and debonding stage. For each stage, closed-form solutions for the load-displacement relationship, the interfacial slip distribution, the interfacial shear stress distribution and the axial stress distribution along the planar reinforcement were derived. The ultimate load and the effective bond length were also obtained. Then the analytical model was calibrated and validated against three pullout experimental tests. The predicted load-displacement curves as well as the internal displacement distribution are in closed agreement with test results. Moreover, a parametric study on the effect of anchorage length, reinforcement axial stiffness, interfacial shear stiffness and interfacial shear strength is also presented, providing insights into the pullout behaviour of planar reinforcements of MSE structures.

New Analytical Method with Curvature Based Kinematic Deflection Curve Theory

  • Tayyar, Gokhan Tansel
    • International Journal of Ocean System Engineering
    • /
    • v.2 no.3
    • /
    • pp.195-199
    • /
    • 2012
  • This paper reports a new analytical method to calculate the planar displacement of structures. The cross-sections were assumed to remain in plane and the deflection curve was evaluated using the curvature values geometrically, despite being solved with differential equations. The deflection curve was parameterized with the arc-length of the curvature values, and was taken as an assembly of chains of circular arcs. Fast and accurate solutions of complex deflections can be obtained easily. This paper includes a comparison of the nonlinear displacements of an elastic tapered cantilever beam with a uniform moment distribution among the proposed analytical method, numerical method of the theory and large deflection FEM solutions.

An Accelerated Simulated Annealing Method for B-spline Curve Fitting to Strip-shaped Scattered Points

  • Javidrad, Farhad
    • International Journal of CAD/CAM
    • /
    • v.12 no.1
    • /
    • pp.9-19
    • /
    • 2012
  • Generation of optimum planar B-spline curve in terms of minimum deviation and required fairness to approximate a target shape defined by a strip-shaped unorganized 2D point cloud is studied. It is proposed to use the location of control points as variables within the geometric optimization framework of point distance minimization. An adaptive simulated annealing heuristic optimization algorithm is developed to iteratively update an initial approximate curve towards the target shape. The new implementation comprises an adaptive cooling procedure in which the temperature change is adaptively dependent on the objective function evolution. It is shown that the proposed method results in an improved convergence speed when compared to the standard simulated annealing method. A couple of examples are included to show the applicability of the proposed method in the surface model reconstruction directly from point cloud data.