An automated algorithm for cleaning and ordering the boundary points of a one-dimensional curve in a segmented image

1998 ◽  
Vol 36 (1) ◽  
pp. 307-312 ◽  
Author(s):  
R.J. McDevitt ◽  
S.D. Peddada
Keyword(s):  
One Dimensional ◽  
Boundary Points ◽  
Automated Algorithm ◽  
Segmented Image

One‐dimensional inversion of natural source magnetotelluric observations

Geophysics ◽  
1979 ◽  
Vol 44 (7) ◽  
pp. 1218-1244 ◽  
Author(s):  
Douglas W. Oldenburg
Keyword(s):  
Numerical Stability ◽  
Natural Source ◽  
Resistivity Structure ◽  
Rapid Convergence ◽  
One Dimensional ◽  
Automated Algorithm ◽  
Parametric Inversion ◽  
Using Data ◽  
River Plain ◽  
Subsurface Resistivity

Natural source magnetotelluric (MT) data are inverted to find a subsurface resistivity which is isotropic and a continuous function of depth. The inversion consists of two parts. In the first, our concern is to construct a resistivity structure whose responses are acceptably close to the observations, that is, the measured amplitudes and/or phases. This construction proceeds iteratively and is realized through an automated algorithm which is characterized by numerical stability and rapid convergence. In the second part, we attempt to investigate the degree of nonuniqueness inherent in the problem. This is accomplished by considering only spatial averages of the resistivity because all models linearly close to the constructed model will have the same average resistivity. The predictions of this statement are examined quantitatively in an example where the averages from five different models which reproduce the observations are compared. In an example using data from a moderately complex layered model, we have inverted jointly and separately the amplitudes and phases and compared their resolution. Finally, data from the Snake River Plain‐Yellowstone area are inverted and the results compared with those from a parametric inversion.

scholarly journals A Novel Depth-Check Algorithm to Detect Macular Hole from Optical Coherence Tomography Images

2019 ◽  
Vol 8 (12) ◽  
pp. 2081-2085
Keyword(s):  
Optical Coherence Tomography ◽  
Macular Hole ◽  
Dark Spot ◽  
Optical Coherence ◽  
Central Vision ◽  
Fiber Layer ◽  
Aged People ◽  
Automated Algorithm ◽  
Segmented Image ◽  
Check Algorithm

Macular hole is a tear or opening forms in the macula. A macular hole forms a dark spot in the central vision and affects central vision, in this case the vision will be blurry, wavy or distorted. Macular hole commonly affects aged people. Optical coherence tomography enables accurate diagnosis of macular hole. Existing algorithms are also done related to finding layers, but macular hole identification in an accurate manner is still a missing entity. Hence we proposed a fully automated algorithm named “depth-check” for the accurate macular hole detection. The proposed method has six modules in process. First it starts with preprocessing the image, followed by nerve fiber layer (NFL) segmentation. The segmented image is then processed using depth-check algorithm. It will help to identify the macular hole from the optical coherence tomography images. For evaluation, we applied the algorithm on the optical coherence tomography images with the subjects- Central serous chorioretinopathy (CSCR) and Pigment epithelial detachment (PED). By experimentation, it is observed that the proposed algorithm provides 91% accuracy.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Intergrowth of modulated structures in high Tc Bi-Sr-Ca-Cu-O superconductors

1990 ◽  
Vol 48 (4) ◽  
pp. 76-77
Author(s):  
A.Q. He ◽  
G.W. Qiao ◽  
J. Zhu ◽  
H.Q. Ye
Keyword(s):  
Twin Structure ◽  
Modulated Structure ◽  
High Tc ◽  
One Dimensional ◽  
Lattice Constants ◽  
Superconducting Phases ◽  
Modulated Structures ◽  
Layer Structures

Since the first discovery of high Tc Bi-Sr-Ca-Cu-O superconductor by Maeda et al, many EM works have been done on it. The results show that the superconducting phases have a type of ordered layer structures similar to that in Y-Ba-Cu-O system formulated in Bi2Sr2Can−1CunO2n+4 (n=1,2,3) (simply called 22(n-1) phase) with lattice constants of a=0.358, b=0.382nm but the length of c being different according to the different value of n in the formulate. Unlike the twin structure observed in the Y-Ba-Cu-O system, there is an incommensurate modulated structure in the superconducting phases of Bi system superconductors. Modulated wavelengths of both 1.3 and 2.7 nm have been observed in the 2212 phase. This communication mainly presents the intergrowth of these two kinds of one-dimensional modulated structures in 2212 phase.

Electronic structure studies of conducting polymers by electron energy-loss spectroscopy

1996 ◽  
Vol 54 ◽  
pp. 160-161
Author(s):  
J. Fink
Keyword(s):  
Electronic Structure ◽  
Conducting Polymers ◽  
Conjugated Polymers ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Light Emitting ◽  
One Dimensional ◽  
New Class ◽  
Electrical Conductivities ◽  
Electron Energy Loss

Conducting polymers comprises a new class of materials achieving electrical conductivities which rival those of the best metals. The parent compounds (conjugated polymers) are quasi-one-dimensional semiconductors. These polymers can be doped by electron acceptors or electron donors. The prototype of these materials is polyacetylene (PA). There are various other conjugated polymers such as polyparaphenylene, polyphenylenevinylene, polypoyrrole or polythiophene. The doped systems, i.e. the conducting polymers, have intersting potential technological applications such as replacement of conventional metals in electronic shielding and antistatic equipment, rechargable batteries, and flexible light emitting diodes.Although these systems have been investigated almost 20 years, the electronic structure of the doped metallic systems is not clear and even the reason for the gap in undoped semiconducting systems is under discussion.

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