scholarly journals The anatomy of a tornillo: puzzles from three-component measurements at Galeras volcano (Colombia)

1999 ◽  
Vol 42 (3) ◽  
Author(s):  
D. Seidl ◽  
M. Hellweg ◽  
H. Rademacher ◽  
D. M. Gomez M. ◽  
R. A. Torres C.
Keyword(s):  
Narrow Band ◽  
Unknown Origin ◽  
Seismic Events ◽  
Polarization Analysis ◽  
Frequency Content ◽  
Sh Waves ◽  
Linearly Polarized ◽  
Source Models ◽  
Active Vent

Many of the recent ash eruptions of Galeras volcano (Colombia) have been preceded by tornillos. These unusual seismic events of unknown origin have screw-like profiles on seismograms and can last up to several minutes. In March, 1996, a broadband, three-component seismometer station was installed 1.6 km south of Cono, Galeras' active vent. With high quality recordings acquired by this system, and methods which work well with narrow band signals, we investigate the frequency content and polarization properties of two tornillos. They have slighty different predominant frequencies, 3.0420 Hz and 3.0595 Hz which remain highly stable for the entire tornillo duration. The polarization analysis shows that the polarization for the two events also differs slightly but remains constant. Most of their energy is linearly polarized and lies in the horizontal plane. If these waves are taken to be SH waves, the remaining energy is confined to the beginning of the tornillo during its initiation or excitation. The remainder of the tornillo is characterized by exponential decay. These observations provide parameters for the classification of tornillos and constraints for source models.

scholarly journals Manual versus Automatic Classification of Laryngeal Lesions based on Vascular Patterns in CE+NBI Images

2020 ◽  
Vol 6 (3) ◽  
pp. 70-73
Author(s):  
Nazila Esmaeili ◽  
Alfredo Illanes ◽  
Axel Boese ◽  
Nikolaos Davaris ◽  
Christoph Arens ◽  
...  
Keyword(s):  
Vocal Fold ◽  
Narrow Band ◽  
Narrow Band Imaging ◽  
Automatic Classification ◽  
Vascular Pattern ◽  
Objective Interpretation ◽  
Laryngeal Lesions ◽  
Malignant Lesions ◽  
Manual Classification

AbstractLongitudinal and perpendicular changes in the blood vessels of the vocal fold have been related to the advancement from benign to malignant laryngeal cancer stages. The combination of Contact Endoscopy (CE) and Narrow Band Imaging (NBI) provides intraoperative realtime visualization of vascular pattern in Larynx. The evaluation of these vascular patterns in CE+NBI images is a subjective process leading to differentiation difficulty and subjectivity between benign and malignant lesions. The main objective of this work is to compare multi-observer classification versus automatic classification of laryngeal lesions. Six clinicians visually classified CE+NBI images into benign and malignant lesions. For the automatic classification of CE+NBI images, we used an algorithm based on characterizing the level of the vessel’s disorder. The results of the manual classification showed that there is no objective interpretation, leading to difficulties to visually distinguish between benign and malignant lesions. The results of the automatic classification of CE+NBI images on the other hand showed the capability of the algorithm to solve these issues. Based on the observed results we believe that, the automatic approach could be a valuable tool to assist clinicians to classifying laryngeal lesions.

Classification of low-grade neuroendocrine tumors of midgut and unknown origin

2002 ◽  
Vol 33 (11) ◽  
pp. 1126-1132 ◽  
Author(s):  
Susanne van Eeden ◽  
Pascal F.H.J. Quaedvlieg ◽  
Babs G. Taal ◽  
G.Johan A. Offerhaus ◽  
Cornelis B.H.W. Lamers ◽  
...  
Keyword(s):  
Neuroendocrine Tumors ◽  
Unknown Origin ◽  
Low Grade

Polarization analysis in magnetic x‐ray scattering using 45° linearly polarized x‐ray incident beam (abstract)

1992 ◽  
Vol 63 (1) ◽  
pp. 1176-1176
Author(s):  
Koichi Mori ◽  
Kazumichi Namikawa ◽  
Yoshisato Funahashi ◽  
Yasuo Higashi ◽  
Masami Ando
Keyword(s):  
Incident Beam ◽  
Polarization Analysis ◽  
X Ray ◽  
X Ray Scattering ◽  
Linearly Polarized ◽  
Ray Scattering

scholarly journals Luminosity Classification of Be Stars by Balmer Line Narrow Band Photometry

1982 ◽  
Vol 98 ◽  
pp. 37-40
Author(s):  
Wolfgang Zeuge
Keyword(s):  
Narrow Band ◽  
Balmer Line ◽  
Be Stars ◽  
The Absolute ◽  
Absolute Luminosity

The absolute luminosity of most Be stars can be determined by using Balmer line narrow band photometry with an accuracy of about 0.4 mag. The few cases in which this method fails can be detected.

VASCULAR PATTERN CLASSIFICATION OF COLORECTAL LESIONS WITH NARROW BAND IMAGING MAGNIFYING ENDOSCOPY

2011 ◽  
Vol 23 ◽  
pp. 106-111 ◽  
Author(s):  
YOSHIKI WADA ◽  
SHIN-EI KUDO ◽  
MASASHI MISAWA ◽  
NOBUNAO IKEHARA ◽  
SHIGEHARU HAMATANI
Keyword(s):  
Pattern Classification ◽  
Narrow Band ◽  
Narrow Band Imaging ◽  
Magnifying Endoscopy ◽  
Vascular Pattern

scholarly journals Abundance Effects in the Classification of K Stars

1976 ◽  
Vol 72 ◽  
pp. 87-90
Author(s):  
P. M. Williams
Keyword(s):  
Spectral Type ◽  
Near Infrared ◽  
Narrow Band ◽  
Infrared Photometry ◽  
Metal Abundance ◽  
Metal Abundances ◽  
Effective Temperatures

The influence of metal abundance and gravity on the relation between spectral type and effective temperatures of late G and K type stars is investigated and calibrated using metal abundances from narrow-band photometry, near infrared photometry and independent luminosity estimates.

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