Erratum: Cutoff frequencies of W-type fibre with polynomial profile core

1981 ◽  
Vol 17 (12) ◽  
pp. 432
Author(s):  
A. Yata ◽  
H. Ikuno
1978 ◽  
Vol 14 (20) ◽  
pp. 676 ◽  
Author(s):  
Arun Kumar ◽  
Ram Chandra ◽  
R.A. Sammut ◽  
A.K. Ghatak

1981 ◽  
Vol 17 (1) ◽  
pp. 9 ◽  
Author(s):  
A. Yata ◽  
H. Ikuno

2014 ◽  
Vol 53 (04) ◽  
pp. 245-249 ◽  
Author(s):  
S. Otte ◽  
L. Wittig ◽  
G. Hüttmann ◽  
C. Kugler ◽  
D. Drömann ◽  
...  

Summary Objectives: Optical Coherence Tomography (OCT) has been proposed as a high resolution image modality to guide transbronchial biopsies. In this study we address the question, whether individual A-scans obtained in needle direction can contribute to the identification of pulmonary nodules. Methods: OCT A-scans from freshly resected human lung tissue specimen were recorded through a customized needle with an embedded optical fiber. Bidirectional Long Short Term Memory networks (BLSTMs) were trained on randomly distributed training and test sets of the acquired A-scans. Patient specific training and different pre-processing steps were evaluated. Results: Classification rates from 67.5% up to 76% were archived for different training scenarios. Sensitivity and specificity were highest for a patient specific training with 0.87 and 0.85. Low pass filtering decreased the accuracy from 73.2% on a reference distribution to 62.2% for higher cutoff frequencies and to 56% for lower cutoff frequencies. Conclusion: The results indicate that a grey value based classification is feasible and may provide additional information for diagnosis and navigation. Furthermore, the experiments show patient specific signal properties and indicate that the lower and upper parts of the frequency spectrum contribute to the classification.


2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Ming Li ◽  
Rony E. Amaya ◽  
Robert G. Harrison ◽  
N. Garry Tarr

This paper explores a variety of different CMOS varactor structures for RF and MMICs. A typical 0.18 μm CMOS foundry process was used as the study platform. The varactors' capacitance-voltage characteristics and cutoff frequencies have been examined up to 55 GHz. The primary aim of this work is to design varactors that can improve nonlinear-transmission-line (NLTL) pulse-compression circuits. The results should also be valuable for other applications up to millimeter wavelengths.


2019 ◽  
Vol 97 (10) ◽  
pp. 1064-1074
Author(s):  
Soufien Karous ◽  
Souhail Dahmen ◽  
Mohamed Shili Bouhdima ◽  
Morched Ben Amor ◽  
Christ Glorieux

This paper studies the propagation of symmetric and antisymmetric Lamb waves along a 1 mm thick iodic acid plate (HIO3) in the 1–50 MHz frequency range. The Lamb mode propagation along three crystallographic planes was theoretically investigated, for two mutually orthogonal propagation directions. Several frequencies were found that correspond to Lamb modes with zero group velocity (ZGV) and non-null phase velocity values. The first symmetric Lamb mode, S1, was found to possess only one ZGV point, regardless of the propagation direction; higher order symmetric and antisymmetric modes with up to four ZGV points were found, depending on the propagation plane. The dependence of the ZGV frequencies on each elastic constant (c11, c13, c33, c55) of the HIO3 plate material was also investigated by changing the constant values by 5% and 10%. It was found that c33 and c55 affect the number of the ZGV points, while c11 and c13 affect the frequency of the ZGV points. The existence and frequencies of the ZGV points are strongly dependent on the proximity of standing longitudinal and transverse waves at nearby cutoff frequencies.


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