Evaluation of Launch-Dependent Frequency Response of Multimode Fibers for Subcarrier-Multiplexing (SCM)

2007 ◽  
Author(s):  
Christian-Alexander Bunge ◽  
Winfried Lieber ◽  
Dan Curticapean
Keyword(s):  
Frequency Response ◽  
Multimode Fibers ◽  
Dependent Frequency ◽  
Subcarrier Multiplexing

Characterization of optoacoustic transducers through the analysis of angular-dependent frequency response

2009 ◽  
Author(s):  
André Conjusteau ◽  
Sergey A. Ermilov ◽  
Richard Su ◽  
Hans-Peter Brecht ◽  
Matthew P. Fronheiser ◽  
...  
Keyword(s):  
Frequency Response ◽  
Dependent Frequency

scholarly journals A Sound Processor for Cochlear Implant Using a Simple Dual Path Nonlinear Model of Basilar Membrane

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Kyung Hwan Kim ◽  
Sung Jin Choi ◽  
Jin Ho Kim
Keyword(s):  
Frequency Response ◽  
Nonlinear Model ◽  
Basilar Membrane ◽  
Frequency Component ◽  
Dominant Frequency ◽  
Response Characteristics ◽  
Frequency Decomposition ◽  
Dependent Frequency ◽  
Filter Array ◽  
Dual Resonance

We propose a new active nonlinear model of the frequency response of the basilar membrane in biological cochlea called the simple dual path nonlinear (SDPN) model and a novel sound processing strategy for cochlear implants (CIs) based upon this model. The SDPN model was developed to utilize the advantages of the level-dependent frequency response characteristics of the basilar membrane for robust formant representation under noisy conditions. In comparison to the dual resonance nonlinear model (DRNL) which was previously proposed as an active nonlinear model of the basilar membrane, the SDPN model can reproduce similar level-dependent frequency responses with a much simpler structure and is thus better suited for incorporation into CI sound processors. By the analysis of dominant frequency component, it was confirmed that the formants of speech are more robustly represented after frequency decomposition by the nonlinear filterbank using SDPN, compared to a linear bandpass filter array which is used in conventional strategies. Acoustic simulation and hearing experiments in subjects with normal hearing showed that the proposed strategy results in better syllable recognition under speech-shaped noise compared to the conventional strategy based on fixed linear bandpass filters.

Doping dependent frequency response of MQW infrared photodetector

2017 ◽  
Vol 104 ◽  
pp. 128-139 ◽  
Author(s):  
Md. Aref Billaha ◽  
Mukul K. Das ◽  
S. Kumar
Keyword(s):  
Frequency Response ◽  
Infrared Photodetector ◽  
Dependent Frequency

scholarly journals Size-dependent frequency response of sandeel schools

2009 ◽  
Vol 66 (6) ◽  
pp. 1100-1105 ◽  
Author(s):  
Espen Johnsen ◽  
Ronald Pedersen ◽  
Egil Ona
Keyword(s):  
Frequency Response ◽  
North Sea ◽  
Acoustic Frequency ◽  
Independent Variables ◽  
Size Dependent ◽  
Frequency Responses ◽  
The North ◽  
Dependent Frequency ◽  
The North Sea ◽  
Acoustic Surveys

Abstract Johnsen, E., Pedersen, R., and Ona, E. 2009. Size-dependent frequency response of sandeel schools. – ICES Journal of Marine Science, 66: 1100–1105. Annual Norwegian sandeel surveys have been conducted in the North Sea since 2005 to measure the stock of lesser sandeel (Ammodytes marinus). Target identification is often a major challenge in acoustic surveys, and discriminant analyses have been used to separate echoes accurately from schools of herring, mackerel, and sandeel based on their acoustic-frequency responses measured at 18, 38, 120, and 200 kHz. At two fishing grounds during the 2008 survey, 332 schools were identified as sandeel, based on the characteristics of the acoustic signal, and validated by trawl samples. The schools consisted almost entirely of 1-year-old sandeels on one of the grounds, and 2-year-olds on the other. In this study, the potential of acoustic-frequency responses is advanced to classify the sizes of fish in them. A discriminant analysis using frequency responses as independent variables was able to differentiate between sandeel schools comprising 1- and 2-year-old fish (p < 0.001). Approximately 83% of the 2-year-old fish and 77% of the 1-year-old fish were classified correctly. The frequency responses at 18 and 38 kHz were the most important independent variables. Sandeel landings in the North Sea are normally dominated by 1- and 2-year-old sandeels in the first half of the year. This study revealed that these two age classes could be identified acoustically; a finding that may be important for acoustic surveys of sandeels and for management of the commercial sandeel fishery.

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