Publications by authors named "Wanjin Kim"
The Long-Range Biomimetic Covert Communication Method Mimicking Large Whale.
Sensors (Basel)
October 2022
Article Synopsis
- The paper presents a new method for underwater covert communication using dolphin whistles, which is aimed at overcoming limitations in long-range communication compared to conventional methods.
- It addresses challenges like multipath delay and maintaining a high degree of mimic (DoM) in low-frequency sounds to ensure effective communication.
- Through simulations and ocean experiments, the proposed method showed improved bit-error rate (BER) performance, and its whistle patterns were even recognized as those of a real humpback whale using machine learning techniques.
Purpose: To determine the survival rates of implant-supported monolithic zirconia crowns and fixed partial dentures (FPD).
Material And Methods: An electronic search for articles in the English language literature published from January 1, 2001 to September 17, 2021 was performed using PubMed, Scopus, and CENTRAL search engines. After applying predetermined inclusion and exclusion criteria, the definitive list of selected articles was used for calculating the interval survival rate (ISR) and cumulative survival rate (CSR).
Underwater acoustic (UWA) biomimicking communications have been developed for covert communications. For the UWA covert communications, it is difficult to achieve the bit error rate (BER) and the degree of mimic (DoM) performances at the same time. This paper proposes a biomimicking covert communication method to increase both BER and DoM (degree of mimic) performances based on the Time Frequency Shift Keying (TFSK).
View Article and Find Full Text PDFArticle Synopsis
- The paper discusses a new method for underwater acoustic covert communications that mimics dolphin whistles more accurately than traditional methods.
- It introduces a technique that not only preserves a high degree of mimicry (DoM) but also achieves a low bit error rate (BER) during communication.
- Computer simulations and real ocean experiments show that the proposed method significantly improves communication reliability, achieving a BER of 0.002 compared to 0.36 for conventional methods.
In this paper, we propose a covert underwater acoustic communication method that is robust to fading using a chirp signal combined with a frequency-hopping spread spectrum scheme. A fractional Fourier transform, which estimates the slope of the signal frequency variation, is applied to the receiver to enable a robust and reliable symbol estimation with respect to the frequency and irregular phase variations. In addition, since the recursive symbol synchronization can be implemented using a chirp signal, compression and expansion effects due to the Doppler shift can be mitigated.
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