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Abstract

This paper presents the concept of the modelling methodology of a payload-vessel system allowing for a comprehensive investigation of mutual interactions of the system dynamics for lifting in the air. The proposed model consists of six degrees of freedom (6-DoF) vessel and three degrees of freedom (3-DoF) lifting model that can replace the industrial practice based on a simplified approach adopted for light lifts. Utilising the response amplitude operators (RAOs) processing methodology provides the ability to incorporate the excitation functions at the vessel crane tip as a kinematic and analyse a wide spectrum of lifted object weights on a basis of regular wave excitation. The analytical model is presented in detail and its solution in a form of numerical simulation results are provided and discussed within the article. The proposed model exposes the disadvantages of the models encountered in engineering practice and literature and proposes a novel approach enabling efficient studies addressing a lack of access to reliable modelling tools in terms of coupled models for offshore lifting operations planning..
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Bibliography

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Authors and Affiliations

Anna Mackojć
1
ORCID: ORCID
Bogumil Chiliński
1
ORCID: ORCID

  1. Institute of Machine Design Fundamentals, Warsaw University of Technology, Poland
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Abstract

This research proposes a method to enhance the payload message by embedding messages on the dilated edge areas by the Least Significant Bit (LSB) method. To add security aspects to messages, messages are not embedded directly on the LSB but encrypted with XOR operations with Most Significant Bit (MSB). The experimental results of the test in this study showed that the dilation process to some extent can increase the payload of 18.65% and the average bpp is 1.42 while maintaining the imperceptibilty quality of stego image with an average PSNR value of about 47 dB, SSIM is 0.9977 and MSE is 1.13.

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Authors and Affiliations

De Rosal Ignatius Moses Setiadi
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Abstract

In this paper, a robust and perceptually transparent single-level and multi-level blind audio watermarking scheme using wavelets is proposed. A randomly generated binary sequence is used as a watermark, and wavelet function coding is used to embed the watermark sequence in audio signals. Multi-level watermarking is used to enhance payload capacity and can be used for a different level of security. The robustness of the scheme is evaluated by applying different attacks such as filtering, sampling rate alteration, compression, noise addition, amplitude scaling, and cropping. The simulation results obtained show that the proposed watermarking scheme is resilient to various attacks except cropping. Perceptual transparency of watermark is measured by using Perceptual Evaluation of Audio Quality (PEAQ) basic model of ITU-R (PEAQ ITU-R BS.1387) on Speech Quality Assessing Material (SQAM) given by European Broadcasting Union (EBU). Average Objective Difference Grade (ODG) measured for this method is -0.067 and -0.080 for single-level and multi-level watermarked audio signals, respectively. In the proposed single-level digital audio watermarking scheme, the payload capacity is increased by 19.05% as compared to the single-level Chirp-Based Digital Audio Watermarking (CB-DAWM) scheme.
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Authors and Affiliations

Farooq Husain
Omar Farooq
Ekram Khan

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