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This paper presents a cooperative game theory approach to improve the video steganography framework. Wherein, the video steganography framework comprises the following steps: (1) Cover video devising, (2) Secret image pre-processing, and (3) Embedding process. In the first step, the cover video is segmented using scene change detection method. Once the scenes are segmented the motion vectors are identified by Block Matching Motion Estimation Algorithm (BMMEA). Based on these motion vectors, the Region of Interest (ROI) is selected. The selected ROI is grouped using their momentum. In order to add an additional layer of security, the secret image is scrambled using pixel-wise Arnold Transform in the next step. Finally, based on the ROI groups, the scrambled secret data is embedded into the ROI's locations. An ideal and perfect video steganography system should be able to maintain the quality of the video after embedding the secret data. The quality factors of the video steganography approach include perceptible invisibility, payload capacity, and robustness. However, these quality factors are conflicted with each other. In order to address this issue, having these three quality factors as players a cooperative 3-players game theory approach is proposed. This technique provides an optimal solution for the video steganography framework using strategy adaption. The optimal solution is acquired by applying the Iterative Elimination of Strictly Dominant Strategies (IESDS) method. The achieved optimal solution comes up with the best trade-off between the quality factors. Experimental results have deduced the best optimal solution from the proposed three-player game theoretic approach that helps the video steganography approach to resolve the quality and security issues. It is also observed that the optimized proposed method outperforms the contemporary methods by attaining significant outcomes. [ABSTRACT FROM AUTHOR]

Several medical consultations and examinations have been undertaken online since the Covid outbreak. However, when private data was communicated over the internet or uploaded to the cloud, medical information became more susceptible to security risks. Steganography is a technique that can be used to hide sensitive information within a cover image. This paper presents four improved algorithms to enhance steganography's performance in medical images. A full-size hidden image that is as huge as a cover image cannot be handled by previous methods, which is what the algorithmic design is meant to address. Several creative methods are presented, including the computation of Discrete Cosine Transform (DCT) coefficients based on scaled floating values, the addition of an adaptive compression matrix, and a new approach for systematically dispersing a concealed number of bits across multiple separate locations in the cover image. The results of the experiment showed a notable advancement over the earlier research. Our secret image size is substantially larger than the past studies, yet the structure similarity index matrix (SSIM) of the best reconstructed secret image is close to ideal, the peak signal-to-noise ratio (PSNR) and the payload capacity are higher than in the previous studies. This research is beneficial since it contributes to a medical application for enhancing the security of information concealed in chest X-ray images. Medical personnel can generate an image that conceals patient information in a secure manner. [ABSTRACT FROM AUTHOR]

Image steganography is one of the prominent technologies in data hiding standards. Steganographic system performance mostly depends on the embedding strategy. Its goal is to embed strictly confidential information into images without causing perceptible changes in the original image. The randomization strategies in data embedding techniques may utilize random domains, pixels, or region-of-interest for concealing secrets into a cover image, preventing information from being discovered by an attacker. The implementation of an appropriate embedding technique can achieve a fair balance between embedding capability and stego image imperceptibility, but it is challenging. A systematic approach is used with a standard methodology to carry out this study. This review concentrates on the critical examination of several embedding strategies, incorporating experimental results with state-of-the-art methods emphasizing the robustness, security, payload capacity, and visual quality metrics of the stego images. The fundamental ideas of steganography are presented in this work, along with a unique viewpoint that sets it apart from previous works by highlighting research gaps, important problems, and difficulties. Additionally, it offers a discussion of suggested directions for future study to advance and investigate uncharted territory in image steganography. [ABSTRACT FROM AUTHOR]

This review paper explores the use of optimization techniques in steganography, the art of hiding secret information within other data. Steganography is a field that has gained significant attention in recent years due to the increasing need for secure communication and data protection. Optimization techniques have been shown to be effective in improving the performance of steganography systems, particularly in terms of maximizing the amount of secret data that can be hidden while minimizing the impact on the cover data. This paper provides a comprehensive overview of the state-of-the-art optimization techniques in steganography, including genetic algorithms, particle swarm optimization, ant colony optimization and fruit fly optimization algorithm. This paper also discusses the advantages and limitations of these techniques and their potential for further development in the future. Also the state-of-the-art methods were compared in terms of PSNR (Peak Signal to Noise Ratio), payload capacity, SSIM (Structured Similarity Index) etc. The review concludes by highlighting the importance of optimization techniques in steganography and their potential impact on the development of more efficient and secure steganography systems. [ABSTRACT FROM AUTHOR]

Steganography involves concealing information by embedding data within cover media and it can be categorized into two main domains: spatial and frequency. This paper presents two distinct methods. The first is operating in the spatial domain which utilizes the least significant bits (LSBs) to conceal a secret message. The second method is the functioning in the frequency domain which hides the secret message within the LSBs of the middle-frequency band of the discrete cosine transform (DCT) coefficients. These methods enhance obfuscation by utilizing two layers of randomness: random pixel embedding and random bit embedding within each pixel. Unlike other available methods that embed data in sequential order with a fixed amount. These methods embed the data in a random location with a random amount, further enhancing the level of obfuscation. A pseudo-random binary key that is generated through a nonlinear combination of eight Linear Feedback Shift Registers (LFSRs) controls this randomness. The experimentation involves various 512x512 cover images. The first method achieves an average PSNR of 43.5292 with a payload capacity of up to 16% of the cover image. In contrast, the second method yields an average PSNR of 38.4092 with a payload capacity of up to 8%. The performance analysis demonstrates that the LSB-based method can conceal more data with less visibility, however, it is vulnerable to simple image manipulation. On the other hand, the DCT-based method offers lower capacity with increased visibility, but it is more robust. [ABSTRACT FROM AUTHOR]

In this paper, the characterization and sizing of heavy-lift multirotor UAVs are carried out. For this purpose, the electric multirotor UAV system is briefly described, and the parameters are carefully selected encompassing a wide range of UAVs regarding size and power. In the first phase, comprehensive experimental measurements are conducted for selected propulsion components. Through a systematic data acquisition process, a database for two series of electric propulsion units (low voltage and high voltage setups), is obtained. Using the presented identification procedure, the data is processed, and the characterization is completed in the following phase. Based on experimental data, a more accurate model of aerodynamic forces and torques and electric power was obtained, compared to previous approaches. In the final phase of this research, sizing of conventional heavy-lift multirotor configurations is carried out, where the diagonal, take-off mass, hovering power, and payload capacity are considered, and results are shown graphically. The proposed sizing steps enable further performance analysis to design a more efficient system, especially from the aspect of payload capacity.

This paper investigates the economic consequences of a haulage company replacing its line-haul diesel trucks with battery-electric ones. It also examines how large truck batteries should be, whether the haulage companies should use public fast chargers to complement their own, and whether public fast chargers have the potential to be profitable. The potential extra cost of losing payload capacity is estimated and there is an investigation of whether a charge-point operator should meet the peak demand for charging. The case under analysis is designed to represent a typical line-haul service between terminals in a major logistics system, with the finding that, in this case, a transition to battery-electric trucks seems cost effective for the company. Moreover, it is advisable for the company to use public fast chargers and these will likely become profitable given that the utilisation factor of the investigated public fast chargers may realistically exceed 20%. [ABSTRACT FROM AUTHOR]

This research proposed the dilated hybrid edge detection on the three most significant bits (MSB) pixels of cover images with the aim of expanding the edge area so as to increase the data embedding capacity in image steganography. This technique can perform extraction without the need to save edge detection on the original cover image. This is because edge detection is performed on 3-bits MSB images, whereas messages are embedded at x LSB and y LSB values, where x is the number of LSB bits replaced in the edge area and y is the number of bits replaced in the non-edge area, where x and y cannot reach 3-bits MSB, so the edge detection of the cover image and the stego image will be the same. Based on the results of tests carried out, the proposed steganography technique succeeded in improving the quality of imperceptibility, where the PSNR value increased by about 1 to 2 dB when compared to the previous method. Similarly, the message embedding capacity can be increased due to a wider edge area, with the same image dataset obtained an average increase of 4,350–12,364 pixels of the edge area, however, the quality of the stego image imperceptibility can be maintained.

This study investigates the compatibility between the soft deformation and high stiffness through the development of a soft robotic gripper for a human-scale payload. Softness is important for robotic systems that physically interact with the environments, especially for adaptive grasping or manipulation of unknown objects. Pursuing only softness would not achieve them either, and creating a certain stiffness is also an essential function in many human-scale applications. Soft robotics is unique in that it employs soft materials for the structure, and will find a lot more applications if it gains the human-scale specifications of force or the equivalent stiffness. We discuss the compatibility of the soft deformation and high stiffness based on a numerical analysis, and then present the design of a soft robotic gripper actuated by high oil-pressure, reporting its experimental validations. [ABSTRACT FROM AUTHOR]

In carrying out reversible image steganography, the Generative Adversarial Networks (GANs-based) models have proven to be the most suitable deep learning models for image steganography. Image steganography is a steganography system that hides secret data in an image cover medium without arousing suspicion, and it is defined by the ability to reconstruct the cover medium with no visible distortion after the steganography system has been decoded by extracting the hidden data. In this study, we try achieve the encoding phase in image steganography, where two GAN-base models (CycleGAN and DCGAN) were proposed. Empirical analysis was done to determine a better model for the encoding of image steganography. The Peak Signal-to-Noise Ratio (PSNR), the Structural Similarity Index Metric (SSIM), and bit per pixel (bpp) were used as the metrics for the analysis. The outcome of DCGAN yielded (SSIM=0.48; PSNR=19.86; bpp=24.79) and the outcome of using CycleGAN yielded (SSIM=0.97; PSNR=41.45; bpp=24.97). These values concluded that the CycleGAN was preferable over the DCGAN. Hence, the CycleGAN was adopted as the encoding model. [ABSTRACT FROM AUTHOR]

This paper investigates the economic consequences of a haulage company replacing its line-haul diesel trucks with battery-electric ones. It also examines how large truck batteries should be, whether the haulage companies should use public fast chargers to complement their own, and whether public fast chargers have the potential to be profitable. The potential extra cost of losing payload capacity is estimated and there is an investigation of whether a charge-point operator should meet the peak demand for charging. The case under analysis is designed to represent a typical line-haul service between terminals in a major logistics system, with the finding that, in this case, a transition to battery-electric trucks seems cost effective for the company. Moreover, it is advisable for the company to use public fast chargers and these will likely become profitable given that the utilisation factor of the investigated public fast chargers may realistically exceed 20%.

This research proposed the dilated hybrid edge detection on the three most significant bits (MSB) pixels of cover images with the aim of expanding the edge area so as to increase the data embedding capacity in image steganography. This technique can perform extraction without the need to save edge detection on the original cover image. This is because edge detection is performed on 3-bits MSB images, whereas messages are embedded at x LSB and y LSB values, where x is the number of LSB bits replaced in the edge area and y is the number of bits replaced in the non-edge area, where x and y cannot reach 3-bits MSB, so the edge detection of the cover image and the stego image will be the same. Based on the results of tests carried out, the proposed steganography technique succeeded in improving the quality of imperceptibility, where the PSNR value increased by about 1 to 2 dB when compared to the previous method. Similarly, the message embedding capacity can be increased due to a wider edge area, with the same image dataset obtained an average increase of 4,350–12,364 pixels of the edge area, however, the quality of the stego image imperceptibility can be maintained. [ABSTRACT FROM AUTHOR]

In this paper, human visual system based adaptive LSB replacement process has been used to develop an image watermarking scheme. A saliency map of the cover image is built up and the watermark is adaptively embedded into that cover image pixels to get a better visual transparency with increased payload. In this approach, the saliency map is generated by using a binary and holistic image descriptor, termed as Image Signature. The hardware execution of this proposed methodology has been set up through Virtex6 FPGA board (xc6vlx760). The experimental results divulge that the proposed framework provides less perceptual inaccuracy with improved payload capacity. [ABSTRACT FROM AUTHOR]

Periodic cruise has been proven an effective trajectory to conserve fuel and alleviate aerodynamic heating for hypersonic cruise vehicles (HCVs). This work studies how to adopt an HCV with active cooling to periodic cruise. In this adaption, payload capacity is to maximize, whereas the cooling requirement is to reduce. The differences in requirements for subsystems between periodic and steady cruises have been made clear. The results indicate that periodic cruise principally transfers the burden of thermal protection to the structure, and that periodic cruise is more effective to trade payload capacity for larger reduction of cooling requirement. Afterward, impacts of design parameters of the vehicle on payload capacity and cooling requirement have been discussed. The results indicate that insulation thinner than 3 mm, a planform loading lower than 220 kg/m2, or a large engine is not suggested for the vehicle studied herein. This work figures out the correlation between design parameters of vehicle and features of periodic cruise trajectory. It could help to improve the feasibility of periodic cruise for a hypersonic vehicle, which is significant for realization of the long-range hypersonic cruise.

A novel major-motion mechanism of forging manipulators is developed using a basic module mechanism combination method. Composed of one 4/1 module mechanism and two 6/1–1 module mechanisms, this major-motion mechanism can realize the lifting, horizontal translation and pitching of the gripper required by forging manipulators. Based on an algorithm module, algorithm flowcharts of the forward and inverse kinematics of the proposed novel major-motion mechanism, the Dango & Dienenthal major-motion mechanism, and the Schloemann-Siemag AG Meer major-motion mechanism are established. Based on the flowcharts, the gripper trajectories of the three major-motion mechanisms in the process of lifting, horizontal translation and pitching are obtained. Then, the maximum lifting deviations of the three major-motion mechanisms are acquired. Moreover, the anti-toppling stabilities of the three major-motion mechanisms are respectively obtained according to an anti-toppling stability function. Furthermore, when the ultimate bearing value of the driver is given, the changing trends of the bearing capacities of the three major-motion mechanisms are obtained via the proportional coefficient method. Our research provides an important theoretical basis for the development and design of novel major-motion mechanisms. [ABSTRACT FROM AUTHOR]

The advantages of a non-equatorial space elevator have attracted the attention of several researchers. In this paper, two static tether models are presented for studying the tapering of a uniform-stress tether using a discretization method. The efficiency and accuracy of the two models are verified by comparing them with models used in other studies. We then study the range of latitudes that allowed for a uniform-stress space elevator and evaluate the influence of the anchor-point latitude on the system payload capacity. The results show that increasing the tensile strength of the tether material can expand the range of the space elevator system deployment. However, a high latitude of anchorage would greatly sacrifice the payload capacity. [ABSTRACT FROM AUTHOR]

This paper proposes a novel audio watermarking scheme based on the discrete cosine transform (DCT) and Schur decomposition. The proposed scheme uses the DCT transformation to increase robustness and the Schur decomposition to achieve perceptual transparency. The proposed scheme first applies the DCT transformation to the original audio signal and then applies the Schur decomposition to the mid-frequency band of the DCT coefficients that generate two matrices (U and S). The watermark bits are embedded into the diagonal elements of the triangular matrix S. The Schur decomposition increases the perceptual transparency and the DCT transformation increases robustness of the proposed audio watermarking scheme by effectively resisting several types of audio signal attacks. The imperceptibility of the proposed watermarking scheme is measured subjectively using subjective difference grades (SDG) and objectively using signal-to-noise ratio (SNR) and objective difference grades (ODG) metrics. Its robustness is evaluated against several types of attacks in terms of NC and BER for different types of audio. The resulting of payload capacity, SNR, NC, and BER are as high as 516.26 bps, 77.95, 0.05326, and 0.9727, respectively. Experimental results confirm the proposed scheme is efficient, imperceptible, and robust with a high payload capacity and no effecting audio signal. [ABSTRACT FROM AUTHOR]

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Wearable robots for carrying heavy loads in an industrial field should be able to carry a load over their entire range of motion. The payload capacity of a wearable robot employing rotary actuators or linear actuators at the knee joints decreases drastically in the knee-flexion posture, because the moment arm of gravity increases and the moment arm of the force generated by the linear actuators at the knees decreases after a certain point. To resolve this issue, this study proposes two types of sublink mechanisms for the knee joints. With only a few modifications to the existing knee-joint configuration, the moment arm in the knee-flexion posture is increased and the payload capacity is effectively increased, and thus, enabling robot pilots to squat down and stand up with heavy loads. The proposed mechanisms were simulated and tested with a wearable robot, and their effectiveness was verified. [ABSTRACT FROM PUBLISHER]

A spectral shaping technique emerging from autoregressive modeling is incorporated into vector modulation to achieve efficient blind audio watermarking. This technique allows the watermarking process to be performed in a broader frequency band with the embedding strength adapting to auditory masking thresholds. To ensure accurate watermark retrieval, we slacken the condition for binary embedding and develop an iterative algorithm to carry out energy-balanced vector modulation. As a result, the proposed scheme reaches a capacity as high as 818.26 bits per second but still possesses sufficient robustness and transparency. The effectiveness of the proposed scheme has been demonstrated using the perceptual evaluation of audio quality (PEAQ) and bit error rates of recovered watermarks. The PEAQ confirms that the watermarked audio signal is perceptually indistinguishable from the original one. Compared with other recently developed DWT-based methods with less payload capacities, the proposed scheme can achieve comparable, if not better, robustness for attacks such as resampling, requantization, amplitude scaling, noise corruption, lowpass filtering, DA/AD conversion, echo addition, jittering and MPEG-3 compression. [ABSTRACT FROM AUTHOR]

In military and industrial applications, wearable robots should meet the required payload capacity in all human motion range owing to dealing with heavy loads, which is safety and work performance issues. But, the payload capacity of wearable robots employing linear actuators gradually decreases while the pilot bends his knees with a stand-to-sit motion, because the moment arm of actuating force varies and decreases drastically. To deal with this issue, this study proposes an elastic mechanism combined with a sub-link mechanism to increase the moment arm of the elastic force in the knee-flexion posture. This mechanism generates additional torque to supplement the force needed during sit-to-stand and stand-to-sit motions with heavy loads. The proposed mechanism was simulated and tested with a wearable robot, and its effectiveness was verified. [ABSTRACT FROM AUTHOR]

In this research paper, an adaptive difference expansion-based reversible data hiding technique with the capability of embedding either three bits or two bits or one bit for each pixel and which can deal with color image is presented. To embed and extract data, the proposed technique has some salient features such as its capability to control the embedding capacity by using three global embedding parameters. These parameters are computed using the statistics of the embedded pixel surrounding pixels. Also, the data embedding steps in the proposed scheme can be reversed to completely retrieve the cover image free from any deformation. Furthermore, in the proposed technique, no reference images or memorization of the embedded pixel positions are needed in the data extraction process. A course of experiments is conducted, and the results demonstrated that the proposed technique outperforms other similar techniques in terms of payload capacity and PSNR. [ABSTRACT FROM AUTHOR]

The design, testing and realisation aspects during the development of a medium size aerostat envelope have been presented in this paper. The payload capacity of this aerostat is 300 kg at 1 km above mean sea level. The aerostat envelope is the aerodynamically shaped fabric enclosure part of the aerostat which generally uses helium for lifting useful payloads to a specified height. The envelope volume estimation technique is discussed which provides the basis for sizing. The design, material selection, testing and realisation aspects of this aerostat envelope are also discussed. The empirical formulas and finite element analysis are used to estimate the aerodynamic, structural and other design related parameters of the aerostat. Equilibrium studies are then explained for balancing forces and moments in static conditions. The tether profile estimation technique is discussed to estimate blow by distance and tether length. A comparison of estimated and measured performance parameters during trials has also been discussed. [ABSTRACT FROM AUTHOR]

This paper presents a new combinatorial search method for the quasi-static stiffness performance evaluation and payload capacity analysis of serial modular reconfigurable robots (MRRs). The goal in this paper is to optimize the external payload capacity to achieve a global set of satisfactory kineto-elastic performance requirements for all module configurations. This problem exhibits considerable numerical complexities since the maximum payload capacity is dependent on a large number of possible module configurations, the worst-case stiffness poses for each configuration, and multiple kineto-elastic performance requirements. Therefore, to alleviate these difficulties, the problem is decomposed into an elimination search algorithm to reduce the configuration search space, a genetic algorithm to directly search the configuration workspaces and find the worst-case stiffness poses, and a bisection method to determine the maximum payload capacity at the worst-case configurations and poses. It is demonstrated that the worst-case stiffness search method in this paper is superior in computational time and numerical accuracy compared to previous hierarchical or incremental search methods, which require searching through a pre-determined number of poses. Through case studies, the new combinatorial search method is proven to be computationally efficient and can obtain accurate results for the worst-case stiffness poses and maximum payload capacity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this paper the workspace and payload capacity of a new design of reconfigurable Delta-type parallel robot is analysed. The reconfiguration is achieved by adjusting the length of the kinematic chains of a given robot link simultaneously and symmetrically during the operation of the robot. This would produce a dynamic workspace in shape and volume. A numerical analysis of the variation of shape and volume of the workspace and payload capacity of the robot is presented. Based both on the results of this analysis and on practical requirements, a proposal for the design of a reconfiguring mechanism is presented. [ABSTRACT FROM AUTHOR]

Lossless data hiding is a special type of data hiding technique that guarantees not only the secret data but also the ability of cover media to be reconstructed without any distortion. A latest lossless data hiding technique is proposed by Hong Lin Jin's that is based on hiding only one data bit in the spatial domain in gray-level image. However, this method uses double difference expansion to embed bits which results in a small embedding capacity. For this purpose, we propose an improved algorithm with the potential of increasing the payload capacity and maintaining good image quality. The proposed improved algorithm is characterized by two aspects. First, the proposed improved reversible data hiding scheme is enhanced to exhibit data hiding in color palette images. Second, the embedding level is improved by using quadruple difference expansion to guarantee the embedding of 2-bit data into color images. Experiments of the proposed improved method have been conducted over several well-known test images. The results show that the proposed improved method significantly improves the embedding capacity over Hong Lin Jin's scheme by the range of 15–35% for grayscale images and 20–46% for color images while still maintaining the quality of the stego-images. [ABSTRACT FROM AUTHOR]