Art : Art in which the subject matter has been simplified or distorted to the point that it may or may not be easily descended. Acrylic: Resin that, when mixed with water and pigment, forms an inorganic and quick drying medium. Acrylic paint therefore is a fast drying synthetic paint made from acrylic resin. Action Painting: The technique of dripping and splashing paint onto canvases stretched on the floor Aesthetic: Pertaining to the appreciation of the beautiful as opposed to the functional or utilitarian, and, by extention, to the appreciation of any form of art. Aesthetic value: The impact of a work of art on our senses, intellect, and emotions. Analogous colours:Pairs of colour such as yellow and orange, that are adjudscent to each other on the colour wheel. Acqatint : A print making process that includes etching and that permits broad areas of black and gray tones. Air brush: Atomizer operated by compressed air used for spraying on paint. Art Deco: A popular art and design style of the 1920s and 30s, and characterized by its intergration of organic and geometric forms. Art: The special expression of ideas, feelings and values in visual forms. Art criticism: A special concentrated way of looking at a piece of art with a purpose to recieve maximum enjoyment and meaning from it. Abstract Expressionism: A twentieth-century painting style in which artists applied paint freely to huge canvases in an effort to show feelings and emotions rather than realistic subject matter.Expressionism: A twentieth-century painting style in which artists applied paint freely to huge canvases in an effort to show feelings and emotions rather than realistic subject matter.

The Ministry of Education

Fingerprint-based wireless indoor positioning approaches are widely used for location-based services because wireless signals, such as Wi-Fi and Bluetooth, are currently pervasive in indoor spaces. The working principle of fingerprinting technology is to collect the fingerprints from an indoor environment, such as a room or a building, in advance, create a fingerprint map, and use this map to estimate the user’s current location. The fingerprinting technology is associated with a high level of accuracy and reliability. However, the fingerprint map must be entirely re-created, not only when the Wi-Fi access points are added, modified, or removed, but also when the interior features, such as walls or even furniture, are changed, owing to the nature of the wireless signals. Many researchers have realized the problems in the fingerprinting technology and are conducting studies to address them. In this paper, we review the indoor positioning technologies that do not require the construction of offline fingerprint maps. We categorize them into simultaneous localization and mapping; inter/extrapolation; and crowdsourcing-based technologies, and describe their algorithms and characteristics, including advantages and disadvantages. We compare them in terms of our own parameters: accuracy, calculation time, versatility, robustness, security, and participation. Finally, we present the future research direction of the indoor positioning techniques. We believe that this paper provides valuable information on recent indoor localization technologies without offline fingerprinting map construction.

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Indoor Positioning Technologies Without Offline Fingerprinting Map: A Survey

Recent progress in and perspectives of underwater wireless optical communication

A new cooperative received signal strength-based localization algorithm is proposed which employs relative error estimation and semidefinite programming (SDP). First, the log-normal shadowing RSS measurement model is transformed into an equivalent multiplicative model. Then, a relative error estimation criterion is used with this model to develop a nonconvex estimator to approximate the maximum likelihood solution. Finally, semidefinite relaxation is applied to the nonconvex estimator to obtain an SDP estimator. The proposed algorithm is first derived for noncooperative RSS-based localization and then extended to the cooperative case. The Cramer–Rao lower bound is derived for cooperative RSS-based localization. Performance results are presented, which demonstrate that the proposed SDP estimator provides a significant improvement over existing localization methods.

Cooperative RSS-Based Localization in Wireless Sensor Networks Using Relative Error Estimation and Semidefinite Programming

The ocean covers nearly two-thirds of the surface on the Earth, and there has been great interest in developing underwater wireless sensor networks (UWSNs) to help us explore the ocean realm. A great deal of efforts have been devoted to it, and significant progress has been made since the beginning of 2000s. However, most of the networks are isolatedly developed currently, inherently hardware-based and application-oriented with inflexible closed-form architectures, which are difficult to reconfigure, reprogram and evolve. They also lack the capability in sharing resources, and are far from service-oriented networks. These limitations impair their capacity for wide range of applications. To further propel the development of UWSNs, next-generation UWSNs have been proposed recently, which are robust, flexible, adaptive, programmable, support resource-sharing feature and are easy to manage and evolve. Moreover, a number of novel software-defined techniques and paradigms, such as software-defined radio, cognitive acoustic radio, network function virtualization, software-defined networking, Internet of Underwater Things, and sensor-cloud, have been emerging. These software-defined technologies have the capability of softwarizing network resources, and then redefining them to satisfy diverse application requirements, improve resource utilization efficiency and simplify network management. Consequently, these evolving technologies are envisioned as critical building blocks and major driving forces, which will transform conventional UWSNs toward software-based, programmable, user-customizable, and service-oriented next-generation UWSNs. In this paper, we provide a comprehensive review of existing works on implementing these techniques, and also present discussions for future research. We hope to inspire more active research on these areas and take a step further toward realizing next-generation UWSNs.

Software-Defined Architectures and Technologies for Underwater Wireless Sensor Networks: A Survey

Design of optical-acoustic hybrid underwater wireless sensor network

Cooperative communication has emerged as a key technique in fifth generation (5G) mobile wireless networks. In this paper, with incremental decode-and-forward (IDF) relaying and transmit antenna selection (TAS), we investigate the outage probability (OP) performance of mobile cooperative networks. Exact closed-form expressions for OP with optimal TAS are derived. These expressions are used to evaluate the impact of power allocation on OP performance. Then we verify the mathematical derivations using Monte Carlo simulations. The OP performance is influenced by power-allocation parameter.

Outage Performance for IDF Relaying Mobile Cooperative Networks

Gaussian/non-Gaussian impulsive noises in underwater acoustic (UWA) channel seriously impact the quality of underwater acoustic communication. The common denoising algorithms are based on Gaussian noise model and are difficult to apply to the coexistence of Gaussian/non-Gaussian impulsive noises. Therefore, a new UWA noise model is described in this paper by combining the symmetric $\alpha$ -stable (S $\alpha$ S) distribution and normal distribution. Furthermore, a novel underwater acoustic signal denoising algorithm called AWMF+GDES is proposed. First, the non-Gaussian impulsive noise is adaptively suppressed by the adaptive window median filter (AWMF). Second, an enhanced wavelet threshold optimization algorithm with a new threshold function is proposed to suppress the Gaussian noise. The optimal threshold parameters are obtained based on good point set and dynamic elite group guidance combined simulated annealing selection artificial bee colony (GDES-ABC) algorithm. The numerical simulations demonstrate that the convergence speed and the convergence precision of the proposed GDES-ABC algorithm can be increased by 25% $\sim$ 66% and 21% $\sim$ 73%, respectively, compared with the existing algorithms. Finally, the experimental results verify the effectiveness of the proposed underwater acoustic signal denoising algorithm and demonstrate that both the proposed wavelet threshold optimization method based on GDES-ABC and the AWMF+GDES algorithm can obtain higher output signal-to-noise ratio (SNR), noise suppression ratio (NSR), and smaller root mean square error (RMSE) compared with the other algorithms.

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A Novel Underwater Acoustic Signal Denoising Algorithm for Gaussian/Non-Gaussian Impulsive Noise

Internet-of-Everything (IoE) has gradually been recognized as an integral part of future wireless networks. In IoE, there can be an ultra-massive number of smart devices of various types to be served, imposing multi-dimensional requirements on wireless communication, sensing, and security. In this article, we provide a tutorial overview of the promising intelligent reflection communication (IRC) technologies, including reconfigurable intelligent surface (RIS) and ambient backscatter communication (AmBC), to support the requirements of IoE applications beyond the fifth-generation (5G) wireless communication network. Specifically, we elaborate on the benefits of IRC-assisted IoE in the context of the space-air-ground integrated communications and green communications, which are regarded as key features of supporting future IoE application from society and industries. Furthermore, we envision that the IRC-assisted communication and sensing can mutually benefit each other and articulate multiple ways of enhancing the security in IoE by the IRC. Numerical results help illustrate the importance of the IRC in unfavorable secrecy environments. Finally, open research issues and challenges about the IRC-assisted IoE are presented.

Intelligent Reflection Enabling Technologies for Integrated and Green Internet-of-Everything Beyond 5G: Communication, Sensing, and Security

An underwater wireless optical communication (UWOC) system with a 450-nm laser diode and a 150-MHz PIN photodiode is presented. The 16-ary quadrature amplitude modulation scheme is employed and realized on a field-programmable gate array (FPGA) to efficiently provide a high data rate. Experimental results show that this system can achieve data rates up to 50 Mbps over a distance of 3 m underwater with a bit error rate (BER) of 7.11×10−4 in artificial seawater at 35‰ salinity, where the attenuation coefficient is 0.481. This BER is below the forward error correction target of 3.8×10−3. Thus, this system can provide reliable high-speed communications over short to moderate distance point-to-point UWOC links.

Wei Shi

Papers

Design of optical-acoustic hybrid underwater wireless sensor network

Outage Performance for IDF Relaying Mobile Cooperative Networks

A Novel Underwater Acoustic Signal Denoising Algorithm for Gaussian/Non-Gaussian Impulsive Noise

Intelligent Reflection Enabling Technologies for Integrated and Green Internet-of-Everything Beyond 5G: Communication, Sensing, and Security

Underwater wireless optical communication system using a 16-QAM modulated 450-nm laser diode based on an FPGA.