Major powers are advancing strategic competition in infrastructure building in the developing world. They cultivate their infrastructure statecraft by securing financial and technological resources, ...making institutional arrangements, and managing infrastructure-related consequences. The infrastructure statecraft which covers physical and digital infrastructure as well as hard and soft infrastructure has connotations of geopolitics, geoeconomics and geotechnology. The Sino-U.S. strategic competition in the infrastructure of the Indo-Pacific has intensified in recent years. China has been proactively advancing infrastructure cooperation under the banner of BRI. The United States has proposed the ＂free and open Indo-Pacific strategy＂ and ＂Partnership for Global Infrastructure and Investment,＂ and it competes with China in the infrastructure field by building networked coalitions with its allies and partners. The infrastructure competition illustrates the development-security nexus challenge of U.S.-China rivalry over connectivity in the Indo-Pacific. China has taken measures to readjust the way it advances the Belt and Road Initiative and improves its infrastructure statecraft. This article argues that Sino-U.S. competition on regional infrastructure is not necessarily a zero-sum game.
The EU brought out a Global Strategy for foreign and security policy in June 2016, which indicates European efforts to reflect on and reshape its grand strategy. Meanwhile, China is also conducting ...an in-depth assessment of the international order under transition, and strives to rebalance its own national development and foreign policies. Beijing is pursuing a connectivity-oriented grand strategy. The peaceful rise of China depends on whether China and other economies can fully leverage each other's development opportunities, and become stronger by taking advantage of increasing interconnectedness in the world. The One Belt, One Road (OBOR) initiative is a key element of such a grand strategy and will have far-reaching implications for China-Europe relations.
Secure Multi-Party Computation (SMPC) is a generic cryptographic primitive that enables distributed parties to jointly compute an arbitrary functionality without revealing their own private inputs ...and outputs. Since Yao’s seminal work in 1982, 30 years of research on SMPC has been conducted, proceeding from pure theoretical research into real-world applications. Recently, the increasing prevalence of the newly emerging technologies such as cloud computing, mobile computing and the Internet of Thing has resulted in a re-birth of SMPC’s popularity. This has occurred mainly because, as a generic tool for computing on private data, SMPC has a natural advantage in solving security and privacy issues in these areas. Accordingly, many application-oriented SMPC protocols have been constructed. This paper presents a comprehensive survey on the theoretical and practical aspects of SMPC protocols. Specifically, we start by demonstrating the underlying concepts of SMPC, including its security requirements and basic construction techniques. Then, we present the research advances regarding construction techniques for generic SMPC protocols, and also the cutting-edge approaches to cloud-assisted SMPC protocols. Then, we summarize the concrete application-oriented protocols that are currently available, and finally, we present a discussion of the current literature and conclude this survey.
Cloud storage plays an important role in today’s cloud ecosystem. Increasingly clients tend to outsource their data to the cloud. In spite of its copious advantages, integrity has always been a ...significant issue. The audit method is commonly used to ensure integrity in cloud scenarios. However, traditional auditing schemes expect a third-party auditor (TPA), which is not always available in the real world. Also, the former scheme implies a limited pay-as-you-go service, as it requires the client to pay for the service in advance.
In this paper, we aim to address the aforementioned drawback by adopting blockchain to replace TPA and designing a blockchain-based fair payment smart contract for public cloud storage auditing. In our system, data owner and cloud service provider (CSP) will run a blockchain-based smart contract. The contract ensures that the CSP is required to submit data possession proof regularly. The CSP gets paid only if the verification is passed; otherwise, it gets no remuneration but has to pay the penalties. To reduce the number of interactions in the execution of contract, we present the notion of non-interactive public provable data possession and design a blockchain-based smart contract for public cloud storage auditing based on this primitive.
The performance of devices fabricated from piezoelectric semiconductors, such as sensors and actuators in microelectromechanical systems, is superior; furthermore, plate structures are the core ...components of these smart devices. It is thus important to analyze the electromechanical coupling properties of piezoelectric semiconductor nanoplates. We established a nanoplate model for the piezoelectric semiconductor plate structure by extending the first-order shear deformation theory. The flexural vibrations of nanoplates subjected to a transversely time-harmonic force were investigated. The vibrational modes and natural frequencies were obtained by using the matrix eigenvalue solver in COMSOL Multiphysics 5.3a, and the convergence analysis was carried out to guarantee accurate results. In numerical cases, the tuning effect of the initial electron concentration on mechanics and electric properties is deeply discussed. The numerical results show that the initial electron concentration greatly affects the natural frequency and electromechanical fields of piezoelectric semiconductors, and a high initial electron concentration can reduce the electromechanical fields and the stiffness of piezoelectric semiconductors due to the electron screening effect. We analyzed the flexural vibration of typical piezoelectric semiconductor plate structures, which provide theoretical guidance for the development of new piezotronic devices.
Target search for moving and invisible objects has always been considered a challenge, as the floating objects drift with the flows. This study focuses on target search by multiple autonomous ...underwater vehicles (AUV) and investigates a multi-agent target search method (MATSMI) for moving and invisible objects. In the MATSMI algorithm, based on the multi-agent deep deterministic policy gradient (MADDPG) method, we add spatial and temporal information to the reinforcement learning state and set up specialized rewards in conjunction with a maritime target search scenario. Additionally, we construct a simulation environment to simulate a multi-AUV search for the floating object. The simulation results show that the MATSMI method has about 20% higher search success rate and about 70 steps shorter search time than the traditional search method. In addition, the MATSMI method converges faster than the MADDPG method. This paper provides a novel and effective method for solving the maritime target search problem.
The underwater environment is still unknown for humans, so the high definition camera is an important tool for data acquisition at short distances underwater. Due to insufficient power, the image ...data collected by underwater submersible devices cannot be analyzed in real time. Based on the characteristics of Field-Programmable Gate Array (FPGA), low power consumption, strong computing capability, and high flexibility, we design an embedded FPGA image recognition system on Convolutional Neural Network (CNN). By using two technologies of FPGA, parallelism and pipeline, the parallelization of multi-depth convolution operations is realized. In the experimental phase, we collect and segment the images from underwater video recorded by the submersible. Next, we join the tags with the images to build the training set. The test results show that the proposed FPGA system achieves the same accuracy as the workstation, and we get a frame rate at 25 FPS with the resolution of 1920 × 1080. This meets our needs for underwater identification tasks.
Based on the nonlinear constitutive equation, a piezoelectric semiconductor (PSC) fiber under axial loads and Ohmic contact boundary conditions is investigated. The analytical solutions of ...electromechanical fields are derived by the homopoty analysis method (HAM), indicating that the HAM is efficient for the nonlinear analysis of PSC fibers, along with a rapid rate of convergence. Furthermore, the nonlinear characteristics of electromechanical fields are discussed through numerical results. It is shown that the asymmetrical distribution of electromechanical fields is obvious under a symmetrical load, and the piezoelectric effect is weakened by an applied electric field. With the increase in the initial carrier concentration, the electric potential decreases, and owing to the screening effect of electrons, the distribution of electromechanical fields tends to be symmetrical.
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