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  1. Arguably, the most conspicuous evidence for anthropogenic climate change lies in the Arctic Ocean. For example, the summer-time Arctic sea ice extent has declined over the last 40 years and the Arctic Ocean freshwater storage has increased over the last 30 years. Coupled climate models project that this extra freshwater will pass Greenland to enter the sub-polar North Atlantic Ocean (SPNA) in the coming decades. Coupled climate models also project that the Atlantic Meridional Overturning Circulation (AMOC) will weaken in the twenty-first century, associated with SPNA buoyancy increases. Yet, it remains unclear when the Arctic anthropogenic freshening signal will be detected in the SPNA, or what form the signal will take. Therefore, this article reviews and synthesizes the state of knowledge on Arctic Ocean and SPNA salinity variations and their causes. This article focuses on the export processes in data-constrained ocean circulation model hindcasts. One challenge is to quantify and understand the relative importance of different competing processes. This article also discusses the prospects to detect the emergence of Arctic anthropogenic freshening and the likely impacts on the AMOC. For this issue, the challenge is to distinguish anthropogenic signals from natural variability.

    This article is part of a discussion meeting issue ‘Atlantic overturning: new observations and challenges’.

     
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    Free, publicly-accessible full text available December 11, 2024
  2. null (Ed.)
    With the extensive application of the Direct Memory Access (DMA) technique, the efficiency of data transfer between the peripheral and the host machine has been improved dramatically. However, these optimizations also introduce security vulnerabilities and expose the process of data transmission to DMA attacks that utilize the feature of direct access to steal the data stored in the live memory on the victim system. In this paper, we propose a lightweight scheme to provide resilience to DMA attacks without physical and protocol-level modification. The proposed scheme constructs a unique identifier for each DMA-supported PCIe device based on profiling time and builds a trusted database for authentication. The experimental result shows that the proposed methodology eliminates most of the noise produced in the measuring process for identifier construction and the success rate of authentication is 100% for all the devices. 
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  3. null (Ed.)
    Abstract Computational oceanography is the study of ocean phenomena by numerical simulation, especially dynamical and physical phenomena. Progress in information technology has driven exponential growth in the number of global ocean observations and the fidelity of numerical simulations of the ocean in the past few decades. The growth has been exponentially faster for ocean simulations, however. We argue that this faster growth is shifting the importance of field measurements and numerical simulations for oceanographic research. It is leading to the maturation of computational oceanography as a branch of marine science on par with observational oceanography. One implication is that ultraresolved ocean simulations are only loosely constrained by observations. Another implication is that barriers to analyzing the output of such simulations should be removed. Although some specific limits and challenges exist, many opportunities are identified for the future of computational oceanography. Most important is the prospect of hybrid computational and observational approaches to advance understanding of the ocean. 
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  4. Integration of complex and high-speed electronic components in the state of art electric power system enhances the need for improved security infrastructure and resilience against invasive and non-invasive attacks on the smart grid. A modern smart grid system integrates a variety of instruments and standards to achieve cost-effective and time-effective energy measurement and management. As the fundamental component in the smart grid, the smart meter supports real-time monitoring, automatic control, and high-speed communication along with power consumption recording. However, the wide use of smart meters also increases privacy and security concerns. In this paper, we demonstrate the vulnerability of side-channel attacks on secure communication in smart grids for software-based and hardware-based implementations. 
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  5. Reconfigurable logic enables architectural updates for embedded devices by providing the ability to reprogram partial or entire device. However, this flexibility can be leveraged by the adversary to compromise the device boot process by modifying the bitstream or the boot process with physical or remote access of device placed in a remote field. We propose a novel multilayer secure boot mechanism for SoCs with a two-stage secure boot process. First stage uses device bound unique response as a key to decrypt application logic. The security function is extended at runtime by integrating intermittent architecture and application locking mechanism to reveal correct functionality. 
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  6. The Internet of Things (IoT) are paradigm shift transforming embedded objects into a smart connected device, ready to sense, analyze and communicate information with other devices. Nowadays, IoT devices are widely used in smart home systems and smart grid systems at a high level of integration and automation. However, the increasing tendency of the smart device also leads to a problem of security. The recent exploitations of the connected smart devices’ vulnerabilities reinforce the importance of security implementation and integration at the system level. In this work, we propose some use cases to show the vulnerability of the smart bulb to different attacks. 
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