Biblio

The problem of authorship attribution has applications from literary studies (such as the great Shakespeare/Marlowe debates) to counter-intelligence. The field of stylometry aims to offer quantitative results for authorship attribution. In this paper, we present a combination of stylometric techniques using machine learning. An implementation of the system is used to analyse chat logs and attempts to construct a stylometric model for users within the presented chat system. This allows for the authorship attribution of other works they may write under different names or within different communication systems. This implementation demonstrates accuracy of up to 84 % across the dataset, a full 34 % increase against a random-choice control baseline.

The spatial-temporal random variation characteristics of underwater acoustic channel make the difference among the underwater acoustic communication network link channels, which make network performance difficult to predict. In order to better understand the fluctuation and difference of network link channel, we analyze the measured channel data of five links in the Qiandao Lake underwater acoustic communication network experiment. This paper first estimates impulse response, spread function, power delay profile and Doppler power spectrum of the time-varying channel in a short detection time, and compares the time-frequency energy distribution characteristics of each link channel. Then, we statistically analyze the discreteness of the signal to noise ratio, multipath spread and Doppler spread parameter distributions for a total of145 channels over a long observation period. The results show that energy distribution structure and fading fluctuation scale of each link channel in underwater acoustic communication network are obviously different.

Magnetized Liner Inertial Fusion (MagLIF) is a magneto-inertial fusion concept that relies on fuel magnetization, laser preheat, and a magnetically driven implosion to produce fusion conditions. In MagLIF, the target is a roughly 10 mm long, 5 mm diameter, 0.5 mm thick, cylindrical beryllium shell containing 1 mg/cm 3 D 2 gas. An axial magnetic field on the order of 10 T is applied to the target, and several kJ of laser energy is deposited into the fuel. Up to 20 MA of current is driven axially through the beryllium target, causing it to implode over approximately 100 ns. The implosion produces a 100-μm diameter, 8-mm tall fuel column with a burn-averaged ion temperature of several keV, that generates 10 11 -10 13 DD neutrons.

The Z machine is a pulsed power generator located at Sandia National Laboratories in Albuquerque, New Mexico. It is capable of producing a \textbackslashtextgreater20 MA current pulse that is directed onto an experimental load. While a diverse array of experiments are conducted on the Z machine, including x-ray production and dynamic materials science experiments, the focus of this presentation are the Magnetic Liner Inertial Fusion (MagLIF) experiments. In these experiments, an axial magnetic field is applied to the load region, where a cylindrical, fuel-filled metal liner is imploded. We explore the effects of this field on the ability to efficiently couple the generator current to the load, and the extent to which this field interrupts the magnetic insulation of the inner-most transmission line. We find that at the present-day applied field values, the effects of the applied field on current coupling are negligible. Estimates of the potential impact on current coupling of the larger applied field values planned for future experiments are also given. Shunted current is measured with B-dot probes and flyer velocimetry techniques. Analytical calculations, 2D particle-in-cell simulations, and experimental measurements will be presented.

X-ray radiography has been used to diagnose a wide variety of experiments at the Z facility including inertial confinement fusion capsule implosions, the growth of the magneto-Rayleigh-Taylor instability in solid liners, and the development of helical structures in axially magnetized liner implosions. In these experiments, the Z Beamlet laser (1 kJ, 1 ns) was used to generate the x-ray source. An alternate x-ray source is desirable in experiments where the Z Beamlet laser is used for another purpose (e.g., preheating the fuel in magnetized liner inertial fusion experiments) or when multiple radiographic lines of sight are necessary.

Third party mobile applications are dominating the business strategies of organisations and have become an integral part of personal life of individuals. These applications are used for financial transactions, sharing of sensitive data etc. The recent breaches in Android clearly indicate that use of third party applications have become a serious security threat. By design, Android framework keeps all these applications in untrusted domain. Due to this a common policy of resource control exists for all such applications. Further, user discretion in granting permissions to specific applications is not effective because users are not always aware of deep functionalities, mala fide intentions (in case of spywares) and bugs/flaws in these third-party applications. In this regard, we propose a security scheme to mitigate unauthorised access of resources by third party applications. Our proposed scheme is based on SEAndroid policies and achieves fine grained confinement with respect to access control for the third party applications. To the best of our knowledge, the proposed scheme is unique and first of its kind. The proposed scheme is integrated with Android Oreo 8.1.0 for performance and security analysis. It is compatible with any Android device with AOSP support.

Magnetized Liner Inertial Fusion (MagLIF) is a magneto-inertial fusion (MIF) concept being studied on the Z-machine at Sandia National Laboratories. MagLIF relies on quasi-adiabatic heating of a gaseous deuterium (DD) fuel and flux compression of a background axially oriented magnetic field to achieve fusion relevant plasma conditions. The magnetic flux per fuel radial extent determines the confinement of charged fusion products and is thus of fundamental interest in understanding MagLIF performance. It was recently shown that secondary DT neutron spectra and yields are sensitive to the magnetic field conditions within the fuel, and thus provide a means by which to characterize the magnetic confinement properties of the fuel. 1 , 2 , 3 We utilize an artificial neural network to surrogate the physics model of Refs. [1] , [2] , enabling Bayesian inference of the magnetic confinement parameter for a series of MagLIF experiments that systematically vary the laser preheat energy deposited in the target. This constitutes the first ever systematic experimental study of the magnetic confinement properties as a function of fundamental inputs on any neutron-producing MIF platform. We demonstrate that the fuel magnetization decreases with deposited preheat energy in a fashion consistent with Nernst advection of the magnetic field out of the hot fuel and diffusion into the target liner.

This paper investigates the impact of the delay resulting from a blockchain, a promising security measure, for a hierarchical control system of inverters connected to the grid. The blockchain communication network is designed at the secondary control layer for resilience against cyberattacks. To represent the latency in the communication channel, a model is developed based on the complexity of the blockchain framework. Taking this model into account, this work evaluates the plant’s performance subject to communication delays, introduced by the blockchain, among the hierarchical control agents. In addition, this article considers an optimal model-based control strategy that performs the system’s internal control loop. The work shows that the blockchain’s delay size influences the convergence of the power supplied by the inverter to the reference at the point of common coupling. In the results section, real-time simulations on OPAL-RT are performed to test the resilience of two parallel inverters with increasing blockchain complexity.

Modern embedded systems need to cater for several needs depending upon the application domain in which they are deployed. For example, mixed-critically needs to be considered for real-time and safety-critical systems and energy for battery-operated systems. At the same time, many of these systems demand for their reliability and security as well. With electronic systems being used for increasingly varying type of applications, novel challenges have emerged. For example, with the use of embedded systems in increasingly complex applications that execute tasks with varying priorities, mixed-criticality systems present unique challenges to designing reliable systems. The large design space involved in implementing cross-layer reliability in heterogeneous systems, particularly for mixed-critical systems, poses new research problems. Further, malicious security attacks on these systems pose additional extraordinary challenges in the system design. In this paper, we cover both the industry and academia perspectives of the challenges posed by these emergent aspects of system design towards designing highperformance, energy-efficient, reliable and/or secure embedded systems. We also provide our views on paths forward.

The semaphore mechanism is an important part of the embedded operating system. Therefore, it is very necessary to ensure its safety. Traditional software testing methods are difficult to ensure 100% coverage of the program. Therefore, it is necessary to adopt a formal verfication method which proves the correctness of the program theoretically. This paper proposes a proof framework based on the theorem proof tool Coq: modeling the semaphore mechanism, extracting important properties from the requirement documents, and finally verifying that the semaphore mechanism can meet these properties, which means the correctness of the semaphore mechanism is proved and also illustrates the feasibility of the verification framework proposed in this paper, which lays a foundation for the verification of other modules of operating systems.

With the construction of power information network, the power grid has built a security protection system based on boundary protection. However, with the continuous advancement of the construction of the power Internet of Things, a large number of power Internet of Things terminals need to connect to the power information network through the public network, which have an impact on the existing security protection system of the power grid. This article analyzes the characteristics of the border protection model commonly used in network security protection. Aiming at the lack of security protection capabilities of this model, a zero-trust security architecture-based power Internet of Things network security protection model is proposed. Finally, this article analyzes and studies the application of zero trust in the power Internet of Things.

SDN marks a paradigm shift towards an externalized and logically centralized controller, unlike the legacy networks where control and data planes are tightly coupled. The controller has a comprehensive view of the network, offering flexibility to enforce new traffic engineering policies and easing automation. In SDN, a high performance controller is required for efficient traffic management. In this paper, we conduct a performance evaluation of two distributed SDN controllers, namely ONOS and OpenDayLight. Specifically, we use the Mininet emulation environment to emulate different topologies and the D-ITG traffic generator to evaluate aforementioned controllers based on metrics such as delay, jitter and packet loss. The experimental results show that ONOS provides a significantly higher latency, jitter and low packet loss than OpenDayLight in all topologies. We attribute the poor performance of OpenDayLight to its excessive CPU utilization and propose the use of Hyper-threading to improve its performance. This work provides practitioners in the telecoms industry with guidelines towards making informed controller selection decisions

This paper is devoted to boundary control design for urban traffic described on a macroscopic scale. The state corresponds to vehicle density that evolves on a continuum two-dimensional domain that represents a continuous approximation of a urban network. Its parameters are interpolated as a function of distance to physical roads. The dynamics are governed by a new macroscopic multi-directional traffic model that encompasses a system of four coupled partial differential equations (PDE) each describing density evolution in one direction layer: North, East, West and South (NEWS). We analyse the class of desired states that the density governed by NEWS model can achieve. Then a boundary control is designed to drive congested traffic to an equilibrium with the minimal congestion level. The result is validated numerically using the real structure of Grenoble downtown (a city in France).

The operation of the modern power grid is becoming increasingly reliant on its underlying communication network, especially within the context of the rapidly growing integration of Distributed Energy Resources (DERs). This tight cyber-physical coupling brings uncertainties and challenges for the power grid operation and control. To help operators manage the complex cyber-physical environment, ensure the integrity, and continuity of reliable grid operation, a two-stage approach is proposed that is compatible with current ICS protocols to improve the deliverability of time critical operations. With the proposed framework, the impact Denial of Service (DoS) attack can have on a Transmission Control Protocol (TCP) session could be effectively prevented and mitigated. This coordinated approach combines the efficiency of congestion window reconfiguration and the applicability of physical-only mitigation approaches. By expanding the state and action space to encompass both the cyber and physical domains. This approach has been proven to outperform the traditional, physical-only method, in multiple network congested scenarios that were emulated in a real-time cyber-physical testbed.

Background: Most of the people are not medically qualified for studying or understanding the extremity of their diseases or symptoms. This is the place where natural language processing plays a vital role in healthcare. These chatbots collect patients' health data and depending on the data, these chatbot give more relevant data to patients regarding their body conditions and recommending further steps also. Purposes: In the medical field, AI powered healthcare chatbots are beneficial for assisting patients and guiding them in getting the most relevant assistance. Chatbots are more useful for online search that users or patients go through when patients want to know for their health symptoms. Methods: In this study, the health assistant system was developed using Dialogflow application programming interface (API) which is a Google's Natural language processing powered algorithm and the same is deployed on google assistant, telegram, slack, Facebook messenger, and website and mobile app. With this web application, a user can make health requests/queries via text message and might also get relevant health suggestions/recommendations through it. Results: This chatbot acts like an informative and conversational chatbot. This chatbot provides medical knowledge such as disease symptoms and treatments. Storing patients personal and medical information in a database for further analysis of the patients and patients get real time suggestions from doctors. Conclusion: In the healthcare sector AI-powered applications have seen a remarkable spike in recent days. This covid crisis changed the whole healthcare system upside down. So this NLP powered chatbot system reduced office waiting, saving money, time and energy. Patients might be getting medical knowledge and assisting ourselves within their own time and place.

Electromagnetic emissions associated with the transmission of automotive controller area network (CAN) messages within a passenger car have been analysed and used to reconstruct the original CAN messages. Concurrent monitoring of the CAN traffic via a wired connection to the vehicle OBD-II port was used to validate the effectiveness of the reconstruction process. These results confirm the feasibility of reconstructing in-vehicle network data for forensic purposes, without the need for wired access, at distances of up to 1 m from the vehicle by using magnetic field measurements, and up to 3 m using electric field measurements. This capability has applications in the identification and resolution of EMI issues in vehicle data network, as well as possible implications for automotive cybersecurity.

Modern cars are becoming more accessible targets for cyberattacks due to the proliferation of wireless communication channels. The intra-vehicle Controller Area Network (CAN) bus lacks authentication, which exposes critical components to interference from less secure, wirelessly compromised modules. To address this issue, we propose vProfile, a sender authentication system based on voltage fingerprints of Electronic Control Units (ECUs). vProfile exploits the physical properties of ECU output voltages on the CAN bus to determine the authenticity of bus messages, which enables the detection of both hijacked ECUs and external devices connected to the bus. We show the potential of vProfile using experiments on two production vehicles with precision and recall scores of over 99.99%. The improved identification rates and more straightforward design of vProfile make it an attractive improvement over existing methods.

Smart Contracts based cryptocurrencies such as Ethereum are becoming increasingly popular in various domains: but with this increase in popularity comes a significant decrease in throughput and efficiency. Smart Contracts are executed by every miner in the system serially without any parallelism, both inter and intra-Smart Contracts. Such a serial execution inhibits the scalability required to obtain extremely high throughput pertaining to computationally intensive tasks deployed with such Smart Contracts. While significant advancements have been made in the field of concurrency, from GPU architectures that enable massively parallel computation to tools such as MapRe-duce that distributed computing to several nodes connected in the system to achieve higher performance in distributed systems, none are incorporated in blockchain-based distributed computing. The team proposes a novel blockchain that allows public nodes in a permission-independent blockchain to deploy and run Smart Contracts that provide concurrency-related functionalities within the Smart Contract framework. In this paper, the researchers present “ConCurrency,” a blockchain network capable of handling big data-based computations. The technique is based on currently used distributed system paradigms, such as MapReduce, while also allowing for fundamental parallelly computable problems. Concurrency is achieved using a sharding protocol incorporated with consensus mechanisms to ensure high scalability, high reliability, and better efficiency. A detailed methodology and a comprehensive analysis of the proposed blockchain further indicate a significant increase in throughput for parallelly computable tasks, as detailed in this paper.

In order to solve the problem of data analysis and application caused by the inefficient integration of hardware and software compatibility of hardware in the Internet of things, this paper proposes and designs a C/S framework communication system based on task driven and multi-user authority. By redefining the relationship between users and hardware and adopting the matching framework for different modules, the system realizes the high concurrent and complex data efficient collaborative processing between software and hardware. Finally, by testing and verifying the functions of the system, the communication system effectively realizes the functions of data processing between software and hardware, and achieves the expected results.

Current network assessment models often ignore the impact of attack-defense timing on network security, making it difficult to characterize the dynamic game of attack-defense effectively. To effectively manage the network security risks and reduce potential losses, in this article, we propose a selection strategy for network defense based on a time game model. By analyzing the attack-defense status by analogy with the SIR infectious disease model, construction of an optimal defense strategy model based on time game, and calculation of the Nash equilibrium of the the attacker and the defender under different strategies, we can determine an optimal defense strategy. With the Matlab simulation, this strategy is verified to be effective.

Cyber-attacks in electrical power system causes serious damages causing breakdown of few equipment to shutdown of the complete power system. Game theory is used as a tool to detect the cyber-attack in the power system recently. Interaction between the attackers and the defenders which is the inherent nature of the game theory is exploited to detect the cyber-attack in the power system. This paper implements the cyber-attack detection on a two-area power system controlled using the Load Frequency controller. Ant Lion Optimization is used to tune the integral controller applied in the Load Frequency Controller. Cyber-attacks that include constant injection, bias injection, overcompensation, and negative compensation are tested on the Game theory-based attack detection algorithm proposed. It is considered that the smart meters are attacked with the attacks by manipulating the original data in the power system. MATLAB based implementation is developed and observed that the defender action is satisfactory in the two-area system considered. Tuning of integral controller in the Load Frequency controller in the two-area system is also observed to be effective.

Edge computing brings processing and storage capabilities closer to the data sources, to reduce network latency, save bandwidth, and preserve data locality. Despite the clear benefits, this paradigm brings unprecedented cyber risks due to the combination of the security issues and challenges typical of cloud and Internet of Things (IoT) worlds. Notwithstanding an increasing interest in edge security by academic and industrial communities, there is still no discernible industry consensus on edge computing security best practices, and activities like threat analysis and countermeasure selection are still not well established and are completely left to security experts.In order to cope with the need for a simplified yet effective threat modeling process, which is affordable in presence of limited security skills and economic resources, and viable in modern development approaches, in this paper, we propose an automated threat modeling and countermeasure selection strategy targeting edge computing systems. Our approach leverages a comprehensive system model able to describe the main involved architectural elements and the associated data flow, with a focus on the specific properties that may actually impact on the applicability of threats and of associated countermeasures.

This article analyzes the possibilities of using cognitive approaches in forming expert assessments for solving information security problems. The experts use the contextual approach by A.Yu. Khrennikov’s as a basic model for the mathematical description of the quantum decision-making method. In the cognitive view, expert assessments are proposed to be considered as conditional probabilities with regard to the fulfillment of a set of certain conditions. However, the conditions in this approach are contextual, but not events like in Boolean algebra.

This paper addresses security and risk management of hardware and embedded systems across several applications. There are three companies involved in the research. First is an energy technology company that aims to leverage electric- vehicle batteries through vehicle to grid (V2G) services in order to provide energy storage for electric grids. Second is a defense contracting company that provides acquisition support for the DOD's conventional prompt global strike program (CPGS). These systems need protections in their production and supply chains, as well as throughout their system life cycles. Third is a company that deals with trust and security in advanced logistics systems generally. The rise of interconnected devices has led to growth in systems security issues such as privacy, authentication, and secure storage of data. A risk analysis via scenario-based preferences is aided by a literature review and industry experts. The analysis is divided into various sections of Criteria, Initiatives, C-I Assessment, Emergent Conditions (EC), Criteria-Scenario (C-S) relevance and EC Grouping. System success criteria, research initiatives, and risks to the system are compiled. In the C-I Assessment, a rating is assigned to signify the degree to which criteria are addressed by initiatives, including research and development, government programs, industry resources, security countermeasures, education and training, etc. To understand risks of emergent conditions, a list of Potential Scenarios is developed across innovations, environments, missions, populations and workforce behaviors, obsolescence, adversaries, etc. The C-S Relevance rates how the scenarios affect the relevance of the success criteria, including cost, schedule, security, return on investment, and cascading effects. The Emergent Condition Grouping (ECG) collates the emergent conditions with the scenarios. The generated results focus on ranking Initiatives based on their ability to negate the effects of Emergent Conditions, as well as producing a disruption score to compare a Potential Scenario's impacts to the ranking of Initiatives. The results presented in this paper are applicable to the testing and evaluation of security and risk for a variety of embedded smart devices and should be of interest to developers, owners, and operators of critical infrastructure systems.

Maintaining critical data and process availability is an important challenge of Industry 4.0. Given the variety of smart nodes, data and the access latency that can be tolerated by consumers in modern IoT-based industry, we propose a method for analyzing the resiliency of an IoT network. Due to the complexity of modern system structures, different components in the system can affect the system’s resiliency. Therefore, a fundamental problem is to propose methods to quantify the value of resilience contribution of a node in each system effectively. This paper aims to identify the most critical vertices of the network with respect to the latency constraint resiliency metric. Using important centrality metrics, we identify critical nodes in industrial IoT networks to analyze the degree of resiliency in the IoT environments. The results show that when nodes with the highest value of Closeness Centrality (CC) were disrupted Resiliency of Latency (RL) would have the lowest value. In other words, the results indicate the nodes with the high values for CC are most critical in an IoT network.