Electronic countermeasures (ECMs) against a radar are actions taken by an adversarial jammer to mitigate the effective utilization of the electromagnetic spectrum by the radar. On the other hand, ...electronic counter-countermeasures (ECCMs) are actions taken by the radar to mitigate the impact of ECMs so that the radar can continue to operate effectively. The main idea of this article is to show that ECCMs involving a radar and a jammer can be formulated as a principal–agent problem (PAP)—a problem widely studied in microeconomics. With the radar as the principal and the jammer as the agent, we design a PAP to optimize the radar’s ECCM strategy in the presence of a jammer. The radar seeks to optimally trade off the signal-to-noise ratio of the target measurement with the measurement cost: cost for generating radiation power for the pulse to probe the target. We show that for a suitable choice of utility functions, the PAP is a convex optimization problem. Furthermore, we analyze the structure of the PAP and provide sufficient conditions under which the optimal solution is an increasing function of the jamming power observed by the radar; this enables computation of the radar’s optimal ECCM within the class of increasing affine functions at a low computation cost. Finally, we illustrate the PAP formulation of the radar’s ECCM problem via numerical simulations. We also use simulations to study a radar’s ECCM problem, wherein the radar and the jammer have mismatched information.
Multiple-stage adaptive architectures are conceived to face with the problem of target detection buried in noise, clutter, and intentional interference. First, a scenario where the radar system is ...under the electronic attack of noiselike interferers is considered. In this context, two sets of training samples are jointly exploited to devise a novel two-step estimation procedure of the interference covariance matrix. Then, this estimate is plugged in the adaptive matched filter to mitigate the deleterious effects of the noiselike jammers on radar sensitivity. Besides, a second scenario, which extends the former by including the presence of coherent jammers, is addressed. Specifically, the sparse nature of data is brought to light and the compressive sensing paradigm is applied to estimate target response and coherent jammers amplitudes. The likelihood ratio test, where the unknown parameters are replaced by previous estimates, is designed and assessed. Remarkably, the sparse approach allows for echo classification and estimation of both angles of arrival and number of the interfering sources. The performance analysis, conducted resorting to simulated data, highlights the effectiveness of the newly proposed architectures also in comparison with suitable competing architectures (when they exist).
A Survey Of Sq1 Injection Countermeasures Mahapatra, R P; Khan, Subi
International journal of computer science and engineering survey,
06/2012, Letnik:
3, Številka:
3
Journal Article
SQL injection has become a predominant type of attacks that target web applications. It allows attackers to obtain unauthorized access to the back-end database to change the intended ...application-generated SQL queries. Researchers have proposed various solutions to address SQL injection problems. However, many of them have limitations and often cannot address all kinds of injection problems. What's more, new types of SQL injection attacks have arisen over the years. To better counter these attacks, identifying and understanding existing countermeasures are very important. In this research , I had surveyed existing techniques against SQL injection attacks and analyzed their advantages and disadvantages. In addition, I identified techniques for building secure systems and applied them to my applications and database system, and illustrated how they were performed and the effect of them.
Local scour at monopile foundations of offshore wind turbines is one of the most critical structural stability issues. This article reviews the contemporary methods of scour countermeasures at ...monopile foundations. These methods include armouring countermeasures (e.g., riprap protection) to enhance the anti-scour ability of the bed materials and flow-altering countermeasures (e.g., collars and sacrificial piles) to reduce downflow or change flow patterns around the monopiles. Stability number and size-selection equations for riprap armour layers are summarised and compared. Moreover, other alternative methods to riprap are briefly introduced and presented. A typical graph of the scour depth reduction with different collar sizes and elevations under specific test conditions is summarised and compared with a plot for a pile founded on a caisson. Reduction rates for different flow-altering countermeasures, including the collar, are listed and compared. A newly developed soil improvement method, namely microbially induced calcite precipitation (MICP), is also reviewed and introduced as a scour protection method. As a popular bio-soil treatment method, MICP has a good potential as a scour countermeasure method. Bio-soil treatment methods and traditional armouring methods are defined as active and passive soil enhancement scour countermeasures, respectively.
This Commentary delves into the current progress and challenges on ongoing research on medical countermeasures (MCs) for chemical, biologic, radiologic, and nuclear (CBRN) threats. CBRN agents pose a ...serious risk to human health and safety, with the potential for mass casualties in both military and civilian settings. Chemical threats are toxic compounds that could be used in a terrorist attack, an accidental release, or chemical warfare. They include nerve agents, organophosphates, pulmonary agents, metabolic/cellular agents, vesicants, ocular toxicants, and opioid agents. Developing effective MCs is crucial for mitigating the acute and chronic effects of exposure to CBRN agents. The papers in this special issue of JPET highlights the latest advancements in MC research, showcasing insightful outcomes on experimental models, mechanisms, and translational research on MCs for CBRN threats. They portray several notable contributions, including the development of neurosteroid and combination anticonvulsant therapies for nerve agent poisoning, the exploration of chronic impacts and diagnostic tracers for OP neurotoxicity, the establishment of innovative pediatric OP models, the identification of novel molecules for ocular, pulmonary and vesicant injuries, and the repurposing of existing drugs for the treatment of botulism, cyanide, and OP poisoning. These crucial outcomes underscore the breadth of current research covering a variety of chemical threats. Overall, this collection of articles highlights the importance of ongoing research and development in the field of MCs, emphasizing the potential of these countermeasures to effectively treat and mitigate the effects of toxicant exposures and thereby enhance our preparedness for mass casualty incidents. SIGNIFICANCE STATEMENT: CBRN agents pose a significant threat to public health. Effective MCs exist for certain chemical threats, but there is a need for new and improved MCs for many others. The research presented in this special issue of JPET highlights the latest advancements in MCs for CBRN threats. This research has the potential to lead to the development of new and repurposed MCs that are more effective, broad-spectrum, and easier to administer to mitigate acute and long-term consequences of chemical exposures.
Abstract In recent years, U.S. navy is exposing frequently some tests and development about shipborne laser weapon, which have attracted aboard attention and passionate discussion. In this paper, the ...review on shipborne laser weapon of U.S. navy from the 21th century is summed up. Some oppugns or baffles are also analyzed in this process. The meaning on developing shipborne laser weapon is discussed more deeply. Furthermore, some advices are put forward.
The paper is devoted to the analysis of countermeasures in the context of cyber operations. This circumstance precluding wrongfulness is one of the tools that states can use in response to (not only) ...malign cyber operations that fulfil the characteristics of an internationally wrongful act. The paper examines the various material and procedural conditions of countermeasures and the specifics of their implementation in cyberspace. The second part of the paper then discusses contentious issues related to countermeasures, namely the relationship between countermeasures and the principle of due diligence, the possibility of implementing forcible countermeasures, and finally the current status of collective countermeasures under customary international law.
Motion sickness (MS) poses challenges for individuals affected, hindering their activities and travel. This study investigates the effect of a visual dynamic device, forming an artificial horizon ...plane, on symptoms and physiological changes induced by MS. This device consists of vertical light-emitting diodes whose illumination varies according to the boat's movements. Fifteen subjects with moderate-to-severe MS susceptibility were exposed to a seasickness simulator with and without the device. Symptoms were assessed immediately after exposure. Time spent in the simulator, heart rate, and temperature were also recorded. Symptom intensity at the end of the experience did not differ, but the time spent in the simulator was significantly longer with the device (+46%). Variations in heart rate were also observed. The device delays symptom onset and can be used as a tool against MS. Further research is needed to evaluate its effects, for example, during more prolonged exposure to MS-inducing stimuli.
A metacognitive radar switches between two modes of cognition—one mode to achieve a high-quality estimate of targets, and the other mode to hide its utility function (plan). To achieve high-quality ...estimates of targets, a cognitive radar performs a constrained utility maximization to adapt its sensing mode in response to a changing target environment. If an adversary can estimate the utility function of a cognitive radar, it can determine the radar's sensing strategy and mitigate the radar performance via electronic countermeasures (ECM). This article discusses a metacognitive radar that switches between two modes of cognition: achieving satisfactory estimates of a target while hiding its strategy from an adversary that detects cognition. The radar does so by transmitting purposefully designed suboptimal responses to spoof the adversary's Neyman–Pearson detector. We provide theoretical guarantees by ensuring that the Type-I error probability of the adversary's detector exceeds a predefined level for a specified tolerance on the radar's performance loss. We illustrate our cognition-masking scheme via numerical examples involving waveform adaptation and beam allocation. We show that small purposeful deviations from the optimal emission confuse the adversary by significant amounts, thereby masking the radar's cognition. Our approach uses ideas from revealed preference in microeconomics and adversarial inverse reinforcement learning. Our proposed algorithms provide a principled approach for system-level electronic counter-countermeasures to hide the radar's strategy from an adversary. We also provide performance bounds for our cognition-masking scheme when the adversary has misspecified measurements of the radar's response.
Frequency agile radar (FAR) is known to have excellent electronic counter-countermeasures performance and the potential to realize spectrum sharing in dense electromagnetic environments. Many ...compressed sensing (CS) based algorithms have been developed for joint range and Doppler estimation in FAR. This paper considers theoretical analysis of FAR via CS algorithms. In particular, we analyze the properties of the sensing matrix, which is a highly structured random matrix. We then derive bounds on the number of recoverable targets. Numerical simulations and field experiments validate the theoretical findings and demonstrate the effectiveness of CS approaches to FAR.
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